全文获取类型
收费全文 | 79篇 |
免费 | 2篇 |
专业分类
化学 | 78篇 |
物理学 | 3篇 |
出版年
2023年 | 2篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 5篇 |
2012年 | 9篇 |
2011年 | 6篇 |
2009年 | 2篇 |
2008年 | 5篇 |
2007年 | 7篇 |
2006年 | 3篇 |
2005年 | 4篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1977年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有81条查询结果,搜索用时 586 毫秒
21.
Ji‐Ho Yoon Prof. Yun‐Je Lee Jeasung Park Dr. Taro Kawamura Dr. Yoshitaka Yamamoto Dr. Takeshi Komai Dr. Satoshi Takeya Dr. Sang Sup Han Dr. Jong‐Won Lee Prof. Yongjae Lee Prof. 《Chemphyschem》2009,10(2):352-355
Easy come, easy go: Hydroquinone forms a channel structure of cages with hydrogen‐bonded hexagons. These may provide an ideal route for the fast inclusion and facile release of hydrogen molecules (see figure), which can lead to reversible hydrogen storage under mild conditions.
22.
Shiori Ogawa Swarup Chattopadhyay Yuya Tanaka Tatsuhiko Ohto Tomofumi Tada Hirokazu Tada Shintaro Fujii Tomoaki Nishino Munetaka Akita 《Chemical science》2021,12(32):10871
Control of charge carriers that transport through the molecular junctions is essential for thermoelectric materials. In general, the charge carrier depends on the dominant conduction orbitals and is dominantly determined by the terminal anchor groups. The present study discloses the synthesis, physical properties in solution, and single-molecule conductance of paddle-wheel diruthenium complexes 1R having diarylformamidinato supporting ligands (DArF: p-R-C6H4-NCHN-C6H4-R-p) and two axial thioanisylethynyl conducting anchor groups, revealing unique substituent effects with respect to the conduction orbitals. The complexes 1R with a few different aryl substituents (R = OMe, H, Cl, and CF3) were fully characterized by spectroscopic and crystallographic analyses. The single-molecule conductance determined by the scanning tunneling microscope break junction (STM-BJ) technique was in the 10−5 to 10−4G0 region, and the order of conductance was 1OMe > 1CF3 ≫ 1H ∼ 1Cl, which was not consistent with the Hammett substituent constants σ of R. Cyclic voltammetry revealed the narrow HOMO–LUMO gaps of 1R originating from the diruthenium motif, as further supported by the DFT study. The DFT-NEGF analysis of this unique result revealed that the dominant conductance routes changed from HOMO conductance (for 1OMe) to LUMO conductance (for 1CF3). The drastic change in the conductance properties originates from the intrinsic narrow HOMO–LUMO gaps.Dominant conduction orbitals of paddle-wheel organodiruthenium complexes can be facilely controlled by the substituents embedded in the amidinato ligands. 相似文献
23.
Kazuo Matsuyama Takeshi Komai Katsukiyo Ito 《Journal of polymer science. Part A, Polymer chemistry》1986,24(10):2425-2432
T-butylperoxy phenylcarbonate (BPPC) was prepared. Its decomposition rate constant in cumene is given by kd = 2.39 × 1015 exp(?17,300/T), where T is the absolute temperature. When BPPC decomposes to polymerize styrene at 100°C, it produces 12% phenoxy radical to total primary radicals. The phenoxy radical hardly adds to styrene and reacts the other primary radicals and polymer radical. Thus it retards the rate of polymerization. 相似文献
24.
Kimitaka Minami Shiori Goto Mehrnoosh Atashfaraz Takanari Togashi Toshihiko Arita Daisuke Hojo Seiichi Takami Tadafumi Adschiri 《Research on Chemical Intermediates》2011,37(2-5):415-419
This paper reports, for the first time, the enhanced dissolution of cellulose in subcritical water by addition of a fatty acid. Simply adding oleic acid dramatically promoted the dissolution of cellulose. High-pressure in-situ observation showed that cellulose dissolved in high-temperature water at approximately 500 K, which is 70 K lower than without oleic acid. The yield of oligo and monosaccharides with oleic acid at 473 K was seven times higher than without oleic acid. 相似文献
25.
Shiori Tsukagoshi Nobutaka Ototake Yusuke Ohnishi Mayu Shimizu Prof. Dr. Osamu Kitagawa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(21):6845-6850
Herein, we report a unique structural property of 2,4,6‐tri‐tert‐butylanilide, which can be separated into its amide rotamers at room temperature. Interconversion between the rotamers of anilide enolates occurs readily at room temperature and their reaction with electrophiles gives mixtures of the rotamers in a ratio that depends on the reactivity of the corresponding electrophile. That is, the reaction of the 2,4,6‐tri‐tert‐butylacetanilide enolate with reactive electrophiles, such as allyl bromide or protic acids, gives mixtures of the anilide rotamers in which the E rotamer is the major component, whereas less‐reactive electrophiles, such as 1‐bromopropane and 2‐iodopropane, yield mixtures of the rotamers in which the Z rotamer is the major component. The rotameric ratio of the product is also strongly dependent on the reactivity of the anilide enolate. Switching between the anilide rotamers can be achieved through protonation of a less‐reactive enolate by a less‐reactive protic acid and thermal isomerization of the anilide. 相似文献
26.
