长白山地区蒙古栎光合特性

基于单叶尺度上的光强-光合响应以及CO2-光合响应测定,对长白山地区蒙古栎成树和幼树的光合特性分别进行了研究.结果表明,蒙古栎成树的光补偿点Lcp为21μmol/(m2·s),光饱和点Lsp为1564μmol/(m2·s),表观量子效率α为0·045;幼树的Lcp、Lsp、α以及CO2补偿点、饱和点分别为29μmol/(m2·s)、1581μmol/(m2·s)、0·049、73μmol/mol、625μmol/mol.幼树和成树具有相似的光响应特征,但前者的光合同化能力要高于后者.蒙古栎具有典型的喜光性,但对高光的利用效率要低于弱光.

黄土丘陵区林草景观界面雨后土壤水分空间变异规律

对黄土丘陵区刺槐林-草地景观界面上雨后土壤表层(0~10 cm)和亚表层(10~20 cm)水分的空间变异规律进行了研究.经典统计学分析表明,草地两层的土壤含水量分别高于林地;林草界面两层的土壤含水量均为弱变异程度,并具有明显的生态梯度.移动窗口法分析表明,林草界面对土壤表层和亚表层的水分影响范围为边界两侧4 m、3 m,影响域分别为8 m6、m.地统计学分析表明,草地两层土壤含水量空间分布均表现为纯块金效应,林地两层均可拟合成线性模型,而林草界面两层均可拟合成球状模型;林草界面土壤表层、亚表层水分空间依赖性和空间自相关较强,其空间结构异质性明显高于林地和草地.克立格制图描述的林草界面土壤水分的空间分布格局为从边界处向两侧的一定距离范围内,土壤含水量呈条带状分布,而在较远的距离,水分的空间分布呈现出几个明显的斑块状.

应用生态学的现状与展望

应用生态学是迅猛发展的现代生态学的主体 .寻求解决人口、资源、环境等问题是应用生态学发展的主要动力 .经过 4 0年的发展 ,应用生态学已发展成为一个庞大的学科门类 .应用生态学未来的发展应更多地关注受人类影响和管理的生态系统并将人视为生态系统的组成成分 .应用生态学在当前和今后应给予优先重视的研究领域 ,包括生态系统与生物圈的可持续利用、生态系统服务与生态设计、转基因生物的生态学评价、生物入侵生态学、流行病生态学、生态预报、生态过程及其调控等 .在今后若干年内 ,围绕这些领域 ,可能会出现广泛而活跃的研究热潮以及一些新的特点 .

Temperature sensitivity of soil respiration is affected by prevailing climatic conditions and soil organic carbon content: A trans-China based case study

National Natural Science Foundation of China [30590381]; Knowledge Innovation Program of the Chinese Academy of Sciences [KZCX2YW-432]; International Partnership Project

Reaction Mechanism of Palladium-Catalyzed Silastannation of Allenes by Density Functional Theory

The reaction mechanism of Pd(O)-catalyzed allenes silastannation reaction is investigated by the density functional method B3LYP. The overall reaction mechanism is examined. For the allene insertion step, the Pd-Si bond is preferred over the Pd-Sn bond. The electronic mechanism of the allene insertion into Pd-Si bond to form sigma-vinylpalladium (terminal-insertion) and sigma-allylpalladium (internal-insertion) insertion products is discussed ill terms of the electron donation and back-donation. It is found that the electron back-donation is significant for both terminal- and internal-insertion. During allene insertion into Pd-Si bond, internal-insertion is preferred over terminal-insertion. By using methylallene, the regio-selectivity for the monosubstituted allene insertion into Pd-Si and Pd-Sn bond is analyzed.

Electrically-controlled near-infrared chiroptical switching of enantiomeric dinuclear ruthenium complexes

Enantiomerically pure dinuclear ruthenium complexes with 1,2-dicarbonylhydrazide as a bridging ligand are optically active in the visible and near infrared spectral regions depending on the oxidation states of the metal centers and are useful as an electrochemically driven near infrared chiroptical switch.

刺五加寡糖的电喷雾多级串联质谱研究

采用小柱层析法从刺五加中分离得到刺五加寡糖类系列化合物(刺五加二糖～刺五加六糖).实验结果表明, 在正离子模式下的ESI-MS谱中, 此类化合物呈现出特征的加合离子峰簇[M+Na]+/[M+K]+或[M+H2O+Na]+/[M+H2O+K]+, 可以确定其分子量; 在负离子模式下的ESI-MS谱中, 刺五加寡糖易形成[M-H]-/[M+nH2O-H]-(n<3).还利用电喷雾多级串联质谱(ESI-MSn)对刺五加三糖进行了系统的研究, 推断出刺五加三糖的组成与结构.

