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1.
志愿举措可以给工商界提供新的市场机会,同时还能针对环境保护.它们也会有助于创造政府与私有部门之间的伙伴关系与信任.与可能是不灵活和代价过高的命令与控制政策不同,志愿协议有利于(发展中世界和发达世界的)工商业释放其创造性才能和向前推进.特别是在气候和能源领域,志愿举措有潜力加强国家和国际行动来缓解气候变化效果  相似文献   

2.
采取少数几个小的志愿步骤南非的志愿举措大部分是由于公司经营所在的不确定法规环境的结果.环境立法的确存在,但过去执法不力,这部分地由于工业界和政府都认为增长和就业机会是与环境管理相冲突的,而且前者优于后者.希望随着可持续发展的信息得到更好的理解,那些冲...  相似文献   

3.
缺乏共同语言与理解,是适当利用志愿举措的最重要障碍之一.因此,这份“问答指南”提供了对正在使用的不同类型志愿举措的综述,和一份进一步信息源的清单.联合国环境署利用志愿举措改善公司环境表现的经验可追溯到1992年地球高峰会议以前很久的时候.关于志愿举措...  相似文献   

4.
从国际工会观点来看的化学工业责任关怀计划   总被引:1,自引:0,他引:1  
在很多国家中,减少了政府对工业的命令与控制法规的承诺,并日益增多地促进志愿工业举措.因此,雇员和社区担心安全与环境保护正在受损害.最近进行了一次全球调查,以确定工人及其工会代表对化学工业责任关怀计划所具有的知识的性质和程度,以及他们对该计划积极参与的程度.在对此次调查进行深入研究之后,本文立论如下:只要涉及既得利益,就必须赢得而不只是需要对责任关怀及其它志愿工业举措的信任,而且必须证实而不是断言可信性  相似文献   

5.
城市河道生态环境需水研究--以湖南省常德市穿紫河为例   总被引:3,自引:2,他引:3  
在系统归纳总结国内外河道生态环境需水理论研究成果的基础上,结合穿紫河作为一条城市河流的实际情况,应用生态学、环境学和水文学理论,系统分析了穿紫河河道生态环境需水的研究范畴和影响因素,对穿紫河不同时段下的河道生态环境需水进行定量研究。研究得出穿紫河河道生态环境需水平均为2.92m^3/s,城市河道生态环境需水与来水水质和河道沿岸的污染物排放情况关系最为密切。一方面,为穿紫河流域水资源的合理调配提供科学依据,有利于穿紫河生态环境的稳定和良性循环;另一方面,对城市河道生态环境需水理论进行一些探索。  相似文献   

6.
志愿举措是一个日益全球化的世界上改善工业界环境表现的一种重要工具.通过扶持工商管理方面的长期文化变革,志愿思路可以超越一些旨在改善工业界环境表现的政府法规,而且比此类法规更有效.在1992年地球高峰会议上,作为联合国环发大会全球行动框架(21世纪议程...  相似文献   

7.
高校银行贷款的风险防范,是一个关系到学校生存与发展的大问题,许多的防范策略都各有一定的实用价值.但传统的预警模型实用性不佳,主要是一些细节存在着理论缺陷,效果不显著.根据高校债务风险的基本状况,排出其风险预警体系的构成因素,对一般的风险预警模型,做出适度调整,引入债务负担率和债务依存度的概念,使预警模型更符合高校实际,能够很好地预警债务风险,以利防范.图2,参6.  相似文献   

8.
与其预防性政策相一致,法国钢铁联盟(FFA)已经到2000年使其CO2比排放量比1990年削减15%,并使总排放量削减10%.FFA的这项志愿协议是Usinor公司在可持续发展范畴内的前瞻性环境保护思路的代表.本文叙述了FFA签署该志愿协议背后的故事,和该协议的基本原则,也论述了另外一些可以探讨的实现可持续发展的道路  相似文献   

