检索结果-南通市图书馆

Science china(Physics,Mechanics & Astronomy) 2008年第9期51卷 1254-1263页

作者： HAN GuangZe1 & CHEN MingDong2 1 department of Physics,south china university of technology,Guangzhou 510640,china 2 Guangzhou Auto College,south china university of technology,Guangzhou 510800,china 1. department of Physics South China University of Technology Guangzhou 510640 China 2. Guangzhou Auto College South China University of Technology Guangzhou 510800 China

Microwave-assisted extraction is a new effective method which has practical ap-plications in many fields. Microwave heating is one of its physical mechanisms,and it also has the characteristic of selectivity. When the applied microwave fre-quency equals a certain absorption frequency of the material (or specific compo-nent),the material will intensively absorb microwave energy. This is also known as resonant absorption,and the frequency is called the peak absorption frequency which depends on the physical structure of the material. In this work,dynamic hy-drogen bond energy was included in molecular activation energy; with the liquid cell model,the expression of interaction energy between dipolar molecules was derived. The rotational relaxation time was gotten from the Eyring viscosity formula. Then based on the relationship between dielectric dissipation coefficient and re-laxation time,the expression of microwave peak absorption frequency as a func-tion of the material physical structure,rotational inertia and electrical dipole mo-ment of molecules was established. These theoretical formulas were applied to water and benzene,and the calculated results agree fairly well with the experi-mental data. This work can not only deepen the study of the interaction between microwave and material,but also provide a possible guide for the experiment of microwave-assisted extraction.

关键词： microwave-assisted extraction microwave heating relaxation time liquid viscosity peak absorption fre-quency

DIMPLE FORMATION ON FRACTURE SURFACE OF STEEL 55SiMnMo

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1993年第2期6卷 140-143页

作者： LIANG Sizu LIANG Yaoneng LIU Zhengyi south china university of technology,Guangzhou,china Lecturer,department of Mechanical Engineering No.2,south china university of technology,Guangzhou 510641,china south china Univ of technology Guangzhou China

The fracture surface of the normalized steel 55SiMnMo was observed,under tensile device at- tached on the SEM,to be of ductile dimple feature on the bainite which is composed of lath ferrite and austenite *** dimple is essentially nucleated in the *** the austenitic plastic deformation is remarkable during fracturing,the tear ridge of dimple is very sharp.

关键词： dimple plastic deformation ductile fracture steel 55SiMnMo

Free orthodox semigroups and free bands with inverse transversals

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2010年第11期53卷 3015-3026页

作者： TANG XiLin department of Mathematics, south china university of technology, Guangzhou 510640, china 1. department of Mathematics South China University of Technology Guangzhou 510640 China

It is well known that the subclass of inverse semigroups and the subclass of completely regular semigroups of the class of regular semigroups form the so called e-varieties of semigroups. However, the class of regular semigroups with inverse transversals does not belong to this variety. We now call this class of semigroups the ist-variety of semigroups, and denote it by IST . In this paper, we consider the class of orthodox semigroups with inverse transversals, which is a special ist-variety and is denoted by OIST . Some previous results given by Tang and Wang on this topic are extended. In particular, the structure of free bands with inverse transversals is investigated. Results of McAlister, McFadden, Blyth and Saito on semigroups with inverse transversals are hence generalized and enriched.

关键词： inverse transversal ist-variety free orthodox semigroup free band

Transitional function of DG to CA3 in the hippocampus

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12期17卷 1436-1444页

作者： Yan Chuankui1 and Liu Shenquan2(1. department of Mathematics, Hangzhou Normal university, Hangzhou 310036, china 2. department of Applied Mathematics, School of Mathematical Sciences, south china university of technology, Guangzhou 510640, china) department of Mathematics Hangzhou Normal University Hangzhou 310036 China department of Applied Mathematics School of Mathematical Sciences South China University of Technology Guangzhou 510640 China

Using single cell channel model, the transmission features of CA3-DG network in the hippocampus are investigated. The influence of the stimulation on discharge pattern of pyramidal neurons is analyzed, which shows that it starts with period spiking discharges, followed by period-doubling bifurcation to chaos, and period 3 discharge evolving into chaos, and ultimately a period of bursting discharges. By the synaptic model, the CA3-DG network model is constructed, which analyzes the summation of postsynaptic currents in the network, the influence of postsynaptic current on discharge rhythm as well as the mechanism of bursting discharges. The strong capacity of spatiotemporal encoding in the network indicates the features of CA3 network during the information transmission process in the hippocampus. The modeling result with time delay of the synaptic transmission is in accordance with the experimental phenomena of action potential in the hippocampus.

