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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 Shanghai Institute of Optics and Fine MechanicsChinese Academy of sciencesShanghaichina department of PhysicsShandong Normal UniversityJinanchina Shandong Institute of Architecture and EngineeringJinanchina

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 control of the Gagua “Wedge” Zone east of Taiwan Island on the southern Okinawa Trough

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science china Earth sciences 2005年第8期48卷 1165-1174页

作者： ZHENG Yanpeng1,2,3. LIU Baohua2,3. WU Jinlong2, LIANG Ruicai2,3. LIU Chenguang2,3.& ZHANG Zhengmin1 1. Marine Geology College, Ocean University of china, Qingdao 266003. china 2. First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, china 3. Key Laboratory of Marine Sedimentology and Environmental Geology, State Oceanic Administration, Qingdao 266061, china Marine Geology College Ocean University of China Qingdao China First Institute of Oceanography State Oceanic Administration Qingdao China Key Laboratory of Marine Sedimentology and Environmental Geology State Oceanic Administration Qingdao China

Based on compositive analysis and interpretation of the observed and historical data, the geophysical field characters and structural properties of the Gagua “Wedge” Zone of the sea area east of Taiwan Island and the primary tectonic stress direction and its variabilities of backarc spreading in the southern Okinawa Trough are studied. It is concluded from the study results that the Gagua “Wedge” Zone is structurally consistent with the Gagua ridge and two fault basins on both sides of the Gagua ridge, and adjusts the moving direction and distance of the western Philippine Sea plate to make the northwestward motion of the plate on its east side change to the northward subduction of the plate on its west side so that the primary tectonic stress direction of the Okinawa Trough changed from NW-SE to nearly N-S, which provided the stress source for the Okinawa Trough to enter the second spreading stage.

关键词： east of Taiwan Island, Gagua "Wedge" Zone, Okinawa Trough, structural control.

Diagnosis of a Severe Rainstorm Event Induced by Eastly Wave and Vortex in Off Southeast Coast of china

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高原气象 2009年第5期28卷 1058-1066页

作者： ZHENG Feng1-3.1.Chinese Academy of Meteorological sciences,Beijing 100081,china 2.nanjing University of Information science & Technology,nanjing 210044,china 3.Wenzhou Meteorological Bureau,Wenzhou 3.5027,china) Chinese Academy of Meteorological sciences 北京 100081

Using the NCEP reanalysis at 1°×1° resolution in conjunction with satellite imagery,a study is undertaken of easterly wave related rainstorm events on August 3.4,2001 in seaboards between northern Fujian and southern Zhejiang,expounding the scheme for computing helicity,and exploring the rainstorm evolution and the genesis of the Yandang mountains-triggered a meso-vortex(Duan and Chen,2005) by means of helicity and Q vector ***,MM5V2 is employed to simulate the easterly wave caused meso-vorte...

关键词： Easterly wave Meso-vortex Helicity Q vector MM5 modeling

Sintering technology for micro heat pipe with sintered wick

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Journal of Central South University 2010年第1期17卷 102-109页

作者：李西兵汤勇李勇周述璋曾志新 department of Mechanical and Power Engineering Harbin University of Science and Technology School of Mechanical Engineering Qiqihar University School of Mechanical and Automotive Engineering South China University of Technology

In order to study reasonable sintering technological parameters and appropriate copper powder size range of micro heat pipe (MHP) with the sintered wick, the forming principle of copper powders in wicks and MHP's heat transfer capabilities were first analyzed, then copper powders with different cell sizes and dispersions were sintered in RXL-12-11 resistance furnace under the protection of the hydrogen at different sintering temperatures for different durations of sintering time, and finally the sintered wicks' scanning electron microscope (SEM) images and their heat transfer capabilities were analyzed. The results indicate that the wick sintered with copper powders of larger cell size or smaller size range has better sintering properties and larger heat transfer capabilities; and that the increase of either sintering temperatures or sintering time also helps to improve the wick's sintering properties and heat transfer capabilities, and the former affects more obviously than the latter. Considering both its manufacturing cost and performance requirements, it is recommended that copper powders with the size range of 140-170 μm are sintered at 900-950℃ for 3.-60 min in practical manufacturing. In addition, two approaches to improve wick's porosity are also proposed through theoretical analysis, which suggests that the larger the wick's porosity, the better the heat transfer capabilities of the MHP.

关键词： micro heat pipe copper powders wick forming principle

A novel endorectal RF coil for high resolution MRI and spectroscopy of the prostate

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Progress in Natural science:Materials International 2005年第5期15卷 472-476页

作者： ZHANG Hongjie 1,2, SONG Xiaoyu1, WANG Xiaoying3. XU Pingfang1 and BAO Shanglian1*(1. Beijing Key Laboratory of Medical Physics & Engineering, Peking University, Beijing 100871, china 2. Navy General Hospital, Beijing 10003., china 3. Peking University First Hospital, Beijing 10003., china) Beijing Key Laboratory of Medical Physics & Engineering Peking University Beijing 100871 China Navy General Hospital Beijing 100037 China Peking University First Hospital Beijing 100034 China

The diagnosis of prostate diseases by magnetic resonance imaging (MRI) in vivo is sometimes difficult for the lower signal to noise ratio (SNR). To increase the SNR of the prostate image, we designed a RF coil that can be inserted into rectum and was named endorectal coil. The properties of RF coil were evaluated using a network analyzer. Moreover the images and spectroscopy of a special phantom were acquired and the results were compared to those of the commercial TORSO coil (G.E. Medical Systems, USA). Our coil gave a significantly higher SNR at the region of interest (ROI). The achieved high local SNR and resulting high spatial resolution would add more anatomic and biochemical information to the diagnosis of prostate diseases.

