共查询到20条相似文献，搜索用时 296 毫秒
1.
ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｒｅｃｅｎｔｙｅａｒｓ,ｗｉｔｈｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｃｏｍｐｕｔｅｒａｎｄｃｏｎｔｒｏｌｔｈｅｏｒｙ ,ｇａｉｎ ｓｃｈｅｄｕｌｉｎｇｉｓｗｉｄｅｌｙｕｓｅｄｉｎｍａｎｙａｐｐｌｉｃａｔｉｏｎｓ,ｓｕｃｈａｓｃｈｅｍ ｉｃａｌｅｎｇｉｎｅｅｒｉｎｇ,ａｉｒｃｒａｆｔｃｏｎｔｒｏｌｅｔｃ .(Ｓｈａｍｍａｅｔａｌ.,1 993;Ｗａｎｇｅｔａｌ. 1 995) .Ｈｏｗｅｖｅｒ,ｔｈｅｒｅａｒｅｍａｎｙｐｒｏｂｌｅｍｓ,ｓｕｃｈａｓｓｔａｂｉｌｉｔｙ,ｗｈｉｃｈａｒｅｓｔｉｌｌｎｏｔｓｏ… 相似文献
2.
《上海大学学报(英文版)》2000,(4)
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｗｉｔｈｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｔｈｅ ｐｏｗｅｒｅｌｅｃｔｒｏｎｉｃｓｔｅｃｈｎｏｌｏｇｙ ,ｓｔａｔｉｏｎａｒｙｐｏｗｅｒｃｏｎｖｅｒｔｉｎｇｄｅｖｉｃｅｓｓｕｃｈａｓＡＣ ＤＣｃｏｎｖｅｒｔｅｒｓａｎｄＤＣ ＡＣｉｎｖｅｒｔｅｒｓａｒｅａｐｐｌｉｅｄｉｎｖａｒｉｏｕｓｉｎｄｕｓｔｒｉａｌａｒｅａｓ .Ｈｏｗｅｖｅｒ ,ｔｈｉｓｈａｓｌｅｄｔｏｓｏｍｅｐｒｏｂｌｅｍｓ ,ｅ .ｇ .ｔｈｅｉｎｃｒｅａｓｅｏｆｈａｒｍｏｎｉｃｓｉｎｐｏｗｅｒｓｕｐｐｌｙ ,ａｎｄｔｈｅＥＭ… 相似文献
3.
ＩＮＴＲＯＤＵＣＴＩＯＮＡＴＭｈａｓｇｒｅａｔｓｕｐｅｒｉｏｒｉｔｙｉｎｃｅｒｔａｉｎａｓｐｅｃｔｓ,ｓｕｃｈａｓｒｅｓｏｕｒｃｅａｌｌｏｃａｔｉｏｎｆｌｅｘｉｂｉｌｉｔｙ ,ｑｕａｌｉｔｙｏｆｓｅｒｖｉｃｅｇｕａｒａｎｔｅｅｉｎｇ ,ｉｎｔｅｇｒａｔｅｄｔｒａｆｆｉｃｓｕｐｐｏｒｔ ｉｎｇ ,ｅｔｃ .ＡＴＭｈａｓｂｅｅｎａｄｏｐｔｅｄｂｙＩｎｔｅｒｎａｔｉｏｎ ａｌＴｅｌｅｃｏｍｍｕｎｉｃａｔｉｏｎＵｎｉｏｎ (ＩＴＵ)ａｓｔｈｅｅｘ ｃｈａｎｇｅａｎｄｍｕｌｔｉｐｌｅｘｉｎｇｔｅｃｈｎｉｑｕｅｓｏｆｔｈ… 相似文献
4.
ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅａｒｃｈｅｄｒｅｔａｉｎｉｎｇｓｔｒｕｃｔｕｒｅ ,ａｎｅｗｔｙｐｅｏｆｒｅｔａｉｎｉｎｇｓｔｒｕｃｔｕｒｅｉｎｆｏｕｎｄａｔｉｏｎｐｉｔｓ(Ｃａｉｅｔａｌ.,1 992 ) ,ｈａｓｍａｎｙｖｉｒｔｕｅｓｓｕｃｈａｓｍｏｒｅｒｅａｓｏｎ ａｂｌｅｓｔｒｕｃｔｕｒｅｓｈａｐｅ ,ｓｍａｌｌｅｒｄｅｆｏｒｍａｔｉｏｎ ,ｌｏｗｅｒｃｏｓｔ,ａｎｄｓｏｏｎ .Ｂｕｔｉｔｈａｓｎｏｔｏｆｔｅｎｂｅｅｎｕｓｅｄｉｎｅｎｇｉｎｅｅｒｉｎｇｂｅｃａｕｓｅｉｔｓａｎａｌｙｓｉｓｍｅｔｈｏｄｉｓｎｏｔｒ… 相似文献
5.
Ⅴ .仔细阅读下列短文 ,并根据短文内容回答问题ＦｉｇｈｔｉｎｇａｇａｉｎｓｔＡＩＤＳＴｈｅＡＩＤＳｖｉｒｕｓｈａｓｂｅｅｎａｒｏｕｎｄｆｏｒａｖｅｒｙｌｏｎｇｔｉｍｅ ,ｂｕｔｔｈｅｓｐｒｅａｄｏｆｔｈｅｄｉｅａｓｅｗｉｔｈｉｎｔｈｅｌａｓｔｔｗｅｎｔｙｙｅａｒｓｏｒｓｏｏｎｓｕｃｈａｓｃａｌｅｈａｓｃａｕｓｅｄｒｅａｌｃｏｎｃｅｒｎ .Ｉｔｓｅｅｍｓｔｈａｔｉｎｔｈｅ 1 980ｓｔｈｅｐｒｉｎ ｃｉｐａｌｃａｒｒｉｅｓｏｆｔｈｅｄｉｅａｓｅｗｅｒｅｈｏｍｏｓｅｘｕａｌｓ,ｄｒｕｇｓｕｓｅｒｓａｎｄｐｒｏｓ… 相似文献
6.
SHI Ding hua PENG Jian ping 《上海大学学报(英文版)》1999,3(3):175-180
１ Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｓｔｏｃｈａｓｔｉｃｇｌｏｂａｌｏｐｔｉｍｉｚａｔｉｏｎａｌｇｏｒｉｔｈｍｉｓｃｏｎｃｅｒｎｅｄｗｉｔｈｕｓｉｎｇｒａｎｄｏｍｌｙｇｅｎｅｒａｔｅｄｐｏｉｎｔｓｔｏａｐｐｒｏｘｉｍａｔｅｏｐｔｉｍａｌｓｏｌｕｔｉｏｎｏｆｍａｔｈｅｍａｔｉｃａｌｐｒｏｇｒａｍｍｉｎｇ（ｓｅｅＲｅｆｓ．１～３ｆｏｒａｓｕｒｖｅｙｏｆｔｈｅｆｉｅｌｄ）．Ｆｏｒｓｏｍｅｓｔｏｃｈａｓｔｉｃｇｌｏｂａｌｏｐｔｉｍｉｚａｔｉｏｎａｌｇｏｒｉｔｈｍｓ,ｔｈｅｎｅｘｔｐｏｉｎｔｓｉｎｔｈｅｓｅｑ… 相似文献
7.
