bluuebunny/crossref_metadata_2025 huggingface dataset:
Popliteal Artery-Related Pathologies in Athletes—A Primer for Musculoskeletal Radiologists
Authors: Thaker Siddharth , Gupta Harun , Beh Joey , Kirwadi Anand , Chari Basavaraj
Published: November 2023

Vascular complications in athletes are common and mimic musculoskeletal injuries such as muscle sprains, fractures, and cartilage abnormalities. They include traumatic vascular injuries and more subtle pathologies like entrapment syndromes, pseudoaneurysms, arterial occlusions, and venous thrombosis. Such vascular complications may be occult on imaging and can be difficult for a musculoskeletal radiologist to diagnose, resulting in a lack of timely diagnosis and potentially limb-threatening consequences. Although the final diagnosis may require multidisciplinary input from orthopaedic, sports and exercise medicine, and vascular and interventional radiology inputs, a musculoskeletal radiologist with prior knowledge of such conditions can be the first to diagnose such conditions aiding the athlete's performance. A musculoskeletal radiologist should pay due attention to anatomical courses of vascular channels and look for potential causes of vascular compression, aberrant myotendinous bands, accessory muscles, etc., before concluding a computed tomography (CT) or magnetic resonance imaging (MRI) as normal. Doppler ultrasound, CT, or MR angiography are commonly employed techniques for primary evaluation, whereas digital subtraction angiography is generally reserved for troubleshooting as advanced dynamic imaging.
Single-item measures of happiness and life satisfaction: the issue of cross-country invariance of popular general well-being measures
Authors: Raudenská Petra
Published: November 2023

Single-item measures of general well-being are increasingly being analysed cross-culturally but without clear evidence of comparability level attainment. The primary objective of this study is to examine the cross-country measurement invariance of the two most common single-item measures—life satisfaction and happiness—across a large number of countries. For this purpose, 45 data sources from large-scale sample surveys conducted between 1976 and 2018 were used. This study presented a novel technique for examining the measurement invariance of individual items and used Bayesian approximation to evaluate the extent of the non-invariance of certain items across nations. The findings revealed that the happiness item’s factor loadings and intercepts deviated less, indicating comparability across more countries than the life satisfaction item. It is possible that the construct of happiness is more universally applicable across cultures than that of life satisfaction. However, the item parameters of the survey items varied among several countries in each round of the program, indicating that the observed score means could only be compared between a few participating countries.
The role of citizen science mobile apps in facilitating a contemporary digital agora
Authors: Hognogi Gheorghe-Gavrilă , Meltzer Monika , Alexandrescu Filip , Ștefănescu Lucrina
Published: November 2023

The advancements in digital technologies, especially for mobile apps, enabled simplified data collection methods. Consequently, through Citizen Science, numerous opportunities arose for citizens to become contributors and not just beneficiaries of scientific research. Furthermore, through such engagement, citizens can participate in decision-making processes at different spatial scales, getting closer to the civic aspiration of a digital agora. This paper offers a systematic review of 303 studies on such initiatives to outline the potential of mobile apps in Citizen Science. Based distinctly on their specificities and the needs they address, three content categories were highlighted: a) monitoring tools, b) validation of techniques and methods to improve mobile technologies for Citizen Science, and c) participatory approaches of citizens employing mobile apps. The review also showed a susceptibility of several domains of activity towards Citizen Science, such as monitoring biodiversity and reconnecting people with nature, environmental risk monitoring or improving well-being. The findings highlight future research potential in addressing topics such as new technologies to increase Citizen Science performance and its contributions to Open Science, as well as diversification and enhancement of citizen scientists’ contributions.
A novel ratiometric fluorescent sensor based on terpyridine derivatives for Zn2+ in aqueous solution
Authors: Bai Qinghong , Jiang Yangming , Hu Enming , Lv Libin , Wang Chenghui , Xiao Xin
Published: November 2023

Terpyridine and its derivatives have good binding affinity for most transition metal ions due to the arrangement of their three pyridine nitrogen atoms. In this work, a new ratiometric fluorescent probe G, which is based on a styrylpyridinium attached to a terpyridine fluorophore, was synthesized and characterized. The fluorescence spectrum of probe G shows a good response to Zn2+ by an intramolecular charge transfer effect. On increasing the concentration of Zn2+, the fluorescence color of probe G changes from blue to yellow. Importantly, probe G has a high selectivity for Zn2+and is not affected by other metal ions, including Cd2+. In addition, the limit of detection (LOD) of probe G for Zn2+ was found to be up to 0.17 µM. The results show that probe G has the ability to selectively recognize Zn2+ in aqueous solution.
Plant response to heavy metal stress toxicity: the role of metabolomics and other omics tools
Authors: Anjitha K. S. , Sarath Nair G. , Sameena P. P. , Janeeshma Edappayil , Shackira A. M. , Puthur Jos T.
Published: November 2023

