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计算机工程与应用 2003年第33期39卷 159-161,198页

作者：卞莹张玉清郎良冯登国中国科学院研究生院国家计算机网络入侵防范中心北京100039 中国科学院研究生院信息安全国家重点实验室北京100039

主动防御攻击工具库是为主动防御攻击平台提供攻击工具的数据库。文章对主动防御平台系统做了简要介绍,重点分析了如何针对攻击工具的特点对攻击工具进行分类,以及如何选取攻击工具,最后给出了基于这些分类所构造的主动防御平台攻击工... 详细信息

主动防御攻击工具库是为主动防御攻击平台提供攻击工具的数据库。文章对主动防御平台系统做了简要介绍,重点分析了如何针对攻击工具的特点对攻击工具进行分类,以及如何选取攻击工具,最后给出了基于这些分类所构造的主动防御平台攻击工具库的结构。

关键词：攻击工具数据库主动防御

The friction and wear characteristics and lubrication mechanism of imidazole phosphate ionic liquid

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Science china(Technological sciences) 2009年第5期52卷 1191-1194页

作者： zhang Lin feng DaPeng XU {2. LIU XuQing LIU WeiMin state key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Research institute of Lanzhou Petrochemical Corporation Lanzhou 730000China Graduate University of chinese academy of sciences Beijing 100039China

Several imidazole phosphate ionic liquids with varying carbon chain length have been synthesized at room *** characteristics and tribological properties of these synthesized ionic liquids were studied using four-ball friction and wear testing *** lubrication mechanism was also investigated by means of electron microscopy and X-ray photoelectron *** ex-perimental results showed that no corrosion was generated when the imidazole phosphate ionic liquid was applied to steel-steel ***,the imidazole phosphate showed excellent anti-wear and lubricating performances,its frictional performance was related to the polarity of ionic *** is suggested that the ionic liquids react with friction surface to form a protective film of iron phosphate and result in reduction in friction and wear.

关键词： imidazole phosphate ionic liquids friction and wear lubrication mechanism

Mechanical and fatigue properties of SA508-Ⅳ steel used for nuclear reactor pressure vessels

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Journal of Iron and Steel Research International 2022年第8期29卷 1312-1321页

作者： Xin Dai Yue-feng Chen Peng Wang Li zhang {2. Yang Lian-sheng Chen Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China state key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China College of Metallurgy and Energy North China University of Science and TechnologyTangshan 063210HebeiChina

The mechanical and fatigue properties of SA508-Ⅳ steel with martensite and granular bainite, respectively, were studied. The mechanical tests results showed that the ultimate tensile strength and impact toughness of the specimen with martensite were 830 MPa and 158 J, respectively, and those of the specimen with granular bainite were 811 MPa and 115 J, respectively. The former had higher tensile strength and impact toughness than the latter. The impact tests results showed that the former belonged to typical dimple fracture, while the latter belonged to brittle fracture. The fatigue tests results showed that the fatigue life of the specimen with martensite was 2.17 cycles, and that of the specimen with granular bainite was 154. cycles under the strain amplitude of ± 0.4.%. The specimen with martensite had fewer crack initiation points, narrower fatigue striations separation, and larger volume fraction of high-angle grain boundaries than the latter. The fewer crack initiation points meant fewer fatigue cracks, the narrower fatigue striations separation meant slower crack propagation rate, and the larger volume fraction of high-angle grain boundaries could more effectively hinder fatigue crack propagation. Based on these facts, the fatigue life of the specimen with martensite was higher than that of the specimen with granular bainite.

