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Journal of Materials Science & Technology 1998年第3期14卷 211-214页

作者： Zhang, ZF Li, XW Su, HH wang, zg Acad Sinica Inst Met Res State Key Lab Fatigue & Fracture Mat Shenyang 110015 Peoples R China

The cyclic saturation dislocation patterns within grains and in the vicinity of low-angle grain boundaries in fatigued copper crystal were successfully observed by electron channeling contrast technique in SEM. The results show that the dislocation patterns within grains consisted of typical two-phase structure, i.e. persistent slip bands (PSB) and veins. With increasing plastic strain amplitude (gamma(pl) greater than or equal to 1.7 x 10(-3)), large amount of PSBs and regular dislocation walls were observed. The dislocation walls and PSBs could cross through the low-angle grain boundaries continuously except that the dislocation-free zone (DFZs) appeared at some local regions. Combining with the cyclic stress-strain response and dislocation patterns, the effect of low-angle grain boundaries on cyclic deformation behavior was discussed.

关键词： Copper

Brief Review and Reconsideration of Fatigue Crack Closure Effect in Materials

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Journal of Materials Science & Technology 1997年第1期13卷 1-14页

作者： Chen, DL Weiss, B Stickler, R wang, zg ACAD SINICA INST MET RESSTATE KEY LAB FATIGUE & FRACTURE MATSHENYANG 110015PEOPLES R CHINA UNIV VIENNA INST PHYS CHEM MAT SCIA-1090 VIENNAAUSTRIA

The state-of-the-art of fatigue crack closure effect, involving the mechanisms, measurements, models, evaluation methods, influencing factors and existing problems is briefly reviewed. Attention is concentrated on a new consideration of closure effect and a re-definition of the effective driving force for the propagation of a fatigue crack. A theoretical basis for measuring the closure effect is established. The proposed closure concept takes into account the role of the tower portion of loading cycle below the opening load. The conventional closure concept is proven to be correct only for some extreme cases which are practically non-existent for engineering materials. A miniature strain gauge technique is developed to measure the crack closure. Stress-ratio-change tests at threshold level clearly indicate the shortcomings of the conventional closure concept, and the validity of the newly-proposed closure concept. The application of the proposed concept can give rise to a new method for the determination of the effective fatigue threshold of materials. If the fatigue threshold is measured at a sufficiently negative stress ratio (R

关键词： FINITE-WIDTH STRESS-RATIO THRESHOLD GROWTH LOAD PLATE

Photoluminescence of ZnS Clusters in Zeolite-Y

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Journal of Materials Science & Technology 1997年第5期13卷 397-404页

作者： Chen, W wang, zg Lin, ZJ Xu, Y Lin, LY Lab. of Semiconductor Materials Sciences Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

Two obvious emissions are observed from the ZnS clusters encapsulated in zeolite-Y. The emission around 355 nm is sharp and weak, locating at the onset of the absorption edge. The band around 535 nm is broad, strong and Stokes-shifted. Both the two emissions shift to blue and their intensities firstly increase then decrease as the loading of ZnS in zeolite-Y or clusters size decreases. Through investigation, the former is attributed to the excitonic fluorescence, and the latter to the trapped luminescence from surface states. The cluster size-dependence of the luminescence may be explained qualitatively by considering both the carrier recombination and the nonradiative recombination rates. Four peaks appearing in the excitation spectra are assigned to the transitions of 1S-1S, 1S-1P, 1S-1D and surface state, respectively. The excitation spectra of the clusters do not coincide with their absorption spectra. The states splitted by quantum-size confinement are detected in the excitation spectra, but could not be differentiated in the optical absorption spectra due to inhomogeneous broadening. The size-dependence of the excitation spectra is similar to that of the absorption spectra. Both the excitation spectra of excitonic and of trapped emissions are similar, but change in relative intensity and shift in position are observed.

关键词： Zeolites

Cyclic Deformation and Fatigue Damage Behavior of Cu Monocrystals, Bicrystals and Tricrystals

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Journal of Materials Science & Technology 1999年第6期15卷 489-508页

作者： wang, zg Li, XW Zhang, ZF Jia, WP Li, SX Chinese Acad Sci Inst Met Res State Key Lab Fatigue & Fracture Mat Shenyang 110015 Peoples R China

In the present work, the cyclic deformation behavior of Cu single crystals oriented for double- and multiple slip as well as Cu bicrystals and tricrystals was investigated under constant plastic strain control at room temperature in air. The main objectives of the study are: (1) to find out the effects of crystallographic orientation and grain boundary (GB) on the cyclic stress-strain (CSS) curves; (2) to compare the cyclic deformation behavior of the double-, multiple-slip crystals, bicrystals and tricrystals with that of single-slip oriented crystals and to correlate the results with those of polycrystals; (3) to examine the corresponding dislocation structures; (4) to investigate the interactions of persistent slip bands (PSBs) with GBs and triple joint (TJ) as well as intergranular fatigue cracking in Cu bicrystals and tricrystals.

