含硝基腐植酸、DCD的氮肥增效剂对水稻生育性状及产量影响的试验研究

<正> 我国农业生产中的主要氮素化肥是尿素和碳酸氢铵。随着作物产量的提高,施用氮肥量也不断增加,但由于施入土壤中的尿素或碳酸氢铵分解速度快,有相当一部分氮素作物尚未吸收利用就流失或挥发而浪费掉。据测定,尿素中氮素利用率只有35％,碳酸氢铵氮素利用率仅15～25％。本试验结果表

辽宁山羊绒品质分析

辽宁山羊绒品质分析李文清麻岩＊李亚乔＊王丽霞刘丹张长恩（中国科学院沈阳应用生态研究所，沈阳１１００１５）（＊辽宁省纤维检验所）在制定《山羊原绒》国家标准过程中，先后对全国山羊绒主产区的内蒙古、新疆、辽宁、太行山地区，西北地区进行了调研，采集和索取了全...

生物制剂对沙土樟子松幼苗光合特性及养分含量的影响

采用盆栽试验研究了Pt菌剂、ABT生根粉、HRC吸水剂和FCS丰产素等生物制剂对沙地樟子松2年生幼苗光合特征和养分含量的影响,结果表明:Pt菌剂(3号)和ABT生根粉与对照相比,显著地促进了樟子松幼苗全株、地下和地上生物量生长,并增加了幼苗的根冠比值,有利地促进幼苗对养分的吸收;Pt菌剂(3号)和ABT生根粉处理的幼苗叶子养分全N、P、K含量显著地高于对照幼苗,促进了幼苗养分的平衡,为提高光合作用能力提供了物质基础;Pt菌剂(3号)和ABT生根粉处理幼苗与对照相比,光合速率和蒸腾效率显著增强。这些是提高樟子松苗木在干旱、半干旱沙地成活生长的生理基础。

采用了剪枝优化的子类型关系判定算法

静态类型化XML处理语言为处理XML数据提供了新的途径,但现有的此类语言大多数效率较低.研究此类语言的一个重要问题——子类型关系的判定,并使用剪枝优化策略对XDuce的子类型关系判定算法进行优化.实验数据显示,优化后算法的执行效率平均提高20%.该策略具有普遍性,对所有使用类似算法的静态类型化XML处理语言都有效.

全球环境管理理念对中国的启示

首先介绍了“全球环境管理”(globalenvironmentalgovernance)理念产生的背景、含义与国际发展态势．全球环境管理是一种多元化、多层面、多视角的理念,包括管理全球环境的制度、法则、规范、标准及其过程与行为．国际上,全球环境管理研究已开始从理念探讨向实践转化．在此基础上,概述了中国参与全球环境管理所面对的挑战和机遇．最后提出,为了更加有效地参与全球环境管理,我国应该：重视提炼关键科学问题,加强原始性创新研究；制定我国参与全球环境管理的发展战略；建立长期有效的高端协调机制；完善配套政策与

Phenylthiolate as a sigma- and pi-donor ligand: synthesis of a 3-D organometallic coordination polymer [K2Fe(SPh)(4)](n)

The synthesis and crystal structure of the first mixed-metal organometallic polymer network containing phenylthiolato ligands, [K2Fe(SPh)(4)](n), are investigated. The simple phenyl-thiolate acts as a sigma- and pi-donor ligand to give a 3-D potassium iron coordination polymer with both metal-carbon and metal-sulfur coordination interactions.

Voltammetric study of the sodium ion transfer across micro-water/1,2-dichloroethane interface facilitated by terminal-vinyl liquid crystal crown ether

Sodium ion transfer across micro-water/1,2-dichloroethane (DCE) interface facilitated by a novel ionophore, terminal-vinyl liquid crystal crown ether (LCCE) was studied by cyclic voltammetry. LCCEs have potential applications because of their physicochemical properties and the utilization of crown ethers as selective ionophoric units in other functionalized compounds are interesting. Host-guest-type behavior for such compounds in the liquid-crystalline state is studied. The experimental results suggest that the transfer of the sodium ion facilitated by LCCE was controlled by diffusion of LCCE from bulk solution of DCE to the interface. The diffusion coefficient of LCCE in DCE was calculated to be equal to (3.62 +/- 0.20) x 10(-6) cm(2)/s. Steady-state voltammograms are due to sodium ion transfer facilitated by the formation of 1: 1 metal (M)-LCCE complex at the interface and the mechanism tends to be transfer by interfacial complexation or dissociation (TIC or TID). The stability constant of the complex formed was determined to be log beta(o) = 5.5 in DCE phase. The influence of parameters such as concentration of sodium ion and concentration of LCCE on the sodium ion transfer was investigated.