关键词： Nuclear reactor pressure vessel SA508-Ⅳsteel Low cycle fatigue Crack initiation Crack propagation

Performance analysis and comparison of PoW,PoS and DAG based blockchains

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Digital Communications and Networks 2020年第4期6卷 480-485页

作者： bin Cao Zhenghui zhang Daquan {2. Shengli zhang Lei zhang Mugen Peng Yun Li The state key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing100876China The state key Laboratory of Integrated Services Networks(Xidian University) Xian710000China School of Communications and Information Engineering and Chongqing key Lab of Mobile Communications Technology Chongqing University of Posts and TelecommunicationsChongqing400065China The Guangdong key Laboratory of Intelligent Information Processing College of Electronic and Information EngineeringShenzhen UniversityShenzhen518060China College of Information Engineering Shenzhen UniversityShenzhen518060China School of Engineering University of GlasgowGlasgowG128QQUK

In the blockchain,the consensus mechanism plays a key role in maintaining the security and legitimation of contents recorded in the *** blockchain consensus mechanisms have been ***,there is no technical analysis and comparison as a guideline to determine which type of consensus mechanism should be adopted in a specific scenario/*** this end,this work investigates three mainstream consensus mechanisms in the blockchain,namely,Proof of Work(PoW),Proof of Stake(PoS),and Direct Acyclic Graph(DAG),and identifies their performances in terms of the average time to generate a new block,the confirmation delay,the Transaction Per Second(TPS)and the confirmation failure *** results show that the consensus process is affected by both network resource(computation power/coin age,buffer size)and network load *** addition,it shows that PoW and PoS are more sensitive to the change of network resource while DAG is more sensitive to network load conditions.

关键词： Blockchain Proof of work Proof of stake Direct acyclic graph Performance comparison

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换流站交流滤波支路断路器燃弧故障建模分析

中国电机工程学报 2018年第5期38卷 1496-1503页

作者：王宾魏向向张国辉温渤婴冯迎春董新洲电力系统及发电设备控制和仿真国家重点实验室(清华大学电机系) 北京市海淀区100084 中国农业大学信息与电气工程学院北京市海淀区100083 国网山东省电力公司电力科学研究院山东省济南市250000 国网山东省电力公司检修公司山东省济南市250118

换流站动态无功平衡需要频繁动作断路器投切滤波支路电容器组,投切容性负荷易诱发暂态过电压,近年来已发生多起断路器击穿爆炸恶性事故。现有模型无法准确模拟断路器投切容性负荷导致的击穿燃弧过程,针对该问题,分析现场实录故障数据,... 详细信息

换流站动态无功平衡需要频繁动作断路器投切滤波支路电容器组,投切容性负荷易诱发暂态过电压,近年来已发生多起断路器击穿爆炸恶性事故。现有模型无法准确模拟断路器投切容性负荷导致的击穿燃弧过程,针对该问题,分析现场实录故障数据,发现动态燃弧电阻是准确模拟的关键因素;针对传统时变电阻模型和Mayr电弧模型以工频熄弧原理为基础的局限性,将预燃弧阶段分为起弧阶段和不完全燃弧阶段,将全熄弧阶段分为准熄弧阶段和熄弧阶段,提出基于高频熄弧过程的二次动态燃弧模型。数值仿真与换流站实测波形对比,验证所提模型的正确性;并基于此模型,对断路器击穿燃弧电压、电流和电阻的动态特性进行分析,为后续换流站交流断路器燃弧故障的识别和预警提供基础。

关键词：换流站交流滤波器燃弧故障高频熄弧动态电弧模型

In-situ anion exchange based Bi_(2.S_(3)/OV-Bi_(2.MoO_(6)heterostructure for efficient ammonia production:A synchronized approach to strengthen NRR and OER reactions

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Journal of Materials Science & Technology 2022年第15期110卷 152-160页

作者： Yuanyuan zhang Li Guo Yingxian Wang Tianyu Wang Taoxia Ma Zhuangzhuang zhang Danjun Wang {2. Xu feng Fu Shaanxi key Laboratory of Chemical Reaction Engineering College of Chemistry&Chemical EngineeringYan’an UniversityYan’an 716000China key Laboratory of Synthetic and Natural Functional Molecule Chemistry College of Chemistry&Materials ScienceNorthwest UniversityXi’an 710127China state key Laboratory of Organic-Inorganic Composites Beijing Key Laboratory of Electrochemical Process and Technology for MaterialsBeijing University of Chemical TechnologyBeijing 100029China

