Little attention has been paid to the role of soil organic matter （OM） in the formation of pedogenic carbonate in desert soils. The relationships among soil OM, soil dehydrogenase activity （DHA）, and soil CaCO3 in...Little attention has been paid to the role of soil organic matter （OM） in the formation of pedogenic carbonate in desert soils. The relationships among soil OM, soil dehydrogenase activity （DHA）, and soil CaCO3 in a plant community dominated by Artemisia ordosica, located on the eastern boundary of Tcngger Desert in the Alxa League, Inner Mongolia, China, were studied to understand whether OM was directly involved in the formation of pedogenic carbonate. The results showed that DHA and CuCO3 positively correlated with OM content, and DHA, OM, and CaCO3 were correlated with each other in their spatial distribution, indicating that abundant OM content contributed to the formation of CaCO3. Therefore, the formation of pedogenic CaCO3 was a biotic process in the plant community dominated by A. ordosica.展开更多
In the context of the top-color-assisted technicolor （TC2） model, the flavor-changing neutral-current （FCNC） interaction induced by the top-higgs （hOt） are predicted at tree level. We study the relevant processe...In the context of the top-color-assisted technicolor （TC2） model, the flavor-changing neutral-current （FCNC） interaction induced by the top-higgs （hOt） are predicted at tree level. We study the relevant processes of e＋e-（γγ）→tcht0 at the International Linear Collider （ILC）. It is found that these rare processes production rates can be enhanced significantly in the TC2 model. Especially for the process γγ→tcht0, the total cross section will reach a few fb in the reasonable parameter space. We also calculate the distributions of transverse momenta, pseudo-rapid and invariant mass of the top-higgs. In view of the main decay modes of top-higgs for mho 〈 2mr, we find that there will be several hundreds FCNC events produced at the ILC with annually integral luminosity of 500 fb-1. Due to the clean background, such FCNC signals can possibly be detected at the ILC.展开更多
One important area where the development of economically viable products can improve the quality and comfort of human existence is natural ventilation inside a building. Despite the wide distribution of air pollutant ...One important area where the development of economically viable products can improve the quality and comfort of human existence is natural ventilation inside a building. Despite the wide distribution of air pollutant sources, the concentration of indoor pollutants may be the dominant risk factor in relation to personal exposure, as most people spend an average of 87% and 6% of their time within enclosed rooms and vehicles, respectively. Under these circumstances, wind driven rotating ventilators, which use natural energy and are cheap to manufacture, install and maintain, can become very effective non-polluting means of alleviating the problems within enclosed spaces. The author has been pioneering design and performance studies of environment friendly products such as the rooftop ventilator for over a decade at the University of New South Wales in Australia. The purpose of this paper is to detail the basic working principles of this ventilator and the series of detailed experimental and numerical investigations that has been performed in the optimization of the rooftop ventilator in terms of performance with higher air mass extraction rate and improved safety in operation has been achieved. Findings from these studies have been incorporated in the design of ventilators that are now commercially produced and marketed throughout the world by CSR Edmonds Pry Ltd of Australia. The conduct and outcomes of these works form the basis of this keynote paper.展开更多
According to the previous experimental works on the low solidity circular cascade diffuser (LSD), a pressure recovery of a centrifugal blower was improved by the LSD significantly in a wide range of flow rate, and the...According to the previous experimental works on the low solidity circular cascade diffuser (LSD), a pressure recovery of a centrifugal blower was improved by the LSD significantly in a wide range of flow rate, and the pres-sure recovery was improved further by the LSD with a tandem cascade in comparison with the LSD with a sin-gle-row cascade. In the present study, the flow behavior in the LSD with the tandem cascade has been analyzed numerically by using the commercial CFD code of ANSYS-CFX12. It was shown clearly that the higher pressure recovery was achieved by applying the LSD with the tandem cascade, and the high pressure recovery is based on the high pressure rise in the vaneless space upstream of the LSD and the high blade loading of the front blade of the LSD. The high pressure recovery in the LSD could be achieved by controlling the flow separation on the suc-tion surface of the front blade and also on that of the rear blade due to formation of the favorable secondary flow and due to increase in mass flow passing through the slit section between the front and rear blades.展开更多
基金Project supported by the National Basic Research Program (973 Program) of China (No. 2007CB106802)the National Natural Science Foundation of China (No. 30970546)
文摘Little attention has been paid to the role of soil organic matter （OM） in the formation of pedogenic carbonate in desert soils. The relationships among soil OM, soil dehydrogenase activity （DHA）, and soil CaCO3 in a plant community dominated by Artemisia ordosica, located on the eastern boundary of Tcngger Desert in the Alxa League, Inner Mongolia, China, were studied to understand whether OM was directly involved in the formation of pedogenic carbonate. The results showed that DHA and CuCO3 positively correlated with OM content, and DHA, OM, and CaCO3 were correlated with each other in their spatial distribution, indicating that abundant OM content contributed to the formation of CaCO3. Therefore, the formation of pedogenic CaCO3 was a biotic process in the plant community dominated by A. ordosica.
