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排序方式: 共有198条查询结果,搜索用时 15 毫秒
31.
Malik Sunita Gupta Heena Sharma Vinod Kumar 《Journal of Thermal Analysis and Calorimetry》2018,132(2):1263-1275
Journal of Thermal Analysis and Calorimetry - In the present study, molar heat capacities, $$\left( {C_{\text{P}}^{{}} } \right)_{123}$$ , at T/K = 293.15–308.15 K... 相似文献
32.
Keinan S Paquette WD Skoko JJ Beratan DN Yang W Shinde S Johnston PA Lazo JS Wipf P 《Organic & biomolecular chemistry》2008,6(18):3256-3263
Quinoid inhibitors of Cdc25B were designed based on the Linear Combination of Atomic Potentials (LCAP) methodology. In contrast to a published hypothesis, the biological activities and hydrogen peroxide generation in reducing media of three synthetic models did not correlate with the quinone half-wave potential, E(1/2). 相似文献
33.
Anubha Sharma Sunita Gamre Siddharth Roy Dibakar Goswami Angshuman Chattopadhyay Subrata Chattopadhyay 《Tetrahedron letters》2008,49(24):3902-3905
A facile asymmetric synthesis of the octalactin lactone was developed staring from (R)-cyclohexylideneglyceraldehyde (1). The key step of the synthesis is an In-mediated diastereoselective crotylation of 1 in water, which furnished the building blocks with the required stereochemistry under operationally simple conditions. Their conversion to the appropriate intermediates, invertive esterification and a ring closing metathesis reaction furnished the target compound. 相似文献
34.
Three and four bond order couplings between carbonyl carbon and other neighboring protons have been investigated in detail with the help of 2D heteronuclear multiple bond correlation (HMBC) spectrum. The methine and methylene protons in pentad and tetrad configuration were found to couple with carbonyl carbon. The intensity ratio of methylene protons’ cross peaks in HMBC spectrum shows that 50% of poly methyl acrylate (PMA) is in isotactic and 50% is in syndiotactic configuration. The configurational analysis was mainly carried out with the help of 2D HMBC spectrum. 相似文献
35.
Mhaske Harshad P. Vaidya Vikas V. Menon Sasikumar N. Shailajan Sunita Gomes Noel A. 《平面色谱法杂志一现代薄层色谱法》2008,21(3):217-219
JPC – Journal of Planar Chromatography – Modern TLC - 相似文献
36.
37.
Based on a thermodynamic model, we investigate how the density variation influences the smectic (Sm A)–isotropic (I) phase transition. We find that the density variation shifts the smectic A–isotropic transition temperature, however, first-order nature of the transition remains the same. Here, we also examine the effect of high pressure on the thermodynamic quantities. The present analysis shows that the pressure strongly influences the enthalpy and density step at the clearing transition. The pressure dependence of the thermodynamic properties is incorporated through the pressure dependent second Landau coefficient and the coefficients which couple the nematic and smectic order parameters to the density. We find a close agreement between theoretical and experimental results. Furthermore, we discuss the implications of the results for achiral liquid crystals. 相似文献
38.
Effect of temporal jitter on the performance of copper vapor laser (CVL) master oscillator power amplifier (MOPA) chain using Monte-Carlo techniques was studied. The MOPA chain comprised an oscillator and five amplification stages. Amplification of CVL signal in each amplifier stage was modeled using rate equation based optical model. The effect of temporal jitter on the pulse energy stability in CVL MOPA chain was estimated for various jitter values. Our studies show that the pulse energy spread and the pulse energy instability increases with increase in jitter which in turn depends on the gain pulse width and the jitter considered. Pulse to pulse gain variation in CVL MOPA chain was studied along with temporal jitter. The acceptable tolerance limit on temporal jitter is ±4 ns for a pulse energy stability of 5% of CVL MOPA chain. 相似文献
39.
Sharma S Vandana Ghoshal SK Arora P Dilbaghi N Chaudhury A 《Applied biochemistry and biotechnology》2009,159(2):310-316
In the present frame of work, Macrophomina phaseolina is encapsulated in silica matrices at various concentrations by low temperature sol-gel technique using tetraethylorthosilicate
(TEOS) as precursor. The optical and photophysical properties of these samples have been studied by second harmonics of Nd:YAG
laser at 532 nm. UV-visible absorption spectra of samples have been recorded and it is found that the absorption increases
with increase in concentration of fungus. Further, a decrease in output transmission intensity of the laser has been observed
with increase in fungus concentration. The temporal response of these samples has also been examined. The results show that
the fungus concentration can be measured within ∼15–20 min. This method of optical sensing of fungus in test sample is faster
than other techniques, such as the conventional colorimetric method which takes about 1 h. 相似文献
40.
Satav SS Karmalkar RN Kulkarni MG Mulpuri N Sastry GN 《Journal of the American Chemical Society》2006,128(24):7752-7753
Ethylene glycol dimethacrylate (EGDMA) and ethylene glycol methacrylate 4-vinyl benzoate (EGMAVB) were shown to form 1:1 inclusion complexes with cyclodextrin and were characterized by instrumental techniques. Computational analysis showed that the bent conformation of the included divinyl monomer was more stable than its linear conformation. Complexation of the divinyl monomer with the first CD molecule offered substantial stabilization than with the second CD molecule. The vinyl group included in the CD cavity did not participate in polymerization. As a result, solvent soluble, linear polymers with pendant vinyl unsaturation per repeat unit were obtained. This was unequivocally established by the polymerization of a complex comprising CD and EGMAVB. The unreacted vinyl group can be polymerized in the subsequent step to yield cross-linked products. 相似文献