Metabolomic investigations offers a significant foundation for improved comprehension of the adaptability of plants to reconfigure the key metabolic pathways and their response to changing climatic conditions. Their application to ecophysiology and ecotoxicology help to assess potential risks caused by the contaminants, their modes of action and the elucidation of metabolic pathways associated with stress responses. Heavy metal stress is one of the most significant environmental hazards affecting the physiological and biochemical processes in plants. Metabolomic tools have been widely utilised in the massive characterisation of the molecular structure of plants at various stages for understanding the diverse aspects of the cellular functioning underlying heavy metal stress-responsive mechanisms. This review emphasises on the recent progressions in metabolomics in plants subjected to heavy metal stresses. Also, it discusses the possibility of facilitating effective management strategies concerning metabolites for mitigating the negative impacts of heavy metal contaminants on the growth and productivity of plants.
Stem rust of wheat in colonial Australia and the development of the plant pathology profession
Authors: Ryley Malcolm J. , Park Robert F.
Published: November 2023

Grain production in the early years of the British colonisation of Australia was characterised by a lack of expertise of farmers, a paucity of farm animals and equipment and the poor work ethics of convicts. In 1803, just when wheat production was increasing and becoming less risky, stem rust of wheat caused by the fungus Puccinia graminis f.sp. tritici was discovered by an exiled Irish rebel Joseph Holt, on Captain William Cox’s Brush Farm. Stem rust became an intermittent and often serious disease culminating in a series of epidemics in the latter part of the nineteenth century. Growing varieties less prone to rust was a key recommendation from a series of rust-in-wheat conferences held from 1891 to 1896. It was William Farrer who was the first in Australia to develop new wheat varieties that resisted the ravages of rust principally by maturing earlier. The rust outbreaks were also catalysts for the New South Wales and Victorian governments to employ Australia’s first plant pathologists, Nathan Cobb and Daniel McAlpine, respectively. A year later, Henry Tryon was employed by the Queensland government as its first vegetable pathologist, although he had conducted plant disease investigations as early as 1889.
William (Bill) Francis Budd 1938–2022
Authors: Allison Ian , Jacka Jo , Budd Derek
Published: November 2023

Professor William (Bill) Budd was a founding figure in Australian glaciology, and the first glaciology program leader of the Australian Antarctic Division (Fig. 1). Bill worked on an enormous range of glaciological and meteorological problems covering numerical modelling of ice sheets and glaciers, including surging glaciers; ice mechanics; ice crystallography; ice core paleoclimatic studies; relationships between sea ice and climate; and katabatic wind and snow drift studies. Bill introduced and led studies of ice sheet mass budget, ice rheology, ice sheet thermodynamics, iceberg distribution and movement, drifting snow, sea ice and climate interactions and much more. He initiated Australian ice core drilling (initially for study of ice dynamics and later for palaeoclimate research), radio echo sounding of ice thickness and satellite remote sensing of ice. Much of what Bill Budd initiated more than fifty years ago remains core to the present-day Australian Antarctic glaciological research program.
Supplementary comparison SIM.QM-S06 - automotive exhaust gases (CO, CO2, C3H8)
Authors: Iglesias Cristiane R A C , Fioravante Andreia L , Ribeiro Claudia C , Mello Viviane F , Zambrano Rocio C T , García Steve A Acco , Almirón Florencia
Published: November 2023

Main text

Supplementary comparison of carbon monoxide, carbon dioxide and propane in nitrogen (model 1).

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Discussion on the relationship between the power generation of single-crystal solar panels and various influencing factors
Authors: Tseng Y M , Mao Z J , Fan J H , Yang X Y
Published: November 2023

Solar panels absorb a large amount of light energy from sunlight and convert it into electrical energy for use. How to increase power and reduce energy loss in various aspects is also the focus of research and development to improve conversion efficiency of solar panels.

Set up 3.6kW solar power generator by single-crystal material to produce the Direct Current (DC) power and it is converted into an Alternating current (AC) power through an inverter which meets the parallel conditions of AC power system and supplies loadings with the national power grid at the same time. Meanwhile, a simple monitoring system of solar power was established to rectify and record the data of solar power generation resources and related parameters by big data to analysis the settlement classification relationship. According to the power generation characteristics of the single-crystal solar panels of the power generation by sampling and related parameter data can be used to observe the relationship between solar power generation efficiency, density of illumination, temperature of panel and actual power generation. The power generation of single crystal solar cells is closely related to photos and temperatures and has a short delay effect by statistics theory and methods.
Study of plane strain compression of composite sheets
Authors: Hwang Y M , Tsui H S R , Tsai S N
Published: November 2023

In the plane strain compression of multi-layers metal, each layer of metal shows a different degree of deformation due to the differences in material properties. Also, the deformation in different positions of a metal layer is always inhomogeneous. In this study, the effects of material ratios, friction between the metal layers and the amount of compression on the deformation behaviors of a bi-layer metal strip under plane strain compression are investigated. 2D plane strain finite element simulation models of AISI-1008/AL6061-T6 bi-layer metal strips are used. The results indicate that the strips show different deformation behaviors under different conditions, and non-smooth interfaces caused by the inhomogeneous material flow during the deformation process are detected in most cases.
FEM simulation and optimization on rotating extrusion of bi-metal rod with constant shear friction
Authors: Huang P H , Huang S W , Teng H Y , Tzou G Y , Lu C
Published: November 2023

