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101.
The confonners of primary ethylene ozonide have been studied by ab initio gradient and MC SCF calculations. At the MC SCF level they are more spread in energy than in SCF calculations. The planar conformer, carbon-carbon half chair and the oxygen envelope are much higher m energy than the other conformers. The MC SCF activation energy for cyclo-addition of ozone and ethylene is 91–99 . 相似文献
102.
The Knight shift of Pd in Ag
x
Pd1–x
has been determined for concentrationsxf" alt="lE" align="MIDDLE" BORDER="0">0.2. In full accordance with the expectations based on the behaviour of the magnetic susceptibility, it was found that the Knight shift of Pd is rapidly reduced in magnitude by adding Ag to Pd. To allow for a detailed interpretation of this finding, we have performed Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA) band structure calculations for Ag
x
Pd1–x
. These calculations clearly demonstrate that the decrease in spin susceptibility with increasingx is accompanied with a decrease in core polarization. In contrast to Pd, the negative Knight shift of Ag on the Pd-rich side of the system is caused by the valence band contribution, as it is demonstrated by our calculations. This is caused by an intersite effect in analogy to the transferred hyperfine field found for non-magnetic elements dissolved in a magnetic host. 相似文献
103.
Atf Koca Tanju Ceyhan Mehmet K. Erbil Ali Rza
zkaya
zer Bekarolu 《Chemical physics》2007,340(1-3):283-292
In this study, electrochemical, electrochromic and spectroelectrochemical properties of a tert-butylcalix[4]arene bridged bis double-decker lutetium(III) phthalocyanine (Lu2Pc4 2) were investigated explicitly as compared with a tert-butylcalix[4]arene bridged dimeric lutetium(III) phthalocyanine [Lu2Pc2(OAc)2 1]. Distinctive differences between electrochemical and electrochromic properties of 1 and 2 were detected. Moreover, the properties of 1 and 2 were compared with previously reported S4(CH2)4 bridged Lu2Pc2(OAc)2 and Lu2Pc4. The calixarene bridged phthalocyanine (Pc) compounds, 1 and 2 showed well-defined electrochromic behaviour with green-blue and blue-purple colour transitions. The enhanced electrochromic properties of 2, as compared to 1, were attributed to its double-decker structure, probably allowing the formation of suitable ion channels for the counter ion movement in the solid film. 相似文献
104.
Kristóf J. Frost R. L. Kloprogge J. T. Horváth E. Makó É. 《Journal of Thermal Analysis and Calorimetry》2002,69(1):77-83
The thermal behaviour of mechanochemically treated kaolinite has been investigated under dynamic and controlled rate thermal analysis (CRTA) conditions. Ten hours of grinding of kaolinite results in the loss of the d(001) spacing and the replacement of some 60% of the kaolinite hydroxyls with water. Kaolinite normally dehydroxylates in a single mass loss stage between 400 and 600°C. CRTA technology enables the dehydroxylation of the ground mineral to be observed in four overlapping stages at 385, 404, 420 and 433°C under quasi-isobaric condition in a self-generated atmosphere. It is proposed that mechanochemical treatment of the kaolinite causes the localization of the protons when the long range ordering is lost.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
105.
Thong Le Ba Ahmed Baqer Mohammed Saad Kamel Gyula Grf Vincent Otieno Odhiambo Somchai Wongwises Lezsovits Ferenc Imre Mikls Szilgyi 《Molecules (Basel, Switzerland)》2022,27(3)
Halloysite nanotube (HNT) which is cheap, natural, and easily accessible 1D clay, can be used in many applications, particularly heat transfer enhancement. The aim of this research is to study experimentally the pool boiling heat transfer (PBHT) performance of novel halloysite nanofluids at atmospheric pressure condition from typical horizontal heater. The nanofluids are prepared from halloysite nanotubes (HNTs) nanomaterials-based deionized water (DI water) with the presence of sodium hydroxide (NaOH) solution to control pH = 12 to obtain stable nanofluid. The nanofluids were prepared with dilute volume concentrations of 0.01–0.5 vol%. The performance of PBHT is studied via pool boiling curve and pool boiling heat transfer coefficient (PBHTC) from the typical heater which is the copper horizontal tube with a thickness of 1 mm and a diameter of 22 mm. The temperatures of the heated tube surface are measured to obtain the PBHTC. The results show an improvement of PBHTC for halloysite nanofluids compared to the base fluid. At 0.05 vol% concentration, HNT nanofluid has the best enhancement of 5.8% at moderate heat flux (HF). This indicates that HNT is a potential material in heat transfer applications. 相似文献
106.
Both N‐ and O‐substituted derivatives of the anti‐inflammatory drug tenoxicam (= 4‐hydroxy‐2‐methyl‐N‐(pyridin‐2‐yl)‐2H‐thieno[2,3‐e] [1,2]thiazine‐3‐carboxamide 1,1‐dioxide; 1 ) were synthesized, and various chemical transformations were investigated. Both selective hydrolysis and reaction of 1′‐N‐methyltenoxicam ( 5 ) with a variety of N‐nucleophiles were performed (Scheme 1). Also, five new 4‐O‐acyl derivatives 10 were prepared as potential prodrugs (Scheme 2). The 4‐chloro derivatives of 1 and its analog 8 could be successfully transformed into the novel tetra‐ and tricyclic ring systems 12 and 13 , respectively, the latter being a conformationally restricted 1,5‐diaryl‐pyrazole designed as a potential COX‐2 inhibitor. 相似文献
107.
108.
L. B. Bragg Albert Schmidt E. Vossieck A. Schmitz I. G. Farbenindustrie M. Shepherd W. A. Ssokolow A. R. Scharnagel A. W. Trusty A. Fraenkel Granjon W. Rimarski E. Streb E. Sauerbrei W. Scheruhn H. S. Davis G. S. Crandall W. E. Higbee Jr. H. R. Ambler J. Dubois G. Heyne E. Hurwitz J. V. Dubsky E. M. J. Mulders F. E. C. Scheffer F. Lüth O. Stadler A. Sieverts S. Halberstadt Ausschuss für Feuerungsfragen und Kohlenstaub und Fachausschuss für Staubtehcnik beim Verein Deutscher Ingenieure 《Analytical and bioanalytical chemistry》1932,90(9-10):350-372
109.
110.