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A reusable planar triggered spark-gap switch batched-fabricated with PCB technology for medium- and low-voltage pulse power systems

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Defence Technology（防务技术） 2021年第4期17卷 1572-1578页

作者： Zhi Yang Ke Wang Peng zhu Peng Liu qiu Zhang Cong Xu Hao-tian jian Rui-qi Shen School of Chemical Engineering Nanjing University of Science and TechnologyNanjing210094China Key Laboratory of Special Energy Materials Ministry of EducationNanjing210094China Micro-Nano Energetic Devices Key Laboratory Ministry of Industry and Information TechnologyNanjing210094China

Triggered spark-gap switch is a popular discharge switch for pulse power *** studies have focused on planarizing this switch using thin film techniques in order to meet the requirements of compact size in the *** switches are one-shot due to electrodes being too thin to sufficiently resist ***,these switches did not employ any structures in securing internal gas composition,resulting in inconsistent performance under harsh *** this work,a novel planar triggered spark-gap switch(PTS)with a hermetically sealed cavity was batched-prepared with printed circuit board(PCB)technology,to achieve reusability with low *** proposed PTS was inspected by micro-computed tomography to ensure PCB techniques meet the requirements of machining *** results from electrical experiments demonstrated that PCB PTS were consistent and reusable with lifespan over 20 *** calculated switch voltage and circuit current were consistent with those derived from real-world ***,PCB PTS was used to introduce hexanitrostilbene(HNS)pellets in a pulse power system to verify its performance.

关键词： Pulse power systems Printed circuit board technology Triggered spark-gap switch Planar discharge switch Electrical performance

Role of permafrost in resilience of social-ecological system and its spatio-temporal dynamics in the source regions of Yangtze and Yellow Rivers

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Journal of Mountain Science 2019年第1期16卷 179-194页

作者： FANG Yi-ping zhu Fu-biao YI Shu-hua qiu Xiao-ping DING Yong-jian Institute of Mountain Hazards and Environment Chinese Academy of Sciences College of Resource and Environment University of Chinese Academy of Sciences School of Economics Hefei University of Technology School of Geographic Sciences Nantong University College of Geography and Resources Science Sichuan Normal University State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences

Permafrost is one of the key components of terrestrial ecosystem in cold regions. In the context of climate change, few studies have investigated resilience of social ecological system(SER) from the perspective of permafrost that restricts the hydrothermal condition of alpine grassland ecosystem. In this paper, based on the structural dynamics, we developed the numerical model for the SER in the permafrost regions of the source of Yangtze and Yellow Rivers, analyzed the spatial-temporal characteristics and sensitivity of the SER, and estimated the effect of permafrost change on the SER. The results indicate that: 1) the SER has an increasing trend, especially after 1997, which is the joint effect of precipitation, temperature, NPP and ecological conservation projects; 2) the SER shows the spatial feature of high in southeast and low in northwest,which is consistent with the variation trends of high southeast and low northwest for the precipitation, temperature and NPP, and low southeast and high northwest for the altitude; 3) the high sensitive regions of SER to the permafrost change have gradually transited from the island distribution to zonal and planar distribution since 1980, moreover, the sensitive degree has gradually reduced; relatively, the sensitivity has high value in the north and south, and low value in the south and east; 4) the thickness of permafrost active layer shows a highly negative correlation with the SER. The contribution rate of permafrost change to the SER is-4.3%, that is, once the thickness of permafrost active layer increases 1 unit, the SER would decrease 0.04 units.

关键词： Resilience of social ecological system Permafrost Permafrost active layer thickness Structural dynamic equation Source regions of Yangtze and Yellow rivers

Spreading-rate dependence of hydroacoustic and teleseismic seismicity of ridge-transform systems:East Pacific Rise,Galapagos Ridge,and Mid-Atlantic Ridge

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Acta Oceanologica Sinica 2022年第5期41卷 124-135页

作者： Tingting Zheng jian Lin qiu Zhong Key Laboratory of Ocean and Marginal Sea Geology South China Sea Institute of OceanologyInnovation Academy of South China Sea Ecology and Environmental EngineeringChinese Academy of SciencesGuangzhou510301China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou511458China China-Pakistan Joint Research Center on Earth Sciences Chinese Academy of Science-Higher Education Commission(Pakistan)Islamabad45320Pakistan Department of Ocean Science and Engineering Southern University of Science and TechnologyShenzhen518055China Department of Geology and Geophysics Woods Hole Oceanographic InstitutionFalmouthWoods HoleMA02543USA

