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21.
The present paper considers the magnifying power and aberration properties of three different catadioptric magnifying systems
useful for application as simple hand-held microfiche readers. These are in the form of a plano-convex lens, a meniscus lens
and an achromatic doublet lens and all their outer surfaces have been coated with a semi-reflecting film so that they behave
like catadioptric elements. These can be designed to give magnification in the range of 15 × to 25 × with sufficient eye relief.
Using such magnifiers, it is possible to read microfiche having frame sizes of 16 × 12 mm and 12 × 9 mm. The cemented achromatic
doublet coated on the outer surfaces seems to give a very good image for use in microfiche reader. 相似文献
22.
S. M. Marathe P. S. Murty M. Sreenivasa Rao K. V. Subba Rao 《Fresenius' Journal of Analytical Chemistry》1982,311(5):507-510
Summary A method has been described for the determination of twelve trace elements (Pb, Sn, Cr, Co, Ni, V, Y, La, Zr, Cu, Zn, Sc) in different types of rocks using optical emission Spectroscopy (OES). The method employs a single set of synthetic standards for analysing any type of rock, basic, acidic or intermediate. When an external element, such as osmium, has been added to serve as internal standard, the analytical data showed poor precision. A new method of internal standardization has, therefore, been attempted. In this, a line due to silicon whose intensity is influenced by two adjacent Fe lines, has been used as the internal standard. Such an approach gave better presision (expressed in terms of coefficient of variation). Six international rock standards have been analysed and the data obtained have been compared with that previously reported.
Bestimmung von Spurenelementen in Gesteinen durch optische Emissions-Spektroskopie: Ein neues Verfahren zur inneren Eichung
Zusammenfassung Zwölf Spurenelemente (Pb, Sn, Cr, Co, Ni, V, Y, La, Zr, Cu, Zn, Sc) werden in verschiedenen Gesteinstypen bestimmt. Basische, saure und intermediäre Gesteine können mit einem einzigen Satz synthetischen Standards analysiert werden. Bei Benutzung eines externen Elements (Os) zur Eichung wurden schlechte Ergebnisse erhalten. Bei dem neuen Verfahren wird eine bessere Reproduzierbarkeit (ausgedrückt als Variationskoeffizient) durch Verwendung einer Siliciumlinie, die durch benachbarte Eisenlinien beeinflußt wird, erzielt. Sechs internationale Standardgesteinsproben wurden nach diesem Verfahren untersucht und die Ergebnisse mit früher erhaltenen verglichen.相似文献
23.
24.
T. V. Ramana Murty 《Czechoslovak Journal of Physics》1989,39(9):991-997
The analysis of flow past a continuously moving semi-infinite flat plate in the presence of transverse magnetic field has been presented. Model solutions have been derived and the resulting equations are integrated numerically. Velocity profiles are displayed graphically and the numerical values of the transverse velocity skin friction are given in the form of tables. It has been observed that an increase inM (magnetic field parameter) leads to a decrease in velocity.The author wishes to express his thanks to Dr. H. N. Siddiquie, Director, and Dr. J. S. Sastry, Head, Physical Oceanography Division, for their keen interest and encouragement throughout this work. 相似文献
25.
J. Satyanarayana V. N. Reddy G. S. Murty A. Dash 《Journal of Radioanalytical and Nuclear Chemistry》1994,188(5):323-330
Zirconium molybdoarsenate (ZrMAs), an inorganic ion exchanger, has been synthesized and the suitable conditions to separate cesium-137 from fission products waste solution are suggested. 相似文献
26.
Jayaprakash KN Chaudhuri SR Murty CV Fraser-Reid B 《The Journal of organic chemistry》2007,72(15):5534-5545
Readily prepared mannosyl n-pentenylorthoesters (NPOEs) serve as donors in themselves and as convenient intermediates for other glycosyl donors, such as n-pentenyl glycosides (NPGs), thioglycosides, and trichloroacetimidates. These various donors are activated by different reagents, and are therefore amenable to versatile, discriminate use. Scandium and ytterbium triflates respond very differently to these donors, with the result that chemoselective discrimination between NPOEs, NPGs, trichloroacetimidates as well as ethyl and phenyl thioglycosides can be achieved. Appropriate NPOEs are also able to provide 2,6 and 3,6 diol acceptors via rearrangement or glycoside formation, and these can be used for one-pot, sequential glycosidations based on orthogonal donors, and in situ double differential glycosidations. Thus NPOEs activated by iodonium ion, specifically generated from ytterbium triflate/N-iodosuccinimide, can be used to monoglycosidate the diols rapidly, with exquisite regio, and sometimes chemo, selectivity. The residual NPOE is converted into disarmed NPG, which is refractory to the reaction conditions, and so poses no threat to the free-OH of the monoglycosidation product. Further glycosidation of the latter can then achieved by direct addition of a trichloroacetimidate or ethyl thioglycoside. This basic strategy has been used to prepare a branched chain pentadecamannan. The success is an example of the efficiency of donor/acceptor MATCH concept for regioselective glycosylation. 相似文献
27.
