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排序方式: 共有226条查询结果,搜索用时 31 毫秒
171.
Johnny Siu-Hang Li 《Insurance: Mathematics and Economics》2010,47(2):176-186
In recent years, there has been significant development in the securitization of longevity risk. Various methods for pricing longevity risk have been proposed. In this paper we present an alternative pricing method, which is based on the maximization of the Shannon entropy in physics. Specifically, we propose implementing this pricing method with the parametric bootstrap (Brouhns et al., 2005), which is highly flexible and can be performed under different model assumptions. Through this pricing method we also quantify the impact of cohort effects and parameter uncertainty on prices of mortality-linked securities. Numerical illustrations based on longevity bonds with different maturities are provided. 相似文献
172.
Johnny Henderson Abdelghani Ouahab 《Nonlinear Analysis: Theory, Methods & Applications》2010,72(3-4):2147-2148
We correct an error made in the paper (J. Henderson and A. Ouahab, Fractional Functional Differential Inclusions with Finite Delay [Nonlinear Anal. 70(5) (2009) 2091–2015]), in an application of Theorem 4.1 in the proof of Theorem 4.2. We have revised the statement of Theorem 4.2 so that Theorem 4.1 is now applicable in its proof. 相似文献
173.
Bjarke Thomas Dalslet Martin Sgaard Henny J.M. Bouwmeester Peter Vang Hendriksen 《Solid State Ionics》2009,180(20-22):1173-1182
This paper is the first part of a two part series, where the effects of varying the A-site dopant on the defect chemistry, the diffusion coefficient and the surface catalytic properties of the materials (La0.6Sr0.4 − xMx)0.99Co0.2Fe0.8O3 − δ, M = Sr, Ca (x = 0.05, 0.1), Ba (x = 0.1, 0.2) (LSMFC) have been investigated. In part I, the findings on the defect chemistry are reported, while the transport properties are reported in part II. Substitution of Sr2+ ions with Ca2+ ions (smaller ionic radius) and Ba2+ ions (larger ionic radius) strains the crystal structure differently for each composition while keeping the average valence of the cations constant. The Ba2+ containing materials show the largest oxygen loss at elevated temperatures, while the purely Sr2+ doped material showed the smallest oxygen loss. This was reflected in the partial oxidation entropy of the materials. The measured oxygen loss was modelled with point defect chemistry models. Measurements at very low pO2 showed several phase transitions. 相似文献
174.
We study the existence of positive solutions for a system of nonlinear second-order ordinary differential equations subject to some multi-point boundary conditions. The nonexistence of positive solutions is also investigated. 相似文献
175.
Johnny Hu Dr. Jas S. Ward Dr. Alain Chaumont Prof. Kari Rissanen Dr. Jean-Marc Vincent Prof. Valérie Heitz Dr. Henri-Pierre Jacquot de Rouville 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(51):23406-23412
A bis-acridinium cyclophane incorporating switchable acridinium moieties linked by a 3,5-dipyridylanisole spacer was studied as a multi-responsive host for polycyclic aromatic hydrocarbon guests. Complexation of perylene was shown to be the most effective and was characterized in particular by a charge-transfer band as signal output. Effective catch and release of the guest was triggered by both chemical (proton/hydroxide) and redox stimuli. Moreover, the dicationic host was also easily switched between organic and perfluorocarbon phases for applications related to the enrichment of perylene from a mixture of polycyclic aromatic hydrocarbons. 相似文献
176.
Chunyin Law Elton Kativhu Johnny Wang Prof. James P. Morken 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(26):10397-10401
Enantioselective conjunctive cross-coupling of enyne-derived boronate complexes occurs with 1,4 addition of the electrophile and migrating group across the π system. This reaction pathway furnishes α-boryl allenes as the reaction product. In the presence of a chiral catalyst, both the central and axial chirality of the product can be controlled during product formation. 相似文献
177.
Weijia Zheng Cristian A. Morales‐Rivera Johnny W. Lee Peng Liu Prof. Ming‐Yu Ngai 《Angewandte Chemie (International ed. in English)》2018,57(31):9645-9649
The intermolecular C?H trifluoromethoxylation of arenes remains a long‐standing and unsolved problem in organic synthesis. Herein, we report the first catalytic protocol employing a novel trifluoromethoxylating reagent and redox‐active catalysts for the direct (hetero)aryl C?H trifluoromethoxylation. Our approach is operationally simple, proceeds at room temperature, uses easy‐to‐handle reagents, requires only 0.03 mol % of redox‐active catalysts, does not need specialized reaction apparatus, and tolerates a wide variety of functional groups and complex structures such as sugars and natural product derivatives. Importantly, both ground‐state and photoexcited redox‐active catalysts are effective. Detailed computational and experimental studies suggest a unique reaction pathway where photoexcitation of the trifluoromethoxylating reagent releases the OCF3 radical that is trapped by (hetero)arenes. The resulting cyclohexadienyl radicals are oxidized by redox‐active catalysts and deprotonated to form the desired products of trifluoromethoxylation. 相似文献
178.
Trifluoromethoxy (OCF3) group exhibits unique properties, which render it a highly desirable structural motif in life and materials sciences. The numbers of newly synthesized trifluoromethyl ethers are booming as new synthetic methods are constantly being developed to access these valuable compounds. This Review summarizes recent catalytic approaches towards preparation of trifluoromethyl ethers. Alkene, allylic, benzylic, and aryl trifluoromethoxylation reactions are discussed herein. 相似文献
179.
Johnny Henderson 《Journal of Mathematical Analysis and Applications》2004,289(1):110-125
This work presents some results for the existence of solutions to boundary value problems on time scales. The ideas rely on the topological transversality of A. Granas. 相似文献
180.
Tak-Wah Lam Tsuen-Wan Johnny Ngan Kar-Keung To 《Journal of Algorithms in Cognition, Informatics and Logic》2004,52(2):69
Earliest deadline first (edf) is a widely used algorithm for online deadline scheduling. It has been known for long that edf is optimal for scheduling an underloaded, single-processor system; recent results on the extra-resource analysis of edf further revealed that edf when using moderately faster processors can achieve optimal performance in the underloaded, multi-processor setting. This paper initiates the extra-resource analysis of edf for overloaded systems, showing that edf supplemented with a simple form of admission control can provide a similar performance guarantee in both the single and multi-processor settings. 相似文献