Seismicity in ocean ridge-transform systems reveals fundamental processes of mid-ocean ridges,while comparisons of seismicity in different oceans remain rare due to a lack of detection of small *** 1996 to 2003,the Pacific Marine Environmental Laboratory of the National Oceanic and Atmospheric Administration(NOAA/PMEL)deployed several hydrophones in the eastern Pacific Ocean and the northern Atlantic *** hydrophones recorded earthquakes with small magnitudes,providing us with opportunities to study the seismic characteristics of ridge-transform systems at different spreading rates and make further comparisons of their *** study comparatively analyzed hydroacoustic and teleseismic data recorded on the fast-spreading East Pacific Rise(EPR,10°S to 12°N),intermediate-spreading Galapagos Ridge(103°W to 80°W),and slow-spreading Mid-Atlantic Ridge(MAR,15°N to 37°N).We present a systematic study of the spatial and temporal distribution of events,aftershock seismicity,and possible triggering mechanisms of aftershock *** analysis yields the following conclusions.(1)From the hydroacoustic data,the EPR transform faults had the highest average seismicity rate among the three regions.(2)Along-ridge event distributions show that a high number of earthquakes were concentrated on the EPR,while they became dispersed on the GR and fewer and more scattered on the MAR,reflecting that the different tectonic origins were closely correlated with the spreading rate.(3)Analysis from mainshock-aftershock sequences shows no significant differences in the aftershock decay rate among the three regions.(4)Multiple types of aftershock triggering models were inferred from Coulomb stress changes:strike-slip mainshocks triggered strike-slip aftershocks and normal faulting aftershocks,and normal faulting mainshocks triggered normal faulting *** these results are case studies,they may be applicable to other ocean ridge-transform systems in future

关键词： East Pacific Rise Galapagos Ridge Mid-Atlantic Ridge hydroacoustic and teleseismic seismicity ridge-transform system

New Finite Difference Mapped WENO Schemes with Increasingly High Order of Accuracy

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Communications on Applied Mathematics and Computation 2023年第1期5卷 64-96页

作者： Jun zhu jianxian qiu College of Science Nanjing University of Aeronautics and AstronauticsNanjing 210016JiangsuChina School of Mathematical Sciences and Fujian Provincial Key Laboratory of Mathematical Modeling and High-Performance Scientific Computing Xiamen UniversityXiamen 361005FujianChina

In this paper,a new type of finite difference mapped weighted essentially non-oscillatory(MWENO)schemes with unequal-sized stencils,such as the seventh-order and ninthorder versions,is constructed for solving hyperbolic conservation *** the purpose of designing increasingly high-order finite difference WENO schemes,the equal-sized stencils are becoming more and more *** more we use wider candidate stencils,the bigger the probability of discontinuities lies in all ***,one innovation of these new WENO schemes is to introduce a new splitting stencil methodology to divide some fourpoint or five-point stencils into several smaller three-point *** the usage of this new methodology in high-order spatial reconstruction procedure,we get different degree polynomials defined on these unequal-sized stencils,and calculate the linear weights,smoothness indicators,and nonlinear weights as specified in jiang and Shu(***.126:202228,1996).Since the difference between the nonlinear weights and the linear weights is too big to keep the optimal order of accuracy in smooth regions,another crucial innovation is to present the new mapping functions which are used to obtain the mapped nonlinear weights and decrease the difference quantity between the mapped nonlinear weights and the linear weights,so as to keep the optimal order of accuracy in smooth *** new MWENO schemes can also be applied to compute some extreme examples,such as the double rarefaction wave problem,the Sedov blast wave problem,and the Leblanc problem with a normal CFL *** numerical results are provided to illustrate the good performance of the new finite difference MWENO schemes.

