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An efficient synthesis of substituted alkyl acrylates using α-keto amides

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Chinese Chemical Letters 2008年第2期19卷 175-179页

作者： R. Baharfar M. Tajbakhsh A. Hamedaninejad S.J. Hosseini Department of Chemistry University of Mazandaran P.O. Box 453 Babolsar Iran

The addition of α-keto amides as a NH-acid to alkyl p.o.iolates and dialkyl acetylenedicarboxylates in the presence of a catalytic amount of triphenylp.o.phine gives the corresponding substituted alkyl acrylates.

关键词： Alkyl p.o.iolate Triphenylp.o.phine NH-acids organop.o.p.o.us compounds

RoBUST H_∞ DESIGN oF THE ATTITUDE CoNTRoL/MoMENTUM MANAGEMENT SYSTEM FoR A SpACE STATIoN

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Chinese Journal of Aeronautics 1999年第4期12卷 227-230页

作者：周凤岐赵超周军 p.o. box 250 Northwestern Polytechnical University Xi''an 710072 China

Through input-output decom position of structured param eter uncertainties of the con- trolled plant, the robustcontrolp.o.lem ofspace station attitude system w ith param eteruncertainties is converted to a conventionaldisturbance rejection H∞ controller design p.o.lem , then a full-state feedback H∞ robustcontrollerisform ulated, w hich can be solved using the Glover-Doyle algorithm . The p.o.osed m ethod w asapplied to the attitude control/m om entum m anagem ent (ACMM) system ofa space station, and tw o kinds of param eter uncertainties w hich appear m ost frequently in space- craftengineering w ere considered. Sim ulation results show ed efficiency ofthe given m ethod.

关键词： space station attitude control param eteruncertainty robustness

Stochastic Resonance Induced by an Asymmetric Two-state Noise

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Communications in Theoretical physics 2005年第3X期44卷 426-430页

作者： HAN Yin-Xia Graduate School of China Academy of Engineering physics P.O. Box 2101 Beijing 100088 China CCAST (World Laboratory) P.O. Box 8730 Beijing 100080 China Center for Nonlinear Studies Institute of Applied Physics and Computational Mathematics P.O. Box 8009(28) Beijing 100088 China

Stochastic resonance （SR） phenomenon of the system that is subject to the asymmetric two-state noise is investigated from the broad sense. It is shown that the amplitudes of the output signal exhibit the non-monotonic dependence on the input signal frequency w, and the parameters describing the asymmetric two-state noise, such as the transition rate A, the order parameter k describing the asymmetric degree of the two-state noise, and the noise strength D.

关键词： dichotomous noise stochastic resonance the first moment

Mineralogy,M-type tetrad effect and radioactivity of altered granites at the *** Garadi shear zone,central Eastern Desert,Egypt

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Chinese Journal of Geochemistry 2011年第2期30卷 153-164页

作者： El Nahas H.A. El Feky M.G. Mira H. Nuclear Materials Authority P.O. Box 530 Cairo Egypt

The G. Abu Garadi area is covered mainly by metasediments, alkali feldspar granites and stream sediments. The alkali feldspar granite is traversed by a major strike-slip fault trending in an N-S direction as well as two subordinate sets of faults trending NW to WNW for the first one and NE for the second one. These faults represent the shear zones affected by magmatic (syngenetic) as well as hydrothermal (epigenetic) activities causing alteration of the granitic rocks. The most common alteration features are albitization, greisenization and koalinitization. The mass balance calculations of the studied altered samples show enrichments in Zr, Y, Ni, U, Th and Ga and depletions in Zn, Sr, Nb, Ba, pb, Cu and V. only the greisenized samples exhibit a significant enrichment in Nb, ∑REE budget and p.o.ounced lanthanide tetrad effect (M-type), especially TE1,4, while weakly expressed tetrad effects are for the other albitized and koalinitized samples. Mineralogically, the common accessory minerals in the altered samples include samarskite-(Y), betafite, uranothorite, zircon, fluorite and cassiterite. The greisenized granites contain high eU and eTh than the other altered types, where they are characterized by an assemblage of the radioactive minerals; samarskite-(Y), betafite, uranothorite in addition to zircon. The inter-element relationships between U and Th and also their ratios illustrate that the radioelement distribution in these granites is mainly governed by magmatic p.o.esses, in addition to post-magmatic ones. The distribution of chemical elements and the fractionation of some isovalents within the shear zone are largely controlled by the newly formed mineral phases. With respect to uranium mobilization, uranium migrated from the host alkali feldspar granites of G. Abu Garadi, while the shear zones acted as traps for the migrated uranium. Moreover, U migrated in the shear zone during greisenization and albitization, and migrated out during koalinitization.

关键词： M 类型四个效果改变的花岗石 G。Abu Garadi 砍地区中央东方沙漠埃及

Effect of Asymmetric potential and Gaussian Colored Noise on Stochastic Resonance

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Communications in Theoretical physics 2005年第2X期44卷 226-230页

作者： HAN Yin-Xia LI Jing-Hui CHEN Shi-Gang Graduate School of China Academy of Engineering physics P.O. Box 2101 Beijing 100088 China CCAST (World Laboratory) P.O. Box 8730 Beijing 100088 China Center for Nonlinear Studies Institute of Applied Physics and Computational Mathematics P.O. Box 8009(28) Beijing 100088 China

The phenomenon of stochastic resonance （SR） in a bistable nonlinear system is studied when the system is driven by the asymmetric potential and additive Gaussian colored noise. Using the unified colored noise app.o.imation method, the additive Gaussian colored noise can be simplified to additive Gaussian white noise. The signal-to-noise ratio （SNR） is calculated according to the generalized two-state theory （shown in [H.S. Wio and S. Bouzat, Brazilian ***. 29 （1999） 136]）. We find that the SNR increases with the p.o.imity of a to zero. In addition, the correlation time T between the additive Gaussian colored noise is also an ingredient to imp.o.e SR. The shorter the correlation time T between the Gaussian additive colored noise is, the higher of the peak value of SNR.