ＳＯＦＴＷＡＲＥＥＶＯＬＵＴＩＯＮＳｏｆｔｗａｒｅｅｖｏｌｕｔｉｏｎｈａｓｂｅｅｎａｄｄｒｅｓｓｅｄｆｒｏｍｍａｎｙｖｉｅｗｐｏｉｎｔｓ .Ｔｈｅｓｅｉｎｃｌｕｄｅｍａｎａｇｅｍｅｎｔｉｓ ｓｕｅｓｓｕｃｈａｓｗｈｉｃｈｐａｒｔｓｏｆａｓｙｓｔｅｍｓｈｏｕｌｄｂｅｒｅｂｕｉｌｔ,ｃｏｎｆｉｇｕｒａｔｉｏｎｉｓｓｕｅｓｓｕｃｈａｓｋｅｅｐｉｎｇｔｒａｃｋｏｆｍａｎｙｖｅｒｓｉｏｎｓｏｆｔｈｅｓａｍｅｓｙｓｔｅｍ ,ｔｅｓｔ ｉｎｇｉｓｓｕｅｓｓｕｃｈａｓｄｅｔｅｒｍｉｎｉｎｇｗｈｉｃｈｔｅｓｔｃａｓｅｓ… 相似文献
8.
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｔｈｅｂｏｕｎｄａｒｙｖａｌｕｅｐｒｏｂｌｅｍｓｏｆｐａｒｔｉａｌｄｉｆｆｅｒｅｎｔｉａｌｅｑｕａｔｉｏｎｓｈａｓｂｅｃｏｍｅａｎｉｍｐｏｒｔａｎｔｓｕｂｊｅｃｔｉｎｍｏｄｅｒｎａｐｐｌｉｅｄｍａｔｈｅｍａｔｉｃｓ.Ｗｉｔｈｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｓｃｉｅｎｃｅａｎｄｔｈｅｒｅｑｕｉｒｅｍｅｎｔｏｆｐｒａｃｔｉｃａｌａｐｐｌｉｃａｔｉｏｎ ,ｉｎｖｅｓｔｉ ｇａｔｉｏｎｓｉｎｔｈｉｓｆｉｅｌｄｈａｖｅｂｅｅｎｔｒａｎｓｆｅｒｒｅｄｆｒｏｍｃｌａｓｓｉ ｃａｌｌｉｎ… 相似文献
9.
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｇｅｎｅｒａｔｉｎｇｌｏｃａｌｉｚｅｄｃｏｈｅｒｅｎｔｓｔｒｕｃｔｕｒｅｓｏｆｔｈｅ (2 +1) ｄｉｍｅｎｓｉｏｎａｌｎｏｎｌｉｎｅａｒｅｖｏｌｕｔｉｏｎｅｑｕａｔｉｏｎｓｈａｓｃｏｎ ｔｉｎｕｅｄｔｏｂｅａｃｈａｌｌｅｎｇｉｎｇｃｏｎｔｅｍｐｏｒａｒｙｐｒｏｂｌｅｍａｆｔｅｒｔｈｅａｄｖｅｎｔｏｆｄｒｏｍｉｏｎｓｗｈｉｃｈａｒｅｅｘｐｏｎｅｎｔｉａｌｌｙｌｏｃａｌ ｉｚｅｄｓｔｒｕｃｔｕｒｅｓｄｒｉｖｅｎｂｙｓｏｍｅｓｔｒａｉｇｈｔｌｉｎｅｇｈｏｓｔｓｏｌｉ ｔｏｎｓｕ… 相似文献
10.
四面体中的Milosevic不等式 总被引：1，自引：0，他引：1
198 7年 ,Ｄ .Ｍ .Ｍｉｌｏｓｅｖｉｃ[1] 提出并证明了下述不等式 :设△ＡＢＣ的三边长为ａ、ｂ、ｃ ,相应边上的高为ｈａ、ｈｂ、ｈｃ,外接圆半径和内切圆半径分别为Ｒ、ｒ.则ａｈｂ+ｈｃ+ ｂｈｃ+ｈａ+ ｃｈａ+ｈｂ≥ 93Ｒ2 (4Ｒ +ｒ) .①文 [2 ]考虑了不等于①的加强形式 :ａｈｂ+ｈｃ+ ｂｈｃ+ｈａ+ ｃｈａ+ｈｂ≥9Ｒ2ｓ.②文 [3 ]得到比②更强的结果 :ａｈｂ+ｈｃ· ｂｈｃ+ｈａ· ｃｈａ+ｈｂ≥2 7Ｒ38ｓ3 .③其中ｓ为△ＡＢＣ的半周长 .本文将不等式③类比到空间四面体 ,得到下述命题 .命题 设四面体Ａ1Ａ2 Ａ3 Ａ4的体积为Ｖ ,外… 相似文献
11.
