bluuebunny/crossref_metadata_2025 huggingface dataset:
High precision three-dimensional ellipse fitting correction for galloping monitoring
Authors: Ma Yongqiang , Zhang Haifeng , Dai Xiang , Zhang Jiangtao , Gong Yu , Helen Law , Ye Baoan
Published: June 2024

In this paper, we propose and demonstrate a high precision three-dimensional (3D) ellipse fitting correction method for optical fiber composite overhead ground wire (OPGW) galloping monitoring, based on weak fiber Bragg grating array. 3D ellipse formed by three outputs of the system is fitted by the coordinate rotation and least square methods, and direct current (DC) components and alternate current (AC) component coefficients of the three outputs are obtained. By differentiating and cross-multiplying the three outputs, those DC components are zeroized, AC component coefficients are normalized, and finally, the interference phase signal is calculated. The experimental results show that the proposed method can demodulate the vibration signals better, and the fitted R2 is above 0.99. The system is implemented on a 220 kV transmission line in the plateau region of Western China, forecasting a galloping period with a wavelength of about 60 m within the span accurately. This method demonstrates suitability for monitoring OPGW transmission line galloping events.
Enhanced piezoelectricity and temperature stability in (1 − x)BiFeO3–xBaTiO3 lead-free ceramics
Authors: Wu Hao-Ran , Zhang Xiu-Hai
Published: June 2024

The relationship between phase structure and piezoelectric characteristics is demonstrated by producing a sequence of (1 − x)BiFeO3–xBaTiO3 ceramics. A morphotropic phase boundary between the R and PC phases in BF–xBT ceramics is observed within the 0.285 ≤ x ≤ 0.315 range. High piezoelectric properties with a piezoelectric constant (d33) of 174 pC/N and a planar electromechanical coupling coefficient of 0.33 are achieved in BF–xBT ceramics at 0.285 ≤ x ≤ 0.315 due to the coexistence of the R and PC phases. In addition, a slight variation (±15%) in Δd33/d33 over the temperature range of 25–400 °C is noted in BF–xBT ceramics at 0.285 ≤ x ≤ 0.315, indicating that BF–xBT ceramics hold promising potential for use in high-temperature applications.
An experimental analysis on sliding wear characteristics of TIG-welded Al6061 reinforced with SiC
Authors: P. K. Jayashree , B. R. N. Murthy , Hiremath Anupama , Giri Jayant , Alotaibi Rajeh , T. Sathish , Laxmi Bhagya
Published: June 2024

In this paper, metal matrix composites of Al6061 strengthened with 6 wt. % SiC were produced by stir casting and further subjected to the Tungsten Inert Gas (TIG) welding fabrication process using ER5356 as the filler material. The effect of TIG welding on hardness and wear resistance was studied by varying current at 150, 170, and 200 A. Samples of cast composite as per ASTM standards were prepared. Hardness tests on TIG-welded composite were carried out on the base, heat-affected, and weld zones. The test results showed higher hardness with an increase in welding current. Sliding wear properties were explored using the pin-on-disc machine. The wear rate and weight loss decreased as the welding current increased. The surface morphological images obtained through SEM indicated that the wear in the non-welded specimen was due to abrasion and delamination, whereas that of the welded specimen showed a reduced delamination and lower wear rate.
Merging weather radar and rain gauges for dryland agriculture
Authors: Weir Peter , Dahlhaus Peter
Published: June 2024

The areal extent of rainfall remains one of the most challenging meteorological variables to model accurately due to its high spatial and temporal variability. Weather radar is a remote sensing instrument that is increasingly used to estimate rainfall by providing unique observations of precipitation events at fine spatial and temporal resolutions, which are difficult to obtain using conventional rain gauge networks. Dense rain gauge networks combined with operational weather radars are widely considered as the most reliable source of rainfall depth estimates. This paper compares the various sources of rainfall data available and explores the benefits of merging radar data with rain gauge data by reviewing the outcomes of a case study of a major agricultural cropping and pasture region. Comparison is made of rainfall measurements obtained from a dense rain gauge network covered by the output from a weather radar installation. We conclude that merging radar data with rain gauge data provides improved resolution of the spatial variability of rainfall, resulting in a significantly improved data source for agricultural water management and hydrological modelling. However, the use of weather radar merged with rain gauge data is generally underrated as a management tool.
Chemical and biological attributes of soil and soybean (Glycine max) yield in integrated systems in the Cerrado of north-east Brazil
Authors: Silva Alcilane Arnaldo , Lacerda Julian Junio de Jesus , Carvalho Suzane Pereira , Ferreira Rubens de Sá , Brito Ramilos Rodrigues de , Vogado Renato Falconeres , Araújo Neto Raimundo Bezerra de , Sagrilo Edvaldo , Cavigelli Michel André , Souza Henrique Antunes de
Published: June 2024

