Simultaneous determination of methylene blue and new methylene blue by slab optical waveguide spectroscopy and artificial neural networks

A slab optical waveguide (SOWG) has been used for study of adsorption of both methylene blue (MB) and new methylene blue (NMB) in liquid-solid interface. Adsorption characteristics of MB and NMB on both bare SOWG and silanized SOWG by octadecyltrichlorosilane (ODS) were compared. The simultaneous determinations of both MB and NMB were explored by flow injection SOWG spectrophotometric analysis and artificial neural networks (ANNs) for the first time. Concentrations of MB and NMB were estimated simultaneously with the ANNs. Results obtained with SOWG were compared with those got by conventional UV-visible spectrophotometry. (C) 2003 Elsevier Science B.V All rights reserved.

抗Her-2-scFv-SEC2融合免疫毒素的构建和功能研究(英文)

用基因工程方法,将金黄色葡萄球菌肠毒素 C2 与抗人表皮生长因子受体 HER-2 单链抗体 scFv-B1,以一连接短肽连接,构建融合免疫毒素 B-L-SEC2,并用改进的新型表达载体 pASK75-EX,在大肠杆菌 BL21(ED3)中表达. 以不溶性包涵体形式表达的目的蛋白经变性后以镍离子螯和层析纯化,并以透析法进行复性. 流式细胞术和 MTT 实验结果表明,纯化复性的融合免疫毒素 B-L-SEC2,在体外具有与 HER-2 过表达的靶细胞 SK-Br-3 特异性结合的活性,并对该细胞产生显著的特异性生长抑制作用.

黄土丘陵区不同土地利用方式土壤团粒结构分形特征

土壤团粒、水稳性团粒和微团粒状况是影响土壤结构和性质的重要因素。运用分形理论研究黄土丘陵区纸坊沟流域7种不同土地利用方式土壤团粒结构的分形特征。结果表明:表层土壤团粒的分形维数在1.641~2.114之间,其大小顺序为人工草地>果园>坡耕地>乔木林地>灌丛>天然草地>人工梯田。土壤水稳性团粒的分形维数在1.774~2.384之间,其变化顺序为果园>乔木林地>人工草地>坡耕地>天然草地>人工梯田>灌丛,二者均表现出≥0.25 mm粒级土壤团粒含量越低,分形维数越高的规律;分形维数与≥5 mm、5~2 mm和≥0.25 mm粒级的土壤团粒、水稳性团粒呈极显著负相关(P<0.01),与<0.25 mm粒级的呈极显著正相关(P<0.01);结合团粒结构体破坏率可知,灌丛土壤结构与稳定性最好,其次为天然草地,人工草地最差;表层土壤微团粒结构分形维数在2.360~2.487之间,大小顺序为天然草地>乔木林地>坡耕地>人工梯田>人工草地>果园>灌丛,灌丛有助于促进土壤微结构形成,分形维数与0.25~0.05 mm和>0.001 mm粒级土壤微团粒含量呈极显著负相关(P<0.01),与<0.001 mm粒级土壤微团粒含量呈极...

樟子松针叶磷组分浓度与土壤有效磷浓度的关系

为弄清科尔沁沙地东南部樟子松人工林是否受土壤磷素供应的限制,找出反映土壤磷素供应状况的最佳叶片养分指标,分析了樟子松人工林不同年龄针叶中全磷、无机磷、有机磷和全氮浓度以及土壤有效磷浓度.结果表明:研究区樟子松人工林土壤有效磷浓度较低,为0.12～0.63mg.kg-1;土壤有效磷浓度与当年生针叶无机磷和全磷浓度显著相关,而与针叶全磷的相关性来源于针叶中无机磷与全磷的相关.与当年生针叶全磷浓度相比,针叶无机磷浓度能更为准确、直接地反映土壤的供磷水平.

1.54 mu m near-infrared photoluminescent and electroluminescent properties of a new Erbium (111) organic complex

The crystal structure of Er(PM)(3)(TP)(2) [PM = 1-Phenyl-3-methyl-4-isobutyryl-5-pyrazoloiie, TP = triphenyl phosphine oxide] was reported and its photoluminescence properties were studied by UV-vis absorption, excited, and emission spectra. The Judd-ofelt theory was introduced to calculate the radiative transition rate and the radiative decay time of 3.65 ms for the I-4(13/2) -> I-4(15/2) transition of Er3+ ion in this complex.

Fabrication of a metal particle array based on a self-assembled template from a two-armed polymer

A two-armed polymer with a crown ether core self-assembles to produce macroporous films with pores perpendicularly reaching through the film down to the substrate. A possible assembling mechanism is discussed. The pore size can be conveniently adjusted by changing the solution concentration. These through-hole macroporous films provide a template for fabricating an array of Cu nanoparticle aggregates.

Organic-phase enzyme electrode for phenolic determination based on a functionalized sol-gel composite

An amperometric biosensor for monitoring phenols in the organic phase was constructed by the silica sol-gel immobilization of tyrosinase on a glassy carbon electrode. The organic-inorganic hybrid materials with different sol-gel precursors and polymers were optimized, and the experimental conditions, such as the effect of the solvent, operational potential and enzyme loading were explored for the optimum analytical performance of the enzyme electrode. The biosensor can reach 95% of steady-state current in about 18 s, and the trend in the sensitivity of different phenols is as follows: catechol > phenol >p-cresol. In addition, the apparent Michaelis-Menten constants (K-m(app)) and the stability of the enzyme electrode were discussed. (C) 2000 Elsevier Science S.A. All rights reserved.

