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以中国为研究区域,利用CanMETOP模型模拟了2005年大气中α-六六六(α-HCH)浓度的变化,并分析了东亚夏季风对我国东部地区大气中α-HCH浓度时空分布的影响.模拟结果表明,6月15日-8月15日期间,东北、华北和东南地区的α-HCH平均大气浓度分别为260 pg·m~(-3),74 pg·m~(-3)和41 pg·m~(-3).大气浓度具有明显的时空分布特征,从6月15日在我国东南地区开始出现了较高的大气浓度堆集,6月24日达到最大值(259 pg·m~(-3)).在向我国北部传输过程中,7月1日在东北形成的气旋区域出现最大值(1947pg·m~(-3)).此后,东南地区的大气浓度均处于较低的水平(<50 pg·m~(-3)),而东北地区的大气浓度一直处于100-350 pg·m~(-3)之间的较高水平.分析结果表明,东亚夏季风可以将东南地区大气中的α-HCH传输至东北地区,并在东北区域堆集. 相似文献
63.
Chandrajith R Kudavidanage E Tobschall HJ Dissanayake CB 《Environmental geochemistry and health》2009,31(3):391-400
Geophagy or deliberate ingestion of soils was observed among Asian elephants (Elephas maximus) in the Udawalwe National Park, Sri Lanka, for several years. The geochemical and mineralogical composition of the clayey
soil layers which are purposefully selected and eaten by elephants in the park were studied, in order to identify the possible
reasons for elephant geophagy. The concentrations of major and trace elements were determined by means of X-ray fluorescence
spectrometry in 21 soil samples from eight geophagic sites and six soil samples collected from four non-geophagic sites. The
mineralogical composition of selected soil samples was investigated using X-ray diffractometry (XRD). These geochemical analyses
revealed that geophagic soils in the study areas are deeply weathered and that most of the elements are leached from the soil
layers under extreme weathering conditions. The XRD data showed that the soils of the area consisted mainly quartz, feldspar,
and the clay minerals kaolinite, Fe-rich illite, and smectite. Although no significant geochemical differences were identified
between geophagic and non-geophagic soils, a clear difference was observed in their clay mineralogical content. Soils eaten
by elephants are richer in kaolinite and illite than non-geophagic soils, which contain a higher amount of smectite. It is
suggested that elephants in Udawalawe National Park ingest soils mainly not to supplement the mineral contents of their forage
but to detoxify unpalatable compounds in their diet. 相似文献
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Studies show that Whites tend to show the lowest level of support for affirmative action (AA) policies. Opponents of AA often argue that this is because it violates principles of meritocracy. However, self‐interest (based on social identification with those adversely affected) could also explain their opposition. In three studies, we varied whether an Asian or White male is adversely affected by AA to test another explanation; namely, that Whites' fairness judgments are based on both the adversely affected person's race and the fairness evaluator's ideological beliefs. Although we found some support for the meritocratic explanation, this was not sufficient to explain why Whites view AA as (un)fair. Instead, we found strong support for our prediction that Whites who are opposed to equality perceive more unfairness when a White (vs. Asian) was harmed by AA, whereas Whites who endorse egalitarian ideologies perceive the opposite. This finding suggests that neither self‐interest nor meritocratic explanations can fully account for Whites' opposition to AA. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
65.
中亚五国气溶胶光学厚度时空分布特征研究 总被引:5,自引:1,他引:4
气溶胶时空变化是影响气溶胶气候效应不确定性的主要因素之一.在生态环境脆弱的中亚五国(哈萨克斯坦、乌兹别克斯坦、土库曼斯坦、吉尔吉斯斯坦和塔吉克斯坦)研究气溶胶光学厚度(Aerosol Optical Depth,AOD)的时空变化对中亚地区及全球生态环境和气候变化具有重要意义.基于2002—2019年MODIS 04_L2气溶胶产品数据集,利用标准差椭圆(Standard Deviation Ellipse,SDE)、加权回归的季节趋势分解(Seasonal Trend Decomposition Procedure based on Loess,STL)和奇异值分解(Singular Value Decomposition,SVD)等方法,在时间和空间两个维度上揭示了中亚五国AOD和气溶胶细模态比例(Aerosol Fine Mode Fraction,FMF)的时空演变特征,以及AOD对气象因子和土地利用/土地覆被变化(Land Use/Cover Change,LUCC)的响应.结果表明:①中亚五国AOD分布呈现出显著的空间异质性,高值区主要集中于咸海区域和费尔干纳盆地,低值区主要分布于海拔相对较高的山区和丘陵;AOD年平均中心在2009年之前分布于中亚东南部,受咸海盐尘的影响,2010年之后偏向于西北部向咸海附近移动.②2002—2019年中亚五国AOD年均值整体呈先增长后下降的态势,2012年达到最大值.③中亚地区AOD的变化受气温、降水、风速的共同影响,AOD与气温的空间变化特征呈基本一致的态势,但与降水和风速存在一定差异;不同土地覆被区对AOD的影响差异显著,城市建设用地、裸地及水域是AOD高值分布区,低值分布于郁闭灌木丛和混杂林等植被覆盖度高的土地利用/土地覆被区.④气溶胶细模态比例(FMF)空间分布格局由自然和人为因素共同作用,呈现出咸海和沙漠区域附近以粗模态气溶胶为主,人口密集区和工业区以细模态粒子占主导地位. 相似文献
66.
