检索结果-南通市图书馆

Design and implementation of an optical simulation environment for bioluminescent tomography studies

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第1期17卷 87-94页

作者： LI Hui, TIAN Jie, LUO Jie, LU Yujie, CONG Wenxiang and WANG Ge ( Department of Education Technology, Capital Normal University, beijing 10003., china Key Laboratory of Complex Systems and Intelligence Science, Institute of Automation, {2. Academy of {3., beijing 100080, china Bioluminescent Tomography Laboratory, Department of Radiology & Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa 52.42. USA) [a]Departhent of Education Technology Capital Normal University Beijing China [b]Key Laboratoiy of Omplex Systems and Intelligence Science Institute of Automation Chinese Academy of Sciences Beijing China [c]Bioluminescent Tomography Laboratoiy Department of Radiology & Department of Biomedical Engineering University of Iowa Iowa City tIowa USA

As a challenging task for bioluminescent tomography simulation, a virtual optical environment is needed to solve the forward problem accurately, that is, to achieve a high precision for bioluminescent signal synthesis on the external body surface of a small animal. The molecular optical simulation environment named MOSE is implemented using the C++ programming language and the OpenGL techniques, including a user-friendly interface with interactive tools facilitating users' operations. The accuracy of the virtual optical environment is verified by error analysis of mesh simplification and comparison between MOSE results and experimental data. This virtual optical environment is accurate, flexible and efficient to simulate the photon propagation in complicated tissues, which has a great potential to become a software platform for bioluminescent tomography studies and other molecular imaging applications.

关键词： molecular imaging biolumlnescent tomography photon propagation Monte Carlo method.

Transverse instability and magnetic structures associated with electron phase space holes

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Transverse instability and magnetic structures associated wi...

中国科学院地质与地球物理研究所第11届（2.11年度）学术年会

作者： Aimin Du,~1 Mingyu Wu,~2.Quanming Lu,~(2.a)) Can Huang,~2.and Shui Wang~2.1 Institute of Geology and Geophysics,chinese Academy of sciences,{2. 10002.,china 2.CAS Key Laboratory of Basic Plasma Physics,School of Earth and Space sciences, University of Science and Technology of china,Hefei,Anhui 2.002.,china

Electron phase space holes(electron holes) are found to be unstable to the transverse instability. Two-dimensional(2.) electromagnetic particle-in-cell simulations are performed to investigate the structures of the fluctuating magnetic field associated with electron *** combined actions between the transverse instability and the stabilization by the background magnetic field (B=Be) lead a one-dimensional electron hole into several 2. electron holes which are isolated in both the x and y *** electrons trapped in these 2. electron holes suffer the electric field drift v=E×B/B due to the existence of the perpendicular electric field E,which generates the current along the z ***,the unipolar and bipolar stmctures are formed for the parallel cut of the fluctuating magnetic field along the x and y directions,*** the same time,these 2. electron holes move along the x direction,and the unipolar structures are formed for the parallel cut of the fluctuating magnetic field along the z direction.

关键词：

Pre-stack full wavefield inversion for elastic parameters of TI media

在线全文

cnki会议

学校读者我要写书评

暂无评论

Pre-stack full wavefield inversion for elastic parameters of...

中国科学院地质与地球物理研究所2.06学术年会

作者： Meigen Zhang~1,Zhongyu Huang~2.Xiaofan Li~1,Miaoyue Wang~1 and Guangyin Xu~3.1 State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics, chinese Academy of sciences,{2. 10002.,china 2.Nanjing Institute of Geophysical Prospecting,Nanjing 2.0014,china 3.Institute of Geophysics,chinese State Bureau of Seismology,{2. 100081,china

re-stack full wavefield inversion for the elastic parameters of transversely isotropical media is *** Jacobian matrix is derived directly with the finite element method,just like the full wavefield forward *** absorbing boundary scheme combining Liao’s transparent boundary condition with Sarma’s attenuation boundary condition is applied to the forward modelling and Jacobian *** input data are the complete ground-recorded wavefields containing full kinematic and dynamic information for the seismic *** with such data is desirable as it should improve the accuracy of the estimated parameters and also reduce data pre-processing,such as wavefield identification and separation.A scheme called energy grading inversion is presented to deal with the instability caused by the large energy difference between different arrivals in the input *** this method,parameters in the shallow areas,which mainly affect wave patterns with strong energy,converge before those of deeper ***,the number of unknowns in each inversion step is reduced,and the stability and reliability of the inversion process is greatly *** a result,the scheme is helpful to reduce the non-uniqueness in the *** synthetic examples show that the inversion system is reliable and accurate even though initial models deviate significantly from the actual ***, the system can accurately invert for transversely isotropic model parameters even with the introduction of strong random noise.

