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Nuclear Science and Techniques 2019年第3期30卷 97-104页

作者： zhan-gang zhang Yun Huang Yun-Fei En Zhi-Feng Lei Science and Technology on Reliability Physics and Application of Electronic Component Laboratory China Electronic Product Reliability and Environmental Testing Research Institute

Existing standards show a clear discrepancy in the specification of the maximum proton energy for qualified ground-based evaluation of single-event effects,which can range from 180 to 500 MeV. This work finds that the threshold linear energy transfer of a tested device is a critical parameter for determining the maximum proton energy. The inner mechanisms are further revealed. Highenergy deposition events(>10 MeV) in sensitive volumes are attributed to the interaction between protons and the tungsten vias in the metallization layers.

关键词： Proton Single-event effect Threshold LET Monte Carlo simulation

Heavy-ion and pulsed-laser single event effects in 130-nm CMOS-based thin/thick gate oxide anti-fuse PROMs

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Nuclear Science and Techniques 2019年第5期30卷 92-102页

作者： Chang Cai Tian-Qi Liu Xiao-Yuan Li Jie Liu zhan-gang zhang Chao Geng Pei-Xiong Zhao Dong-Qing Li Bing Ye Qing-gang Ji Li-Hua Mo Institute of Modern Physics Chinese Academy of Sciences University of Chinese Academy of Sciences School of Physical Science and Technology Lanzhou University Academy of Shenzhen State Microelectronic Co. Ltd. Science and Technology on Reliability Physics and Application of Electronic Component Laboratory

Single event effects of 1-T structure programmable read-only memory(PROM) devices fabricated with a 130-nm complementary metal oxide semiconductorbased thin/thick gate oxide anti-fuse process were investigated using heavy ions and a picosecond pulsed laser. The cross sections of a single event upset(SEU) for radiationhardened PROMs were measured using a linear energy transfer(LET) ranging from 9.2 to 95.6 MeV cm^2mg^(-1).The result indicated that the LET threshold for a dynamic bit upset was ～ 9 MeV cm^2mg^(-1), which was lower than the threshold of ～ 20 MeV cm^2mg^(-1) for an address counter upset owing to the additional triple modular redundancy structure present in the latch. In addition, a slight hard error was observed in the anti-fuse structure when employing209 Bi ions with extremely high LET values(～ 91.6 MeV cm^2mg^(-1)) and large ion fluence(～ 1×10~8 ions cm^(-2)). To identify the detailed sensitive position of a SEU in PROMs, a pulsed laser with a 5-μm beam spot was used to scan the entire surface of the device.This revealed that the upset occurred in the peripheral circuits of the internal power source and I/O pairs rather than in the internal latches and buffers. This was subsequently confirmed by a ^(181)Ta experiment. Based on the experimental data and a rectangular parallelepiped model of the sensitive volume, the space error rates for the used PROMs were calculated using the CRèME-96 prediction tool. The results showed that this type of PROM was suitable for specific space applications, even in the geosynchronous orbit.

关键词： Anti-fuse PROM Single event effects Heavy ions Pulsed laser Space error rate

Aero-structural design of joined-wing aircraft based on high-fidelity model

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Chinese Journal of Aeronautics 2024年第4期37卷 363-377页

作者： Cheng HE Fengjiang zhan Luchuang MA gang CHEN Jianying MA Unmanned Air Vehicle Research Institute Nanjing University of Aeronautics and AstronauticsNanjing 210016China Key Laboratory of Advanced Technology for Small and Medium-sized UAV Ministry of Industry and Information TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China Aerospace System Engineering Shanghai Shanghai 201108China

