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Fracture behavior and mechanism of highly fragmented steel cylindrical shell under explosive loading

Defence Technology（防务技术） 2024年第6期36卷 122-132页

作者： kang Wang Peng Chen Xingyun Sun Yufeng Liu Jiayu Meng xiaoyuan Li Xiongwei zheng Chuan xiao Xi'an Modern Chemistry Research Institute Xi'an 710065China Shanxi Jiangyang Chemical Company Limited Taiyuan 030051China Central Iron&Steel Research Institute Company Limited Beijing 100081China China Research and Development Academy of Machinery Equipment Beijing 100089China

An in-depth understanding of the fracture behavior and mechanism of metallic shells under internal explosive loading can help develop material designs for warheads and regulate the quantity and mass distribution of the fragments *** study investigated the fragmentation performance of a new high-carbon silicon-manganese(HCSiMn)steel cylindrical shell through fragment recovery *** with the conventional 45Cr steel shell,the number of small mass fragments produced by the HCSi Mn steel shell was significantly increased with a scale parameter of 0.57 g fitted by the Weibull distribution *** fragmentation process of the HCSi Mn shell exhibited more brittle tensile fracture characteristics,with the microcrack damage zone on the outer surface being the direct cause of its high *** the one hand,the doping of alloy elements resulted in grain refinement by forming metallographic structure of tempered sorbite,so that microscopic intergranular fracture reduces the characteristic mass of the fragments;on the other hand,the distribution of alloy carbides can exert a"pinning"effect on the substrate grains,causing more initial cracks to form and propagate along the brittle carbides,further improving the shell *** the killing power radius for light armored vehicles was slightly reduced by about 6%,the dense killing radius of HCSiMn steel projectile against personnel can be significantly increased by about 26%based on theoretical *** results provided an experimental basis for high fragmentation warhead design,and to some extent,revealed the correlation mechanism between metallographic structure and shell fragmentation.

关键词： Projectile fragmentation Fragment mass distribution Fracture mode Metallographic structure Damage power

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Crystallographic texture and earing behavior analysis for different second cold reductions of double-reduction tinplate

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International Journal of Minerals,Metallurgy and Materials 2018年第6期25卷 652-662页

作者： Lu-hai Liao xiao-fei zheng Yong-lin kang Wei Liu Yan Yan Zhi-ying Mo School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Shougang Jingtang United Iron and Steel Co. Ltd. Tangshan 063200 China

Since the production of tinplate with non-earing properties is difficult, especially when it is produced via the double-reduction process, the optimal degree of second cold reduction is particularly important for achieving desirable drawing properties. The evolution of texture and the earing propensity of double-reduction tinplate with different extents of second reduction were investigated in this study. Optical microscopy and scanning electron microscopy were used to observe the changes in the microstructure at various extents of reduction. Two common testing methods, X-ray diffraction（XRD） and electron backscatter diffraction, were used to investigate the texture of the specimens, which revealed the effects of deformation percentage on the final texture development and the change in the grain boundary. The earing rate was determined via earing tests involving measurement of the height of any ear. The results obtained from both XRD analyses and earing tests revealed the same ideal value for the second cold reduction on the basis of the relationship between crystallographic texture and the degree of earing.

关键词： double reduced tinplate crystallographic texture earing second cold reduction

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Deciphering fungal metabolon coupling tandem inverse-electrondemand Diels-Alder reaction and semipinacol rearrangement for the biosynthesis of spiro polycyclic alkaloids

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Science China Chemistry 2025年第01期 288-296页

作者： Shuai Liu Wen-Qiang Xu Ying-Tong Di Man-Cheng Tang Ding-kang Chen Ming-Ming Cao Yao-Wen Chang Hong-Yu Tang Chun-Mao Yuan Jun-Bo Yang Zhi-Li Zuo Han Guo Zi-Fei Xu Ying Zeng Yun-Dong Wu xiao-Jiang Hao Key Laboratory of Phytochemistry and Natural Medicines (Chinese Academy of Sciences) Kunming Institute of Botany Chinese Academy of Sciences University of Chinese Academy of Sciences Lab of Computational Chemistry and Drug Design State Key Laboratory of Chemical Oncogenomics Peking University Shenzhen Graduate School Shenzhen Bay Laboratory State Key Laboratory of Microbial Metabolism School of Life Sciences & Biotechnology Shanghai Jiao Tong University State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical University Molecular Biology Experimental Center Germplasm Bank of Wild Species in Southwest China Kunming Institute of Botany Chinese Academy of Sciences Yunnan Key Laboratory for Wild Plant Resources Kunming Institute of Botany Chinese Academy of Sciences Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical Sciences

In the intricate process of natural product biosynthesis, a metabolon can enhance metabolic flux by associating sequential enzymes. A fungal metabolon, comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G, is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B. Using notoamide E as a substance, Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation, followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium unit. Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement. This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.

