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341.
Miguel Ángel Tobarra-González 《Journal of Environmental Planning and Management》2015,58(8):1479-1489
In this paper, it is proposed one method to recode protest responses applicable to the simple dichotomous format valuation question made to visitors to natural environment in contingent valuation studies. Those respondents that give a protest response but have a travel cost greater than the bid proposed in the valuation question are recoded as an affirmative answer to the proposed payment. The economic justification lies in the minimum willingness to pay for enjoying the environment that travel cost reveals, while valuation question tries to obtain information about respondent maximum willingness to pay. Recoding allows to recover information and to improve estimates, accuracy. It also avoids computational complexity associated with sample selection models used to avoid biases derived from excluding protest responses. 相似文献
342.
Zn/Cr型阴离子黏土的制备、表征及其对活性艳橙X-GN的去除性能研究 总被引:1,自引:0,他引:1
采用共沉淀法制备了Zn/Cr摩尔比为1∶1~5∶1的Zn/Cr型阴离子黏土(Zn/Cr-LDHs),选取2∶1 Zn/Cr-LDHs分别在300、400、500℃条件下放入马弗炉中煅烧2 h,制备了煅烧阴离子黏土(Zn/Cr-LDO).采用X射线衍射光谱(XRD)、傅里叶红外光谱(FTIR)、原子吸收法(ASS)、比表面积测试法(BET)对上述制备的材料结构形态进行表征.研究2∶1 Zn/Cr-LDHs和Zn/Cr-LDO在紫外和避光条件下对活性艳橙X-GN的去除.实验表明,2∶1 Zn/Cr-LDHs的吸附效果不受紫外光照射的影响,煅烧后形成的Zn/Cr-LDO在紫外光的照射下,对活性艳橙X-GN的去除率是避光条件下的2倍,说明煅烧后的Zn/Cr阴离子黏土具有光催化性能,Zn/Cr-LDO对活性艳橙X-GN的去除是吸附和光催化的共同作用. 相似文献
343.
随着城市化的推进,城市的脆弱性不断加剧。近年来频发的生产安全事故,凸显了传统风险治理范式的局限性。源头防控、多元参与、数据驱动是当下生产安全风险治理的重要议题,而多元主体风险和系统性风险是治理的焦点。以整体性思维为指引,建构“三生”空间相互作用下的“双环模型”,为安全多维及时空多维视角下生产安全风险的治理提供理论基础和总体思路。挖掘信息技术对国土空间动态监测、风险认知积累和风险防控能力成长的积极作用,提出“扁平化”的风险监测评估框架体系并探讨信息平台的需求与架构。以风险交织的化工行业为例,重点关注工业园区主导下的生产安全风险多元防控范式和基础框架,为不同行业的多类型风险防控提供思路借鉴。 相似文献
344.
针对二维水权分配公平性评估的特点,对邓氏灰色关联度进行了拓展,提出了双因素灰色关联度概念,构建了系统比较序列为双因素序列组的灰色关联分析方法.将水量权和排污权的分配比例向量组作为双因素系统比较序列组,将水权理想公平分配比例向量作为系统主行为序列,基于两者之间的双因素灰色关联度,评估二维水权分配方案的公平性.双因素灰色关联分析方法可实现对水量权和排污权分配公平性的有机统一评估.以北江流域为例进行了分析. 相似文献
345.
346.
