全文获取类型
收费全文 | 775篇 |
免费 | 30篇 |
国内免费 | 7篇 |
专业分类
化学 | 563篇 |
晶体学 | 11篇 |
力学 | 28篇 |
数学 | 27篇 |
物理学 | 183篇 |
出版年
2023年 | 7篇 |
2022年 | 14篇 |
2021年 | 11篇 |
2020年 | 15篇 |
2019年 | 32篇 |
2018年 | 30篇 |
2017年 | 15篇 |
2016年 | 26篇 |
2015年 | 22篇 |
2014年 | 35篇 |
2013年 | 72篇 |
2012年 | 57篇 |
2011年 | 51篇 |
2010年 | 37篇 |
2009年 | 26篇 |
2008年 | 48篇 |
2007年 | 27篇 |
2006年 | 36篇 |
2005年 | 26篇 |
2004年 | 27篇 |
2003年 | 17篇 |
2002年 | 15篇 |
2001年 | 4篇 |
2000年 | 11篇 |
1999年 | 3篇 |
1997年 | 5篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 9篇 |
1993年 | 3篇 |
1992年 | 6篇 |
1991年 | 9篇 |
1990年 | 3篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1984年 | 8篇 |
1982年 | 6篇 |
1981年 | 9篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 4篇 |
1977年 | 9篇 |
1976年 | 7篇 |
1975年 | 8篇 |
1974年 | 5篇 |
1973年 | 3篇 |
1969年 | 3篇 |
1962年 | 2篇 |
排序方式: 共有812条查询结果,搜索用时 15 毫秒
1.
Nonlinear Dynamics - In this paper, a novel robust tracking control strategy for nonlinear unmatched uncertain systems is formulated using the event-based adaptive dynamic programming (ADP)... 相似文献
2.
A new third‐order WENO scheme is proposed to achieve the desired order of convergence at the critical points for scalar hyperbolic equations. A new reference smoothness indicator is introduced, which satisfies the sufficient condition on the weights for the third‐order convergence. Following the truncation error analysis, we have shown that the proposed scheme achieves the desired order accurate for smooth solutions with arbitrary number of vanishing derivatives if the parameter ε satisfies certain conditions. We have made a comparative study of the proposed scheme with the existing schemes such as WENO‐JS, WENO‐Z, and WENO‐N3 through different numerical examples. The result shows that the proposed scheme (WENO‐MN3) achieves better performance than these schemes. 相似文献
3.
Surapuraju Pavan Kumar Raju Mallikarjun Narayanam Banothu Kranthi Kumar Sreeram Tejaswee Saranjit Singh 《Chromatographia》2015,78(19-20):1245-1250
4.
5.
6.
Nagu A. Vasikerappa K. Gidyonu P. Prathap Ch. Venkata Rao M. Rama Rao K. S. David Raju B. 《Research on Chemical Intermediates》2020,46(5):2669-2681
Research on Chemical Intermediates - MgO-supported Ni catalysts were selectively catalysed by the hydrogenation of benzonitrile to benzylamine in continuous flow at atmospheric pressure without any... 相似文献
7.
Arulraj Ruba A. Gajjela Raju Chauthe Siddheshwar Kisan Bagadi Muralidhararao Mathur Arvind 《Chromatographia》2022,85(6):497-506
Chromatographia - In drug discovery environment, determination of residual solvents is indispensable and requires rapid analysis covering a maximum number of commonly used solvents especially with... 相似文献
8.
Towards Stereoselective Synthesis of the C(31)–C(39) and C(20)–C(27) Fragments of Phorboxazole A 下载免费PDF全文
Kammari Bal Raju Bejjanki Naveen Kumar Bandari Sampath Kumar Kommu Nagaiah 《Helvetica chimica acta》2015,98(3):386-399
The stereoselective synthesis of the C(31)–C(39) and C(20)–C(27) fragments of phorboxazole A ( 1 ) was achieved from commercially available and inexpensive D ‐mannitol. Crimmins aldol reaction and a decarboxylative Claisen‐type reaction are the key steps for the C(31)–C(39) fragment, and L ‐proline‐catalyzed aldol reaction, Sharpless asymmetric epoxidation, and epoxide ring opening reaction with Gilman's reagent are the key steps for the C(20)–C(27) fragment of phorboxazole. 相似文献
9.
Raju Suresh Kumar Abdulrahman I. Almansour Natarajan Arumugam D. Kotresha J. Carlos Menéndez Raju Ranjith Kumar 《Journal of heterocyclic chemistry》2021,58(2):580-588
A three-component, [3 + 2]-cycloaddition/annulation domino protocol is described for the synthesis in excellent yield of a polycyclic cage-like heterocyclic hybrid (PCHH) that comprises various advantaged structural units viz., α,β-unsaturated ketone moiety, 4-pyridinone and pyrroloisoquinoline in a cage-like framework. The antitumor activity of PCHH on human breast (MCF7), colon (HCT116), cervical (JURKAT) and lung (NCI-H460) malignant cell lines inhibited the propagation of all cell lines. This hybrid molecule displayed increased broad-spectrum anticancer activity with higher doses of PCHH. Furthermore, the compound induced 45.21% of early apoptosis and 46.32% of late apoptosis in the Jurkat cancer cell line. Cell cycle analysis showed that this cage-like compound caused cell cycle arrest of Jurkat cells at the S phase and sub G0/G1 phase. Additionally, it led to increased DNA fragmentation and mitochondrial membrane permeabilization through activation of caspase-3 enzyme. Present investigation demonstrates the specific cytotoxic activity of the cage-like compound and the induction of apoptosis through the intrinsic pathway of Jurkat cells. 相似文献
10.