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611.
中国公众参与环境管理的研究   总被引:18,自引:0,他引:18  
回顾了中国公众参与环境管理的发展历程,分析了公众参与环境管理存在的问题。针对公众参与环境保护管理的有效性的影响因子,例如主观因素、传统背景、时效因素及执行技巧等进行一系列的探讨,并根据公众参与计划的设计构思、公众参与计划的关键两方面的讨论,提出增加公众参与环境保护管理有效性的一些建议。  相似文献   
612.
Honey bee foragers need to asses and make trade-offs between a number of potentially conflicting floral attributes. Here, we investigate multi-attribute decision making in the eastern honey bee, Apis cerana, when foraging on food sources that varied in warmth and sucrose concentration. We show that foragers prefer warm (30 °C) sucrose solution over cool (10 °C) sucrose solution and concentrated (30 % w/w) sucrose solution over dilute (15 % w/w) sucrose solution. When we offered the preferred sucrose concentration (30 % w/w) at the less-preferred temperature (10 °C), and the less-preferred sucrose concentration (15 % w/w) at the preferred temperature (30 °C), foragers prioritized warmth by choosing the warmer, but lower concentration solution. When the temperature difference was less extreme, bees preferred more concentrated cooler syrup (30 % ww at 15 °C over 15 % 30 °C). However, the addition of a decoy item to the choice set had a significant effect on the bees' preferences. Our results highlight the critical importance of considering context effects when measuring the foraging preferences of animals.  相似文献   
613.
对生长在不施农药转Bt基因抗虫水稻华恢1号(HH1)、非Bt稻明恢63(MH63)及施药的明恢63(MH63C)3种稻田生境中的中华圆田螺抗氧化系统物质(SOD、CAT、GSH-PX、GSH)及代谢酶(GST、ACP)差异进行了研究.结果表明:HH1稻田生境田螺肝脏和鳃SOD、CAT、GSH-PX活性均高于MH63稻田,其中SOD和CAT活性差异极显著(p<0.01);肝脏GSH含量和GST活性在HH1和MH63稻田生境中差异不显著;HH1稻田生境中田螺肝脏ACP活性显著高于MH63稻田生境组(p<0.01).对于MH63C和MH63组,MH63C稻田生境田螺肝脏中SOD、CAT和GST活性均显著提高,而鳃GSH-PX、GST活性和GSH含量在MH63C生境组表现为明显提高.由此可见,转Bt水稻生境可提高田螺抗氧化能力,对解毒酶系统活性没有明显影响,即对田螺未产生明显的毒副作用;而施用农药明显激活田螺抗氧化系统和解毒代谢酶活性.  相似文献   
614.
黑素皮质素受体-1(MC1R)在鱼体中对黑色素细胞的分化及迁移起主要的调控作用,而且在神经系统和免疫系统中表现出不同功能。本研究对黄颡鱼表皮黑色素细胞的培养条件进行探索,并在此基础上对MC1R基因进行克隆,为后续研究黄颡鱼黑色素异常的细胞及分子机理研究提供基础。结果表明,黄颡鱼表皮黑色素细胞在27 ℃培养条件下,72 h开始贴壁生长,培养基中添加20 %小牛血清培养效果比添加10%小牛血清好。MC1R基因克隆方面,黄颡鱼MC1R基因全长为936 bp,编码312个氨基酸,与剑尾鱼(Xiphophorus maculates)、孔雀鱼(Poecilia reticulata)、条斑星鲽(Verasper moseri)、海鲈(Dicentrarchus labrax)、大菱鲆(Psetta maxima)等5种鱼类MC1R基因的同源性分别为97%、96%、90%、90%、90%,系统分析结果显示,黄颡鱼MC1R基因在进化树上的位置与黄颡鱼的分类所处位置基本吻合。证明黄颡鱼表皮黑色素细胞原代培养的条件为:27℃,添加20% 小牛血清,所克隆基因为黄颡鱼MC1R基因。  相似文献   
615.
Combustion-generated hydrogen chloride (HCl) is considered to be a very hazardous acid gaseous pollutant. This paper presents a laboratory study on the dry adsorption of HCl. The experiments were conducted in a dual-layer granular bed filter, at gas temperatures of 500℃-700℃ and n(Ca)/n(Cl)molar ratios of 1.0-5.0 using the silver nitrate titration method by dry adsorbent powders Ca(OH)2. Mainly, the adsorption efficiency of HCI and utilization efficiency of Calcium were studied, by varying relevant factors including n(Ca)/n(Cl), tempera- ture, feeding method, water vapor and CO2. With a relatively higher HCl concentration of 1000ppm, the experimental results revealed that 600℃ may be the optimum temperature for HCl adsorption when optimum n (Ca)/n(Cl) was 2.5 in our tests. The results also demonstrated that the feeding at a constant pressure was more effective, and the HCl adsorption efficiency could rapidly reach over 90% with n(Ca)/n(Cl) = 2.5 at 600℃. Furthermore, the HCl adsorption efficiency was found to be slightly promoted by water vapor, while could be impeded by CO2, and the utilization efficiency of calcium could be up to 74.4% without CO2, while was only 36.8% with CO2 when n(Ca)/n(Cl) was 2.5 at 600℃.  相似文献   
616.