The joined-wing configuration reduces induced drag and structural weight by connecting the rear wing to the front wing.In addition,the rear wing can replace the role of the horizontal tail of a conventional aircraft,thus eliminating the aerodynamic drag and weight associated with the horizontal tail.This particular shape creates a highly coupled relationship between aerodynamics and structure,which must be fully considered during the overall design process to enhance aircraft performance.In this research,an aero-structural design model of the joined-wing aircraft is constructed based on high-fidelity computational fluid dynamics and structural finite element methods.The model is able to obtain accurate aerodynamic loads for the non-planar wing and to simulate the statically indeterminate structure of the closed wing configuration.The influence of the joined-wing shape parameters on the aerodynamic and structural disciplines,as well as the influence of geometric nonlinear characteristics,deformation constraints and buckling constraints on the structural weight are all taken into consideration.The model is applied to complete the aero-structural design optimization of a high-altitude long-endurance joined-wing aircraft,and wind tunnel tests are conducted.The test results verify the credibility of the design model proposed and the validity of the design environment.

关键词： Joined-wing configuration Aircraft design Aero-structural design Finite element Wind tunnel test

Iron-nickel alloy particles with N-doped carbon “armor” as a highly selective and long-lasting catalyst for the synthesis of Nbenzylaniline molecules

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Nano Research 2024年第4期17卷 2308-2319页

作者： gang Wang Longchao Sun Wanyi Liu Haijuan zhan Shuxian Bi College of Chemistry and Chemical Engineering Ningxia UniversityYinchuan 750021China

A scalable strategy for the convenient and rapid preparation of nitrogen-doped carbon-coated iron-based alloy catalysts was developed.By controlling the type and amount of metal salts in the precursor,various types of nitrogen-doped carbon-coated alloy catalysts can be prepared in a targeted manner.Fe_(2)Ni2@CN materials with small particle sizes and relatively homogeneous basic sites showed promising results in the N-alkylation reaction of benzyl alcohol with aniline(optimum yield:99%).It is worth noting that the catalyst can also be magnetically separated and recovered after the reaction,and its performance can be regenerated through simple calcination.Furthermore,it was confirmed by kinetic experiments that the activation of C–H at the benzyl alcohol benzylic position is the rate-determining step(RDS).According to density flooding theory calculations,Fe_(2)Ni2@CN catalysts require less energy than other materials(Fe@CN and Ni@CN)for the RDS(dehydrogenation reaction)process.Therefore N-alkylation reactions are more easily carried out on Fe_(2)Ni2@CN catalysts,which may be the reason for the best catalytic activity of Fe-Ni alloy materials.These carbon-coated alloy materials will show great potential in more types of heterogeneous catalysis.

关键词： iron-nickel alloy catalyst N-alkylation reaction magnetic separation reaction path dehydrogenation reaction

Classification of knowledge graph completeness measurement techniques

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Journal of Systems Engineering and Electronics 2024年第1期35卷 154-162页

作者： zhang Ying XIAO gang Institute of Systems Engineering Academy of Military SciencesBeijing 100107China

At present,although knowledge graphs have been widely used in various fields such as recommendation systems,question and answer systems,and intelligent search,there are always quality problems such as knowledge omissions and errors.Quality assessment and control,as an important means to ensure the quality of knowledge,can make the applications based on knowledge graphs more complete and more accurate by reasonably assessing the knowledge graphs and fixing and improving the quality problems at the same time.Therefore,as an indispensable part of the knowledge graph construction process,the results of quality assessment and control determine the usefulness of the knowledge graph.Among them,the assessment and enhancement of completeness,as an important part of the assessment and control phase,determine whether the knowledge graph can fully reflect objective phenomena and reveal potential connections among entities.In this paper,we review specific techniques of completeness assessment and classify completeness assessment techniques in terms of closed world assumptions,open world assumptions,and partial completeness assumptions.The purpose of this paper is to further promote the development of knowledge graph quality control and to lay the foundation for subsequent research on the completeness assessment of knowledge graphs by reviewing and classifying completeness assessment techniques.

