显微镜下测定温度的新仪器——盖克斯麦卡(Chaixmeca)显微测温计

气液包裹体研究中所遇到的主要困难是包裹体的体积太小,以致长期来局限于用常规化学方法进行某种测量来分析包裹体的成分。不过,矿物学家们总是试图用物理学方法确定包裹体的特征,其中起着重要作用的就是显微测温计(显微镜下测定相转变温度)。 目前,关于H_2O、CO_2、H_2O-CO_2、H_2O-NaCl、CH_4和H_2O-CH_4系的物理化学方面已经有许多实验数据。很显然,这些     

孔隙介质中胶体及金属运移的模式——文献调研

本文讨论了与地表下介质中胶体运移有关的问题。本文的最终目的是提出一个能用来评价胶体运移对金属活动性的影响的模式。首先对野外和实验室研究作了评述,以便提出证据证明胶体是在地表下介质中运移的。其次,活跃于该领域的研究人员相互联络,以确定目前进行的研究领域,以及征求有关对控制胶体运移机制认识水平的意见。第三是对胶体运移机制的有关文献进行调研,其中特别强调了胶体(和粒子)的过滤作用以及由于静电排斥和范德华引力对胶体稳定性的影响。第四是提出胶体-金属运移的理论模式(COMET),并将该模式与EPA的CML模式相合并,后一模式可用来模拟溶质由不饱和区的填土中运移到饱和区的集收场所(如饮水井)的过程。胶体-金属运移的理论模式的主要特点是能模拟已溶解或吸附到活动胶体上的多金属化学形式(结合地球化学平衡模式的研究成果),能模拟多种胶体的影响,并能在有从源区运移来的胶体存在的情况下调节源区胶体粒子的浓度和逗留时间。正文内方程(2)和(3)概括了该模式的这些作用。正如所预料的那样,该模式的模拟研究结果表明,活动金属相的浓度(溶解浓度加活动胶体所吸附金属的浓度)随胶体的浓度增大而增大,而可溶性金属化学形式(溶质)到达恒定集收位置的时间趋于减小。当溶质-胶体吸附作用和溶质-土壤     

Mechanics and Morphology of Silk Drawn from Anesthetized Spiders

 CO₂ and N₂ anesthetized Nephila spiders produced dragline silk with mechanical properties that differed from control silk as a function of time under anesthesia. Silk from CO₂ spiders had a significantly lower breaking strain and breaking energy, significantly higher initial modulus, and marginally lower breaking stress. At the onset of anesthesia the silk diameter became highly variable. During deep anesthesia silk either became thinner or retained cross-section but fibrillated. Received: 26 August 1999 / Accepted in revised form: 22 December 1999     

活性氮和世界:200年的变化

本文通过将19世纪后期和20世纪后期的氮流动情况进行对比,分析了食物和能源生产对全球氮循环的影响.我们虽然对人类产生的活性氮的数量及其释放到环境所产生的主要影响有了充分的认识,但是,我们对于环境库中氮的累积速度缺乏了解,由于积累在环境中的氮具有阶式效应,因此,对其在环境中的积累尚有不明之处.未来活性氮的产生、分布状况及其形成速度增加的可能性(尤其是在亚洲)存在巨大的区域性差异,因而需要制定"总活性氮措施",以优化食物和能源生产,保护环境系统.     

源自车辆的微粒磁性与Ficus infectoria(一个关键种)对它的改善

引言 源自车辆燃烧的磁性矿物质主要是磁铁矿和金属铁颗粒,大小为0.1～0.7 μm[1].这种大小的颗粒对人类特别有害,因为它能被吸入肺里.而且,在悬浮尘粒中,磁铁与其它重金属(如锌、镉、铬)[2]和对人体健康有害的诱变有机化合物[3]结合在一起.     

壬基酚聚氧乙烯醚在污水处理过程中的迁移转化行为

用正相色谱－质谱联用法（NPLC－MS）分离分析高聚合度的NPnEO(n＞2）,用气相色谱－质谱联用方法（GC－MS）测定其中的NP,NP1EO和NP2EO浓度,对NPnEO在城市污水处理厂的迁移转化行为进行了研究。在污水处理厂的进水中,检测出NP和NPnEO(n=1-23）,总浓度为174nmol/L,其中NP2EO的浓度最高,为89．6nmol/L;其次分别为NP（42．2nmol/L）和NP1EO（12．2nmol/L）;出水中同样检测出NP和NPnEO(n=1-18),其中NP2EO的浓度最高,为37．2nmol/L;其次分别为NP（6．64nmol/L）和NP1EO（0．135nmol/L)。在城市污水处理过程中,NPnEO从高聚合度降妥成低聚合度,NP和NPnEO的总去降率为71％。另外,NP和NPnEO在污泥及污泥过滤水中的分配表明污泥对NPnEO有明显的吸附作用,并近似符合Dubinin-Astakhov等温吸附。     

