微生物混合培养及其应用

简述了混合培养微生物资源及其应用的研究进展。在长期的实验和生产实践中 ,人们发现很多生物过程是微生物纯培养不能完成或只能微弱进行的 ,必须依靠两种或两种以上的微生物共同培养完成。对于很多工业污染物、生物农药、纤维素、几丁质的生物降解 ,微生物混合培养是必要的 ;微生物混合培养可用于维生素C、维生素B1 2 、组氨酸、缬氨酸、L 苹果酸等发酵生产 ,还可用于药物的甾体转化、沼气发酵、湿法冶金等。混合培养的微生物资源应受到人们更多的重视。

流域水土资源优化配置的几种方法比较

目前关于流域水土资源优化配置研究的特点表现为:对单项的水、土资源优化配置研究较多,把两者结合起来的研究较少;分别从宏观和微观两个尺度研究的较多,将两种尺度结合起来研究的较少;越来越重视资源配置模式下的生态系统服务功能状况及其能否满足特定区域可持续发展的需要;研究方法逐渐由定性向定量化转变,在定量研究中,较多使用一般线性规划、灰色线性规划、动态规划、多目标决策和系统动力学等方法;越来越重视以3S技术为基础,结合专业模型进行模拟,为水土资源配置和管理提供高质量的科学决策支持,但目前还没有建立完善的区域性的支持

区域尺度城市增长时空动态模型及其应用

区域尺度城市增长动态模拟(Reg-UGM)是城市化影响下的土地利用/覆盖变化以及全球环境变化研究的重要手段之一。针对单个城市增长未来情景模拟难以在区域尺度刻画与解释城市化影响下的土地利用/覆盖变化以及与全球环境变化交互过程与作用机理主要问题,本研究集成人工神经网络模型(ANN)与元胞自动机模型(CA)构建适合不同情景的区域尺度城市增长动态模型,通过1979年以来高分辨率遥感信息探测获取的4个时段京津唐都市圈城市增长时空特征分析提取先验知识规则,模拟京津唐都市圈在基准模式、经济模式、政策模式与结构调整模式未来不同情景模式下城市增长过程。研究表明,Reg-UGM在模拟区域尺度受国家宏观政策等影响城市非线性增长过程具有较好的可靠性,为进一步研究城市化影响下的宏观生态效应提供前提保障。模拟结果显示京津唐都市圈在不同情景模式下城市增长呈现较大的时空格局差异,未来城市增长结构调整模式更符合区域城市化的实际情况,未来区域城市增长将由特大城市向中小城市转移,滨海沿线城镇发展带将经历更快的城市增长过程。

Considerable effects of diversity indices and spatial scales on conclusions relating to ecological diversity

The relationships between ecological diversity and ecosystem functions such as stability and productivity have long been debated and have no final conclusion until now. It is ignored that the debate should be firstly based on the same diversity index, which should be theoretically complete, and on same observation scale. For the issue on the scale of ecotope observation, ecosystems should be distinguished according to intensity of human disturbance. For the issue on the scale of species observation, either number diversity or biomass diversity should be identified. This paper takes grassland ecosystems located within the Bayin Xile grassland of Xilin Gol League of Inner Mongolia Autonomous Region as an example to analyze effects of different diversity indices and spatial scales on the conclusions of ecological diversity and its relationships with ecosystem functions. The analysis results both on the scale of ecotope observation and on the scale of species observation show that different diversity indices might give different conclusions and spatial resolution has a great effect on the relative conclusions. (c) 2005 Elsevier B.V. All rights reserved.

Fixation of carbon dioxide into aliphatic polycarbonate, cobalt porphyrin catalyzed regio-specific poly(propylene carbonate) with high molecular weight

Cobalt porphyrin complex ((TPPCoX)-X-III) (TPP = 5, 10, 15, 20-Tetraphenylporphyrin; X = halide) in combination with ionic organic ammonium salt was used for the regio-specific copolymerization of propylene oxide and carbon dioxide. A turnover frequency of 188 h(-1) was achieved after 5 h, and the byproduct propylene carbonate was successfully controlled to below 1%, where the obtained poly(propylene carbonate) (PPC) showed number average molecular weight (M-n) of 48 kg/mol, head-to-tail content of 93%, and carbonate linkage of over 99%.