关键词： Finite difference Mapped WENO scheme Mapping function Mapped nonlinear weight Unequal-sized stencil Extreme example

Microscopic experimental and numerical research on rejuvenators: A review

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Journal of Traffic and Transportation Engineering(English Edition) 2022年第2期9卷 180-207页

作者： Zhiyu Han Peiliang Cong jian qiu Engineering Research Center of Transportation Materials Ministry of EducationSchool of Materials Science and EngineeringChang’an UniversityXi'an 710064China Asfalt Nu C.V. Culemborg 4100 ADthe Netherlands

Prompting high content of reclaimed asphalt pavement(RAP) to be used in road building and maintenance has drawn great attention. The application of rejuvenators is an efficient way to ensure the performance of recycled asphalt mixtures. However, as various types of rejuvenators emerging, limited understanding about rejuvenation poses challenges to put effective ones into use. For precisely evaluating the performance of rejuvenators, plenty of studies were conducted to ascertain the fundamental mechanism of rejuvenating from the microscopic view. This paper provides an overview of studies focusing on the change inside asphalt after adding rejuvenators. Chemical compositions of rejuvenators were collected as basic information. Both laboratorial experiments and molecular dynamic simulations were investigated to not only compare the effectiveness of several rejuvenators but also explain the rejuvenating mechanism. Finally, functional groups of rejuvenator structures were comprehensively examined to provide global understanding about how chemical compositions influence the efficacy of rejuvenators. This review highlights that the essential capacity of a true rejuvenator is to disturb asphaltene agglomerations. Besides, the molecular structures of rejuvenators will not only affect their deagglomerating abilities but also the performances of diffusion and durability. It has been found that gel-permeation chromatography(GPC) analysis is effective in evaluating the performance of rejuvenators, while Fourier transform infrared spectroscopy(FT-IR) and SARA(saturates, aromatics, resins and asphaltenes) analysis are only suitable for assessing asphalt oxidization. In addition, comparing some tests can only detect changes, molecular dynamic simulation can reveal the mechanism both of data and vision. The results of this work can provide comprehensive knowledge for the evaluation and development of rejuvenators.

关键词： Road engineering Rejuvenator Deagglomeration Molecular simulation GPC

Activity Calculation Model for Ternary Slag System of Al_2O_3-BaO-B_2O_3

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Journal of Iron and Steel Research International 2013年第11期20卷 46-50页

作者： ZHOU jian WANG Qiang QIN Zhe qiu Sheng-tao GAN Yong zhu Guo-ling National Engineering Research Center of Continuous Casting Technology Central Iron and Steel Research Institute

According to the ion and molecule coexistence theory, the activity model of Al2O3- BaO-B2O3 ternary slag system was established, and the influences of BaO/Al2O3 molar ratio, B2O3 mole fraction and temperature on the activity of the slag system were investigated. Finally, the equal activity curves were drawn with the model results. The results show that with the increase of BaO/Al2O3 ratio, the activity of Al2O3 is significantly reduced, the activi- ty of BaO3-Al2O3 is increased obviously, and the activity of 2Al2O3· B2O3 is also decreased. With the increase of B2O3 mole fraction, the activity of BaO · Al2O3 decreased significantly, while the activities of BaO·B2O3 and 2Al2O3·B2O3 increased. In addition, the influence of temperature on the activities of different components is com paratively smaller than the influence of BaO/Al2O3 ratio and B2O3 mole fraction.

关键词： molecule and ion coexistence theory Al2O3- BaO-B2O3 ternary slag system activity calculation model

Relationship between martensite microstructure and ductility of H13 steel from aspect of crystallography

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Journal of Iron and Steel Research International 2021年第10期28卷 1268-1281页

作者： jian zhu Zhi-hao Zhang jian-xin Xie Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing100083China Key Laboratory for Advanced Materials Processing(MOE) University of Science and Technology BeijingBeijing100083China

Based on the parent austenite orientation reconstruction method,it is aimed to reveal the origination of high angle grain boundaries(HAGBs)and its relationship with ductility of H13 *** orientation relationship between martensite and parent austenite of quenched H13 samples was(123.5°,9.3°,192.5°),which agreed with the Kurdumov–Sachs *** variant distribution of quenched samples was dominated by close-packed plane group,and its high length fraction of V1/V2 inter-variant boundaries of calculated 62.6%was mainly contributed to HAGBs(>45°).When the quenched H13 samples underwent the pre-tempering treatment,their density of HAGBs(>45°)notably increased from 1.33 to 2.39μm^(−1),which improved its total elongation from 8.3%to 11.5%.Compared with the quenched H13 samples,the length fraction of V1/V2 inter-variant boundaries of H13 samples with pre-tempering for 5,10 and 60 min was reduced by 6.7%,7.0%and 7.5%,*** pre-tempering treatment,V1/V3&V5 variant pairs,etc.,merged V1/V2 variant pair by strain-induced grain boundary migration,which decreased the length fraction of V1/V2 inter-variant boundaries by 7.0%.The pre-tempering treatment significantly increased HAGBs(>45°)of H13 samples by sub-grains coarsening and strain-induced grain boundary migration mechanism.

