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Evaluation and improvement of pearlite microstructure and mechanical properties in 45Cr4NiMoV and 50Cr5NiMoV steels

Journal of Iron and Steel Research International 2022年第12期29卷 1995-2005页

作者： Kai-quan Liu Xue-jiao Zhang Xiao-yang Song lin Zhao lin Zhu State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004HebeiChina Tianjin Heavy Industries Research&Development Co. Ltd.CFHITianjin 300457China China First Heavy Industry Qiqihar 161042HeilongjiangChina Central Iron and Steel Research Institute Co. Ltd.Beijing 100081China

The microstructure and mechanical properties of pearlite in 45Cr4NiMoV and 50Cr5NiMoV steels were studied and *** microstructural characteristics of pearlite of two steels were carefully examined by optical microscopy,scanning electron microscopy and transmission electron microscopy(TEM),and the type,size and relative amount of extracted carbide particles were analyzed by X-ray diffraction and TEM coupled with selected area electron *** hardness,tensile property,impact and fracture toughness of pearlite of two steels were also ***,the carbide dissolution kinetics of 45Cr4NiMoV and 50Cr5NiMoV steels were *** results indicated that the carbides in 50Cr5NiMoV steel exhibited higher dissolution temperature than those in 45Cr4NiMoV steel,which induced different morphologies of pearlite after eutectoid *** to the pearlite with lamellar M_(23)C_(6)carbides in 45Cr4NiMoV steel,the pearlite with the mixture of spheroidized M_(7)C_(3)and lamellar M_(23)C_(6)carbides in 50Cr5NiMoV steel possessed higher impact and plane-strain fracture toughness but lower hardness and strength,because different pearlite morphologies led to different mechanical *** order to further improve the comprehensive properties of the steels,the fraction of M_(7)C_(3)for the material with acceptable properties was examined and dissolution kinetic of M_(7)C_(3)was ***,the austenitizing temperature and holding time could be appropriately selected to keep enough undissolved M_(7)C_(3)in the steels.

关键词： Microstructure Carbide Back-up roll Mechanical property Toughness Spheroidization

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Beam-beam effects and mitigation in a future proton-proton collider

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Nuclear Science and Techniques 2022年第10期33卷 90-105页

作者： Li-jiao Wang Tanaji Sen Jing-Yu Tang lin-Hao Zhang Institute of High Energy Physics CASYuquan Road 19BBeijing 100049China University of Chinese Academy of Sciences CAS19A Yuquan RoadBeijing 100049China Spallation Neutron Source Science Center Dongguan 523803China Fermi National Accelerator Laboratory P.O.Box 500BataviaIL 60510USA

The beam-beam effects in a hadron collider with an unprecedented energy scale were *** effects are strongly related to the attainable luminosity of the ***-range interactions were identified as the major factor limiting the dynamic aperture,which is strongly dependent on the crossing angle,β*,and bunch *** mitigation methods of the beam-beam effects were addressed,with a focus on the compensation of long-range interactions by electric curren *** CEPC-SPPC project is a two-stage large circular collider,with a first-stage circular electron-positron collider(CEPC)and a second-stage super proton-proton collider(SPPC).The design of the SPPC aims to achieve a center-of-mass energy of 75 TeV and peak luminosity of approximately 1×10^(35) cm^(-2)s^(-1).We studied the beam-beam effects in the SPPC and tested the effectiveness of the mitigation *** found that with compensation using electric current wires,the dynamic aperture is at an acceptable ***,considering the significant emittance damping in this future proton-proton collider the beam-beam effects and compensation are more complicated and are studied using long-term *** was found that with a smaller emittance,the head-on interactions with a crossing angle become more prominent in reducing the beam stability,and combined head-on and long-range compensation is needed to improve the beam *** the reduction in population owing to burnoff was included,it was found that the coupling between the transverse and longitudinal planes at smaller emittance is the main driving source of the ***,crab cavities and emittance control are also necessary than just the compensation of the long-range interactions to improve the beam *** study serves as an example for studying the beam-beam effects in future proton-proton colliders.