To provide information on reclamation of multi-heavy metal polluted soils with conception of phytostabilization, a field survey on the uptake and accumulation of potentially toxic elements such as antimony (Sb), arsenic (As), lead (Pb), cadmium (Cd), copper (Cu), and zinc (Zn) in colonized plant species around the world’s largest antimony mine area, China, was conducted. Samples including leaves and shoots (including roots and stems) of colonized plants as well as rhizospheric soils were collected from eight sampling zones in the studied area. The results showed that the contents of Cu, Zn, and Pb in rhizospheric soils below plants were comparable to the corresponding background values of Hunan province, otherwise Sb, Cd, and As contents were extremely high (17–106, 17–87, and 3–7 times of the corresponding background values). The highest concentration of Sb was found in Aster subulatus (410 mg kg?1); Cd, As, and Zn were in Herba bidentis bipinnatae (10.9, 264, and 265 mg kg?1, respectively); and Cu was in Artemisia lavandulaefolia (27.1 mg kg?1). It also exhibited that all the contents of As in leaves were several times of those in shoots of plants, Cd and other heavy metals showed in a similar pattern in several studied species, implying that the uptake route of these heavy metals via foliar might contribute to the accumulation. With high bioconcentration factors of heavy metals (more than 1, except for Zn), together with the growth abundance, Herba bidentis bipinnatae was considered as the most suitable colonized species for phytostabilization of the multi-heavy metal pollution in soils on this antimony mine area.  相似文献   
617.
This research aimed to screen Bacillus spp. to prevent the production of fly maggot on kitchen wastes from soil in the experimental bases of the South China Agricultural University. A nutrient-rich medium was used to isolate the Bacillus spp. with high temperature treatment. The seventeen Bacillus strains were obtained and assigned to three groups by using Insertion Sequence based PCR (IS-PCR) DNA fingerprinting patterns. The homology of the 16S rDNA gene was 100% between Group I and Bacillus methylotrophicus CBMB 205T, 99.61% between Group II and Bacillus aerophilus 28KT, and 99.87% between Group III and Bacillus cereus ATCC 14579T. The results of kitchen waste tests proved that the representative bacteria of Group I RF2 had the ability to prevent fly maggot production on kitchen wastes. Furthermore, the results of physiological and biochemical tests, carbon utilization tests, and antagonists against plant pathogen tests showed that the bacteria from Group I RF2 had the ability to decompose glucose into pyruvate and then decarboxylate pyruvate to diacetyl under alkaline conditions, convert ammonia to intracellular amino acids or other kinds of nitrogenous compounds, use many kinds of carbon source for self-growth, and be antagonistic against plant pathogenic rice sheath blight disease, banana fusarium wilt, and Fusarium oxysporum. Besides, the bacteria from RF2 could secret organic acids to dissolve insoluble phosphate [Ca3(PO4)2] for its own growth by decreasing the pH. Group I RF2 was a strong plant-promotion bacterium, and had good prospects of application for preventing fly maggot production on kitchen wastes. © 2018 Science Press. All rights reserved.  相似文献   
618.
Plastics are one of the most used materials in human activities, where consumer consumption and industrial production together has imposed vast rise in demand for this material in last century. While plastic is ideally derived from crude oil as a primary source from manufacturers’ perspective, varying crude oil prices are driving manufacturers economically to seek for alternative sources for plastics production. Waste plastic recovered from obsolete consumer products thus becomes an economic substitution for virgin plastics, which is further intensified with the possibility of international waste plastic trading. This study focuses on waste plastic trade between the US and mainland China by performing a correlation analysis of trade data. It is suggested in this study that although waste plastics are traded from the US to mainland China in general, as many of us believes, the route is gradually shifting in the past years. With tightening Chinese customs regulations, waste plastic from the US now tends to take a transit in a third destination (Hong Kong SAR for instance) for preliminary treatment to bypass Chinese customs inspection. Such phenomenon is worth noting, as a complication in waste plastic trading route hinders waste plastic transboundary movement monitoring. Furthermore, it will have adverse consequent consumer, industrial, and environmental impacts. It is thus necessary for national competent authorities to strengthen cooperative study and communication capacity in the future as a response to the changing waste plastic trade pattern.  相似文献   
619.
Nitrous oxide (N2O), a potent greenhouse gas, is emitted during nitrogen removal in wastewater treatment, significantly contributing to greenhouse effect. Nitrogen removal generally involves nitrification and denitrification catalyzed by specific enzymes. N2O production and consumption vary considerably in response to specific enzyme-catalyzed nitrogen imbalances, but the mechanisms are not yet completely understood. Studying the regulation of related enzymes’ activity is essential to minimize N2O emissions during wastewater treatment. This paper aims to review the poorly understood related enzymes that most commonly involved in producing and consuming N2O in terms of their nature, structure and catalytic mechanisms. The pathways of N2O emission during wastewater treatment are briefly introduced. The key environmental factors influencing N2O emission through regulatory enzymes are summarized and the enzyme-based mechanisms are revealed. Several enzymebased techniques for mitigating N2O emissions directly or indirectly are proposed. Finally, areas for further research on N2O release during wastewater treatment are discussed.
  相似文献   
620.
针对某26层设置了防屈曲支撑的钢管混凝土组合框架的benchmark模型,以振型分解反应谱法作为基础算法,编制了基于遗传算法的优化程序,通过改变结构各层的抗侧刚度比,对设置防屈曲支撑的钢管混凝土组合框架结构进行了防屈曲支撑截面面积的优化设计,对以变化抗侧刚度比设计的结构和以固定抗侧刚度比设计的结构进行了弹性阶段和弹塑性阶段的地震响应对比分析。结果表明:以变化抗侧刚度比设计的结构能在不减弱抗震性能的同时,减少48%的防屈曲支撑用量。在罕遇地震作用下,以变化抗侧刚度比设计的防屈曲支撑的耗能比例达54.98%,充分发挥防屈曲支撑的塑性变形能力消耗地震能量,起到保护框架梁、柱的作用。  相似文献   
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