全文获取类型
收费全文 | 66篇 |
免费 | 0篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 19篇 |
金属工艺 | 2篇 |
机械仪表 | 11篇 |
建筑科学 | 2篇 |
能源动力 | 1篇 |
轻工业 | 19篇 |
无线电 | 1篇 |
一般工业技术 | 4篇 |
原子能技术 | 1篇 |
自动化技术 | 5篇 |
出版年
2023年 | 2篇 |
2022年 | 7篇 |
2021年 | 8篇 |
2020年 | 4篇 |
2019年 | 1篇 |
2017年 | 3篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2011年 | 7篇 |
2010年 | 5篇 |
2009年 | 3篇 |
2008年 | 3篇 |
2007年 | 1篇 |
2006年 | 6篇 |
2005年 | 1篇 |
2004年 | 5篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
排序方式: 共有66条查询结果,搜索用时 15 毫秒
1.
Phenylbutazone was recrystallized from its solutions by using a supercritical fluid antisolvent process. It was dissolved
in acetone and supercritical carbon dioxide was injected into the solution, thereby inducing supersaturation and particle
formation. Variation in the physical properties of the recrystallized phenylbutazone was investigated as a function of the
crystallizing temperature and the carbon dioxide injection rate. The recrystallized particles showed cleaner surfaces and
more ordered morphology compared to the particles obtained by other methods such as solvent evaporation. X-ray diffraction
patterns indicated that the crystallinity of the particles had been modified upon the recrystallization. Differential scanning
calorimetry measurement revealed that the crystallizing temperature influenced the thermal stability of the resulting crystals.
Larger crystals were produced when the carbon dioxide injection rate was reduced. 相似文献
2.
Synthesis of silver/polymer colloidal composites from surface-functional porous polymer microspheres
This study presents a different colloidal silver (Ag)/polymer system where Ag nanoparticles are deposited uniformly onto surface-functional porous poly(ethylene glycol dimethacrylate-co-acrylonitrile) (poly(EGDMA-co-AN)) microspheres. The formation and morphology of the composite microspheres were characterized from electron microscopy and X-ray diffraction analyses. The significance of the present report is that owing to the high affinity between Ag and nitrile group (CN) on the large surface of the microspheres, the Ag nanoparticles having a face-centered cubic phase were incorporated evenly into the deep pores of the microspheres with fine size and size distribution. In the preservation test, the Ag/poly(EGDMA-co-AN) composite microspheres obtained showed an excellent anti-bacterial performance, elucidating a high applicability for a new preservative. 相似文献
3.
Dong-Yoon Lee Su-Jin Kim Hyun-Chul Kim Sung-Gun Lee Min-Yang Yang 《The International Journal of Advanced Manufacturing Technology》2006,27(7-8):797-803
This paper presents a new paradigm for three-axis tool path generation based on an incomplete two-manifold mesh model; namely,
an inexact polyhedron. When geometric data is transferred from one system to another system and tessellated for tool path
generation, the model does not have any topological data between meshes and facets. In contrast to the existing polyhedral
machining approach, the proposed method generates tool paths from an incomplete two-manifold mesh model. In order to generate
gouge-free tool paths, cutter-location meshes (CL-meshes) are generated by offsetting boundary edges, boundary vertices, and
facets. The CL-meshes are sliced by machining planes and the calculated intersections are sorted, trimmed, and linked. The
grid method is used to reduce the computing time when range searching problems arise. The method is fully implemented and
verified by machining an incomplete two-manifold mesh model. 相似文献
4.
5.
Seung-Eek Park Su-Jin Chung In-Tae Kim 《Journal of the American Ceramic Society》1996,79(5):1290-1296
The ferroic phase-transition behavior of two (Na1/2 Bi1/2 )TiO3 (NBT) crystals grown by flux and by the Czochralski method has been investigated in the present study. Although both the tetragonal and the rhombohedral phases of NBT are expected to be ferroelastic, these crystals exhibit different ferroelastic behavior. The two NBT crystals also show differences in the amount of temperature hysteresis and the thermal expansion coefficients. These differences can be attributed to nonstoichiometry and structural variations dependent on the growing method. The present investigation has revealed a second maximum at −450°C in dielectric constant (( T )) curves, which could indicate that the intermediate tetragonal phase is either polar or antipolar. This maximum, however, originates from space-charge polarization and interaction between the charge carrier and the electrode, such that the tetragonal phase, in fact, is para-electric. The diffuse phase transition (DPT) of the NBT crystal, therefore, is from a paraelectric and ferroelastic tetragonal phase to a ferroelectric and ferroelastic rhombohedral phase. The crystallographic supergroup-subgroup relationships in the ferroic phase transitions of NBT crystals are discussed. 相似文献
6.
