Relevance of molecular weight of chitosan-N-2-hydroxypropyl trimethyl ammonium chloride and their antioxidant activities

The antioxidant potency of high/low molecular weight quatemary chitosan derivatives was investigated employing various established systems in vitro, such as superoxide (O-2(center dot-)) and hydroxyl (center dot OH) radicals scavenging, reducing power and iron ion chelating. As expected, we obtained several satisfying results, as follow: firstly, low molecular weight quaternary chitosan had stronger scavenging effect on O-2(center dot-) and center dot OH than high molecular weight quaternary chitosan. Secondly, the reducing power of low molecular weight quaternary chitosan was more pronounced than that of high molecular weight quaternary chitosan. Thirdly, ferrous ion chelating potency were showed to increase first and decrease afterwards with increasing concentration for two kinds of quaternary chitosans, namely, they have not concentration-dependence. However, the scavenging rate and reducing power of high and low molecular weight quaternary chitosans increased with their increasing conc centrations, and hence were concentration-dependent. (c) 2007 Elsevier Masson SAS. All rights reserved.

The preparation and antioxidant activity of 2-[phenylhydrazine (or hydrazine)-thiosemicarbazone]-chitosan

Chitosan (CS) with two different molecular weight were modified by reacting with methyl hydrazine-dithiocarboxylate and methyl phenylhydrazine-dithiocarboxylate to give 2-(hydrazine-thiosemicarbazone)-chitosan (2-HTCHCS, 2-HTCLCS) and 2-(phenylhydrazine-thiosemicarbazone)chitosan (2-PHTCHCS, 2-PHTCLCS). The structure of the derivatives was characterized by FT-IR spectroscopy and elemental analysis. The antioxidant activities of the derivatives were investigated employing various established systems, such as hydroxyl radical (*OH)/superoxide anion (O-2(center dot-)) scavenging/reducing power and chelating activity. All of the derivatives showed strong scavenging activity on hydroxyl radical than chitosan and ascorbic acid (Vc), and IC50 of 2-HTCHCS, 2-HTCLCS, 2-PHTCHCS and 2-PHTCLCS was 0.362, 0.263, 0.531 and 0.336 mg/mL respectively. The inhibitory activities of the derivatives toward superoxide radical by the PMS-NADH system were strong. The results showed that the superoxide radical scavenging effect of 2-[phenylhydrazine (or hydrazine)-thiosemicarbazone]-chitosan were higher than that of chitosan. The derivatives had obviously reducing power and chelating activity. The data obtained from vitro models clearly establish the antioxidant potency of 2-[phenylhydrazine (or hydrazine)-thiosemicarbazone]-chitosan. (C) 2010 Elsevier B.V. All rights reserved.

影响内蒙古典型草原3种牧草饱和链烷回收率的因素研究

2004年秋季在中国科学院内蒙古草原生态系统定位站，用不同放牧演替阶段的优势植物羊草、糙隐子草和冷蒿分别按30％、20％和50％的比例混合组成日粮，饲喂12只（39±2．1kg）2岁羯羊（内蒙古细毛羊×蒙古羊）。试验分2个组，投喂胶囊组9只羊，每只羊投喂l粒QSM胶囊，对照组3只羊不投喂；试验期14d内每天记录绵羊实际牧草采食量和排粪量，并收集牧草样品在45℃烘箱中烘干；粪便样品连续收集7d，分别在45℃烘干和冷冻；利用气相色谱分析牧草和粪便样品中链烷含量，计算粪便中链烷的回收率。试验结果表明，牧草链烷含量存在物种间差异，绵羊粪便中链烷的回收率与链烷长度存在线性增加关系，烘干处理粪样的链烷回收率高于冷冻干燥处理的回收率。两者存在显著的正相关，且投喂QSM胶囊不会影响其他链烷的回收率。

青海种子植物特有种及其生态地理分布

主要依据中国科学院西北高原生物研究所青藏高原生物标本馆内所存标本为基础,结合对相关资料的全面收集,整理出青海特有植物82种和37变种,隶属19科54属.文中除了分科、属列出每个种或种下类型在青海境内到县一级的产地、生境和海拔高度等以外,还列出了它们的原始文献和可供引证、查阅的标本号.是研究青海高原植物区系的组成、性质和特点以及发生和演变规律等方面问题的基础资料.

Stable Carbon Isotopic Composition in Soil Organic Carbon and C3/C4 Source Variations at the Haibei Alpine Meadow

Stable carbon isotopes of organic matter originated from different soil layers (0～5 cm, 5～15 cm, 15～25 cm, 25～35 cm, 35～50 cm, 50～65 cm) were investigated in the Haibei Alpine Meadow Ecosystem Research Station of the Chinese Academy of Sciences. The preliminary results indicated that δ13C values of soil organic matter increased with increased soil depth. δ13C of soil organic carbon in 0～5 cm layer showed the lowest value, -25.09‰; while 50～65 cm soil layer possessed the lowerδ13C value, -13.87‰. Based on mass balance model of stable isotopes, it was proposed that the percentage of C4 carbon source tend to increase with increased soil depth. The preliminary study indicated that alpine meadow might have undergone a successive process from C4-dominated community to C3-dominated one. However, changing δ13C values in atmospheric CO2 overtime and different processes of soil organic carbon formation (or eluviation) might somewhat contribute to increasing δ13C values. In this case, mass balance model would underestimate C3 community and overestimate C4 community.

