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941.
Synthesis of Complex Druglike Molecules by the Use of Highly Functionalized Bench‐Stable Organozinc Reagents 下载免费PDF全文
Thomas J. Greshock Keith P. Moore Ray T. McClain Ana Bellomo Cheol K. Chung Spencer D. Dreher Peter S. Kutchukian Zhengwei Peng Ian W. Davies Petr Vachal Mario Ellwart Sophia M. Manolikakes Prof. Dr. Paul Knochel Philippe G. Nantermet 《Angewandte Chemie (International ed. in English)》2016,55(44):13714-13718
The reactivity of a representative set of 17 organozinc pivalates with 18 polyfunctional druglike electrophiles (informers) in Negishi cross‐coupling reactions was evaluated by high‐throughput experimentation protocols. The high‐fidelity scaleup of successful reactions in parallel enabled the isolation of sufficient material for biological testing, thus demonstrating the high value of these new solid zinc reagents in a drug‐discovery setting and potentially for many other applications in chemistry. Principal component analysis (PCA) clearly defined the independent roles of the zincates and the informers toward druggable‐space coverage. 相似文献
942.
Simple and Efficient Ruthenium‐Catalyzed Oxidation of Primary Alcohols with Molecular Oxygen 下载免费PDF全文
Ritwika Ray Shubhadeep Chandra Prof. Debabrata Maiti Prof. Goutam Kumar Lahiri 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(26):8814-8822
Oxidative transformations utilizing molecular oxygen (O2) as the stoichiometric oxidant are of paramount importance in organic synthesis from ecological and economical perspectives. Alcohol oxidation reactions that employ O2 are scarce in homogeneous catalysis and the efficacy of such systems has been constrained by limited substrate scope (most involve secondary alcohol oxidation) or practical factors, such as the need for an excess of base or an additive. Catalytic systems employing O2 as the “primary” oxidant, in the absence of any additive, are rare. A solution to this longstanding issue is offered by the development of an efficient ruthenium‐catalyzed oxidation protocol, which enables smooth oxidation of a wide variety of primary, as well as secondary benzylic, allylic, heterocyclic, and aliphatic, alcohols with molecular oxygen as the primary oxidant and without any base or hydrogen‐ or electron‐transfer agents. Most importantly, a high degree of selectivity during alcohol oxidation has been predicted for complex settings. Preliminary mechanistic studies including 18O labeling established the in situ formation of an oxo–ruthenium intermediate as the active catalytic species in the cycle and involvement of a two‐electron hydride transfer in the rate‐limiting step. 相似文献
943.
Elizabeth E. Hwang Taylor R. Wilson‐Hill Ji Won Ahn Andrew P. Platt Katherine E. Rutledge Sarah L. Goh 《Journal of polymer science. Part A, Polymer chemistry》2011,49(4):871-878
Nanoparticles formed from amphiphilic block copolymers can be used as drug delivery vehicles for hydrophilic therapeutics. Poly(ethylene glycol) (PEG)‐peptide copolymers were investigated for their self‐assembling properties and as consequent potential delivery systems. Mono‐ and dihydroxy PEGs were functionalized with a pentavaline sequence bearing Fmoc end groups. The molecular weight of the PEG component was varied to evaluate copolymer size and block number. These di‐ and tri‐block copolymers readily self‐assemble in aqueous solution with critical aggregation concentrations (CACs) of 0.46–16.29 μM. At concentrations above the CAC, copolymer solutions form spherical assemblies. Dynamic light scattering studies indicate these aggregates have a broad size distribution, with average diameters between 33 and 127 nm. The copolymers are comprised β‐conformations that are stable up to 80 °C, as observed by circular dichroism. This peptide secondary structure is retained in solutions up to 50% MeOH as well. The triblock copolymers proved to be the most stable, with copolymers synthesized from 10 kDa PEG having the most stable particles. Loading of carboxyfluorescein at 2–5 mol % shows that these copolymers have the potential to encapsulate hydrophilic drugs for delivery applications. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
944.
Ray T. Barton Hassan Kellawi Frank Marken Roger J. Mortimer David R. Rosseinsky 《Journal of Solid State Electrochemistry》2012,16(12):3723-3724
Prussian-blue (PB) film for electro-chromism can be electro-deposited on to an electrode (usually tin-doped indium oxide/glass) either directly from a PB colloid or from ferric ferricyanide in a two-electrode electro-chemical cell by applying a reductive potential. Alternatively, a “sacrificial” electron-producing silver flag electrode in the solution, when connected to the PB-receiving electrode, can effect the required reductive deposition. A silver spot, here innovatively applied as silver paint directly onto the deposition electrode, produces PB film on immersion in the iron(III)(III) solution, obviating the separate counter-electrode method. 相似文献
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948.
Sarbani Dey Ray 《Natural product research》2015,29(16):1529-1536
The various parts of Zizyphus nummularia has been used traditionally in several disease conditions. However, its anticancer activity and mechanism of action remain to be elucidated. Considering this, the objective of this study was to isolate, identify and screen for possible anticancer activity in vitro and in vivo of the ethanolic extract (EE) and isolated identified compound (IC) from Z. nummularia root bark. The in vitro activity against human breast cancer, leukaemia, ovarian cancer, colon adenocarcinoma and human kidney carcinoma cell lines was determined. The in vivo activity in female Swiss albino mice against Ehrlich ascites carcinoma (EAC) was determined. The isolated compound is a new triterpene derivative. EE/IC showed cytotoxicity against different cell lines. The administration of EE/IC decreased tumour parameters such as tumour volume, viable tumour cell count and increased body weight, haematological parameters and life span in comparison to the EAC control mice. 相似文献
949.
K. J. Patel G. G. Bhatt J. R. Ray Priya Suryavanshi C. J. Panchal 《Journal of Solid State Electrochemistry》2017,21(2):337-347
Electrochromic devices (ECDs) are currently attracting much interest in academic and industry for both research and their commercial applications because of their controllable transmission, absorption, and/or reflectance. This paper reviews the progress that has taken place from 1969 until the year 2015 with regard to all-solid-state inorganic ECD fabrication. The main aim of this review article is to provide an easy entrance to literature of all-inorganic solid-state ECD. 相似文献
950.
We study the interaction of a shock with a density-stratified gaseous interface (Richtmyer–Meshkov instability) with localized
jagged and irregular perturbations, with the aim of developing an analytical model of the vorticity deposition on the interface
immediately after the passage of the shock. The jagged perturbations, meant to simulate machining errors on the surface of
a laser fusion target, are characterized using Haar wavelets. Numerical solutions of the Euler equations show that the vortex
sheet deposited on the jagged interface rolls into multiple mushroom-shaped dipolar structures which begin to merge before
the interface evolves into a bubble-spike structure. The peaks in the distribution of x-integrated vorticity (vorticity integrated in the direction of the shock motion) decay in time as their bases widen, corresponding
to the growth and merger of the mushrooms. However, these peaks were not seen to move significantly along the interface at
early times i.e. t < 10 τ, where τ is the interface traversal time of the shock. We tested our analytical model against inviscid simulations
for two test cases – a Mach 1.5 shock interacting with an interface with a density ratio of 3 and a Mach 10 shock interacting
with a density ratio of 10. We find that this model captures the early time (t/τ ∼ 1) vorticity deposition (as characterized by the first and second moments of vorticity distributions) to within 5% of
the numerical results.
PACS 47.40.Nm; 47.20.Ma 相似文献