共查询到20条相似文献,搜索用时 0 毫秒
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In order to analyze and research the scattering problem of the ground penetrating radar under the ground, a hybrid method combining FDTD and MOMTD is constructed to solve the problem. The curve of current on central feeding point of pick-up antenna is obtained by simulating when different distance between the ideal conductor and the ground is considered, correctness of the result gained by employing the hybrid method is proved through qualitative and quantitative analysis. 相似文献
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The radiation field created by the transmission line stroked by lightning far from the lightning channel has been analyzed by the FDTD method.The authors we establish the calculation model and FDTD calculation method of transmission line,and discusses the import of lightning excitation source.The simulation of lightning stroked on a single transmission line in free space or stroked on three-phase high voltage transmission lines in actual environments has been done,and gives the distribution of transient radiation field around the transmission lines when lightning overvoltage wave transmits along the transmission line.The simulation result shows that: the effect of the transient radiation field caused by lightning over voltage wave done with environment is obvious,and the high frequency component of transient radiation field may disturb or do harm to the electronic facility or communication facility around the transmission lines. 相似文献
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Vacuum-surcharge combined preloading method have been become the most commonly used method on the dredger fill and saturated soft clay soil consolidation beside the coast.The long time of consolidation is one of this method’s most characteristics,as we always think that 3 months is the academic time.In fact,we always can’t accomplish the consolidation of siaturated soft clay soil by using vacuum-surcharge combined preloading method in 3 months because of the complex nature of the soil horizon and the effects of the construction technology.The mian mission of the article is to supply a substantial time and a reliable basis that are needed by the vacuum-surcharge combined preloading method and the construction period.The mian data sources are come from the ground treatment project of a cogeneration power plant in Zhuhai Guangzhou.We adopt the exponential curve fitting method and the method of Asaoka to count the degree of consolidation of the saturated soft clay soil. 相似文献
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Yu Jihui Tang Cuifeng Huang Jian 《保鲜与加工》1998,(6):35-40
In this paper,we derive the necessary extension to the FD TD(finite difference time domain) method for absorbing coating of composite material.The scattering of electromagnetic waves(EW) from absorbing coating is considered,and the comparision of obtained results with exact analytic ones shows that the method used in this paper is correct and available. 相似文献
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In the Lorentz Invariable Coupling Model of interaction between pion and nucleon (antinucleon), by applying the complex function integral method, the authors have strictly calculated the one-dimensional integral, which is derived from the great momentum integral limit, of the renormalized finite quantity of one-loop propagator and chain propagator in the momentum renormalization scheme and gained the finally strict analysis result. At the last, they have detailed these numerical results of the renormalized finite quantity, and also done the relevant discussion about these minute radiation corrections. 相似文献
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ZHANG Zhong-can~ 《保鲜与加工》2005,(2):119-123
By using the Lorentz invariable coupling model of interaction between neutral meson and nucleon (antinucleon), Feynman convergence integral method is often used to deal with the finite quantity of one-loop correction scheme. On the basis of analyzing, discussing and researching the method, a new method is found. That is the large momentum integral limitation method. With the effective method, we obtain the integral convergence formulation for the finite quantity, by deducting-dimensionally calculating the finite quantity gained after renormalizing the meson loop propagator. 相似文献
