中国东北植被生态学研究中的焦点问题

中国东北植被经过半个多世纪的系统研究 ,但有关植被生态学一些争论性问题尚未统一 .本文仅就作者近年来研究工作涉及到的内容和关注的问题 ,提出一些看法 :1)中国东北植被地带性分布规律可用Kira的温暖指数 (WI)、寒冷指数 (CI)和作者的湿度指数 (HI)进行定量解释 .2 )大兴安岭北部山地 ,在海拔14 0 0m以上存在冻原植被 ,是作者于 196 3年首次发现的我国第三块冻原植被 ,其WI <15℃·月 .3)大小兴安岭植被分界线是我国植被区划中第一级分区界线 ,其位置在爱辉 -果松沟 -嫩江以南附近 ,WI为 4 5℃·月 .4 )大兴安岭植被地带性分异显著 ,南段、中段为典型草原地带和森林草原地带 ,北段为针叶林地带 ,HI值分别为 3 5～ 5 5、5 5～ 7 5、>7 5mm/℃·月 .大兴安岭东麓阔叶林是森林草原带上的森林植被类型 .5 )东北东部山地岳桦林是山地植被垂直带谱重要组成部分之一 ,是山地森林垂直分布林线 ,WI为 2 0～ 15℃·月为地带性植被类型 ,而WI>2 0℃·月为非地带性植被类型 .6 )内蒙古浑善达克沙地云杉林是陆地上非常罕见的森林生态系统类型 ,但这种云杉林究竟是哪一树种组成 ,在中国植物分类上一直是个争论性问题 ,作者通过核型分析和同工酶实验进一步证明是一个新种即沙地云杉Piceamongolica(H .Q .Wu)W .D .

Radiation-use efficiency and the harvest index of winter wheat at different nitrogen levels and their relationships to canopy spectral reflectance

Radiation-use efficiency (RUE, g/MJ) and the harvest index (HI, unitless) are two helpful characteristics in interpreting crop response to environmental and climatic changes. They are also increasingly important for accurate crop yield simulation, but they are affected by various environmental factors. In this study, the RUE and HI of winter wheat and their relationships to canopy spectral reflectance were investigated based on the massive field measurements of five nitrogen (N) treatments. Crop production can be separated into light interception and RUE. The results indicated that during a long period of slow growth from emergence to regreening, the effect of N on crop production mainly showed up in an increased light interception by the canopy. During the period of rapid growth from regreening to maturity, it was present in both light interception and RUE. The temporal variations of RUEAPAR (aboveground biomass produced per unit of photosynthetically active radiation absorbed by the canopy) during the period from regreening to maturity had different patterns corresponding to the N deficiency, N adequacy and N-excess conditions. Moreover, significant relationships were found between the RUEAPAR and the accumulative normalised difference vegetation index (NDVI) in the integrated season (R-2 = 0.68), between the HI and the accumulative NDVI after anthesis (R-2 = 0.89), and between the RUEgrain (ratio of grain yield to the total amount of photosynthetically active radiation absorbed by the canopy) and the accumulative NDVI of the whole season (R-2 = 0.89) and that after anthesis (R-2 = 0.94). It suggested that canopy spectral reflectance has the potential to reveal the spatial information of the RUEAPAR, HI and RUEgrain. It is hoped that this information will be useful in improving the accuracy of crop yield simulation in large areas.

Determination of isocyanates by capillary electrophoresis with tris(2,2 '-bipyridine) ruthenium(II) electrochemiluminescence

CE with tris(2,2'-bipyridyl) ruthenium(II) (Ru(bpy)(3)(2+)) electrochemiluminescence (ECL) detection for the quantitative determination of isocyanates was first reported. Hexamethylene diisocyanate (HDI) and hexyl isocyanate (HI) were used as the model analytes. Commercially available N,N-diethyl-N'-methylethylenediamine was used as the derivatization reagent. It has both a secondary amine group and a tertiary amine group. The secondary amine group can quantitatively react with isocyanate group, and the tertiary amine group can react with Ru(bpy)(3)(2+) to produce strong ECL signal for sensitive detection. The derivatization reaction was almost instantaneous and is much faster than other reported derivative reactions using other derivative reagents.

