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111.
Ritu B. Dixit Ankit P. Bulsara Hemal B. Mehta Bharat C. Dixit 《Journal of Saudi Chemical Society》2012,16(2):193-197
New bis-hydrazonothioxothiazolidinone derivatives based on 2-thioxothiazolidin-4-one were synthesized in good yields using a simplified experimental condition. The structure of synthesized compounds was established with the help of common physico-chemical analysis and various spectroscopic techniques like FT-IR, mass and 1H NMR. The results of characterizations are in good agreement with the proposed structure of all the synthesized compounds. Further, the antimicrobial (antibacterial and antifungal) activities of all the synthesized derivatives were carried out against various species like Bacillus subtilis, Escherichia coli, Aspergillous niger and Aspergillous flavus by using agar-cup method. The results of antimicrobial screening showed that all the compounds have mild to moderate activity. However, some of the compounds (3a, 3b, 3d, 3e, 3f, 3g, 3i and 3j) have shown better activity than the other. 相似文献
112.
Szostak M Spain M Parmar D Procter DJ 《Chemical communications (Cambridge, England)》2012,48(3):330-346
Samarium diiodide (SmI(2)) is one of the most important reductive electron transfer reagents available in the laboratory. Key to the popularity of SmI(2) is the ability of additives and co-solvents to tune the properties of the reagent. Over the last decade water has emerged as a particularly valuable additive, opening up new chemical space and leading to the discovery of unprecedented selectivity and new reactions promoted by SmI(2). In this Feature Article we review recent progress in the application of SmI(2)-H(2)O systems, with an emphasis on mechanistic considerations and the development of new transformations. 相似文献
113.
We describe the design, synthesis and biological evaluation of conformationally-locked 5'-acyl sulfamoyl adenosine derivatives as new parasitic inhibitors against Trypanosoma and Leishmania. The conformationally-locked (3'-endo, North-type) nucleosides have been synthesized by covalently attaching a 4'-CH(2)-O-2' bridge () across C2'-C4' of adenosine in order to reduce the conformational flexibility of the pentose ring. This is designed to decrease the entropic penalty for complex formation with the target protein, which may improve free-energy of stabilization of the complex leading to improved potency. Conformationally-locked 5'-acyl sulfamoyl adenosine derivatives (16-22) were tested against parasitic protozoans for the first time in this work, and showed potent inhibition of Trypanosoma cruzi, Trypanosoma brucei, Trypanosoma rhodesiense and Leishmania infantum with IC(50) = 0.25-0.51 μM. In particular, the potent 5'-pentanyl acyl sulfamoyl adenosine derivative 17 (IC(50) = 0.25 μM) against intracellular L. infantum amastigotes and Trypanosoma subspecies is interesting in view of its almost insignificant cytotoxicity in murine macrophage host cells (CC(50) >4 μM) and in diploid human fibroblasts MRC-5 cell lines (CC(50) 4 μM). This work also suggests that variable alkyl chain length of the acyl group on the acylsulfamoyl side chain at 5' can modulate the toxicity of 5'-O-sulfamoylnucleoside analogues. This conformationally-locked sulfamoyl adenosine scaffold presents some interesting possibilities for further drug design and lead optimization. 相似文献
114.
115.
Vijay S. Parmar Dr. David P. Mills Prof. Richard E. P. Winpenny 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(28):7625-7645
Recent studies have shown that mononuclear lanthanide (Ln) complexes can be high-performing single-molecule magnets (SMMs). Recently, there has been an influx of mononuclear Ln alkoxide and aryloxide SMMs, which have provided the necessary geometrical control to improve SMM properties and to allow the intricate relaxation dynamics of Ln SMMs to be studied in detail. Here non-aqueous Ln alkoxide and aryloxide chemistry applied to the synthesis of low-coordinate mononuclear Ln SMMs are reviewed. The focus is on mononuclear DyIII alkoxide and aryloxide SMMs with coordination numbers up to eight, covering synthesis, solid-state structures and magnetic attributes. Brief overviews are also provided of mononuclear TbIII, HoIII, ErIII and YbIII alkoxide and aryloxide SMMs. 相似文献
116.
D. A. Sparrow B. Balko S. Dixit 《Journal of Quantitative Spectroscopy & Radiative Transfer》1988,40(6):741-750
Deexcitation of isomeric levels via virtual excitation of higher levels with short lifetimes is calculated for a variety of circumstances. On and off resonance processes as well as single and multiple photon excitations are considered. Parameters characteristic of atomic and nuclear systems are contrasted. For the nuclear systems, the small excitation cross sections resulting from the small nuclear size leads to enormous intensity requirements for the pumping of nuclear isomers. 相似文献
117.
118.
P. Munshi P. Jayakumar P. Satyamurthy T. K. Thiyagarajan N. S. Dixit N. Venkatramani 《Experiments in fluids》1998,24(5-6):424-430
A steady-state vertical mercury-nitrogen flow system has been investigated using three tomographic algorithms. Void-fraction
profiles have been reconstructed by the data collected by a 60 mCi gamma-ray source and a single Na(Tl) detector. The results
indicate excellent agreement (within ±1%) between the least-squares-solution and the chord-segment-inversion algorithms. The
data-collection time for each data-ray was varied so that in each case 3000 counts could be collected to reduce the detrimental
effect of Poisson statistics in the reconstructed profiles. Eleven sets of data have been collected for nitrogen flow-rates
between 0.00123 and 0.00884 kg/s. The mercury flow-rates were between 17.6 and 34.1 kg/s. The resulting cross-sectional average
void varied between 0.10 and 0.38.
Received: 13 March 1997/Accepted: 12 September 1997 相似文献
119.
Virinder S Parmar Kirpal S Bisht Amarjit Singh Amitabh Jha 《Journal of Chemical Sciences》1996,108(6):575-583
Enantioselection effected by commercially available hydrolytic enzymes reported in recent years from our own laboratory and
those published by other groups is described. The discussion is confined to enantioselection in symmetric diols, amino acids
and benzopyran derivatives only. The paper describes a variety of substrates accepted by these hydrolytic enzymes to produce
compounds in high enantiomeric excess which can be used as chiral building blocks for the synthesis of compounds of pharmaceutical
and synthetic interest. 相似文献
120.