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391.
摘要企业社会责任是指企业在创造利润、对股东利益负责的同时,还应承担对员工、社会和环境的责任,包括遵守商业道德、生产安全、职业健康、保护消费者合法权益、节约资源等.企业承担社会责任是企业为生存而适应制度环境变迁的产物.伴随着制度环境变迁,西方企业社会责任的发展经历了无意识期、启蒙期和成熟期三个阶段.建国以来,中国企业的制度环境经历计划经济体制和向市场经济体制转型时期,均出现了企业承担社会责任功能的“失范”,即计划经济时期的“企业办社会”和向市场经济转型时期下的凸显“经济人本性”.当前,企韭利益与社会利益矛盾的凸显和社会公平公正期望的提升,使企业社会责任问题在中国变得日益紧迫、上下关注.党发出了“科学发展”的号召.科学发展这一制度环境,是对中国企韭承担社会责任的期待.而中国企业社会责任的实现,则亟待制度化建设保证,即要求企业产权制度明晰化,企业社会责任法制化,企业社会责任评价体系科学化,企业社会责任信息披露制度化,企业社会责任监督主体多元化.  相似文献   
392.
Changes in physicochemical conditions and lotic benthic macroinvertebrates along the recovery gradient of the impounded Colorado (USA) and Duratón (Spain) Rivers were examined to identify and compare major factors affecting the structure of the macrobenthic community. Although both impounded rivers were exposed to hypolimnial releases from dams, they exhibited different impoundment use; Granby Dam (Colorado River) is used for water storage whereas Burgomillodo Dam (Duratón River) is used for hydroelectric production. The major factor responsible for macroinvertebrate responses in the Colorado River appeared to be the anomalous temperature pattern caused by Granby Dam, with relatively cool temperatures during the summer and relatively warm temperatures during the winter. In contrast, the major factors responsible for macroinvertebrate responses in the Duratón River seemed to be short-term flow fluctuations and low oxygen concentrations caused by Burgomillodo Dam. Values of taxonomic richness and relative abundances of shredders (Colorado River) and scrapers (Duratón River) increased along the recovery gradient of the impounded rivers. In general, chironomids (Diptera) were tolerant to both types of impoundment use, whereas elmids (Coleoptera) and psychomyiids (Trichoptera) were very sensitive. Overall, this environmental monitoring study denotes that the downstream changes in the biotic and abiotic components of impounded rivers is a function of the particular use of impoundments.  相似文献   
393.
高盐浓度对工业废水生化处理的影响研究   总被引:4,自引:0,他引:4  
研究了生物制药废水的不同含盐量对生化处理系统效果的影响,以及对该系统中的生物学变化规律的影响。在含盐量低于2.5×104mg/L时,废水生化处理系统COD去除率可稳定在92%左右,污泥活性良好;随着进水盐浓度的增加,含盐量达到2.5×104mg/L时,污泥活性开始受到抑制,COD去除率急剧下降至80%左右;当废水含盐量达到3.5×104mg/L时,污泥活性明显受到抑制,污泥絮体开始部分解体,COD去除率下降到60%左右;当废水含盐量达到6.0×104mg/L时,污泥活性系统趋于崩溃,原生动物近乎绝迹,污泥絮体细碎分散,可见少量球形游离细菌,COD去除率仅有45%左右。  相似文献   
394.
ABSTRACT: Transient events in water chemistry in small coastal watersheds, particularly pH depressions, are largely driven by inputs of precipitation. While the response of each watershed depends upon both the nature of the precipitation event and the season of the year, how the response changes over time can provide insight into landscape changes. Neural network models for an urban watershed and a rural‐suburban watershed were developed in an attempt to detect changes in system response resulting from changes in the landscape. Separate models for describing pH depressions for wet season and dry season conditions were developed for a seven year period at each watershed. The neural network models allowed separation of the effects of precipitation variations and changes in watershed response. The ability to detect trends in pH depression magnitudes was improved by analyzing neural network residuals rather than the raw data. Examination of sensitivity plots of the models indicated how the neural networks were affected by different inputs. There were large differences in effects between seasons in the rural‐suburban watershed whereas effects in the urban watershed were consistent between seasons. During the study period, the urban watershed showed no change in pH depression response, while the rural‐suburban watershed showed a significant increase in the magnitude of pH depressions, likely the result of increased urbanization.  相似文献   
395.
In this article the evolution of the aluminium and copper industries is examined, with a view to deriving policy options open to Third World copper producers, which face a declining rate in the growth of consumption. Market structure, company behaviour and performance are analysed for both industries. The impact of energy and general economic crisis in copper and aluminium industries is assessed and market concentration trends are discussed. We conclude that Third World copper producers must change their basic orientation and become seriously involved in market development.  相似文献   
396.