关键词： Crystals

Determination of global mean sea surface WHU2000 using multi-satellite altimetric data

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Chinese Science Bulletin 2002年第19期47卷 1664-1668页

作者： Jiang, WP Li, JC wang, zg Wuhan Univ Sch Geodesy & Geophys Wuhan 430079 Peoples R China

In this study, the overall editing criteria for altimetric data are considered and the geophysical correction models is improved. The datum for various altimetric data is also unified and the method of a full-combined crossover adjustment for different altimetric tracks is used to improve the radial orbits of Geosat, ERS-1 and ERS-2 data. In addition, the method for determining mean sea surface (MSS) by using multi-altimetric data is developed. The data used to compute WHU2000 MSS include 7-year Topex/Poseidon data (cycles 11-249), 2-year Geosat ERM data (cycles 1-44), 5-year ERS2 data (cycles 1-52) and all ERS-1 168-day data. The WHU2000 MSS is determined with a grid resolution of 2’×2’ within the ± 82° latitude and its precision is better than 0.05 m. Comparing WHU 2000MSS with 3.75’×3.75’ CLS_SHOM98.2 MSS, 3’×3’ GFZ MSS95A and 3.75’×3.75’ OSU MSS95, as external checks, the corresponding standard deviation (STD) of their differences is 0.090 m, 0.211 m and 0.079 m respectively.

关键词： altimetry mean sea surface crossover adjustment.

Indium Composition Dependence of the Size Uniformity of InGaAs Quantum Dots on (311)B GaAs Grown by Molecular Beam Epitaxy

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Journal of Materials Science & Technology 1999年第6期15卷 523-526页

作者： Jiang, WH Xu, HZ Xu, B Zhou, W Gong, Q Ding, D Liang, JB wang, zg Chinese Acad Sci Inst Semicond Lab Semicond Mat Sci Beijing 100083 Peoples R China

The deposition of InxGa1-xAs (0.2 less than or equal to x less than or equal to 0.5) on (311)B GaAs surfaces using solid source molecular beam epitaxy (MBE) has been studied. Both AFM and photoluminescence emission showed that homogeneous quantum dots could be formed on (311)B GaAs surface when indium composition was around 0.4. Indium composition had a strong influence on the size uniformity and the lateral alignment of quantum dots. Compared with other surface orientation, (100) and (n11) A/B (n=1,2,3), photoluminescence measurement confirmed that (311)B surface is the most advantageous in fabricating uniform and dense quantum dots.

关键词： Semiconducting gallium arsenide

Geological thermal events in Tarim Basin

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Chinese Science Bulletin 1997年第7期42卷 580-584页

作者： Chen, HL Yang, SF Dong, CW Zhu, GQ Jia, CA Wei, GQ wang, zg Department of Earth Sciences Zhejiang University Hangzhou China Geological Research and Exploration Center Kuerle China Shanghai University Shanghai China

TARIM Basin is the biggest sedimentary basin in China, and it is also an important area of

关键词： Tarim Basin 40Ar/39Ar plateau age thermal events.

New records of submarine hydrothermal activity in middle part of the Okinawa Trough

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Chinese Science Bulletin 1997年第7期42卷 574-577页

作者： Zhao, YY Zhai, SK Li, RZ Li, FY Gao, AG He, LJ wang, zg Zhu, XQ Institute of Oceanology Chinese Academy of Sciences Qingdao China Institute of Geochemistry Chinese Academy of Sciences Guiyang China

THE hydrothermal activity area investigated is located at the middle of the trough (126°50′—127°30′E; 27°20′—27°50′N). Some surface sediment samples and core samples were collected, with other samples from non-hydrothermal activity area (128°20′—129°10′E; 30°30′—31°40′N) in the north of the trough for comparison. Analyses for elements and

关键词： hydrotKermal activity chemical elements the Okinawa Trough.