INTRODUCTION Nitrogen oxide (NOx) is one of the main air pol- lutants found in the flue gases from chemical and power plants belching acid rain and photochemical smog. Over 90 percent of all man-made nitrogen ox- ides that enter our atmosphere are produced by the combustion of various fuels. Compared with the ad- vanced stage of SO2 gas removal technologies devel- opment, the removal of NOx gases is still in the initial stages of development as roughly 90 to 95 percent of NOx emitted i… 相似文献
12.
1 Introduction Ahugeamountofliteratureexistsonthestudyofi dentifyingtracemetalionsbymeansofspectropho tometry[1 3] ,fluorimetry[4 6 ] aswellas polarogra phy[7 9] ,whichhaveactiononlocatingtheendpointoftheindicatingreaction .Howeverbothspectropho tometryandfluorimetryareeasytobeinterferedbycolororprecipitation ,whilepolarographyhasanissueofmercurypollution .Thecatalyzingkineticanalysishasthecharacteristicsofhighsensitivityandspeedi ness.Oscillographicpotentiometryisasimpleintu itionisticanal… 相似文献
13.
Isolation and characteristics of Arthrobacter sp. strain CW-1 for biodegradation of PAEs 总被引：1，自引：0，他引：1
WU Dong-lei ZHENG Ping MAHMOOD Qaisar YANG Xiao-sheng 《浙江大学学报(A卷英文版)》2007,8(9):1469-1474
Isolation of new bacterial strains and recognition of their metabolic activities are highly desirable for sustainability of natural ecosystems. Biodegradation of dimethyl phthalate (DMP) under anoxic conditions has been shown to occur as a series of sequential steps using strain CW-1 isolated from digested sludge of Sibao Wastewater Treatment Plant in Hangzhou,China. The microbial colony on LB medium was yellowish,3～5 mm in diameter,convex in the center,and embedded in mucous externally. The individual cells of strain CW-1 are irregular rods,measuring (0.6～0.7)×(0.9～1.0) μm,V-shaped,with clubbed ends,Gram positive and without any filaments. 16S rDNA (1438 bp) sequence analysis showed that the strain was related to Arthrobacter sp. CW-1 and can degrade PAEs utilizing nitrate as electron acceptor,but cannot mineralize DMP completely. The degradation pathway was recommended as: dimethyl phthalate (DMP)→monomethyl phthalate (MMP)→phthalic acid (PA). DMP biodeg-radation was a first order reaction with degradation rate constant of 0.3033 d-1 and half-life 2.25 d. The DMP conversion to PA by CW-1 could be described by using sequential kinetic model. 相似文献
14.
Pakistani wheat varieties are grown over a wide agro-climatic range and as such are anticipated to exhibit yield and quality differences. It is therefore necessary to investigate the nutritional status of wheat varieties in terms of biochemical and physiochemical characteristics available for food and nutritional purposes in Pakistan. The result shows that wheat grains of different varieties contain a net protein level of 9.15%～10.27%, 2.15%～2.55% total fats, 1.72%～1.85% dietary fibers,77.65×10^-6～84.25×10^-6 of potassium and 7.70× 10 6～35.90× 10^-6 of sodium ions concentration, 0.24× 10^-6～0.84× 10^-6 of phosphorus, 1.44%～2.10% ash, 31.108～43.602 g of thousand grain mass （TGM） and 8.38%～9.67% moisture contents. This study is significant in providing an opportunity to explore the available wheat varieties and to further improve their nutritional excellence and also essential for setting nutritional regulations for domestic and export purposes. 相似文献
15.