关键词： MRI RF coil endorectal coil.

A new DNA algorithm to solve graph coloring problem

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Progress in Natural science:Materials International 2007年第6期17卷 733-738页

作者： Jiang Xingpeng1, Li Yin2, Meng Ya3.and Meng Dazhi2(1. National Laboratory of Pattern Recognition,Institute of Automation, Chinese Academy of sciences, Beijing 100080, china 2. College of Applied sciences, Beijing University of Technology, Beijing 100022, china 3. School of science, Beijing Institute of Technology, Beijing 100081, china) National Laboratory of Pattern Recognition Institute of Automation Chinese Academy of Sciences Beijing 100080 China National High Magnetic Field Laboratory Florida State University 1800 East Paul Dirac Drive Tallahassee Florida 32306 USA

Using a small quantity of DNA molecules and little experimental time to solve complex problems successfully is a goal of DNA computing. Some NP-hard problems have been solved by DNA computing with lower time complexity than conventional computing. However, this advantage often brings higher space complexity and needs a large number of DNA encoding molecules. One example is graph coloring problem. Current DNA algorithms need exponentially increasing DNA encoding strands with the growing of problem size. Here we propose a new DNA algorithm of graph coloring problem based on the proof of four-color theorem. This algorithm has good properties of needing a relatively small number of operations in polynomial time and needing a small number of DNA encoding molecules (we need only 6R DNA encoding molecules if the number of regions in a graph is R).

关键词： DNA computing NP-hard problem graph coloring problem.

Discovery of immune related factors in Fenneropenaeus chinensis by annotation of ESTs

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Progress in Natural science:Materials International 2004年第1期14卷 48-55页

作者： SHEN Yaoqing 1,2 , XIANG Jianhai 1*, WANG Bing 1,2 , LI Fuhua 1 and TONG Wei 3.1. Experimental Marine Biology Laboratory, Institute of Oceanology, Chinese Academy of sciences, Qingdao 266071,china 2. Graduate School of the Chinese Academy of sciences, Beijing 10003., china 3. Genomics & Bioinformatics Institute, Chinese Academy of sciences, Beijing 1013.0, china) Experimental Marine Biology Laboratory Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China. Graduate School of the Chinese Academy of sciences Beijing 100039 China. Genomics & Bioinformatics Institute Chinese Academy of Sciences Beijing 101300 China

A total of 10446 expressed sequence tags (ESTs) are obtained by a large scale sequencing of a cDNA library from cephalothorax of adult Fenneropenaeus chinensis . An EST analysis platform was built up based on local computers and bioinformatic techniques were used to annotate these ESTs in order to promptly find possible functional genes, especially for immune related factors. About 4% of the ESTs show similarity to the coding sequences of such factors, including lectin, serine protease, serpin, lysozyme, etc. These ESTs provide a partial profile of the immune system in F. chinensis and useful information for further study on these genes.

关键词： Fenneropenaeus chinensis bioinformatics ESTs immune factors

Predicting bioconcentration factor values of organic pollutants based on medv descriptors derived QSARs

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science china Chemistry 2007年第5期50卷 587-592页

作者： CUI ShiHai1,2, YANG Jing1, LIU ShuShen2,3.& WANG LianSheng2 1 College of Chemistry and Environment, nanjing Normal University, nanjing 210097, china 2 State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, nanjing University, nanjing 2.0093. china 3.Key Laboratory of Yangtze Aquatic Environment, Ministry of Education, College of Environmental science and Engineering, Tongji University, Shanghai 200092, china College of Chemistry and Environment Nanjing Normal UniversityNanjing 210097China 2 State Key Laboratory of Pollution Control and Resources Reuse School of the EnvironmentNanjing UniversityNanjing 210093China Key Laboratory of Yangtze Aquatic En

The molecular electronegativity-distance vector (MEDV) is employed todescribe the chemical structure of organic *** linear relationships between themolecular descriptors and BCF values are developed by best subset regression and partial leastsquare regression *** main structural factors influencing the bioactivities are -CH2,-X,-Cnot <,- C not <,-O-.The high values of r2 and q2_(LOO) present good estimation ability and stabilityof *** prediction power for external samples is validated by the model developed from thetraining set.

关键词： POPs, BCF, MEDV, QSAR

Gonadectomy affects brain derived neurotrophic factor in rats after chronic constriction nerve injury

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Acta Pharmacologica Sinica 2004年第3期25卷 32-38页

作者： Xin ZHAO,Xin WANG,Shu-yun ZHENG,Jian-guo XU1 School of Life science,nanjing University,nanjing {3.department of Anesthesiology,Jinling Hospital,nanjing 210002,china School of Life science Nanjing University Nanjing 210093

AIM: To assess the effect of gonadectomy on brain derived neurotrophic factor (BDNF) expression in neuropathic pain. METHODS: Using chronic constriction injury (CCI) model, we detected BDNF mRNA in dorsal root gan- glion and protein content in spinal cord by reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay respectively. The time point we chose was post CCI operation d 0, 3. 7, 14, and 21. RESULTS: After CCI surgery, BDNF mRNA in ipsilateral DRGs was upregulated and reached its maximum on post operation d 7. BDNF protein level in ipsilateral spinal cord was also increased and reached its maximum on post operation d 14. The magnitude of this increase in gonadectomy (GDX) rats was significantly smaller than the GDX-sham rats at each time point. CONCLUSION: Gonadectomy reduced the BDNF increment after CCI surgery. Estrogen may affect nociceptive processing by its effect on BDNF.

关键词： gonadectomy estrogens brain-derived neurotrophic factor gene expression regulation pain chronic constriction injury