[Objective] Study on the effects of rice-duck mutualism on weeds and insects pests and economic benefits of paddy field. [Method] Comparison of the incidence of weeds, sheath blight and insects pest under rice-duck mu...[Objective] Study on the effects of rice-duck mutualism on weeds and insects pests and economic benefits of paddy field. [Method] Comparison of the incidence of weeds, sheath blight and insects pest under rice-duck mutualism, conventional cultivation and control treatment, the yield and economic benefits were analyzed under the 3 treatments. [Result] Average occurrence of weeds in rice-duck mutualism group decreased by 2.33 and 52.0g ind/m^2 compared with that in conventional cultivation and control treatment ; the control rate of mutualism was up to 75% against rice hopper, but just between 25% -60% against rice leaf roller and Chilo suppressalis. The rates of diseased plant and diseased bell against rice sheath blight were higher and disease indices were lower compared with control group. The yield of mutualism group was identical with conventional cultivation, Which was greatly higher than that of control group. The results suggested an higher economic benefits and lower cost benefit ratio for rice-duck mutualism treatment. [Conclusion] Rice-duck mutualism gives birth to a positive effect to control the diseases, insect pests and weeds, as well as to economic benefits, providing basis on extension of rice-duck mutualism system.展开更多
The President of the Republic of Korea (ROK) Roh Moo-hyun announced that Ko- rea fully recognized China’s market economy status. Roh’s announcement was made during a joint press conference with Chinese President Hu ...The President of the Republic of Korea (ROK) Roh Moo-hyun announced that Ko- rea fully recognized China’s market economy status. Roh’s announcement was made during a joint press conference with Chinese President Hu Jintao. who was on a state visit to ROK in November. China is now the largest trading part- ner of ROK, with trade volume between the two countries expected to reach 100 billion US dollars this year. The two leaders agreed that the bilat- eral trade volume should be doubled to 200 billion US dollars by 2012. A significant milestone having been reached between the two countries, what kind of impact can be expected to follow from the events in regards to the bilateral economic and trade relations between China and ROK? With such questions in mind. China’s Foreign Trade reporters in- terviewed Kim Ha-joong. Ambassador of ROK to China.展开更多
The symbiotic relationship between Lolium perenne and Epichloëfestucae var.lolii,a fungal endophyte that lives asymptomatically in its above-ground parts,benefits both the host and fungus.In an outdoor container ...The symbiotic relationship between Lolium perenne and Epichloëfestucae var.lolii,a fungal endophyte that lives asymptomatically in its above-ground parts,benefits both the host and fungus.In an outdoor container experiment,the effects of three distinct endophyte haplotypes(AR1,AR37 and CT)on natural infestations of a root aphid,Aploneura lentisci and a mealybug Phenococcus graminicola were compared with an endophyte-free(Nil)control.Populations of these insects were suppressed in a genetically identical set of plants treated with insecticide.Over 18 months,foliar and root growth,tiller numbers and plant mortality were compared between the different endophyte treatments and between insecticide-treated and untreated plants.Hyphal densities were recorded once during the trial.Untreated plants infected with AR37 had the lowest populations of A.lentisci and P.graminicola,and the highest root and foliar growth compared with other treatments.Growth parameters of untreated plants infected with CT often exceeded that of AR1 and Nil due to low infestations of P.graminicola and lower populations of A.lentisci.Growth of Nil,AR1 and CT plants were higher in insecticide-treated than in corresponding untreated plants but was unaffected in AR37.Untreated Nil and AR1 plants had a lower survival than AR37 and CT plants.Cumulative root outgrowth for treated AR37 plants was significantly lower than for treated AR1 on three sampling occasions.These Epichloëhaplotypes are primarily mutualists,although there are circumstances when they may be disadvantageous to their host.Opposing outcomes likely originate in the ecosystems in which associations evolved.展开更多
In recent years,with the advancement of geothermal heating engineering technology,the projects and scale of geothermal heating have continued to grow.At present,geothermal development and utilization projects are most...In recent years,with the advancement of geothermal heating engineering technology,the projects and scale of geothermal heating have continued to grow.At present,geothermal development and utilization projects are mostly researched on economic evaluation methods,main control factors of benefits and case analysis of project benefits.Post-evaluation of economic benefits can provide strong support for improving existing projects,adjusting projects under construction,and guiding proposed projects,but there are few studies on post-evaluation of economic benefits of completed geothermal heating projects.In order to improve the economic benefits of geothermal heating projects and change extensive management to intensive management,this paper studies the post-evaluation principles,methods and evaluation indicators of the economic benefits of hydrothermal geothermal heating projects,and take the geothermal water heating project of S community in Xianyang City as an example to carry out the post-evaluation research on economic benefits.Through research,it is suggested to carry out post-economic evaluation of geothermal utilization projects that have been completed and run for 3 to 5 years.In order to do a good job in the post-evaluation of economic benefits,the evaluators should continue to track the progress of the project,collect and analyze various historical data in a timely manner,and select a variety of methods for prediction,comparison and mutual correction.In order to fully reflect the benefits of geothermal heating,the indirect benefit evaluation of energy conservation and emission reduction of geothermal heating projects will be strengthened in the future.展开更多
The expression of mutual impedance between two probes in a circular waveguide is derived by means of a vector potential function, reaction concept and reciprocity theorem. The waveguide is semi-infinite, and one end o...The expression of mutual impedance between two probes in a circular waveguide is derived by means of a vector potential function, reaction concept and reciprocity theorem. The waveguide is semi-infinite, and one end of the waveguide is terminated to a load with a reflection coefficient. The contribution to the mutual resistance is found to come from the dominant mode, while the contribution to the mutual reactance comes from the dominant mode and the higher order modes. The major contribution to the mutual reactance is from the dominant mode, since the higher modes decay rapidly with the increasing the probes’ of separation distance. However, as the separation distance approaches zero, the higher modes become dominant, which results in a large value of the mutual reactance. The mutual impedance is dependent on the location and height of the probes, their separation distance and the location of the terminal plane.展开更多
基金Supported by Ministry of Science and Technology of China“National Project of Science and Technology for Food Production”(2004ba520a04)~~
文摘[Objective] Study on the effects of rice-duck mutualism on weeds and insects pests and economic benefits of paddy field. [Method] Comparison of the incidence of weeds, sheath blight and insects pest under rice-duck mutualism, conventional cultivation and control treatment, the yield and economic benefits were analyzed under the 3 treatments. [Result] Average occurrence of weeds in rice-duck mutualism group decreased by 2.33 and 52.0g ind/m^2 compared with that in conventional cultivation and control treatment ; the control rate of mutualism was up to 75% against rice hopper, but just between 25% -60% against rice leaf roller and Chilo suppressalis. The rates of diseased plant and diseased bell against rice sheath blight were higher and disease indices were lower compared with control group. The yield of mutualism group was identical with conventional cultivation, Which was greatly higher than that of control group. The results suggested an higher economic benefits and lower cost benefit ratio for rice-duck mutualism treatment. [Conclusion] Rice-duck mutualism gives birth to a positive effect to control the diseases, insect pests and weeds, as well as to economic benefits, providing basis on extension of rice-duck mutualism system.
