全文获取类型
收费全文 | 679篇 |
免费 | 20篇 |
国内免费 | 2篇 |
专业分类
化学 | 534篇 |
晶体学 | 17篇 |
力学 | 14篇 |
数学 | 42篇 |
物理学 | 94篇 |
出版年
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 4篇 |
2019年 | 12篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 13篇 |
2014年 | 11篇 |
2013年 | 42篇 |
2012年 | 38篇 |
2011年 | 30篇 |
2010年 | 17篇 |
2009年 | 19篇 |
2008年 | 31篇 |
2007年 | 36篇 |
2006年 | 41篇 |
2005年 | 26篇 |
2004年 | 32篇 |
2003年 | 22篇 |
2002年 | 16篇 |
2001年 | 5篇 |
2000年 | 9篇 |
1998年 | 6篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 10篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 8篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 5篇 |
1985年 | 11篇 |
1984年 | 17篇 |
1983年 | 5篇 |
1982年 | 12篇 |
1981年 | 15篇 |
1980年 | 14篇 |
1979年 | 7篇 |
1978年 | 10篇 |
1977年 | 11篇 |
1976年 | 17篇 |
1975年 | 14篇 |
1974年 | 18篇 |
1973年 | 15篇 |
1968年 | 4篇 |
1929年 | 3篇 |
排序方式: 共有701条查询结果,搜索用时 62 毫秒
1.
Taito Hashimoto Dr. Ryusei Oketani Masaki Nobuoka Prof. Dr. Shu Seki Prof. Dr. Ichiro Hisaki 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(1):e202215836
Porous frameworks composed of non-stoichiometrically mixed multicomponent molecules attract much attention from a functional viewpoint. However, their designed preparation and precise structural characterization remain challenging. Herein, we demonstrate that cocrystallization of tetrakis(4-carboxyphenyl)hexahydropyrene and pyrene derivatives ( CP-Hp and CP-Py , respectively) yields non-stoichiometric mixed frameworks through networking via hydrogen bonding. The composition ratio of CP-Hp and CP-Py in the framework was determined by single crystalline X-ray crystallographic analysis, indicating that the mixed frameworks were formed over a wide range of composition ratios. Furthermore, microscopic Raman spectroscopy on the single crystal indicates that the components are not uniformly distributed such as ideal solid solution, but are done gradationally or inhomogeneously. 相似文献
2.
Takahiro Takayama Toshiki Mochizuki Kenichiro Todoroki Jun Zhe Min Hajime Mizuno Koichi Inoue Hiroyasu Akatsu Ichiro Noge Toshimasa Toyo'oka 《Analytica chimica acta》2015
Chiral metabolites are found in a wide variety of living organisms and some of them are understood to be physiologically active compounds and biomarkers. However, the overall analysis of chiral metabolomics is quite difficult due to the high number of metabolites, the significant diversity in their physicochemical properties, and concentration range from metabolite-to-metabolite. To solve this difficulty, we developed a novel approach for chiral metabolomics fingerprinting and chiral metabolomics extraction, which is based on the labeling of a pair of enantiomers of chiral derivatization reagents (i.e., DMT-(S,R)-Pro-OSu and DMT-3(S,R)-Apy) and precursor ion scan chromatography of the derivatives. The multivariate statistics is also required for this strategy. The proposed procedures were evaluated by the detection of a diagnostic marker (i.e., d-lactic acid) using the saliva of diabetic patients. This method was used for the determination of biomarker candidates of chiral amines and carboxyls in Alzheimer's disease (AD) brain homogenates. As the results, l-phenylalanine (L-Phe) and l-lactic acid (L-LA) were identified as the decreased and increased biomarker candidates in the AD brain, respectively. Therefore, the proposed approach seems to be helpful for the determination of non-target chiral metabolomics possessing amines and carboxyls. 相似文献
3.
Ichiro Hisaki Shoichi Nakagawa Norimitsu Tohnai Mikiji Miyata 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(10):3051-3055
A C3‐symmetric π‐conjugated macrocycle combined with an appropriate hydrogen bonding module (phenylene triangle) allowed the construction of crystalline supramolecular frameworks with a cavity volume of up to 58 %. The frameworks were obtained through non‐interpenetrated stacking of a hexagonal sheet possessing three kinds of pores with different sizes and shapes. The activated porous material absorbed CO2 up to 96 cm3 g−1 at 195 K under 1 atm. 相似文献
4.
Dr. Yoshifumi Sasano Dr. Yohei Haketa Hiroki Tanaka Dr. Nobuhiro Yasuda Prof. Ichiro Hisaki Prof. Hiromitsu Maeda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(27):6712-6717
Phenyl groups were introduced at the β-positions proximal to the meso-hydroxy moiety in hydroxyporphyrin NiII complexes by oxidized BINAP PdII complexes. Ion-pairing assemblies of deprotonated π-electronic anions, anionic site of which was stabilized by the introduced phenyl moieties with a bulky cation, were formed. They showed charge-by-charge assemblies, assembly modes of which were modulated by the anionic building units. 相似文献
5.
Koichiro Shirota Ichirou Yamaguchi Kiyoshi Kanie Tomiki Ikeda Tamejiro Hiyama Ichiro Kobayashi 《Liquid crystals》2013,40(5):555-558
The optical properties of two kinds of photochromic antiferroelectric liquid crystal (AFLC) containing an azo group have been examined. Depending on the substituting group at the chiral centre, these AFLCs showed different photoinduced phase transitions by Ar+ laser light irradiation. This phase transition has led to a new form of optical switching controlled by a bias voltage. In addition, it was found that these AFLCs caused an azimuthal photoalignment effect regulated by linearly polarized Ar+ laser light irradiation. These phenomena were applied to image storage. 相似文献
6.
7.
8.
Masaaki Yoshifuji Katsuhiro Shibayama Ichiro Shima Naoki Inamoto 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-3):11-14
Abstract Some reactions of diphosphenes and the related species involving oxidation, reduction, alkylation, sulfurization, and 6η-coordination are described. 相似文献
9.
10.