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61.
为明确正念对应急疏散行为的影响机制,提高应急疏散效率,构建包含应急正念、风险感知、自我效能、掩蔽效应和应急疏散行为的概念模型,基于调查问卷结果,利用结构方程模型进行实证研究。研究结果表明:正念、风险感知和自我效能对应急疏散行为存在正向影响,正念通过风险感知和自我效能对应急疏散行为产生部分中介效应;掩蔽效应在自我效能影响应急疏散行为过程中具有显著调节作用;正念通过风险感知能力提高自我效能,进一步对应急疏散行为产生影响。研究结果可为缓解突发事件带来的不良情绪及压力,增强个体自信程度及风险感知能力,提高应急疏散效率提供参考和借鉴。  相似文献   
62.
The paper deals with two major problems in ecological modelling today, namely how to get reliable parameters? and how to build ecosystem properties into our models? The use of new mathematical tools to answer these questions is mentioned briefly, but the main focus of the paper is on development of structural dynamic models which are models using goal functions to reflect a current change of the properties of the biological components in the models. These changes of the properties are due to the enormous adaptability of the biological components to the prevailing conditions. All species in an ecosystem attempt to obtain most biomass, i.e. to move as far away as possible from thermodynamic equilibrium which can be measured by the thermodynamic concept exergy. Consequently, exergy has been proposed as a goal function in ecological models with dynamic structure, meaning currently changed properties of the biological components and in model language currently changed parameters. An equation to compute an exergy index of a model is presented. The theoretical considerations leading to this equation are not presented here but references to literature where the basis theory can be found are given. Two case studies of structural dynamic modelling are presented: a shallow lake where the structural dynamic changes have been determined before the model was developed, and the application of biomanipulation in lake management, where the structural dynamic changes are generally known. Moreover. it is also discussed how the same idea of using exergy as a goal function in ecological modelling may be applied to facilitate the estimation of parameters.  相似文献   
63.
Taking 29 Chinese lakes and 29 Italian lakes as two separate case studies, the paper presented the variations of exergies and structural exergies along eutrophication gradients in Chinese and Italian lakes. The exergies (Ex) and structural exergies (Exst) were calculated based on phytoplankton biomass (BA) and zooplankton biomass (BZ). A trophic state index (TSI) scaling from 0 to 100 was developed to classify trophic status for Chinese and Italian lakes based on three indicators, chlorophyll-a concentration (Chl-a, in mg/m3), total phosphorus (TP in mg/m3) and transparency in Secchi disk depth (SD in m). The relationships between TSI and Ex, Exst, total biomass, BZ/BA ratios were analyzed. The following results were obtained: (1) with the increase of TSI in Chinese and Italian lakes, there is an increasing trend for Ex, and a decreasing trend for Exst, generally. The obvious negative correlations exist between TSI and Exst, at the significant level of 0.01 for Italian lakes, and 0.05 for Chinese lakes. The obvious positive correlations exist between TSI and Ex, at the significant level of 0.01 for Chinese lakes, and for Italian lakes in Spring, Autumn and the all-year. (2) The structural exergy is more dependent on the ratio of phytoplankton biomass to zooplankton biomass (BZ/BA) than the exergy, and the exergy is more dependent on total biomass than the structural exergy. (3) The phytoplankton biomass (BA) and zooplankton biomass (BZ) are increased with the increasing TSI in Chinese and Italian lakes, and phytoplankton biomass (BA) increases more rapidly then zooplankton biomass (BZ) does. This results in the definite decrease of BZ/BA ratio with the increasing trophic status index. Such changes of BA, BZ and BZ/BA ratio could explain successfully the variations of exergies and structural exergies along eutrophication gradients in Chinese and Italian lakes. From the two separate case studies of Chinese lakes and Italian lakes, it could be concluded that exergy and structural exergy are feasible to serve as the system-level ecological indicators to give appropriate information on the trophic status of different lakes.  相似文献   
64.
为探究心智技能对飞行员安全绩效的影响规律,提高飞行员的安全绩效,采用结构方程模型(SEM)建立了心智技能与飞行员安全绩效之间的假设关系模型。首先选取210名飞行员发放调查问卷,收集飞行员的观察力、记忆力、思维力和想象力相关数据;然后采用SPSS 21.0软件对调查问卷数据进行信效度分析和影响因子分析;最后从QAR(快速存取记录器)数据中提取飞行员的不安全事件发生率作为飞行员的安全绩效,验证了观察力、记忆力、思维力和想象力对飞行员安全绩效的假设关系模型,得出两者之间的内在影响规律、影响程度以及相关作用关系。结果表明:观察力、思维力、记忆力和想象力对飞行员安全绩效的标准化路径系数分别为0.61、0.52、0.43、0.36;观察力、思维力、记忆力和想象力均对飞行员安全绩效有正向显著影响,且影响作用依次减小。  相似文献   
65.
