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801.
A catalytic oxidative esterification of aldehydes using V2O5-H2O2   总被引:1,自引:0,他引:1  
[reaction: see text] Aldehydes, in the presence of methanol, undergo oxidative transformation to the corresponding esters upon treatment with catalytic amounts of vanadium pentoxide in combination with oxidant hydrogen peroxide. Mild reaction conditions, shorter reaction times, high efficiencies, cost-effectiveness, and facile isolation of the desired products make the present methodology a practical alternative.  相似文献   
802.
The management of a fishery is a complex task generally involving multiple, often conflicting, objectives. These objectives typically include economic, biological and social goals such as improving the income of fishers, reducing the catch of depleted species and maintaining employment.Multicriteria decision making (MCDM) techniques appear wellsuited to such a management problem, allowing compromises between conflicting objectives to be analysed in a structured framework. In comparison to other fields, such as water resource planning, forestry and agriculture, there have been few applications of MCDM to fisheries.In this paper, a goal programming model of the North Sea demersal fishery is presented. The model is used to demonstrate the potential applicability of this type of approach to the analysis and development of fisheries management plans with multiple objectives. Alternative scenarios are considered for the problem, and tradeoffs between given objectives are also highlighted and discussed.  相似文献   
803.
Using 13.4 fb(-1) of data collected with the CLEO detector at the Cornell Electron Storage Ring, we have observed 300 events for the two-photon production of ground-state pseudoscalar charmonium in the decay eta(c)-->K(0)(S)K-/+pi(+/-). We have measured the eta(c) mass to be [2980.4+/-2.3 (stat)+/-0.6 (syst)] MeV and its full width as [27.0+/-5.8 (stat)+/-1.4 (syst)] MeV. We have determined the two-photon partial width of the eta(c) meson to be [7.6+/-0.8 (stat)+/-0.4 (syst)+/-2.3 (br)] keV, with the last uncertainty associated with the decay branching fraction.  相似文献   
804.
In this paper we present a novel technique for the computation of orthonormal polynomial expansions. The proposed method is very straightforward; given a function to be expanded in a polynomial series, we first use the FFT to compute a vector of Fourier coefficients. Then, using a change of basis transformation, we go from the Fourier coefficients to the polynomial coefficients. Convergence properties for this new approach are investigated.  相似文献   
805.
The nitrosation of monophenylamido substituted quadridentate Schiff base complexes of copper(II) are observed to adopt N-bonded isonitroso coordination whereas the phenylisocyanation of the corresponding mononitrosated quadridentate complexes are found to prefer O-bonded isonitroso coordination.  相似文献   
806.
807.
1-Aryl-2-(2′-benzimidazolyl)-4,6-diphenyl-pyridiniums are converted photochemically into 2-[2′-(1′-arylbenzimidazolyl)]-4,6-diphenylpyridines. X-Ray crystal analysis comfirms the structure for the p-chlorophenyl derivative.  相似文献   
808.
809.
Lattice entrapment of glycolytic enzymes   总被引:1,自引:0,他引:1  
  相似文献   
810.
It is shown that in junction lasers containing absorbing traps the onset of stimulated emission is followed by a reduction of spontaneous emission such as observed by Nicoll and Brosson et al. Detailed agreement with the latter's experimental results is obtained.  相似文献   
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