北京城市生态系统的能值动态分析

采用能值理论与分析方法,对北京市1990~2001年间的能值结构动态进行了分析,并采用人均能值、能值密度、生态功能潜力、人口基本承载力、能值自给率、能值货币比率、环境负载率、输入能值比等重要能值指标对该时期北京市城市生态系统的能值状况作了详细分析。研究表明,北京城市生态系统正处于较高发展水平,已基本跨入发达国家水平的行列;但高强度、快速发展给本市带来了巨大的生态环境压力,未来北京的可持续能力建设已势在必行。文章也提出了北京城市生态系统可持续发展能力建设的基本方向。     

柠檬醛对赤子爱胜蚓(Eisenia fetida)再生的影响

用不同浓度柠檬醛处理不同部位剪切的蚯蚓,和处理剪切后不同时间段的蚯蚓体段,探讨了柠檬醛对赤子爱胜蚓再生作用的体段、作用浓度和敏感时间段.结果表明,柠檬醛对蚯蚓再生有明显影响,但这种作用依不同体段而异,以体段P7和P25作用最显著,而A25,A90和P60的受柠檬醛影响较小; 柠檬醛影响蚯蚓头部再生,而不影响尾部再生;对再生有影响的柠檬醛浓度为1mmolkg-1, 0. 1mmolkg-1和0. 01mmolkg-1 (土壤),对蚯蚓再生作用的时间为切后0. 5~1d.试验显示,柠檬醛干扰蚯蚓再生头部形成而且还影响再生头尾体轴形成;内源视黄酸在蚯蚓头尾轴再生图式形成中有重要作用. 图4表4参18     

Observations of planktonic bioluminescence in the euphotic zone of the California Current

The distributions of bioluminescence, temperature, salinity, oxygen. pH, and chlorophyll a were measured at 10 m intervals, to a depth of 100 m at a station (33°46N; 119°36W) in the California Current from 17 to 20 July 1982. The distribution of bioluminescence showed a marked day-night change which was consistent over the sampling period. The nighttime maximum was at the surface, and the daytime maximum was between 30 and 40 m. The shapes of the day and night distributions were independent of the absolute intensity of bioluminescence and were also insensitive to advection, as inferred from changing temperature-salinity relationships. The nighttime depth distribution broadened during a period of high wind Day to night differences in the color spectrum at the depth of maximum bioluminescence suggest that the luminescent organisms differed from day to night.     

宜兴、溧阳河流主要水质指标的年际变化与成因分析

探讨了宜溧地区河流水环境的演化趋势及其主要影响因子。结果表明 :总磷总氮年际变化无明显上升趋势 ,CODMn则相反 ;影响CODMn浓度变化的因子是工业点源排放 ,影响总氮浓度变化的因子是化肥使用量 ,影响总磷浓度变化的因子是生活污染。     

城市协调发展理论与对策的探讨

本文对城市科技、经济、社会、环境协调发展结构、功能、机理、机制及对策进行了探讨.     

南京住宅小区雨水回用方案技术经济分析

分析了南京城区雨水资源量和杂用水需求量的关系，通过示例，提出了住宅小区4种雨水回用方案，进行工程造价、雨水处理成本等方面的技术经济比较，结果方案3最优。     

地磁Z分量整点值空间相关法在江苏地区地震预报中的初步应用

应用江苏地磁台站Ｚ分量整点值资料,研究了江苏地区Ｚ分量整点值的相关性及在江苏地区地震预报中的作用,给出了该法在江苏地区的异常判据指标,并应用该指标提取了１９９０～１９９７年的三个异常,其中两个异常有地震对应。     

锅炉型煤质量的影响因素分析

分析了配煤组分、成型工艺条件、型料粒度等方面对工业型煤质量的影响，指标合理确定惰性组分含量、成型水分和型料粒度组成是型煤生产的关键，并对实际生产提供帮助。     

Comparison of Black Carbon,Total Organic Carbon,and PAH Concentrations in Surface Sediments from Two Main Rivers in Henan Province,China

Black carbon (BC) in surface sediments from Henan section of Yellow River and Huaihe River, China, was determined. Average content of BC in Huaihe River was 0.33%, higher than that in Yellow River (n?=?23) with mean value of 0.15%. Distribution patterns of BC in Yellow River and Huaihe River were similar, namely that tributaries had higher BC content than main stream. In addition, BC content in the mainstream of Yellow River and Huaihe River decreased with altitude. The BC content presented a significant positive correlation with clay (r?=?0.672; p?<?0.01) content in Yellow River, while neither did in Huaihe River. The ratio of BC/TOC ranged from 1.8–57.4% (median 29.6%), evidencing pyrogenic fossil fuel source of BC in Yellow River. Relatively low values of BC/TOC in Huaihe River (5.3%–28.8%, median 7.5%,) reflected that the origin of BC is from burning of biomass. In addition, Pearson rank correlation analysis showed that BC was in strong correlation with lighter PAH in Yellow River, while BC was in significant correlation with heavier PAH in Huaihe River. The ratio of BC/TOC indicated that BC in Yellow River mainly came from fossil fuel combustion, while BC in Huaihe River was primarily from biomass burning.     

Comparison of a rhizosphere-based method with other one-step extraction methods for assessing the bioavailability of soil metals to wheat

There is no method recognized as a universal approach for evaluation of bioavailability of heavy metals in soil. Based on the simulation of the rhizosphere soil conditions and integration of the combined effects of root-soil interactions as a whole, a rhizosphere-based method has been proposed. Wet fresh rhizosphere soil was extracted by low-molecular-weight organic acids (LMWOAs) to fractionate metal fractions of soil pools, which were then correlated with the metal contents of wheat roots and shoots. The rhizosphere-based method was compared with other one-step extraction methods using DTPA, EDTA, CaCl2, and NaNO3 as extractants and the first step of the Community Bureau of Reference (BCR) method. Simple correlation and stepwise multiple regression analysis were used for the comparison. Simple correlation indicated that the extractable Cu, Zn, Cr, and Cd of soils by the rhizosphere-based method were significantly correlated with the metal contents of wheat roots. For DTPA, BCR1 and EDTA methods there was a relatively poor correlation between the extractable Cu, Zn and Cd of soil and metal contents of wheat roots. Stepwise multiple regression analysis revealed that the equation of the rhizosphere-based method was the simplest one, and no soil properties variables needed to be added. In contrast, the equations of other one-step extraction methods were more complicated, and soil properties variables needed to be entered. The most distinct feature of the rhizosphere-based method was that the recommended method was suitable for acidic, neutral and near alkaline soils. However, the DTPA and EDTA extraction methods were suitable for calcareous soils only-or-only for acidic soils. The CaCl2, and NaNO3 extraction methods were only suitable for exchangeable metals. In short, the rhizosphere-based method was the most robust approach for evaluation of bioavailability of heavy metals in soils to wheat.