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991.
江苏省县域“三生”功能时空变化及协同/权衡关系   总被引:2,自引:0,他引:2  
李欣  方斌  殷如梦  荣慧芳 《自然资源学报》2019,34(11):2363-2377
揭示江苏省县域“三生”功能的时空关联特征及协同/权衡关系,可为县域空间规划布局提供理论支持。从生产—生活—生态三个维度构建国土空间三生功能识别体系,以空间自相关和相关系数法定量测算江苏省55个县域1996年、2005年、2015年三个时期的“三生”功能时间效应及协同/权衡关系。结果表明:(1)江苏省“三生”功能生态位宽度变化各异,空间分布各具特色,具体表现为:1996-2015年生产功能生态位宽度时序上总体呈增长状态,变化过程具阶段性;空间上呈“南高北低”格局特征,长江南岸条带状集中分布,长江北岸则呈多集聚斑块状。1996-2015年生活功能生态位宽度不断压缩,空间上具以市辖区为中心向外同心圆衰减规律。1996-2015年生态功能生态位宽度不断增大,空间上生态功能生态位宽度具依山傍水呈高值特征。(2)江苏省1996-2015年间,生产功能、生活功能、生态功能均有随时间变化正相关类型(高高、低低)集聚明显,“组团”式分布;负相关类型(高低、低高)集聚性低,“离散”状分布规律。 (3)生产与生活功能存在空间协同关系,生产与生态功能呈协同/权衡波动变化态势,生活功能与生态功能变化趋势类似于生产与生态功能,交叉变化更明显,不同年份协同/权衡关系在不同单元有明显差异。研究表明,以上特征均与区域经济社会发展有较强的吻合性,未来应逐步改变以生产功能过速扩张压缩生活、生态功能的现象,应以保护生态环境、提升生活质量实现“三生”更加协同。  相似文献   
992.
对洛阳LYC轴承有限公司清洁生产环节中废水再生工艺的技改资金投配决策方案进行比选分析,构建灰色局势决策,进行目标量化与效果值白化,效果测度计算,得到决策结果。通过分析认为,灰色局势决策能够针对实际决策问题,为不同目标提供较为方便和科学的决策依据和决策结果。  相似文献   
993.
Triazophos and chlorpyrifos are organophosphorus pesticides (OPs), and their primary hydrolytic metabolites are 1-phenyl-3-hydroxy-1,2,4-triazole (BZC) and 3,5,6-trichloro-2-pyridinol (TCP). In this study, the adsorption and degradation of triazophos, chlorpyrifos, BZC and TCP were investigated in paddy soil from Chaohu Lake, China. Adsorption tests demonstrated that the adsorption of these compounds to soils could be described by the Freundlich equation. Moreover, chlorpyrifos displayed the highest affinity for adsorption, followed by triazophos, BZC and TCP. Degradation of these compounds in non-sterile soil followed first-order exponential decay kinetics, and the half-life (t(1/2)) of these contaminants ranged from 8.40 to 44.34 d. Sterilization of soil decreased the degradation rate, indicating that microorganisms played a significant role in the degradation of these compounds. The values of t(1/2) and K(oc) were fitted to obtain models that could predict the leaching potential of the contaminants from soil. Compared to their parent compounds, BZC and TCP showed high potential for leaching into groundwater. The inoculation of OPs-degrading bacterium (Diaphorobacter sp. GS-1) removed 95.38%, 100% and 100% of triazophos, chlorpyrifos and BZC in paddy soil after 21 d, respectively. The pollution risk of triazophos, chlorpyrifos and BZC could be greatly decreased by inoculating soil with Diaphorobacter sp. GS-1, which decreases the t(1/2) of the contaminants.  相似文献   
994.
人工湿地植物净化生活污水研究现状与展望   总被引:1,自引:0,他引:1  
随着经济的发展,人民生活水平提高,农村生活污水造成的环境污染不断加剧.成为影响水环境质量的重要因素.植物在人工湿地中具有非常重要的作用,是人工湿地生态系统中重要的组成部分.在检索相关文献的基础上,从人工湿地植物类型、常用植物、植物选择、去污机理、去污作用的影响因素等方面,对生活污水的人工湿地净化作了简要综述,并从6个方...  相似文献   
995.
赵军  石凯  姚斌 《火灾科学》2011,20(4):206-215
大型建材家居类商场存在建筑面积大,人员密度小,所需疏散宽度小等特点,这类商场往往存在两方面问题:①为满足2层以上楼层对疏散距离的需要,致使首层部分楼梯的疏散出口不能直通室外以及疏散距离过长;②为满足疏散出口直通室外,楼梯沿建筑外墙布置,致使某些楼层的一些区域的疏散距离过长。对比了国家规范和地方规范对人员密度规定的差异,...  相似文献   
996.
