全文获取类型
收费全文 | 141篇 |
免费 | 1篇 |
专业分类
化学 | 123篇 |
力学 | 2篇 |
物理学 | 17篇 |
出版年
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 4篇 |
2019年 | 8篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 6篇 |
2012年 | 9篇 |
2011年 | 8篇 |
2010年 | 4篇 |
2009年 | 2篇 |
2008年 | 8篇 |
2007年 | 12篇 |
2006年 | 6篇 |
2005年 | 12篇 |
2004年 | 12篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 1篇 |
2000年 | 8篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1996年 | 3篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有142条查询结果,搜索用时 31 毫秒
1.
Katoh Katsumi Fukui Satomi Haba Ayane Higashi Eiko Saburi Tei Okada Ken 《Journal of Thermal Analysis and Calorimetry》2022,147(13):7563-7571
Journal of Thermal Analysis and Calorimetry - Nitrocellulose (NC) is prone to spontaneous decomposition with exothermic heat release and thus is generally evaluated for stability during the storage... 相似文献
2.
We have studied the algorithm for the automatic chromatic dispersion compensation using bit error rate (BER) and Q-factor optimization for realization of dynamically reconfigurable all-optical network. We have made sure good performance using the compensation system by laboratory experiments. 相似文献
3.
Kameo S Nakai K Kurokawa N Kanehisa T Naganuma A Satoh H 《Analytical and bioanalytical chemistry》2005,381(8):1514-1519
Mercury vapor is effectively absorbed via inhalation and easily passes through the blood–brain barrier; therefore, mercury poisoning with primarily central nervous system symptoms occurs. Metallothionein (MT) is a cysteine-rich metal-binding protein and plays a protective role in heavy-metal poisoning and it is associated with the metabolism of trace elements. Two MT isoforms, MT-I and MT-II, are expressed coordinately in all mammalian tissues, whereas MT-III is a brain-specific member of the MT family. MT-III binds zinc and copper physiologically and is seemed to have important neurophysiological and neuromodulatory functions. The MT functions and metal components of MTs in the brain after mercury vapor exposure are of much interest; however, until now they have not been fully examined. In this study, the influences of the lack of MT-I and MT-II on mercury accumulation in the brain and the changes of zinc and copper concentrations and metal components of MTs were examined after mercury vapor exposure by using MT-I, II null mice and 129/Sv (wild-type) mice as experimental animals. MT-I, II null mice and wild-type mice were exposed to mercury vapor or an air stream for 2 h and were killed 24 h later. The brain was dissected into the cerebral cortex, the cerebellum, and the hippocampus. The concentrations of mercury in each brain section were determined by cold vapor atomic absorption spectrometry. The concentrations of mercury, copper, and zinc in each brain section were determined by inductively coupled plasma mass spectrometry (ICP-MS). The mercury accumulated in brains after mercury vapor exposure for MT-I, II null mice and wild-type mice. The mercury levels of MT-I, II null mice in each brain section were significantly higher than those of wild-type mice after mercury vapor exposure. A significant change of zinc concentrations with the following mercury vapor exposure for MT-I, II null mice was observed only in the cerebellum analyzed by two-way analysis of variance. As for zinc, the copper concentrations only changed significantly in the cerebellum. Metal components of metal-binding proteins of soluble fractions in the brain sections were analyzed by size-exclusion high-performance liquid chromatography (HPLC) connected with ICP-MS. From the results of HPLC/ICP-MS analyses, it was concluded that the mercury components of MT-III and high molecular weight metal-binding proteins in the cerebellum of MT-I, II null mice were much higher than those of wild-type mice. It was suggested that MT-III is associated with the storage of mercury in conditions lacking MT-I, and MT-II. It was also suggested that the physiological role of MT-III and some kind of high molecular weight proteins might be impaired by exposure to mercury vapor and lack of MT-I and MT-II. 相似文献
4.
5.
5-(2-Oxazolynyl)cyclopentadiene was designed on the basis of the orbital mixing rule to react with dienophiles with highly contrasteric manner in Diels-Alder reactions. The design was validated by the synthesis and reactions of the corresponding pentamethyl derivative, 5-(2-oxazolynyl)-1,2,3,4,5-pentamethylcyclopentadiene, to afford the products with the ratios of syn/anti=89-93/11-7. 相似文献
6.
The liquid-liquid extraction of copper(I) with 12-, 13-, 15- and 16-membered cyclic tetrathio ethers ([n]aneS4, where n represents the total number of carbon and sulphur atoms in the cyclic ligand ring) was examined stoichiometrically using picrate ion (Pic?) for the formation of the ion pair. Copper(I) was extracted with four ligands (L) into 1,2-dichloroethane as the ion-pair compound, [Cu(I)L]+Pic?. The extraction constant, Kex, with each ligand was determined. As the ring size of cyclic tetrathio ethers increases, the log Kex values, including that previously reported for [14]aneS4, increase from 7.7 to 9.4. The value of Δ log Kex, which represents the increase in log Kex due to the addition of one carbon atom to the macrocyclic ring, was large between [13]aneS4 and [14]aneS4 (Δ log Kex=1.0) and small between [14]aneS4 and [15]aneS4 (Δ log Kex=0.1). 相似文献
7.
