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101.
示踪技术用于气体泄漏扩散模拟的多元线性回归分析   总被引:3,自引:0,他引:3  
采用江苏工业学院油气储运安全综合实验模型平台,利用示踪技术(以CO2为示踪剂),模拟了有害气体瞬时泄漏扩散的整个过程.并结合多元线性回归分析的基本方法,定量分析了气体泄漏扩散过程,建立了多元线性回归模型,初步确定了泄漏气体浓度与相关物理量的变化关系,在此基础上得到了2个定量评价指标:确定性系数R=0.991,相关系数r=0.995.研究表明,在实验室建立的试验模型能较好地反映现实情况,模型仿真度较高,数据拟合效果较好.研究可为评价模型的相似性提供理论参考,对有害气体泄漏扩散事故应急救援、实施有效的现场控制,具有一定的科学参考价值.  相似文献   
102.
伊宁市空气中硫酸盐化速率与二氧化硫相关性研究   总被引:1,自引:1,他引:0  
对伊宁市1999-2002年空气中硫酸盐化速率和二氧化硫监测值进行回归分析,结果表明,二者之间存在显著的线性正相关关系,但对各年度回归方程斜率和截距进行统计检验,则表现出显著的差异。  相似文献   
103.
104.
Fishing pressure has increased the extinction risk of many elasmobranch (shark and ray) species. Although many countries have established no‐take marine reserves, a paucity of monitoring data means it is still unclear if reserves are effectively protecting these species. We examined data collected by a small group of divers over the past 21 years at one of the world's oldest marine protected areas (MPAs), Cocos Island National Park, Costa Rica. We used mixed effects models to determine trends in relative abundance, or probability of occurrence, of 12 monitored elasmobranch species while accounting for variation among observers and from abiotic factors. Eight of 12 species declined significantly over the past 2 decades. We documented decreases in relative abundance for 6 species, including the iconic scalloped hammerhead shark (Sphyrna lewini) (?45%), whitetip reef shark (Triaenodon obesus) (?77%), mobula ray (Mobula spp.) (?78%), and manta ray (Manta birostris) (?89%), and decreases in the probability of occurrence for 2 other species. Several of these species have small home ranges and should be better protected by an MPA, which underscores the notion that declines of marine megafauna will continue unabated in MPAs unless there is adequate enforcement effort to control fishing. In addition, probability of occurrence at Cocos Island of tiger (Galeocerdo cuvier), Galapagos (Carcharhinus galapagensis), blacktip (Carcharhinus limbatus), and whale (Rhincodon typus) sharks increased significantly. The effectiveness of MPAs cannot be evaluated by examining single species because population responses can vary depending on life history traits and vulnerability to fishing pressure.  相似文献   
105.
International case studies of protected area performance increasingly report that conservation and socio‐economic outcomes are interdependent. Effective conservation requires support and cooperation from local governments and communities, which in turn requires that protected areas contribute to the economic well‐being of the communities in which they are sited. Despite increasing recognition of their importance, robust studies that document the socio‐economic impacts of protected areas are rare, especially in the developed world context. We proposed 3 potential pathways through which protected areas might benefit local communities in the developed world: the improved local housing value, local business stimulus, and increased local funding pathways. We examined these pathways by undertaking a statistical longitudinal analysis of 110 regional and rural communities covering an area of approximately 600,000 km2 in southeastern Australia. We compared trends in 10 socio‐economic indicators describing employment, income, housing, business development and local government revenue from 2000 to 2010. New protected areas acquisitions led to an increased number of new dwelling approvals and associated developer contributions, increased local business numbers, and increased local government revenue from user‐pays services and grants. Longer‐term effects of established protected areas included increased local council revenue from a variety of sources. Our findings provide support for each of our 3 proposed benefit pathways and contribute new insights into the cycling of benefits from protected areas through the economy over time. The business and legislative models in our study are typical of those operating in many other developed countries; thus, the benefit pathways reported in our study are likely to be generalizable. By identifying and communicating socio‐economic benefits from terrestrial protected areas in a developed world context, our findings represent an important step in securing local support and ongoing high‐level protection for key components of the world's biodiversity.  相似文献   
106.
The existing literature (i) examines bycatch and discard behavior in a static framework and (ii) treats bycatch as a deterministic process uniform across vessels. Using a dynamic representative agent model in a two-stock resource, this paper explores strategic interactions between a social planner and two groups of harvesters, one of which imposes a stochastic “technological externality” (bycatch) on the other. In addition to limitations on entry and the number of trips taken in each industry, three bycatch control instruments are compared to the unconstrained case: taxes, trip limits, and value-based quotas. Implementation and enforcement costs aside, taxes dominate both types of quota, and value limits outperform trip limits by eliminating one type of discarding. In simulations, relative performance depends upon variance in the bycatch process, differences in the ex vessel prices of stocks, relative efficiency of the harvester types, and fixed costs on the trip and industry margins.  相似文献   
107.
In this paper the data of a forest health inventory are analyzed. Since 1983 the degree of defoliation, together with various explanatory variables (covariates) concerning stand, site, soil and weather, are recorded by the second of the two authors, in the forest district of Rothenbuch (Spessart, Bavaria). The focus is on the space and time dependencies of the data. The mutual relationship of space-time functions and the set of covariates is evaluated. For this we use generalized linear models (GLMs) for ordinal response variables and semiparametric estimation approaches. By using goodness-of-fit measures it turns out that (i) the contribution of space-time functions is quantitatively comparable with that of the set of covariates, (ii) the contribution of space-time functions is small compared with the contribution of a set of variables describing the last-year and neighboring response values. By applying appropriate residual methods a detailed analysis of the individual sites in the area can be carried out. This analysis reveals where the predictive power of the covariates fail to explain the observed defoliation.  相似文献   
108.
边镜贸易作为我国作为开放的重要组成部分,进展显著。本文在概述我国边境贸易发展所产生的环境问题的基础上,以我国最大的陆边口岸--满州里市为例,运用灰色预测,动态规划等方法探讨边境贸易与环境保护协调发展的途径。  相似文献   
109.
城市河段污染控制灰色动态规划的应用   总被引:1,自引:0,他引:1  
本文探讨了含灰数的城市河段污染控制的灰色动态规划的理论与方法。通过分析城市河段污染控制系统的广义不确定性,将灰数表征这些不确定性,建立了描述城市河段水污染控制的灰色动态规划中广义不确定性的灰数运算、灰数大小的比较及灰动态规划的初步理论和求解方法,通过对淮河蚌埠河段有机污染控制实例研究,说明了水污染控制灰色动态规划问题研究意义和求解方法的实用性。  相似文献   
110.
唐波  何锡文 《环境化学》1996,15(1):61-68
本文研究了Δλ(λem-λex)为130nm和PH12.0条件下,萘、1-萘粉和2-萘酚混合物的同步荧光光谱,获三者同步荧光峰信息,且萘被完全分辨,另外,提出用拟面积多波长线性双组合计算解析重叠的1-萘酚和2-萘酚同步荧光光谱,解析结果的精密度、组份间浓度比范围均较多波长线性回归、双峰增配平和一阶导数解析混合物同步荧光光谱结果为优。  相似文献   
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