bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biased self-diffusion on Cu surface due to electric field gradients
Authors: Kimari Jyri , Wang Ye , Kyritsakis Andreas , Zadin Veronika , Djurabekova Flyura 
Published: September 2022

Abstract
Under strong electric fields, an arc of strong current flowing through plasma can link two metal surfaces even in ultra high vacuum. Despite decades of research, the chain of events leading to vacuum arc breakdowns is hitherto unknown. Previously we showed that a tall and sharp Cu nanotip exposed to strong electric fields heats up by field emission currents and eventually melts, evaporating neutral atoms that can contribute to plasma buildup. In this work, we investigate by means of molecular dynamics (MD) simulations whether surface diffusion biased by the presence of an electric field gradient can provide sufficient mass transport of atoms toward the top of the nanotip to maintain supply of neutrals for feeding plasma. To reach the necessary timescales and to add electric field in MD, we utilized a novel combination of collective variable-driven hyperdynamics acceleration and coupling to a finite element mesh. In our simulations, we observed biased self-diffusion on Cu surfaces, that can contribute to the continuous replenishment of particle-emitting nanotips. This mechanism implies a need to reduce the rate of surface diffusion in devices that are susceptible to vacuum arcs. Finding suitable alloys or surface treatments that hinder the observed biased diffusion could guide the design of future devices, and greatly improve their efficiency.
The influence of contact metals on epitaxially grown molybdenum disulfide for electrical and optical device applications
Authors: Tsai Po-Cheng , Yan Coung-Ru , Chang Shoou-Jinn , Lin Shih-Yen 
Published: September 2022

Abstract
Bottom-gate transistors with mono-layer MoS2 channels and polycrystalline antimonene source/drain contact electrodes deposited at 75 °C are fabricated. Significant performance enhancement of field-effect mobility 11.80 cm2 V−1·s−1 and >106 ON/OFF ratio are observed for the device. Increasing photocurrents are also observed for the MoS2 transistor under light irradiation, which is attributed to the reduced carrier recombination at the metal/2D material interfaces. The results have demonstrated that besides the matching of work function values with the 2D material channel, the crystallinity of the contact electrodes is the other important parameter for the Ohmic contact formation of 2D material devices.
Reflectivity of Different Texturing Structures Fabricated by Femtosecond Laser Etching
Authors: Liang Long , Liu Wenwen 
Published: September 2022

Abstract
Femtosecond laser etching is applied to fabricate cylindrical, quadrangular and circular hole micro-structures to explore the variation patterns of their reflectivity. The results show that the cylindrical and quadrangular texturing structures have the optimal anti-reflection effect (the reflectivity is always below 6%) in the wavelength range of 350-1000 nm, which is of reference value for the study of fabricating low-reflectivity texturing on monocrystalline silicon surfaces.
Analysis of piping and support weld defects of VVP system in nuclear power plant and study on treatment measures
Authors: Li Cheng 
Published: September 2022

Abstract
The main steam system(VVP) support of nuclear power plant protects the main pipe by welding the guard plate on the main pipe. This paper takes defect treatment of the VVP main steam system(VVP) pipe and support weld in a nuclear power plant as an example. From the analysis of the effective mechanism of the weld generation to the proposal, discussion and implementation of the final scheme, the technical points are comprehensive described, defect types were determined by penetrant testing and metallographic observation, and further root reason analysis was carried out. Accordingly, the defects are eliminated by technical means to avoid the expansion of defects and ensure the safe and stable operation of the unit. The analysis and treatment scheme of the defects in this project provides a technical scheme for inspection and maintenance in the nuclear power field, and provides an important reference for the future treatment of defects.
Research on Sealing Assembly and Adjustment Method of Assembled Cabin Door of Space Station
Authors: Liu Shufen , Zhang Bin , Wang Tianming , Yi Zhuoxun , Huang Ning , Cui Xiaohang , Zhang Xun , Yu Junyu 
Published: September 2022

