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71.
JPC – Journal of Planar Chromatography – Modern TLC - Sensitive and selective detection of monocrotophos after TLC is possible by use of vanillin as reagent. The product from alkaline... 相似文献
72.
JPC – Journal of Planar Chromatography – Modern TLC - Cypermethrin is frequently encountered in poisoning cases in India. In TLC, the compound can be detected by spraying the plate with... 相似文献
73.
74.
R. Nageswara Rao R. Mastan Vali Dhananjay D. Shinde 《Biomedical chromatography : BMC》2009,23(11):1145-1150
A highly sensitive and selective on‐line two‐dimensional reversed‐phase liquid chromatography/electrospray ionization–tandem mass spectrometry (2D‐LC‐ESI/MS/MS) method was developed and validated to determine rifaximin in rat serum by direct injection. The 2D‐LC‐ESI/MS/MS system consisted of a restricted access media column for trapping proteins as the first dimension and a Waters C18 column as second dimension using 0.1% aqueous acetic acid:acetonitrile as mobile phase in a gradient elution mode. Rifampacin was used as an internal standard. The linear dynamic range was 0.5–10 ng/mL (r2 > 0.998). Acceptable precision and accuracy were obtained over the calibration range. The assay was successfully used in analysis of rat serum to support pharmacokinetic studies. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
75.
Jaiprakash N. Sangshetti Nagnnath D. Kokare Sandeep A. Kotharkar Devanand B. Shinde 《Monatshefte für Chemie / Chemical Monthly》2008,139(2):125-127
Summary. 2,4,5-Triaryl-1H-imidazoles were efficiently synthesized from benzoin or benzil, ammonium acetate, and aromatic or heteroaromatic aldehydes
in the presence of sodium bisulfite as catalyst. The present protocol offers significant improvements for the synthesis of
2,4,5-triaryl-1H-imidazoles with regard to yield of products, simplicity in operation, and cheap catalyst. 相似文献
76.
We have developed simple, greener, safer multicomponent synthesis series of 4-arylidene-2-phenyl-5(4H) oxazolones 4(a-r) catalyzed by Bronsted acid ionic liquid as triethylammonium hydrogen sulfate [Et3NH][HSO4] and catalytic amount of acetic anhydride and sodium acetate with excellent yields (90–99%). The protocol offers economical, environmentally benign, solvent-free conditions, and recycle–reuse of the catalyst and easily available starting as benzoyl chloride 1, amino acid 2 and a variety of aldehydes 3. The cyclization followed by condensation of benzoyl chloride, amino acid, and a variety of aldehydes catalyzed by ILs [Et3NH][HSO4] and catalytic amount of acetic anhydride and sodium acetate. The final products were confirmed by their characterization data such as FTIR, 1H-NMR, 13C-NMR, Mass, high-resolution mass spectra and were compared with its reported method. 相似文献
77.
Large dendrimers, noted G(n)-3(n+2)cage, containing 3(n+2) o-carborane cluster cages MeC(2)B(10)H(10) at their peripheries (n = number of generation noted G(n)) have been synthesized by Huisgen-type azide alkyne Cu(I)-catalyzed dipolar "click" cycloaddition reactions (CuAAC) between an o-carborane monomeric cluster containing an ethynyl group and arene-centered azido-terminated dendrimers G(n)-3(n+2)N(3) of generations 0, 1, and 2. Attempts to synthesize higher-generation dendrimers of this family yielded insoluble materials. The carborane dendrimers G(0)-9cage, G(1)-27cage, and G(2)-81cage have been characterized by (1)H, (13)C, (11)B NMR, elemental analysis, matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectroscopy, and size exclusion chromatography (SEC) showing low polydispersities, dynamic light scattering (DLS) showing hydrodynamic diameters of 5.7 nm for the G(1)-27cage and the 12.9 nm for the G(2)-81cage. These dendrimers are extremely robust thermally, with 10% mass loss temperatures of 411 °C for the G(0)-9cage, 371 °C for the G(1)-27cage, and 392 °C for the G(2)-81cage. They all showed a strong absorption in the UV region peaking at 258 nm, whereas emission spectra of low intensities were observed between 280 and 480 nm. 相似文献
78.
Pravin V. Shinde 《Tetrahedron letters》2010,51(9):1309-6782
A one-pot three-component condensation of an aldehyde, malononitrile, and thiophenol has been achieved by conventional and ultrasound method. The reaction has been catalyzed by boric acid in aqueous medium. This protocol afforded corresponding 2-amino-3,5-dicarbonitrile-6-thio-pyridines in shorter reaction times and high yields with the green aspects by avoiding toxic catalysts and solvents. 相似文献
79.
Abstract
An enhanced rate of intramolecular nitrile oxide cycloaddition and hence a rapid synthesis of isoxazoles and isoxazolines is described. Formation of nitrile oxides from oximes using only 1 or 2 Eq (equivalents) of aqueous sodium hypochlorite solution is also described. 相似文献80.
The Dy3+ and Eu3+ activated K3Al2 (PO4)3 phosphors were prepared by a combustion synthesis. From a powder X-ray diffraction (XRD) analysis the formation of K3Al2 (PO4)3 was confirmed. In the photoluminescence emission spectra, the K3Al2(PO4)3:Dy3+ phosphor emits two distinctive colors: blue and yellow whereas K3Al2(PO4)3:Eu3+ emits red color. Thus the combination of colors gives BYR (blue–yellow–red) emissions can produce white light. These phosphors
exhibit a strong absorption between 340 and 400 nm which suggest that present phosphor is a promising candidate for producing
white light-emitting diodes (LED). 相似文献