高速铁路场景下时变信道的平稳区间研究

The non-stationary behavior, caused by the train movement, is the main factor for the variation of high speed railway channel. To measure the time-variant effect, the parameter of stationarity interval, in which the channel keeps constant or has no great change, is adopted based on Zhengzhou-Xi'an (Zhengxi) passenger dedicated line measurement with different train speeds. The stationarity interval is calculated through the definition of Local Region of Stationarity (LRS) under three train velocities. Furthermore, the time non-stationary characteristic of high speed railway channel is compared with five standard Multiple-Input Multiple-Output (MIMO) channel models, i.e. Spatial Channel Model (SCM), extended version of SCM (SCME), Wireless World Initiative New Radio Phase II (WINNERII), International Mobile Telecommunications-Advanced (IMT-Advanced) and WiMAX models which contain the high speed moving scenario. The stationarity interval of real channel is 9 ms in 80% of the cases, which is shorter than those of the standard models. Hence the real channel of high speed railway changes more rapidly. The stationarity intervals of standard models are different due to different modeling methods and scenario definitions. And the compared results are instructive for wireless system design in high speed railway.     

基准面旋回原理在储层研究中的应用——以川中公山庙构造沙一油藏为例

以川中公山庙构造沙一油藏为例,以高分辨率层序地层学的基准面旋回原理为指导思想,在储层沉积学特征研究的基础上,从“沉积作用-基准面旋回-非均质性研究”的思路出发,较详细地分析了沙一油藏不同级次的基准面旋回的特点及其对储层宏观非均质性的控制.在沙一油藏滨浅湖-三角洲相沉积体系中共划出1个长期、6个中期和29个短期旋回层序.在此基础上指出沙一油藏储层宏观非均质性受控于基准面的旋回变化,一般在中期基准面旋回上升半旋回的下部砂体比较发育,非均质性弱;各中期基准面旋回上升半旋回末期和下降半旋回期泥质沉积较发育,非均质性强;同时探讨了基准面旋回原理在储层表征和油气田开发中的应用前景.     

柯克亚地区天然气的成因

柯克亚地区天然气的成因众说纷纭。通过对天然气的地球化学特征的详细分析,发现柯克亚天然气碳同位素相对较重,与塔里木盆地下古生界海相天然气的碳同位素组成区别较大,并明确指出柯克亚地区的气源不是单一来源,而具有混源特征。绝大多数天然气的成熟度在1.8%~2.2%之间,也混有一些成熟度在0.9%~1.2%的源岩形成的天然气,推测天然气主要来源于石炭系—二叠系源岩,部分来源于侏罗系源岩。     

川南龙马溪组页岩孔隙结构综合表征及其分形特征

为了科学评价川南地区龙马溪组页岩孔隙发育特征对页岩气赋存与流动过程的影响,综合采用压汞、液氮吸附及二氧化碳吸附等测试方法,对页岩孔隙结构进行全尺度表征,并对不同尺寸的孔隙进行分形拟合,计算综合分形维数,最后结合地球化学和矿物组成对综合分形维数的影响因素进行探讨。结果表明：页岩样品孔径分布呈多峰态,各阶段孔隙均对总体积有一定贡献,而孔隙比表面积主要由微孔和介孔贡献。龙马溪组页岩孔隙符合分形规律,具有自相似性,宏孔孔隙结构较介孔、微孔更为复杂。以2个孔径段的孔体积比为加权值,计算获得综合分形维数为2.491～2.623,平均为2.560,孔隙结构较为复杂。有机碳含量和矿物组成对综合分形维数具有明显控制作用,有机碳含量越高,综合分形维数越大。孔隙结构复杂程度与综合分形维数呈正相关关系,脆性矿物含量与综合分形维数呈负相关关系,有机质成熟度和黏土矿物对孔隙综合分形维数有积极影响。     