9.
任何一家公司,无论其规模、行业还是地点如何,都可以通过改善内部的环境、健康与安全管理而对可持续发展做出显著贡献.国际商会工商业可持续发展宪章强调在企业内部引进和发展环境管理实践与体系,作为对可持续发展的一种基本贡献.本文认为,志愿举措,包括像国际商会宪章这样以原则为基础的志愿举措,在全球化、活动家压力和公司环境管理进展等范畴内既是恰当的也是成功的  相似文献   

10.
2,4-D对铜在蒙脱石上吸附与释放的影响   总被引:3,自引:0,他引:3  
倪利晓  郑正  李时银 《环境化学》2003,22(4):345-349
研究了在2,4-D的影响下,Cu^2 在蒙脱石上的吸附与脱附行为.结果表明.有2,4-D存在时,Cu^2 在蒙脱石上的吸附低于单纯Cu^2 的吸附,而当蒙脱石先吸附2,4-D后再吸附Cu^2 (连续吸附)时,Cu^2 的吸附比二者同时存在时(同时吸附)的效果好,表明两种吸附质间存在竞争吸附.研究还表明,所有的吸附过程都符合Langmuir和Freundlich吸附等温模型.在有2,4-D同时存在时,Cu^2 的脱附最大,可达30%;而单纯Cu^2 在蒙脱石上的吸附似乎是不可逆的,脱附百分比最小。  相似文献   

11.
Sperm allocation in an uncertain world   总被引:3,自引:0,他引:3  
Models of optimal sperm allocation are constructed using stochastic dynamic programming techniques, yielding predictions about sperm allocation when males mate sequentially, breeding time is finite, sperm stores are limited and females vary in quality. The models suggest that uncertainty of future reproductive opportunities should favour withholding of sperm, so that males tend to allocate less (for a given level of stored sperm) earlier in the breeding season. This effect is more pronounced the greater the variance in female quality. We also show that while allocation will be influenced by mate value, it is not necessarily optimal to allocate preferentially to high-quality females, since the benefits of a higher-quality mate may be offset by increased risk of rejection of sperm or higher sperm competition. The relationship between mate quality and level of allocation will depend strongly on the amount of remaining stored sperm, with males whose supplies are depleted being more likely to favour lower-quality partners. Received: 12 September 1997 / Accepted after revision: 28 June 1998  相似文献   

12.
In a sex role reversed pipefish, Syngnathus typhle, we found that basic life history allocations were directly influenced by sexual selection. We investigated time allocation to foraging and mating, respectively, in a choice experiment, giving males and females, of small or large body size, a choice between food and a potential partner. We found that males were more interested in foraging than mating, i.e., were more frequently observed in front of the food than in front of the partner, whereas females were more interested in the potential partner. This reflects sexual selection operating differently on the two sexes, as males and females are relatively similar in other life history traits, such as growth, mortality, age of maturity, dispersal, and parental expenditure. Moreover, large individuals allocated more time to mating activities, small to feeding. Individuals more interested in mating compared to food were subsequently more critical when given a choice between a large (high-quality) and a small (low-quality) partner, whereas individuals more interested in food were not selective. These findings are consistent with our predictions: sex-role reversed males can be relatively sure of achieving one or more matings, and should allocate more time to feeding and, hence, to parental investment, growth and/or future reproduction. Females, on the other hand, have more uncertain mating prospects and should allocate time to imminent reproductive activities, thereby foregoing other life history traits such as growth and future egg production. By this, they also sacrifice future fecundity and attractiveness.  相似文献   