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An improved installation of 2-hydroxy-4-methoxybenzyl(iHmb)method for chemical protein synthesis

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Chinese Chemical Letters 2024年第5期35卷 145-150页

作者： Ying Li Long-Jie Wang Yong-kang Zhou Jun Liang Bin xiao Ji-Shen zheng The First Affiliated Hospital of USTC MOE Key Laboratory for Membraneless Organelles and Cellular DynamicsDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230001China Department of Chemistry University of Science and Technology of ChinaHefei 230027China

The 2-hydroxy-4-methoxybenzyl(Hmb)backbone modification can prevent amide bond-mediated sidereactions(e.g.,aspartimide formation,peptide aggregation)by installing the removable Hmb group into a peptide bond,thus improving the synthesis of long and challenging peptides and ***,its use is largely precluded by the limited Hmb’s installation *** this report,an improved installation of Hmb(iHmb)method was developed to achieve the flexible installation and the convenient removal of *** iHmb method involves two critical steps:(1)oxidative diazotization of the readily installed 2-hydroxy-4-methoxy-5-amino-benzyl(Hmab)to give 2-hydroxy-4-methoxy-5-diazonium-benzyl(Hmdab)by combining soamyl nitrite(IAN)/HBF_(4),and(2)reductive elimination of Hmdab to give the desired Hmb by 1,2-ethanedithiol(EDT).The iHmb method enables the installation of Hmb at any primary amino acid including the highly sterically hindered amino acids(e.g.,valine and isoleucine).The practicality and utility of the iHmb method was demonstrated by one-shot solid-phase synthesis of a challenging aspartimide-prone peptide,the mirror-image version of a hydrophobic peptide and a long-chain peptide up to ***,the iHmb method can be utilized to facilitate chemical protein ligation,as exemplified by the synthesis of the single-spanning membrane protein *** iHmb method expands the toolkit for peptide synthesis and ligation and facilitates the preparation of peptides/proteins.

关键词： Chemical protein synthesis Solid-phase peptide synthesis Removable backbone modification 2-Hydroxy-4-methoxybenzyl(Hmb)group Aspartimide-prone peptides Difficult peptides Membrane proteins

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Effect of Cooling Start Temperature on Microstructure and Mechanical Properties of X80 High Deformability Pipeline Steel

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Journal of Iron and Steel Research International 2011年第10期18卷 42-46,71页

作者： zheng xiao-fei kang Yong-lin MENG De-liang AN Shou-yong XIA Dian-xiu School of Materials Science and Engineering State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China Jinan Iron and Steel Group Corp Jinan 250101 Shandong China

The effect of cooling （laminar cooling） start temperature on the phase constitution was analyzed by quanti- tative metallography. The martensite/austenite （M/A） island distribution was fixed by colour metallography. The strength and uniform elongation of the steels were tested with quasi-static tensile testing machine. The in-coordinate deformation of the soft and hard phases was analyzed using FEM. The results indicate that when the cooling start temperature is 690 ℃, the mechanical properties are the best, meeting the requirements of X80 high deformability pipeline steel.

关键词： high deformability pipeline steel cooling start temperature carbon diffusion in-coordinate deformationsM/A island

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A combined geophysical and lithological study on eruptive history and Quaternary lacustrine stratigraphy of a maar in Leizhou Peninsula, China

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Journal of Palaeogeography 2021年第1期10卷 98-111页

作者： Cong Chen Zhuo zheng Li-Feng Zeng Fan xiao Li-Ping Tian kang-You Huang Guangdong Provincial Key Lab of Geodynamics and Geohazards School of Earth Sciences and EngineeringSun Yat-sen UniversityGuangzhou 510275Guangdong ProvinceChina Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082Guangdong ProvinceChina

