PET光学膜紫外光固化硬涂层的制备

本文以改性聚氨酯丙烯酸酯为主体,制备了一种PET光学膜用透明硬涂层材料.讨论了光固化树脂、活性稀释剂、光引发剂等因素对PET光学膜加硬后的硬度、耐磨性、附着力等性能的影响,并从反应机理方面分析探讨了实验结果.经测试:实验制备的涂层硬度5H,附着力100%,经RCA纸带耐磨擦试(500g,1000cycles),PET膜可见光透过率无损失,同时具有低表面张力,出色的柔韧性和良好的耐化学品性.     

泥岩三轴蠕变实验研究

采用MTS伺服刚性压力实验机对高家梁煤矿泥岩进行了三轴蠕变实验研究,获得了泥岩在不同应力条件下的蠕变变形规律。实验表明围压对泥岩微观缺陷的发展有一定的限制作用。随着围压的增加,泥岩的三轴抗压强度和弹性模量均有所增加。在围压一定时:衰减蠕变量随轴压的增大而增大;衰减蠕变率随偏应力的增加而增大;稳态蠕变率随偏应力的增大而增大。在偏应力一定时,稳态蠕变率随围压的增大而减小。当围压大于4MPa后,围压的限制作用将明显减小。随着围压继续增大,稳态蠕变率变化并不明显。根据获得的实验数据,用回归法求出了H-K模型蠕变方程的参数。结果表明H-K模型能较好地模拟实验结果。在实际工程中可通过支护增加围压以提高围岩屈服强度,也可根据实际工程中泥岩蠕变的变化趋势确定合理的二次支护时间,避免流变破坏的发生。     

逆冲断层地震主震的突变理论分析

逆冲断层系统作准静态形变时的功、能量增量关系可以分解为关于体积应变能的功能增量关系和关于偏应力能的功能增量关系．采用突变理论方法对逆冲断层系统的偏应力功能量增量关系进行的分析表明:折迭突变模型展示的性状可对逆冲断层地震主震的发震条件、演化过程和若干震后特性作恰当描述．围岩的围压大,最大主应力大,逆冲潜断层面倾角小,围岩切向刚度与断层抗剪强度曲线软化段拐点处斜率的比值小, 则震时围岩弹性能释放量大、 震级高, 断层破裂半错距大, 围岩端面位移振幅也大．断层岩体破裂扩容和震时围岩体积应变能释放, 增强了前述效应．     

Effect of sonochemical scouring on the surface morphologies,mechanical properties,and dyeing abilities of wool fibres

Ultrasonics has the potential to reduce the cost and environmental impact of textile processing. This work investigates the effects of ultrasonic irradiation during wool scouring on fibre surface morphologies, fibre mechanical properties, and fibre dyeing abilities. A range of ultrasonic frequencies were used in the scouring bath to examine the forms of fibre cuticle damage. It is observed that wool fibres underwent ultrasonic irradiation at a low frequency have severe modifications of the fibre surface structure. Despite some visible disruptions to the fibre scale structure however, ultrasonic irradiation has shown a negligible impact on the fibre mechanical properties, especially bending abrasion resistance which depends largely on the fibre surface conditions, and is responsible for the handle and pilling propensity of the resultant fabrics. Dyeing abilities were investigated on wool samples using commercially available acid dye and reactive dye. It is found that ultrasonically scoured wool has a quicker dye uptake in the early stage of low temperature dyeing for both acid dye and reactive dye, than the conventionally scoured wool.     

基于AMESim的制动钳动态所需液量检测仿真研究

制动钳所需液量检测是制动钳性能检测中十分重要的一部分,目前关于制动钳动态所需液量检测研究缺乏理论和仿真依据,无法结合实际检测实现制动钳故障诊断,针对这一问题,在研究主缸位移差值法动态所需液量检测系统数学模型的基础上搭建AMEsim仿真模型,对主缸活塞速度和钳体结构因素进行仿真分析,并通过实验验证模型的正确性。结果表明：主缸活塞速度对动态所需液量检测影响较小;回位弹簧刚度、制动间隙和摩擦块、橡胶密封圈硬度对动态所需液量曲线有不同程度的影响,可以根据曲线特征实现制动钳故障诊断。     

变论域模糊控制器单元机组SCR烟气脱硝控制研究

SCR烟气脱硝系统的脱硝率由喷氨量来控制,而喷氨流量控制系统控制喷氨量,因此,优化喷氨流量控制系统能有效提高脱硝率。设计了一种基于变论域的模糊控制器来实现喷氨量的优化控制,并采用 MATLAB 仿真软件对此控制方案进行仿真,并与传统的控制方案的结果进行对比分析。结果表明,基于变论域的模糊控制喷氨流量系统相对于传统的PID控制,其超调小,且鲁棒性较强,有效地提高了控制品质。     

Hepatic lipid composition analysis using 3.0-T MR spectroscopy in a steatotic rat model

Purpose

To investigate the feasibility of in vivo assessment of hepatic lipid composition using 3.0-T proton magnetic resonance spectroscopy (¹H-MRS) in a steatotic rat model and compare it to histopathological and biochemical assessment.

