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A low frequency piezoelectric power harvester using a spiral-shaped bimorph

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Science China(physics,Mechanics & Astronomy) 2006年第6期49卷 649-659页

作者： HU Yuantai1,2,HU Hongping2 & YANG Jiashi3.1. Institute of Mechanics and Sensing Technology,Central South university,Changsha 410083.China 2. department of Mechanics,Huazhong university of Science and Technology,Wuhan 43.074,China 3. department of Engineering Mechanics,university of Nebraska,Lincoln,NE 68588-0526,USA 1. Institute of Mechanics and Sensing Technology Central South University Changsha 410083 China 2. department of Mechanics Huazhong University of Science and Technology Wuhan 430074 China 3. department of Engineering Mechanics University of Nebraska Lincoln NE 68588-0526 USA

We propose a spiral-shaped piezoelectric bimorph power harvester operating with coupled flexural and extensional vibration modes for applications to low frequency energy sources. A theoretical analysis is performed and the computational results show that the spiral structure has relatively low operating frequency compared to beam power harvesters of the same size. It is found that to optimize the performance of a piezoelectric spiral-shaped harvester careful design is needed.

关键词： spiral-shaped bimorph,piezoelectric harvester,power density.

X-ray spectra induced by ^(129)Xe^(q+) impacting the metal surface

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Science China(physics,Mechanics & Astronomy) 2008年第1期51卷 82-89页

作者： ZHANG XiaoAn 1,2 ,XIAO GuoQing 1 ,YANG ZhiHu 1 ,CHEN XiMeng 3.,ZHAO YongTao 1 , LI FuLi 4 ,WANG Li 1,2 ,CUI Ying 3.,ZHANG HongQiang 3.&ZHAN WenLong 1 1Institute of Modern physics,Chinese Academy of Sciences,Lanzhou 73.000,China 2department of physics,Xianyang Normal {3.,Xianyang 712000,China 3.1} of Modern physics,Lanzhou {3.,Lanzhou 73.000,China 4department of Applied physics,Xi’an Jiaotong {3.,Xi’an 710049,China 1. Institute of Modern physics Chinese Academy of Sciences Lanzhou 730000 China 2. department of physics Xianyang Normal University Xianyang 712000 China 3. department of Modern physics Lanzhou University Lanzhou 730000 China 4. department of Applied physics Xi’an Jiaotong University Xi’an 710049 China

Using the slow highly charged ions 129 Xe q+ (q=25,26,27;initial kinetic T0≤4.65 keV/a.u.)to impact Au surface,the Au atomic Mαcharacteristic X-ray spectrum is *** result shows that as long as the charge state of projectile is high enough,the heavy atomic characteristic X-ray can be effectively excited even though the incident beam is very weak(nA magnitude),and the X-ray yield per ion is in the order of 10-8and increases with the kinetic energy and potential energy of *** measuring the Au Mα-X-ray spectra,Au atomic N-level lifetime is estimated at about 1.3.×10-18s based on Heisenberg uncertainty relation.

关键词： slow highly charged ions characteristic X-ray level lifetime

β-delayed proton decays near the proton drip line

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Science China(physics,Mechanics & Astronomy) 2005年第3期48卷 257-267页

作者： XU Shuwei 1 , LI Zhankui 1 , XIE Yuanxiang 1 , HUANG Wenxue 1 , SHU Nengchuan 2 , CHEN Yongshou 2 , XU Furong 3., WANG Kun 4 , PAN Qiangyan 1 , WANG Xudong 1 , YU Yong 1 & XING Yebing 1 1. Institute of Modern physics, Chinese Academy of Sciences, Lanzhou 73.000, China 2. Nuclear physics department, China Institute of Atomic Energy, Beijing 102413. China 3. department of Technical physics, Peking university, Beijing 100871, China 4. Shanghai Institute for Nuclear Research, Shanghai 201800, China 1. Institute of Modern physics Chinese Academy of Sciences 730000 Lanzhou China 2. Nuclear physics department China Institute of Atomic Energy 102413 Beijing China 3. department of Technical physics Peking University 100871 Beijing China 4. Shanghai Institute for Nuclear Research 201800 Shanghai China