As the second common type of volcanic vent on Earth, maar-diatreme volcanoes and their post-eruptive lacustrine sediments are a main focus of volcanology, palaeolimnology, palaeoclimatology and palaeontology. A number of maar-type volcanoes have been found in Leizhou Peninsula, South China, but little is known about their eruption processes and detailed stratigraphy of the post-eruptive sediments. We present a combined geophysical and geological analysis to study the eruptive history and post-eruptive sediment stratigraphy of a large maar, the elliptical(1.8 × 3.0 km^(2)) Jiudouyang(JDY) maar. The lacustrine stratigraphy revealed by drilling cores shows that the JDY maar lake has three major stages of evolution:(i) deep-lake sedimentary environment characterized by high autochthonous diatom productivity;(ii) shallow lake to swamp with very low water levels, characterized by a high total organic carbon(TOC) and abundant wood fragments;and,(iii) intermittent shallow lake and alluvial deposits composed of clay minerals and sand. The electrical resistivity tomography(ERT) values and lithological features are highly consistent, which clearly reveal the presence of ca. 50 m thick lacustrine sediments, directly underlain by a ca. 70 m thick basaltic lava rather than diatreme breccia in the crater. This infill sequence implies an alternation of eruption style from phreatomagmatic to Strombolian and/or lava flow, due to high magma flux and ascent rate of the Hainan Plume during the middle Pleistocene. The ERT data also reveal the initial phreatomagmatic crater floor at ca. 120 m depth. The initial crater had a large diameter/depth ratio(ca. 17), with an elongated shape(major axis to minor axis = 0.6), implying possible lateral vent migration during the eruption. A significant erosion under tropical weathering condition during the last few hundred thousand years, accounted for the large size of the maar crater. The study provides insights into the eruptive history and post-er

关键词： Maar crater Eruptive history Infill sequence Lake evolution Lacustrine stratigraphy Leizhou Peninsula

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Self-Powered Absorptive Reconfigurable Intelligent Surfaces for Securing Satellite-Terrestrial Integrated Networks

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China Communications 2024年第9期21卷 276-291页

作者： Lin Zhi Niu Hehao He Yuanzhi An kang Zhong Xudong Chu zheng xiao Pei College of Electronic Engineering National University of Defense TechnologyHefei 230037China Sixty-Third Research Institute National University of Defense TechnologyNanjing 210007China Institute of Systems Engineering Academy of Military ScienceBeijing 100141China Department of Electrical and Electronic Engineering University of Nottingham Ningbo ChinaNingbo 315100China Institute for Communication Systems University of SurreyGuildford GU27XHU.K.

Satellite communications have attracted significant interests due to its advantages of large footprint and massive ***,the commonly used onboard beamforming is hard to achieve reliable security because of the highly correlated legitimate and wiretap downlink *** exploit the benefits of satellite-terrestrial integrated network(STIN)and a novel absorptive reconfigurable intelligent surface(RIS)for improving the security of satellite downlink communications(SDC)in the presence of eavesdroppers(Eves).This paper aims to maximize the achievable secrecy rate of the earth station(ES)while satisfying the signal reception constraints,harvested power threshold at the RIS,and total transmit power *** solve this nonconvex problem,we propose a penalty-function based dual decomposition scheme,which firstly transforms the original problem into a two-layer optimization ***,the outer layer and inner problems are solved by utilizing the successive convex approximation,Lagrange-dual and Rayleigh quotient methods to obtain the beamforming weight vectors and the reflective coefficient ***,simulation results verify the effectiveness of the proposed scheme for enhancing the SDC security.

关键词： absorptive RIS beamforming design secure communications STIN

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贻贝肽对厚壳贻贝稚贝生长发育及微生物群落结构的影响

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渔业科学进展 2025年第1期46卷 115-126页

作者：林倩李政杨金龙马蕃梁箫上海海洋大学水产与生命学院科技部海洋生物科学国际联合研究中心上海201306 上海市水产动物良种创制与绿色养殖协同创新中心上海201306 中国-葡萄牙星海“一带一路”联合实验室上海200120

为探究海洋生物活性肽对厚壳贻贝(Mytilus coruscus)生长发育的影响,本研究以厚壳贻贝稚贝为实验对象,通过投喂不同浓度的贻贝肽(0、7、9、10、70和90 mg/L),测定壳长、壳高、湿重等指标,以确定最适贻贝肽浓度,并对投喂前后的稚贝微生... 详细信息

