孤东油田高压调整井固井技术

通过对孤东油田的固井技术研究,总结了高压调整井的固井技术措施,解决了高压调整井固井的技术难题。研究与应用结果表明,套管外封隔器可有效地防止注水泥过程中及封固后油气上窜或层间窜扰;早强水泥浆体系可有效地提高水泥石的早期强度;管外封隔器和早强水泥浆体系配合使用能够明显提高高压调整井的固井质量,也为调整井固井提供了新的思路。     

粘土颗粒的分形特征及分维数的测定方法

粘土颗粒具有分形特征。分维数是一定类型的粘土矿物颗粒在一定环境中颗粒几何性质衣几何形貌的定量反映,可用于表征颗粒的分散和聚集方式及其机理。综述了粘土颗粒的分形研究,介绍了三种分维数的实验测定方法,即吸附法、SAXS(小角度X射线散射)法和NMR(核磁共振)法,并讨论了各方法的分辨率及各自的特点。     

The 1996 North American Interagency Intercomparison of Ultraviolet Monitoring Spectroradiometers

Concern over stratospheric ozone depletion has prompted several government agencies in North America to establish networks of spectroradiometers for monitoring solar ultraviolet irradiance at the surface of the Earth. To assess the ability of spectroradiometers to accurately measure solar ultraviolet irradiance, and to compare the results between instruments of different monitoring networks, the third North American Interagency Intercomparison of Ultraviolet Monitoring Spectroradiometers was held June 17–25, 1996 at Table Mountain outside Boulder, Colorado, USA. This Intercomparison was coordinated by the National Institute of Standards and Technology (NIST) and the National Oceanic and Atmospheric Administration (NOAA). Participating agencies were the Environmental Protection Agency; the National Science Foundation; the Smithsonian Environmental Research Center; the Department of Agriculture; and the Atmospheric Environment Service, Canada. The spectral irradiances of participants’ calibrated standard lamps were measured at NIST prior to the Intercomparison. The spectral irradiance scales used by the participants agreed with the NIST scale within the combined uncertainties, and for all lamps the spectral irradiance in the horizontal position was lower than that in the vertical position. Instruments were characterized for wavelength uncertainty, bandwidth, stray-light rejection, and spectral irradiance responsivity, the latter with NIST standard lamps operating in specially designed field calibration units. The spectral irradiance responsivity demonstrated instabilities for some instruments. Synchronized spectral scans of the solar irradiance were performed over several days. Using the spectral irradiance responsivities determined with the NIST standard lamps, the measured solar irradiances had some unexplained systematic differences between instruments.     

β-乳球蛋白凝胶及其应用

综述了β-乳球蛋白凝胶的种类、影响β-乳球蛋白凝胶的因素以及β-乳球蛋白凝胶在食品工业上的应用,并对β-乳球蛋白凝胶的开发前景进行了展望。     

3,6-二(3,5-二甲基吡唑-1-基)-1,2,4,5-四嗪的晶体结构

采用NO2氧化3,6-二(3,5-二甲基吡唑-1-基)-1,2-二氢-1,2,4,5-四嗪(BDT)制备了3,6-二(3,5-二甲基吡唑-1-基)-1,2,4,5-四嗪(BT),在无水乙醇中用缓慢蒸发法培养了其单晶,用X射线衍射分析确定了其晶体结构。结果表明,分子属于单斜晶系,P21/c空间群,晶体学参数为a=1.096 nm,b=1.651 nm,c=0.714 nm,β=103.895(4)°,Z=4。     

运载火箭推进剂利用系统建模与仿真

推进剂利用系统是运载火箭的关键分系统之一,可有效提高火箭的运载能力。为进一步了解推进剂利用系统的工作原理与工作特性,采用模块化思想对推进剂利用系统中相互独立的子系统进行数学建模,并在Matlab/Simulink仿真平台上建立了推进剂利用系统动态仿真模型,通过实例仿真对模型的准确性进行了验证。仿真结果表明,该模型具有较高的精度,能够准确模拟推进剂利用系统的工作过程,具有较强的工程实用价值。     

Seismic collapse analysis of high‐rise reinforced concrete frames under long‐period ground motions

