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991.
992.
Ren Zhen Ran Li Lan Qinghua 《保鲜与加工》1992,(6):31-35
The effect of phase angles of commutating voltages on the performance of dc filters is analgzed for the first time and a heurestic method is presented to choose appropriate parameters for swoothing reactors and dc filters. 相似文献
993.
Inactivation of microorganisms can be realized by the accurately controlling the pulse electric field the strength and time for microorganism cell membrane. Use of high pulsed electric field for inactivation of microorganisms is one of the more promising nonthermal processing methods. Compare with pasteurization,it possesses the advantage of instant and even distribution throughout a conductive food system,short treatment time and very little heating of the medium in continuous processing. In addition, HPEF can decrease the loss of nutrition as little as possible. The author critically review the results of earlier experiment studies on HPEF,the mechanisms of inactivation by HPEF,and we suggest the future work that is required in this field. 相似文献
994.
An approach is described on the automated tracking of interference circle fringe to get the flatness accurately based on the Equal Inclination Interference Theory (EIIT). The system,based on the theory of EIIT, can be applied to grasp the changing fringe information, which is white alternating with black through the CCD camera. Following the basic principle of fringes image centro-symmetric, we create some windows, process only the interference fringes information in the windows. According to the position of the processed interference fringe and the position of the last adjacent interference fringe in the windows, the interference fringe variation value N from the starting measured point is received, it implies the changed altitude value from the starting measurement point. This method allows us not only get the fringe information of the half-wavelength integer multiple but also denote those of the half-wavelength decimal multiple. The system is proved to be effective experimentally. It is useful in metrology department for the high-precision flatness standard unit. 相似文献
995.
The authors establish the physical and mathomatical model of the Marangoni convection in liquid bridge with liquid encapsulation (or two immiscible coaxial liquid columns). A Numerical simulation of the Marangoni convection in liquid bridge with liquid encapsulation is performed by employed vorticity-streamfunction method and the Alternative Direction Implicit scheme in finite difference. The distribution of temperature and flow in two liquid columns is then obtained. The influence law of the dynamic viscosity ratio of the inner liquid to the outer liquid to the Marangoni convection in liquid bridge with liquid encapsulation is obtained. 相似文献
996.
板栗叶片性状表型多样性研究 总被引:13,自引:0,他引:13
对中国板栗自然分布区8个产地采集的板栗叶片进行取样测定,分别测定叶片3项形态指标,结果表明,各指标在同一群体不同品种间差异显著。板栗叶片形态在群体间和群体内存在广泛差异,其中,叶片长、叶片宽及叶片长宽比等3个性状群体内的差异均达极显著水平,F值分别为7.50、6.36及7.39;群体间,叶片长、叶片宽及叶片长宽比3个性状差异均达极显著水平,其F值分别为19.36、18.32和3.40。根据3个性状的平均,群体间的方差分量占总变异的11.417%,群体内的占39.86%,机误占48.72%。板栗叶片3个性状群体间的表型分化系数平均为13.03%,而群体内的平均表型变异占86.97%,表明群体内变异是板栗叶片表型变异的主要来源。 相似文献
997.
影响红掌愈伤组织诱导、增殖和芽分化的因素 总被引:17,自引:0,他引:17
以Pink champion等盆栽植株和试管苗为材料,研究了影响红掌愈伤组织诱导、增殖和芽分化的因素。结果表明,不同品种的愈伤组织诱导率和外植体褐变率均存在显著差异,诱导率和褐变率之间呈显著的负相关关系。外植体、外源激素和培养基对愈伤组织的诱导有显著影响,不同品种和外植体的适宜诱导培养基不同。光照对愈伤组织的诱导有显著的抑制作用;高浓度生长素、低浓度细胞分裂素,促进愈伤组织的增殖,高浓度细胞分裂素及低浓度生长素促进愈伤组织芽分化;固体培养比液体培养更有利于愈伤组织的增殖和芽分化。 相似文献
998.
999.
1000.
The problem of old urban district regeneration has to be solved in process of ur-ban development.According to the practice of urban construction and the current situation of urbandevelopment in our country,solving this problem is very urgent. At present.there is fewer discussionon old urban district regeneration from its economic and social effect; In this paper.by means of an-alyzing old urban district regeneration and its investment effect, a set of criteria evaluating the in-vestment effect of old urban district regeneration is eastablished. For the first tirne, a new method. Set Statistics-AHP (The Analytic Hierarchy Process)-Entropy method is adopted to evaluate the in-vestment effect,and successfully solve two critical problems,individual criterion evaluation and crit-era' s weight. 相似文献