AbstractFor the new assembled sealed cabin door of space station, its structural characteristics, sealing working principle and sealing assembly and adjustment difficulties are analyzed. The static simulation based on the minimum loading point deformation is studied to obtain the minimum compression ratio boundary. Based on the maximum operating force, the sealing stress calculation and simulation analysis are carried out to obtain the maximum compression rate boundary. It realizes the transformation of multiple open constraints into the compression rate interval, which effectively improves the assembly and adjustment accuracy and efficiency of the assembled cabin door.
Analysis of Austempering Characteristics of Cr12MoV Die Steel
Authors: Wang Huizhen , Zhai Yuewen , Zhou Leyu , Zhang Zibo , Liu Bo 
Published: September 2022

Abstract
The characteristics of microstructure and properties of Cr12MoV die steel with austempering were investigated by scanning electron microscope, electron backscattered scattering detection, X-ray diffractometer and Rockwell hardness tester. The results indicated that the tempering process reduced retained austenite apparently, especially after direct quenching process which decreased the volume fraction of retained austenite from 24.8% to 8.5%. Prolonging the holding time of isothermal quenching from 3h to 5h promoted the transformation of lower bainite and reduced the content of residual austenite. The bainite formed in isothermal combined with the secondary hardening caused by austenite decomposition made the hardness of 55.9-56.6HRC similar to that of 57.2HRC by direct quenching and tempering.
Effect of heat treatment process on microstructure and hardness of Ni48Co30Cr16Al3Ti3 high entropy alloy
Authors: Li Xin , Wang Chenglei , Zhang Zhenjun , Tan Hong , Xie Yingguang , Qin Haiqing , Liu Chong , Liang Mulin , Liu Weijie , Yang Jijie 
Published: September 2022

Abstract
Ni48Co30Cr16Al3Ti3 HEA was made by suspension melting, and treated by different heat treatment methods. The microstructure, phase composition and microhardness of the prepared alloy samples were analyzed by means of XRD, SEM, X-ray energy spectrum analyzer and microhardness tester. And the results show that the Ni48Co30Cr16Al3Ti3 HEA after different heat treatments has face centered cubic structure, and the alloy structure presents dendrite morphology. Under different heat treatment conditions, the diffraction peaks of the alloy samples treated by secondary aging at (800°C×12h+1000°C×4h) are the highest and strongest, and the precipitates of the alloy samples treated by aging at (800°C×12h) are the most dense and subtle. The distribution of elements in the samples are relatively uniform, but after heat treatments, part of the alloy grain structure and grain boundaries dissolve, the degree of dissolution increases with the increase of heat treatment time, so that some elements are not distributed in the alloy structure and grain boundaries. The microhardness value of alloy samples first increases and then decreases with the prolongation of heat treatment time, and the microhardness values of the samples were the highest after aging treatment at (800°C×12h), which was 357HV1.
Charge density wave in low dimensional materials
Authors: Zhu Hua , Han Hui 
Published: September 2022

AbstractCharge density wave(CDW) is an important physical phenomenon and has always been one of the significant research contents in condensed matter physics. The study of CDW helps people to have a deeper understanding of the interactions between various particles in low-dimensional systems. At the same time, the control of CDW in the material can effectively control the physical properties such as superconductivity. The study of CDW originated from one-dimensional and quasi-one-dimensional materials. This paper introduces the origin of CDW and the main formation mechanism of CDW at this stage. Discuss the common regulation methods of CDW and the competitive relationship with other physical properties. Finally, the possible research directions in related fields and the potential applications of CDW are prospected.
Research on Surface Quality of 38CrMoAl Polished Based on Abrasive Water Jet
Authors: Wang Jiasheng , Yuan Yuefeng , Xie Fei 
Published: September 2022

Abstract
Because the screw surface is slender and complex, it is difficult to process by traditional polishing methods. In order to improve the surface quality of screw, the abrasive water jet polishing (AWJP) technology was used to polish 38CrMoAl steel, which is commonly used in screw. The effects of different inlet pressure, target distance and abrasive particle size on surface roughness are analyzed. The experimental results show that with the increase of inlet pressure, the surface roughness first decreases and then increases. With the increase of target distance, the surface roughness first decreases and then increases. The smaller the abrasive particle size, the better the polishing effect.
Fluorinated poly(aryl ether nitrile)s containing pendant cyclohexyl groups toward low k materials
Authors: Liu Chenchen , Liu Shuning , Feng Xiaofang , Bai Zhongxiang , Lin Guo , Xia Yunqing , Wang Lingling , Liu Xiaobo 
Published: September 2022

