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991.
Karl Wisseroth 《Colloid and polymer science》1959,166(1):14-19
Summary In this paper the best available inorganic insecticides were chosen as emulsifying agents. While preparing the emulsions it
was kept in mind to take minimum of the substance as an economical measure. The ratio of water to oil was so kept, as to have
the most stable and mobile emulsion, in order that it could be easily-used for practical purposes. It was found that the percentage
of 0.5 and 0.25 of the emulsifying agent with a ratio of oil to water as 20∶80, best stable emulsions are produced. The substances
taken were copper arsenate and arsenite, lead, calcium and aluminium arsenates. With the addition of natural colloids, the
stability is increased to a great extent. The natural colloids easily formed a highly solvated membrane which envelops the
oil globules, thereby making the emulsions very stable. The addition of soaps deteriorates or breaks the emulsions in all
cases, but with aluminium arsenate. The addition of soaps instead of having an antagonistic effect, re-inforces aluminium
arsenates. The aluminium arsenate is hydrolysed producing aluminium hydroxide. It has already been seen by previous workers
that aluminium hydroxide and sodium or potassium oleate act as very good emulsifying agents.
Zusammenfassung Die erreichbaren anorganischen Insektizide werden als emulgierende Agentien untersucht. Es wurde bei der Emulsion angestrebt, als m?gliches ?konomisches Ma? mit einem Minimum an Substanzen auszukommen. Das Verh?ltnis von Wasser zu ?l wurde so gew?hlt, da? m?glichst stabilste und flüssige Emulsionen erreicht wurden, so da? leichte Anwendbarkeit für praktische Zwecke besteht. Ein Gehalt an 0,5 und 0,25% und ein Verh?ltnis ?l zu Wasser wie 20 zu 80 ergab die stabilsten Emulsionen. Es wurden Kupferarsenat und -arsenit Blei-, Calzium- und Aluminiumarsenate verwendet. Zufügung von natürlichen Kolloiden verst?rkte die Stabilit?t au?erordentlich. Die natürlichen Kolloide bilden hochsolvatisierte Membranen, die die ?ltr?pfchen einhüllen und so die Stabilit?tserh?hung bedingen. Die Zufügung von Seifen zerst?rt oder bricht die Emulsionen, au?er im Falle von Aluminiumarsenat. In diesem Falle wird der Effekt statt dessen verst?rkt. Al-Arsenat wird hydrolysiert, es entsteht Al-Hydroxyd. Schon von anderer Seite wurde gezeigt, da? Al-Hydroxyd mit Na- oder K-Oleat sehr gut emulgierend wirkt.相似文献
992.
Andrzej Czerwiński Iwona Kiersztyn Michał Grdeń 《Journal of Solid State Electrochemistry》2003,7(6):321-326
The effect of temperature on hydrogen and deuterium electrosorption into a palladium LVE (limited-volume electrode) has been
investigated. A decrease in hydrogen capacity (H/Pd ratio) with increasing temperature has been observed. Temperature strongly
influences the plots of measured H(D)/Pd values vs. potential scan rate. In addition, hydrogen absorption was found to be
dependent on the composition of the surrounding electrolyte solution. These results have confirmed the hypothesis that two
different mechanisms of hydrogen desorption from the palladium electrode take place, namely electrochemical oxidation and
non-electrochemical recombination. Further, the ratio between the rate constants for these two processes has been found to
change with temperature.
Electronic Publication 相似文献
993.
Summary The thermal behavior of KH2PO4, NaH2PO4 and Na2HPO4 under non-isothermal conditions using TG method with different heating rates was studied. The values of the reaction rate were processed by means of Friedmans differential-isoconversional method. A dependence of the activation energy vs. conversion was observed. Therefore a procedure based on the compensation effect (suggested by Budrugeac and Segal) was applied. A less speculative data processing protocol was offered by the non-parametric kinetics method suggested by Serra, Nomen and Sempere. Three steps were observed by non-isothermal heating: a dehydration, a dimerization and a polycondensation. The differences in the intimate reaction mechanism are determined by the initial number of water molecules. 相似文献
994.
Employing hot tungsten filament to thermal dissociate molecular hydrogen,we generated gas phase atomic hydrogen under ultra-high vacuum(UHV)conditions and investigated its interaction with Pt(111) surface.Thermal desorption spectroscopy(TDS)results demonstrate that adsorption of molecular hy- drogen on Pt(111)forms surface Had species whereas adsorption of atomic hydrogen forms not only surface Had species but also bulk Had species.Bulk Had species is more thermal-unstable than surface Had species on Pt(111),suggesting that bulk Had species is more energetic.This kind of weakly- adsorbed bulk Had species might be the active hydrogen species in the Pt-catalyzed hydrogenation reactions. 相似文献
995.