文摘The President of the Republic of Korea (ROK) Roh Moo-hyun announced that Ko- rea fully recognized China’s market economy status. Roh’s announcement was made during a joint press conference with Chinese President Hu Jintao. who was on a state visit to ROK in November. China is now the largest trading part- ner of ROK, with trade volume between the two countries expected to reach 100 billion US dollars this year. The two leaders agreed that the bilat- eral trade volume should be doubled to 200 billion US dollars by 2012. A significant milestone having been reached between the two countries, what kind of impact can be expected to follow from the events in regards to the bilateral economic and trade relations between China and ROK? With such questions in mind. China’s Foreign Trade reporters in- terviewed Kim Ha-joong. Ambassador of ROK to China.
文摘The symbiotic relationship between Lolium perenne and Epichloëfestucae var.lolii,a fungal endophyte that lives asymptomatically in its above-ground parts,benefits both the host and fungus.In an outdoor container experiment,the effects of three distinct endophyte haplotypes(AR1,AR37 and CT)on natural infestations of a root aphid,Aploneura lentisci and a mealybug Phenococcus graminicola were compared with an endophyte-free(Nil)control.Populations of these insects were suppressed in a genetically identical set of plants treated with insecticide.Over 18 months,foliar and root growth,tiller numbers and plant mortality were compared between the different endophyte treatments and between insecticide-treated and untreated plants.Hyphal densities were recorded once during the trial.Untreated plants infected with AR37 had the lowest populations of A.lentisci and P.graminicola,and the highest root and foliar growth compared with other treatments.Growth parameters of untreated plants infected with CT often exceeded that of AR1 and Nil due to low infestations of P.graminicola and lower populations of A.lentisci.Growth of Nil,AR1 and CT plants were higher in insecticide-treated than in corresponding untreated plants but was unaffected in AR37.Untreated Nil and AR1 plants had a lower survival than AR37 and CT plants.Cumulative root outgrowth for treated AR37 plants was significantly lower than for treated AR1 on three sampling occasions.These Epichloëhaplotypes are primarily mutualists,although there are circumstances when they may be disadvantageous to their host.Opposing outcomes likely originate in the ecosystems in which associations evolved.
文摘In recent years,with the advancement of geothermal heating engineering technology,the projects and scale of geothermal heating have continued to grow.At present,geothermal development and utilization projects are mostly researched on economic evaluation methods,main control factors of benefits and case analysis of project benefits.Post-evaluation of economic benefits can provide strong support for improving existing projects,adjusting projects under construction,and guiding proposed projects,but there are few studies on post-evaluation of economic benefits of completed geothermal heating projects.In order to improve the economic benefits of geothermal heating projects and change extensive management to intensive management,this paper studies the post-evaluation principles,methods and evaluation indicators of the economic benefits of hydrothermal geothermal heating projects,and take the geothermal water heating project of S community in Xianyang City as an example to carry out the post-evaluation research on economic benefits.Through research,it is suggested to carry out post-economic evaluation of geothermal utilization projects that have been completed and run for 3 to 5 years.In order to do a good job in the post-evaluation of economic benefits,the evaluators should continue to track the progress of the project,collect and analyze various historical data in a timely manner,and select a variety of methods for prediction,comparison and mutual correction.In order to fully reflect the benefits of geothermal heating,the indirect benefit evaluation of energy conservation and emission reduction of geothermal heating projects will be strengthened in the future.
基金Biographies: The National Natural Science Foundation of China(29776012).
文摘The expression of mutual impedance between two probes in a circular waveguide is derived by means of a vector potential function, reaction concept and reciprocity theorem. The waveguide is semi-infinite, and one end of the waveguide is terminated to a load with a reflection coefficient. The contribution to the mutual resistance is found to come from the dominant mode, while the contribution to the mutual reactance comes from the dominant mode and the higher order modes. The major contribution to the mutual reactance is from the dominant mode, since the higher modes decay rapidly with the increasing the probes’ of separation distance. However, as the separation distance approaches zero, the higher modes become dominant, which results in a large value of the mutual reactance. The mutual impedance is dependent on the location and height of the probes, their separation distance and the location of the terminal plane.
