bluuebunny/crossref_metadata_2025 huggingface dataset:
Network physics of attractive colloidal gels: Resilience, rigidity, and phase diagram
Authors: Nabizadeh Mohammad , Nasirian Farzaneh , Li Xinzhi , Saraswat Yug , Waheibi Rony , Hsiao Lilian C. , Bi Dapeng , Ravandi Babak , Jamali Safa
Published: January 2024

Colloidal gels exhibit solid-like behavior at vanishingly small fractions of solids, owing to ramified space-spanning networks that form due to particle–particle interactions. These networks give the gel its rigidity, and with stronger attractions the elasticity grows as well. The emergence of rigidity can be described through a mean field approach; nonetheless, fundamental understanding of how rigidity varies in gels of different attractions is lacking. Moreover, recovering an accurate gelation phase diagram based on the system’s variables has been an extremely challenging task. Understanding the nature of colloidal clusters, and how rigidity emerges from their connections is key to controlling and designing gels with desirable properties. Here, we employ network analysis tools to interrogate and characterize the colloidal structures. We construct a particle-level network, having all the spatial coordinates of colloids with different attraction levels, and also identify polydisperse rigid fractal clusters using a Gaussian mixture model, to form a coarse-grained cluster network that distinctly shows main physical features of the colloidal gels. A simple mass-spring model then is used to recover quantitatively the elasticity of colloidal gels from these cluster networks. Interrogating the resilience of these gel networks shows that the elasticity of a gel (a dynamic property) is directly correlated to its cluster network’s resilience (a static measure). Finally, we use the resilience investigations to devise [and experimentally validate] a fully resolved phase diagram for colloidal gelation, with a clear solid–liquid phase boundary using a single volume fraction of particles well beyond this phase boundary.
Meta-semantic practices in social interaction
Authors: Deppermann Arnulf
Published: January 2024

In social interaction, different kinds of word-meaning can become problematic for participants. This study analyzes two meta-semantic practices, definitions and specifications, which are used in response to clarification requests in German implemented by the formatWas heißt X(‘What does X mean?’). In the data studied, definitions are used to convey generalizable lexical meanings of mostly technical terms. These terms are either unknown to requesters, or, in pedagogical contexts, requesters ask in order to check the addressee’s knowledge. Specifications, in contrast, clarify aspects of local speaker meanings of ordinary expressions (e.g., reference, participants in an event, standards applied to scalar expressions). Both definitions and specifications are recipient-designed with respect to the (presumed) knowledge of the addressee and tailored to the topical and practical relevancies of the current interaction. Both practices attest to the flexibility and situatedness of speakers’ semantic understandings and to the systematicity of using meta-semantic practices differentially for different kinds of semantic problems. Data are come from mundane and institutional interaction in German from the public corpus FOLK.
Domain dichotomy and sociolinguistic inequality in Philippine museum spaces
Authors: Manalastas Nicko Enrique L.
Published: January 2024

The prevailing notion on the scholastic domains of English and Filipino is that the former is used for science, whereas the latter is reserved for the social sciences. Despite its questionable veracity, this domain dichotomy has nevertheless been adopted in Philippine education, particularly in the 1974 Bilingual Education Policy (Sibayan, 1978; Gonzalez, 1990). Using Scollon and Scollon’s (2003) concept of emplacement and Kress and van Leeuwen’s (1996) information value as theoretical points of departure and Tupas’ (2008, 2015a) ‘Unequal Englishes’ paradigm as an analytical framework, this paper investigates whether this dichotomy has permeated into the Linguistic Landscapes of two national museums in Manila. It finds that there is a strong tendency for the natural history museum to privilege English in bilingual signs and the anthropological museum to privilege Filipino, thereby suggesting that this split has already been reified in language practices outside the realm of education policy making and politics.
Electrical transport in epitaxially grown undoped and Si-doped degenerate GaN films
Authors: Monish Mohammad , Major S S
Published: January 2024

This study investigates the electrical transport properties of undoped and Si-doped, degenerate GaN heteroepitaxial films grown on sapphire by reactive rf sputtering of GaAs (and Si) in Ar-N2 mixture. The room temperature electrical measurements showed that the resistivity of undoped GaN film grown at 100% N2 was ∼2 × 105 Ω cm, which reduced to ∼1 Ω cm in Si-doped film, revealing the effect of Si doping. With decrease of N2 from 100% to 75%, the carrier concentration of Si-doped films increased from ∼7 × 1018 cm−3 to ∼2 × 1019 cm−3, but remained practically unchanged as N2 was decreased to 20%, which is explained by effects due to saturation of Si doping and increase of Ga interstitials as well as compensation by N interstitials and Ga vacancies. Undoped and Si-doped films grown below 20% N2 displayed similar carrier concentrations (∼1020 cm−3), due to dominance of Ga interstitials. Both undoped and Si-doped films were degenerate and displayed increase of mobility with carrier concentration and temperature, which was analyzed by the combined effect of ionized impurity and dislocation scattering, using compensation ratio as fitting parameter. At carrier concentrations ≲1019 cm−3, the mobility was governed by both ionized impurity and dislocation scattering, while at higher carrier concentrations, ionized impurity scattering was found to dominate, limited by compensation due to acceptors. In spite of the degenerate character, the films displayed a small decrease of carrier concentration with temperature, along with a nearly linear decrease of mobility, which are explained by a marginal increase of compensation ratio with decrease of temperature, taking into account the band edge fluctuation effects. These features of electrical transport have not been much explored for heteroepitaxial, n-type degenerate GaN films, possessing high density of dislocations and point defects.
Insight into the physical properties of Rb2YCuX6 (X = Br and I) lead-free elpasolite for high-energy applications
Authors: Bibi Safia , Husain Mudasser , Tirth Vineet , Ben Ahmed Samia , Rahman Nasir , Azzouz-Rached Ahmed , Ullah Hamid , Khan Muhammad Yaqoob , Khan Aurangzeb
Published: January 2024

