千岛湖水源水微生物安全性评价

千岛湖作为国家战略水源地,其微生物安全直接关系到千万居民的用水安全.为了研究千岛湖湖水的生物安全性,于2018-2019年采集了金竹牌取水口不同深度的水样,并检测了水样的可生物降解溶解性有机碳(BDOC)、细菌再生长的潜力(BGP)、可培养细菌数、潜在的条件致病菌和细菌群落结构.结果显示,千岛湖水质属地表水Ⅱ～Ⅲ类水,...     

企业安全投资背后的利益博弈探讨

利用职业安全卫生费用模型结合博弈论原理,对企业安全投资背后的利益冲突与协调问题进行了浅析.研究表明:企业凭借资本优势在与政府和劳动者的利益博弈中为了寻求经济利益最大化减少安全投资,使企业安全度大大降低,导致事故频发是政府、企业和劳动者之间利益博弈的结果.此外,劳动者的合法权益得不到保护,造成其在利益博弈中处于弱势地位是造成安全生产现状的重要原因之一.     

Coupled infrared extinction spectra and size distribution measurements for several non-clay components of mineral dust aerosol (quartz, calcite, and dolomite)

Simultaneous size distributions and Fourier transform infrared (FTIR) extinction spectra have been measured for several representative components of mineral dust aerosol (quartz, calcite, and dolomite) in the fine particle size mode (D=0.1–1 μm). Optical constants drawn from the published literature have been used in combination with the experimentally determined size distributions to simulate the extinction spectra. In general, Mie theory does not accurately reproduce the peak position or band shape for the prominent IR resonance features in the 800–1600 cm⁻¹ spectral range. The resonance peaks in the Mie simulation are consistently blue shifted relative to the experimental spectra by 20–50 cm⁻¹. Spectral simulations, derived from a simple Rayleigh-based analytic theory for a “continuous distribution of ellipsoids” particle shape model, better reproduce the experimental spectra, despite the fact that the Rayleigh approximation is not strictly satisfied in these experiments. These results differ from our previous studies of particle shape effects in silicate clay mineral dust aerosols where a disk-shaped model for the particles was found to be more appropriate.     

Is the integration of hormesis and essentiality into ecotoxicology now opening Pandora's Box?

Hormesis and essentiality are likely real and common effects at the level of the individual. However, the widespread incorporation of stimulatory effects into applications of ecotoxicology requires the acceptance of assumptions, value judgements and possibly lowering of water/sediment quality standards. There is also currently little data appropriate for considering hormetic effects in the ecotoxicological context. Except perhaps in the case of fitting concentration-response curves, it is not clear that incorporation of hormetic and essentiality type responses into ecotoxicology is necessary. Furthermore, its incorporation presents considerable intellectual and practical changes for ecotoxicology and could have unanticipated consequences.     

面向灾害应用的遥感影像融合统一理论体系设计

由于缺乏统一的理论体系指导,目前遥感影像融合研究相对比较混乱。针对像素级融合统一理论框架的思想,指出了遥感影像融合研究的方向和思路,将像素级融合统一理论框架逐步向特征级和决策级推广,着重发展了一套遥感影像融合统一理论体系。在统一体系下,面向灾害监测应用,按照理论研究、方法研究和应用研究的3个层次进行该理论体系的设计。     

火灾高温下CFRP加固钢筋混凝土梁温度场分析

综合国外CFRP加固混凝土结构抗火试验相关研究,总结了CFRP的高温热工性能参数。用ANSYS软件对火灾高温下不同情况(无防火保护层和有防火保护层)和不同工况(防火涂料涂抹形式)下CFRP加固后的钢筋混凝土梁进行了温度场数值模拟研究。结果表明,防火涂料厚40 mm时,梁耐火极限可达2.5小时以上,且底面和两侧面全面涂抹防火涂料的防火效果最好。本文研究有助于进一步深入认识CFRP加固钢筋混凝土结构在高温下的力学性能和耐火极限,且对CFRP加固后的结构防火设计具有一定的指导意义。     