Robust core-shell supramolecular assemblies based on cationic vesicles and ring-shaped {Mo-154} polyoxomolybdate nanoclusters: Template-directed synthesis and characterizations

Substantial progress has been made recently in extending the supramolecular assembly of biomimetic structures to vesicle-based sophisticated nanocomposites and mesostructures. We report herein the successful preparation of unilamellar surfactant vesicles coated with a monolayer of ring-shaped {Mo-154} polyoxometalate (POM) nanoclusters, (NH4)(28)[Mo-154 (NO)(14)O(448)Hi(4)(H2O)(70)].approximate to 350H(2)O, by coulomb attractions using preformed didodecyldimethylammonium bromide (DDAB) surfactant vesicles as templates. The resultant vesicle-templated supramolecular assemblies are robust (they do not disintegrate upon dehydration) both at room-temperature ambient and vacuum conditions, as characterized by conventional transmission electron microscopy (TEM) and atomic force microscopy (AFM). The flexibility of the complex soft assemblies was also revealed by AFM measurements. The effect of POM-vesicle coulomb attractions on the dimensions of the templating vesicles was also investigated by using dynamic light scattering (DLS).Although origins of the structure stability of the as-prepared supramolecular assemblies are not clear yet, the nanometer scale cavities and the related properties of macroions of the POM clusters may play an important role in it.

Morphology-controllable synthesis and characterization of single-crystal molybdenum trioxide

Molybdenum trioxide nanobelts and prism-like particles with good crystallinity and high surface areas have been prepared by a facile hydrothermal method, and the morphology could be controlled by using different inorganic salts, such as KNO3, Ca(NO3)(2), La(NO3)(3), etc. The possible growth mechanism of molybdenum trioxide prism-like particles is discussed on the basis of the presence of HI and the modification of metal cations. The as-prepared nanomaterials are characterized by means of powder X-ray diffraction (PXRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), Fourier transformation infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and ultraviolet and visible spectroscopy (UV-vis). TEM and HRTEM micrographs show that the molybdenum trioxide nanobelts and prism-like particles have a relatively high degree of crystallinity and uniformity. BET specific surface areas of the as-prepared molybdenum trioxide nanocrystals are 67-79 m(2)g(-1). XPS analysis indicates that the hexavalent molybdenum is predominant in the nanocrystals. UV-vis spectra reveal that the direct band gap energy of the annealed molybdenum trioxide prism-like particles shows a pronounced blue shift compared to that of bulk MoO3 powder.

具有内孔道的层状超分子化合物[(CuI)_2(o-phen)_2]的水热合成与晶体结构

固态金属配位超分子的晶体工程是化学和分子科学最活跃的研究领域之一 ,它不仅因存在内孔和隧道等新颖网络特殊性而具有理论研究价值 ,而且在催化、光学、主 -客体化学以及分子电学等领域中具有巨大的潜在应用价值 [1～ 8] .用于构筑这类功能化合物的方法主要依赖于构筑网络的相互作用 ,即利用分子间的氢键 ,π- π作用及其它的分子间弱的相互作用 .由于 Cu- X体系超分子化合物优异的光学和催化性能 ,它们的合成与表征近来已引起人们的极大兴趣 [9,10 ] .迄今 ,一直未得到 [( Cu I) 2 ( 2 ,2′-bidy) 2 ]及其类似化合物的晶体 ,只是推断其结构可能是通过碘桥形成的二聚体 .我们选用 Cu I,o-phen和 H2 O为原料 ,在水热条件下得到了具有 C— H… I氢键的双核铜卤化合物 1 [( Cu I) 2 ( o- phen) 2 ]的晶体 .单晶结构测定不仅验证了碘桥连接的正确性 ,同时表明二聚体通过不寻常的 C— H…I氢键连接成一维超分子链 ,而链间通过 π- π作用呈现出二维层状超分子网络 .1　实验部分1 .1　单晶的合成　将 Cu I,o- phen和 H2 O按物质的...

Catalytic reduction of NO, by CO on hydrotalcites-derived mixed oxides CoAlM and MgAlM (M = Cr, Mn, Fe, Co, Ni, Cu)

Two series of mixed oxides, CoAlM and MgAlM (M = Cr, Mn, Fe, Co, Ni, Cu), were prepared by calcining their corresponding hydrotalcite-like compounds (HTLc). The ratio of Mg: Al: M (or Co: Al: hi) was 3:1:1. The catalytic activity of all samples for the reaction of NO + CO was investigated. The results showed that the activity of CoAlM was much higher than that of MgAlM. The structure and the property of redox were characterized by XRD and H-2-TPR. The results indicated that only MgO phase was observed after calcining MgAlM hydrotalcites, and the transition metals became more stable. The spinel-like phase appeared in all of CoAlM samples after the calcination, and the transition metals were changed to be more active, and easily reduced. The activities of three series of mixed oxides CoAlCu obtained from different preparation methods, different ratio of Co:Al: Cu and at different calcination temperatures, were studied in detail for proposing the mechanism of reaction. The ability of adsorption of NO and CO were investigated respectively for supporting the mechanism.

