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1.
Wei YOU 《等离子体科学和技术》2018,20(11):115601
The design of the poloidal field (PF) system includes the ohmic heating field system and the equilibrium (EQ) field system, and is the basis for the design of a magnetic confinement fusion device. A coupling between the poloidal and plasma currents, especially the eddy current in the stabilizing shell, yields design difficulties. The effects of the eddy current in the stabilizing shell on the poloidal magnetic field also cannot be ignored. A new PF system design is thus proposed. By using a low-μ material (μ=0.001, ε=1) instead of a conductive shell, an electromagnetic model is established that can provide a continuous eddy current distribution on the conductive shell. In this model, a 3D time-domain problem with shells translates into a 2D magnetostatic problem, and the accuracy of the calculation is improved. Based on these current distributions, we design the PF system and analyze how the EQ coils and conductive shell affect the plasma EQ when the plasma ramps up. To meet the mainframe design requirements and achieve an efficient power-supply design, the position and connection of the poloidal coils are optimized further. 相似文献
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Changing requirements and on-going decision making along the entire project life cycle are well handled by Agile methods. However Agile projects still use evaluation methods during the RFP stage that do not fulfill the flexibility mandated by the Agile manifesto. 相似文献
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Kiyoyuki Yambe Shinsuke Maki Hideki Arimoto Koichi Sato 《Electrical Engineering in Japan》2005,150(1):1-7
In this paper, the authors study the magnetic and electric properties of ferromagnetic substance/semimetal (Fe/Bi) system multilayered thin films prepared by ion beam sputtering. The multilayered thin film was prepared with 99.6% Fe and 99.99% Bi. The experimental results are summarized as follows. From XRD in the small‐degree region (2θ = 2 to 4°), Fe/Bi system thin films for N = 3,4, and 5 Fe layers have formed multilayer structures. Coercive force Hc increased with increasing number of Fe layers. The maximum value was 4.522 kA/m at N = 6 Fe layers. The coercive force then decreased and its value was constant at more than 15 layers. Electrical resistivity, ρ, of Fe/Bi system multilayered thin films changed from conductivity to semiconductivity at temperatures in the range for T = 380 to 400 K. Magneto‐resistance (MR) ratio decreased with increasing applied field H when the current was parallel to an applied magnetic field (I‖H). MR ratio reached a maximum of 0.154% at N = 4 Fe layers at room temperature. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 151(1): 1–8, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20068 相似文献
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Keith Kaseman 《Architectural Design》2009,79(2):70-75
Cultural projects today are often unprecedented in their complexity, scale and collaborative effort. Keith Kaseman, partner of Kaseman Beckman Advanced Strategies (KBAS), describes how building information modelling (BIM) enabled the realisation of the Pentagon Memorial in Arlington, Virginia. Twenty-eight contractors and consultants were brought on board in the design and delivery of the monument's 184 ‘memorial units’, which collectively commemorate the individual lives lost at the Pentagon on 11 September 2001. 相似文献
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We describe new heterologous modules for PCR-based gene targeting in the fission yeast Schizosaccharomyces pombe. Two bacterial genes, hph and nat, which display dominant drug-resistance phenotypes, are used as new selectable markers in these modules. Both genes have been used successfully in the budding yeast Saccharomyces cerevisiae, in which hph confers resistance to hygromycin B, while nat confers nourseothricin resistance (Goldstein and McCusker, 1999). Vector modules for gene disruption and C-terminal tagging with 3HA, 13Myc and GFP(S65T) are constructed using previously constructed pFA6a-MX6-derived plasmids (B?hler et al., 1998; Wach et al., 1997). In combination with the existing systems that are based upon the G418-resistance gene (kan), triple gene deletions or tags could be constructed. In addition a vector for one-step integration of a monomeric RFP (mRFP) to the C-terminus of proteins of interest is developed. Finally, oligonucleotides that allow a simple marker switch from kan to hph or nat, and vice versa, are described. The new constructs developed here should facilitate post-genomic molecular analysis of protein functions in fission yeast. 相似文献
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A method of 3D kinematics simulation of robot fighting platform (RFP) in virtual environment is proposed with the aim of enhancing vision telepresence. Based on the theory of space coordinate transformation, kinematics equations of RFP are formulated; followed by applying a method of modeling using 3DMAX software to build an RFPs 3D geometric model before a 3D kinematics simulation system of RFP is completed based on virtual reality technology and Open Inventor VC++. Test results have indicated that this system can perform RFPs kinematics simulation in virtual environment. It can also imitate RFPs motion states and environmental features well. Moreover, not only can better real-time performances and interactions be achieved but also operators vision telepresence be enhanced, therefore this approach may help lay the foundation for the realization of RFPs teleoperation with vision telepresence. 相似文献
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Sarojrani Pattnaik D. Benny KarunakarP.K. Jha 《Journal of Materials Processing Technology》2012,212(11):2332-2348
Investment casting has been used to manufacture weapons, jewellery and art castings during the ancient civilization. Today, its applications include jewellery/art castings, turbine blades and many more industrial/scientific components. The present paper reviews various investigations made by researchers in different stages of investment casting and highlights their importance. The paper initially highlights the investigations made on pattern wax properties, effects of blending, additives and fillers. Different ways through which pattern properties (like surface finish, dimensional accuracy, etc.) could be enhanced by properly controlling the injection processing parameters are thoroughly discussed. The paper also looks into the investigations made to enhance the strength, surface finish, etc. of ceramic shell for ferrous alloys/non-ferrous alloys as well as superalloys in investment casting. Investigations made on incorporation of nylon fibers and polymer additions confirm that a ceramic shell reinforced with nylon fibers attains additional permeability compared to the one with polymer additions. 相似文献
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探讨了影响利福平铁磁性微球(FRS)的制备工艺条件,并测定了微球粒径、药物组分含量及体外降解等主要物理性能。考察了制备工艺中的w/o型分散体系程度、投药量和定位磁场强度等物理量对形态、粒度、分布和体外降解等的作用。结果表明乳化时间、搅拌速度和白蛋白投料比等量对微球粒径大小影响较大,最佳的磁性微球粒径范围为30~70μm,铁磁性物质含量为2.24%~24.3%,药物含量为3.1~3.6μg/mg左右,且具有一定缓释性能。自制的FRS符合临床使用要求,可作为新型缓释药物临床应用 相似文献
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S. Masamune A. Sanpei R. Ikezoe T. Onchi K. Oki T. Yamashita H. Shimazu H. Himura R. Paccagnella 《Journal of Fusion Energy》2009,28(2):187-190
The low-aspect-ratio (A) reversed field pinch (RFP) offers attractive properties such as enhanced bootstrap current and simpler MHD mode dynamics.
The RELAX (REversed field pinch of Low-Aspect ratio eXperiment) machine with the world’s lowest A of 2 (R/a = 0.5 m/0.25 m) has been constructed to explore the RFP properties in low-A regime. In flat-topped low-A RFP discharges in RELAX, plasma current of ~50 kA has been attained with discharge duration of ~2 ms. In round-topped discharges
with plasma current of ~70 kA, quasi-periodic growth of a single helical mode has been observed. When the dominant m = 1/n = 4 mode grows, the toroidal mode spectrum looks like that of the quasi-single helicity (QSH) RFP state with higher amplitude.
MHD equilibrium analyses using a reconstruction code have shown that the bootstrap current fraction is lower than ~5% in the
present RELAX plasmas, and it will be ~25% if we could achieve the plasma density of 4 × 1019 m−3 and electron temperature of 300 eV at plasma current of ~100 kA. 相似文献