青海海北地区高山嵩草草甸植物群落的结构特征及其分布格局

对高山草甸主要植物群落结构特征及其分布格局的研究结果表明, 矮嵩草草甸植物群落的丰富度最大, 隶属18科, 43属45种, 呈多优势种植物群落; 小嵩草草甸居中, 隶属11科, 30属35种, 小嵩草(K obresia py gm aea) 为优势种; 藏嵩草沼泽化草甸最小, 隶属9科, 21属23种, 藏嵩草(K. tibetica) 为优势种。其中, 有9个种群为3个群落中的共有种, 分别占矮嵩草草甸、小嵩草草甸和藏嵩草沼泽化草甸总种数的20100%、25171% 和39113%。它们在水分资源位上的生态位宽度较大。3个植物群落类型的种2面积关系呈对数曲线分布, 群落的最小样方面积为0125m 2或015m 2较适宜。种2多度分布呈对数正态分布, 其分布模型的表达式如下: S (R ) = S 0e- (a2R 2)

基于SOA的银联智能商业平台的研究与实现

智能商业平台是大型企业商务应用的一个新兴领域，智能商业平台通过数据仓库、数据挖掘技术对企业的大量数据进行分析从而发现企业发展的内部规律，为企业的科学决策提供有效支持。目前的智能商业平台在体系结构上采用传统的集中式的IT架构，尚存在如下问题：1）不能与其它的信息系统间进行交互；2）采用重建系统的方式开发，不能有效利用现有信息系统资源；3）不能适应快速变化的业务需求进行灵活的系统扩充；4）由于系统的所有功能集中在同一服务器中，严重影响了系统的访问性能。 面对上述具有挑战的问题，本文将Web服务同智能商业平台相结合，从体系结构角度出发，提出一种基于SOA(Service-Oriented Architecture)的智能商业平台，并在银联需求基础上开发基于SOA的银联智能商业平台，解决传统智能商业平台无法与其它系统交互、资源浪费、不能灵活扩展及访问性能等方面的问题。 本文首先分析了国内外智能商业平台的研究现状，指出了其中尚未解决的问题，然后结合SOA的设计思想和传统的OOAD方法进行银联智能商业平台的业务流程建模，提出了面向服务的业务流程模型，并根据对用户需求的分析和理解设计了基于SOA的分层体系结构。然后文章着重阐述了服务管理层、核心服务层和应用服务层的设计思想与实现方法：1）服务管理层负责系统中所有服务的统一维护和管理，其中重点分析、讨论了基于UDDI的服务注册中心等核心技术；2）核心服务层是我们为了支撑上层应用服务所开发的大量底层服务，包括报表统计服务、多维分析服务、数据挖掘服务、用户管理、日志管理服务等，文中详细介绍了这些核心服务的设计和工作流程描述；3）应用层主要是各种系统功能的应用集成，提供了统一的门户交互系统，在这部分将着重给出统一门户集成的实现。 通过构建面向服务的业务流程和体系结构，基于SOA的银联智能商业平台在解决了传统智能商业平台问题的基础上还具有多项优势：标准化，构件化，可重用性，可扩展性，可互操作性等。

关于我院发展技术科学的探讨

技术科学是与国计民生联系很密切的科学,在整个科学技术体系中占有很重要的位置。但是,对技术科学,特别是在我院如何发展等方面的问题上,长期以来意见不一,影响了这门学科的更好发展。周光召院长最近数次指出,今年我们重点要抓好技术科学方向的讨论,研究清楚我院技术科学如何发展的问题。为促进百家争鸣,并供领导部门决策时参考,本期特刊登沈阳自动化研究所所长蒋新松和力学研究所所长薛明伦就这方面问题发表自己见解的文章,期望能引起大家的讨论,欢迎大家踊跃投稿。