关键词： H13 steel Pre-tempering treatment Variant selection Parent austenite orientation reconstruction High angle grain boundary

Differential Thermal Regimes of the Tarim and Sichuan Basins in China:Implications for Hydrocarbon Generation and Conservation

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Acta Geologica Sinica(English Edition) 2022年第4期96卷 1308-1322页

作者： CHANG jian LI Dan qiu Nansheng zhu Chuanqing ZHONG Ningning FENG Qianqian ZHANG Haizu WANG Xiang State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing 102249China College of Geosciences China University of PetroleumBeijing 102249China Research Institute of Exploration and Development Petro China Tarim Oilfield CompanyKorla 841000China

The uncertainty surrounding the thermal regimes of the ultra-deep strata in the Tarim and Sichuan basins,China,is unfavorable for further hydrocarbon *** study summarizes and contrasts the present-day and paleo heat flow,geothermal gradient and deep formation temperatures of the Tarim and Sichuan *** average heat flow of the Tarim and Sichuan basins are 42.5±7.6 mW/m^(2)and 53.8±7.6 mW/m^(2),respectively,reflecting the characteristics of’cold’and’warm’*** geothermal gradient with unified depths of 0-5,000 m,0-6,000 m and 0-7,000 m in the Tarim Basin are 21.6±2.9℃/km,20.5±2.8℃/km and 19.6±2.8℃/km,respectively,while the geothermal gradient with unified depths of 0-5,000 m,0-6,000 m and 0-7,000 m in the Sichuan Basin are 21.9±2.3℃/km,22.1±2.5℃/km and23.3±2.4℃/km *** differential change of the geothermal gradient between the Tarim and Sichuan basins with depth probably results from the rock thermal conductivity and heat production *** formation temperatures at depths of 6,000 m,7,000 m,8,000 m,9,000 m and 10,000 m in the Tarim Basin are 80℃-190℃,90℃-220℃,100℃-230℃,110℃-240℃and 120℃-250℃,respectively,while the formation temperatures at depths of 6,000 m,7,000 m,8,000 m and 9,000 m in the Sichuan Basin are 120℃-200℃,140℃-210℃,160℃-260℃and 180℃-280℃,*** horizontal distribution pattern of the ultra-deep formation temperatures in the Tarim and Sichuan basins is mainly affected by the basement relief,fault activity and hydrothermal *** thermal modeling revealed that the paleo-heat flow in the interior of the Tarim Basin decreased since the early Cambrian with an early Permian abrupt peak,while that in the Sichuan Basin experienced three stages of steady state from Cambrian to early Permian,rapidly rising at the end of the early Permian and declining since the late *** thermal regime of the Sichuan Basin was always higher than that of the Tarim Basin,which results in differential oil and gas generation

关键词： ultra-deep strata heat flow geothermal gradient formation temperature hydrocarbon generation and conservation Sichuan Basin Tarim Basin

Neighbor Sum Distinguishing Index of Sparse Graphs

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Acta Mathematica Sinica,English Series 2020年第6期36卷 673-690页

作者： Ji Hui WANG Bao jian qiu jian Sheng CAI School of Mathematical Sciences University of JinanJinan 250022P.R.China School of Mathematics and Information Sciences Weifang UniversityWeifang 261061P.R.China

A proper k-edge coloring of a graph G is an assignment of one of k colors to each edge of G such that there are no two edges with the same color incident to a common *** f(v)denote the sum of colors of the edges incident to v.A k-neighbor sum distinguishing edge coloring of G is a proper k-edge coloring of G such that for each edge uv∈E(G),f(u)≠f(v).Byχ’_∑(G),we denote the smallest value k in such a coloring of *** mad(G)denote the maximum average degree of a graph *** this paper,we prove that every normal graph with mad(G)<10/3 andΔ(G)≥8 admits a(Δ(G)+2)-neighbor sum distinguishing edge *** approach is based on the Combinatorial Nullstellensatz and discharging method.

关键词： Proper edge coloring neighbor sum distinguishing edge coloring maximum average degree Combinatorial Nullstellensatz