检索结果-南通市图书馆

Semi-stable distributions in free probability theory

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2006年第3期49卷 387-397页

作者： shandong university, ji’nan 250100, china Department of Mathematics and Statistics, Memorial university of Newfoundland, HH 3050, St. John’s, A1C 5S7, Canada shandong university Ji’nan China Department of Mathematics and Statistics Memorial University of Newfoundland St. John’s Canada

Semi-stable distributions, in classical probability theory, are characterized as limiting distributions of subsequences of normalized partial sums of independent and identically distributed random variables. We establish the noncommutative counterpart of semi-stable distributions. We study the characterization of noncommutative semi-stability through free cumulant transform and develop the free semi-stability and domain of semi-stable attraction in free probability theory.

关键词： stable distributions, semi-stable distributions, noncommutative random vari-ables, Voiculescu transform, free cumulant transform.

Magnetic properties and giant magnetoresistance effect of nanometer Fe-In_2O_3 granular films

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2002年第24期47卷 2025-2028页

作者： ZHANG Lin, LIU Yihua & HUANG BaoxinInstitute of Physics and Microelectronics, shandong university, ji’nan 250100, china Institute of Physics and Microelectronics Shandong University Ji'nan China

nanometer ferromagnetic metal-semiconductor matrix Fe-In2O3 granular films are fabricated by the radio frequency sputtering. Magnetic properties and the giant magnetoresistance (GMR) effect of Fex(In2O3)1-x granular film samples are studied. The result shows that the magnetoresistance (MR) ratio value of the granular film samples with Fe volume fraction x = 35% is 4.5% at room temperature. The temperature dependence (r = 1.5-300 K) of the MR ratio value of Fe0.35(In2O3)0.65 granular films shows that value below 10 K increases rapidly with the decrease of the temperature, and when T = 2 K, value is 85%. Through the study of the dependence of low field susceptibility on temperature and the hysteresis loops at different temperatures, it has been found that, when the temperature decreases to a critical point TP = 10 K, the change of the structure in Fe0.35(In2O3)0.65 granular films results in the transformation of state from ferromagnetic to spin-glass-like. The remarkable increase of the MR ratio value

关键词： granular films magnetic property giant magnetoresistance effect structure superparamagnetic.

EDGE RECONSTRUCTION OF PLANAR GRAPHS WITH MINIMUM DEGREE AT LEAST THREE-(IV)

在线全文

学校读者我要写书评

暂无评论

Systems Science and Mathematical Sciences 1994年第2期7卷 218-222页

作者： FAN Hongbing (Department of Mathematics, shandong university, ji’nan 250100, china)

ＥＤＧＥＲＥＣＯＮＳＴＲＵＣＴＩＯＮＯＦＰＬＡＮＡＲＧＲＡＰＨＳＷＩＴＨＭＩＮＩＭＵＭＤＥＧＲＥＥＡＴＬＥＡＳＴＴＨＲＥＥ－（ＩＶ）￥ＦＡＮＨｏｎｇｂｉｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，Ｓｈａｎｄ... 详细信息

ＥＤＧＥＲＥＣＯＮＳＴＲＵＣＴＩＯＮＯＦＰＬＡＮＡＲＧＲＡＰＨＳＷＩＴＨＭＩＮＩＭＵＭＤＥＧＲＥＥＡＴＬＥＡＳＴＴＨＲＥＥ－（ＩＶ）￥ＦＡＮＨｏｎｇｂｉｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＳｈａｎｄｏｎｇＵｎｉｖｅｒｓｉｔｙ，Ｊｉ＇...

关键词： Reconstruction planar graph embedding.

MAXIMUM PRINCIPLE FOR OPTIMAL CONTROLPROBLEM OF FULLY COUPLEDFORWARD-BACKWARD STOCHASTIC SYSTEMS

在线全文

学校读者我要写书评

暂无评论

Systems Science and Mathematical Sciences 1998年第3期11卷 249-259页

作者： WU Zhen(College of Mathematics and System Sciences, shandong university, ji’nan 250100, china) 山东大学数学学院山东济南

The optimal control problem of fully coupled forward-backward stochastic systems is put forward. A necessary condition, called maximum principle, for an optimal control of the problem with the control domain being con... 详细信息

关键词： Stochastic differential equations forward-backward stochastic systems maximumprinciple

Dissecting and Exploiting Nonribosomal Peptide Synthetases

在线全文

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2004年第4期36卷 243-249页

作者： Qing-Tao SHEN, Xiu-Lan CHEN, Cai-Yun SUN, and Yu-Zhong ZHANG*State Key Laboratory of Microbial Technology, shandong university, ji’nan 250100, china State Key Laboratory of Microbial Technology Shandong UniversityJi'nan 250100 China

A large number of therapeutically useful cyclic and linear peptides of bacteria or fungal origin are synthesized via a template-directed, nucleic-acid-independent nonribosomal mechanism. This process is carried out by mega-enzymes called nonribosomal peptide synthetases (NRPSs). NRPSs contain repeated coordinated groups of active sites called modules, and each module is composed of several domains with different catalytic activities. The familiarity to these domains lays base for the future genetic engineering of NRPSs to generate entirely “unnature” products. The details about NRPSs domain structures and the exploi- tation of NRPSs are described in this review.

