化学物质诱导对马氏珠母贝眼点幼虫附着的影响

【目的】研究血清素(5-HT)、蜕皮激素、γ-氨基丁酸(GABA)、腺嘌呤核苷、次黄嘌呤核苷和次黄嘌呤对马氏珠母贝眼点幼虫附着的影响。【方法】以不同浓度的5-HT、蜕皮激素、GABA、腺嘌呤核苷、次黄嘌呤核苷和次黄嘌呤溶液处理马氏珠母贝眼点幼虫,不同时间后,分析眼点幼虫附着率的变化。【结果】在24~96 h作用时间里,5-HT、蜕皮激素、GABA对眼点幼虫附着的诱导效果整体上均呈上升趋势;在24~120 h作用时间里,腺嘌呤核苷、次黄嘌呤核苷和次黄嘌呤对眼点幼虫附着的诱导效果整体上呈上升趋势。眼点幼虫在10^-5 mol/L的5-HT和GABA处理24、48、72和96 h后,附着率均显著高于对照组(P<0.01);10^-5 mol/L的蜕皮激素处理24 h和72 h,10^-6 mol/L的蜕皮激素处理24 h和96 h,10^-7 mol/L的蜕皮激素处理24 h,附着率均显著高于对照组(P<0.01);10μmol/L腺嘌呤核苷处理24、48、72和120 h,1μmol/L腺嘌呤核苷处理24、48、72、96和120 h,附着率均显著高于对照组(P<0.01);10μmol/L次黄嘌呤核苷处理48和72 h,1μmol/L次黄嘌呤核苷处理48、72、96和120 h,附着率均显著高于对照组(P<0.01);10μmol/L的次黄嘌呤处理72、96和120 h,附着率均显著高于对照组(P<0.01)。【结论】5-HT、蜕皮激素、GABA、腺嘌呤核苷、次黄嘌呤核苷和次黄嘌呤溶液在适宜的浓度和处理时间均可诱导马氏珠母贝眼点幼虫附着,其中10^-5 mol/L的5-HT处理24 h对附着率的诱导效果最佳,可达对照组的6.3倍。     

农用化学物质对环境的影响及对策

农用化学物质主要是指化肥、农药和农膜。农用化学物质在农业生产中对增加农产品产量起到了巨大的作用,但由于使用过量、不合理使用以及农用化学物质本身结构的原因引起了一系列环境问题,严重地影响了人类的生存环境和人类的健康。本文概述了农用化学物质的种类及农用化学物质对水体、土壤、大气及农产品的影响,并在借鉴国外先进经验的基础上,结合我国的实际情况,提出了6项防治措施。     

深海热液环境中脂肪酸组成的研究进展

1977年科学家们在东太平洋拉帕戈斯裂谷发现了深海热液喷口,揭示了以化能合成为基础的一个新的生命世界。围绕喷口的热液环境不同于一般深海环境,具有异常的化学特征:高温、高压且硫化物含量丰富,因此,接近热液的生物,     

美国钻油有新招 有望五年增产两成

美国石油行业分析师说,一种以页岩层石油为开采对象的钻井技术今后5年将大幅推高美国原油产量,减轻对进口原油的依赖。这种钻油新技术先前应用于天然气开采领域。为获得地表下页岩层的天然气,钻井人员在钻头抵达页岩层后水平钻人岩石,随后向钻孔注入水、沙子和一些化学物质,迫使岩层出现裂缝,使天然气溢出。石油分子黏性较强,体积较大,钻井工程人员认为,使用此法也可强制把石油“压出”页岩层。     

“生物坏小子”克霉格·文特尔轶事

他用了“四瓶化学物质”为他们的“人造细胞”设计了染色体，然后把这个基因信息植入另一个修改过的细菌细胞中，这个由合成基因组控制的细胞具有自行复制的能力——这就是人类成功制造的第一个“合成”生命，取名为“辛西娅”。     

浮游生物对某些化学物质在海洋微表层中富集所起的作用

本文综合分析了浮游生物对有机物、痕量金属、氮磷营养盐在海洋微表层中富集所起的作用。浮游植物和部分浮游细菌释放的溶解有机物大部分具有表面活性且能与痕量金属络合,它们能靠Gibbs吸附富集于微表层,并促成与络合的痕量金属的富集。浮游细菌对微表层中富集的含氮和含磷有机物的分解可能是促成氮磷营养盐在微表层中富集的重要原因。     

Organochlorine pesticides in marine environment of Quanzhou Bay, Southeast China

As one of the most important buildup of persistent organic pollutants （POPs）, organochlorine pesticides （OCPs） have received more and more attention. Samples including sediments, water and marine products were collected. In the lab, nineteen types of organochlorine pesticides were tested using GC-ECD following US-EPA 8080A method. In the top sediments, the concentration of HCHs was 0.1-3.08 ng/g and the concentration of DDTs was 3.53-75.83 ng/g. In the bottom sediments, the concentration of HCHs was 0.1-3.59 ng/g and the concentration of DDTs was 1.56-81.68 ng/g. The concentration ranges of HCHs and DDTs in sea water were 1.31-9.96 ng/L and 0.78-6.51 ng/L, respectively. And the concentration ranges of HCHs and DDTs in land surface water were 7.04-14.08 ng/L and 3.82-9.66 ng/L, respectively. The residual levels of HCHs and DDTs in marine product samples ranges from 0.1 to 0.6 ng/g and from 0.57 to 85.02 ng/g, respectively. In this thesis, discussions of DDTs and HCHs in sediment, water and marine product samples were made. The following are the main results and conclusions： A general decreasing trend was found from the inner to outer sectors of the Bay for both sediment and water samples. The distribution of OCPs depends greatly on the different properties pertaining to them. The topography, redox, hydrodynamic condition as well as other factors also play an important role in controlling the distribution and fate of OCPs.     

Simulation of Tropospheric Ozone with MOZART-2： An Evaluation Study over East Asia

Climate changes induced by human activities have attracted a great amount of attention. With this, a coupling system of an atmospheric chemistry model and a climate model is greatly needed in China for better understanding the interaction between atmospheric chemical components and the climate. As the first step to realize this coupling goal, the three-dimensional global atmospheric chemistry transport model MOZART-2 (the global Model of Ozone and Related Chemical Tracers, version 2) coupled with CAM2 (the Community Atmosphere Model, version 2) is set up and the model results are compared against observations obtained in East Asia in order to evaluate the model performance. Comparison of simulated ozone mixing ratios with ground level observations at Minamitorishima and Ryori and with ozonesonde data at Naha and Tateno in Japan shows that the observed ozone concentrations can be reproduced reasonably well at Minamitorishima but they tend to be slightly overestimated in winter and autumn while underestimated a little in summer at Ryori. The model also captures the general features of surface CO seasonal variations quite well, while it underestimates CO levels at both Minamitorishima and Ryori. The underestimation is primarily associated with the emission inventory adopted in this study. Compared with the ozonesonde data, the simulated vertical gradient and magnitude of ozone can be reasonably well simulated with a little overestimation in winter, especially in the upper troposphere. The model also generally captures the seasonal, latitudinal and altitudinal variations in ozone concentration. Analysis indicates that the underestimation of tropopause height in February contributes to the overestimation of winter ozone in the upper and middle troposphere at Tateno.