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Properties of meso-tetrakis (4-n-alkanoyloxyphenyl) porphyrin liquid crystal Co and Ni complexes

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science china Chemistry 2007年第4期50卷 488-493页

作者： LIU Wei1,2 & SHI TongShun2 1 College of Materials science and Engineering, Shandong University of technology, Zibo 255049, china 2 department of Chemistry, Jilin University, Changchun 130023, china 1. College of Materials science and Engineering Shandong University of Technology Zibo 255049 China 2. department of Chemistry Jilin University Changchun 130023 China

Six series of meso-tetrakis (4-n-alkanoyloxyphenyl) porphyrin Co and Ni complexes (12 kinds) were reported. Nine of the compounds were found to exhibit liquid crystal properties and display a hexagonal columnar discotic columnar (Colh) phase. Molecular structure of all synthesized compounds was confirmed by IR, UV, MS, 1H NIVR, and elemental analysis. These liquid crystalline compounds have been studied by cyclic voltammetry, luminescence, and surface photovoltage spectroscopy.

关键词： porphyrin liquid crystal cyclic voltammetry luminescence surface photovoltage spectroscopy

Lie bialgebras of generalized Witt type

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science china Mathematics 2006年第4期49卷 533-544页

作者： SONG Guang’ai & SU Yucai College of Mathematics and Information science, Shandong Institute of Business and technology, Yantai 264005, china department of Mathematics, University of science and technology of china, Hefei 230026, china department of Mathematics, Shanghai Jiaotong University, Shanghai 200240, china College of Mathematics Information science Shandong Institute of Business technology Yantai 264005 China department of Mathematics University of Science technology of china Hefei 230026 China department of Mathematics Shanghai Jiaotong University Shanghai 200240 China

In this paper, all Lie bialgebra structures on the Lie algebras of generalized Witt type are considered. It is proved that, for any Lie algebra W of generalized Witt type, all Lie bialgebras on W are the coboundary triangular Lie bialgebras. As a by-product, it is also proved that the first cohomology group H1(W, W(?)W) is trivial.

关键词： Lie bialgebras, Yang-Baxter equation, Lie algebra of generalized Witt type.

Dynamic behavior of polymer surface and the time dependence of contact angle

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science china Chemistry 2005年第6期48卷 553-559页

作者： WANG Xinping1, CHEN Zhifang1 & SHEN Zhiquan2 1. Key Laboratory of Advanced Textile Materials and Manufacturing technology of Education Ministry, department of Applied Chemistry, Zhejiang Institute of science and technology, Hangzhou 310033, china 2. department of Polymer science and Engineering, Zhejiang University, Hangzhou 310027, china 1. department of Applied Chemistry Zhejiang Institute of Science and Technology Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Education Ministry 310033 Hangzhou China 2. department of Polymer science and Engineering Zhejiang University 310027 Hangzhou China

Time-dependent contact angles were measured by depositing sessile drops of wa-ter on the polymer surfaces and monitoring the drop shape as a function of time. It was found that contact angles decreased sharply with contact time and the equilibrium contact angle was finally attained after a certain time. Values of starting (θ s) and equilibrium contact angles (θ e) obtained by the sessile drop method depend on polymer properties. The Wilhelmy plate technique was used to measure advancing and receding contact angles. The variations of starting (θ s) and equilibrium contact angles (θ e), advancing (θ a) and receding contact angles (θ r) have been studied on the oxidized surface of polymers containing polybutadiene block to explore the cause of time-dependence in contact angle measurement and the meaning of θ s and θ e. The results showed the linear relationships between starting (θ s) and advancing contact angles (θ a), the equilibrium (θ e) and receding contact angles (θ r). The similar relationship was also established between the contact angle hysteresis (θ a?θ r) and differences (θ s ?θ e) in starting contact angles and equilibrium contact angles. Therefore, time-dependence in contact angle measurement was mainly attributed to the surface reconstruction when water drops were deposited on polymer surfaces. The starting contact angle was contributed by the hydrophobic component on polymer surface and the equilibrium contact angle mainly by the hydrophilic component of polymer. These results not only demonstrated the interdependency between two contact angle measurements, the sessile drop method and the Wilhelmy plate technique, but also provided the experimental evidence to explain the cause of time-dependent contact angle. This may also provide a new method to study dynamic behavior of polymer surface.

