排序方式: 共有42条查询结果,搜索用时 15 毫秒
1.
Microsystem Technologies - Since traction motors for electric vehicles require a variety of features to be used simultaneously, research on the design optimization of permanent magnet synchronous... 相似文献
2.
Young-Joon Park Yong-Min Cho Woo-Yeol Cha Youn-Bae Kang 《Journal of the American Ceramic Society》2020,103(3):2210-2224
In order to effectively remove alumina inclusions suspending in ultra-low C steel during RH process, the dissolution kinetics of alumina in molten CaO–Al2O3–FetO–MgO–SiO2 oxide was investigated. A crucible dissolution technique was used where the alumina crucible was allowed to dissolve in the slag of various conditions ((% CaO)/(% Al2O3), (% FetO), temperature). The obtained data were interpreted using a kinetic mass transport equation to obtain the mass transport coefficient (km) in each condition. Increasing (% CaO)/(% Al2O3), (% FetO), and temperature increased the dissolution rate as well as the km provided that the slag composition is not close to its saturation composition by alumina. In order to simulate the dissolution of alumina inclusion in the RH slag, which cannot be measured by a confocal scanning laser microscopy (CSLM) at present due to the opaqueness of the slag, the modified invariant interface approximation was employed. Along with the obtained km, the viscosity of slag, and a reference experiment using the CSLM, the dissolution kinetics of alumina inclusion in the FetO-containing RH slag was predicted. The time required for the dissolution of alumina inclusions from liquid steel to RH slag was discussed. 相似文献
3.
Kyeong-Ho Yeon Heesu Park Seung-Hak Lee Yong-Min Park Sang-Hyup Lee Masakazu Iwamoto 《Korean Journal of Chemical Engineering》2008,25(5):1040-1046
Eutrophication caused by the excessive supply of phosphate to water bodies has been considered as one of the most important
environmental problems. In this study, the powder of zirconium mesostructure (ZM), which was prepared with the template of
surfactant, was immobilized in calcium alginate for practical application and the resulting material was tested to evaluate
the phosphate removal efficiency. Sorption isotherms and kinetic parameters were obtained by using the entrapped ZM beads
with 30 to 60% of ZM. The maximum sorption capacity increased with the higher ZM content. Q
max
in Langmuir isotherm was 51.74 mg/g for 60% of ZM with 7 mm of size. The smaller the particle size of the ZM beads, the faster
the rate of phosphate removal, because the phosphate ions had less distance to reach the internal pores of the immobilized
ZM beads. Chemical and electrochemical regeneration techniques were compared. Phosphates adsorbed on the ZM beads were effectively
desorbed with NaCl, NaOH, and Na2SO4 solutions. An electrochemical regeneration system consisting of an anion exchange membrane between two platinum-coated titanium
electrodes was successfully used to desorb and regenerate the phosphate-saturated ZM beads. Complete regeneration was reached
under optimal experimental conditions. Chemical and electrochemical regeneration proved the reusability of the bead form of
the entrapped ZM, and will enhance the economical performance of the phosphate treatment process. 相似文献
4.
河南省电力需求发展趋势预测分析 总被引:6,自引:0,他引:6
受国际和国内宏观经济形势影响,河南省电力需求增长速度大幅降低,2012年增速降为3.33%,2013年上半年增速为1.17%,远远低于“十一五”期间11.7%的年平均增速,其中2013年上半年工业用电增速为-0.86%,占全省用电比重达54%的六大高耗能行业用电增速仅为-3.8%。通过对近期河南省用电增速与经济增速背离现象以及典型行业的市场环境及用电趋势分析,对未来河南省电力需求发展趋势进行了预判,并得出了在新形势下电力需求增速放缓将使得电力供需形势有所缓和,未来电力工业发展将成为经济发展的推动力而非制约因素的结论。 相似文献
5.
6.