This study explores the intriguing properties of lead-free Rb2YCuX6 (X = Br and I) elpasolite, a novel class of A2B’B‘X6 double perovskite materials, focusing on their structural, mechanical, and optoelectronic characteristics. The stability of the cubic structures was rigorously confirmed by calculating the tolerance factor, and octahedral factor, and employing the Birch-Murnaghan equation of states. Mechanical stability was confirmed through the examination of various parameters, revealing the materials as incompressible, hard, ductile, and anisotropic double perovskites. Analyzing the electronic band structure and density of states unveiled a distinctive indirect band gap of 2.46 eV for Rb2YCuBr6 and 2.12 eV for Rb2YCuI6, from L-X symmetry points. The optical parameters of these double perovskites were computed to evaluate their use in optical devices. Notably, their minimal light scattering, refractive index ranging from approximately 1.5 to 2, and broad absorption band within the visible spectrum make them highly suitable for optoelectronic applications, emphasizing their potential role in energy conservation and high-energy scenarios.
Fitness effects of a demography-dispersal trade-off in expanding Saccharomyces cerevisiae mats
Authors: Hall Rebekah , Bandara Akila , Charlebois Daniel A
Published: January 2024

Fungi expand in space and time to form complex multicellular communities. The mechanisms by which they do so can vary dramatically and determine the life-history and dispersal traits of expanding populations. These traits influence deterministic and stochastic components of evolution, resulting in complex eco-evolutionary dynamics during colony expansion. We perform experiments on budding yeast strains genetically engineered to display rough-surface and smooth-surface phenotypes in colony-like structures called ‘mats’. Previously, it was shown that the rough-surface strain has a competitive advantage over the smooth-surface strain when grown on semi-solid media. We experimentally observe the emergence and expansion of segments with a distinct smooth-surface phenotype during rough-surface mat development. We propose a trade-off between dispersal and local carrying capacity to explain the relative fitness of these two phenotypes. Using a modified stepping-stone model, we demonstrate that this trade-off gives the high-dispersing, rough-surface phenotype a competitive advantage from standing variation, but that it inhibits this phenotype’s ability to invade a resident smooth-surface population via mutation. However, the trade-off improves the ability of the smooth-surface phenotype to invade in rough-surface mats, replicating the frequent emergence of smooth-surface segments in experiments. Together, these computational and experimental findings advance our understanding of the complex eco-evolutionary dynamics of fungal mat expansion.
High power narrow linewidth fiber laser based on superfluorescent white noise modulation
Authors: Shan X , Hou T , Li F , Zhu R
Published: January 2024

High power narrow linewidth fiber lasers have important applications in the fields of national defense, military and industrial intelligent manufacturing. At present, the power enhancement of narrow linewidth lasers is limited by the nonlinear and thermal effects of fiber, among which the stimulated Brillouin scattering (SBS) effect is highly destructive due to its low threshold. The SBS effect is easily produced using a single frequency laser as the seed of a high power narrow linewidth laser directly. The Brillouin scattering threshold can be effectively increased by broadening the spectrum line at a single frequency. A spectral broadening technique for single frequency lasers based on superfluorescent white noise modulation was proposed. The broadband characteristics of the amplified spontaneous emission light source to generate noise voltage on the photodetector was employed, and the lithium niobate electro-optical modulator was driven to perform broadband phase modulation in a single frequency laser. The phase modulation broadening of the single frequency laser was carried out using superfluorescent white noise. Different linewidth broadening effects of single frequency lasers were realized by changing the amplitude of the white noise. An experimental platform of the four-stage main oscillation power amplification structure was built, and a high power narrow linewidth laser with output power of 2 kW and spectral linewidth of 0.15 nm (10 dB) was realized, which effectively inhibited the SBS effect of the laser.
Coherent control of parametric generation of laser beams via intersubband transitions in quantum wells
Authors: Batoo K M , Kamona S M Husein , Zaki Sh H , Lafta H A , Hussain S , Khazaal W M , Hamoody A H M , Abdulkadhim A H , Shaghnab M L , Rasen F A , Alawadi A , Alsalamy A
Published: January 2024

This paper investigates the propagation dynamics of laser beams within a semiconductor quantum well (QW) system. The study explores various scenarios involving different detuning values and spatially varying incident beams. The light–matter interaction within the QW system shows a complex interplay between detuning, spatial characteristics, and beam properties. In the resonant case, where the detuning values for probe and signal beams are zero, we observe exponential relaxation of both beams reaching a common value. Introducing detuning leads to oscillatory behaviors, with larger detuning values promoting more pronounced oscillations and an enhanced signal beam. The investigation takes an intriguing turn when we consider position-dependent incident beams. In these cases, the spatial patterns of the initial beam are transferred to the generated beam, leading to soliton-like propagation and the creation of beams with specific spatial dependencies. Remarkably, under substantial detuning, both incident and generated beams adopt periodic patterns in two dimensions, forming lattice structures with spot-like peak intensities. These findings underscore the versatility and controllability of the QW system, offering opportunities for engineered spatial and spectral properties in laser beams.
A global model of intensity autocorrelation to determine laser pulse duration
Authors: Peng 彭 Yufei 雨菲 , Liu 刘 Liqiang 励强 , Hong 洪 Lihong 丽红 , Li 李 Zhiyuan 志远
Published: January 2024

