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941.
Shambhu Nath Singh Sridhar Regati Abir Kumar Paul Mohosin Layek Sarva Jayaprakash K. Venkateshwara Reddy Girdhar Singh Deora Soumita Mukherjee Manojit Pal 《Tetrahedron letters》2013
CuI facilitated three-component reaction of isatin derivatives, l-proline and terminal alkynes containing an amide or ester functional group. The multi-component reaction (MCR) afforded a faster and practical synthesis of spirooxindole derivatives. A range of novel spirooxindoles were synthesized by using this straightforward and one-pot efficient methodology. A representative compound showed significant inhibition of PDE4B enzyme in vitro and good interactions with this protein in silico. 相似文献
942.
Ashish Pandey Anoop Kelkar R. K. Singhal Chetan Baghra Amrit Prakash Mohd. Afzal J. P. Panakkal 《Journal of Radioanalytical and Nuclear Chemistry》2012,293(3):743-749
Pyrohydrolysis is a fast, reliable and convenient method for the decomposition of solid refractory samples. Thoria based mixed oxide nuclear fuels requires more than 1,200?°C reaction temperature to lose its structural integrity so as to release the halides. In the present paper, we report WO3 accelerated pyrohydrolytic extraction technique for the separation of F? and Cl? from thoria based fuels along with the feasibility of using MoO3 and V2O5. The mechanism of extraction has been investigated in detail using X-ray diffraction and recovery studies. ThO2 along with its halides undergo high temperature solid state reaction with WO3 forming Th(WO4)2 and releasing the halides for their subsequent hydrolysis. The quantification was carried out by ion chromatography with suppressed ion conductivity detection. The average recoveries of the spiked samples for F? and Cl? were 93?C99%. The method was successfully applied for simultaneous determination of F? and Cl? in thorium based nuclear fuel samples at 950?°C. 相似文献
943.
A differential quadrature based numerical method for highly accurate solutions of Burgers' equation 下载免费PDF全文
V. S. Aswin Ashish Awasthi Mohammad Mehdi Rashidi 《Numerical Methods for Partial Differential Equations》2017,33(6):2023-2042
In this article, we introduce a new, simple, and accurate computational technique for one‐dimensional Burgers' equation. The idea behind this method is the use of polynomial based differential quadrature (PDQ) for the discretization of both time and space derivatives. The quasilinearization process is used for the elimination of nonlinearity. The resultant scheme has simulated for five classic examples of Burgers' equation. The simulation outcomes are validated through comparison with exact and secondary data in the literature for small and large values of kinematic viscosity. The article has deduced that the proposed scheme gives very accurate results even with less number of grid points. The scheme is found to be very simple to implement. Hence, it applies to any domain requires quick implementation and computation.© 2017 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 33: 2023–2042, 2017 相似文献
944.
Manoj Gaur Mayurika Goel L. Sridhar Tara Devi S. Ashok S. Prabhakar P. Dureja P. Raghunathan S. V. Eswaran 《Monatshefte für Chemie / Chemical Monthly》2012,44(15):283-288
Abstract
Click chemistry was used to synthesize a series of biaryl-based bis(1,2,3-triazoles). Their antifungal activity was evaluated against three soil-borne plant pathogenic fungi, viz. Rhizoctonia bataticola, Sclerotium rolfsii, and Fusarium oxysporum, using the food poison technique at concentrations of 62.5–500 μg/cm3. 相似文献945.
S. Sridhar V. Chinnathambi P. Arumugam P K Suresh 《Applied biochemistry and biotechnology》2013,169(3):911-922
The objective of this paper is to compare in silico data with wet lab physicochemical properties of crude laccase enzyme isolated from Rigidoporus sp. using wheat bran as solid substrate support towards dye decolorization. Molecular docking analysis of selected nine textile and non-textile dyes were performed using laccase from Rigidoporus lignosus as reference protein. Enzyme-based remediation methodology using crude enzyme enriched from solid state fermentation was applied to screen the effect of four influencing variables such as pH, temperature, dye concentration, and incubation time toward dye decolorization. The extracellular crude enzyme decolorized 69.8 % Acid Blue 113, 45.07 % Reactive Blue 19, 36.61 % Reactive Orange 122, 30.55 % Acid Red 88, 24.59 % Direct Blue 14, 18.48 % Reactive Black B, 16.49 % Reactive Blue RGB, and 11.66 % Acid Blue 9 at 100 mg/l dye concentration at their optimal pH at room temperature under static and dark conditions after 1 h of incubation without addition of any externally added mediators. Our wet lab studies approach, barring other factors, validate in silico for screening and ranking textile dyes based on their proximity to the T1 site. We are reporting for the first time a combinatorial approach involving in silico methods and wet lab-based crude laccase-mediated dye decolorization without any external mediators. 相似文献
946.
