Invariant Subspace Approach to Linear H∞-Control via Measurement Feedback

This paper analyzes, and thus reveals the structure of the stable invariant subspace of the related Hamiltonian matrix arising from the measurement feedback H -control problem. Using this, it presents another method for the verification of the admissibility of the controller derived by Doyle et al. in 1989. The method not only eliminates unnecessary assumptions on stabilizability and detectability, but also gives deeper insight into the relationship among the stable parts of the associated matrices.     

超高效液相色谱-四极杆飞行时间质谱测定动物饲料中3种巴比妥类违禁药物

建立了超高效液相色谱-四极杆飞行时间质谱(UPLC-O-TOF-MS)快速检测动物饲料中违禁添加的巴比妥、苯巴比妥和异戊巴比妥3种药物的分析方法.样品经甲醇振荡提取,再用C18固相萃取柱净化处理后,采用UPLC-O-TOF-MS分析检测.在电喷雾负离子模式和飞行时间模式下,以20mDa为提取离子窗口,输入各化合物的精确...     

Nanostructured polyelectrolyte-surfactant complex pervaporation membranes for ethanol recovery: the relationship between the membrane structure and separation performance

Polyelectrolyte-surfactant complexes (PESCs) were fabricated through the interaction of poly(acrylic acid) and four different cationic surfactants or their mixtures.PESC membranes were prepared by solution casting method and were applied in ethanol recovery from aqueous solution via pervaporation.Elemental analysis (EA),Fourier transform infrared spectroscopy (FTIR),water contact angle (CA) measurement,differential scanning calorimetry (DSC) and X-ray scattering were employed to characterize the composition,structure and properties of PESCs.The results reveal that the investigated PESCs are similar in hydrophobicity but different in hierarchical nanostructures.In separating 5 wt％ ethanol/water mixture,PESC membranes with high crystallinity will have both low flux and ethanol selectivity because of the high packing density and low permeability of crystalline regions.Meanwhile,the hierarchical nanostructures of PESC membranes change under pervaporation environment as was revealed by in situ synchrotron radiation X-ray scattering measurement.That is,the crystalline region could melt at high temperature in swelling state,thus consequently enhancing the ethanol selectivity.     

Palladium-catalyzed carbonylative annulation reaction of 2-(1-alkynyl)benzenamines: selective synthesis of 3-(halomethylene)indolin-2-ones

A novel and selective palladium-catalyzed carbonylative annulation process for the synthesis of 3-(halomethylene)indolin-2-ones was demonstrated. In the presence of PdX2 and CuX2, 3-(halomethylene)indolin-2-ones were selectively obtained from the carbonylative annulations of 2-(1-alkynyl)benzenamines with CO in moderate to good yields.     

Asymptotic Behavior of Soliton Solutions with a Double Spectral Parameter for Principal Chiral Field

The soliton solutions with a double spectral parameter for the principal chiral field are derived by Darboux transformation. The asymptotic behavior of the solutions as time tends to infinity is obtained and the speeds of the peaks in the asymptotic solutions are not constants.     

Asymptotic Behavior of Soliton Solutions with a Double Spectral Parameter for Principal Chiral Field

The soliton solutions with a double spectral parameter for the principal chiral field are derived by Darboux transformation. The asymptotic behavior of the solutions as time tends to infinity is obtained and the speeds of the peaks in the asymptotic solutions are not constants.     

高Tg交联型二阶非线性光学聚合物的合成

合成了双羟基双氨基偶氮苯化合物，将其分别与六亚甲基二异氰酸酯的缩二脲和２，４－甲苯二异氰酸酯进行交联反应合成了两种交联型二阶非线性光学聚合物，利用ＦＴＩＲ光谱和ＤＳＣ对交反应过程和交联聚合物的玻璃化转变温度进行研究。采用ＵＶ－Ｖｉｓ吸收光谱对极化交联反应前后膜的取向及取向稳定性进行了研究。     

Preparation of pH-responsive phenolphthalein poly(ether sulfone) membrane by redox-graft pore-filling polymerization technique

In this communication, a simple method for the preparation of environmentally responsive membrane, in situ redox-graft pore filling polymerization, was reported. Phenolphthalein poly(ether sulfone) dissolved in dimethyl sulfoxide was used to prepare porous membranes by means of classical phase inversion method. After that, methylacrylic acid was grafted successfully onto the membranes using the method reported here. Then, surface chemical changes and membrane morphology changes before and after graft polymerization were investigated by the ATR–FTIR and FESEM, respectively, to ascertain the formation and location of graft. Besides, the graft yield was also determined gravimetrically under different monomer concentrations. At last, in the hydraulic permeability experiments and diffusional permeability experiments using VB₁₂ and KCl as solutes, the grafted membranes prepared using the reported method exhibited marked, rapid and reversible pH-response.