新型等壁厚螺杆钻具定子结构设计及力学分析

等壁厚螺杆钻具定子以其独特的性能受到国内外专家学者的推崇,但是其细长内螺旋曲面的存在带来了加工上的困难。提出了套装式螺杆钻具马达定子结构设计方案,变定子整体加工为分层加工,降低加工难度。通过有限元法对其在不同过盈量、均匀内压下的力学性能进行分析,获得套装式定子结构的应力分布规律,为套装式等壁厚螺杆钻具定子设计与应用提供理论依据。     

提高热带轧机精轧AGC控制精度初探

武钢热轧厂在设备老化、产品厚度工下降的情况下，对ＡＧＣ控制模型及参数进行了分析与修改，通过采缩小允许锁定偏差值计算公式中的α值，调整ＧＭ方式ＡＧＣ用比例因子值，增加调节量与Ｘ射线厚度偏差矛盾值的判断程序，适当放大Ｘ射线厚度差值等措施，提高了厚度精度，带来了可观的经济效益。     

An Analysis of Characteristics of Coplanar Transmission Lines with Finite Conductivity and Finite Strip Thickness by the Method of Lines

The method of lines (MoL) has been applied for analyzing the characteristics of various structures of coplanar transmission lines widely. But in most previous literatures, the metallizations are considered as infinitely thin or PEC(Perfect Electric Conductor). In this paper, the characteristics of coplanar transmission lines (take an example for shielding microstrip lines) with finite conductivity and finite strip thickness are analyzed by MoL and the computation results are shown.     

Improvement of thickness uniformity in nickel electroforming for the LIGA process

An effective method to improve thickness uniformity in nickel electroforming for the LIGA process to produce metallic microstructures is described. The deposited metal distribution is naturally a concave shape over the whole area of the plating base proved by experiments. The edge thickness of the plating area is usually twice or higher than the center of the plating area. A secondary cathode (guard ring) was applied to improve the electroform uniformity. The experimental result of a Joule–Thomson micro-cooler proved its feasibility. The thickness ratio of edge to center of a 500 μm sample decreased from 2.5 to 1.4. The thickness uniformity improvement is achieved without a loss in plating rate in the center of the features.     

Investigation of deformation and pore formation in isotactic polypropylene containing active nano‐CaCO3

In order to improve the β‐lamellae distribution and properties of β‐isotactic polypropylene (β‐iPP) membranes, amounts of 5 and 10% active nano‐CaCO₃ were added into β‐iPP. Differential scanning calorimetry, X‐ray diffraction and scanning electron microscopy results show that nano‐CaCO₃ does not reduce the content of β‐crystals, but the thickness, lamellae thickness distribution and stability of β‐lamellae decrease apparently. Tensile testing was conducted at 25 and 90 °C. The results manifest that the second yield point, which has a strong negative correlation with lamellae thickness distribution, is delayed monotonically with addition of nano‐CaCO₃ when stretched at 25 °C, indicating that nano‐CaCO₃ could narrow effectively the lamellae thickness distribution of β‐iPP. Furthermore, when stretched at 90 °C, the subdued yield peak, retarded necking‐down phenomenon and enhanced strain‐hardening modulus demonstrate that the deformation stability improves gradually with introduction of nano‐CaCO₃, which is completely opposite to the trend for β‐lamellae stability. Through further detailed characterization of morphological evolutions during stretching, we found that interfacial debonding between nano‐CaCO₃ and β‐iPP is triggered and abundant microviods can be formed, which can retard the rotation and slip of β‐lamellae and make the β–α transformation slow down in the initial stage of stretching, consequently leading to better isotropic deformation. Moreover, nano‐CaCO₃ could efficiently restrain the formation of coarse fibrils, leading to more uniform pore size distribution within the biaxial stretching microporous membrane. However, excessive nano‐CaCO₃ (10%) would cause aggregation within the β‐iPP cast film and finally result in larger pores and poor pore distribution in the membrane. © 2017 Society of Chemical Industry     

Molecular engineering to improve carrier lifetimes for organic photovoltaic devices with thick active layers

The morphology of the bulk heterojunction absorber layer in an organic photovoltaic (OPV) device has a profound effect on the electrical properties and efficiency of the device. Previous work has consistently demonstrated that the solubilizing side-chains of the donor material affect these properties and device performance in a non-trivial way. Here, using Time-Resolved Microwave Conductivity (TRMC), we show by direct measurements of carrier lifetimes that the choice of side chains can also make a substantial difference in photocarrier dynamics. We have previously demonstrated a correlation between peak photoconductance measured by TRMC and device efficiencies; here, we demonstrate that TRMC photocarrier dynamics have an important bearing on device performance in a case study of devices made from donor materials with linear vs. branched side-chains and with variable active layer thicknesses. We use Grazing-Incidence Wide Angle X-ray Scattering to elucidate the cause of the different carrier lifetimes as a function of different aggregation behavior in the polymers. Ultimately, the results help establish TRMC as a technique for screening OPV donor materials whose devices maintain performance in thick active layers (>250 nm) designed to improve light harvesting, film reproducibility, and ease of processing.     

高压U形管式换热器的管箱设计探讨

以一台小直径高压U形管式换热器的管箱设计为例,探讨在应用GB151中的b型管板时,校核与其直接相连的法兰时附加弯矩的计算,同时简要介绍了当δ/D值较小时,平盖计算应注意的问题。     

镀锡钢丝锡层厚度的测定

介绍利用原电池及失重法相结合测定镀锡钢丝的镀层厚度的方法。     

厚度方向性能Q345EZ35中厚板的开发

介绍了厚度方向性能Q345EZ35中厚板开发的主要技术和关键环节,该中厚板的实物质量符合国家标准要求。     

The Analysis of the Parameters and the Functions of Rectangular Waveguide E-plane Filter

In this paper, to analyze the discontinuity structure of E-plane metal insert by mode matching method, and metal insert thickness and resonator length impact on filter design. This work was supported by the Natural Science Foundation of Jiangsu Province of China under Grant No. BK2008357.