全文获取类型
收费全文 | 374篇 |
免费 | 21篇 |
国内免费 | 75篇 |
专业分类
化学 | 452篇 |
晶体学 | 6篇 |
综合类 | 2篇 |
物理学 | 10篇 |
出版年
2024年 | 2篇 |
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 15篇 |
2020年 | 16篇 |
2019年 | 15篇 |
2018年 | 11篇 |
2017年 | 17篇 |
2016年 | 20篇 |
2015年 | 15篇 |
2014年 | 22篇 |
2013年 | 48篇 |
2012年 | 39篇 |
2011年 | 19篇 |
2010年 | 16篇 |
2009年 | 22篇 |
2008年 | 27篇 |
2007年 | 23篇 |
2006年 | 14篇 |
2005年 | 19篇 |
2004年 | 16篇 |
2003年 | 14篇 |
2002年 | 24篇 |
2001年 | 9篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 7篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有470条查询结果,搜索用时 31 毫秒
461.
A novel dinuclear copper(Ⅱ) complex [CuL(NO3)]2·2MeOH was obtained by the coordination reaction of Cu(NO3)2·3H2O with ligand HL (HL=N-(methyl-2-benzimidazol- methylidene)-2-hydroxyaniline). The single-crystal X-ray analysis has revealed that the complex crystallizes in triclinic, space group P with a=9.535(3), b=10.009(3), c=10.666(4) , α=104.303(4), β=100.105(4), γ=115.917(4)o, V=839.0(5) 3, C16H16CuN4O5, Mr=407.87, Z=2, Dc=1.614 g/cm3, F(000)=418, μ=1.338 mm-1, R=0.0543 and wR=0.0980. The basic dinuclear copper(Ⅱ) complex units [CuL(NO3)]2 are formed by NO3- as co-bridging ligands and L as NNO tridentate chelate coordinating to the copper ions. The ladder-like one-dimensional chain motifs are formed by O…H-O and O…H-N hydrogen bonds from methanol molecules connecting the dinuclear copper(Ⅱ) units. 相似文献
462.
The title compound 4-oxo-1,2,4-triazino[4,5-a]benzimidazole(C9H6N4O,Mr = 186.18) has been synthesized and structurally characterized by IR,NMR and single-crystal X-ray diffraction. The crystal belongs to monoclinic,space group P21/c,with a = 9.1530(18) ,b = 7.2260(14),c = 12.604(3) ,β = 106.92(3) ,V = 797.5(3) 3,Z = 4,Dc = 1.551 g/cm3,λ(MoKa) = 0.71073,F(000) = 384,μ(MoKa) = 0.109 mm-1,the final R = 0.0632 and wR = 0.1095. A total of 1444 unique reflections were collected,of which 767 with I > 2σ(I) were observed. The structure of the title compound is planar. In packing,the molecules are intersected to each other to form chains along three dimensions,together by intermolecular N-H…O and C-H…N hydrogen bonds. The whole structure is further stabilized by π…π interaction between two adjacent tricyclic ring systems,with the centroid-to-centroid distance of 3.369(4) . 相似文献
463.
464.
465.
466.
467.
468.
《Mendeleev Communications》2023,33(3):306-310
New small molecule photovoltaic materials containing benzimidazole fragment were prepared by cross-coupling of the corresponding 1-bromo-4-(imidazol-2-yl)benzenes with multiborylated/stannylated polycyclic (het)arenes. Energies of HOMO/LUMO levels were calculated from cyclic voltammetry and UV/VIS spectroscopy data and are within the ranges –5.27... –5.73 and –2.33...–2.89 eV, respectively. Solar cells based on three different perovskites as light absorbing layers and compound SM7 as electron transporting material demonstrated power conversion efficiency values up to 10.78% without doping additives or perovskite engineering. 相似文献
469.
470.