如何处理交通运输中的几项辨证关系

交通运输是物质生产的一个特殊部门,是生产过程在消费领域中的再延续,它把生产与消费空间有机地连接起来,是实实在在的“流通领域”,它使人和物在全球范围内进行着生产、工作和学习的重新配置。交通活动是一个复杂的动态系统,在交通过程中人与人、人与车、人与路、车...     

不锈钢板卷生产过程中的危险因素及对策

根据国内的不锈钢板卷生产工艺状况 ,分析并指出了生产过程中可能出现的危险和有害因素 ,同时对生产性粉尘、噪声和高温进行了劳动条件分级 ,从而提出了相应的对策。     

A Sensitive Electrochemical Impedance Spectroscopy Method for Detection of Polyimide Degradation by Microorganisms

An electrochemical impedance spectroscopy (EIS) technique was evaluated for monitoring microbial degradation of electronic packaging polyimides. The microbial inoculum was a mixed culture of fungi isolated previously from deteriorated polyimides. The active fungal consortium comprised Aspergillus versicolor, Cladosporium cladosporioides, and a Chaetomium species. After inoculation, fungal growth on the polyimides resulted in distinctive EIS spectra indicative of polymer insulation failure, which directly related to polymer integrity. Degradation appeared to occur in a number of steps and two distinctive stages in the decline of film resistance were observed in the inoculated EIS cells within the 2 and 10 weeks after inoculation. The early stage of resistance decrease may be related to the ingress of water molecules and ionic species into the polymeric materials, whereas the second stage probably resulted from partial degradation of the polymers by fungal growth on the polymer film. The relationship between changes of impedance spectra and microbial degradation of the polymer was further supported by scanning electron microscopy (SEM) observations of fungi growing on the surface of the inoculated polyimides. Our data indicate that the EIS can be used in detection of early degradation of resistant polymers and polyimides that are susceptible to biodeterioration.     

回顾性环境影响评价的特点及发展趋势

依据回顾性环境影响评价的内涵,结合其发展过程和作用,总结了回顾性环境影响评价工作的主要特点,并探索了今后该项工作的发展趋势。     

锐颈特与马拉硫磷交替使用对麦穗鱼脑乙酰胆碱酯酶活性恢复的 …

研究了５％锐颈特县浮剂与９５％马拉硫磷文替使用对麦穗鱼（Ｐｓｅｕｄｏｒａｓｂｏｒａ ｐａｒｏａ）乙酰胆碱酯酶（ＡＣｈＥ,ＥＣ３．１．１．７）活性的影响。结果表明,０．２ｍｇ／Ｌ,锐颈物与２ｍｇ／Ｌ马拉硫磷交替使用均影响被抑制的ＡＣｈＥ活性恢复。文中还探讨了研究农药影响对于合理评价农药环境毒性的意义。     

重大工业隐患的地域监控体系研究

系统地分析了重大工业危险源与事故隐患 ;研究了地域监控、预警、应急预案的体系建设以及隐患监控的新技术应用基础 ;提出了职业安全卫生监控体系中的工业危险源和隐患监控。笔者认为 :应该分为过程安全监控和安全目标监控两个层次     

室内空气中多环芳烃(PAHs)的源及贡献率

采用因子分析及多元线性回归对杭州市室内外空气中PAHs的来源及其贡献率进行研究,求得PAHs总量与公共因子间的特征方程.结果表明,影响室内外空气中PAHs浓度的主要因子依次为烹调、卫生球的挥发、吸烟及加热、汽车尾气.在吸烟者家庭中,室内吸烟是影响室内空气中PAHs浓度的最重要的影响因子,其对室内空气中苯并(a)芘BaP的贡献率为25.8%.     

Combined amendment reduces soil Cd availability and rice Cd accumulation in three consecutive rice planting seasons

The scientific application of stabilized materials has been considered an effective method for the in situ remediation of Cd-contaminated soil. This study aimed to investigate the persistence of the effect of a combined amendment of limestone and sepiolite(LS) on soil Cd availability and accumulation in rice grown in a mildly Cd-contaminated paddy field(0.45 mg/kg of Cd) over three consecutive rice seasons. 1125–4500 kg/ha of LS was applied to the soil before the first rice planting season and 5...     

Mass effects mediate coexistence in competing shrews

Recent developments in metacommunity theory have raised awareness that processes occurring at regional scales might interfere with local dynamics and affect conditions for the local coexistence of competing species. Four main paradigms are recognized in this context (namely, neutral, patch-dynamics, species-sorting, and mass-effect), which differ according to the role assigned to ecological or life-history differences among competing species, as well as to the relative time scale of regional vs. local dynamics. We investigated the patterns of regional and local coexistence of two species of shrews (Crocidura russula and Sorex coronatus) sharing a similar diet (generalist insectivores) over four generations, in a spatially structured habitat at the altitudinal limit of their distributions. Local populations were small, and regional dynamics were strong, with high rates of extinction and recolonization. Niche analysis revealed significant habitat differentiation on a few important variables, including temperature and availability of winter resting sites. In sites suitable for both species, we found instances of local coexistence with no evidence of competitive exclusion. Patterns of temporal succession did not differ from random, with no suggestion of a colonization-competition trade-off. Altogether, our data provide support for the mass-effect paradigm, where regional coexistence is mediated by specialization on different habitat types, and local coexistence by rescue effects from source sites. The strong regional dynamics and demographic stochasticity, together with high dispersal rates, presumably contributed to mass effects by overriding local differences in specific competitive abilities.     

Temporal analysis of population genetic composition in the overexploited Japanese eel <Emphasis Type="Italic">Anguilla japonica</Emphasis>

The Japanese eel has dramatically declined in Asia since the 1970s. Over the past two decades, glass eel productivity in Taiwan has decreased, but is highly variable among each year catch, though the cause for this is unknown. The impact of both population decline and instability on genetic diversity, however, is unknown. In this study, we investigated changes in allele frequencies of Japanese eel recruitment events over the past 20 years using six polymorphic microsatellite DNA loci. Specimens of glass eels were collected yearly from a single location in northern Taiwan from 1986 to 2007. Overall genetic differentiation among all samples was very low but significant (F_ST = 0.002, P = 0.002), and only 2 out of 120 pairwise tests were significant. The relationship between genetic and temporal distance showed a slight but insignificant correlation (R² = 0.03, P = 0.0504). There were no overall significant differences in allelic richness (P = 0.35) or genetic heterozygosity (P = 0.73) among annual recruitment events. No apparent loss of genetic diversity and occurrence of a genetic bottleneck for eel populations were observed. Estimates of the effective population size (N_e) generally exceeded 500, although confidence intervals were very wide. While El Niño /Southern Oscillation (ENSO) events had little impact on genetic diversity, they may account for the annual fluctuation in glass eel catch. These results indicate long-term stability of genetic diversity in the Japanese eel with little evidence for sweepstakes recruitment.