全文获取类型
收费全文 | 440篇 |
免费 | 18篇 |
专业分类
化学 | 383篇 |
晶体学 | 2篇 |
力学 | 2篇 |
数学 | 6篇 |
物理学 | 65篇 |
出版年
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 9篇 |
2019年 | 8篇 |
2018年 | 4篇 |
2016年 | 6篇 |
2015年 | 11篇 |
2014年 | 10篇 |
2013年 | 15篇 |
2012年 | 18篇 |
2011年 | 30篇 |
2010年 | 11篇 |
2009年 | 17篇 |
2008年 | 20篇 |
2007年 | 13篇 |
2006年 | 28篇 |
2005年 | 15篇 |
2004年 | 12篇 |
2003年 | 11篇 |
2002年 | 12篇 |
2001年 | 9篇 |
2000年 | 12篇 |
1999年 | 8篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1994年 | 6篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1990年 | 8篇 |
1989年 | 4篇 |
1988年 | 9篇 |
1987年 | 12篇 |
1986年 | 6篇 |
1985年 | 16篇 |
1984年 | 11篇 |
1983年 | 6篇 |
1982年 | 8篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1975年 | 3篇 |
1968年 | 2篇 |
1967年 | 3篇 |
1966年 | 5篇 |
1929年 | 2篇 |
1927年 | 2篇 |
排序方式: 共有458条查询结果,搜索用时 46 毫秒
451.
Tada M Ishiguro N Uruga T Tanida H Terada Y Nagamatsu S Iwasawa Y Ohkoshi S 《Physical chemistry chemical physics : PCCP》2011,13(33):14910-14913
μ-XAFS analysis using an X-ray μ-beam (1000 nm (h) × 800 nm (v)) was successfully carried out on a single particle of a practical catalyst NiO(x)/Ce(2)Zr(2)O(y) (0 ≤x≤ 1, 7 ≤y≤ 8). The oxidation state and local coordination structure of the NiO(x)/Ce(2)Zr(2)O(y) particle were characterized by Ni K-edge μ-XANES and μ-EXAFS, which showed the catalytically active and inactive phases of a single catalyst particle. 相似文献
452.
Yasuo Yoshihashi Masaki Sato Yuto Kawano Etsuo Yonemochi Katsuhide Terada 《Journal of Thermal Analysis and Calorimetry》2013,113(3):1281-1285
Magnesium Stearate (MgSt) is a widely used lubricant for preventing tablet compression trouble. It is known that the powder characteristic of MgSt is different among MgSts manufactured by different methods and conditions. These differences affect blending efficiency with pharmaceutical additives. The purpose of this study is to evaluate the physicochemical properties of MgSt by thermal effusivity sensor for in-process monitoring of powder blending. MgSts having different physicochemical properties and granulated sugar spheres were used for model excipients. V-blender was used for powder blending. Thermal effusivity values of each of the ingredients in the blend were measured using one of the sensors prior to placing the ingredient in the blender. The effect of magnesium stearate addition to uniform ingredients can be clearly identified using the sensors. Compared to effusivity data and powder density, effusivity data correlated with the powder characteristics of magnesium stearate. These results suggested that effusivity can be used for end point detection of blending process for various magnesium stearates with sugar sphere. When various magnesium stearates were added to the granule, required time for achieving homogeneous powder blend was different. Blending behavior would be affected by the physicochemical characters. Blend uniformity and blended states of granules containing magnesium stearate can be detected nondestructively without intricate sampling process. Thermal effusivity sensors are an efficient tool to monitor the real time blending behavior of pharmaceutical ingredients. 相似文献
453.
Tomoda K Terashima H Suzuki K Inagi T Terada H Makino K 《Colloids and surfaces. B, Biointerfaces》2011,88(2):706-710
Nanoparticles effectively deliver therapeutic agent by penetrating into the skin. Indomethacin (IM) and coumarin-6 were loaded in PLGA nanoparticles with an average diameter of 100 nm. IM and coumarin-6 were chosen as a model drug and as a fluorescent marker, respectively. The surfaces of the nanoparticles were negatively charged. Permeability of IM-loaded PLGA nanoparticles through rat skin was studied. Higher amount of IM was delivered through skin when IM was loaded in nanoparticles than IM was free molecules. Also, iontophoresis was applied to enhance the permeability of nanoparticles. When iontophoresis with 3 V/cm was applied, permeability of IM was much higher than that obtained by simple diffusion of nanoparticles through skin. The combination of charged nanoparticle system with iontophoresis is useful for effective transdermal delivery of therapeutic agents. 相似文献
454.
