满发流量对梯级水电站发电量的影响

满发流量是水电站规划设计的重要参数,但其对梯级水电站发电量的影响却鲜有研究。以串联型梯级水电站为例,构建了梯级水电系统的数学模型和约束条件,给出了梯级水电系统的调度策略,通过实例仿真得出满发流量与梯级水电站发电量之间的关系曲线。结果表明,上级水电站的满发流量对下级水电站发电量的影响很小,梯级水电站的发电量主要受本级电站满发流量的影响。各级水电站的满发流量与其发电量之间的关系曲线态势相似,都存在一个峰值点。     

基于ABAQUS的群锚加固岩质边坡 效果评价方法研究

针对在岩质边坡内存在多组锚索群且缺乏预应力锚索周围注浆体参数的情况,提出了一种岩 质边坡加固效果的评价方法,即:在用摩尔一库伦本构模型模拟岩质边坡的基础上,利用ABAQUS 有限元软件中的TRUSS单元模拟预应力锚索,并结合强度折减法,通过数值计算对岩质边坡的群锚 加固效果进行评价。研究结果表明,与未进行群锚加固相比,群锚加固可显著提高岩质边坡稳定安全 系数,并且减缓边坡塑性区的发展和破坏过程。为此,该评价方法可用于实际工程中对各类群锚加固 方案进行比较优选。     

3D navigation and monitoring for spinal milling operation based on registration between multiplanar fluoroscopy and CT images

Milling operations in spinal surgery demand much experience and skill for the surgeon to perform the procedure safely. A 3D navigation method is introduced aiming at providing a monitoring system with enhanced safety and minimal intraoperative interaction. An automatic registration method is presented to establish the 3D-3D transformation between the preoperative CT images and a common reference system in the surgical space, and an intensity-based similarity metric adapted for the multi-planar configuration is introduced in the registration procedure. A critical region is defined for real-time monitoring in order to prevent penetration of the lamina and avoid violation of nerve structures. The contour of the spinal canal is reconstructed as the critical region, and different levels of warning limits are defined. During the milling procedure, the position of the surgical instrument relative to the critical region is provided with augmented display and audio warnings. Timely alarm is provided for surgeons to prevent surgical failure when the mill approaches the critical region. Our validation experiment shows that real-time 3D navigation and monitoring is advantageous for improving the safety of the milling operation.     

Investigation of thermo-mechanical contact between slider and bit patterned media

Contact between a slider and bit patterned media (BPM) is investigated using finite element analysis. The effect of contact conditions and material properties at the interface between slider and disk on plastic deformation and temperature is studied. In addition, the planarization of bit pattern media on temperature and plastic deformation is investigated for different filler materials. It is found that filler material results in reduction of plastic deformation and temperature.     

基于CPS的协议识别优化算法

目的：自美国将CPS的发展列为重点研究项目,引起了各国广泛的关注。不同于传统的系统,在通信方面,CPS融合了大量的异构网络,其规模远大于现有的控制网络。为提高对协议识别的效率和准确度,并对其进行分类,系统中大量数据传输带来的网络拥堵是我们要解决的主要问题。方法：基于网络流的特征,提出了对协议进行识别的变精度粗糙集的权值计算法和决策构造优化算法。结果：基于变精度粗糙集算法协议识别算法,其准确率可达98.7%。结论：基于变精度粗糙集的决策算法相较于普通决策算法,其识别准确度更高、更容易实现。     

水资源脆弱性评价研究进展

水资源是影响区域、国家甚至全球环境可持续发展的关键,水资源脆弱性是制约水资源安全的基础性问题。本文从水资源脆弱性的概念、评价指标体系和评价方法方面,综述了国内外水资源脆弱性评价的研究进展,并对其未来的发展方向进行了展望。     

丹江口大坝升船机监控系统设计

针对丹江口水电站过坝垂直升船机和斜面升船机,以确保设备运行的可靠性、安全性为前提,结合当前计算机监控技术的发展,对两套升船机受控对象进行了分析,对监控设备进行了选型设计。提出了以100 M工业光纤以太环网为主干通讯网,上位监控和现地监控两层控制结构的监控系统整体解决方案,达到对丹江口升船机进行运行控制的目的。经厂内及机电联调试验验证,整个监控系统设计合理、满足要求。     

Deformation bands in fully pearlitic steel during wire drawing

The deformation of fully pearlitic steels during wire drawing has been investigated for both longitudinal section and transverse section by back-scattered electron imaging(BSEI),electron back-scattered diffraction(EBSD),and transmission electron microscope(TEM).The results show that a large number of deformation bands(DBs)composed of a mixture of kink-like bands and shear-like bands were observed both in the longitudinal section and the traverse section of the drawn wires.The formation of such bands involves two aspects:heterogeneous deformation in the scale of pearlite colonies and instability of ferrite-cementite interfaces due to stress concentration during wire drawing.The development of such bands in fully pearlitic steels dominates the formation of metallographic texture,reduces the pearlite interlamellar spacing and promotes the development of<110>fiber crystalline texture of ferrite matrix during wire drawing.     

实时多波束海底地形数据三维瀑布图绘制方法

针对深水多波束测深数据的特点和实时显控的需求,提出了一种通过内存缓存技术以队列方式有效组织多Ping海底测深数据,采用局部更新技术提高数据更新效率,利用查表方法减少顶点高程赋色计算代价,进而结合VBO技术加速渲染过程的实时多波束海底地形探测数据三维瀑布图快速绘制方法,并在三维瀑布图实时绘制过程中实现了支持平移、旋转和缩放等交互操作。对实际多波束海底地形探测数据实时绘制的实验结果表明,该方法高效、稳定、光照效果佳,能很好地满足多波束海底地形探测数据的实时显控需求。     

基于反步法的欠驱动UUV的3维路径跟踪控制

研究了欠驱动无人水下航行器(unmanned underwater vehicle,UUV)在3维空间中的路径跟踪控制器设计及其稳定性分析问题.首先建立2阶积分器形式的欠驱动UUV空间6自由度运动模型和动力学模型.针对该运动模型,以位置误差作为虚拟控制变量,基于反步法(backstepping)设计路径跟踪控制器.根据李亚普诺夫理论,在理论上证明了所设计的路径跟踪控制系统是稳定的.该控制器实现了欠驱动UUV 3维空间的路径跟踪控制.仿真结果验证了控制器的有效性.