有机物料及无机氮对耕地黑土团聚体水稳性的影响

用室内模拟试验研究了有机C、无机N添加对耕地黑土不同粒级团聚体水稳性的影响。结果表明 ,在不添加任何物料的湿培养条件下 ,随团聚体粒径增大抵抗浸水分散能力减弱 ;添加葡萄糖和玉米根干粉对 >1mm水稳团聚体有良好保护作用 ,但不能保护小粒径的团聚体。单纯添加无机N会引起耕地黑土团聚体水稳性下降。

手性指数的研究及其应用

该工作对手性化合物的构效关系进行了研究,其内容包括:(1)对二维拓扑指数A_(mi)进行了扩展,即在指数的衍生中加入手性碳原子的因素,使之成功地应用于14个手性化合物活性的预测;(2)描述了构象独立的手性指数(CICC法)和构象依赖的手性指数(CDCC法),采用CDCC和CICC预测了80个二级醇的~1H NMR化学位移差的符号,并由此可以确定该类化合物的绝对构型;(3)描述了原子构象依赖的手性指数(aCDCC),并将这种方法用于手性仲醇的α-碳原子的~(13)C NMR在不同手性溶剂中的化学位移差的预测,获得了满意的结果.

A novel tris(2,2 '-bipyridine)ruthenium(II)/tripropylamine cathodic electrochemiluminescence in acetonitrile for the indirect determination of hydrogen peroxide

A novel tris(2,2'-bipyridine)ruthenium(II) (Ru(bpy)3(2+)) cathodic electrochemiluminescence (ECL) was generated at -0.78V at the Pt electrode in acetonitrile (ACN), which suggested that the cathodic ECL differed from conventional cathodic ECL It was found that tripropylamine (TPrA) could enhance this cathodic ECL and the linear range (log-log plot) was 0.2 mu M-0.2 mM. In addition, hydrogen peroxide (H2O2) could inhibit the cathodic ECL and was indirectly detected with the linear range of 27-540 mu M. The RSD (n = 12) of the ECL intensity in the presence of 135 mu M H2O2 was 0.87%. This method was also demonstrated for the fast determination of H2O2 in disinfectant sample and satisfactory results were obtained.

聚苯乙烯/反式十氢化萘溶液在绝对负压下的相转变

用自制的高压光散射设备 ,测试了高压下聚苯乙烯 (PS) 反式十氢化萘 (TD)溶液的相转变温度受系统压力的影响情况 ,得到了不同组成的高分子溶液的相转变温度随高分子溶液压力的变化 ,不同压力下在组成 温度平面内的高分子溶液相图以及不同温度下在组成 压力平面内的高分子溶液相图 .结果表明在组成 压力平面内和较低的温度下 ,正压范围内不能得到完整的相图 ;此时 ,只有把压力外推到负压下才可能得到完整的相图 ,即在较低的温度下 ,某些组成的高分子溶液只有在负压范围内才能观察到高分子溶液的相转变

A COMPARATIVE-STUDY ON STM IMAGING AND ELECTROCATALYTIC ACTIVITY OF DIFFERENT SURFACES MODIFIED WITH FLAVIN ADENINE-DINUCLEOTIDE

Flavin adenine dinucleotide (FAD) was modified onto the highly oriented pyrolytic graphite (hopg) and glassy carbon electrode (gee) surfaces with three methods, respectively. Corresponding image analysis for FAD-modified hopg surfaces has been performed by scanning tunnelling microscope (STM) for the first time. The molecular resolution STM image of FAD adsorbed on the freshly-cleaved hopg was obtained, the quantitative size determination suggests that the FAD molecules adsorb side lying on the substrate surface. The anodization treatment of hopg surface yields many pits, which were clearly observed under STM. These pits provide active sites on the hopg surface for modification and the treated hopg can strongly adsorb FAD molecules, the latter exhibiting an irregular cluster structure on such a surface. When FAD was electrochemically deposited on the substrate surface, a chain structure was successfully observed. The adsorbed FAD on anodized glassy carbon electrode (gee) surface can effectively catalyze the reduction of glucose oxidase, hemoglobin and myoglobin, with a large decrease in the overvoltage, whereas the deposited FAD film exhibits excellent electrocatalysis towards dioxygen reduction.

