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High-resolution dipole ( e, e ) study for optical oscillator strengths of valence shell excitation of nitrogen

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Chinese Science Bulletin 1997年第17期42卷 1426-1429页

作者： Zhang, XJ Feng, RF Zhong, Zp ji, q Zhu, LF Wu, SL Xu, KZ Department of Modern physics Univ. of Sci. and Technol. of China Hefei 230027 China

NITROGEN is the most abundant element in the earth’s atmosphere. The study of optical oscillator strengths of nitrogen is of great significance in atmosphere physics, space physics and environment science. These results are also used in many fields, such as fusion plasma and developments of the nitrogen laser. As we know, calculation of absolute optical oscillator strengths of molecular nitrogen are still at the level of electronic rather than vibronic states resolved.

关键词： nitrogen optical oscillator strength high-resolution dipole (e e) method electron energy-loss spectrum.

淬火-配分处理对30CrMnSiA钢冲击韧性的影响

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材料科学与工艺 2024年第3期32卷 18-28页

作者：冀宣名王礼榕杨明王攀智贵州大学材料与冶金学院贵阳550025 高性能金属结构材料与制造技术国家地方联合工程实验室贵阳550025 贵州航宇科技发展股份有限公司贵阳550081

淬火-配分(quenching and partitioning,q&p)钢由于具有优异的综合性能而备受关注。本文设计了一步等温和二步等温处理工艺,通过改变淬火温度和等温温度获得了不同含量一次马氏体(pM)、残余奥氏体(RA)、二次马氏体(FM)及贝氏体(BF)的多... 详细信息

淬火-配分(quenching and partitioning,q&p)钢由于具有优异的综合性能而备受关注。本文设计了一步等温和二步等温处理工艺,通过改变淬火温度和等温温度获得了不同含量一次马氏体(pM)、残余奥氏体(RA)、二次马氏体(FM)及贝氏体(BF)的多相微观结构。采用XRD、EBSD综合分析了淬火配分处理对马氏体/贝氏体形态、位错密度、体积含量、变体选择行为以及冲击韧性的影响。示波冲击试验结果表明:330℃是一步淬火配分和二步淬火配分处理的最佳淬火温度,该温度能够获得最佳的冲击韧性。与一步淬火配分处理比较,二步淬火配分处理可以提高复相组织中的RA含量,并降低FM含量。最优的淬火温度和配分温度有利于降低马氏体/贝氏体(M/B)中的位错密度、增加RA和大角度晶界(HAGB)体积含量,从而显著改善q&p钢的冲击韧性。

关键词：复相组织一步淬火配分(Oq&p) 两步淬火配分(Tq&p) 冲击韧性大角度界面

The effect of Co and Cr substitutions for Ni on mechanical properties and plastic deformation mechanism of FeMnCoCrNi high entropy alloys

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Journal of Materials Science & Technology 2020年第13期47卷 146-155页

作者： H.F.Zhang H.L.Yan H.Yu Z.W.ji q.M.Hu N.jia Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Material Science and EngineeringNortheastern UniversityShenyang 110819China State Key Lab Rolling&Automat Northeastern UniversityShenyang 110819China Institute of Metal Research Chinese Academy of ScienceShenyang 110016China Shen Yang University of Technology Shenyang 110870China Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China

The elastic constants,ideal tensile strength(ITS),stacking fault energy(SFE),lattice constant and magnetic moment of FeMnCoCrNi high entropy alloys with varying Co and Cr contents at 0 and 300 K were systematically investigated by first-principle *** the alloys with Co substitution for Ni,at both temperatures the elastic stability of the face-centered cubic(fcc)phase,bulk elastic modulus(B),Young’s modulus(E),shear modulus(G)and ITS increase monotonically with increasing Co ***,the Cauchy pressure(Cp),pugh ratio(B/G),poisson ratio(v),Zener anisotropy ratio(AZ)and elastic anisotropy ratio(AVR)decrease *** SFE also decreases with the increase of Co,resulting in the change of plastic deformation mechanism from dislocation slip to mechanical twinning,and then to hcp-martensitic *** elucidates the underlying mechanism of the effect of Co addition on the strength and micromechanical behavior of FeMnCoCrNi *** with Co,the Cr substitution for Ni leads to the more complex change of elastic constants and *** increase of Cr shows the similar effect on SFE and deformation mechanism as that of *** variation of valence electron concentration and magnetism affect the *** increase of either Co or Cr leads to the reduced magnetic moments of Fe and *** could be responsible for the monotonic decrease of both lattice constant and SFE as the Co content ***,for the Cr addition case,multiple factors may affect the evolution of lattice constant and *** findings shed light on the deformation mechanism of the alloys with different compositions.

