共查询到20条相似文献，搜索用时 15 毫秒
1.
超高温灭菌牛乳在贮藏过程中会出现一些质量问题(如脂肪上浮、结块、酸包和苦包等)。耐热酶具有较强的耐热能力,经超高温灭菌后仍有残留,因而导致产品出现上述质量问题。阐述了超高温灭菌牛乳在贮藏过程中会出现的质量问题及乳中耐热酶的性质;论述了产品质量问题与UHT乳中耐热酶的关系及其解决办法。 相似文献
2.
Cao Xinpu Xiao Baolin 《保鲜与加工》1988,(4)
In this paper the NP-complete problems are studied. They contain such important problems as the integer-programming and the Hamiltonian circuit problems which are worth studying but equally difficult to compute. Based on the thought of dividing and conquering-merge, an algorithm is designed, with which the knight's tour on an international chessboard can be quickly found. 相似文献
3.
Wu Shoubao 《保鲜与加工》1994,(2)
The problems of the current real estate are conscientiously analyzed.The maineight prublems of the current real eqtate are enumerated.In accordance with the problems.six coun-termeasures are advanced. 相似文献
4.
The improvement of research on simulation of structural seismic responses based on neural networks(NN) is reviewed in this paper.Three key problems to simulate linear structures,selection of NN model,determination of NN structure and control of simulating precision,are discussed and the method to deal with the problems are suggested.Main problems of the research on simulating nonlinear structures under the action of earthquake ground motions based on NN are presented. 相似文献
5.
Based on the present problems in university city planning of China, in this paper the reasons for these problems from viewpoint of axiology and methodology are analyzed and the corresponding planning methods are offered, finally the prospects for the future university city planning method are given. 相似文献
6.
Gan Jianxue Jiang Zejia Yu Jihui 《保鲜与加工》1991,(3):1-8
The spline boundary element method is presented for electromagnetic field problems. Based on B-spline function interpolation, the formulation of calculation of two dimensional statical electromagnetic field problems is obtained. Boundary corner and singular integration problems are efficiently handled. Furthermore,the Method is used for solving two calculation examples. 相似文献
7.
Due to a series of wonderful characteristics, submicron particles are of high value in national economy, defense modernization and high technology fields, with wide application prospects. Submicron particle sizing methods and techniques are difficult problems in particle research field. Modern methods for particle sizing are stated and analyzed. Some problems are discussed when these methods are used for submicron particles. 相似文献
8.
食品工程原理课程教学改革与实践 总被引：1，自引：0，他引：1
作为食品科学与工程专业课程体系中一门实践性和工程性较强的专业基础课,其教学质量的好坏直接影响着整个专业的教学质量。分析了目前该课程教学过程中存在的问题,并在教学过程中针对存在的问题,进行了课程教学的探索与改革,取得了较好的教学效果。 相似文献
9.
According to an analysis of three-dimensional convection diffusion problems and object-oriented programming method,the classes of finite element models for convection diffusion problems are designed in C++.There are vector classes,matrix classes,element classes,material classes and method classes of finite element among these classes.On the basis of these classes,an object-oriented finite element program for three-dimensional convection diffusion problems is accomplished,which is able to simulate similar problems.The program's reuse,maintenance expansion and integration with other ones are easier than traditional ones which are designed with structural language,it can be applied to a large universal computational software for science and engineering. 相似文献
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Considering the need in practical applications the authors extend thecomplementary variational principles from single-medium to multi-medium. The equivalencebetween variational problems and multi-region boundary value problems is proved,Utilizing theextended functional and complementary functional,we construct the complementary variationalproblem in a sinusoidal el ectromagnetic field.Several special forms in computating differentsinusoidal electromagnetic field problems are given. 相似文献
12.
探讨了出口速冻方便食品企业HACCP体系运行中易被忽视的关键问题,并针对这些问题提出了处理方法与改进建议. 相似文献
13.
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
14.
介绍了食品质量与安全专业的发展、发展中存在的主要问题和业务培养目标;指出了食品质量与安全专业食品添加剂教学存在的问题;并介绍了从优化理论教学内容和实验项目、改进教学方法和改革考核形式等方面的改革和实践。教改实践证明,改革效果良好。 相似文献
15.
关于发展都市农业的思考 总被引：6，自引：0，他引：6
都市农业是依托大城市发展起来的,反映了工业化和城市化发展后人类对新时代农业的一种探索,它是现代都市经济社会发展的必然趋势。在中国,都市农业是一种新形态,它对中国农业的发展与新农村建设具有重要战略意义。改革开放以来,由于城市经济社会高速发展,乡镇企业迅速崛起,大批小城市、小城镇、县城规模不断扩大,许多已经转为城市,都市型农业在中国的一些大城市中应运而生。在20多年的发展过程中,都市农业取得了显著的成就,但也存在着一些问题。因此,笔者从都市农业产生的背景出发,对都市农业的基本内涵和意义进行了描述,同时对中国都市农业的发展现状进行了综述,讨论了目前中国都市农业发展存在的问题,进而对都市农业的发展提出了建议。 相似文献
16.
Combined with the design practice in foundation excavation engineering,the problems for combined supporting from inner supports and composite soil nailing wall under binary geological conditions,including soil layers and rock stratum with weak intercalation in range of excavation depth,are analyzed.These problems mainly include the following: calculation model of earthen pressure,the local bearing capacity of foundations below steel pipe piles,stiffness coordination at the junction of rigid and flexible supports,internal bracing stability influencd by restrained condition of upright post,etc.Problems of concern for design of similar foundation pit supports are pointed out,and measures for solving these problems are proposed.All these can provide references for similar projects. 相似文献
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The environmental quality problems of construction engineering are endangering the existence and sustainable development of human beings, so their treatment is becoming common understanding of all levels of governments and the public. In this paper, the forming course and affecting factors of environmental quality and main symptoms of its problems are analyzed from the definition of environmental quality in construction engineering. Then, the essence of the problem is revealed, that is comprehensive abilities for quality activities and their results can't meet the regulated requirements. Finally, it expounds five basic characteristics of the problems to enhance people's understanding. 相似文献
19.
A sufficient and necessary optimality conditions is established for vector extremum problems with set constraint by applying the alternative theorem under generalized subconvexlike maps in orderd locally-convex Hausdorff spaces. Then, several optimality conditions are obtained for differentiable vector extremum problems with set constraint by applying the sufficient and necessary optimality conditions and the properties of the twice G-differentiable functions. And finally, the vector-valued Lagrange duality is obtained for the vector extremum problems. 相似文献
20.
摘要：中国农业问题产生的原因既有自然方面的,也有社会经济方面的。对自然的过分依赖性、劳动对象的生理性、生产的长期性、对土地的过分依赖性是中国农业问题产生的自然原因;工业化中农业的弱势地位、城乡间的制度壁垒等是中国农业问题产生的社会经济原因。 相似文献