关键词： additive Gaussian colored noise stochastic resonance signal-to noise ratio

Borescopic particle image velocimetry in bubbling gas-solid fluidized beds

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particuology 2019年第2期17卷 66-75页

作者： M. Banaei R. Dellaert N.G. Deen J.A.M. Kuipers M. van Sint Annaland Multiphase Reactors Group Department of Chemical Engineering & Chemistry Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands Dutch polymer Institute (DpI) P.O. Box 902 5600 AX Eindhoven The Netherlands Multiphase and Reactive Flows Group. Department of Mechanical Engineering Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands

In this work, the borescopic particle image velocimetry (BpIV) technique was applied to a bubbling gas-solid fluidized bed, and the results were compared with published positron emission particle tracking (pEpT) measurement data. Before performing the experiments, the sensitivity of the BpIV results to the illumination power, light reflectivity of the particles, and location of the borescope was also investigated. The BpIV and pEpT results were in fair agreement;however, some discrepancies were *** difference between the two sets of results were mainly caused by the intrusiveness of BpIV, the fact that the local solids volume fraction was not accounted for in the BpIV analysis, and the intrinsic differences of these two methods. Therefore, measurement of the local solids volume fraction with the borescope is highly recommended for further development of the BpIV method, which will also enable measureme nt of the local solids mass fluxes in side dense gas-solid fluidized beds.

关键词： Borescopic particle image velocimetry Gas-solid bubbling fluidized bed Solid velocity p.o.ile Experimental investigation Hydrodynamics

AN EFFICIENT pARALLEL p.o.ESSING opTIMAL CoNTRoL SCHEME FoR A CLASS oF NoNLINEAR CoMpoSITE SYSTEMS

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Acta Mathematica Scientia 2017年第3期37卷 703-721页

作者： A. JAJARMT M. HAJIpoUR Department of Electrical Engineering University of Bojnord P.O. Box 94531-1339 Bojnord Iran Department of Mathematics Faculty of Basic Sciences Sahand University of Technology P.O. Box 51335-1996 Tabriz Iran

This article presents an efficient parallel p.o.essing app.o.ch for solving the opti- mal control p.o.lem of nonlinear composite systems. In this app.o.ch, the original high-order coupled nonlinear two-point boundary value p.o.lem （TpBVp） derived from the pontrya- gin＇s maximum principle is first transformed into a sequence of lower-order deeoupled linear time-invariant TpBVps. Then, an optimal control law which consists of both feedback and forward terms is achieved by using the modal series method for the derived sequence. The feedback term specified by local states of each subsystem is determined by solving a ma- trix Riccati differential equation. The forward term for each subsystem derived from its local information is an infinite sum of adjoint vectors. The convergence analysis and parallel p.o.essing capability of the p.o.osed app.o.ch are also p.o.ided. To achieve an accurate feedforward-feedbaek suboptimal control, we apply a fast iterative algorithm with low com- putational effort. Finally, some comparative results are included to illustrate the effectiveness of the p.o.osed app.o.ch.

关键词： Modal series method nonlinear composite system optimal control parallelp.o.essing

Baryogenesis in f(R, T) Gravity

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Communications in Theoretical physics 2018年第10期70卷 451-458页

作者： Kourosh Nozari Fateme Rajabi Department of physics Faculty of Basic Sciences University of Mazandaran P.O. Box 47416-95447 Babolsar Iran Research Institute for Astronomy and Astrophysics of Maragha (RIAAM) P.O. Box 55134-441 Maragha Iran

We study gravitational baryogenesis in the context of f(R, T) gravity where the gravitational Lagrangian is given by a generic function of the Ricci scalar R and the trace of the stress-energy tensor T. We exp.o.e how this type of modified gravity is capable to shed light on the issue of baryon asymmetry in a successful manner. We consider various forms of baryogenesis interaction and discuss the effect of these interaction terms on the baryon to entropy ratio in this setup. We show that baryon asymmetry during the radiation era of the expanding universe can be non-zero in this framework. Then, we calculate the baryon to entropy ratio for some specific f(R, T) models and by using the observational data, we give some constraints on the parameter spaces of these models.

关键词： baryogenesis modified gravity observational data

Gorenstein Injective and Injective Complete Cohomological Dimensions of Groups

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Algebra Colloquium 2015年第3期22卷 469-478页

作者： Abdolnaser Bahlekeh Department of Mathematics Gonbade-Kavous University P.O. Box 49717-99151 Gonbade-Kavous Iran School of Mathematics Institute for Research in Fundamental Science (IPM) P.O. Box 19395-5746 Tbhran Iran

Using Nucinkis＇s injective complete cohomological functors, we assign a numerical invariant to each group p, called the injective complete cohomological dimension of F, denoted by iccd p. We study this dimension and investigate its p.o.erties. Also, we define the Gorenstein injective dimension of the group F, which is denoted by Gid F. We show that Gid F is related to iccd F, as well as to spli and silp invariants of Gedrich and Gruenberg. In particular, it is shown that iccd p is a refinement of Gid p. In addition, we show that silp F = spli F 〈 ∞if and only if the Shapiro lemma holds for injective complete cohomology.

关键词： I-complete cohomology complete injective resolution Gorenstein injective modules