关键词： quality assessment completeness assessment closed world assumptions open world assumption partial completeness assumption

Allelic reprogramming of chromatin states in human early embryos

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National Science Review 2024年第3期11卷 58-71页

作者： Shenli Yuan Lei Gao Wenrong Tao Jianhong zhan gang Lu Jingye zhang Chuanxin zhang Lizhi Yi Zhenbo Liu Zhenzhen Hou Min Dai Han Zhao Zi-Jiang Chen Jiang Liu Keliang Wu Center for Reproductive Medicine Shandong University CAS Key Laboratory of Genome Sciences and Information Collaborative Innovation Center of Genetics and Development Beijing Institute of Genomicsand China National Center for BioinformationChinese Academy of Sciences University of Chinese Academy of Sciences CUHK-SDU Joint Laboratory on Reproductive Genetics School of Biomedical Sciences the Chinese University of Hong Kong Key Laboratory of Reproductive Endocrinology of the Ministry of Education Shandong University Center for Reproductive Medicine Ren Ji Hospital School of Medicine Shanghai Jiao Tong University CAS Center for Excellence in Animal Evolution and Genetics Chinese Academy of Sciences

The reprogramming of parental epigenomes in human early embryos remains elusive. To what extent the characteristics of parental epigenomes are conserved between humans and mice is currently unknown. Here,we mapped parental haploid epigenomes using human parthenogenetic and androgenetic embryos. Human embryos have a larger portion of genome with parentally specific epigenetic states than mouse embryos.The allelic patterns of epigenetic states for orthologous regions are not conserved between humans and mice. Nevertheless, it is conserved that maternal DNA methylation and paternal H3K27me3 are associated with the repression of two alleles in humans and mice. In addition, for DNA-methylation-dependent imprinting, we report 19 novel imprinted genes and their associated germline differentially methylated regions. Unlike in mice, H3K27me3-dependent imprinting is not observed in human early embryos.Collectively, allele-specific epigenomic reprogramming is different in humans and mice.

关键词： human embryo epigenetics reprogramming DNA methylation H3K27me3 chromatin accessibility

Nanophononic metamaterials induced proximity effect in heat flux regulation

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Frontiers of physics 2024年第2期19卷 149-156页

作者： Jian zhang Haochun zhang gang zhang School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China Institute of High Performance Computing Agency for ScienceTechnology and Research(A*STAR)Singapore 138632Singapore

Recent studies have shown that the construction of nanophononic metamaterials can reduce thermal conductivity without affecting electrical properties,making them promising in many fields of application,such as energy conversion and thermal management.However,although extensive studies have been carried out on thermal conductivity reduction in nanophononic metamaterials,the local heat flux characteristic is still unclear.In this work,we construct a heat flux regulator which includes a silicon nanofilm with silicon pillars.The regulator has remarkable heat flux regulation ability,and various impacts on the regulation ability are explored.Surprisingly,even in the region without nanopillars,the local heat current is still lower than that in pristine silicon nanofilms,reduced by the neighboring nanopillars through the thermal proximity effect.We combine the analysis of the phonon participation ratio with the intensity of localized phonon modes to provide a clear explanation.Our findings not only provide insights into the mechanisms of heat flux regulation by nanophononic metamaterials,but also will open up new research directions to control local heat flux for a broad range of applications,including heat management,thermoelectric energy conversion,thermal cloak,and thermal concentrator.