13.
Abstract: When translocating individuals to found new populations, managers must allocate limited funds among release and monitoring activities that differ in method, cost, and probable result. In addition, managers are increasingly expected to justify the funding decisions they have made. Within the framework of decision analysis, we used robust optimization to formulate and solve different translocation problems in which both population growth and future funding were uncertain. Performance criteria included maximizing mean population size and minimizing the risk of undesirable population-size outcomes. Robust optimization provided several insights into the design of translocation strategies: (1) risk reduction is obtained at the expense of mean population size; (2) as survival of released animals becomes more important, funds should be allocated to release methods with lower risks of failure, regardless of costs; (3) the performance gain from monitoring drops as the proportion of a fixed budget required to pay for monitoring increases; and (4) as the likelihood of obtaining future funding increases, more of the existing budget should be spent on building release capacity rather than saved for future operating costs. These relationships highlight the importance of performance criteria and economic costs in determining optimal release and monitoring strategies.  相似文献   

14.
The theory of life history evolution assumes trade-offs between competing fitness traits such as reproduction, somatic growth, and maintenance. One prediction of this theory is that if large individuals have a higher reproductive success, small/young individuals should invest less in reproduction and allocate more resources in growth than large/old individuals. We tested this prediction using the common toad (Bufo bufo), a species where mating success of males is positively related to their body size. We measured testes mass, soma mass, and sperm stock size in males of varying sizes that were either (1) re-hibernated at the start of the breeding season, (2) kept without females throughout the breeding season, or (3) repeatedly provided with gravid females. In the latter group, we also estimated fertilization success and readiness to re-mate. Contrary to our predictions, the relationship between testes mass and soma mass was isometric, sperm stock size relative to testes mass was unrelated to male size, fertilization success was not higher in matings with larger males, and smaller males were not less likely to engage in repeated matings than larger males. These results consistently suggest that smaller males did not invest less in reproduction to be able to allocate more in growth than larger males. Causes for this unexpected result may include relatively low year-to-year survival, unpredictable between-year variation in the strength of sexual selection and low return rates of lowered reproductive investment.  相似文献   

15.
注意力经济--文化产业的策略选择   总被引:2,自引:0,他引:2  
随着信息技术的无限进展,信息的丰富造成了注意力的贫乏,这是现代社会人民遇到的一个矛盾.作为从计划经济步入市场经济的我国文化产业,已经完全进入市场化的运作,文化产品可经选择的多样性决定了受众的主体地位,大众不再是商家和媒体教育的对象,而是他们的服务对象.我国文化产业要得以长足发展,其首要任务是吸引最大多数人的关注,赢得他们的关心.文化产业的发展需要为大众的注意力买单,要寻找与发掘大众注意力兴奋点,实行吸引受众注意力的产业营销策略.这就是遵从大众认知心理,强化娱乐功能;认同受众的好奇心理,提升品牌形象;紧扣受众的表现心理,倡导时尚消费;认同受众遵从心理,因势利导;巧借受众移情心理,打造个性品牌.  相似文献   

16.
The photocatalytic activity of TiO2 deposits (Degussa P25 and Millennium PC500) has been studied using sulfamethoxazole (SMX) as a model water pollutant and a UV fluorescent lamp as a light source (365 nm). Both catalysts have shown very similar properties in the photocatalytic degradation of SMX. Special attention has been given to the effect of the irradiation time, pH, and pollutant concentration. No mass-transfer limitations are observed. The degradation of SMX is accelerated at low concentration, and the photocatalytic degradation kinetics obey the Langmuir–Hinshelwood model, allowing the adsorption and apparent rate constants to be determined for both catalysts.  相似文献   

17.
As the distribution of food resources shifts over time, central place foragers are likely to be repeatedly faced with the question of when to abandon a forage site that is declining in value and to subsequently search elsewhere. Although there has been a great deal of investigation into how individual foragers allocate time between exploration and exploitation, few studies have sought to explore this issue within a larger functional context. We take a comparative approach to this problem by examining decision making in individual honeybees and bumblebees as they responded to a downshift in food reward. Our results show not only that honeybees and bumblebees have significantly divergent strategies with regards to abandoning a food source that is declining in value but also in terms of the subsequent tendency to seek an alternative food source. We interpret these results in terms of both biological and social distinctions between these species and highlight how group-level characteristics are likely to shape the evolutionarily derived foraging strategies of individual animals.  相似文献   