Context Cultivation of forage grasses intercropped with maize (Zea mays) improves soil quality and yield of subsequent crops. However, for the Cerrado of north-east Brazil, little is known about the effects of this practice on soil chemical and biological attributes and on succeeding soybean crop’s yield and nutrition. Aims This study aimed to evaluate the influence of intercropping maize with forage grasses on soil chemical and biological properties and on the nutritional status and yield of succeeding soybean in the Cerrado of Piauí, Brazil. Methods In the 2016/2017 cropping season, maize (M) was grown in monoculture and intercropped with Megathyrsus maximus cvs Zuri, Massai, Tanzania, and Tamani; Urochloa brizantha cv. Marandu, and Urochloa ruziziensis cv. Ruziziensis. In the 2017/2018 and 2018/2019 cropping seasons, soybean (Glycine max) was grown on the same plots. Key results In the 2017/2018 cropping season, highest soil K concentrations in the 0–0.1 m depth were observed following M + Zuri and M + Massai. In the 2018/2019 cropping season, soybean grown after monoculture maize, M + Zuri, M + Tanzania and M + Ruziziensis promoted the highest soil basal respiration. Intercropping maize with forage grasses of the genus Urochloa increased the soil humic substances and carbon concentrations. The M + Tanzania treatment increased soybean leaf P and K concentrations in the 2017/2018 cropping season. Conclusions Intercropping maize with forage grasses improved soil fertility and increased cumulative soybean grain yield by 15%. Implications Maize intercropped with forage grasses, especially of the genus Urochloa, increases humic fractions and total soil organic carbon, and is thus a feasible agricultural management.
German nominal number interpretation in an impaired mental lexicon
Authors: Plag Ingo , Heitmeier Maria , Domahs Frank
Published: June 2024

There is an ongoing debate on how speakers and listeners process and interpret information in a morphological
system that is very complex and not very transparent. A well-known test case is the German nominal number system. In this paper we
employ discriminative learning (e.g., Ramscar & Yarlett, 2007; Baayen et al., 2011, 2019) to test whether
discriminative learning networks can be used to better understand the processing of German number. We analyse behavioral data
obtained from a patient with primary progressive aphasia (Domahs et al., 2017), and the
unimpaired system. We test a model that implements the traditional cues borrowed from the schema approach (Köpcke, 1988, 1993; Köpcke
et al., 2021), and compare it to a model that uses segmental and phonotactic information only. Our results for the
unimpaired system demonstrate that a model based on only biphones as cues is better able to predict the number of a given
word-form than a model using structural phonological cues. We also test whether a discriminative learning model can predict the
number decisions by the aphasic patient. The results demonstrate that a biphone-based discriminative model trained on the
patient’s responses is superior to a structure-based model in approximating the patient’s behavior.
Beyond the Secret (gsang ba): The Performativity of Citation in an Exile Tibetan Buddhist Ritual
Authors: Nair Urmila
Published: June 2024

This article focuses on the Nechung kang-so (bskang gso), a ritual performed at Nechung monastery in exile, and deemed secret (gsang ba) by the monks. In my interactions with the monks, this secret presented itself as an unremitting series of contradictions and conundrums. I attempt here to portray and understand them. I posit that the secret invoked an implicit “cultural concept” (Silverstein 2004), namely, the kang-so’s transmissibility. For the kang-so’s transmission within the monastery involved a specific semiotics of authorization, rooted in a karmic ethic. To reveal the secret to me was to extricate the esoteric ritual from that traditional “social organization of interdiscursivity,” and the ethic shaping it (Gal 2018). The monks’ citations of the esoteric ritual, whereby they spoke to me of the secret, thus performed an alteration in the kang-so’s transmissibility, a reorganization of the esoteric ritual’s interdiscursivities, toward enabling its “circulation” among academic publics.
The Rise of Cross-Language Internet Memes: A Social Semiotic Analysis
Authors: Huang Xinyu , Han Yifan , Ran Yi , Yang Yakun , Yang Yixin
Published: June 2024

Cross-language internet memes have emerged as a unique and popular mode of online communication, combining bilingual elements with visually textual components. These memes exhibit distinctive characteristics at semantic, syntactic, and pragmatic levels, rendering them a noteworthy semiotic phenomenon in contemporary digital culture. To deepen our understanding of cross-language internet memes, this study investigates user perceptions through a questionnaire, employing SPSS Statistics software for analysis. Applying a social semiotic approach, we decipher the semiotic mechanisms of cross-language memes, shedding light on their potential implications for identity construction. Additionally, we reflect on two prominent trends in internet meme development: the shift from monomodal to multimodal communication and from monolingual to multilingual expressions. This research hopes to provide insights for meme research and online discourse investigations.
Highly luminescent, fast switching electro-optical device based on core–shell bimetallic nanoparticles/ ferroelectric liquid crystal composites
Authors: Abhilash T K , Abdul Hakkeem Hasna M , Anas S , Pillai Saju , Chandran Achu
Published: June 2024

