MIXED H_2/l_1 OPTIMIZATION PROBLEMS FOR SISO DISCRETE TIME CONTROL SYSTEMS

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｄｅｓｉｇｎｏｆｃｏｎｔｒｏｌｌｅｒｓｓａｔｉｓｆｙｉｎｇｍｉｘｅｄｐｅｒｆｏｒｍａｎｃｅｃｒｉｔｅｒｉａ ,ｓｕｃｈａｓｍｉｘｅｄＨ2 /Ｈ∞ｐｒｏｂｌｅｍ(Ｋａｍｉｎｅｒｅｔａｌ.,1 993 ) ,ｍｉｘｅｄｌ1 /Ｈ∞ｐｒｏｂｌｅｍ(Ｓｚｎａｉｅｒｅｔａｌ.,1 996) ,ｍｉｘｅｄｌ1 /Ｈ2ｐｒｏｂｌｅｍ(Ｓａｌａｐａｋａｅｔａｌ.,1 995) ,ｈａｖｅｒｅｃｅｎｔｌｙｂｅｅｎｔｈｅｆｏｃｕｓｏｆｒｅｓｅａｒｃｈｅｒｓ.Ｖｏｕｌｇａｒｉｓ(1 995)ｉｎｔｒｏｄｕｃｅｄｍｉｘｅｄＨ2 /ｌ1 ｏｐｔｉｍ…     

A SISO mixed H_2/l_1 optimal control problem and its solution

INTRODUCTIONOneofthemethodsforsolvingoptimalregu lationandtrackingproblemsinlinearsystemsistheH2 optimalcontrolscheme,wherethecon trollerminimizestheexpectedvalueofanH2normcriterion .Itiswellknown ,however,thattheperformanceoftheH2 optimalcontrollersmaybehighlysensitivetoparameteruncertainty(Doyle,1982 ) .ThisiswhyalternativemethodsthathavebeentriedmayprobablybesuboptimalwithrespecttotheH2 normcriterionofthenom inalsystemononehand ,butwillguaranteesomekindofrobustnesswithrespecttothelarg…     

Mixedl 2/l 1 control for discrete-time systems via lagrange multiplier theory

The dual formulation of the discrete-time mixedl ₂/l ₁ control design problem was achieved by using the duality theory of Lagrange multipliers. For some special dual mixedl ₂/l ₁ problems, an approximation method for the optimal value is introduced. A suboptimal value of the infinite-dimensional dual problem can be obtained by solving a sequence of truncated problems. The convergence property of the solution scheme is investigated. This paper gives a low approximation method for the primal problem. Project(699085) supported by Zhejiang Provincial Natural Science Foundation of China.     

A SISO mixed H2/l1 optimal control problem and its solution

Study of the SISO mixed H2/l1 problem for discrete time systems showed that there exists a unique optimal solution which can be approximated within any prescribed missing error bound in l2 norm with solvable suboptimal solutions and solvable superoptimal solutions.     

锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2的研究概况

本文综述了近几年来锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2的研究进展,重点讨论了LiNi1/3Co1/3Mn1/3O2正极材料的结构,制备方法和改性研究状况。     

化学共沉淀法合成锂离子电池LiNi1/3Co1/3Mn1/3O2正极材料的研究

采用共沉淀法合成了锂离子电池层状LiNi1/3Co1/3Mn1/3O2正极材料。采用TG/SDTA、XRD和SEM对LiNi1/3Co1/3Mn1/3O2正极材料的成分、结构和形貌进行了表征。结果表明,在900℃下煅烧15h制得的材料结晶程度最佳,样品具有最大I（003）/I（104）强比值,层状结构特征最为突出。从单个颗粒来看,样品表面光滑,界面清晰,粒子呈类球状,粒径大约在0.5μm左右,分散较为均匀。另外,添加剂对粒子形貌具有一定的影响。     

化学共沉淀法合成锂离子电池LiNi1/3 Co1/3 Mn1/3 O2正极材料的研究

采用共沉淀法合成了锂离子电池层状LiNi1/3Co1/3Mn1/3O2正极材料。采用TG/SDTA、XRD和SEM对LiNi1/3Co1/3Mn1/3O2正极材料的成分、结构和形貌进行了表征。结果表明,在900℃下煅烧15h制得的材料结晶程度最佳,样品具有最大I（003）/I（104）强比值,层状结构特征最为突出。从单个颗粒来看,样品表面光滑,界面清晰,粒子呈类球状,粒径大约在0.5μm左右,分散较为均匀。另外,添加剂对粒子形貌具有一定的影响。     

La2/3Ca1/3-xBaxMnO3系列稀土锰氧化物Rietveld结构分析

用固相反应法制备了La2/3Cai/3-xBaxMnO3系列样品,利用Rietveld方法精修晶体结构,结果表明,当x≥0.20时,样品由正交结构(Pnma)转变为六方结构(R-3c).本文详细介绍了Rietveld精修过程并分析了Sr2++、Ba2+对材料结构的影响.     