Vacuum ultraviolet optical properties of (La,Gd)PO4 : RE3+ (RE = Eu, Tb)

Vacuum ultraviolet excitation spectra of phosphors (La,Gd)PO4:RE3+ (RE = Eu or Tb) and X-ray photoelectron spectra of LaPO4 and GdPO4 are investigated. The vacuum ultraviolet excitation intensity of (La,Gd)PO4:RE3+ is enhanced with the increasing of Gd3+ content, which implies that Gd3+ plays an intermediate role in energy transfer from host absorption band to RE3+. When Gd3+ is doped into LaPO4:Eu, charge transfer band (CT band) begins to shift to higher energy region and the overlap degree of CT band and the host absorption band gets greater with more Gd3+ doped into LaPO4. These results suggest that the dopant (Gd3+) gives an important influence on energy transfer efficiency. The top of LaPO4 valance band is formed by the 2p level of O2-, whereas that of GdPO4 valance band is formed by the 2p level of O2- and the 4f level of Gd3+, showing the differences in band structures between LaPO4 and GdPO4.

Processible nanostructured materials with electrical conductivity and magnetic susceptibility: Preparation and properties of maghemite polyaniline nanocomposite films

We here present a versatile process for the preparation of maghemite/polyaniline (gamma-Fe2O3/ PAn) nanocomposite films with macroscopic processibility, electrical conductivity, and magnetic susceptibility. The gamma-Fe2O3 nanoparticles are coated and the PAn chains are doped by anionic surfactants of omega-methoxypoly(ethylene glycol) phosphate (PEOPA), 4-dodecylbenzenesulfonic acid (DBSA), and 10-camphorsulfonic acid (CSA). Both the coated gamma-Fe2O3 and the doped PAn are soluble in common organic solvents, and casting of the homogeneous solutions gives free-standing nanocomposite films with gamma-Fe2O3 contents up to similar to 50 wt %. The morphology of the gamma-Fe2O3 nanoparticles are characterized by transmission electron microscopy, UV-vis spectroscopy, and X-ray diffractometry. The gamma-Fe2O3/PAn films prepared from chloroform/m-cresol solutions of DBSA-coated gamma-Fe2O3 and CSA-doped PAn are conductive (sigma = 82-237 S/cm) and superpapamagnetic, exhibiting no hysteresis at room temperature. The zero-field-cooled magnetization experiment reveals that the nanocomposite containing 20.8 wt % gamma-Fe2O3 has a blocking temperature (T-b) in the temperature region of 63-83 K.

高效液相色谱-蒸发光散射检测法测定那保胶囊中黄芪甲苷含量

目的：采用高效液相-蒸发光散射检测器（HPLC-ELSD）法测定藏药那保胶囊中黄芪甲苷的含量。方法：色谱柱为KromasilC_(18)柱（4．6mm×250mm，5μm）；流动相为乙腈-水（36：64）；ELSD（蒸发光散射检测器）检测。结果：黄芪甲苷在1-10μg范围内具良好的线性关系（r=0．999），平均回收率为99．05，RSD为2．48％。结论：该法简便可行，重复性好，适用于那保胶囊的质量控制。

醇溶蛋白水平上甘、青两省春小麦品种间的遗传多样性现状及演变趋势

用APAGE技术检测了43个春小麦品种在醇溶蛋白水平上的遗传变异，在计算Jaccard相似系数的基础上用UPGMA方法进行聚类分析。共得到42种不同的带型，电泳共分离出37条带，其中33条具有多态性。品种间在醇溶蛋白水平上的遗传距离变异范围很大（0.0000～0.8148），平均遗传距离GD＝0.5073。说明43个品种在醇溶蛋白编码位点上存在较大变异。聚类结果显示，除佛手麦自成一类外（GS＝0.28），地方品种和引进品种与大多数育成品种（GS＝0.46）分属不同的亚类，说明育成品种同地方品种和引进品种在醇溶蛋白编码基因上存在较大变异。育成品种间在醇溶蛋白水平上的遗传多样性程度不高，这一结果提示在这一地区进行与醇溶蛋白相关的品质育种很难在现在的育成品种间杂交的基础上取得成功。从遗传多样性的演变趋势来看，历史上以地方品种间醇溶蛋白的遗传变异程度最大（GD＝0.5455），50年代引进品种变异程度最小（GD＝0.3310）。从60～90年代，育成品种醇溶蛋白水平上的遗传多样性有一先增后减的过程，但总体上变异程度要低于地方品种，其原因与亲本单一和育种目标由高产到优质变化条件下人工选择压由弱到强有关。

企业综合自动化系统体系结构

阐述了一般综合自动化系统的二维层次体系结构，以及系统的功能、信息、资源、组织四视图在三个层次的内涵及相互关系。

企业经营系统的对象模型──资金流模型

本文阐述了大型工业企业综合自动化系统体系结构中经营管理层的对象模型（资金流模型）。首先论述了该模型在自动化体系结构中的地位和作用，然后分析了企业生产经营过程中发生的资金流，提出用借贷流程图方法表达资金流模型，并将这一方法与国际通用的借贷记帐法相联系，从而揭示了资金流模型与会计核算的内在联系．本文还对企业生产与经营活动的几个主要过程用借贷流程图进行了细化描述。