判断电力电缆绝缘劣化的新方法

通过实际的操作程序,论述了判断电力电缆绝缘劣化的新方法及其工作原理.     

矿井巷道可移动式超前临时支护装置的设计与应用

井下巷道掘进后顶板空顶面积大,在无超前支护作用下补打顶板支护时顶板出现冒落破碎的现象,威胁着支护安全。对此,通过技术研究,设计了一套可移动式超前临时支护装置。经实际应用,153208巷采用该装置后能有效地控制顶板破碎现象,取得了显著的成效。     

一种新型超高温固井水泥石抗强度衰退材料

在200 ℃以上超高温下,加砂水泥石强度发生衰退,导致超高温深井固井水泥环层间封隔失效,无法满足高温油气井长期开采的需求。对加砂水泥石的强度衰退机理进行探索,研究发现超高温下加砂水泥水化生成平行疏松的硬硅钙石,孔隙率增大,是其力学性能衰退的根本原因。通过高温水化产物优化设计,优选晶体层间距为纳米尺寸的含铝矿物和纳米管材料,开发了一种新型超高温水泥石抗强度衰退材料DRB-4S。在240 ℃下,DRB-4S加量为10%～20%时,水泥石28 d强度不衰退且大于50 MPa。通过X射线衍射分析、扫描电镜测试、孔结构测试等方法进一步对DRB-4S抗强度衰退机理进行了分析,晶体层间距为纳米尺寸的含铝矿物促进了高温稳定水化产物铝硅钙石的生成,纳米管的加入抑制了雪硅钙石向硬硅钙石转化,并且在水泥石中起到桥联填充作用,降低了水泥石的孔隙率。掺有DRB-4S的固井水泥浆失水量小于50 mL,稠化时间易调,稳定性良好,总体施工性能良好,为高温油气井长期开采提供了有力的技术支持。      

Adaptive Track Predicting Control for Target Tracking Control Systems

The target trackingsystemis widely usedin mil-itary andindustry,such as radar track and uncertainrobot manipulators.It’s difficult to realize high pre-cision real-ti me trackingto a maneuveringtarget.Formaneuvering target,its motion direction,velocityand acceleration are uncertain,it requires that theservo system must have fast response.For commonoutput feedback control system,the hysteresis alwaysexists between the input and output because anyphysical actuator needs a period of response ti m…     

Line-element based nonlinear adaptive piecewise compensating correction for LVDT sensors

In order to solve the linear variable differential transformer （LVDT） displacement sensor nonlinearity of overall range and extend its working range, a novel line-element based adaptively seg- menting method for piecewise compensating correction was proposed. According to the mechanical structure of LVDT, the output equation was calculated, and then the theoretic nonlinear source of output was analyzed. By the proposed line-element adaptive segmentation method, the nonlinear output of LVDT was divided into linear and nonlinear regions with a given threshold. Then the com- pensating correction function was designed for nonlinear parts employing polynomial regression tech- nique. The simulation of LVDT validates the feasibility of proposed scheme, and the results of cali- bration and testing experiments fully prove that the proposed method has higher accuracy than the state-of-art correction algorithms.     

电能计量装置故障接线分析

笔者在全国各地进行电能计量装置的故障接线培训过程中总结了一种可以快速准确地判断电能计量装置接线错误的方法。 现结合三相三线错误接线电压的3种形式：正常、断相、极性反进行分析。假设负载感性,功率因数角为0°～30°。     

Synthesis and luminescent properties of Pr-doped Lu3Al5O12 translucent ceramic

Lutetium aluminum garnet (LuAG) precursors doped with different Pr3+ concentration (0.25at.%, 0.5at.%, 1.0at.%, 3.0at.%, 5.0at.%) were synthesized via a co-precipitation method using ammonium hydrogen carbonate as precipitant. The phase evolution and mor-phology of the precursor were characterized with X-ray diffractometer (XRD) and transmission electron microscopy (TEM). The resultant LuAG:Pr3+ powder was sintered into translucent ceramic without any additives in vacuum at 1150℃ and then in nitrogen atmosphere at 1700℃. Photohiminescence spectra of LuAG:Pr3+ powder and ceramic were measured at room temperature in vacuum ultraviolet (VUV) and ultraviolet (VU) region. For the 5d-4f transition of Pr3+ ions, dominant emission of ceramic samples peaking round 311 nm had higher lumines-cence intensity. And the host absorption in ceramic samples was not as intensive as that in powder samples. The luminescent intensity of LuAG:Pr3+ varied with the Pr3+ contents and the quenching concentration was about 1.0at.% for ceramic and 3.0at.% for powder, which was much higher than 0.24at.% for LuAG:Pr3+ single crystals. This phenomenon showed that the ceramic had some superiority over single crystals.     

WSN经典路由协议比较

本文首先介绍了WSN路由协议的特殊性、路由协议的分类等,然后针对WSN的几个经典路由协议,从协议的实现过程、协议特点、优缺点、适用领域等方面进行了分析,最后对这些路由协议的节能性、可扩展性、鲁棒性等方面进行了比较,以期为WSN路由协议的选用及进一步研究提供参考。     

侧钻井固井工艺技术的改进与应用

固井工作对于油气井的高效运行有着根本性的作用。为了确保其产量和寿命,就必须结合油气井的实践,采取针对性的固井工艺技术。以侧钻井故障工艺技术为例,就固井工艺技术的原理、改进和应用提出建议,以更好地促进固井效果的提升。     

僵尸网络流量检测与控制追踪技术研究

借助僵尸网络进行的各种网络攻击对目前互联网的安全已构成严重威胁,对僵尸网络的检测、阻断和控制及僵尸网络控制者跟踪定位已成为当前网络安全研究的热点。文中首先对当前基于网络流量特征识别僵尸网络的方法进行了分类概括,其次对僵尸网络阻断和控制的主要技术进行了归纳整理,最后对当前僵尸网络控制者追踪定位的主要方法进行了梳理总结。现有研究表明,从网络流量角度对僵尸网络进行检测和追踪是非常有效的途经之一,但在准确性和效率方面有待提高。