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131.
Recently, van Neerven, Weis and the author, constructed a theory for stochastic integration of UMD Banach space valued processes. Here the authors use a (cylindrical) Brownian motion as an integrator. In this note we show how one can extend these results to the case where the integrator is an arbitrary real-valued continuous local martingale. We give several characterizations of integrability and prove a version of the Itô isometry, the Burkholder–Davis–Gundy inequality, the Itô formula and the martingale representation theorem. 相似文献
132.
H. X. Phu 《Numerical Functional Analysis & Optimization》2013,34(7-8):915-920
H. Minkowski proved C= convext C whenever C is a compact convex subset of a finite-dimensional linear space. If C is bounded but not closed, this representation does not hold anymore. In this case, we introduce the set of so-called γ-extreme points extγC of C and show C = convext γ C = raco extγ C, where raco M denotes the rational convex hull of M. 相似文献
133.
An investigation by high-resolution transmission electron microscopy of the precipitation process during ageing a Cu–1.2?wt%Be–0.1?wt%Co alloy at 320°C has revealed that the transition phases follow a γ″→ γ″?+?γ′?→?γ sequence. The γ′ phase heterogeneously precipitates on the γ″ phase. The effects of an external stress on the nucleation and growth of disc-shaped γ″ and plate-shaped γ′ precipitates have been examined for the alloy aged at 320°C. A compressive stress applied in the [001] direction during ageing preferentially accelerates the nucleation and growth of the γ″ variant normal to the [001] axis among three crystallographically equivalent variants and the specific four γ′ variants formed on the γ″ variant normal to the [001] axis. A tensile stress does not significantly affect those of γ″ and γ′ precipitates. The critical diameter of the disc-shaped γ″ nucleus is estimated as about 1?nm from evaluation of the interaction energy between the applied stress and the misfit strains of γ″ precipitates. It is proposed that applied external stress does not affect the diffusion rate but the interphase boundary velocity. 相似文献
134.
Y. P. Zhao Y. Xie Q. Wang T. Liu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,49(3):379-382
With pure Ar and gaseous mixtures of Ar-He, the laser spike of Ne-like Ar 46.9 nm pumped by capillary discharge is measured
with XRD (X-ray diode) at low pressure. We observe the effects of the Ar pressure and the He ratio on the amplitude of laser
pulse. Compared with the laser spike of pure Ar, a mixture of Ar and a small quantity of He enhances the laser output. The
time of lasing onset and the duration of laser pulses are not affected by mixing He. In addition, a monochromator is used
to measure the laser pulse at 46.9 nm. This is the first observation of laser output with a Ar-He mixture. 相似文献
135.
Chen Chen Jie Ding Yuebo Wang Xiaonan Shi Dequan Jiao Bolin Zhu 《Tetrahedron letters》2019,60(36):151000
A copper-catalyzed iminohalogenation of unactivated alkenes of γ, δ-unsaturated oxime esters is achieved by using readily available halide salts. Utilizing this protocol, a sequence of structurally diversiform 2-halomethyl pyrrolines are efficiently synthesized and a mechanism involving iminyl radical intermediates, which were initiated by Cu(I) species, was proposed. 相似文献
136.
以NO3-插层类水滑石(NiAl-NO3-LDH)为前驱体制备了一系列不同Ni/Al摩尔比的Ni-Al2O3催化剂,考察了其催化乙酰丙酸液相加氢性能.表征结果表明,随着Ni/Al摩尔比的增加,类水滑石层板结构中存在的游离态γ-AlOOH物种逐步演变为游离的Ni(OH)2物种,制备的催化剂中金属-载体相互作用逐渐减弱,Ni物种分散度逐渐降低,表面酸性中心数量先增多后减少;当Ni/Al摩尔比为3时,所制备的催化剂表面具有最丰富的酸性中心和加氢中心.在酸性中心和加氢中心的协同作用下,该催化剂表现出优异的催化乙酰丙酸加氢合成γ-戊内酯性能及良好的使用稳定性.在160℃,4 MPa氢气条件下反应5 h时,γ-戊内酯的收率最高可达92.7%. 相似文献
137.
The radiation effects induced effects by electron beam (EB) treatment on the catalytic activity of Ni/γ-Al2O3 were studied for the carbon dioxide reforming of methane with different EB energy and absorbed radiation dose. Transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to determine the change in structure and surface states of Ni/γ-Al2O3 catalyst before and after the EB treatment. Higher energy EB treatment is useful for increasing the proportion of the active sites (such as Ni0 and NiAl2O4-phase) on the surface. The increase of Ni/Al-ratio indicates that the Ni dispersion on the surface increased with the EB-treatment, resulting in an increase of the active sites, which leads to improving the catalytic activity. XPS measurement also showed a decrease of the surface carbon with EB dose. The maximum 20% increase in the conversion of CO2/CH4-mixture into CO/H2 gas was observed for the catalyst treated with 2 MeV energy and 600 kGy dose of EB relative to untreated. 相似文献
138.
Federica Valentini Giulia Brufani Benedetta Di Erasmo Luigi Vaccaro 《Current Opinion in Green and Sustainable Chemistry》2022
The great challenge for modern research is to define the most efficient tools to make more sustainable the industrial production and manufacturing. Among the different aspects that require attention the replacement of toxic and/or non-renewable solvents it is certainly playing a crucial role. Dealing with widely used dipolar aprotic solvents, among the different alternatives proposed in the literature γ-valerolactone (GVL) plays a pivotal role covering different application area. In this contribution, the benefits derived from the use of GVL as a circular, safe, biomass-derived reaction medium are highlighted covering most recent publications (2021). The presentation has been divided into three major sections: (i) biomass valorization, (ii) materials synthesis, manufacturing and recycle and (iii) new synthetic methodologies. 相似文献
139.
An expedient oxidative phosphorylation of pyrroles has been disclosed. The reaction of dialkyl phosphite and pyrrole in the presence of AgNO3/K2S2O8 in DMF/H2O (8:1) produced pyrrole-2-phosphonates in good yields. In the absence of dialkyl phosphite, γ-hydroxy-γ-butyrolactam derivative was formed as a major product. 相似文献
140.
Aicha Mhamdi 《Green Chemistry Letters and Reviews》2018,11(1):12-17
A green and versatile method for the preparation of γ-hydroxyphosphonate and phosphine oxide derivatives in 5?min, is accomplished through the reduction of γ-phosphonylketones with sodium borohydride supported on alumina, at room temperature, under solvent free conditions. 相似文献