Photocatalytic ammonia generation via nitrogen reduction reaction(NRR)is a green and prospective nitrogen fixation ***,NRR is often hampered by the high N_(2. adsorption/activation energies and is accompanied by a slow kinetics oxygen evolution reaction(OER).Herein,a robust Bi_(2.S_(3)/OVBi_(2.MoO_(6)S-scheme heterojunction is constructed using a simple in-situ anion exchange process,which enables oxygen vacancy(OVs)abundant Bi_(2.Mo O_(6) microspheres with surface deposited Bi_(2.S_(3).The asfabricated Bi_(2.S_(3)/OVBi_(2.MoO_(6) functioned as an effective photocatalyst to convert N_(2.-to-NH_(3) under mild *** photocatalytic NH_(3)/NH_(4.^(+) production rate reached 12.μmol g_(cat)^(-1)under visible light for2.5 h with 2.of Bi_(2.S_(3)/OVBi_(2.MoO_(6)photocatalyst,which was 8-fold higher than pristine Bi_(2.MoO_(6).Furthermore,the as-fabricated Bi_(2.S_(3)/Bi_(2.MoO_(6)heterojunction exhibited good selectivity,high stability and *** excellent photocatalytic NRR performance was ascribed to the Bi_(2.S_(3)/Bi_(2.MoO_(6)heterojunction formed subsequent to the strong interaction between Bi_(2.S_(3)and Bi_(2.MoO_(6).The OVs facilitated the chemical adsorption process allowing activation of N_(2.molecule on the Bi_(2.S_(3)/Bi_(2.MoO_(6).Simultaneously,the S-scheme heterojunction prolonged the lifetime of photogenerated carriers,accelerated the electrons/holes spatial separation and accumulation on the Bi_(2.S_(3)(reduction)and Bi_(2.MoO_(6)side(oxidation),respectively,thus strengthening both OER and NRR *** simple in-situ anion exchange method offers a novel technique for strengthening OER and NRR half-reactions in Bi-based photocatalysts for effective photocatalytic ammonia generation.

关键词： Anion exchange method Bi_(2.S_(3)/Bi_(2.MoO_(6)s-scheme heterojunction Nitrogen activation Photocatalytic ammonia generation

Plate-to-Layer Bi2.oO6/MXene-Heterostructured Anode for Lithium-Ion Batteries

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Nano-Micro Letters 2019年第4期11卷 439-452页

作者： Peng zhang Danjun Wang Qizhen Zhu Ning Sun feng Fu {2. Xu state key Laboratory of Organic-Inorganic Composites Beijing Key Laboratory of Electrochemical Process and Technology for MaterialsBeijing University of Chemical TechnologyBeijing 100029People’s Republic of China Shaanxi key Laboratory of Chemical Reaction Engineering School of Chemistry and Chemical EngineeringYan’an UniversityYan’an 716000People’s Republic of China

Bi2.oO6 is a potentially promising anode material for lithiumion batteries(LIBs)on account of its high theoretical capacity coupled with low desertion *** to low conductivity and large volume expansion/contraction during charge/discharge cycling of Bi2.oO6,effective modification is indispensable to address these *** this study,a plate-to-layer Bi2.oO6/Ti3C2.x(MXene)heterostructure is proposed by electrostatic assembling positive-charged Bi2.oO6 nanoplates on negative-charged MXene *** nanosheets in the heterostructure act as a highly conductive substrate to load and anchor the Bi2.oO6 nanoplates,so as to improve electronic conductivity and structural *** the mass ratio of MXene is optimized to 30%,the Bi2.oO6/MXene heterostructure exhibits high specific capacities of 692.mAh g?1 at 100 mA g?1 after 2.0 cycles and 54..1 mAh g?1 with 99.6%coulombic efficiency at 1 A g?1 after 1000 *** results provide not only a highperformance lithium storage material,but also an effective strategy that could address the intrinsic issues of various transition metal oxides by anchoring them on MXene nanosheets to form heterostructures and use as anode materials for LIBs.

