数学建模方法在饲料配方设计中的应用

用数学建模的方法建立了饲料配方设计的数学模型,通过对0～6周龄的蛋用雏鸡饲料配方的设计及采用简便的EXCEL方法求解的介绍,为配合饲料生产提供了一个科学、简便、实用的配方设计方法。     

Application of a FDTD/MOMTD Hybrid Method to the Scattering Problem of the Ground Penetrating Radar

In order to analyze and research the scattering problem of the ground penetrating radar under the ground, a hybrid method combining FDTD and MOMTD is constructed to solve the problem. The curve of current on central feeding point of pick-up antenna is obtained by simulating when different distance between the ideal conductor and the ground is considered, correctness of the result gained by employing the hybrid method is proved through qualitative and quantitative analysis.     

Readout Method about Time Parameters in Network Based on the Structure of Abacus

This paper provides a simple method of readout of time parameters in network. It will be helpful to planning without calculation or with a little calculation.     

Apply the Hybrid Method of FDTD/MoM to Calculate the Radiation from the Aperture

This paper presents a hybrid method of the Finite-Difference Time-Domain(FDTD) and the method of moment(MoM) to compute the radiation from the aperture.The FDTD is a commonly used electromagnetic simulation way.It can solve the question with complex dielectric,but it is difficult(even cannot) for FDTD to calculate the far field because of large compute time and computer memory.So the authors can make use of the FDTD to get a large number of near electric field intensity,and then use the MoM,which based on electric field integral equation to compute the far field.Using this procedure,the authors solve the radiation of the box with apertures on one or more sides and reduced the compute time and the computer memory.     

凯氏定氮法测定豆粕中蛋白质的不确定度评定

粗蛋白是评定饲料原料及其产品的重要指标之一,在理化分析中,测定结果存在不确定度。找出影响测量不确定度的因素,对各个不确定度分量进行评估和计算合成,并最终得出豆粕中蛋白质含量的合成标准不确定度和扩展不确定度。分析了不确定度的来源,提出减小不确定度的方法。     

Damage Analysis on Coal and Rocks and the Method of the Checking Damage by the Deviator Stress

The characteristic of the original damage and the breaking of the coal and rocks under the loading has been discussed by a lot of microscopic structure analysis and by whole stress strain testing on the coal and rocks. The non homogeneity causes the stress locating in a small spot. It is the essential cause of the damage developing and causing the structure breaking of the coal rocks. The failure of brittle fracturing, rubbing later on and granulating should be a major pattern in the outburst of coal and gas. The method of the examining damage by the deviator stress, is proposed. It can be used to analyse the characteristic of the coal and rocks.     

新型城镇化背景下长三角城市群产城融合路径探讨

产城融合是针对城镇化推进的形势和问题提出的新理念,作为产城融合进程中产业繁荣的投入要素和城市建设的服务对象,人的发展是产城融合的出发点和根本落脚点.因此在人本视角下以产-城-人系统协同发展为导向探究区域产城融合进程和路径具有重要意义.基于城市建设、产业发展和人的发展三者的内在作用机制,利用熵权法将长三角城市群的产城融合...     

几种凯氏加速剂对植物全氮消煮时间和结果的比较分析

探讨了几种凯氏加速剂对植物全氮的消煮测定情况,浓H2SO4分别加入K2SO4 CuSO4、H2O2、K2SO4 CuSO4 Se和Na2SO4 Se对苜蓿、高丹草、狼尾草、油菜花粉等4种植物材料进行消煮和测定,统计结果表明:消煮液在380℃消煮清亮后继续加热120 min,测定的全氮差异显著,K2SO4 CuSO4、K2SO4 CuSO4 Se和Na2SO4 Se分解出的氮较多,加入H2O2氧化分解出的氮少;含Se的加速剂消煮所需时间最短,H2SO4加入H2O2消化速度最慢;样品消煮清亮后应继续加热40 min以上;用Na2SO4 Se作加速剂代替H2SO4 H2O2可同时测定植物氮磷钾。     

Computation of Scattering of Electromagnetic Waves from Absorbing Coating Using the Finite Difference Time Domain Method

In this paper,we derive the necessary extension to the FD TD(finite difference time domain) method for absorbing coating of composite material.The scattering of electromagnetic waves(EW) from absorbing coating is considered,and the comparision of obtained results with exact analytic ones shows that the method used in this paper is correct and available.     

Research On Laws of Actually Consolidation time Calculate in Saturated Soft Clay Soil by Using Vacuum-Preloading Method

Vacuum-surcharge combined preloading method have been become the most commonly used method on the dredger fill and saturated soft clay soil consolidation beside the coast.The long time of consolidation is one of this method’s most characteristics,as we always think that 3 months is the academic time.In fact,we always can’t accomplish the consolidation of siaturated soft clay soil by using vacuum-surcharge combined preloading method in 3 months because of the complex nature of the soil horizon and the effects of the construction technology.The mian mission of the article is to supply a substantial time and a reliable basis that are needed by the vacuum-surcharge combined preloading method and the construction period.The mian data sources are come from the ground treatment project of a cogeneration power plant in Zhuhai Guangzhou.We adopt the exponential curve fitting method and the method of Asaoka to count the degree of consolidation of the saturated soft clay soil.     

Evaluation of the Energy Release Rate of Three-point-bending Beam Using Finite Element Method

Calculation of the energy release rate with finite element method (FEM ) is conducted. The concrete beam model is meshed using a method without need of considering the crack-tip singular element. Two columns of nodes, which belong to the right-and left-parts of the beam, respectively, are generated on the central line of the model and released one after another in a proper sequence. Energy release rate is evaluated based on the virtual crack closure technique. Comparison between the calculated values and theoretical values is made, which shows that they are in good agreement.