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11.
中国科协本着择优支持的原则,自1997年决定对中国科协所属全国性学会、协会、研究会主办的优秀基础性和高科技学术期刊给予专项经费资助,重点资助那些能够代表我国基础研究学术水平、与国民经济发展战略密切相关、在国内外有较大影响的基础性和高科技的学术期刊.《中国环境科学》继获中国科协1997年度择优支持专项资助经费后,1998年再度成为中国科协择优支持的基础性和高科技学术期刊之一.1997—1998年,《中国环境科学》编辑部利用此项经费提高了期刊纸张规格,并将版面增至100页.1999年,《中国环境科学…  相似文献   
12.
1 DEVELOPMENT OF SCIENCE PARKSThe concept of science park originated in the US. Manyterms are used to describe science parks, such as researchpark, technology park, science centre, research centre,innovation centre, and with various combination of these(MacDonald, 1987). The first science park in the worldis Stanford Industrial Park established in 1951. In 1955,only seven companies were located in the park. By 1980there were ninety companies including Hewlett PackardCompany, whic…  相似文献   
13.
稀土元素的测定,特别是镧系元素,在各种工业中是很重要的。例如,在核动力工业中,对处置放射燃料的镧系分裂产物的测定就是称为燃耗(burnup)参数的衡量尺度。在矿业中各种岩石样中的痕量镧系元素的测量有助于勘探者寻找镧系矿藏。 同样,地质样中痕量镧系元素的浓度可为判断一些地质形成过程提供线索。岩石中镧系元素的浓度一般都不随时间而变。因此分析镧系物对探索地质成因及其运动可提供一个“指痕”(fingerprint),因为没有任何两个取自不同地点的样品是具有相同断  相似文献   
14.
<正> 引言自 H.Ramberg(1963)在实验室开始他的著名的模拟底辟构造研究,并将这些模拟研究应用于解释造山带主要构造的成因以来,至今将近二十年了。在此期间,构造地质学思想发生了一场革命,即基于地球板块构造运动的水平构造的思想比与底辟有关的垂直构造的思想来说占优势地位。因此考虑,应及时地回顾一下底辟作用在区域变形中的相对作用,于是构造研究组(隶属伦敦地质学会)于1980年3月25-  相似文献   
15.
INTRODUCTIONIn recent thirty years, due to the decreasing fertility andincreasing life expectancy, China's population is aging ata very rapid pace and the elderly population size is keepingon growing. During the dramatic aging progress, the oldestold group in China is catching our eyes. More and moreold people of China are becoming the oldest old. Theextremely old population (aged 80 and above) is increasingat 5.1% annually, while the old population above 65 isincreasing at 2.9%, and the…  相似文献   
16.
As a special basic economic region in China, Xinjiang is situated in the arid area in the Northwest China. Oasis agriculture is the basis of the national economy. The development of oasis agriculture helps to accelerate the development of economy, social and environment. After 50 years of practice, from 1949 to 2002, oasis agriculture in Xinjiang enhanced rapidly the scale of agricultural industry and had great changes in its structure. The amount of cultivated area rose from 120.97*102 ha t…  相似文献   
17.
<正> 1 地震危险性评定历史地震危险性评定在塞浦路斯虽处于初始阶段,但并未忽视其重要性。地震危险性评定对结构(如构筑物和大坝)的设计安全性参数确定所起的关键作用已有充分认识。到目前为止,已进行了两个场地的地震危险性评定。第一项是确定一大坝坝址预期最大可能地面加速度(Neophyton,1981),第二项估计尼科西亚老城墙以内地区不同烈度地震过程中人员及财产可能损失(Constantinon,1990),研究结果公布于地质调查局的内部报告上。对市区及近郊的岩土工程编图方面,也做了大量工作。测定了Larnaca镇沿海地区的潜在疑难层,如冲积层和高有机含量沉积层(Michaelides,1988)。在塞浦路斯,尽管全国地震危险性图有震中分布图(公元前180~公元1972年)、具有预期最大地面加速度值的观测烈度带图(公元前180~公元1980)和最大能量释放带图(1901~1972),但至今尚未进行综合地震危险性评定研究。  相似文献   
18.