绿辉石固溶体NaAlSi_2O_6-CaMgSi_2O_6的合成和高压下熔化过程研究

在2×10~9～5×10~9Pa,1 000～2 300℃下合成了由二元组分NaAlSi_2O_6(Jadeit)-CaMgSi_2O_6(Diopside)构成的绿辉石,通过XRD分析数据计算了绿辉石Jd_xDi_(1-x)的晶胞参数随组成变化的规律。采用高温高压淬火法和XRD研究了Jd_xDi_(1-x)(x=0～1.0)高压下(2×10~9～5×10~9 Pa)的固溶关系,并根据Jd_xDi(1-x)的固溶相图计算了不同压力下的熔化热。

EQUATION OF STATE FOR POLYMER SOLIDS

A new equation of state for polymer solids is given by P = B0/4 98[(V0/V)7.14 - (V0/V)2.16 + T/T0] comparison of the equation of state with experimental data is made for six kinds of polymers at different temperatures and pressures. The results obtained shown that the equation is suitable to describe the compression behavior of solid polymers in the region without transition.

小型富氧器的研制

用改性甲基硅橡胶膜制成了富氧组件。当膜两侧的压力比为0.26或集气管的绝对压力为20cmHg时,其富氧性能:流量0.80—1.40升/分,富氧空气的氧气含量27.7—33.5%。由组件制成了7组件富氧器,这个富氧器在实验室进行了操作,其操作条件,膜两侧压力比(P_L/P_H)对富氧空气流量及富氧空气中氧含量或分离系数有巨大的影响。

固态高聚物状态方程的研究

本文从理论上导出了一个新的三参数固态高聚物的状态方程p=(B_o/4.98)[(V_o/V)~(7.14)-(V_o/V)~(2.16)+(T/T_o)] 在不发生转变的温度区域内,它适用于描述固态高聚物的压强-体积-温度关系.方程形式简单,物理参数的意义较明确.

Cytoglobosins A-G, Cytochalasans from a Marine-Derived Endophytic Fungus, Chaetomium globosum QEN-14

Financial support from the Ministry of Science and Technology of China (2010CB833802 and 2007AA09Z446) and from the National Science Foundation of China (30910103914) is gratefully acknowledged.

AiC1qDC-1, a novel gC1q-domain-containing protein from bay scallop Argopecten irradians with fungi agglutinating activity

The globular C1q-domain-containing (C1qDC) proteins are a family of versatile pattern recognition receptors via their globular C1q (gC1q) domain to bind various ligands including several PAMPs on pathogens. In this study, a new gC1q-domain-containing protein (AiC1qDC-1) gene was cloned from Argopecten irradians by rapid amplification of cDNA ends (RACE) approaches and expressed sequence tag (EST) analysis. The full-length cDNA of AiC1qDC-1 was composed of 733 bp, encoding a signal peptide of 19 residues and a typical gC1q domain of 137 residues containing all eight invariant amino acids in human C1qDC proteins and seven aromatic residues essential for effective packing of the hydrophobic core of AiC1qDC-1. The gC1q domain of AiC1qDC-1, which possessed the typical 10-stranded beta-sandwich fold with a jelly-roll topology common to all C1q family members, showed high homology not only to those of Cl qDC proteins in mollusk but also to those of C1qDC proteins in human. The AiC1qDC-1 transcripts were mainly detected in the tissue of hepatopancreas and also marginally detectable in adductor, heart, mantle, gill and hemocytes by fluorescent quantitative real-time PCR. In the microbial challenge experiment, there was a significant up-regulation in the relative expression level of AiC1qDC-1 in hepatopancreas and hemocytes of the scallops challenged by fungi Pichia pastoris GS115, Gram-positive bacteria Micrococcus luteus and Gram-negative bacteria Listonella anguillarum. The recombinant AiC1qDC-1 (rAiC1qDC-1) protein displayed no obvious agglutination against M. luteus and L. anguillarum, but it aggregated P. pastoris remarkably. This agglutination could be inhibited by D-mannose and PGN but not by LPS, glucan or D-galactose. These results indicated that AiC1qDC-1 functioned as a pattern recognition receptor in the immune defense of scallops against pathogens and provided clues for illuminating the evolution of the complement classical pathway. (C) 2010 Elsevier Ltd. All rights reserved.

