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401.
The connectivity of remnant patches of habitat may affect the persistence of species in fragmented landscapes. We evaluated the effects of the structural connectivity of forest patches (i.e., distance between patches) and matrix class (land-cover type) on the functional connectivity of 3 bird species (the White-crested Elaenia [Elaenia albiceps], the Green-backed Firecrown Hummingbird [Sephanoides sephaniodes], and the Austral Thrush [Turdus falklandii]). We measured functional connectivity as the rate at which each species crossed from one patch to another. We also evaluated whether greater functional connectivity translated into greater ecological connectivity (dispersal of fruit and pollen) by comparing among forest patches fruit set of a plant pollinated by hummingbirds and abundance of seedlings and adults of 2 plants with bird- and wind-dispersed seeds. Interpatch distance was strongly associated with functional connectivity, but its effect was not independent of matrix class. For one of the bird-dispersed plants, greater functional connectivity for White-crested Elaenias and Austral Thrushes (both frugivores) was associated with higher densities of this plant. The lack of a similar association for the wind-dispersed species suggests this effect is linked to the dispersal vector. The abundance of the hummingbird-pollinated species was not related to the presence of hummingbirds. Interpatch distance and matrix class affect animal movement in fragmented landscapes and may have a cascading effect on the distribution of some animal-dispersed species. On the basis of our results, we believe effort should be invested in optimizing patch configuration and modifying the matrix so as to mitigate the effects of patch isolation in fragmented landscapes.  相似文献   
402.
针对煤矿灾害预警过程存在的问题,首先运用解释结构模型分析各影响因素之间的相互关系,其次运用系统动力学原理和方法,对影响煤矿灾害预警的各因素进行动态仿真,对比分析各因素水平增加量对预警水平的影响程度,得出灾害预警中不同因素对预警水平的实际作用率。仿真结果有助于煤矿采取针对性的预警管理措施,同时为煤矿安全管理决策提供一个新的思路。  相似文献   
403.
Porous ZIF-7 with the sodalite (SOD) cage structure (ZIF, Zeolitic imidazolate framework) were synthesized by the solvothermal method. Synthesized material was characterized by powder X-ray diffraction (PXRD), thermal gravity (TG), scanning electron micro- scopy (SEM) and Na adsorption analysis. ZIF-8 with the SOD structure and a littl larger pore window was synthesized in a similar way and was characterized for comparisons. Thermal stability and structural stability of ZIF-7 were tested through PXRD analysis, and the capability of the material for CO2 capture from simulated flue gas was investigated through physical adsorption method. The results showed that CO: adsorption capacity on ZIF-7 was about 48 mL. gl while the capacity on ZIF-8 was about 18mg.g-1 (at 12C and 0.98 P/Po relative pressure). Furthermore, the impact of flue gas components on adsorption capacity of ZIF-7 and the selectivity of CO2 against N2 on ZIF-7 was also investigated in this work  相似文献   
404.
This study aims to examine the mediating role of the customer environmental satisfaction in the effect of environmental friendliness of products and the company on customer loyalty in using green products in Malaysia. Structural equation modeling (SEM) analysis is performed to test the proposed hypotheses among 200 full time university students with purchasing experience at least once a week green products like organic vegetables. SEM results showed that customer environmental satisfaction significantly affected customer loyalty. This pair of relationships has the highest standardized beta coefficients, signifying the most important aspect of consideration by respondents among the rest of the proposed hypotheses. Next, customer environmental satisfaction partially mediated the relationship between environmental friendliness of products and customer loyalty in using green products. The results confirmed that customers are satisfied with their decision to purchase green products as they consume the least amount of resources and energy which results in minimum environmental damage and are also easy to recycle, disassemble, decompose, and reuse. Marketers should focus on creating effective marketing strategies and green promotional activities to attract customers for their green products. Marketers should control and enhance the quality of green products, as well as emphasizing their environmental satisfaction and increasing customer loyalty levels. This empirical study advanced marketers’ and policy makers’ understanding of the identification of customer environmental satisfaction as a mediator in the relationship between environmental friendliness of products and customer loyalty has been inspected in Malaysian context.  相似文献   
405.
有机污染物对水生生物毒性作用机理的判别及影响因素   总被引:1,自引:0,他引:1  
有机污染物对水生生物急性毒性作用机理的判别及影响因素是定量结构与活性相关研究的基础,对准确预测有机污染物对水生生物的毒性具有重要的意义.本文根据目前国内外在该领域的研究现状和本课题组在该领域的研究成果,系统地总结了有机污染物对水生生物的急性毒性作用机理、毒性作用机理的判别方法、及影响毒性作用机理判别的因素.有机污染物对水生生物的急性毒性作用机理可分为非极性麻醉型、极性麻醉型、反应型和特殊作用型;化合物的毒性比率、毒性临界值和结构警示是目前判别毒性作用机理的主要方法;有机化合物的生物富集、非生物转化、生物代谢、离子化率和溶解度是毒性作用机理判别的主要影响因素.  相似文献   
406.