We present a new global model of collinear autocorrelation based on second harmonic generation nonlinearity. The model is rigorously derived from the nonlinear coupled wave equation specific to the autocorrelation measurement configuration, without requiring a specific form of the incident pulse function. A rigorous solution of the nonlinear coupled wave equation is obtained in the time domain and expressed in a general analytical form. The global model fully accounts for the nonlinear interaction and propagation effects within nonlinear crystals, which are not captured by the classical local model. To assess the performance of the global model compared to the classic local model, we investigate the autocorrelation signals obtained from both models for different incident pulse waveforms and different full-widthes at half-maximum (FWHMs). When the incident pulse waveform is Lorentzian with an FWHM of 200 fs, the global model predicts an autocorrelation signal FWHM of 399.9 fs, while the classic local model predicts an FWHM of 331.4 fs. The difference between the two models is 68.6 fs, corresponding to an error of 17.2%. Similarly, for a sech-type incident pulse with an FWHM of 200 fs, the global model predicts an autocorrelation signal FWHM of 343.9 fs, while the local model predicts an FWHM of 308.8 fs. The difference between the two models is 35.1 fs, with an error of 10.2%. We further examine the behavior of the models for Lorentzian pulses with FWHMs of 100 fs, 200 fs and 500 fs. The differences between the global and local models are 17.1 fs, 68.6 fs and 86.0 fs, respectively, with errors approximately around 17%. These comparative analyses clearly demonstrate the superior accuracy of the global model in intensity autocorrelation modeling.
Advances in neuromorphic computing: Expanding horizons for AI development through novel artificial neurons and in-sensor computing
Authors: Yang 杨 Yubo 玉波 , Zhao 赵 Jizhe 吉哲 , Liu 刘 Yinjie 胤洁 , Hua 华 Xiayang 夏扬 , Wang 王 Tianrui 天睿 , Zheng 郑 Jiyuan 纪元 , Hao 郝 Zhibiao 智彪 , Xiong 熊 Bing 兵 , Sun 孙 Changzheng 长征 , Han 韩 Yanjun 彦军 , Wang 王 Jian 健 , Li 李 Hongtao 洪涛 , Wang 汪 Lai 莱 , Luo 罗 Yi 毅
Published: January 2024

AI development has brought great success to upgrading the information age. At the same time, the large-scale artificial neural network for building AI systems is thirsty for computing power, which is barely satisfied by the conventional computing hardware. In the post-Moore era, the increase in computing power brought about by the size reduction of CMOS in very large-scale integrated circuits (VLSIC) is challenging to meet the growing demand for AI computing power. To address the issue, technical approaches like neuromorphic computing attract great attention because of their feature of breaking Von-Neumann architecture, and dealing with AI algorithms much more parallelly and energy efficiently. Inspired by the human neural network architecture, neuromorphic computing hardware is brought to life based on novel artificial neurons constructed by new materials or devices. Although it is relatively difficult to deploy a training process in the neuromorphic architecture like spiking neural network (SNN), the development in this field has incubated promising technologies like in-sensor computing, which brings new opportunities for multidisciplinary research, including the field of optoelectronic materials and devices, artificial neural networks, and microelectronics integration technology. The vision chips based on the architectures could reduce unnecessary data transfer and realize fast and energy-efficient visual cognitive processing. This paper reviews firstly the architectures and algorithms of SNN, and artificial neuron devices supporting neuromorphic computing, then the recent progress of in-sensor computing vision chips, which all will promote the development of AI.
Anomalous valley Hall effect in two-dimensional valleytronic materials
Authors: Chen 陈 Hongxin 洪欣 , Yuan 原 Xiaobo 晓波 , Ren 任 Junfeng 俊峰
Published: January 2024

The anomalous valley Hall effect (AVHE) can be used to explore and utilize valley degrees of freedom in materials, which has potential applications in fields such as information storage, quantum computing and optoelectronics. AVHE exists in two-dimensional (2D) materials possessing valley polarization (VP), and such 2D materials usually belong to the hexagonal honeycomb lattice. Therefore, it is necessary to achieve valleytronic materials with VP that are more readily to be synthesized and applicated experimentally. In this topical review, we introduce recent developments on realizing VP as well as AVHE through different methods, i.e., doping transition metal atoms, building ferrovalley heterostructures and searching for ferrovalley materials. Moreover, 2D ferrovalley systems under external modulation are also discussed. 2D valleytronic materials with AVHE demonstrate excellent performance and potential applications, which offer the possibility of realizing novel low-energy-consuming devices, facilitating further development of device technology, realizing miniaturization and enhancing functionality of them.
Measuring small longitudinal phase shifts via weak measurement amplification
Authors: Xu 徐 Kai 凯 , Hu 胡 Xiao-Min 晓敏 , Hu 胡 Meng-Jun 孟军 , Wang 王 Ning-Ning 宁宁 , Zhang 张 Chao 超 , Huang 黄 Yun-Feng 运锋 , Liu 柳 Bi-Heng 必恒 , Li 李 Chuan-Feng 传锋 , Guo 郭 Guang-Can 光灿 , Zhang 张 Yong-Sheng 永生
Published: January 2024

