定容气田开发规划概算法

基于物质平衡方程、产能方程和递减方程的结合,提出了定容气田开发规划的概算法.该法可用于预测地层压力、井底流动压力、井口流动压力和稳产年限.实际应用表明,本文提供的方法是实用有效的.     

石油价格机制改革之对策

文章在阐述我国石油价格形成机制的演变过程的基础上,针对我国目前石油定价机制所导致的诸如石油价格变动滞后以及由此带来的市场信号失灵等问题思考了相应的改革对策,提出了调整政府价格管理职能、建立平等竞争的市场规则、完善稳定油价的调控体系以及加快建立石油战略储备等7个方面的建议。     

一种微机控制的多测头凸轮轴测量系统

本文介绍一种由机械装置，高精度圆光栅编码器，光栅位移传感器，微型计算机，接口控制电路等组成的多测头凸轮轴测量系统，该系统安装调整方便，定位准确，测量精度高，操作简单，工作可靠，能快速实现对凸轮轴的自动测量。     

Dynamic deviation reduction‐based concurrent dual‐band digital predistortion

This article introduces the concurrent dual‐band digital predistortion (DPD) architecture with only one upconvertion unit, which is suitable for the linearization of wideband power amplifiers (PAs) excited by concurrent dual‐band signals. By extending the conventional dynamic deviation reduction (DDR) model to the concurrent dual‐band mode, we propose two DDR‐based concurrent dual‐band models, the dual‐band DDR (DB‐DDR) model and the simplified dual‐band DDR (SDB‐DDR) model. The performance of these two models is experimentally assessed with two types of wideband PAs (a GaN Class F PA and a GaN Doherty PA) driven by the concurrent dual‐band signal, and compared with the prior two‐dimensional digital predistortion (2D‐DPD) model and the two‐dimensional modified memory polynomial (2D‐MMP) model. The results prove the good DPD performance and low computational complexity of the proposed models. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:401–411, 2014.     

基于模型参考自适应系统理论的异步电机矢量控制系统研究

采用模型参考自适应系统对系统转速进行估算,实现了异步电机的无速度传感器控制.在一个4kW的三相异步电动机上进行了实验,异步电机结果表明:该系统具有快速的动态响应能力和良好的稳定性.     

Nondestructive measurements of residual stress in air plasma-sprayed thermal barrier coatings

Premature spallation of thermal barrier coatings (TBCs) is a critical issue during the service of gas turbines, and nondestructive evaluation is crucial to address this problem. Herein, a novel approach that indicates delamination by measuring the residual stress evolution of thermally grown oxide (TGO) for air plasma spraying (APS) TBCs is proposed and verified via the combination of photoluminescence piezo-spectroscopy (PLPS) and X-ray computed tomography. A mineral-oil-impregnating approach and a cold-mount low-shrinkage epoxy-mounting approach are used to alleviate the signal attenuation by pores and microcracks in APS TBCs, improving the detectable PLPS signal and X-ray transmission for stress measurement and delamination characterization, respectively. We have nondestructively measured the TGO residual stress mapping in APS TBCs and its evolution with oxidation. Furthermore, the evolution of TGO morphology and critical microcracks are obtained by X-ray computed tomography. The synchronous evolution of TGO residual stress, TGO thickness, and critical microcracks as a function of oxidation time is obtained and correlated. The transition point, as experimentally identified, at which the TGO stress starts to drop, agrees well with the critical moment of microcrack coalescence. This directly verifies that the TBC delamination can be effectively indicated by residual stress evolution of TGO in APS TBCs.     

WLAN技术在静爆威力测试中的应用

冲击波测试中测点分布数量较多,难以集中管理以及监测各测点的状态存在困难,并且测试参数一旦设置好在现场难以更改。针对以上问题,设计了基于WLAN技术的冲击波测试系统。建立了能有效覆盖各测试节点的无线网络,实现了所有测点远程集中管理、运行状态监测以及测试数据无线传输,并且可现场设置节点测试参数,以适应测试环境的变化,提高了系统的灵活性。设计了硬件电路和软件时序相结合的方法智能管理节点无线模块,有效降低了系统功耗并实现了可循环进行多次不同的测试。采用多参数组合的负延迟分区存储数据的方法,有效获取了完整的冲击波信号并减少了随机触发前的冗余数据。系统参加了多次弹药测试实验,验证了系统的稳定性、可靠性。     

Numerical simulation for aerodynamic derivatives of bridge deck

An improved domain decomposition method is proposed to compute aerodynamic derivatives of bridge deck based on commercial Computational Fluid Dynamic (CFD) code FLUENT. In this method, the computational region is discretized into rigid boundary layer mesh region, dynamic mesh region and static mesh region. A simplified formula used to control the body-fitted grid height is deduced from the standard wall function. Aerodynamic derivatives of a flat plate and two long span bridge decks are computed and compared with the theoretical values and the wind tunnel tests results. Numerical results show that several aerodynamic derivatives are influenced by the accessory structures of the bridge deck such as guardrails and inspecting vehicle rails, etc.     

配电网精细化线损检测与分析方法研究

针对我国目前电力需求因素增多,而基于人工经验的传统配电网静态模型及调整模式工作效率低,不能满足配电网精细化线损等高级应用实际需求的问题,提出以巴盟某几个台区为试点,通过从跨平台海量数据中提取的负荷数据、遥信数据,构建10 kV馈线线损模型、台区线损模型和台区分支线损模型。开发自动拓扑校核技术的线损精细化系统,让线损指标可视化。通过对比传统方法与所提方法的10 kV线损,得到了所提方法在一定程度上有优势的结论。     

An adaptive surrogate model based on support vector regression and its application to the optimization of railway wind barriers

This study provides evidence supporting the use of the update strategies for the support vector regression (SVR) model. Firstly, the fitting and interpolation method (FIM) is presented to select SVR parameters, and three infill strategies are adopted to search for update points. Secondly, the infill strategy and parameter selection method are illustrated by test functions that illustrate their dependability. The distribution of update points, the sample density and the proportion of update points are discussed. Finally, the adaptive SVR surrogate model is applied to optimize the protective effect of railway wind barriers. The result shows that the parameter selection method has high stability. On the whole, the accuracy of the adaptive SVR model using a suitable infill strategy will be improved with an increasing proportion of update points if the final number of training points is identical. The optimization result shows an optimal porosity of 0.117 when the height of the railway wind barrier is 2.05 m (full scale).