检索结果-南通市图书馆

Approaches to improving critical current density of YBCO superconducting thick films deposited by electrophoresis

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2004年第2期47卷 165-172页

作者： ZHU Yabin1,2. ZHOU Yueliang2. LIU Zhen2. WANG Shufang2. CHEN Zhenghao2. L?Huibin2. YANG Guozhen2. XIAO Ling3, REN Hongtao3, JIAO Yulei3 & ZHENG Minghui3 1. department of physics, College of Science, Beijing Jiaotong {2., Beijing 100044, China 2. Laboratory of Optical physics, Institute of physics and Center for Condensed Matter physics, Chinese Academy of Sciences, Beijing 100080, China 3. General Research Institute for Nonferrous Metals, Beijing 100088, China Correspondence should be addressed to Zhu Yabin (email: ybzhu@***) department of physics College of Science Beijing Jiaotong University Beijing China Laboratory of Optical physics Institute of physics and Center for Condensed Matter physics Chinese Academy of Sciences Beijing China General Research Institute for Nonferrous Metals Beijing China

Fabrication of YBCO superconducting thick films by electrophoresis has been widely reported. However, the value of critical current density (J c) is far from what the practical application requires. The superconducting thick films are obtained using top-seeded melt growth method with different proportional Y2.aCuO5 (Y2.1) addition. High-pressure oxygen has been used in the annealing process to improve the uniformity of the oxygen content in the superconducting thick films. When 40mol% Y2.1 powder is added to the YBa2.u3O7–5 (Y12.) powder,J c for the superconducting thick film by approaches described above reaches 7.008×103 A/cm2.(77 K, 0 T), which is greater than the value ever reported.

关键词： YBCO thick films, electrophoretic deposition, melt-textured.

Quantum statistical entropy corresponding to cosmic horizon in five-dimensional spacetime

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2008年第2期51卷 140-146页

作者： ZHAO Ren1,2.& ZHANG ShengLi1 1 department of Applied physics, Xi’an Jiaotong {2., Xi’an 710049, China 2.department of physics, Shanxi Datong {2., Datong 037009, China department of Applied physics Xi’an Jiaotong University Xi’an China department of physics Shanxi Datong University Datong China

The generalized uncertainty relation is introduced to calculate the quantum statis-tical entropy corresponding to cosmic horizon. By using the new equation of state density motivated by the generalized uncertainty relation, we discuss entropies of Bose field and Fermi field on the background of five-dimensional spacetime. In our calculation, we need not introduce cutoff. There is no divergent logarithmic term in the original brick-wall method. And it is obtained that the quantum statistical en-tropy corresponding to cosmic horizon is proportional to the area of the horizon. Further it is shown that the entropy corresponding to cosmic horizon is the entropy of quantum state on the surface of horizon. The black hole's entropy is the intrinsic property of the black hole. The entropy is a quantum effect. In our calculation, by using the quantum statistical method, we obtain the partition function of Bose field and Fermi field on the background of five-dimensional spacetime. We provide a way to study the quantum statistical entropy corresponding to cosmic horizon in the higher-dimensional spacetime.

关键词： quantum statistical entropy generalized uncertainty relation high-dimensional spacetime

Orthogonal design for optimization of pigment extraction from surface sediments of the Changjiang River Estuary

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2011年第4期30卷 33-42页

作者： ZHAO Jun YAO Peng YU Zhigang Thomas S Bianchi Key Laboratory of Marine Environment and Ecology Ministry of Education Ocean University of China Qingdao 266100 China department of Oceanography Texas A ＆ M University College Station TX 77843 USA Key Laboratory of Marine Chemistry Theory and Technology Ministry of Education Ocean University of China Qingdao 266100 China Institute of Marine Organic Geochemistry College of Chemistry and Chemical Engineering Ocean University of China Qingdao 266100 China

