全文获取类型
收费全文 | 63篇 |
免费 | 1篇 |
专业分类
化学 | 41篇 |
数学 | 10篇 |
物理学 | 13篇 |
出版年
2021年 | 4篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2015年 | 1篇 |
2013年 | 4篇 |
2012年 | 3篇 |
2011年 | 2篇 |
2010年 | 5篇 |
2009年 | 2篇 |
2008年 | 4篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2004年 | 1篇 |
2002年 | 2篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1973年 | 5篇 |
1972年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1896年 | 1篇 |
排序方式: 共有64条查询结果,搜索用时 31 毫秒
1.
Mathavaraj S. Padhi Radhakant 《Journal of Optimization Theory and Applications》2021,191(2-3):823-845
Journal of Optimization Theory and Applications - A new quasi-spectral version of unscented model predictive static programming is proposed, which is a fusion of two philosophies, namely the... 相似文献
2.
3.
MM. J. Duflos D. Letouz G. Queguiner P. Pastour 《Journal of heterocyclic chemistry》1973,10(6):1083-1084
This communication describes the synthesis of l-methyl-2,3-diformylpyrrole. This new compound is used to prepare a new heterocycle, l-methylcyclohepta[b]pyrrol-6-one and thus allows a new synthesis of l-methylpyrrolo[2,3-d]pyridazine. 相似文献
4.
The synthesis of two new heterocycles is described: pyrido-[2,3-d]-.s-triazolo[ 3,4-f] pyrimidine and pyrido[3,2-d]-.s-triayzolo-[3,4-f] pyrimidine. 4-[I'-Pyrazolyl]pyrido[2,3-d]pyrimidines and 4-[1′-pyrazoly1] pyrido[ 3,2-d] pyrimidine are obtained by the action of 4-hydrazinopyrido[2,3-d]pyrimidine and 4-hydrazinopyrido-[3,2-d]pyrimidine with several β-diketones. 相似文献
5.
Background
Several studies have shown that Stroop interference is stronger in children than in adults. However, in a standard Stroop paradigm, stimulus interference and response interference are confounded. The purpose of the present study was to determine whether interference at the stimulus level and the response level are subject to distinct maturational patterns across childhood. Three groups of children (6–7 year-olds, 8–9 year-olds, and 10–12 year-olds) and a group of adults performed a manual Color-Object Stroop designed to disentangle stimulus interference and response interference. This was accomplished by comparing three trial types. In congruent (C) trials there was no interference. In stimulus incongruent (SI) trials there was only stimulus interference. In response incongruent (RI) trials there was stimulus interference and response interference. Stimulus interference and response interference were measured by a comparison of SI with C, and RI with SI trials, respectively. Event-related potentials (ERPs) were measured to study the temporal dynamics of these processes of interference.Results
There was no behavioral evidence for stimulus interference in any of the groups, but in 6–7 year-old children ERPs in the SI condition in comparison with the C condition showed an occipital P1-reduction (80–140 ms) and a widely distributed amplitude enhancement of a negative component followed by an amplitude reduction of a positive component (400–560 ms). For response interference, all groups showed a comparable reaction time (RT) delay, but children made more errors than adults. ERPs in the RI condition in comparison with the SI condition showed an amplitude reduction of a positive component over lateral parietal (-occipital) sites in 10–12 year-olds and adults (300–540 ms), and a widely distributed amplitude enhancement of a positive component in all age groups (680–960 ms). The size of the enhancement correlated positively with the RT response interference effect.Conclusion
Although processes of stimulus interference control as measured with the color-object Stroop task seem to reach mature levels relatively early in childhood (6–7 years), development of response interference control appears to continue into late adolescence as 10–12 year-olds were still more susceptible to errors of response interference than adults. 相似文献6.
R. C. Padhi H. Labischinski A. Patel 《Journal of polymer science. Part A, Polymer chemistry》1983,21(10):2863-2872
The small-angle, x-ray scattering method was applied to evaluate macromolecular parameters of defated proteinous silk fibers like Eri, Muga, Tussah, and raw silk. For the experimental measurement of scattering intensities the small-angle Kratky camera, coupled with an automatic-step scanning device, pulse-height discriminator, and counter attachment was used. Macromolecular parameters like specific inner surface, percentage of void, length of coherence, range of inhomogeneity, and transversal length were evaluated by using the theories of Kratky, Porod and Debye, and Bueche. The physical properties of these defated fibers were also evaluated with Scott's IP2-inclined plane tester. The correlation of the tertiary structural parameters with textile properties like average breaking strength of the proteinous fibers indicated a dependence of physical properties on certain macromolecular parameters. 相似文献
7.
MM. P. Duballet A. Godard G. Queguiner P. Pastour 《Journal of heterocyclic chemistry》1973,10(6):1079-1080
This article describes the synthesis of a new heterocycle, pyrido[2,3,f]phtalazine and three new diformylquinolincs. 相似文献
8.
9.
10.
Aqueous polymerization of acrylonitrile (M) initiated by the Ce(IV)-glucose (R) redox system has been studied under nitrogen in the temperature range of 30–40 °C. The rate of polymerization (Rp) is proportional to [M]2, [R] and inversely proportional to [Ce(IV)]. The rate of ceric ion disappearance is proportional to [R] and [Ce(IV)]. The end group in the polymer is characterised by IR spectra. A suitable kinetic scheme has been proposed and explained in the light of these experimental findings. 相似文献