La空位(La(1-x-y)Yy)2/3Ca1/3MnO3的结构和输运性质研究

用固相反应法制备La（1-x）2／3Ca1／3MnO3（V-LCMO）和（La（0.7-x）Y0.3）2／3Ca1/3MnO3）（V-LY-CMO）（x〈0．15）系列的La空位锰氧化物样品。X射线衍射（XRD）测量分析表明所有的样品均为单相,具有正交对称性（Prima）。体系的晶构参数以及Mn-O键长和Mn-O-Mn键角随空位浓度不同而改变,表明局域Jahn-Teller效应的存在。输运测量表明,不同的空位及空位浓度影响磁电阻效应,在X=0．04时磁电阻值在转变温度‰处达到最大值约为220％,我们认为很大的磁电阻效应与Y部分替代La有关,是双交换作用与Jahn-Teller效应竞争的结果。     

从“一+N1+N2”序列的分析实例看三个平面理论的功用

通过对“三个平面”语法理论与“小三角”理论进行比较,可以看出,虽然“三平面”和“小三角”理论的研究指向、研究目的、研究方法有所差异,但是“三平面”和“小三角”都会在具体的研究实践中发挥各自的特定作用,从而使汉语语法事实的描写和解释更加详尽、准确。     

竞技健美操剪式变身跳转体180°动作身体训练的研究

通过采用文献资料法、调查法、特尔菲法等方法,就剪式变身跳转体180°动作的完成所需的身体素质及训练内容进行了深入细致的研究,集合专家意见,得出对此动作进行身体素质训练中柔韧素质训练最为重要,其次是速度素质、力量素质和协调素质的训练.     

黄旭跳马踺子跳转180°接直体笠松的运动学分析

运用运动生物力学三维录相解析方法、文献资料法和访谈法 ,对黄旭完成的跳马踺子跳转 180°接直体笠松动作进行了运动学分析 ,得出了这一动作的有关参数及一般的运动学规律 .主要从上板踏跳、第一腾空、推手、第二腾空四个部分进行了论述     

Positive temperature coefficient of resistivity effects of semiconducting (Bi1/2Na1/2) TiO3-CaTiO3-BaTiO3 ceramics sintered in air atmosphere

Y3+-doped (Bi1/2Na1/2)TiO3-CaTiO3-BaTiO3 (BNCBT) positive temperature coefficient of resistivity (PTCR) ceramics sintered in air atmosphere were investigated in this study. (Bi1/2Na1/2) TiO3 (BNT) component can remarkably increase the onset temperature Tc of PTCR ceramics with the expensive of the resistivity R25 increase. CaTiO3 (9-27 mol%) component can decrease the resistivity, and adjust the effects of BNT phase on the Tc point. For the sample containing 3 mol% CaTiO3, the Tc raises from 122° to 153° when only 0.6 mol% BNT added, while for the ones with higher CaTiO3 content (9-27 mol%), Tc is only increased by a rate of 8-9°/1.0 mol% BNT. The effects of BNT and CaTiO3 components on Rmln (negative temperature coefficient effect) are also discussed.     

Catalytic properties of CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 in NO＋CO reaction

Using SnxTi1-xO2 as carriers, CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 catalysts with different loading amounts of copper oxide (CuO) were prepared by an impregnation method. The catalytic properties of CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 were examined using a microreactor-gas chromatography (GC) NO CO reaction system and the methods of BET (Brun- auer-Emmett-Teller), TG-DTA (themogravimetric and differential thermal analysis), X-ray diffraction (XRD) and H2-temperature programmed reduction (TPR). The results showed that NO conversions of Sn0.9Ti0.1O2 and Sn0.7Ti0.3O2 were 47.2% and 43.6% respectively, which increased to 95.3% and 90.9% at 6 wt% CuO loading. However, further increase in CuO loading caused a decrease in the catalytic activity. The nitrogen adsorption-desorption isotherm and pore-size distribution curve of Sn0.9Ti0.1O2 and Sn0.7Ti0.3O2 represented type IV of the BDDT (Brunauer, Deming, Deming and Teller) system and a typical mesoporous sample. There were two CuO diffraction peaks (2θ 35.5° and 38.7°), and the diffraction peak areas increased with increasing CuO loading. TPR analysis also detected three peaks (α, β and γ) from the CuO-loaded catalysts, suggesting that the α peak was the reduction of the highly dispersed copper oxide, the β peak was the reduction of the isolated copper oxide, and the γ peak was the reduction of crystal phase copper oxide. In addition, a fourth peak (δ) of the catalysts meant that the SnxTi1-xO2 mixed oxides could be reductive.     

