以1,4-二氯甲氧基丁烷为氯甲基化试剂合成线型氯甲基化聚苯乙烯

采用自制的氯甲基化试剂——1,4-二氯甲氧基丁烷(BCMB),使用Lewis酸催化剂,在均相反应体系中高效地实现了聚苯乙烯的氯甲基化.研究了反应机理,考察了各种因素对氯甲基化反应的影响规律,优化了反应条件,通过红外光谱法与Volhard分析法表征了产物的化学结构与组成.实验结果表明,反应机理可能由苯环亲电取代与伴随着醚键断裂的亲核取代两类反应构成,氯甲基化试剂用量、催化剂的酸性与用量、溶剂的性质与用量及反应温度等因素对反应都有显著的影响,其一,会影响聚苯乙烯的氯甲基化程度,其二,会导致或避免大分子链之间通过Friedel-Crafts反应而发生交联.以四氯化碳为溶剂、以SnCl4为催化剂并在较低温度(18℃)下进行反应,可制得氯甲基化程度达80%且完全线型化的氯甲基化聚苯乙烯.     

AutoCAD在机械设计基础中的应用

本文结合机电专业机械设计基础课程的教学特点，将AutoCAD引入课程的设计教学中。这将有益于该课程教学质量的进一步提高。     

Mononitrosated and phenylamido substituted chelate linkage isomers of quadridentate Schiff base copper(II) complexes

The nitrosation of monophenylamido substituted quadridentate Schiff base complexes of copper(II) are observed to adopt N-bonded isonitroso coordination whereas the phenylisocyanation of the corresponding mononitrosated quadridentate complexes are found to prefer O-bonded isonitroso coordination.     

连接子化学在聚合物-缀合物中的应用*

聚合物的缀合物化学近年来发展迅速,其反应产物既具有聚合物良好的稳定性、力学性能与特殊的结构形貌特点,亦因缀合各种分子而体现出完全不同的物理化学特性与独特的功能性。连接子化学是一类新型的具有高活性、高产率、高选择性的化学反应,对官能团位点敏感程度极高,对于聚合物与缀合分子的连接非常适合,适用于多种不同分子的缀合。本文旨在结合一些近年来具创新性的研究成果,介绍并总结连接子化学在聚合物缀合物中的应用进展,并对其广泛的前景进行合理的展望。     

Parallel Algorithms for Hierarchical Clustering and Applications to Split Decomposition and Parity Graph Recognition

We present efficient (parallel) algorithms for two hierarchical clustering heuristics. We point out that these heuristics can also be applied to solving some algorithmic problems in graphs, including split decomposition. We show that efficient parallel split decomposition induces an efficient parallel parity graph recognition algorithm. This is a consequence of the result of S. Cicerone and D. Di Stefano [[7]] that parity graphs are exactly those graphs that can be split decomposed into cliques and bipartite graphs.     

基于混合患病兄弟对IBD数据的连锁分析

患病兄弟对(affected sib-pair,ASP)设计在遗传统计中有着广泛的应用,这种设计针对的是完全兄弟对(full-sib),而在实际问题中,被抽样的患病兄弟对中常会混有一定数目的半兄弟对(half-sib).论文对这种基于IBD信息的混有半兄弟对NASP(称为mixed affected sib-pair,...     

THE ROLE OF ISSUE LINKAGE IN MANAGING NONCOOPERATING BASINS: THE CASE OF THE MEKONG

The Mekong River (MR) is the major water source in Southeast Asia, sharedby six countries. There is a rush, by riparian states, to acquire sources of alternative energy and other benefits to meet growing demands for water and energy. China and Myanmar have refused to cooperate fully in the MR Forum, leading to increase risks within the region. Development of the water resources of the MR Basin is the subject of intense debate both within the Mekong region and internationally. This paper investigates the concept of issue linkage to resolve unidirectional externalities in the MR. Using linked games, the paper shows that the downstream nations can consider the use of linkage as a form of side payment in achieving a basin‐wide agreement. While this approach supports the Integrated Water Resource Management‐based Basin Development Strategy adopted by the Mekong River Commission in April 2011 for managing the region's sustainability development, facts on the ground suggest that traditional issues to be linked may not be sufficient. The paper addresses this observation and suggests a cadre of issues, including nontraditional ones, to be analyzed in a future work.     

Synthesis,Characterization and Thermal Properties of Imide-Containing Phthalonitrile Polymers

A series of novel imide-containing phthalonitrile polymers with flexible aryl ether units have been synthesized and characterized. Bisphenol monomers were synthesized by a multi-step synthesis involving a condensation reaction between aromatic aldehydes and 2,6-dimethyl phenol, respectively. The bisphenols obtained were reacted with 4-nitrophthalonitrile to form aryl ether linkage containing bisphthalonitriles. These products were hydrolyzed to tetra carboxylic acid, which were subsequently converted into corresponding dianhydrides. The obtained dianhydrides were reacted with synthesized 4-(4′-aminophenoxy) phthalonitrile by thermal imidization leading to the formation of imide-containing phthalonitrile monomers. The synthesized monomers were cured with 3.5 wt% of aromatic diamine, 4,4′-diaminodiphenylsulphone(DDS). The structure and properties of all compounds synthesized were confirmed by using elemental analysis, FT-IR, ¹H-NMR, ¹³C-NMR, DSC, TGA and rheometric studies. The cure temperatures are found to be in the range of 283–302°C, the temperature of 5% and 10% weight loss from TGA are in the range of 433–492°C in N₂ and 424–478°C in air, char yield at 800°C is 40–51%.     

Identification of a genetic locus on chromosome 4q34-35 for type 2 diabetes with overweight

The incidence of type 2 diabetes is rising rapidly because of an increase in the incidence of being overweight and obesity. Identification of genetic determinants for complex diseases, such as type 2 diabetes, may provide insight into disease pathogenesis. The aim of the study was to investigate the shared genetic factors that predispose individuals to being overweight and developing type 2 diabetes. We conducted genome-wide linkage analyses for type 2 diabetes in 386 affected individuals (269 sibpairs) from 171 Korean families and association analyses with single-nucleotide polymorphisms of candidate genes within linkage regions to identify genetic variants that predispose individuals to being overweight and developing type 2 diabetes. Through fine-mapping analysis of chromosome 4q34-35, we detected a locus potentially linked (nonparametric linkage 2.81, logarithm of odds 2.27, P=6 × 10⁻⁴) to type 2 diabetes in overweight or obese individuals (body mass index, BMI⩾23 kg m⁻²). Multiple regression analysis with type 2 diabetes-related phenotypes revealed a significant association (false discovery rate (FDR) P=0.006 for rs13144140; FDR P=0.002 for rs6830266) between GPM6A (rs13144140) and BMI and waist–hip ratio, and between NEIL3 (rs6830266) and insulin level from 1314 normal individuals. Our systematic search of genome-wide linkage and association studies, demonstrate that a linkage peak for type 2 diabetes on chromosome 4q34-35 contains two type 2 diabetes-related genes, GPM6A and NEIL3.     

分子标记与QTL间连锁的检测与估计Ⅱ.利用双单倍体(DH)群体

将数量性状基因定位的“相关方法”应用到双单倍体（ＤＨ）群体，给出了适用于ＤＨ群体之标记座位（ＭＬ）与数量性状座（ＱＴＬ）间连锁测验的统计方法，并进而给出了重组值及其抽样误差估计的理论公式．