This study assuming constant shear friction adopts FEM simulation and the optimization to investigate into extrusion of bi-metal rod which consisted of Aluminum alloy (Core) and Copper alloy (Sleeve) with a rotating die taking tonto account the interface at bi-metal rod under the bonding situation. The forming characteristics, e.g. the effective stress, the effective strain, the velocity field, the extrusion force, the extrusion torque, and die stress can be gained by using FEM commercial software. The FEM optimization for extrusion force combines Taguchi method to establish the L934 orthogonal table that includes four control factors which are rotating angular velocity (ω), frictional factor at the interface of sleeve and die (m1), half die angle (α°), and inner die filet (R). The ranking of influence factors and the optimization combination can be obtained from FEM simulation to provide the reference to the industries.
Design and analysis of marine permanent magnet synchronous motor based on Motor-cad
Authors: Lin W , Liu Z S
Published: November 2023

In the marine electric propulsion system, the motor is an important part to ensure safe navigation, which should have the characteristics of low noise, low vibration, high performance protection level, etc. The permanent magnet synchronous motor (PMSM) has the advantages of rapid dynamic response, stable operation, strong overload capacity, high efficiency and small size, which is especially suitable for electric propulsion systems in marine environments. According to the performance requirements of marine motors and the permanent magnet synchronous motor structural characteristics, an electromagnetic design and simulation of a 120kW marine permanent magnet synchronous motor is completed in this paper. Meanwhile, the stator skewed slot is used to reduce the amplitude of harmonic distortion and the additional torque caused by tooth harmonic. At same time, the rotor structure with U-shaped magnetic steel groove is used to enhance the density of power and overload capacity of the motor, expand the scope of motor constant power operation effectively. A prototype with high efficiency, reliability and a small volume has been developed. According to the simulation results, the marine permanent magnet synchronous motor designed in this paper fully meets the design requirements.
A single-phase full-bridge soft-switching inverter circuit with an auxiliary resonant circuit
Authors: Yang C C , Zeng T H , Huang C W , Hsu W T
Published: November 2023

A new topological structure is proposed in this article for the traditional single-phase full-bridge inverter circuit by adding an auxiliary synchronizing resonant circuit. Without extra switching transistors, the complexity of the control circuit is simplified while enabling zero voltage switching (ZVS) functionality. The significance of this proposed topology is that the switching transistors of all bridge arms are sharing one common synchronizing unit which is constructed with an absorbing inductor and capacitor. In this way, the added-on components can be substantially reduced for the main switching transistor circuit. By utilizing a big-volume capacitor as the constant voltage source, the sourceless energy feedback unit can minimize the switching losses. In the meantime, the proportional-resonant feedback circuit can modify the sinusoidal pulse width modulation (SPWM) duty ratio to stabilize the output current. In the PSIM power electronic simulation software environment, the operation of the soft-switching inverter circuit is analyzed to demonstrate our proposed topology can reduce the on-off switching losses as expected for the switching transistors of the soft-switching inverter circuit.
The simulation and experimentation of spiral flat bottom engraving
Authors: Chen D C , You C S
Published: November 2023

The study uses rigid-plastic finite element (FE) DEFORM TM 3D software to investigate the plastic deformation behaviour of spiral flat bottom engraving. The finite element analysis assumes that the spiral flat bottom is a rigid body. During the engraving process, the deformation causes an increase in temperature and wear inside the blank. The FE analyses investigate the effects of cutting speed, depth of cut, and the feed of the workpiece on the damage, effective strain, stress, temperature, and wear induced within the workpiece. The simulation results confirm the suitability of the DEFORM TM 3D software for modelling the spiral flat bottom engraving. Comparisons of engraving of spiral flat bottom with clockwise and counter-clockwise have been performed. The analysis of following stress-strain simulation has been predicted by machine learning in this study. Eventually, the experiment of spiral flat bottom engraving is used.
Development of eDART-based weight prediction system in injection molding via Taguchi design and fuzzy logic
Authors: Chen J C , Krisshnasamy R
Published: November 2023

This research describes developing a Fuzzy Logic based weight prediction system (FL-eWPS) during the process of injection molding. The main purpose is to apply Fuzzy Logic to predict defects during injection molding operations while processing parameters, such as shot size, barrel temperature, cooling time, and holding pressure. The parameters are varied within a shorter range when using Delrin 511 DP plastic from DuPont Engineering Polymers. eDART data logging system was used for real-time data collection for the different parameters by using the sensors during the injection filling stages. A Fuzzy Logic reasoning algorithm was applied to gain the threshold values of weight prediction with various processing parameter settings. During the injection molding process, the FL-eWPS system was shown to predict weight with 99% accuracy.
Development of a cell counting system based on machine learning
Authors: Wu R C , Chiu W C , Kuo F T , Xu H W , Wu T T , Liu C H
Published: November 2023

