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Upendra Nath Dash Banka Behari Das Uttam Kumar Biswal Tapodhan Panda 《Thermochimica Acta》1984,80(2):331-342
The standard potentials of silver—silver bromide and silver—silver iodide electrodes in glycerol+water mixtures containing 5, 10, 20 and 30 wt% glycerol were determined from electromotive force measurements of the cell Ag(s), AgX(s), KX(c)//KCl(c), AgCl(s), Ag(s), where X is Br or I, at seven different temperatures in the range 5–35°C. The standard potentials in each solvent are represented as a function of temperature. The standard thermodynamic functions for the electrode reactions, the primary medium effects of various solvents upon X−, and the standard thermodynamic quantities for the transfer of 1 g-ion of X− from water to the respective glycerol + water media are evaluated and discussed in the light of ion—solvent interactions as well as the structural changes of the solvents. From the values of the Ag/Ag+ and Ag/AgX, X− electrodes, the thermodynamic solubility product constants of silver chloride, silver bromide and silver iodide have been determined in glycerol + water solvent mixtures at different temperatures. 相似文献
3.
Landa Purushottam Unnikrishnan V. B. Dattatraya Gautam Rawale Mansi Gujrati Surya Dev Mishra Sajeev T. K. Neelesh C. Reddy Srinivasa Rao Adusumalli Ram Kumar Mishra Vishal Rai 《Chemical science》2020,11(48):13137
Analytically pure proteins are indispensable for diverse applications, including therapeutics. Here, we report a methodology where a single amino acid, glycine, enables metal-free protein purification. This robust platform is enabled by a Gly-tag resin for site-specific capture, enrichment, and release through chemically triggered C–C bond dissociation by resonance-assisted electron density polarization.Gly-tag resin precisely captures and releases a protein with one glycine at the N-terminus. The user-friendly protocol delivers analytically pure protein free of metal contaminants. 相似文献
4.
Papia Datta Dibakar Sardar Uttam Panda Ajanta Halder Nabin Baran Manik Chun‐Jung Chen Chittaranjan Sinha 《应用有机金属化学》2016,30(5):323-334
Os(II) hydridocarbonyl complexes of coumarinyl azoimidazoles, [Osh(CO)(PPh3)2(CZ‐4R‐R′)]0/+ ( 3 , 4 ) (CZ‐R‐H = 2‐(coumarinyl‐6‐azo)‐4‐substituted imidazole or 1‐alkyl‐2‐(coumarinyl‐6‐azo)‐4‐substituted imidazole), were characterized from spectroscopic data and the single‐crystal X‐ray data for one of the complexes, [Osh(CO)(PPh3)2(CZ‐4‐Ph)] ( 3c ) (CZ‐4‐Ph = 2‐(coumarinyl‐6‐azo)‐4‐phenylimidazolate), confirmed the structure. The complexes show higher emission (quantum yield ? = 0.0163–0.16) and longer lifetime (τ = 1.4–10.3 ns) than free ligands (? = 0.0012–0.0185 and τ = 0.685–1.306 ns). Cyclic voltammetry shows quasi‐reversible metal oxidation at 0.67–0.94 V for [Os(III)/Os(II)] and 1.21–1.36 V for [Os(IV)/Os(III)] and subsequent azo reductions (?0.68 to ?0.95 V for [? N?N? ]/[? N N? ]? and irreversible < ?1.2 V for [? N N? ]?/[? N? N? ]2?) of the chelated coumarinyl azoimidazole. The complexes are photostable and show better photovoltaic power conversion efficiency than free ligands. Also, the complexes were used as catalysts for the oxidation of primary/secondary alcohols to aldehydes/ketones using oxidizing agents like N‐methylmorpholine N‐oxide, t‐BuOOH and H2O2. Density functional theory computation was carried out from the optimized structures and the data obtained were used to interpret the electronic and photovoltaic properties. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
5.
Hemant P. Narkhede Uttam B. More Dipak S. Dalal Nilesh S. Pawar Dhananjay H. More 《合成通讯》2013,43(4):573-577
Microwave‐assisted, solvent‐free alkylation and acylation of 2‐mercaptobenzothiazole has been attempted using silica gel, alumina, and a new solid support, fly ash. Fly ash, a waste generated at thermal power stations, could be used as solid support just as efficiently as commercial supports. The additional features of methodology include a much faster reaction, easy workup, higher yields, higher purity of the products, and an ecofriendly approach. 相似文献
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A one‐pot, multistep synthesis of acridine‐1,8(2H,5H)‐diones ( 4a–m ) was achieved by three‐component reaction of dimedone ( 1 ) with an aromatic aldehyde ( 2a–m ) and an ammonium acetate ( 3 ) using water as a green solvent without any catalyst and a simple, easily handled, and ultrasonic technique as well as conventional method. 相似文献
8.
Poojali P. Warekar Priyanka T. Patil Kirti T. Patil Dattatraya K. Jamale Govind B. Kolekar 《合成通讯》2016,46(24):2022-2030
An ecofriendly route has been investigated for the synthesis of 4-(4-nitro-phenyl)-2-phenyl-1,4-dihydro-benzo[4,5]imidazo[1,2-a]pyrimidine-3-carboxylic acid ethyl ester derivatives by one-pot, three-component condensation of ethyl benzoylacetate, aromatic aldehydes, and 2-amino benzimidazole using 260?mol% of citric acid as reaction mediator. Citric acid is an inexpensive, nontoxic, and green medium with smoothly activates the rate of reaction. The synthesized compounds were assessed for in vitro antimycobacterial activity against Mycobacterium tuberculosis H37RV strain using the microplate alamar blue assay (MABA). The results indicate that among all the synthesized compound series, P-4 and P-9 compounds illustrate effective activity with a minimum inhibitory concentration of 25?µg/ml. 相似文献
9.
Kalkote Uttam Ramrao Choudhary Anil Ramkumar Natu Arvind Anant Ayyangar Nagaraja Ramanuja 《合成通讯》2013,43(10-11):1129-1135
1-Alkylaminoanthraquinones ( 2 a-f) and 1,4-bisalkylaminoanthraquinones ( 4 a-c) were prepared from aminoanthraquinones ( 1,3 ) by alkylation with alkyl sulphate/alkyl halide in presence of powdered sodium hydroxide, potassium carbonate and phase transfer catalyst. 相似文献
10.
Uttam C. Paul Avinash P. Manian Barbora Široká Heinz Duelli Thomas Bechtold 《Cellulose (London, England)》2013,20(5):2481-2490
Multivalent ions take a significant role in the sorption of soluble polysaccharides on solid cellulose substrates and thus demonstrate an important principle in structural polysaccharide organisation. Sorption of Fe(III)–alginate complexes on lyocell fibres as model for the insoluble cellulose matrix has been studied between pH 3–13, at 30 and 60 °C. Sorption maximum of the Fe(III)–alginate complex was observed at pH 3 where the sorbed amounts of alginate and iron were 6,600 and 85 mg iron per kg cellulose respectively. Under the experimental conditions used, a concentration of 0.05 mM Fe(III) is sufficient to achieve surface sorption of Fe(III)–alginate complex. The alginate sorption exhibited minor dependence on molar ratio of Fe(III) to alginate. In environmental scanning electron microscopy no deposition of Fe-hydroxides on the fiber surface was detected. The thickness of the adsorbed Fe(III)–alginate layer on the fiber surface was estimated with 12–22 nm. Tensile strength and abrasion resistance of Fe(III)–alginate treated fibers were not reduced through the sorption treatment. Alginate modified cellulose is of interest as material for medical application, as sorbent and textile finish. 相似文献