Abstract
To obtain low k materials with good comprehensive performances, fluorinated poly(aryl ether nitrile)s containing pendant cyclohexyl groups (FCPEN) have been designed and synthesized via nucleophilic aromatic substitution polymerization. The polymer exhibits excellent dielectric properties with a dielectric constant of 2.96 and a dielectric loss of 3.95 × 10-3 at at 1 MHz. Besides, FCPEN displays satisfactory thermostability with a 5% weight loss temperature (T
d5%) of 489 °C and a glass transition temperature (T
g) of 191 °C. The resultant film shows good mechanical performance and optical transmittance. The outstanding comprehensive properties indicate that FCPEN is a promising low k material for the fabrication of microelectronic devices used in 5G communication.
Enhancing the dielectric properties of poly (arylene ether nitrile) by introducing co-modified BaTiO3
Authors: Xia Yunqing , Lin Guo , Liu Chenchen , Bai Zhongxiang , Liu Shuning , Liu Xiaobo 
Published: September 2022

Abstract
In this study, a facile co-modification of dopamine (DA) and methylphenyldimethoxysilane (MPDS) was utilized to functionalize barium titanate (BaTiO3) nanoparticles with organic functional film. With the organic film coated on surface of BaTiO3, the compatibility between BaTiO3 and PEN matrix was greatly enhanced, which led to the promotion in thermal and dielectric properties. Results indicated that the glass transition temperature (Tg) of BaTiO3@(MPDS+PDA)/PEN composite showed increment from 171.9°C to 181.2°C. Besides, the dielectric constant of PEN composite containing 20 wt.% of BaTiO3@(MPDS+PDA) improved to 9.32 with a relative low dielectric loss compared to BaTiO3/PEN under the same additive ratio.
Effect of Ce addition on microstructure and hardness of (Ni2CoFe)86Ti8Al6 high entropy alloy
Authors: Liu Chong , Wang Chenglei , Zhang Zhenjun , Tan Hong , Xie Yingguang , Qin Haiqing , Li Xin , Liang Mulin , Liu Weijie , Yang Jijie 
Published: September 2022

Abstract
The effects of different Ce contents on the microstructure and hardness of (Ni2CoFe)86-xTi8Al6Cex (x = 0, 0.1, 0.3, 0.5, 0.7, 1.0 molar ratio) high entropy alloys were systematically studied. The results show that the addition of Ce promotes the precipitation of new FCC and BCC phases. The precipitates were promoted by Ce, and the grains and structures were refined by Ce. With the gradual increase of Ce content, the hardness gradually increases. The microhardness (HV) of (Ni2CoFe)85Ti8Al6Ce HEA is 458.6. The increase of precipitate volume fraction and fine grain strengthening are the main reasons for the increase of hardness.
Research on system identification method of buffer system based on experimental signal pre-processing
Authors: Yu Bin , Tan Ruoyu , Zheng Jieji , Li Baoyu , Fan Dapeng , Xie Xin 
Published: September 2022

Abstract
In order to obtain the theoretical model of a gun buffer system, the dynamic vibration characteristics of the buffer system were studied by force hammer experiments, and the vibration acceleration response curves of the buffer system after being excited by the impact load were obtained. The acquired signals were processed by noise reduction, detrending, data smoothing and frequency domain integration, and the second-order free vibration model was used to identify the stiffness, damping and other parameters of the system, and compared with the experimental results. The deviation between the calculated results of the identification model and the experimental results is less than 4%, which compared with the general direct identification method, the error is reduced by about 10%. This method can provide a simple and fast technical way for the accurate identification of vibration system models.
The Design Theory of the Shaving Cutter of Conjugate Curved Gears
Authors: Zhu Jiao , Zhang Luhe , Tang Yu , Chen Bingkui 
Published: September 2022