阵性泥石流运动与堆积的欧拉─拉格朗日模型──Ⅰ.理论

自然界中的泥石流具有突发性和非恒定性的特点。为了模拟典型泥石流现象,在流团模型的 基础上,进一步完善了基于欧拉─拉格朗日（Ｅ—Ｌ）观点的ＰＩＣ（Ｐａｒｃｅｌ　Ｉｎ　Ｃｅｌｌ）算法,细化了流元结 构,建立了能够模拟典型阵性泥石流发生、运动和堆积的准结构两相流模型。求解该模型不仅可以 模拟泥石流运动过程,而且可以对泥石流的堆积过程、停积形态、冲刷特征及泥石流中多组分颗粒 的分选特征进行定量描述。     

RETRACTED ARTICLE: Environmental Impact Assessment of Industrial Structure Change in a Rural Region of China

As the embodiment of human activities, the change of regional industrial structure is an essential driving factor of global environmental change. Consequently, the research on the change of regional industrial structure and associated effects on the environment is one of the key issues of researches on sustainable development, human–environment relationship, and regional response to global environment change. However, compared to the flourish of researches on environmental impact assessment of industrial departments, few studies have been conducted to assess the environmental impact of regional industrial structure. In this study, based on a synthetic analysis of environmental disturbances of different industrial departments, the environmental impact coefficient of industrial department associated with the index of environmental impact of industrial structure was constructed, so as to make a quantitative assessment of environmental impact of the change of regional industrial structure. And the results of the case study in Lijiang City, a rural region of China, have showed that there are two obvious changes of industrial structure in the study area from 1992 to 2003, associated with a continuous decreasing of the index of environmental impact of industrial structure, which indicated a positive environmental effects of the change of regional industrial structure.     

Chemical composition of the slippery epicuticular wax blooms on Macaranga (Euphorbiaceae) ant-plants

Summary. The stems of many Macaranga ant-plants (Euphorbiaceae) are covered by epicuticular wax crystals rendering the surface very slippery for most insects. These wax blooms act as selective barriers protecting the symbiotic ant partners, which are specialized “wax-runners”, against the competition of other ants. Glaucous stems occur almost exclusively among the ant-plants of the genus Macaranga (). We analyzed the cuticular lipids of 16 Macaranga species by GC-MS and investigated the wax crystal morphology using SEM. Presence of crystalline wax blooms was strongly correlated with high concentrations (52%–88%) of triterpenoids. In contrast epicuticular waxes of glossy Macaranga surfaces contained only 0% to 36% of these dominant components. Therefore we conclude that triterpenoids are responsible for the formation of the thread-like Macaranga wax crystals. In all Macaranga ant-plants investigated, the principal components were epitaraxerol and taraxerone accompanied by smaller portions of taraxerol, β-amyrin and friedelin. Only in the case of the non-myrmecophytic M. tanarius did β-amyrin predominate. Moreover, we found that only in M. tanarius, the dense wax crystal lacework is torn into large mosaic-like pieces in the course of secondary stem diameter growth. Both chemical and macroscopic differences may contribute to a reduced slipperiness of M. tanarius stems and appear to be functionally important. The distribution of wax crystals and their composition amongst different sections of the genus suggests that glaucousness is a polyphyletic character within Macaranga. Received 7 October 1999; accepted 3 December 1999     

玉兰油细胞的发育及其与器官结构发育的关系

利用石蜡切片法及半薄切片法对玉兰茎、叶、花和种子中油细胞的发育进行了研究,结果表明：在所研究的各器官中油细胞以相同的方式发生。油细胞原始细胞因其细胞质染色较深、细胞核大明显及液泡化程度低而易与周围组织细胞分辨,以后,原始细胞逐渐液泡化,最终形成一个中央大液泡,其细胞质及细胞核呈一薄层,当油细胞成熟时,其细胞质和细胞核解体,而大液泡充满整个油细胞腔,成为储油的囊,在一些油细胞中,可观察到怀形构造,但