Komatsu T Terada H Kobayashi N 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(6):1849-1854
This report describes the synthesis and enzyme activities of multilayered protein nanotubes with an α-glucosidase (αGluD) interior surface. The nanotubes were prepared by using an alternating layer-by-layer (LbL) assembly of human serum albumin (HSA) and oppositely charged poly-L-arginine (PLA) into a track-etched polycarbonate (PC) membrane (pore size=400 nm) followed by addition of αGluD as the last layer of the wall. Subsequent dissolution of the PC template yielded (PLA/HSA)(2)PLA/αGluD nanotubes. SEM measurements revealed the formation of uniform hollow cylinders with (413±17) nm outer diameter and (52±3) nm wall thickness. In aqueous media, the nanotubes captured a fluorogenic glucopyranoside, 4-methyl-umbelliferyl-α-D-glucopyranoside (MUGlc), into their one-dimensional pore space and hydrolyzed the substrate efficiently to form α-D-glucose. We determined the enzyme parameters (Michaelis constant, K(M), and catalytic constant, k(cat), values) of the protein nanotubes. The several-micrometers-long cylinders were of sufficient length to be spun down by centrifugation at 4000 g, so the product could therefore be easily separated. Similar biocatalysts were prepared by complexation of biotinylated-αGluD into HSA-based nanotubes bearing a single avidin layer as an internal surface. The obtained hybrid nanotubes also exhibited the same enzyme activity for the MUGlc hydrolysis. 相似文献
455.
Terada Y Tamada D Kose K 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2011,212(2):355-361
A temperature variable magnetic resonance imaging (MRI) system has been developed using a 1.0 T permanent magnet. A permanent magnet, gradient coils, radiofrequency coil, and shim coil were installed in a temperature variable thermostatic bath. First, the variation in the magnetic field inhomogeneity with temperature was measured. The inhomogeneity has a specific spatial symmetry, which scales linearly with temperature, and a single-channel shim coil was designed to compensate for the inhomogeneity. The inhomogeneity was drastically reduced by shimming over a wide range of temperature from −5 °C to 45 °C. MR images of an okra pod acquired at different temperatures demonstrated the high potential of the system for visualizing thermally sensitive properties. 相似文献
456.
T. Yamamoto K. Tanaka A. Yamanaka T. Okuda K. Obara K. Tokiwa T. Watanabe A. Iyo Y. Tanaka A. Sundaresan N. Terada 《Physica C: Superconductivity and its Applications》2010
Artificially stacked structures of [(infinite layer CaCuO2)k/(superconducting (Cu, C)Ba2CuOx:(Cu, C)-1201)l]m were fabricated on SrCuO2 buffer layer by means of sequential deposition of each block using pulsed laser deposition. Smooth and epitaxial growth all over the deposition cycles of (Cu, C)-1201 and CaCuO2 were confirmed by streak patterns of in situ RHEED. In comparison with (Cu, C)-1201 single layer films, the artificial stacking resulted in a rise of superconducting properties, Tc-onset and Tc(ρ=0) up to 95 K and 65 K, respectively. 相似文献
457.
458.
Yasuhiko Terada Satomi Hirano Takayuki Ikehara Toshio Nishi 《Macromolecular Symposia》2001,175(1):209-214
The morphology and formation process of interpenetrated spherulites of poly(butylene succinate)/poly(vinylidene choloride‐co‐vinyl chloride) (PBSU/PVDCVC) blends were investigated by confocal laser scanning microscopy (CLSM). CLSM images showed that the dense fibrils of PBSU spherulites penetrated into the sparse PVDCVC spherulites. For a blend with PBSU content 50% and crystallization temperature Tc = 368 K, the simultaneous growth of PBSU and PVDCVC spherulites was observed. After PBSU fibrils collided with PVDCVC spherulites, they kept growing through PVDCVC spherulites. For a blend with PBSU content 30% and Tc = 363 K, PBSU started to nucleate after PVDCVC spherulites filled the whole space. 相似文献