A pair of two-component regulatory genes ecrA1/A2 in S. coelicolor

INTRODUCTION S.coelicolor as a model system has been ex-tensively studied with the aid of genetic and mo-lecular techniques. Its ability to produce four anti-biotics (Hopwood et al., 1995), namely actinorhodin (Act), undecylprodigiosin (Red), Calcium-Depend- ent Antibiotic (CDA) and methylenomycin (Mmy), enables studies of pathyway-specific and pleiotropic regulation of antibiotic production. In which, Red is a red-pigmented antibiotic and Act is coelicolor- pigmented antibiotic tha…     

二氧化硅负载硅钨钼酸催化合成异丁醛1,2-丙二醇缩醛

以H4SiW6Mo6O40/SiO2为催化剂,通过异丁醛和1,2-丙二醇为原料合成异丁醛1,2-丙二醇缩醛,探讨了H4SiW6Mo6O40/SiO2催化剂对缩醛反应的催化活性,较系统地研究了原料量比,催化剂用量,反应时间诸因素对产品收率的影响.实验表明:H4SiW6Mo6O40/SiO2是合成异丁醛1,2-丙二醇缩醛的良好催化剂,在n(1,2-丙二醇)∶n(异丁醛)=1.5∶1,催化剂用量为反应物料总质量的1.2%,环己烷为带水剂,反应时间1.0 h的优化条件下,异丁醛1,2-丙二醇缩醛的收率可达75.2%.     

Catalytic dechlorination and detoxification of 1-（2-chlorophenyl） ethanol by Pd/Fe

1-（2-chlorophenyl） ethanol （CPE） is of health and environmental concern due to its toxicity and its use as an intermediate in pharmaceutical manufacturing. The current work deals with the catalytic reductive dechlorination and detoxification of CPE by Pd/Fe bimetal. CPE was effectively dechlorinated to l-phenyl ethanol （PE） accompanied by the equivalent release of chloride. The extent of CPE dechlorination increased with temperature, Fe dosage and Pd loading. A decrease in solution pH increased CPE dechlorination, resulting presumably from an increase in hydrogen production. Under the specific conditions of 20 g/L Pd/Fe, 0.10% Pd （w/w） and initial pH 5-6, the CPE dechlorination was completed within 145 rain. The dechlorination followed a pseudo-first-order kinetics with an activation energy of 56.7 kJ/mol. The results of toxicity testing showed that CPE was very toxic to Chlorella, whereas PE showed little toxicity. The toxicity of the reaction solution declined gradually and the promoting effects on Chlorella intensified consequently with the dechlorination process. Thus, the reductive dechlorination of CPE to PE by Pd/Fe was a detoxification process. It may be used to effectively reduce the toxicological effects of CPE-contaminated wastewater, thereby enhancing the performance of subsequent biological processes in wastewater treatment.     

Positive temperature coefficient of resistivity effects of semiconducting （Bi（1/2）Na（1/2））TiO3-CaTiO3-BaTiO3 ceramics sintered in air atmosphere

Y^3＋-doped （Bi 1/2 Na 1/2） TiO 3-CaTiO 3-BaTiO 3 （BNCBT） positive temperature coefficient of resistivity （PTCR） ceramics sintered in air atmosphere were investigated in this study. （Bi 1/2 Na 1/2） TiO 3 （BNT） component can remarkably increase the onset temperature T c of PTCR ceramics with the expense of the resistivity R 25 increase. CaTiO 3 （9–27 mol%） component can decrease the resistivity, and adjust the effects of BNT phase on the T c point. For the sample containing 3 mol% CaTiO 3 , T c raises from 122 ℃ to 153 ℃ when only 0.6 mol% BNT added, while for the ones with higher CaTiO 3 content （9–27 mol%）, T c is only increased by a rate of 8–9℃/1.0 mol% BNT. The effects of BNT and CaTiO 3 components on R25/Rmin （negative temperature coefficient effect） are also discussed.     

温度场中斜梁受简谐激励的1/2次亚谐-主参数共振

以温度场中斜梁受简谐激励的非线性振动方程为基础,应用非线性振动的多尺度法,求得非线性振动系统1/2亚谐-主参数共振的一次近似解,并进行定常解稳定性分析和数值计算.分析了温度、激励、几何尺寸对1/2亚谐-主参数共振幅频响应曲线的影响.