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941.
942.
Gowravaram Sabitha Teega Rammohan Reddy Chitti Srinivas Jhillu Singh Yadav 《Helvetica chimica acta》2011,94(2):224-229
The total synthesis of aspinolide A ( 1 ) was successfully achieved by an iterative acetylene? epoxide coupling strategy and a Yamaguchi lactonization as the key steps. 相似文献
943.
944.
Renu Yadav Nitin Labhsetwar Swati Kotwal Sadhana Rayalu 《Journal of nanoparticle research》2011,13(1):263-271
Nanoparticle technology is being increasingly used in environmental sciences. We prepared single enzyme nanoparticle (SEN)
by modifying the surface of carbonic anhydrase (CA) with a thin layer of organic/inorganic hybrid polymer. SEN-CA appears
to be improving the stability of free enzyme. CA, as ubiquitously found enzyme, is involved in gaseous CO2 sequestration and is being looked as a promising candidate for combating global warming. We report here physical characterization
of SEN-CA using transmission electron microscope (TEM), Fourier-transform infrared analysis (FTIR), X-ray diffraction analysis
(XRD), and energy dispersive X-ray (EDX). Average size of SEN-CA particles appears to be in the range of 70–80 nm. We also
report the effect of SEN formation on the kinetic parameters of free CA such as Michaelis–Menten constant (K
m), maximum reaction velocity (V
max), and storage stability of free CA and SEN-CA. The V
max of SEN-CA (0.02857 mmol/min/mg) and free enzyme (0.02029 mmol/min/mg) is almost similar. K
m has decreased from 6.143 mM for SEN-CA to 1.252 mM for free CA. The stabilization of CA by SEN formation results in improved
the half-life period (up to 100 days). The formation of carbonate was substantiated by using gas chromatography (GC). The
conversion of CO2 to carbonate was 61 mg of CaCO3/mg of CA and 20.8 mg of CaCO3/mg of CA using SEN-CA and free CA, respectively. 相似文献
945.
A one dimensional mathematical model is developed to optimize the design parameters of desiccant wheel. The result shows that after some value of design parameters, change in moisture removal is negligible. The optimum isotherm shape should be R = 0.1. At this isotherm optimum value of wheel length, and channel pitch should be in the range of 0.2–0.25 and 0.003–0.004 m respectively. 相似文献
946.
One-pot tandem reactions of a variety of aldehydes with aqueous ammonia, molecular iodine, and O,O-diethyl dithiophosphoric acid readily afford the corresponding primary thioamides. This is an inexpensive, practical, and metal-free way of accessing various thioamides from aldehydes in aqueous media. The pure products are obtained simply by filtration followed by successive washing with aqueous sodium thiosulfate and water.
[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] 相似文献
947.
948.
A convergent synthesis of C19–C27 fragment (2) of bryostatin-11 is described. The key steps involved in this approach are kinetic resolution, Grignard reaction, and Sharpless dihydroxylation. AIBN catalyzed radical cyclization strategy has been used for the first time to construct the six-membered pyran system. 相似文献
949.
A stereoselective synthesis of tetrahydropyran–tetrahydrofuran (THP–THF) core 2 of (+)-muconin (1) has been achieved using Prins cyclization as a key step to construct tetrahydropyran moiety. Other important transformations such as Wittig olefination, Sharpless epoxidation, regio-, and stereoselective exo-cyclization of the epoxy alcohol, titanocene induced regioselective deoxygenation of 2,3-epoxy alcohol, Grignard reaction, and Barton–McCombie reaction are successfully employed to accomplish the synthesis of THP–THF core 2. 相似文献
950.
Shabana Khatoon Ashok K. Yadav 《Phosphorus, sulfur, and silicon and the related elements》2013,188(2):345-352
Some new nucleosides, viz. 4-imino-3,5,7-trisubstituted-1-(2′,3′,5′-tri-O-kbenzyl–β-D-ribofuranosyl)pyrido[2,3-d]pyrimidin/e–2(1H)-ones/ thiones(VII/VIII), have been synthesized by condensation of trimethylsilyl derivatives of 4-imino-3,5,7-trisubstituted pyrido[2,3-d]pyrimidin/e-2(1H)-ones/thiones (III/IV) with β-D-ribofuranosyl1-acetate-2,3,5-tribenzoate. Compounds III/IV have been synthesized by refluxing 2-amino-3-cyano-4,6-disubstituted pyridine (II) with substituted an arylisocyanate or an isothiocyanate respectively. The structure of all the synthesized compounds have been established by IR and 1H NMR studies. These compounds have been screened for antimicrobial activities in order evaluate. The possibility of the derivatives to be used as potential chemotherapeutic agents. 相似文献