全文获取类型
收费全文 | 137篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
化学 | 72篇 |
晶体学 | 2篇 |
力学 | 2篇 |
数学 | 4篇 |
物理学 | 59篇 |
出版年
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 3篇 |
2012年 | 3篇 |
2011年 | 5篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2008年 | 9篇 |
2007年 | 6篇 |
2006年 | 4篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 2篇 |
2001年 | 4篇 |
2000年 | 1篇 |
1999年 | 4篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 11篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 4篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有139条查询结果,搜索用时 15 毫秒
101.
102.
Summary A high-performance liquid chromatographic (HPLC) method has been developed and validated for the determination of FK506, a new immunosuppressant, in bulk drug samples and dosage forms. Equilibration between FK506 (I) and its tautomeric compounds (II and III) was accomplished artificially in water-dehydrated alcohol (11) employed as an extraction solvent. After reaching equilibrium, separation of I, treated as the representetive of equilibrated FK506, from its related substances was achieved by reversed-phase HPLC on a C18 column with water-isopropyl alcohol-tetrahydrofuran (522, v/v) as the mobile phase, and detection at 220 nm. Component I in dosage forms could be recovered satisfactorily and determined with good precision. The calibration graph was linear over the range 2–6 g for I. 相似文献
103.
Matsuoka T Yasuda K Yamamoto K Koda S Nomura H 《Colloids and surfaces. B, Biointerfaces》2007,56(1-2):72-Optics
This review summarized our experimental studies of ultrasonically induced birefringence on aqueous solution of rigid rod-like colloids and rod-like micelles from the view point of dynamics of particle orientation. For rigid rod-like colloids in dilute concentration, the orientational relaxation time was described in terms of the Debye–Einstein equation. This indicated that the ultrasonically induced birefringence could be one of useful tools for determining the size of particles of anisotropic shape. For rod-like micelles, the birefringence showed anomalous damping oscillation when the rod-like micelle was in an entangling state. The mechanism of damping oscillation was discussed using the results of the rheological measurements. 相似文献
104.
Oka K Yamada I Azuma M Takeshita S Satoh KH Koda A Kadono R Takano M Shimakawa Y 《Inorganic chemistry》2008,47(16):7355-7359
The magnetic properties of PbVO 3, a PbTiO 3-type perovskite with a large tetragonal distortion ( c/a = 1.229), were investigated. The temperature dependence of the measured magnetization of multidomain single-crystal samples showed a broad maximum centered around 180 K, indicating a two-dimensional antiferromagnetism. muSR measurement revealed the presence of a long-range order below 43 K. The two-dimensional magnetism is due to the ordering of d xy orbitals, which is thought to also be related to the large tetragonal distortion of PbVO 3. 相似文献
105.
Yosuke Tsuzuki Yuta Oikubo Yoshinari Matsuura Kiyoshi Itatani Seiichiro Koda 《Journal of Sol-Gel Science and Technology》2008,47(2):131-139
We studied the effect of vacuum ultraviolet (vuv) irradiation on siliceous coatings of polycarbonate (PC) substrates derived
by the sol–gel method, with the aim of improving the abrasion resistance of the substrate surface. Methyltriethoxysilane with
colloidal silica was used to prepare the sol solution. The sol solution was spin-coated on PC and this was followed by vuv
irradiation with a Xe excimer lamp at 172 nm under N2 atmosphere. The PC substrate with vuv irradiated coating retained its high transmittance in the visible region for about
3 or more times of scraping turns by a steel wool tester on the surface, compared with the non-irradiated or mercury lamp-irradiated
coatings, which demonstrated the remarkable improvement of the abrasion resistance by the vuv irradiation. The chemical changes
under the vuv irradiation were also investigated by FTIR–ATR spectroscopy, composition analysis conducted with X-ray photoelectron
spectroscopy and hardness measurements. It was concluded that the vuv light irradiation resulted in degrading the Si–CH3 bond in sol–gel derived siliceous coatings to yield hardening of the coatings. The transmittance of the coating in vuv region
also increased with the Xe lamp irradiation. 相似文献
106.
