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991.
C. B. Zamboni M. F. Suzuki S. Metairon M. D. F. Carvalho O. A. Sant’Anna 《Journal of Radioanalytical and Nuclear Chemistry》2009,281(1):97-99
The Br (0.0022 ± 0.0006 gL−1), Ca (0.113 ± 0.012 gL−1), Cl (3.07 ± 0.36 gL−1), K (2.63 ± 0.14 gL−1), Mg (0.045 ± 0.002 gL−1) and Na (2.09 ± 0.10 gL−1) concentrations were determined in whole blood of SJL/J mice using the Neutron Activation Analysis (NAA) technique. Eleven
whole blood samples were analyzed in the IEA-R1 nuclear reactor at IPEN (S?o Paulo, Brazil). These data contribute for applications
in veterinary medicine related to biochemistry analyses using whole blood. Moreover, the correlation with human blood estimation
allows to checking the similarities for studying muscular dystrophy using this model animal. 相似文献
992.
An introduction to conjugated steroids and the justification for their analysis is provided covering both environmental and
biological samples. Determining conjugated steroids or indeed any organic chemical which is conjugated upon excretion from
the body has relevance in diagnostic monitoring, forensic screening and environmental analysis (from the endocrine disrupter
perspective). The various analytical approaches and the accompanying issues are application-dependent. There are numerous
options at each stage of analysis, from extraction, hydrolysis, derivatisation, and detection, and advances can be confined
to the specific application for which it was developed. Emphasis is placed on the choice of separation and how gas or liquid
chromatography necessitates different preparative stages to enable conjugated steroid determination. Possible future directions
and research for conjugated steroid analysis are discussed. 相似文献
993.
Irina G. Filippova Olesea A. Gherco Yurii A. Simonov Alexandra A. Deseatnic-Ciloci Steliana F. Clapco Janeta P. Tiurina Svetlana G. Baca 《Polyhedron》2010
Four new nickel(II) phthalate compounds: mononuclear complexes [Ni(Im)]6(Pht)·H2O (1), [Ni(Pht)(Im)3(H2O)2]·H2O (2) and [Ni(Pht)(2-MeIm)3(H2O)3]·H2O (3), and coordination polymer [Ni(Pht)(4-MeIm)2(H2O)]n (4) (where Pht = dianion of o-phthalic acid, Im = imidazole, 2-MeIm = 2-methylimidazole, 4-MeIm = 4-methylimidazole) have been synthesized. The complexes 1–4 were characterised by elemental analysis, IR data, thermogravimetric, and X-ray diffraction analyses. X-ray analysis shows that the asymmetric unit of 1 consists of [Ni(Im)]62+ cation, Pht2− anion and solvate H2O molecule. The phthalate dianion does not take part in coordination to metal ion. The cations, anions and water molecules are linked via N–H?O and O–H?O interactions forming 2D hydrogen-bonded networks. The structures of 2 and 3 are similar to other mononuclear Ni(II) phthalate complexes where Pht2− anions act as monodentate ligands and uncoordinated carboxylate oxygen atoms participate in the formation of hydrogen bonded double-chains. The structure of 4 consists of [Ni(4-MeIm)2(H2O)] building units connected by phthalate ions to form helical chains. The complexes 1–4 were tested for their ability to increase the biosynthesis of enzymes. 相似文献
994.
995.
996.
Cassiano NM Lima VV Oliveira RV de Pietro AC Cass QB 《Analytical and bioanalytical chemistry》2006,384(7-8):1462-1469
A quick overview of published methods for analyzing compounds in complex biological samples reveals that the most difficult step is the clean-up or extraction of a required compound from the matrix. The strategy required to analyze exogenous compounds in biological fluids depends greatly upon the nature of the compound and upon the biomatrix. Coupled-column separation using restricted-access media as the first dimension in order to exclude macromolecules and retain micromolecules has been successfully used for a number of biological fluids. This paper presents the history of the development of restricted-access media supports and of their application to the direct injection of biological fluid samples in high-performance liquid chromatography. 相似文献
997.
Identification of sulfation sites of metabolites and prediction of the compounds’ biological effects
Yi L Dratter J Wang C Tunge JA Desaire H 《Analytical and bioanalytical chemistry》2006,386(3):666-674
Characterizing the biological effects of metabolic transformations (or biotransformation) is one of the key steps in developing
safe and effective pharmaceuticals. Sulfate conjugation, one of the major phase II biotransformations, is the focus of this
study. While this biotransformation typically facilitates excretion of metabolites by making the compounds more water soluble,
sulfation may also lead to bioactivation, producing carcinogenic products. The end result, excretion or bioactivation, depends
on the structural features of the sulfation sites, so obtaining the structure of the sulfated metabolites is critically important.
We describe herein a very simple, high-throughput procedure for using mass spectrometry to identify the structure—and thus
the biological fate—of sulfated metabolites. We have chemically synthesized and analyzed libraries of compounds representing
all the biologically relevant types of sulfation products, and using the mass spectral data, the structural features present
in these analytes can be reliably determined, with a 97% success rate. This work represents the first example of a high-throughput
analysis that can identify the structure of sulfated metabolites and predict their biological effects. 相似文献
998.
999.
Zougagh M Rudner PC de Torres AG Cano Pavón JM 《Analytical and bioanalytical chemistry》2004,378(2):423-428
This paper reports the development of a new methodology for the determination of cobalt in biological samples by using a flow injection system with loaded DPTH-gel as solid phase to preconcentrate analytes. The procedure is based on the on-line preconcentration of cobalt on a microcolumn of 1,5-bis(di-2-pyridyl)methylene thiocarbohydrazide immobilized on silica gel (DPTH-gel). The trapped cobalt is then eluted with 1% tartaric acid and 1% citric acid (7.1 mL) and determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The analytical figures of merit for the determination of cobalt are as follows: detection limit (3S), 8.5 ng mL–1; precision (RSD), 5.8% for 100 ng mL–1 of cobalt; enrichment factor, 13 (using 7.3 mL of sample); sampling frequency, 40 h–1 using a 60-s preconcentration time. For a 120-s preconcentration time (14.6 mL of sample volume) a detection limit of 5.7 ng mL–1, an RSD under 5% at 50 ng mL–1, an enrichment factor of 25, and a sampling frequency of 24 h–1 were reported. The precision and accuracy of the method were checked by analysis of biological certified reference materials. 相似文献
1000.
基于GaAs场效应管电压控制电流和开关的特性,设计了一种任意电脉冲发生器,并成功应用于激光脉冲整形装置。该电脉冲发生器利用超宽带窄脉冲触发多个GaAs场效应管,产生多路负脉冲,通过模拟延时线依次将各路负脉冲延迟一定时间后经微带线耦合输出多路负脉冲叠加的波形;通过多路不同幅度的脉冲堆积效应来获得形状任意可调的整形电脉冲。为了满足惯性约束聚变(ICF)实验中对电脉冲幅度不能过小的要求,在电路的输出端接入增益可调的超宽带电压放大器,使脉冲幅度达到实验要求。利用设计的任意电脉冲发生器实现了脉冲幅度0~5 V可调、脉宽0~10ns可调、时域调节精度为330 ps,整形方波脉冲下降沿为330 ps、上升沿为240 ps。实验结果表明,将产生的电脉冲注入光波导调制器,可获得理想形状的整形激光脉冲,提高激光脉冲的输出能量。 相似文献