一种新型薄膜发光材料—稀土羧酸配合物掺杂的SiO_2凝胶发光薄膜的制备和表征

二元稀土Tb水杨酸(Sal)与苯甲酸(BA)的配合物Tb(Sal)_3和Tb(BA)_3通过溶胶-凝胶过程利用两步原位合成的方法掺入二氧化硅凝胶中,然后利用旋转涂覆法将凝胶在石英片上制得溶胶-凝胶发光薄膜。同时为比较起见利用高分子聚合物聚已烯缩丁醛(PVB)的良好成膜性将其加入溶有相应稀土羧酸配合物的二甲基甲酰胺(DMF)溶液中,利用同样方法制得PVB发光薄膜。利用荧光光谱、荧光寿命等表征手段研究了稀土配合物在两种薄膜中的发光行为。荧光光谱结果表明在凝胶薄膜中形成了稀土有机羧酸配合物,荧光寿命结果表明凝胶薄膜中稀土离子的荧光寿命要大于在PVB薄膜中稀土离子的荧光寿命。

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 of cis-(+/-)-2-hydroxymethyl-5-(cytosine-1 '-yl)-1,3-oxathiolane (BCH-189)

The target compound BCH-189 was synthesized with high yield via four steps from benzoyloxy acetylaldehyde and p-dithiane-2,5-diol as starting materials. The synthetic route is preferable to what literature reported.

Impedance spectrum measurement in liquid/liquid interface electrochemistry .2. Study on the ion transfer at L/L interface by impedance spectrum technique

In this paper we study the ion transfer across the liquid/liquid interface by impedance spectrum technique in the four - electrode system. We present a method of getting the real interfacial impedance curve from the apparent impedance curve obtained in the four - electrode system. A practical kinetics investigation on the transfer of tetramethylammonium ion at the water/nitrobenzene interface was done with the method to verify the validity of the method. The transfer of tetramethylammonium ion at the W/O interface is really a reversible transfer.

液/液界面的电化学阻抗谱测量 Ⅱ.液/液界面上离子传递的研究

本文成功地运用四电极系统阻抗谱技术来研究液/液界面上的离子传递.提出了从表观阻抗曲线获取真实界面阻抗曲线的方法.并用此方法对四甲铵离子在水/硝基苯界面上的传递进行了实际的动力学研究,证实了四甲铵离子在水/硝基苯界面上的传递是可逆离子传递

富钇混合稀土－镁中间合金的制备及其物性的研究

本文研究了用低品位富钇混合稀士（５０ｗｔ％～６０ｗｔ％）代替高品位钇（≥８５ｗｔ％），电解制备富钇稀土高强镁合金的最佳电解工艺及其富钇稀土－镁合金ＭＢ２６与原钇－镁合金ＭＢ２５物理机械性能对比研究。

涂渍极性及强极性固定相硅膜改性弹性玻璃毛细管柱的研制

本工作研究了极性、强极性固定液直接涂渍在硅膜改性弹性玻璃毛细管内壁上,经优化温度老化色谱柱,成功地研制出OV-225、DEGS、Silar5、Silar9、Silar10等硅膜改性弹性玻璃毛细管柱。各种柱子均具有柱效高、惰性好、热稳定性好的色谱性能。

CRYSTAL-STRUCTURE AND THERMODYNAMIC PARAMETERS OF NYLON-1010

WAXD, SAXS, FTIR, DSC and density techniques have been used to investigate the crystal structure, crystal density rho(c), amorphous density rho(a), equilibrium heat of fusion DELTAH(m)degrees and equilibrium melting temperature T(m)degrees. By extrapolating the straight lines in the FTIR absorbance against density plot to zero intensity, rho(c) and rho(a) were estimated to be 1.098 and 1.003 g/cm3 respectively. The rho(c) obtained was too low in value. From X-ray diffraction patterns of uniaxially oriented fibres, the crystal structure of Nylon-1010 was determined. The Nylon-1010 crystallized in the triclinic system, with lattice dimensions: a = 4.9 angstrom, b = 5.4 angstrom, c = 27.8 angstrom, alpha = 49-degrees, beta = 77-degrees, gamma = 63.5-degrees. The unit cell contained one monomeric unit, the space group was P1BAR, and the correct value of rho(c) was 1.135 g/cm3. The degree of crystallinity of the polymer was determined as about 60% (at RT) using Ruland's method. SAXS has been used to investigate the crystalline lamellar thickness, long period, transition zone, the specific inner surface and the electron density difference between the crystalline and amorphous regions for Nylon-1010. The analysis of data was based upon a one-dimensional electron-density correlation function. DELTAH(m)degrees was estimated to be 244.0 J/g by extrapolation of DELTAH(m)degrees in the plot of heat of fusion against specific volume of semicrystalline specimens to the completely crystalline condition (V(sp)c = 1/rho(c)). Owing to the ease of recrystallization of melt-crystallized Nylon-1010 specimens, the well-known Hoffman's T(m)-T(c) method failed in determining T(m)degrees and a Kamide double extrapolation method was adopted. The T(m)degrees value so obtained was 487 K.