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91.
A protocol to generate parameters for the AMOEBA polarizable force field for small organic molecules has been established,
and polarizable atomic typing utility, Poltype, which fully automates this process, has been implemented. For validation,
we have compared with quantum mechanical calculations of molecular dipole moments, optimized geometry, electrostatic potential,
and conformational energy for a variety of neutral and charged organic molecules, as well as dimer interaction energies of
a set of amino acid side chain model compounds. Furthermore, parameters obtained in gas phase are substantiated in liquid-phase
simulations. The hydration free energy (HFE) of neutral and charged molecules have been calculated and compared with experimental
values. The RMS error for the HFE of neutral molecules is less than 1 kcal/mol. Meanwhile, the relative error in the predicted
HFE of salts (cations and anions) is less than 3% with a correlation coefficient of 0.95. Overall, the performance of Poltype
is satisfactory and provides a convenient utility for applications such as drug discovery. Further improvement can be achieved
by the systematic study of various organic compounds, particularly ionic molecules, and refinement and expansion of the parameter
database. 相似文献
92.
Chen D Love KT Chen Y Eltoukhy AA Kastrup C Sahay G Jeon A Dong Y Whitehead KA Anderson DG 《Journal of the American Chemical Society》2012,134(16):6948-6951
The discovery of potent new materials for in vivo delivery of nucleic acids depends upon successful formulation of the active molecules into a dosage form suitable for the physiological environment. Because of the inefficiencies of current formulation methods, materials are usually first evaluated for in vitro delivery efficacy as simple ionic complexes with the nucleic acids (lipoplexes). The predictive value of such assays, however, has never been systematically studied. Here, for the first time, by developing a microfluidic method that allowed the rapid preparation of high-quality siRNA-containing lipid nanoparticles (LNPs) for a large number of materials, we have shown that gene silencing assays employing lipoplexes result in a high rate of false negatives (~90%) that can largely be avoided through formulation. Seven novel materials with in vivo gene silencing potencies of >90% at a dose of 1.0 mg/kg in mice were discovered. This method will facilitate the discovery of next-generation reagents for LNP-mediated nucleic acid delivery. 相似文献
93.
Sharma K Police A Kumar A Pawar GV Giri S Rajagopal S Mullangi R 《Biomedical chromatography : BMC》2012,26(7):833-838
A highly sensitive, rapid assay method was developed and validated for the estimation of lorglumide in mouse plasma using liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in positive‐ion mode. The assay procedure involves extraction of lorglumide and phenacetin (internal standard, IS) from mouse plasma with simple protein precipitation. Chromatographic separation was achieved using an isocratic mobile (0.2% formic acid solution–acetonitrile, 20:80, v/v) at a flow‐rate of 0.5 mL/min on an Atlantis dC18 column maintained at 40 °C with a total run time of 4.0 min. The MS/MS ion transitions monitored were 459.2 → 158.4 for lorglumide and 180.1 → 110.1 for IS. Method validation was performed as per FDA guidelines and the results met the acceptance criteria. The lower limit of quantitation achieved was 0.42 ng/mL and the linearity range extended from 0.42 to 500 ng/mL. The intra‐ and inter‐day precisions were in the ranges of 1.47–10.9 and 3.56–7.53, respectively. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
94.
Sharma K Kandaswamy M Mithra C Meena AK Giri S Rajagopal S Mullangi R 《Biomedical chromatography : BMC》2012,26(2):247-255
A highly sensitive and specific LC-MS/MS-ESI method was developed for simultaneous quantification of albenadazole (ABZ) and ricobendazole (RBZ) in rat plasma (50 μL) using phenacetin as an internal standard (IS). Simple protein precipitation was used to extract ABZ and RBZ from rat plasma. The chromatographic resolution of ABZ, RBZ and IS was achieved with a mobile phase consisting of 5 m m ammonium acetate (pH 6) and acetonitrile (20:80, v/v) at a flow rate of 1 mL/min on a Chromolith RP-18e column. The total chromatographic run time was 3.5 min and the elution of ABZ, RBZ and IS occurred at 1.66, 1.50 and 1.59 min, respectively. A linear response function was established for the ranges of concentrations 2.01-2007 and 6.02-6020 ng/mL for ABZ and RBZ, respectively. The intra- and inter-day precision values for ABZ and RBZ met the acceptance as per FDA guidelines. ABZ and RBZ were stable in battery of stability studies, viz. bench-top, auto-sampler and freeze-thaw cycles. The developed assay was applied to a pharmacokinetic study in rats. 相似文献
95.
