磁流变减振器的模糊控制及实验研究

基于磁流变减振器的振动响应信号,将模糊控制方法应用于磁流变减振器的控制。实验结果表明,模糊控制器能有效地调节磁流变减振器在复原行程和压缩行程中的阻尼力,控制效果明显。     

超声波在渠道水位测量中的应用

介绍了气介式超声波测位仪在水位测量中的应用方法，并针对原型水位测量中的实际情形，着重讨论了温度、湿度对测量结果的影响和校正方法，以及信号的远距离传输和波动水面的数据采集和处理的有关方法。     

对局部运动模糊图像进行复原的研究

文章分析了导致运动图像模糊的原因,简要叙述了局部运动模糊的复原方法并建立了相关模型。引入了点扩展函数PSF,该函数含有两个模糊因子分别为模糊角度和模糊尺度,清晰图像在模糊因子和噪声的影响下变成模糊图像。为了简化计算,本文只考虑不加噪的退化模型。在对图像进行恢复之前,首先考虑将运动模糊物体与背景图分离,这里采用了RPCA算法。然后通过对已提取出的图片的频谱图的分析得到模糊角度,采用微分自相关PDA的方法就可以得到模糊尺度。在复原的过程中,选取了常用的维纳滤波法对局部运动模糊的图像进行复原。     

传感器输出特性的线性处理

介绍了传感器电源和放大电路在系统中的重要性，提出了通过合理设计传感器电源、信号放大电路以及用面向对象程序设计方法编制的线性回归数据处理程序达到提高系统精度和可靠性的方法。     

农机振动信号处理方法应用现状和展望

介绍了振动信号处理方法在农机振动研究中的重要性,总结了国内外农机振动信号分析所使用的三种处理方法——幅值法、频谱法和小波变换,对比分析了这三种方法的适用性和优缺点。结果表明:当前的农机振动信号处理方法存在应用单一且片面的问题。农机振动信号处理方法全面化、系统化的应用是其未来的发展方向。     

基于DSP的光伏水泵无刷直流电机的控制研究

介绍了应用于光伏水泵系统中的直流无刷电机及其控制方法，利用定子绕组反电势信号，用TI公司的TMS320F2812DSP实现了对直流无刷电机的控制。实验证明，过零点识别电路简单有效，三段式起动适用于光伏水泵系统。     

双向进水流道模型脉动压力测试及其特性

分析了脉动压力测试过程中的主要影响因素，针对泵站流道模型脉动压力的测试主要受水泵振动影响的特点，提出了采用隔振原理进行模型设计，从而有效减小水泵运行时振动对脉动压力信号影响的方法，成功地对水泵启动及稳定运行过程中流道内的脉动压力进行了量测，并根据水泵不同的运行方式，采用不同的采样频率对脉动压力信号进行采集和分析处理，得出了各种工况下脉动压力的幅值和频域特性。     

基于EDM-VKF的转子时变复杂信号时频表示方法

轴轨道的时频表示已被证明是分析非平稳振动信号的有效工具，但是传统时频表示方法分辨率较低，不易区分分布较近的特征频率。为解决该问题，提出转子时变复杂信号时频表示方法，首先运用基于经验模态分解的多尺度小波阈值降噪算法处理原始信号，得到降噪后的转子振动信号；其次针对信号时频谱图，引入欧几里得距离重构时频矩阵，不但提高信号的时频聚集性，而且使时频矩阵具有更好的极值点连贯性避免极值点偏移，进而更准确地检出时频脊线并估计信号基频分量瞬时频率值；最后采用Vold-Kalman滤波器在时域信号中分离基频和其谐波分量，并计算谐波分量的瞬时全谱参数，构建转子信号的高分辨率时频表示。通过对转子系统模拟仿真信号和转子不对中信号分析，验证了该方法的有效性。     

引起绝缘监视装置动作的三种故障分析

在１０ｋＶ交流不接地系统中，有多种故障能引起绝缘监视装置动作，可发出的故障信号却都是“单相接地”，混淆了运行视线。该文就此对单相接地、断相、互感器高压保险熔断三种故障进行分析，并指出了在实际中的判别方法。     

引起绝缘监视装置动作的三种故障分析

在１０ＫＶ交流不接地系统中，有多种故障能引起绝缘监装置动作，可发出的故障信号却都是“单相接地”，混淆了运行视线。该文就此对单相接地、断相、互感器高压保险熔断三种故障进行分析，并指出了在实际中的判别方法。     

