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51.
Stable equivalences are studied between any finite dimensional algebra A with a simple projective module and a simple injective module and an algebra B obtained from A by ‘gluing’ the corresponding idempotents of A; this extends results by Martinez-Villa. Stable equivalences modulo projectives are compared to stable equivalences modulo semisimples, and in either situation a characterization is given for a radical embedding to induce such a stable equivalence. 相似文献
52.
This paper is concerned with chaos induced by regular snap-back repellers. One new criterion of chaos induced by strictly coupled-expanding maps in compact sets of metric spaces is established. By employing this criterion, the nondegenerateness assumption in the Marotto theorem established in 1978 is weakened. In addition, it is proved that a regular snap-back repeller and a regular homoclinic orbit to a regular expanding fixed point in finite-dimensional spaces imply chaos in the sense of Li-Yorke. An illustrative example is provided with computer simulations. 相似文献
53.
Alan R. Katritzky Yuming Song Rajeev Sakhuja Reena Gyanda Nabin K. Meher Ling Wang Randolph S. Duran David A. Ciaramitaro Clifford D. Bedford 《Journal of polymer science. Part A, Polymer chemistry》2009,47(15):3748-3756
Second‐, third‐, and fourth‐generation hyperbranched aliphatic polyols namely Boltorn® H20, Boltorn H30, and Boltorn H40 were endcapped with azido and activated acetylenic groups in good to excellent yields (75–95%) following an acid catalyzed procedure. The resultant terminally functionalized dendritic azido and acetylenic groups undergo 1,3‐dipolar cycloaddition using methyl (or ethyl) propiolate and benzyl azide, respectively, under catalytic or noncatalytic conditions below 40 °C to yield 1,2,3‐triazole dendrimeric polymers in 82–95% yield, under extremely mild conditions that could be applied for compounds sensitive to acid, base, or heat. The dendritic azido and activated acetylenic derivatives may act as novel scaffolds to tune the mechanical properties of different polymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3748–3756, 2009 相似文献
54.
对a∈(0,1/2)和r∈(0,1),Ramanujan广义模方程中的广义Grǒtzsch环函数μa(r)定义如下:μa(r)=[πκa^1(r)]/[2sin(πa)κa(r)].该文通过研究μs(r)和μ(r)的关系,以及μa(r)和一些初等函数的组合的单调性和凹凸性,获得了μa(r)的几个精确不等式,从而把μ(r)的一些熟知的性质推广到μa(r)上. 相似文献
55.
Yang Y Nie W Yuan J Zhang B Wang Z Wu Z Guo Y 《Experimental & molecular medicine》2010,42(11):768-776
Deregulation of endothelial nitric oxide synthase (eNOS) plays an important role in the development of multiple cardiovascular diseases. Our recent study demonstrated that genistein supplementation attenuates pulmonary arterial hypertension in broilers by restoration of endothelial function. In this study, we investigated the molecular mechanism by using broiler pulmonary arterial endothelial cells (PAECs). Our results showed that genistein stimulated a rapid phosphorylation of eNOS at Ser(1179) which was associated with activation of eNOS/NO axis. Further study indicated that the activation of eNOS was not mediated through estrogen receptors or tyrosine kinase inhibition, but via a phosphatidylinositol 3-kinase (PI3K)/Akt-dependent signaling pathway, as the eNOS activity and related NO release were largely abolished by pharmacological inhibitors of PI3K or Akt. Thus, our findings revealed a critical function of Akt in mediating genistein-stimulated eNOS activity in PAECs, partially accounting for the beneficial effects of genistein on the development of cardiovascular diseases observed in animal models. 相似文献
56.
A series of carbazole cationic compounds based on donor- Π—acceptor (D-Π-A) structure were synthesized and characterized.
They exhibit large two-photon absorption cross sections when excited by a 810 nm a laser beam, and their photophysical properties
show that the intramolecular charge transfer (ICT) character is predominant. Moreover these compounds can easily pass though
the intact cell membrane of living cells, amongst, 3-(1-hydroxyethyl -4-vinylpyridium iodine)-N-butyl carbazole (9B-HVC) has
been proven to be capable of accumulating within the mitochondria possessing large membrane potential and imaging this organelle
in living cells by means of two-photon fluorescence microscopy. At the same time usable fluorescent photos can be obtained
at lower incident excitation power (5 mW) and low-micromolar concentrations (2 μM), which does not result in significant reduction
in cell viability over a period of at least 24 h. 相似文献
57.
Cerium oxide based coatings were prepared on AA2024 Al alloy by brush plating. The characteristic of this technology is that hydrogen peroxide, which usually causes the plating solution to be unstable, is not necessary in the plating electrolyte. The coating showed laminated structures and good adhesive strength with the substrate. X-ray diffraction and X-ray photoelectron spectroscopy analysis showed that the coatings were composed of Ce(III) and Ce(IV) oxides. The brush plated coatings on Al alloys improved corrosion resistance. The influence of plating parameters on structure and corrosion resistance of the cerium oxide based coating was studied. 相似文献
58.
Dan Zhang Binxiang Dai Yuming Chen 《Mathematical Methods in the Applied Sciences》2014,37(10):1538-1552
In this paper, we consider the existence of solutions for second‐order nonlinear damped impulsive differential equations with Dirichlet boundary condition. By critical point theory, we obtain some existence theorems of solutions for the nonlinear problem. We extend and improve some recent results. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
59.
Yiwei Zhang Yuming Zhou Lihui Wan Mengwei Xue Yongzheng Duan Xuan Liu .School of Chemistry Chemical Engineering Southeast University Nanjing Jiangsu China .Biochemical Environmental Engineering College Nanjing Xiaozhuang University Nanjing 《天然气化学杂志》2011,20(6):639-646
Catalytic dehydrogenation of isobutane has recently received considerable attention because of the increasing demand for isobutene.In this study,the synergistic effect between Sn and K on PtSnK/γ-Al2O3 catalysts has been investigated by changing the content of Sn.It was found that with the presence of potassium,suitable addition of Sn could not only increase the metal dispersion,but also reduce the catalyst acidity.In these cases,the synergistic effect could also strengthen the interactions between the metal and support,which resulted in an increase in both catalytic activity and stability.In our experiments,Pt-0.6SnK/Al catalyst exhibited the lowest deactivation rate (12.4%) and showed a selectivity to isobutene higher than 94% at the isobutane conversion of about 45.3% after running the reaction for 6 h.However,with the excessive loading of Sn,surface property of active sites and the interactions between metal and support were changed.As a result,the initial optimal ratio between the metallic function and acid function would be destroyed,which was disadvantageous to the reaction. 相似文献
60.
We prove that if a space X is well ordered (αA), or linearly semi-stratifiable, or elastic then X is a D-space. 相似文献