为探究海洋生物活性肽对厚壳贻贝(Mytilus coruscus)生长发育的影响,本研究以厚壳贻贝稚贝为实验对象,通过投喂不同浓度的贻贝肽(0、7、9、10、70和90 mg/L),测定壳长、壳高、湿重等指标,以确定最适贻贝肽浓度,并对投喂前后的稚贝微生物群落进行分析,实验周期为56 d。结果显示,相较于未投喂贻贝肽的对照组,投喂9 mg/L的贻贝肽显著促进稚贝生长,且壳长、壳高和湿重分别提升了27.37%、32.35%和115.49%;同时发现,高浓度贻贝肽(70 mg/L和90 mg/L)对厚壳贻贝稚贝产生了致死效应。通过16S rRNA基因扩增和测序对比分析了28 d和56 d贻贝肽投喂组与未投喂组的厚壳贻贝稚贝微生物组群落结构变化。研究结果显示,投喂9 mg/L贻贝肽改变了稚贝微生物群落结构组成,提高了拟杆菌门(Bacteroidota)和变形菌门(Proteobacteria)的丰度,降低了放线菌门(Actinobacteriota)的丰度;同时,属水平分析发现,贻贝肽投喂组有效增加了鲁杰氏菌属(Ruegeria)、黏着杆菌属(Tenacibaculum)、居海杆菌属(Maribacter)、栖砂杆菌属(Arenibacter)、十八碳杆菌属(Octadecabacter)和希瓦氏菌属(Shewanella)等有益菌的物种丰度,显著减少了红球菌属(Rhodococcus)、气单胞菌属(Aeromonas)等潜在致病菌的丰度。综上,贻贝肽能有效促进厚壳贻贝的稚贝生长发育,并且可以优化厚壳贻贝微生物群落结构,研究成果将为后续开展贻贝肽等海洋生物活性肽对贝类稚贝中间培育以及海水贝类养殖可持续发展提供基础和数据支撑。

关键词：厚壳贻贝生长微生物群落结构贻贝肽

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磁共振扫描对经直肠超声引导前列腺穿刺活检的影响

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天津医科大学学报 2017年第2期23卷 99-102页

作者：张一然潘盼连振鹏郑小康刘冉录天津医科大学第二医院泌尿外科天津市泌尿外科研究所天津300211

目的:研究前列腺穿刺前行磁共振(MRI)扫描对结果的影响,并分析其对于前列腺癌(PCa)诊断的帮助。方法:回顾性选取行经直肠超声引导前列腺穿刺的住院患者,按照穿刺前是否行MRI扫描分为两组,调查其病理结果、穿刺针数、前列腺特异性抗原(P... 详细信息

目的:研究前列腺穿刺前行磁共振(MRI)扫描对结果的影响,并分析其对于前列腺癌(PCa)诊断的帮助。方法:回顾性选取行经直肠超声引导前列腺穿刺的住院患者,按照穿刺前是否行MRI扫描分为两组,调查其病理结果、穿刺针数、前列腺特异性抗原(PSA)、前列腺体积(PV)等,对确诊PCa患者,统计其阳性针数占比、Gleason评分、局部侵犯神经和骨转移情况。使用统计学方法分析MRI扫描对穿刺的影响。结果:共372例患者纳入统计,其中行MRI患者255例,未行MRI患者117例。MRI组患者穿刺阳性率(52.2%vs41.0%,P=0.046)、高危患者比例(78.9%vs64.6%,P=0.049)、阳性针数占比(69.9%vs54.2%,P=0.048)均高于Non-MRI组。年龄(P=0.116)、PSA(P=0.078)、f/t PSA(P=0.329)、PV(P=0.291)、PSAD(P=0.302)之间均无组间差异,在穿刺针数(P=0.001)、阳性针数占比(P=0.039)中存在统计学差异。结论:前列腺穿刺作为PCa术前确诊最重要的技术手段,有必要在前列腺穿刺前为所有可疑患者行MRI检查,在此基础上增加穿刺针数,以获得更高的穿刺效率。

关键词：前列腺穿刺磁共振前列腺癌

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Sand particle dislodgement in windblown sand

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Acta Mechanica Sinica 2014年第6期30卷 910-916页

作者： Tian-Li Bo zheng Li xiao-Jing zheng Key Laboratory of Mechanics on Western Disaster and Environment Lanzhou University Department of Mechanics Lanzhou University School of Electronical and Machanical Engineering Xidian University

The incipient motion of sand particle from sand bed plays a very important role in the prediction of windblown *** this paper,we proposed a new method for predicting the incipient motion of sand particle based on wind speed fluctuation as follows,when the wind speed is larger than the critical wind speed,if the total impulse on sand particle is larger than the critical impulse,incipient motion of sand particle would take place,otherwise if ***,from the analysis of entrainment in the rolling and lifting modes,we come to the following *** the average wind speed is smaller than the critical wind speed,if the average wind speed is used to judge the incipient motion of sand particle,one will underestimate the number of sand particles jumping from the bed,if the instantaneous wind speed is used to judge incipient motion of sand particle,one will overestimate the number of sand particles jumping from the bed;When the average wind speed is larger than the critical wind speed,either the average or the instantaneous wind speeds is used to judge the incipientmotion of sand particles,one will overestimate the number of sand particles jumping from the bed.

关键词： Incipient motion Rolling mode Average wind speed Total impulse Windblown sand

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