关键词： full wavefield inversion TI elastic parameter energy grading inversion absorbing boundary

A NEW IRIDOID FROM HEDYOTIS CRYSOTRICHAE

在线全文

cnki会议

学校读者我要写书评

暂无评论

chinese Chemical Letters 1995年第11期6卷 965-966页

作者： Jiang Nan PENG Xiao Zhang FENG Xiao Tian LIANG(Institute of Materia Medica, chinese Academy of Medical sciences, {2. 100050) chinese Acad Med Sci Inst Mat Med Beijing 100050 Peoples R China

A new iridoid, 6'-acetyl asperuloside was isolated from the whole plant of Hedyotis crysotrichae. Its structure has been elucidated by means of H-1-NMR and C-13.NMR spectra.

关键词：

Dependence of the IMF sector structure on the solar dipole tilt angle

在线全文

学校读者我要写书评

暂无评论

Dependence of the IMF sector structure on the solar dipole t...

中国科学院地质与地球物理研究所2.08学术年会

作者： A.M.Du,W.Y.Xu,and X.S.Feng 1 Institute of Geology and Geophysics,chinese Academy of sciences, {2.,{3.. 2.State Key Laboratory for Space Weather,chinese Academy of sciences,{2.,{3..

[1]The quasiperiodic variations of the interplanetary magnetic field(IMF) sector structure at the ACE satellite(L1) are investigated using power spectrum *** appears that the two-sector structure of the IMF dominates during the solar maximum, lasting 3.years from 2.00 through 2.03.and the four-sector structure dominates during the solar activity minimum.A possible explanation is introduced for this phenomenon in which the IMF sector structures vary with the tilt angle of the heliospheric current sheet (HCS) with respect to the solar rotation *** the solar activity maximum,the HCS is perpendicular to the ecliptic *** the spacecrafts at L1 point are expected to pass through the HCS only twice in one solar rotation,which gives rise to the observed two-sector structure of the *** the other hand,during the solar activity minimum,the HCS is nearly parallel to the ecliptic plane,and the polarity of IMF Bx changes several times in one solar rotation due to the wavy nature of the HCS, which may lead to the observed four-sector structure.

关键词：

Hyperglycemia Increases Adipogenesis andlnhibits Osteogenic Differentiation in MG-63.Cell

在线全文

cnki会议

学校读者我要写书评

暂无评论

Hyperglycemia Increases Adipogenesis andlnhibits Osteogenic ...

第二届中国医学细胞生物学学术大会暨细胞生物学教学改革会议

作者： Weiwei Wang Xiaolin Zhang Jianhong Yang College of Life Science graduate University of chinese Academy of {2. 19 Yuquan Road {3. 100049

It is well known that insulin dependent diabetes mellitus(IDDM),marked by high blood glucose level and no insulin secretion,is associated with increased risk of osteopenia and ***,t

关键词：

Key Problems of Cold Power Spinning of Ti-15-3.Alloy

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2001年第1期17卷 125-126页

作者： Debin SHAN Yan LU and Ping LI School of Materials Science and Engineering, Harbin institute of Thchnology, Harbin 150001, china Yi XU Institute of Metal Research, chinese Academy of {2., Shenyang 110015, china Harbin Inst Technol Sch Mat Sci & Engn Harbin 150001 Peoples R China chinese Acad Sci Inst Met Res Shenyang 110015 Peoples R China

The key problems of cold power spinning of Ti-15-3.alloy are studied. Reasonable billet preparation methods are presented to improve crystal structure and avoid crack of billet. Influences of original wall thickness, reduction rate and feed rate on expanding in diameter are analyzed and some methods to prevent expanding in diameter are given.