Shaohong Wu Jikun Huang Yanhua Liu Jiangbo Gao Jun Yang Wentao Wang 《中国人口.资源与环境(英文版)》2013,11(2):95-102
Climate change strongly affected the structure and functions of natural ecosystems, e.g. the vegetation productivity decreased in the Northeast permafrost region due to the higher temperature and less precipitation, whereas in the Tibetan Plateau, the vegetation productivity increased, owing to the improved thermal resource. Climate change led to reduced precipitation in North and Northeast China and thus the reduced surface runoff. The public needs for energy were changed because of climate change, e.g. the shorter heating period in winter. Climate change profoundly influenced human health, pathophoresis and major projects by increasing extreme events, including frequency and magnitude, and causing more serious water shortage. Under the background of climate change, although the improved thermal resources can be helpful for extending the crop growth period, more extreme events may resulted in more instability in agricultural productivity. Not only did climate change indirectly affect the secondary and tertiary industries through the impacts on agriculture and natural resources, but also climate change mitigation measures, such as carbon tax, tariff and trading, had extensive and profound influences on the socioeconomic system. Further analysis indicated that the impact of climate change presented significant regional differences. The impact had its pros and cons, while the advantages outweighed the disadvantages. Based on the above analysis on the impacts of climate change, we put forward suggestions on coping with climate change. First, scientifically dealing with climate change will need to seek advantages while avoiding the disadvantages of climate change in order to achieve the orderly adaptation to climate change, which is characterized with “Overall best, long-term benefit.” Second, quantitative adaptation should be given more attention, e.g. proposing operational schemes and predictable goals and using uncertainty analysis on adaptation measures. Third, more active coping strategy should be adopted to enhance China’s future comprehensive competitiveness. The strategies include but are not limited to gradually adjusting the industrial structure, intensifying the research and development (R&D) of emission reduction technology and actively responding to the influence of carbon tax, tariff and trading on socioeconomic development in China. 相似文献
347.
高炉出铁场采用两电场除尘器在国内还没有应用实例,从理论和测试结果两方面阐述高炉出铁场采用两电场除尘器的可行性。 相似文献
348.
Louise Chuang Pao-Lin Kuo Hsiao-Bai Yang Chung-Ho Chien Pei-Yi Chen Chiung-Hsin Chang Fong-Ming Chang 《黑龙江环境通报》2003,23(2):134-137
The presence of two independent translocations in one person is rare. Herein, we report the prenatal diagnosis of two sibling fetuses with holoprosencephaly, whose father is a carrier of double translocations. The karyotype of the father is 46,XY, t(1;7) (q32;q32), t(14,15) (q32.1;q26.3). The two fetuses had variable facial dysmorphisms and identical cytogenetic abnormality—a derivative (7) t(1;7) (q32;q32) inherited from the father. The proband 1 showed a small mouth, a single median eye and a proboscis above the eye, while the proband 2 showed hypotelorism, a flat nose, cleft lip and cleft palate. Both fetuses also had alobar holoprosencephaly. Haploinsufficiency of the sonic hedgehog gene at 7q36 does account for the occurrence of holoprosencephaly in the two fetuses with a deletion of distal 7q (7q32 → qter). Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
349.
316L与X65在模拟流动地层水中电偶腐蚀行为 总被引:1,自引:1,他引:0
目的研究316L与X65在模拟流动地层水中电偶腐蚀行为,方法进行复合管材料X65和316L耦合在模拟流动地层水饱和CO2环境中的浸泡实验,通过电化学工作站测量电偶电流、电偶电位、开路电位及试样在不同温度和流速下极化曲线和交流阻抗图谱,另外通过电子扫描显微镜观察腐蚀形貌,对复合管电偶腐蚀行为进行分析。结果在模拟流速为0,0.2 m/s地层水中,X65耦合后的腐蚀速率分别为0.883,1.169 mm/a。结论 X65阳极反应极化程度较小,316L的阴极反应过程是整体反应速度的控制步骤。X65表面不仅发生阳极溶解,还伴随阴极反应。 相似文献
350.
地铁与燃气管道等高危管道均为线性工程,地铁隧道下穿管道的情况不可避免,一旦因地铁施工导致管道泄漏,后果难以承受,管道沉降值是考量其安全性的关键指标。为对双线盾构地铁隧道下穿管线安全性进行预测,采用修正的Peck公式理论方法进行计算,并与数值模拟结果相对比,研究结果表明:双线盾构地铁隧道下穿管道安全风险可控,修正Peck公式及数值模拟法均能较真实地描绘地表以下任意土层的沉降槽曲线,进而可以比较准确地计算土体竖向沉降,可作为一种用于计算隧道开挖所引起管道竖向位移的方法。 相似文献