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The premise for improved first-order perturbation is that all original modes of structure have been known. It will take much error for modes if the conventional method of truncated higher frequency modes is used. Taking higher frequency modes into account, an accurate expansion method based on the improved first-order perturbation is put forward, which can improve the precise of modes obviously. 相似文献
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The characteristic of the original damage and the breaking of the coal and rocks under the loading has been discussed by a lot of microscopic structure analysis and by whole stress strain testing on the coal and rocks. The non homogeneity causes the stress locating in a small spot. It is the essential cause of the damage developing and causing the structure breaking of the coal rocks. The failure of brittle fracturing, rubbing later on and granulating should be a major pattern in the outburst of coal and gas. The method of the examining damage by the deviator stress, is proposed. It can be used to analyse the characteristic of the coal and rocks. 相似文献
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不同栽植密度杂交稻分蘖成穗规律及其穗部性状研究 总被引:4,自引:2,他引:2
xynkqyl@.com 《中国农学通报》2006,22(5):177-177
(河南信阳市农业科学研究所,河南信阳 464000) 相似文献
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For the requirement of building up the battery management system (BMS) of hybrid vehicles(HEVs), the real time measurement and estimation of charge (SOC) of the Ni MH batteries are investigated, because the popular SOC definition is unsuitable under the condition of variable current discharge. The origin of this kind unsuitability are analyzed ,and the characteristics and existing problems of different kinds of SOC measuring methods are compared. On the basis of mentioned above, some corrections are given to the popular SOC definition, and the new conception of SOC is proposed. The corrected definition of SOC is suitable for the real time SOC estimation under the variable current condition of the batteries used in HEVs. Based on the corrected SOC definition, the computational model of the new SOC is built and simulated. Satisfactory result has been obtained from comparisons of the simulating results, which shows that the theoretical model provides a basis for optimizing the adaptation of power system to the hybrid vehicles (HEVs). 相似文献
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超级杂交稻的优化(稀植、结构施肥)栽培试验于2002-2004年在长沙进行,以比较不同栽培方法对超级杂交稻产量及物质生产的影响。以两优培九为材料,并以汕优63作为对照。结果表明,两种栽培法,两个供试品种的产量表现不同,其中两优培九采用优化栽培单产为8.20~10.37t/hm2,比传统栽培增产显著。主要表现为有效穗多,而结实率、千粒重、穗实粒等产量因子差异不明显。汕优63采用优化栽培单产比传统栽培减产0.37%~8.8%。两种栽培方法间的茎蘖发生动态和单株分蘖数存在极显著差异,两组合单株分蘖数优化栽培比传统栽培分别多110.36%和110.64%,但由于移栽密度不同,两种栽培方式间的单位面积分蘖数没有明显差异。两优培九采用优化栽培的在各个生育时期,植株体内的含氮量比传统栽培的高。 相似文献
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园艺风信子品种染色体倍性变异丰富,染色体倍性高的品种杂交更易获得杂种后代,致使其杂种后代真实性鉴定较为困难。本研究利用3条引物对风信子3个杂交组合(‘Ostara’בFondant’,‘Sky Jacket’בFondant’,‘White Pearl’בBlue Jacket’)的杂种后代进行ISSR分子标记研究,以鉴定各杂交组合杂种后代的真实性。结果表明:‘Ostara’בFondant’组合中12个杂种后代为真实杂种,真实杂种率为92%;‘Sky Jacket’בFondant’杂种后代中7个为真实杂种,真实杂种率为41%;‘White Pearl’בBlue Jacket’14个杂种后代均鉴定为真实杂种,真实杂种率为100%。研究结果显示ISSR分子标记方法可以用于风信子杂种后代真实性的鉴定,将为开展风信子品种间大量杂种后代的快速鉴定和早期选择提供理论依据和实践方法。 相似文献
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为了探寻优化山豆根DNA提取的方法,本研究以山豆根的叶片为材料,用3种改良的CTAB法提取山豆根DNA,并将提取的DNA经分光光度计和电泳检测,用于cpDNA引物筛选试验,找出最有效的山豆根DNA提取方法。结果显示,高PVP和β-巯基乙醇提取法和样品预处理法可用于提取山豆根基因组DNA。其中,样品预处理法山豆根DNA的效果最好,提取DNA浓度高、质量好,引物筛选结果条带清晰且单一。本研究建立了山豆根高质量的DNA提取方法,为进行分子生物学研究提供支持。 相似文献
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Pei Liujin Tang Feng Zhang Ling 《保鲜与加工》1998,(2):26-29
The maximum intensity of direct solar radiation falling on a vertical surface and the relative solar altitude and azimuth angles under this condition are given, which can be used in urban planning to determine the relative location of buildings. 相似文献
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影响籼粳稻杂交F1花药培养效果的因素分析 总被引:1,自引:0,他引:1
以津稻291/IRBB60籼粳杂交F1、反交F1及其亲本的花药为外植体,对诱导和分化培养基、激素配比及有机附加物和高温预培养时间等影响花药培养效果的因素进行研究。结果表明,在SK3基本培养基中添加2 mg/L 2,4-D,1 mg/L NAA和1 mg/L KT比只添加2 mg/L 2,4-D的愈伤诱导率高0.67~2.78个百分点;在诱导培养基中添加水解酪蛋白能明显提高正交F1的愈伤诱导率;MS 1 mg/L NAA 2 mg/L 6-BA 0.5 mg/L KT分化培养基得到了较高的绿苗分化率;正交F1的愈伤诱导率、绿苗分化率和花培力显著高于反交F1;30℃高温预培养36 h,正交F1花培力达到最高值。 相似文献