Surface-modified Nafion membranes with mesoporous SiO2 layers via a facile dip-coating approach for direct methanol fuel cells

In this study. Nafion (R) 117 membrane is surface-modified with mesoporous silica layers through in situ surfactant-templated sol-gel reaction. The reaction makes use of tetraethyl orthosilicate (TEOS) under acidic condition via dip-coating technique on both sides. Scanning electron microscopy (SEM), Fourier transformation infrared (FTIR), and thermogravimetric analysis (TGA) are employed to characterize the resultant membranes. Proton conductivity and methanol permeability of the membranes are also studied.

Preparation of Ni0.65Zn0.35Cu0.1Fe1.9O4/SiO2 nanocomposites by sol-gel method

(Ni0.65Zn035Cu0.1Fe1.904)-Cu-./SiO2 natiocomposites were fabricated by the sol-gel method using tetraethylorthosilicate as a precursor of silica, and metal nitrates as precursors of NiZnCu ferrite. With infrared spectra, X-ray diffraction, transmission electron microscope, Raman spectra, Mossbauer spectroscopy and vibrating sample magnetometer measurements, the formation of single phase nanocrystalline NiZnCu ferrites dispersed in silica matrix is confirmed when the sample is annealed at 550degreesC. The transition from the paramagnetic to the ferromagnetic state is observed as the annealing temperature increases from 750degreesC to 1150degreesC. The magnetic properties of these nanocomposites are clearly size dependent. The saturation magnetization increases with the annealing temperature.

Novel indigo light emitting long-lasting phosphors CdSiO3: RE3+ (RE = Y, La, Gd, Lu)

A series of novel indigo light emitting long-lasting phosphors CdSiO3: RE3+ (RE = Y, La, Gd, Lu) was prepared by the conventional high-temperature solid-state method. The XRD, photoluminescence (PL) spectra and afterglow intensity decay were used to characterize the synthesized phosphors. These phosphors emitted indigo light and showed long-lasting phosphorescence. The phosphorescence can be seen with the naked eye in the dark clearly even after the 254-nm UV irradiation have been removed for more than 30 min.

In-situ circular dichroism spectroelectrochemical study on the redox process of norepinephrine

The redox process of norepinephrine in pH = 7.0 phosphate buffer solution at glassy carbon electrode was studied by circular dichroism spectroelectrochemistry with a long optical path thin layer cell. The spectroelectrochemical data were analyzed with the double logarithm method. According to the double logarithsmic plot results, the mechanism of electrochemical oxidation of norepinephrine is an irreversible process with a subsequent chemical reaction (EC) to form a norepinephrinechrome. Both of norepinephrinequinone and norepinephrinechrome are followed E mechanisms. Some kinetic parameters about the electrochemical process, i.e. the electron transfer coefficient and number of electron transfered, alpha n = 0.38, the formal potential, E-1(0)' = 0.20 V, the standard heterogenous electron transfer rate constant, k(1)(0) = 1.2 x 10(-4) cm s(-1) for the oxidation of norepinephrine, alpha n = 0.37, E-2(0)' = 0.25 V and k(2)(0) = 4.4 x 10(-5) cm . s(-1) for the reduction of norepinephrinequnone and alpha n = 0.33, E-3(0)' = -0.25V and k(3)(0) = 1.1 x 10(-4) cm . s(-1) for the reduction of norpinephrinechrome, were also estimated.

去甲肾上腺素电极过程的圆二色谱电化学研究

现场圆二色薄层光谱电化学研究去甲肾上腺素的电化学氧化还原过程 .研究表明去甲肾上腺素 ( pH =7.0磷酸缓冲溶液中 )在玻碳电极上经历了不可逆的电化学氧化 ,且遵从后行化学反应 (EC)机理 ,去甲肾上腺素醌和去甲肾上腺素红的再还原遵从简单电子转移 (E)机理 .由双对数法获得去甲肾上腺素电化学氧化的式电位为E10’=0 .2 0V ,电子转移系数和电子转移数之积为αn =0 .38,标准复相电极反应常数k10 =1 .2× 1 0 -4 cm·s-1.去甲肾上腺素醌和去甲肾上腺素红的电化学还原反应参数分别为E2 0’=0 .2 5V ,αn =0 .37,k2 0 =4.4× 1 0 -5 cm·s-1和E3 0’=- 0 .2 5V ,αn =0 .33,k3 0 =1 .1× 1 0 -4 cm·s-1.