Owing to the passive nature of liquid crystal (LC) materials, achieving luminous displays using pure LC materials is challenging. In addition, it is difficult to achieve a fast switching time using pristine ferroelectric LC devices without compromising their cell thickness. Herein, we have developed a fast switching and highly luminescent electro-optical device by dispersing a minute concentration of bimetallic nanoparticles (Au@Ag NPs) having a spherical gold core and a silver shell within a ferroelectric liquid crystal (FLC) host matrix, ZLI3654. Au@Ag core–shell NPs having synergic attributes of both counterparts were successfully synthesized by a facile seed-mediated route. The Au core helps to tune the shape of the Ag shell and provides enhanced electron density as well as improved stability against oxidation. Introducing nanoparticles induces little structural modifications to the host FLC, resulting in an improvement in the mesogenic alignment. Interestingly, ∼29-fold enhancement in the photoluminescence (PL) intensity is observed on dispersing 0.25 wt% of Au@Ag NPs into the FLC host matrix. The enhanced electromagnetic field in the FLC-nanocomposite is attributed to the Localized Surface Plasmon Resonance of Au@Ag NPs, which strengthens the photon absorption rates by the FLC molecules, culminating in the massive enrichment of the PL intensity. In addition, the improved localized electric field inside the FLC device led to a noticeable enhancement in the spontaneous polarization, dielectric permittivity, and, most interestingly, ∼53% fastening in the switching time at an optimum concentration (0.25 wt%) of Au@Ag NPs. The improved electro-optical parameters of the Au@Ag NPs/FLC composite have been compared with the performance of both pristine Au NPs/FLC and Ag NPs/FLC composites, respectively, for the comprehensiveness of the study. The present study paves a systematic way to develop FLC-based advanced electro-optical devices with faster switching and higher luminescence properties.
Tailoring the visible light band of Watt-level SCs pumped via picosecond pulse with different Raman extent
Authors: Guo Yashuai , Wang Zhenguang , Hu Xiaohong , Zhang Ting , Zhang Zhao , Zhang Wei , Wang Yishan
Published: June 2024

We investigate the supercontinuum (SC) tailoring property by varying the transmission fiber length after the master oscillator power amplifier system. The conversion efficiency of the visible light band is effectively enhanced via tailoring the Raman extent of the injected 30 ps pulse into the nonlinear photonic crystal fiber (PCF). Experimentally, a 3.6 W all-fiber SC spanning from 414 nm to over 1750 nm (@20 dB) is accomplished by using a high duty cycle domestic PCF through precisely controlling the extent of Raman effect. The proposed method is instructive for the further realization of high power SC with an enhanced spectral intensity in the visible light band.
Cryptographic computer generated hologram watermarking technology based on DWT-SVD
Authors: Liu Songxiao , Yu Nana , Ji Xiangxiang , Song Danying , Xi Sixing , Zhu Zhuqing , Wang Xiaolei , Lang Liying
Published: June 2024

To improve the security and invisibility of image encryption and concealment, an encrypted computer generated hologram (CGH) watermarking technology based on discrete wavelet transform (DWT) and singular value decomposition (SVD) is proposed. Firstly, the image to be encrypted is encoded and converted into a binary real-valued CGH. The encrypted CGH is then embedded into the host image as a watermark, implementing image encryption and concealment. During decryption, the encrypted CGH watermark is first extracted using the inverse DWT-SVD and the correct keys. Subsequently, the decrypted image is obtained by applying the correct optical key for computational holographic reproduction. The method introduces computational holographic coding and optical keys into the digital watermarking technique and combines the characteristics of DWT and SVD, solving the problem of the high false positive rate of the SVD algorithm. Simulation results show that the security of image encryption and concealment is greatly improved with the introduction of CGH into watermarking technology, especially in terms of robustness to watermark attacks and noise. This method can be applied in the fields of copyright protection and anti-counterfeiting for digital and printed images.
A quantum-enhanced magnetometer using a single high-spin nucleus in silicon
Authors: Xin 辛 Tao 涛 , Zhang 张 Ke 科 , Li 李 Jun 俊
Published: June 2024

Quantum enhanced metrology has the potential to go beyond the standard quantum limit and eventually to the ultimate Heisenberg bound. In particular, quantum probes prepared in nonclassical coherent states have recently been recognized as a useful resource for metrology. Hence, there has been considerable interest in constructing magnetic quantum sensors that combine high resolution and high sensitivity. Here, we explore a nanoscale magnetometer with quantum-enhanced sensitivity, based on 123Sb (I = 7/2) nuclear spin doped in silicon, that takes advantage of techniques of spin-squeezing and coherent control. With the optimal squeezed initial state, the magnetic field sensitivity may be expected to approach 6 aT⋅Hz−1/2⋅cm−3/2 and 603 nT⋅Hz−1/2 at the single-spin level. This magnetic sensor may provide a novel sensitive and high-resolution route to microscopic mapping of magnetic fields as well as other applications.
Simulation of magnetization process and Faraday effect of magnetic bilayer films
Authors: Gao 高 Sheng 升 , Du 杜 An 安 , Zhang 张 Lei 磊 , Li 李 Tian-Guang 天广 , Ma 马 Da-Cheng 大成
Published: June 2024