Chemical oxidation was applied to an artificially contaminated soil with naphthalene (NAP). Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. Evaluation of NAP distribution and mass reduction in soil, water and air phases was carried out through mass balance. The importance of the air phase analysis was emphasized by demonstrating how NAP behaves in a sealed system over a 4 hr reaction period. Design of Experiments method was applied to the following variables: sodium persulfate concentration [SP], ferrous sulfate concentration [FeSO4], and pH. The system operated with a prefixed solid to liquid ratio of 1:2. The following conditions resulted in optimum NAP removal [SP] = 18.37 g/L, [FeSO4] = 4.25 g/L and pH = 3.00. At the end of the 4 hr reaction, 62% of NAP was degraded. In the soil phase, the chemical oxidation reduced the NAP concentration thus achieving levels which comply with Brazilian and USA environmental legislations. Besides the NAP partitioning view, the monitoring of each phase allowed the variabilities assessment over the process, refining the knowledge of mass reduction. Based on NAP distribution in the system, this study demonstrates the importance of evaluating the presence of semi-volatile and volatile organic compounds in the air phase during remediation, so that there is greater control of the system as to the distribution and presence of the contaminant in the environment. The results highlight the importance of treating the contaminant in all its phases at the contaminated site.  相似文献   
19.
Air pollution causes deleterious effects on human health with aerosols being among the most polluting agents.The objective of this work is the characterization of the PM_(2.5) and PM_(10) aerosol mass in the atmosphere.The methods of analysis include WD-XRF and EDS.Data were correlated with meteorological information and air mass trajectories(model HYSPLIT)by multivariate analysis.A morphological structural analysis was also carried out to identify the probable sources of atmospheric aerosols in the city of Sao Jose do Rio Preto,Brazil.The mean mass concentration values obtained were 24.54 μg/m~3 for PM_(10),above the WHO annual standard value of 20 μg/m~3 and 10.88 μg/m~3 for PM_(2.5) whose WHO recommended limit is10 μg/m~3.WD-XRF analysis of the samples revealed Si and Al as major components of the coarse fraction.In the fine fraction,the major elements were Al and S.The SEM-FEG characterization allowed identifying the morphology of the particles in agglomerates,ellipsoids and filaments in the PM_(10),besides spherical in the PM_(2.5).The analysis by EDS corroborated WD-XRF results,identifying the crustal elements,aluminosilicates and elements of anthropogenic origin in the coarse fraction.For the fine fraction crustal elements were also identified;aluminosilicates,black carbon and spherical particles(C and O) originating from combustion processes were predominant.The use of multivariate analysis to correlate air mass trajectories with the results of the morpho-structural characterization of the particulate matter allowed confirmation of the complex composition of the particles resulting from the combination of both local and long-distance sources.  相似文献   
20.
Understanding the degradation behavior of azo dyes in photocatalytic wastewater treatment is of fundamental and practical importance for their application in textile-processing and other coloration industries. In this study, quantum chemistry, as density functional theory, was used to elucidate different degradation pathways of azo pyridone dyes in a hydroxyl radical (HO?)-initiated photocatalytic system. A series of substituted azo pyridone dyes were synthesized by changing the substituent group in the para position of the benzene moiety, ranging from strong electron-donating to strong electron-withdrawing groups. The effect of dye molecular structure on the photocatalytic degradation reaction mechanism was analyzed and quantification of substituent effects on the thermodynamic and kinetics parameters was performed. Potential energy surface analysis revealed the most susceptible reaction site for the HO? attack. The calculated reaction barriers are found to be strongly affected by the nature of substituent group with a good correlation using Hammett σp constants and experimentally determined reaction rates. The stability of pre-reaction complexes and transition state complexes were analyzed applying the distortion-interaction model. The increased stability of the transition state complexes with the distancing from the substituent group has been established.  相似文献   
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