This work exemplifies how a given lake (Lake Huljesjön, Sweden) would likely respond to changes in pH-values and to liming (a standard measure against anthropogenic acidification). The basic questions are: How would a liming influence pH? How long would the changes last? How would the changes influence the structure and function of lake ecosystems? The work uses a comprehensive lake ecosystem model, LakeWeb, which accounts for production, biomasses, predation, abiotic/biotic interactions of nine key functional groups of organisms, phytoplankton, bacterioplankton, two types of zooplankton (herbivorous and predatory), two types of fish (prey and predatory), zoobenthos, macrophytes and benthic algae. LakeWeb is a dynamic model and gives weekly variations. It has been critically tested using empirical data and regressions from many lakes. Those tests are not presented here but have shown that the model can capture typical functional and structural patterns in lakes very well. This gives credibility to the results presented in this work, which would be very costly to obtain in the traditional manner by extensive field studies in one or a few lakes. This work presents for the first time predictions at the ecosystem level of how functional groups of organisms (and not individual species) are likely to respond to acidification and liming. Two existing dynamic models, one for liming, the other for Hg-concentrations in fish, have been added to the LakeWeb-model. These two models have previously been tested and proven to yield good predictions. The results presented here indicate that there are several probable changes in the structure and function of the lake foodweb related to acidification and liming. The predicted changes in macrophyte cover will influence the predation pressure on fish, and thereby the fish biomass. Reductions in primary production at low pH-values will cause reductions in fish biomass. There are several interesting compensatory effects between factors that increase fish biomass and factors that tend to decrease the biomass. Such matters can be handled quantitatively by the LakeWeb-model.  相似文献   
397.
The changes of the chemical composition in Latvianinland waters over the last twenty years weredetermined, based on data of the National MonitoringProgramme. Relationships between the water compositionwere studied. The chemical composition and seasonalchange pattern depend a lot on hydrological factorswhich differed between eastern and western Latvia.Different pattern of long-term changes is found forsubstances which have different sources andsinks, at first for nutrients (decrease only in the lastfew years) and inorganic ingredients (commonlyincreasing trend). An attempt was made to identify themain sources of the major water ingredients and linkchanges of their concentrations with changes inloading to waters.  相似文献   
398.
To find suitable wetland plants for constructed wetland-microbial fuel cells(CW-MFCs),four commonly used wetland plants, including Canna indica, Cyperus alternifolius L., Acorus calamus, and Arundo donax, were investigated for their electrogenic performance and physiological changes during non-growing seasons. The maximum power output of12.82 mW/m~2 was achieved in the A. donax CW-MFC only when root exudates were being released. The results also showed that use of an additional carbon source could remarkably improve the performance of electricity generation in the C. indica and A. donax CW-MFCs at relatively low temperatures(2–15°C). However, A. calamus withered before the end of the experiment, whereas the other three plants survived the winter safely, although their relative growth rate values and the maximum quantum yield of PSII(Fv/Fm) significantly declined, and free proline and malondialdehyde significantly accumulated in their leaves.On the basis of correlation analysis, temperature had a greater effect on plant physiology than voltage. The results offer a valuable reference for plant selection for CW-MFCs.  相似文献   
399.
旅游者是乡村旅游发展中的核心要素,但当前研究缺乏从城乡空间转换中的人地关系变迁角度对旅游者进行的思考。以经历城乡生活空间重构的旅游者为研究对象,运用分析多变量交互作用的模糊集定性比较分析方法,探索旅游者乡村游憩影响因素的复杂路径。研究发现:地方情感、怀旧情感、主观规范、知觉行为控制、态度、愿望(欲望)、旅游目的地知名度形成的128种组合中,其中有8个充分性条件构型特定组合路径能够影响乡村旅游者游憩行为;单项中地方情感、怀旧情感、知觉行为控制的一致性相对较高,但都不能构成旅游者乡村游憩影响因素的必要条件;8条旅游者乡村游憩行为影响因素路径条件组合的总体覆盖率约为0.918919,总体一致性约为1,均达到了0.9的阈值标准。其中,地方情感和怀旧情感特性是最关键的影响因素;旅游者具有地方情感、怀旧情感特征时,其他影响因素都可能在“特定情境”下发挥作用。据此提出了生活空间重构旅游者的乡村游憩影响路径模型,揭示了“乡村情感—游憩意向路径”“计划行为—游憩意向路径”“游憩愿望路径”和“情感行为综合路径”四类影响路径的作用机制。旅游从业者可以据此寻找与旅游者游憩最匹配的产品开发解决方案。  相似文献   
400.
40多年来秦皇岛市气候发生了明显的变化,致使农业气象灾害增加:第一,冬暖、倒春寒、春末高温等灾害频次增多,冬季低温冻害频次和程度减少;第二,冬旱、春旱、秋旱、秋冬连旱、冬春连旱增多,伏旱次数明显减少,盛夏洪涝频次减少;第三,低温连阴雨、高温干旱、干热风等灾害在频次和程度上均发生明显变化。因此,秦皇岛农业生产防灾减灾的重点和方法也适当调整。  相似文献   
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