基于远程监控的农业气象自动采集系统设计

针对传统农业气象观测和当前传感器技术系统、方法存在的不足,设计了一套基于远程监控的农业气象自动采集系统,其硬件设备由农田小气候信息采集前端、视频图像信息采集前端、数据采集装置、数据传输装置和供电设备组成。该系统实现了农田小气候和视频图像信息参数采集与传输的高度集成,自动采集降水量、气温、空气湿度、风速、风向、光合有效辐射、土壤温度、土壤湿度和农作物视频图像信息,并通过远程客户端软件实现各要素信息的实时动态显示和远程监控。通过在郑州市、鹤壁市、温江市和荆州市开展的采集试验和系统试运行表明,系统显示出较好的稳定性,农田小气候和视频图像要素数据的采集、传输、动态实时显示与远程监控等各项功能均可满足各级用户需求。     

导向管喷动床中煤和稻秸粒混料的流动特性试验

将导向管喷动床改进为煤粒和稻秸粒混料气化设备,通过导向管喷动床内进行的稻秸粒与煤粒混合物料冷态流动特性试验,给出喷动的流体力学条件。研究了床层压降随表观风速的变化规律,稻秸粒和煤粒混合比例、喷口直径和导向管喷口间距3因素对床层压降与表观风速关系曲线的影响以及对物料循环速率与风量关系曲线的影响。进行了3因素12拟水平的均匀设计试验,采用SPSS软件进行回归分析,分别得到了物料循环速率、单位床高压降及单位有效功率的物料循环速率3个因变量各自与稻秸粒和煤粒混合比例、导向管喷口间距及喷口直径3个自变量之间关系的多元回归方程,用于预测稻秸煤粒混料在导向管喷动床中喷动时的流体力学参数。     

农产品贮藏设施温控仪表温度漂移控制方法

选择3种具有代表性的贮藏设施通用温控仪表,检测其温度漂移幅度和方向。根据仪表电路原理并结合测试,进行了针对性电路改进,使温控仪表温漂误差幅度由3.5℃下降到0.3℃,贮藏环境温度波动幅度由5.3℃下降到1.4℃。试验筛选出3种简易温度补偿法,可在不改造仪表电路的前提下抑制温漂。     

Performance of A Sludge Reduction System on Removal of Nitrogen and Phosphorous Controlled by Low Dissolved Oxygen

The influences of dissolved oxygen (DO) on the removal process of nitrogen and phosphorous in a sludge reduction system had been studied by controlling aeration amounts. It was found that under the conditions of low doses of 2,4,5trichlorophenol (TCP), endogenous sour values of activated sludge increased with the extension of low DO state duration in SBR system and the decrease of cyclic average DO, which led to a low DO environment favored the formation of simultaneous nitrification and denitrification(SND).TCP concentration was recommended as 2mg / L and cyclic average DO value in SBR system was kept at 2mg / L based on the impacts of TCP concentration on sludge reduction, removal of nitrogen and phosphorous and sludge performance. Compared with the control system, aeration amounts increased by 23% and the discharge of excess sludge decreased by 34.6%. The water quality in effluents was equivalent in the aeration sludge reduction system with 2mg/LTCP, which met the discharge standards. Therefore, it was indicated that the removal of nitrogen and phosphorous and sludge reduction can obtain excellent performance in TCP system under low DO state with removing Phosphrous rich sewage.     

Generalized conforming quadrilateral membrane element with vertex rotational freedom

A new generalized conforming quadrilateral membrane element is developed by introducing additional rigid vertex rotational freedoms to the normal 4 node quadrilateral membrane element. The rotational stiffness of the present element is not zero so that the singularity of the stiffness matrix is avoided. Numerical analysis of the Cook problem cantilever beam shows that the EAE/Mem element passes the patch test and possesses good convergence, reliability, and precision without a zero energy mode. It provides a lock free solution to the MacNeal beam problem. Numerical results also show that the EAE/Mem element is insensitive to mesh distortion. The results demonstrate that the generalized conforming technique is an efficient tool for developing high performance finite element models.     

A contour extraction algorithm for digital images based on water balloons snake model

Due to weak edges and low contrast areas in digital images, such as a left ventricle in Magnetic Resonance Imaging (MRI) images, a deformation curve may leak from the outer boundary when images are segmented using the traditional snake model. An improved algorithm based on the water balloons snake model is introduced to solve this problem. Firstly, the barycenter and the boundary shape area of the left ventricle in a digital MRI image are obtained through mathematical morphology. The left ventricular watershed line is obtained next using a watershed transform algorithm, which is taken as the initial deformation curve in a balloon snake model to capture the contour. Different snake models are tested to digitally tagged MRI images of left ventricles of small pigs. Contrast results indicate that the water balloons snake model can solve the leakage problem in traditional snake and balloon snake models. In addition, the processing speed is improved significantly.     

Ecological Coupling Theory and the Method System of Urban countryside Space Planning

Since P. R. China has experienced extensive land resource use, environmental degradation, lagging rural development and other difficulties in 20th century, urban countryside integration and ecological planning has become an important subject to build a harmonious society in the 21st century. The country attempted to use complexity science and ecological thinking based on recognizing the relationship between the city and countryside and raising the city countryside space ecology coupling concept to construct a city countryside space planning methods system consisting of the identification of urban and rural land uses, urban and rural non construction land planning, city countryside coupled environmental conditions assessment, coordinated city countryside space development and city countryside space system fractal optimization, and more.     

Experimental study on natural convection of cold water near the maximum density in horizontal annulus

This paper conducts the experimental study on the natural convection characteristics of cold water near the maximum density in horizontal annulus with the fixed inner radius ri=14 mm and different width l=6~18 mm. The temperature at outer wall is maintained at 0 ℃, and the temperature differences between the inner and outer walls range from 2 to 24 ℃. The results show that the heat transfer coefficient at inner wall increases with the increase of the annulus width. When the temperature difference is bellow 4 ℃ or above 8 ℃, the heat transfer coefficient increases with the increase of the temperature difference. When the temperature difference is between 4 ℃ and 8 ℃, it decreases with the increase of the temperature difference. The formula of heat transfer at inner walls is obtained by using the method of linear regression.     

Application of GC FTIR technology in the analysis of SF6 decomposition products

The composition of SF6 decomposition products is directly associated with the safe operation of equipment. Through GC FTIR coupling technique,the SF6 decomposition products are divided, the qualitative analysis is made with FTIR to the outlier,and spectrogram was processed with subtract and searched the analogous one. Above data is used to generate the tridimensional atlas of infrared spectrum absorbance GC holding time. Single gas analysis is compared with local measurement, the foregoing method can make the qualitative analysis and quantitative analysis for the decomposition products, the fault features detected by gas composition and chroma is anastomotic with the actual fault, the result indicates that this method can be used in GIS fault diagnosis.     

An aeroelastic model design of ultra high voltage power transmission line systems

We present an aeroelastic model design and method creation based on the case of an ±800 kV ultra high voltage (UHV) power transmission line from Xiang Jiaba to Shanghai, P. R. Chin, Both the centralized and discreted stiffness modeling methods are unsuitable for tower aeroelastic modeling. Taking these stiffness and aerodynamic characteristics into account, we introduce a new method to create an aeroelastic model that includes a semi rigid model segment and U shaped springs. Because the span of this transmission line is too long to fit within the wind tunnel in the same proportions as the tower, the proportions of the line model is condensed further. Aeroelastic test requirements can be satisfied by comparing theoretical analysis and actual measurements of the system model dynamics.