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111.
Measurements of boundary parameters and their fluctuations have been performed in ohmic (OH) plasma and Ion Bernstein Wave (IBW) and Lower Hybrid Current Drive (LHCD) enhanced confinement plasma using a pneumatically driven Langmuir probe array on HT-7 toka-maX. In the enhanced confinement plasma~ the gradients of electron density and temperature become higher and a transport barrier comes into being in the vicinity of the limiter. The boundary potential shows a clear modification in the same region. The fluctuation levels are significantly depressed and the coherences between fluctuations are reduced evidently in the enhanced plasma.Meanwhile, we obtained the spectral features and the poloidal phase velocity of fluctuations us-ing a two-point correlation technique and found obvious modifications of the turbulence and the poloidal flow. The results suggest that the improved confinement in the IBW and LHCD enhanced plasma is at least partially due to the modification of the boundary parameters and the suppression of the boundary fluctuations and fluctuation induced fluxes. 相似文献
112.
In this paper, the calculated results about the propagation properties of electromag-netic wave in a plasma slab are described. The relationship of the propagation properties with frequencies of electromagnetic wave, and parameters of plasma (electron temperature, electron density, dimensionless collision frequency and the size of the plasma slab) is analyzed. 相似文献
113.
Abstract The experimental system for electrically exploding single metal wire has been de-signed and manufactured. Expansion of the dense plasma column formed from an electricallyexploding Cu wire of diameter 30 μm has been studied with a high-speed photographer to obtainthe time-dependent radius (R-t) curve. The experimental results demonstrate that the mean ex-pansion rate of the dense plasma column is 1.94 μm/ns, 2.6 μm/ns and 3.75 μm/ns according tothe peak pulse current 4.5 kA, 7 kA and 9.5 kA respectively. The results can be beneficial to givinga profound understanding of the early stage of wire-array Z-pinch physics and to improvement ontheir design. 相似文献
114.
The Experiments, methods and results of obtaining micron beam in the Microbeam Facility of the Institute of Plasma Physics were discussed in this paper. The H2^ beam was accelerated by the Van de Graa/f electrostatic accelerator, and the collimator at the end of the beam line is a 60μm thick stainless steel chip. And as a result, particle tracks on the solid track probes (CR39 film) etched in the solution of NaOH showed that the beam can go through the collimator with a small aperure (2000, 300, 55, 30, or 10μm) and 3.5μm thick vacuum film(Mylar). Besides the CR39 method, the beam was measured by an energy spectrum detector after the 10μm diameter aperture and the 3.5 μm thick vacuum film too. 相似文献
115.
Tritium self-sustainment, which will meet the fuel requirement of fusion reactor, is one of the key issues of fusion power development. The tritium breeding performances of various tritium-breeding materials are compared based on a series of neutronics calculations using three-dimensional Monte Carlo neutron-photon transport code MCNP/4C with the IAEA FENDL-2 data library. The effects of the dimensions of the tritium-breeding zone and the enrichment of 6Li on Tritium Breeding Ratio (TBR) are analyzed. The effects of Be as a neutron multiplier on TBR are also calculated. 相似文献
116.
为满足环境磁学研究、陶瓷和塑料等对原料中磁性杂质的要求,研制了一种自动化程度高、效率高、磁选效果佳的CXG-I型磁选装置。该装置的磁路设计独特,当待选的原材料(浆料、粉末.沉积物等)沿该装置内置与外露的工作磁路流动时,永磁体的强磁场从各个方向将MnO-Fe2O3、Fe3O4和Fe屑等有效地吸附在其表面,由自动冲洗装置把它们清徐。其磁选纯度达到99.92—99.96%,能保证原材料的单纯性,该装置具有多用途、适宜各种场合、节省经费开支等特点,有极大的应用前景。 相似文献
117.
本为记访谈录。章从防洪和通航、投资、移民、泥沙、生态环境、地质灾害、科学与技术及民主的论证工作方式等七个方面阐述三峡工程论证过程,并指出论证结论完全符合客观实际。 相似文献
118.
语句拼音-汉字转换的智能处理机制分析 总被引:4,自引:4,他引:4
语句拼音- 汉字转换是中文信息处理研究的一个重要方面,是键盘汉字输入和语音输入的核心技术,其主要特征是对动态输入的拼音串进行词法分析,给出所有可能的汉语句子,然后对这些汉语句子根据上下文环境进行句法分析和语义分析,动态调整句子中的字词,输出最佳结果。近年来,语句拼音- 汉字转换系统大量应用了人工智能技术和机器翻译的理论,以期提高系统转换的准确率和增强系统的智能处理功能。本文分析了语句拼音- 汉字转换系统所采用的核心技术,即知识支持、自动分词和动态调整等,讨论了语句拼音- 汉字转换的处理方法和过程,知识库的组成结构,用于拼音串自动分词的算法和实现,音字转换中动态调整的概率模型等,本文还分析了现有语句拼音- 汉字转换系统在拼音串自动分词和音字转换的动态调整中发生错误的原因,并提出了改进方法。 相似文献
119.
三唑并嘧啶磺酰胺类除草剂的QSAR研究(II) 总被引:1,自引:1,他引:1
三唑并嘧啶类除草剂是作用于乙酰乳酸合成酶的新一类超高效除草剂,本文采用CASAC软件中的逐步线性回归方法,在二维水平上通过讨论三唑并嘧啶类化合物对油菜rape(Gossypiumspp.)欧龙牙草cocklebur(Xanthium,spp.)曼陀罗jimsonweed(Datura,stramonium),牵牛花annualmorningglory(lpomoeaspp。)苋菜pigweed(A 相似文献
120.