关键词： nanophononic metamaterials proximity effect

Selective extinction and habitat nestedness are the main drivers of lizard nestedness in the Zhoushan Archipelago

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Current Zoology 2024年第2期70卷 244-252页

作者： Minchu zhang Chaonan Tang Qing zhang Chengxiu zhan Chuanwu Chen Yanping Wang Laboratory of Island Biogeography and Conservation Biology College of Life SciencesNanjing Normal UniversityNanjing 210023China

Nested subset pattern(nestedness)is an important part of the theoretical framework of island biogeography and community ecology.However,most previous studies often used nestedness metrics or randomization algorithms that are vulnerable to type I error.In this study,we inves-tigated the nestedness of lizard assemblages on 37 islands in the Zhoushan Archipelago,China.We used the line-transect method to survey species occurrence,abundance,and habitat types of lizards on 37 islands during 2 breeding seasons in 2021 and 2022.We applied the nested metric WNODF and the conservative rc null model to control for type I error and quantify the significance of nestedness.Spearman rank cor relations were used to evaluate the role of 4 habitat variables(island area,2 isolation indices,and habitat diversity)and 4 ecological traits(body size,geographic range size,clutch size,and minimum area requirement)in generating nestedness.The results of WNODF analyses showed that lizard assemblages were significantly nested.The habitat-by-site matrix estimated by the program NODF was also significantly nested,support-ing the habitat nestedness hypothesis.The nestedness of lizard assemblages were significantly correlated with island area,habitat diversity.clutch size,and minimum area requirement.Overall,our results suggest that selective extinction and habitat nestedness were the main drivers of lizard nestedness in our system.In contrast,the nestedness of lizard assemblages was not due to passive sampling or selective colonization.To maximize the number of species preserved,our results indicate that we should protect both large islands with diverse habitats and species with largearea requirement and clutch size.

关键词： clutch size habitat nestedness lizards minimum area requirement nestedness selective extinction WNODF Zhoushan Archipelago.

Kinetic model of vibration screening for granular materials based on biological neural network

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Particuology 2024年第5期88卷 98-106页

作者： zhan Zhao Yan zhang Fang Qin Mingzhi Jin School of Agricultural Engineering Jiangsu UniversityZhenjiang212013China Shandong Academy of Agricultural Machinery Sciences Ji'nan250100China

The kinetic model is the theoretical basis for optimizing the structure and operation performance of vibration screening devices.In this paper,a biological neurodynamic equation and neural connections were established according to the motion and interaction properties of the material under vibration excitation.The material feeding to the screen and the material passing through apertures were considered as excitatory and inhibitory inputs,respectively,and the generated stable neural activity landscape was used to describe the material distribution on the 2D screen surface.The dynamic process of material vibration screening was simulated using discrete element method(DEM).By comparing the similarity between the material distribution established using biological neural network(BNN)and that obtained using DEM simulation,the optimum coefficients of BNN model under a certain screening parameter were determined,that is,one relationship between the BNN model coefficients and the screening operation parameters was established.Different screening parameters were randomly selected,and the corresponding relationships were established as a database.Then,with straw/grain ratio,aperture diameter,inclination angle,vibration strength in normal and tangential directions as inputs,five independent adaptive neuro-fuzzy inference systems(ANFIS)were established to predict the optimum BNN model coefficients,respectively.The training results indicated that ANFIS models had good stability and accuracy.The flexibility and adaptability of the proposed BNN method was demonstrated by modeling material distribution under complex feeding conditions such as multiple regions and non-uniform rate.

关键词： Kinetic model Material distribution Vibration screening Biological neural network DEM simulation Adaptive neuro-fuzzy inference systems

Color-kinematics duality and dual conformal symmetry for a four-loop form factor in N=4 SYM

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 64-71页

作者： Guanda Lin gang Yang Siyuan zhang CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China International Centre for Theoretical Physics Asia-Pacific Beijing/Hangzhou 310024China

We obtain the integrand of full-color four-loop three-point form factor of the stress-tensor supermultiplet in N=4 SYM,based on the color-kinematics(CK)duality and generalized unitarity method.Our result not only manifests all dual Jacobi relations via CK duality but also contains 133 free parameters.This suggests the constructibility of the form factor at even higher loops via CK duality.We also find that the planar form factor has a hidden dual conformal symmetry in the lightlike limit of the operator momentum,which is checked up to four loops.

关键词： S-matrix supersymmetric model perturbative calculations