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921.
ICCLP: An Inexact Chance-Constrained Linear Programming Model for Land-Use Management of Lake Areas in Urban Fringes 总被引:3,自引:1,他引:2
Lake areas in urban fringes are under increasing urbanization pressure. Consequently, the conflict between rapid urban development
and the maintenance of water bodies in such areas urgently needs to be addressed. An inexact chance-constrained linear programming
(ICCLP) model for optimal land-use management of lake areas in urban fringes was developed. The ICCLP model was based on land-use
suitability assessment and land evaluation. The maximum net economic benefit (NEB) was selected as the objective of land-use
allocation. The total environmental capacity (TEC) of water systems and the public financial investment (PFI) at different
probability levels were considered key constraints. Other constraints included in the model were land-use suitability, governmental
requirements on the ratios of various land-use types, and technical constraints. A case study implementing the system was
performed for the lake area of Hanyang at the urban fringe of Wuhan, central China, based on our previous study on land-use
suitability assessment. The Hanyang lake area is under significant urbanization pressure. A 15-year optimal model for land-use
allocation is proposed during 2006 to 2020 to better protect the water system and to gain the maximum benefits of development.
Sixteen constraints were set for the optimal model. The model results indicated that NEB was between $1.48 × 109 and $8.76 × 109 or between $3.98 × 109 and $16.7 × 109, depending on the different urban-expansion patterns and land demands. The changes in total developed area and the land-use
structure were analyzed under different probabilities (q
i
) of TEC. Changes in q
i
resulted in different urban expansion patterns and demands on land, which were the direct result of the constraints imposed
by TEC and PFI. The ICCLP model might help local authorities better understand and address complex land-use systems and develop
optimal land-use management strategies that better balance urban expansion and grassland conservation. 相似文献
922.
Xi Lu Yingying He Hongyu Mao Jacek Makini Jakub Drewnowski Bing Wu Jun Xu Li Xie 《环境科学学报(英文版)》2023,35(2):146-155
In this study,the effects of soluble readily biodegradable COD (sCOD) and particulate slowly biodegradable COD (pCOD) on anammox process were investigated.The results of the longterm experiment indicated that a low sCOD/N ratio of 0.5 could accelerate the anammox and denitrification activity,to reach as high as 84.9%±2.8% TN removal efficiency.Partial denitrification-anammox (PDN/anammox) and denitrification were proposed as the major pathways for nitrogen removal,accounting for 91.3% and 8.7% o... 相似文献
923.
Yang Jie Mao Hanying 《中国人口.资源与环境(英文版)》2006,4(3):3-10
Urban Agglomeration is an inevitable outcome of urbanization and industrialization, and a main form of urban development. Based on the analysis of urbanization and urban system situation, this paper will discuss the integration of urban agglomeration development, using the urban area of Cheng (Chengdu)-Yu (Chongqing) Urban agglomeration (CYUA) as a case study. By means of industries, population and spatial integrations, the function, strength and competition of CYUA will be improved and this urban agglomeration will transit from a budding state to a growing and mature one in future. The sustainable development of CYUA will depend on countermeasures, such as accelerating industrialization and urbanization, building a traffic network and express roads, strengthening the ability of self-sufficiency, enlarging the ecological construction and environmental protection, and establishing the synergetic institution of cross districts. 相似文献
924.
为了减少工业排放氮氧化物(NOx)对大气造成的污染,需要去除难溶性的NO。活性氧簇(ROS)可以将NO氧化为水溶性NO_2,超重力机可以强化气液传质效果。结合二者的优势,文章提出了一种在超重力环境下利用ROS氧化去除NO的方法。研究了吸收液pH值、转速、温度、气液比、气体浓度、吸收液循环对NO脱除率的影响,并对吸收产物进行了测定。结果表明,在20℃,H_2O_2浓度为1 mol/L,H_2O_2溶液pH为13,超重力机转速为1 200 r/min时,NO的脱除效率最好。当NO体积浓度为500×10~(-6),气液比为100时,NO的脱除效率可达96%。NO最终变为NO_3~-存在于液相中,且该吸收液可以用于同步脱硫脱硝。 相似文献
925.
