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141.
在深入分析地震新闻报道同质化特征及其原因的基础上,本文认为有效解决地震新闻报道同质化的途径有三:一是相关部门要转变思想,明确地震新闻在地震科普中的重要作用;二是新闻媒体要转变地震新闻报道方式,追求差异化报道;三是要引导受众转变新闻消费观念,以刺激新闻生产者的积极性。  相似文献   
142.
薛固文 《环境科学》1991,(1):90-92,40
鉴于目前国内大多数图书馆尚未建立计算机检索专业文献系统,本文介绍了国内外常用的检索环境科学文献资料的工具书,论述了手工检索科技文献资料的方法和步骤.为科技工作者查阅有关国内外科技文献资料提供参考.  相似文献   
143.
在总结回顾全国乡镇工业污染源调查数据录入、汇总计算机软件系统的基础上,针对进一步使用现代信息技术———多媒体技术、地理信息系统技术和网络技术对调查数据进行深层次加工处理,提出了一些设想。   相似文献   
144.
The Euroconference on Coastal Management Research held in San-Feliu de Guixols, Spain, in December 1997 brought together scientists from a great variety of disciplines in the natural and social sciences, in a search for modes of transdisciplinary cooperation in the context of integrated coastal management. During the conference the participants discussed which interactions among disciplines are required for different coastal issues. Discussion groups each focused on a particular type of coastal environment, characterized by a particular type and degree of development. The group discussions were inspired by background papers which were prepared for this purpose by invited speakers. A selection of these background papers were redrafted on the basis of the conference outcome, and are published in this issue of theJournal of Coastal Conservation. The reports of the discussion groups are published in a conference proceedings booklet issued by EMAPS (1998), the European Polar and Marine Sciences Secretariat. A synthesis of ideas on the challenge of transdisciplinarity, expressed during the discussion group sessions, is presented in this introduction. The statements reflect opinions or suggestions which received broad support from the participants; they should not be taken as proven knowledge.  相似文献   
145.
We analyzed 13 years of hourly measurements of SO2, NOx, and O3, at forest ecosystem research sites in SE Germany. A quasi-continuous data record was obtained by combining data sets from two locations. Before interpreting trends in the combined data set, we analyzed if the change of location introduced a systematic bias. We employed autocorrelation functions, Hurst statistics, complexity analysis, and recurrence quantification and found that the partial data sets exhibited no indication of the presence of any bias. For SO2, we also compared the data from the forest sites with data obtained in nearby cities and also found no indications for any systematic effects. Applying nonparametric trend statistics we found a significant decrease of the SO2. Most of the observed decrease is due to the reductions of SO2 emissions in eastern Germany, but reductions in western Germany and the Czech Republic also played important roles. For O3, we observed a significant increase, the causes of which are unclear from our data alone. No trend was identified for NOx.  相似文献   
146.
Although illegal wildlife trade (IWT) represents a serious threat to biodiversity, research into the prevalence of illegal plant collection and trade remains scarce. Because cacti and succulents are heavily threatened by overcollection for often illegal, international ornamental trade, we surveyed 441 members of the cacti and succulent hobbyist collector community with a mixed quantitative and qualitative approach. We sought to understand collector perspectives on the Convention on the International Trade in Endangered Species of Wild Flora and Fauna (CITES) and on the threats IWT poses to cactus and succulent conservation. Most respondents (74% of 401 respondents) stated that illegal collection in cacti and succulents represents a “very serious problem” and that the problem of wild plant collection is increasing (72% of 319 respondents). Most forms of illegal collection and trade were seen as very unacceptable by respondents. Self-reported noncompliance with CITES rules was uncommon (11.2% of 418 respondents); it remains a persistent problem in parts of the cacti and succulent hobbyist community. People engaging in rule breaking, such as transporting plants without required CITES documents, generally did so knowingly. Although 60.6% of 381 respondents regarded CITES as a very important tool for conservation, sentiment toward CITES and its efficacy in helping species conservation was mixed. Collectors in our survey saw themselves as potentially playing important roles in cactus and succulent conservation, but this potential resource remains largely untapped. Our results suggest the need for enhanced consultation with stakeholders in CITES decision-making. For challenging subjects like IWT, developing evidence-based responses demands deep interdisciplinary engagement, including assessing the conservation impact of species listings on CITES appendices.  相似文献   
147.
传统的模糊综合评价法用于地表水水质评价,当指标数较多时需要设计很多隶属函数,设计和计算工作量皆很大,实际使用不便。在设定指标参照值和规范变换式基础上,将指标按各级标准规范值相近程度进行适当分类,只需分类设计隶属函数即可,大幅减少了计算工作量,使模糊综合评价法应用于地表水水质评价变得简化。  相似文献   
148.
This paper seeks to investigate the effect of economic complexity on environmental degradation in 20 selected African countries over the period 1991–2014. The Feasible Generalized Least Square (FGLS), and Driscoll-Kraay estimators (DK) are used to capture the objectives of the study. The results suggest that economic complexity and economic growth enhance environmental degradation. Also, natural resources rents and globalization improve environmental quality. Furthermore, the findings reject the U-shaped relationship between economic complexity and environmental degradation. In addition, the Dumitrescu-Hurlin panel causality test shows a bidirectional causal relation between economic complexity and environmental degradation. Taking into account the ecological deficit or ecological reserve status of country, it is shown that while the natural resource rents reduce environmental degradation in ecological reserve countries, they increase environmental degradation in ecological deficit countries. The results are robust when an alternative measure of economic complexity is used. Based on these findings, the paper suggests that the governments of African countries should take into account economic complexity when designing their environmental protection policies.  相似文献   
149.
模式搜索算法在毒气泄漏中的源强反算   总被引:2,自引:2,他引:0  
基于泄漏源下风向的浓度监测数据并结合大气扩散模式建立反算模型,以确定泄漏源的位置和强度。以扩散模式仿真的浓度数据与监测数据的匹配度作为目标函数,将反演问题转化为优化问题,利用模式搜索算法迭代优化。以高斯模型为例验证了算法的可行性,结果表明利用探测器提供的测量浓度值,模式搜索算法能够在较短时间内搜索到最优解,在计算复杂性或时间上较梯度型算法和智能优化算法有一定优势。该算法能够及时而准确地反算出泄漏源强度和位置,为事故的应急响应与救援提供依据。  相似文献   
150.
Understanding complex systems is essential to ensure their conservation and effective management. Models commonly support understanding of complex ecological systems and, by extension, their conservation. Modeling, however, is largely a social process constrained by individuals’ mental models (i.e., a small-scale internal model of how a part of the world works based on knowledge, experience, values, beliefs, and assumptions) and system complexity. To account for both system complexity and the diversity of knowledge of complex systems, we devised a novel way to develop a shared qualitative complex system model. We disaggregated a system (carbonate coral reefs) into smaller subsystem modules that each represented a functioning unit, about which an individual is likely to have more comprehensive knowledge. This modular approach allowed us to elicit an individual mental model of a defined subsystem for which the individuals had a higher level of confidence in their knowledge of the relationships between variables. The challenge then was to bring these subsystem models together to form a complete, shared model of the entire system, which we attempted through 4 phases: develop the system framework and subsystem modules; develop the individual mental model elicitation methods; elicit the mental models; and identify and isolate differences for exploration and identify similarities to cocreate a shared qualitative model. The shared qualitative model provides opportunities to develop a quantitative model to understand and predict complex system change.  相似文献   
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