Recycling across Ireland has increased incrementally since the introduction and implementation of the Landfill Directive 1999/31/EC, the WEEE directive 2002/96/EC, and the Waste Framework Directive 2008/98/EC. As a result of the implementation of the aforementioned directives, the volume of waste sent to landfill has fallen, household composting increased and recovery of municipal waste recyclables continues to improve. The improvements witnessed, are in part achieved as a result of the introduction of the 2-bin and 3-bin collection service. The improvement of facilities at recycling centres and bring banks have been instrumental in the gains achieved in recycling rates.NIMBYism, however, remains a constant impediment to procuring suitable sites for the recycling receptacles. It is not unusual for people to seek convenience whilst not wanting the associated problems on their doorstep. NIMBYism is something that most individuals are guilty of and it is considered to be quite normal. The structural difficulties associated with recycling rates are the first that need to be confronted. By altering the landscape, behaviours can be changed and improved. In the instance of bring banks and the social problems that are associated with them such as fly-tipping, changing the visual aspect of the receptacles and their positioning may improve recycling rates and reduce the number of instances of fly-tipping and littering.This paper presents the results of 509 questionnaires distributed to nine schools in the Limerick City and County environs. The questionnaires, distributed to primary schools actively participating in the Green School Programme, were analysed so as to get an understanding of the motivations and the deterrents surrounding household recycling of waste. From the analysis recommendations are made to reduce the social problems associated with bring banks and to increase the percentage of householders availing of waste collection services.  相似文献   
66.
People's perception of crime and incivilities vary considerably depending on their attitudes towards environmental conditions. This paper investigated the hypothesised relationships between Crime Prevention Through Environmental Design (CPTED), victimisation and fear of crime. The checklist was administered by using on-site observation to measure the CPTED construct followed by a self-administered questionnaire to explore the residents' perceptions of victimisation and fear of crime in their area of residency. In all, 164 respondents from a selected group of residents were involved in this study. The structural equation modelling technique was employed and the results indicate that CPTED is negatively related to victimisation. The model also shows that there is a significant positive direct influence of victimisation on fear of crime. However, no direct significant relationship was found between CPTED and fear of crime, but a negative indirect relationship between CPTED and fear of crime was observed through victimisation.  相似文献   
67.
A multivariate statistical approach integrating the absolute principal components score (APCS) and multivariate linear regression (APCS-MLR), along with structural equation modeling (SEM), was used to model the influence of water chemistry variables on chlorophyll a (Chl a) in Lake Qilu, a severely polluted lake in southwestern China. Water quality was surveyed monthly from 2000 to 2005. APCS-MLR was used to identify key water chemistry variables, mine data for SEM, and predict Chl a. Seven principal components (PCs) were determined as eigenvalues >1, which explained 68.67% of the original variance. Four PCs were selected to predict Chl a using APCS-MLR. The results showed a good fit between the observed data and modeled values, with R2 = 0.80. For SEM, Chl a and eight variables were used: NH4-N (ammonia-nitrogen), total phosphorus (TP), Secchi disc depth (SD), cyanide (CN), arsenic (As), cadmium (Cd), fluoride (F), and temperature (T). A conceptual model was established to describe the relationships among the water chemistry variables and Chl a. Four latent variables were also introduced: physical factors, nutrients, toxic substances, and phytoplankton. In general, the SEM demonstrated good agreement between the sample covariance matrix of observed variables and the model-implied covariance matrix. Among the water chemistry factors, T and TP had the greatest positive influence on Chl a, whereas SD had the largest negative influence. These results will help researchers and decision-makers to better understand the influence of water chemistry on phytoplankton and to manage eutrophication adaptively in Lake Qilu.  相似文献   
68.
The European Union's Structural Funds are implemented by means of Regional Development Plans (RDP), whose regionally scoped environmental assessment is required. We highlight the deficiencies faced by this approach when subregional areas with high conservation natural values are involved and illustrate it with the case of the RDP of Andalusia region on Doñana National Park area (Spain). Commissioned by the World Wildlife Fund, a Strategic Environmental Assessment (SEA) of the Andalusian RDP was carried out focusing on Doñana and its area of influence. This is a complex space where some of the most environmentally valuable features in the continent coexist with a surrounding intense and multi-sector economic activity, threatening its conservation. In the absence of an established sustainability framework in the Region, a “trickle-down” SEA approach evidenced the need to produce a set of environmental, economic and social guidelines for sustainable management of land, against which the RDP objectives were tested for coherence. An “incremental” SEA approach was also tested, which involved the identification of 79 measures and actions stemming from the RDP provisions and other concurrent planning documents reviewed and the qualitative assessment of their individual and cumulative potential impacts on Doñana environments. In the light of the results, a set of complementary mitigating measures was proposed for inclusion in tiered stages of the planning process. Measures to avoid, reduce, remedy and monitor the major types of impact were proposed, including provisions for public participation. SEA emerges as an instrument for non-governmental organizations (NGOs) to carry out independent assessment of public development initiatives.  相似文献   
69.
人才应具有德、识、才、学、体五种基本要素。安技人才要适应现代安全工作全员全过程动态管理的要求所应具有的基本素质是什么?作者就其结构模型从德育结构、知识结构、智力结构及体育结构等方面进行了探讨。  相似文献   
70.
INTRODUCTION: Several fields are showing increasing interest in safety culture as a means of reducing accidents in the workplace. The literature shows that safety culture is a multidimensional concept. However, considerable confusion surrounds this concept, about which little consensus has been reached. METHOD: This study proposes a model for a positive safety culture and tests this on a sample of 455 Spanish companies, using the structural equation modeling statistical technique. RESULTS: Results show the important role of managers in the promotion of employees' safe behavior, both directly, through their attitudes and behaviors, and indirectly, by developing a safety management system. IMPACT ON INDUSTRY: This paper identifies the key dimensions of safety culture. In addition, a measurement scale for the safety management system is validated. This will assist organizations in defining areas where they need to progress if they wish to improve their safety. Also, we stress that managers need to be wholly committed to and personally involved in safety activities, thereby conveying the importance the firm attaches to these issues.  相似文献   
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