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101.
Supramolecular Interactions of Nonsteroidal Anti‐inflammatory Drug in Nanochannels of Molecular Containers: A Spectroscopic,Thermogravimetric and Microscopic Investigation
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Banibrata Maity Aninda Chatterjee Sayeed Ashique Ahmed Dr. Debabrata Seth 《Chemphyschem》2014,15(16):3502-3514
Supramolecular host–guest complexation between the nonsteroidal anti‐inflammatory drug indomethacin (IMC) and molecular containers were investigated. The weakly fluorescent drug molecule becomes highly fluorescent on complexation with different molecular containers, and time‐resolved fluorescence emission spectroscopy reveals that the lifetime components of IMC significantly increase in the presence of molecular containers, compared with the lifetimes in neat water. The respective solid host–guest complexes were synthesised and characterised by Fourier transform infrared and 1H nuclear magnetic resonance spectroscopic analysis. Microscopy techniques were used to analyse modifications of the surface morphology, owing to the formation of supramolecular complexes. The effect of the molecular container on the optical properties of IMC has also been investigated to determine the effect of nanochannels of different size and structure. 相似文献
102.
Ritwika Ray Rahul Dev Jana Mayukh Bhadra Prof. Debabrata Maiti Prof. Goutam Kumar Lahiri 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(47):15618-15624
The present article describes novel oxidative protocols for direct esterification of alcohols. The protocols involve successful demonstrations of both “cross” and “self” esterification of a wide variety of alcohols. The cross‐esterification proceeds under a simple transition‐metal‐free condition, containing catalytic amounts of TEMPO (2,2,6,6‐tetramethyl‐1‐piperidinyloxy)/TBAB (tetra‐n‐butylammonium bromide) in combination with oxone (potassium peroxo monosulfate) as the oxidant, whereas the self‐esterification is achieved through simple induction of Fe(OAc)2/dipic (dipic=2,6‐pyridinedicarboxylic acid) as the active catalyst under an identical oxidizing environment. 相似文献
103.
Debabrata Goswami 《Pramana》2002,59(2):235-242
We show how the use of optimally shaped pulses to guide the time evolution of a system (‘coherent control’) can be an effective
approach towards quantum computation logic. We demonstrate this with selective control of decoherence for a multilevel system
with a simple linearly chirped pulse. We use a multiphoton density-matrix approach to explore the effects of ultrafast shaped
pulses for two-level systems that do not have a single photon resonance, and show that many multiphoton results are surprisingly
similar to the single-photon results. Finally, we choose two specific chirped pulses: one that always generates inversion
and the other that always generates self-induced transparency to demonstrate an ensemble CNOT gate. 相似文献
104.
105.
Dr. Debabrata Mukherjee Satoru Shirase Prof. Dr. Kazushi Mashima Prof. Dr. Jun Okuda 《Angewandte Chemie (International ed. in English)》2016,55(42):13326-13329
Triphenylborane (BPh3) was found to catalyze the reduction of tertiary amides with hydrosilanes to give amines under mild condition with high chemoselectivity in the presence of ketones, esters, and imines. N,N‐Dimethylacrylamide was reduced to provide the α‐silyl amide. Preliminary studies indicate that the hydrosilylation catalyzed by BPh3 may be mechanistically different from that catalyzed by the more electrophilic B(C6F5)3. 相似文献
106.
Chatterjee D Sikdar A Patnam VR Theodoridis A van Eldik R 《Dalton transactions (Cambridge, England : 2003)》2008,(29):3851-3856
The reactions of [Ru(III)(edta)(H(2)O)](-) (1) (edta = ethylenediaminetetraacetate) with tert-butylhydroperoxide ((t)BuOOH) and potassium hydrogenpersulfate (KHSO(5)) were studied kinetically as a function of oxidant concentration and temperature (10-30 degrees C) at a fixed pH of 6.1 using stopped-flow techniques. Kinetic results were analyzed by using global kinetic analysis techniques. The reaction was found to consist of two steps involving the rapid formation of a [Ru(III)(edta)(OOR)](2-) intermediate, which subsequently undergoes heterolytic cleavage to form [(edta)Ru(V)=O](-). Since [(edta)Ru(V)=O](-) was produced almost quantitatively in the reaction of 1 with the hydroperoxides (t)BuOOH and KHSO(5), the common mechanism is one of heterolytic scission of the O-O bond. The water soluble and easy to oxidize substrate 2,2'-azobis(3-ethylbenzithiazoline-6-sulfonate (ABTS), was employed to substantiate the mechanistic proposal. Reactions were carried out under pseudo-first order conditions for [ABTS] > [hydroperoxide] > [1], and were monitored as a function of time for the formation of the one-electron oxidation product ABTS (*+). The detailed suggested mechanism is consistent with the reported rate and activation parameters, and discussed in reference to the results reported for the reaction of [Ru(II)(edta)(H(2)O)](-) with H(2)O(2). 相似文献
107.
