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41.
42.
Görlitz A Vogels JM Leanhardt AE Raman C Gustavson TL Abo-Shaeer JR Chikkatur AP Gupta S Inouye S Rosenband T Ketterle W 《Physical review letters》2001,87(13):130402
Bose-Einstein condensates of sodium atoms have been prepared in optical and magnetic traps in which the energy-level spacing in one or two dimensions exceeds the interaction energy between atoms, realizing condensates of lower dimensionality. The crossover into two-dimensional and one-dimensional condensates was observed by a change in aspect ratio and by the release energy converging to a nonzero value when the number of trapped atoms was reduced. 相似文献
43.
Vara Prasad JV 《Organic letters》2000,2(8):1069-1072
[formula: see text] A simple synthesis of heterocyclic thiosulfonates containing indole, indoline, benzoimidazole, and quinoxaline rings is described. The synthesis of these thiosulfonates involves the preparation of the appropriately substituted thiols followed by sulfonylation to give thiosulfonates. The corresponding thiols were prepared in a simple and efficient manner by using a thiocyanation reaction either prior to heterocycle ring formation or after heterocycle ring formation. These thiosulfonates were coupled successfully to the 5,6-dihydropyran-2-one ring to give products that showed excellent HIV protease activity. 相似文献
44.
P. Santhana Raman K.G.M. Nair R. Kesavamoorthy B.K. Panigrahi S. Dhara V. Ravichandran 《Applied Physics A: Materials Science & Processing》2007,87(4):709-713
Indium nanoclusters are synthesized in an amorphous silica matrix using an ion-implantation technique. Indium ions (In2+) with energy of 890 keV are implanted on silica to fluences in the range of 3×1016–3×1017 cm-2. The formation of indium nanoclusters is confirmed by optical absorption spectrometry and glancing incidence X-ray diffraction
studies. A low frequency Raman scattering technique is used to study the growth of embedded indium nanoclusters in the silica
matrix as a function of fluence and post-implantation annealing duration. Rutherford backscattering spectrometry studies show
the surface segregation of implanted indium. Photoluminescence studies indicate the formation of a small quantity of indium
oxide phase in the ion-implanted samples.
PACS 85.40.Ry; 78.67.Bf; 73.20.Mf; 82.75.Fq 相似文献
45.
A consistent LES/filtered-density function formulation for the simulation of turbulent flames with detailed chemistry 总被引:3,自引:0,他引:3
A hybrid large-Eddy simulation/filtered-density function (LES–FDF) methodology is formulated for simulating variable density turbulent reactive flows. An indirect feedback mechanism coupled with a consistency measure based on redundant density fields contained in the different solvers is used to construct a robust algorithm. Using this novel scheme, a partially premixed methane/air flame is simulated. To describe transport in composition space, a 16-species reduced chemistry mechanism is used along with the interaction-by-exchange with the mean (IEM) model. For the micro-mixing model, typically a constant ratio of scalar to mechanical time-scale is assumed. This parameter can have substantial variations and can strongly influence the combustion process. Here, a dynamic time-scale model is used to prescribe the mixing time-scale, which eliminates the time-scale ratio as a model constant. Two different flame configurations, namely, Sandia flames D and E are studied. Comparison of simulated radial profiles with experimental data show good agreement for both flames. The LES–FDF simulations accurately predict the increased extinction near the inlet and re-ignition further downstream. The conditional mean profiles show good agreement with experimental data for both flames. 相似文献
46.
A bidentate ligand derived from cinnamaldehyde and acetylacetone and its copper(II) complex have been synthesized and characterized
by elemental analysis, UV-Vis, IR, ESR and magnetic susceptibility measurements. Magnetic susceptibility measurements, ESR
and electronic spectral data indicate the presence of six coordinated Cu(II) ion. The ligand and complex are tested for antibacterial
activity againstPseudomonas aeroginosa. They are found to show the antibacterial activity. 相似文献
47.
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This paper provides an example of the application of Pressure Sensitive Paint (PSP) to complex internal suspersonic flows
and demonstrates the relationship between ejector wall pressure and aerodynamic performance. Details of such jet mixer-ejector
nozzles are relevant to jet noise reduction programs. Several ejector configurations with straight, convergent, and divergent
side walls were used in our experiments. The side-wall that was painted with PSP was also instrumented with an array of 156
pressure taps connected to Electronically Scanned Pressure (ESP) modules, enabling simultaneous measurement of “true” reference
pressures. The PSP results agreed very well with the “true” reference pressures and also provided a detailed map of the complicated
pressure patterns that could not be detected using the pressure taps. Finally, we also demonstrated the direct relationship
between ejector side-wall pressure distribution and ejector performance characteristics such as exit mean flow uniformity,
pumping, and thrust augmentation.
Received: 16 December 1997/Accepted: 21 August 1998 相似文献
50.
Knoevenagel condensate Schiff base ligands [L = 3‐cinnamalideneacetylacetone‐thiosemicarbazone (CAT)/3‐cinnama‐ lideneacetylacetoneethylthiosemicarbazone (CAET)/3‐cinnamalideneacetylacetonephenylthiosemicarbazone (CAPT)] and their copper/zinc complexes were synthesized. They were characterized by analytical and spectral techniques. From these data it was found that the ligands adopt square‐planar geometry on metalation with Cu2+ and Zn2+. To evaluate the antitumor and cytotoxic activity of the synthesized complexes in mice and human cancer cell lines, the antitumor activity of the complexes was evaluated against an Ehrlich ascites carcinoma (EAC) tumor model. The activity was assessed using survival time and short‐term in vitro cytotoxic activity. Oral administration of complexes (100 mg/kg) increased the survival time. The cytotoxic activity of complexes was evaluated using human breast cancer (MDA‐MB‐231), colon cancer (HCT‐116) and nonsmall lung cancer (NCI‐H‐23) cell lines. Both the complexes possessed significant antitumor and cytotoxic activity on EAC and human cancer cell lines. The in vitro antimicrobial screening effect of the investigated compounds was also tested against the various organisms by well diffusion method. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献