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751.
论述了环保科研要适应市场经济的需要,转变观念,走向市场,并由市场来引导科研的几点措施和途径。提出了要制定有关政策,为环保科研走向市场创造良好的内外部环境和必要条件,促使环保科研成果更快地转化为生产力,并产生效益,来增强环保科研本身的活力。 相似文献
752.
The study of effects of acid rain in Southwestern China on forest ecosystems .has been inrestigated since 1984. The results have shown that the ecosystem of Pinus massoniana forest has been damaged severely by acid rain. Comparing the areas where the annual mean pH value is lower than 4.5 with that higher than 4.5, the productivity of the ecosystems decreased 50 percent. Both the percentages of the green leaves and the content of chlorophyll cut down; the acidity of soil increased a bit and the fertility showed the tendency to lower. The microbial population components in surface soil were changed and the total number of soil microbes reduced from 63.5 to 92.6 percent. Besides the direct effects of acid rain, the insect pest, especially, Blastophagus piniperdoz and Monochamus galloprovincialis, seized the opportunity to enter and reproduce in it so as to aggravate the forest dieback of P.massoniana in the areas where the annual average pH value is lower than 4.5.Additionally, the simulation study on the 相似文献
753.
Liao Ruizhang Shen Qiuqin Jin Lizhi Shen Shuling Qian Houyin Guan ZhenshengInstitute of Soils Fertilizers Chinese Academy of Agricultural Sciences Beijing China 《环境科学学报(英文版)》1990,(3)
A physiological strain of microorganism - Azotobacter sp. has been adopted as an indicator to detect the toxicity of heavy metals in soils. The concentration of heavy metals to which Azotobacter sp. was behaving initially to have the resistance to heavy metals is defined as the critical poisoning concentration. The method of physiological threshold adopted can have a quantitative determination with reproducible results. The determined critical poisoning concentration is basically consistent with the results of heavy metals and arsenic toxicities to the bacteria reported recently in literatures. Total 9 typical soils, including 6 zonal soils and 3 purple soils, in the whole country were determined for the toxicities of 5 heavy metals and arsenic to Azotobacter sp. that resulted in 48 critical poisoning concentrations. 相似文献
754.
Wu Kunjun Gong Peiyu Li Xiuzhen Shu Jianmin Cao HongfaInstitute of Zookogy Academia Sinica Beijing ChinaInstitute of Zookogy Chinese Research Academy of Environmental Science Beijing China 《环境科学学报(英文版)》1990,(4)
Effects of SO2 pollution on growth of the army worm, Mythimna separata, were investigated by rearing the larvae for 12 days on the wheat plants being exposed to SO2 levels ranged from 50 to 200 ppb in the field open-top fumigation devices. Larval period shortened while their mean relative growth rate (MRGR) increased as SO2 dose elevated. Similar experiment with the insect on the artificial diet excluded the possibility that SO2 pollution directly stimulated growth of the army worm.The patterns of change in amino acid hydrolysates in the host foliage suggested that contents of methionine, and perhaps, arginine in food material exposed to unpolluted air were at such levels that they could only support sub-optimum growth of the insect, and SO2 pollution increased concentrations of these limiting amino acids, resulting in better performance of the larvae. 相似文献
755.
756.
Study on the proposed environmental guidelines for Cd, Hg, Pb and As in soil of China 总被引:4,自引:2,他引:4
This paper deals with the soil-environmental standard. According to the current situation of researching on the soil-environmental quality guideline at home and abroad, and on the basis of the foundations and principles of enacting the soil-environmental standard, the soil environment quality guideline values of Hg, Cd, Pb and As were suggested. 相似文献
757.
Chen Li ding 《环境科学学报(英文版)》1999,11(1):33-39
1IntroductionAsoneofthemostimportantsourcesforpowergeneration,coalminingindustryisstilincreasingwithpopulationgrowthandeconom... 相似文献
758.
调查按10×l0km~2网格布点,共布点224个。测量结果,全区宇宙射线空气吸收剂量率室外为2.94×10~(-8)Gy·h~(-1),室内为2.55×10~(-8)Gy·h~(-1):原野γ辐射剂量率为6.25×10~(-8)Gy·h~(-1)。道路γ辐射量率为7.34×10~(-8)Gy·h~(-1),建筑物室内γ辐射剂量率为10.44×10~(-8)Gy·h~(-1). 相似文献
759.
760.