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981.
本文对安徽测震台网的系统构成、子台分布、地震设备情况、传输信道、台网的技术系统功能进行了介绍。安徽测震台网部的建成,使得地震监控能力得到更大的提升,在安徽省地震应急中必将发挥积极的作用。 相似文献
982.
Quantitative structure-property relationship of aromatic sulfurcontaining carboxylates 总被引:1,自引:0,他引:1
LIUXin-hui YANGZhi-feng WANGLian-sheng 《环境科学学报(英文版)》2003,15(6):721-727
983.
研究了TNT及其还原产物色谱分析方法,鉴定了铜-铁金属对还原柱处理TNT废水所产生的降解产物,并对这一还原反应的机制进行了探讨.动力学研究结果表明,金属对还原柱还原TNT的反应是一级反应. 相似文献
984.
985.
实验教学在高校环境专业教学工作中发挥着越来越重要的作用。通过对高校环境专业实验教学的现状和所存在的问题进行分析,提出了优化实验教学内容、改进实验教学方法和考核方式等改进措施,以提高高校环境专业实验教学水平。 相似文献
986.
本文首先叙述了合肥台地电阻率值ρS的观测环境,并根据合肥台近年几次ρS的异常变化,通过初步理论分析,找出了DD-1接地体、电缆沟开挖、大气降水、太阳黑子引起的自然电场对ρS的干扰,为以后排除和识别地电干扰起参考作用. 相似文献
987.
The presence of Bacillus thuringiensis (Bt) protein in earthworms Eisenia fetida has no deleterious effects on their growth and reproduction 总被引:1,自引:0,他引:1
Earthworms Eisenia fetida, bred in substances with stover of two genetically-engineered Bacillus thuringiensis (Bt) corns (5422Bt1 (Event Bt11) and 5422CBCL (MON810)) expressing Cry1Ab and their near-isogenic non-Bt corn (5422), were used to investigate the non-target effects of Bt corn on soil-dwelling organisms. Cry1Ab concentrations in substances, casts and guts of E. fetida were also investigated by Enzyme-linked immunosorbent assay (ELISA). More than 90% individuals of E. fetida survived over a period of 30 d, irrespective of whether they received Bt corn or non-Bt corn. Compared to 5422 treatments, significantly higher relative growth rate and more number of new offspring and cocoons of E. fetida were found in 5422Bt1 and 5422CBCL treatments. These results were unlikely to be directly caused by Cry1Ab released from Bt corns but rather by differences in other factors of plants such as plant components (soluble sugar, total organic carbon, total protein and available phosphorus of Bt corns were more than 5422). ELISA results indicated immunoreactive Cry1Ab was detectable in substances, and the casts, guts of E. fetida from Bt corns treatments, of which the highest levels were detected in substances under the corresponding experimental conditions. With the increase of treated time, a strong decline was observed in Cry1Ab from substances and casts of E. fetida, whereas Cry1Ab in guts of E. fetida from 5422Bt1 treatments gradually increased and that from 5422CBCL treatments increased between 14 and 30 d. Therefore, the presence of Cry1Ab in E. fetida had no deleterious effects on their growth and reproduction. 相似文献
988.
Current status and historical variations of phthalate ester (PAE) contamination in the sediments from a large Chinese lake (Lake Chaohu) 总被引:1,自引:0,他引:1
Lei Kang Qing-Mei Wang Qi-Shuang He Wei He Wen-Xiu Liu Xiang-Zhen Kong Bin Yang Chen Yang Yu-Jiao Jiang Fu-Liu Xu 《Environmental science and pollution research international》2016,23(11):10393-10405
The residual levels of phthalate esters (PAEs) in the surface and two core sediments from Lake Chaohu were measured with a gas chromatograph–mass spectrometer (GC–MS). The temporal–spatial distributions, compositions of PAEs, and their effecting factors were investigated. The results indicated that di-n-butyl phthalate (DnBP), diisobutyl phthalate (DIBP), and di(2-ethylhexyl) phthalate (DEHP) were three dominant PAE components in both the surface and core sediments. The residual level of total detected PAEs (∑PAEs) in the surface sediments (2.146?±?2.255 μg/g dw) was lower than that in the western core sediments (10.615?±?9.733 μg/g) and in the eastern core sediments (5.109?±?4.741 μg/g). The average content of ∑PAEs in the surface sediments from the inflow rivers (4.128?±?1.738 μg/g dw) was an order of magnitude higher than those from the lake (0.323?±?0.093 μg/g dw), and there were similar PAE compositions between the lake and inflow rivers. This finding means that there were important effects of PAE input from the inflow rivers on the compositions and distributions of PAEs in the surface sediments. An increasing trend was found for the residual levels of ΣPAEs, DnBP, and DIBP from the bottom to the surface in both the western and eastern core sediments. Increasing PAE usage with the population growth, urbanization, and industrial and agricultural development in Lake Chaohu watershed would result in the increasing production of PAEs and their resulting presence in the sediments. The significant positive relationships were also found between the PAE contents and the percentage of sand particles, as well as TOC contents in the sediment cores. 相似文献
989.
990.
Genetic diversity and population structure of the Chinese mitten crab <Emphasis Type="Italic">Eriocheir sinensis</Emphasis> in its native range 总被引:1,自引:0,他引:1
Liying Sui Fumin Zhang Xiaomei Wang Peter Bossier Patrick Sorgeloos Bernd Hänfling 《Marine Biology》2009,156(8):1573-1583
The Chinese mitten crab Eriocheir sinensis is an indigenous and economically important species in China, but can also be found as invasive species in Europe and America.
Mitten crabs have been exploited extensively as a food resource since the 1990s. Despite its ecological and economic importance,
the genetic structure of native mitten crab populations is not well understood. In this paper, we investigated the genetic
structure of mitten crab populations in China by screening samples from ten locations covering six river systems at six microsatellite
loci. Our results provide further evidence that mitten crabs from the River Nanliujiang in Southern China are a genetically
differentiated population within the native range of Eriocheir, and should be recognized as a separate taxonomic unit. In contrast, extremely low levels of genetic differentiation and
no significant geographic population structure were found among the samples located north of the River Nanliujiang. Based
on the reproductive biology of mitten crabs and the geography of their habitat we argue that both natural and human-mediated
gene flow are unlikely to fully account for the similar allele frequency distributions at microsatellite loci. Large population
sizes of mitten crabs suggest instead that a virtual absence of genetic drift and significant homoplasy of microsatellite
alleles have contributed to the observed pattern. Furthermore, a coalescent-based maximum likelihood method indicated a more
than two-fold lower effective population size of the Southern population compared to the Northern Group and low but significant
levels of gene flow between both areas. 相似文献