Endothelial cells of the aorta are an excellent model system for studying inflammatory responses, angiogenesis, atherosclerosis, blood clotting, vascular contraction, and vasodilation. Cell counting is necessary when culturing human aortic endothelial cells (HAECs) in order to determine cell concentration and quantity, as well as to assess cell viability and proliferation. Here, a machine learning-based image recognition system was developed to create a cell counter. The system’s hardware includes a digital microscope, Raspberry Pi, and operating screen. Image capture, image processing, machine learning, and computer recognition are utilized in the processing techniques. The processing steps consist of training and testing stages. In the training stage, five HAECs images were selected as training samples while the remaining HAECs images were used as testing samples. Positive and negative samples were labeled using LabelImg and used to generate training images for the classifier program. The classifier program was trained using the built-in Adaboost and LBP models in Opencv to create a HAECs classifier. The system achieved a recognition rate of 95% for HAECs and 98% for colon cells in practical tests, demonstrating that this technology can be used as a tool for cell counting and can replace expensive and potentially inaccurate commercial cell counting software, making cell counting a more practical technique.
Investigation on thread rolling processes of screws for intelligent thread rolling system
Authors: Huang X , Liu C C
Published: November 2023

The traditional screw production equipment is very large, and many procedures need manual operation, which has a certain influence on the production of screws. In order to improvement the production efficiency, a new type of “Intelligent Thread Rolling System” is to be designed for the requirement. In this system, it is necessary to provide and transmit the relevant data for screw manufacturing, especially in the process of thread rolling. The thread plate design changes the traditional flat shape to become the curved shape. This paper has used the numerical model of the finite element method to calculate and simulate thread rolling process of thread plate of curved shape to understand the applicability. The results of relevant parameters on the thread rolling are obtained to compare with experimental data of Intelligent Thread Rolling System. Under certain test condition, the screw embryonal material can produce threads and cut off tails, but the created thread shape and depth are non-standard. The results are consistent with experimental data. The main reason is that the thread surface of thread plates of curved shape has not been redesigned. Due to the comparison and verification, the numerical parameters can be provided for the actual thread rolling operation of the ITRS. This is very helpful for the completion of the ITRS development.
Two-dimensional Ga2XY monolayer containing vacancies for highly efficient electrocatalytic hydrogen reaction: based on first-principles calculations
Authors: Wei F , Gao J M , Jia B N , Hao J B , Liu G , Lu P F
Published: November 2023

Hydrogen energy as an excellent substitute for traditional fossil fuels, has received widespread attention. There is an urgent need to find an efficient and environmentally friendly electrocatalyst to increase hydrogen production. In this study, the Ga2XY (X, Y=O, S, Se, Te, X≠Y) system of group III-VI compounds was constructed, and the HER catalytic properties of its vacancy structure were investigated based on first principles. The research results show that all the structures are stable, and the introduction of O vacancy and Ga vacancy can significantly improve the structure’s Gibbs free energy (ΔGH). When the H atom is adsorbed on the bottom Ga atom, the HER with Ga2OSe structure containing outer Ga vacancy is very excellent, and its ΔGH can reach 0.07 eV, which is significantly superior to the currently recognized best HER catalyst Pt. Our research provides a new strategy for the design of HER electrocatalysts and a new method for the regulation of Ga2XY monolayers.
Corrosion behavior of AFA steel in lead-bismuth eutectic alloy with saturated oxygen at 500°C
Authors: Yang Lingfeng , Zhu Huiping , Chen Ran , Ma Yan , Zheng Gang , Niu Fenglei
Published: November 2023

Alumina-forming Austenitic (AFA) steel is one of the candidate corrosion-resistant structural materials for lead-cooled fast reactors, exhibiting excellent high-temperature corrosion resistance. However, its corrosion mechanisms in lead-bismuth eutectic (LBE) environment at the design operating temperature of lead-cooled fast reactors have not been fully elucidated. In this study, AFA steel was immersed in static LBE with saturated oxygen at 500 °C for 3000 hours. The corrosion behavior of AFA samples was obtained by analyzing the morphology of corrosion cross section and the distribution of elements. The results showed that the AFA steel did not form an oxide film that could effectively resist LBE. Dissolution corrosion of the matrix becomes more severe the longer the exposure time. When the NiAl phase in the matrix is located at the surface, oxide nodules are generated. It has a double-layer oxide structure, which has better resistance to LBE corrosion. Nb undergoes oxidative rupture and has a tendency to detach from the surface of the substrate when it is located on the surface. Cracks occur on the surface of the matrix after 3000 hours of corrosion, and LBE penetrates into the matrix along the cracks.
Type-II van der Waals heterostructures constructed by V-V binary monolayers for ultra-thin solar cells
Authors: Zhao Huiyan , Wei Feng , Jia Baonan , Gao Jingming , Zhao Jiaxiang , Liu Gang , Lu Pengfei
Published: November 2023

