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81.
Composite polymer electrolyte membranes composed of poly(ethylene oxide) (PEO), poly(vinylidene fluoride-hexafluoropropylene)
{P(VdF-HFP)} blends, dedoped (insulating) polyaniline (PAni) nanofibers, and LiClO4 as salt have been synthesized with varying fraction of dedoped PAni nanofibers (from 2 to 10 wt.%). The ionic conductivity
of PEO–P(VdF-HFP)–LiClO4 electrolyte system increases with increase in the fraction of dedoped polyaniline nanofibers. This could be attributed to
the incorporation of nanofibers (aspect ratio >50), which may provide high ion conducting path along the interface due to
Lewis acid–base interactions between Li+ ions and lone pair of electrons of nitrogen atom of polyaniline. However, at higher fraction (>6 wt.%), the nanofibers get
phase separated from the polymer matrix and form domain-like structures, which may act as physical barrier to the conduction
of Li+ ions resulting in decreased ionic conductivity. Electrochemical potential window and interfacial stability of nanofibers
dispersed polymer electrolyte membranes are also better than that of nanofibers free membranes. 相似文献
82.
The first fluorescent sensor for HF2 ? anion, N1, N3-di(naphthalene-1-yl)isophthalamide (L) has been derived from α-Napthylamine and isopthaloyl chloride. In 1:1 (v/v) DMSO:H2O, L exhibits high selectivity towards HF2 ? anion with a 4-fold enhancement in fluorescent intensity. Very little enhancement in fluorescence intensity is observed for F?, Cl?, Br?, I?, SCN?, PO4 3?, SO4 2?, and CH3COO? anions. The stoichiometry interaction between L and HF2 ? is found to be 1:1 from fluorescence and UV/Visible spectral data. DFT calculation shows that binding between HF2 ? and L is 1:1 and increases the relative planarity between the two naphthyl rings causing fluorescence enhancement. A shift of 0.080 V in oxidation potential of L is observed on interaction with HF2 ? by cyclic voltammetry and square wave voltammetry. 相似文献
83.
In this paper, we establish several theorems for the explicit evaluations of Ramanujan-G?llnitz-Gordon continued fraction
by using some parameterizations of Ramanujan’s theta-functions.
Nayandeep Deka Baruah, Corresponding author. Research partially supported by grant SR/FTP/MA-02/2002 from DST, Govt. of India.
Authors’ address: Nayandeep Deka Baruah and Nipen Saikia, Department of Mathematical Sciences, Tezpur University, Napaam-784028,
Assam, India 相似文献
84.
Theoretical studies on atmospheric chemistry of HFE‐347mcc3: reactions with OH radicals and Cl atoms
Bhupesh Kumar Mishra Makroni Lily Asit K. Chandra Ramesh Chandra Deka 《Journal of Physical Organic Chemistry》2014,27(10):811-817
Detailed theoretical investigation has been performed on the mechanism, kinetics and thermochemistry of the gas phase reactions of CF3CF2CF2OCH3 (HFE‐347mcc3) with OH radicals and Cl atoms using M06‐2X/6‐31 + G(d,p) level of theory. Reaction profiles are modeled including the formation of pre‐reactive and post‐reactive complexes at entrance and exit channels, respectively. Using group‐balanced isodesmic reactions, the standard enthalpies of formation for species are also reported. The calculated bond dissociation energy for C―H bond is in good agreement with previous data. The rate constants of the two reactions are determined for the first time in a wide temperature range of 250–1000 K. At 298 K, the calculated rate coefficients are in good agreement with the experimental results. The atmospheric life time of HFE‐347mcc3 is estimated to be 4.4 years. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
85.
Density functional calculations within the generalized gradient approximation have been used to investigate the lowest energy electronic and geometric structures of neutral, cationic, and anionic Pd(n) (n=1-7) clusters in the gas phase. In this study, we have examined three different spin multiplicities (M=1, 3, and 5) for different possible structural isomers of each neutral cluster. The calculated lowest energy structures of the neutral clusters are found to have multiplicities, M=1 for Pd(1), Pd(3), Pd(5), Pd(6), and Pd(7), while M=3 for Pd(2) and Pd(4). We have also determined the lowest energy states of cationic and anionic Pd(n) (n=1-7) clusters, formed from the most stable neutral clusters, in three spin multiplicities (M=2, 4, and 6). Bond length, coordination number, binding energy, fragmentation energy, bond dissociation energy, ionization potential, electron affinity, chemical hardness, and electric dipole moment of the optimized clusters are compared with experimental and other theoretical results available in the literature. Based on these criteria, we predict the four-atom palladium cluster to be a magic-number cluster. 相似文献
86.