Localized molecular orbitals, two- and three-center bond indices of 1,5-dicarba-closo-pentaborane ( 5 ) and 1,5-dicarba-closo-pentaborane ( 3 ) and their hydrocarbon analogs bicyclo [1,1,1]-pentane and [1,1,1] propellane, respectively, have been calculated using a suitable basis set. No previously reported three-center CBC bond has been found. However, a new three-center BCB bond has been observed in 1,5-dicarba-closo-pentaborane ( 5 ). © 1995 John Wiley & Sons, Inc. 相似文献
996.
Heinz Falk Karl Grubmayr Martha Marko 《Monatshefte für Chemie / Chemical Monthly》1989,120(8-9):771-779
Summary A violinoid and a 2,3-dihydrobilindione chromophore is attachedvia an appendix anchored at rings A of the pigments by means of reacting them with the polyacryl-N-acryloxysuccinimid copolymer to yield water-soluble chromopolymers. They are characterized by a molecular mass of about 4000 to 6000 and a relation of one chromophoric unit per 6 to 22 monomers. Their absorption spectra and circular dichroism recorded in water and dimethylsulfoxide as solvents are discussed with respect to structural aspects, and in comparison with monomeric chromophore derivatives.
Herrn Prof. Dr. K. Schlögl mit den besten Wünschen zum 65. Geburtstag gewidmet 相似文献
997.
Ahmad Shaabani Abbas Rahmati Soheila Naderi 《Monatshefte für Chemie / Chemical Monthly》2007,138(6):553-557
Summary. Reaction of triphenylphosphine and an electron deficient acetylenic ester in the presence of strong N–H acid such as alkyl
and aryl sulfamides or acetamide produces phosphorous ylides at room temperature in CH2Cl2. The aryl sulfamide phosphoranes undergo a smooth transformation reaction in boiling toluene and produce iminophosphoranes. 相似文献
998.
Crown ethers were reacted with HN-proton-donor molecules to obtain crystalline molecular host-guest complexes. It was found that complexes with crown ethers of different structure are formed, depending on the linear dimensions and mode of steric shielding of active centers of the proton-donor molecules.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 12, 2004, pp. 2030–2033.Original Russian Text Copyright © 2004 by Wang, Ganin.This revised version was published online in April 2005 with a corrected cover date. 相似文献
999.
Soonam Park Feng Liao John M. Larson Steven L. Girshick Michael R. Zachariah 《Plasma Chemistry and Plasma Processing》2004,24(3):353-372
A molecular beam mass spectrometry system for in situ measurement of the concentration of gas phase species including radicals impinging on a substrate during thermal plasma chemical vapor deposition (TPCVD) has been designed and constructed. Dynamically controlled substrate temperature was achieved using a variable thermal contact resistance method via a backside flow of an argon/helium mixture. A high quality molecular beam with beamtobackground signal greater than 20 was obtained under film growth conditions by sampling through a small nozzle (75 m) in the center of the substrate. Mass discrimination effects were accounted for in order to quantify the species measurements. We demonstrate that this system has a minimum detection limit of under 100 ppb. Quantitative measurements of hydrocarbon species (H, H2, C, CH3, CH4, C2H2, C2H4) using Ar/H2/CH4 mixtures and silicon species (Si, SiH, SiH2, SiCl, SiCl2, Cl, HCl) using Ar/H2/SiCl4 mixtures were obtained under thermal plasma chemical vapor deposition conditions. 相似文献
1000.
Daniela Schlemmer E. R. de Oliveira M. J. Araújo Sales 《Journal of Thermal Analysis and Calorimetry》2007,87(3):635-638
Conventional plastics has a
large impact in increasing the environment’s pollution. That’s
why the interest has turned towards novel partially and completely biodegradable
polymers. In this work, blends of polystyrene and thermoplastic starch with
glycerol and Buriti (Mauritia flexuosa
L.) oil as plasticizers were prepared. Samples were analyzed using TG/DTG
and DSC techniques. The TG results indicated that the blends with Buriti oil
are thermally more stable than those with glycerol. The DSC analysis that
Buriti oil provides a higher degree of plasticization of PS, compared to the
blends plasticized using glycerol under the studied conditions. 相似文献