AN ACCELERATION SEARCH METHOD FOR UNCONSTRAINED OPTIMIZATION AND ITS APPLICATION IN MODEL PARAMETER ESTIMATION     

Sun Dihua Yang Yongzhen 《保鲜与加工》1991,(6):62-68

In order to improve the convergence rate of the algorithms, an acceleration search method along a straight or curve is proposed,and the specific calculation steps of the algorithms are presented. The numerical results in model parameter estimation show that the convergence rate is improved and the calculation accords with the practical demands.  相似文献   

A Caculation Method of Portfolio Investment under the Risk Mininiz     

Liu Xing  Yang Xiutai 《保鲜与加工》1995,(6):7-12

According to the security investment theory of Markowitz,this paper presents aCaculation method of portfolio investment under the risk minimization,and some mathematic expres-sions of the efficient frontier for portfolio investment are conducted.Based on these,the efficientfrontier is proved as a parabola,and a practical caculation process is given.  相似文献   

菲牛蛭抗凝血活性物质提取方法研究     

汪波  杨思毅  周子华  陈鑫  颜亨梅 《中国农学通报》2015,31(20):51-54

为对菲牛蛭抗凝血活性物质的提取进行优化,通过采取不同方法对菲牛蛭活体(6种)、干体(6种)及唾液腺分泌物(3种)进行提取得出最适提取方法。结果表明对于菲牛蛭活体和干体均是采取80%预冷丙酮提取得到的抗凝血物质含量高,最高分别达至(61.20±1.13)AT-U/g和(89.19±1.13)AT-U/g;对于菲牛蛭唾液腺分泌物则是采取10%的三氯乙酸提取得到的抗凝血物质含量高,最高达(24.41±0.98)AT-U/g。研究结果得出了适合菲牛蛭活体、干体和唾液腺分泌物中提取抗凝血活性物质的最适方法,有利于推动水蛭素的大规模生产和广泛的临床应用。  相似文献   

不同熔化速率下的电渣重熔过程数值模拟分析     

贺铸  蔡辉  刘双  王强  李宝宽 《保鲜与加工》2015,(5):104-111

电渣重熔能提高钢锭的质量,从而满足特种行业的需要,其过程伴随着复杂的物理现象,存在着磁流体流动、传热和传质以及电化学等多方面的影响。通过耦合电磁以及流动和温度方程对电渣重熔过程的三维瞬态进行了数学模拟,研究了熔化速率对重熔过程的影响。结果表明：电流密度、焦耳热和电磁力都随着熔化速率的增大而增大,当熔化速率由14.4 kg/h增加到27.0kg/h,电流密度、焦耳热和电磁力最大值的增大比例超过100%。随着熔化速率的增大,温度最大值有小幅的增加,而且速度最大值的增大幅度接近50%;金属熔池深度则由27 mm增大到38 mm,不利于保证铸坯的质量。  相似文献   

Control Strategy and Simulation Study on NiMH Battery Quick Charging for Regenerative Braking of HEV     

YANG Yang  LIN Zhi-huang  QIN Da-tong  HU Ming-hui  YANG Ya-lian 《保鲜与加工》2007,(3):1-5

Based on the result of NiMH battery performance experiments, changing trend of maximal temperature and difference in temperature of HEV NiMH battery in different SOC and different charging current is analyzed. Considering the working situation of HEV NiMH battery and the theory of battery quick charging, a control strategy for NiMH battery quick charging is described which adapts to HEV regenerative braking system based on Mascc law. By Modeling and simulating the process of NiMH battery quick charging with this strategy, constant voltage charge method and constant current charge method, validates this control strategy.  相似文献   

The Design of Heart Function Detection System Based on the Virtual Instrument     

PI Xi-tian  HEI Xiao-guang  ZHENG Xiao-Lin  CHEN Feng  LI Yong-an  HOU Wen-sheng  YANG Jun  LU Bo 《保鲜与加工》2007,(9):109-112

  相似文献   

Performance Analysis of MIPv4 Regional Registration Combined with Low Latency Handoffs     

LIU Hui  LIU Xing-qian  LIU Xiang 《保鲜与加工》2006,(3):76-79

The mechanism of MIPv4 regional registration and the low latency handoff protocols are introduced. Ways and procedure of pre-registration handoff and post-registration handoff are discussed also. The authors analyze the performance of the low latency handoff protocols combined with low latency handoffs over a wireless access based on IEEE 802. 11 standard in a tree-like network topology. The performance of pre-registration and post-registration scheme is given by simulation.  相似文献   

Experiment for Condensing Heat Transfer Performance in a New Type of Horizontal Three Dimensional Inner Microfin Tubes     

Du Yang Xin Mingdao Huang Shaoming 《保鲜与加工》1995,(5):50-56

A new type of three dimenstional inner microfin tube is devoloped. Under four different pressures and in the range of condensing mass velocities from 33 to 153 kg/m2 . s,and by the experimental study of the three kinds of tubes with different microfin parameters, the performances of the condensation heat transfer for R11 in the horizontal microfin tubes and obtained. The experiments show that the inner microfin tube is a hopeful and nighty effective condensing heat transfer enhancement tube.  相似文献   

对酒泉玉米制种隔离问题的思考?     

杨六保 《中国种业》2006,(2):40-41

酒泉得天独厚的自然资源优势成为全国玉米种子生产的重要基地.但由于各方面的原因,隔离问题日益突出,严重制约着酒泉玉米制种产业健康、协调、持续发展.  相似文献   

DYNAMIC ANALYSIS OF SPINDLE     

Yang Yudin Liu Dejun 《保鲜与加工》1990,(1):110-118

In this paper, taking a D1201 spindle as an example, we discuss the dynamic analysis of spindle by using the theory of the complex model, we also analyse the factors which effect the dynamic characterics of spindle and give results which arc reference value to improving the structure of spindle,  相似文献