以邻菲咯啉为配体的铬系催化剂制备1,2-聚丁二烯

以邻菲咯啉(简称Phen)为配体、异辛酸铬(简称Cr)-三异丁基铝(简称Al)为催化剂、己烷为溶剂合成1,2-聚丁二烯,考察了Phen和Al用量以及聚合温度对1,2-聚丁二烯微观结构及其相对分子质量的影响。结果表明,低相对分子质量聚合物是Cr和Al作用的结果,高相对分子质量聚合物是Cr、Phen和Al作用的结果;在Phen/Cr(摩尔比)为1.0、Al/Cr(摩尔比)为20、聚合温度为50℃的条件下,Cr-Phen-Al催化剂具有高活性,可得到1,2-结构摩尔分数约为50%、相对分子质量呈双峰分布、间同度为28%的聚丁二烯。

Chitosan/heteropolyacid composite membranes for direct methanol fuel cell

As inorganic proton conductors. phosphomolybdic acid (PMA), phosphotungstic acid (PWA) and silicotungstic acid (SiWA) are extremely attractive for proton-conducting composite membranes. An interesting phenomenon has been found in our previous experiments that the mixing of chitosan (CS) solution and different heteropolyacids (HPAs) leads to strong electrostatic interaction to form insoluble complexes. These complexes in the form of membrane (CS/PMA, CS/PWA and CS/SiWA composite membranes) have been prepared and evaluated as novel proton-conducting membranes for direct methanol fuel cells. Therefore, HPAs can be immobilized within the membranes through electrostatic interaction, which overcomes the leakage problem from membranes.

Organic/inorganic nanocomposite polymer electrolyte

The organic/inorganic nanocomposites polymer electrolytes were designed and synthesized. The organic/inorganic nanocomposites membrane materials and their lithium salt complexes have been found thermally stable below 200 degrees C. The conductivity of the organic/inorganic nanocomposites polymer electrolytes prepared at room temperature was at magnitude range of 10(-6) S/cm. (c) 2007 Li Qi. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Determination of atenolol and metoprolol by capillary electrophoresis with Tris(2,2 '-bipyridyl)ruthenium(II) electrochemiluminescence detection

Capillary electrophoresis (CE) coupling with a tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)(3)(2+)) electrochemiluminescence (ECL) detection technique was developed for the analysis of two 8-blockers, atenolol (AT) and metoprolol (ME). The parameters that influence the separation and detection, including the buffer pH and concentration, the separation voltage, the detection potential and Ru(bpy)(3)(2+) concentration, were optimized in detail. The calibration curve was linear over a concentration range of two or three orders of magnitude for the two beta-blockers. The detection limits for AT and ME were 0.075 and 0.005 mu M (S/N = 3). The relative standard deviations (n = 8) of the ECL intensity and the migration time were 2.65 and 0.22% for AT, 2.82 and 0.34% for ME, respectively. The proposed method was applied to determine AT and ME in spiked urine samples; satisfactory results were obtained.

VIV-UV excited luminescent properties of LnCa4O(BO3)3 : RE3+(Ln = Y, La, Gd; Re=Eu, Tb, Dy, Ce)

Calcium lanthanide oxyborate doped with rare-earth ions LnCa(4)O(BO3)(3):RE3+ (LnCOB:RE, Ln = Y, La, Gd, RE = Eu, Tb, Dy, Cc) was synthesized by the method of solid-state reaction at high temperature. Their fluorescent spectra were measured from vacuum ultraviolet (VUV) to visible region at room temperature. Their excitation spectra all have a broadband center at about 188 nm, which is ascribed to host absorption. Using Dorenbos' and J phi rgensen's work [P. Dorenbos, J. Lumin. 91 (2000) 91, R. Resfeld, C.K. J phi rgensen. Lasers and Excite States of Rare Earth [M], Springer, Berlin, 1977, p. 45], the position of the lowest 5d levels E(Ln,A) and charge transfer band E-ct were calculated and compared with their excitation spectra.Eu3+ and Tb3+ ions doped into LnCOB show efficient luminescence under VUV and UV irradiation. In this system, Ce3+ ions do not show efficient luminescence and quench the luminescence of Tb3+ ions when Tb3+ and Ce3+ ions are co-doped into LnCOB. GdCOB doped with Dy3+ shows yellowish white light under irradiation of 254 nm light for the reason that Gd ions transfer the energy from itself to Dy.

