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961.
土地资源系列研究方法的探讨——以新疆呼图壁县绿洲为例 总被引:4,自引:1,他引:4
新疆呼图壁县位于天山中段北麓,准噶尔盆地南缘,总面积9394km2,绿洲面积1131km2,占全县总面积的12%。 相似文献
962.
湘江水体中重金属的化学形态及分布特征的研究 总被引:14,自引:0,他引:14
水体中重金属的生态效应和迁移转化规律与其化学形态密切相关。本文结合湘江重金属水容量与背景值的研究,较系统地研究了铜、铅、镉和锌的化学形态及其在全江段水中的分布特征。应用阳极溶出伏安法,得到湘江水中重金属总量、溶解态含量和悬浮态含量的分配与分布特征,还有溶解态所包含的金属的主要存在形态及与之共存的其它多种形态(包括悬浮态)共十种,该文对其形成、分配和相互转化进行了综合分析。 相似文献
963.
Functional zones in cities constitute the most conspicuous components of newly developed urban areas,and have been a hot spot for domestic and foreign investors in China,which not only show the expanse of urban space accompanied by the shifts both in landscape(from rural to urban)and land use(from less extensive to extensive),but also display the transformation of regional ecological functions.By using the theories and methods of landscape ecology,the structure of landscapes and landscape ecological planning can be analyzed and evaluated for studying the urban functional zones‘layout.In 1990,the Central Govermment of China declared to develop and open up Pudong New Area so as to promote economic development in Shanghai.Benefited from the advantages of Shanghai‘s location and economy,the government of Pudong New Area has successively built up 7 different functional zones over the past decade according to their functions and strategic goals.Based on the multi-spectral satellite imageries taken in 1990,1997and 2000,a landscape ecolgy analysis was carried out for Pudong New Area of Sanghai ,supported by GIS technology.Green space(including croplands )and built-up areas are the major factors considered in developing urban landscape.This paper was mainly concerned with the different spatial patterns and dynamics of green space,built-up areas and new buildings in different functional zones,as influenced by different spatial patterns and dynamics of green space,built-up areas and new buildings in different functional zones,as influenced by different functional layouts and development strategies.The rapid urbanization in Pudong New Area resulted in a more homogeneous landscape.Agricultural landscape and suburban landscape were gradually replaced by urban landscape as the degree of urbanization increased.As a consequence of urbanization in Pudong,not only built-up patches,but also newly-built patches and green patches merged into one large patch,which should be attributed to the construction policy of extensive green space as the urban development process in Pudong New Area.The shape of green area of 7 functional zones became more and more regular because of the horticultural needs in Shanghai urban planning.Some suggestions were finally made for the study of future urban planning and layout. 相似文献
964.
Mei Li Yao Zhang Chenglei Pei Jinwen Zhang Chunlei Cheng Xiufeng Lian Mubai Chen Bo Huang Zhong Fu Zhen Zhou 《环境科学学报(英文版)》2023,35(2):806-822
The real-time detection of the mixing states of polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs in ambient particles is of great significance for analyzing the source, aging process, and health effects of PAHs and nitro-PAHs; yet there is still few effective technology to achieve this type of detection. In this study, 11 types of PAH and nitro-PAH standard samples were analyzed using a high performance-single particle aerosol mass spectrometer (HP-SPAMS) in lab studies. The identification principles ‘parent ions’ and ‘mass-to-charge (m/z) = 77’ of each compound were obtained in this study. It was found that different laser energies did not affect the identification of the parent ions. The comparative experiments of ambient atmospheric particles, cooking and biomass burning emitted particles with and without the addition of PAHs were conducted and ruled out the interferences from primary and secondary organics on the identification of PAHs. Besides, the reliability of the characteristic ions extraction method was evaluated through the comparative study of similarity algorithm and deep learning algorithm. In addition, the real PAH-containing particles from vehicle exhaust emissions and ambient particles were also analyzed. This study improves the ability of single particle mass spectrometry technology to detect PAHs and nitro-PAHs, and HP-SPAMS was superior to SPAMS for detecting single particles containing PAHs and nitro-PAHs. This study provides support for subsequent ambient observations to identify the characteristic spectrum of single particles containing PAHs and nitro-PAHs. 相似文献
965.
