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Effect of Water Absorption on the Impact Properties of Carbon Fiber/Epoxy Composites

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Chinese Journal of Aeronautics 2006年第B12期19卷 14-18页

作者： lu xiao-jun ZHANG Qi School of Materials Science and Engineering Bejing University of Aeronautics and Astronautics Beijing 100083 China

In this paper, the effects of test temperatures and time on the impact damage behavior of unidirectional carbon fiber reinforced epoxy resin composites, immersed in pure water, on a pendulum impact tester, was studied. The results show that immersion in liquids has a significant effect on the impact resistance of the unidirectional composite material. It is obvious that after immersion, the mass of the material increases. The fracture initiation forces as well as the fracture initiation energy decrease as the immersion time lengthens. Moreover, the higher the temperature and the longer the time are, the more the crack propagation energy and the ductility index will be. Immersion makes the fracture mode change from the dominant fiber fracture into dominant delamination. All in all, immersion decreases the impact resistance of the composites and causes the fracture mode to change.

关键词： carbon fiber composites impact damage immersion fracture mechanisms

地塞米松诱导近交系和封闭群Wistar大鼠骨骼肌萎缩效应比较

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中华骨质疏松和骨矿盐疾病杂志 2017年第1期10卷 58-65页

作者：翟玉莹李青南刘洋林晓文叶小天陈珺卢丽杨国柱陆幸妍广东药科大学生命科学与生物制药学院/广东省生物技术候选药物研究重点实验室广州510006 广东省实验动物监测所/广东省实验动物重点实验室广州510633

目的比较近交系和封闭群Wistar大鼠对地塞米松(dexamethasone,Dex)诱导骨骼肌萎缩的药物效应,探讨建立大鼠糖皮质激素性骨骼肌萎缩症(glucocorticoid-induced muscular atrophy,GIMA)模型的优选方案。方法两品系大鼠各32只采用数字表法... 详细信息

目的比较近交系和封闭群Wistar大鼠对地塞米松(dexamethasone,Dex)诱导骨骼肌萎缩的药物效应,探讨建立大鼠糖皮质激素性骨骼肌萎缩症(glucocorticoid-induced muscular atrophy,GIMA)模型的优选方案。方法两品系大鼠各32只采用数字表法随机分为4组:对照组(C组)肌肉注射0.9%氯化钠注射液1.0 m L/kg,每周3次;低频组(L组)、中频组(M组)和高频组(H组)分别每周1、3、5次肌肉注射Dex 1.0 mg/kg,给药90 d,取腓肠肌进行形态学及糖皮质激素受体(glucocorticoid receptors,GR)和肌肉萎缩盒F蛋白(muscle atrophy F-box,MAFbx)基因mRNA表达水平检测。结果 (1)两品系大鼠H组的体质量[近交系:(158.4±7.3)g,封闭群:(196.5±14.4)g]较对照组[近交系:(223.7±10.5)g,封闭群:(279.5±14.5)g]显著减小;两品系大鼠H组的腓肠肌系数变化率[近交系:(-10.90±0.07)%,封闭群:(-13.60±0.12)%]较对照组[近交系:(±0.05)%,封闭群:(±0.01)%]显著减小;M、H组肌纤维横截面积变化率[近交系M和H组:(-13.00±2.00)%、(-29.00±2.00)%,封闭群M和H组:(-31.00±2.00)%、(-35.00±2.00)%较对照组近交系:(±3.40)%,封闭群:(±2.30%)]显著减小;用药组Ⅱ型纤维横截面积变化率[近交系L、M和H组:(-18.00±2.00)%、(-25.00±3.00)%、(-38.00±2.00)%,封闭群L、M和H组:(-45.00±1.00)%、(-53.00±1.00)%、(-44.00±2.00)%较对照组近交系:(±3.00)%,封闭群:(±3.00)%]显著减少。随给药频次增加,近交系大鼠Ⅱ型纤维横截面积变化率减少且组间差异有统计学意义(P<0.05)。(2)两品系大鼠各给药组MAFbx mRNA表达变化率[近交系L、M、H组:(175.00±10.00)%、(675.00±25.00)%、(2 125.00±25.00)%,封闭群L、M、H组:(15.00±2.00)%、(21.00±6.00)%、(33.00±3.00)%]均随给药频次增加而显著增高且组间差异有统计学意义(P<0.05)。近交系大鼠M组GR mRNA表达变化率(400.00±25.00)%和H组GR mRNA表达变化率(750.00±37.00)%较对照组(±37.00)%显著增高,但封闭群大鼠M组GR mRNA表达变化率(-26.00±5.00)%和H组GR mRNA表达变化率(-55.00±6.00)%较对照组(±2.00)%显著下降。结论以Dex 1.0 mg/kg每周1、3、5次肌肉注射均能诱导两品系大鼠不同程度的骨骼肌萎缩病变,但近交系大鼠较封闭群大鼠骨骼肌萎缩病变更为典型。

