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Poonia Nisha Lal Kashmiri Kumar Ashwani Kumar Anil Sahu Srikanta Baidya Anurag T. K. Kumar Rajnish 《Molecular diversity》2022,26(5):2375-2391
Molecular Diversity - Some urea-thiazole/benzothiazole hybrids with a triazole linker were synthesized via Cu(I)-catalysed click reaction. After successfully analysed by various spectral techniques... 相似文献
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Real time band selective F1‐decoupled proton NMR for the demixing of overlay spectra of chiral molecules 下载免费PDF全文
Nilamoni Nath Ajay Verma Bikash Baishya Chunni Lal Khetrapal 《Magnetic resonance in chemistry : MRC》2017,55(6):553-558
The small chemical shift dispersion and complex multiplicity pattern in proton NMR limit quantifications, for instance the determination of enantiomeric excess (ee) for an enantiomeric mixture. Herein, we present a simple proton–proton correlation experiment with band selective homonuclear (BASH) decoupling in both F1 and F2 dimensions, for the removal of scalar and residual dipolar couplings to provide collapsed singlet for each chemical site. The method has been demonstrated to separate the severely overlapped spectra of enantiomers using both chiral isotropic and anisotropic phases as well as a small biomolecule, particularly for the diastereotopic protons and also for the determination of ee. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Kumar Vijay Kushwaha Vikram Gandhi Yashika Mishra Sujeet K. Charde Vaibhav Jagtap Chandrashekhar Babu G. Singh Arjun Singh Ravindra Srikanth Narayanam 《平面色谱法杂志一现代薄层色谱法》2022,35(1):23-33
JPC – Journal of Planar Chromatography – Modern TLC - A new, simple, selective, sensitive, precise, and robust high-performance thin-layer chromatography (HPTLC) method for the... 相似文献
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Elena Shanina Sakonwan Kuhaudomlarp Kanhaya Lal Peter H. Seeberger Anne Imberty Christoph Rademacher 《Angewandte Chemie (International ed. in English)》2022,61(1):e202109339
Carbohydrate-binding proteins (lectins) are auspicious targets in drug discovery to combat antimicrobial resistance; however, their non-carbohydrate drug-like inhibitors are still unavailable. Here, we present a druggable pocket in a β-propeller lectin BambL from Burkholderia ambifaria as a potential target for allosteric inhibitors. This site was identified employing 19F NMR fragment screening and a computational pocket prediction algorithm SiteMap. The structure–activity relationship study revealed the most promising fragment with a dissociation constant of 0.3±0.1 mM and a ligand efficiency of 0.3 kcal mol?1 HA?1 that affected the orthosteric site. This effect was substantiated by site-directed mutagenesis in the orthosteric and secondary pockets. Future drug-discovery campaigns that aim to develop small molecule inhibitors can benefit from allosteric sites in lectins as a new therapeutic approach against antibiotic-resistant pathogens. 相似文献
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Synthesis, Crystal Structure and Antibacterial Activity of 1-((2-Chloroquinolin-3-yl)-methyl)-pyridin-2(1H)-one 总被引:1,自引:0,他引:1
S. Mohana Roopan Venkatesha R. Hathwar F. Nawaz Khan Atul Kumar Kushwaha 《结构化学》2010,29(11):1612-1617
On the basis of the interesting structures and biological activities exhibited by several heterocyclic systems possessing the pyridone nucleus such as mappcine and camptothecin, we have planed to design the synthesis, crystal studies and antibacterial activity of the new 1-((2- chloroquinolin-3yl)-methyl)-pyridine-2(1H)-one building block. An X-ray analysis has provided valuable insight into the effect of steric factors on the three-dimensional shape of this compound which serves as a useful advanced intermediate in the synthesis of these biologically active molecules. A multistep synthesis of camptothecin (5) has been designed by retrosynthetic analysis as part of an ongoing program on lead anticancer drug. 相似文献
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Ram A. Lal Sanjesh Choudhury Aziz Ahmed Rosmita Borthakur Mrityunjaya Asthana Arvind Kumar 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2010,75(1):212-224
The diamagnetic dioxomolybdenum(VI) complex [(MoO2)2(CH2L)(H2O)2]H2O (1) has been isolated in solid state from reaction of MoO2(acac)2 with bis(2-hydroxy-1-naphthaldehyde)malonoyldihydrazone (CH2LH4) in 3:1 molar ratio in ethanol at higher temperature. The reaction of the complex (1) with electron donor bases gives diamagnetic molybdenum(VI) complexes having composition [Mo2O5(CH2LH2)]·2A·2H2O (where A = pyridine (py, 2), 2-picoline (2-pic, 3), 3-picoline (3-pic, 4), 4-picoline (4-pic, 5)). Further, when the complex (1) is allowed to react with protonic bases such as isonicotinoylhydrazine (inhH3) and salicyloylhydrazine (slhH3), reduction of molybdenum(VI) centre occurs leading to isolation of homobimetallic molybdenum(V) complexes [Mo2(CH2L)(inh)2(H2O)2] (6) and [Mo2(CH2L)(slh)2] (7), respectively. The composition of the complexes has been established by analytical, thermo-analytical and molecular weight data. The structure of the molybdenum(VI) complexes (1)–(5) has been established by electronic, IR, 1H NMR and 13C NMR spectral studies while those of the complexes (6) and (7) by magnetic moment, electronic, IR and EPR spectral studies. The dihydrazone is coordinated to the metal centres in staggered configuration in complex (1) while in anti-cis configuration in complexes (2)–(7). The complexes (6) and (7) possess magnetic moment of 2.95 and 3.06 BM, respectively, indicating presence of two magnetic centre in the complexes per molecule each with one unpaired electron on each metal centre without any metal–metal interaction. The electronic spectra of the complexes are dominated by strong charge transfer bands. All of the complexes involve six coordinated molybdenum centre with octahedral arrangement of donor atoms except in the complex (6), in which the molybdenum centre has rhombic arrangement of ligand donor atoms. The probable mechanism for generation of oxo-group in the complexes (2)–(5) involving coordinated water molecule has been proposed. 相似文献