The paper introduced the development of aerodynamics & configuration technology for large aircraft.The technique of fuselage and the advanced aerodynamics configuration — blended wing body (BWB) were described. The impact of aerodynamics & configuration technology on safety, economical, comfortable and environmental characters for large aircraft was analyzed.The proposal for enhancing the research of aerodynamics in China was presented.
A newly developed technology for the pretreatment of copper anode slime, which has a prosperous industrial application prospect was introduced. Small-scale and half-industrialized tests show that direct pressure acid leaching of copper anode slime can make full use of the catalyzed oxidation of the water soluble copper ion in raw copper anode slime and quicken reaction speed. The trends of Ag, Se and Te in continuous leaching process are obviously different from those in discontinuous leaching process, and the leaching results are better than those of discontinuous pressure leaching technology. The new technology is good for comprehensive recycle of valuable elements.
High-speed turnout serves as a vital part of track structure for high-speed railway, and its structure and condition play an important role in train running safety and quality. In this paper, design parameters and linear plane of high-speed turnout, main structure characteristics of components (including fastening, turnout sleeper, switching system etc.), design theories of high-speed turnout, relevant technical requirements as well as innovative achievements are described, which will offer remarkable guiding significance for the further R&D, test, verification and wide-use of high-speed turnout in China railways.
In this paper, the development status of the domestic large power AC motor variable frequency speed regulation technology is introduced. The domestic large power AC drivers fed by cycloconverters have been greatly developed, and some innovation on the theory and engineering technique has been realized. They have been applied to rolling mill, mine winder and so on, and remarkable economic and social benefit has been achieved. The development of the first domestic 7.5 MVA IGCT AC-DC (direct current)-AC converter is also introduced. This converter has excellent performance and reliable operation, and it has been used in traction.
Objective: To evaluate an integrated strategy for the national program on schistosomiasis control with emphasis on eliminating transmission of Schistosoma japonicum in marsh and lake region, since it is of difficulty to control the transmission of S. japonicum by using previous strategies in the region with the changes of environmental and social context in China. Methods: a comprehensive control strategy was evaluated in two intervention villages and two control villages along Poyang Lake in southeast of Jiangxi Province, where annual synchronous chemotherapy is routinely used. New interventions, implemented from 2005 through 2007, included removing cattle from snail-infested grasslands, providing farmers with mechanized farm equipment, improving sanitation by supplying tap water and building lavatories and latrines, providing boats with fecal-matter containers, and implementing an intensive health-education program. During the intervention period,changes were observed in S. japonicum infection in humans, measured the rate of infection in snails, and tested the infectivity of lake water in mice. Results After three transmission seasons, the rate of infection in humans decreased to less than 1.0 % in the intervention villages, from 11.3 % to 0.7 % in one village and from 4.0 % to 0.9 % in the other (P<0.001 for both comparisons). And the rate of infection in humans sustainably decreased to 0.2 % and 0 % after the fourth transmission seasons.The rate of infection in humans in control villages fluctuated but remained at baseline levels. In intervention villages, after four transmission seasons, the percentage of sampling sites with infected snails decreased from 2.2 % and 0.3 % to no infection in two marshlands, respectively (P<0.001 for both comparisons). The rate of infection in mice after exposure to lake water decreased from 79 % to no infection (P<0.001). Conclusions: A comprehensive control strategy based on interventions to reduce the rate of transmission of S. japonicum infection from cattle and humans to snails was highly effective. These interventions have been adopted as the national strategy to control schistosomiasis in China.
Detection system makes the core equipment for collecting feature information of radiation fields, and is the key point and technical basis for carrying out pulsed radiation detection. Its performance directly determines the choice of measuring method and the quality of measured data. A systematic description of characteristic parameters affecting its performance in pulsed radiation detection is the basis for the design, development, application and comprehensive performance assessment of the detection system. Main parameters of detection systems for measuring time spectrum and intensity of mixed pulsed neutron/gamma radiation fields include detection sensitivity, time response, energy response, linear current and discrimination of neutron to gamma rays, etc. To realize these parameters in designing a detection system, certain detection construction and technical principles have to be established in accordance with the basic interaction principles of neutron/gamma rays with materials. Designing principles include balancing energy collection with charge collection, geometry efficiency with high signal-noise ratio, separation of signal response from irradiation response, detection sensitivity with time response, overall performance with application reliability, etc. The designing technology of radiation detection systems can be developed with an integrated utilization of these principles.
Global warming is the most serious environmental problem that we ever had. One of the reasons for that focus on the mass emission of greenhouse gas has made the cosmopolitan warming problem more and more serious. It is such a great threaten to our environment that the international community must take active and effective measures. In 2006, a 973 project named "Research for Utilizing Greenhouse Gas as Resource in EOR and Storaging It Underground " was authorized by The Ministry of Science and Technology of the People's Republic of China. The researches include establishing a system suits China`s national conditions and sequestrate CO2 effectively, obtaining society benefit from reducing CO2 emission and obtaining economic benefit from CO2 utilization, developing CO2 storage theories, phase state of multiphase and multicomponent mixtures, nonlinear percolation mechanisms of multiphase and multicomponent mixtures and CO2 capture & transport.. In China the CO2 sequestration security and the efficient use of research is at the international level. From those basic researches above, it is expected to get state owned CO2 storage and utilization technology, which will be served as useful theory and practice basis for efficiently global resource & environment development and sustainable development.
