简易温控装置在轴流风机保水降温通风中的运用

轴流风机常用于保水降温通风,通风时间相对延长,把握最有利低温时机较难,保管员工作量相对增大,将简易温控装置应用于轴流风机保水通风过程中,既能解决把握低温通风时段难和保管员工作量相对增大的问题,又能达到降温、保水和降低通风单位能耗的目的。     

THE SPECIFIC OPERATING SIZES AND THE DIGGING PATH ENVELOPING DRAWING FOR HYDRAULIC EXCAVATOR WITH BACKHOE ATTACHMENT

This paper introduces the calculating methods of bucketteeth position,specific operating sizes and respective lengths of 3 setsof hydraulic cylinders by coordinate transformation,establishes themathematical models of digging path enveloping curve and presents thecalculatinig method of the enveloping drawing area.In the meantime,example is given.     

CALCULATING APPROACH FOR SOLVING LARGE-SCALE POWER SYSTE WITH TOPOLOGY AND PARAMETER GHANGES

A straightforward and unified approach for solving the large-scale, faulted power systems is presented in this paper. In contrast .with conventional algorithms, the various changes of topology and impedance of the systems and its boundary conditions of fault can be handled flexibility and effectively in one-step procedure by proposed method, and it is convenient to choose the computational procedure more resonable according to the situation of power systems. One of the noteworthy features of the proposed method is the natural manner to handle mutual effects, and it is easy to design programs. The calculating technique for easy-to-program is given in this paper. It shows that effectiveness of calculating large-scale faulte power systems with topology and impedance changes by the modified current sources.     

AN OPTIMIZATION OF THE DIE PROFILE SURFACE FOR THE DEEP- DRAWING PROCESS OF CYLINDRICAI. CUPS WITHOUT A BLANKHOEDER

The die profile on the drawing performance is invrstigaled by the optimization method. The optimization model based on the critical condition of wrinkling is established the optimization solution can avoid the accurrence of wrinkinp; and assure the smallest Fmax and the biggest deep-drawing ratio.     

THE SUFFICIENT AND NECESSARY CONDITION FOR A PLANAR TO BE HAMILTONIAN

This paper presents a sufficient and necessary condition for any planarembedding G(namely plane graph)of a planar graph to be Hamiltonian.If Gis Hamiltonian,a method that an adjacent edge subgraph method for finddingits Hamilton cycles are given.     

A MULTI -OBJECTIVE FUZZY DECISION -MAKING APPROACH FOR POWER NETWORK PLANNING UNDER UNCERTAINTY

This paper proposes a multi - objective fuzzy decision - making approach for power network planning under uncertainty ,which simutaneously considers not only the least investment cost,the minimum power loss,the maximum reliability,and the least environmental impacts, but also the uncertainty about the future load growth and the capital investment availability. The validity and effectiveness of the proposed approach is verified with numerical examples.     

求解粮食调运问题的两阶段优化算法

粮食调运优化问题过去已有研究,但是当问题较为复杂时,传统算法就要花费大量时间而且准确性也难以保证.针对这一缺陷,本文对已有的粮食调运模型进行改进,并基于该改进模型提出了一个解决粮食调运优化问题的两阶段求解方法,在第一阶段,由图搜索算法产生所有可行的运输路线,并根据约束条件对搜索树进行剪枝;在第二阶段,采用蚁群算法从第一阶段产生的可行路线集合中选取最佳路线,使总的运输成本最低.经过实例测试,该算法在粮食调运过程中具有较好的效果.     

A METHOD OF FILE TRANSFER AND CODE CONVERSION FOR THE DIFFERENT KINDS OF COMPUTERS

The interconnection of different kinds of computers is the main evalution direction of modern computer network. Sharing the data file is one of the target of implementing network interconnection. The paper wants to discuss how to rapidly transfer various files after implementing interconnection between the different kinds of computers and give a detailed implementing principle for file transfer and code conversion.     

A NONLINEAR PROGRAMMING MODEL AND ITS ALGORITHM FOR TRANSMISSION NETWORK PLANNING

The problem of transmission network planning is studied thoroughly by applying the mathmatical optimal tecqhniue in this paper. A novel approach is put forward for computer aided transmission network planning, which is quite different from what is based on D.C. load flow equations. A nonlinear transmission planning model is set up by regarding A.C. load flow equations as the system model. A practical model which can be solved more easily, and an united algorithm are obtained by applying the SUMT to the nonlinear model. The results of some practical examples indicate that this method can not only make the planning results more accurate, but also provide the voltage qualities and produce planning plans autometically and seek the plans optimally and fast.     

STUDY ON YINCHUAN, A FAMOUS CITY WITH BEAUTIFUL SCENERY AND CHARACTERISTICS IN THE NORTH OF THE GREAT WALL

This paper presents the style and features of Yinchuan with a long history and culture,and analyses the relations between protection of the city and the modernization of the city.     

A STUDY ON HEAT AND MOISTURE STATE OF HULL LAYER FOR THERMAL INSTULATION OF A COLD STORAGE

This paper analyses the thermal moist characteristics of the hull layer beside an air layer at lower temperature in an envelope for a cold storage and presents a new method of waterproof by air layer. With test data from engineering practice, the theory on the barrier of self moisture proof at the surface sublayer of the hull layer in an attic on a cold storage is proven. The dried zone about three phase point is confirmed. It is a new knowledge for thermophysics on thermal design of a cold storage with an optimum thermal performance.     

A NEW COMPENSATIVE SNUBBER FOR ELIMINATING THE SURGE AND NOISE IN PWM CONVERTERS

A new compensative snubber is presented for eliminating the surge current and high frequency parasitic oscillation in rectified circuit of the PWM DC-DC converters. The output surge and noise voltages are de-creased over 4/5. The working principle of the sunbber is analyesd in detail, the designing formulas are derived. The theoretic analysis is consistent with the experimental results.     

畜禽全、半同胞有规律系谱迭代法计算近交系数的研究与应用

在实践中研究出用迭代法计算有规律系谱畜禽的近交系数.在满足使用条件下,此法不必查找通径回路数,即可用计算机迅速、准确地算出多世代育种个体的近交系数.已实际应用于蛋鸡育种的数值计算中.比用人工查找通径法计算近交系数提高工效60倍以上.获得良好结果.因方法简便也适合于手算,有实用价值.但本迭代公式并非通用近交系数计算公式,有使用条件.这是其局限性.有待于进一步研究发展.     

A NEW METHOD FOR AMELIORATING INDOOR THERMAL ENVIRONMENT BY DEHUMIDIFYING

The climate in the region of the Yangtze River is sultry in summer and wet and cold in winter. The conventional building measures are shading in summer and insulating in winter,which have heen gotten some effects. Becasue the sultry,wet and cold sensation still affect, the indoor thermal environment can not get an ideal improvement. This paper shows that the new method by dehumidifying is the most effective and the most economic.