Yong-Min Ha Seong-Hoon Lee Chul-Hi Han Choong-Ki Kim 《Journal of Electronic Materials》1994,23(1):39-45
Oxygen ions were implanted into the amorphous silicon film deposited at 540°C in order to study the effects of oxygen on the
solid phase crystallization of silicon films. The resulting films were investigated using transmission electron microscopy,
x-ray diffraction (XRD), and also by measuring the electrical characteristics of polycrystalline silicon thin film transistors
(TFTs) fabricated in the crystallized films. The development of {111} texture as a function of annealing time is similar to
films implanted with Si, with higher oxygen samples showing more texture. Transmission electron microscopy shows that the
grain size of completely crystallized films varies little with oxygen concentration. The electrical performances of TFTs are
found to degrade with increasing oxygen dose. The trap state density increases from 5.6 × 1012/cm2 to 9.5 × 1012/cm2 with increasing oxygen dose. It is concluded that for a high performance TFT, oxygen incorporation in the Si film should
be kept to 1019/cm3 or less. 相似文献
7.
Nam-Hoi Park Young-Jong Kang Yong-Min Jo Nam-Hyoung Lim 《Engineering Structures》2007,29(12):3293-3300
Finite element buckling analyses of monosymmetric I-beams subjected to transverse loading applied at different heights with respect to the mid-height of the cross-section were conducted. Transverse loads consisting of a mid-span point load and a uniformly distributed load were considered in the investigation. Four types of end restraint also were considered. The method suggested in SSRC Guide was compared with the finite element method (FEM) results. In order for C-equation in the SSRC Guide to be applicable for monosymmetric I-beams, it must be modified to contain three variables; Am, Bm, and Dm. The first two variables Am and Bm are modified variables A and B in the SSRC Guide whereas the third variable, Dm, developed herein, is the new modification factor for monosymmetric I-beams. The applicability of this new design rule is limited to monosymmetric I-beams in which the degree of monosymmetry, ρ, is within the range from 0.1 to 0.9. 相似文献
8.
We synthesized novel fluorescent magnetic silica nanoparticles (FMSNPs) containing large magnetic components for biomedical application. By employing assemblies of magnetic nanoparticles as kernels against FMSNPs, both the saturation of magnetization and the magnetic resonance (MR) signal intensity were significantly enhanced. Furthermore, the cellular binding of FMSNPs was improved by introducing a positive charge on the surface of the FMSNPs, and fluorescent dyes on the surface of FMSNPs enable optical imaging of sub-cellular regions. 相似文献
9.
Bongjune Kim Jaemoon Yang Myeonghwan Hwang Jihye Choi Hyun-Ouk Kim Eunji Jang Jung Hwan Lee Sung-Ho Ryu Jin-Suck Suh Yong-Min Huh Seungjoo Haam 《Nanoscale research letters》2013,8(1):399
Nucleic acid-based aptamers have been developed for the specific delivery of diagnostic nanoprobes. Here, we introduce a new class of smart imaging nanoprobe, which is based on hybridization of a magnetic nanocrystal with a specific aptamer for specific detection of the angiogenic vasculature of glioblastoma via magnetic resonance (MR) imaging. The magnetic nanocrystal imaging core was synthesized using the thermal decomposition method and enveloped by carboxyl polysorbate 80 for water solubilization and conjugation of the targeting moiety. Subsequently, the surface of the carboxylated magnetic nanocrystal was modified with amine-functionalized aptamers that specifically bind to the vascular growth factor receptor 2 (VEGFR2) that is overexpressed on angiogenic vessels. To assess the targeted imaging potential of the aptamer-conjugated magnetic nanocrystal for VEGFR2 markers, the magnetic properties and MR imaging sensitivity were investigated using the orthotopic glioblastoma mouse model. In in vivo tests, the aptamer-conjugated magnetic nanocrystal effectively targeted VEGFR2 and demonstrated excellent MR imaging sensitivity with no cytotoxicity. 相似文献
10.
This paper investigates the minimum-energy joint path-following problem for space manipulators whose base attitude is stabilized by reaction wheels. In the problem, manipulator joint path is specified for rest-to-rest motion and constraints are imposed as the upper bound on both motion completion time and the voltage/current limits of DC motors in manipulator joints and reaction wheels. We suggest a simple two-stage algorithm to address this problem. The algorithm first tries to find a global optimal solution by solving a relaxed convex problem. If the convex relaxation is not successful, then the algorithm solves subproblems iteratively to find a suboptimal solution. Since both problems are formulated as second-order cone programming (SOCP) form, they can be solved efficiently using dedicated SOCP solvers. The effectiveness of the proposed method is verified by numerical experiments. 相似文献