The development of solar cells holds great importance in the field of renewable energy and sustainability. Type-II van der Waals heterostructures, constructed from V-V binary monolayers, which exhibit easily-tunable electronic and optical properties, represent promising materials. In this work, we constructed and screened type-II van der Waals heterostructures using V-V binary monolayers for ultra-thin solar cells, and predicted their solar cell performance based on first-principles study. Five stable type-II van der Waals heterostructures were selected from forty-five heterostructures. The results showed that BiP/SbAs and BiP/BiAs heterostructures are promising candidates for solar cells with the power conversion efficiency as high as 17% and well light absorption performance. It will provide insights into the development and refinement of ultra-thin photovoltaic cells utilizing type-II van der Waals heterostructures composed of V-V binary monolayers.
Life cycle assessment of SBS modified bitumen waterproofing membrane
Authors: Chen Tao , Zheng Yan , Liu Yu , Li Xiaoqing , Gong Xianzheng
Published: November 2023

Building waterproofing membranes constitute essential components of construction materials. This study utilizes the life cycle assessment (LCA) methodology to develop a comprehensive life cycle inventory and conduct an environmental impact assessment of typical styrene-butadiene-styrene (SBS) modified bitumen waterproofing membrane products. The main research objective of this paper is to identify the key factors influencing the environmental impact of products and to provide data for the selection of green materials in the construction industry. The results reveal that the production of raw materials for SBS-modified bitumen waterproofing membranes contributes the most to all environmental impact categories, followed by the transportation and energy production stages, while the production stage of the membranes exhibits a relatively smaller contribution. Within the raw material production stage, the bitumen production process exhibits the highest contribution to fossil fuel depletion (FFP) environmental impact, surpassing 50%. The production process of polyester tire cloth demonstrates the greatest influence on human toxicity potential (HTPc), global warming potential (GWP), freshwater eutrophication (FEP), marine eutrophication potential (MEP), and mineral resource scarcity potential (SOP), accounting for 54.63%, 32.86%, 68.55%, 72.41%, and 61.69%, respectively. Additionally, the production process of base oil exhibits the most significant contribution to fine particulate matter formation (PMFP) and terrestrial acidification potential (AP) among the environmental impact indicators. Variations in the quantities of polyester tire cloth and base oil exhibit the most notable influence on the environmental indicators of the product. Specifically, the sensitivity analysis reveals that polyester tire cloth has the greatest impact on mineral resource scarcity potential (SOP); base oil exhibits the highest sensitivity to fossil fuel depletion (FFP).
Progress in Green and Low-carbon Technologies development of Building Ceramics Industry
Authors: Liu Jianing , Liu Yu , Zheng Yan , Li Xiaoqing
Published: November 2023

As global and domestic concerns about climate change intensify, the development and adoption of green and low-carbon manufacturing technologies to effectively reduce resource consumption, energy usage, and greenhouse gas emissions have emerged as primary trends in the evolution of the building ceramics industry under the backdrop of the “dual carbon” strategy. This article systematically reviews the commercially applied and research-stage green and low-carbon technologies within the current building ceramics industry. It conducts a carbon emission reduction potential analysis for various technologies, identifies constraints in the technology promotion process, and highlights the substantial carbon reduction potential of clean energy substitution technologies and manufacturing process optimization technologies. Technologies such as raw material substitution, high-quality service, and waste ceramic tile recycling and regeneration contribute significantly to economic and environmental benefits, but are still in developmental stages. The article also discusses the application of methods such as life cycle assessment and carbon footprint analysis in the evaluation of green and low-carbon technologies in the field of building ceramics. It discusses the trends and limiting factors of different green and low-carbon technologies, offering suggestions and support for the building ceramics industry’s transition towards a low-carbon and environmentally friendly direction.
DFT predicting structural stability of Li-doped Al-Li solid solution using first principles
Authors: Huang Lei , Zhou Xing
Published: November 2023

By using the first-principles method based on density functional theory (DFT), the CASTEP module in Materials studio was used to calculate the substitution positions of Li atom doped with Al lattice, and different substitution configurations, total energy, average atom formation energy, and charge density distributions were calculated. By calculating the total energy and the average forming energy of atoms, it is concluded that when the Li atom is doped with an Al lattice to form a replacement solid solution, it is the easiest to replace the Al atom on the surface, and the resulting replacement solid solution has the smallest binding energy and the most stable structure. By calculating the density of electron states and analyzing the Fermi energy surface, it is found that the Al-Li solid solution substituting Al atoms at the zero Fermi surface has the smallest electron state density and the most stable structure.
Process Optimization Method for Inhibiting TCP Precipitation in A Nickel-Based Single Crystal Superalloy with High Refractory Element Content
Authors: Yue X D , Wang R , Zhao J Q , Shi Z X , Yang W P , Li J R
Published: November 2023

In order to study the optimization method of microstructure stability of high generation single crystal superalloys, the influence of manufacturing process on the microstructure stability of a single crystal superalloy containing high content of refractory elements was studied, and the corresponding process optimization method was obtained. The microstructure characteristics of the alloy at different stages were observed and the corresponding element distribution were tested. The microstructure and element distribution of the alloy at different stages of preparation were analyzed with the assistance of kinetic calculation. Results show that the element dendrite segregation is an important reason to reduce microstructural stability. Reducing the dendrite spacing in directional solidification and increasing element diffusion in solid solution heat treatment can reduce the segregation of refractory elements in the dendrite core. As a result, less TCP precipitates in the dendrite core, and thus improve microstructure stability. Based on analyzed results, the manufacturing process were optimized and proved to be effective.
Influence of Alloying Elements Content on High Temperature Properties of Ti-V-Cr and Ti-Al-V Series Titanium Alloys: A JMatPro Program Calculation Study
Authors: Sun Ruochen , Mi Guangbao
Published: November 2023