Using a suitable solvent for extracting pigments from sediment for high performance liquid chromatography（HPLC） analysis is critical for obtaining qualitative and quantitative estimates of phytoplanktonic and benthic algal biomass,as well as community composition. Five methodological factors（sample dehydration,extraction solvent,extraction duration,number of extractions,and ratio of solvent volume：sample weight） were studied using an L 9（3 4 ） orthogonal design in a sedimentary pigment extraction experiment on samples collected from the Changjiang large-river delta-front estuary（LDE）,using HPLC analysis. The results show that the optimal extraction method for sedimentary pigments should include freeze-drying samples prior to extraction. The effects of different factors on sedimentary pigment extraction were separated by the L 9（3 4 ） orthogonal design experiments and showed that the extraction solvent was the most important,with extraction duration the second most important,and numbers of extraction and ratio of solvent volume：sample weight was the least important. The mixed solvent treatment comprised of acetone,methanol and water（80：15：5,by volume） was best for polar pigment extraction,with 100% acetone better for apolar pigments. For most pigments employed in this study（i.e.,peridinin,fucoxanthin,alloxanthin,diatoxanthin,zeaxanthin,pheophytin-a and β-carotene） ,3 h was found to be enough time for extraction from these deltaic sediments. However,for chlorophyll-a,the most important pigment used for estimating algal biomass,12.h was needed. A small amount of solvent（3 ml） with duplicate extractions obtained the greatest amount and diversity of pigments. Unfortunately,no extraction method was found to be suitable for all pigments in sediments. The choice of extraction procedure should be made in accordance with the objective of each study,taking into consideration the properties of sediments and pigments in question.

关键词： sedimentary pigments extraction orthogonal design HPLC Changjiang River Estuary

Boundary conditions for the bending of a piezoelectric beam

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2008年第7期51卷 847-856页

作者： GAO Yang1, XU SiPeng2.& ZHAO BaoSheng3 1 College of Science, China Agricultural university, Beijing 100083, China 2.College of Engineering, Ocean university of China,{2., China 3 School of Mechanical Engineering, university of Science and Technology Liaoning, Anshan 114044, China College of Science China Agricultural University Beijing China College of Engineering Ocean University of China Qingdao China School of Mechanical Engineering University of Science and Technology Liaoning Anshan China

For beam bending in transversely isotropic piezoelectric media, the reciprocal theorem and the general solution of piezoelasticity are applied in a novel way to obtain the appropriate stress and mixed boundary conditions accurate to all orders for the beam of general edge geometry and loadings. By generalizing the method developed by Gregory and Wan, a set of necessary conditions on the edge-data for the existence of a rapidly decaying solution is established. The prescribed edge-data of the beam must satisfy these conditions in order that they could generate a decaying state within the beam. When stress and mixed conditions are imposed on the beam edge, these decaying state conditions for the case of bending deformation of piezoelectric beam are derived explicitly. They are then used for the correct formulation of boundary conditions for the beam theory solution (or the interior solution). Besides, an analytical solution of elastic beam is formulated to verify validity of our boundary conditions. For the stress data, our boundary conditions coincide with those obtained in conventional forms of beam theories. More importantly, the appropriate boundary conditions with two sets of mixed edge-data are obtained for the first time.

关键词： boundary conditions beam bending piezoelectric media decaying states regular states

Recombination and Heterologous Expression of Aliophycocyanin Gene in the Chloroplast of Chlamydomonas reinhardtii

在线全文

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2005年第10期 709-712页

作者： Zhong-Liang SU~~(1,3) Kai-Xian QIAN~(1*) Cong-Ping TAN~(2.4) Chun-Xiao MENG~(2.4) Song QIN~(2.) 1 department of Biotechnology.College of Life Sciences.Zhejiang university,Hangzhou 31002..China 2.Institute of Oceanology,Chinese Academy of Sciences,{2. 2.6071,China 3 qingdao university of Science and Technology,{2. 2.6061,China 4 Graduate university of Chinese Academy of Sciences,Beijing 100039,China

Heterogeneous expression of multiple genes in the nucleus of transgenic plants requires theintroduction of an individual gene and the subsequent backcross to reconstitute multi-subunit proteins ormetabolic *** order to accomplish the expression of multiple genes in a single transformationevent,we inserted both large and small subunits of allophycocyanin gene (apcA and apcB) into Chlamydomonasreinhardtii chloroplast expression vector,resulting in *** constructed vector was then introducedinto the chloroplast of *** by micro-particle *** chain reaction and Southernblot analysis revealed that the two genes had integrated into the chloroplast *** blot andenzyme-linked immunosorbent assay showed that the two genes from the prokaryotic cyanobacteria couldbe correctly expressed in the chloroplasts of *** expressed foreign protein in transformantsaccounted for about 2.-3% of total soluble *** findings pave the way to the reconstitution ofmulti-subunit proteins or metabolic pathways in transgenic *** chloroplasts in a single transformationevent.

