全文获取类型
收费全文 | 5905篇 |
免费 | 213篇 |
国内免费 | 52篇 |
专业分类
化学 | 3240篇 |
晶体学 | 55篇 |
力学 | 262篇 |
数学 | 1509篇 |
物理学 | 1104篇 |
出版年
2023年 | 53篇 |
2022年 | 154篇 |
2021年 | 169篇 |
2020年 | 174篇 |
2019年 | 189篇 |
2018年 | 210篇 |
2017年 | 178篇 |
2016年 | 256篇 |
2015年 | 178篇 |
2014年 | 254篇 |
2013年 | 439篇 |
2012年 | 384篇 |
2011年 | 404篇 |
2010年 | 234篇 |
2009年 | 236篇 |
2008年 | 295篇 |
2007年 | 259篇 |
2006年 | 204篇 |
2005年 | 171篇 |
2004年 | 164篇 |
2003年 | 123篇 |
2002年 | 114篇 |
2001年 | 88篇 |
2000年 | 75篇 |
1999年 | 54篇 |
1998年 | 48篇 |
1997年 | 54篇 |
1996年 | 68篇 |
1995年 | 54篇 |
1994年 | 52篇 |
1993年 | 52篇 |
1992年 | 43篇 |
1991年 | 45篇 |
1990年 | 39篇 |
1989年 | 34篇 |
1988年 | 34篇 |
1987年 | 47篇 |
1986年 | 43篇 |
1985年 | 53篇 |
1984年 | 41篇 |
1983年 | 30篇 |
1982年 | 48篇 |
1981年 | 37篇 |
1980年 | 34篇 |
1979年 | 49篇 |
1978年 | 37篇 |
1977年 | 33篇 |
1976年 | 31篇 |
1975年 | 29篇 |
1974年 | 20篇 |
排序方式: 共有6170条查询结果,搜索用时 15 毫秒
991.
Thuy An Trinh Thai Minh Duy Le Hien Thi-Thanh Nguyen Thanh Loc Nguyen Jaeyun Kim Dai Phu Huynh Doo Sung Lee 《Macromolecular bioscience》2023,23(11):2300221
Type 2 Diabetes Mellitus (T2D) is a chronic, obesity-related, and inflammatory disorder characterize by insulin resistance, inadequate insulin secretion, hyperglycemia, and excessive glucagon secretion. Exendin-4 (EX), a clinically established antidiabetic medication that acts as a glucagon-like peptide-1 receptor agonist, is effective in lowering glucose levels and stimulating insulin secretion while significantly reducing hunger. However, the requirement for multiple daily injections due to EX's short half-life is a significant limitation in its clinical application, leading to high treatment costs and patient inconvenience. To address this issue, an injectable hydrogel system is developed that can provide sustained EX release at the injection site, reducing the need for daily injections. In this study, the electrospray technique is examine to form EX@CS nanospheres by electrostatic interaction between cationic chitosan (CS) and negatively charged EX. These nanospheres are uniformly dispersed in a pH-temperature responsive pentablock copolymer, which forms micelles and undergoes sol-to-gel transition at physiological conditions. Following injection, the hydrogel gradually degraded, exhibiting excellent biocompatibility. The EX@CS nanospheres are subsequently released, maintaining therapeutic levels for over 72 h compared to free EX solution. The findings demonstrate that the pH-temperature responsive hydrogel system containing EX@CS nanospheres can be a promising platform for the treatment of T2D. 相似文献
992.
993.
Nguyen Minh Chuong Ha Duy Hung Nguyen Thi Hong 《P-Adic Numbers, Ultrametric Analysis, and Applications》2016,8(1):31-44
In this paper we aim to investigate the boundedness of the p-adic weighted Hardy-Cesàro operators and their commutators on weighted functional spaces of Morrey type. In each case, we obtain the corresponding operator norms. 相似文献
994.
Nguyen Thi Quynh Trang 《Optimization Letters》2016,10(6):1221-1231
In the previous paper (Optim lett 6:749–762, 2012), under some technical assumptions, we proved that the solution mapping of variational inequalities over perturbed polyhedral convex sets is not Lipschitz-like around points at which the positively linear dependence of the active vectors defining the constraint set is valid. This note shows that the result holds without such assumptions. In addition, for more deeply understanding the results on the Lipschitz-like stability, some examples have been presented. 相似文献
995.