基金Supported in part by the National Natural Science Foundation of China (NNSFC) under Grant Nos.10975047,10979008,and 10775039 Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20094104110001
文摘In the context of the top-color-assisted technicolor （TC2） model, the flavor-changing neutral-current （FCNC） interaction induced by the top-higgs （hOt） are predicted at tree level. We study the relevant processes of e＋e-（γγ）→tcht0 at the International Linear Collider （ILC）. It is found that these rare processes production rates can be enhanced significantly in the TC2 model. Especially for the process γγ→tcht0, the total cross section will reach a few fb in the reasonable parameter space. We also calculate the distributions of transverse momenta, pseudo-rapid and invariant mass of the top-higgs. In view of the main decay modes of top-higgs for mho 〈 2mr, we find that there will be several hundreds FCNC events produced at the ILC with annually integral luminosity of 500 fb-1. Due to the clean background, such FCNC signals can possibly be detected at the ILC.
文摘One important area where the development of economically viable products can improve the quality and comfort of human existence is natural ventilation inside a building. Despite the wide distribution of air pollutant sources, the concentration of indoor pollutants may be the dominant risk factor in relation to personal exposure, as most people spend an average of 87% and 6% of their time within enclosed rooms and vehicles, respectively. Under these circumstances, wind driven rotating ventilators, which use natural energy and are cheap to manufacture, install and maintain, can become very effective non-polluting means of alleviating the problems within enclosed spaces. The author has been pioneering design and performance studies of environment friendly products such as the rooftop ventilator for over a decade at the University of New South Wales in Australia. The purpose of this paper is to detail the basic working principles of this ventilator and the series of detailed experimental and numerical investigations that has been performed in the optimization of the rooftop ventilator in terms of performance with higher air mass extraction rate and improved safety in operation has been achieved. Findings from these studies have been incorporated in the design of ventilators that are now commercially produced and marketed throughout the world by CSR Edmonds Pry Ltd of Australia. The conduct and outcomes of these works form the basis of this keynote paper.
文摘According to the previous experimental works on the low solidity circular cascade diffuser (LSD), a pressure recovery of a centrifugal blower was improved by the LSD significantly in a wide range of flow rate, and the pres-sure recovery was improved further by the LSD with a tandem cascade in comparison with the LSD with a sin-gle-row cascade. In the present study, the flow behavior in the LSD with the tandem cascade has been analyzed numerically by using the commercial CFD code of ANSYS-CFX12. It was shown clearly that the higher pressure recovery was achieved by applying the LSD with the tandem cascade, and the high pressure recovery is based on the high pressure rise in the vaneless space upstream of the LSD and the high blade loading of the front blade of the LSD. The high pressure recovery in the LSD could be achieved by controlling the flow separation on the suc-tion surface of the front blade and also on that of the rear blade due to formation of the favorable secondary flow and due to increase in mass flow passing through the slit section between the front and rear blades.