Hirota J Satomi Y Yoshikawa K Takao T 《Rapid communications in mass spectrometry : RCM》2003,17(5):371-376
Epsilon -N,N,N-trimethyllysine (K(me3)) is a component of a number of proteins and plays an important role in the expression of their biological functions. Trimethylation, which causes an incremental increase in mass of 42.0470 Da from that of the corresponding MH(+) ion, cannot be distinguished from the acetylation (+42.0106 Da), which also occurs on epsilon-amino groups of Lys or alpha-amino groups in many proteins, without high-accuracy mass measurement which is accurate to within the second decimal place. MALDI-MS and MS/MS have been applied for the analyses of post-translational modifications of histone H3, which is known to contain both multiple acetylation and methylation sites in its sequence. During the measurements of the modified peptides, a novel fragmentation which involves the loss of trimethylamine from K(me3) was found. This characteristic fragmentation, which was observed to produce ions separated by 59 Da from the conventional precursor ion or sequence ions, would be useful for probing K(me3) units in the sequence. 相似文献
8.
S. Iwama N. Satomi M. Yamanaka S. Goto T. Ishimura H. Ito 《International Journal of Infrared and Millimeter Waves》1981,2(6):1199-1208
A high-power CW 27.972 m water vapor laser has been constructed in order to use as a light source of an interferometer for plasma diagnostics. The laser consists of 220 cm length and 2.0 cm small bore Pyrex glass discharge tube, semi-confocal resonator and Michelson coupler. From the measurement of cavity detuning curves, it is found that two waveguide modes, EH11 and EH21 oscillate. The increase of the output power is found to become more than seven times larger by adding He(50%)–H2(50%) mixed gas. Under the optimum condition, the maximum output power of 65 mW or the output power per unit cavity volume of 83 W/cm3 is obtained. 相似文献
9.
Hiroshi Hata Dr. Shigeru Yamaguchi Goro Mori Satomi Nakazono Taisuke Katoh Keishi Takatsu Satoru Hiroto Hiroshi Shinokubo Prof. Dr. Atsuhiro Osuka Prof. Dr. 《化学:亚洲杂志》2007,2(7):849-859
Highly regioselective and efficient borylation of a variety of porphyrins has been achieved by reaction with bis(pinacolato)diboron through C? H bond activation under iridium catalysis on the basis of the synthetic protocol developed by Miyaura, Hartwig, and Smith. A boryl group can be selectively introduced at sterically uncongested positions in the peripheral aryl groups of porphyrin substrates whose peripheral β‐positions are sterically hindered. Curiously, β substituents adjacent to the aryl group to be borylated have unexpectedly large effects on the regioselectivity, because the iridium catalyst can discriminate between subtle steric differences. Chemoselective borylation was also achieved for several functionalized porphyrins. This borylation protocol can be applied to various monomeric and oligomeric functional porphyrins, hence offering an efficient route to elaborate multiporphyrin‐based molecular constructs. 相似文献
10.
Xiaoxue Ye Satomi Mori Zhongqi Xu Shinjiro Hayakawa Takeshi Hirokawa 《Electrophoresis》2013,34(22-23):3155-3162
The phenomenon of peak area decrease due to high injection voltage (Vinj, e.g. 10–30 kV, 200–600 V/cm in the 50 cm capillary) was found in the analysis of very dilute DNA fragments (<0.2 mg/L) by using high‐sensitive electrokinetic supercharging‐CGE. The possibility of DNA cleavage in aqueous solution was suggested, in addition to the aggregation phenomenon that is already known. The analysis of intentionally voltage‐affected fragments (at 200 V/cm) also showed decreased peak areas depending on the time of the voltage being applied. Computer simulation suggested that a high electric field (a few kV/cm or more) could be generated partly between the electrode and the capillary end during electrokinetic injection (EKI) process. After thorough experimental verification, it was found that the factors affecting the damage during EKI were the magnitude of electric field, the distance between tips of electrode and capillary (De/c), sample concentration and traveling time during EKI in sample vials. Furthermore, these factors are correlating with each other. A low conductivity of diluted sample would cause a high electric field (over a few hundred volts per centimeter), while the longer De/c results in a longer traveling time during EKI, which may cause a larger degree of damage (aggregation and cleavage) on the DNA fragments. As an important practical implication of this study, when the dilute DNA fragments (sub mg/L) are to be analyzed by CGE using EKI, injection voltage should be kept as low as possible. 相似文献