We briefly reviewed the experimental study on a-delayed proton decays near the proton drip line published by our group during the period of 1996―2004, namely the first observation of the a-delayed proton decays of 9 new nuclides in the rare-earth region and the new measurements of a-delayed proton decays of 5 nuclides in the mass ～90 region near the N = Z line with the aid of the “p-?” coincidence in combination with a He-jet tape transport system. In the meantime some important experimental technique details were supplemented. The experimental results, including the half -lives, spins, parities, deformations and production reaction cross sections for the 14 nuclei were summarized and compared with the current nuclear-model predictions, and then the following points were represented. (1) The experimental half-lives for 85Mo and 92Rh as well as the predicted “waiting point” nuclei 89Ru and 93.d are 5―10 times longer than the theoretical predictions given by M?ller et al. using a macroscopic-microscopic model. It considerably influences the predictions of the abundances of the nuclides produced in the rp-process. (2) The current-model predictions are not consistent with the experimental assignments of the spins and parities for the proton drip-line nuclei 142Ho and 128Pm. However, the nuclear potential energy surface (PES) calculated by using a Woods- Saxon-Strutinsky method reproduced the experimental results. (3. The Alice code overestimated the production reaction cross sections of the studied 9 rare-earth nuclei by one order of magnitude or two, while HIVAP code overestimated them by one order of magnitude approximately.

关键词： proton drip line, β-delayed proton decay, He-jet tape transport system, "p-γ" coincidence, spin, parity, deformation, production reaction cross section.

The optical near-field speckles and their first order statistics on the basis of the integral equations of electromagnetic field

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Science China(physics,Mechanics & Astronomy) 2004年第3期47卷 365-380页

作者： CHENG Chuanfu1, 2, SONG Hongsheng2, LIU Chunxiang2, REN Xiaorong2, ZHANG Ningyu3. TENG Shuyun1 & XU Zhizhan1 1. Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P. O. Box 800-211, Shanghai 201800, China 2. department of physics, Shandong Normal university, Jinan 250014, China 3. Shandong Institute of Architecture and Engineering, Jinan 250014, China 1. Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences P. O. Box 800-211 201800 Shanghai China 2. department of physics Shandong Normal University 250014 Jinan China 3. Shandong Institute of Architecture and Engineering 250014 Jinan China

From Helmholtz equation of the harmonic electromagnetic waves, the integral equations of the light field at the medium boundaries are obtained by use of the Green's theorem and are discretized into linear equation set with the values of the light field and its derivative as the unknowns. On solving the linear equation set, we realize the rigorous computations of the light fields at the boundaries. Then the intensities of the light waves scattered by the random self-affine fractal surfaces in the optical near-field are calculated, and the propagation characteristics, the evolutions of the contrast and the intensity probability density function of the near-field speckles are studied in detail. The near-field speckles are much different from the conventional speckles in the diffraction regions and in the imaging systems. There are obvious local fluctuations in the intensity distributions of the near-field speckles and such fluctuations disappear after propagating a distance of one wavelength from the medium surfaces. For the random surfaces with smaller lateral correlation lengths, the speckle contrasts approach the saturation values and the speckle fields approach Gaussian distribution within the near-field, while for the random surfaces with larger lateral correlation lengths, such evolutions become comparatively slow.

关键词： speckle, near-field optics, first order statistics, Green's function.

Structural phase transition in nanostructured γ-Fe_2O_3

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Chinese Science Bulletin 1997年第11期42卷 894-897页

作者： YE Xisheng, SHA Jian, SONG Hongqin, JIAO Zhengkuan, LU Guanglie, PENG Zifei and ZHANG Lide1. department of physics, Zhejiang university, Hangzhou 3.0027, China 2. Central Laboratory, Hangzhou university, Hangzhou 3.0028, China 3. Institute of Solid State physics, Chinese Academy of Sciences, Hefei 23.03., China department of physics Zhejiang IJniversity Hangzhou China Central laboratory Hangzhou University Harigzhou China Institute of Solid State physics Chinese Academy of Sciences Hefei China

DUE to their specific physical,chemical and mechanical properties and large application proba-bility in many fields,nanostructured materials have been developing very fast in the recent *** stability is an important property of the *** interesting resultshave been obtained in the study of the thermal stability of nanostructured materials.

关键词： nanostructured γ-Fe2O3 differential thermal analysis (DTA) XRD microstructlire structural phase transition.

Observations favor the crossing of phantom divide lines

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Science China(physics,Mechanics & Astronomy) 2010年第3期53卷 562-566页

作者： HUANG TieTie1,2,3. WU PuXun2,3.& YU HongWei2,3.1department of physics, Xiangnan College, Chenzhou 423.00, China 2department of physics and Institute of physics, Hunan Normal university, Changsha 410081, China 3.ey Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Hunan Normal university, Changsha 410081, China 1. department of physics Xiangnan College Chenzhou 423000 China2. Department of Physics and Institute of Physics Hunan Normal University Changsha 410081 China3. Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education Hunan Normal University Changsha 410081 China

Using three different parameterized dark energy models, we reconstruct the properties of dark energy from the latest 3.7 Sne Ia, CMB and BAO with the present matter density, Ωm0, given prior. We find that, when Ωm0 is not small, for example, Ωm0 = 0.28 or 0.3., an evolving dark energy with a crossing of phantom divide line is favored and this conclusion seems to be model independent. We also find that the evolving properties of dark energy become more and more evident with the increase of Ωm0 given prior.

