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51.

Problem

Empirical studies on the effectiveness of workplace safety regulations are inconclusive. This study hypothesizes that the asynchronous effects of safety regulations occur because regulations need time to become effective. Safety regulations will work initially by reducing the most serious accidents, and later by improving overall safety performance.

Method

The hypothesis is tested by studying a provincial level aggregate panel dataset for China's coal industry using two different models with different sets of dependent variables: a fixed-effects model on mortality rate, which is defined as fatalities per 1,000 employees; and a negative binominal model on the annual number (frequency) of disastrous accidents.

Results

Safety regulations can reduce the frequency of disastrous accidents, but have not reduced mortality rate, which represents overall safety performance.

Discussion and summary

Policy recommendations are made, including shifting production from small to large mines through industrial consolidation, improving the safety performance of large mines, addressing consequences of decentralization, and facilitating the implementation of regulations through carrying on institutional actions and supporting legislation.

Impact on industry

Until recently, about 4,000 coal miners perished annually in China, demonstrating that workplace safety in China's coal industry is an urgent and important issue. This research provides evidence that safety regulations have asynchronous effects and identifies the priorities in improving safety in China's current coal mining. This may assist the Chinese government to design more effective safety improvement policies and improve the effectiveness of safety regulations and safety performance.  相似文献   
52.
Model fitting for individual-based effects in forests has some problems. Because samples measuring the separate influence of each individual are rarely available, the measured value in the sample represents the influence of all surrounding individual trees. Therefore, it is helpful to build inverse models that use the spatial pattern of the variable as well as that of the source trees. For example, since seed dispersal is influenced by wind effects, a model is discussed describing anisotropic effects to ensure an unbiased estimate of the total fruit number. Further, we present a model describing the absorption of radiation by trees. In this case a multiplicative combination of individual effects yields the total effect. Our approach uses logarithmic transformations of the original data to model multiplicative combinations as sum of transformed single effects. For fitting model parameters we propose an approach based on Bayesian statistics, to ensure ecologically interpretable parameters.  相似文献   
53.
1. The HGPRT (Hypoxanthine‐Guanine‐Phospho‐Ribosyl‐Transferase) assay with Chinese Hamster V79 cells was used to measure the mutagenic effects of UV irradiation, potassium dichromate and nickel chloride. The agents were tested separately and in the combinations of UV plus nickel and dichromate plus nickel.

2. UV, Cr(VI) and Ni(II) were confirmed to be mutagenic in the V79 cell assay. The combination of UV(5J/m2) and Ni(II) (0.5 mM) caused a mutation rate 11.2 times above that corresponding to the sum of the individual mutation rates of these agents. The combined action of Cr(VI) (0.1 mM) and Ni(II) (0.5 mM) produced a mutation rate 2.8 fold above that corresponding to the sum of the individual rates of the separate agents.