Flavour symmetry breaking is introduced in the approximate formula for quark mass reported earlier. We use SLAC-MIT as well
as NMC data to estimate the up, down and strange quark masses from structure functions. Using the approximateQ
2 evolutions of Altarelli-Parisi equations, we also estimate its perturbative and nonperturbative components. 相似文献
87.
Nayandeep Deka Baruah 《Journal of Combinatorial Theory, Series A》2007,114(6):1024-1045
We show that certain modular equations and theta function identities of Ramanujan imply elegant partition identities. Several of the identities are for t-cores. 相似文献
88.
Manab Sharma Bhaskar J. Sarmah Pradip Bhattacharyya Ramesh C. Deka Dipak K. Dutta 《应用有机金属化学》2007,21(4):255-263
The complexes [Rh(CO)2ClL]( 1 ), where L = 2‐aminophenol ( a ), 3‐aminophenol ( b ) and 4‐aminophenol ( c ), have been synthesized and characterized. The ligands are coordinated to the metal centre through an N‐donor site. The complexes 1 undergo oxidative addition ( OA ) reactions with various alkyl halides ( RX ) like CH3I, C2H5I and C6H5CH2Cl to produce Rh(III) complexes of the type [Rh(CO)(COR)XClL], where R = ? CH3( 2 ), ? C2H5( 3 ), X = I; R = C6H5CH2? and X = Cl ( 4 ). The OA reaction with CH3I follows a two‐stage kinetics and shows the order of reactivity as 1b > 1c > 1a . The minimum energy structure and Fukui function values of the complexes 1a–1c were calculated theoretically using a DND basis set with the help of Dmol3 program to substantiate the observed local reactivity trend. The catalytic activity of the complexes 1 in carbonylation of methanol, in general, is higher (TON 1189–1456) than the species [Rh(CO)2I2]? (TON 1159). Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
89.
Ethane‐Bridged Periodic Mesoporous Organosilicas Functionalized with High Loadings of Carboxylic Acid Groups: Synthesis,Bifunctionalization, and Fabrication of Metal Nanoparticles 下载免费PDF全文
Dr. Juti Rani Deka Prof. Hsien‐Ming Kao Shu‐Ying Huang Wei‐Chieh Chang Dr. Chun‐Chiang Ting Purna Chandra Rath Prof. Ching‐Shiun Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(3):894-903
Well‐ordered periodic mesoporous organosilicas (PMOs) functionalized with high contents of carboxylic acid (?COOH) groups, up to 85 mol % based on silica, were synthesized by co‐condensation of 1,2‐bis(triethoxysilyl)ethane (BTEE) and carboxyethylsilanetriol sodium salt (CES) under acidic conditions by using alkyl poly(oxyethylene) surfactant Brij 76 as a structure‐directing agent. A variety of techniques including powder X‐ray diffraction (XRD), nitrogen adsorption/desorption, Fourier‐transformed infrared (FTIR), transmission electron microscopy (TEM), 13C‐ and 29Si solid‐state nuclear magnetic resonance (NMR) were used to characterize the products. The materials thus obtained were used as an effective support to synthesize metal nanoparticles (Ag and Pt) within the channel of 2D hexagonal mesostructure of PMOs. The size and distribution of the nanoparticles were observed to be highly dependent on the interaction between the carboxylic acid functionalized group and the metal precursors. The size of Pt nanoparticles reduced from 3.6 to 2.5 nm and that of Ag nanoparticles reduced from 5.3 to 3.4 nm with the increase in the ?COOH loading from 10 to 50 %. 相似文献
90.
Nabanita Saikia Sanchaita Rajkhowa Ramesh C. Deka 《Journal of computer-aided molecular design》2013,27(3):257-276
The potential biomedical application of carbon nanotubes (CNTs) pertinent to drug delivery is highly manifested considering the remarkable electronic and structural properties exhibited by CNT. To simulate the interaction of nanomaterials with biomolecular systems, we have performed density functional calculations on the interaction of pyrazinamide (PZA) drug with functionalized single-wall CNT (fSWCNT) as a function of nanotube chirality and length using two different approaches of covalent functionalization, followed by docking simulation of fSWCNT with pncA protein. The functionalization of pristine SWCNT facilitates in enhancing the reactivity of the nanotubes and formation of such type of nanotube-drug conjugate is thermodynamically feasible. Docking studies predict the plausible binding mechanism and suggests that PZA loaded fSWCNT facilitates in the target specific binding of PZA within the protein following a lock and key mechanism. Interestingly, no major structural deformation in the protein was observed after binding with CNT and the interaction between ligand and receptor is mainly hydrophobic in nature. We anticipate that these findings may provide new routes towards the drug delivery mechanism by CNTs with long term practical implications in tuberculosis chemotherapy. 相似文献