For the issues of high temperature performance affected by the alloying elements content in Ti-V-Cr and Ti-V-Cr alloys, the thermodynamic calculation method based on JMatPro program was applied in this study. The research is mainly focused on the analysis of phase composition, thermodynamic parameters and mechanical properties of Ti-Al-V and Ti-V-Cr series alloys with different element proportions under high temperature environment. Those obtained results show that the proportion of Al in Ti-Al-V alloys has a great influence on the high temperature properties. Increasing the content of Al not only increases the transformation temperature of β single-phase structure and delays the transformation process of α/β microstructure to β single-phase structure, but also helps to improve the high temperature thermal conductivity and elastic deformation resistance of the alloy. In Ti-V-Cr alloys, the influence of V element on high temperature properties is mainly focused on the improvement of thermal conductivity and high temperature deformation properties, while the influence of Cr element is relatively weak. Besides, adding a small amount of Al element to Ti-V-Cr alloy can further improve the thermal conductivity of the alloy. The Young’s modulus of the Ti-V-Cr alloy increases when 0.3%-1% of C element is added. Finally, the effect of Si element on the high temperature elastic deformation of the alloy is relatively weak.
Oxygen vacancy induced conductivity in Sr
n+1Ti
n
O3n+1/SrTiO3 heterostructures
Authors: Zhang T T , Chen X F , Lv Y Q , Wen K R , Du W , Xiao Y X
Published: November 2023

SrTiO3-based heterostructures have attracted much attention due to the abundant properties compared to single components. Here, we fabricate oxide heterostructure of layed perovskite/perovskite Sr
n+1Ti
n
O3n+1/SrTiO3 and investigate the n value-dependent and thickness-dependent conductivity. X-ray diffraction peaks and reflective high energy electron diffraction indicate good film quality. For films of n=6, the heterostructures are conductive, and the conductivity is better for thicker film. On the contrary, heterostructures with films of n=1, 2, 3, 4, ∞ are insulating. Conductive atomic force microscopy results and surface conductivity tests manifest that the oxygen vacancy induced conductive layer exists near the interface between film and substrate. This work provides feasible method to modulate the transport properties of functional transition metal oxides.
Effect of coiling temperature on the microstructure and mechanical properties of DP 980 steel
Authors: Jiang Yinghua , Liu Huasai
Published: November 2023

The effect of coiling temperature on the microstructure and mechanical properties of annealed dual phase steels was investigated. It was found that the rate of ferrite recrystallization with coiling temperature 550°C is faster than that with coiling temperature 650°C. That is low coiling temperature accelerates the recrystallization of ferrite during heating compared with high coiling temperature, which in turn promotes the formation of austenite through the nucleation process. Under the same annealing conditions, the martensite content of annealed steels obtained at low temperature coiling 550°C is higher than that of annealed steels obtained at high coiling temperature 650°C. Compared with high coiling temperature, the low coiling temperature favors the formation of the homogeneous and fine microstructure. Thus, the dual phase steel obtained at low coiling temperature has finer and uniform microstructure and high hole expansion ratio at annealing temperature 800°C in comparision with the dual phase steel obtained at high coiling temperature.
Compression performance and low-frequency damping characteristics of pyramidal lattice cylinder skeleton structure
Authors: Li Zeyu , Hu Feng , Lin Congcong , Xue Xin
Published: November 2023

The lattice structure has obvious advantages over traditional materials in terms of light weight, energy absorption, vibration and noise reduction, and is therefore widely used in many fields such as shipping and aerospace. In this work, a cylinder skeleton structure is designed based on pyramidal lattice structure by circumferential and axial array arrangement. The load-bearing capacity of the pyramidal lattice cylinder skeleton structure under quasi-static compression and its axial vibration characteristics are investigated by numerical method. The effects of key element geometric parameters such as diameter of metal wire, circumferential angle and axial angle on the compression and vibration damping performances of the pyramidal lattice cylinder skeleton structure were investigated. The results show that the developed structure has excellent compression and vibration damping capacity. It is able to provide a pronounced damping effect in the low-frequency range of 204-367 Hz, and the attenuation intensity of elastic wave in this frequency range can be up to 20dB.
Effect of the addition of acetic acid on spinning sol and mullite fibers properties
Authors: Wang X P , Liu Z , Qi X L , Zhang M X , Li R , Xu H N , Wang Y J , Ding W C
Published: November 2023

