车辆AMT离合器离散变结构控制

以车圆舞曲机械式自动变速系统（AMT）的离合器液压执行机构为研究对象，建立系统非线性动力学模型。进一步应用基于微分几何的反馈线性化方法，将原非线性系统等价为完全可控型线性化模型。在此基础上设计了离散变结构控制器，并且证明了离散变结构系统的稳定性，实验结果证明，这一控制器跟踪精度高，并且对系统的非线性和不确定性表现出很强的鲁棒性。     

粘性Cahn-Hilliard方程的高精度线性化差分方法

讨论粘性Cahn-Hilliard方程的高精度线性化差分方法.利用降阶法对粘性Cahn-Hilliard方程建立三层线性化紧差分格式.用离散能量分析法证明差分格式的唯一可解性及在L_∞-范数下的收敛性,其收敛阶为时间方向二阶、空间方向四阶.最后,通过数值算例验证了差分格式的理论结果.     

Time dependence of hydraulic parameters estimation from transient analysis of mini disc infiltrometer measurements

The transient analysis of mini disc infiltrometer (MDI) measurements is an established method for characterising near-surface hydraulic characteristics of soils. The reliability of hydraulic characteristics obtained from transient analysis depends on the (1) adequacy of model, (2) adequacy of data, (3) measurement time and (4) measurement footprint. The measurement time dependence recommendations are reported only for a few soil textures, initially wet samples and tension infiltrometer (TI) with a higher measurement footprint than the MDI. This study investigated the adequacy of infiltration data (using cumulative linearization [CL] and differentiated linearization [DL]) and measurement time influence on the hydraulic parameters determined from the transient analysis of MDI measurements for six soil textures. The objective of the study is to identify suitable MDI measurement durations for different soil textures for the initially dry state, considering both adequacy of data and time fractionation (measurement time influence). The data adequacy time obtained from the DL (T_DL) was found to be 0.8 times less than the value obtained from CL (T_CL). The marginal difference in T_DL and T_CL had a significant influence on the determination of infiltration equation coefficient C₁ and negligible influence on coefficient C₂. The time fractionation procedure adopted for identifying adequate MDI measurement time (T_m) was found to be comparable based on sorptivity (S₀) and hydraulic conductivity (K₀). The average T_m was also comparable with T_DL and T_CL with a strong positive correlation. The C₂ values obtained based on T_m, T_DL, and T_CL were in better agreement than the corresponding C₁ values. The adequate MDI measurement times identified by considering T_m, T_DL, and T_CL were texture dependent, ranging from 45 min for silt to 120 min for silt loam and silty clay loam. For loamy sand, it was 50 min; for sand, it was 70 min, followed by 60 min for loam.     

SJ—1型数字粮食水分计的研制

Sj—1型数字粮食水分计采用平行板电容器作为传感器,较通用的圆柱形电容传感器性能稳定。测量电路及显示电路均采用数字电路。非电量经A/D转换后,通过EPROM查表的方法,实现了数据的线性化,测量精度高。     

一元非线性回归问题的改进方法

本文分析了用一般线性化方法解决一元非线性回归问题的各种缺陷。在此基础上,根据最小二乘法的思想,对Y=β_o·e~(β(1/x))+ε、Y=β_oe~(βx)+ε和Y=β_oX~β+ε三类回归问题提出了一种有效的改进方法     

基于鲁棒反馈线性化的联合收获机割台高度控制策略

谷物联合收获机割台高度控制非常重要,有效的割台高度控制有助于提高喂入量的稳定性、降低整机各环节的负荷波动。本文提出一种基于鲁棒反馈线性化的割台高度控制策略,该方法可以使割台跟随地面起伏进行俯仰控制调节。首先基于割台结构和动力学分析建立系统数学模型选取正弦角度的近似约简条件,将多变量的复杂非线性系统线性转换为典型的非线性系统;通过分析传统的反馈线性化控制研究可控仿射的模型构建方法,在集成鲁棒优化设计控制器基础上,提出鲁棒反馈线性化(Robust feedback linearization,RFL),通过构建灵敏度方程、选取增益来稳定系统;选取液压控制机构,根据控制液压输出的电流参数设计为基于鲁棒反馈线性化控制系统的控制器。将传统的PID控制和本文提出的鲁棒反馈线性化控制进行对比实验结果表明在不同行驶速度、地形正弦振幅和地形周期条件下,鲁棒反馈线性化控制下的高度误差均小于传统的PID控制;以3种不同行驶速度在同一起伏地面上行进,鲁棒反馈线性化控制下的高度误差受行驶速度增加的影响小于传统的PID控制。     

费用函数线性化影响因素分析

对非线性的费用函数利用线性化方法求解进行了探讨，研究了线性化过程对排放口规划结果的影响因素，得出区间划分、分段次数，参数大小均有不同影响程度的结论。     

Holling圆盘方程拟合的一种新方法

本文将Ｈｏｌｌｉｎｇ圆盘方程线性化后，运用线性化中的加权处理办法，提出了圆盘方程参数估计的误差加权方法，通过实例验证，本方法具有拟合精度高，计算量小，计算并不复杂便于应用等优点，同时可与Ｇａｕｓｓ－Ｎｅｗｔｏｎ及Ｍａｒｑｕａｒｄｔ迭代法的拟合相近，由于，可为建立天敌－害虫作用系统的量化关系提供了一种新的研究办法。     

Evaluation of a Radioimmunoassay Technique Measuring Calcitonin in The Bovine,Ovine and Porcine Species

A heterologous RIA system was set up for measuring bovine, ovine and porcine calcitonin (CT). The system consisted of porcine GT used as standard and for the preparation of an iodinated tracer. The antiserum used was raised against ovine GT. For each analysis was used 25–200 µl blood plasma. Practical detection limit was 0.25 µg of CT per litre of blood plasma.The parallelism between the dose response curves for the p-GT standard and for the assay of increasing amounts of bovine, ovine and porcine blood plasma showed the suitability of the present assay system to study the GT secretion in these species. Furthermore, the reliability of the method was verified by a clearly recognized CT response to calcium infusion.     

关于中立型时滞微分方程的线性化振动性问题

本文证明了：在适当的假设下，一类非线性中立型时带微分方程的一切解振动的充要条件是与其相关联的一个具周期系数的线性方程的一切解皆振动。