关键词： Wistar大鼠近交系 Wistar大鼠封闭群地塞米松糖皮质激素性骨骼肌萎缩造模

Exact Calculations of Vertex ^-sγb and ,^-sZb in the Unitary Gauge

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Communications in Theoretical Physics 2007年第3X期48卷 502-508页

作者： WU lu-Sen xiao Zhen-jun Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing 210097 China

In this paper, we present the exact calculations for the vertex ^-sγb and ^sZb in the unitary gauge. We find that （a） the divergent- and μ-dependent terms are left in the effective vertex function Г^γμ（p, k） for b → sγ transition even after we sum up the contributions from four related Feynman diagrams; （b） for an on-shell photon, such terms do not contribute et al.; （c） for off-shell photon, these terms will be canceled when the contributions from both vertex ^sγb and ^sZb are taken into account simultaneously, and therefore the finite and gauge-independent function Zo（xt） = Co（xt）＋ Do（xt）/4, which governs the semi-leptonic decay b → sl^- l^＋, is derived in the unitary gauge.

关键词： unitary gauge Feynman diagram vertex

Synthesis of chiral phosphine derivatives through a copper（I）-catalyzed desymmetric SNAr reaction

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Science China Chemistry 2025年

作者： Shuai Zhang Pei-Zhi Liu Yan-Bo Li Qi Zhang jun-Zhao xiao Yi-Fan Wang Tian-Yu Wei Jia-Wei Jiang Ye Wang Qian Peng Liang Yin Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials Shanghai Institute of Organic Chemistry University of Chinese Academy of Sciences Chinese Academy of Sciences State Key Laboratory of Elemento-Organic Chemistry and Tianjin Key Laboratory of Biosensing and Molecular Recognition College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Haihe Laboratory of Sustainable Chemical Transformations

Axially chiral phosphines are a class of extremely important ligands in asymmetric catalysis. Herein, an unprecedented copper（I）-catalyzed asymmetric SNAr reaction with HP（S）R2is uncovered, which delivers a series of axially chiral phosphine derivatives in high yields with excellent enantioselectivity. Furthermore, the diastereoselective reaction with the kinetic resolution of racemic HP（S）ArR proceeds smoothly, providing the products with moderate diastereoselectivity and excellent enantioselectivity. Control experiments indicate that HP（S）Ph2is much more active than HPPh2and HP（O）Ph2as the pronucleophile in the present reaction. It is found that the SNAr reaction （the first SNAr） proceeds in a desymmetric manner, providing the desired chiral products while a continued SNAr reaction （the second SNAr） slightly occurs in a kinetic resolution manner in the present catalytic system, which enhances the ee of the desired chiral products. DFTcalculations support a concerted reaction pathway rather than a step-wise mechanism. Finally, axially chiral olefin-phosphines produced by the present method work as suitable ligands in Pdcatalyzed asymmetric allylic substitution with C-, N-, and O-nucleophiles and Rh-catalyzed asymmetric addition of arylboronic acid to benzil.