Superlattice structure of gold nanoparticles film deposited by Langmuir-Blodgett technique

Dodecanethiol-capped gold nanoparticles could spread on water subphase and be transferred by LB technique. The superlattice structure of gold nanoparticles multilayer was discussed.

Studies of non-covalent protein complexes by MALDI methods

Several specific non-covalent protein complexes were successfully observed by matrix assisted desorption ionization mass spectrometry(MALDI MS). The methods described in this paper include the matrixes use of sinapinic acid(SA) and 6-aza-2-thiothymine (ATT) in neutral pH solution, as well as the improvement of two-layer sample preparation method to achieve a high sensitivity detection of stable non-covalent complexes, Myoglobin-heme complex was found simultaneously with the sinapinic acid matrix in the various pH solution(pH=2 or pH=5), The RNase S complex showed a striking intensity at the first shot, which was decreased with more laser shots. Most importantly, the observation of specific non-covalent complex in the brome mosaic virus(BMV) coat proteins would open up a new possibility to investigate the assembly and disassembly of viral capsids.

Genetic characterization of asymmetric reciprocal hybridization between the flatfishes Paralichthys olivaceus and Paralichthys dentatus

Interspecific reciprocal crosses between the two flatfishes Paralichthys olivaceus and P. dentatus yielded hybrids with different viabilities. Specifically, the hybrids of P. olivaceus female and P. dentatus male (HI) were found to be viable, while the reciprocal hybrids from P. dentatus female and P. olivaceus male (HII) were completely inviable. All the HII individuals showed morphological deformities and died before first feeding. The chromosome analysis showed that HI individuals had the same chromosome number as parents. However, two chromosomes were missing in HII offspring indicating that the latter were aneuploids. Genomic inheritance from the parents to F-1 progeny was also examined by amplified fragment length polymorphism (AFLP) analyses, and the results showed differences between reciprocal hybrids. Almost all AFLP bands (97.71%) observed in parents were passed on to HI individuals. In contrast, only 86.64% of the AFLP bands from parents were scored in HII individuals. Frequency of lost parental bands was thus significantly higher in HII than that in HI and intraspecific crosses, which was probably associated with chromosomal elimination. In addition, higher segregation distortions were found in hybrids than in controls, although these differences were not significant. The present study indicates that chromosomal elimination and loss of AFLP loci occurred in inviable HII individuals, while such genomic changes were not found in viable HI individuals. Possible implications of such difference on genomic changes for asymmetric viability in reciprocal hybrids are discussed.

Diversity, abundance and distribution of amoA-encoding archaea in deep-sea methane seep sediments of the Okhotsk Sea

The authors would like to thank Jin Sun, Jian Sun, Liangliang Kong, Nianshuang Wang, Chunhui Wang, Linbao Zhang and Ying Zhang for their assistance in the project. This work was supported by China Ocean Mineral Resources R&D Association grants DYXM-115-02-2-20 and DYXM-115-02-2-6, Hi-Tech Research and Development Program of China grant 2007AA091903, China National Natural Science Foundation grant 40576069, National Basic Research Program of China grant 2009CB219506 and the Fundamental Research Funds for the Central Universities of China grant 09CX05005A. M. G. K. was funded by incentive funds provided by the UofL-EVPR office and the US National Science Foundation (EF-0412129).

Modern sedimentary environments and dynamic depositional systems in the southern Yellow Sea

