检索结果-南通市图书馆

Microwave assisted synthesis,spectroscopy and biochemical aspects of lanthanum(Ⅲ) and praseodymium(Ⅲ) complexes with oxadiazole functionalised dithiocarbazinates

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2009年第5期27卷 698-704页

作者： Shweta singh O p pandey S K Sengupta Department of Chemistry D.D.U.Gorakhpur University Chemistry Department University of Surrey

The new lanthanum (Ⅲ) and praseodymium (Ⅲ) complexes of the general formula [Ln(L)3] (Ln=La(Ⅲ) or pr(Ⅲ); LK=potassium salt of dithiocarbazinates) were prepared by both, conventional thermal and by the use of microwave technology. Elemental analyses, electrical conductance, magnetic moment and electronic, infrared, far-infrared, 1H and 13C NMR spectral studies were used to characterize the complexes. The molecular weights of few complexes were determined by FAB-mass spectra. Nephelauxetic ratio, covalency parameter and bonding parameter for these complexes were also calculated. The probable structures of the complexes were proposed. The antifungal and antibacterial activities of the complexes were evaluated. The activities were correlated with the structures of the compounds.

关键词： lanthanum (Ⅲ) praseodymium (Ⅲ) dithiocarbazinates microwave synthesis structures antifungal antibacterial rare earths

Microbial Biomass C,N and p in Disturbed Dry Tropical Forest Soils,India

在线全文

学校读者我要写书评

暂无评论

pedosphere 2010年第6期20卷 780-788页

作者： J.S.singh D.p.singh A.K.KASHYAp Department of Environmental Science Babasaheb Bhimrao Ambedkar University Department of Botany Banaras Hindu University

Variations in microbial biomass C (MB-C),N (MB-N) and p (MB-p) along a gradient of different dominant vegeta- tion covers (natural forest,mixed deciduous forest,disturbed savanna and grassland ecosystems) in dry tropical soils of Vindhyan plateau,India were studied from January 2005 to December *** water holding capacity,organic C,total N,total p and soil moisture content were comparatively higher in forest soils than in the savanna and grassland *** different study sites the mean annual MB-C,MB-N and MB-p at 0-15 cm soil depth varied from 312.05 ± 4.22 to 653.40 ± 3.17,32.16 ± 6.25 to 75.66 ± 7.21 and 18.94 ± 2.94 to 30.83 ± 23.08 μg g ?1 dry soil,*** all the investigated sites,the maximum MB-C,MB-N and MB-p occurred during the dry period (summer season) and the minimum in wet period (rainy season).In the present study,soil MB-C,MB-N and MB-p were higher at the forest sites compared to savanna and grassland *** differences in MB-C,MB-N and MB-p were significant (p p p p (p positively correlated with organic C,while the relationship between soil moisture and MB-C,MB-N and MB-p (p p p pectively) was *** decreasing order of MB-C,MB-N and MB-p along study ecosystems was natural forest > mixed deciduous forest > savanna > *** results suggested that deforestation and land use practices (conversion of forest into savanna and grassland) caused the alterations in soil properties,which as a consequence,led to reduction in soil nutrients and MB-C,MB-N and MB-p in the soil of disturbed sites (grassland and savanna) compared to undisturbed forest ecosystems.

关键词： deciduous forest grassland savanna soil moisture vegetation

An Approximate Analytical Solution of Imploding Strong Shocks in a Non-Ideal Gas through Lie Group Analysis

在线全文

学校读者我要写书评

暂无评论

Chinese physics Letters 2010年第1期27卷 178-181页

作者： L. p. singh Akmal Husain M. singh Department of Applied Mathematics Institute of Technology & DST-CIMS Banaras Hindu University Varanasi-221005 INDIA

The method of Lie group transformation is used to obtain an approximate analytical solution to the system of first-order quasilinear partial differential equations that govern a one-dimensional unsteady planer, cylindrically symmetric and spherically symmetric motion in a non-ideal gas, involving strong shock waves. Invariance groups admitted by the governing system of partial differential equations, which are indeed continuous group of transformations under which the system of partial differential equations remains invariant, are determined, and the complete Lie algebra of infinitesimal symmetries is established. The infinitesimal generators are used to construct the similarity variables. These similarity variables are used to reduce the governing system of partial differential equations into a system of ordinary differential equations.

关键词： Chinese climate network complex systems small world community

Network and plage indices from Kodaikanal Ca-K data

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2014年第2期14卷 229-232页

作者： K.p.Raju Jagdev singh Indian Institute of Astrophysics

The Ca II K filtergrams from Kodaikanal Solar Observatory have been used to study solar activity. The images are dominated by the chromospheric network and plages. programs have been developed to obtain the network and plage indices from the daily images as functions of solar latitude and time. preliminary results from the analysis are reported here. The network and plage indices were found to follow the sunspot cycle. A secondary peak is found during the period of declining activity in both the indices. A comparison of network indices from the northern and the southern hemispheres shows that the former is more active than the latter. However such an asymmetry is not clearly seen in the plage index.

关键词： Sun chromosphere

photon interaction with semiconductor and scintillation detectors

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2016年第3期27卷 159-170页

作者： v.p.singh n.m.badiger Department of physics Karnatak UniversityDharwad 580003India

Mass attenuation coefficients,effective atomic numbers,and electron densities for semiconductor and scintillation detectors have been calculated in the photon energy range 1 keV-100 *** interaction parameters have been found to vary with detector composition and the photon *** variation in the parameters with energy is shown graphically for all the partial photon interaction *** effective atomic numbers of the detector were compared with the ZXCOM program,and the results were found to be *** of semiconductor and scintillation detectors are presented in terms of effective atomic *** study should be useful for comparing the detector performance in terms of gamma spectroscopy,radiation sensitivity,radiation measurement,and radiation *** results of the present investigation should stimulate research work for gamma spectroscopy and radiation measuring materials.