Weak measurement amplification, which is considered as a very promising scheme in precision measurement, has been applied to various small physical quantities estimations. Since many physical quantities can be converted into phase signals, it is interesting and important to consider measuring small longitudinal phase shifts by using weak measurement. Here, we propose and experimentally demonstrate a novel weak measurement amplification-based small longitudinal phase estimation, which is suitable for polarization interferometry. We realize one order of magnitude amplification measurement of a small phase signal directly introduced by a liquid crystal variable retarder and show that it is robust to the imperfection of interference. Besides, we analyze the effect of magnification error which is never considered in the previous works, and find the constraint on the magnification. Our results may find important applications in high-precision measurements, e.g., gravitational wave detection.
One-step quantum dialogue
Authors: Zhu 朱 Peng-Hui 鹏辉 , Zhong 钟 Wei 伟 , Du 杜 Ming-Ming 明明 , Li 李 Xi-Yun 喜云 , Zhou 周 Lan 澜 , Sheng 盛 Yu-Bo 宇波
Published: January 2024

Quantum dialogue (QD) enables two communication parties to directly exchange secret messages simultaneously. In conventional QD protocols, photons need to transmit in the quantum channel for two rounds. In this paper, we propose a one-step QD protocol based on the hyperentanglement. With the help of the non-local hyperentanglement-assisted Bell state measurement (BSM), the photons only need to transmit in the quantum channel once. We prove that our one-step QD protocol is secure in theory and numerically simulate its secret message capacity under practical experimental condition. Compared with previous QD protocols, the one-step QD protocol can effectively simplify the experiment operations and reduce the message loss caused by the photon transmission loss. Meanwhile, the non-local hyperentanglement-assisted BSM has a success probability of 100% and is feasible with linear optical elements. Moreover, combined with the hyperentanglement heralded amplification and purification, our protocol is possible to realize long-distance one-step QD.
Size Optimization of Spherical Silver Nanoparticles Synthesized with Baicalin and Sodium Dodecyl Sulfate Using Response Surface Methodology
Authors: Wang Dong , Wang Lihui , Sun Qingyi , Qu Jincheng , Zhang Xiaowen
Published: January 2024

This study aimed to optimize the synthesis of silver nanoparticles mediated by Baicalin and sodium dodecyl sulfonate using Single factor experiment method and response surface methodology, to optimize their process parameters so as to prepare spherical silver nanoparticles with smaller particle size, and to compare the particle size of silver nanoparticles prepared under different conditions by comparing the wavelength of the maximum absorption peak measured by UV-visible spectrophotometer. Thus, the best synthesis program was determined. The average particle size of the silver nanoparticles prepared under the optimal conditions was 32.25 nm with high sphericity, and the silver nanoparticles synthesized under the optimized conditions were characterized by SEM, FTIR, particle size distribution and UV-vis.
Study on the Pull-Out Behavior of Glass Fiber Bundle in Mortar
Authors: Liang Yuehua , Cheng Congmi , Ling Shan , Jiang Shusen , Luo Xu
Published: January 2024

In this paper, the influence of the embedment depth of glass fiber bundle in mortar on its pull-out behavior was studied. The time-dependent pull-out behavior of glass fiber bundle in mortar at 28 d, 56 d, 84 d, and 168 d under natural curing was investigated. The results show that there are three stages of pulling out the fiber bundle from the mortar: complete elastic stage, debonding stage, and sliding pull-out stage. With the increase of embedment depth, the pull-out energy of the fiber bundle first increased and then decreased. The pull-out energy was the highest when the fiber bundle embedment depth was 15 mm. The greater the embedment depth, the lower the ultimate bonding strength of the fiber bundle. This is because the larger the initial embedment depth of the fiber bundle, the greater the bonding force between the fiber monofilament and the mortar, which is more likely to cause the fiber monofilament to fracture.
Robot-Assisted Ultrasonic Testing Technology for Complex Revolved Workpiece
Authors: Wang Jingpin , Zhang Hanming , Xu Honghai , Wang Changyu , Cao Jiarui , Liu Tianqi , Li Zefeng , Yang Jiaji
Published: January 2024

High temperature, fatigue, and impact are the main causes of internal cracks in revolved workpieces. Crack propagation assessment is an effective method to avoid fracture. Ultrasonic testing has been widely used when testing internal cracks in revolved workpieces. However, the existing ultrasonic detection equipment makes it difficult to detect revolved workpieces with complex structures. This paper proposes an automation system including six degrees of freedom (DOF) robot, ultrasonic transducer, and turntable. The system can realize non-destructive testing automatically for complex revolved workpieces. A new method is designed to measure and correct verticality error and eccentricity error. The method was applied to detect complex revolved workpieces and the detecting resolution can be effectively improved.
Cam Profile Design of Low-Speed Marine Diesel Engine Based on the Grey Theory
Authors: Xu Zhen , Chen Jianzhi , Jing Xuwen
Published: January 2024