VA Tamhane DG Dhaware N Khandelwal AP Giri V Panchagnula 《Journal of colloid and interface science》2012,383(1):177-183
Bicontinuous microemulsions (BCMEs) have excellent solubulizing properties along with low interfacial tension and aqueous content that can be controlled. In this work, water soluble plant protease inhibitor (PI), well characterized for its activity against insect pests, was incorporated into a BCME system and explored for permeation on hydrophobic leaf surfaces and protease inhibition activity. The bicontinuous nature of the microemulsion containing water:2-propanol:1-butanol (55:35:10 w/w) was characterized using conductivity and self-diffusion coefficient measurements. The PI was soluble in the water-rich bicontinuous domains, stable in the microemulsions, and protease inhibition activity was retained for a prolonged duration. The microemulsions ensured greater wettability and a wider spread of the PI on hydrophobic leaf surfaces as revealed by contact angle measurements. Significantly, trypsin inhibition activity assays of the PI recovered from the leaves after delivery from the microemulsion indicated a significant increase in the PI retention on the leaf. This BCME enabled greater leaf permeation and retention of the PI can be attributed to a temporary disruption of the waxy leaf surface followed by self-repair without causing any long term damage to the plant. 相似文献
96.
Chattaraj PK Giri S Duley S 《The journal of physical chemistry. A》2012,116(1):790-1; discussion 792-5
97.
Ashok K. Varma Ashwini Nangia Gautam R. Desiraju Venkatachalam S. Giri Parasuraman Jaisankar 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(1):97-99
3-Acetyl-1,6,7,12b-tetrahydroindolo[2,3-a]quinolizin-2(12H)-one, C17H16N2O2, consists of two symmetry-independent molecules and each forms a layered structure stabilized by N—H⃛O and C—H⃛O hydrogen bonds. In 3-acetyl-6,7-dihydroindolo[2,3-a]quinolizin-4(12H)-one monohydrate, C17H14N2O2·H2O, the structure is stabilized by O—H⃛O, N—H⃛O and C—H⃛O hydrogen bonds, with the ordered water molecule playing a crucial role in the self-assembly. Contribution from the weak interactions to the strong hydrogen-bonded network is a common feature in both structures. 相似文献
98.
Chapala Vijaya Lakshmi Katari Naresh Kumar Malavattu Giri Prasad Kerru Nagaraju Reddy Pedavenkatagari Narayana Marisetti Vishnu Murthy 《Russian Journal of General Chemistry》2021,91(5):932-938
Russian Journal of General Chemistry - Large-scale enantioselective synthesis of the chiral amine unit of HCV NS5A inhibitor Elbasvir has been accomplished in six steps, with 55% overall yield. The... 相似文献
99.
Narayan C. Giri 《Annals of the Institute of Statistical Mathematics》1988,40(2):381-394
In this paper we give an extension of the theory of local minimax property of Giri and Kiefer (1964, Ann. Math. Statist., 35, 21–35) to the family of elliptically symmetric distributions which contains the multivariate normal distribution as a member.This work was partially supported by the Canadian N.S.E.R.C. grant 相似文献
100.
We study the effect of the FCNC mediated Z boson in the rare semileptonic baryonic decays Λb → Λl+l-. We consider the model where the standard model fermion sector is extended by an extra vector-like down quark, as a consequence
of which it allows for CP-violating Z mediated flavor changing neutral current at the tree level. We find that due to this non-universal Zbs coupling, the branching ratios of the rare semileptonic Λb decays are enhanced reasonably from their corresponding standard model values and the zero point of the forward-backward
asymmetry for Λb → Λμ+μ- is shifted to the left.
Received: 2 June 2005, Published online: 26 October 2005
PACS:
13.30.Ce, 12.60.-i, 11.30.Hv 相似文献