百色水利枢纽人工砂石加工系统

介绍百色水利枢纽主坝工程人工砂石料加工系统的生产规模、工艺流程、主要设备的选择与配置、系统的平面布置、环保措施、生产过程中质量控制、系统的供电电气控制和系统运行中发现的问题及改进措施     

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概要介绍了人工智能（AI）技术的应用和发展：AI与传统问题求解、AI与人类知识之区别以及AI技术应用分类，并在此基础上，提出了AI技术解决油气勘探开发工程中非均质、多样性、变异性、不精确性、不确定性的复杂系统难题的应用实现方法以及应用领域分类，介绍了AI应用技术的新方法并指出了发展方向。     

人工水晶的压痕断裂行为及其 K_(1c)测量

藉助于声发射技术,研究了在 Vickers 钻石压头作用下人工水晶的压痕断裂行为。压头对角线与晶体试样的相对取向是,使得水晶Ⅰ和水晶Ⅱ的压痕诱发径向/中位断裂,分别沿着(10(?)0)/(1(?)10)和(11(?)0/(1(?)00)晶面对发展。压痕断裂过程中的声发射特征表明,除了随着压痕特征参数的发展所引起的准静态—声发射外,有三个相互独立的,与径向/中位裂纹的成核、径向/中位裂纹突入试样表面、以及裂纹分岔或侧向裂纹萌生等过程相关的声发射效应。以 Vickers 压痕技术测得 K_(c2)的结果与以一般力学法及 Knoop 压痕技术的测试结果作了比较。断裂韧性与晶体学取向的关系亦作了分析。实验表明,水晶Ⅰ和水晶Ⅱ具有相同的 K_(1c)值。其原因是,两种试样的径向/中位裂纹实际上沿着同样的{1100}/{1120}晶面对扩展。至于从缺口梁法或 Knoop 压痕技术得到的 K_(1c)值,由于水晶Ⅰ和水晶Ⅱ的主裂纹分别沿着(1(?)10)和(1(?)00)晶面扩展;它们的 K_(1c)值与断裂能随着晶体学取向而变有关,因而也就各不相同。     

基于人工神经网络BP算法的倒立摆控制研究

基于人工种经网络BP算法的倒立摆小车实验仿真训练模型，其倒立摆BP网络为4输入3层结构．输入层分别为小车的位移和速度、摆杆偏离铅垂线的角度和角速度．隐含层单元数16个．输出层设置为1个输出单元．输入层采用Tansig函数，隐含层采用Logsig函数，输出层采用Purelin函数．用Matlab6．5数值计算软件对模型进行学习训练，并与模糊控制逻辑算法对比，表明倒立摆控制BP算法精度高、收敛快，在非线性控制、鲁捧控制等领域具有良好的应用前景。     

Relationship between physicochemical properties and maximum residue levels and tolerances of crop-protection products for crops set by the USA, European Union and Codex

Residues on foodstuffs resulting from the use of crop-protection products are a function of many factors, e.g. environmental conditions, dissipation and application rate, some of which are linked to the physicochemical properties of the active ingredients. Residue limits (maximum residue levels (MRLs) and tolerances) of fungicides, herbicides and insecticides set by different regulatory authorities are compared, and the relationship between physicochemical properties of the active ingredients and residue limits are explored. This was carried out using simple summary statistics and artificial neural networks. US tolerances tended to be higher than European Union MRLs. Generally, fungicides had the highest residue limits followed by insecticides and herbicides. Physicochemical properties (e.g. aromatic proportion, non-carbon proportion and water solubility) and crop type explained up to 50% of the variation in residue limits. This suggests that physicochemical properties of the active ingredients may control important aspects of the processes leading to residues.     

Parameter Estimation in Groundwater Hydrology Using Artificial Neural Networks

The capability of artificial neural networks to act as universal function approximators has been traditionally used to model problems in which the relation between dependent and independent variables is poorly understood. In this paper, the capability of an artificial neural network to provide a data-driven approximation of the explicit relation between transmissivity and hydraulic head as described by the groundwater flow equation is demonstrated. Techniques are applied to determine the optimal number of nodes and training patterns needed for a neural network to approximate groundwater parameters for a simulated groundwater modeling case study. Furthermore, the paper explains how such an approximation can be used for the purpose of parameter estimation in groundwater hydrology.     

An active microphotodiode array of oscillating pixels for retinal stimulation

We have developed an active microphotodiode array (MPDA) for retinal stimulation. The unique feature of the device is that each pixel acts as an independent oscillator, whose frequency is controlled by the incident light intensity. The design is based on a double inverter relaxation oscillator, and the photodiodes are of PIN-type. These oscillating pixels stimulate the nervous tissue with bipolar pulses. The prototype stimulator chips are realized in standard 0.35 μm CMOS technology. The reported preliminary data and performance demonstrate the potential of the new concept for future retinal prostheses.     

Production of a functionally graded artificial tooth root by unique sequence of processes

 A unique sequence of processes is used to produce a prototype of a functionally graded artificial tooth root: (1) Dry-jet spraying of the mixture of Ti and Al₂O₃ ultrafine particles (UFPs) produced by radio-frequency plasma onto the surface of a cylindrical Ti rod, where the composition of the UFPs is changed gradually in the outward radial direction from Ti to Al₂O₃; (2) Temperature-gradient sintering of the deposited composite, where the Ti – and the Al₂O₃– rich sides are heated simultaneously at about 1400 K and 1800 K, respectively; (3) Plasma spray coating of hydroxyapatite (HAP) onto the outermost Al₂O₃ surface of the sintered composite. The final product has compressive strength of more than 200 MPa and is durable against fatigue test of 10⁷ stress cycles at 1000 N. The adhesion strength between the Ti substrate and the Ti-Al₂O₃ functionally graded layer exceeds 65 MPa. No contamination with heavy metals is detected throughout the processes and biological cell growth is confirmed to occur on the HAP surface. With these mechanical and biochemical properties the composite produced here is considered to be highly suitable for an artificial tooth root. A series of processes developed here are expected to be applied to the production of various kinds of fine-grained functionally graded materials with complicated forms. Received: 13 October 1997 / Accepted: 27 October 1997     

Hygienic Aspects of Ground-Coupled Air Systems

Abstract Numerous ground-coupled air systems have been constructed in combination with heat recovery units in mechanically ventilated buildings in Switzerland. The objective of this study was to investigate the microbial content within these ventilation systems and to monitor the quality of the air supply. The concentrations and the types of microorganisms in the outdoor air, in the air of the pipes and in the supply air of twelve ground-coupled air systems were determined. In addition, three buildings were examined four times a year to cover seasonal changes. In general, the concentrations of fungal spores and bacteria in the air at the end of the underground pipes were lower than in the outdoor air, but great differences were observed between ventilation systems of large buildings and one-family houses. Occasionally, an increase in the concentration of Penicillium, Aspergillus or Actinomycetes was noted within a piping system. The concentrations in the supply air behind the filters were always low. Based on these investigations, the operation of ground-coupled air systems can be recommended as long as regular controls are undertaken and cleaning facilities are available.     

降低物业人工成本的方法初探

人工成本在物业成本中比例很大 ,而且呈刚性增长趋势 ,必须降低。绝对降低人工成本和相对降低人工成本是降低物业成本的两条途径。降低人工成本也是企业内部改革的一项重要措施。