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101.
Summary A simple, rapid and non-destructive technique has been devised for the detection of triazine herbicides by making use of the fluorescence inhibition properties of such compounds on fluorescing silica gel layers. The sensitivity of this method has been found to be increased up to 20 times in comparison to conventional spray techniques and approaches the detection limits obtained by radiochemical methods.
Zusammenfassung Ein einfaches, rasches, ohne Zerstörung der Probe durchführbares Verfahren zum Nachweis von Triazin-Herbiziden beruht auf deren Eigenschaft, die Fluoreszenz von Silicagelschichten zu löschen. Die Empfindlichkeit dieses Nachweisverfahrens ist bis zu 20mal besser als die üblicher Sprühverfahren und kommt damit rdiochemischen Methoden nahe.相似文献
102.
T. Shimmura H. Nomura H. Hock E. Fritz E. S. Grumell J. G. King E. G. Bailey F. Heathcoat W. Franke F. Eck I. A. Davies R. Vondráček D. Florentin C. Holthaus W. A. Selvig W. D. Pohle G. Speckhardt A. R. Powell C. C. Russell E. L. Skau I. L. Newell F. H. Gibson 《Analytical and bioanalytical chemistry》1934,99(3-4):148-153
103.
Dr. Randa K. Gabr Prof. Dr. Takuji Hatakeyama Prof. Dr. Kazuhiro Takenaka Prof. Dr. Shinobu Takizawa Yoshihiro Okada Prof. Dr. Masaharu Nakamura Prof. Dr. Hiroaki Sasai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(29):9518-9525
The reaction pathway of an enantioselective 5‐endo‐trig‐type cyclization of 3‐alkenoic acids catalyzed by a chiral palladium–spiro‐bis(isoxazoline) complex, Pd–SPRIX, has been studied by density functional theory calculations. The most plausible pathway involves intramolecular nucleophilic attack of the carboxylate moiety on the C?C double bond activated by Pd–SPRIX and β‐H elimination from the resulting organopalladium intermediate. The enantioselectivity was determined in the cyclization step through the formation of a π‐olefin complex, in which one of the two enantiofaces of the olefin moiety was selected. The β‐H elimination occurs via a seven‐membered cyclic structure in which the acetate ligand plays a key role in lowering the activation barrier of the transition state. In the elimination step, the SPRIX ligand was found to behave as a monodentate ligand due to the hemilability of one of the isoxazoline units thereby facilitating the elimination. Natural population analysis of this pathway showed that the more weakly electron‐donating SPRIX ligand, compared with the bis(oxazoline) ligand, BOX, facilitated the formation of the π‐olefin complex intermediate, leading to a smaller overall activation energy and a higher reactivity of the Pd–SPRIX catalyst. 相似文献
104.
105.
Thermal properties of organoindium thiolates were investigated by means of thermogravimetric (TG) and differential thermal (DT) analysis. Dibutyl-indium propylthiolates (Bun2InSPrn, Bun2InSPri, Bui2InSPrn and Bui2InSPri) decomposed up to 280°C along with an exothermic DT peak and gave indium(I) sulfide (InS) powders. Although the arylthiolate Bun2InSPh also afforded InS powders, it decomposed at a slightly higher temperature. In contrast, the dithiolate and the dithiocarbamate complexes [BunIn(SPri)2 and In (S2CNBu2)3] gave indium(III) sulfide (In2S3) powders. 相似文献
106.
Ken Okada Miyako Akiyoshi Atsumi Miyake Terushige Ogawa Mitsuo Nomura Takehiro Matsunaga 《Journal of Thermal Analysis and Calorimetry》2009,97(2):769-774
On January 21, 2003, an explosion occurred while ion exchange resin (IER) was being used to separate impurities from uranium
solution. To clarify the cause of the accident and go/no-go criteria of the explosion, elemental analysis of the IER, DSC
analysis, and SIKAREX analysis (a screening tool for runaway reactions) were performed. Finally, experiments on the same scale
as the accident were conducted in an explosion chamber. When HClO4 was added to IER-NO3, the IER violently exploded without any heating nor metal ions such as uranium. It was confirmed that the accident was caused
by an incorrect procedure in the chemical process. From the standpoint of explosion safety, IER-NO3 in particular should be kept away from perchloric acid in the laboratory. 相似文献
107.
Poly(2-vinylpyridine) or poly(4-vinylpyridine) coated on a piezoelectric quartz crystal adsorbed copper, thus decreasing the oscillation frequency. The bound copper could be removed by EDTA solution. Poly(4-vinylpyridine) is recommended to determine copper (5–35 μM) in a maleate buffer at pH 6.6 flowing over the coated crystal for 5 min. Iron(III) and cadmium interfered. 相似文献
108.
The diffusion of protons in porous media was observed and evaluated using a pH-imaging microscope with a flat semiconductor. Small particles were packed on the sensing surface of the flat sensor, followed by the addition of a lactic acid droplet on the top of the packed particle layer. The pH distribution accompanied by the diffusion of lactic acid was visualized at the bottom of the layer using the flat sensor. The difference in the diffusion property was confirmed depending on the particle type. The effective diffusion coefficients of the lactic acid in some porous media were estimated by combining the experimental results and mathematical calculation. 相似文献
109.
110.
We confirmed that the light intensity (λ=785 nm) scattered from an isolated hemispherical Au nanoparticle was resonantly enhanced
at a diameter of 200 nm and a height of 50 nm, as observed experimentally using a collection-mode near-field optical microscope.
The experimental results agreed with the calculated results using Mie’s theory. Furthermore, we observed resonant energy transfer
of the optical near-field energy along a chain of Au nanoparticles. The magnitude of the transferred energy increased resonantly
at the size of resonant light scattering for an isolated Au nanoparticle (200 nm diameter with 240 nm center-to-center separation).
PACS 42.82.Et; 73.20.Mf; 78.67.Bf 相似文献