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A general observatory control software framework design for existing small and mid-size telescopes

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Research in Astronomy and Astrophysics 2015年第7期15卷 1077-1088页

作者： Liang Ge xiao-Meng lu xiao-jun Jiang Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences

A general framework for observatory control software would help to improve the efficiency of observation and operation of telescopes, and would also be advantageous for remote and joint observations. We describe a general framework for observatory control software, which considers principles of flexibility and inheritance to meet the expectations from observers and technical personnel. This framework includes observation scheduling, device control and data storage. The design is based on a finite state machine that controls the whole process.

关键词： telescopes -- instrumentation: detectors -- control software

DepthGAN: GAN-based depth generation from semantic layouts

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Computational Visual Media 2024年第3期10卷 505-522页

作者： Yidi Li jun xiao Yiqun Wang Zhengda lu School of Artificial Intelligence University of Chinese Academy of SciencesBeijingChina College of Computer Science Chongqing UniversityChongqingChina

Existing GAN-based generative methodsare typically used for semantic image synthesis. Wepose the question of whether GAN-based architecturescan generate plausible depth maps and find thatexisting methods have difficulty in generating depthmaps which reasonably represent 3D scene structuredue to the lack of global geometric ***, we propose DepthGAN, a novel method ofgenerating a depth map using a semantic layout asinput to aid construction, and manipulation of wellstructured 3D scene point clouds. Specifically, wefirst build a feature generation model with a cascadeof semantically-aware transformer blocks to obtaindepth features with global structural *** our semantically aware transformer block, wepropose a mixed attention module and a semanticallyaware layer normalization module to better exploitsemantic consistency for depth features ***, we present a novel semantically weighteddepth synthesis module, which generates adaptivedepth intervals for the current scene. We generate thefinal depth map by using a weighted combination ofsemantically aware depth weights for different depthranges. In this manner, we obtain a more accuratedepth map. Extensive experiments on indoor andoutdoor datasets demonstrate that DepthGAN achievessuperior results both quantitatively and visually for thedepth generation task.

关键词： depth map generation generative model transformer scene generation

LiMn_(2)O_(4) Microspheres:Synthesis,Characterization and Use As a Cathode in Lithium Ion Batteries

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Nano Research 2010年第10期3卷 733-737页

作者： xiaoling xiao jun lu Yadong Li Department of Chemistry and State Key Laboratory of New Ceramics and Fine Processing Tsinghua UniversityBeijing 100084China

Solid and hollow microspheres of LiMn_(2)O_(4) have been synthesized by lithiating MnCO_(3) solid microspheres and MnO_(2) hollow microspheres,*** LiMn_(2)O_(4) solid microspheres and hollow microspheres had a similar size of about 1.5μm,and the shell thickness of the hollow microspheres was only 100 *** used as a cathode material in lithium ion batteries,the hollow microspheres exhibited better rate capability than the solid ***,the tap density of the LiMn_(2)O_(4) solid microspheres(1.0 g/cm^(3))was about four times that of the hollow microspheres(0.27 g/cm^(3)).The results show that controlling the particle size of LiMn_(2)O_(4) is very important in terms of its practical application as a cathode material,and LiMn_(2)O_(4) with moderate particle size may afford acceptable values of both rate capability and tap density.

关键词： Cathode LiMn_(2)O_(4)microspheres tap density rate capability particle size

Persistent alterations in gray matter in COVID-19 patients experiencing sleep disturbances:a 3-month longitudinal study

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Neural Regeneration Research 2025年第10期20卷 3013-3024页

作者： Kaixuan Zhou Gaoxiong Duan Ying Liu Bei Peng xiaoyan Zhou Lixia Qin Lingyan Liang Yichen Wei Qingping Zhang xiaocheng Li Haixia Qin Yinqi Lai Yian lu Yan Zhang Jiazhu Huang Jinli Huang Yinfei Ouyang Bolin Bin Mingming Zhao jun Liu Jianrong Yang Demao Deng Guangxi Key Laboratory of Special Biomedicine School of MedicineGuangxi UniversityNanningGuangxi Zhuang Autonomous RegionChina Department of Radiology the People’s Hospital of Guangxi Zhuang Autonomous RegionGuangxi Academy of Medical SciencesNanningGuangxi Zhuang Autonomous RegionChina Department of Sleep Medicine the People’s Hospital of Guangxi Zhuang Autonomous RegionNanningGuangxi Zhuang Autonomous RegionChina Department of Radiology The Second Xiangya HospitalCentral South UniversityChangshaHunan ProvinceChina Guangxi Clinical Research Center for Sleep Medicine the People’s Hospital of Guangxi Zhuang Autonomous RegionNanningGuangxi Zhuang Autonomous RegionChina