The camshaft profile is one of the important parameters of the engine, the reasonableness or otherwise of its design directly influences the engine’s power output, fuel consumption, emissions, noise and reliability. However, most existing cam profile optimization designs are based on the basic software operation, profile parameter selection and tuning lack a scientific theoretical basis. In order to address this issue, this study establishes a single valve kinematic model of the gas delivery mechanism of diesel engines by using the AVL-EXCITE Timing Drive, and performs a model-based multinomial kinematic acceleration cam profile design. Subsequently, an orthogonal design method is employed to obtain the parameter combinations that can satisfy the dynamic requirements. The research investigates the influence of cam profile design parameters (C
4, p, q, r, and s) on valve fullness, maximum jerk, cam contact stress, and valve seating force through a systematic study. Lastly, based on the grey correlation theory, a thorough analysis of the performance indices of cams with different profile parameter combinations is conducted. The optimization problem of the profile parameters with multiple performance indicators is transformed into a single-objective grey relational optimization problem, resulting in the optimal cam profile parameter combination of C4
=0.1, p=14, q=20, r=28 and s=36. The optimal method proposed in the paper is straightforward to implement and is applicable to the optimum design of cam profiles of the engine, which is of great importance for the optimal design of cam fabrication processes.
Acid Fracturing Technology and Effect Evaluation of Carbonate Horizontal Well in Fuman Oilfield
Authors: Li Wei , Chen Liang , Wang Xin , Fan Qinghu , Xu Guowei , Xiao Wenliang , Li Xinting , Ye Zhiquan
Published: January 2024

Since the deep and ultra-deep carbonate rocks in the Fuman oilfield have made continuous breakthroughs, the acidification and fracturing of the reservoir on the south bank of Tarim River have been faced with problems such as faster acidification and shorter effective acidification fracture length with the increased burial depth and formation temperature, which seriously restrict the effect of acidification and fracturing. At present, the Fuman oilfield has achieved remarkable results after acid fracturing construction. In this paper, the acid fracturing construction effects of multiple reservoir reconstruction Wells in Tahe Yueman, Fuyuan, Guole, and Manshen blocks are evaluated and classified by analyzing acid fracturing construction curves, using fracture static pressure fitting and fracture conductivity curve analysis. The characteristics and distribution law of carbonate reservoirs corresponding to different construction curves are studied, and various situations of artificial fractures communicating with natural fracture-cavity systems are analyzed. The research results can accurately guide the design optimization and development of acid pressure.
Fabrication of Strong Basic Sites on Cr3+ Doped Reductive Support and Its Catalytic Application for Transesterification
Authors: Yu Xiang , Mo Xuekun , Chen Hanming , Jiang Xiangyang , Xu Bingbing , Zhu Mingqiao
Published: January 2024

Solid strong base catalysts have attracted much attention for their excellent catalytic performance and environmental friendliness due to heterogeneous properties. However, this kind of catalyst usually needs a higher temperature to be activated. Therefore, it is still a challenge to obtain high-activity catalysts at lower fabrication temperatures. In this paper, a reductive catalyst support containing low-valence metal centers (Cr3+) was prepared. Through the redox reaction between the Cr3+ and KNO3, the basic sites can be produced at lower temperatures on the reductive support (Cr-MeIM). Thermogravimetry-mass (TG-MS) spectrometer results showed that the base precursor began to be transformed into basic sites at about a low temperature of 180°C. The solid base catalyst was applied into transesterification between ethylene carbonate (EC) and methanol. By using 0.05 g of catalyst for 3 h at 70°C, we obtained a dimethyl carbonate (DMC) yield of up to 60.9%, which means that the catalyst has high activity.
Testing and Analysis of Frictional Performance of Carbon Fiber/Metal Composite Materials
Authors: Jiao Yuxin , Li Jing , Li Qinghua
Published: January 2024

In order to enhance the friction and wear performance of carbon fiber/steel composite structures, experiments were conducted to adjust the ratio of thermosetting epoxy resin and C12-C14 glycol ether. A modified liquid was developed that could fully fill the gaps in the carbon fiber and enhance the adhesion characteristics between the fiber surface and 18CrMnTiH round steel material. The effects of self-made modified epoxy adhesive and single-component epoxy adhesive on the mechanical properties of composite materials were compared using ISO814-86 determination of the bond strength of sulfur-cured rubber to metal—two-plate method and international standard ISO1747-1976 determination of the shear strength of sulfur-cured rubber bonded to rigid metal plates—four-plate shear method. The friction and wear performance test analyzed the friction coefficient of composite materials under different pretreatment times. The results showed that the pretreatment treatment effectively reduced the friction coefficient of carbon fiber and effectively extended the service life of the material. This study has certain reference significance for extending the friction and wear resistance performance of carbon fiber-reinforced relative motion metal parts.
Properties of Rubidium-Doped Potassium Titanyl Phosphate (Rb: KTP) Grown by Hydrothermal Method
Authors: Lv Hu , Zhang Changlong , Zhang Jian , He Xiaoling , Zhou Haitao , Wang Dongjie , Wang Dong , Luo Yong , Ma Zhi , Wu Wenyuan , Deng Zhengzhong
Published: January 2024