关键词： hippocampus CA3-DG period-doubling bifurcation chaos.

Inhibition of ethanol-induced toxicity by tanshinone ⅡA in PC12 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 2006年第6期27卷 659-664页

作者： Xian-fang MENG~2 Xiao-jing ZOU~3 Bin PENG~2 Jing SHI~2 Xin-min GUAN~2 Chun ZHANG~(4,5)2 department of Neurobiology,Tongji Medical College,Huazhong university of Science and technology,Wuhan 430030,china 3 department of Anesthesiology,4 department of nephrology,Union Hospital,Tongji Medical College,Huazhong university of Science and technology,Wuhan 430022.china department of Neurobiology Tongji Medical College Huazhong University of Science and Technology Wuhan China department of Anesthesiology Union Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China department of nephrology Union Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China

Aim:To observe the effects of tanshinone IIA(Tan IIA)on the neurotoxicityinduced by ethanol in PC 12 cells and to explore its protective ***:PC 12cell survival was measured by MTT *** formation of reactive oxygenspecies(ROS)and lactate dehydrogenase(LDH)release were detected by 2′,7′-dichlorofluorescin(DCF)fluorescence and calorimetric method,*** of cell apoptosis was monitored by flow *** expression ofp53 was detected by immuno-fluorescence and flow ***:Ethanolsignificantly impaired the survival of PC12 cells as demonstrated by MTT *** also induced significant ROS formation and increased LDH ***-incubation with Tan IIA in the culture medium significantly reversed these *** caused cell apoptosis and the upregulation of p53 *** anti-apoptosis effects of Tan IIA on ethanol-induced toxicity were accompanied by thedownregulation of pro-apoptotic p53 protein ***:Tan IIAcan protect neurons from apoptosis and might serve as a potential therapeuticdrug for neurological disorders induced by ethanol.

关键词： apoptosis ethanol PC12 cells p53 tanshinone ⅡA

CATHODIC REDUCTION OF METAL-CHLORIDE COORDINATION IONS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 1994年第1期4卷 39-44页

作者： Zen, Zhenou(department of Applied Chemistry Chemistry,south china university of technology, Guangzhou510641, china)Yang, Songqing(department of Chemistry, Central south university of technology, Changsha 410083, china)

ＣＡＴＨＯＤＩＣＲＥＤＵＣＴＩＯＮＯＦＭＥＴＡＬ－ＣＨＬＯＲＩＤＥＣＯＯＲＤＩＮＡＴＩＯＮＩＯＮＳＺｅｎ，Ｚｈｅｎｏｕ（ＤｅｐａｒｔｍｅｎｔｏｆＡｐｐｌｉｅｄＣｈｅｍｉｓｔｒｙＣｈｅｍｉｓｔｒｙ，ＳｏｕｔｈＣｈｉｎａ... 详细信息

ＣＡＴＨＯＤＩＣＲＥＤＵＣＴＩＯＮＯＦＭＥＴＡＬ－ＣＨＬＯＲＩＤＥＣＯＯＲＤＩＮＡＴＩＯＮＩＯＮＳＺｅｎ，Ｚｈｅｎｏｕ（ＤｅｐａｒｔｍｅｎｔｏｆＡｐｐｌｉｅｄＣｈｅｍｉｓｔｒｙＣｈｅｍｉｓｔｒｙ，ＳｏｕｔｈＣｈｉｎａＵｎｉｖｅｒｓｉｔｙｏｆＴｅｃｈｎ...

