CITECT驱动程序结构及其重用性的研究

本文通过对CITECT驱动程序的工作方式分析．讨论了CITECT软件与其提供的驱动程序之间交换数据和命令的方式．研究了基于二进制代码的CITECT驱动程序的可重用性。     

A gel sample preparation method for the analysis of zinc concentrates by WD-XRF

This article describes a methodology for analyzing zinc in zinc concentrates materials by wavelength-dispersive X-ray fluorescence (WD-XRF) spectrometry with gel for sample preparation. The sample was decomposed with aqua regia. The sample solution mixed with agaron gel was heated to boiling. The mixture became quasi-solid gel under normal temperature. The elements dispersed in gel medium were detected by WD-XRF spectrometry. The method has both advantages of the solution preparation method and the solid preparation method. In addition, this method was adapted in detecting high content ores, because it avoided the risking of using platinum crucible. The method has been applied to the determination of lead, zinc and iron in zinc concentrates successfully.     

Robust Lyapunov–Krasovskii based design for explicit control protocol against heterogeneous delays

Single-carrier frequency division multiple access (SC-FDMA) is currently a widely used transmission technology that has been designated as the uplink transmission technology for the 4G mobile communications standard. SC-FDMA also has a lower peak-to-average power ratio (PAPR) compared with orthogonal frequency division multiple access (OFDMA), where OFDMA is the downlink transmission technology in the 4G standard. However, the PAPR of SC-FDMA increases with the M value in an M-ary modulation scheme, causing a decrease in the efficiency of high-power amplifiers at the transmission end. This study proposes a technique for minimizing the PAPR in SC-FDMA systems by dividing a 16-QAM product code (PC) into two subblocks, one of which is dedicated to encoding transmission data for enhanced error correction, and the other is for generating PAPR-reduction signals. Moreover, this study employed the constellation extension scheme to generate PAPR reduction signals because it can prevent additional data loss caused by the generated PAPR reduction signals. Simulation results show that the proposed technique not only reduces PAPR in SC-FDMA system, but its transmission signals also outperform conventional SC-FDMA signals in error correction because of the incorporated PCs.     

BIM技术在双曲金属屋面重竹吊顶深化中的应用

某工程重竹吊顶曲面与金属屋面板曲面平行,均为双曲造型,且曲率变化多,传统的二维深化设计无法完成对双曲面的重竹吊顶分析,以实现编制合理施工方案及材料下料、精确加工的需求。工程采用建立三维空间信息模型,对整个曲面的每一个板块进行排版及矢高分析,结合材料的变形性能,选择较优的安装方法,复核碰撞,避免后续施工中误差累积、碰撞拆改或无法安装等问题,较好地保证了设计效果,节约工程造价。     

生物质锅炉对流受热面积灰冷态模拟实验研究

燃用生物质的CFB锅炉的尾部受热面上容易出现严重的积灰问题,严重影响换热并可能导致停炉等问题。惯性碰撞是引起生物质锅炉积灰的主要机理,而温度通过影响灰中熔融质所占的比例,进而影响积灰程度。采用加热熔融的石蜡与循环灰的混合物来模拟真实的高黏性飞灰,并搭建了冷态积灰实验台。发现石蜡与循环灰的熔融物可以快速地黏附在受热面上,大大缩短了实验时间。通过图像处理得到沉积厚度随时间的变化情况,沉积过程的生长趋势与真实生物质积灰实验一致。在冷态下实验发现,随着熔融质比例、烟气速度、颗粒粒径的增加,积灰程度呈上升趋势,为生物质锅炉的设计和运行提供了一定的参考依据。     

低高程长距离充填输送管网参数及阻力研究

为了设计合理的低高程、长距离管道泵送输送系统,对开磷集团马路坪矿区的充填输送管道进行了选择,并对其阻力大小进行了理论研究。研究结果表明,选取20#无缝钢管,外径140 mm,壁厚9.5 mm,在16 MPa静压作用下完全满足充填料浆的输送要求;料浆质量浓度53%~58%,浆体流速1.6~2 m/s,最大输送阻力2 083.04~15 368.53 kPa。通过研究,为泵送系统提供合理的设计依据。     

Design and application of a novel coal-fired drum boiler using saline water in heavy oil recovery

In this paper, the design and operation of a novel coal-fired circulating fluidized bed (CFB) drum boiler that can generate superheated steam using saline water were introduced. The natural circulation water dynamics with a drum was adopted instead of the traditional once-through steam generator (OTSG) design, so that superheated steam can be generated for the better performance of the steam assisted gravity drainage (SAGD) technology in heavy oil recovery. The optimized staged evaporation method was proposed to further decrease the salinity of water in the clean water section of the boiler. The evaporating pipes of the salted water section were rearranged in the back pass of the boiler, where the heat load is low, to further improve the heat transfer safety. A CFB combustion technology was used for coal firing to achieve a uniform heat transfer condition with low heat flux. Pollutant control technologies were adopted to reduce pollutant emissions. Based on the field test, the recommended water standard for the coal-fired CFB drum boilers was determined. With the present technology, the treated recovery wastewater can be reused in steam-injection boilers to generate superheated steam. The engineering applications show that the boiler efficiency is higher than 90%, the blowdown rate is limited within 5.5%, and the superheat of steam can reach up to 30 K. Besides, the heavy oil recovery efficiency is significantly improved. Moreover, the pollutant emissions of SO₂, NO_x and dust are controlled within the ranges of 20–90 mg/(N·m³), 30–90 mg/(N·m³) and 2–10 mg/(N·m³) respectively.     

常德市农村水电企业安全隐患浅析及对策

随着常德市水能资源开发利用程度的不断提高,农村水电企业数量的不断增多,农村水电企业的安全问题越来越受到上级领导和机关的关注。如何贯彻落实"安全第一,预防为主,综合治理"的安全工作总方针,切实查找和消除常德市农村水电企业存在的安全隐患,确保农村水电企业的安全,成为常德市水行政主管部门近年来的重点工作之一。文章试图从常德市农村水电企业安全隐患的类型、成因分析,寻找出解决问题的办法,从而提高常德市农村水电企业的安全裕度。     

The effect of mixed soft segment on the microstructure of thermoplastic polyurethane

In this work, we fixed the hard segment content (Ch%) and synthesized thermoplastic polyurethane (TPU) elastomers with one-soft segment (HTPB-PU, PTMG-PU, and PCL-PU) and bi-soft segment (PTMG-HPU and PCL-HPU), using 4,4′-diphenylmethane diisocyanate, 1,4-butanediol, and different oligomer diols as raw materials. This work was used to explore the impact of two polar diols (polytetrahydrofuran diol [PTMG]; polycaprolactone diol [PCL]) of the hydroxy-terminated polybutadiene (HTPB)-based TPU on the microstructure and macroscopic properties. Using Fourier transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimetry to characterize TPU, the results showed that the introduction of PCL was better than PTMG in promoting microphase mixing and crystallization, and reducing microphase separation. This result was closely related because the carbonyl group in PCL was stronger than the ether bond in PTMG in forming hydrogen bonds with ─NH bond. Through mechanical test and isopropyl alcohol (IPA) resistance test, the results showed that HTPB-based TPU with PCL (PCL-HPU) significantly improved tensile strength and elongation at break, and only a small reduction of Young's modulus was observed. PCL-HPU had the best retention of the IPA resistance of HTPB-based TPU.     

Delphi连接SQL Server的三种方法及其性能

文章给出了Delphi与SQL Server连接的三种具体方法,并详细讨论了每种方法的实现与性能。