Materials and Methods

Hepatic steatosis was induced by feeding rats with a methionine/choline-deficient (MCD) diet for 1, 2, 3, 5 or 7 weeks (n=5 per group). At the end of the diet period, ¹H-MRS of the liver was performed, and rats were sacrificed for histopathological and biochemical assessment of the liver. Spectra were acquired in a single voxel (1.2 cc) using a point-resolved spectroscopic sequence with TE/TR=35/2000 ms and 64 signal acquisitions. From the MR spectra, peak area ratios were calculated to estimate hepatic lipid composition.

Results

During MCD diet periods, hepatic steatosis significantly increased on histopathology (P<.001). The ¹H-MRS measurements of total hepatic fat content [1.3/(1.3+4.65) ppm] correlated strongly with histological macrovesicular hepatic steatosis (r=0.93, P<.001) and with the biochemical total hepatic fatty acids (r=0.94, P<.001). Total unsaturated fatty acids [TUFA, 5.4/(1.3+4.65) ppm] estimated with ¹H-MRS strongly correlated with the biochemical unsaturated fatty acids (r=0.90, P<.001). Polyunsaturated fatty acids [PUFA, 2.8/(1.3+4.65) ppm] estimated with ¹H-MRS strongly correlated with biochemical PUFA (r=0.91, P<.001). The proportion of total unsaturated fatty acids relative to the amount of total fatty acids (rTUFA, 5.4/1.3ppm) measured with ¹H-MRS strongly correlated with the biochemical amount of unsaturated relative to total hepatic fatty acids (r=0.81, P<.001). The proportion of PUFA relative to the amount of total fatty acids (rPUFA, 2.8/1.3 ppm) measured with ¹H-MRS correlated with the biochemical amount of PUFA relative to total fatty acids (r=0.59, P=0.005,) and with the biochemical amount of omega-6 PUFA relative to total fatty acids (r=0.73, P<.001).PUFA at ¹H-MRS correlated with the histopathologically assessed degree of lobular inflammation in the liver (r=0.57, P=.001).

Conclusion

3.0T ¹H-MRS is able to measure poly- and unsaturated hepatic fatty acids and this strongly correlates with biochemical assessment. This study provides evidence that 3.0-T ¹H-MRS is a noninvasive technique to assess hepatic lipid composition.     

“运价”为负的运输模型计算机求解问题的处理

为解决一些计算机软件求解"运价"既有正值又有负值运输模型时"不可求解"的问题,本文采用"运价同额增减法"决策模型转换的方法,将原模型的"运价"全部转换为正值后再用计算机软件求解,并分别编写了EXCEL求解模板和求解程序对该方法的计算加以印证。结果表明,采用该方法求解得出的最优解(最优决策方案)与原模型求得的最优解完全一样,而最优值(最优决策效果)减去虚增(或加上虚减)的部分就是原模型的最优值。采用这种方法能成功地解决一些计算机软件"不可求解"的问题。     

动能侵彻弹体的质量侵蚀模型分析

通过对高速侵彻弹体的质量侵蚀实验现象进行分析,建立了质量侵蚀的工程理论模型,可对动能侵彻弹体头部侵蚀后的头形和质量侵蚀进行预期. 讨论弹体质量侵蚀的主要影响因素,认为弹体动能(或质量和速度)以及混凝土骨料硬度对弹体的质量侵蚀有显著影响,给出了更一般化的弹体质量侵蚀与撞击函数$I$的关系. 通过图形分析明确弹体的质量侵蚀主要发生于头部,并且侵蚀后的弹头仍接近尖卵形,可以通过头形变化预期弹体的质量损失.      

走滑式断层地震的折迭突变模型

利用过势函数微分形式的途径,计入远场外力功的影响,对走滑式断层地震机制进行分析．研究表明:突变理论中折迭突变模型展示的性状,与走滑式断层地震的主要特征之间一一对应．折迭突变可对包括震前、震后围岩-断层系统稳定性描述在内的断层失稳起、终点位置、断层失稳错距等作出描述．给出3种性状可相互印证的断层失稳围岩弹性能释放量图解．走滑式断层地震强度与围岩压力及围岩断层的刚度比等有关,围岩压力大、刚度比小、主切应力轴与发震断层面夹角大,则地震强度大．