合肥台CTS-1分析系统网络组建 总被引:1,自引:0,他引:1
本文阐述了利用UNIX和WIN98/2000互联的局域网技术,对CTS-1系统进行优化配置,组建CTS-1网络分析系统,实现CTS-1系统数据共享,提高地震分析的效率,确保数据备份。利用代理软件用一个MODEM让各个子机同时上网,同时充分利用台站现有的计算机设备,最大限度的实现地震监控、速报、分析以及地震研究的同时开展。 相似文献
966.
Chen WH 《Journal of the Air & Waste Management Association (1995)》2003,53(2):136-142
An experimental investigation on waste combustion characteristics of a mass burn incinerator is conducted in this study. Three different charging modes, including operator manipulation, periodic feeding, and temperature control, are taken into consideration. The results indicate that the burning characteristics in the combustion chambers are closely related to the operating modes. For the operator manipulation where the wastes are sent into the incinerator in two short periods, the entire temperature distribution of the primary combustion chamber can be partitioned into two parts, thereby yielding waste group combustion. Temperature oscillations in both the primary and secondary combustion chambers are characterized for the periodic feeding. However, because of the shorter charging period and smaller amount of waste, the burning interaction between the two chambers is initially weak and becomes notable in the final stage. When temperature control is performed, the burning oscillation of the primary combustion chamber is further amplified so the combustion interaction is drastic. These exhibitions are mainly caused by the competition between endothermic and exothermic reactions. The instantaneous heat exchange efficiency of the cyclone heat recovery system (CHRS) installed in the incineration system is also evaluated to obtain details of energy recovery behaviors. As a result, the efficiency tends to decrease linearly with increasing temperature of hot flue gas. This arises from the fact that heat loss from the gas to the environment is increased when the temperature of the former is higher, even though the temperature gradient across the cyclone is enlarged. 相似文献
967.
968.
利用驯化污泥研究了邻氟苯胺、对氟苯胺、2,4-二氟苯胺的好氧生物降解性能.结果表明,3种氟苯胺的好氧生物降解性能从高到低依次为对氟苯胺、邻氟苯胺和2,4-二氟苯胺.降解动力学分析表明,除2,4-二氟苯胺在实验质量浓度8.56 mg/L时为一级反应,其他为零级反应;且它们的降解规律都符合Monod方程;30 ℃、振荡速率140 r/min为氟苯胺的最佳降解条件.同时研究了共基质条件下葡萄糖和苯胺对2,4-二氟苯胺的好氧降解的影响,葡萄糖的引入有促进作用,而苯胺只在一定浓度范围内有促进作用.氟苯胺的生产废水与生活污水合并处理以及多种组分混合废水处理是可行的. 相似文献
969.
华北山区位于华北平原与陕甘黄土高原以及内蒙古高原之间,是我国经济欠发达地区之一。它又是我国华北平原、京津唐等大城市工农业和生活用水的主要源地,生态环境类型复杂多样,但由于人类活动频繁,自然植被破坏严重,生态系统结构紊乱,功能脆弱,自身恢复能力较弱。积极开展华北山区的环境综合整治与生态建设不仅对解决当地人民的生活和生存问题具有重要的意义,而且对于我国华北地区经济的发展也具有重要的战略意义。本文详细分析了华北山区的生态系统特点和存在的问题,并在此基础上提出在该区环境综合整治与生态建设的具体措施和途径。 相似文献
970.
A three-month incubation study was undertaken to examine the influence of N, P and K on the various forms (soluble plus exchangeable (SE), weakly specifically adsorbed (WSA), Fe-Mn oxides bound (OX), organic matter complexed (OM) and residual fractions (RES)) of lead (Pb) and cadmium (Cd) in a red soil. Application of urea at the rate of 200 mg N/kg significantly lowered the SE fraction, but raised the WSA or OX fraction of both metals. Supply of 80 mg P/kg caused a decrease in the SE fraction of the two metals. The WSA fraction of Pb was reduced, whereas that of Cd increased by adding P. However, addition of 100 mg K/kg led to an increase in the SE fraction, but a decrease in the WSA fraction of Pb and Cd. Applying chemical fertilizers had no significant consistent influences on the other fractions of metals. These findings suggest that in heavy metal contaminated red soil, applying fertilizers does not only provide plant nutrients, but may also change the speciations and thus biovailability of heavy metals. 相似文献