关键词：相互作用参数闪烁探测器半导体光子有效原子序数光谱探测器质量衰减系数能量变化

Visible light photocatalysis in the synthesis of pharmaceutically relevant heterocyclic scaffolds

在线全文

学校读者我要写书评

暂无评论

Organic Chemistry Frontiers 2022年第5期9卷 1485-1507页

作者： Vishal Srivastava pravin K.singh Shraddha Tivari praveen p.singh Department of Chemistry CMP Degree CollegeUniversity of AllahabadPrayagraj 211002India Department of Chemistry United College of Engineering&ResearchNainiPrayagraj 211010India

Visible light and photoredox catalysis have emerged as a powerful and long-lasting tool for organic syn-thesis,demonstrating the importance of a variety of chemical bond formation *** products,physiologically active substances,medicines,and agrochemicals all contain heterocyclic *** impact of visible light-promoted chemistry on the functionalization of heterocycles as well as the syn-thesis and modification of heterocyclic compounds of medicinal importance is summarized in this review.

关键词： heterocyclic Visible synthesis

Oxygen Fugacity and Water Activity during Thermal peak and Retrogression of Granulites around the Sarvapuram Area, Karimnagar Granulite Terrane, Andhra pradesh, India

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2019年第6期93卷 1900-1908页

作者： p.Chandra singh D.pRAKASH Department of Earth Sciences Indian Institute of TechnologyPowaiMumbai400076India Centre of Advanced Study in Geology Banaras Hindu UniversityVaranasi221005India

The investigated area around Sarvapuram represents a part of the Karimnagar granulite terrane of the Eastern Dharwar Craton, India. Garnet–bearing gneiss is hosted as enclaves, pods within granite gneiss and charnockite. It is largely made up of garnet, orthopyroxene, cordierite, biotite, plagioclase, K–feldspar, sillimanite and quartz. The peak metamorphic stage is represented by the equilibrium mineral assemblage i.e. garnet, orthopyroxene, cordierite, biotite, plagioclase, sillimanite and quartz. Breakdown of the garnet as well as preservation of the orthopyroxene–cordierite symplectite, formation of cordierite with the consumption of the garnet + sillimanite + quartz represents the decompressional event. The thermobarometric calculations suggest a retrograde p–T path with a substantial decompression of c. 3.0 kbar. The water activity(XH2 O) conditions obtained with the win TWQ program for core and symplectite compositions from garnet–bearing gneiss are 0.07–0.14 and 0.11–0.16 respectively. The quantitative estimation of oxygen fugacity in garnet–bearing gneiss reveal log f O2 values ranging from-11.38 to-14.05. This high oxidation state could be one of the reasons that account for the absence of graphite in these rocks.

关键词： metamorphic conditions oxygen fugacity water activity garnet–bearing gneisses Karimnagar granulite terrane India

Exopolysaccharide-producing plant Growth-promoting Rhizobacteria Under Salinity Condition

在线全文

学校读者我要写书评

暂无评论

pedosphere 2011年第2期21卷 214-222页

作者： S.K.UpADHYAY J.S.singh D.p.singh Department of Environmental Science Babasaheb Bhimrao Ambedker (Central) UniversityRaibarelly RoadLucknow-226025 (India)

Salt-tolerant plant growth-promoting rhizobacteria （pGpR） can play an important role in alleviating soil salinity stress during plant growth and bacterial exopolysaccharide （EpS） can also help to mitigate salinity stress by reducing the content of Na＋ available for plant uptake. In this study, native bacterial strains of wheat rhizosphere in soils of Varanasi, India, were screened to identify the EpS-producing salt-tolerant rhizobacteria with plant growth-promoting traits. The various rhizobacteria strains were isolated and identified using 16S rDNA sequencing. The plant growth-promoting effect of inoculation of seedlings with these bacterial strains was evaluated under soil salinity conditions in a pot experiment. Eleven bacterial strains which initially showed tolerance up to 80 g L-1 NaC1 also exhibited an EpS-producing potential. The results suggested that the isolated bacterial strains demonstrated some of the plant growth-promoting traits such as phosphate solubilizing ability and production of auxin, proline, reducing sugars, and total soluble sugars. Furthermore, the inoculated wheat plants had an increased biomass compared to the unoinoculated plants.

关键词： NaCl plant uptake rhizosphere salt tolerance wheat

Seismic analysis of structures with a fractional derivative model of viscoelastic dampers

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2002年第2期1卷 251-260页

作者： Tsu-sheng Chang Mahendra p.singh Department of Engineering Science and Mechanics.Virginia polytechnic Institute and State Universigy.Blacksburg Virginia24061.USA

Viscoelastic dampers are now among some of the preferred energy dissipation devices used for passive seismic response *** evaluate the performance of structures installed with viscoelastic dampers,different analytical models have been used to characterize their dynamic force deformation *** fractional derivative models have received favorable attention as they can capture the frequency dependence of the material stiffness and damping properties observed in the tests very ***,accurate analytical procedures are needed to calculate the response of structures with such damper *** paper presents a modal analysis approach,similar to that used for the analysis of linear systems,for solving the equations of inotion with fractional derivative terms for arbitrary forcing functions such as those caused by earthquake induced ground *** uncoupled modal equations still have fractional derivatives,but can be solved by numerical or analytical *** numerical and analytical procedures are *** procedures are then used to calculate the dynamic response of a multi-degree of fleedom shear beam structure excited by ground motions. Numerical results demonstrating the response reducing effect of viscoelastic dampers are also presented.

关键词： viscoelastic damper fractioal derivative seismic response