关键词： nonribosomal peptide synthetase domain combinatorial biosynthesis

Numerical simulation and application of three-dimensional oil resources migration-accumulation of fluid dynamics in porous media

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2008年第8期51卷 1144-1163页

作者： YUAN YiRang1 & HAN Yuji2 1 Institute of Mathematics,shandong university,ji’nan 250100,china 2 Physical Exploration Institute of Shengli Petroleum Administration,Dongying 257022,china Institute of Mathematics Shandong University Ji’nan China Physical Exploration Institute of Shengli Petroleum Administration Dongying China

Numerical simulation of oil migration and accumulation is to describe the history of oil migration and accumulation in basin evolution. It is of great value in evaluation of oil resources and determination of the location and amount of oil deposits. Based on such actual conditions as the effects of fluid mechanics in porous media and 3-dimensional geology characteristics,a kind of modified method of second order upwind finite difference fractional steps implicit interactive scheme was put forward. As for the actual problem of Dongying hollow,Huimin hollow,Tanhai region and Yangxin hollow in Shengli Petroleum Oil Field,a numerical simulation test was carried out,and the result is basically coincident with the actual conditions. For the model problem,optimal order estimates were derived. Thus the well-known problem on oil resources was solved.

关键词： nonlinear mechanics of immiscible flow 3-dimensional migration-accumulation of oil resources upwind fractional steps numerical simulation numerical analysis

Integrin β4 mAb inhibited apoptosis induced by deprivation of growth factors in vascular endothelial cells

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2004年第6期25卷 31-35页

作者： Ke-wen ZHAO, Qi-tao ZHAO, Shang-li ZHANG, Jun-ying MIAO2 Institute of Developmental Biology, School of Life Science, shandong university, ji-nan 250100, china Institute of Developmental Biology School of Life Science Shandong University Jinan 250100

AIM: To understand the mechanism by which anti-β4 integrin monoclonal antibody (mAb) inhibits apoptosis of vascular endothelial cells (VEC). METHODS: Viability was determined by counting the cells that attached to dishes after treatments. DNA fragmentation was analyzed by agarose gel electrophoresis and fluorescence microscopy. The intracellular content of cAMP was measured by radioimmunoassay (RIA). The levels of p53 and Ras expres- sions were analyzed by fluorescence microscopy combined with immunofluorescence under laser scanning confo- cal microscopy. RESULTS: After the cells were deprived of fibroblast growth factor (FGF) and serum were exposed to the mAb 5 mg/L for 24 h, the detachment and DNA fragmentation of these cells were suppressed. When cells were deprived of FGF and serum, the intracellular cAMP level and Ras protein content decreased (P<0.05), while the level of p53 protein expression increased (P<0.05). But in the presence of anti-β4 integrin mAb, VEC apoptosis was inhibited, and at the same time, the changes mentioned above were obviously blocked (P<0.05). CONCLUSION: Anti-4 integrin mAb inhibited apoptosis by affecting the level of cAMP, and blocking down- regulation of Ras protein and up-regulation of p53 protein in VEC.

关键词： integrin 4 monoclonal antibodies apoptosis umbilical veins vascular endothelium cyclic AMP protein p53 ras genes

D609 induces vascular endothelial cells and marrow stromal cells differentiation into neuron-like cells

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2004年第4期25卷 44-48页

作者： nan WANG, Chun-qing DU, Shao-shan WANG, Kun XIE, Shang-li ZHANG, Jun-ying MIAO2 Institute of Developmental Biology, School of Life Science, shandong university, ji-nan 250100, china Institute of Developmental Biology School of Life Science Shandong University Jinan 250100

AIM: To investigate the effect of tricyclodecane-9-yl-xanthogenate (D609) on cell differentiation in vascular endo- thelial cells (VECs) and marrow stromal cells (MSCs). METHODS: Morphological changes were observed under phase contrast microscope. Electron microscope and immunostaining were used for VECs identification. The expressions of neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP) were examined by immunohistochemistry. RESULTS: After 6 h of induction with D609, some VECs showed morphological changes characteristic of neurones. 9 h later, more VECs became neuron-like cells. About 30.8 % of VECs displayed positive NSE (P<0.01), while the expression of GFAP was negative. When MSCs were exposed to D609, the cells displayed neuronal morphologies, such as pyramidal cell bodies and processes formed extensive networks at 3 h. 6 h later, almost all of the cells exhibited a typical neuronal appearance, and 85.6 % of MSCs displayed intensive positive NSE, but GFAP did not express. CONCLUSION: D609 induces VECs and MSCs differentiation into neuron-like cells.

关键词： tricyclodecane-9-yl-xanthogenate cell differentiation vascular endothelial cells marrow stromal cells neuron-like cells

ON CONTROLLABILITY FOR STOCHASTIC CONTROL SYSTEMS WHEN THE COEFFICIENT IS TIME-VARIANT

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2010年第2期23卷 270-278页

作者： Feng LIU Shige PENG School of ElecLronics and Information Engineering Beijing Jiaotong University Beijing 100044 China. School of Mathematics and System Sciences Shandong University Ji'nan 250100 China

This paper investigates the controllability problem of time-variant linear stochastic controlsystems.A sufficient and necessary condition is established for stochastic exact controllability,whichprovides a useful algebraic criterion for stochastic control ***,when the stochasticsystems degenerate to deterministic systems,the algebraic criterion becomes the counterpart for thecomplete controllability of deterministic control systems.

关键词： Backward stochastic differential equation (BSDE) E-well-posedness Stochastic controlsystem stochastic exact controllability.