Physical diffusion and electron-transfer dynamics of electroactive solutes in polymer electrolytes .3. Effect of the polymer solvents

The diffusion coefficients(D-app) and the heterogeneous electron transfer rate constants(k(s)) for ferrocene in several polymer solvents were determined by using steady-state voltammetry. The temperature dependence of the two parameters indicates Arrhenius behavior, The polymer solvent effects on diffusion and electron transfer dynamics of ferrocene were discussed.

Direct decomposition of NO over the mixed oxide catalysts Nd_(2-)Sr_xNiO_(4±λ)

The nitrogen oxides (NO_x) are serious pollutants in earth's atmosphere in the sensethat they are one of the main sources to cause the acid rain. The removal of NO_x is oneof the key research topics in the protection of environmen.

三维同步荧光法研究喜树生物碱衍生物的荧光光谱性质

本文用三维同步荧光法详细研究了喜树生物碱衍生物的共性和特性,以及它们之间荧光光谱的变化过程,说明结构、取代基和溶剂在荧光光谱的变化中所起的作用,并用同步荧光法不经分离同时测定实际样品中的喜树碱和羟基喜树碱。

钐的氟化物体系中钐离子价态及其转换

H_2气流中多次还原SmF_3,合成了非整比系列SmF_x(2.0≤x≤3.0),并获得了接近整比的二氟化钐,讨论了各类非整比氟化钐化合物的结构及钐离子的价态,考察了在不同气氛中二氟化钐中钐离子价态的高温转换过程。

大菱鲆（Scophthatmus maximus）两种转基因方法的研究

本实验对外源基因导入大菱鲆的两种方法进行了研究。采用经过改进的电脉冲方法以及哺乳动物细胞中常用的转染法将该外源DNA片段导入到大菱鲆（Scophthalmus maximus）受精卵内，并对两种方法进行比较。 本实验综合考虑仔鱼的孵化率和外源DNA的导入率，确定了电脉冲最佳导入条件：脉冲电压为300 V/cm，脉冲次数为5，外源DNA浓度为20 mg/L。首先分别对脉冲电压、脉冲次数和外源DNA的浓度进行单因子实验，得到各因素的适宜水平范围。然后利用最适导入条件，实现基因元件大规模转移。转染试剂使用参数的确定根据Qbiogene公司用户手册上的使用说明进行，转染法的最佳操作时间为受精后50 min。应用上述两种方法进行批量转基因鱼实验，采用PCR技术对一月龄的原代转基因大菱鲆仔鱼的染色体DNA进行分析，得到外源基因的导入率分别为20~28％和60~70％。本实验表明利用转染试剂jetPEI处理单细胞期的大菱鲆受精卵能得到较高的孵化率及较高的转基因效率。 本实验初步建立了利用电脉冲精子载体法和转染法实现基因转移的作方法，为经济鱼类转基因育种及其生产应用提供了理论及方法依据。

气候变暖对青海农业生产格局的影响

分析了现实状况下不同地区农牧业生产格局，并建立各界限温度及持续天数与现实条件的关系方程。在设定未来气候变暖一定幅度的情况下，利用该方程组对青海各地未来热量资源予以分析，探讨未来气候变暖后青海各地农、林、牧生产方式所改变的可能性。结果表明：青海各地在气温升高２℃，降水增加１０％后，日平均气温稳定通过各界限温度期间的积温将增加３８０℃左右，所对应的持续天数约增加２０ｄ。其结果会导致青海种植业（特别是经济作物）面积扩大，并向高海拔地带延伸，林线上升。但气候变暖的同时，地表蒸发的加大远比降水的增加来得快，导致青海各地干旱加剧。

