全文获取类型
收费全文 | 401篇 |
免费 | 32篇 |
国内免费 | 6篇 |
专业分类
化学 | 334篇 |
力学 | 5篇 |
数学 | 32篇 |
物理学 | 68篇 |
出版年
2023年 | 6篇 |
2022年 | 16篇 |
2021年 | 16篇 |
2020年 | 30篇 |
2019年 | 33篇 |
2018年 | 33篇 |
2017年 | 30篇 |
2016年 | 38篇 |
2015年 | 23篇 |
2014年 | 30篇 |
2013年 | 47篇 |
2012年 | 20篇 |
2011年 | 19篇 |
2010年 | 15篇 |
2009年 | 9篇 |
2008年 | 20篇 |
2007年 | 17篇 |
2006年 | 9篇 |
2005年 | 3篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2002年 | 6篇 |
2001年 | 2篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有439条查询结果,搜索用时 203 毫秒
91.
Ahmad Shaabani Abbas Rahmati Masoumeh Sharifi Jafar Mogimi Rad Behnaz Aghaaliakbari Elham Farhangi Donald G. Lee 《Monatshefte für Chemie / Chemical Monthly》2007,138(7):649-651
Summary. The oxidation of arenes and sulfides by potassium permanganate was accomplished in good yields under solvent free and heterogeneous
conditions when manganese(II) sulfate is used as a solid support. After extraction of the organic products, the inorganic
products can be reoxidized to permanganate. This result is important because it provides an approach to oxidation reactions
that is, in theory, infinitely sustainable. 相似文献
92.
93.
Hossein F. Dastjerdi Manijeh Nematpour Elham Rezaee Mehdi Jahani Sayyed A. Tabatabai 《中国化学会会志》2019,66(11):1537-1541
A one‐pot synthesis of functionalized benzo thiazine derivatives via a Cu‐catalyzed, multicomponent reaction of isocyanides, aniline, and heterocumulenes in acetonitrile at room temperature was developed. Transition metal‐catalyzed activation of C‐H bonds under mild copper‐catalytic reaction conditions, using simple and available starting materials, also obtaining a pure product with high yield without applying column chromatography are the major advantages of the applied method among the other ones used for this purpose. The structures are confirmed spectroscopically (1H‐ and 13C‐NMR, IR, and EI‐MS) and through elemental analyses. 相似文献
94.
Heck and oxidative boron Heck reactions employing Pd(II) supported amphiphilized polyethyleneimine‐functionalized MCM‐41 (MCM‐41@aPEI‐Pd) as an efficient and recyclable nanocatalyst
下载免费PDF全文
![点击此处可从《应用有机金属化学》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Fatemeh Ashori Alireza Samzadeh‐Kermani Hosein Hamadi Mohammad Reza Ganjali Hamideh Aghahosseini Ali Ramazani Mehdi Khoobi Elham Gholibegloo 《应用有机金属化学》2018,32(3)
A novel nanocatalyst was developed based on covalent surface functionalization of MCM‐41 with polyethyleneimine (PEI) using [3‐(2,3‐Epoxypropoxy)propyl] trimethoxysilane (EPO) as a cross‐linker. Amine functional groups on the surface of MCM‐41 were then conjugated with iodododecane to render an amphiphilic property to the catalyst. Palladium (II) was finally immobilized onto the MCM‐41@PEI‐dodecane and the resulted MCM‐41@aPEI‐Pd nanocatalyst was characterized by FT‐IR, TEM, ICP‐AES and XPS. Our designed nanocatalyst with a distinguished core‐shell structure and Pd2+ ions as catalytic centers was explored as an efficient and recyclable catalyst for Heck and oxidative boron Heck coupling reactions. In Heck coupling reaction, the catalytic activity of MCM‐41@aPEI‐Pd in the presence of triethylamine as base led to very high yields and selectivity. Meanwhile, the MCM‐41@aPEI‐Pd as the first semi‐heterogeneous palladium catalyst was examined in the C‐4 regioselective arylation of coumarin via the direct C‐H activation and the moderate to excellent yields were obtained toward different functional groups. Leaching test indicated the high stability of palladium on the surface of MCM‐41@aPEI‐Pd as it could be recycled for several runs without significant loss of its catalytic activity. 相似文献
95.
96.
97.
Foad Kazemi Ali Reza Kiasat Elham Fadavipoor 《Phosphorus, sulfur, and silicon and the related elements》2013,188(2):433-436
A simple convenient procedure for dehydration of aldoximes has been developed using silica gel/thionyl chloride in heterogeneous conditions. The method has been found to be effective for a wide range of aromatic oximes. 相似文献
98.
Hosseinirad Elham Hormozi Faramarz 《Journal of Thermal Analysis and Calorimetry》2019,135(3):1849-1861
Journal of Thermal Analysis and Calorimetry - In the present work, different passive methods have been numerically investigated to improve the thermal performance in a miniature channel. The heat... 相似文献
99.
100.
Ahmad Shaabani Abbas Rahmati Elham Farhangi Ali Hossein Rezayan 《Monatshefte für Chemie / Chemical Monthly》2007,35(1):615-618
A novel class of 3,4-dihydrobenzimidazo[2,1-b]quinazolin-1(2H)-ones was synthesized in very short reaction times with good yields in the presence of 3-butyl-1-methyl imidazolium bromide
as a room temperature ionic liquid at 120°C. The ionic liquid can be recycled for subsequent reactions without any loss of
efficiency. 相似文献