“两宽一高”地震资料在花岗岩潜山储层表征中的应用——以乍得邦戈盆地为例

随着乍得邦戈盆地在L-1井区的花岗岩潜山获得油气发现,在该区开展了“两宽一高”（宽方位、宽频带、高密度）的油气勘探地震资料采集处理解释一体化技术攻关。充分利用“两宽一高”地震资料的高信噪比、全方位观测、低频信号的强穿透能力和抗干扰能力等优势,有效提高了潜山顶面偏移成像质量,获得了丰富的潜山内幕信息,为花岗岩型潜山的储层表征和潜山目标评价奠定了良好基础。本文基于“两宽一高”地震资料提出了花岗岩潜山复杂储层表征技术,根据储层的储集空间组合特征、储层类型、岩石物理特征和对应的地震响应特征,将花岗质基岩潜山储层序列划分为风化淋滤带、缝洞发育带、半充填裂缝发育带和致密带;将裂缝型和孔隙型储层分类表征,孔隙型储层通过地震多属性融合和地震反演技术进行储层定性和定量预测,裂缝型储层结合区域构造特征,分别应用曲率体、相干和OVT域地震属性等进行裂缝识别与预测;综合裂缝预测和孔隙型储层预测结果进行储层评价和优质储层预测。该配套技术在乍得邦戈盆地的实践表明,应用“两宽一高”地震资料及针对性配套技术,能有效提高邦戈盆地花岗岩潜山储层预测的精度和勘探成功率,在B区块实施的潜山探井成功率高达79%。     

常压塔塔顶压降升高的原因分析

某常压蒸馏装置掺炼轻质原油或回炼轻污油时常压塔负荷变大,当常压塔塔顶（简称常顶）回流量大于22 t/h时,常顶和进料段压差由20 kPa增加到40 kPa以上,常顶油和常一线油出现馏程重叠。现场调研发现,常压塔上数第9~16层塔盘、浮阀有大量结垢沉积物,几乎堵塞整块塔盘。对现场堵塞位置垢样进行采样,元素分析、XRD、XRF表征结果表明,常压塔一中段处垢样的主要成分是NH4FeP2O7。通过高温缓蚀剂模拟结垢试验确定了塔顶结垢堵塞的原因,并针对性提出优化解决措施。     

采用差分相位测量方法的MEMS运动表征系统

介绍了一种基于计算机控制的频闪干涉测试系统,用于测量可动微机电系统(MEMS)器件的离面运动,实现了nm级分辨力.系统采用五步相移高精度干涉测量方法,通过选择器件上的固定点作为参考点,实现差分测量模式,有效消除了随机误差的影响,提高了系统测量的重复性,10次测量的重复精度为3.17 nm.通过研究微谐振器的离面运动特性,说明该系统的强大功能.     

An experimentally validated thermo-mechanical model for the prediction of thermal contact conductance

A predictive model for estimating thermal contact conductance between two nominally flat metallic rough surfaces has been developed and experimentally validated. The predictive model consists of two complementary parts, the first of which is a surface deformation analysis to calculate the actual area of contact for each contact spot, while the second accounts for the effects of constriction resistance and gas gap conductance between the contacting surfaces. A surface characterization technique is developed which generates an equivalent 3-D surface profile from multiple 2-D profiles and determines the unique wavelengths of importance for the surface deformation and constriction resistance models. For given surface profiles and material properties of two contacting surfaces, and a specified contact pressure, the surface characterization technique filters out non-essential wavelengths on the surface, after which the surface deformation analysis calculates the deformation and contact area of each contacting asperity by considering three different modes of deformation, namely, elastic, elastic–plastic, and plastic. The constriction resistance model is then used to calculate the constriction resistance for each contacting asperity based on the area of contact and radius of curvature of the asperity. The constriction resistance values for all the contacting asperities are then used to calculate the total thermal contact conductance. An experimental facility has also been constructed to measure thermal contact conductance of interfaces to verify the results of the predictive model. Good agreement has been found between the model predictions and experimental measurements, validating the modeling approach.     

Commercial-scale rapid thermal processing of biomass

Rapid Thermal Processing (RTP) utilizes proprietary reactor systems to convert both biomass and petroleum-based materials to high yields of chemical and liquid fuel products. The essential feature is the ability to transfer heat rapidly with precise control of short contact times. The process involves thermal or thermocatalytic refining of biomass, and is somewhat analogous to the refining of petroleum materials. Nevertheless, the chemical and fuel products from biomass are unique, and not similar to petroleum-derived products. Furthermore, RTP is not to be confused with conventional pyrolysis, from which it differs fundamentally with respect to product yield and quality, and process conditions and chemistry. Short-term applications include the production of specialty chemicals, fuel oil substitutes and engine fuels for both diesel and turbine applications. Research in support of these applications is in progress and is briefly reviewed. The paper focuses primarily on the status of RTP hardware, including the operation of a 2.5 tonne day⁻¹ plant and a 25 tonne day⁻¹ commercial plant.