关键词： Bi2.oO6 MXene Electrostatic self-assembly Heterostructure Lithium-ion batteries

Multifunctional Waterborne Polyurethane Nanocomposite Films with Remarkable Electromagnetic Interference Shielding,Electrothermal and Solarthermal Performances

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chinese Journal of Polymer Science 2023年第2期41卷 267-277页

作者： Ming-Ke Xu Xin-Jie Luo Hao-bin zhang Yu zhang Lulu Li Xin-feng Zhou Zhong-Zhen Yu beijing key Laboratory of Advanced Functional Polymer Composites Beijing University of Chemical TechnologyBeijing100029China state key Laboratory of Organic-Inorganic Composites College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing100029China

To impart polymers with high electrical conductivity and satisfactory electromagnetic interference shielding efficiency,it is crucial to efficiently construct interconnecting networks of conductive nanofillers in polymer ***,on the basis of the three-dimensional(3D)skeleton and volume-exclusion effect of silane-modified tetra-needle ZnO(ST-ZnO)whiskers and the high conductivity of two-dimensional MXene nanosheets,multifunctional MXene/ST-ZnO/waterborne polyurethane(MTW)nanocomposite films are fabricated by coating of MXene on ST-ZnO followed by compounding with waterborne *** 3D four-needles of the whiskers facilitate the formation of an interconnecting network in the waterborne polyurethane matrix,while the coating of MXene efficiently makes the interconnecting network of the whiskers conductive at a low amount of the *** resultant MTW ternary nanocomposite film exhibits not only a high electrical conductivity of 4.8×10^(4.S/m,but also an excellent electromagnetic interference shielding effectiveness of over 70 dB in the X-band at a low thickness of 100µ*** addition,the ternary film also exhibits outstanding Joule heating performances with an equilibrium temperature of 113℃at a low driving voltage of 3 *** multifunctional nanocomposite films are promising for applications in portable and wearable electronics and flexible electromagnetic interference shielding devices.

关键词： Electrical conductivity Electromagnetic interference shielding Nanocomposite films Waterborne polyurethane MXene nanosheets

Carboniferous and Permian integrative stratigraphy and timescale of North china Block

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Science china Earth sciences 2022年第6期65卷 983-1011页

作者： Boheng SHEN Shuzhong SHEN Qiong WU Shuichang zhang bin zhang Xiangdong WANG zhangshuai HOU Dongxun YUAN Yichun zhang feng LIU Jun LIU Hua zhang Yukun SHI Jun WANG Zhuo feng state key Laboratory for Mineral Deposits Research School of Earth Sciences and Engineering and Frontiers Science Center for Critical Earth Material CyclingNanjing UniversityNanjing 210023China Research institute of Petroleum Exploration and Development PetroChinaBeijing 100083China School of Resources and Geosciences China University of Mining and TechnologyXuzhou 221116China state key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and PaleoenvironmentChinese Academy of SciencesNanjing 210008China key Laboratory of Vertebrate Evolution and Human Origins of chinese academy of sciences Institute of Vertebrate Paleontology and Paleoanthropology and Center for Excellence in Life and PaleoenvironmentChinese Academy of SciencesBeijing 100044China institute of Palaeontology Yunnan UniversityKunming 650500China