关键词： Ti Key Problems of Cold Power Spinning of Ti-15-3.Alloy

Evolution of plant microRNA gene families

在线全文

学校读者我要写书评

暂无评论

Cell Research 2007年第3期17卷 212-218页

作者： Aili Li~1 Long Mao~(1,2. ~1Institute of Crop sciences,chinese Academy of Agricultural sciences and The National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI),Beoing 100081,china ~2.epartment of Biological sciences,Northern Illinois University,DeKalb,IL 60115,USA Institute of Crop sciences Chinese Academy of Agricultural Sciences and The National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI) Beijing 100081 China.

MicroRNAs(miRNAs)are important post-transcriptional regulators of their target genes in plants and animals,miR-NAs are usually 2.-2. nucleotides *** their unusually small sizes,the evolutionary history of miRNA genefamilies seems to be similar to their protein-coding *** contrast to the small but abundant miRNA familiesin the animal genomes,plants have fewer but larger miRNA gene *** of plant miRNA gene familiesare often highly similar,suggesting recent expansion via tandem gene duplication and segmental duplication *** many miRNA genes are conserved across plant species,the same gene family varies significantly in size andgenomic organization in different species,which may cause dosage effects and spatial and temporal differences in targetgene *** this review,we summarize the current progress in understanding the evolution of plant miRNA genefamilies.

关键词： microRNAs post-transcriptional regulation tandem duplication segmental duplication

Morphological and functional changes in the blood-spinal cord barrier of rabbits in an experimental spinal cord presyrinx state

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2006年第7期1卷 597-600页

作者： Jianfeng Li1, Haiying Liu1, Qingjun Zhang2.1Department of Neurosurgery, Fourth Hospital, Hebei Medical University, Shijiazhuang 050011, Hebei Province, china 2.epartment of Neurosurgery, People’s Hospital, Peking University, {3. 100044, china Department of Neurosurgery Hebei Medical University Shijiazhuang 050011 Hebei Province China Department of Neurosurgery People's Hospital Peking University Beijing 100044 China

BACKGROUND: Presyrinx state of spinal cord can reflect the initial lesion of syringomyelia (SM). The early trials has proved that ischamia and edema are main pathological changes of presyrinx state. OBJECTIVE: To establish SM model of rabbits for investigating the relationship between changes of morphous and function of blood-spinal cord barrier and the edema degree, histological changes in presyrinx state of SM, and to explore the mechanism of the presyrinx state of SM. DESIGN: Randomized controlled animal experiment. SETTING: Department of Neurosurgery, Fourth Hospital, Heibei Medical University. MATERIALS: Sixty chinese healthy white rabbits, aged 3.5-4.5 months, weighing 1.5-2.0 kg, were provided by Experimental Animal Center of Hebei Medical University [certification: (SYXK(Ji)2.03.002.)]. Evan's blue (EB) and dimethylformamide (DMF) were purchased from Jingmei Biotech Co., Ltd. RM2.2. paraffin section cutter (Leica Company, Japan), H-7500 transmission electron microscope (Hitachi Company, Japan), PM-2. light microscope photograph system (Olympus Company, Japan). METHODS: The experiment was carried out in the Laboratory of Neurosurgery Department, Second Hospital of Hebei Medical University from January to June 2.06. ① All the rabbits were randomly divided into two groups: model group (n =40), control group (n =2.). Rabbits in two groups were divided into five subgroups once again at five time points (1st, 3.d, 7th, 14th, 2.st days, n =8 and n =4 at each time point in the model group and control group, respectively). Under ketamine anesthesia, 0.6 mL Kaolin solution (2.0 g/L, 3. ℃) was injected into the cisterna magna of rabbits in model group, while 0.6 mL physiological saline (3. ℃) was injected into the rabbits of control group. ② On the 1st, 3.d, 7th, 14th, 2.st days after kaolin injection, cervical cord samples were harvested after sacrifice of animal. Quantitative analysis on the function of blood-spinal cord barrier was performed by Evan's blue technique

关键词： Morphological and functional changes in the blood-spinal cord barrier of rabbits in an experimental spinal cord presyrinx state