18.
Trussell GC  Matassa CM  Luttbeg B 《Ecology》2011,92(9):1799-1806
There is strong evidence that the way prey respond to predation risk can be fundamentally important to the structuring and functioning of natural ecosystems. The majority of work on such nonconsumptive predator effects (NCEs) has examined prey responses under constant risk or constant safety. Hence, the importance of temporal variation in predation risk, which is ubiquitous in natural systems, has received limited empirical attention. In addition, tests of theory (e.g., the risk allocation hypothesis) on how prey allocate risk have relied almost exclusively on the behavioral responses of prey to variation in risk. In this study, we examined how temporal variation in predation risk affected NCEs on prey foraging and growth. We found that high risk, when predictable, was just as energetically favorable to prey as safe environments that are occasionally pulsed by risk. This pattern emerged because even episodic pulses of risk in otherwise safe environments led to strong NCEs on both foraging and growth. However, NCEs more strongly affected growth than foraging, and we suggest that such effects on growth are most important to how prey ultimately allocate risk. Hence, exclusive focus on behavioral responses to risk will likely provide an incomplete understanding of how NCEs shape individual fitness and the dynamics of ecological communities.  相似文献   

19.
Summary This study compares time budgets of males and females of two sympatric species of bee flies, Lordotus pulchrissimus and L. miscellus. These species occur synchronously in sand dune habitat on the north shore of Mono Lake, Mono Co., California, and feed almost exclusively on the flowers of a composite shrub, Chrysothamnus nauseosus. The two closely related species, with similar ecological requirements and in an identical environment, allocate time and energy in very different ways, even when accomplishing the same ecological goals. L. pulchrissimus males and females engage respectively in aggressive interactions and feeding primarily in the morning. In contrast, L. miscellus males and females intersperse brief periods of resting with flying when defending territories and feeding, and they keep up these activities until later in the day. Similarly within species, males are involved in aggressive interactions for a shorter period each day, and females feed over a longer period. Flies in all sex-species classes but male pulchrissimus allocate their time energetically in similar ways. Male pulchrissimus spend more time each day in energetically costly activities; they engage in continuous hovering flight and intense interactions in aerial aggregations. While male miscellus feed little, male pulchrissimus spend a large portion of their time feeding, approximately as much as females, contrary to the expectation that males should be foraging-time minimizers. This study corroborates the conclusions of previous studies on bee-fly communities by showing that nectar and pollen are important resources for adult bee flies, at least for some species: Individuals of these two species spend a large proportion of their adult lifetimes feeding.  相似文献   

20.
Ecologists wish to understand the role of traits of species in determining where each species occurs in the environment. For this, they wish to detect associations between species traits and environmental variables from three data tables, species count data from sites with associated environmental data and species trait data from data bases. These three tables leave a missing part, the fourth-corner. The fourth-corner correlations between quantitative traits and environmental variables, heuristically proposed 20 years ago, fill this corner. Generalized linear (mixed) models have been proposed more recently as a model-based alternative. This paper shows that the squared fourth-corner correlation times the total count is precisely the score test statistic for testing the linear-by-linear interaction in a Poisson log-linear model that also contains species and sites as main effects. For multiple traits and environmental variables, the score test statistic is proportional to the total inertia of a doubly constrained correspondence analysis. When the count data are over-dispersed compared to the Poisson or when there are other deviations from the model such as unobserved traits or environmental variables that interact with the observed ones, the score test statistic does not have the usual chi-square distribution. For these types of deviations, row- and column-based permutation methods (and their sequential combination) are proposed to control the type I error without undue loss of power (unless no deviation is present), as illustrated in a small simulation study. The issues for valid statistical testing are illustrated using the well-known Dutch Dune Meadow data set.  相似文献   

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