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111.
Phytochrome Control of Anthocyanin Biosynthesis in Tomato Seedlings: Analysis Using Photomorphogenic Mutants 总被引:5,自引:0,他引:5
L. H. J. Kerckhoffs M. E. L. Schreuder A. Van Tuinen M. Koornneef R. E. Kendrick 《Photochemistry and photobiology》1997,65(2):374-381
Anthocyanin biosynthesis has been studied in hypocotyls and whole seedlings of tomato (Lycoperskon esculentum Mill.) wild types (WTs) and photomorphogenic mutants. In white light (WL)/dark (D) cycles the fri1 mutant, deficient in phytochrome A (phyA), shows an enhancement of anthocyanin accumulation, whereas the tri1 mutant, deficient in phytochrome Bl (phyBl) has a WT level of anthocyanin. Under pulses of red light (R) or R followed by far-red light (FR) given every 4 h, phyA is responsible for the non-R/FR reversible response, whereas phyBl is partially responsible for the R/FR reversible response. From R and blue light (B) pretreatment studies, B is most effective in increasing phytochrome responsiveness, whereas under R itself it appears to be dependent on the presence of phyBl. Anthocyanin biosynthesis during a 24 h period of monochromatic irradiation at different flu-ence rates of 4 day-old D-grown seedlings has been studied. At 660 nm the fluence rate-response relationships for induction of anthocyanin in the WT are similar, yet complex, showing a low fluence rate response (LFRR) and a fluence rate-dependent high irradiance response (HIR). The high-pigment-1 (hp-1) mutant exhibits a strong amplification of both the LFRR and HIR. The fri1 mutant lacks the LFRR while retaining a normal HIR. In contrast, a transgenic tomato line overexpressing the oat PHYA3 gene shows a dramatic amplification of the LFRR. The tri1 mutant, retains the LFRR but lacks the HIR, whereas the fri1, tri1 double mutant lacks both components. Only an LFRR is seen at 729 nm in WT; however, an appreciable HIR is observed at 704 nm, which is retained in the tri1 mutant and is absent in the fri1 mutant, indicating the labile phyA pool regulates this response component. 相似文献
112.
8-Quinolinol reacts with Ru3(CO)12 to give Ru3(CO)8(C9H6NO)2 and Ru- (CO)2(C9H6NO)2. A single-crystal X-ray study of the cluster compound shows that the three ruthenium atoms define an isosceles triangle, with two distances of 2.77 Å and one of 3.04 Å. Since both metalated oxygens act as three-electron donors (RuO distances 2.12 and 2.18 Å), the cluster is a fifty-electron species with a formal zero bond order for the elongated RuRu bond. Four other hydroxyhydrocarbylpyridine compounds also give complexes of composition Ru3(CO)8(L)2 which probably have analogous structures. 相似文献
113.
J.W. Hofstraat M. Engelsma R.J. Van De Nesse C. Gooijer N.H. Velthorst U.A.Th. Brinkman 《Analytica chimica acta》1986
The coupling of liquid chromatography (l.c.) on narrow-bore columns to thin-layer chromatography (t.l.c.) is described. The effluent from a l.c. column can be deposited on a t.l.c. plate after a normal-phase or reversed-phase separation without serious loss of chromatographic information. Both silica and alkyl-modified silica plates can be used for storage. The interface is a fused silica capillary which connects the column outlet to the spray jet assembly of a Linomat applicator for t.l.c. The stored chromatogram can serve as starting point for a new separation, but also allows the use of detection principles which are normally not compatible with l.c. The chromatography of some polynuclear aromatic hydrocarbons is used to illustrate the possibilities of the combinations. 相似文献
114.
Vinylversatate-10 (VV10)1 has successfully been used to synthesise a large number of lower vinyl esters by transvinylation in presence of mercuric acetate and sulfuric acid. The synthesis of vinylhalo esters proceeds with more difficulty. It has been observed that neither Hg(OAc)2 nor H2SO4 alone is capable of initiating the transvinylation. Furthermore, it has been found that a molar ratio 2:1 of VV10 to carboxylic acid is sufficient to drive the reaction to the right by continuous distillation of the vinyl ester formed, and as a result a high yield of vinyl ester is obtained. A mechanism for this reaction and for the formation of side products has been proposed. 相似文献
115.
