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51.
A hybrid finite element method/method of moments (FEM/MoM) technique is used to analyze a printed circuit board power bus structure where the source and observation points are in the near field. The FEM is used to model the lossy region between the planes of the board including the source. The MoM is used to model the region outside the planes and provide a radiation boundary condition to terminate the FEM mesh. Numerical results for a bridged power bus structure are compared with measurements. A nonphysical interior resonance of the electric field integral equation is observed. The problem can be avoided by using a hybrid technique based on a combined field integral equation 相似文献
52.
卞韵 《常州信息职业技术学院学报》2005,4(4):95-96
以票据为主体的结算制度,是我国结算改革的重大突破,也是结算改革取得显著成绩的表现。根据票据的特征,对票据使用在我国的可能性和必要性进行分析,并结合我国结算改革中存在的一些问题,提出几点设想。 相似文献
53.
54.
A practical resource management method that can significantly reduce cochannel interference (CCI) and improve spectrum utilisation in FH-OFDMA packet-based cellular networks is presented. The proposed method seeks an effective combination of dynamic resource allocation with fractional coding and bit loading to respectively minimise CCI and maximise system throughput for a desired performance. 相似文献
55.
Ho Nam Kwon Man Geun Kim Il-Han Hwang Young Kab Yun Seon-Ju Kim Jong-Hyun Lee 《Photonics Technology Letters, IEEE》2005,17(4):774-776
We developed a micromachined X-type 2/spl times/4 optical add-drop module (OADM) featuring no difference in propagation length. Four pairs of lensed fibers are aligned in "X" position, and four micromirrors are located between the pairs of optical fibers. The OADM was fabricated utilizing a silicon-on-insulator process. Electrostatic comb actuators can be driven up to 90 /spl mu/m to change the light path within 1 ms. The insertion loss and the on-off ratio were less than 3 and 70 dB, respectively. The loss uniformity in every channel was 1.5 dB. 相似文献
56.
数字图书馆是图书馆发展的主要方向。在我国,数字图书馆建设存在一些问题。探索解决问题的方法和途径,是摆在我们面前的一项任务。 相似文献
57.
Shinsook Yoon Mi-Kyoung Kim In-Young Lee Mikyung Yun Jeong E. Nam Shin 《Journal of Industrial and Engineering Chemistry》2008,14(6):759-764
We have developed a mutant strain derived from Agrobacterium sp. ATCC 31750, which produces a water-soluble polysaccharide having potential utility to the food, feed, pharmaceutical and cosmetic industries. A high concentration of product (15 g/L) is obtained by 48 h cultivation of the mutant strain under optimized fermentation conditions. The water-soluble polysaccharide obtained from cultures of the mutant strain beta82 has Glc:Man:Gal in approximate molar ratios of 5.8:6.7:1.0. The molecular weight of the polysaccharide was determined to be approximately 1000 kDa by HPSEC analysis. Linkage analysis contained 3-Glcp, 3-Manp, terminal Glcp and terminal Manp, as well as a small proportion of 3- and 3,4-Galp, and 4,6-Manp residues. Based on analyses using FT-IR and 13C NMR spectrometers, most glycosidic bonds joining these sugar residues are of the α-type, and acetyl groups are apparently attached to the polymer chain at random. 相似文献
58.
Yun‐Seok Cho Bheong‐Uk Lee Kye‐Heon Oh 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2008,83(9):1211-1217
BACKGROUND: Environmental contamination by nitroaromatic compounds such as 2,4,6‐trinitrotoluene (TNT), hexahydro‐1,3,5‐trinitro‐1,3,5‐s‐triazine (RDX), atrazine, and/or simazine (TRAS) generated as waste from military and agricultural activities is a serious worldwide problem. Microbiological treatment of these compounds is an attractive method because many explosives and herbicides are biodegradable and the process can be made cost‐effective. We explored the feasibility of using cultures of Pseudomonas putida HK‐6 for simultaneous degradation of TRAS with the aim of microbial application in wastewater treatment in bench‐scale bioreactors. RESULTS: Experiments were conducted to study the effects of supplemental carbons, nitrogens, and Tween‐80 on the degradation of Ps. putida HK‐6 in media containing TRAS as target substrate(s). The most effective TRAS degradation was shown in the presence of molasses. Addition of nitrogen sources produced a delayed effect for the target substrate(s). Tween‐80 enhanced the degradation of target substrate(s). Simultaneous degradation of these compounds proceeded to completion within the given period. CONCLUSIONS: Ps. putida HK‐6 was capable of growth with TRAS, and the effects of supplements on TRAS degradation and simultaneous TRAS degradation were evaluated in bench‐scale bioreactors. The results of this study have practical applications in the processes of industrial waste stream treatment where the disposal of TRAS may be problematic. Copyright © 2008 Society of Chemical Industry 相似文献
59.
1项目背景1.1公司面临的内外形势一方面,市场竞争加剧,客户对时间、价格、质量及个性化服务的要求越来越苛刻,市场瞬息万变,定单忽多忽少;另一方面,企业生产计划不准确,订单无法及时交付,库存积压严重。企业粗放式的管理造成产品成本居高不下,效率降低,越来越不能适应市场的需要,企业在行业中的排名也逐年下滑。 相似文献
60.