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Densification of W-Ni-Cu and W-Fe-Cu Alloys at 1573 K

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Journal of mat.rials Science & Technology 1999年第1期15卷 94-96页

作者： Xiong, Huaping Zhang, Lianmeng Shen, Qiang Yuan, Runzhang Wuhan Univ Technol State Key Lab Mat Synth & Proc Wuhan 430070 Peoples R China

The tungsten alloys with Ni-Cu and Fe-Cu additives were sintered at 1573 K for 1 h by hot-pres.ing method. It was found that the alloy relative density can be improved with the addition of Cu when Cu content is not very high, and W95Ni3Cu2 alloy with full density can be obtained Under the sintering condition. However, with the Cu content further increasing, the relative density change of W-Ni-Cu alloy and W-Fe-Cu alloy shows different trends, the former tends to decrease obviously, but the latter shows little change. According to the analysis res.lts, the element Cu has different effects on the activation capability of Ni and Fe during sintering of the tungsten alloys. (Edited author abstract) 7 Refs.

关键词： Tungsten alloys

Effects of high modes on the wind-induced res.onse of super high-rise buildings

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Earthquake Engineering and Engineering Vibration 2012年第3期11卷 427-434页

作者： Feng Ruoqiang Guirong Yan Ge Jinming The key lab.ratory of concrete and Pres.res.ed concrete Structures.of Ministry of Education Southeast University Nanjing 210096 China state key lab.of Subtropical Building Science South China University of Technology China Department of Civil Engineering University of Texas at El Paso E1 Paso Texas 79968 USA

For super high-rise buildings, the vibration period of the basic mode is several seconds, and it is very close to the period of the fluctuating wind. The damping of super high-rise buildings is low, so super high-rise buildings are very sensitive to fluctuating wind. The wind load is one of the key loads in the design of super high-rise buildings. It is known that only the basic mode is needed in the wind-res.onse analysis of tall buildings. However, for super high-rise buildings, especially for the acceleration res.onse, because of the frequency amplification of the high modes, the high modes and the mode coupling may need to be considered. Three typical super high-rise projects with the SMPSS in wind tunnel tests and the random vibration theory method were used to analyze the effect of high modes on the wind-induced res.onse. The conclusions can be drawn as follows. First, for the displacement res.onse, the basic mode is dominant, and the high modes can be neglected. Second, for the acceleration res.onse, the high modes and the mode coupling should be considered. Lastly, the strain energy of modes can only give the vibration energy distribution of the high-rise building, and it cannot describe the local wind-induced vibration of high-rise buildings, especially for the top acceleration res.onse.

关键词： super high-rise building wind tunnel test mode couple wind-induced res.onse

Polishing technology of surface for diamond film using the method of laser ablation

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Chinese Science Bulletin 1997年第23期42卷 2010-2013页

作者： Gu, CZ Jin, ZS Wang, YG Zhuang, RS Lu, XY Zhao, ST Zou, GT Jilin Univ State Key Lab Superhard Mat Changchun 130023 Peoples R China

THE chemical vapor deposition (CVD) methods have been developed so much in the past tenyears that it has become less expensive to deposit a thick CVD diamond film than to polish thediamond. The polycrystalline films nomnally exhibit a pronounced roughness because there arelots of large pointed grains on the surface of the films. On the other hand, the thickness unityof diamond film is poor because of the effects of deposition condition, especially for those syn-thesized by the methods of hot filament CVD (HFCVD) and electron assistant CVD(EACVD). Poor thickness unity and rough surface of thick diamond film limits their poten-

关键词： diamond film laser ablation polishing of surface.

Synthesis and Characterization of a New Organic Up-conversion Laser Dye HMASPS

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Chinese Chemical Letters 2000年第5期11卷 395-398页

作者： Ren, Y Fang, Q Yan, YX Wang, XM Liu, Z Zhou, GY Wang, C Zhao, X Jiang, MH Shandong Univ State Key Lab Crystal Mat Jinan 250100 Peoples R China

A new organic dye, trans-4-[4'-(N-hydroxyethyl-N-methylamino)styryl]-N-methylpyridinium p-toluene sulfonate (HMASPS) has been synthesized and its structure has been determined. Pumped with a 1064 nm, 50 ps laser pulses, 0.05 mol/L HMASPS/DMF solution showed the two-photon pumped (TPP) output/input efficiency of 8.4% which is higher than that of trans-4-[p-(N-hydroxyethyl-N-methylamino) styryl]-N-methylpyridinium iodide (ASPI)(1) at the same pump level.