A correlation has been fround between the stereochemistry of 3-methoxyeyclopentyl and 3-methoxyccyelohexyl acetic acid esters and their methane or isobutane themical ionizaion spectra: only the cis compounds yield quasimolecular ions and the [MH? CH3OH]+ ions are more abundant for the trans isomers. A similar situation occurs in the iow temperature methane chemical ionization spectra of the coresponding trimethylsilylethers. 相似文献
116.
A. Michel T. Van Hoang B. Perrin Marie France Llauro 《Polymer Degradation and Stability》1981,3(2):107-119
It has been possible to explain the mechanisms of stabilisation and of the synergistic effects of the β-diketone derivatives claimed in a patent as new stabilisers for improving the efficiency of those recipes based upon zinc and calcium soaps in the prevention of the initial discoloration of poly(vinyl chloride).Using chlorohexene as a model compound for allylic chloride structures and benzoylacetone as a model compound for enolised β-diketone derivatives, it has been shown that the benzoylacetone can substitute allylic chlorine atoms through a C-alkylation reaction which takes place only in the presence of ZnCl2 as catalyst. This reaction drastically changes the percentage of the enol and causes the appearance of two bands at 1720 cm?1 and 1680 cm?1 in the infra-red spectrum due to the ketonic structures During the processing of the PVC on a rolling mill at 180°C in the presence of zinc and calcium stearates and benzoylacetone there is grafting of the ketone derivative through a C-alkylation reaction. There is a closed parallelism between the influence of the benzoylacetone on the dehydrochlorination of the chlorohexene and on the accumulation of chloride ions in the polymer matrix in the presence of zinc and calcium stearate. The synergistic effect of the benzoylacetone in the prevention of the initial discoloration is related to the substitution reaction through a C-alkylation which takes place only in the presence of zinc stearate which generates ZnCl2 which, in turn, acts as a catalyst for both the C-alkylation and dehydrochlorination. 相似文献
117.
J. A. Van Allan G. A. Reynolds J. F. Stenberg 《Journal of heterocyclic chemistry》1979,16(8):1661-1662
A general method for the preparations of pyranthiones is particularly useful for preparing substituted xanthiones which are unavailable by established procedures. Reaction of a xanthone with p-tosyl isocyanate or with trichloroacetyl isocyanate produces the corresponding imino derivatives, which upon treatment with n-butylamine followed by hydrogen sulfide gives the desired xanthione in good yield. 相似文献
118.
C. Le Van 《Journal of Optimization Theory and Applications》1980,30(1):33-44
We define the degree of a family of convex functionsf
x, wherex
, and prove that, if this degree is different from zero, one has at least one Nash equilibrium point in . This is a criterion of localization of such equilibrium points. 相似文献
119.
1H, 13C and 29Si NMR data for the compounds VixSiX4?x are reported. While the 1H and 13C resonances from the π system are indicative of the electron-withdrawing inductive effect (-I) of the halogens, the 29Si chemical shift data reveal not only a shift contribution originating from this inductive effect but also the important influence of a {d, σ*-π} hyperconjugation [1]. This back-donation originates from the vinyl π system and not from the halogens. The chemical shift data and the coupling constants also show an important influence from steric interaction and even from an electric field effect caused by polarization of the silicon—halogen bond. 相似文献
120.
F. Van Meurs A.J. Hoefnagel B.M. Wepster H. Van Bekkum 《Journal of organometallic chemistry》1977,142(3):299-308
The thermodynamic dissociation constants of a series of 38 substituted π-(tricarbonylchromium)benzoic acids in 50% aqueous ethanol at 25°C have been determined. The results require revision of some literature values.The pKa*-values of the π-(tricarbonylchromium)benzoic acids were correlated with the electronic substituent parameters in terms of the Yukawa-Tsuno equation. The reaction constant (ρ) decreases from 1.4 for the benzoic acids to 0.8 for the π-(tricarbonylchromium)benzoic acids, reflecting the decreased ability of the complexed aromatic system to transmit electronic substituent effects. For the alkylsubstituted π-(tricarbonylchromium)benzoic acids, conformational effects of the Cr(CO)3 group can account for some of the anomalies observed. The substituent parameters, σmeta and σpara, of the π-(Cr(CO)3)phenyl group as a substituent were derived from the dissociation constants of the complexed phenylbenzoic acids. 相似文献