3. The enhancing effect of nickel chloride on the mutagenicity of UV or Cr(VI) is interpreted by an interference of Ni(II) with the repair of DNA lesions.  相似文献   
54.
55.
提高能源效率已成为我国节能减排政策的重点,但是由于经济系统内在的调整机制作用,在宏观层面所能实现的节能效果可能不及微观技术层面能源效率提高的程度,甚至还会诱发更多的能源消耗,该现象被称为“宏观能耗回弹”效应.本文通过构建一个中国环境资源CGE模型,测算生产部门提高能源效率的宏观能耗回弹效应.结果显示,能源效率提高5%后,短期回弹效应为52.38%,节能效果仅达到技术层面预期的一半左右;长期回弹效应达178.61%,在高耗能部门竞争力提高、耗能产品出口扩张和经济增长的推动下,节能效果不但被完全抵消,总能耗还进一步增加.因此,生产部门提高能源效率在短期内确实能够降低我国能源消耗,但是由于回弹效应的存在,长期来看,在技术层面“产量相同投入更少”的努力反映到宏观经济层面则转变成“生产更多投入更多”,并且加剧了我国经济高耗能的偏好,提高能源效率所引发的产出增长和结构调整对能耗增加的刺激作用可能最终会抵消或者超过提高能源效率的节能效果.  相似文献   
56.
采用莱特生物强化技术(LTBR—Littoral BioReactor),对兰州石化公司化工园区高浓度有机废水进行了中试试验,进行了正常运行的常规标定、水量冲击标定、浓度冲击标定。结果表明:采用LTBR生物处理工艺,使用特效微生物和营养基质,可以在高COD、高含盐等不利条件下正常进行有机物降解,达到了必须将废水中的COD降至2000mg/L以下的试验要求,为处理高浓度有机化工废水的工程应用开辟了新思路。  相似文献   
57.
Disturbance regime is a critical organizing feature of stream communities and ecosystems. The position of a given reach in the river basin and the sediment type within that reach are two key determinants of the frequency and intensity of flow-induced disturbances. We distinguish between predictable and unpredictable events and suggest that predictable discharge events are not disturbances. We relate the dynamics of recovery from disturbance (i.e., resilience) to disturbance regime (i.e., the disturbance history of the site). The most frequently and predictably disturbed sites can be expected to demonstrate the highest resilience. Spatial scale is an important dimension of community structure, dynamics, and recovery from disturbance. We compare the effects on small patches (⩽1 m2) to the effects of large reaches at the river basin level. At small scales, sediment movements and scour are major factors affecting the distribution of populations of aquatic insects or algae. At larger scales, we must deal with channel formation, bank erosion, and interactions with the riparian zone that will affect all taxa and processes. Our understanding of stream ecosystem recovery rests on our grasp of the historical, spatial, and temporal background of contemporary disturbance events.  相似文献   
58.
In a recently published annex to the National Environmental Policy Plan of the Netherlands (1989), attention was paid to ecotoxicological effects assessment. The proposed procedure was based on the advice of the Health Council of the Netherlands (1989) on risk assessment of toxic chemicals for ecosystems. The various extrapolation methods described by the Health Council are critically discussed in this paper. The extrapolation method of Van Straalen and Denneman (1989) is evaluated for eight chemicals and 11 aquatic species. Conclusions are drawn about the quality and quantity of the ecotoxicological data needed for aquatic effects assessment. For the soil—a compartment that is often at risk—ecotoxicological effects assessment is not possible because suitable ecotoxicological test methods still have to be developed.  相似文献   
59.
ABSTRACT: Outdoor recreation is a major, growing use of water resources in the United States. The economic effects of expenditures by visitors to three recreational river sites on local economies surrounding the sites were estimated using an input-output model (IMPL.AN). Expenditure data were from the Public Area Recreation Visitors Study (PARVS). Results indicate that visitor spending stimulates a considerable amount of economic activity and growth in local economies. Economic effects include increases in total gross output ranging from $2.6 million to $13.4 million, increases in total income ranging from $1.2 million to $5.6 million, and increases in employment ranging from 60 to 292 jobs.  相似文献   
60.
The cumulative effects of forest management activities on water quality at a downstream point were monitored from 1972-1980 during development of a watershed for timber resources. Suspended sediment concentration and turbidity were measured at two hydrologic stations which bracketed a 10-km reach of the Middle Santiam River in the Western Cascades of Oregon as it flowed through an 8000-ha block of intensively managed forest land. Slope failures often accompany road building and harvesting in steep forested watersheds and pose the most serious threat to water quality. Although 180 km of road were constructed and 3400 ha of old-growth forests were harvested from slopes averaging over 60 percent, long-term changes in sediment yields remained undetectable during the period of measurement. The geologic characteristics of the basin and the road construction and maintenance techniques as prescribed by Oregon's forest practice regulations helped to minimize the occurrence of slope failures so that long-term changes in suspended sediment export rates did not occur. Throughout the nine-year measurement period, seven slope failures which added sediment directly to streams produced measurable short-term responses at the downstream sampling location, but these erosion events were too small and too infrequent to produce long-term changes in sediment yield from the watershed.  相似文献   
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