Infinite Polyiodide Chains in the Pyrroloperylene–Iodine Complex: Insights into the Starch–Iodine and Perylene–Iodine Complexes
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. Sheri Madhu Hayden A. Evans Dr. Vicky V. T. Doan‐Nguyen Dr. John G. Labram Dr. Guang Wu Prof. Dr. Michael L. Chabinyc Prof. Dr. Ram Seshadri Prof. Dr. Fred Wudl 《Angewandte Chemie (International ed. in English)》2016,55(28):8032-8035
We report the preparation and X‐ray crystallographic characterization of the first crystalline homoatomic polymer chain, which is part of a semiconducting pyrroloperylene–iodine complex. The crystal structure contains infinite polyiodide I∞δ?. Interestingly, the structure of iodine within the insoluble, blue starch–iodine complex has long remained elusive, but has been speculated as having infinite chains of iodine. Close similarities in the low‐wavenumber Raman spectra of the title compound and starch–iodine point to such infinite polyiodide chains in the latter as well. 相似文献
996.
Improvement of the Water Resistance of a Narrow‐Band Red‐Emitting SrLiAl3N4:Eu2+ Phosphor Synthesized under High Isostatic Pressure through Coating with an Organosilica Layer
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. Yi‐Ting Tsai Dr. Hoang‐Duy Nguyen Dr. Agata Lazarowska Dr. Sebastian Mahlik Prof. Dr. Marek Grinberg Prof. Dr. Ru‐Shi Liu 《Angewandte Chemie (International ed. in English)》2016,55(33):9652-9656
A SrLiAl3N4:Eu2+ (SLA) red phosphor prepared through a high‐pressure solid‐state reaction was coated with an organosilica layer with a thickness of 400–600 nm to improve its water resistance. The observed 4f65d→4f7 transition bands are thought to result from the existence of Eu2+ at two different Sr2+ sites. Luminescence spectra at 10 K revealed two zero‐phonon lines at 15377 (for Eu(Sr1)) and 15780 cm?1 (for Eu(Sr2)). The phosphor exhibited stable red emission under high pressure up to 312 kbar. The configurational coordinate diagram gave a theoretical explanation for the Eu2+/3+ result. The coated samples showed excellent moisture resistance while retaining an external quantum efficiency (EQE) of 70 % of their initial EQE after aging for 5 days under harsh conditions. White‐light‐emitting diodes of the SLA red phosphor and a commercial Y3Al5O12:Ce3+ yellow phosphor on a blue InGaN chip showed high color rendition (CRI=89, R9=69) and a low correlated color temperature of 2406 K. 相似文献
997.
Nguyen Viet Dang 《Annales Henri Poincare》2016,17(4):819-859
Let M be a smooth manifold, \({I\subset M}\) a closed embedded submanifold of M and U an open subset of M. In this paper, we find conditions using a geometric notion of scaling for \({t\in \mathcal{D}^{\prime}(U{\setminus} I)}\) to admit an extension in \({\mathcal{D}^\prime(U)}\). We give microlocal conditions on t which allow to control the wave front set of the extension generalizing a previous result of Brunetti–Fredenhagen. Furthermore, we show that there is a subspace of extendible distributions for which the wave front of the extension is minimal which has applications for the renormalization of quantum field theory on curved spacetimes. 相似文献
998.
A system is considered, which is subject to external and possibly fatal shocks, with dependence between the fatality of a shock and the system age. Apart from these shocks, the system suffers from competing soft and sudden failures, where soft failures refer to the reaching of a given threshold for the degradation level, and sudden failures to accidental failures, characterized by a failure rate. A non-fatal shock increases both degradation level and failure rate of a random amount, with possible dependence between the two increments. The system reliability is calculated by four different methods. Conditions under which the system lifetime is New Better than Used are proposed. The influence of various parameters of the shocks environment on the system lifetime is studied. 相似文献
999.
In the paper, we establish necessary and sufficient optimality conditions for quasi-relative efficient solutions of a constrained set-valued optimization problem using the Lagrange multipliers. Many examples are given to show that our results and their applications are more advantageous than some existing ones in the literature. 相似文献
1000.