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排序方式: 共有921条查询结果,搜索用时 15 毫秒
1.
Ravula Sharada Nukala Satheesh Kumar Thirukovela Narasimha Swamy Sirassu Narsimha Dasari Gouthami Kurma Srimathi Bandari Srinivas 《Russian Journal of General Chemistry》2022,92(4):702-708
Russian Journal of General Chemistry - In the current study, some new quinoxaline linked 1,3,4-oxadiazole sulfonamide hybrids have been designed, synthesized and characterized by IR, 1H and 13C... 相似文献
2.
Kumar B. Ravi Kumar A. Kishore Reddy B. Srinivas Shashikala K. Laxminarayana E. 《Russian Journal of Organic Chemistry》2022,58(4):580-583
Russian Journal of Organic Chemistry - tert-Butyl 4-[(E)-but-1-en-3-yn-1-yl]-3-{[tert-butyl(dimethyl)silyl]oxy}-1H-indole-1-carboxylate has been synthesized with a good yield and selectivity... 相似文献
3.
Nishtala Venkata Bharat Mahesh Chityala Bhargavi G. Pasala Vijay Kumar Basavoju Srinivas 《Molecular diversity》2020,24(4):1139-1147
Molecular Diversity - A series of new spirooxindolocarbamates 4a–l and 6a–d were synthesized by using the Betti reaction. All the target compounds were well characterized by IR, NMR and... 相似文献
4.
Vinay Kiran Narayanan Balaji Bhavesh Babulal Gabani Manjuanth Bajantri Rajesh Chandran Abhishek Dixit Nuggehally R. Srinivas Ramesh Mullangi 《Biomedical chromatography : BMC》2020,34(9):e4879
We developed and validated a simple, sensitive, selective, and reliable LC–MS/MS–ESI method for the direct quantitation of lumefantrine (LFN) enantiomers [(−)-LFN and (+)-LFN] in mice plasma as per regulatory guideline. LFN enantiomers and carbamazepine (internal standard) were extracted from mice plasma using Strata X SPE (solid-phase extraction) cartridges. Good resolution between enantiomers was achieved on a Chiralpak IA-3 column using an isocratic mobile phase (0.1% of diethyl amine in methanol), which was delivered at a flow rate of 0.8 mL/min. Detection and quantitation were performed using multiple reaction monitoring mode following the transitions m/z 530.27 → 512.30 and 237.00 → 194.00 for LFN enantiomers and the internal standard, respectively, in the positive-ionization mode. The proposed method provided accurate and reproducible results over the linearity range of 2.39–895 ng/mL for each enantiomer. The intra- and inter-day precisions were in the range of 1.03–6.14 and 6.36–8.70 and 2.03–4.88 and 5.82–11.5 for (−)-LFN and (+)-LFN, respectively. Both (−)-LFN and (+)-LFN were found to be stable under different stability conditions. The method was successfully used to delineate stereoselective pharmacokinetics of LFN enantiomers in mice after an oral administration of rac-LFN (20 mg/kg). The pharmacokinetic results indicated that the disposition of LFN enantiomers was stereoselective in mice. 相似文献
5.
Bhavesh Babulal Gabani Neeraj Kumar Saini Ravi Kumar Jairam Pavan Shrinivas Ravi Kumar Trivedi Nuggehally R. Srinivas Ramesh Mullangi 《Biomedical chromatography : BMC》2020,34(11):e4939
A selective, sensitive and rapid LC–MS/MS method has been developed and validated as per US Food and Drug Administration regulatory guidelines for the simultaneous quantitation of colchicine and febuxostat in rat plasma. Colchicine and febuxostat were extracted from the rat plasma using 10% tert-butyl methyl ether in ethyl acetate using colchicine-d6 as an internal standard (IS). The chromatographic separation of colchicine, febuxostat and the IS was achieved using a mobile phase comprising 5 mm ammonium formate and 0.025% formic acid in acetonitrile (20:80, v/v) in isocratic mode on an Eclipse XDB-C18 column. The injection volume and flow rate were 5.0 μl and 0.9 ml/min, respectively. Colchicine and febuxostat were detected by positive electrospray ionization in multiple reaction monitoring mode using transition pairs (Q1 → Q3) of m/z 400.10 → 358.10 and 317.05 → 261.00, respectively. The assay was linear in the ranges of 0.25–254 and 2.60–622 ng/ml for colchicine and febuxostat, respectively. The inter- and intra-day precision values were 0.58–13.0 and 1.03–4.88% for colchicine and febuxostat, respectively. No matrix or carryover effects were observed during the validation. Both analytes were stable on the bench-top, in the autosampler and in storage (freeze–thaw cycles and long-term storage at −80 ° C). A pharmacokinetic study in rats was performed to show the applicability of the validated method. 相似文献
6.