The single‐phase Ba1‐xEuxTiO3 (0.1≤x≤0.4) samples have been synthesized by solid state reaction under high pressure and ‐temperature. X‐ray powder diffraction data was determined by MS Modeling using Reflex Powder Indexing technique. The Ba1‐xEuxTiO3 series exhibited an interesting orthorhombic‐tetragonal‐cubic structural transformation as Eu composition increases, the distinct change of the X‐ray diffraction peak profile in the vicinity of 45.5º is characteristic of structural transformation. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
107.
U. Tanaka K. Masuda Y. Akimoto K. Koda Y. Ibaraki S. Urabe 《Applied physics. B, Lasers and optics》2012,107(4):907-912
We report a surface electrode trap with a relatively large trap depth (0.6–1.0?eV). The trap electrodes are formed by gold plating an alumina substrate. Calcium ions are trapped approximately 400?μm above the trap surface. We demonstrate micromotion compensation based on parametric resonance for surface electrode traps. Unlike the conventional method based on radio-frequency (rf)–photon correlation in which the wave vector of the laser beam must have a component parallel to the micromotion to be detected, the proposed method is independent of the laser propagation direction. This enables the micromotion component normal to the electrode surface to be detected without increasing the scattered light. 相似文献
108.
Bungo Ochiai Kazuhiro Koda Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2012,50(1):47-51
A branched cationic polymer was synthesized by polyaddition of 4‐chloromethyl‐1,3‐dioxolan‐2‐one and diethylenetriamine in molten salts. The polyaddition proceeded through nucleophilic addition of the primary amino group to the cyclic carbonate structure and quarternization of the secondary amino group with the chloromethyl group. The resulting cationic polymer was a good and recyclable catalyst for the reaction of carbon dioxide and epoxides owing to the ammonium structure. The complexation with DNA was confirmed by dynamic light scattering and zeta potential measurements, and it suggests the potential application as a carrier for drug delivery system. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
109.
We have previously reported the development of a far-ultraviolet (FUV) absorbance detector capable of detecting wavelengths down to 175 nm in high-performance liquid chromatography (HPLC). Although the FUV detector can detect substances with weak to non-existent ultraviolet (UV) absorption (e.g., sugars at 185 nm and peptides at 190 nm), a large baseline drift occurs in the gradient elution due to differences in the FUV absorbance properties of water and acetonitrile. To overcome the problem of baseline drift, we have proposed a new baseline correction method using the absorption of water at 1450 nm. It is well known that water has a relatively large absorption peak at 1450 nm in the near-infrared (NIR) region. By contrast, acetonitrile used in reversed-phase HPLC shows negligible absorbance compared to water at 1450 nm. Sugars and peptides also show negligible absorbance at 1450 nm. Thus, it is expected that changes in absorbance at 1450 nm only reflect the volume fraction of water in the gradient elution. The baseline correction method by a linear combination of FUV and NIR chromatograms was applied to the HPLC separation of sugars and peptides in water/acetonitrile-gradient HPLC coupled with FUV detection. The results showed that flat baselines were successfully obtained in the gradient HPLC coupled with FUV detection. 相似文献
110.
The effect of ultrasonic frequency on polymerization of styrene under sonication at 50 degrees C was studied at the frequencies of 23.4, 45.7, 92, 518 kHz and 1 MHz. Polymerization under sonication was carried out at the ultrasonic intensity that gives the same reaction rate of decomposition of porphyrin. The magnitude of the polymerization rate increases in the order of 92, 45.7 and 23.4 kHz. At the high frequencies of 518 kHz and 1 MHz, no polymerization was observed. These facts mean that there is an optimum frequency in the range from 92 to 518 kHz for effective polymerization. The average-number molecular weights at the sonication time of 3 h are 5.5 x 10(4), 8.0 x 10(4) and 11.5 x 10(4) for the irradiated frequencies of 92, 45.7 and 23.4 kHz, respectively. Sonication for 3 h at 92 kHz gives polystyrene with very high polydispersity, about 5.0, in comparison with the results obtained at 23.4 and 45.7 kHz. These observations indicate that polymerization under sonication is influenced by the irradiated frequency. 相似文献