The nonlinear effect of materials and sensors in high-energy laser calorimeters is especially obvious-due to the steep temperature gradients of their absorbers. Significant measurement errors occur when traditional integral temperature sensors and methods are utilized. In an effort to remedy this, a method is proposed in this paper in which an absorption cavity is divided into many parts and multiple discrete thermocouple sensors are used to measure the temperature rise of the absorbers. The temperature distribution in the absorbers is theoretically analyzed, numerically simulated, and verified through experimentation. Energy measurement results are compared according to the temperature distribution for different layouts of thermocouples. A high-accuracy calorimeter is developed by setting and optimizing thermocouple layout, as well as correcting various elements such as the specific heat of graphite and responsivity of thermocouples. The calorimeter employing this measurement method is calibrated against a standard energy meter, resulting in correction coefficient of 1.027 and relative standard deviation of the correction coefficient of only 0.8%. Theoretical analysis, numerical simulation, and experimental verification all prove that the proposed method successfully improves measurement accuracy.

The objectives of the present study were to discuss the status and utilization of resources and the mutual relationship of dominant plant population,to reveal the stability of phytocoenosium and ecological adaptability of plant population under the specific environment,to accumulate theory data for further research on Alsophila spinulosa competion with other species,meanwhile,to provide reference of the protection,utilization and related research for China Danxia world natural heritage. Based on the sample investigation of A. spinulosa community of Danxia Landform in North Area,Guizhou,with the method of quantitative analysis,the niche breadths proportional similarity and overlaps of main dominant species were measured using a series of indices proposed. The results showed that the niche breadth values of Brassaiopsis glomerulata,Maesa japonica and A. spinulosa are the biggest,Shannon Wiener indices were 7. 607 6,7. 344 9 and 6. 910 5,Levins indices were0. 531 4,0. 593 1 and 0. 651 5,respectively,which showed that they are all widely distributed within the community,having strong ability to adapt to the environment; Cinnamomum wilsonii and Mallotus repandusniche proportional similarity value was 0. 998 6,it was the biggest in all species pairs; Ficuslaceratifolie Levl and Beilschmiedia delicata niche overlap values were the biggest,the index was 0. 336 5. Normally,if the niche breadth of the species pairs is wider,the interspecific niche proportional similarity value is higher,niche overlap is also bigger,but niche overlap and niche proportional similarity of some species does not necessarily high. It was closely related to ecological and biological characteristics of species. From the view of the distribution pattern of niche overlap and proportional similarity,there were generally niche overlaps among main populations,but the niche overlaps were mostly at low level,indicated that the interspecific competition generated by utilizing same resources or occupying specific resources was not intense,and the environmental resources could be sufficiently shared by different populations. The Alsophila spinulosa forest communities of Danxia Landform in North Guizhou were at relatively stable stage.

The invention discloses a large-sized workpiece welded intelligent robot device, relates to robot technology, in particular to the robot device based on visual control technology. The device consists of a robot body, a sensing system, a robot controller and a welding auxiliary mechanism. The welded robot is provided with nine moving shafts, including three macrographic moving translational movingshafts, three microscopic moving translational moving shafts and three rotating shafts. The robot body comprises a robot frame and a robot head which is arranged on a transverse arm of the robot frame, and the robot frame consists of the three macrographic moving translational moving shafts, namely a horizontal lead rail, an upright post and the transverse arm. The robot head consists of the three microscopic moving translational moving shafts, the three rotating shafts and a welding gun. The robot frame provides the large-scale three-dimensional movement of the robot; the precision of macrographic moving movement is compensated by the microscopic moving mechanisms of the robot head which also provides rotating freedom of motion. The robot device can meet the movement requirements of large scale and precise positioning for the welding operation of large-sized workpieces. Through the visual sensing technology and intelligent visual controlling technology, the device can improve the automatic welding quality and efficiency of the welded robot.

The invention discloses a sight measuring method and a device used for solving the problem of poor adaptability; two sets of video cameras are synchronously driven to rotate oppositely by a stepping motor; simultaneously, the video cameras are driven to rotate twice, the two video cameras track an object so as to lead the x-coordinate of an object image to be in the central area of the image collected by the tracking video cameras; the three-dimensional coordinate of the object is calculated according to the rotation angles of two times of rotation and the coordinates of the object in the twovideo cameras. The two cameras are installed on the brackets at the tops of left and right connecting rods, a left belt wheel and a right belt wheel are installed at the bottom of the left and the right connecting rods; the output shaft of the stepping motor is equipped with a drive belt wheel, an inverting belt wheel and a tensioner are installed beside the left belt wheel; the right belt wheel,the inverting wheel, the left belt wheel, the tensioner and the drive belt wheel are connected together by a double-cog synchronous belt. As the method and the device do not relay on the internal parameters of the video camera, the internal parameters of the camera are not needed to be calibrated. The method and the device are convenient to use, and can greatly improve the adaptability and usability of sight measurement.