Nirmal Kumar S. Appari Srinivas Kuncharam Bhanu Vardhan Reddy 《Catalysis Surveys from Asia》2021,25(4):362-388
Catalysis Surveys from Asia - Sulfur poisoning of catalyst is a well-known phenomenon observed during the production of syngas (CO?+?H2). The presence of traces of sulfur... 相似文献
7.
Suresh P S Ravi Kumar Trivedi Nuggehally R. Srinivas Ramesh Mullangi 《Biomedical chromatography : BMC》2020,34(1):e4742
Quantitation of drugs used for the treatment of chronic lymphocytic leukemia in various biological matrices during both pre-clinical and clinical developments is very important, often in routine therapeutic drug monitoring. The first developed methods for quantitation were traditionally done on LC in combination with either UV or fluorescence detection. However, the emergence of LC with mass spectrometry in tandem in early 1990s has revolutionized the quantitation as it has provided better sensitivity and selectivity within a shorter run time; therefore it has become the choice of method for the analysis of various drugs. In this article, an overview of various bioanalytical methods (HPLC or LC–MS/MS) for the quantification of drugs for the treatment of chronic lymphocytic leukemia, along with applicability of these methods, is given. 相似文献
8.
Dr. Zhenghai Yang Dr. Srinivas Doddipatla Dr. Chao He Vladislav S. Krasnoukhov Prof. Dr. Valeriy N. Azyazov Prof. Dr. Alexander M. Mebel Prof. Dr. Ralf I. Kaiser 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(60):13584-13589
The silene molecule (H2SiCH2; X1A1) has been synthesized under single collision conditions via the bimolecular gas phase reaction of ground state methylidyne radicals (CH) with silane (SiH4). Exploiting crossed molecular beams experiments augmented by high-level electronic structure calculations, the elementary reaction commenced on the doublet surface through a barrierless insertion of the methylidyne radical into a silicon-hydrogen bond forming the silylmethyl (CH2SiH3; X2A′) complex followed by hydrogen migration to the methylsilyl radical (SiH2CH3; X2A′). Both silylmethyl and methylsilyl intermediates undergo unimolecular hydrogen loss to silene (H2SiCH2; X1A1). The exploration of the elementary reaction of methylidyne with silane delivers a unique view at the widely uncharted reaction dynamics and isomerization processes of the carbon–silicon system in the gas phase, which are noticeably different from those of the isovalent carbon system thus contributing to our knowledge on carbon silicon bond couplings at the molecular level. 相似文献
9.
Applied Mathematics and Mechanics - In many industrial applications, heat transfer and tangent hyperbolic fluid flow processes have been garnering increasing attention, owing to their immense... 相似文献
10.
Vladislav S. Krasnoukhov Prof. Dr. Valeriy N. Azyazov Prof. Dr. Alexander M. Mebel Dr. Srinivas Doddipatla Dr. Zhenghai Yang Shane Goettl Prof. Dr. Ralf I. Kaiser 《Chemphyschem》2021,22(14):1497-1504
The chemical dynamics of the elementary reaction of ground state atomic silicon (Si; 3P) with germane (GeH4; X1A1) were unraveled in the gas phase under single collision condition at a collision energy of 11.8±0.3 kJ mol−1 exploiting the crossed molecular beams technique contemplated with electronic structure calculations. The reaction follows indirect scattering dynamics and is initiated through an initial barrierless insertion of the silicon atom into one of the four chemically equivalent germanium-hydrogen bonds forming a triplet collision complex (HSiGeH3; 3 i1 ). This intermediate underwent facile intersystem crossing (ISC) to the singlet surface (HSiGeH3; 1 i1 ). The latter isomerized via at least three hydrogen atom migrations involving exotic, hydrogen bridged reaction intermediates eventually leading to the H3SiGeH isomer i5 . This intermediate could undergo unimolecular decomposition yielding the dibridged butterfly-structured isomer 1 p1 (Si(μ-H2)Ge) plus molecular hydrogen through a tight exit transition state. Alternatively, up to two subsequent hydrogen shifts to i6 and i7 , followed by fragmentation of each of these intermediates, could also form 1 p1 (Si(μ-H2)Ge) along with molecular hydrogen. The overall non-adiabatic reaction dynamics provide evidence on the existence of exotic dinuclear hydrides of main group XIV elements, whose carbon analog structures do not exist. 相似文献