We described ferromagnetic film and bilayer films composed of two ferromagnetic layers coupled through antiferromagnetic interfacial interaction by classical Heisenberg model and simulated their magnetization state, magnetic permeability, and Faraday effect at zero and finite temperature by using the Landau–Lifshitz–Gilbert (LLG) equation. The results indicate that in a microwave field with positive circular polarization, the ferromagnetic film has one resonance peak while the bilayer film has two resonance peaks. However, the resonance peak disappears in ferromagnetic film, and only one resonance peak emerges in bilayer film in the negative circularly polarized microwave field. When the microwave field’s frequency exceeds the film’s resonance frequency, the Faraday rotation angle of the ferromagnetic film is the greatest, and it decreases when the thickness of the two halves of the bilayer is reduced. When the microwave field’s frequency remains constant, the Faraday rotation angle fluctuates with temperature in the same manner as spontaneous magnetization does. When a DC magnetic field is applied in the direction of the anisotropic axis of the film, the Faraday rotation angle varies with the DC magnetic field and shows a similar shape of the hysteresis loop.
Telluric Lines on Stellar Spectra: Prospect for Earth’s Atmospheric Study
Authors: Puspitarini L , Najla F , Malasan H L , Akbar E I
Published: June 2024

Astronomical spectroscopy aims to measure the spectrum of a celestial object(s). However, in the case of ground-based observation, the observed spectrum will not only present absorption or emission features from the astronomical object but also features caused by the Earth’s atmosphere, namely telluric absorption lines or telluric contamination. The telluric contamination is unwanted features in astronomy and is usually removed in the data processing. Nevertheless, they might be useful for Earth’s atmospheric study as the telluric lines will vary due to several causes (temperature, pressure, humidity, ozone content, etc.). We used spectroscopic data observed at the Bosscha Observatory, and applied spectral fitting by using the telluric transmission model. From the analysis of optical depth values, we detected variation in the telluric lines due to seasonal (monsoon). This demonstrates that stellar spectra from ground-based observation can also be used for atmospheric study.
Exploring the Impact of Variations in Earth’s Obliquity and Eccentricity on Its Spatial and Temporal Distribution of Surface Temperature
Authors: Husen B F , Premadi P W
Published: June 2024

The study of habitable planets has gained popularity, with a recent focus on finding Earth-like planets in the habitable zone. However, assessing habitability involves considering factors beyond just orbital position, including variations in surface temperature driven by obliquity and eccentricity. Understanding these orbital parameters is crucial for predicting surface temperature spatial and temporal distributions. Using a simplified energy balance model (EBM), we estimate surface temperature distributions through computational experiments, varying its obliquity. Extreme obliquities (>60°) lead to rapid, extreme temperature fluctuation, making it inhospitable for life.
A study of open clusters in the local galactic environment using Gaia DR3
Authors: Cahyaningtyas A F N , Leon S , Hidayat T , Alfaro E J , Bergond G
Published: June 2024

The presence of Gaia DR3 data allows us to conduct more comprehensive research about the large population of open clusters in the Galaxy. Investigating the effects of the Galactic environment on open clusters will provide some insights regarding their evolution driven by external factors. Observing the clusters’ shapes and movements is genuinely essential since they represent the physical conditions under their relationship with the Galactic environment. By harnessing the latest and most complete stellar data, we measure the influence of the Galactic environment on a large population of open clusters enclosing an area of 1 kpc in radius through the clusters’ compression in velocity and dispersion spaces. In this study, we observed that open clusters are compressed to the Galactic plane direction, both in velocity and dispersion spaces.
Differences in Maximum Tides Responses of the North Coast and the South Coast of Java on the Effects of the Position of the Moon and the Sun
Authors: Djamaluddin T , Susanti R D , Pranowo W S , Aditiya A , Mariyam A S , Mareta L , Hasanuddin A P
Published: June 2024

The influence of the earth-moon-sun system on tide events has long been known. However, the impact can vary in different coast areas. The short-term (monthly and yearly) impact of maximum tides needs to be watched out for in relation to tidal flooding, especially if it is reinforced by bad weather at sea. In 2021 NASA reported the results of the Sea Level Change Science Team study that in the 2030s tidal floods will become more frequent and threatening the coasts of the United States due to the 18.6-year lunar orbit nodal cycle which amplifies the effects of global warming. Analysis of maximum tides on the north coast of Java (using data from Jakarta and Surabaya) and on the south coast of Java (using data from Cilacap) shows that on both the north and the south coast of Java, there is no indication of the nodal cycle of the 18.6 year due to lunar orbit. However, this study shows that in short-term annual and monthly cycles there is a difference in the pattern of maximum tides on the north coast and the south coast of Java. The declination of the sun when it is most northerly (the end of June) and most southerly (the end of December) affects maximum tides on the north coast of Java, as semi-annual cycle. Meanwhile on the south coast of Java, only the southernmost declination of the sun (in the end of December) has an effect on the maximum tide, as annual cycle. For monthly cycles, maximum tides on the north coast of Java are affected by the maximum declination of the moon and moon’s perigee (in Jakarta) or by the moon phases and perigee (in Surabaya). Meanwhile, on the south coast of Java it is only affected by the moon’s phases and perigee.
Analysis of sky brightness variations in full days based on sky quality meter measurement in Pekalongan
Authors: Salma A , Herdiwijaya D
Published: June 2024

