Method for calculating ecological water storage and ecological water requirement of marsh

As one of the most typical wetlands, marsh plays an important role in hydrological and economic aspects, especially in keeping biological diversity. In this study, the definition and connotation of the ecological water storage of marsh is discussed for the first time, and its distinction and relationship with ecological water requirement are also analyzed. Furthermore, the gist and method of calculating ecological water storage and ecological water requirement have been provided, and Momoge wetland has been given as an example of calculation of the two variables. Ecological water use of marsh can be ascertained according to ecological water storage and ecological water requirement. For reasonably spatial and temporal variation of water storage and rational water resources planning, the suitable quantity of water supply to marsh can be calculated according to the hydrological conditions, ecological demand and actual water resources.

Synthesis, characterization and catalytic properties of chiral BINOL functionalized mesoporous silicas for enantioselective Morita-Baylis-Hillman reaction

Several Chiral BINOL functionalized mesoporous silicas were prepared by post grafting of organosilane derivatives of (S)-BINOL (1,1'-bi-2-naphthol) on SBA-15 and characterized by C-13 CP/MAS NMR, FT-IR, UV-visible absorption spectra, elemental analysis, powder XRD, nitrogen adsorption-desorption isotherms and TEM techniques. Their catalytic properties were demonstrated in enantioselective Morita-Baylis-Hillman reaction of 3-phenylpropanal and cyclohexenone.

Synthesis and properties of soluble poly[bis(benzimidazobenzisoquinolinones)] based on novel aromatic tetraamine monomers

Four aromatic tetraamine monomers possessing flexible ether linkages were successfully synthesized by nucleophilic aromatic substitution of hydroquinone, 4,4'-dihydroxybiphenyl, 2,2'-bis(4-hydroxyphenyl)propane, and 2,7-dihydroxynaphthalene with 5-chloro-2-nitroaniline, followed by reduction, respectively. With these monomers, a new class of soluble poly[ bis(benzimidazobenzisoquinolinones)] was prepared by a one-step, high-temperature solution polycondensation. The resulting polymers were completely soluble in phenolic solvents and had high inherent viscosities ranging from 1.2 to 1.5 g dL(-1). These polymers had glass transition temperatures in the range of 427-449 degrees C. Thermogravimetric analysis showed that all polymers were thermally stable, with 5% weight loss recorded above 510 degrees C in nitrogen.

Architectures of Strontium Hydroxyapatite Microspheres: Solvothermal Synthesis and Luminescence Properties

Strontium hydroxyapatite (Sr-5(PO4)(3)OH, SrHAp) microspheres with 3D architectures have been successfully prepared through a efficient and facile solvothermal process. The experimental results indicate that the SrHAP microspheres are composed of a large amount of nanosheets, which are assembled in a radial form from the center to the surface of the microspheres. The as-obtained SrHAp samples show an intense and bright blue emission from 350 to 570 nm centered at 427 nm (CIE coordinates: x = 0.153, y = 0.081; lifetime: 9.2 ns; quantum efficiency: 31%) under long-wavelength UV light excitation (344 nm). This blue emission might result from the CO2 center dot- radical impurities in the crystal lattice. Furthermore, the surfactants CTAB and trisodium citrate have an obvious impact on the morphologies and the luminescence properties of the products, respectively.

Dependence of performance of organic light-emitting devices on sheet resistance of indium-tin-oxide anodes

The dependence of the performance of organic light-emitting devices(OLEDs) on the sheet resistance of indium-tin-oxide(ITO) anodes was investigated by measuring the steady state current density brightness voltage characteristics and the electroluminescent spectra. The device with a higher sheet resistance anode shows a lower current density, a lower brightness level, and a higher operation voltage. The electroluminescence(EL) efficiencies of the devices with the same structure but different ITO anodes show more complicated differences. Furthermore, the shift of the light-emitting zone toward the anode was found when an anode with a higher sheet resistance was used. These performance differences are discussed and attributed to the reduction of hole injection and the increase in voltage drop over ITO anode with the increase in sheet resistance.

可生物降解聚合物的现状及生物降解性研究

综述了可生物降解聚合物的现状及发展、影响生物降解性的因素和生物降解性的评价方法。

Hydrothermal synthesis and characterization of a new compound [Ni(en)(3)](2)[Ni(en)(2)(H2O)(2)][As6V15O42] center dot 4H(2)O

A new compound, [Ni(en)(3)](2)[Ni(en)(2)(H2O)(2)][As6V15O42] . 4H(2)O, was first prepared by hydrothermal synthesis and characterized by elemental analysis, IR, TGA-DSC, ESR and single crystal X-ray diffraction. Crystal data: monoclinic, space group C-c, a = 1. 523 6(3) nm, b = 2. 051 8(4) nm, c = 2.395 9(5) nm, beta = 97. 41(3)degrees, V = 7.427(3) nm(3), Z = 4, R = 0. 057 0, wR(2) = 0.135 7. The polyanion consists of six AsO3 pyramids and fifteen VO5 pyramids. Counterions are complex ions with octahedral structure, which consist of NH2CH2CH2NH2 and Ni2+.

