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91.
The paper considers two mutually independent pests in presence of their common predator and discusses their control biologically by release of additional predators and chemically by using non-selective non-residual pesticide. It also verifies the results by special choice of parameters. 相似文献
92.
Amandeep Kaur Deepshikha Karan Singh Vinayak Suneel Kumar 《Physics of Atomic Nuclei》2016,79(4):474-480
We performed a theoretical investigation of different mass-asymmetric reactions to access the direct impact of the density-dependent part of symmetry energy on multifragmentation. The simulations are performed for a specific set of reactions having same system mass and N/Z content, using isospin-dependent quantum molecular dynamics model to estimate the quantitative dependence of fragment production on themass-asymmetry factor (τ) for various symmetry energy forms. The dynamics associated with different mass-asymmetric reactions is explored and the direct role of symmetry energy is checked. Also a comparison with the experimental data (asymmetric reaction) is presented for a different equation of states (symmetry energy forms). 相似文献
93.
Harshita Phougat Vandana Devi Sanjay Rai T. Shreedhar Reddy Karan Singh 《Journal of heterocyclic chemistry》2021,58(10):1992-1999
A series of novel N-cycloalkyl/aryl-4-(1,3-diphenyl-1H-pyrazole-4-carbonyl)piperazine-1-carboxamides 9a-g has been synthesized for biological interest by simple base catalyzed reaction of various N-cycloalkyl/aryl isocyanates with (1,3-diphenyl-1H-pyrazol-4-yl)(piperazin-1-yl)methanone hydrochloride 8 . The compound 8 was synthesized in excellent yield by the reaction of 1,3-diphenyl-1H-pyrazole-4-carbonyl chloride with boc-piperazine followed by deprotection of boc group with dioxane-HCl. All the novel intermediates and urea derivatives have been screened for antimicrobial activity. The compound 9a was found an excellent compound to be active against all Gram (−ve) and Gram (+ve) bacterial strains E. coli, Y. enterocolitica, B. cereus, and S. aureus. It also showed comparable antifungal activity against C. albicans with MIC 78.1 μg/ml as compared to reference standard miconazole. 相似文献
94.
A forced degradation study on ropinirole hydrochloride in bulk and in its modified release tablets was conducted under the conditions of hydrolysis, oxidation and photolysis in order to develop an isocratic stability-indicating LC-UV method for quantification of the drug in tablets. An impurity peak in standard solution was found to increase under acidic and neutral hydrolytic conditions while another degradation product was formed under alkaline condition. The drug and its degradation products were optimally resolved on a Hypersil C18 column with mobile phase composed of diammonium hydrogen orthophosphate (0.05 M; pH 7.2), tetrahydrofuran and methanol (80:15:5% v/v) at a flow rate of 1.0 mL min?1 at 30 °C using 250 nm as detection wavelength. The method was linear in the range of 0.05–50 μg mL?1 drug concentrations. The %RSD of inter- and intra-day precision studies was <1. The system suitability parameters remained unaffected during quantification of the drug on three different LC systems. Excellent recoveries (101.59–102.28%) proved that the method was sufficiently accurate. The LOD and LOQ were found to be 0.012 and 0.040 μg mL?1, respectively. Degradation behaviour of the drug in both bulk and tablets was similar. The drug was very unstable to hydrolytic conditions but stable to oxidative and photolytic conditions. The method can be used for rapid and accurate quantification of ropinirole hydrochloride in tablets during stability testing. Based on chemical reactivity of ropinirole in different media, the degradation products were suspected to be different from the known impurities of the drug. 相似文献
95.
Sol-gel process has gained tremendous attention in past decades for the preparation of pure and composite material for numerous
applications. Organically modified sol-gel glasses (ormosils) have hybrid properties of rigid inorganic silica matrix and
organic functionalities. Ormosils provide ambient environment for bio-molecules encapsulation and such systems have been used
widely for biosensor applications. Biological elements including enzymes, antibodies, antigens, DNA, whole cells, tissues,
proteins, biologically derived material, and biomimetic materials provide the possibility of biological recognition to the
device and transducer to detect the biological signals with the help of associated electronics and software to amplify these
signals into a readable form for the user. In this review we report on the formation of sol-gel based composite materials
primarily on ormosil along with carbon nano tubes, metal nano particles, mediators, inorganic complexes, polymers, ionomers
and biological materials and cite the electrochemical sensor/biosensor system based on it. 相似文献
96.
We consider a portfolio optimization problem of the Black–Litterman type, in which we use the conditional value-at-risk (CVaR) as the risk measure and we use the multi-variate elliptical distributions, instead of the multi-variate normal distribution, to model the financial asset returns. We propose an approximation algorithm and establish the convergence results. Based on the approximation algorithm, we derive a closed-form solution of the portfolio optimization problems of the Black–Litterman type with CVaR. 相似文献
97.
In order to enhance the ionic conductivity of polyethylene oxide (PEO)–KI(80:20) based alkaline polymer electrolytes, nanosized inorganic filler ZnS has been incorporated into PEO–KI matrix and the corresponding nanocomposite polymer electrolytes are synthesized by the usual solution casting procedure. Atomic force microscope image of composite polymer electrolyte exhibits that the introduction of ZnS nanoparticles changes the surface morphology and aggregates them to form an arborization pattern. The prepared nanocomposite polymer electrolyte reveals an ionic conductivity of about 10?4 S cm?1 for 5 wt% ZnS at room temperature. 相似文献
98.
The application of the WCl6–e?–Al–CH2Cl2 system to acyclic diene metathesis polymerization of 1,9‐decadiene is reported. The polyoctenamer formed is of a weight‐average molecular weight of 9000 with a polydispersity of 1.92. IR and NMR spectral analyses indicate the retention of the double bonds in the polymer structure with high trans content as expected from a step condensation reaction. This relatively stable catalytic system, however, also activates the competing vinyl addition reactions while being inactive in ring‐closure metathesis reactions. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
99.
100.
N. K. Karan R. S. Katiyar T. Maiti R. Guo A. S. Bhalla 《Journal of Raman spectroscopy : JRS》2009,40(4):370-375
This paper reports a systematic study of the composition and the temperature‐dependent‐Raman spectra of Zr4+‐rich BaZrxTi1−xO3 (BZT) ceramic compositions (0.50⩽x⩽1.00). On the basis of the dielectric behavior of Zr rich BZT ceramics, the observed relaxor behavior has been hypothesized as a result of increasing long‐range interactions of nanosized, Ti4+‐rich polar regions in a Zr4+‐rich nonpolar matrix. Beyond an optimum concentration of BaTiO3 (BT) in the nonpolar matrix of BaZrO3 (x⩽0.75), a critical size and density of the polar regions is reached when the polar clusters start showing the relaxor like behavior, which finally show classical relaxor behavior for compositions with x = 0.5 and 0.6. This hypothesis is strongly supported from the Raman data on Zr‐rich BZT presented in this paper. Well‐defined BT Raman spectra for 5% BT in BZT composition were recorded, which followed completely up to the 50% Ti addition in the BZT samples. The temperature‐dependent Raman spectra collected on the BZT ceramics far beyond the dielectric transition temperatures supported the existence of the nano‐polar BT regions, like in typical relaxor samples. The full width at half‐maximum (FWHM), integrated intensity of the peaks in the Raman spectra has been analyzed to further support the conclusions. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献