关键词： Particle collider Beam-beam effects Luminosity Tune footprint Dynamic aperture

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Electrodeposition of rare refractory metals in low-temperature ionic liquids

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Rare Metals 2024年第10期43卷 4921-4933页

作者： lin-lin Wang Han-Dong jiao Rui Yuan Le-Yang Li Man-Peng lin Rui-Yang Sun Jiu-San Xiao Shu-Qiang jiao Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

Rare refractory metals(RRMs)play a significant role in fundamental industries,including electronics,chemical industry,machinery,etc.,and future advanced fields,such as aerospace and ***,the traditional production processes of RRMs based on high-temperature thermal reduction cannot meet the requirements of low-energy *** dilemma could be addressed efficiently by using a low-temperature electrodeposition strategy in ionic liquids(ILs).This review summarizes a panoramic view of the latest developments on the electrodeposition of RRMs in ILs after a brief review on the current industrial production methods of *** on this,the electrochemical mechanism occurring at the cathode during the electrodeposition process of RRMs in different electrolytes and under different conditions is thoroughly discussed,because it is crucial for the successful production of pure *** addition,this review not only analyses the main challenges that hinder the industrial application of the electrodeposition of RRMs in ILs,but also proposes corresponding *** hope this review can provide a valuable guidance for the fundamental research and industrial development of lowtemperature electrodeposition of RRMs.

关键词： Rare refractory metals Ionic liquids Electrodeposition Production process

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Modification of MgO·Al_2O_3 spinel inclusions in Al-killed steel by Ca-treatment

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International Journal of Minerals,Metallurgy and Materials 2011年第1期18卷 18-23页

作者： Shu-feng Yang Jing-she Li Zai-fei Wang jiao Li lin lin School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China

The modification of MgO·Al2O3 spinel inclusions in Al-killed steel by Ca-treatment has been studied by industrial trials and thermodynamic *** the industrial trials,samples were taken systematically during the refining process in which the molten steel was treated by calcium,and the characters of the inclusions were analyzed using scanning electron microscopy （SEM） and energy dispersive spectra （EDS）.The effects of Ca-treatment were evaluated by tracking the compositions of the *** results show that the modification of MgO·Al2O3 spinel inclusions by Ca-treatment is effective and the transformation sequence of the inclusions during the refining is Al2O3 →MgO·Al2O3 →liquid complex *** modification of spinel inclusions by Ca-treatment was calculated by FactSage 6.0 utilizing its free-energy minimization *** results of thermodynamic calculations indicate that spinel inclusions are easier to be modified than Al2O3 inclusions and the spinel inclusions in 30CrMo steel would transform to liquid complex inclusions when the content of dissolved Ca in the molten steel exceeds 1×***,the results show that adding more calcium into the molten steel would lower the contents of Al2O3 and MgO and increase the CaO content of the inclusions,while the change in SiO2 content is little.

关键词： steel metallurgy inclusions magnesia alumina chemical modification thermodynamics

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富血小板血浆联合脂肪干细胞移植加速伤口愈合的临床前研究:系统评价和Meta分析

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中国组织工程研究 2025年第13期29卷 2753-2763页

作者：蔺莉焦琳茜于芳宁马逸朝张博徐旭英首都医科大学附属北京中医医院北京市100010

目的:研究表明,富血小板血浆和脂肪来源干细胞的组合可加速皮肤损伤的愈合,但仍缺乏二者联合治疗的系统证据。该文评价两种干预措施在临床啮齿动物皮肤创伤模型中的联合疗效。方法:检索PubMed、Embase和Cochrane及CNKI数据库,选择各数... 详细信息

