全文获取类型
收费全文 | 328篇 |
免费 | 13篇 |
国内免费 | 13篇 |
专业分类
化学 | 319篇 |
晶体学 | 1篇 |
数学 | 6篇 |
物理学 | 28篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 2篇 |
2020年 | 10篇 |
2019年 | 11篇 |
2018年 | 18篇 |
2017年 | 14篇 |
2016年 | 11篇 |
2015年 | 4篇 |
2014年 | 8篇 |
2013年 | 85篇 |
2012年 | 11篇 |
2011年 | 11篇 |
2010年 | 13篇 |
2009年 | 24篇 |
2008年 | 26篇 |
2007年 | 31篇 |
2006年 | 11篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2002年 | 10篇 |
2001年 | 12篇 |
2000年 | 7篇 |
1999年 | 10篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有354条查询结果,搜索用时 15 毫秒
101.
102.
Navabeeh Nami Chamazi Majid M. Heravi Bernhard Neumüller Prof. Dr. 《无机化学与普通化学杂志》2007,633(8):1239-1242
Organoalkoxochlorogallanes Me2GaCl was treated with nBuOH and iBuOH in a molar ration of 1:2, respectively. However, only one equivalent of the alcohol reacted with MeGaCl2 to give [MeGa(Cl)OnBu]3 ( 1 ) or [MeGa(Cl)OiBu]3 ( 2 ). 1 and 2 were characterized by NMR and IR techniques as well as by X‐ray structure determinations. According to that 1 and 2 form trimers in solution and the solid state. In solution both isomers Cs and C3v were observed while the trimers exist only as Cs isomers in the solid state which exhibit strongly distorted boat conformations with a disorder of the Cl/Me position at one of the gallium atoms. 相似文献
103.
Na2S/Al2O3 catalyzed the Knoevenagel condensation between an aldehyde and an active methylene compound to yield various trisubstituted alkenes. 相似文献
104.
Chromium trioxide/periodic acid supported onto wet silica gel oxidizes primary alcohols to the corresponding carboxylic acids in very short reaction times in very good yields. 相似文献
105.
Mitra Ghassemzadeh Forough Adhami Abas Taeb Majid M. Heravi Bernhard Neumüller 《无机化学与普通化学杂志》2005,631(9):1568-1570
The reaction of 4‐amino‐6‐methyl‐1,2,4‐triazine‐3‐thione‐5‐one, HAMTTO, with silver (I) nitrate in methanol led under deprotonation to the polymeric compound [(AMTTO)Ag]n. The coordination polymer {[Ag(HAMTTO)]ClO4}n ( 1 ) is synthesized from the reaction of the latter polymeric compound with perchloric acid. Both compounds were characterized by elemental analysis and IR spectroscopy. Single‐crystal X‐ray diffraction studies on compound 1 showed that HAMTTO acts as a bidentate ligand and chelates the silver atom via its hydrazine nitrogen atom and its sulfur atom. Crystal data for 1 at ?90 °C: space group P21, Z = 2, a = 629.3(1), b = 748.7(1), c = 1071.7(1) pm, β = 98.28(1)°, R1 = 0.0533. 相似文献
106.
107.
Majid M. Heravi Dariush Ajami Bagher Mohajerani Mahmood Tajbakhsh Mitra Ghassemzadeh Kourosh Tabar-Hydar 《Monatshefte für Chemie / Chemical Monthly》2001,132(7):881-883
Summary. A new, efficient, and environmentally benign method for the cleavage of semicarbazones has been achieved by a simple reaction
of semicarbazones with clayfen under microwave irradiation.
Received January 4, 2001. Accepted (revised) March 1, 2001 相似文献
108.
Farahnaz K. Behbahani Majid M. Heravi Hossien A. Oskooie 《Monatshefte für Chemie / Chemical Monthly》2009,102(2):181-184
Abstract A mild and efficient method was developed for selective benzylation and methylation of hydroxyl compounds in the presence
of a catalytic amount of ferric perchlorate. We showed that ferric perchlorate was very effective in selectively promoting
the benzylation and methylation of primary aliphatic and benzylic alcohols versus secondary aliphatic alcohols and phenolic
hydroxy groups.
Graphical abstract
相似文献
109.
Majid M. Heravi Sodeh Sadjadi Rahim Hekmatshoar Hossein A. Oskooie Fatemeh F. Bamoharram 《Monatshefte für Chemie / Chemical Monthly》2008,139(2):107-110
Summary. Some N-aminotriazines and -triazoles were treated with Preyssler’s anion as catalyst in acetic acid to afford the corresponding deaminated triazines and triazoles. The reaction is suggested
to proceed via formation of N-nitrosamines with subsequent N–NO bond cleavage. 相似文献
110.
Rahim Hekmatshoar Majid M. Heravi Yahya S. Beheshtiha Karim Asadolah 《Monatshefte für Chemie / Chemical Monthly》2002,133(1):111-114
Summary. Aldoximes can be efficiently and rapidly dehydrated to nitriles by treatment with phthalic anhydride under microwave irradiation.
Received April 18, 2001. Accepted (revised) June 7, 2001 相似文献