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1.
Sándor G?r?g 《Analytical sciences》2004,20(5):767-782
The development during the last 15 years and the state-of-the-art in the analysis of bulk steroid hormone drugs and hormone-like structures and pharmaceutical formulations made thereof are summarized. Other steroids (sterols, bile acids, cardiac glycosides, vitamins D) as well as biological-clinical aspects and pharmacokinetic and metabolic studies are excluded from this review. The state-of-the-art is summarized based on comparisons of monographs in the latest editions of the European Pharmacopoeia, United States Pharmacopoeia and the Japanese Pharmacopoeia. This is followed by sections dealing with new developments in the methodology for the fields of spectroscopic and spectrophotometric, chromatographic, electrophoretic and hyphenated techniques as well electroanalytical methods. The review is terminated by two problem-oriented sections: examples on impurity and degradation profiling as well as enantiomeric analysis. 相似文献
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4.
S. Görög 《Analytical and bioanalytical chemistry》1998,362(1):4-8
The present and past use of chemical derivatization reactions is overviewed with emphasis on the present role of derivatization
in chromatographic and electrophoretic methods with special respect to fluorogenic derivatization to increase the selectivity
and sensitivity, chiral derivatization to transform enantiomeric pairs to easily separable diastereomers, and GC/GC-MS derivatization.
Non-chromatographic derivatization is also discussed with emphasis on UV-VIS spectrophotometry, fluorimetry, and immunoassay
methods. The up-to-dateness of derivatization methods with negative examples mainly from the field of UV-VIS analysis are
also discussed. Finally, examples are given on how the experiences obtained in the course of old studies can be used to solve
current problems with the aid of chemical derivatization.
Received: 19 January 1998 / Revised: 2 March 1998 / Accepted: 6 March 1998 相似文献
5.
Åse Støg»rd 《Chemical physics letters》1975,36(3):357-360
Ab initio as well as semi-empirical SCF MO calculations are presented for ClCN and ONCl. The relative intensities for Cl Kβ emission in the two molecules were calculated. The calculated spectra from the ab initio wavefunctions are in excellent agreement with experiments. 相似文献
6.
The molecular electric dipole moments are reported for the series of tin-substituted tetracarbonyl cobalt compounds Rgt;gt;ngt;gt;Ygt;gt;m?ngt;gt;Sn{Co(CO)gt;4gt;}gt;4?gt;gt;gt;mgt;gt; (gt;m = 1–3gt;; gt;ngt; ? gt;mgt;; R = alkyl, phenyl; Y = halogen). The effect of the substituents at the tin atom on the nature of the CoSn bond is established on calculating the (CO)gt;4gt;CoSn group dipole moments. It is shown that the charge transfer in the CoSn bond is mainly determined by the inductive properties of the ligands attached to tin. 相似文献
7.
3-O-Acetyl-1,2-O-isopropylidene-g src="/content/p202x5k268606h31/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-gt;Dgt;-allofuranose (gt;2 bgt;) was prepared from 1,2:5,6-di-O-isopropylidene-g src="/content/p202x5k268606h31/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-gt;Dgt;-allofuranose (gt;1 bgt;). Treatment ofgt;2 bgt; with triphenylphosphine-diethyl azodicarboxylate afforded regio- and stereospecifically the 5,6-epoxy-g src="/content/p202x5k268606h31/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-gt;Dgt;-allo derivative (gt;3gt;). The other diastereomeric compound, 5,6-epoxy-1,2-O-isopropylidene-g src="/content/p202x5k268606h31/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-gt;Lgt;-talofuranose (gt;6gt;) was also prepared stereoselectively fromgt;2 bgt;
gt;viagt; the intermediatesgt;5 agt; andgt;5 bgt;. The epoxy sugarsgt;3gt; andgt;6gt; were converted with lithium aluminum hydride to the corresponding 6-deoxy-1,2-O-isopropylidene-g src="/content/p202x5k268606h31/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-gt;Dgt;-allofuranose (gt;4 agt;) and -g src="/content/p202x5k268606h31/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-gt;Lgt;-talofuranose (gt;7 agt;) derivatives. Hydrolysis ofgt;4 agt; andgt;7 agt; afforded 6-deoxy-gt;Dgt;-allose and 6-deoxy-gt;Lgt;-talose, respectively. The corresponding 3,5-di-O-acetyl- (gt;4 bgt; andgt;7 bgt;) and the 3,5-O-(tetraisopropyldisiloxane-1,3-diyl) derivatives (gt;4 cgt; andgt;7 cgt;) are also described. Selective removal of the isopropylidene group and subsequent acetylation offers a convenient route to prepare sugar derivatives containing furanose ring, likegt;8 bgt;, as a suitable precursor for nucleoside analogs.Herrn Prof. Dr.gt;K. Komarekgt; mit den besten Wünschen zum 60. Geburtstag gewidmet. 相似文献
8.