Computer simulation of miscibility and self-assembly structure for polymer-containing systems with special interactions

The miscibility and structure of A-B copolymer/C homopolymer blends with special interactions were studied by a Monte Carlo simulation in two dimensions. The interaction between segment A and segment C was repulsive, whereas it was attractive between segment B and segment C. In order to study the effect of copolymer chain structure on the morphology and structure of A-B copolymer/C homopolymer blends, the alternating, random and block A-B copolymers were introduced into the blends, respectively. The simulation results indicated that the miscibility of A-B block copolymer/C homopolymer blends depended on the chain structure of the A-B copolymer. Compared with alternating or random copolymer, the block copolymer, especially the diblock copolymer, could lead to a poor miscibility of A-B copolymer/C homopolymer blends. Moreover, for diblock A-B copolymer/C homopolymer blends, obvious self-organized core-shell structure was observed in the segment B composition region from 20% to 60%. However, if diblock copolymer composition in the blends is less than 40%, obvious self-organized core-shell structure could be formed in the B-segment component region from 10 to 90%. Furthermore, computer statistical analysis for the simulation results showed that the core sizes tended to increase continuously and their distribution became wider with decreasing B-segment component.

Sr_4Al_(14)O_(25)∶RE~(3+)(RE=Eu,Ce,Tb)中稀土离子的发光性质

采用高温固相反应合成了Sr4Al14O25∶RE3+(RE=Eu,Ce,Tb)样品,研究了其中Eu3+,Ce3+和Tb3+的光谱性质,以及Ce3+与Tb3+共掺时的能量传递现象;发现Eu3+,Ce3+和Tb3+占有两个格位,与Eu2+在此基质中的情况相似;在Tb3+的发射光谱中同时观察到了来自5D3与5D4的发射,表明两能级间无辐射跃迁过程不显著;Ce3+对Tb3+有敏化作用。

Synthesis and crystal structure of cyclopentylindene rare earth complex (C5H9C9H6)(3)SMCl-Li+ (THF)(4)

Rare earth complex (C5H9C9H6)(3)SmCl-Li+ (THF)(4)( I ) was synthesized by reacting anhydrous SmCl3 with two equivalents of C5H9C9H6Li. From mix-solvent of THF and hexane, red color single crystals were obtained. The crystal belongs to a cubic system, space group P2(1)3 with unit cell parameters a= b=c= 1. 754 0(2) nm, alpha=beta=gamma=90degrees, V=5. 396 4(11) nm(3), Z = 4. The ten-coordinated samarium atom is bonded to three cyclopentylindenyl rings and a chlorine atom to form the anionic part of the title complex, ring centroids and the chlorine atom form a tortured tetrahedron around samarium. In the cationic part, lithium atom coordinates to four oxygen atoms of THF molecules to form a normal tetrahedron. The Sm-C(within the same ring) distance varies from 0. 268 to 0. 299 nm.

三(环戊基茚基)钐配合物(C_5H_9C_9H_6)_3SmCl~-Li~+(THF)_4的合成与晶体结构

稀土配合物能使极性和非极性单体聚合[1] .虽然目前已测定了几乎所有的三 (环戊二烯基 )稀土配合物及部分三 (取代环戊二烯基 )稀土配合物的晶体结构 ,但有关三 (茚基 )稀土配合物的报道较少 .第一个三 (茚基 )稀土配合物是无水三氯化稀土与 3倍物质的量的茚基钠 C9H7Na在四氢呋喃中反应而得 ,但未报道其晶体结构[2 ] .后来用同样的反应却分离出以氯为桥的二聚体离子对配合物[Na( THF) 6][Ln( η5- C9H7) 3μ( Cl) Ln( η5- C9H7) 3]( Ln=Nd,Sm) [3] .无水三氯化稀土与 Mg( C9H7) 2 或C9H7K等物质的量反应则生成非溶剂化的 ( C9H7) 3Sm[4 ] ,而与茚基钠和环辛四烯钾 ( C8H8K)以 1∶ 2∶ 1物质的量比反应时 ,则得到 ( C9H7) 3Ln( THF) ( Ln=Nd,Gd) [5] .Bottomley[6] 曾用 ( C9Me7) K(七甲基茚基钾 )与 L n Cl3(物质的量比 3∶ 1 )反应制备 ( C9Me7) 3Nd( THF) 5和 ( C9Me7) 3Er· ( THF) 3,但未报道晶...