Overland water and salt flows in a set of rice paddies

Cultivation of paddy rice in semiarid areas of the world faces problems related to water scarcity. This paper aims at characterizing water use in a set of paddies located in the central Ebro basin of Spain using experimentation and computer simulation. A commercial field with six interconnected paddies, with a total area of 5.31 ha, was instrumented to measure discharge and water quality at the inflow and at the runoff outlet. The soil was classified as a Typic Calcixerept, and was characterized by a mild salinity (2.5 dS m⁻¹) and an infiltration rate of 5.8 mm day⁻¹. The evolution of flow depth at all paddies was recorded. Data from the 2002 rice-growing season was elaborated using a mass balance approach to estimate the infiltration rate and the evolution of discharge between paddies. Seasonal crop evapotranspiration, estimated with the surface renewal method, was 731 mm (5.1 mm day⁻¹), very similar to that of other summer cereals grown in the area, like corn. The irrigation input was 1874 mm, deep percolation was 830 mm and surface runoff was 372 mm. Irrigation efficiency was estimated as 41%. The quality of surface runoff water was slightly degraded due to evapoconcentration and to the contact with the soil. During the period 2001–2003, the electrical conductivity of surface runoff water was 54% higher than that of irrigation water. However, the runoff water was suitable for irrigation. A mechanistic mass balance model of inter-paddy water flow permitted to conclude that improvements in irrigation efficiency cannot be easily obtained in the experimental conditions. Since deep percolation losses more than double surface runoff losses, a reduction in irrigation discharge would not have much room for efficiency improvement. Simulations also showed that rice irrigation performance was not negatively affected by the fluctuating inflow hydrograph. These hydrographs are typical of turnouts located at the tail end of tertiary irrigation ditches. In fact, these are the sites where rice has been historically cultivated in the study area, since local soils are often saline-sodic and can only grow paddy rice taking advantage of the low salinity of the irrigation water. The low infiltration rate characteristic of these saline-sodic soils (an experimental value of 3.2 mm day⁻¹ was obtained) combined with a reduced irrigation discharge resulted in a simulated irrigation efficiency of 60%. Paddy rice irrigation efficiency can attain reasonable values in the local saline-sodic soils, where the infiltration rate is clearly smaller than the average daily rice evapotranspiration.     

瓦房店市水果生产标准化发展研究

瓦房店市是我国重要的水果生产基地,在国内水果生产领域占有重要地位。随着水果市场化的不断深入,如何满足和适应国内外市场需求成为瓦房店市水果生产的关键问题。从瓦房店市水果生产实际出发,阐述了实施水果生产标准化的必要性,提出了发展水果生产标准化的具体措施。     

金谷子耐旱TG118引种试种及推广应用

对引进的谷子新品种金谷子耐旱TG118进行品种比较试验和多点试种。结果表明：该品种抗旱、耐瘠、适应性强,稳产、高产、抗病抗风抗倒伏强,品质优良,粮草兼用,种植简单,省工易管;一般产量在6000kg/hm2以上,比当地主栽品种增产20%以上。最高产量达9450kg/hm2,适于在辽西北地区推广应用。     

对《种子法》存在问题的探讨

《种子法》是我国种植业第一部法律。自实施以来,为依法加强种子管理提供了有力的法律支撑,促进我国种子产业发生翻天覆地的变化。但随着依法管理工作的深入和种子产业的快速发展,《种子法》及配套规章的一些问题逐步显现出来。对《种子法》及配套规章存在的问题进行深入分析,对需要进一步补充的章节以及需要调整的内容进行深入探讨,以求更加完善和明确。     

Review of the Egyptian experience in implementing land drainage projects

About 30 years have passed since the Government of Egypt embarked on implementing a series of large scale drainage projects. At present, about 3.8 million acres have been provided with drainage systems on the basis of systematic pre-drainage investigations and designs. The target is to provide drains in approximately 6.4 million acres in the Nile Valley and Delta.The implementation of the subsurface drainage system is carried out by the public sector and private contractors under direct supervision of governmental regional departments. The implementation process depends on many factors related to the drainage material, machinery, manpower, site requirements, farmers and organizations involved. Problems and constraints are sometimes challenging, however, the annual rate of implementation has gradually increased to 170,000 acre/year.This paper discusses the different aspects involved in the implementation process of drainage systems. The development in materials, machinery and construction technologies will be reviewed. Institutional and management factors are going to be also considered.     

和谐社会理论建设的几点哲学思考

在新世纪,面对机遇和挑战,党的十六大把“社会更加和谐”作为全面建设更高水平的小康社会的一个重要目标。中国人素有社会和谐的理想;西方人自古也向往社会和谐;借鉴东西方两种和谐社会思想的经验、教训,构建社会主义和谐社会理论。     

A European irrigation map for spatially distributed agricultural modelling

We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications.     

粉质仪和拉伸仪在面粉生产中的应用

在介绍粉质仪和拉伸仪结构和原理的基础上,探讨了粉质曲线中吸水率、形成时间、稳定时间、弱化度和评价值等指标与面粉品质的关系,以及如何根据拉伸曲线中面团最大拉伸阻力、延伸度和拉伸曲线面积等指标来评价面团品质,并结合生产实际,概述了粉质仪和拉伸仪在面粉生产中的作用。     

农村信息化服务的现状及建设措施

分析当前我国农村信息化服务的现状,提出加强农村信息化服务的新举措。     

车辆ABS控制算法的研究及探讨

对现代汽车的ABS控制算法作了一些简单的介绍,同时指出了它们的一些缺陷,相应地提出了几种对ABS的其它控制方法并加以探讨,其中着重论述了ABS门限值控制算法中参考车速的确定方法和基于附着系数的控制算法。