It is of local, regional and global importance to understand the environmental changes on the Yunnan-Guizhou Plateau. Difference on bio-geochemical process of the sediment-water interface exists among lakes so that protection approaches to water resources vary. a. The coal mining in the catchment of Lake Aha causes Fe-Mn accumulation in the sediment leading to the seasonal secondary pollution. In anoxic condition, the sulphate deoxidization migrates to the upper layer of sediments which results in Fe2+ screening of the diffusive boundary layer. The Fe-Mn cycling is controlled by both the sediment-water geological interface and oxidation-reduction chemical interface. Controlling Fe-Mn release and reducing their flux into the lake, selecting good-quality water district and cleaning sludge are efficient ways to control pollutions. b. Paroxysmal deterioration of water quality in Lake Baihua appeared in autumn, 1994 in Guizhou. Analysis of incident cross-correlation water-quality indicators indicated that the "Lake Black Tide" resulted from the coupling of bio-oxidation of depositional organic matters under the specific season and climatic conditions; pH-restraint of de-nitric process led to increase in NO-2 concentration. The water quality was expected to recover in times with the balancing of oxygen in waters, input of water flow and better weather conditions. This was confirmed by the late monitoring. c. The average sedimentation rate of Lake Erhai is 0.047 g ·cm-2 ·a-1. The Pb-isotopic compositions of recent sediments indicate that may have a stable source. The depositional organic matter originates mainly from the land. In the chemical processes of early diagenesis, the Corg vertical profiles of sediments show three stages "Deposition-Decomposition-Accumulation" . In the last 460 years, small-scope frequent fluctuation of δ13Corg and synchronically decreasing trends of δ13Cinorg and δ18Oinorg indicate an obvious influence of human activity in the catchment. Control of input flux of terrestrial organic matters into Lake Erhai is a fundamental strategy. d. Lake Chenghai in Yunnan is a moderate-eutrophic lake with a total ion concentration close to a low limit of saline lake. The atomic ratios of Horg/Corg and Corg/Norg indicate that the organic matters mainly stem from the endogenous plankton algae remains; there is a good synchronous relationship of the depositional fluxes between 210Pbex and Corg in the sedimentary records. In particular, the synchronizations over the time indicate the increase in the lake primary productivity. The Clean-Effect reflects an adjustive role of lake nature function in the lake eutrophication.
This thesis, based on innovations and practices of methane drainage in multiseams of low permeability and complicated geology in Huainan mining district, systematically describes theories and key technologies of integrated pillarless coal production and methane extraction with "Y" type ventilation system in multiseams of low permeability. Through analyses of deformation, fracturing and failure of rocks around goaf, methane movement and accumulation in and around the goaf are revealed, technologies to retain goaf edge roadways with innovative fill technologies are developed, and technological innovations in methane extraction are made with the retained goaf edge roadways and "Y" type ventilation systems.
Differentiated somatic cells can be rep rogrammed into induced p luripotent stem cells ( iPS) by transduction of a defined transcrip tion factors. Undoubtedly, iPS cell technology is a great breakthrough of stem cell research field in recent years. As a novelmethod for achieving an embryonic like state without the ethical dilemma of destroying human embryos, iPS cell technology elicit a great p romise for patient specific cell therapy and regen erative medicine. In addition, iPS2cell technology p rovides novel p latforms for research of rep rogramming mecha nism and pathological p rocess of human disease. However, the p resent development of p luripotent cells from indi vidual somatic cells just opened up a new door to stem cell research world, much work remains to be done before iPS cells can be considered as a clinically reliable cell source. Here, the iPS cell research advances in recent years were reviewed and the feasible app lications of iPS cell technology were discussed.
In early 2000, 41 of Poll Dorset sheep were introduced from New Zealand into Yongchang mutton sheep breeding farm, which is located at the Hexi Corridor in Gansu Province,China. The introduced sheep were mainly rearing in confinement, and the grazing was used as assistant. After the systematic study of the introduced sheep, such as behavior, physiological and biochemical index, growth and development, reproductive performance, polymorphic loci of blood protein gene and gene type frequency, and disease resistance, the results indicate that the introduced Poll Dorset sheep had both good adaptability and germplasm characteristics. By the end of 2008, the total number of 1~3 generation hybrid sheep were more than 200 000 in Yongchang County, and more than 1 300 000 of different generation hybrid sheep were got in Gansu, Ningxia, Qinghai and Henan provinces where were used as spread areas. Significant economic benefits were made. Poll Dorset sheep is one of the main paternal breeds which are using for cultivating the modern mutton sheep breed in Gansu Province.