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801.
Conservation of surrogate species is expected to benefit co-occurring species with similar distributions that share the same habitat, yet the usefulness of this approach to protect nontarget species has been extensively challenged. In this study, we aimed to assess whether co-occurring species could be afforded protection under the conservation of two proposed surrogate species, the giant panda and the takin. We undertook a thorough study on the habitat requirements of these two endangered species, based on the analysis of their habitat preferences. The results revealed that the giant panda exhibits more specialized habitat preferences than does the takin and that habitat separation between these species mainly reflected differences in their dietary requirements and preferences. We suggest that these differences might facilitate their coexistence in sympatric areas. Meanwhile, results of a discriminant function analysis showed that protection of giant pandas would protect 82.1 % of the panda’s habitat, but only 25.4 % of the takin’s habitat and just 57.0 % of the joint habitats of these species. Importantly, our results also showed that a joint surrogate species approach to conservation would protect 86.9 % of the panda’s habitat, 53.7 % of the takin’s habitat, and 72.2 % of the joint habitats of these species. This is a higher degree of habitat protection than the single surrogate conservation of pandas. We conclude that the joint surrogate species approach should be adopted to improve biodiversity conservation.  相似文献   
802.
● Status of inactivation of pathogenic microorganisms by SO4•− is reviewed. ● Mechanism of SO4•− disinfection is outlined. ● Possible generation of DBPs during disinfection using SO4•− is discussed. ● Possible problems and challenges of using SO4•− for disinfection are presented. Sulfate radicals have been increasingly used for the pathogen inactivation due to their strong redox ability and high selectivity for electron-rich species in the last decade. The application of sulfate radicals in water disinfection has become a very promising technology. However, there is currently a lack of reviews of sulfate radicals inactivated pathogenic microorganisms. At the same time, less attention has been paid to disinfection by-products produced by the use of sulfate radicals to inactivate microorganisms. This paper begins with a brief overview of sulfate radicals’ properties. Then, the progress in water disinfection by sulfate radicals is summarized. The mechanism and inactivation kinetics of inactivating microorganisms are briefly described. After that, the disinfection by-products produced by reactions of sulfate radicals with chlorine, bromine, iodide ions and organic halogens in water are also discussed. In response to these possible challenges, this article concludes with some specific solutions and future research directions.  相似文献   
803.
This study examined the mediating influence of protege‐initiated mentoring relationships on the relationship between personality and situational characteristics and mentoring received. Data were obtained from Hong Kong Chinese graduate employees (N=184) in their early career stage. Results of the regression analysis showed that protege‐initiated mentoring relationships mediated the relationship between the personality (extraversion) but not the situational (individual development culture and opportunities for interactions on the job) characteristics and mentoring received. In other words, extraversion was indirectly related to mentoring received through protege‐initiated mentoring relationships but individual development culture and opportunities for interactions on the job were directly related to mentoring received. Additionally, opportunities for interactions on the job indirectly influenced mentoring received through protege‐initiated mentoring relationships. Limitations of the study, implications of the findings and directions for future research are discussed. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   
804.
人工泳池水质的模糊综合评判及分析   总被引:1,自引:0,他引:1  
用模糊数学方法 ,处理人工泳池水质监测数据 ,综合评判泳池水质状况 ,分析水质参数间关系 ,探讨了该方法应用的可能性  相似文献   
805.
Atmospheric aerosols were collected during the scientific expedition to Mt. Qomolangma (Everest) in May–June, 2005. The elemental concentrations of the aerosols were determined by inductively coupled plasma mass spectrometry. This yielded data for the concentration of 14 elements: Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, and Pb. The mean elemental concentrations were generally comparable with those from central Asia and the Arctic, while much higher than those from Antarctic. Size, morphology, and chemical composition of 900 individual aerosol particles were determined by scanning electron microscopy and energy-dispersive X-ray microanalysis. Based on morphology and elemental composition, the particles were clustered into eight groups: soot (8%), tar ball (3%), alumosilicates/silica (55%), calcium sulfate (16%), Ca/Mg carbonate (2%), Fe/Ti-rich particles (3%), Pb-rich particles (1%), and biological particles (12%). The sampling site, located at 6,520 m in the Himalayas, is particularly remote and located at high altitude. Nonetheless, high aerosol enrichment factors for copper, chromium, lead, nickel, vanadium, and zinc all suggest the influence of long-range transported pollution, while enrichment in calcium and the presence of alumino-silicates in individual particle analyses indicates a distinct mineral dust influence. The backward air mass trajectories showed that the northwestern part of India may contribute to the atmospheric aerosol in the central high Himalayas.  相似文献   
806.
为使注册安全工程师行业在初始阶段就纳入科学的管理,通过对注册安全工程师行业监管模式的探讨,在分析注册安全工程师执业资格制度基本特点及注册安全工程师执业定位的基础上,参照国外的发达国家和我国目前注册安全工程师发展现状,提出了3种监管模式,即政府监管模式、行业自律监管模式和政府监管与行业自律结合的监管模式。并且通过运用建立数学模型的方法和规律性分析,比较了3种不同的注册安全工程师行业监管模式效力的异同和利弊,最终得出应采用政府监管与自律监管结合模式的结论。并对完善和规范注册安全工程师执业资格制度方面进行了探讨。  相似文献   
807.
饮用水源地水质评价的变权欧式距离模型的建立及应用   总被引:2,自引:0,他引:2  
通过改进加权欧式距离模型,建立变权欧式距离模型,以体现相同水质评价因子在不同饮用水源评价单元中的客观各异性.采用污染贡献率确定评价因子在各评价单元中的权重.结合规范化数据建立符合各评价单元自身特点的评价距离尺度准则,对饮用水源地的水质进行评价.结果表明,与综合指数法比较,变权欧式距离模型的分割灵敏性较高、评价效果良好.本研究提供了一种符合饮用水质特点的科学评价方法.  相似文献   
808.
注册安全工程师执业资格制度是在市场经济条件下,加强企业安全与卫生工作的一项重要管理制度。我国注册安全工程师制度刚刚兴起,一个高效的行业监管模式尚未建立起来,因此有必要对这一新兴行业的监管开展先行研究。目前,国际上通行的注册安全工程师行业监管模式主要有行业自律和政府监管两种,并呈现出逐步向独立监管方向发展的趋势。不同监管模式具有不同的优缺点和不同的适应条件,中国注册安全工程师行业的监管既应借鉴国际先进经验,又必须着眼于中国的实际情况,分别从短期、中期和长期的综合监管绩效考虑,采纳混合监管模式不失为一种现实可行的抉择。  相似文献   
809.
于2009年3月11日—5月29日在衡山采集云雾水样品,采用荧光分光光度法对样品中的总过氧化氢浓度进行了测定,分析了衡山云雾水中总过氧化氢的浓度特征及气象影响因素。结果表明,衡山云雾水中总过氧化氢平均浓度为8.46 μmol/L,呈现出明显的日夜浓度差异。分析风向、风速、辐射强度和温度对云雾水总过氧化氢浓度的影响,发现总过氧化氢浓度与风速间存在明显的负相关关系,风向主要来自海洋时,其浓度较高,来自陆地时则较低,这与来自陆地的气流携带有大量的氮氧化物和二氧化硫有关。此外,总过氧化氢浓度随温度的升高具有明显增加的趋势,且当辐射强度大于50 w/m2时,总过氧化氢与辐射强度呈良好的正相关,相关系数为0.713,说明总过氧化氢的浓度分布与光化学反应关系密切。  相似文献   
810.
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