Kim G Kim SJ Harada K Schultz MK Burnett WC 《Environmental science & technology》2005,39(13):4894-4899
We have investigated the cycling of naturally occurring 210Po in waters from seasonally anoxic Pond B (South Carolina) and permanently anoxic Jellyfish Lake (Palau Islands, western Pacific Ocean). The maximum 210Po activity in Pond B was about 14 mBq L(-1) during summer. This activity was much higher than its parent 210Pb activity, indicating excess 210Po inputs from bottom sediments. The summertime excess 210Po activity was accompanied by increases in Fe and Mn, suggesting 210Po diffusion from bottom sediments under reducing conditions. Activity of 210Po was much lower underwinter oxic conditions, most likely a consequence of efficient coprecipitation with Fe and Mn oxides that occurs with destruction of Pond B stratification. In permanently anoxic Jellyfish Lake, the maximum activity of 210Po was 133 mBq L(-1), among the highest reported from any surface aqueous environment. A box model suggests that the release of only 2% of 210Po, produced from the 210Pb in the bottom sediments, would account for the observed excess. Our results suggest that 210Po can be naturally enriched in anoxic environments to a high level, perhaps in concert with the Fe and Mn redox cycles. 相似文献
7.
Seung-Eek Park Su-Jin Chung In-Tae Kim Kug Sun Hong 《Journal of the American Ceramic Society》1994,77(10):2641-2647
Crystals of (Na1/2 Bi1/2 )TiO3 have grown by the flux technique and the Czochralski method. Nonstoichiometry, twin configurations, and long-range cation ordering in the crystals have been investigated using X-ray diffraction and an optical polarizing microscope. It has been found that nonstoichiometry was induced in the crystal grown by the Czochralski method owing to the volatilization of Bi-rich phase during the crystal growth. This nonstoichiometry in the crystal resulted in less lattice distortion from cubic symmetry, a lower degree of cation ordering, and a larger domain width in twin configuration. Variations in twinning with temperature and isotropization have been investigated. 相似文献
8.
9.
Park TJ Lee SY Lee SJ Park JP Yang KS Lee KB Ko S Park JB Kim T Kim SK Shin YB Chung BH Ku SJ Kim do H Choi IS 《Analytical chemistry》2006,78(20):7197-7205
An efficient strategy for immobilizing proteins on a gold surface was developed by employing the gold binding polypeptide (GBP) as a fusion partner. Using the enhanced green fluorescent protein (EGFP), severe acute respiratory syndrome coronavirus (SARS-CoV) envelope protein (SCVme), and core streptavidin (cSA) of Streptomyces avidinii as model proteins, specific immobilization of the GBP-fusion proteins onto the gold nanoparticles and generation of protein nanopatterns on the bare gold surface were demonstrated. The GBP-fused SCVme bound to gold nanoparticles successfully interacted with its antibody and showed changes in absorbance and color, allowing efficient diagnosis of SARS-CoV. The fusion proteins could be successfully immobilized on the gold surface by nanopatterning and microcontact printing as examined by atomic force microscopy and surface plasmon resonance analysis. The poly(dimethylsiloxane) microfluidic channels were created on the gold surface and were used for antigen-antibody and DNA-DNA interaction studies. Specific immobilization of GBP-EGFP fusion protein and its interaction with the antibody in the microchannels could be demonstrated. By immobilizing the DNA probe through the use of GBP-fused cSA, specific hybridization of the target DNA prepared from Salmonella could also be achieved. The GBP-fusion method allows immobilization of proteins onto the gold surface without surface modification and in bioactive forms suitable for studying protein-protein, DNA-DNA, and other biomolecular interaction studies. Furthermore, these studies can be carried out in a microfluidic system, which allows high-throughput analysis of biomolecular interactions. 相似文献
10.
Jong-Do KIM Myeong-Hoon LEE Su-Jin LEE Woon-Ju KANG 《中国有色金属学会会刊》2009,19(4):941-945
Laser transformation hardening(LTH) is one of the laser surface modification processes. The surface hardening of rod-shaped carbon steel (SM45C) was performed by lathe-based laser composite processor with Gaussian-beam optical head. The LTH characteristics by dominant processes, longitudinal and depth directional hardness distributions and behaviors of phase transformation in hardened zones were examined. Especially, two concepts of circumferential speed and theoretical overlap rate were applied. When laser power increased or circumferential speed decreased, the surface hardening depth gradually increases due to the increased heat input. Moreover, the longitudinal hardness distribution particularly shows periodicity of repetitive increase and decrease, which results from tempering effect by overlap. Finally, the feasibility of laser transformation hardening is verified by using the beam with Gaussian intensity distribution. 相似文献