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991.
主要研究改进集的一些拓扑运算性质。首先在改进集条件下给出了拓扑向量空间中两个非空集之和的拓扑内部的一些运算性质。进一步,利用改进集获得了 Flores-Baz′an 和 Hern′andez 提出的假定 B 的一个加强形式。此外,给出了一些例子对主要结果进行了解释。 相似文献
992.
In this paper, we propose a projection subgradient method for solving some classical variational inequality problem over the set of solutions of mixed variational inequalities. Under the conditions that $T$ is a $\Theta $ -pseudomonotone mapping and $A$ is a $\rho $ -strongly pseudomonotone mapping, we prove the convergence of the algorithm constructed by projection subgradient method. Our algorithm can be applied for instance to some mathematical programs with complementarity constraints. 相似文献
993.
Dongzhen Li Xiaodong Xu Yan Cheng Shishu Cheng Dahua Zhou Feng Wu Changtai Xia Jun Xu Jian Zhang 《Journal of Crystal Growth》2010,312(14):2117-2121
A Yb3+-doped CaYAlO4 laser crystal has been grown by the Czochralski technique. The segregation coefficient was measured by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The cell parameters were analyzed with X-ray diffraction experiments. Color defects in Yb:CaYAlO4 have been evidenced to be similar to those in undoped CaYAlO4. The polarized absorption spectra and the fluorescence spectrum of the Yb:CaYAlO4 crystal were measured at room temperature. The fluorescence decay time of the Yb3+ ion was investigated. The results show that Yb:CaYAlO4 has potential as a laser gain medium for an ultrashort laser system. 相似文献
994.
Polypropylene/poly(butyl methacrylate)(PP/PBMA) blends were prepared by diffusion and subsequent polymerization of butyl methacrylate(BMA) in commercial isotactic polypropylene(iPP) pellets.The diffusion kinetics,diametrical distribution of PBMA in a pellet and phase morphology of a typical PP/PBMA blend were investigated. 相似文献
995.
Interfacial area transport equation (IATE) is considered promising to evaluate dynamic changes of the interfacial area concentration in gas–liquid two-phase flows, which is of significance in characterizing the interfacial structure of the flows. Efforts were made by the authors in the past on the implementation of the IATE into computational fluid dynamics codes, such as Fluent. However, it remained unclear whether the IATE model coefficients derived from one-dimensional IATE model calibrations can be applied to three-dimensional simulations. The current study aimed to examine, primarily by investigating the lateral profiles of phase distributions, the applicability of the coefficients obtained from the one-dimensional IATE model calibration to a three-dimensional simulation of bubbly flow in a pipe. In addition, effects of the lift force on the lateral phase distributions were studied. A new set of the IATE model coefficients was suggested for a three-dimensional bubbly flow simulation. Good agreement was obtained with the updated coefficients between the predicted and measured flow parameters. 相似文献
996.
Cheng-Fang Qiao Qing Wei Zheng-Qiang Xia Chun-Sheng Zhou San-Ping Chen 《Journal of Thermal Analysis and Calorimetry》2012,107(2):527-533
Six lanthanide compounds [Ln(H2O)9](m-BDTH)3·9(H2O) where Ln = La (1), and [Ln(H2O)8](m-BDTH)3·9(H2O) (m-BDTH2 = 1,3-benzeneditetrazol-5-yl) where Ln = Lu (2), Yb (3), Er (4), Ho (5) and Y (6) were hydrothermally synthesized and characterized by elemental analyses, infrared spectra, powder X-ray diffraction (PXRD)
and X-ray single crystal diffraction. PXRD indicates that 2–6 are isomorphous. Structural analyses reveal that 1 is coordinated by nine water molecules forming a capped-square antiprism, while 2–6 are coordinated by eight water molecules forming a simple square antiprismatic geometry. Effects of water molecules on thermal
stability were also discussed by thermogravimetric (TG), DSC, and PXRD under different temperatures. TG analyses suggest that
1 loses lattice and coordinated water molecules with no diacritical boundary, and 6 removes lattice water molecules first and then coordinated water molecules. DSC and PXRD further confirm the consequence. 相似文献
997.
A self-intermolecular cyclocondensation reaction of 3,4-dihydropyrimidine-2-thione(DHPM) to give a novel tricyclic structure containing DHPM core in the presence of diethyl azodicarboxylate(DEAD) and triphenylphosphine(TPP) at room temperature is reported. 相似文献
998.
An oxidative rearrangement of cyclic tertiary a-hydroxy allylsilanes has been carried out in refluxing ClCH2CH2Cl with pyridinium chlorochromate(PCC).The reaction provides a convenient method to synthesize cyclicβ-silylenones in modest to excellent yields. 相似文献
999.
Disulfides have been synthesized by oxidation of thiols using air as oxidant catalyzed by Co-Salophen with high yields,mild and neutral conditions,and easy procedures of the catalyst.The products were confirmed by ~1H NMR and IR. 相似文献
1000.
In this paper, current-driven state-bistability and power-bistability in a distributed feedback (DFB) semiconductor laser
(LD) subject to external optical injection have been investigated experimentally. The results show that, by sweeping the bias
current of slave LD along different routes nearby the threshold, both the power-bistability and the state-bistability between
locking and bimodal regime can be observed under the suitable injection power, but these bistable phenomena will disappear
under much large injection power. Additionally, the dependence of the width of the state-bistablility loop on the injection
power has been discussed. 相似文献