目的:研究表明,富血小板血浆和脂肪来源干细胞的组合可加速皮肤损伤的愈合,但仍缺乏二者联合治疗的系统证据。该文评价两种干预措施在临床啮齿动物皮肤创伤模型中的联合疗效。方法:检索PubMed、Embase和Cochrane及CNKI数据库,选择各数据库建库至2023年7月发表的富血小板血浆与脂肪干细胞移植联合使用以及单独使用于实验动物皮肤伤口的研究,以伤口愈合及伤口中转化生长因子β、CD31、Ⅰ型胶原蛋白和血管内皮生长因子为观察指标,使用RevMan 5.3和Stata 15.0软件对数据进行Meta分析。结果:共纳入12项研究,其中8项研究使用大鼠作为实验对象,4项研究使用小鼠作为实验对象,实验组采用富血小板血浆联合脂肪干细胞移植治疗,对照组采用单独的富血小板血浆治疗。Meta分析结果显示,实验组治疗后第3,7,10天的伤口愈合率均大于对照组[SMD=2.65,95%CI(1.29,4.01),Z=3.81,P=0.0001;SMD=3.38,95%CI(2.47,4.30),Z=7.24,P<0.00001;SMD=2.62,95%CI(1.50,3.73),Z=4.61,P<0.00001],实验组伤口愈合时间短于对照组[SMD=-2.12,95%CI(-3.5,-0.74),P=0.003],实验组伤口中的转化生长因子β表达、CD31阳性率、Ⅰ型胶原蛋白及血管内皮生长因子表达均高于对照组[SMD=5.65,95%CI(1.22,10.08),Z=2.50,P=0.01;SMD=2.49,95%CI(1.96,3.02),Z=9.28,P<0.00001;SMD=3.44,95%CI(0.72,6.17),Z=2.48,P=0.01;SMD=2.38,95%CI(0.97,3.79),Z=3.30,P=0.0010]。结论:研究结果表明,富血小板血浆与脂肪干细胞联合治疗可提高伤口愈合率、缩短伤口愈合时间,同时增加转化生长因子β、CD31、Ⅰ型胶原蛋白和血管内皮生长因子的表达,加速伤口愈合。由于模型的局限性,需要进行更多的动物实验和临床试验进行进一步证实。

关键词：富血小板血浆脂肪干细胞伤口愈合临床前研究荟萃分析系统评价

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Design and simulation of a tuning fork micromachined gyroscope with slide film damping

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光学精密工程 2005年第5期13卷 519-524页

作者： CHE Lu-feng XIONG Bin jiao Ji-wei WANG Yue-lin State Key Laboratory of Transducer Technology Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200050 China

A novel tuning fork micromachined gyroscope, based on slide-film damping, is presented. The electrostatic driving gyroscope consists of two driving masses each of which supports one sensitive mass. The angular rate is sensed by the differential capacitances consisted of movable bar electrodes and fixed bar electrodes located on the glass wafer. The gyroscope can operate at atmospheric pressure with slide film damping in the driving and sensing directions, eliminate vacuum packaging and restrain cross-axis acceleration signal. The results of design and simulation show that the driving and sensing mode frequencies are 3 106 Hz and 3 175 Hz,respectively, and the Q-values in driving and sensitive modes are 1 721 and 1 450 respectively. The design resolution is 0.025°/s.

关键词：等效电路模拟角度传感器微电子力学系统电路等效方程

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GTS40, an active fraction of Gou Teng-San (GTS), protects PC12 from H2O2-induced cell injury through antioxidative properties

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Chinese Journal of Natural Medicines 2017年第7期15卷 495-504页

作者： CHEN Lei WEI Meng-lin ZHAO jiao-jiao HONG Hao QU Wei FENG Feng LIU Wen-Yuan Department of Natural Medicinal Chemistry China Pharmaceutical University Nanjing 210009 China Department of Pharmaceutical Analysis China Pharmaceutical University Nanjing 210009 China Department of Pharmacology China Pharmaceutical University Nanjing 210009 China

Oxidative stress, a predominant cause of apoptosis cascades triggered in neurodegenerative disorders, has been regarded as a critical inducement in the pathogenesis of Alzheimer's disease(AD). Gou Teng-San(GTS) is a traditional Chinese herbs preparation commonly utilized to alleviate cognitive dysfunction and psychological symptoms of patients with dementia. The present study aimed to investigate the protective effects of GTS40, an active fraction of GTS, on H_2O_2-induced oxidative damage and identify the potential active ingredients. Our results revealed that GTS40 exhibited radical scavenging activity, elevated cell viability, decreased the levels of intracellular reactive oxygen species(ROS), and stabilized mitochondrial transmembrane potential(MMP) in H_2O_2-treated PC12 cells. In addition, GTS40 blocked the apoptotic cascade by reversing the imbalance of Bcl-2/Bax and inhibiting the activity of caspase-3. Furthermore, an HPLC-QTOFMS method was developed to characterize major chemical constituents in GTS40. Our results revealed twenty-seven identified or tentatively characterized compounds through comparing their retention time(t_R) and MS spectra with reference standards. These results suggested that GTS40 was a promising active fraction that may be beneficial in the prevention and treatment of oxidative stress-mediated neurodegenerative disorders.

