全文获取类型
收费全文 | 146篇 |
免费 | 1篇 |
专业分类
化学 | 96篇 |
晶体学 | 1篇 |
力学 | 3篇 |
数学 | 7篇 |
物理学 | 40篇 |
出版年
2023年 | 1篇 |
2019年 | 1篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 13篇 |
2012年 | 10篇 |
2011年 | 4篇 |
2010年 | 7篇 |
2009年 | 10篇 |
2008年 | 6篇 |
2007年 | 8篇 |
2006年 | 8篇 |
2005年 | 10篇 |
2004年 | 12篇 |
2003年 | 8篇 |
2002年 | 7篇 |
2001年 | 6篇 |
2000年 | 1篇 |
1992年 | 2篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1978年 | 2篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1968年 | 3篇 |
1967年 | 2篇 |
1932年 | 2篇 |
排序方式: 共有147条查询结果,搜索用时 15 毫秒
131.
The structure and stability of hydrogen bonds in alpha-chitin were investigated by (13)C solid-state NMR measurements at different temperatures. Splitting of the carbonyl carbon signal for alpha-chitin was interpreted as two types of hydrogen bonding; the peaks at 173.5 and 175.8 ppm were assigned, respectively, to a carbonyl carbon hydrogen bonded exclusively to the NH group and a carbonyl carbon hydrogen-bonded to both NH and C(6)-OH groups. Approximately 60% of carbonyl groups exclusively contributed to the intermolecular hydrogen bonding and ca. 40% of them to the combination of intermolecular and intramolecular hydrogen bonding. Internal rotation around the C(5)-C(6) bond was detected at 55 degrees C. 相似文献
132.
Hasegawa M Aliu E Andringa S Aoki S Argyriades J Asakura K Ashie R Berns H Bhang H Blondel A Borghi S Bouchez J Burguet-Castell J Casper D Cavata C Cervera A Chen SM Cho KO Choi JH Dore U Espinal X Fechner M Fernandez E Fukuda Y Gomez-Cadenas J Gran R Hara T Hasegawa T Hayashi K Hayato Y Helmer RL Hill J Hiraide K Hosaka J Ichikawa AK Iinuma M Ikeda A Inagaki T Ishida T Ishihara K Ishii T Ishitsuka M Itow Y Iwashita T Jang HI Jeon EJ Jeong IS Joo KK Jover G Jung CK Kajita T Kameda J Kaneyuki K 《Physical review letters》2005,95(25):252301
We report the result from a search for charged-current coherent pion production induced by muon neutrinos with a mean energy of 1.3 GeV. The data are collected with a fully active scintillator detector in the K2K long-baseline neutrino oscillation experiment. No evidence for coherent pion production is observed, and an upper limit of is set on the cross section ratio of coherent pion production to the total charged-current interaction at 90% confidence level. This is the first experimental limit for coherent charged pion production in the energy region of a few GeV. 相似文献
133.
The measurement is based on monitoring dissolved oxgyen consumed by the two sequential reactions catalyzed by the enzymes immobilized in photo-cross-linkable poly (vinyl alcohol) resin (PVA-SbQ). A linear correlation was observed between current decrease and 0.3–2.6 mM oleic or palmitic acid. The sensor was stable in use for three days and could be used to monitor the freshness of oily food. 相似文献
134.
135.
136.
Carrington A Manzano F Prozorov R Giannetta RW Kameda N Tamegai T 《Physical review letters》2001,86(6):1074-1077
Tunneling and theoretical studies have suggested that Andreev bound states form at certain surfaces of unconventional superconductors. Through studies of the temperature and field dependence of the in-plane magnetic penetration depth lambda(ab) at low temperature, we have found strong evidence for the presence of these states in clean single crystal YBCO and BSCCO. Crystals cut to expose (110) surfaces show a strong upturn in lambda(ab) at around 7 K, when the field is oriented along the c axis. In YBCO this upturn is completely suppressed by a field of approximately 0.1 T. 相似文献
137.