关键词： Chlamydomonas reinhardtii chloroplast transformation allophycocyanin gene

Particle tunnels across the horizon of Garfinkle-Horowitz-Strominger dilaton black hole

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) 2007年第5期50卷 601-610页

作者： FANG HengZhong1 & ZHAO Zheng2.1 department of physics, China {2. of Petroleum, Dongying 2.7061, China 2.department of physics, Beijing Normal {2., Beijing 100875, China department of physics China University of Petroleum Dongying China department of physics Beijing Normal University Beijing China

We promote the work of Parikh and Wilczek on the black hole radiation to the emission of massive and charged particles from Garfinkle-Horowitz-Strominger black hole. The energy and charge of the space-time are conservational during the course of the evaporation. The calculation shows that the emission spectrum is not precisely thermal, while has a correction, and the conclusion supports the view- point of information conservation.

关键词： Hawking radiation, black body spectrum, barrier, information loss, entropy of black hole, Komar energy

Mixed boundary conditions for piezoelectric plates

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2009年第5期52卷 755-761页

作者： GAO Yang 1 ,XU SiPeng 2.&ZHAO BaoSheng 3 1College of Science,China Agricultural university,Beijing 100083,China 2.ollege of Engineering,Ocean university of China,{2. 2.6071,China 3 School of Mechanical Engineering,university of Science and Technology of Liaoning,Anshan 114044,China College of Science China Agricultural University Beijing China College of Engineering Ocean University of China Qingdao China School of Mechanical Engineering University of Science and Technology of Liaoning Anshan China

For plate bending and stretching problems in piezoelectric materials,the reciprocal theorem and the general solution of piezoelasticity are applied in a novel way to obtain the appropriate mixed boundary conditions accurate to all order.A decay analysis technique is used to establish necessary conditions that the prescribed data on the edge of the plate must satisfy in order that it should generate a decaying state within the *** the case of axisymmetric bending and stretching of a circular plate,these decaying state conditions are obtained explicitly for the first time when the mixed conditions are imposed on the plate *** are then used for the correct formulation of boundary conditions for the interior solution.

关键词： boundary conditions piezoelectric plates mixed data bending problems stretching problems

A simulation analysis on pelagic-benthic coupling ecosystem of the northern Jiaozhou Bay, qingdao, China

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2001年第3期20卷 443-453页

作者： Wu Zengmao, Zhai Xuemei, Zhang Zhinan, Yu Guangyao, Zhang Xinling, Gao Shanhong 1. College of Physical and Environmental Oceanography, Ocean university of qingdao, qingdao 2.6003, China 2. College of Marine Biology Science, Ocean university of Qi Coll. Physical/Envrn. Oceanography Ocean University of Qingdao Qingdao 266003 China College of Marine Biology Science Ocean University of Qingdao Qingdao 266003 China

INTRODUCTIONWith the development of economy and the exploitation of coastal resources, the coastal en vironment of the northern part of China was seriously damaged, especially in the Jiaozhou *** attention was paid to... 详细信息

关键词： Ecosystem model the Jiaozhou Hay pelagic-benthic coupling ecosystem seasonal variation simulation

Total Synthesis of (3S,6S)-(+)-3,7-Dimethyl-3-acetoxy-6-hydroxy-octa-1,7-diene

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1999年第2期10卷 111-112页

作者： Zuo Sheng LIU Jiong LAN Yu Lin LI(National Laboratory of Applied Organic Chemistry and Institute of Organic Chemistry,Lanzhou university, Lanzhou, 730000)Ya Cheng XING Wen CEN(department of Chemistry,{2., qingdao, 2.6071) Natl. Lab. of Appl. Organ. Chemistry Institute of Organic Chemistry Lanzhou University Lanzhou 730000 China department of Chemistry Qingdao University Qingdao 266071 China

A total synthesis of(3S, 6S)- (+)-3,7-dimethyl-3-acetoxy-6-hydroxy-octa-1,7-diene via the rearrangement of chiral 2.3-epoxy alcohol, with the system of Ph3P, pyridine, I-2.and H2., is described.

关键词： 2.3-epoxy alcohol rearrangement synthesis