关键词： GTS40 Oxidative stress Neuroprotective effects Apoptosis HPLC-QTOF-MS/MS

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Mineralogical characterization of airborne individual particulates in Beijing PM10

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Journal of Environmental Sciences 2006年第1期18卷 90-95页

作者： LU Sen-lin SHAO Long-yi WU Ming-hong jiao Zheng Shanghai Applied Radiation Institute School of Environmental and Chemical Engineering Shanghai University Shanghai 201800 China Department of Earth Science China University of Mining and Technology Beijing 100083 China

This work mainly focuses on the mineralogical study of particulate matter（PM10） in Beijing. Samples were collected on polycarbonate filter from April, 2002 to March, 2003 in Beijing urban area. Scanning electronic microscopy coupled with energy dispersive X-ray（SEM/EDX） was used to investigate individual mineral particles in Beijing PM10. 1454 individual mineral particulates from 48 samples were analysed by SEM/EDX. The results revealed that mineral particulates were complex and heterogeneous. 38 kinds of minerals in PM10 were identified. The clay minerals, of annual average percentage of 30.1%, were the main composition among the identified minerals, and illite/smectite was the main composition in clay minerals, reaching up to 35%. Annual average percentage of quartz, calcite, compound particulates, carbonates were 13.5%, 10.9%, 11.95%, 10.31%, respectively. Annual average percentage less than 10% were gypsum, feldspar, dolomite, and so on. Fluorite, apatite, halite, barite and chloridize zinc（ZnCl2） were firstly identified in Beijing PM10. Sulfurization was found on surface of mineral particles, suggested extensive atmospheric reaction in air during summer.

关键词： inhalable particulate matter(PM10) individual analysis mineral composition

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Kinetic Energy of Trapped Ions Cooled by Buffer Gas

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Chinese Physics Letters 2010年第6期27卷 82-84页

作者： CHEN Liang SHE Lei LI jiao-Mei GAO Ke-lin State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan 430071 Center for Cold Atom Physics Chinese Academy of Sciences Wuhan 430071 Graduate School of the Chinese Academy of Sciences Beijing 100049

The average kinetic energy of 40 Ca＋ ions is measured by the method of evaporating ions in an rf ion trap. The kinetic energy of the ion 40Ca＋ varies from 0.5eV to 0.2eV with changing buffer gas pressure from 10^-7 mbar to 10^-5 mbar. The Brownian motion model is also introduced to calculate the average kinetic energy of the trapped ions.

关键词： STOPPING power (Nuclear physics) ION traps CALCIUM ions EVAPORATION (Chemistry) VAPOR pressure BROWNIAN motion processes

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Differential Analysis of ARX Block Ciphers Based on an Improved Genetic Algorithm

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Chinese Journal of Electronics 2023年第2期32卷 225-236页

作者： KANG Man LI Yongqiang jiao lin WANG Mingsheng State Key Laboratory of Information Security Institute of Information EngineeringChinese Academy of Sciences School of Cyber Security University of Chinese Academy of Sciences State Key Laboratory of Cryptology

Differential cryptanalysis is one of the most critical analysis methods to evaluate the security strength of cryptographic algorithms. This paper first applies the genetic algorithm to search for differential characteristics in differential cryptanalysis. A new algorithm is proposed as the fitness function to generate a high-probability differential characteristic from a given input difference. Based on the differential of the differential characteristic found by genetic algorithm, Boolean satisfiability(SAT) is used to search all its differential characteristics to calculate the exact differential probability. In addition,a penalty-like function is also proposed to guide the search direction for the application of the stochastic algorithm to differential cryptanalysis. Our new automated cryptanalysis method is applied to SPECK32 and SPECK48. As a result, the 10-round differential probability of SPECK32 is improved to 2-30.34, and a 12-round differential of SPECK48 with differential probability2-46.78is achieved. Furthermore, the corresponding differential attacks are also performed. The experimental results show our method’s validity and outstanding performance in differential cryptanalysis.

关键词： Ciphers Technological innovation Probability Genetic algorithms

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