Sleep disturbances are among the most prevalent neuropsychiatric symptoms in individuals who have recovered from severe acute respiratory syndrome coronavirus 2 *** studies have demonstrated abnormal brain structures in patients with sleep disturbances who have recovered from coronavirus disease 2019(COVID-19).However,neuroimaging studies on sleep disturbances caused by COVID-19 are scarce,and existing studies have primarily focused on the long-term effects of the virus,with minimal acute phase *** a result,little is known about the pathophysiology of sleep disturbances in the acute phase of *** address this issue,we designed a longitudinal study to investigate whether alterations in brain structure occur during the acute phase of infection,and verified the results using 3-month follow-up data.A total of 26 COVID-19 patients with sleep disturbances(aged 51.5±13.57 years,8 women and 18 men),27 COVID-19 patients without sleep disturbances(aged 47.33±15.98 years,9 women and 18 men),and 31 age-and gender-matched healthy controls(aged 49.19±17.51 years,9 women and 22 men)were included in this *** COVID-19 patients with sleep disturbances were included in a longitudinal *** found that COVID-19 patients with sleep disturbances exhibited brain structural changes in almost all brain *** cortical thicknesses of the left pars opercularis and left precuneus were significantly negatively correlated with Pittsburgh Sleep Quality Index ***,we observed changes in the volume of the hippocampus and its subfield regions in COVID-19 patients compared with the healthy *** 3-month follow-up data revealed indices of altered cerebral structure(cortical thickness,cortical grey matter volume,and cortical surface area)in the frontal-parietal cortex compared with the baseline in COVID-19 patients with sleep *** findings indicate that the sleep disturbances patients had altered morphology in the cortical an

关键词： brain structure cortical gray matter volume cortical surface area cortical thickness hippocampus magnetic resonance imaging Pittsburgh Sleep Quality Index severe acute respiratory syndrome coronavirus 2 infections sleep disturbances sub-cortical volume

2000-2014年甘肃省7～18岁汉族学生身体素质六项指标动态分析研究

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通化师范学院学报 2018年第6期39卷 133-138页

作者：高晓君卢辉袁筱平镡玉敏陇南师范高等专科学校体育与健康学院陇南市成县城关中学

对2000-2014年以来甘肃省7~18岁汉族学生身体素质六项指标进行研究,研究认为:甘肃省汉族学生50米跑的成绩总体上保持着缓慢增长的趋势,下肢爆发力总体上呈现出明显的下降趋势;学生力量素质呈现增长趋势,7~12岁乡村男生增长幅度大于同年... 详细信息

对2000-2014年以来甘肃省7~18岁汉族学生身体素质六项指标进行研究,研究认为:甘肃省汉族学生50米跑的成绩总体上保持着缓慢增长的趋势,下肢爆发力总体上呈现出明显的下降趋势;学生力量素质呈现增长趋势,7~12岁乡村男生增长幅度大于同年龄组城市男生,13~18岁年龄段乡村男生呈现缓慢下降趋势,而乡村女生力量素质增长优势明显;7~12岁的男生和城市女生耐力素质成绩呈现下降趋势;但13~18岁城市男生和城市女生的耐力素质增长趋势明显,同一年龄组的乡村女生耐力成绩出现了下降趋势;柔韧素质增长趋势缓慢,且城乡差异明显;学生身体素质的各项成绩的城乡、年代差异显著,个别年代和年龄组成绩的突增或突减现象明显.研究旨在找出甘肃省汉族学生身体素质的动态变化特点,为今后学生身体素质提升工作提供理论参考.

关键词：汉族学生身体素质指标动态