墨西哥湾西北部石油钻探对钻台附近沉积物中和生物体内微量金属元素含量的影响

一口典型海上石油钻井排入海中的钻井泥浆为500—1000t(干重,岩屑除外)。本项研究对墨西哥湾钻探位置周围表层沉积物、大型表栖生物群和钴井泥浆中某些微量元素(Ba、Cd、Cr、Cu、Fe、Pb、Ni和V)在钻探作业前、中和后均作了测定。生物体内Fe含量和沉积物中Ba、Cr含量的明显增高是由于钻井排放所致。深入研究了区内的虾类。钻探作业最后几天采集的虾类,其腹部肌肉的Fe含量比钻进前后采集的虾类的腹部肌肉高一倍。由钻井泥浆中可溶性有机螯合剂引起的海水中Fe溶解度(生物可吸收性)的提高,是上述Fe含量观测值增高的最合适的解释。在各采样环内的沉积物中都观测到Ba含量有明显增加,但只是在钻探位置的几百米范围内才大量增加(达7.5倍)。对钻探位置1000m范围内沉积物中的总排放Ba(过剩Ba)进行了质量平衡测定。在钻探结束时,只有占所用Ba总量9.3%的Ba以及估计还有由Ba示踪的其他类似泥浆组分在1000m范围内保存下来。在2.6mo以后只有6.6%保存下来。在海上高海流研究位置(水深24m)发生的沉积物明显再悬浮和迁移是造成排放Ba在沉积物中停滞时间短和快速丢失的主要原因。在1000m采样范围内的沉积物中,Cr的平均含量增加最高(26%)。     

Age-related decline in metabolic competence of small and medium-sized synaptic mitochondria

A computer-assisted morphometric investigation of cytochrome oxidase (COX) activity, selectively evidenced by preferential diaminobenzidine cytochemistry, has been carried out on synaptic mitochondria in the cerebellar cortex of adult and old rats. The ratio (R) of the area of the cytochemical precipitate (CPA) to the overall area of each mitochondrion (MA) was calculated. R refers to the fraction of the inner mitochondrial membrane actively involved in cellular respiration, thus its quantitative estimation constitutes a reliable index of the mitochondrial metabolic competence (MMC). In adult rats a significant negative correlation between MA and R values was found, while in old animals there was just a positive trend. Paired-quartile comparisons of R values showed a significant age-related decrease in small and medium-sized mitochondria, whereas the lowest and not significant age-related reduction was found in oversized organelles. A paired decrease in number and increase in size is reported to be a general trend for mitochondria during aging, but oversized organelles, according to their low R value, constitute a scanty, though functional, compensating reaction. Thus, the present findings support the argument that the currently reported age-related cellular metabolic decay appears to rely both on the decline in MMC of the small and medium-sized mitochondria, and on their specific reduction in number. This novel result is of biological relevance since it is largely the small and medium-sized mitochondria that are required for the provision of adequate amounts of ATP for actual cellular performance, while the significantly enlarged organelles are thought to represent an intermediate ultrastructural feature in mitochondrial genesis and/or remodelling.     

用抽提法除去污染土壤中的重金属

本试验的目的是开发从污染过的土壤中除去重金属的技术。试验是将六种不同的荷兰土壤用人工污染上五种不同的重金属,然后将污染过的土壤用三倍的0.1M的HCI溶液进行抽提,可将土壤中的Cu、Pb与Zn抽出90～99％,将Ni抽出80～90％,但是三价铬(Cr)只能抽出0～25％,可用次氯酸(HOCI)溶液在pH为8时抽出大部份铬(三价)。在水力旋流器中进行了固液分离试验。用化学凝聚与絮凝试验表明,几种絮凝剂都可收到很好的分离效果,这种絮凝并不影响抽提结果。在抽提与分离试验结果的基础上,安装了一套实验室规模的连续装置。抽提是在几只装有搅拌器的槽内进行,也可在有筛板的柱子中进行连续抽提。絮凝剂可以帮助     

Gamergates in the myrmicine genus <Emphasis Type="Italic">Metapone</Emphasis> (Hymenoptera:Formicidae)

Gamergates (i.e. mated reproductive workers) are mostly known from ant species within the Ponerinae. We report here the discovery of gamergates in two species of the subfamily Myrmicinae. Until now, mated reproductive females in colonies of myrmicine species have been considered morphologically distinct from the worker caste. However, in two species of the myrmicine Metapone (Metapone madagascarica and a newly discovered, not yet described Metapone species) all workers have six ovarioles and a spermatheca; and some of them are mated. There are no morphological differences between mated and non-mated workers. Field observations and laboratory studies indicate that colonies of the Metapone species can reproduce with gamergates only.