Meldola拉蓝修饰双层类脂膜的电化学研究

双层类脂膜(BLM)作为生物膜的基本结构主体已被广泛接受。通过掺杂和化学修饰可以改变BLM的特性,并能应用于多种生物膜过程的研究。特别是制成生物传感器和双分子电子器件将有广阔的应用前景。多种有机染料被称作生物着色剂并常用于生物学、生理学、药物学和医学。一般来说,染色和着色过程包括吸附、溶解、渗透和化学反应。但染料如何影响磷脂膜仍然不十分清楚。本文选用用于生物传感器中的生物催化剂Meldola蓝来修饰BLM,并对它的传输性质进行了分析。

含联苯结构侧链液晶聚合物的合成及相行为的研究

液晶聚合物从结构上可分为3种:侧链型、主链型和主侧链型。侧链型液晶聚合物主要是聚丙烯酸酯类、聚硅氧烷类以及磷腈聚合物类。Gray等对聚丙烯酸酯类含不同取代基的联苯结构液晶聚合物进行了研究,结果表明无间隔基且取代基为氰基和饱和脂肪基时,该聚合物呈现近晶型液晶行为。为了增加介晶单元的长径比及刚性,本文在聚甲基丙烯酸酯侧链

α-羰基烯酮环二硫代缩醛化学(Ⅹ)——β,β-1,5-亚丙二硫基-α,β-不饱和酮与烯丙基Grignard试剂加成物的酸催化反应取向研究

β,β-1,5-亚丙二硫基-α,β-不饱和酮2b和2-甲基烯丙基氯化镁加成可得醇3b.在BF_3·Et_2O催化下,3b经分子内环合芳构化生成芳硫醚5b.2和烯丙基溴化镁反应得醇4,4在BF_3·Et_2O催化下经β-消除脱水生成共轭多烯类化合物6.二硫缩醛基以环和非环结构及环的大小对2与烯丙基Grignard试剂加成物在酸催化下的反应取向有重要影响.

Molecular cloning and characterization of a thioester-containing protein from Zhikong scallop Chlamys farreri

Thioester-containing proteins are a family of proteins characterized by the unique intrachain beta-cysteinyl-gamma-glutamyl thioester, which play important roles in innate immune responses. The cDNA of Zhikong scallop Chlamys farreri thioester-containing protein (designated as CfTEP) was cloned by expressed sequence tag (EST) and rapid amplification of cDNA ends (RACE) approaches. The full-length cDNA of CfTEP was of 4616 bp, consisting of a 5 '-terminal untranslated region (UTR) of 30 bp and a 3 ' UTR of 140 bp with a polyadenylation signal sequence AATAAA and a poly(A) tail. The CfTEP cDNA encoded a polypeptide of 1481 amino acids with the theoretical isoelectric point of 5.98 and the predicted molecular weight of 161.4 kDa. The deduced amino acid sequence of CfTEP contained the canonical thioester motif GCGEQ, nine potential N-glycosylation sites and a C-terminal distinctive cysteine signature. It also contained a presumed catalytic histidine and proteolytic cleavage sites that were similar to C3 molecules. The high similarity of CfTEP with the thioester-containing proteins in other organisms, such as the TEPs from insects, the complement component C3, C4, C5 and the protease inhibitor alpha(2)-macroglobulin indicated that CfTEP should be a member of TEP family. The phylogenetic analysis revealed that CfTEP was closely related to TEPs from mollusc, nematodes and insects, and they formed a separate branch apart from the branches of complements factors and alpha(2)-macroglobulins. The spatial expression of CfTEP transcripts in healthy and bacterial challenged scallops was examined by semi-quantitative RT-PCR. The CfTEP transcripts were mainly detected in the tissues of hepatopancreas and gonad, and remarkably up-regulated by Microbial challenge, which suggested that CfTEP was a constitutive and inducible acute-phase protein involved in immune defense. These results provided new insights into the role of CfTEP in scallop immune responses, as well as the evolutionary origin of this important, widespread and functionally diversified family of proteins. (c) 2007 Published by Elsevier Ltd.

Generation and evolution of magma beneath the East Pacific Rise: Constraints from U-series disequilibrium and plagioclase-hosted melt inclusions

Mid-ocean ridge basalt (MORB) samples from the East Pacific Rise (EPR 12 degrees 50'N) were analyzed for U-series isotopes and compositions of plagioclase-hosted melt inclusions. The Ra-226 and Th-230 excesses are negatively correlated; the Ra-226 excess is positively correlated with Mg# and Sm/Nd, and is negatively correlated with La/Sm and Fe-8; the Th-230 excess is positively correlated with Fe-8 and La/Sm and is negatively correlated with Mg# and Sm/Nd. Interpretation of these correlations is critical for understanding the magmatic process. There are two models (the dynamic model and the "two-porosity" model) for interpreting these correlations, however, some crucial parameters used in these models are not ascertained. We propose instead a model to explain the U-series isotopic compositions based on the control of melt density variation. For melting either peridotite or the "marble-cake" mantle, the FeOt content, Th-230 excess and La/Sm ratio increases and Sm/Nd decreases with increasing pressure. A deep melt will evolve to a higher density and lower Mg# than a shallow melt, the former corresponds to a long residence time, which lowers the Ra-226 excess significantly. This model is supported by the existence of low Ra-226 excesses and high Th-230 excesses in MORBs having a high Fe-8 content and high density. The positive correlation of Ra-226 excess and magma liquidus temperature implies that the shallow melt is cooled less than the deep melt due to its low density and short residence time. The correlations among Fe-8, Ti-8 and Ca-8/Al-8 in plagioclase-hosted melt inclusions further prove that MORBs are formed from melts having a negative correlation in melting depths and degrees. The negative correlation of Ra-226 excess vs. chemical diversity index (standard deviation of Fe-8, Ti-8 and Ca-8/Al-8) of the melt inclusions is in accordance with the influence of a density-controlled magma residence time. We conclude that the magma density variation exerts significant control on residence time and U-series isotopic compositions. (c) 2010 Elsevier B.V. All rights reserved.