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741.
742.
The Five-hundred-meter Aperture Spherical radio Telescope(FAST)is the largest single-dish aperture telescope with a cable-driven parallel robot introduced to achieve the highest sensitivity in the world.However,to realize the high-precision,mechanical equations of such a robot are always complicated,so that it is difficult to achieve real-time control by the traditional iterative method.In this regard,this paper proposes an approximately analytical solution method,which uses the approximately linear relationship between the main parameters of FAST to bypass some iterations.With the coefficients of the relationship extracted,static or quasi-static mechanical equations can be analytically solved.In this paper’s example,this method saves at least 90%of the calculating time and the calculated values are consistent with the experimental data.With such huge efficiency improvements,real-time and high-precision control of the FAST will no longer be difficult work.Besides,all the work in this paper is expected to be used in the FAST. 相似文献
743.
We report the discovery of four new open clusters(named QC 1,QC 2,QC 3 and QC 4)in the direction of Cygnus Cloud and select their members based on five astrometric parameters(l,b,ω,μα*,μδ)of Gaia DR2.We also derive their astrophysical parameters for each new cluster.Structure parameters are generated by fitting the radial density distribution with a King’s profile.Using solar metallicity,we performed isochrone-fitting on their purified color-magnitude diagrams(CMDs)to derive the age of the clusters.The known cluster NGC 7062 in an adjacent area is chosen to verify our identification process.The estimated distance,reddening and age of NGC 7062 are in good agreement with the literature. 相似文献
744.
745.
Study on the isotherms of the interaction between suspended particles and Cu (II) in the Huanghe River 总被引:4,自引:0,他引:4
The isotherms of the interaction between the suspended particles and Cu2+, and the effects of lysine and asparaginic acid on the isotherms in the Huanghe (Yellow) River were studied by applying the
theory and method of interfacial stepwise ion/coordination particle exchange. We obtained a new stepped river isotherm, formed
by two curves joined together with a “plateau” in the middle. The adsorption equilibrium constantsK
1 andK
2 were calculated by using the isothermal equation of surface stepwise ion exchange. Amino acid in small amount promotes exchange
adsorption of the suspended particles with Cu2+. The degree of promotive action relates to the isoelectric point of amino acid. The promotive effect of lysine is bigger
than that of asparaginic acid.
Project 29361001 supported by NSFC. 相似文献
746.
The ice algal and phytoplankton assemblages were studied from Nella Fjord near Zhongshan Station, East Antarctica from April 12 to December 30, 1992. Algal blooms occurred about 3 cm thick on the bottom of sea ice in late April and mid November to early December respectively, and a phytoplankton bloom appeared in the underlying surface water in mid December following the spring ice algal bloom. The biomass in ice bottom was 1 to 3 orders of magnitude higher than that of surface water. Amphiprora kjellmanii, Berkeleya sp., Navicula glaciei, Nitzschia barkelyi, N. cylindrus /N. curta, N. lecointei and Nitzschia sp. were common in the sea ice temporarily or throughout the study period. The biomass in a certain ice segment was decreased gradually and the dominant species were usually succeeded as the season went on. Nitzschia sublineata and Dactyliosolen antarctica were two seasonal dominant species only observed in underlying water column. The assemblages between bottom of ice and underlying surface water were different except when spring ice algae bloomed. The evidence shows that the ice algal blooms occurred mainly by in situ growth of ice algae, and the phytoplankton bloom was mostly caused by the release of ice algae. 相似文献
747.
Based on the data obtained from tens of the investigated soil profiles scattered over the Fildes Peninsula, King George Island, the maritime Antarctic, the soil-forming processes were discussed. It was concluded that on the weathering crusts resulted from various physical courses, the strong freeze-thaw action within regolith, significant organic matter accumulation, evident leaching and illuviation, as well as initial argillification dominated the formation and development of the soils on the Fildes Peninsula. Furthermore, this study indicated that the juvenility of genesis, poor profile-expression, variation in column thickness, etc. characterized the pedogenetic features of the soils of the Fildes Peninsula. 相似文献
748.
INTRODUCTIONEmpiricalorthogonalfunction (EOF)isastatisticalmethodwidelyusedtoquantitativelyexam inemeteorologicalandoceanicdata (PreisendorferandBarnett,1 977;Rasmussonetal.,1 981 ;KnappenbergerandMichaels,1 993 ;LeeandCornillon ,1 995) .Themethodseeksoutthefirstfeworth… 相似文献
749.
李京文 《地球信息科学学报》2000,2(4):1-4
本文重点讨论了在经济全球化进程中我国西部经济的发展问题。较系统地分析了经济全球化与我国西部大开发的关系以及西部发展融入经济全球化进程的战略措施和利用亚欧大陆桥推进西部地区融入经济全球化的进程. 相似文献
750.
以二氧化氯作为一种新型的消毒剂和杀菌剂 ,以传统含氯制剂 (如漂白粉、二氯异氰尿酸钠、三氯异氰尿酸 )作为对照 ,比较其在治疗欧洲鳗细菌性疾病及改善养殖水质方面的显著特性 ,其作用活性与环境 (如 p H、温度、氨及有机物 )因子的关系。结果表明 ,二氧化氯 (Cl O2 )对爱德华氏菌、嗜水气单胞菌和柱状屈挠杆菌有很好的杀灭效果 ,能迅速治愈欧洲鳗的赤鳍病和肝肾病 ,且能有效改善养殖水体 ,水中生化需氧量比对照组下降 10 %~ 30 % ,化学耗氧量下降 5% ,溶氧量提高 8%~ 10 %。当二氧化氯体积分数为 8m L/m3时 ,其杀菌率均高达 90 %以上 ,为氯制剂的 1.8倍 ,且活性不受环境因子的影响 相似文献