关键词： C24H28N2O4S.H2O TPP up-conversion laser dye

A New Organic Up-conversion Laser Dye HEASPS

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Chinese Chemical Letters 2000年第8期11卷 685-688页

作者： Ren, Y Zhou, GY Wang, C Wang, XM Liu, Z Zhao, X Yu, WT Jiang, MH Shandong Univ State Key Lab Crystal Mat Jinan 250100 Peoples R China

A new organic dye, trans-4-[p-(N-hydroxyethyl-N-ethylamino)styryl]-N-methyl- pyridinium p-toluene sulfonate (HEASPS) has been synthesized and its structure has been determined. Pumped with a 1064 nm, 50 ps laser pulses, 0.05 mol/L HEASPS/DMF solution showed the two-photon pumped (TPP) output/input efficiency of 9.1% which is higher than that of known TPP laser dyes trans-4-[p-(N-hydroxyethyl-N-methylamino) styryl]-N-methylpyridinium iodide (ASPI) and trans-4-[p-(N-hydroxyethyl-N-methylamino) styryl]-N-methylpyridinium p-toluene sulfonate (HMASPS) at the same experimental conditions.

关键词： C25H30N2O4S TPP up-conversion laser dye

Synthesis, Structure of a Symmetrically Substituted Stilbene with Strong Two-photon Absorption and Up-converted Blue Fluores.ence

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Chinese Chemical Letters 2001年第11期12卷 1001-1004页

作者： Wang, XM Zhou, GY Yu, WT Jiang, MH Shandong Univ State Key Lab Crystal Mat Jinan 250100 Peoples R China

Efficient Ti-catalyzed reductive coupling methodology was first employed to synthesize the symmetrical bis-donor stilbene, trans-4, 4'-bis[diphenyl amino] stilbene (BDPAS). X-ray diffraction analyses reveal that this new crystal belongs to the triclinic crystal system of centro-symmetric P-1 space group. The DBPAS solution, with the linear transmission at wavelength of greater than or equal to 450 nm, possesses large two-photon absorption cross section as high as 39.4x10(-48) cm(4).s/photon res.lting in strong two-photon induced blue fluores.ence of 460 nm, pumped by 740 nm laser irradiation.

关键词： symmetrical bis-donor stilbene synthesis crystal structure two-photon absorption two-photon-induced fluores.ence

Brief Review and Reconsideration of Fatigue Crack Closure Effect in mat.rials

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Journal of mat.rials 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 mat.rials. A miniature strain gauge technique is developed to measure the crack closure. Stres.-ratio-change tests at thres.old 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 thres.old of mat.rials. If the fatigue thres.old is measured at a sufficiently negative stres. ratio (Rres.old of the mat.rial.

关键词： FINITE-WIDTH STres.-RATIO THres.OLD GROWTH LOAD PLATE

Thermal Stres. Behavior of Diffusion-bonded SiC/6061Al Laminates during Thermal Cycling

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Journal of mat.rials Science & Technology 1999年第2期15卷 117-120页

作者： Li, Huan Li, Jiabao Wang, Zhongguang Jiang, Chuanhai Wang, Dezun Acad Sinica Inst Met Res State Key Lab Fatigue & Fracture Mat Shenyang 110015 Peoples R China Harbin Inst Technol Sch Mat Sci & Engn Harbin 150001 Peoples R China

In addition to the study of thermal stres. behavior, the stres. relaxation at elevated temperature (205 degree C) was also investigated by means of X-ray diffraction. It was found that the elastic and elastoplastic deformat.on in the 6061 Al layer takes place during thermal cycling, and the same closed stres. temperature loop is formed in the second cycling for the aged and low temperature treated specimen. Meanwhile, it was demonstrated that the compres.ive stres. relaxed in 6061 Al layer at 205 degree C within the range of 0.5-16 h, and which is nearly unchanged with further prolongation of time. (Edited author abstract) 19 Refs.

关键词： Laminates

THERMO-ELASTIC-PLASTIC res.ONSE AND OPTIMUM DESIGN OF CERAMIC-METAL FGMS-CYCLIC THERML LOADING PROBLEM

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Journal of Wuhan University of Technology(mat.rials Science) 1999年第2期14卷 8-17页

作者： Zhai, PC Zhang, QJ Yuan, RZ Wuhan Univ Technol State Key Lab Mat Synth & Proc Wuhan 430070 Peoples R China

The mat.rials are made with a graded composition and microstructure in the thickness direction from the ceramic side to the metal side. The cyclic thermal loading and high temperasure gradient environment are simulated by heating the ceramic surface with a cyclic hear flux input and cooling the metal surface with a flowing liquid niterogen. The thermal and themo-elastic-plastic res.onse of the mat.rials is calculated using the isotropic hardening model and kinetic hardening model. Emphasis is placed on the res.onse analysis under the different graded compositional distributions. Through the res.onse analysis, the optimum design process of the graded composition under the dynamic case is established, which is bused on a unified viewpoint of the heat insulation property, thermal stres. relaxation property and stres. history feature.

关键词： functionally graded mat.rials cyclic thermal loading thermal-elastic-plastic res.onse