关键词： High entropy alloys First-principle calculations Elastic constants Ideal tensile strength Stacking fault energy

Strong, lightweight, and highly conductive CNT/Au/Cu wires from sputtering and electroplating methods

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Journal of Materials Science & Technology 2020年第5期40卷 99-106页

作者： Thang q.Tran Jeremy Kong Yoong Lee Amutha Chinnappan W.A.D.M.Jayathilaka Dongxiao ji Vishnu Vijay Kumar Seeram Ramakrishna Department of Mechanical Engineering National University of Singapore9 Engineering Drive 1EA-07-05Singapore 117575Singapore

In this study, we present a 2-step deposition method via sputtering and electroplating that uses carbon nanotube(CNT) wires synthesized from a wet-spinning technique to produce high-performance CNT/Au/Cu composite wires. After the Au sputtering pre-treatment, the deposition of Cu on the CNT wires was found to be much more homogeneous due to improved wettability and reactivity of the wire surface. At different electrodeposition time, the mechanical strength of the CNT/Au/Cu composite wires could be as high as 0.74 Gpa(~2 times stronger than metal wires) while their electrical conductivity could reach 4.65 × 10~5 S/cm(~80% of that for copper). More importantly, the CNT/Au/Cu composite wires with high CNT volume fraction are expected to be lightweight(up to 42% lower than Cu mass density), suggesting that our high-performance composite wires are a promising candidate to substitute conventional heavy metal wires in the future applications.

关键词： Carbon nanotube wires Sputtering Electrical conductivity Electrodeposition

基于pLUS-InVEST模型的酒泉市生态系统碳储量时空演变与预测

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环境科学 2024年第1期45卷 300-313页

作者：石晶石培基王梓洋程番苑西北师范大学地理与环境科学学院兰州730070 甘肃省土地利用与综合整治工程研究中心兰州730070

基于“双碳”战略背景探讨西北干旱区土地利用变化对碳储量的影响及碳储量空间分异驱动因素,对提高区域生态系统碳汇增量和促进区域碳收支平衡具有重要意义.中国西北干旱区为自然生态极端脆弱区,随着新型城镇化快速推进,土地利用变化速... 详细信息

基于“双碳”战略背景探讨西北干旱区土地利用变化对碳储量的影响及碳储量空间分异驱动因素,对提高区域生态系统碳汇增量和促进区域碳收支平衡具有重要意义.中国西北干旱区为自然生态极端脆弱区,随着新型城镇化快速推进,土地利用变化速率明显加快并对生态系统碳储量及固持能力产生一定影响.运用pLUS-InVEST模型模拟了酒泉市2035年自然发展、集约发展、水资源约束和生态保护情景下碳储量的时空演变特征,并采用参数最优地理探测器模型分析了碳储量空间分异驱动力.结果表明:①1990~2020年酒泉市耕地、水域和建设用地面积呈显著增加趋势,其余土地利用类型面积呈减小趋势.②1990~2020年酒泉市碳储量从7722808.1 t增至7784371 t,草地转换成未利用地是造成区域碳储量损失的主要原因,占损失总量的85%.③2035年4种发展情景的碳储量均为增加趋势,其中生态保护情景增幅最为显著,增量为76989.29 t.④土地利用程度、人口密度、GDp密度和NDVI是酒泉市碳储量空间分异的主要驱动因子,其中土地利用程度解释力最强(q值为0.849),自然与人为因子的交互作用增强了各因子对碳储量空间分异的解释力.研究结果可为酒泉市生态系统综合管理及国土空间优化提供科学基础和决策依据.