The night sky brightness has an ecological impact, especially for nocturnal animals. Likewise, the shift from transition night to day and vice versa known as the fajr/dawn phase, has on impact on crepuscular animals. Continuous measurement are important in astronomy due to the impact of sky brightness. The sky brightness is slower to lighten at dawn and slower to darken at dusk which can be affected by light pollution sourced from human activities, meteorological, and natural factors (Moon phase and zodiacal light). Quantization of the sky brightness continuously in full days based on the function of light pollution, Sun position, and shadow length in the daytime are important to do. Analysis of the sky brightness at the limits of the beginning of dawn, the end of dusk, the sunrise/sunset, during mid-morning/evening, and the time of culmination are useful for testing the Islamic prayers time. Measurement of sky brightness in full days has been done using Sky Quality Meter photometer at coordinates 6˚50’42” southern latitude and 109˚37’55” eastern longitude for 25 days with 3 seconds retrieval resolution that installed neutral density variable and battery. Analysis of sky brightness data was carried out using Difference, Moving average, and Polynomial methods. This research concludes that the sky brightness during twilight shows relatively small variation, with the beginning of dawn identified at -15.301˚ of Sun elevation and the end of dusk at -18.853˚ of Sun elevation. The sky brightness profiles before and after 12 noon are asymmetrical. In the evening, the average difference in sky brightness at shadow lengths of 1 to 2 is 0.9 MPSAS with 0.39 standard deviation and the average shadow length of object during fluctuations is 1.36. The average difference in sky brightness at noon compared to midnight is 9.02 MPSAS.
Observational Technique Development and Instruments Status in Observatorium Universitas Ahmad Dahlan
Authors: Pramudya Yudhiakto , Dhimas Prayoga Jullyantama A.R. , Khairul Ardi M. , Ayu Wandira Cintha , Muchlas
Published: June 2024

The Observatorium Universitas Ahmad Dahlan (UAD) is an urban telescope located in close proximity to city lights. Light pollution monitoring is performed using a Sky Quality Meter and an All Sky Camera, revealing a maximum Night Sky Brightness (NSB) value of 18 mag/arcsec2. A 17-inch Planewave Telescope housed in a 5-meter dome is used to image nebulae and galaxies. Portable telescopes are used to observe the crescent moon, with the use of a buffle and stacking techniques enabling daytime imaging. Lunar elongation and altitude data were obtained to assess the telescope’s capabilities and site feasibility.
The Lofar Global Citizenship Radio Array - “Gloray” (Ska-Low-North)
Authors: Miley George K.
Published: June 2024

This talk describes a proposed transformation of LOFAR, the world’s largest, most sensitive high-resolution radio telescope that operates at low frequencies (<300 MHz), into a multidisciplinary intercontinental facility that will be a unique engine for capacity building and development throughout Europe, North Africa, the Middle East and West Asia. As an astronomical array, GLORAY would be the “Hubble Space Telescope” of low-frequency radio astronomy, having a resolution more than 50 times better than any other presently planned low-frequency facility, including SKA-LOW. The mutually interdependent network of LOFAR antenna stations that presently stretch from Ireland to Latvia would be extended to cover North Africa, the Middle East and West Asia and converted into “innovation hubs”. These would form an intercontinental network for pure research, applied research, capacity building, education and science diplomacy within and between the participating countries.
Bridging Science Education: Empowering Teachers Through Astronomy Training
Authors: Sulistiyowati  , Putri Gerhana P. , Hasan Faadillah M. , Jaelani Anton T.
Published: June 2024

We present a short report on the Astronomy training activities targeting junior and high school science teachers in Banjar City and its neighboring districts. The training is aimed to introduce the use of Astronomy as a means of delivering and exercising science since Astronomy rarely fails to attract people’s interest. More than 30 teachers, comprising mostly science teachers in the area, joined our 3-day training program, which consists of short talks, hands-on experiments, as well as presentation and discussion. The program covers the following topics: Solar System, Motion of Celestial Bodies, Telescopes and Observation, Stars, and Galaxy-Cosmology; focusing mainly on pedagogical content knowledge using experience-based learning. By the end of the training, the participants considered Solar System and Stars as the topics with the most and the least impact/comprehension improvement for them, respectively. Nevertheless, there are only slight differences on the impact scale among the topics, all of which show a mean impact scale > 3.75 out of 5. Additionally, 75% of the participants stated the materials were helpful and beneficial for them as a teacher. This indicates that, according to the participants, the training in general was fruitful and increased their understanding on the topics delivered.
From interfacial contact to thermal transport: a molecular dynamics simulation of SiO2/epoxy resin composites
Authors: Yu Shixiang , Su Xinqing , You Chaoqun , Lu Ran , Zhao Guanghui
Published: June 2024

