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991.
Morton E. Harris 《Results in Mathematics》2008,51(3-4):249-259
As in Finite Group Modular Representation Theory, let be a commutative complete noetherian ring with an algebraically closed residue field k. Let G be a finite group and let N be a normal subgroup of G. First suppose that V is an indecomposable -module, so that Inf
G
G/N
(V) is an indecomposable G-module. We relate the Green invariants of V as an -module to those of Inf
G
G/N
(V) as an G-module. Secondly, let V and W be indecomposable G-modules. Assume that W is an endo-permutation lattice and that is also an indecomposable G-module. We relate the Green invariants of the G-modules V and . (This situation arises under important Morita equivalences.)
Received: December 11, 2006. Revised: August 22, 2007. 相似文献
992.
Low-pressure membrane filtration of secondary effluent in water reuse: Pre-treatment for fouling reduction 总被引:3,自引:0,他引:3
Linhua Fan Thang Nguyen Felicity A. Roddick John L. Harris 《Journal of membrane science》2008,320(1-2):135-142
Fouling in the low-pressure membrane filtration of secondary effluent for water reuse can be severe due to the complex nature of the components in the water. Pre-filtration, coagulation and anion exchange resin were investigated as pre-treatments for reducing fouling of microfiltration (MF) and ultrafiltration (UF) membranes in the treatment of activated sludge-lagoon effluent. The key fouling components were determined using several analytical techniques to detect differences in the organic components between the feed and permeate.Pre-filtration (1.5 μm) enhanced the permeate flux for MF by removing particulates, but had little effect for UF. Marked flux improvement was obtained by coagulation pre-treatment at 5 mg L−1 Al3+ with internal membrane fouling being substantially alleviated. Anion exchange resin removed >50% of effluent organic matter but did not improve the flux or reduce irreversible membrane fouling. These results, together with detailed organic compositional analyses, showed that the very high-molecular weight organic materials (40–70 kDa) comprised of hydrophilic components such as soluble microbial products, and protein-like extracellular matter were the major cause of membrane fouling. 相似文献
993.
Pandey AS Harris TV Giles LJ Peters JW Szilagyi RK 《Journal of the American Chemical Society》2008,130(13):4533-4540
An X-ray crystallographic refinement of the H-cluster of [FeFe]-hydrogenase from Clostridium pasteurianum has been carried out to close-to atomic resolution and is the highest resolution [FeFe]-hydrogenase presented to date. The 1.39 A, anisotropically refined [FeFe]-hydrogenase structure provides a basis for examining the outstanding issue of the composition of the unique nonprotein dithiolate ligand of the H-cluster. In addition to influencing the electronic structure of the H-cluster, the composition of the ligand has mechanistic implications due to the potential of the bridge-head gamma-group participating in proton transfer during catalysis. In this work, sequential density functional theory optimizations of the dithiolate ligand embedded in a 3.5-3.9 A protein environment provide an unbiased approach to examining the most likely composition of the ligand. Structural, conformational, and energetic considerations indicate a preference for dithiomethylether as an H-cluster ligand and strongly disfavor the dithiomethylammonium as a catalytic base for hydrogen production. 相似文献
994.
995.
Jiang B Xu D Allocco J Parish C Davison J Veillette K Sillaots S Hu W Rodriguez-Suarez R Trosok S Zhang L Li Y Rahkhoodaee F Ransom T Martel N Wang H Gauvin D Wiltsie J Wisniewski D Salowe S Kahn JN Hsu MJ Giacobbe R Abruzzo G Flattery A Gill C Youngman P Wilson K Bills G Platas G Pelaez F Diez MT Kauffman S Becker J Harris G Liberator P Roemer T 《Chemistry & biology》2008,15(4):363-374
Natural products provide an unparalleled source of chemical scaffolds with diverse biological activities and have profoundly impacted antimicrobial drug discovery. To further explore the full potential of their chemical diversity, we survey natural products for antifungal, target-specific inhibitors by using a chemical-genetic approach adapted to the human fungal pathogen Candida albicans and demonstrate that natural-product fermentation extracts can be mechanistically annotated according to heterozygote strain responses. Applying this approach, we report the discovery and characterization of a natural product, parnafungin, which we demonstrate, by both biochemical and genetic means, to inhibit poly(A) polymerase. Parnafungin displays potent and broad spectrum activity against diverse, clinically relevant fungal pathogens and reduces fungal burden in a murine model of disseminated candidiasis. Thus, mechanism-of-action determination of crude fermentation extracts by chemical-genetic profiling brings a powerful strategy to natural-product-based drug discovery. 相似文献
996.
