大超篮球联赛对校园文化建设的影响分析

本文对大超篮球联赛(中国大学生男子篮球超级联赛)所带来的校园体育文化建设的问题进行了探析,并对校园体育文化的内涵、价值及作用进行了阐述.校园体育文化是校园文化的重要组成部分,是实施素质教育的重要途径.大超篮球联赛既丰富了校园文化的内容,并促进校园体育文化的发展,对构建和谐校园也具有重要意义.     

沥青混凝土路面摊铺找平方式探讨

介绍了沥青混凝土摊铺的基本要求、准备工作,对摊铺机各部件的工作原理、找平方式进行了叙述,给施工操作提供了一些具体方法,以提高沥青混凝土的摊铺质量.     

聚合物降解与稳定化

文章通过对聚合物降解现象、导致降解的因素及降解机理的阐述,提出了防止聚合物降解即对聚合物进行稳定化所采用的物理及化学方法.     

浅谈林场职工思想政治教育工作

对于林杨职工来说,构建和谐的人际关系,既是构建社会主义和谐社会的必然要求,同时也为新时期林场恩想政治工作指明了目标和方向。     

川西北高原野生垂穗披碱草居群穗部形态研究

对分布于川西北高原的12个垂穗披碱草（Elymus nutans）种群的15个穗部形态性状进行了研究。Shannon-weaver指数分析表明,12个种群穗部形态学性状上具有丰富的遗传多样性(H′=1．86748),且遗传多样性主要集中在种群内部（71．91%）大于种群间遗传变异（28．09%）;聚类分析把12种群的材料聚为4类;主成分分析表明小穗宽、小穗长、外稃长、内稃长、穗长、单穗重和穗节数是造成12个种群垂穗披碱草穗部特征差异的主要因素。     

矩形管成品拉拔的芯头工作带设计与变形平滑化

分析矩形管带芯头拉拔工艺实质和变形平滑化机理,提出"以小变形量控制矩形截面管坯均匀的从模具工作带挤压出来"的拉拔平滑化方法.建立了带芯头拉拔工艺简化的三维运动模型及弹塑性有限元模拟模型,采集矩形长边中点、短边中点、圆角中点三个研究的关键点,分析获得直线型与带台阶型两种方案关键点的等效塑性应变和接触应力变化规律.在表面质量最难以保证的长边中点,带台阶方案的等效塑性应变较直线型芯头提高45.5%,其接触应力由0提高到13 MPa.采用带台阶型的芯头工作带拉拔,获得"一拉二压"的应力状态,以少量挤压变形调控壁厚偏差、提高矩形管材内外表面质量.     

东北平原典型农业县不同利用方式对耕地土壤养分状况的影响研究

研究不同利用方式对耕地土壤养分状况的影响,可以为有效地指导农业生产、促进土地资源的保护和持续利用提供科学依据。在获取大量土壤养分数据的基础上,系统地分析了不同耕地利用方式对吉林省德惠市土壤养分状况的影响。结果表明,在11种土壤养分中,有效锰、有效磷、有效锌、有效铁和有效铜在不同利用方式下变异系数较大。不同耕地利用方式对土壤全氮、有效磷、速效钾、缓效钾具有显著影响,而对土壤有机质的影响不显著。因农户对菜地的投入及管理水平明显高于粮田,造成菜地土壤的大量元素含量高于粮田。除有效钼在旱田和水田中的含量无显著差异外,水田中的有效铜、锌、铁、锰、硼均明显高于旱田,主要原因为水稻田施微肥较多。表4,参16。     

A new drug carrier: Magnetite nanoparticles coated with amphiphilic block copolymer

This paper reports on the synthesis and characterization of 4 nm magnetite nanoparticles coated with amphiphilic block copolymers of poly(ethyl methacrylate)-b-poly(2-hydroxyethyl methacrylate) (PEMA- b-PHEMA) by surface-initiated atom transfer radical polymerization (ATRP), which can act as new po-tential carriers for hydrophobic targeted drug delivery. Vibrating sample magnetometer analysis indi-cated that the magnetite nanoparticles were superparamagnetic at room temperature. Thermogravim-etric analysis (TGA) was applied to studying the property of surface of magnetite nanoparticles, and the surface density of macromolecules was calculated. The grafting density of oleic acid, BrMPA and PEMA was 5.8, 3.9, 0.16 chain/nm2 respectively, which indicates that the initiation efficiency decreases due to the influence of large space of oleic acid molecules. In vitro progesterone and (-)-isoproterenol hy-drochloride release in phosphate buffered saline (PBS) at pH 7.0 and 37℃ was conducted in order to demonstrate the function of drug loading and release. The results showed that the amount of drug carried into the core-shell Fe₃O₄@PEMA-b-PHEMA depends on the length of hydrophobic segment of block copolymer. The release of progesterone (37% after 22 h in our previous work) was compared with the release of (-)-isoproterenol hydrochloride (80% after 50 min), demonstrating that the strong hy-drophobic interaction between hydrophobic segment and drug can effectively control the release of hydrophobic drugs.     

Numerical simulation on gas production from a hydrate reservoir underlain by a free gas zone

Physical and mathematical models of gas production by depressurization from a hydrate reservoir underlain by a free gas zone are established. The mathematical model can interpret the effects of the flow of multiphase fluids, the process of hydrate dissociation, ice-water phase transition, the variation of permeability, the convection and conduction on hydrate dissociation and gas and water production. The evolutions of temperature, pressure, and saturations in the hydrate and free gas zones are elucidated during gas production. The variation of some parameters, such as gas and water rates, with time is presented. The results show that the overlying hydrate zone can supply a certain amount of gas to improve the output of a production well and evidently prolong the lifespan of a gas reservoir. Supported by the National High Technology Research and Development Program of China (Grant No. 2006AA09A209) and the National Basic Research Program of China (Grant No. 2009CB219507)