D. Kameda H. Ueno K. Asahi D. Nagae M. Takemura K. Shimada A. Yoshimi T. Nagatomo T. Sugimoto M. Uchida T. Arai K. Takase S. Suda T. Inoue J. Murata H. Kawamura H. Watanabe Y. Kobayashi M. Ishihara 《Hyperfine Interactions》2007,180(1-3):61-64
The electric quadrupole moments for the ground states of 32Al and 31Al have been measured by the β ray-detected nuclear quadrupole resonance method. Spin-polarized 32Al and 31Al nuclei were obtained from the fragmentation of 40Ar projectiles at E/A?=?95 MeV/nucleon, and were implanted in a single crystal α-Al2O3 stopper. The measured Q moment of 32Al, |Q(32Al)|?=?24(2) mb, is in good agreement with a conventional shell-model calculation with a full sd model space and empirical effective charges, while that of 31Al is considerably smaller than the sd calculations. 相似文献
138.
Jong Hwa Jung Jeong Ah Rim Soo Jin Lee Naohiro Kameda Toshimi Shimizu 《Tetrahedron》2007,63(31):7449-7456
Asymmetric bolaamphiphilic sugar-based hydrogelators (1-3) were synthesized and their gelation ability with and without alkylammonium ions was investigated by CD, TEM, FTIR and NMR. These compounds acted as versatile gelators for organic solvents and water. The xerogels 1-3 obtained from water showed well-developed structures of fibrils with diameters of 10-38 nm and length of several hundred micrometers. Particularly, the gelation ability of crown-appended gelator 1 was drastically enhanced by addition of alkylammonium ions 4 and 5, suggesting that the bridging effect of alkyldiammonium ions could be the primary driving-force for the stabilization due to the intermolecular hydrogen bonding and electrostatic interactions. The present result is a rare case of a hydrogel being stabilized by a host-guest interaction. In addition, the hydrogel 1 with AgNO3 and KClO4 induced the formation of nanotubular and vesicular structures of silica by sol-gel polymerization of TEOS, respectively. These results indicate that hydrogel 1 acted as a template to produce inorganic nanomaterials. 相似文献
139.
Takayuki Kameda Ayuko Akiyama Akira Toriba Ning Tang Kazuichi Hayakawa 《International journal of environmental analytical chemistry》2013,93(13):976-987
A correction method for the determination of atmospheric monohydroxylated derivatives of 1-nitropyrene (hydroxy-1-nitropyrenes, OHNPs) based on their degradation rates during high volume air sampling was established. OHNPs adsorbed directly on a quartz fibre filter (QFF) or on airborne particles collected on a QFF were exposed to ambient air passively or actively in a high volume air sampling system. The influence of ozone flux and exposure time on the degree of degradation of OHNPs was investigated. Up to 50% of OHNPs degraded over 1 h of exposure to ambient air containing ~60 ppbv of ozone in the active system. The degradation rate constants of OHNPs were found to correlate with the number of ozone molecules passing through the QFF in a unit time (NO3) during high volume air sampling. The chemical loss of OHNPs under high volume air sampling conditions was successfully evaluated by the exposure time and the pseudo-first-order rate constant for OHNP degradation estimated from the correlation with NO3. Concentrations of 3-, 6-, and 8-hydroxy-1-nitropyrenes in airborne particles collected in Osaka, Japan were determined using the established correction method. 相似文献
140.
Dr. Atsushi Hirano Dr. Takeshi Tanaka Dr. Hiromichi Kataura Dr. Tomoshi Kameda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(17):4922-4930
Charged peptides and proteins disperse single‐wall carbon nanotubes (SWCNTs) in aqueous solutions. However, little is known about the role of their side chains in their interactions with SWCNTs. Homopolypeptide–SWCNT systems are ideal for investigating the mechanisms of such interactions. In this study, we demonstrate that SWCNTs are individually dispersed by poly‐L ‐arginine (PLA). The debundled SWCNTs exhibited a distinct fluorescence. The dispersibility of SWCNTs with PLA was greater than that of SWCNTs with poly‐L ‐lysine (PLL). Molecular dynamics simulations suggest that the side chains of PLA have stronger interactions with the sidewalls of SWCNTs compared with those of PLL. The guanidinium group at the end of the side chain of an arginine residue plays an important role in the interaction with SWCNTs, likely through hydrophobic, van der Waals, and π–π interactions. PLA can be useful as a tool for the dispersion of SWCNTs and can be used to non‐covalently anchor materials to SWCNTs with strong binding. 相似文献