Abstract In the research, five test groups were set, including urea at O, 120, 240, 360 and 480 kg/hm^2, respectively, and analysis was conducted on mulberry leaf yield and some characters of the quality in order to e...Abstract In the research, five test groups were set, including urea at O, 120, 240, 360 and 480 kg/hm^2, respectively, and analysis was conducted on mulberry leaf yield and some characters of the quality in order to establish utility functions of ap-plied N in mulberry gardens with different production purposes and to provide schemes of rational N fertilization. The results indicated that yield of mulberry leaf and content and yield of active nutritional substances in the leaves would be reduced either by insufficient or excessive N quantity. In addition, 240 kg/hm^2 of applied N significantly improved active nutritional substances in leaf and 360 kg/hm^2 of applied N significantly improved yields of mulberry leaf and active nutritional sub-stances. Therefore, utility functions of applied N quantity with leaf yield, DNJ content and yield were established accordingly. The optimal N quantity in mulberry gardens for sericulture is recommended 360 kg/hm^2 and the optimal N quantities in mulberry gardens for increase of yield and content of DNJ are 299.56 and 294.72 kg/hm^2, respectively.展开更多
From 1980s to 1990s, Wulingyuan World Natural Heritage in Hunan Province witnessed improper and overexploitation which has obviously imposed a negative impact upon its tourism resources. The weak ecological awareness ...From 1980s to 1990s, Wulingyuan World Natural Heritage in Hunan Province witnessed improper and overexploitation which has obviously imposed a negative impact upon its tourism resources. The weak ecological awareness of the related government decision-makers, the poor management, backward regulation constructions, the immature tourist market mechanism as well as the great pressure brought about by the tourist demands all account for this serious outcome. Therefore, in the future, it is essential to further deal with the relations properly between the opening and protection of the heritages, the relations between tourism industry and economic and social development so as to gradually realize in tourist activities a harmony between human beings and tourism resources and environment, a coordinated development among tourism industry, the other industries and social undertakings. Meanwhile, the future tourism development in this area should take a major form of sustainable civilized tourism to give full play to its scientific research, aesthetic and educational functions while developing commercial mass tourism moderately with restricted capacity control under the principle of maintaining the original features and intactness of this invaluable world natural heritage.展开更多
Sixteen priority polycyclic aromatic hydrocarbons(PAHs) in surface water samples were analyzed by gas chromatograph-mass spectrometer(GC-MS) to study their distribution and characterizing sources.The water samples wer...Sixteen priority polycyclic aromatic hydrocarbons(PAHs) in surface water samples were analyzed by gas chromatograph-mass spectrometer(GC-MS) to study their distribution and characterizing sources.The water samples were collected from five sites(J1-J5) in the Jialing River of Chongqing downtown area from September 2009 to August 2010.The results demonstrate that the concentration of total PAHs in three samples upstream are relatively higher than those in other two sites downstream,with average concentration of total PAHs for each site ranging from 811.5 ng/L to 1585.8 ng/L.The 2,3 and 4-ring PAHs for sampling stations account for 13.0%,56.6% and 28.6%,respectively,in total PAHs.There are obvious tendencies of seasonal change for PAHs concentration in surface water.The PAHs concentration in April of wet season is 1 301.6 ng/L,which is 1.3 times the lowest amount of total PAHs in August of flood season.Ratios of specific PAH compounds were used to characterize the possible pollution sources.Experimental results indicate that the PAHs in surface water samples are primarily from pyrolytic PAHs because of factories along these sites,while the direct leakage of petroleum products may be significant for two sites,Jiahua Bridge(J4) and Huanghuayuan Bridge(J5),because of the wharf boat nearby.展开更多
基金Supported by Special Fund of Modern Agricultural Industry Technology System(No.CARS-22)Special Fund of Major Industry Technology of Sichuan Economic and Trade Commission(No.2008NC00365)+1 种基金Excellent Paper Fund of Sichuan Academy of Agricultural Sciences(No.2011JYGC-LWJJ-07)Special Fund of Sichuan Financial Genetic Engineering(No.2011JYGC-QNJJ-021)~~
文摘Abstract In the research, five test groups were set, including urea at O, 120, 240, 360 and 480 kg/hm^2, respectively, and analysis was conducted on mulberry leaf yield and some characters of the quality in order to establish utility functions of ap-plied N in mulberry gardens with different production purposes and to provide schemes of rational N fertilization. The results indicated that yield of mulberry leaf and content and yield of active nutritional substances in the leaves would be reduced either by insufficient or excessive N quantity. In addition, 240 kg/hm^2 of applied N significantly improved active nutritional substances in leaf and 360 kg/hm^2 of applied N significantly improved yields of mulberry leaf and active nutritional sub-stances. Therefore, utility functions of applied N quantity with leaf yield, DNJ content and yield were established accordingly. The optimal N quantity in mulberry gardens for sericulture is recommended 360 kg/hm^2 and the optimal N quantities in mulberry gardens for increase of yield and content of DNJ are 299.56 and 294.72 kg/hm^2, respectively.
文摘From 1980s to 1990s, Wulingyuan World Natural Heritage in Hunan Province witnessed improper and overexploitation which has obviously imposed a negative impact upon its tourism resources. The weak ecological awareness of the related government decision-makers, the poor management, backward regulation constructions, the immature tourist market mechanism as well as the great pressure brought about by the tourist demands all account for this serious outcome. Therefore, in the future, it is essential to further deal with the relations properly between the opening and protection of the heritages, the relations between tourism industry and economic and social development so as to gradually realize in tourist activities a harmony between human beings and tourism resources and environment, a coordinated development among tourism industry, the other industries and social undertakings. Meanwhile, the future tourism development in this area should take a major form of sustainable civilized tourism to give full play to its scientific research, aesthetic and educational functions while developing commercial mass tourism moderately with restricted capacity control under the principle of maintaining the original features and intactness of this invaluable world natural heritage.
基金Project(41101457) supported by the National Natural Science Foundation of ChinaProject(2009-122) supported by the Fund of Chongqing Municipal Construction Commission, China
文摘Sixteen priority polycyclic aromatic hydrocarbons(PAHs) in surface water samples were analyzed by gas chromatograph-mass spectrometer(GC-MS) to study their distribution and characterizing sources.The water samples were collected from five sites(J1-J5) in the Jialing River of Chongqing downtown area from September 2009 to August 2010.The results demonstrate that the concentration of total PAHs in three samples upstream are relatively higher than those in other two sites downstream,with average concentration of total PAHs for each site ranging from 811.5 ng/L to 1585.8 ng/L.The 2,3 and 4-ring PAHs for sampling stations account for 13.0%,56.6% and 28.6%,respectively,in total PAHs.There are obvious tendencies of seasonal change for PAHs concentration in surface water.The PAHs concentration in April of wet season is 1 301.6 ng/L,which is 1.3 times the lowest amount of total PAHs in August of flood season.Ratios of specific PAH compounds were used to characterize the possible pollution sources.Experimental results indicate that the PAHs in surface water samples are primarily from pyrolytic PAHs because of factories along these sites,while the direct leakage of petroleum products may be significant for two sites,Jiahua Bridge(J4) and Huanghuayuan Bridge(J5),because of the wharf boat nearby.