The Carboniferous-Permian strata in the North china Block(NCB) contain abundant fossils, coals and natural *** a high-resolution timescale for the Carboniferous and Permian in the NCB is essential to understand the geologic events and explore the spatial and temporal distributions of the natural resources. The upper Carboniferous and the basal part of Permian are relatively well correlated because they yield marine conodont and fusuline fossils. However, the Permian terrestrial strata mostly rely on poorly constrained palynostratigraphy and phytostratigraphy and are short of the precise geochronologic constraints on the correlation with the marine strata. This study provides a critical review on the state-of-the-art of the latest Carboniferous and Permian chronostratigraphic and biostratigraphic frameworks and stratigraphic correlation in the NCB. The Penchi Formation ranges from lower Bashkirian to lower Gzhelian;the Taiyuan Formation is assigned to the upper Gzhelian to lower Asselian;the Shansi and Lower Shihhotse formations are from middle Asselian to lower Sakmarian;the Upper Shihhotse Formation is assigned to upper Artinskian to lower Kungurian, and the Sunjiagou Formation was assigned to Lopingian, respectively. A long hiatus up to ~2. Myr between the Upper Shihhotse and Sunjiagou formations, mainly marked by a large-scale erosional surface at the base of a coarse conglomeratic sandstone unit and/or multiple paleosol layers as well as significant differences of floras between these two lithostratigraphic units, is present probably due to tectonic uplift in association with the closure of the Paleo Asian Ocean(PAO) during the Cisuralian and Guadalupian. The possible amplitude of sea-level changes from Carboniferous to Permian on the NCB is estimated from 0 to 4. *** floral succession, depositional records and organic carbon isotope profiles suggest that the latest Carboniferous and earliest Permian was a favorable period for coal accumulation

关键词： North china Block Carboniferous-Permian Geochronology Biostratigraphy Correlation

X-ray irradiation-induced degradation in Hf_(0.5)Zr_(0.5)O_(2. fully depleted silicon-on-insulator n-type metal oxide semiconductor field-effect transistors

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Rare Metals 2021年第11期40卷 3299-3307页

作者： Yu-Dong Li Qing-Zhu zhang Fan-Yu Liu Zhao-Hao zhang {2.-Yuan zhang Hong-{4. Zhao Bo Li Jiang Yan key Laboratory of Microelectronics Devices and Integrated Technology Integrated Circuit Advanced Process Center(ICAC)Institute of MicroelectronicsChinese Academy of SciencesBeijing 100029China University of chinese academy of sciences Beijing 100049China state key Laboratory of Advanced Materials for Smart Sensing GRINM Group Co.LtdBeijing 100088China institute of Microelectronics Chinese Academy of SciencesBeijing 100029China School of Information Science and Technology North China University of TechnologyBeijing 100144China

The n-type ultrathin fully depleted silicon-on-insulator(FDSOI) metal-oxide-semiconductor field-effect transistors(MOSFETs),with a Hf_(0.5)Zr_(0.5)O_(2. high dielectric permittivity(high-k) dielectric as gate insulator,were *** total ionizing dose effects were investigated,and an X-ray radiation dose up to 1500 krad(Si) was applied for both long-and short-channel *** short-channel devices(0.02.-0.100 μm) exhibited less irradiation sensitivity compared with the long-channel devices(0.35-16 μm),leading to a 71% reduction in the irradiation-induced drain current growth and a 2.% decrease in the shift of the threshold *** was experimentally demonstrated that the OFF mode is the worst case among the three working conditions(OFF,ON and A110) for short-channel ***,the determined effective electron mobility was enhanced by 38% after X-ray irradiation,attributed to the different compensations for charges triggered by radiation between the highk dielectric and buried *** extracting the carrier mobility,gate length modulation,and source/drain(S/D)parasitic resistance,the degradation mechanism on X-ray irradiation was ***,the split capacitance-voltage measurements were used to validate the analysis.

关键词： Total ionizing dose Fully depleted silicon-on-insulator(FDSOI) Metal–oxide–semiconductor field-effect transistor(MOSFET) High-k Hf_(0.5)Zr_(0.5)O_(2.