关键词： cosmology auelerating expansion dark energy

Preparation and Characterization of Bi_4Ti_3._(12) Platelets by a Novel Low-temperature Molten Salt System

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Journal of Wuhan university of Technology(Materials Science) 2009年第2期24卷 241-244页

作者：隋万美 College of physics Science Qingdao University

Bismuth titanate （Bi4Ti3.12） platelets were prepared by molten salt method in a new salt system of CaCl2·NaCl at 650-750℃, using bismuth nitrate pentahydrate （Bi （NO3.3.H2O） and titanium butoxide （Ti （OC4H9）4） as raw materials. The synthesis temperature of Bi4Ti3.12 platelets was decreased to 650℃ from 900-1100℃. The phase compositions and crystalline morphology of Bi4Ti3.12 platelets were investigated by XRD and SEM. The experimental results indicate that Bi4Ti3.12 platelets containing tetragonal and orthorhombic phase with the size of 1-3.m can be synthesized at 650℃ for 2 h, and the orthorhombic phase becomes the dominant phase at 750℃ for 5 h. The size and proportion of Bi4Ti3.12 platelets increase with the increment of the calcining temperature and holding time. The proportion of platelets increases to about ninety percent, and the platelets grow up to about 3.10μm at 750℃ for 5 h from 1-2μm at 650℃ for 2 h. This technical route provides a new low-temperature molten salt system for preparing platelets by molten salt methods.

关键词： CaCl2-NaC1 molten salt Bi4Ti3.12 platelets

Pre-ligation of afflicted hepatic inflow and outflow blood vessels of lesioned liver lobe during hepatectomy

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Hepatobiliary & Pancreatic Diseases International 2003年第3期2卷 358-361页

作者： Zhe-Fu Li Min Song the department of Hepatobiliary, qingdao Municipal Hospital, qingdao university Medical College, qingdao 266011, China department of Hepatobiliary Qingdao Municipal Hospital Qingdao University Medical College Qingdao 266011 China. lizhefu@***

OBJECTIVE: To compare the merits of hepatectomy after pre-ligation of the hepatic inflow and outflow blood vessels of the lesioned liver lobe with those of Pringle's maneuver. METHODS: A total of 68 patients were divided into two groups A and B. In the group A (n=3.), Pringle's maneuver was employed, whereas in the group B (n=3.), hepatectomy after pre-ligation of the hepatic inflow and outflow blood vessels of the lesioned side of the liver was used. Perioperative blood loss, postoperative bleeding and drainage, time of liver function recovery as well as incidence of postoperative complications were compared between the 2 groups. RESULTS: The mean perioperative blood loss, the mean amount of postoperative bleeding and drainage, the time of liver function recovery as well as incidence of postoperative complications were significantly higher in the group A than in the group B (P<0.01). CONCLUSION: Hepatectomy after pre-ligation of the hepatic inflow and outflow blood vessels of the lesioned side of the liver is superior to Pringle's maneuver.

关键词： hepatectomy blood flow clamping

Spectral anomalies and spectral switches of partially coherent and polychromatic light diffracted at an aperture

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Science China(physics,Mechanics & Astronomy) 2004年第1期47卷 24-35页

作者： Lü Baida1, 3.& PAN Liuzhan1, 2 1. Institute of Laser physics and Chemistry, Sichuan university, Chengdu 610064, China 2. department of physics, Luoyang Normal College, Luoyang 471022, China 3. State Key Laboratory of Laser Technology, Huazhong university of Science and Technology, Wuhan 43.074, China Correspondence should be addressed to L Baida (email: badalu@***) Received July 10, 2003 1. Institute of Laser physics and Chemistry Sichuan University 610064 Chengdu China 2. State Key Laboratory of Laser Technology Huazhong University of Science and Technology 430074 Wuhan China 3. department of physics Luoyang Normal College 471022 Luoyang China

Based on the propagation theory of partially coherent light in the space-frequency domain, the anomalous spectral behavior and spectral switches in the far field of partially coherent and polychromatic light diffracted at an aperture are studied. It is shown that, as compared with spatially fully coherent and polychromatic light whose spectral anomalies are induced only by aperture diffraction, the spectral anomalies and spectral switches of partially coherent and polychromatic light depend on the aperture diffraction, spatial correlationβ and bandwidth of the original spectrum. Detailed numerical calculations are made to illustrate the behavior of spectral switches of partially coherent and polychromatic light, and the results for spatially fully coherent and polychromatic light are treated as a special case ofβ=1 and included in our theory.

关键词： spectral anomaly spectral switch partially coherent and polychromatic light far field aperture diffraction