介绍了国内外生物质能源技术的应用及生物质燃料的研发制备情况,分析了目前生物质燃料制备技术、资源化利用的现状以及存在的问题,针对符合中国国情的生物质(秸秆)成型燃料生产技术及市场需求进行了分析探讨。  相似文献   
997.
Particle-associated polycyclic aromatic hydrocarbon (PAH) concentrations were investigated at eight sampling sites during cold periods where heating is used (heating period) (February to March, 2005) and warm periods where heating is not required (non-heating periods) (August to September 2006) in the urban area of Anshan, an iron and steel city in northeastern China. Eleven PAH species were measured using GC-MS. The total average concentrations of PAHs ranged from 46.14 to 385.60 ng m(-3) in the heating period and from 5.28 to 146.40 ng m(-3) in the non-heating period. The lowest concentration of ∑PAHs was observed at Qianshan, a monitoring site far from the city and industrial area, and the highest concentration occurred in the site located at the factory area of Anshan Iron and Steel Incorporation. Moreover, ambient PAH profiles were studied and high molecular weight PAH (including 4-6 rings) species occurred in the high fractions. Toxic equivalent factors analysis gave the potential carcinogenic risks in Anshan. For the heating sampling period, BaP equivalent concentration is in the range of 41.98 to 220.83 ng m(-3), and 9.23 to 126.00 ng m(-3) for the non-heating sampling period. By diagnostic ratio analysis, traffic emission and combustion (coal or biomass) were potential sources for PAHs in Anshan. Finally, PCA results indicated the major sources were vehicle emission, steel industry emission, and coal combustion for both heating and non-heating seasons, which agreed with the results from the diagnostic ratio analysis.  相似文献   
998.
This paper analyses structural and personal exposure to Hurricane Katrina. Structural exposure is measured by flood height and building damage; personal exposure is measured by the locations of 911 calls made during the response. Using these variables, this paper characterises the geography of exposure and also demonstrates the utility of a robust analytical approach in understanding health‐related challenges to disadvantaged populations during recovery. Analysis is conducted using a contemporary statistical approach, a multiple additive regression tree (MART), which displays considerable improvement over traditional regression analysis. By using MART, the percentage of improvement in R‐squares over standard multiple linear regression ranges from about 62 to more than 100 per cent. The most revealing finding is the modelled verification that African Americans experienced disproportionate exposure in both structural and personal contexts. Given the impact of exposure to health outcomes, this finding has implications for understanding the long‐term health challenges facing this population.  相似文献   
999.
Contamination of wastewater by organic pollutants is a major worldwide issue. For instance plastic additives such as phthalates are found in wastewater. Efficient techniques are thus needed to clean wastewaters. The Fenton reaction involving H2O2 and Fe(II) salts can be used to treat polluted water. During the Fenton reaction pollutants are decomposed directly by hydroxyl radicals. In some cases toxic by-products are produced. Here dimethyl phthalate, diethyl phthalate, and dipropyl phthalate by-products formed during the Fenton reaction were studied. Fenton degradation of selected phthalates yielded numerous transformation products such as hydroxylated phthalates. The hydroxylation reaction occurred at the aromatic ring of phthalates and yielded mono- and dihydroxylated phthalates. For monohydroxylated phthalate, 3-hydroxy- and 4-hydroxydialkylphthalates are the main transformation products. In addition to hydroxylated derivatives, aliphatic chain degraded mono- and dihydroxylated phthalates were also detected.  相似文献   
1000.
磺胺类兽药对土壤酶活性的影响   总被引:2,自引:0,他引:2  
采用室内培养的方法,研究磺胺类兽药(磺胺二甲基嘧啶、磺胺甲唑)污染对土壤蔗糖酶、硝酸还原酶、过氧化氢酶、磷酸酶、脲酶和多酚氧化酶活性的影响。结果表明,磺胺类兽药可显著抑制土壤蔗糖酶的活性,其抑制率可达50%以上。兽药对土壤硝酸还原酶活性的影响表现为先抑制后激活的趋势,最大抑制率和激活率可达98.6%、580%。兽药对土壤过氧化氢酶活性的影响主要以激活作用为主,对土壤磷酸酶活性的影响则呈现"激活-抑制"的循环趋势。兽药对土壤脲酶活性的影响表现为,培养前期低浓度时激活,高浓度时抑制;培养后期低、高浓度时均抑制。兽药对土壤多酚氧化酶活性的影响表现为,培养前期激活,培养后期抑制。  相似文献   
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