全文获取类型
收费全文 | 693篇 |
免费 | 24篇 |
国内免费 | 3篇 |
专业分类
化学 | 445篇 |
晶体学 | 3篇 |
力学 | 15篇 |
数学 | 51篇 |
物理学 | 206篇 |
出版年
2023年 | 5篇 |
2021年 | 9篇 |
2020年 | 17篇 |
2019年 | 18篇 |
2018年 | 8篇 |
2017年 | 8篇 |
2016年 | 19篇 |
2015年 | 9篇 |
2014年 | 16篇 |
2013年 | 39篇 |
2012年 | 27篇 |
2011年 | 29篇 |
2010年 | 14篇 |
2009年 | 16篇 |
2008年 | 23篇 |
2007年 | 16篇 |
2006年 | 21篇 |
2005年 | 27篇 |
2004年 | 15篇 |
2003年 | 17篇 |
2002年 | 33篇 |
2001年 | 9篇 |
2000年 | 16篇 |
1999年 | 10篇 |
1997年 | 5篇 |
1996年 | 9篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 17篇 |
1992年 | 9篇 |
1990年 | 5篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1985年 | 10篇 |
1984年 | 5篇 |
1983年 | 12篇 |
1982年 | 9篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1978年 | 14篇 |
1977年 | 10篇 |
1976年 | 8篇 |
1975年 | 5篇 |
1974年 | 5篇 |
1973年 | 5篇 |
1972年 | 8篇 |
1971年 | 5篇 |
1970年 | 8篇 |
1967年 | 6篇 |
排序方式: 共有720条查询结果,搜索用时 15 毫秒
81.
Meade Bolton C. Kraus T. Leone Link Heraeus Flügge A. Pfeiffer E. Esmarch Carl Fränkel von Sehlen's M. Hochstetter G. Bischof Alex Köbrich O. Kasper Dupré Joseph Klein John Henry Smith J. W. Mallet's E. Reichardt Mayrhofer Leopold Spiegel Katharine J. Williams W. Ramsay A. B. Cooper Baeseler Nobbe Will W. Knop C. W. Heaton Thomas Stevenson Odling Tidy Crookes P. T. Austen Austen und Francis A. Wilber 《Fresenius' Journal of Analytical Chemistry》1888,27(1):77-84
Ohne Zusammenfassung 相似文献
82.
Andreas Hegetschweiler Aljosha-Rakim Jochem Anna Zimmermann Johannes Walter Thorsten Staudt Tobias Kraus 《Particle & Particle Systems Characterization》2021,38(7):2000236
Different colloidal particle characterization methods are examined for their suitability to determine the particle size distribution of particles extracted from steels. Microalloyed steels are dissolved to extract niobium and titanium carbonitride particles that are important for the mechanical properties of these steels. Such particles have sizes ranging from several nanometers to hundreds of nanometers depending on the precipitation stage during the thermomechanically controlled rolling process. The size distribution of the particles is analyzed by dynamic light scattering (DLS), analytical ultracentrifugation (AUC), and hollow fiber flow field-flow fractionation (HF5) and compared to data obtained for reference particles as well as data from electron microscopy, the standard sizing technique used in metallurgy today. AUC and HF5 provide high-quality size distributions, average over large particle numbers that enables statistical analysis, and yield useful insights for alloy design; however, DLS fails due to a lack of resolution. Important aspects in the conversion and comparison of size distributions obtained for broadly distributed particle systems with different measurement principles and the role of surfactants used in sample preparation are discussed. 相似文献
83.
The reaction of phenols with 7a led to the synthesis of aurones, while the reaction of phenols with 7b led to the synthesis of flavones. 相似文献
84.
85.
Bucaro JA Kraus L Houston BH Simpson H Sarkissian A 《The Journal of the Acoustical Society of America》2011,129(6):3453-3456
A 48 m rail with a moving receiver was used to measure forward scattering from a spherical shell lying on the bottom in the Gulf of Mexico. The target was mid-way between the source and rail, on a line from the source bisecting the rail. The major obstacle to the measurement of forward scattering is the much stronger source signal which overlaps the scattered signal in space and time. Here, forward scattered target strength is obtained by processing the received signals using a wavenumber filter to remove the incident wave. The result compares favorably to that obtained from numerical predictions. 相似文献
86.
Product line selection and pricing decisions are critical to the profitability of many firms, particularly in today’s competitive business environment in which providers of goods and services are offering a broad array of products to satisfy customer needs.We address the problem of selecting a set of products to offer and their prices when customers select among the offered products according to a share-of-surplus choice model. A customer’s surplus is defined as the difference between his utility (willingness to pay) and the price of the product. Under the share-of-surplus model, the fraction of a customer segment that selects a product is defined as the ratio of the segment’s surplus from this particular product to the segment’s total surplus across all offered products with positive surplus for that segment.We develop a heuristic procedure for this non-concave, mixed-integer optimization problem. The procedure utilizes simulated annealing to handle the binary product selection variables, and a steepest-ascent-style procedure that relies on certain structural properties of the objective function to handle the non-concave, continuous portion of the problem involving the prices. We also develop a variant of our procedure to handle uncertainty in customer utilities. In computational studies, our basic procedures perform extremely well, producing solutions whose objective values are within about 5% of those obtained via enumerative methods. Our procedure to handle uncertain utilities also performs well, producing solutions with expected profit values that are roughly 10% higher than the corresponding expected profits from solutions obtained under the assumption of deterministic utilities. 相似文献
87.
88.
89.
Edward C. Kraus 《Fresenius' Journal of Analytical Chemistry》1924,65(10):426
Ohne Zusammenfassung 相似文献
90.
A boundary version of Ahlfors’ Lemma is established and used to show that the classical Schwarz-Carathéodory reflection principle
for holomorphic functions has a purely conformal geometric formulation in terms of Riemannian metrics. This conformally invariant
reflection principle generalizes naturally to analytic maps between Riemann surfaces and contains among other results a characterization
of finite Blaschke products due to M. Heins.
D. Kraus was supported by a HWP scholarship
O. Roth and S. Ruscheweyh received partial support form the German-Israeli Foundation (grant G-809-234.6/2003) 相似文献