Dr. Meijia Li Dr. Liqi Qiu Dr. Ilja Popovs Dr. Weiwei Yang Dr. Alexander S. Ivanov Dr. Takeshi Kobayashi Dr. Bishnu P. Thapaliya Dr. Debabrata Moitra Xinbin Yu Dr. Zili Wu Dr. Zhenzhen Yang Dr. Sheng Dai 《Angewandte Chemie (International ed. in English)》2023,62(28):e202302684
Boron-enriched scaffolds have demonstrated unique features and promising performance in the field of catalysis towards the activation of small gas molecules. However, there is still a lack of facile approaches capable of achieving high B doping and abundant porous channels in the targeted catalysts. Herein, construction of boron- and nitrogen-enriched nanoporous π-conjugated networks (BN-NCNs) was achieved via a facile ionothermal polymerization procedure with hexaazatriphenylenehexacarbonitrile [HAT(CN)6] sodium borohydride as the starting materials. The as-produced BN-NCN scaffolds were featured by high heteroatoms doping (B up to 23 wt. % and N: up to 17 wt. %) and permanent porosity (surface area up to 759 m2 g−1 mainly contributed by micropores). With the unsaturated bonded B species acting as the active Lewis acid sites and defected N species acting as the active Lewis base sites, those BN-NCNs delivered attractive catalytic performance towards H2 activation/dissociation in both gaseous and liquid phase, acting as efficient metal-free heterogeneous frustrated Lewis pairs (FLPs) catalysts in hydrogenation procedures. 相似文献
108.
The complex [RuIII(edta)(H2O)]? (edta4? = ethylenediaminetetraacetate) catalyzes the oxidation of captopril (CapSH) using primary oxidants, hydrogen peroxide (H2O2) and peroxomonosulfate (\( {\text{HSO}}_{5}^{ - } \)). The kinetics of the oxidation reaction were studied as a function of both oxidant (H2O2, \( {\text{HSO}}_{5}^{ - } \)) and substrate (CapSH) concentrations using stopped-flow and rapid scan stopped-flow techniques. Spectral and kinetic data are suggestive of a pathway involving rapid formation of the intermediate complex [RuIII(edta)(CapS)]2? followed by direct attack of the oxidant (H2O2 or \( {\text{HSO}}_{5}^{ - } \)) at the S atom of the coordinated CapS?. ESI–MS and HPLC analysis of the reaction products showed that captopril disulfide (CapSSCap) is the major oxidation product. A probable mechanism in agreement with the spectral and kinetic data is presented. 相似文献
109.
We have investigated solvent and rotational relaxation of coumarin 153 (C-153) in room-temperature ionic liquid (RTILs) 1-butyl-3-methyl-imidazolium tetrafluoroborate ([bmim][BF(4)]) and the ionic liquid confined in alkyl poly(oxyethylene glycol) ethers containing micelles. We have used octaethylene glycol monotetradecyl ether (C(14)E(8)) and octaethylene glycol monododecyl ether (C(12)E(8)) as surfactants. In the [bmim][BF(4)]-C(14)E(8) micelle, we have observed only a 22% increase in solvation time compared to neat [bmim][BF(4)], whereas in the [bmim][BF(4)]-C(12)E(8) system, we have observed approximately 57% increase in average solvation time due to micelle formation. However, the slowing down in solvation time on going from neat RTIL to RTIL-confined micelles is much smaller compared to that on going from water to water confined micellar aggregates. The 22-57% increase in solvation time is attributed to the slowing down of collective motions of cations and anions in micelles. The rotational relaxation times become faster in both the micelles compare to neat [bmim][BF(4)]. 相似文献
110.