As an electro-optical crystal with excellent properties, potassium titanyl phosphate (KTP) has high conductivity limits electro-optical applications. In this experiment, Rb-doped KTP crystals were grown by the hydrothermal technique of micro-doping and sustained-release, the crystal structure was determined by XRD, the presence of Rb in the crystals was explored by EDS, and the role of Rb in the crystals was investigated by Raman technique. Frequency-dependent dielectric constants were studied at room temperature, which decreases sharply at low frequencies. The variation of the conductivity of the crystals at different temperatures was investigated, and it was found that the room temperature conductivity of the KTP crystals, which were micro-doping by large ionic, was able to drop to 10−13 S/cm, which is about two orders of magnitude lower than that of the pure KTP crystals.
Parameter Selection for Milling Machining of Thin-Walled Parts Based on Spatial Distribution of Side Blades
Authors: Tang Lianyao , Cai Xiaona
Published: January 2024

In the machining of thin-walled components, the tool’s side edges play a pivotal role in the cutting process. This paper presents the establishment of the AdvantEdge 3D simulation model for the analysis of the contact conditions and the variation in cutting forces between the side edge and the machined surface across varying cutting depths. Subsequently, milling experiments were conducted to assess the impact of the side edge’s contact conditions on the surface quality of the machined parts, considering different cutting depths. The findings reveal that during side milling of thin-walled components, a lower number of teeth result in reduced cutting edges, decreased cutting forces, and improved surface quality. The selection of cutting depth should be made with due consideration to the contact conditions between the tool’s side edge and the workpiece. Ideally, the cutting depth should be less than the pitch of the side edge’s spatial curve to ensure that only a single cutting edge is engaged in the cutting process.
Preparation and Pesticide Release Performance of Carboxymethyl Chitosan Film
Authors: Xu Qing , Long Shangjun , Zhu Guangjuan , Li Jinyan , Zhou Yuanjing
Published: January 2024

The slow/controlled release technology is effective in enhancing the utilization of pesticide and reducing the environment pollution caused by pesticide. In this study, the slow/controlled release carboxymethyl chitosan films were prepared by film casting method, and the pesticide release properties were investigated. The results showed that the pesticide-loaded carboxymethyl chitosan films were smooth and uniform. Different pesticide-loaded films had different film thicknesses, pesticide loading and encapsulation efficiency, but had the same pesticide release trend, which might be the result of multiple pesticide release mechanisms including the swelling and erosion of the carboxymethyl chitosan. This study would promote the application of slow/controlled release technologies in pesticides and accelerate the green and efficient development of agriculture.
Analysis of Wax Formation Mechanism and Anti Wax Effect of Oil Well Tubing in a Certain Oilfield
Authors: Feng Shaobo , Huang Kun , Zhao Mifeng , Xiong Maoxian , Teer Ba , Wang Shuai
Published: January 2024

During the production process of oil wells, wax deposition is caused by factors such as temperature reduction and dissolved gas precipitation. Severe wax deposition in oil wells can cause tubing blockage, leading to a decrease in oil well production and even stopping production due to wax blockage, affecting normal oil well production. Therefore, wax deposition can have a serious impact on the wellbore and even oilfield production. This article takes a certain oilfield block as an example to analyze the mechanism of wax deposition in oil wells and compares the effectiveness of commonly used wax removal and prevention measures such as different hot washing processes, adding wax removers, running acoustic viscosity reduction and wax prevention devices along with the oil pipe, and hot washing packers for sealing wells. The results show that superconducting hot washing, adding wax remover, and using acoustic wave viscosity reducing and wax preventing devices can effectively slow down wax deposition in oil wells. The use of hot washing packers effectively solves the problem of long-term inability to hot wash sealed wells, and it is recommended to promote their use.
Research on Precision Bending Forming Technology of Aluminum Alloy Outer Frame
Authors: Tian Jun , Gong Weilun , Chen Xiong , Wang Zhihua , Hu Zhigang , Li Kang , Jin Shuoxun
Published: January 2024

In this paper, the 6063 aluminum alloy outer frame is prone to cracking during bending forming. We analyze the strength and plasticity of the material through tensile experiments (in situ stretching, high-temperature stretching), and establish constitutive models based on component material parameter equations. Using COMSOL Multiphysics software, numerical simulation was conducted on the bending forming of 6063 aluminum alloy profiles, analyzing the stress and deformation of the material during the extrusion process. By utilizing simulation results to design and improve the process and mold, the aluminum alloy outer frame will not produce cracks during the bending forming process, thereby improving the product qualification rate.
Key Technology of 240°C High-Temperature Drilling Fluid
Authors: Shan Wenjun , Duan Xiaoqing , Jiang Guancheng , Sun Jinsheng , Meng Xianglong , Song Bingqian
Published: January 2024

Hot dry rock (HDR) is a renewable green and clean energy source from the depths of the earth. It has the characteristics of high efficiency, environmental protection, safety, and stability, and is not restricted by seasons and climates. Difficulties in exploration and development include deep burial, formation fragmentation, abnormal pressure, high well temperature gradient, and high hole bottom temperature (usually >200°C), key technical issues such as sticking. This paper analyzes the difficulties of high-temperature resistant drilling fluid in dry hot rock: temperature resistance of treatment agents and systems, foaming, leakage, wellbore instability, and other problems. The optimization and experiment of treatment agents such as loss reducers, high-temperature protective agents, etc., and research on drilling fluid technology resistant to high temperature of 240°C in hot dry rock drilling has been carried out, through the optimization experiment of pulping materials and high temperature treatment agent. The main formula is: 3%-4% Sodium bentonite + 2%-3% HPS + 3%-4% SPNH + 2%-4% GJA + 3%-4% JSJ-1 + 0.5%-1.0% GGDP + 1% GBHJ. The drilling fluid formula has good rheology after hot rolling at 240°C, API filtrate loss<5ml, the viscosity recovery rate is over 90%. It provides effective technical support guarantee for promoting the exploration and development of hot dry rock resources in China.
Efficiency and Cost of the “Fenton+Recapter” Combined Process for Treating the Electroplating Nickel Wastewater
Authors: Han Qi , Huang Yi , Wang Xiaojiang , Liu Yang , Lin Wu , Zhang Fan , Chen Xiaodan , Wang Hongjie
Published: January 2024