SO4^2- / TiO2-La2O3, a novel solid superacid, was prepared and its catalytic activities at different synthetic conditions are discussed with esterification of n-butanoic acid and n-butyl alcohol as probing reaction. The optimum conditions have also been found, mole ratio of n（La^3＋）：n（Ti^4＋） is 1：34, the soaked consistency of H2SO4 is 0.8 tool/L, the soaked time of HESO4 is 24 h, the calcining temperature is 480 ℃, the calcining time is 3 h. Then it was applied in the catalytic synthesis often important ketals and acetals as catalyst and revealed high catalytic activity. Under these conditions on which the molar ratio of aldehyde/ketone to glycol is l： 1.5, the mass ratio of the catalyst used in the reactants is 0.5%, and the reaction time is 1.0 h, the yields of ketals and acetals can reach 41.4%-95.8%. 相似文献
16.
RH和RH-KTB精炼过程中钢液流动和混合特性的研究 总被引：7，自引：0，他引：7
The flow and mixing characteristics of molten steel during the vacuum circulation refining,including RH(Ruhrstahl-Heraeus) and RH-KTB(Ruhrastahl-Heraeus-Kawasaki top blowing) processes,were investigated on a 1/5 linear scale water model of a 90t multifunction RH degasser,The circulation rate was directly and more accurately determined,using a new method by which the more reliable results can be obtained.The fluid flow pattern and flow field in the ladle were demonstrated,observed and analyzed.The mixing time of liquid in the ladle was measured using electrical conductivity method.The residence time distribution in the RH model was obtained by tracer response technique.The influence of the main technological and geometric factors,including the gas top blowing*(KTB) operation,was examined.The results indicated that the circulation rate of molten steel in the RH degasser can be fairly precisely calculated by the formula:Q1p=0.0333Qg^0.26Du^0.69Dd^0.80(t/min),where Qg-the lifting gas flow rate(NL/min);Du and Dd-the inner diameters of the up and down-snorkels(cm),respectively.The maximum value of circulation rate of molten steel in the case of the 30cm diameters either of the up-and down-snorkels for the RH degasser(the “Saturated” rate) is approximately 31 t/min.the corresponding gas flow rate is 900NL/min.Blowing gas into the vacuum chamber through the top lance like KTB operation does not markedly influence the circulatory flow and mixing charateristics of the RH process under the conditions of the present work.There exist a major loop and a large number of small vortices and eddies in the ladle during the RH refining process.A liquidliquid two-phase flow is formed between the descnding stream from the down-snorkel and the liquid around the stream.All of these flow situation and pattern will strongly influence and determine the mixing and mass transfer in the ladle during the refining.The correlation between the mixing time and the stirring energy density is τmε^0.50 for the RH degasser.The mixing time rapidly shortens with an increase in the lifting gas flowrate.At a same gas flow rate,the mixing times with the up-and down-snorkel diameters either of 6 and 7cm are essentially same.The 30cm diameters either of the up-and down-snorkels for the RH degasser would be reasonalble.The concentration-time curve showed that three circulation cycles are at least needed for complete mixing of the liquid steel in the RH degasser. 相似文献
17.
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｔｈｅａｌｌｏｙｉｎｇｏｆｈｉｇｈｍｏｌｙｂｄｅｎｕｍａｎｄｈｉｇｈｎｉｔｒｏｇｅｎｉｓｔｈｅｆｕｎｄａｍｅｎｔａｌｏｆｄｅｖｅｌｏｐｉｎｇｍｏｄｅｒｎｈｉｇｈｌｙ ａｌｌｏｙｅｄａｕｓｔｅｎｉｔｉｃｓｔａｉｎｌｅｓｓｓｔｅｅｌｓ,ｉｔｓｏｐｔｉｍｕｍｒｅｓｉｓｔａｎｃｅｔｏｐｉｔ ｔｉｎｇａｎｄｓｔｒｅｓｓｃｏｒｒｏｓｉｏｎｉｓｃｏｍｍｏｎｌｙａｃｋｎｏｗｌ ｅｄｇｅｄ[1 ,2 ].Ｉｎｔｈｉｓｓｙｓｔｅｍ ,0 0Ｃｒ2 0Ｎｉ18Ｍｏ6Ｃｕ[Ｎ]ａｎｄ0 0Ｃｒ2 0Ｎｉ18Ｍｏ5Ｃｕ [Ｎ ]… 相似文献
18.
