鄂东北缘低阶煤渗透性特征及主控因素

为了分析低阶煤储层渗透率对煤层气勘探选区和产能建设的影响,在分析煤层气储层渗透率特征的基础上,通过煤层地应力、埋藏深度、显微组分、煤级及割理间距、煤体结构与渗透率之间相关性分析,探讨鄂尔多斯东北缘低阶煤渗透率主控因素。结果表明,该区低阶煤储层渗透率高于我国中高阶煤层气田煤储层渗透率,且主要受到煤级及割理间距和地应力的共同作用,煤级及割理间距通过煤演化过程改变煤岩力学性质控制渗透率,地应力通过影响割理的开启程度和方向控制渗透率,而埋藏深度与渗透率相关性不强。     

Effect of auxiliary blowing agents on properties of rigid polyurethane foams based on liquefied products from peanut shell

The bio‐based rigid polyurethane (PU) foams were successfully prepared based on liquefied products from peanut shell with water as the blowing agent. The influence of reaction parameters on properties of rigid PU foams was investigated. Rigid PU foams showed excellent compressive strength and low shrinkage ratio, whereas their open‐cell ratio and water absorption were higher. Therefore, rigid PU foams were synthesized with petroleum ether, diethyl ether, and acetone as auxiliary blowing agents and their inner temperature, shrinkage performance, density, compressive strength, water absorption, and open‐cell ratio were determined. The results indicated that above rigid PU foams showed lower compressive strength than the original foam but their water absorption and close‐cell ratio were improved. Compared with the original foam, the highest inner temperature of rigid PU foams with petroleum ether, diethyl ether, and acetone as auxiliary blowing agents was reduced by 11, 19, and 23 °C, respectively. Typically, foams with petroleum ether as auxiliary blowing agent displayed better water absorption and swelling ratio in water and exhibited obvious improvement in close‐cell ratio. These foams were preferable for application in thermal insulation materials because of low thermal conductivity and better corrosion resistance. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45582.     

机加工孔套管抗挤压强度有限元分析

套管屈服强度直接影响套管抗挤压性能,套管在加工孔过程中可能诱发孔眼附近材料发生金属相变,导致套管屈服强度不再均匀分布,进而影响套管抗挤压强度。在相同工况下,对比了P110完整套管和机加工孔套管的抗挤压强度,以此为参照组分析了相变区域面积和相变区域屈服强度对机加工孔套管抗挤压强度的影响。结果表明,机加工孔会改变材料屈服强度,进而影响套管抗挤压性能。随金属相变区域屈服强度减小,机加工孔套管抗挤压强度减弱;当金属相变区域屈服强度增大时,机加工孔套管抗挤压强度增强。且机加工孔套管相变区域面积对机加工孔套管抗挤压强度的影响随相变区域屈服强度增加而逐渐削弱。     

DETA的气相色谱分析

介绍了选择3％OV－1／chromosorb W-HP色谱柱,以正十八烷为内标物,采用气相色谱法测定DETA的分析方法。该方法的标准偏差0．14,变异系数0．74％,平均回收率99．82％。     

液化气脱硫装置闪蒸效率的探讨

对液化气脱硫装置闪蒸罐闪蒸效率进行了分析,提出了调整洗涤剂量、闪蒸罐液位、闪蒸压力及闪蒸温度,从而提高闪蒸效率的问题,并对效益作了分析。     

钛酸钾晶须的高温热稳定性

用分析纯K2CO3和TiO2为原料,按摩尔比n（K2CO3）／n（TiO2）为1：3.5混料均匀后,用烧结法反应合成钛酸钾晶须。通过X射线衍射仪和扫描电镜分析不同煅烧工艺下钛酸钾晶须的微观结构,研究钛酸钾晶须的高温热稳定性。结果表明：四钛酸钾（K2Ti4O9）的热稳定性低于六钛酸钾（K2Ti6O13）的。K2Ti4O9在高温煅烧时将向K2Ti6O13转变,其转变的临界温度约为1100℃。K2Ti6O13在1200℃煅烧的热稳定性略有下降。     

多因素条件下单级齿轮系统的非线性特性

考虑啮合刚度、齿侧间隙和轴承支撑间隙等因素,运用集中质量法建立了三自由度直齿圆柱齿轮副弯扭耦合非线性振动模型,并据此研究了各参数对齿轮系统非线性振动特性的影响。结果表明：齿侧间隙一定时,随着频率的升高,系统由周期运动通过激变直接进入混沌,然后又由混沌通过激变变为周期运动;在周期运动中,系统经过倍周期分岔,由双周期运动变为四周期运动,然后又通过逆倍周期分岔,由四周期运动变为双周期运动,之后又由双周期运动变为单周期运动;不同的输入转频条件下,间隙变化使系统表现出不同分岔特性,在某些特定频率下,间隙变化只增加系统响应能量变化,并不改变其动力学特性。     

上海世博会专用燃料电池加氢站系统配置的研究

氢燃料电池汽车以其"绿色环保、科技创新、节能减排"的特性在世博园内展示和应用。加氢站是氢燃料电池汽车基础设施,文章借鉴燃料电池汽车加氢站技术相关技术资料,阐述上海世博会专用燃料电池加氢站的系统组成及配置等功能。     

非圆锥齿轮节曲线的平面展开算法研究

以曲面上曲线的短程曲率为媒介,导出了球面节曲线伸展成平面当量节曲线的算法.以平面当量节曲线为基础,通过确定插齿刀的节圆沿平面当量节曲线做纯滚动时插齿刀上各点的运动轨迹,模拟了插齿加工包络出当量齿轮的齿形过程,将非圆锥齿轮的设计转化为平面齿轮的设计,简化了非圆锥齿轮的设计.     

一种抗几何攻击的视频水印算法

提出了一种基于视频序列时空不变信息的视频水印算法。在嵌入水印时生成同步帧,并确定同步帧时空不变特征点位置,检测时根据同步帧时空不变特征点的位置,实现对视频序列几何失真的矫正,对水印信息进行检测和提取。实验表明,该算法能有效地抵抗帧插入和帧丢失等时间轴同步攻击和高强度几何攻击。