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A NOVEL INTERPRETATION OF CONCENTRATION DEPENDENCE OF VISCOSITY OF DILUTE POLYMER SOLUTION

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Chinese Journal of Polymer Science 2000年第1期18卷 57-67页

作者： Yan Pan Rong-shi Cheng College of material Science and Engineering, South China University of Technology, Guangzhou 510641, China College of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China 华南理工大学广东广州

The concentration dependence of the reduced viscosity of dilute polymer solution is interpreted in the light of a new concept of the self-association of polymer chains in dilute solution. The apparent self-association constant is defined as the molar association constant divided by the molar mass of individual polymer chain and is numerically interconvertible with the Huggins coefficient. The molar association constant is directly proportional to the effective hydrodynamic volume of the polymer chain in solution and is irrespective of the chain architecture. The effective hydrodynamic volume accounts for the non-spherical conformation of a short polymer chain in solution and is a product of a shape factor and hydrodynamic volume. The observed enhancement of Huggins coefficient for short chain and branched polymer is satisfactorily interpreted by the concept of self-association. The concept of self-association allows us to predict the existence of a boundary concentration C-s(dynamic contact concentration) which divides the dilute polymer solution into two regions.

关键词： self-association polymer solution viscosity concentration dependence

REHEATING TEMPERATURE CONTRAST AND MICROSTRUCTURES OF 7075 Al ALLOY CAST BY LIQUIDUS SEMI-CONTINUOUS CASTING

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Acta Metallurgica Sinica(English Letters) 2002年第6期15卷 551-555页

作者： J. Dong, G.M. Lu and J.Z. CuiThe Key Lab. of Electromagnetic Processing of material, Ministry of Education, Northeastern University, Shenvane 110004, China Ministry of Education Northeastern Univ. Shenyang 110004 China

In this study, reheating of liquidus semi-continuous cast billets of 7075 Al alloy was carried out in a resistance furnace, and the temperature contrast of the outer and the center of the reheated billets was investigated, then the reheating microstructures were investigated. Results show that: the difference of temperature between the outer and center is small and the difference of their microstructures are also small. During reheating at 576℃ the spheroidization of grains is significant after 5min and no rosettes are visible after 20min by optical microscopy. Similar observations were madeon materials reheated at 596℃, but the ripening process is faster. The grains growup to 30-60μm, fine enough for thixoforming.

关键词： reheating 7075 Al alloy liquidus casting micro structure

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材料系统的观念

城市建筑 2011年第5期8卷 38-43页

作者： Duoxiang studio 多相工作室

本文阐述了多相工作室对材料系统这一观念的思考,包括材料系统的定义、内容、自身的观念、背后的概念及其局限性,并配以多相完成的4个作品(系列)加以说明,包括木梳系列、穿墙术系列、纸空间壹和2010上海世博会万科馆。

关键词：材料系统建构涌现戏剧性感官体验时间性空间性绿色建筑

NEW material OF HSISOSUCHUS CHUNGKINGENSIS FROM SICHUAN, CHINA

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古脊椎动物学报(中英文） 1994年第2期 121-126页

作者： Li Jinling Wu Xiaochun Li Xuanmin(Institute of Vertebratc Paleontology (Chongqing natural History and Paleoanthropology, Museum)Acadcmia Sinica)

Hsisosuchus chungkingensis was described by Young and Chow (1953) on the basis of a cranium and some caudal osteoderms of an old individual from the Late Jurassic Shangshaximiao Formation, near Chongqing (Chungking) city, Sichuan province, China. A new family, the Hsisosuchidae, was then erected for this species on the basis of a number of peculiar features, such as the closure of the suborbital fenestra, the closure of the external mandibular fenestra and the presence of a pronounced transverse ridge of the pterygoid across the palate. H. chungkingensis is as yet a poorly known taxa, because certain Laspects of the cranial anatomy are obscured by extensive fusions among elements and the lack of its postcranium.

关键词： Sichuan Yongchuan Shangshaximiao Formation(J3) Hsisosuchidae

Studying on the Interaction of Myoglobin with Levofloxacin by Flow Injection Chemilummescence Analysis

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Studying on the Interaction of Myoglobin with Levofloxacin b...

“2011国际化学年在中国”——中国化学会第十届全国发光分析学术研讨会

作者： Donghua Chen,Zhenghua Song (Key Laboratory of Synthetic and natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry & material Science,Northwest University,Xi’an,710069,China)

Study on the interaction of protein with drug has become a hot spot in the fields of medicine, chemistry and biology in recent *** this work,the interaction of myoglobin(Mb)with levofloxacin was studied by flow inject... 详细信息

关键词： myoglobin levofloxacin chemiluminescence luminol flow injection

来源： cnki会议评论

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cnki会议

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麦垛 2010年上海世博会万科馆

时代建筑 2010年第3期53卷 124-129页

作者： Duoxiang studio 多相工作室

2010上海世博会万科馆的昵称是"麦垛"。在设计竞赛阶段,多相工作室基于建筑及建材生命周期中CO_2排放量的研究成果,选用秸秆板作为结构材料,并以"材料→结构→空间"的推演为基础生成建筑形体。最终实现的设计通过自然材料(秸秆板)、自... 详细信息

