全文获取类型
收费全文 | 148篇 |
免费 | 7篇 |
国内免费 | 3篇 |
专业分类
化学 | 67篇 |
晶体学 | 2篇 |
力学 | 13篇 |
数学 | 47篇 |
物理学 | 29篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 9篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 12篇 |
2012年 | 16篇 |
2011年 | 8篇 |
2010年 | 11篇 |
2009年 | 9篇 |
2008年 | 3篇 |
2007年 | 14篇 |
2006年 | 8篇 |
2005年 | 6篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有158条查询结果,搜索用时 281 毫秒
21.
In this article, we introduce a conditional marginal model for longitudinal data, in which the residuals form a martingale
difference sequence. This model allows us to consider a rich class of estimating equations which contains several estimating
equations proposed in the literature. A particular sequence of estimating equations in this class contains a random matrix
R
i−1*(β) as a replacement for the “true” conditional correlation matrix of the ith individual. Using the approach of [12], we identify some sufficient conditions under which this particular sequence of
equations is asymptotically optimal (in our class). In the second part of the article, we identify a second set of conditions
under which we prove the existence and strong consistency of a sequence of estimators of β defined as roots of estimation equations which are martingale transforms (in particular, roots of the sequence of asymptotically
optimal equations). 相似文献
22.
Adriana Balan 《代数通讯》2013,41(4):1129-1150
If H is a finite dimensional quasi-Hopf algebra and A is a left H-module algebra, we show that there is a Morita context connecting the smash product A#H and the subalgebra of invariants A H . We define also Galois extensions and prove the connection with this Morita context, as in the Hopf case. 相似文献
23.
Adriana Balan 《代数通讯》2013,41(4):1491-1525
In this article, we consider categories of all semimodules over semirings which are p-Schreier varieties, i.e., varieties whose projective algebras are all free. Among other results, we show that over a division semiring R all semimodules are projective iff R is a division ring, prove that categories of all semimodules over proper additively π-regular semirings are not p-Schreier varieties (in particular, this result solves Problem 1 of Katsov [8]), as well as prove that categories of all semimodules over cancellative division semirings are, in contrast, p-Schreier varieties. 相似文献
24.
Varga Zsolt Wallenius Maria Nicholl Adrian Mayer Klaus Balan Ionel Benea Vasile 《Journal of Radioanalytical and Nuclear Chemistry》2019,322(3):1585-1591
JRC-Karlsruhe obtained a swipe sample from a highly enriched uranium seizure, which had taken place in 2011. Due to the very low amount of uranium (nanograms) a new method needed to be developed to determine the U production date (age). The particles on the swipe were collected on a pyrolytic graphite planchet using a vacuum impactor and they were subsequently leached with ccHNO3. The “bulk” U isotopic composition (235U: 72.51?±?0.03 wt%) and the production date (December 1992?±?1 year) determined by MC-ICP-MS indicated that the material showed similarity with two other HEU cases seized earlier in Europe.
相似文献25.
26.
Inside Back Cover: Molecular Imaging of Growth,Metabolism, and Antibiotic Inhibition in Bacterial Colonies by Laser Ablation Electrospray Ionization Mass Spectrometry (Angew. Chem. Int. Ed. 48/2016)
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Hang Li Pranav Balan Prof. Akos Vertes 《Angewandte Chemie (International ed. in English)》2016,55(48):15181-15181
27.
We study convergence in law of partial sums of linear processes with heavy-tailed innovations. In the case of summable coefficients, necessary and sufficient conditions for the finite dimensional convergence to an \(\alpha \)-stable Lévy Motion are given. The conditions lead to new, tractable sufficient conditions in the case \(\alpha \le 1\). In the functional setting, we complement the existing results on \(M_1\)-convergence, obtained for linear processes with nonnegative coefficients by Avram and Taqqu (Ann Probab 20:483–503, 1992) and improved by Louhichi and Rio (Electr J Probab 16(89), 2011), by proving that in the general setting partial sums of linear processes are convergent on the Skorokhod space equipped with the \(S\) topology, introduced by Jakubowski (Electr J Probab 2(4), 1997). 相似文献
28.
Complex formation of pyromellitic diimide derivatives with beta-cyclodextrin and anthracene-appended beta-cyclodextrin was studied with use of induced circular dichroism and 1H NMR spectroscopies. It is revealed that pyromellitic diimides form rim-binding type complexes with beta-CD and in these complexes the pyromellitic diimides lie just outside of the narrow rim of the CD. With anthracene-appended beta-CD the pyromellitic diimides form true inclusion complexes. Implications of the formation of rim-binding type complexes are also discussed. 相似文献
29.
R. Schrittwieser C. Ionita P.C. Balan J.A. Cabral F.H. Figueiredo V. Pohoata C. Varandas 《等离子体物理论文集》2001,41(5):494-503
In experimental fusion devices, up to now, only cold probes were used to determine the plasma potential in the s crape‐ o ff l ayer (SOL), and their floating potential was assumed to be proportional to the plasma potential. However, drifting electrons or beams shift the current‐voltage characteristic of a cold probe by a voltage, which corresponds to the mean kinetic energy of the drifting electrons. This problem can be avoided by the use of electron emissive probes, since an electron emission current is independent of electron drifts in the surrounding plasma. In addition emissive probes are insensitive to electron temperature fluctuations in the plasma. We have used an arrangement of three emissive probes in the edge plasma region of ISTTOK (Instituto Superior Técnico tokamak) at Lisbon. The probes have been mounted in such a way that the tips are positioned on the same poloidal meridian but on different minor radii in the SOL. With this arrangement, the plasma potential has been measured in the edge region of the ISTTOK, and first results are presented in this contribution. 相似文献
30.
Vera Balan Ivona Andreea Petrache Marcel Ionel Popa Maria Butnaru Eugen Barbu John Tsibouklis Liliana Verestiuc 《Journal of nanoparticle research》2012,14(2):730
Haemocompatible biotinylated superparamagnetic nanoparticles (size range 300–700 nm) have been obtained by coating magnetite
through ionic gelation with a mixture of chitosan and sodium tripolyphosphate, followed by subsequent functionalisation with
biotin. The evaluations of their magnetic properties together with haemocompatibility tests have shown that these nanoparticles
exhibit the prerequisite behaviour for use in magnetic field–assisted separations within biological systems. 相似文献