We report a technique for carrying out in situ solid-state NMR studies of crystallization from solution, allowing the evolution of different solid state structures (polymorphs) produced during the crystallization process to be identified. The technique exploits selectivity in NMR properties (specifically, the efficiency of cross-polarization from (1)H to (13)C) between molecules in the solid and solution states, such that the first solid particles produced during the crystallization process are observed selectively, without detecting any signal from dissolved solute (or solvent) molecules. The application of the technique is demonstrated to reveal new insights concerning an isotope effect on the polymorphic outcome of crystallization of glycine from water. As revealed by this example, the in situ solid-state NMR approach reported here creates significant new opportunities for probing and understanding details of the evolution of solid state structures produced during crystallization from solution. 相似文献
997.
Coe BJ Harris JA Brunschwig BS Garín J Orduna J 《Journal of the American Chemical Society》2005,127(10):3284-3285
We have used several techniques, including Stark spectroscopy and MO calculations, to investigate the optical and electronic properties of two new dipolar chromophoric cations containing diquat-based electron acceptor groups. Both the Stark data and the calculated parameters show that the strong electron-accepting properties of a diquat unit lead to static first hyperpolarizabilities beta0 which are considerably larger than those of a related stilbazolium chromophore. In addition, one compound has a strongly 2D quadratic NLO response, providing a very rare example of a charged molecule displaying such behavior. 相似文献
998.
Long-term phosphorus effects on evolving physicochemical properties of iron and aluminum hydroxides 总被引:1,自引:0,他引:1
Makris KC Harris WG O'Connor GA El-Shall H 《Journal of colloid and interface science》2005,287(2):552-560
Iron (Fe) and aluminum (Al) hydroxides are highly reactive components in environmental processes, such as contaminant fate and transport. Phosphorus (P) sorption by these components can decrease environmental problems associated with excess accumulation of P in soils. The long-term stability of P sorbed by Fe/Al hydroxides is of major concern. Synthetic Fe and Al hydroxides coprecipitated with P (1:1 metal:P molar ratio) were incubated at 70 degrees C for 24 months to simulate natural long-term weathering processes that could influence the stability of sorbed P. Heat incubation (70 degrees C) of the untreated (no P) Al hydroxides resulted in drastic decreases (within the first month of incubation) in oxalate-Al extractability, specific surface area (SSA), and micropore volume with time. These changes were consistent with the formation of pseudoboehmite. Untreated Fe hydroxides showed no formation of crystalline components following heating (70 degrees C) for 24 months. Much smaller changes in oxalate-Al, P extractability, and SSA values were observed in the P-treated Al particles when compared with the untreated. Phosphorus treatment of both Fe and Al hydroxides stabilized the particle surfaces and prevented structural arrangements toward a long-range ordered phase. Slight reduction in SSA of the P-treated particles was related to dehydration phenomena during heating at 70 degrees C. Monitoring of physicochemical properties of the solids after heating at 70 degrees C for 2 years showed that sorbed P may be stable in the long-term. Understanding long term physicochemical properties may help engineers to optimize the Fe/Al hydroxides performance in several environmental/industrial applications. 相似文献
999.
Fuller BT Fuller JL Sage NE Harris DA O'Connell TC Hedges RE 《Rapid communications in mass spectrometry : RCM》2005,19(18):2497-2506
While past experiments on animals, birds, fish, and insects have shown changes in stable isotope ratios due to nutritional stress, there has been little research on this topic in humans. To address this issue, a small pilot study was conducted. Hair samples from eight pregnant women who experienced nutritional stress associated with the nausea and vomiting of morning sickness (hyperemesis gravidarum) were measured for carbon (delta13C) and nitrogen (delta15N) stable isotope ratios. The delta13C results showed no change during morning sickness or pregnancy when compared with pre-pregnancy values. In contrast, the delta15N values generally increased during periods of weight loss and/or restricted weight gain associated with morning sickness. With weight gain and recovery from nutritional stress, the hair delta15N values displayed a decreasing trend over the course of gestation towards birth. This study illustrates how delta15N values are not only affected by diet, but also by the nitrogen balance of an individual. Potential applications of this research include the development of diagnostic techniques for tracking eating disorders, disease states, and nitrogen balance in archaeological, medical, and forensic cases. 相似文献
1000.
Pyrazolo[1,5-a]pyridines as p38 kinase inhibitors 总被引:1,自引:0,他引:1
Stevens KL Jung DK Alberti MJ Badiang JG Peckham GE Veal JM Cheung M Harris PA Chamberlain SD Peel MR 《Organic letters》2005,7(21):4753-4756
[reaction: see text] A convergent synthesis of substituted pyrazolo[1,5-a]pyridines has been achieved either via a regioselective [3 + 2] cycloaddition of N-aminopyridines with alkynes or by thermal cyclization of disubstituted azirines. Subsequent palladium-catalyzed introduction of pyridines or de novo synthesis of pyrimidines affords inhibitors of p38 kinase. 相似文献