Investigations of microbial origin of karst corrosion of soils depending on different temperatures

The acids accumulating in soils and controlling the solution of carbonates including the predominant CO2, mostly derive from three processes: i) root respiration of higher plants; ii) decomposition of soil organic matter by microorganisms (microbiota) and iii) other decomposition processes not associated with microbial activities. The solution effect under rendzina soils is primarily used for the dissolution of the enclosed limestone fragments and thus here the solution of bedrock is of limited scale. Below karst soils of high clay content the corrosion of bedrock is more intensive than under rendzinas. On the whole, the amount of carbonates dissolved and transported into the depths of the karst is smaller than below rendzinas. In each soil type studied the solution caused by microbial activities manifold exceeds the rate of solution resulting from temperature factor but there is a manifest dropping trend from rendzina to clays.     

两相厌氧法处理含硫草浆造纸黑液的工业应用

根据两相生物厌氧法处理含硫草浆造纸黑液的工业化实践,分析硫酸盐还原菌在生物厌氧消化过程中的地位,及其与产酸菌、产甲烷菌的相互作用。为两相生物厌氧法处理含硫草浆造纸黑液的稳定运行提供理论依据。     

基于观测量扩展的捷联惯导动基座快速初始对准

动基座条件下捷联惯导系统由于动态环境的影响,即使采用辅助信息下的组合初始对准也需要较长时间。针对这一问题提出了一种基于观测量扩展的捷联惯导动基座快速初始对准方法。在不改变系统状态方程的情况下,利用车体坐标系横向和垂直方向上速度为零这一约束条件,将基于车体坐标系横向和垂直方向的速度作为扩展的观测量。推导了扩展后的观测方程。进而利用卡尔曼滤波完成捷联惯导动基座初始对准。进行了运动条件下的仿真。仿真结果表明新方法在保证对准精度的同时缩短了对准时间。该方法算法简单,不需要增加辅助信息,具有很好的工程应用价值。     

克拉玛依油田微生物吞吐矿场试验及效果分析

针对克拉玛依油田稠油沥青质组分所占比例大的特点,通过室内菌种筛选,选育出适合克拉玛依稠油的微生物菌种,该菌种能够显著降解稠油中的沥青质。微生物吞吐矿场试验结果表明：六口油井措施有效率100%,累计增油936.883t,取得明显的经济效益,该技术为新疆油田稠油蒸汽吞吐后进一步提高采收率提供了一种工序简单、安全环保的新方法。     

环境激素邻苯二甲酸丁基苄酯的毒理学研究

邻苯二甲酸丁基苄酯的大量生产与广泛应用,成为全球性的有机污染物．其作为一种环境激素,使人类赖以生存的生态环境受到威胁,逐渐引起各国学者高度重视和关注．介绍了近几年国内外有关邻苯二甲酸丁基苄酯的研究概况,主要包括该化合物的理化性质、来源、毒理学及生物降解等．     

Mechanism of Kenaf Retting Using Aerobes

The experimental results showed that the duration of microbial retting processing of kenaf fibers by using aerobic microbe was four times shorter than that by using anaerobic microbe. The residual gum percentage, breaking strength, breaking elongation and linear density of aerobic retted kenaf bundle fibers did not show significantly difference with that of anaerobic retted kenaf bundle fibers by ANOVA-Tukey's studentized test at a = 5% except for the softness. The bioenergetic principle and the calculation of the amount of ATP produced during the decomposition processing of kenaf gums were used to explain why the retting duration in the case of using aerobic microbes was much shorter than that of using anaerobic microbes.     

How plants recognize pathogens and defend themselves

Plants have an innate immunity system to defend themselves against pathogens. With the primary immune system, plants recognize microbe-associated molecular patterns (MAMPs) of potential pathogens through pattern recognition receptors (PRRs) that mediate a basal defense response. Plant pathogens suppress this basal defense response by means of effectors that enable them to cause disease. With the secondary immune system, plants have gained the ability to recognize effector-induced perturbations of host targets through resistance proteins (RPs) that mediate a strong local defense response that stops pathogen growth. Both primary and secondary immune responses in plants depend on germ line-encoded PRRs and RPs. During induction of local immune responses, systemic immune responses also become activated, which predispose plants to become more resistant to subsequent pathogen attacks. This review gives an update on recent findings that have enhanced our understanding of plant innate immunity and the arms race between plants and their pathogens. Received 24 June 2007; received after revision 18 July 2007; accepted 15 August 2007     

灵芝与中药共发酵产物的药理学初步研究

为考察灵芝培养基在添加不同中药后,其发酵液药理作用的变化,选择小鼠负重游泳实验,戊巴比妥钠睡眠时间试验,小鼠断头后致急性脑缺氧试验,以及对S180荷瘤小鼠瘤重的影响,研究在灵芝培养基中添加不同中药后其发酵液的抗疲劳、改善睡眠、耐缺氧与抑制肿瘤作用,并研究了这几味中药对灵芝生长的影响.结果发现在灵芝培养基中添加黄芪、姜黄、补骨脂、红毛五加后,其发酵液能明显延长小鼠负重游泳时间;在培养基中添加黄芪、红毛五加的发酵液对小鼠急性脑缺血性缺氧具有较好的保护作用;在培养基中添加巴戟天后,其发酵液灌胃的小鼠,瘤重减轻.表明在灵芝培养基中添加中药后,会改变灵芝发酵液的药理作用.     

一种基于虚拟手术的三维碰撞检测算法

为了解决虚拟手术的快速碰撞检测问题,提出了一种新的基于方向包围盒层次树的快速碰撞检测算法,利用简化的几何模型表示一方向包围盒层次树来实现复杂物体间的实时碰撞检测.算法在继承一般基于方向包围盒的碰撞检测算法优点的同时,突破了它们的局限性,能够在保证效率的前提下处理任意形状多面体之间的碰撞检测问题.同时采用了三角形带压缩技术和方向包围盒技术来加快碰撞检测阶段的绘制速度,从而提高碰撞检测的效率.     

微生物生态学研究进展——第十一届国际微生物生态学大会综述

第11届国际微生物生态学会于2006年8月在奥地利维也纳召开。此次会议以“隐藏的力量——行动中的微生物群落”为主题,特邀了当今世界在微生物生态学领域最为著名的科学家作专题报告,内容广博,反映了当今微生物生态学研究的发展动向。本文简要介绍了第十一届国际微生物生态学大会的概况和部分演讲摘要。