The increasing demand for and amounts of XML documents require the need to store, search and query XML documents efficiently. XML is emerging as the format of choice for a variety of types of data, especially documents. With its ability to tag different fields, XML makes searching simpler and more dynamic. In this paper, we propose a novel relational storage structure which can store and manage XML documents efficiently based on paths using relational database systems (SMX/R). In this approach, any set of XML documents can be stored in a single relational schema consisting of two tables: the first table is Path_Table, stores the paths, value pairs and associated hierarchical information for the XML data and the second table is Path_Index_Table, assigns unique path IDs to path string, thereby avoiding duplicated storage of large path strings. We also propose an algorithm to efficiently map XML documents into relational schema. The statistics shows that our approach is more efficient than XRel.

In this paper, we propose a real time elliptical head contour detection method based on quadrant arcs, which is efficient and robust to arbitrary head pose and wide distance range. First, the moving object area is detected according to background model which is built on three color channels. Then, all the valid elliptical arcs are extracted out from connected edges, and classified into four kinds of quadrant arc sets according to their gradient information. Finally, the arcs lying in different sets are combined to fit out the elliptical head contour based on the least square method. Experimental results confirm the robustness and the accuracy of this method under arbitrary head pose and wider distance range, as well as the real time property, strong robustness to long or short hair and with or without hat.

This paper presents a new video segmentation scheme, which consists of two stages: initial segmentation and motion estimation. In the initial segmentation, the watershed transformation followed by a region adjacency graph guided region merging process is used to partition the first video frame into spatial homogenous regions. Then the motion of changed region is estimated. Based on the highly efficient quadratic motion model, the motion estimation is undertaken using Gauss-Newton Levenberg-Marquardt method to minimize the least-square error function. Experimental results show the proposed scheme provides high performance in terms of segmentation accuracy and video compression ratio.

提出了基于正交切削模拟的零件铣削加工变形的预测方法,建立了三维铣削加工的有限元模型.基于正交切削加工模拟结果,利用铣削温度、铣削力的分析模型求解了三维铣削加工的瞬态温度和瞬态切削力,并将其作为动态载荷应用于三维切削加工的有限元模型,模拟了零件的三维铣削加工过程,预测了零件的变形.通过模拟结果与现场加工情况对比,证明该预测方法是行之有效的.

非均匀分布的残余应力是引起工件变形的主要原因.为了揭示装夹方案对残余应力的影响,利用有限元技术模拟了工件加工过程中不同的装夹方案,并分析了模拟结果.结果表明,装夹位置对残余应力分布具有重要影响,而装夹顺序对残余应力的分布和幅值无较大影响.通过进一步对比分析各种装夹方案中残余应力引起的工件变形得出结论:夹具分布较平均的装夹方案可获得比较均布的残余应力和较小的变形.

In this minireview,the fundamental parameters of chlorophyll fluorescence analysis and some advances in applicatioh of chlorophyll fluorescence to cultivation,stress physiology and photosynthesis of fruit trees ,storage and quality identification of fruits were summarized briefly.

The residual stress field of the stress-free aeronautic aluminum-alloy(7050-T7451) in the milling is studied with three-dimension FEM, and four typical tool-routes are simulated and analyzed respectively. According to the optimization goal of NC milling machining, a reasonable route is selected. In the course of this work, the cutting process is simulated using the dynamic loading step, and the removal of material is realized with the “birth and death” element technique. With this calculating model, the accuracy of simulation is improved greatly, and the research result can be used to support the selection of practical technology for guaranteeing the dimension stability of the workpiece during it in NC milling.

提出了确定整体结构件弯曲变形位移量和特征曲线曲率的方法。在分析弯曲变形零件校正需要满足曲率关系的基础上,通过采用弹塑性理论,推导出了校正给定初始变形曲率的U形截面工件所需要的反向弯曲曲率关系式;为了便于生产操作,进一步给出了校正时需要的反向压下位移量的计算公式。还给出了对于特定尺寸的航空整体结构件初始变形曲率与校正曲率、校正压下位移量的关系曲线。实例表明,对于U形截面工件弯曲变形的校正,计算校正压下位移量的方法是有效的。

The adaptive Smith generalized predictive controller is employed to improve the dynamic behavior of the time delay system. Predictive model is constituted by Smith predictor that makes up of identifiable parameters using RFF(recursive forgetting factor) method, based on the model matching on the frequency of zero. The simulation results show that the method is effective when time delay and parameters change slowly.\;

Homedoctor is a prototype of speech user interface that people can get medical information through a mouse, command and control language or by conversation with computer. In this project, we examine, some of the issues encountered in speech interface design and introduce some of our approaches to resolve these challenges. We also give the architecture of the homedoctor system and describe how to implement it. We aim to examine the mode of human-computer interaction with speech through this research test bed.

In light of the theory on the cultivation and development of creative ability, this paper discusses basic methods of developing creative ability in physical education class.