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991.
992.
This paper aims to identify the main driving force for changes of total primary energy consumption in Beijing during the period of 1981-2005. Sectoral energy use was investigated when regional economic structure changed significantly. The changes of total primary energy consumption in Beijing are decomposed into production effects, structural effects and intensity effects using the additive version of the logarithmic mean Divisia index (LMDI) method. Aggregate decomposition analysis showed that the major contributor of total effect was made by the production effect followed by the intensity effect, and the structural effect was relatively insignificant. The total and production effects were all positive. In contrast, the structural effect and intensity effect were all negative. Sectoral decomposition investigation indicated that the most effective way to slow down the growth rate of total primary energy consumption (TPEC) was to reduce the production of the energy-intensive industrial sectors and improving industrial energy intensity. The results show that in this period, Beijing's economy has undergone a transformation from an industrial to a service economy. However, the structures of sectoral energy use have not been changed yet, and energy demand should be increasing until the energy-intensive industrial production to be reduced and energy intensity of the region reaches a peak. As sequence energy consumption data of sub-sectors are not available, only the fundamental three sectors are considered: agriculture, industry and service. However, further decomposition into secondary and tertiary sectors is definitely needed for detailed investigations. 相似文献
993.
Samples of raw and finished water were collected from water treatment plants in southeastern Louisiana between January 1975 and May 1976. The water source for each plant is the Mississippi River. Finished water samples also were obtained at water treatment plants at St. Francisville, LA. and Baton rouge, LA. where deep wells serve as sources of water. All samples were assayed for mutagens using histidine dependent mutant strains of Salmonella typhimurium. Almost twice as many of the finished water samples collected at Luling, Jefferson and New Orleans induced reversions than did the corresponding raw water samples. Often reversion of finished water samples occurred only with metabolic activation. When samples from Belle Chasse and Port Sulphur were assayed, the number of finished water samples inducing reversion were comparable or less than comparable to those with raw water. Nearly equal numbers of finished water samples from St. Francisville and from Baton Rouge induced genetic change. However, the majority of the samples from Baton Rouge which caused reversion, did so only with liver enzyme activation. Discussed is the significance of these findings, as well as the possible role of chlorination procedures in halogenating hydrocarbons into compounds which are mutagenic and/or carcinogenic. 相似文献
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998.
Martin J. Atkins Michael R.W. Walmsley James R. Neale 《Journal of Cleaner Production》2010,18(9):927-934
The integration of non-continuous processes such as a milk powder plant presents a challenge for existing process integration techniques. Current techniques are generally based on steady and continuous operation which for some industries is not the case. Milk production varies considerably during the year as dairy cows in New Zealand are grazed on pasture. In this paper the potential for indirect heat transfer between the several plants using a heat recovery loop and stratified tank at a typical New Zealand dairy factory is investigated. The maximum amount of heat recovery is calculated for a range of recirculation loop temperatures. The maximum amount of heat recovery can be increased considerably if the temperature of the hot fluid in the recirculation loop is varied depending on which condition the site is operating under. 相似文献
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Queen control of egg fertilization in the honey bee 总被引:3,自引:0,他引:3
The study investigated the precision with which honey bee queens can control the fertilization of the eggs they lay. Because
males and workers are reared in different-sized cells, the honey bee is one of the few Hymenoptera in which it is possible
for the experimenter to know which type of egg a queen “intends” to lay. Eggs were collected from both worker and drone (male)
cells from four honey bee colonies. Ploidy of the embryo was determined using polymorphic DNA microsatellites. All 169 eggs
taken from worker cells were heterozygous at at least one microsatellite locus showing that the egg was fertilized. All 129
eggs taken from drone cells gave a single band at the B124 locus, strongly suggesting haploidy. These data show that honey
bee queens have great, and quite possibly complete, ability to control the fertilization of the eggs they lay. Data from the
literature suggest that in two species of parasitoid Hymenoptera (Copidosoma floridanum, Colpoclypeus florus) females have great, but not complete, ability to control fertilization.
Received: 23 December 1997 / Accepted after revision: 17 May 1998 相似文献