关键词： contact angle, surface dynamic behavior, polymer surface, dynamic contact angle, time-dependence.

Roles of urban vegetation on balance of carbon and oxygen in Guangzhou, china

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Journal of environmental sciences 2003年第2期15卷 155-159页

作者： GUAN Dong-sheng, CHEN Yu-juan (department of environmental science, Zhongshan University, Guangzhou 510275, china. department of environmental science Zhongshan University Guangzhou 510275 China

The plant biomass and net primary production(NPP) of urban vegetation in Guangzhou were estimated by dimension analysis, tree truck volume, and harvest methods as well as relationship between biomass and NPP and so on. The biomass and NPP were respectively 2875150t and 1058122 t/a. They were respectively 392495t and 64948 t/a in the built-up area and 2482655t and 993147 t/a in the unbuilt-up area. It would make plant biomass, especially NPP decline obviously, if the unbuilt-up area were changed to the built-up area. The carbon content of plant was 1328649 for the total and 13.78 t/hm 2 for the mean, and amounts of carbon fixed and oxygen made by urban vegetation were respectively 4.80 t/(hm 2·a) and 12.79 t/(hm 2·a) for the mean and 462624 t/a and 1232430 t/a for the total, which were equal to 1.45 times and 1.04 times of those by human breathing. However, they were only equal to 7.61% and 4.97% of amount of carbon released and oxygen consumption in urban Guangzhou. The biomass and NPP of urban vegetation in Guangzhou only corresponded to 7.8% and 47.3% of those of southern subtropical evergreen broad-leaf forest in Dinghu Mountain. Therefore, the roles of Guangzhou urban vegetation in balance of carbon and oxygen would be increased greatly if it could be conserved and improved in some way.

关键词： urban vegetation carbon oxygen balance Guangzhou

A blow-up criterion for classical solutions to the compressible Navier-Stokes equations

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science china Mathematics 2010年第3期53卷 671-686页

作者： HUANG XiangDi 1 & XIN ZhouPing 2, 1 department of Mathematics, University of science and technology of china, Hefei 230026, china 2 department of Mathematics, The Chinese University of Hong Kong, Hong Kong, china 1. department of Mathematics University of Science and Technology of China Hefei 230026 China2. Department of Mathematics The Chinese University of Hong Kong Hong Kong China

In this paper, we obtain a blow-up criterion for classical solutions to the 3-D compressible Navier-Stokes equations just in terms of the gradient of the velocity, analogous to the Beal-Kato-Majda criterion for the id... 详细信息

关键词： blow-up classical solutions compressible Navier-Stokes

An innovative membrane bioreactor and packed-bed biofilm reactor combined system for shortcut nitrification-denitrification

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Journal of environmental sciences 2009年第5期21卷 568-574页

作者： ZHANG Yunxia, ZHOU Jiti, ZHANG Jinsong, YUAN Shouzhi School of environmental and Biological science and technology, Dalian University of technology, Dalian 116024, china. [a]School of environmental and Biological science and technology Dalian University of Technology Dalian 116024 China

An innovative shortcut biological nitrogen removal system, consisting of an aerobic submerged membrane bioreactor （MBR） and an anaerobic packed-bed biofilm reactor （PBBR）, was evaluated for treating high strength ammonium-bearing wastewater. The system was seeded with enriched ammonia-oxidizing bacteria （AOB） and operated without sludge purge with a decreased hydraulic retention time （HRT） through three phases. MBR was successful in both maintaining nitrite ratio over 0.95 and nitrification efficiency higher than 98% at HRT of 24 h, and PBBR showed satisfactory denitrification efficiency with very low effluent nitrite and nitrate concentration （both below 3 mg/L）. By examining the nitrification activity of microorganism, it was found that the specifc ammonium oxidization rate （SAOR） increased from 0.17 to 0.51 g N/（g VSS.d） and then decreased to 0.22 g N/（g VSS.d） at the last phase, which resulted from the accumulation of extracellular polymers substances （EPS） and inert matters enwrapping around the zoogloea. In contrast, the average specific nitrite oxidization rate （SNOR） is 0.002 g N/（g VSS.d）, only 1% of SAOR. Because very little Nitrobactor has been detected by fluorescence in situ hybridization （FISH）, it is confirmed that the stability of high nitrite accumulation in MBR is caused by a large amount of AOB.

