野棉花研究综述

野棉花主要含有皂苷、有机酸类、甾类和挥发性成分等化学成分,主治泄泻、痢疾、黄疸、疟疾、蛔虫病、清湿热和解毒杀虫等.本文从名称考证、化学成分及药理活性等方面进行综述,旨在为进一步开发利用野棉花提供科学依据.     

内蒙岱海游乐场孔沉积物分析及其3000年来环境演变

本文通过对游乐场钻孔剖面沉积物的粒度分析、粘土矿物分析、微量元素分析、ＣａＣｏ３含量、ｐＨ值、有机质含量分析、孢粉分析、介形类组合分析及其附近地区历史文献资料分析，研究了该地区３０００年来环境演变的过程和各阶段的环境特征。     

PSF and CMF,autocrine factors that regulate gene expression during growth and early development ofDictyostelium

Throughout growth and development,Dictyostelium cells secrete autocrine factors that accumulate in proportion to cell density. At sufficient concentration, these factors cause changes in gene expression. VegetativeDictyostelium cells continuously secrete prestarvation factor (PSF). The bacteria upon which the cells feed inhibit their response to PSF, allowing the cells to monitor their own density in relation to that of their food supply. At high PSF/bacteria ratios, which occur during late exponential growth, PSF induces the expression of several genes whose products are needed for cell aggregation. When the food supply has been depleted, PSF production declines, and a second density-sensing pathway is activated. Starving cells secrete conditioned medium factor (CMF), a glycoprotein of Mr 80 kDa that is essential for the development of differentiated cell types. Antisense mutagenesis has shown that cells lacking CMF cannot aggregate, and preliminary data suggest that CMF regulates cAMP signal transduction. Calculations indicate that a mechanism of simultaneously secreting and recognizing a signal molecule, as used byDictyostelium to monitor cell density, could also be used to determine the total number of cells in a tissue.     

化学成分对铸态复合基体球铁组织与性能的影响研究

试验研究了化学成分对铸态球铁复合基体组织与性能的影响．结果表明,Ｓｉ２．４％～２．８％、Ｍｎ０．４％～０．６％时,在试样中可稳定地获得铸态复合基体组织;当Ｓｉ＜２．８％、Ｍｎ＜０．５％、Ｐ∶Ｆ为４∶６或３∶７时,综合机械性能均能超过ＱＴ５０５所规定的各项指标．但当Ｓｉ＞２．８％、Ｍｎ＞０．５％时,低温冲击韧性将显著下降．     

南美藜的化学组成和营养价值

本文介绍了正被现代人重新认识的南美洲古老作物南美藜的基本情况 ,通过对我国西藏地区种植的南美藜种子的化学成份及营养特点的分析 ,并与禾谷类作物在营养方面进行的比较 ,发现南美藜具有很高的营养价值     

二维单位球上不同加权Dirichlet空间之间的总体紧复合算子列

设n:Ｂ→Ｂ是一全纯映射列并且是单叶的,n(0)=0,n的Fréchet导数是有界的,并且｜Ｊn(z)｜≠０且有界,Ｃn:D２α（Ｂ,dυa）→Ｄ２β（Ｂ,dυB）（α,β＞２２＋１）是一致有界线性复合算子列．作者利用测度给出了此复合算子列的总体紧性．     

不同曝气强度下MBR污泥混合液可滤性分析

研究了曝气强度对膜-生物反应器（MBRs）污泥混合液的可滤性的影响．2套MBRs采用曝气强度分别为500L/h及100L／h恒流出水模式连续运行60d,应用污泥混合液过滤装置测定污泥混合液的可滤性．结果表明：过高的曝气强度将恶化污泥混合液的可滤性,增加膜污染速率;曝气强度的增加将导致污泥混合液上清液中相对分子质量大于10000的溶解性微生物代谢产物（SMP）浓度增加,此部分大分子有机物浓度的增加恶化了污泥混合液的可滤性;曝气强度大于500L／d也将导致污泥絮体中1～10um细小颗粒和胞外聚合物（EPS）含量的增加．     

The carbon isotopic compositions of Non-methane Hydrocarbons in atmosphere

Carbon isotopic compositions of atmospheric Non-methane Hydrocarbons(NMHCs) in the urban areas of Taiyuan and Lanzhou in summer were reported and the sources of NMHCs are discussed.Carbon isotopic ratios(δ 13C) of vehicle exhaust,coal-combustion exhaust,fuel volatiles and cooking exhaust were also measured with thermal desorption-gas chromatography-isotope ratio-mass spectrometry(TD-GC-IR-MS).δ 13C values of NMHCs in the urban areas of Lanzhou and Taiyuan range from-32.3‰ to-22.3‰ and from-32.8‰ to-18.1‰.δ ...     

金属纳米颗粒的极化率与异常光学性质

基于金属纳米材料的异常光学现象,考虑了束缚电荷作用的情况,从理论上推导出在光波照射下金属纳米颗粒的极化率与颗粒尺度关系的结果,进而得到金属颗粒对光波的吸收率,并讨论颗粒尺度对极化率和吸收率的影响,即当金属粒子尺寸达到纳米级时,将金属粒子看作纳米小球,小球极化率出现半径的立方因子,且小球半径小于电子平均自由程,电子的衰减因子受小球半径的制约.由推导结果可以得出,光吸收峰增强,并产生红移.这些结果为深入理解金属纳米颗粒的异常光学性质,揭示和开发应用金属纳米材料的性质提供理论基础.     

异步冷轧纯铁回复与再结晶的电子背散射衍射研究

本文采用异步轧制工艺成功制取等轴状超细晶纯铁,通过DSC曲线确定其退火工艺,使用电子背散射衍射（EBSD）观测超细晶工业纯铁在不同温度退火后的组织形貌和晶粒尺寸,研究其回复再结晶行为.结果表明,在400℃时,材料开始发生回复,再结晶形核开始,随着退火温度的提高,再结晶程度加深.当退火温度达600℃时,再结晶过程基本完成.