Based on analyses of more than 600 surface sediment samples together with large amounts of previous sedimentologic and hydrologic data, the characteristics of modern sedimentary environments and dynamic depositional systems in the southern Yellow Sea (SYS) are expounded, and the controversial formation mechanism of muddy sediments is also discussed. The southern Yellow Sea shelf can be divided into low-energy sedimentary environment and high-energy sedimentary environment; the low-energy sedimentary environment can be further divided into cyclonic and anticyclonic ones, and the high-energy environment is subdivided into high-energy depositional and eroded environments. In the shelf low-energy environments, there developed muddy depositional system. In the central part of the southern Yellow Sea, there deposited the cold eddy sediments under the actions of a meso-scale cyclonic eddy (cold eddy), and in the southeast of the southern Yellow Sea, an anticyclonic eddy muddy depositional system (warm eddy sediment) was formed. These two types of sediments showed evident differences in grain size, sedimentation rate, sediment thickness and mineralogical characteristics. The high-energy environments were covered with sandy sediments on seabed; they appeared mainly in the west, south and northeast of the southern Yellow Sea. In the high-energy eroded environment, large amounts of sandstone gravels were distributed on seabed. In the high-energy depositional environment, the originally deposited fine materials (including clay and fine silt) were gradually re-suspended and then transported to a low-energy area to deposit again. In this paper, the sedimentation model of cyclonic and anticyclonic types of muddy sediments is established, and a systematic interpretation for the formation cause of muddy depositional systems in the southern Yellow Sea is given.

栉孔扇贝大规模死亡病原学研究

用平板画线法从患病栉孔扇贝（Chlamys farreri）体内分离到了一种原核生物（简称QDP）。QDP可以在改进的液体培养基MEM（含2.2%NaCl，5%小牛血清）和脑心浸液（含2.2% NaCl）中生长；菌落在显微镜下（150×）为无色、透明的小点状；革兰氏染色阴性；菌体为圆形或近似圆形。QDP在发育过程中有两种状态，一种为未成熟阶段，直径小于100nm；另一种为成熟阶段，直径变化很大，最小约60nm，最大可达4µm以上。较小的个体有拟核、核糖体和新月状的空泡，未见细胞壁；较大的个体有细胞壁，胞内大部分被空泡充满，未见拟核和核糖体。栉孔扇贝组织超簿切片电镜观查证实QDP的存在。QDP的密度随着生长发育时间的不同而有所变化，繁殖高峰期密度较大。 建立了密度梯度离心结合滤膜过滤分离技术，优化人工培养条件。最适生长温度为23℃，最适生长pH值为7.4，最适生长盐度相当于细胞培养液所需的盐浓度（0.85%NaCl）。 提取的QDP核酸能被RNase A 降解，且没有检测到DNA。以PCR、RT-PCR扩增其16SrRNA基因序列片段，PCR反应没有扩增出扩增子，而RT-PCR则扩增出了16S rRNA基因序列片段，经测定其序列全长度为1430bp，经与GENEBANK中的16S rRNA片段比较分析，与6种不同科的微生物的同源率最高的为95%-95.47%。 采用温度梯度和病原浓度梯度回归感染实验方法，较为系统地研究了QDP的致病性。研究结果表明：QDP对栉孔扇贝有强烈的致病作用，高温（23℃以上）是其致病的必要条件，证实DQP是栉孔扇贝大规模死亡的病原体之一。

IL15／PAP融合蛋白基因克隆及其原核与植物表达载体的构建

将IL15和PAP基因通过一甘氨酸接头（Gly4Ser）3连接在一起，构建原核和植物表达载体，以期表达具有导向杀伤活性的融合蛋白．在引物设计中，通过引物在IL15基因下游引入（Gly4Ser）3的编码序列和Bam HI位点，然后采取分步克隆及PCR、酶切、连接等一系列分子克隆方法，将IL15和PAP基因融合在一起，构建融合蛋白的原核与植物表达载体．经PCR和Nco Ⅰ／Sal Ⅰ双酶切鉴定及测序，证实原核表达载体pET32a-IL15／PAP及植物表达载体pB-ⅠP中均插入了正确的融合基因序列．

双机器人协调控制系统

本文描述了基于集散控制原理,采用分层递阶结构建立的一个3级结构双机器人协调控制系统.该系统共分3层,最高层为任务规划级.它对双机器人作业进行离线编程及仿真,并负责对整个系统的监控和管理.第2层为协调级,它实现机器人作业的协调控制.并通过传感器信息对机器人轨迹进行实时修正.该层既可接收来自上层的命令或指令.对机器人进行控制,亦可在该层上独立编程.实现对机器人的控制.第3层为执行级,它实现高精度伺服控制.此外,该系统还提供了灵活的编程环境及良好的人机界面.用户可根据需要选择离线编程环境或实时编程环境,并且可在其相应的界面下工作,运行结果表明,系统性能稳定可靠,结构合理,编程环境灵活.我们在该系统上,成功地进行了PUMA562机器人和PUMA760机器人的点位协调和轨迹协调以及复杂的联合作业.