A high-frequency working environment makes the heat generated by electronic components increase rapidly. The atomic level of interfacial thermal transfer between epoxy (EP) resin and various functionalized silica (SiO2) in underfill was investigated by molecular dynamics simulation (MDS) methods. The interfacial thermal transfer mechanism was examined by calculating the interfacial binding energy, atomic density distribution, phonon vibrational power spectrum (VPS), and interfacial thermal resistance (ITR) studies. This work revealed the generalized relationship between interfacial thermal transport and SiO2/EP interface interaction, which was regulated by coupling agents and the grafting ratio in chemical modification processes. The calculation results showed that interfacial thermal resistance was strongly correlated with the calculated binding energy. The interfacial contact and phonon coupling in composites were improved when SiO2 was functionalized by 3-glycidyloxypropyltrimethoxysilane (GOTMS) and 3-aminopropyltriethoxysilane (APTES). The binding energies of the two interfaces above exceeded −350 kcal/mol and relatively low ITRs of 5.05×10−9 m2KW−1 and 5.03×10−9 m2KW−1 were observed. In addition, 12% was the optimal grafting rate for SiO2 in GOTMS-modified SiO2/EP composites, and the highest interfacial binding energy of −386.88 kcal/mol in this work was obtained.
A poly (para-terphenyl piperidine)/layered double hydroxide hybrid membrane with reduced ammonia permeability for direct ammonia fuel cell
Authors: Cao Yingjian , Hu Zijun , Guo Yu , Gui Fukang , Xiao Qiangfeng
Published: June 2024

Anion exchange membrane fuel cells (AEMFCs) have attracted extensive attention in recent years due to their high electrode activity, potential non-noble metal catalyst application, and low requirement for fuel purity. Anion exchange membrane (AEM) is the core component of AEMFCs, which plays the role of conducting ions, blocking fuel mixing, and providing catalyst carriers. Its performance directly affects the efficiency and service life of the fuel cell. In most cases, the conductivity of AEM is generally low, and its durability is poor, which cannot meet the requirements of practical application temporarily. In this paper, from the point of view of material nanocomposite enhancement, the organic polymer and inorganic nanomaterials with high ionic conductivity are prepared using the suspension blending method, and the various properties of AEMs are tested. Compared with the bulk material, the ionic conductivity and ammonia inhibition performance are significantly improved, among which AEM doped with 4.8% LDH has the best performance, the ionic conductivity is increased by nearly an order of magnitude, and the ammonia permeation relative content is only 14.1% of the bulk material.
Structural design and magnetic study of a 2p-4f dimer complex built from a functional nitronyl nitroxide radical
Authors: Wang Yifan , Dong Huiyang , Zhu Mei
Published: June 2024

A novel 2p-4f cyclic [Tb (hfac)3 (NIT-4-OMe-3PyPh)]2 complex has been obtained. The crystal structure shows that the NIT-4-OMe-3PyPh radical bridged two TbIII ions by O atoms of NO units and N atoms on pyridine rings. The variable temperature magnetic susceptibility shows that both ferromagnetic and crystal field effects exist in the complex. Alternating-current magnetic data for the Tb complex exhibits slow magnetic relaxation behavior. This complex is a typical example of molecular nanomagnetic materials.
Improved design of railway wagon underframe flipping machine
Authors: Wang Yongming , Wang Chuanjian , Zhou Qi , Sun Yongwen
Published: June 2024

This paper took a railway wagon underframe flipping machine of a railway company as the research object and introduced its flipping process and working principle. To solve the current problems of underframe slipping and the over-deformation of the clamping mechanism and underframe, the structure of the flipping machine was improved in design. By adding centering clamping blocks to clamp both sides of the underframe, the problem of the underframe slipping was solved. A mechanical analysis of the improved clamping mechanism was conducted, and the results showed that the thrust required by the hydraulic cylinder of the improved clamping mechanism was reduced from 200 kN to 128 kN. Finite element analysis of the clamping mechanism and underframe was conducted based on Workbench software. The results showed that the maximum deformation of the improved clamping mechanism was reduced from 4.4497 mm to 2.5395 mm, and the maximum deformation of the improved underframe was reduced from 5.8123 mm to 3.1583 mm. The above results verify that the stability of the improved flipping machine has been greatly improved, and it can better realize the clamping and flipping of the railway wagon underframe.
Research on the design and damping control of rocket maritime transportation device
Authors: Luo Liang , Liu Dong , Jiang Zhen , Cheng Dong
Published: June 2024

Unlike conventional land-based launch vehicles, sea-launched launch vehicles can fully utilize the additional speed of Earth’s rotation to achieve the goal of saving fuel for launch vehicles. To ensure the safety of transportation and storage of rockets before sea launch, this article studies the damping absorption and protection measures of rockets during sea transportation before launch, based on the workflow and characteristics of the sea environment of rocket sea launch. Taking the maximum allowable vibration acceleration of the rocket and the vibration spectrum of the maritime transportation platform as constraints, a technical route combining “active+passive” multi-level vibration reduction methods was adopted to conduct a scheme demonstration and simulation analysis of the vibration reduction control effect of the rocket maritime transportation device. It was able to reduce the acceleration response of the rocket in the heave direction (vertical direction) by about 79%, meeting the overall indicator requirements.
Application of TRIZ theory in optimization design of end tooling for large automotive parts
Authors: Du Hao-Yu , Liu Shang , Wu Han , Guo Xiao-Xia , Wang Peng-Fei , Zhu Yu-Hang , Wang Yu-Hao
Published: June 2024

