基于RBF神经网络优化的装备保障系统效能评估

针对现有装备保障系统效能评估方法存在依赖专家经验、主观性强等问题,提出一种基于径向基函数（RBF）神经网络优化的装备保障系统效能评估方法。通过完备交叉与预变异策略对遗传算法（GA）进行改进,利用改进的GA对RBF神经网络中心、宽度及输出权值进行全局寻优,并采用优化的RBF神经网络实现装备保障系统效能评估。仿真结果表明,该方法相比AGA-RBF和GA-RBF评估方法能更准确地评估装备保障系统效能值,并且可在一定程度上降低评估过程中主观因素的影响,确保评估结果更客观真实。     

土工格栅加筋包边填砂路堤模型试验研究

为探究包边填砂路堤荷载作用下的极限承载力特性、破坏形态规律及加筋性状,设计了土工格栅加筋包边填砂路堤结构,改装美国GCTS公司的USTX-2000动静三轴加载装置进行加载,通过改变加筋层数、筋材布置长度及包边土厚度对土工格栅包边填砂路堤进行一系列试验。对不同工况下包边填砂路堤的极限承载力、封层及坡面法向累积变形、位移变化进行研究。试验结果表明:土工格栅加筋和增加包边土厚度可以显著提高包边填砂路堤的极限承载力,并能减小封层中、封层右及坡顶、坡中的法向累积变形;无筋路堤的滑动面在路堤内呈折线状且并未通过坡脚侵入地基,在坡顶的黏土和砂芯交界处产生最大位移;土工格栅加筋及增加包边土厚度可以使滑动面向路堤内部迁移但形态不变,且最大位移处向路堤内部迁移。     

Variable sorting based on fault tree structure adjustment for multi-valued decision diagrams

The dynamic fault tree does not have the ability of fault calculation when analyzing the reliability of the system, so it needs to be modeled and analyzed by means of multi-valued decision diagrams and so on. The dynamic fault tree is translated into a multi-valued decision diagram according to the ordering of variables of basic events which affects the size of the generated multi-valued decision diagram and the cost of traversal to get cut sequences. An adjustment method of the dynamic fault tree structure is proposed based on the importance degree of repeated events, dynamic gates and the locations of events of the dynamic fault tree. By taking the fact that the basic events at the same level are equally important into account, an improved dynamic variable ordering method and ordering generation algorithm for the multi-valued decision diagram are presented in this paper. The result analysis of an example shows that the improved dynamic variable ordering method can reduce the size of the multi-valued decision diagram and space and time complexity of the reliability calculation compared to the similar methods.     

新建桥墩对东围电排站排涝影响的试验研究

采用正态物理模型试验研究引水渠中新建桥墩对东围电排站排涝的影响。研究结果表明:常遇洪水时,新建桥墩引起电排站附近水位变化(上游渠道壅高、前池降低)较大,电排站前池流态明显恶化;大洪水时,新建桥墩客观上对水流起到了调节作用,使电排站自身设计问题造成的较差流态略有改善。综合来看,由于电排站在常遇洪水条件下运行更为频繁,新建桥墩造成的流态恶化对水泵机组的正常高效运行造成影响,给排涝带来一定的安全隐患。     

生物质真空裂解制备磁性活性炭

以生物质杉木屑为原料、四氧化三铁为磁性添加剂、十六烷基三甲基氯化铵和聚氧乙烯月桂醚为复配表面活性剂,采用真空裂解技术,制备了杉木屑基磁性活性炭。考察了体系压力、活化温度、磁性剂质量分数和活化时间对磁性活性炭的碘吸附值、亚甲基蓝吸附值和磁性能的影响。单一因素变量试验结果表明:磁性活性炭对碘和亚甲基蓝的吸附值随着各体系压力、活化温度和活化时间的增加而呈现出先增大后减小的变化规律性,而随着磁性剂添加质量分数的增加而降低。综合考虑各因素,确定其最优制备条件为体系压力10k Pa、活化温度450℃、磁性剂的质量分数10%和保温时间60 min,此条件下制备的磁性活性炭对碘和亚甲基蓝的吸附值分别为935 mg·g~(-1)和315 mg·g~(-1),磁性活性炭的饱和磁化强度为8.24 emu·g~(-1),满足中等强度磁场磁选回收活性炭的要求。     

