塔机动态特性的研究

分析、比较了当前塔式起重机动态特性研究中几种常用的方法，着重介绍了动力有限元法，利用ＡＬＧＯＲ有限元软件对实例进行了计算，得到了满意的结果。     

一种新型的交流稳压电源

提出一种新型的交流稳压电源，采用直接的“交流，交流”的变换电路和PWM控制。该稳压电源电路简单可靠、稳压性能好．对由高次谐波产生的纹波亦有很好的抑制作用。     

基于实测模型的通信铁塔抗震性能仿真分析

针对目前通信铁塔抗震性能仿真分析结果存在较大误差的问题,提出基于实测模型进行仿真分析的方法.通过现场测试得到铁塔的动态参数,依据测得的动态参数对建成的有限元模型进行修正,使其能更加准确地反映铁塔的动力特性.依据相关标准,选用人工合成地震波和2条真实地震波对铁塔模型进行抗震性能分析.结果表明铁塔的响应位移和应力均小于标准要求值,满足抗震要求.     

Self-assembly synthesis of cactuslike Cu2O 3D nanoarchitectures via a low-temperature solution approach

Cu₂O nanocactuses were synthesized via a simple, low-temperature, and no time-consuming wet chemical route. The synthesized products were systematically studied by X-ray powder diffraction, scanning electron microscopy, and transmission electron microscopy. The results showed that the formation of Cu₂O nanocactuses was strongly depended on the addition of CTAB and NaOH. The structural evolution of the cactuslike Cu₂O was found to follow dissolution and recrystallization processes. It is noteworthy that the stepwise synthetic procedure was crucial to the growth of the final nanoarchitectures. UV–vis spectrum was also used to estimate the absorption and photodegradation ability of the nanocactuses.     

空战训练模拟系统目标敌机生成问题的研究

空战训练系统是利用空战模拟技术结合航空兵部队指挥自动化系统开发的,该系统具有结构复杂、模型多、实时性要求高的特点,空战训练模拟系统中,目标敌机是计算机生成和控制的仿真实体,生成的敌机仿真实体不需要人的交互而自动地对战场仿真环境中的事件和状态做出反应,因此必须对作战行为进行足够的建模,目标敌机生成的好坏,很大程度上决定了空战战法训练模拟系统的仿真逼真程度,文中论述了建立目标敌机模型的方法,以及应注意的问题。     

一拖三变频供水控制系统

介绍一台变频器控制三台水泵的变频供水系统控制方案和控制系统的组建.并介绍了如何通过上位机、PLC对其设备进行手动、自动、远程控制.经现场实际运行,证明该系统运行可靠,提高了供水的效率.     

Research and experimental analysis of drill string dynamics characteristics and stick-slip reduction mechanism

Stick-slip of the drill string, as one of the critical factors affecting drilling efficiency, has always been a hot topic for experts and scholars in related fields. Serious stick-slip vibration affects the well construction efficiency, drilling cost and even lead to a downhole accident. Therefore, based on the current research, this paper takes a new type of composite vibration tool as the research object, studies the working mechanism of the tool and analyzes the effect of stick-slip reduction. After establishing the multi-degree-of-freedom torsional dynamics model, we obtained the results of torsional vibration dynamics by cases analysis based on working conditions and related mechanical parameters. In addition, the results of the examples, compared with the field experimental data, verify that the vibration shock generated by the new composite tool can effectively reduce the torque fluctuation range of the system, avoid the occurrence of stick-slip phenomenon, improve the ROP (rate of penetration), and make drilling process more stable. This paper can provide reference for the optimization and development of stick-slip technology in drilling engineering, and the theoretical methods can also be developed to study the dynamics of drill string.     

氮化硅铁对炮泥高温抗折强度及抗渣性的影响

以棕刚玉、碳化硅、沥青及焦炭为主要原料,研究了氮化硅铁加入量为0、4%、8%、12%、16%、20%、24%、28%时对炮泥高温抗折强度的影响及加入量为6%、12%、18%、24%时对炮泥抗高炉炉渣侵蚀的影响。结果表明:氮化硅铁加入量在24%以内时,不能提高炮泥800℃的高温抗折强度,而当氮化硅铁加入量≥12%时,对1000℃以上高温抗折强度的提高效果即已显现,尤其对1400℃的高温抗折强度的提高非常明显;氮化硅铁的加入对炮泥高温抗渣侵蚀性影响不大。     

Si3N4对镁质浇注料抗渣性能的影响

以95烧结镁砂为主要原料,以SiO2微粉为结合剂,在配料的细粉部分分别以0、3%、4%、5%的β-Si3N4细粉替代等量的镁砂细粉,搅拌均匀后浇注成氮化硅含量不同的镁质坩埚试样。选用宝钢中间包渣,采用静态坩埚法,在1550℃3h条件下对这些坩埚试样进行了抗渣试验。试验结果表明:加入Si3N4可以明显改善镁质浇注料的抗渣性能,并且随着Si3N4加入量的增加,试样的抗渣性能提高;在含氮化硅的镁质浇注料表面,由于Si3N4被氧化为SiO2而形成了致密烧结层,能阻止渣的进一步渗透;在加入Si3N4的镁质浇注料试样内部深处,由于氧分压非常低,Si3N4稳定存在;由于Si3N4在还原气氛下难以烧结,造成镁质浇注料内部结构疏松。     

横波估算方法探讨

叠前地震反演是寻找隐蔽油气藏的有力手段,而横波估算是开展叠前地震反演的必要条件,又是难点之一。目前大部分井缺少横波测井数据,或数据质量差而无法应用。在对比目前常用的3种横渡估算方法的基础上,在Y38井应用实例中,采用经验公式和理论计算相结合的方法估算横波速度,旨在探寻有效的方法,获得可使用的横波测井数据。实际应用的结果符合理论上的一般认识,基本可靠。