R. Sridhar 《Tetrahedron》2009,65(51):10701-10708
An efficient protocol for the asymmetric synthesis of triacetyl-d-erythro-sphingosine and D-1-deoxyallonojirimycin has been developed starting from commercially available propargyl alcohol. The key steps involved Sharpless asymmetric epoxidation and Miyashita C2 selective endo-mode azide opening of the 2,3-epoxy alcohol. 相似文献
947.
Shailesh Thakrar Abhay Bavishi Dhairya Bhavsar Shrey Parekh Hardev Vala Ashish Radadiya 《合成通讯》2013,43(22):3269-3278
A new series of 1,4-dihydropyridines bearing a pyrazole moiety in the 4-position were synthesized by a variation of the classical Hantzsch synthesis. The reaction of 1,3-diphenyl-1H-pyrazole-4-carbaldehyde 4a–n with 3-amino crotononitrile in the presence of glacial acetic acid afforded novel 3,5-dicyano-2,6-dimethyl 1,4-dihydropyridines 5a–n. The procedure has short reaction time (15–20 min), easy workup, and good yield of product. The structures of all synthesized compounds were well characterized by mass, infrared, 1H and 13C NMR, and elemental analysis. 相似文献
948.
Influence of mesoporosity on the sorption of 2,4-dichlorophenoxyacetic acid onto alumina and silica 总被引:1,自引:0,他引:1
Goyne KW Chorover J Zimmerman AR Komarneni S Brantley SL 《Journal of colloid and interface science》2004,272(1):10-20
Two SiO2 and three Al2O3 adsorbents with varying degrees of mesoporosity (pore diameter 2-50 nm) were reacted with 2,4-dichlorophenoxyacetic acid (2,4-D) at pH 6 to investigate the effects of intraparticle mesopores on adsorption/desorption. Anionic 2,4-D did not adsorb onto either SiO2 solid, presumably because of electrostatic repulsion, but it did adsorb onto positively charged Al2O3 adsorbents, resulting in concave isotherms. The Al2O3 adsorbent of highest mesoporosity consistently adsorbed more 2,4-D per unit surface area than did the nonporous and less mesoporous Al2O3 adsorbents over a range of initial 2,4-D solution concentrations (0.025-2.5 mM) and reaction times (30 min-55 d). Differences in adsorption efficiency were observed despite equivalent surface site densities on the three Al2O3 adsorbents. Hysteresis between the adsorption/desorption isotherms was not observed, indicating that adsorption is reversible. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy studies confirm that 2,4-D adsorption does not occur via ligand exchange, but rather via electrostatic interaction. The results indicate that adsorbent intraparticle mesopores can result in consistently greater 2,4-D adsorption, but the amount adsorbed is dependent upon surface charge and the presence of adsorbent mesoporosity. The data also suggest that when mineral pores are significantly larger than the adsorbate, they do not contribute to diffusion-limited adsorption/desorption hysteresis. Adsorbent transformations through time are discussed. 相似文献
949.
We propose a shallow water model that combines the dispersion relation of water waves and Boussinesq equations, and that extends the Whitham equation to permit bidirectional propagation. We show that its sufficiently small and periodic traveling wave is spectrally unstable to long wavelength perturbations if the wave number is greater than a critical value, like the Benjamin‐Feir instability of a Stokes wave. We verify that the associated linear operator possesses infinitely many collisions of purely imaginary eigenvalues, but they do not contribute to instability to the leading order in the amplitude parameter. We discuss the effects of surface tension. The results agree with those from a formal asymptotic expansion and a numerical computation for the physical problem. 相似文献
950.
Maheswaran H Prasanth KL Krishna GG Ravikumar K Sridhar B Kantam ML 《Chemical communications (Cambridge, England)》2006,(39):4066-4068
The dichloro[(-)-sparteine-N,N']copper(II) complex provides Henry adducts with high enantioselectivities (73-97% ee) in Henry reaction between nitromethane and various aldehydes. 相似文献