Nitrogen‑Doped Magnetic‑Dielectric‑Carbon Aerogel for High‑Efficiency Electromagnetic Wave Absorption

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Nano-Micro Letters 2024年第1期16卷 313-327页

作者： Shijie wang Xue Zhang Shuyan Hao Jing Qiao Zhou wang Lili Wu Jiurong Liu Fenglong wang Key Laboratory for Liquid‑Solid Structural Evolution and Processing of Materials Ministry of Education Shandong UniversityJinan 250061People’s Republic of China School of Mechanical Engineering Shandong UniversityJinan 250061People’s Republic of China Shenzhen Research Institute of Shandong University Shenzhen 518057GuangdongPeople’s Republic of China

Carbonbased aerogels derived from biomass chitosan are encountering a flourishing moment in electromagnetic protection on account of lightweight,controllable fabrication and ***,developing a facile construction method of component design with carbon-based aerogels for high-efficiency electromagnetic wave absorption(EWA)materials with a broad effective absorption bandwidth(EAB)and strong absorption yet hits some ***,the nitrogen-doped magnetic-dielectric-carbon aerogel was obtained via ice template method followed by carbonization treatment,homogeneous and abundant nickel(Ni)and manganese oxide(MnO)particles in situ grew on the carbon *** to the optimization of impedance matching of dielectric/magnetic components to carbon aerogels,the nitrogen-doped magnetic-dielectric-carbon aerogel(Ni/MnO-CA)suggests a praiseworthy EWA performance,with an ultra-wide EAB of 7.36 GHz and a minimum reflection loss(RLmin)of−64.09 dB,while achieving a specific reflection loss of−253.32 dB mm−***,the aerogel reveals excellent radar stealth,infrared stealth,and thermal management ***,the high-performance,easy fabricated and multifunctional nickel/manganese oxide/carbon aerogels have broad application aspects for electromagnetic protection,electronic devices and aerospace.

关键词： Electromagnetic wave absorption Wide bandwidth Dielectric-magnetic synergy Multifunction

转化生长因子β1抗体复合缓释载体生物蛋白胶应用于鞘管区预防屈肌腱粘连的生物力学分析

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中国组织工程研究与临床康复 2007年第48期11卷 9637-9640页

作者：王志刚房清敏张志敏刘建吴尧平滨州医学院附属医院骨外科山东省滨州市256603 解放军第四军医大学西京医院骨科陕西省西安市710032

目的:单纯生物蛋白胶是一种良好的缓释载体,拟通过与转化生长因子β1抗体复合应用于肌腱损伤局部,观察其对鞘管区屈肌腱粘连的预防作用和对肌腱愈合的影响。方法:实验于2003-01/04在解放军第四军医大学西京医院骨科研究所完成。①实验动... 详细信息

目的:单纯生物蛋白胶是一种良好的缓释载体,拟通过与转化生长因子β1抗体复合应用于肌腱损伤局部,观察其对鞘管区屈肌腱粘连的预防作用和对肌腱愈合的影响。方法:实验于2003-01/04在解放军第四军医大学西京医院骨科研究所完成。①实验动物:将72只来亨鸡(leghorn)按随机化原则分为单纯转化生长因子β1抗体组、单纯生物蛋白胶组、转化生长因子β1抗体复合生物蛋白胶组及生理盐水组,每组18只。实验过程中对动物处置符合动物伦理学要求。②实验方法:分别将鸡左足第三、四趾趾深屈肌腱横断,作The 4-strand Cruciate repair缝合,然后按照分组,用1 mL无菌注射器,向鞘管区分别注入0.2 mL转化生长因子β1抗体(8 mg/L)和生理盐水,用生物蛋白胶专用注射器向鞘管区分别注入0.2 mL生物蛋白胶和转化生长因子β1抗体生物蛋白胶复合液。③实验评估:术后5 d行早期功能锻炼,在第1,3,8周麻醉后处死取材,第四趾标本分别行大体观察、组织学检查和缝合处粘连评分。第三趾在SHIMADZU SPL-10kN型材料实验机上进行生物力学测试。结果:转化生长因子β1抗体复合生物蛋白胶组术后3,8周,缝合处粘连程度评分、肌腱滑动距离、模拟主动屈曲度及屈曲功均优于其余3组,且差异有显著性意义(P0.05)。结论:转化生长因子β1抗体复合缓释载体生物蛋白胶可以有效预防术后肌腱粘连,并且不影响肌腱的正常愈合进程。

关键词：肌腱粘连转化生长因子β1抗体生物蛋白胶鸡