知识表示在牡丹栽培技术专家系统中的应用

介绍了协同式专家系统的概念和基于关系的知识表示的原理，详细分析了牡丹栽培技术专家系统中用于知识表示的关系模式，提出了一种协同式专家系统的设计方案。     

Analysis of the most energetic late arrival in axially transmitted signals in cortical bone

Axial transmission techniques are particularly suitable for the ultrasonic assessment of cortical bone. The generic term "axial transmission technique" indicates a measurement configuration in which emitters and receivers are placed on the same side of the skeletal site, along the bone axis. Whereas axially transmitted signals are composed of several contributions, only the first arriving signal was shown to be a robust indicator of bone status, because its velocity discriminates osteoporotic from healthy patients in clinical studies. Later arrivals may provide additional bone indicators enhancing diagnostic value, but the precise determination of their velocities is challenging. In this paper, we focus on the most energetic contribution and we applied a singular-valuedecomposition- based extraction method not yet employed in the domain of bone assessment with the aim of determining the velocity of this contribution. Signals acquired in vitro on human radii, together with academic models, were used to reveal the relationship between the velocity of the most energetic component and bone properties. The velocity of the most energetic component is highly correlated to cortical layer thickness in the in vitro database (R² = 0.6, P < 10^-5; compared with R² = 0.20, P < 10^-2 for the first arriving signal), consistent with a flexural type of wave on regular tubes or plates. Conclusions are in agreement with published papers based on other axial transmission and signal processing approaches.     

非线性迟滞系统的参数分离识别

迟滞振动系统的非线性恢复力通常包含三部分：（１）仅与位移ｙ（ｔ）有关的ｇＮ（ｙ）；（２）仅与速度ｙ（ｔ）有关的ｈＮ（ｙ）；（３）有记忆恢复力ｒ（ｔ）。当ｒ（ｔ）可用图１的双折线模型来表示时，在ｙ＝ｙ＝０点，ｒ（ｔ）＝±ｒｓ，为常数值。据此可将ｒ（ｔ）分离出来。而后，考虑到ｙ＝０，通常ｈＮ（ｙ）＝０；ｙ＝０时，通常ｇＮ＝（ｙ）＝０，又可以将ｇＮ（ｙ）和ｈＮ（ｙ）分离开来。识别时，将ｇＮ（ｙ）和ｈＮ（ｙ）分别用正交的函数项级数来逼近。分离识别和正交性使运算过程大大简化。识别时应用响应的Ｆｏｕｒｉｅｒ变换所得的频域函数，又增加了抗噪能力，提高了识别精度。     

In situ crystallisation in ZrO2 thin films during high temperature X-ray diffraction

The crystallisation behaviour of ZrO₂ thin films on Si(0 0 1) wafers, deposited either by ALCVD or by evaporation, was studied by using high temperature grazing incidence X-ray diffraction. The tests indicate that the crystallisation temperature of the ZrO₂ films is depending on the film thickness, but below 500°C. The possibility of using these films as high-k gate stacks is discussed, with respect to the crystallisation temperatures measured in the films.     

油相-气相两相流对湿式离合器带排转矩影响的数值分析

为减小怠速工况下湿式离合器因油液剪切产生的带排转矩,考虑油相-气相两相混合的影响,对摩擦副油路进行数值求解。基于k-ε两层湍流模型和欧拉方法中流体体积模型,采用流场计算STAR-CCM+软件建立含径向槽的摩擦副内流域模型,进行稳态计算。研究入口流量和相对转速对带排转矩的影响,并与试验结果进行对比,结果趋势相似,平均数值误差7. 54%.改变槽角结构,研究油相-气相两相流动同带排转矩的相关性。结果表明:入口流量越大,带排转矩越大,当流量为7 L/min时,带排转矩最大值为4. 63 N·m;当流量由7 L/min分别降低至5 L/min、3 L/min时,带排转矩值分别下降20. 95%、33. 69%;槽角有利于减小带排转矩,负向槽角的优势更为明显;单相流转速区,正向槽角越大,油液流通性越好,带排转矩越大;两相流转速区,槽角越大,油液连续性越差,油液占比越小,带排转矩越小。     

渗碳炉单片机控制系统的研究与实施

主要介绍井式渗碳炉渗碳过程中单片机控制系统的构成和设计要点。该系统可实现对工艺过程中7段温度、炉气碳势值及运行时问的自动控制。文中还对系统的硬件构成及软件设计措施进行了详细地描述。     

LSPMIS系统分布式数据库设计

本文论述基于网络的MIS系统中分布式数据的特点、功能和设计与实施技术，并结合LSPMIS系统中分布式数据库的具体设计与实施给出了设计过程、步骤、方法和结果。     

Robust self-tuning control based on discrete-time sliding mode for auto-regressive mathematical model in the presence of unmodelled dynamics

In this paper, we propose a new robust self-tuning control, called the generalized minimum variance αl-equivalent selftuning control (GMVSTC-αl) for the linear timevarying (LTV) systems, which can be described by the discrete-time auto-regressive exogenous (ARX) mathematical model in the presence of unmodelled dynamics. The estimation of the parameters contained in this mathematical model is made on the basis of the proposed modified recursive least squares (m-RLS) parametric estimation algorithm with dead zone and forgetting factor. The stability analysis of the proposed parametric estimation algorithm m-RLS is treated on the basis of a Lyapunov function. A numerical simulation example is used to prove the performances and the effectiveness of the explicit scheme of the proposed robust self-tuning control GMVSTC-αl.     

芒砀山地区地热资源开发条件分析

分析了芒砀山地区区域地热背景、大地热流及地下水的水文地质特征,探讨了影响现今地温和热流分布的地质构造背景,最后通过对地热田盖层、控热导热及热储构造进行评价,阐明了地热田的成因模式.运用电测深法进行岩性剖面划分,确定了有利的含热地段.