关键词：碳储量 InVEST模型 pLUS模型参数最优地理探测器酒泉市

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血脂参数及脂质比值与糖代谢异常的关联研究

现代预防医学 2024年第14期51卷 2628-2633页

作者：计叶徐文超江阴市疾病预防控制中心慢非传科江苏省现场流行病学培训项目常州市疾病预防控制中心慢非传科

目的探索血脂参数、脂质比值与糖代谢异常的关联性以及脂质比值与糖代谢异常的剂量反应关系。方法选取2022年7月至2023年3月，35岁及以上的常州市常住居民7 527人作为研究对象，收集其基本信息、血压、空腹血糖、血脂四项等资料，采用... 详细信息

目的探索血脂参数、脂质比值与糖代谢异常的关联性以及脂质比值与糖代谢异常的剂量反应关系。方法选取2022年7月至2023年3月，35岁及以上的常州市常住居民7 527人作为研究对象，收集其基本信息、血压、空腹血糖、血脂四项等资料，采用logistic回归探索影响糖尿病前期、糖尿病与血脂参数、脂质比值的关联强度，采用三次立方样条函数来分析脂质比值与糖代谢异常潜在的剂量反应关系。结果本研究发现TC、LDL-C、TC/HDL-C、TG/HDL-C、LDL-C/HDL-C、non-HDL-C/HDL-C升高是糖尿病前期和糖尿病的危险因素(pp<0.05)。TC/HDL-C、TG/HDL-C、LDL-C/HDL-C、non-HDL-C/HDL-C与糖代谢异常之间存在剂量反应关系，截断值分别为3.78、1.07、2.10、2.77。结论 TC/HDL-C、TG/HDL-C、LDL-C/HDL-C、non-HDL-C/HDL-C升高会增加糖尿病前期和糖尿病的患病风险，对糖代谢异常有预测作用。

关键词：糖尿病前期糖尿病血脂脂质比值

基于TNFR/RIpK1通路探索紫草素对大鼠脊髓损伤的作用及机制

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中国骨伤 2024年第1期37卷 61-68页

作者：史吉胜钱吉泽王金广林斌庞同涛山东大学齐鲁医院德州医院骨科山东德州253600 中国人民解放军第909医院骨科福建漳州363000

目的:初步探讨紫草素对大鼠急性脊髓损伤(spinal cord injury,SCI)后神经功能恢复的影响及作用机制。方法:将96只Sprague-Dawley(SD)雄性大鼠分为4组:假手术组,即A组;假手术+紫草素组,即B组;脊髓损伤+二甲基亚砜(dimethyl sulfoxide,DM... 详细信息

目的:初步探讨紫草素对大鼠急性脊髓损伤(spinal cord injury,SCI)后神经功能恢复的影响及作用机制。方法:将96只Sprague-Dawley(SD)雄性大鼠分为4组:假手术组,即A组;假手术+紫草素组,即B组;脊髓损伤+二甲基亚砜(dimethyl sulfoxide,DMSO)组,即C组;脊髓损伤+紫草素组,即D组;每组24只。C、D组采用钳夹法制作大鼠急性SCI模型。所有大鼠硬膜下置管,A组不给药,B组和D组造模后30 min经导管注射紫草素100 mg·kg^(-1),C组注射等量DMSO,每日1次,至取材时间点。各组分别于造模后6、12 h和3 d每组取8只大鼠,行Basso-Beattie-Bresnahan(BBB)评分及造模后1、3、7、14、21d行斜板实验,再处死动物取脊髓组织。造模后1h每组大鼠腹腔注射碘化丙啶(propidine iodide,pI)1 mg·kg^(-1),术后24 h取材检测脊髓组织pI红染细胞数;24 h时取材采用苏木素-伊红(haematoxylin eosin,HE)染色观察脊髓损伤情况,尼氏(Nissl)染色观察神经元存活数量,使用Western-blot技术检测B细胞淋巴瘤-2(B cell lymphoma-2,Bcl-2)蛋白及调亡相关蛋白受体相互作用蛋白激酶1(receptor-interacting protein kinase1,RIpK1)的表达水平。结果:造模后A组和B组各时间点的BBB评分均正常,C、D组各时间点均低于A、B组,D组造模后12 h和3d的BBB评分高于同时间点C组(ppI红染细胞较C组明显减少,神经元崩解减轻(pppK1蛋白在A组、B组表达很低;RIpK1在C组表达明显增高,在D组表达明显下降,差异有统计学意义(pppK1信号通路介导的坏死性凋亡有关。

关键词：脊髓损伤紫草素功能恢复

pERSpECTIVES IN MECHANICS OF HETEROGENEOUS SOLIDS

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Acta Mechanica Solida Sinica 2011年第1期24卷 1-26页