关键词： shortcut nitrification-denitrification ammonia-oxidizing bacteria nitrite accumulation FISH

OBSERVATIONS ON DEFORMATION BEHAVIOR OF HIGH PERFORMANCE FIBERS BY POLARIZING OPTICAL MICROSCOPY

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Chinese Journal of Polymer science 2000年第1期18卷 81-86页

作者： Chang-fa Xiao Yu-feng Zhang department of Materials science, Tianjin Institute of Textile science and technology, Tianjin 300160, china Tianjin Inst Text Sci & Technol Dept Mat Sci Tianjin 300160 Peoples R China

By means of polarizing optical microscopy (POM), deformation behavior of four kinds of fibers, i.e, ultra high molecular weight polyethylene (UHMW-PE) fiber, polyvinyl alcohol (PVA) fiber, polyethylene terephthalate (PET) fiber, and wholly aromatic (rho-hydroxybenzoic acid/2-hydroxy-6-naphthoic acid) copolyester [P(HBA/HNA)]/PET (ACPET blend) fiber, in axial compression, axial impacting, and bending was observed. In compression, kink bands formed at an angle of 55-60 degrees ro the fiber axis in 10-times-drawn UHMW-PE fiber, 75-80 degrees in 40-times-drawn sample, 80 degrees in PVA fiber, and 90 degrees in the ACPET blend fiber. In impacting and bending, band angles of UHMW-PE, PVA and PET fibers are nearly the same as those formed in compression, indicating that slip systems do not change. For any of the four kinds of fiber, band spacing exhibits great differences in compression, in impacting, and in bending, which may be attributed to the differences in the degrees of strain or stress concentration.

关键词： high performance fiber axial compression axial impacting bending

NMDA and AMPA receptors mediate intracellular calcium increase in rat cortical astrocytes

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Acta Pharmacologica Sinica 2004年第6期25卷 12-18页

作者： Bo HU, Sheng-gang SUN2, E-tang TONGNeurology department, Union Hospital, Tongji College, Huazhong University of science and technology, Wuhan 430022, china Neurology department Union Hospital Tongji College Huazhong University of Science and Technology Wuhan 430022 China

AIM: To study the effect of glutamate on the intracellular calcium signal of pure cultured rat astrocytes and the roleof N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) re-ceptors in the procedure. METHODS: The fluorescence of calcium was measured by Fura-2/AM (F345/F380).RESULTS: L-Glutamate induced [Ca2+]i increase in most of the cells in concentration- and time-dependent *** 50 mmol/L induced the fluorescence increase by almost three to four times, while the effect of AMPA 50mmol/L was just half of that of D-(-)-2-amino-5-phosphonopentanoic acid (D-AP-5; a selective antagonist of theNMDA receptor). 6-Cyano-7-nitroquinoxaline-2,3-dione (CNQX, a selective antagonist of the AMPA receptor)abolished the effects of NMDA and AMPA, respectively. D-AP-5 and CNQX simultaneously or respectively attenu-ated the effect of L-glutamate at different degrees, but could not abolish it entirely. CONCLUSION: Glutamatemodulated intracellular Ca2+ of pure cultured rat astrocytes through different pathways. The activation of NMDAand AMPA receptors took part in the complex mechanisms.

关键词： glutamate astrocytes NMDA receptors AMPA receptors calcium

Effective temperature and exergy of monochromic blackbody radiation

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Progress in Natural science:Materials International 2007年第10期17卷 1250-1254页

作者： Chen Zeshao and Mo Songping(department of Thermal science and Energy Engineering, University of science and technology of china, Hefei 230027, china) department of Thermal science and Energy Engineering University of Science and Technology of China Hefei 230027 China

A new parameter named monochromic effective temperature Tλ is proposed, which represents the thermodynamic quality of monochromic blackbody radiation. The exergy of the monochromic blackbody radiation is expressed by Tλ. The monochromic effective temperature equation is developed, which shows that the product of Tλ and the wavelength is constant, which equals 5.33016×10-3 m·K. The exergy function of monochromic blackbody radiation is presented. The cause of the view that there is negative entropy production in photosynthesis can be explained by the results of this work.

关键词： photon monochromic effective temperature exergy of monochromic radiation.