关于中小型水电站实施微机监控问题的探讨

中小型水电站微机监控的功能，包括数据采集和处理、程序操作、闭环控制、事故分析指导及离线计算等。监控的模式以实现ＣＢＳＣ为目标，采用分层式系统结构；主控层用微型机，单元层以单片微机为核心构成。以ＩＢＭ－ｐＣ／ＸＴ微型机为例，叙述其过程通道及其抗干扰问题。常规布线逻辑自动化系统的改造是实施微机监控的基础。     

HDPE耐环境应力开裂性能的研究及改进

对HDPE的耐环境应力开裂性能进行了研究。试验表明:采用共混及化学改性的方法,HDPE的耐环境应力开裂性能有了很大提高,为解决HDPE树脂在制作管材时出现的短时间内应力开裂问题提供了依据。     

超微粒子的合成及其应用

本文综述了超微粒子的合成方法和应用。着重叙述了超微粒子在催化、生物、医学、记录材料、传感材料等方面的应用。     

双峰PE80级管材专用树脂的开发

介绍了高密度聚乙烯管材专用树脂6366M的结构特性、物理性能及其加工应用试验的情况。结果表明，6366M具有相对高的相对分子质量，其相对分子质量分布结构特性呈双峰分布。该材料具有优异的力学性能和耐环境应力开裂性能，而且加工性能较好，实现了刚性和韧性的平衡。成品管材的性能指标可以满足用户的需求。     

基于传播模拟的消息流行度预测

社交网络中的消息流行度预测问题对于信息推荐和病毒式营销等应用具有重要意义。该文提出了一种基于传播模拟的消息流行度预测方法,首先使用最大熵模型学习并预测用户转发消息的概率,然后使用独立级联传播模型在真实的社会网络上模拟消息的传播过程,从而完成消息流行度的预测。该方法的优点在于更充分的利用了社会网络的结构和用户特征信息。该文在Twitter数据集上的实验结果表明,相对于基准方法,该文提出的方法具有更高的准确率和稳定性。     

Performance study of combined test rig for metro train traction

This paper deals with a combined test rig for a traction system in the laboratory environment. An experimental system was designed and implemented to verify the performance of the traction system for a metro train. For a highly accurate control of the system, a hybrid control algorithm combining vector control and slip frequency control was applied to control the traction inverter. The design method of the flywheels, which represent the equivalent model of the train moment inertia, was elaborated. A train runtime diagnosis system was completed by adopting the multifunction vehicle bus (MVB) protocol. The dynamic performance of the metro power traction system was emulated under the control of the train runtime diagnosis system. Using the combined test rig, the performances of the traction system in traction, braking, temperature rise, etc., were verified through traction and breaking experiments.

     

Influence of Structural Parameters of Turbocharger Floating Bearing on Its Dynamic Characteristic Coefficients

The structure parameters in an actual industrial production have a great influence on the coefficient of supercharger floating bearing dynamic characteristics,but there has been little systematic study so far. In this paper, the influence of structural parameters of the turbocharger floating bearing on its dynamic characteristic coefficientsis systematically investigated based on the theories of hydrodynamic lubrication and tribology. The influence of clearance ratio on eccentricity and the influence of internal to external radius ratios, and Sommerfeld number were analyzed.A new formula of responding characteristics of the oil film force caused by the displacement or velocity disturbance was deduced near an equilibrium in the steady state. Applying the newly developed formula, the dynamic characteristic was studied for floating bearings. Regularity for change of oil film stiffness and damping was analyzed with the structural parameters of floating bearing such as radius ratios and eccentricity.It has been found that the clearance ratio increases with eccentricity when the radius ratio is unchanged.The eccentricity decreases with the internal to external radius ratio of floating rings when the clearance ratio is constant.The absolute value of total principal stiffness and total main damping decrease with the clearance ratio and radius ratio of floating rings when the total cross damping is stable. The results and findings in this paper can contribute to nonlinear dynamics designs of turbocharger rotor-bearing systems.     

混凝土收缩徐变对系杆拱桥的影响分析

收缩徐变作为混凝土结构固有特性,随着时间地延伸,它会不断地变化[1]。尤其针对一些比较敏感的混凝土结构,如悬臂端、预应力混凝土连续梁等,其收缩徐变影响更为明显。本文以一工程实例为背景,利用有限元软件Midas进行桥梁模拟,通过对不同收缩徐变情况的探讨,得出混凝土收缩徐变对系杆拱桥的影响。     

Laser‐Assisted Large‐Scale Fabrication of All‐Solid‐State Asymmetrical Micro‐Supercapacitor Array

The micro‐supercapacitors are of great value for portable, flexible, and integrated electronic equipments. Here, the large‐scale and integrated asymmetrical micro‐supercapacitor (AMSC) array is fabricated in virtue of the laser direct writing and electrodeposition technology. The AMSC shows the ideal flexibility, high areal specific capacitance (21.8 mF cm^?2), and good rate capability. Moreover, its energy density reaches 12.16 µW h cm^?2, outperforming most micro‐supercapacitors reported previously. Meanwhile, large‐scale series‐connected AMSCs are integrated on the flexible substrates (e.g., indium tin oxide‐polyethylene terephthalate film), which can power a veriety of the commercial electronics. The combination of AMSCs array, solar cell, and electronic device proves the feasibility for practical application in the portable, flexible, and integrated electronic equipments.