The preparation of mullite fibers by sol-gel method is the preferred method in industrial production, where the stability, rheological properties and microstructure of spinning sols are essential for the preparation of continuous, low-defect fibers. In this study, aluminum carboxylate solutions (ACs) were prepared using aluminum powder, formic acid and acetic acid as raw materials, silica sol was added, and spinnable sol was obtained by concentration and aging. After dry spinning and calcination at 1200 °C, continuous mullite fibers with mullite as the main crystal phases were obtained. The effect of acetic acid addition on the stability of Al-Si mixed sol was studied, and the polymerization process of spinning sol was studied on its rheological properties and microstructure. The cross-section of mullite fibers obtained after calcination at 1200 °C was “dumbbell” type, and the cause of this cross-section was discussed, which laid a foundation for subsequent optimization research.
Study on the flowability and strength of cement-based materials added with limestone powder and PVA fiber
Authors: Xie Weiliang , Chen Jiajian , Duan Denghui
Published: November 2023

In order to improve the mechanical properties of cement-based materials, limestone powder (LP) was used as a filler as 0% to 20% cement paste replacement by volume in the mortar. Polyvinyl alcohol (PVA) fiber with 0% to 0.6% by volume were added to produce multiple sets of cement-based materials for basic mechanical properties tests including flowability, compressive strength and tensile strength. The test results indicated that an increase in the amount of PVA fiber and the replacement amount of LP continuously reduce the flowability of cement-based materials. PVA fiber led to the most significant reduction effect. The addition of an appropriate amount of PVA fiber can improve the tensile and compressive strength of cement-based materials, but excessive addition has a negative impact on the compressive strength. When the increase in replacement ratio of LP, the compressive strength of cement-based materials increased. Comparatively, the decrease in tensile strength is not significant.
Poly-lactic acid self-reinforcing composites with improved toughness utilising solid-state drawn oriented tape
Authors: Niu G L , Tao Y P , Xu W , Zhang R M , Feng X , Ren M S , Sun J L
Published: November 2023

With the increasing white pollution problem and the enhancement of people’s awareness of environmental protection, the bio-based and biodegradable polymers have received unprecedented attention. Poly-lactic acid (PLA) is considered as one of the most potential alternatives to petroleum-based polymer materials. However, Due to its inherent brittleness and the difficulties of post-disposal and recycling caused by traditional processing methods, PLA has not been fully accepted by the market. To overcome the issues, self-reinforcing PLA composites (SRPLA) were prepared with different PLA grades as the matrix and the reinforcement respectively. High toughness SRPLA were prepared by hot pressing using PLA3052 casting films as the matrix and PLA6202 oriented tapes fabricated by solid state drawing as the reinforcement. In addition, the toughening mechanism was analyzed. Mechanical tests showed that the strength, modulus and elongation at break were increased by 124.3%, 114% and 145.2% respectively compared with pure PLA hot pressed film. Particularly, the tensile toughness of SRPLA is more than 200% that of pure PLA. The interface debonding and tape pullout were the main toughening mechanisms.
ZrO2-doped Zn0.5Ti0.5TaO4 microwave dielectric ceramics with low dielectric loss and excellent temperature stability
Authors: Liu Kui , Zhang Huaiwu , Liu Cheng , Li Jie , Zhang Dainan , Liao Yulong
Published: November 2023

Herein, the weight fraction of the tri-rutile and ixiolite structures in Zn0.5Ti0.5-xZr
x
TaO4 (ZTZTO
x
, 0 ≤ x ≤ 0.10) was successfully adjusted by the substitution of Ti4+ ions by Zr4+.Zn0.5Ti>0.48Zr0.02TaO4 ceramics exhibited excellent dielectric properties when sintered at 1290°C with τ
f
= -3.73 ppm/°C, εr
= 33.22, and Q×f=79,266 GHz, respectively. As the amount of Zr4+- substitution increases, the tri-rutile structure content gradually decreases, and the tri-rutile structure is completely transformed into an ixiolite structure at 0.06 ≤x. This leads to the grain size showing a trend of decreasing and then increasing. Non-intrinsic factors suggest that ixiolite structures with lower εr
and higher Q×f values are the main cause of the change in dielectric properties. Intrinsic factors suggest that an increase in the number of Raman characteristic waves leads to a gradual decrease in εr
. The damping loss of the lattice vibrational behavior decreases, leading to a gradual increase in Q×f. In conclusion, Zn0.5Ti0.48Zr0.02TaO4 ceramics with aτf
close to zero have good prospects for application in microwave communications.
Comparison and analysis of testing methods for magnetic properties of oriented silicon steel sheets
Authors: Gu L Y , Wang X Y , Wu Y , Zhang X , Ren Y , Xue Z Y
Published: November 2023