In the process of automobile final assembly, auxiliary assembly end tooling is often designed on the key stations to ensure the quality and efficiency of the production line. This study applies TRIZ theory and scenario analysis methods to solve the potential fault problems in the design and development stage of end tooling products to provide more reliable and high-quality products or systems. Through Ansys Workbench, the proposed scheme is simulated and optimized to verify the feasibility of the end tooling product design. Implementing this research method will help effectively deal with the challenges faced by heavy lifting in modern industrial production and improve production efficiency and operation safety.
Performance evaluation of fused magnesia production process based on exergy-economics and environmental-economics analysis
Authors: Jiang Tianchi , Wang Xin , Zhang Weijun
Published: June 2024

Based on the basic theories of thermal economics and thermal engineering, a magnesia factory in Liaoning Province was chosen as a research object. Researchers construct the production flow structure of different fused magnesia processes and establish mathematical models that consider calculating exergy income, exergy cost, exergy transfer, and carbon emission. The changes in the system economy and environmental protection of different production processes are analyzed through calculation. The results show that the cleaner fused magnesia system has unique advantages in exergy economic income and carbon emission.
Optimized designing of process parameters for CP980 steel resistance spot welding based on Orthogonal Test
Authors: Tian Shuai , Feng Qiaobo , Wang Chunliang , Zhang Rui
Published: June 2024

Based on the orthogonal experimental design method, taking CP980 steel as the research object and the tensile sheer force of spot-welded joints as the evaluation index, the effect of different process parameters on the welding performance of resistance spot welding was studied with the extreme variance method. The results indicated that welding current had a significant effect on the shear force, followed by electrode pressure, while welding time had the least effect; the optimal welding parameter of the CP980 spot welded joint was that the welding time was 400 ms, the welding current was 9.5 kA, and the electrode pressure was 3.6 kN. The formation of lath martensite during solidification led to a higher hardness in the nugget region, reaching a maximum of 434 HV. The subcritical heat-affected zone formed a softened zone with an average hardness value of 299 HV as a result of welding thermal cycling.
IGBT power module based on pressureless nano-silver sintering optimization process and its performance characterization
Authors: Wu Sheng , Xu Fan , Zhang Ru , Jiang Weibin , Jiang Nian , Hu Zechen , Zhang Zhiyang
Published: June 2024

In this paper, a nano-silver solder paste with a large intrinsic driving force was selected for pressureless sintering. The pressureless sintering process determined by simulated shear experiments was optimized according to the TGA results of this silver solder paste. Based on the optimized process, we realized the void-free and low-porosity sintering of large-area IGBT chips. At the same time, we used this process to fabricate complete silver sintered IGBT power modules. The silver sintered modules were characterized by static, dynamic, and thermal resistance levels, and their performance was compared with that of reflow soldered modules of the same power level. The final results indicate that the optimized process can solve the problem of voids and pore growth generated when the process determined by simulation shear experiments is directly applied to real chip sintering. The module using this process has excellent electrical performance, and the thermal resistance is reduced by 11.06% compared to the reflow soldered module, which guarantees its long-term stable operation in high-power power conversion systems.
Lightweight simulation design of integrated die-casting body rear wheel cover and seat crossbeam
Authors: Zhang Nan , Deng Guohui , Liu Guojun , Du Wencan , Zhang Yunfeng , Sun Gang , Ma Pinkui
Published: June 2024

This paper is based on the integrated die-casting process for the lightweight development problem of the rear wheel cover assembly and seat beam in certain vehicles. It uses heat-treat-free materials to develop and design the integrated structure of the rear wheel cover and seat beam. The manufacturability of the part is verified by mold flow analysis and a study of the impact of integrated die-casting parts on the stiffness of the entire vehicle. The simulation results show that this scheme can meet the requirements of parts manufacturability and achieve a weight reduction of 2.7 kg for the welding area, compared with the traditional steel structure, and the body stiffness is better. Comfort stiffness increased by about 6%.
Design scheme research on key technologies of portable and efficient grinding equipment for high dose stop valves in the primary circuit of nuclear power plants
Authors: Wang Yongxing , Wei Hongyu , Sun Hexing , Tao Meng , Chen Song , Luo Zhiyuan
Published: June 2024

In the high-dose radiation environment of the primary circuit of nuclear power plants, there are problems such as low grinding efficiency and low automation level in the grinding and repair process of the sealing surface of the stop valve seat. Using the working principle of grinding repair and manual grinding technology experience, we extracted the key process parameters for automation control. We researched the design scheme of key technologies for automated grinding equipment. In addition, we provided a detailed description of the equipment’s performance, purpose, structure, and function.
Research on quality inspection and process optimization of ship surface shot blasting and sand blasting treatment
Authors: Li Min , Huang Jiyuan , Li Songhao , Peng Moxuan , Yan Zhihong , Song Qiheng
Published: June 2024

