大学生政治信仰状况的调查与思考

当今社会正处于加速转型期,大学生的政治信仰状况值得关注和深思.通过调查分析发现,大学生的政治信仰呈现多元化趋势,表现出个性化的特点.加强大学生政治信仰教育极为重要,必须强化思想政治教育课程主阵地作用,营造政治信仰教育的良好社会氛围,拓宽大学生政治信仰教育新渠道,发挥大学生在政治信仰教育中的主观能动性.     

Research on the Control Strategy of Variable Nozzle Turbocharger for Natural Gas Engine

A variable nozzle turbocharger (VNT) was applied to a 2.2-liter L4 natural gas engine,and a VNT control system was designed to operate it.Based on VNT matching test results,a VNT control strategy was studied,in which VNT adjustment is carried out through pre-calibrated VNT handling rod position,combined with a closed-loop target boost pressure feedback using proportional-integral-derivative(PID) algorithm.Experimental results showed that the VNT control system presented in this thesis can lead to optimized ...     

Development of AMT Fault Diagnosis Technique Based on KWP2000

In order to make automatic mechanical transmission (AMT) capable of performing fault self-diagnoses and adaptive to standard communication interface,through technical analysis and intensive study concerning on-board diagnostic protocols now widely applied in Europe and America,KWP2000 on CAN is accepted as a technological path.An AMT fault communication system using hardware-in-the-loop simulation by dSPACE is developed,and communications compatible with ISO 15031-6 is realized on this module.Moreover,a han...     

共振散射光谱法研究槲皮素与DNA相互作用

在BR缓冲液中,槲皮素存在微弱的共振散射现象,分别在288 nm、466 nm、562 nm处出现共振散射峰,随着DNA的加入,散射信号逐渐增强,且以上3处的峰值明显增加,并且562 nm处的增加值与DNA在3.024×10-7 mol/L～9.072×10-5 mol/L范围内呈现出良好的线性关系.在20℃时,通过Scatchard方程计算出槲皮素与DNA结合常数K=9.91×106 mol-1.L.     

波导-带状线耦合传输的分析

文章分析了波导-带状线通过小孔耦合的传输特性,通过保角变换求出带状线中的场分布,利用小孔衍射理论得到波导-带状线间的耦合度的表达式,并且理论计算值与测量值吻合较好.通过数值分析,结果表明:耦合小孔半径和厚度对耦合度的影响比较大,传输线的工作频带比较宽.     

少齿差减速器偏心轴及偏心套加工工艺研究

针对具有较高精度的偏心轴及偏心套加工问题,采用了组合式工艺偏心轴——套,并利用电火花线切割保证偏心精度。     

上海东方体育中心综合体育馆屋盖结构风振分析

在屋盖同步风洞试验测量的基础上,采用CQC法对上海东方体育中心综合体育馆大跨屋盖进行了较为准确的空间风振分析。分析了多个复杂空间振型对有代表性节点的动位移根方差的影响,得到本体育馆的最大参振振型为30阶;考虑了两种荷载组合工况,比较了工况1、工况2和自重作用下屋盖结构的节点位移和基底反力,工况1作用下的节点位移和基底反力最大,工况2作用下的相应结果最小;最后给出了5个不利风向下的位移风振系数,可供参考。     

Optimum location of surface wells for remote pressure relief coalbed methane drainage in mining areas

Based on engineering tests in the Huainan coal mining area,we studied alternative well location to improve the performance of surface wells for remote pressure relief of coalbed methane in mining areas.The key factors,affecting location and well gas production were analyzed by simulation tests for similar material.The exploitation results indicate that wells located in various positions on panels could achieve relatively better gas production in regions with thin Cenozoic layers,low mining heights and slow rate of longwall advancement,but their periods of gas production lasted less than 230 days,as opposed to wells in regions with thick Cenozoic layers,greater mining heights and fast rates of Iongwall advancement.Wells near panel margins achieved relatively better gas production and lasted longer than centerline wells.The rules of development of mining fractures in strata over panels control gas production of surface wells.Mining fractures located in areas determined by lines of compaction and the effect of mining are well developed and can be maintained for long periods of time.Placing the well at the end of panels and on the updip return airway side of panels,determined by lines of compaction and the effect of mining,would result in surface wells for remote pressure relief CBM obtaining their longest gas production periods and highest cumulative gas production.     

POLYFLOW逆向挤出功能在挤出方型物口模设计中的应用

以方型材挤出口模设计为例,建立了几何模型、数学模型及有限元模型。通过在POLYFLOW模拟软件中构建任务并定义各项参数,利用重新生成网格技术,进行了数值模拟和分析,得出如何有效应用POLYFLOW逆向挤出功能对方型材挤出口模进行设计。研究表明:POLYFLOW逆向挤出功能可以提前预测其变形倾向,提高了口模设计一次性成功率,缩短口模的开发周期,降低成本。     

Preparation,characterization and salt-resistance of a coal based super absorbent composite

Potassium humate was extracted from brown coal.A novel super absorbent composite,poly (acrylic acid-co-acrylamide)/potassium humate (PAA-AM/KHA),was prepared by graft polymerization of acrylic acid,acrylamide and coal based potassium humate using N,N'-methylenebisacrylamide as a crosslinker and potassium peroxydisulfate as an initiator.The effects of reaction temperature,degree of neutralization of the poly (acrylic acid) and the amounts of crosslinker,initiator and potassium humate were investigated.Salt resistance tests were also carried out.The composite prepared under optimal conditions had a potassium humate content of 10% and exhibited a water absorption of 770 g/g in distilled water,and 349,286 and 41 g/g in 0.5 mol/L KC1,MgCl2 and AlCl3 solutions respectively.The results indicate that the salt resistance of PAA-AM/KHA was superior to that of poly (acrylic acid-co-acrylamide) because of the collaborative effect of functional groups of the coal based potassium humate.The PAA-AM/KHA micro powder was characterized by IR spectroscopy and the micrographic surface was characterized by scanning electron microscopy.Introduction of potassium humate into the poly (acrylic acid-co-acrylamide) structure creates a composite more suitable for use as a water-managing material in the renewal of arid and desert environments.The salt resisting property of the composite is improved,production costs are reduced and the growth stimulant effect is still present.