2005年10月22日至2006年10月21日,在云南腾冲一典型背景点进行了每周一次的大气采样,以监测季风期东南亚地区生物质燃烧导致的多环芳烃(PAHs)的输入状况.结果表明,监测期内总PAHs含量为43.1~156ng/m3 (平均值为87.9ng/m3).其中气相PAHs均值为85.8ng/m3,无明显的季节变化;颗粒相PAHs均值为2.35ng/m3,在春季出现显著高值,可能与东南亚生物质燃烧释放的PAHs在南亚季风作用下向腾冲的跨境迁移有关.颗粒相PAHs以毒害性较大的高环PAHs化合物为主,其在偏远地区生态系统中的累积可能带来一定的生态风险. 相似文献
67.
James Otto Deputy Director Koh Naito Mining Expert George Pring Professor 《Natural resources forum》1999,23(4):323-334
This paper offers a new perspective on the environmental laws in Asian nations affecting the exploration, mining, and reclamation activities of the mineral resource industry: the perspective of the senior government officials in those countries, whose job is to enforce these new environmental laws. The article presents the results of a 1998 survey of national environmental officials in Asia conducted by the Colorado School of Mines and the Metal Mining Agency of Japan. Officials in 10 diverse countries—Cambodia, China, Indonesia, Lao PDR, Malaysia, Myanmar, Mongolia, Philippines, Thailand and Vietnam—responded to a detailed questionnaire covering applicable laws, agencies, protected areas, covered mineral activities, financial assurance, environmental impact assessment, public involvement, environmental standards, permit and reclamation requirements.
The survey confirms that Asian nations are part of the global trend towards national government regulatory structures that balance mineral development objectives with environmental considerations. The survey also shows developing regulatory systems (some embryonic, some more mature) utilizing a combination of mining and environmental acts, and often an 'insider' perspective of the national officials administering the laws. While that perspective is not without its biases (not least the rigor of enforcement), it may nevertheless be of use in company planning. The emerging regulatory picture contradicts the conventional notion that it is the 'lower' level of regulation in Asia that is attracting foreign direct investment in mining. 相似文献
The survey confirms that Asian nations are part of the global trend towards national government regulatory structures that balance mineral development objectives with environmental considerations. The survey also shows developing regulatory systems (some embryonic, some more mature) utilizing a combination of mining and environmental acts, and often an 'insider' perspective of the national officials administering the laws. While that perspective is not without its biases (not least the rigor of enforcement), it may nevertheless be of use in company planning. The emerging regulatory picture contradicts the conventional notion that it is the 'lower' level of regulation in Asia that is attracting foreign direct investment in mining. 相似文献
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Introduction: The U.S. experience with motorcycle helmets affords an important insight into the responses of adolescents to age-specific laws. Political contention has led to a number of U.S. state law changes back and forth between universal and age-specific laws. Because both kinds of law require adolescent motorcyclists to wear helmets, relatively few studies have focused on how the law type affects their behavior. Method: Differential behavior is tested by a systematic review of literature, leading to a meta-analysis, in relation to the experience of various states’ motorcycle helmet laws. An electronic search was conducted for before-and-after studies in U.S. states that include data on adolescent helmet usage – both with a universally applicable motorcycle helmet law, and with an age-restricted law (usually, under-21 or under-18) – from observational, injury or fatality records for a certain period (e.g., 12 months) pre and post the state law change. Results: The search yielded ten studies, including two that compared a set of age-specific law states with a set of universal law states over the same time period. Heterogeneity analysis of seven single-state studies with raw data revealed an acceptable fit for a random-effects model. Additional noncompliance with age-restricted laws was indicated by an attributable percentage among exposed of over 65% and odds ratio exceeding 4. Conclusions: About two-thirds of adolescent noncompliance with age-restricted motorcycle helmet usage laws disappears with universal applicability. Evidence from numerous international studies of youth reaction to helmet laws suggests that a large part of the greater compliance with universal laws is due to their conveying a more convincing message that helmets afford protection against injury. Practical Applications: The meta-analysis provides fresh, young-rider perspective on the continuing debate over motorcycle-helmet laws. Broader insight into adolescent psychology suggests considering alternatives to age-restricted laws more widely in safety and health policy. 相似文献