贵州是华南最重要的煤电和粉煤灰生产省份,粉煤灰的放射性安全评估是综合利用的基础。对贵州不同产煤区域典型电厂粉煤灰进行了放射性核素比活度测定并根据国标GB6566-2001进行了安全性评估,结果表明:西部纳雍电厂粉煤灰内照射指数IRa和外照射指数Iγ均较低,使用范围不受限制;中部大方、金沙电厂和东部黔东电厂粉煤灰I_(Ra)较低而I_γ接近限值,可以作为建筑主体材料(其中大方一级灰仅限于空心率大于25%的主体材料)和A类装修材料;北部桐梓和二郎电厂粉煤灰I_(Ra)和I_γ均超出限值,分别可作为B类和C类装修材料,作为建筑主体材料应严格控制掺量比例。综合本次研究和前人数据,确证了粉煤灰中U、Th含量和相关放射性核素比活度具有良好相关性,推导了利用粉煤灰U、Th含量(C_U,C_(Th),×10~(-6))进行快速评估的经验公式:I_(Ra)=0. 0616×C_U+0. 0049;I_γ=0. 0341×C_U+0. 0159×C_(Th)+0. 0517。 相似文献
926.
Tianpeng Hu Yao Mao Weijie Liu Cheng Cheng Mingming Shi Zhanle Chen Qian Tian Jiaquan Zhang Shihua Qi Xinli Xing 《环境科学学报(英文版)》2020,32(11):1-10
Variations of levels, possible source and air mass transmission were investigated for 16 USEPA priority-controlled PAHs in PM2.5 during 2018 Chinese Spring Festival (CSF) in Xiangyang City, central China which is the North-South pollutant airmass transport channel of China. Totally 37 samples were collected. Mass concentrations of Σ16PAHs for the Pre–CSF day (Pre–CSFD), during the CSF day (CSFD) and after the CSF day (Af–CSFD) are 33.78 ± 17.68 ng/m3, 22.98 ± 6.49 ng/m3, and 8.99 ± 4.44 ng/m3, respectively. High resolution samples showed that Σ16PAHs are higher in the morning (06:00–11:00) or afternoon (11:30–16:30), than those in the evening (17:00–22:00) and at night (22:30–05:30), whereas the result is reversed during the CSFD. Fireworks burning can obviously increase the mass concentration of PAHs. Air mass trajectory indicated that Xiangyang is a sink area of pollutants for northwest and southeast, and the sources of the northeast and southwest. The air mass only can be transmitted out through northeast and southwest. It is effective for improvement of air quality in Wuhan and Hunan to control fireworks emission in Henan and local areas. Fireworks burning was an important source for PAHs during CSFD, biomass, coal combustion, and traffic emission were the main sources of PAHs for Pre–CSFD and Af–CSFD periods. The health risk on the CSFD was higher than the acceptable levels, especially during the intensive fireworks burning, the risk value far exceed 1.0 × 10?4, controlling burning fireworks is required. 相似文献
927.
928.
国际推行清洁生产的发展趋势 总被引:13,自引:1,他引:12
本文是本系列的第二部分,在对世界范围及中国推行清洁生产局势进行判断的基础上,归纳了国际推行清洁生产的成功做法和发展趋势,指出我国今后5-10年内的工作重点并提出政策建议。 相似文献
929.
毛竹枯梢病病原菌毒素的生物测定及成分研究 总被引:3,自引:0,他引:3
毛竹枯梢病病原菌培养液的不同浓度粗提液对高粱胚根抑制率明显大于对胚芽抑制率,胚根对毒素的敏感性大于胚芽对毒素的敏感性;在121℃加热15分钟,胰蛋白酶处理2hr后,培养滤液对胚根和胚芽的抑制作用与对照比较无差异;培养滤液及粗提液经过透析后,毒性显著降低,并且透析后的培养滤液对胚根已无抑制作用;通过α-萘酚反应、班乃德反应和茚三酮反应等化学测定和薄层层析进一步分析表明毒素为一种分子量较小、且含有葡萄糖和果糖或两者其一的还原性多糖。 相似文献
930.