Kannan Srinivasan Hironaka Kanbe Takuya Ohkura Shin-Ichi Komai Yuichi Kamiya Tadashi Hattori Atsushi Satsuma 《Research on Chemical Intermediates》2008,34(5-7):455-465
A novel approach for the preparation of promoted vanadyl pyrophosphate in well-defined structure was examined. Lamellar vanadyl benzylphosphate (LVBP) was used as a host material and iron acetylacetonate as a guest. It was found that iron acetylacetonate was successfully inserted into the interlayer of LVBP by heating of LVBP and iron acetylacetonate in toluene solution. Calcination of this in tercalated material resulted in a well-crystallized vanadyl pyrophosphate phase with uniform dispersion of Fe in bulk and surface. The obtained Fe-promoted vanadyl pyrophosphate showed an enhancement in the activity for selective oxidation of n-butane, especially at high temperature and long contact time. 相似文献
27.
Assist. Prof. Dr. Shiori Suzuki Prof. Dr. Kenji Takahashi 《Chemical record (New York, N.Y.)》2023,23(8):e202200264
Ionic liquids (ILs) are the only media that can allow the homogeneous organocatalytic reactions of lignocellulosic biomass (lignocellulose), since the designability of their cations and anions offers the dual functions of solubility and catalytic activity. This review provides an account of our recent achievements in the organocatalytic approaches for converting lignocellulose into polymer materials based on the principles of IL design that we have originally established. These methodologies include the simple and mild chemical modification of cellulose and lignin under high conversions, with high selectivity, and/or with efficient atom economy. Similar reactions and subsequent fractionation processes are applied to lignocellulose, and a highly productive reaction system is developed using a twin-screw extruder that is specific to the IL media. 相似文献
28.
Aoki S Matsuo Y Ogura S Ohwada H Hisamatsu Y Moromizato S Shiro M Kitamura M 《Inorganic chemistry》2011,50(3):806-818
29.
Masami Fukushima Mitsuo Yamamoto Takeshi Komai Kanako Yamamoto 《Journal of Analytical and Applied Pyrolysis》2009,86(1):200-206
Pyrolysis-gas chromatography/mass spectrometry using tetramethylammonium hydroxide (TMAH-py-GC/MS) was used to characterize the humic acids (HAs) produced during the composting of conifer bark. The syringyl to guaiacyl ratios of HAs during composting were estimated from the peak area ratios for 3,4,5-trimethoxy to 3,4-dimethoxy benzene derivatives (0.11–0.50), which are characteristic of conifer species. The peak areas for nitrogen-containing and fatty acid pyrolysate compounds increased significantly during composting, indicating the degree of humification during composting. HA samples from the bark composts contained higher levels of diterpene resin acids, monoterpenes and sesquiterpenes. To investigate the species of terpenes, the HA was extracted with ethanol, and the components of the extract classified into α-HA and hymatomelanic acid (HMA) fractions, respectively. The peak areas for terpenes in the α-HA fraction were much smaller than those in the original HA, indicating that the majority of terpenes were extracted into the HMA fraction. If terpenes were to bind to HMA via unspecified interactions, no peaks would be apparent for the direct injection of HMA in ethanol into the GC/MS without pyrolysis. A comparison of the total ion chromatograms of HMA for the TMAH-py-GC/MS and GC/MS revealed that terpenes in the HA had been incorporated into polymeric structures of HMA. These results indicate that terpenes are transferred from the raw bark and incorporated into HA fractions during the composting processes. 相似文献
30.
Masashi Hasegawa Kazuhiro Takahashi Ryota Inoue Shiori Haga Yasuhiro Mazaki 《化学:亚洲杂志》2019,14(10):1647-1650
An efficient cyclization toward a cyclic tetramer of dithienothiophene (DTT) linked by divalent selenium atoms has been developed via palladium‐catalyzed coupling reaction of (nBu3Sn)2Se. X‐ray analysis revealed its highly symmetrical structure had an alternate arrangement of DTT units. There are several Se???π interactions forming a supramolecular network leading to large void channel space. The cyclic tetramer possesses moderate electron‐donating ability. Furthermore, the cyclic tetramer undergoes complexation with C60 in a 1:2 ratio in the solid state to give a highly symmetrical three‐dimensional array of C60. 相似文献