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排序方式: 共有841条查询结果,搜索用时 31 毫秒
1.
Tomoyuki Nakatsuka 《Mathematische Nachrichten》2021,294(1):98-117
We study the existence of a time‐periodic solution with pointwise decay properties to the Navier–Stokes equation in the whole space. We show that if the time‐periodic external force is sufficiently small in an appropriate sense, then there exists a time‐periodic solution of the Navier–Stokes equation such that and uniformly in as . Our solution decays faster than the time‐periodic Stokes fundamental solution and the faster decay of its spatial derivatives of higher order is also described. 相似文献
2.
Hiroyuki Saimoto Tomoyuki Onitsuka Satoko Okabe Minoru Morimoto 《Tetrahedron letters》2004,45(48):8777-8780
Treatment of 1,3-dihydroxyacetone and acrolein with aqueous KOH gave a tetrahydrofuran derivative, 1,4-dihydroxy-3,7-dioxabicyclo[3.3.0]octane, in 80% yield. Similarly, 6-alkyl substituted 1,4-dihydroxy-3,7-dioxabicyclo[3.3.0]octanes were obtained by reaction of 1,3-dihydroxyacetone with various α,β-unsaturated aldehydes. In the cases of long chain alkenals, the reaction was effectively accelerated in the presence of organic co-solvent. On the other hand, the corresponding tricyclic products were synthesized by reaction of 1,3-dihydroxyacetone with cyclic enones, such as 2-cyclopentenone and 2-cyclohexenone. This method was successfully applied to the reaction of a tetrulose in the absence of any protecting groups. 相似文献
3.
Seiichi Nishizawa Tomoyuki Kamaishi Tomoyuki Yokobori Ryo Kato Ying-Yu Cui Takeshi Shioya Norio Teramae 《Analytical sciences》2004,20(11):1559-1565
Facilitated SO4(2-) transfers by hydrogen bond-forming ionophores are investigated across the nitrobenzene (NB)-water interface by using polarography with a dropping electrolyte electrode. Bis-thiourea 1, alpha,alpha'-bis(N'-p-nitrophenylthioureylene)-m-xylene, is found to significantly facilitate the transfer of the highly hydrophilic SO4(2-) whereas its counterpart, N-(p-nitrophenyl)-N'-propylthiourea (ionophore 2), cannot. In contrast to the predominant formation of a 1:1 complex with SO4(2-) in the bulk NB phase, the SO4(2-) transfer assisted by 1 is indeed based on the formation of a 1:2 complex between SO4(2-) and ionophore, even under the condition of [SO4(2-)]aq > [1]org. Such an exclusive formation of the 1:2 (SO4(2-) to ionophore) complex at the NB-water interface is not observed with structurally similar bis-thiourea 3, alpha,alpha'-bis(N'-phenylthioureylene)-m-xylene, where p-nitrophenyl moietes of bis-thiourea 1 are simply replaced by phenyl groups. The facilitated transfer of SO4(2-) with bis-thiourea 1 is further compared to that of HPO4(2-) and H2PO4- across the NB-water interface, which was previously shown to be assisted by 1 through the formation of the 1:1 and 2:1 (anion to ionophore) complexes, respectively. On the basis of these examinations, unique binding behaviors of hydrogen bond-forming ionophores at the NB-water interface are discussed, with a view towards development of ionophore-based anion-selective chemical sensors. 相似文献
4.
5.
T. Takebe 《Journal of Mathematical Sciences》1995,77(2):3133-3136
Using certain asymptotic conditions, we prove the uniqueness of the form factors of the energy-momentum tensor for the reduced
sine-Gordon model (2/3) (RSG(2/3)). Bibliography: 5 titles.
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 199, 1992, pp. 177–181.
Translated by I. A. Izergina. 相似文献
6.
Kazunori Tanaka Kaoru Okuno Tomoyuki Hattori Kiyoaki Moriuchi Hiroshi Hayami Wataru Katsurashima Yoshikyo Tamekuni 《光学学报》2003,23(Z1)
A non-halogen highly flame-retardant 0.9mm optical fiber and 2.0mm simplex optical cord, which are harmonized with the ecosystem, have been developed. The characteristics of them are presented in this paper. 相似文献
7.
We found a strong paraoxon-hydrolyzing activity (23.4 +/- 8.50 nmol/h/individual and 137 +/- 86.2 nmol/h/mg protein) in the crude extract from larvae of Culex tritaeniorhynchus Toyama 89, which is markedly resistant to organophosphorous insecticides. The activity was higher than those from Cx. tritaeniorhynchus re-e-ae (0.175 +/- 0.0336 and 1.83 +/- 0.651), Anopheles omorii (0.112 +/- 0.0301 and 1.86 +/- 0.746) and An. stephensi (0.0651 +/- 0.0713 and 0.789 +/- 0.910), which are susceptible to organophosphorous insecticides. These facts suggest that the high paraoxon-hydrolyzing activity plays a role in the development of organophosphorous resistance in Cx. tritaeniorhynchus. The enzyme preparation obtained from Toyama 89 showed higher activity in the alkaline pH range and its Km values to paraoxon were 0.67 mM in larvae and 0.50 mM in adults. A calcium ion was strictly required for the hydrolysis of paraoxon. Fenitroxon was also hydrolyzed, in addition to paraoxon. However, it did not degradate parathion and fenitrothion at all. Dichlorvos and phenyl acetate competitively inhibited the enzyme. The phenyl acetate-hydrolyzing activity in the preparation of Toyama 89 was significantly (p less than 0.01) lower than those in susceptible strains, and was irreversibly inhibited by paraoxon. Therefore, the paraoxon-hydrolyzing activity belongs to the class of organophosphate compound hydrolases; it must be thus distinguished from bacterial phosphotriesterase. 相似文献
8.
Haitao Yang Tomoyuki Ogawa Daiji Hasegawa C.N. Chinnasamy Migaku Takahashi 《Journal of magnetism and magnetic materials》2006
Monodisperse bimetallic Pd–Co nanoparticles were prepared via a thermal decomposition of cobalt carbonyl using palladium seeds at the Pd/Co molar ratios 0.5%, 1%, and 5%. The heterogeneously nucleated nanoparticles without any size-selective precipitation are sufficiently uniform to self-assemble into ordered arrays. The as-synthesized nanoparticles are each a single crystal with a complex cubic structure called ε-Co. The presence of Pd seeds seems to improve the stability of Co nanoparticles against oxidation based on the results from time-dependent magnetization measurement. 相似文献
9.
Mathematische Annalen - 相似文献
10.
The electronic effect on the regioselectivity in the alkynylation of phenyloxiranes was investigated using three kinds of metal acetylides. BF3 mediated lithium acetylide provided either the α- or β-alkynylated products by controlling the effect of the para-substituents of the phenyloxiranes. LiClO4 mediated lithium acetylide and titanium acetylide, on the other hand, afforded predominantly the β- and α-products, respectively. 相似文献