全文获取类型
收费全文 | 151篇 |
免费 | 4篇 |
专业分类
化学 | 124篇 |
力学 | 4篇 |
数学 | 14篇 |
物理学 | 13篇 |
出版年
2022年 | 2篇 |
2021年 | 2篇 |
2019年 | 3篇 |
2016年 | 4篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 4篇 |
2012年 | 7篇 |
2011年 | 10篇 |
2010年 | 7篇 |
2009年 | 7篇 |
2008年 | 5篇 |
2007年 | 2篇 |
2006年 | 4篇 |
2005年 | 2篇 |
2003年 | 9篇 |
2002年 | 5篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1957年 | 2篇 |
1940年 | 1篇 |
1916年 | 1篇 |
1914年 | 1篇 |
1913年 | 1篇 |
1909年 | 7篇 |
1904年 | 1篇 |
1903年 | 6篇 |
1902年 | 3篇 |
1900年 | 4篇 |
1898年 | 3篇 |
1895年 | 3篇 |
1890年 | 1篇 |
1887年 | 5篇 |
1886年 | 1篇 |
1885年 | 5篇 |
1884年 | 4篇 |
1882年 | 1篇 |
1881年 | 2篇 |
1879年 | 1篇 |
1878年 | 1篇 |
1870年 | 1篇 |
1865年 | 1篇 |
排序方式: 共有155条查询结果,搜索用时 109 毫秒
11.
12.
Ohne Zusammenfassung 相似文献
13.
14.
Iványi T Vander Heyden Y Visky D Baten P De Beer J Lázár I Massart DL Roets E Hoogmartens J 《Journal of chromatography. A》2002,954(1-2):99-114
This paper focuses on the classification or differentiation of RP-HPLC columns based on measured chromatographic properties. A chemometric study has been conducted on a published data set consisting of 85 RP-HPLC columns and on a data set consisting of 47 self-tested columns. Principal component analysis enables determination of the number of parameters necessary for a rational differentiation. The results show that reducing the number of parameters for such differentiation still allows classification of the columns just as a higher number did. It is shown that three test parameters produce a classification similar to that obtained with five parameters. 相似文献
15.
Agibert SA Moreira MB Ratusznei SM Rodrigues JA Zaiat M Foresti E 《Applied biochemistry and biotechnology》2007,136(2):193-206
The effect of temperature on the performance of an anaerobic sequencing biofilm batch reactor (ASBBR) with liquid-phase recirculation
was assessed. Assays were performed using a recirculation velocity of 0.20 cm/s, 8-h cycles, and an average treated synthetic
wastewater volume of 2 L/cycle with a concentration of 500 mg of Chemical Oxygen Demand (COD)/L. Operation temperatures were
15, 20, 25, 30, and 35°C. At 25, 30, and 35°C, organic matter removal efficiencies for filtered samples ranged from 81 to
83%. At lower temperatures, namely 15 and 20°C, removal efficiency decreased significantly to 61 and 65%, respectively. A
first-order model could be fitted to the experimental concentration profile values. The first-order kinetic parameter value
of this model varied from 0.46 to 0.81 h1 considering the lowest and highest temperature studied. Moreover, analysis of the removal profile values allowed fitting
of an Arrhenius-type equation with an activation energy of 5715 cal/mol. 相似文献
16.
17.
Ohne Zusammenfassung 相似文献
18.
Esters and chlorides of oxalic mono-esters can be estimated volumetrically. After saponification precipitation is carried out by means of a calcium chloride solution, the excess of which is measured by chelatometry. 相似文献
19.
Nikolaos S. Papageorgiou Eugénio M. Rocha Vasile Staicu 《Calculus of Variations and Partial Differential Equations》2008,33(2):199-230
In this paper we study second order elliptic equations driven by the Laplacian and p-Laplacian differential operators and
a nonlinearity which is (p-)superlinear (it satisfies the Ambrosetti–Rabinowitz condition). For the p-Laplacian equations
we prove the existence of five nontrivial smooth solutions, namely two positive, two negative and a nodal solution. Finally
we indicate how in the semilinear case, Morse theory can be used to produce six nontrivial solutions.
This paper was completed while the first author was visiting the University of Aveiro as an Invited Scientist. The hospitality
and financial support of the host institution are gratefully acknowledged. The second and third authors acknowledge the partial
financial support of the Portuguese Foundation for Science and Technology (FCT) under the research project POCI/MAT/55524/2004. 相似文献
20.
Eugène Cremmer Jean-Loup Gervais Jens Schnittger 《Communications in Mathematical Physics》1997,183(3):609-643
In a previous paper, the quantum-group-covariant chiral vertex operators in the spin 1/2 representation were shown to act,
by braiding with the other covariant primaries, as generators of the well known Uq(sl(2)) quantum group symmetry (for a single screening charge). Here, this structure is transformed to the Bloch wave/Coulomb
gas operator basis, thereby establishing for the first time its quantum group symmetry properties. A Uq(sl(2)) Uq(sl(2)) symmetry of a novel type emerges: The two Cartan-generator eigenvalues are specified by the choice of matrix element
(Vermamodules); the two Casimir eigenvalues are equal and specified by the Virasoro weight of the vertex operator considered;
the co-product is defined with a matching condition dictated by the Hilbert space structure of the operator product. This
hidden symmetry possesses a novel Hopf-like structure compatible with these conditions. At roots of unity it gives the
right truncation. Its (non-linear) connection with the Uq(sl(2)) previously discussed is disentangled.
Received: 25 April 1996/Accepted: 20 July 1996 相似文献