掌裂橐吾的胚胎学

首次报道了掌裂橐吾的胚胎发育过程。药壁发育双子叶型; 绒毡层发育属“The Cos-mos bip innatus”型；成熟花粉为3 细胞型； 单珠被, 薄珠心, 倒生胚珠；具发达的珠被绒毡层；胚囊发育为4 孢子型, 类似德鲁撒型(Drusa)； 胚乳发育为核型, 胚胎发育为紫菀型千里光变型。

用微移动机器人群进行超精密加工与测量的现状和发展

本文讨论了何谓超精密加工,为何要超精密加工以及怎样实现超精密加工,并且简要介绍我国面向精密工程所研究的微滑动机器人。

海拉尔盆地贝尔凹陷基岩潜山特征及储层预测

The lithology of the buried hill of Triassic Budate group in Beier depression is epimetamorphic clastic rock and volcanic clastic rock stratum. Recently the favorable hydrocarbon show was discovered in buried hill of base rock, and large-duty industrial oil stream was obtained in some wells in Beier depression. Based on the information of seismos and wells, the tectonic framework, tectonic deformation times and faulted system of the Beier depression are comprehensively studied, then configuration, evolutional history, genetic type and distributed regularity of buried hill are defined. According to observing description and analysis of core sample, well logging and interpretive result of FMI, the lithological component, diagenetic type and diagenetic sequence of buried hill reservoir are confirmed, then reservoir space system of buried hill is distinguished, and vegetal feature, genetic mechanism and distributed regularity of buried hill fissure are researched, at the same time the quantitative relationship is build up between core fissures and fissures interpreted by FMI. After that fundamental supervisory action of fault is defined to the vegetal degree of fissure, and the fissure beneficial places are forecasted using fractal theory and approach. At last the beneficial areas of Budate group reservoir are forecasted by reservoir appraisal parameters optimization such as multivariate gradually regression analysis et. al. and reservoir comprehensive appraisal method such as weighing analyze and clustering procedure et. al. which can provide foundation for the next exploratory disposition. Such production and knowledge are obtained in this text as those: 1. Four structural layers and two faulting systems are developed, and four structural layers are carved up by three bed succession boundary surfaces which creates three tectonic distortional times homology. Three types of buried hill are divided, they are ancient physiognomy buried hill, epigenetic buried hill, and contemporaneous buried hill. 2. Reservoir space of Budate buried hill is mainly secondary pore space and fissure, which distributes near the unconformity and/or inside buried hill in sections. The buried hill reservoir experienced multi-type and multi-stage diagenetic reconstruction, which led to the original porosity disappeared, and multi secondary porosity was created by dissolution, superficial clastation and cataclasis et. al. in diagenetic stage, which including middle crystal pore, inter crystal pore, moldic pore, inter particle emposieu, corrosion pore space and fissure et. al. which improved distinctly reservoir capability of buried hill. 3. The inner reservoir of buried hill in Beier depression is not stratigraphic bedded construction, but is fissure developing place formed by inner fault and broken lithogenetic belt. The fissures in inner reservoir of buried hill are developed unequally with many fissure types, which mainly are high angle fissure and dictyonal fissures and its developing degree and distribution is chiefly controlled by faulting. 4. The results of reservoir comprehensive evaluate and reservoir predicting indicates that advantageous areas of reservoir of buried hill chiefly distributes in Sudeerte, Beixi and Huoduomoer, which comprehensive evaluate mainly Ⅱand Ⅲ type reservoir. The clues and results of this text have directive significance for understanding the hydrocarbon reservoir condition of buried hill in Beier depression, for studying hydrocarbon accumulated mechanism and distributed regularity, and for guiding oil and gas exploration. The results of this text also can enrich and improve nonmarine hydrocarbon accumulated theory.