The process of shot blasting and sandblasting is a crucial step before the coating of ship surfaces, as the quality of this treatment affects the adhesion and service life of the applied paint. In this paper, we have developed a machine vision inspection system for evaluating the quality of shot blasting and sandblasting on ship surfaces, enabling the acquisition of 3D microscopic surface topography under real operating conditions. Based on this, we have investigated the relationship between surface preparation techniques and the quality of the treatment, as well as the correlation between surface preparation quality and coating performance. Furthermore, we have established corresponding models to facilitate the control of shot blasting and sandblasting quality and optimize the associated processes.
Analysis of pressure loss and transmission loss under flow field effects in multi-chamber muffler
Authors: Wo Jinjin , Hu Haigang , Chen Yuehua , Liu Yifan , Linghu Shixun
Published: June 2024

In order to achieve broadband sound attenuation, a muffler utilizes multiple internal impedance structures, which unavoidably impacts its aerodynamic performance. Multi-chamber muffler configurations, incorporating interconnecting tubes, perforated plates, and other sound-absorbing elements, can generate several resonance peaks within the frequency range of sound attenuation, showcasing effective sound attenuation capabilities. These configurations are commonly employed in marine muffler structures. This paper examines the factors influencing the flow field performance of such mufflers and the impact of the internal flow field on their acoustic performance by using principles of fluid mechanics and the finite element method of acoustics. Initially, a flow field domain model of the multi-chamber muffler is developed by using the 3D modeling software SOLIDWORKS, and the mesh division of the flow field is executed by using the FLUENT MESHING preprocessing software. Subsequently, the mesh model is employed to simulate the flow field performance in the ANSYS Fluent environment, calculating the pressure loss of various structural mufflers under different inlet flow boundary conditions. Finally, field data is imported into the LMS Virtual. Lab software to validate the correlation between the flow field network and the acoustic field network, enabling the mapping of flow field data to simulate the silencer’s acoustic performance under different flow field conditions. The study demonstrates that a well-designed arrangement of interconnected pipes and perforated elements inside the silencer can notably diminish its pressure loss. Furthermore, it highlights that the impact of a temperature gradient on the silencer’s acoustic performance is more significant compared to the local flow rate.
Laboratory experimental study on evaluation of plugging effect
Authors: Bai Wenlong , Wang Suling , Dong Kangxing
Published: June 2024

Aiming at the research of water-controlled fracturing and stimulation technology of high water content Wells in Chaoyanggou low-permeability oilfield, several laboratory experiments of plugging agents are carried out. The traditional plugging agent displacement experiments mostly adopt the way of filling sand tubes, but the filling sand tube is extremely difficult to clean after the curing of the Plugging Agent And takes a long time, which is not conducive to the simulation of multi-group experiments. Therefore, a new artificial core method is used to simulate the reservoir under two permeability conditions, and the performance of three kinds of plugging agents is studied from several aspects, such as plugging performance, breakthrough pressure, and distribution law of plugging agents after injection into the core. The experimental results show that Plugging Agent A (particle class) is suitable for plugging large pores, the plugging strength is high, and the breakthrough pressure gradient is more than 9 MPa/m. Plugging Agent B (gel class) is suitable for plugging small voids, and has good plugging performance, with a plugging rate of up to 99%. The pore structure characteristics of the core after plugging are determined by SEM experiments.
Detecting climate milestones on the path to climate stabilization
Authors: MacDougall Andrew H , Rogelj Joeri , Jones Chris D , Liddicoat Spencer K , Grassi Giacomo
Published: June 2024

The era of anthropogenic climate change can be described by defined climate milestones. These milestones mark changes in the historic trajectory of change, and include peak greenhouse gas emissions, peak greenhouse gas concentration, deceleration of warming, net-zero emissions, and a transition to global cooling. However, given internal variability in the Earth system and measurement uncertainty, definitively saying that a milestone has passed requires rigour. Here CMIP6 simulations of peak-and-decline scenarios are used to examine the time needed to robustly detect three climate milestones: (1) the slowdown of global warming; (2) the end of global surface temperature increase; and (3) peak concentration of CO2. It is estimated that it will take 40 to 60 years after a simulated slowdown in warming rate, to robustly detect (

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change) the signal in the global average temperature record. Detecting when warming has stopped will also be difficult and it takes until the mid 22nd century to have enough data to conclude warming has stopped. Detecting that CO2 concentration has peaked is far easier and a drop in CO2 concentration of 3 ppm is consistent with a greater than 99% chance that CO2 has peaked in all scenarios examined. Thus it is likely that as the rate of CO2 emissions is reduced, and net-zero emissions is approached, interpreting the global temperature record will become difficult—with a high potential to create confusion amongst policy makers and the general public.