The aim of this work was to investigate the “Fenton+Recapter” combined process for treating electroplating nickel wastewater. Firstly, five commonly used dithiocarbamate heavy recapters (DTC types) were compared and selected through trial tests. Then, the optimization of the sole Fenton process was carried out, including the dosing molar ratio of Fe2+/H2O2, the dosage of H2O2 and the reaction time. At last, the optimization and cost analysis of the combination process was carried out to meet the nickel wastewater treatment standards and to determine the optimal fit point. The experimental results showed that DTC-2 was a more suitable heavy recapter, with advantages of wide pH adaptation range (3.0-11.0), strong anti-interference, fast Ni removal rate, and low cost (1.20 ¥/t). The optimal molar ratio of Fe2+/H2O2 in the sole Fenton process was determined to be 0.8, which resulted in the optimum breaking effect and a 98.5% removal rate of Ni. The optimization of the combined process parameters showed that when the dosage of heavy recapter DTC-2 (1%) was 0.08 mg/L, 0.19 mg/L, 0.5 mg/L, 1.25 mg/L, 7.5 mg/L, and 25 mL/L respectively, the residual concentration of Ni in Fenton effluent was 0.2 mg/L, 0.3 mg/L, 0.5 mg/L, 0.7 mg/L, 1.0 mg/L, and 1.5 mg/L, which all could meet the discharge standards (concentration of Ni ≤0.1 mg/L). The best fit for the “Fenton+Recapter” combined process was to first treat nickel wastewater with Fenton until the Ni concentration was about 1.0 mg/L, and then use heavy recapter DTC-2 to capture and treat the wastewater until it meets the standard discharge. Under this condition, the treatment cost of the combined process was the lowest (7.79 ¥/t).
Impacts of Future Climate Change on the Distribution of Typical Endangered Bird Species in Beijing
Authors: Yu Jianqi , Ma Xiaoyan , Wang Jia , Feng Li
Published: January 2024

Understanding the habitat needs of endangered bird species in the context of dynamic climate change is essential for guiding the design of existing conservation areas. The Maximum Entropy Model (MaxEnt) was used to predict the suitable habitats of 18 typical endangered birds in the “Key Protected Wildlife List of Beijing Municipality”, 19 climatic variables from 2041 to 2060, and 8 habitat environment variables affecting the distribution of birds were comprehensively analysed. SPSS 26 was utilised to evaluate the environmental variables incorporated into the MaxEnt model, while ArcGIS was utilised to process the prediction results. The dependability of the method was validated by the reliability of the model (mean AUC value of 0.93 and standard deviation of 0.045 for the training set; mean AUC value of 0.88 and standard deviation of 0.079 for the test set). The most significant variables, according to the jackknife test, were yearly precipitation (6.415%), precipitation in the heaviest month (5.390%), annual temperature range (2.945%), distance to water sources (29.330%), and the normalised vegetation index (11.775%). The results suggest that highly suitable habitats cover 18.67% of the region (3064.14 km2), while unsuitable habitats cover 10.61% (1741.101 km2). Formal protection and management measures for the study objects were advised based on the prediction results.
Effects of Rhizosphere Microbial Composition on the Growth of Cajanus cajan in Coal Gangue Reclaimed Soil
Authors: Wang Yuexia , Shi Kaiyi , Han Shiming , Zhou Xiaoji , Gao Liangzhi
Published: January 2024

This study aimed to investigate the microbial diversity and functions of Cajanus cajan root systems planted in plateau waste dumps collected in Liupanshui City, Guizhou Province, China. The gangue dump (1,390 m above sea level) in the Guizhou Plateau was covered with soil and planted with YN and JX C. cajan. After 1 year, the C. cajan root system was collected, and high-throughput sequencing was used to examine its bacterial and fungal biodiversity. The unclassified_f_Enterobacteriaceae and Cedecea were the most abundant genera. Venn and heatmap analyses revealed differences in the dominant species Lactococcus and Fusarium in the rhizosphere of C. cajan varieties. In JX and YN, Pseudoarthrobacter is a unique genus of bacteria; in JX, Robillarda is a unique genus of fungi; and in YN, Scytalidium is a unique genus of fungi. Endophytic fungi mainly play the roles of saprotroph, plant pathogen, and endophyte. Among the bacterial properties, L-arabinose isomerase and adenosine triphosphatase were the most abundant in all samples, while chitinase, catalase, and laccase played important roles in photosynthesis and the degradation of lignin, chitin, and chitosan. Our findings may guide the selection of reclamation plants and strategies for the mitigation and restriction of heavy metals in soil.
Research on the Current Situation and Protection Measures of the Water Environment of Tianjin Qilihai Wetland
Authors: Zhang Yi , Peng Junhan , Hong Wu , Zheng Lin
Published: January 2024

