川西地区须家河组地层各向异性及可钻性研究

从不同角度进行岩样可钻性试验,通过对须家河二段地层的研究,分析其地层各向异性的成因,并建立常规钻井条件下可钻性级值剖面图。研究表明,岩样切削面不同,导致岩石的可钻性级值差异较大。地层沉积作用、构造作用等因素,对岩石的分布差异有所影响。     

基于Visual C++的Pro/E组件的二次开发

应用Pro/E软件的组件环境对产品进行自顶而下修改,进而生成新模具是新产品设计的重要方式.而Pro/E自身组件模式下的尺寸修改功能效率低,以Visual C++为工具对Pro/E进行与尺寸修改对话框类似的"尺寸收集修改器"的二次开发,可实现组件模式下新产品的快速设计.     

Sintering technology for micro heat pipe with sintered wick

In order to study reasonable sintering technological parameters and appropriate copper powder size range of micro heat pipe (MHP) with the sintered wick, the forming principle of copper powders in wicks and MHP’s heat transfer capabilities were first analyzed, then copper powders with different cell sizes and dispersions were sintered in RXL-12-11 resistance furnace under the protection of the hydrogen at different sintering temperatures for different durations of sintering time, and finally the sintered wicks’ scanning electron microscope (SEM) images and their heat transfer capabilities were analyzed. The results indicate that the wick sintered with copper powders of larger cell size or smaller size range has better sintering properties and larger heat transfer capabilities; and that the increase of either sintering temperatures or sintering time also helps to improve the wick’s sintering properties and heat transfer capabilities, and the former affects more obviously than the latter. Considering both its manufacturing cost and performance requirements, it is recommended that copper powders with the size range of 140–170 μm are sintered at 900–950°C for 30–60 min in practical manufacturing. In addition, two approaches to improve wick’s porosity are also proposed through theoretical analysis, which suggests that the larger the wick’s porosity, the better the heat transfer capabilities of the MHP.     

浅谈混凝土裂缝的成因及预防

裂缝是混凝土结构中普遍存在的一种现象,它的出现不仅会降低建筑物的抗渗能力,影响建筑物的使用功能,而且会引起钢筋的锈蚀,混凝土的碳化,降低材料的耐久性,并影响其承载能力,因此要对混凝土裂缝进行认真研究,区别对待,采取合理的方法进行预防处理。     

一种块递推实时FFT算法模块设计与实现

文中提出了一种基于FPGA-IP核的FFT算法硬件模块的设计方案,该方案采用四分块递推FFT算法,具有结构规范、递推性好、实时性强等特点,结合DSP对模块的数据输入和输出的软件控制,实现了一种硬件和软件相结合的实时FFT模块.对该模块性能进行测试,FFT模块运行稳定,输出的计算结果正确,与DSP软件实现的标准FFT算法程序库相比,文中的FFT模块实时性能提高了35倍,该模块已被用于实时信号处理系统中.     

利用弯管测量流体流量的实验研究

利用火力发电厂中循环水管道与凝汽器之间连接所形成的弯管,首先从弯管流量测量基本理论入手,分别用自由涡流理论和强制涡流理论,建立了循环水在弯管内流动过程中,弯管内外径的压力差与循环水流量之间关系的数学关系模型.其次,利用实验室实验确定循环水流量与弯管内外径之间压差的关系,实现了利用弯管对流体流量进行测量.     

Numerical analysis on Joule heating of double-loop channel induction furnaces

In order to investigate Joule heating power, a three-dimensional finite element model (FEM) was developed to predict Joule heating power in the channels of double-loop inductor. The simulated results were compared with experimental data from low load trials for a 400 kW inductor. The results, such as power factor and Joule heating power, show reasonable correlation with experimental data, and Joule heating rate reaches the maximum at the corners and the minimum at the centre of the cross-section area. With increasing relative permeability of iron core, length of coils, current frequency and resistivity of metal melt, the power factor and Joule heating power change. It is concluded that current frequency, the resistivity and length of the coil play a critical role in determining the power factor and Joule heating power, whereas relative permeability of the magnetic core shows no significant influence on them.     

一种高深宽比微细槽的电火花加工工艺

为实现高深宽比微槽的加工,提出了一种自成形和扫描加工相结合的微细扁平电极制作及微细槽加工的工艺方法.采用棒状毛坯电极在一平板试件上扫描加工出一定长度的通槽,将毛坯电极沿垂直通槽方向向左和右偏移,两侧分别进行电火花反拷加工,得到扁平微细电极.再采用该扁平电极在线进行扫描加工即可得到期望的微细槽.实验获得了深径比大于18及尺寸一致性较高的阵列微细槽.与反拷或线电极磨削得到微细电极相比,自成形电极方法降低安装精度要求.而采用扁平电极进行微深槽的微细电火花加工,相对提高电极截面面积,降低电极损耗率,有利于提高加工效率.     

刨煤机组支架电液控制关键

介绍了刨煤机组支架电液控制系统结构,重点阐述了支架电液控制关键,包括推移精度控制、快速移架方法及最优梁端距排列控制,给出了相应的解决方案。实践表明,刨煤机组支架电液控制系统能够精准控制支架自动推移步距,移架时间约为8s,且工作面未出现掉顶或片帮现象。     

粉煤灰效应的模糊综合评价

我们从粉煤灰的具体特性出发,总结和吸取了人们长期积累的实践经验,建立了粉煤灰效应的模糊综合评价层次结构模型,构造了需水量比、强度比、颗粒形态等因素的隶属函数,采用层次分析法计算了各因素在粉煤灰效应模糊综合评价中的权重。最后应用模糊综合评价方法综合了各因素对粉煤灰效应的“贡献”程度,工程实例证明该方法可以有效地描述粉煤灰效应的评价结果。