新疆萨吾尔金矿带构造-流体地球化学及成矿作用

The Sawuer gold belt is located in the transition belt between Siberian plate and Kazakhstan-Junggar plate. Based on the geological and geochemical studies on the Kuoerzhenkuola and Buerkesidai gold deposits, in Sawuer gold mineralization belt, the time-space structure of mineralization and mineralizing factor are studied, the metallogenic regularity is concluded in thistheses. The ore bodies have the regularity that orebody are of the extensive and compressive in the sallow and depth of volcanic apparatue, respectively, and the vertical extension of orebody is more intensive than the horizontal extension. The gold deposits were controlled by the fractures of volcanic apparatus and regional faults, and featured by the hydrothermal alteration and metasomatism type disseminated mineralization and filling type vein mineralization. By virtue of the geological and geochemical studies on the two deposits that the formation of the two deposits are significantly related to the volcanic activity, we propose new ideas about their origin: (1) the two deposits are located in the same strata, and share the same genesis. (2) both of two deposits are volcanogenic late-stage hydrothermal gold deposits. Based on mapping of volcanic lithofacies and structure for the first time, it is discovered that a volcanic apparatus existed in the study area. Volcanic-intrusive activity can be divided into three cycles and nine lithofacies. where the two deposits are hosted in the same volcanic cycle, in this case, the wall-rock should belong to the same strata. The 40Ar-39Ar age method is employed in this work to analyze the fluid inclusions of quartz in the ore bodies from Kuoerzhenkuola and Buerkesidai gold deposits. The results show that the main mineralization occurred in 332.05 + 2.02-332.59 + 0.5IMa and 335.53 + 0.32Ma~336.78 + 0.50Ma for Kuoerzhenkuola and Buerkesidai gold deposits respectively, indicating that the two deposits are formed almost at the same time, and the metallogenic epoch of the tow deposits are close to those of the hosting rocks formed by volcanic activity of Sawuer gold belt. This geochronological study supplies new evidence for determining the timing of gold mineralization, the geneses of gold deposits? and identifies that in Hercynian period, the Altai developed tectonic-magmatic-hydrothermal mineralization of Early Carboniferous period, except known two metallogenic mineralization periods including tectonic-magmatic-hydrothermal mineralization of Devonian period and Late Carboniferous-Permian period respectively. The study of fluid inclusions indicates that the ore-forming fluid is a type of NaCl-HbO fluid with medium-low temperature and low salinity, Au is transported by the type of auric-sulfur complex (Au (HS)2-), the ore is formed in reduction condition. Hydrogen and oxygen isotopes of fluid inclusions in the major mineralizating stage show that the solutions mainly originated from magmatic water and meteoric water. The fluid mixing and water-rock reaction cause the deposition of Au. The helium and argon isotope compositions of fluid inclusions hosted in pyrite have been measured from Kuoerzhenkuola and Buerkesidai gold deposits in Sawuer gold belt. The results show that the ore-forming fluids of two deposits possessed the same source and is a mixture of mantle- and partial meteoric water-derived fluid, and the reliability of He and Ar isotopic compositions in Hercynian period is discussed. Isotopic studies including H, O, He, C, S, Pb and Sr reveal the same result that the ore-forming fluids of two deposits possessed the same source: the water derived mainly from magmatic water, partially from meteoric water; the mineralizers and ore materials derived mainly from mantle beneath the island arc, and partially from crust. The ore-forming fluids of two deposits are a mixture of mantle-derived fluids being incorporated by crust-derived fluid, and shallow partial meteoric water. Based on these results, it is proposed that the geneses of the two gold deposits are the same, being volcanogenic late-stage hydrothermal gold deposits that the ore-forming fluids filled in fractures of volcanic apparatus and metasomatized the host rocks in the volcanic apparatus. It is the first time we carried out the geophysical exploration, that is, the EH-4 continuous electrical conductivity image system measurement, the results show that relative large-size mineralizing anomalies in underground have been discovered.lt can confirm the law and genesis of the deposits mentioned above, and change the two abandoned mines to current large-size potenial exploration target.

中国东南部地幔柱及其与中生代大规模成矿关系初探

中国东南部是我国的钨锡铅多金属矿床集中区，燕山期发生大规模成矿作用。研究大规模成矿的地球动力学显得尤为重要。本文结合前人的研究资料，初步讨论中国东南部地幔柱及其与中生代大规模成矿关系。通过对中国东南部地幔柱的地质和地球物理方面特征综合分析后，初步探讨了地幔柱构造的岩浆作用和成矿制约。本文认为中国东南部地幔柱不仅可能造成中生代火山－岩浆大爆发，而且可能与中生代大规模成矿有关。

Heat capacity and thermochemical study of trifluoroacetamide (C2H2F3NO)

The low-temperature heat capacities of trifluoroacetamide were precisely determined with a small sample precision automated adiabatic calorimeter over the temperature range from 78 to 404 K. A solid-to-solid phase transition, a fusion and a phase transition from a liquid crystalline phase to fully liquid phase have been observed at the temperatures of 336.911+/-0.102, 347.622+/-0.094 and 388.896+/-0.160 K, respectively. The molar enthalpies of these phase transitions as well as the chemical purity of the substance were determined to be 5.576+/-0.004, 11.496+/-0.007, 1.340+/-0.005 kJ mol(-1) and 99.30 mol%, respectively, on the basis of the heat capacity measurements. The molar entropies of the three phase transitions were calculated to be 16.550+/-0.012, 33.071+/-0.029 and 3.447+/-0.027 J mol(-1) K-1, respectively. Further researches of the thermochemical properties for this compound have been carried out by means of TG and DSC techniques. (C) 2000 Elsevier Science B.V. All rights reserved.