Structural damages associated with buckling of longitudinal reinforcing steel and crushing of concrete induce strength and stiffness degradation in reinforced concrete (RC) beams and columns. This paper presents a numerical investigation on earthquake‐induced damages and collapse of typical high‐rise RC buildings model incorporating strength degradation (SD) effects. In a simple finite‐element analysis program with the generalized stress fiber discretization, hysteretic constitutive models primarily dominate the inelastic behavior. Buckling of reinforcing steel and crushing of confined concrete are taken into accounted to the stress–strain relationship of fiber elements. The SD effect in components with small hoop ratio tends to amplify the seismic responses high‐rise RC moment‐resisting frames when the intensity of ground motions exceeds the design level. Buckling of steel rebar and crushing of concrete should be fully considered together with the P‐Δ effect for collapse simulations.     

Comparative Study on Corrosion Behavior and Mechanism of As-Cast Mg-Zn-Y and Mg-Zn-Gd Alloys

Rare earth (RE) elements have large solid solubility in magnesium and are widely used to regulate the microstructure and property of advanced magnesium alloys. However, different kinds of RE elements have different effects on microstructure and property of the alloy. In this study, a Mg-Zn-Y alloy and a Mg-Zn-Gd alloy with alloying elements of the same atomic percentage were designed to clarify the effect of yttrium (Y) and gadolinium (Gd) on the corrosion behavior of as-cast MgZn₂Y_2.66 and MgZn₂Gd_2.66 alloys. The results show that the MgZn₂Y_2.66 alloy is mainly composed of α-Mg phase and long period stacking ordered (LPSO) phase, while MgZn₂Gd_2.66 alloy is mainly composed of α-Mg phase and (Mg, Gd)₃Zn phase (W phase). Generally speaking, the corrosion phenomena of the two alloys in 3.5 wt% NaCl solution are similar. In the early stages of exposure, the alloys underwent uniform corrosion at a relatively low corrosion rate. With prolonged exposure, localized corrosion became dominated and the corrosion rate was greatly increased. However, the corrosion rate of the MgZn₂Y_2.66 alloy, in terms of the corrosion current density, is about one order of magnitude lower than that of the MgZn₂Gd_2.66 alloy. The high corrosion resistance of the MgZn₂Y_2.66 alloy is mainly attributed to the presence of LPSO phase in form of continuous networks and the relatively high corrosion resistance of the corrosion product layer on the alloy.     

Measuring the built environment of green transit-oriented development: A factor-cluster analysis of rail station areas in Singapore

Green transit-oriented development (TOD) is an evolution of the TOD theory, influenced by sustainable development and green urbanism. This advancement expands the environmental and ecological dimensions of conventional TOD. However, relevant research has only just started, particularly in combination with high-density cities in Asia. This study measures the built environment of Green TOD and identifies the key factors and characteristics of the Green TOD built environment. An evaluation method for the Green TOD built environment is developed on the basis of the 5D (density, diversity, design, destination, and distance) built environment framework and combined with green urbanism theories. Data from 23 rail station areas in Singapore were collected and analyzed using factor and cluster analysis. Five factors, namely, neighborhood spatial form factor, facility completeness factor, open space factor, high-density mixed land-use factor, and walking amenity factor, are extracted. Twenty-three station areas are classified into five clusters. The characteristics and optimization strategies of each cluster are analyzed on the basis of the statistical and graphical analyses. This research displays the characteristics and typology of the Green TOD built environment in an empirical way and offers a foundation for further research in diverse urban contexts.     

苏州中心"未来之翼"超长异形网格结构关键技术创新与应用

苏州中心"未来之翼"为目前世界上最大的自由曲面单层钢网格屋面之一,屋面结构展开长度达630米,超长不设缝,同时跨越下方4个单体,跨越运营地铁的中庭最大跨度达55m;不同于通常自由曲面采用三点共面的三角形网格,项目以四边形网格拟合自由曲面形态,并需同时保证玻璃幕墙的安装.项目组基于全过程数字协同,对项目难点逐个击破,完成多项技术创新,从整体形态的数字优化,抗震抗风的数字模拟,到数字化预安装,冷弯玻璃工艺创新,再到14.4万个玻璃穹顶空间点位的激光测绘与BIM联动等,各阶段都保证了完美的契合度,最终以远小于常规结构的构件尺寸和玻璃板的自然冷弯实现了舒展灵动的穹顶效果,体现了数字技术在设计、分析、建造和安装全过程运用的高水准和高精度.