关键词： cathodic reduction metal chloride coordination ions copper chloride zinc chlo-ride lead chloride chronopotential method

A MECHANICAL MODEL FOR THE CHIP SIDE DEFORMATION IN ALUMINIUM ALLOY CUTTING

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 1995年第4期5卷 168-172页

作者： Xia Wei Li Yuanyuan Zhou Zehua(department of Mechanical Engineering,south china university of technology,Guangzhou 510641) south china Univ of technology Guangzhou China

ＡＭＥＣＨＡＮＩＣＡＬＭＯＤＥＬＦＯＲＴＨＥＣＨＩＰＳＩＤＥＤＥＦＯＲＭＡＴＩＯＮＩＮＡＬＵＭＩＮＩＵＭＡＬＬＯＹＣＵＴＴＩＮＧＸｉａＷｅｉ；ＬｉＹｕａｎｙｕａｎ；ＺｈｏｕＺｅｈｕａ（ＤｅｐａｒｔｍｅｎｔｏｆＭｅｃｈ... 详细信息

ＡＭＥＣＨＡＮＩＣＡＬＭＯＤＥＬＦＯＲＴＨＥＣＨＩＰＳＩＤＥＤＥＦＯＲＭＡＴＩＯＮＩＮＡＬＵＭＩＮＩＵＭＡＬＬＯＹＣＵＴＴＩＮＧＸｉａＷｅｉ；ＬｉＹｕａｎｙｕａｎ；ＺｈｏｕＺｅｈｕａ（ＤｅｐａｒｔｍｅｎｔｏｆＭｅｃｈａｎｉｃａｌＥｎｇｉｎｅｅｒｉｎｇ...

关键词： metal cutting mechanical model cutting force chip side deformation

The phase transition and classification of critical points in the multistability chemical reactions

在线全文

学校读者我要写书评

暂无评论

Communications in Nonlinear Science and Numerical Simulation 2000年第1期5卷 36-43页

作者： Chunhua ZHANG Fugen WU Chunyan WU and Fa OU department of Physics, Guangdong university of technology, Guangzhou510090, china department of Applied Physics, south china university of technology, Guangzhou 510641, china department of Physics Guangdong University of Technology Guangzhou 510090 China department of Applied Physics South China University of Technology Guangzhou 510641 China

In this paper, we study the phase transition and classification of critical points in multistability chemical reaction systems. Referring to the spirit of Landau's theory of phase transitions, this paper deals with the varied transitions and critical phenomena in multistable chemical systems. It is demonstrated that the higher the order of the multistability, the wider the variety of phase transitions will be. A classification scheme of critical points according to the stability criterion and the thermodynamic potential continuity is suggested. It is useful for us to study critical phenomena especially in the non-equilibrium systems including the multi-Stable chemical ones.

关键词： nonlinear chemistry non-equilibrium phase transition critical points

Ti/Al_2O_3 Functionally Gradient Material Prepared by the Explosive Compaction/SHS Process

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 Materials Science & technology 1999年第3期15卷 271-275页

作者： Yimin LI(Powder Metallurgy Research Institute, Central-south university of technology, Changsha 410083, china)Ziqiao ZHENG(department of Materials Science and Engineering, Central-south university of technology, Changsha 410083, china) Cent S Univ Technol Powder Met Res Inst Changsha 410083 Peoples R China Cent S Univ Technol Dept Mat Sci & Engn Changsha 410083 Peoples R China

Ti1Al2O3 Functionally Gradient Material (FGM) was prepared by an explosive compaction/SHS process. Ten sheets of the compounding powder were laminated and pressed to get a green body of FGM. It was then compacted explosively By burying the explosive compaction body into a stoichiometric Al/TiO2 mixture and igniting the combustion of the stoichiometric Al/TiO2 mixture, the SHS reaction of the explosive compaction body was initiated by the heat released from the combustion of the stoichiometric Al/TiO2 mixture. In this way, Ti/Al2O3 FGM was synthesized. The adiabatic temperatures of each gradient layer were calculated when the preheating temperatures were 298 K and 1173 K, respectively The microstructure, composition and properties of Ti/Al2O3 FGM and the reaction mechanism of each gradient layer were studied. It was found that Ti/Al2O3 FGM prepared by the explosive compaction/SHS process had a high density and a high microhardness. Its structure, composition and properties showed apparent gradient distribution. The structure of the standard stoichiometric ratio gradient layer of FGM was a network structure. Its reaction mode could be described as follows: Al powder melted first, then the molten Al penetrated into the TiO2 zone and reacted with TiO2, and big pores were left in the original positions of Al powder. The reaction of gradient layers with the addition of Al3O3 as diluents was similar to that of the standard stoichiometric ratio gradient layer, so were their structure and composition. However, the reaction of gradient layers with the addition of Ti as diluents was more complex and the composition deviated slightly from the designed one

关键词： Al SHS Ti/Al2O3 Functionally Gradient Material Prepared by the Explosive Compaction/SHS Process