The magnetic properties of oriented silicon steels with different thickness of 0.18 mm, 0.23 mm, 0.27 mm, and 0.30 mm in rolling direction and transverse direction were studied using the excitation current method and H-coil method. The magnetic field strength deviation and specific total loss of two methods were compared based on the excitation current method. The magnetic field distribution was analyzed using MagNet finite element simulation, and it was found that the measurement deviation of the excitation current method is mainly determined by the effective magnetic circuit length. The higher the magnetic flux density, the smaller the effective magnetic path length. Therefore, under low magnetic flux density conditions, the actual effective magnetic path length is greater than the specified effective magnetic path length, resulting in high measurement results, while under high magnetic flux density conditions, the measurement results are low. Due to the influence of hysteresis loss, the deviation ratio of the two methods on the total loss is generally smaller than the deviation ratio of magnetic field strength, and the 0.18mm oriented silicon steel is smaller than other thickness oriented silicon steel. Due to the difficulty of magnetization in the transverse direction of oriented silicon steel, the variation trend of magnetic field strength deviation and specific total loss along the transverse direction is significantly different from that along the rolling direction. In addition, a measurement correction strategy was proposed by determining the actual effective magnetic circuit length of the excitation current method, which achieved good results. This work has certain significance for the accurate measurement of the magnetic properties of oriented silicon steel, and is expected to provide important reference for the application of 0.18mm oriented silicon steel.
Progress in manufacturing and processing of Al-Sc alloy targets
Authors: Cao Z Q , Xiong X D , Zhang Y A , Jia Q , Cao X M , Ding Z C , Luo J F
Published: November 2023

The development of the fifth-generation mobile communication technology (5G) puts forward higher requirements for radio frequency (RF) filters. Due to its higher frequency and larger bandwidth, bulk acoustic wave (BAW) filter will become the mainstream RF filter solution. Scandium doped aluminium nitride (AlScN) piezoelectric film has attracted much attention due to its excellent piezoelectric response coefficients and electromechanical coupling coefficients. The doped Sc concentration will directly affect the piezoelectric coefficient and electromechanical coupling coefficient of the film. The most common technique for producing AlScN thin films is magnetron sputtering of targets made of Al-Sc alloy. However, with the increase of Sc content, the solid-liquid solidification interval, the number of intermetallic compounds, and the brittleness of the material will all increase significantly. Additionally, it will result in component macro-segregation, uneven phase distribution, and poor processing deformability. Therefore, it is extremely difficult to manufacture and process Al-Sc alloy targets. The mainstream processes for preparing Al-Sc alloy targets are divided into direct reaction method and powder metallurgy method. This paper reviews the research progress in manufacturing and processing of Al-Sc alloy targets.
Investigation on Thermal Conductivity Silver-coated Copper/GaInSn Composite Thermal Interface Materials
Authors: Zhang Jie , Sun Mingmei , Du Shijie , Xie Zhongnan , Guo Hong
Published: November 2023

To enhance the heat transfer performance of GaInSn liquid metal, a new type of composite thermal interface material with GaInSn as thermal conductive matrix and silver-coated copper particles as thermal conductive fillers was prepared in this article. The morphology of the composites were characterized by scanning electron microscopy. The thermal conductivity of silver-coated copper/GaInSn composites with different silver-coated copper particle contents were measured by laser flash method. The interfacial bonding of the composites were investigated by X-ray diffraction. The results show that when the volume ratio of silver-coated copper particles is 15%, thermal conductivity of the silver-coated copper/GaInSn composite reaches the largest value of 25.01 W·m−1·K−1. The silver-coated copper/GaInSn composite material and commercially available thermal grease were put into the chip and copper plate to simulate the actual application scenarios for comparison. The heat dissipation capacity of silver-coated copper/GaInSn composite material is obviously better than that of the two commercially available thermal grease, and the chip temperature can be reduced by about 5°C.
Mg4Nb2O9:Cr3+: broadband near-infrared luminescence
Authors: Yin Mei , Wang Xudong , Zhou Tianliang , Xie Rong-Jun
Published: November 2023

The exploration of broadband Near infrared (NIR) phosphors is one of the research priorities to enable the advancement of NIR devices. In this work, Mg4Nb2O9:Cr3+ phosphors were prepared by high-temperature solid-state reaction method. Mg4Nb2O9:Cr3+ can emit ultra-broadband NIR centred at 880 nm with an extremely full width at half maximum (FWHM) of near 200 nm, and NIR phosphor-converted LED (pc-LED) has been fabricated by combining a 450 nm blue LED with MNO:0.5%Cr to demonstrate its application prospect in night vision.
Fracture failure of internal thread joint on back redressing stabilizer
Authors: Ji Nan , Wu Feng , Feng Chun , Wang Peng , Zhu Lijuan , Bai Zhenquan
Published: November 2023

Stabilizers have been one of the most critical components in the drilling string, due to their great function to prevent the unintentional sidetracking and vibrations in whole drilling assembly. In recent years, with the increasing of the well depth, the rising of the harsh service conditions have pose big challenges to the stabilizers. So it is very necessary to conduct systematic research on the failure mechanism of the stabilizer and carry out ideal failure prevention measures. In this article, the fracture failure analysis of an internal thread joint of the back redressing stabilizer was carried out, and the failure causes were investigated by nondestructive testing, mechanical property tests, chemical composition analysis, metallographic analysis and scanning electron microscope analysis. The results show that the mechanical tests and chemical composition analysis results all meet the requirements of the SY/T 5051-2016 standard, the fracture mode of the back redressing stabilizer is fatigue fracture, and the causes of the failure is mainly belong to the pit shape defects on the surface of internal thread and the quenching crack in the internal thread.