Abstract
Based on the existing research on the conjugate curve gear, the meshing equation of the shaving process is deduced according to the gear meshing principle and the working principle of the disc shaving cutter, so as to obtain the tooth surface equation of the shaving cutter corresponding to the conjugate curve gear, which provides a theoretical basis for the design of the shaving cutter of the conjugate curve gear.
Lightweight design of brake callipers based on OSF response surface algorithm
Authors: Zhang TongShuai , Chen XiuSheng , Zhang LiangZheng , Song JiuLing , Sun WenXue 
Published: September 2022

Abstract
In this paper, ANSYS Workbench software is used to establish the brake caliper finite element model, finite element analysis of the model. Under the premise of satisfying the strength, stiffness and stability of the caliper model, Workbench DesignXplorer module was used to optimize the caliper parts' dimensions, and a two-level response surface model was constructed based on OSF algorithm. The caliper mass was taken as the main output parameter, and the lightweight design was carried out through MOGA multi-objective optimization. In terms of material lightweight, new vermicular cast iron was selected to replace QT450, QT600 and Q235 materials. After lightweight design, the yield strength and tension and compression strength of calipers were satisfied, and the mass was reduced by 15.4%
Research on Power Load Prediction Based on Elman Network with Improved Particle Swarm Optimization
Authors: Liu Shijian , Zhang Li , Xia Huiwen 
Published: September 2022

Abstract
Because electricity is so difficult to store, the electric power department needs to store enough power in advance, whether customers use it or not. To lower the cost of the electric power department in this aspect, it is essential to realize high-precision power load forecasting. The Elman neural network (ElmanNN) prediction model based on the improved Particle Swarm Optimization (IPSO) algorithm is constructed. The Particle Swarm Optimization (PSO) algorithm is brought in, and the learning factor of the algorithm is optimized for the limitation that the PSO algorithm can easily obtain the local optimal solution. Finally, the improved algorithm is applied to the ElmanNN. The improved ElmanNN solves the problems of slow training speed and is effortless to obtain the local minimum. Finally, simulation experiments verify that the ElmanNN model based on the improved PSO algorithm has a smaller prediction error in power load prediction.
Dynamic model of fine-pitch gear pair considering multi-clearance coupling
Authors: Zeng Xi , Zhang Luhe , Tang Yu , Li Zhaoyang , Chen Bingkui 
Published: September 2022

Abstract
In this paper, the parallel shaft fine-pitch involute plastic-powder metallurgy engagement spur gear pair produced according to the recommended backlash value of DIN standard is taken as research object. The coupling between the backlash and the bearing radial clearance is considered. And the expression of the dynamic backlash is derived. A three-degree-of-freedom two-state dynamic mathematical model of the parallel shaft gear transmission system is established. The time-domain curves of gear displacement, velocity, engagement force and dynamic backlash are obtained. The results of mathematical model show that a larger backlash range than DIN standard recommended is more conducive to smooth transmission.
Research on multi-cylinder synchronous control system of multi-directional forging hydraulic press
Authors: Xu Cong , Xu Xiao , Liu Zhao , wang Xin 
Published: September 2022

Abstract
A master-slave synchronization control strategy based on RBF network adaptive sliding mode control is proposed to solve the problem of lack of effective control strategy and control accuracy in the process of synchronous motion of three horizontal cylinders of multi-directional die forging hydraulic press in VL ball cage forming process. According to the high-order nonlinear mathematical model of the single-cylinder electro-hydraulic servo system, the RBF network adaptive sliding mode controller is designed. The joint simulation model is established by using AMEsim and MATLAB to solve the tracking accuracy and synchronous control accuracy of the system, and the control effect is verified by comparing with the conventional PID control. The simulation results show that the RBF network adaptive sliding mode controller has strong robustness, and the three horizontal cylinder displacement synchronization controllers of the multi-directional die forging press designed in this paper have good synchronization performance.
Understanding human–water feedbacks of interventions in agricultural systems with agent based models: a review
Authors: Alam Mohammad Faiz , McClain Michael , Sikka Alok , Pande Saket 
Published: September 2022