Dissolved oxygen and O-2 flux across the water-air interface of the Changjiang Estuary in May 2003

The field observation of this study was carried out in the Changjiang Estuary from May 19 to 26,2003, just a few days before the Three Gorges Dam began to store water. A total of 29 stations, including 2 anchor stations, were distributed through almost the whole salinity gradient Based on the data gained from these stations, the biogeochemical characteristics of dissolved oxygen (DO) were examined. Spatial distribution of DO concentrations showed the pattern that it increased in a downriver direction. DO concentration generally varied within a narrow range of 733-8.10 mg l(-1) in the freshwater region and the west part of the mixed water region, and after that it increased rapidly. In vertical direction, the differences in DO concentrations between surface and 2 m above the bottom were big at the stations with water depths exceeding 20 m; DO concentration up to 14.88 mg l(-1) was recorded at the sea surface, while at 2 m above the bottom its concentration was only about 4 mg l(-1). The fluctuation in DO concentrations was small during a period of 48 h in the mixed water region and 2 m above the bottom of the seawater region; while it was large during the same period in the seawater region for surface and 5 m below the surface layer, and a maximum variation from 8.77 to 12.66 mg l(-1) in 4 h was recorded. Oxygen fluxes also showed a marked spatio-temporal variation. As a whole, the freshwater region and mixed water region were an oxygen sink while the seawater region was a source. Relationships between dissolved oxygen and some biogeochemical parameters which could markedly influence its spatio-temporal distribution were discussed in this paper. (C) 2008 Elsevier B.V. All rights reserved.

青海高寒草甸土壤放线菌区系研究

2001～2002年从海北高寒草甸生态系统采集土样,用不同方法从中分离放线菌300余株,根据其形态和分类特征,分别归入小单孢菌属(Micromonospora)、诺卡氏菌属(Nocardia)、糖多孢菌属(Saccharopolyspora)、原小单孢菌属(Promicromonospora)和链霉菌属(Streptomyces),并将链霉菌归入7个类群.同时对230株中温菌和110株低温菌的部分酶活性及其对真菌和细菌的拮抗性进行了测定,发现链霉菌不仅具有许多酶活性,而且对真菌和细菌有拮抗性.

青藏高原不同海拔矮蒿草抗氧化系统的比较

对生长在青藏高原不同海拔自然生境下的多年生典型抗寒植物－矮蒿草（Kobresia humilis）的抗氧化系统进行了比较研究。结果表明，矮蒿草的叶组织中，非酶抗氧化系统物质脯氨酸（Pro）和抗坏血酸（AsA），随着海拔升高具有明显的增加趋势。在抗氧化酶系统中，过氧化物酶（POD）和过氧化氢酶（CAT）活性均随海拔的升高，而明显增强。但叶中的超氧化物歧化酶（SOD），随着海拔的升高，其活性有下降趋势，三者变化趋势并不一致。高海拔矮蒿草的植株与低海拔的植株相比，叶细胞内的膜脂过氧化加剧，丙二醛（MDA）含量明显增。细胞可溶性蛋白也随海拔升高显著增加。根中的抗氧化系统变化与叶中的有所不同。根中AsA含量随海拔而显著升高，且较叶中的增加明显，但Pro含量则有所减少。根中的CAT和POD活性变化与叶中的变化趋势基本一致，且随海拔高度的增加，根中的CAT活性较叶中的变化更为明显。而根中的SOD活性变化不如叶中明显，MDA含量随海拔增高，其变化趋势比叶中的小。可见，青藏高原典型抗寒植物矮蒿草体内的两类抗氧化系统，在不同海拔条件下可能存在互补协同的调节作用，这可能是矮蒿草适应或抵抗高原极端高寒低温和强UV－B辐射等环境胁迫的重要生理机制之一。