Crystal structure of tris(methylcyclopentadienyl) tetrahydrofuranatosamarium

The first crystal structure of tris(methylcyclopentadienyl) tetrahydrofuranato (THF) lanthanide complexes, (CH3Cp)(3)Sm . THF, is determined. The complex crystallizes from mixed solvents of tetrahydrofuran and hexane as a monomer in the orthorhombic space group Pc2(1)n with the unit cell parameters a = 9.135(2) Angstrom, b = 13.263(2) Angstrom, c = 16.176(3) Angstrom, and Z = 4.

仲壬基苯氧基乙酸萃取金属离子

研究了仲壬基苯氧基乙酸在盐酸介质中对 Eu3+ ,Zn2 + ,Cd2 + ,Co2 + ,Ni2 + ,Cu2 + ,Mn2 + ,Mg2 + 等金属离子的萃取行为 ,考察了平衡水相酸度 ,萃取剂浓度等因素对萃取平衡的影响 ,得到了萃取平衡方程 .根据金属离子之间的分离系数值可看出 ,通过控制适当的酸度 ,有可能分离 Eu3+中通常伴生的一些金属离子 ,同时还可能达到 Co2 +与 Ni2 + ,Zn2 +与 Cd2 +等金属离子之间的相互分离

Decomposition of circular dichroism of norepinephrine by singular value decomposition-least square method

Singular value decomposition - least squares (SVDLS), a new method for processing the multiple spectra with multiple wavelengths and multiple components in thin layer spectroelectrochemistry has been developed. The CD spectra of three components, norepinephrine reduced form of norepinephrinechrome and norepinephrinequinone, and their fraction distributions with applied potential were obtained in three redox processes of norepinephrine from 30 experimental CD spectra, which well explains electrochemical mechanism of norepinephrine as well as the changes in the CD spectrum during the electrochemical processes.

奇异值分解-最小二乘解析去甲肾上腺素的圆二色谱

提出了一种新的光谱电化学数据处理方法:奇异值分解-最小二乘法(SVDLS).该方法用于解析在三个氧化还原过程中30个不同电位下的去甲肾上腺素圆二色(CD)光谱,获得去甲肾上腺素,去甲肾上腺素醌和去甲肾上腺素红在不同过程中的CD谱及其组分分布曲线.很好地解释了去甲肾上腺素的氧化还原机理和相应的CD光谱的变化.

M_2B_5O_9Cl:Eu(M=Ca,Sr,Ba)的真空紫外光谱特性的研究

采用高温固相反应法合成了M_2B_5O_9Cl:Eu(M=Ca,Sr,Ba)中荧光体,测量了荧光体的真空紫外激发光谱,研究了M_2B_5O_9Cl:Eu(M=Ca,Sr,Ba)的真空紫外光谱特性,观察到基质吸收带位于120～200 nm区域,Eu~(2+)离子的5d能级劈裂随着M~(2+)的半径的增加而减小,同时也观察到基质与稀土离子之间存在的能量传递。

Synthesis and crystal structure of a novel compound constructed from tris-(2, 2 '-bipy)ruthenium(II) and decatungstate

Self-assembly of tris-[2,2 ' -bipyridine]ruthenium(II) chloride with decatunstate produced a novel cation radical salt, [Ru(bpy)(3)](2)[W10O32] . 3DMSO. This is the first product of 2,2 ' -bipyridineruthenium(II)-polyoxometalates species. Crystal data: Monoclinic, P2(1)/c, a = 12.902(3) Angstrom, b = 21.487(3) Angstrom, c = 15.854(5) Angstrom, beta = 93.46(2)degrees, V = 4387(2) Angstrom (3), Z = 2, R-1 = 0.0599, wR2 = 0.1183. X-ray crystallographic study showed that the crystal structure was constructed by electyrostatic attraction and C-H . . .O hydrogen bonds between tris-[2,2 ' -bipyridine]ruthenium(II) and decatungstate polyanion. The tris-[2,2 ' -bipyridine]ruthenium molecules occupy cavities in the polyoxometalate lattice ordered along b-axis. (C) 2001 Elsevier Science B.V. All rights reserved.

Synthesis, structure characterization and transesterification of the complexes of beta-alkoxycarbonylethyltin trichlorides

Thirteen title complexes ROCOCH2CH2SnCl3 . L(R = C(1 similar to 5)alkyl;L = DBSO,HMPA) were synthesized and characterized by elemental analysis, IR,H-1 NMR. The crystal structure of n -PrOCOCH2CH2SnCl3 . DBSO was determined by the X-ray diffraction analysis. The crystal belongs to orthorhombic system,space group P2(1)2(1)2(1) with a = 1.062, b = 1.427, c = 1.635nm; Z = 4. The complex exists as a discrete molecule, and the tin atom attains a distorted octahedral geometry via the coordination of intramolecular carbonyl oxygen and the Lewis base donor atom. The transesterification of CH3OCOCH2CH2SnCl3 . L with alcohol was studied, and the intramolecular Lewis acid catalytic mechanism was suggested.