SHAMSI Imran Haider 《Journal of Zhejiang University. Science. B》2007,8(4):266-271
The effects of salinity(50 mmol/L NaCl) and Cd(1 μmol/L CdCl2) as sole and combined on growth and photosyn-thetic parameters were studied using two soybean genotypes,Huachun 18 and NGB.The concentrations of Cd2 ,Zn2 ,Ca2 ,Mg2 ,K and Na were also determined in seeds and pods.Huachun 18 suffered a more serious decrease than NGB in net photosynthetic rate(Pn) in the treatments of salinity stress alone and combined stress(NaCl Cd),showing that it is relatively sensitive to salinity.The decrease in Pn caused by salt stress in Huachun 18 was mainly due to the reduced total chlorophyll content and photosynthetic efficiency(the ratio of variable fluorescence to maximal fluorescence,Fv/Fm),whereas the decease in NGB was mainly related to reduced stomatal conductance(Gs).The combined stress of both Na and Cd did not induce further decrease in photosynthesis and fluorescence in the two genotypes relative to salt or Cd stress alone.Greater change in the pod concentrations of Zn2 ,Ca2 ,Mg2 ,K and Na was detected under salt stress for Huachun 18 than for NGB.The results suggested that the interactive effect of NaCl-Cd on growth and nutrient uptake differs between the two soybean genotypes. 相似文献
19.
INTRODUCTION With the development of modern electronics,there is a growing trend of designing a low-voltagehigh precision current reference in many mixed-signaland analog circuits such as data converters (Mehr andSinger, 2000; Oh et al., 2004), oscillators and PLLs(Razavi, 2001; Banba and Shiga, 1999). Low-costreasons need the reference to be realized in simplestandard CMOS logic process technology, withoutresorting to the use of BiCMOS process and specialdevices such as floating-g… 相似文献
20.
ZAKHARENKO A.A. 《浙江大学学报(A卷英文版)》2007,8(4):669-674
Acoustic wave propagation in piezoelectric crystals of classes?43m and 23 is studied. The crystals Tl3VS4 and Tl3TaSe4 (43m) of the Chalcogenide family and the crystal Bi12TiO20 (23) possess strong piezoelectric effect. Because the surface Bleustein-Gulyaev waves cannot exist in piezoelectric cubic crystals, it was concluded that new solutions for shear-horizontal surface acoustic waves (SH-SAWs) are found in the monocrystals using different electrical boundary conditions such as electri- cally “short” and “open” free-surfaces for the unique [101] direction of wave propagation. For the crystal Tl3TaSe4 with coefficient of electromechanical coupling (CEMC) Ke2=e2/(C×g)～1/3, the phase velocity Vph for the new SH-SAWs can be calculated with the following formula: Vph=(Va Vt)/2, where Vt is the speed of bulk SH-wave, Vt=Vt4(1 Ke2)1/2, Va=aKVt4, aK=2[Ke(1 Ke2)1/2-Ke2]1/2, and Vt4=(C44/ρ)1/2. It was found that the CEMC K2 evaluation for Tl3TaSe4 gave the value of K2=2(Vf–Vm)/Vf～0.047 (～4.7%), where Vf～848 m/s and Vm~828 m/s are the new-SAW velocities for the free and metallized surfaces, respectively. This high value of K2(Tl3TaSe4) is significantly greater than K2(Tl3VS4)～3% and about five times that of K2(Bi12TiO20). 相似文献