Abstract
Increased variability of the water cycle manifested by climate change is a growing global threat to agriculture with strong implications for food and livelihood security. Thus, there is an urgent need for adaptation in agriculture. Agricultural water management (AWM) interventions, interventions for managing water supply and demand, are extensively promoted and implemented as adaptation measures in multiple development programs globally. Studies assessing these adaptation measures overwhelmingly focus on positive impacts, however, there is a concern that these studies may be biased towards well-managed and successful projects and often miss out on reporting negative externalities. These externalities result from coevolutionary dynamics of human–water systems as AWM interventions impact hydrological flows and their use and adoption is shaped by the societal response. We review the documented externalities of AWM interventions and present a conceptual framework classifying negative externalities linked to water and human systems into negative hydrological externalities and unexpected societal feedbacks. We show that these externalities can lead to long term unsustainable and inequitable outcomes. Understanding how the externalities lead to undesirable outcomes demands rigorous modeling of the feedbacks between human and water systems, for which we discuss the key criteria that such models should meet. Based on these criteria, we showcase that differentiated and limited inclusion of key feedbacks in current water modeling approaches (e.g. hydrological models, hydro-economic, and water resource models) is a critical limitation and bottleneck to understanding and predicting negative externalities of AWM interventions. To account for the key feedback, we find agent-based modeling (ABM) as the method that has the potential to meet the key criteria. Yet there are gaps that need to be addressed in the context of ABM as a tool to unravel the negative externalities of AWM interventions. We carry out a systemic review of ABM application to agricultural systems, capturing how it is currently being applied and identifying the knowledge gaps that need to be bridged to unravel the negative externalities of AWM interventions. We find that ABM has been extensively used to model agricultural systems and, in many cases, the resulting externalities with unsustainable and inequitable outcomes. However, gaps remain in terms of limited use of integrated surface–groundwater hydrological models, inadequate representation of farmers’ behavior with heavy reliance on rational choice or simple heuristics and ignoring heterogeneity of farmers’ characteristics within a population.
The spatiotemporal trajectory of US agricultural irrigation withdrawal during 1981–2015
Authors: Zeng Ruijie , Ren Weiwei 
Published: September 2022

Abstract
Irrigation has enhanced food security and biofuel production throughout the world. However, the sustainability of irrigation faces challenges from climate variability and extremes, increasing consumption from irrigated cropland expansion, and competing demands from other water use sectors. In this study, we investigated the agricultural water withdrawal landscape of the contiguous United States (CONUS) over 1981–2015, assessed its spatial and temporal changes, and analyzed the factors driving the changes. We introduced the concept of ‘center of mass’ to calculate the spatiotemporal trajectory of water withdrawal, along with climatic and agricultural factors at state, regional and CONUS scales. At the CONUS level, the total agricultural water withdrawal has decreased during 1981–2015, and the centroid of water withdrawal consistently moved toward the east, caused by reduced water withdrawal in the western states and increased withdrawal in the eastern states. While the CONUS irrigation trajectory is not mainly affected by climatologic trends, extreme drought conditions (e.g. the mega droughts in western states since 2000) may interrupt the trend. In the Western US, irrigation withdrawal reduction was mainly achieved by adoption of high-efficiency irrigation technology, while the irrigated acreage remains relatively stable. Under drought conditions, irrigation withdrawal often switched from surface water to groundwater sources, posing challenges on groundwater sustainability under prolonged drought conditions. The Eastern US has experienced accelerating agricultural withdrawal from both surface water and groundwater sources. This was mainly driven by expansion in irrigated acreage in the Midwest and lower Mississippi River, with irrigated croplands supplied by mixed flood irrigation and high-efficiency irrigation methods. At the state level, some states exhibited discrepancy in agricultural withdrawal centroids from surface water and groundwater sources, as results of climate heterogeneity, water availability and infrastructure development. This study provides understanding of the driving forces in the spatiotemporal trends of CONUS agricultural water withdrawal in different regions and implications for predicting future agricultural withdrawal under changing climatic and socioeconomic uncertainties.