The intramolecular cycloaddition of the previously described azidoalkene 16 , the related diacetates 7 and 13 , and the monoacetate 8 led diastereoselectivity to the (2R)- and (2S)-configurated hydropyridotriazoles 17 , 9 and 11 , 14 and 15 , and 10 and 12 , respectively (Scheme 1). Thermolysis of 16 gave also the aziridine 18 , its proportion increasing with reaction time. The diastereoselectivity of the cycloaddition- is rationalized on the basis of steric interactions and of H? bonds in the transition state. Photolysis in benzene partially transformed 9 into the aziridine 19 . Treatment of 9 with aqueous AcOH gave 19 and the tetrahydrofuran 20 , with AcOH in benzene 20 and the triacetate 23 , and with aqueous H2SO4 in THF, the primary alcohol 22 (room temperature) or 19 and 22 (0°). Deacetylation of 9 followed by reaction with pyridinium hydrochloride led to the tetrahydrofuran 21 and the chloride 24 (Scheme 2). The diacetate 22 and the triacetate 23 gave the tripl 25 which was deprotected to 26 . Reduction of the keto-aziridine 18 (NaBH4) gave the alcohols 27 and 29 which were acetylated to give 28 and 19 , respectively (Scheme 3). Treatment of the aziridine 28 with AcOH in benzene followed by deacetylation gave 30 and hence 31 . AcOH in benzene transformed the triazoline 15 first into the aziridine 32 and hence into 33 , which was deprotected to give the triol 34 and hence 35 . The 2-(hydroxymethyl)piperidines 26 , 31 , and 35 inhibited Vibrio cholerae sialidase with K1 = 3.8 · 10?2 M, 3.4 · 10?3 M, and 1.5 · 10?4 M, respectively. The conformation of the glycerol side chain of these compounds and of the unbranched piperidines 2–4 deviates from the one of Neu5Ac (and Neu2en5Ac). This finding is rationalized by an H-bond between OH? C(8) and NH? C(6). The conformations and the K1 values of 26 , 31 , and 35 correlate with each other. 相似文献
28.
Reaction of 4-amino-2-methylbenzimidazo[1,2-a][1,3,5]triazines 2 with diethyl ethoxymethylenemalonate afforded 3-carboethoxy-6-methyl-4-oxo-4H-pyrimido[1′,2′:5,6][1,3,5]triazino[1,2-a]benzimidazoles 3 , a new ring system. 相似文献
29.
Lakshmi VV Murty MR Reddy TJ Ravikumar M Prabhakar S Vairamani M 《Rapid communications in mass spectrometry : RCM》2006,20(6):981-986
Off-site detection of the hydrolysed products of sulfur mustards in aqueous samples is an important task in the verification of Chemical Weapons Convention (CWC)-related chemicals. The hydrolysed products of sulfur mustards are studied under positive and negative electrospray ionisation (ESI) conditions using an additive with a view to detecting them at trace levels. In the presence of cations (Li(+), Na(+), K(+) and NH(4) (+)), the positive ion ESI mass spectra of all the compounds include the corresponding cationised species; however, only the [M+NH(4)](+) ions form [M+H](+) ions upon decomposition. The tandem mass (MS/MS) spectra of [M+H](+) ions from all the hydrolysed products of the sulfur mustard homologues were distinct and allowed these compounds to be characterised unambiguously. Similarly, the negative ion ESI mass spectra of all the compounds show prominent adducts with added anions (F(-), Cl(-), Br(-), and I(-)), but the [M-H](-) ion can only be generated by decomposition of an [M+F](-) ion. The MS/MS spectra of the [M-H](-) ions from all the compounds result in a common product ion at m/z 77. A precursor ion scan of m/z 77 is shown to be useful in the rapid screening of these compounds in aqueous samples at trace levels, even in the presence of complex masking agents, without the use of time-consuming sample preparation and chromatography steps. An MS/MS method developed to measure the detection limits of the hydrolysed products of sulfur mustards found these to be in the range of 10-500 ppb. 相似文献
30.