共查询到20条相似文献,搜索用时 8 毫秒
1.
Tang Jian Duan Yurong 《保鲜与加工》1991,(1):33-41
A new trust region algorithm is proposed for solving unconstrained optimization problems. According to the quadratic approximate model of the original optimization problem,the trust region algorithm uses directions,a convex combination of the quasi-newton direction and the steepest descent direction. This algorithm with new strategy is analyzed and the global and local quadratic convergent theorems are proved. At last,the implementation and computational results of the algorithm are demonstrated. 相似文献
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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
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Zeng Yongning 《保鲜与加工》1990,(4):66-73
An approach for evaluating the performance of relational database is introduced, the stroage cost, responding time and maintenance ccst oi a relational database based on B+ tree index are theoretically analyzed, and the evaluation model is proposed 相似文献
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Wang Caihua Zhu Yudong 《保鲜与加工》1992,(6):92-97
A processing method for the weight of the object in the fuzzy solving method for the multiojectide optimization are presented. The methods are using different type of membership functions and using the same kind membership function adjusting the parameter. Some corresponding analysis and examples are discussed and the results show that the two methods are very effective. 相似文献
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Tang Jian Duan Yurong 《保鲜与加工》1991,(1):42-51
This paper presents two trust region algorithms for solving general nonlinear equality constrained optimization problems. The different techniques are used in minimizing a quadrdtic approximate model of the original optimization problems in trust region. By the convergence analysis, the global convergences and local superlinear convergences of the algorithms are obtained. Finally,the implementations of the algorithms are given. 相似文献
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以谷蠹为研究对象,采用L16(45)正交组合实验和单因素梯度实验对MgCl2、dNTP、随机引物、Taq酶、模板DNA浓度和退火温度、循环次数等影响RAPD扩增的重要因素进行优化,以期建立最优的RAPD反应体系与程序。实验结果表明:各因素最适条件为:25μL PCR反应体系中,10×Buffer 2.5μL,MgCl22.5 mmol/L,dNTP0.4 mmol/L,随机引物960 pmol/L,Taq酶0.5 U,模板DNA 20ng;退火温度为37℃,循环次数为45次。在对谷蠹进行RAPD分析时,采用优化的反应条件,规范实验操作,使用同厂家同批次的试剂,实验结果就会具有很好的重复性和稳定性。 相似文献
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THERMODYNAMIC ANALYSIS AND PERFORMANCE EVALUATION OF CONVECTIVE HEAT TRANSFER THROUGH DUCTS 总被引:1,自引:0,他引:1
Li Yourong Jin Mingcong Tang Jingwen 《保鲜与加工》1992,(3):68-72
A second law analysis is carried out on convective heat transfer in fully developed region with constant wall temperature through circular, trianglar and rectangular ducts. Besides, the entropy generation rate expression is obtained and the loss rate of available energy in convective heat transfer processes is defined as well. At the same time, the influence of initial temperature difference between fluid and wall as well as the influence of fluid friction on the loss rate of available energy is discussed. Then, the thermodynamic performances of several typical ducts are compared. Finally , the optimum initial temperature difference with the minimum loss rate of available energy is also obtained. 相似文献
9.
Ren Yuanzhi 《保鲜与加工》1994,(1)
The condition when forces are applied to load mechnical mornent limiter of tow-er cranes is analysed and disctissed in this paper.A lifting performance curve adapted for the me-chanical load moment limiter is also obtained.And finally,the curve drawing method is explainedthrough the practical example. 相似文献
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Gong Jinxin 《保鲜与加工》1992,(4)
In this paper,the four-moment reliability analysis method for perfopmance function implicit structure is discussed. Discrete formulas expressed by Gauss-quadrature are presented when determine the parameter of probability density function which is established based on maximum entropy theory. The method in this paper is proposed for performance function implicit structure. Particularly, the discrete formulas used in this paper largely reduce calculating work with the same precision, so that the time-consume problem of four-moment reliability anlaysis is solved. 相似文献
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This paper presents an optimization method for solving the boundary value question of a differential equation on the basis of the trial-and-error method and the optimization method. As compared with the differential method, this method has some advantages such as quiker velocity at count, higher precision(especially at the boundary points) and can be widely used. 相似文献
13.
Chen Qigao 《保鲜与加工》1996,(1):9-26
This paper studys the appraisal of thermal performance quality of cold storage. Analyses therom-moist perfomance of envelopes of cold storage and cheCks them with the measured data tested in site for seven cold storages, presents a optimum construction proogramme for fruit cold storage. 相似文献
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A model and a heuristic algorithm for reliabilty op timi zation in generalized stochastic flow networks are proposed in this paper. The stochastic characteristic of the demands at terminal nodes is considered in the model. The algorithm proposed is powerful and can be applied to optimal planning of transmission capacity for large scale stochastic flow networks, because it can facilitate a fast location of optimal capacity expansion from the information obtained by the last iteration by making full use of the relationships of the k-weak link set and failure events set to the paramsters in generalized stochastic flow networks 相似文献
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南阳彩色小麦中氨基酸含量的研究及初步评价 总被引:1,自引:0,他引:1
研究南阳彩色小麦中氨基酸的含量水平,为该小麦系列新品种的开发利用提供科学依据,以南阳灰色、蓝色、紫色小麦为原料,以河南几种豫麦品种为对照,用高效液相色谱法对其氨基酸组成和营养品质进行了初步分析.实验结果表明:南阳彩色小麦的氨基酸含量较高,质量分数依次为普通紫色小麦15.88%,硬质紫色小麦15.63%,蓝色小麦14.84%,灰色小麦为14.35%.小麦蛋白质中氨基酸的种类齐全,紫色小麦中苏氨酸的含量较普通小麦增幅115.15%.8种必需氨基酸比例合适,组成合理,其中酪氨酸和苯丙氨酸的比例较高.经综合分析,紫色上麦的营养价值较高,建议做进一步的开发研究. 相似文献
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Dong Liang Zhang Hongji Chen Junguo 《保鲜与加工》1990,(1):35-41
On the basis of the mechanism of the boiling heat transfer on low finned tube, the influence of the geometric parameters of low finned tube on boiling heat transfer is synthetically analyzed and relevant criteria which affect the optimal structure of low finned tube is deduced in this paper. The boiling heat transfer experiment on low finned tube is conducted. Distilled water and R-113 are used as test fluids The experiment is performed at local atmospheric pressure. Synthesizing a large amount of experimental data, the semiempirical equations for the optimal geometric parameters of lowfinned tube are established 相似文献
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Yu Zhigang Wang Bingle Song Liquan Zhou Shouguang Department of Mechanical Electronical Engineering 《保鲜与加工》1990,(2)
This paper introduces the main structure and function,the theor-etical basis and the main features of the computer aided design software system QT-SCAD for the steel structure of tower crane.The QT-SCAD is suitable for allkinds of movable or fixable tower crane with level arm which rotates above thecrane body,and has single or double hanging points.It can be used for the stre-ngth,stiffness and stability analyses of the structure,the vibrative and dynamiccalculation of mechanisms and structure,and the optimal design of the structureof tower crane or its components. 相似文献