Ion Association and Hydration in Aqueous Solutions of Nickel(II) and Cobalt(II) Sulfate 总被引:1,自引:0,他引:1
Ting?Chen Glenn?HefterEmail author Richard?Buchner 《Journal of solution chemistry》2005,34(9):1045-1066
Aqueous solutions of nickel(II) and cobalt(II) sulfate have been investigated at 25 gt;∘gt;C by dielectric relaxation spectroscopy (DRS) over a wide range of frequencies (0.2 ≤ ν (GHz) ≤ 89) and salt concentrations
(0.025 ≤ gt;cgt;(mol-gt;Lgt;gt;−1gt;) ≤ 1.4). The spectra indicate, as for MgSOgt;4gt;(aq) studied previously, the simultaneous presence of double solvent-separated, solvent-shared and contact ion pairs in both
NiSOgt;4gt;(aq) and CoSOgt;4gt;(aq). The stepwise formation constants for each ion-pair type and the overall association constant, obtained from the data
are in good agreement with ultrasonic relaxation and other estimates. The DR spectra at higher concentrations (gt;cgt; ≥ 0.5 mol-Lgt;−1gt;) suggest the existence of a nonlinear triple ion Mgt;2gt;SOgt;4gt;gt;2+gt;(aq). Consistent with the very strong hydration of the salts, which have ‘effective’ hydration numbers approaching 27 at infinite
dilution, there are no significant differences in any of the relaxation or thermodynamic parameters for NiSOgt;4gt;(aq) and CoSOgt;4gt;(aq), except that the triple ion appears to be somewhat more stable for the latter. 相似文献
9.
A normal-phase ion-pair chromatographic system has been developed for the high-performance liquid chromatographic investigation of pipecuronium bromide (2 beta,16 beta-bis-(N'-dimethyl-l-piperazinyl)-3 alpha,17 beta-diacetoxy-5 alpha-androstane dibromide) and related quaternary ammonium steroids. The use of silica as the stationary phase and a 96:4 mixture of acetonitrile and water containing 0.1 mol/dm3 sodium perchlorate as the eluent with detection at 213 nm enable the potential impurities as well as the hydrolytic and oxidative degradation products of pipecuronium bromide to be separated and detected down to the 0.01% level. The above system is also applicable to the high-performance liquid chromatographic investigation of other quaternary ammonium steroids (pancuronium bromide, vecuronium bromide). 相似文献
10.
Mihly
vri Gbor Murnszky Michaela Zeiner Istvn Virg Ilse Steffan Victor G. Mihucz Enik Tatr Sergio Caroli Gyula Zray 《Microchemical Journal》2007,87(2):159-162
The Platinum Group Elements (PGEs) used in automotive catalytic converters are partly emitted into the air during use and can enter the human respiratory system. Due to the increasing use of automotive catalytic converters, the importance of this problem cannot be overlooked.The goal of this investigation was to determine the concentration of Pt in the urine of individuals occupationally exposed to urban air with heavy traffic. Sector field inductively coupled plasma mass spectrometry (SF–ICP–MS) was used for determination of Pt in the urine of tram drivers. 38 and 34 subjects were investigated in Vienna and Budapest, respectively. Samples were taken from the tram drivers both before and after the shift.The results for Pt were compared to those from a previous study performed by our team. The comparison showed that the concentration medians were 4 times higher than the previous ones. Moreover, the values in Budapest were about twice as high as those from Vienna. A partly significant change could be observed between the two sets of data: before, and after the shift. 相似文献