2010上海世博会万科馆的昵称是"麦垛"。在设计竞赛阶段,多相工作室基于建筑及建材生命周期中CO_2排放量的研究成果,选用秸秆板作为结构材料,并以"材料→结构→空间"的推演为基础生成建筑形体。最终实现的设计通过自然材料(秸秆板)、自然采光、自然通风降温这几个方面表达了对自然的尊重。

关键词：麦垛秸杆板自然生命周期评价 CO2 排放量

Technology of Arc-added Glow-discharge Brazing and Brazing of Ceramic to Metal

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厦门大学学报(自然科学版) 2002年第S1期 83-84页

作者： WANG Wen-xian, ZHANG Yong-qing, ZHAO Peng-sheng (College of material Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China)

A new brazing method, arc-added glow-discharge br az ing (AGB), was studied in respects of mechanism, technology, application and equ ipment in which the workpiece is directly heated by both ion bombardment of glow discharge and radiation heat of arc discharge. The AGB equipment was manufactured by Taiyuan University of Technology and i t mainly consists of: (1) brazing furnace; (2) vacuum system; (3) power closet; (4) measuring and control system. The heating cycle of brazing was composed of heating speed, brazing temperatu re, heat-shielding time, and cooling speed and determined by brazing parameter such as limit degree of vacuum (Va), work pressure (P), glow voltage ( V), arc current (I), P-V match and brazing time (t). The effect o f brazing parameter on the quality of brazing joints was analyzed and discussed. The heating cycle of brazing was designed according to the material and structu re of the workpiece and the result of their optimization were controlled by a FX 2 industrial PC computer. Many metals or alien metals can be brazed by means of AGB method like steel, cop per, aluminum and stainless steel. However, the dominance of AGB is that non-me tals such as ceramic are brazed in AGB method. In the process of AGB, it is possible to deposit active active metallic elements on ceramic surface by glow discharge metallizing with arc source in which the s pattering deposition goes on with a high speed and can occur at a comparatively low temperature. Si 3N 4 ceramics have been put to test by using the above pro cess. Take the T-shaped joint brazing of Si 3N 4 to 45 # steel as an example (Si 3N 4 is of 13×13×7 mm in vertical position and 45 # steel is 1 mm thic k in horizontal position). After brazing, the compositions at different position s of the brazing fillet have been examined by EDX. EPMA analysis showed the exis tence of TiN on ceramic surface, which was produced by the following reaction: S i 3N 4+4Ti = 4TiN+3Si. TiN is a compound similar to metal, whi

关键词： brazing arc-added glow-discharge brazing tech nology ceramic

Fractal Characteristics and Fractal Dimension Measurement on Broken Surfaces of Aluminum Electric Porcelain

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Journal of Wuhan University of Technology(materials Science) 2005年第1期20卷 37-41页

作者：杨志远 Dept.of material Science and Technology Xi'an University of Science and Technol ogyXi'an 710054China

The characteristics of broken surfaces were r esearched by a scanning electron microscope (SEM) and a reflection microscope, a nd the fractal dimensions of broken surfaces were measured by the Slit Island me thod. The experimental results indicate that the broken surface of aluminum elec tric porcelain is a fractal body in statistics, and the fractal dimensions of br oken surfaces are different with the different amplification multiple *** a ll of measured fractal dimensions,both of values measured in 100× under reflect ion microscope and in 500× under SEM are maximum, whereas the values measur ed in 63× under reflection microscope and in 2000× under SEM are obviously min imum. The fractal dimensions of broken surfaces are also affected by the degrees of gray comparison and the kinds of measuring methods. The relationships betwee n the fractal dimensions of broken surfaces and porcelain bend strengths are tha t they are in positive correlation on the low multiples and in negative correlat ion on the high multiples.

关键词： broken surface fractal dimension Slit Island m ethod electric porcelain

Electrochemical hydrogen storage performance of AB_(5-)CoB composites synthesized by a simple mixing method

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Rare Metals 2009年第6期28卷 629-632页

作者： SONG Dawei WANG Yijing WANG Yaping JIAO Lifang YUAN Huatang Institute of New Energy material Chemistry Engineering Research Center of Energy Storage ＆ Conversion （Ministry of Education of China） and Key Laboratory of En-ergy-Material Chemistry （Tianjin） Nankai University Tianjin 300071 China

AB5 （MlNi4.0Al0.3Cu0.5Zn0.2） alloy and CoB alloy were prepared by arc melting. AB5-CoB composites were synthesized by simple mixing of AB5 alloy powders and CoB alloy powders, and their electrochemical hydrogen storage properties were studied as negative electrodes in KOH aqueous solution. The maximum discharge capacity of the AB5-CoB（50%） composite （the content of CoB in the composite is 50 wt.%） reached 365.3 mAh.g^-1. After 100 charge-discharge cycles, the discharge capacity of the AB5-CoB（50%） composite was still much higher than that of the AB5 alloy. The high rate discharge capability （HRD） and potentiodynamic polarization were also tested.

关键词： composite materials powder metallurgy electrochemical techniques electrochemical properties