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831.
A study on the orbit of air temperature movement 总被引:1,自引:0,他引:1
Zong-Chang Yang 《Environmental Modeling and Assessment》2007,12(2):131-143
In this paper, we describe an air temperature movement by mapping its time series to the polar coordinates: the value of the
time series is plotted on the radial coordinate and the time on the angular coordinate. In this way, both the yearly and daily
air temperature movements from five different locations of China are used to demonstrate that, in an intuitionistic view,
air temperature movement is neither random nor chaotic, but has its own orbit. We then propose an elliptic orbit model for
the air temperature movement. Our proposed model provides quite good results when it is applied to the evaluation of yearly
air temperature movements in eight locations in various parts of the world, and the evaluation of daily air temperature movements
in five locations in Hunan Province of China on December 17, 2005. Results show that our approach provides a concise and helpful
model for air temperature analysis. 相似文献
832.
Polycyclic aromatic hydrocarbons in Dalian soils: distribution and toxicity assessment 总被引:2,自引:0,他引:2
Concentrations of 15 polycyclic aromatic hydrocarbons (PAHs) were measured in surface soils collected from Dalian, China, for examination of distributions and composition profiles and their potential toxicity. The sum of 15 PAHs (SigmaPAHs) ranged from 190 to 8595 ng g(-1) dry weight, and showed an apparent urban-suburban-rural gradient in both SigmaPAHs and composition profiles. Using hierarchical cluster analysis (HCA), the sampling sites were grouped into four clusters corresponding to traffic area, park/residential area, suburban and rural areas. The ratios of naphthalene (Nap) and fluorene (Fl) versus fluoranthene (Flu), pyrene (Pyr) and indeno(1,2,3-cd)pyrene (InP) in the four clusters provided evidence of local distillation. The diagnostic ratios indicated the prevalent PAH sources were petroleum combustion and coal combustion in Dalian, and a cross plot of diagnostic ratios distinguished the urban samples from suburban and rural ones. Toxic potency assessment of soil PAHs presented a good relationship with benzo(a)pyrene (BaP) levels, toxic equivalent concentrations based on BaP (TEQ(BaP)) and dioxin-like toxic equivalent concentrations (TEQ(TCDD)). The study highlights that BaP is a good indicator for assessing the potential toxicity of PAHs, and presents a promising toxicity assessment method for soil PAHs. 相似文献
833.
834.
课证融合模式下实训教学改革研究 总被引:3,自引:0,他引:3
课证融合模式就是将课程与职业资格证书相结合的教学模式,是对职业教学改革的探索。但当前存在的实训教学标准模糊、校企合作实训教学条件不足、教师队伍转型滞后、教材开发混乱等现象严重阻碍了课证融合模式的推行,职业院校应当从明确考核评价标准、改进培养方案、加大双师教师的引进和培养、科学开发实训教材等途径进行尝试,推进课证融合。 相似文献
835.
杨安行 《中国环境管理干部学院学报》2011,21(4):9-11
通过论述秦皇岛市在城市垃圾收集、压缩、运输、无害化处理方面取得的成功经验,提出环境卫生工作统一领导,分工负责;对不同季节、不同发生主体垃圾成份进行分析,开展垃圾减量化、资源化科学研究;开展垃圾填埋场环境监测工作,防止对水、土壤和大气造成污染,以期把秦皇岛市真正建设成为宜居、宜业、宜游的现代化城市。 相似文献
836.
城市老工业区搬迁规划环评具有层次多、涉及面广的特点。评价首先要分清规划的层次,理清3个层面规划内容,分析所涉及到的主要环境问题,按照规划、区域和项目环评3个层次分别开展评价工作。在规划层面上应重点解决好产业发展政策的符合性和选址合理性论证;区域环评层面重点进行区域布局、结构、基础设施的支撑能力和环境的承载力评价;项目层次重点弄清污染特征、污染源和污染控制措施,评价其环境影响。 相似文献
837.
Cetacean-focused tourism in Taiwan has grown rapidly since 1997. This development, measured in terms of both number of tour
boats and visitors, has resulted in many resource management challenges stemming from the absence of regulation and scientific
data. To fill this void in empirical evidence, we used 464 sighting records from 2002 to 2005 to model the impact of cetacean-focused
tourism. Cox proportional hazard analysis indicated cetacean avoidance responses to cetacean watching boats were strongly
associated with pod size, mother–calf pairs, and cetacean-vessel distances. Mother–calf pairs abandoned their avoidance tactic
by 55% compared to noncalf groups when tour boats approached. Second, the hazard ratio of abundance was 0.996, suggesting
that the odds of encountering avoidance responses by the cetaceans decreased by 42% for every 100-member increase in the cetacean
pod size. Last, distances maintained by boats from the cetaceans was positively related to avoidance responses (i.e., less
avoidance behavior with closer interaction). Based on our findings, we have the following recommendations: (a) limit vessels
from approaching mothers with calves, (b) limit vessels from approaching small groups of cetaceans, (c) reduced avoidance
behavior to boat traffic may be a red flag for potential long-term disturbance, and (d) apply the “precautionary principle”
based on the best scientific information available in cetacean-based tourism in Taiwan. These recommendations will help contribute
to the sustainable development of cetacean-focused tourism in Taiwan. 相似文献
838.
The management of wild mushroom is interdisciplinary in nature, whereby the biophysical considerations have to be incorporated
into the context of a wide range of social, economic and political concerns. However, to date, little documentation exists
illustrating an interdisciplinary approach to management of wild mushrooms. Moreover, the empirical case studies necessary
for developing applicable and practical methods are even more rare. This paper adopted an interdisciplinary approach combining
participatory methods to improve the habitat management of Thelephora ganbajun, an endemic and one of the most economically valuable mushroom species in Southwest China. The paper documents an empirical
case of how an interdisciplinary approach facilitated the development of a scientific basis for policy and management practice,
and built the local capacity to create, adopt and sustain the new rules and techniques of mushroom management. With this integrative
perspective, a sustainable management strategy was developed, which was found not only technically feasible for farmers, but
also acceptable to the government from an ecological and policy-related perspective. More importantly, this approach has greatly
contributed to raising the income of farmers. The paper highlights how the integration of biophysical and socioeconomic factors
and different knowledge systems provided a holistic perspective to problem diagnosis and resolution, which helped to cope
with conventional scientific dilemmas. Finally, it concludes that the success of this interdisciplinary approach is significant
in the context of policy decentralization and reform for incorporating indigenous knowledge and local participation in forest
management. 相似文献
839.
840.
Formulation of criteria for pollution control on cement products produced from solid wastes in China
The process of producing cement products from solid waste can increase the level of pollutants in the cement products. Therefore, it is very important to establish a pollution control standard for cement products to protect the environment and human health. This paper presents acceptance limits for the availability of heavy metals in cement products which have been produced from solid wastes and explains how the limits have been calculated. The approach and method used to formulate these criteria were based on EN 12920. The typical exposure scenarios used in this paper involve concrete being used for drinking water supply pipelines and concrete pavements and are based on an analysis of typical applications of cement in China, and the potential for contact with water. The parameters of a tank test which was based on NEN 7375 were set in accordance with the environmental conditions of typical scenarios in China. Mechanisms controlling the release of heavy metals in concrete and a model for that release were obtained using the leaching test. Finally, based on acceptance criteria for drinking water and groundwater quality in China, limit values for the availability of heavy metals in concrete were calculated. 相似文献