作者： C.q. Chen J.Z. Cui H.L. Duan X.q. Feng L.H. He G.K. Hu M.J. Huang Y.Z. Huo B.H. ji B. Liu X.H. peng H.J. Shi q.p. Sun J.X. Wang Y.S. Wang H.p. Zhao Y.p. Zhao q.S. Zheng W.N. Zou Department of Engineering Mechanics AML Tsinghua University Beijing 100084 China Academy of Mathematics and Systems Sciences Chinese Academy of Sciences Beijing 100190 China State Key Laboratory for Turbulence and Complex System and Department of Mechanics and Aerospace Engineering College of Engineering Peking University Beijing 100871 China CAS Key Laboratory of Mechanical Behavior and Design of Materials University of Science and Technology of China Hefei Anhui 230026 China School of Aerospace Engineering Beijing Institute of Technology Beijing 100081 China Institute for Advanced Study Nanchang University Nanchang 330031 China Depariment of Mechanics and Engineering Sciences Fudan University 220 Handa Road Shanghai 200433 China Department of Mechanical Engineering Hong Kong University of Science and Technology Hong KongChina Department of Mechanical Engineering Hong Kong University of Science and Technology Hong Kong China Institute of Engineering Mechanics Beijing Jiaotong University Beijing 100044 China State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China

The Micro- and Nano-mechanics Working Group of the Chinese Society of Theoretical and Applied Mechanics organized a forum to discuss the perspectives, trends, and directions in mechanics of heterogeneous materials in January 2010. The international journal, Acta Mechanica Solida Sinica, is de- voted to all fields of solid mechanics and relevant disciplines in science, technology, and engineering, with a balanced coverage on analytical, experimental, numerical and applied investigations. On the occasion of the 30TM anniversary of Acta Mechanica Solida Sinica, its editor-in-chief, professor q.S. Zheng invited some of the forum participants to review the state-of-the-art of mechanics of heterogeneous solids, with a particular emphasis on the recent research development results of Chinese scientists. Their reviews are organized into five research areas as reported in different sections of this paper. ~I firstly brings in fo- cus on micro- and nano-mechanics, with regards to several selective topics, including multiscale coupled models and computational methods, nanocrystal superlattices, surface effects, micromechanical damage mechanics, and microstructural evolution of metals and shape memory alloys. ~II shows discussions on multifield coupled mechanical phenomena, e.g., multi-fields actuations of liquid crystal polymer networks, mechanical behavior of materials under radiations, and micromechanics of heterogeneous materials. In ~III, we mainly address the multiscale mechanics of biological nanocomposites, biological adhesive surface mechanics, wetting and dewetting phenomena on microstructured solid surfaces. The phononic crystals and manipulation of elastic waves were elaborated in ~IV. Finally, we conclude with a series of perspectives on solid mechanics. This review will set a primary goal of future science research and engineering application on solid mechanics with the effort of social and economic development.

关键词： heterogeneous materials smart materials biological materials multiscale mechanics micro- and nano-mechanics damage and fracture constitutive relation elastic wave surface effects

Self-Assembly and photocatalysis of Mesoporous TiO2 Nanocrystal Clusters

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Nano Research 2011年第1期4卷 103-114页

作者： qiao Zhang ji-Bong Joo Zhenda Lu Michael Dahl Diana q. L. Oliveira Miaomiao Ye Yadong Yin Department of Chemistry University of California Riverside California 92521 USA

Mesoporous nanocrystal clusters of anatase TiO2 with large surface area and enhanced photocatalytic activity have been successfully synthesized. The synthesis involves the self-assembly of hydrophobic TiO2 nanocrystals into submicron clusters, coating of these clusters with a silica layer, thermal treatment to remove organic ligands and improve the crystallinity of the clusters, and finally removing silica to expose the mesoporous catalysts. With the help of the silica coating, the clusters not only maintain their small grain size but also keep their mesoporous structure after calcination at high temperatures （with BET surface area as high as 277 m2/g）. The etching of SiO2 also results in the clusters having high dispersity in water. We have been able to identify the optimal calcination temperature to produce TiO2 nanocrystal clusters that possess both high crystallinity and large surface area, and therefore show excellent catalytic efficiency in the decomposition of organic molecules under illumination by UV light. Convenient doping with nitrogen converts these nanocrystal clusters into active photocatalysts in both visible light and natural sunlight. The strategy of forming well-defined mesoporous clusters using nanocrystals promises a versatile and useful method for designing photocatalysts with enhanced activity and stability.

关键词： Mesoporous titanium dioxide photocatalysis self-assembl~ nitrogen doping nanocrystals