石膏板生产线消防系统设计

以圣戈班石膏建材(常州)有限公司石膏板生产线为例,针对石膏板厂消防设计的技术特点和该厂厂区情况,对全厂的消防系统设计作了介绍.其室内外消防给水系统采用稳高压消防给水系统,两台消防水泵分别采用电动机驱动和柴油机直接传动,可供无法设置高位消防水箱及只有一路供电的类似工程消防设计参考用.     

基于物联网的智能停车场系统

针对目前国内智能停车场存在全程物理导航费用高、部分导航表达不明确和无法实现二次导航寻车等问题,设计了利用物联网将数据传输给移动设备实现全程导航的方案,并给出了硬件结构和软件组成。采集停车场停车数据于PC机,通过停车场基站号码段识别技术将数据传输给用户手机,用户利用手机接收的数据进行停车场全程导航和二次导航寻车。通过软硬件设计和调试实验结果表明,数据能够可靠传输到用户手机,用户利用手机接收的数据链接百度地图能够轻松实现停车场内定位、导航和二次导航寻车。     

边坡工程中抗滑群桩工程特性的数值分析

针对建立抗滑群桩的设计方法问题,分析了抗滑群桩在水平推力作用下的力学行为.以重庆江东边坡的典型断面为例,应用有限元程序CORE3D分析了群桩的桩间颗粒土的土拱区域,结合桩的荷载位移曲线、土拱效应解释了土体应力传递到抗滑桩的规律,通过对影响土拱效应的参数,如桩间距、土体厚度、抗滑桩嵌入深度和桩径等的深入研究,提出了相应的群桩布置参数估算公式.研究成果在重庆江东边坡的防护工程设计中得到了应用,并取得了较好的效果.     

Non-complete relief method for measuring surface stresses in surrounding rocks

The measurement of surface stresses in surrounding rocks with the use of a relief method of annular hole-drilling was studied by numerical analysis. The stress relief process by hole-drilling was then simulated with the use of finite element method. The influences of the borehole diameter（d）, the initial stresses and the ratio of the initial principle stresses on the variations of the remained stress and the released stress in function of the relief depth（h） were discussed. The relation between the non-dimensional ratio of the released principle strains and that of the initial principle stresses, and the effect of the elastic modulus and the Poisson ratio of the rock mass on the stress relief curves were studied. The results show that the stress relief behavior formulated with the non-dimensional ratio of the released stress and the ratio of h/d is only sensitive to the ratio of the initial principle stresses and the Poisson ratio. The stresses are completely released when h equals 1.6d, and the tensile stresses take place on the bore core surface in the relief measurement process. Finally, a non-complete relief method of annular hole-drilling for measuring surface stress in surrounding rocks is proposed and the procedure is presented.     

Effects of coagulation bath temperature on structure and performance of poly （vinyl butyral） hollow fiber membranes via thermally induced phase separation

Poly （vinyl butyral） （PVB） hollow fiber membranes were fabricated via thermally induced phase separation （TIPS）. The effects of coagulation bath temperature （CBT） on the structure and performance of membranes were investigated in detail. The morphologies of the membranes were studied by scanning electron microscopy （SEM）, the performances of water permeability, rejection, breaking strength and elongation were measured, respectively. The results indicate that all the membranes have the asymmetric morphology and the thickness of the skin layer decreases and the pore size of the outer layer increases with the increase of CBT. The permeability of membranes prepared at air gap 1.0 cm and take-up speed 0.253 m/s increases from 1.047×10-7 to 5.909×10-7 m3/（m2·s-kPa） with the CBT increasing from 20 ℃ to 40℃, and sharply increases to 35.226×10 7 m3/（m2.s.kPa）once the CBT arrives at 50 ℃. While the carbonic ink rejections have no significant decrease, totally exceed 98%, but that of acid-maleic acid copolymer greatly decreases with the increase of CBT. Both the breaking strength and elongation decrease with the increase of CBT.