The Qilihai Wetland located in Tianjin is one of the important wetlands in northern China and an important transfer station for migratory birds. Its water environment quality is crucial for improving the regional ecosystem function, and is therefore known as the “green lung of the Beijing-Tianjin region”. This paper conducted on-site monitoring and a comprehensive evaluation of the current situation of the Qilihai environment during the dry season and the rainy season. Based on this, countermeasures and suggestions for water environment protection were proposed from the aspects of optimizing water sources, reducing interference, and strengthening governance.
Pretreatment Method of Landfill Leachate for Lessening Membrane Fouling Effect
Authors: Zhang Yaqiong , Jiang Linyu , Zeng Enhua
Published: January 2024

This experiment involved membrane pollution cycle experiments to identify the optimal pretreatment method, which was found to be raw water combined with PAC, effectively reducing membrane fouling. Following pretreatment, the first-stage recovery rate reaches 80%, the chemical cleaning cycle spans approximately 90 hours, and the conductivity of the concentrated water ranges between 35 ms/cm and 40 ms/cm.
Preliminary Study on Ecological Restoration Technology of Highway Slopes in High Altitude Mountain Areas—Taking Gansu Zhuohe Expressway Phase I Project as an Example
Authors: Li Yongpeng , Bai Fuhong , Min Haifeng , Wang Liang
Published: January 2024

This study focuses on the technical difficulties of ecological restoration of highway slopes in high-altitude mountainous areas. Based on the theory of ecological restoration, starting from the characteristics of the ecological environment of highway slopes and the current status of ecological restoration technology of highway slopes, combined with the first phase of the Zhuoni Hezuo Expressway project in Gansu Province, we conducted research on ecological restoration technology of highway slopes in high-altitude mountainous areas. Based on the characteristics of the project and the natural environment, On the basis of investigation and evaluation of slope restoration design, it was proposed to add local leguminous plant combinations, including Astragalus adsurgens, yellow clover, and small crown flower. Grass family plants were selected, including smooth bromegrass, drooping elymus, flat ice grass, Chinese fescue, and cold early maturing bluegrass. The plant combination design was carried out; At the same time, according to the characteristics of the slope, ecological protection technologies such as vegetation blanket, spraying thin soil, planting bags+hydraulic spraying+planting shrub seedlings have been proposed for the slope; And proposed requirements for surface soil utilization and plant maintenance. This study aims to explore a technical solution suitable for ecological restoration of highway slopes in the Gannan region, in order to improve the stability and erosion resistance of slopes, improve the ecological environment, and ensure the safe operation of highways. It has guiding significance for ecological restoration of highway slopes in high-altitude mountainous areas and can be used as a reference for research on rock slope restoration in other regions.
A Preliminary Methane Emission Study of Typical Coalbed Methane Production Areas Based on Multi-satellites Remote Sensing Data
Authors: Song Shasha , An Wei , Wang Mengxiao , Jin Weiwei , Zhang Qingfan , Li Jianwei
Published: January 2024

The monitoring of methane emission is helpful for reducing the concentration of atmospheric greenhouse gases. A preliminary methane emission study of typical coalbed methane production areas based on multi-satellites remote sensing data was proposed. Methane monitoring for typical coalbed methane production areas in Shanxi Province, methane anomaly analysis, associated gas flaring identification as well as emission estimation were carried out, using Sentinel-5P TROPOMI (TROPOspheric Monitoring Instrument) CH4 data, Sentinel-2 false color images and VIIRS (Visible Infrared Imaging Radiometer Suite) active fire data. The research showed that typical coalbed methane production areas in Shanxi Province were featured with high CH4 concentration in the southeast and low concentration in the northwest. The maximum methane anomaly of about 80 ppb was discovered and the emission rate was estimated to be approximately 20 t/h-23 t/h for the identified associated gas flaring location. The estimation was consistent with the results from PRISMA data for the Shanxi coal mining region. The research demonstrated the capability of satellite observation to support the coalbed methane production emission source identification from space and indicated the method provided was favorable for methane anomaly analysis, emission identification as well as emission rate estimation for coalbed methane production areas.
Effect of rare earth oxides on the energy storage performance of Sr0.7Bi0.2TiO3 ceramics
Authors: Chen Jingjing , Zhao Peng , Si Feng , Zhang Shuren , Tang Bin
Published: January 2024

In this study, Sr0.7Bi0.2TiO3 (SBT) ceramics doped with Y2O3, Dy2O3 and Gd2O3 rare earth oxides were designed and prepared by the conventional solid-state reaction method. The results show that all ceramics exhibit typical relaxor ferroelectric behavior, and the breakdown strength (BDS) of SBT ceramics is improved. Among them, Sr0.7Bi0.15Y0.05TiO3 ceramics demonstrate excellent energy storage performance, with a high recoverable energy density (Wrec
) of 2.4 J/cm3 and an efficiency (η) of 88.1% under 290 kV/cm. Furthermore, Y2O3-doped SBT ceramics exhibit a rapid discharge speed of 0.05 µs and a high power density (PD
) of 144.1 MW/cm3 under 300 kV/cm in charge-discharge tests. These characteristics have significant potential in pulse power applications.