ABSTRACT

The main purpose of Green Supply Chain Management (GSCM) is to improve the quality of supply chain management strategies and environmental performance. As per current statistics, the chemical industry is growing fast in Bangladesh. In order to compete for global competition, GSCM is essential in this sector. This paper proposes a systematic approach of structural framework whose aim is to enhance the probability of constructive implementation of GSCM in the field chemical industry in Bangladesh. Therefore, this framework evaluates the appropriate interrelationship along with the drivers of GSCM in the chemical industry. In total, eight drivers were finalized from an associated literature review with the help of survey and by taking expert opinions via the Delphi methodology. In addition to MICMAC analysis, the driving and the dependence powers for all the drivers were determined. Moreover, the structural frameworks for the drivers were developed by means of total interpretive structural modeling (TISM) technique. As a result, the findings indicate that the most significant driver was supplier pressure and willingness and the most important barrier was high cost. Finally, the main objective of this research is expected to help industrial managers to evaluate and understand the critical areas where they should emphasize to implement GSCM in the chemical industry.  相似文献   
407.
基于结构方程模型的京津冀城市用地行政边界效应分析   总被引:2,自引:0,他引:2  
行政边界如何影响城市用地规模?论文以京津冀为研究案例,基于结构方程构建5个时段(1990、1995、2000、2005、2010年)的城市用地行政边界效应模型,揭示行政边界影响下城市用地的扩张机理和演化特征。研究结果表明:行政边界对城市用地规模的直接影响效应不显著;行政边界通过对经济、人口等中间要素的影响间接作用于城市用地的扩张过程;1990—2010年的5个时间节点,京津冀城市用地行政边界效应的间接影响要素中,财政支出和非农业人口的主导作用明显,社会固定资产、实际利用外资和职工平均工资也在不同阶段发挥了不可忽视的作用;在社会经济发展水平较低、市场化和区域一体化滞后的阶段,社会固定资产是行政边界影响城市用地规模的重要间接要素,而在要素流动较为频繁的时期,实际利用外资和职工平均工资成为构筑在行政边界和城市用地规模间不可忽视的中间要素。本研究可为京津冀城市用地的理性扩张和城市开发边界的划定提供理论支持和政策建议。  相似文献   
408.
为减少维修差错导致的不安全事件,从维修资源管理对机务人员不安全行为的影响进行探讨,以团队合作、沟通交流、工作压力、领导能力、工作环境及惯例作为维修资源管理变量,考虑不安全行为意向对不安全行为的中介作用,提出了维修资源管理各因素对机务人员不安全行为的影响假设。通过实证分析,采用结构方程模型(SEM)的方法验证了维修资源管理各因素对机务人员不安全行为的影响假设。实证结果表明:维修资源管理各因素对机务人员不安全行为及意向有不同的影响作用。为机务人员的安全行为管理提供理论支持。  相似文献   
409.
China has developed more than 20 water pollution control plans for river basins (RBWPs) since 1996. However, the implementation has generally lagged. This paper proposes a three-step, post-evaluation methodology to analyze the implementation result of a RBWP and its influential factors. First, a multi-attribute evaluation method based on an index system is established to score the enforcement results of a RBWP. Indicators measure how well a RBWP has achieved its objectives, which include water quality compliance, pollution load control, project construction, financial inputs, and related management requirements. Second, an interpretive structural model is used to detect the significant factors that affect RBWP implementation. This model can effectively analyze the cause-effect chain and hierarchical relationship among variables. Five groups of factors were identified, namely, plan preparation, water resource endowment, policy, institution, and management. Both qualitative and quantitative methods are employed in the third step to evaluate the extent to which these factors have influenced the execution result of a RBWP, including pre-post contrast, scenario analysis, and correlation analysis. This research then post-evaluated the implementation of the Huai River Basin water pollution control plans (H-RBWPs) over a period of 10 years as a case study. Results showed that the implementation of the H-RBWPs was unsatisfactory during 2001–2005, although it improved during 2006–2010. The poor execution of these plans was partially caused by the underestimation of regional economic development in combination with ineffective industrial structure adjustment policies. Therefore, this case study demonstrates the feasibility and flexibility of the proposed post-evaluation methodology.  相似文献   
410.
采用Motic数码显微镜观察SRT为3 d和15 d的活性污泥絮体以及它们的LEPS和TEPS絮凝污泥悬浮液形成的生物絮体的结构。结果表明,高SRT(15 d)活性污泥絮体较低SRT(3 d)活性污泥絮体的颜色深且密实;同一活性污泥中,内层的絮体结构较外层的絮体结构密实,细菌细胞与菌胶团之间的结合更为紧密。最后,结合絮体结构图片,从大分子作用力的角度,提出了活性污泥絮体结构模型,以形象地描述不同SRT活性污泥EPS及其表面性质变化对活性污泥絮凝沉降性能的影响。  相似文献   
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