吸湿型路面抑尘剂配方研制及工业试验

针对露天采场路面扬尘特点及机理,研制出一种吸湿型路面抑尘剂.基于正交试验,以失水率为评价指标,对抑尘剂各组分进行优化,并在实验室条件下对最优配方进行吸湿性、抗风吹等性能测试.结果表明,实验室研制的配方在25 d内最低含水率达到8.18%,具有很好的防风抑尘性能.将该抑尘剂配方进行工业试验,结果表明,该抑尘剂的有效抑尘时间为10 d,与传统洒水方法相比,抑尘费用降低了30.71%,节水效率达到94.67%.     

林木直径分布结构转移参数的辨识

在林木直径分布结构转移连续性方程的基础上,进行离散化分析,讨论了林木直径转移参数的性质和辨识方法,该方法对林木生长状态进行预测、预报及林业资源的最优生长控制具有重大意义。     

侧视孔内电视系统测量井径的研究

从侧视式孔内电视系统视场角恒定这一原理出发,从理论上分析了利用该电视系统能够直观而又简便地测量计算出井孔的井径,并在实验中得到了证明。     

α-淀粉酶产生菌的平板筛选法的研究与改进

用平板水解圈法筛选到若干株 α 淀粉酶产生菌,它们的平板水解圈直径大小与摇瓶酶活不相关,进一步研究了３０ ℃平板淀粉的质量分数对水解圈直径的影响以及淀粉的质量分数、温度、琼脂等多种因素对离体 α 淀粉酶水解圈直径的影响,并在此基础上建立了一种快速筛选高产菌株的简便方法。     

金属橡胶在巧克力奶过滤上的应用研究

金属橡胶兼有金属和橡胶的双重性质,具有一系列优良特性.运用VHX-600超景深三维显微镜和HPCA-2便携式污染度检测仪等设备,选用不同结构参数的金属橡胶,对巧克力奶进行过滤研究.通过改变材料孔隙度、丝径和成型厚度3个因素,绘制出巧克力奶过滤前后污染度等级变化折线图.最后对折线图进行横向和纵向比较,总结出材料孔隙度的降低、丝径的减小以及厚度的增大均可提高材料的过滤性能.     

改进型收卷系统的实时卷径检测方法

对已有的卷径检测方法进行改进,提出一种间接测量卷径的方法。通过对安装在引导辊与收卷辊侧的接近开关发出的脉冲进行计数,利用卷径模型将脉冲数转换为收卷辊的周长,在可编程逻辑控制器中进行运算,可间接获得实时卷径。阐述了改进后的方法硬件及软件的实现,完成了系统的设计,通过实验及实际使用验证了改进后的方法具有全数字化、简单可靠、实时性好且精度较高的优点。     

Study on the resistance spot welding technology of 22MnMoB hot stamping quenched steel

In this paper, the spot welding technology of a new kind of 22MnMoB hot stamping quenched steel sheet was systematically studied by power frequency spot welder. Through a series of technology and test experiments, we have obtained the optimal spot welding technological parameter condition. According to the results, the relations among spot welding technological parameter, welding nugget, mechanical property and fracture mode were discussed. The effects of all the welding parameters such as welding current, welding time and electrode force on the quality of joint can be boiled down to one thing--the diameter of welding nugget. The experimental results showed that welding nugget diameter determines the mechanical property of spot welding joint and the relation between welding nugget diameter and the mechanical property of joint presents a kind of linear mathematic representation. There are two typical fracture models of 22MnMoB hot stamping quenched steel sheet, i.e., interracial fracture and nugget pullout. Other than mild steel or normal high strength steel, in the shearing tensile test, hot stamping quenched steel has a great tendency to fail in interfacial mode due to the effects of high strength matrix structure, welding soft zone and the porosity level of fusion zone.     

Blasting technologies of vibration damping in subway tunnel passing under upper buildings closely

Reducing the blasting vibration is important for blasting excavation in subway tunnel construction. Taking the 3rd bid section of Line 3 of Qingdao subway project as an example, the distance between tunnel vault and ground is 5 - 8 m. In order to insure the safety of the upper buildings, technologies of parallel cut with large diameter empty hole, one-time initiation and delay by parts, and multiple shallow holes were adop- ted in the project. The results showed that the maximum value of vertical vibration was limited in the criterion allowance, and the upper buildings were not damaged. Besides, problems were solved that the number of nonel detonator was difficult to meet the requirements of excavating a large cross-section tunnel by blasting, multiple cross-section could＇ t be initiated simultaneously, and construction efficiency was low, which ensure the con- struction safety and schedule.     

软土中大直径顶管管道受力特性测试

采用现场实测方法,对深覆软土、长距离顶进、外径4.64m钢筋混凝土顶管的管壁接触压力和环向钢筋受力进行了测试,并与已有文献研究进行对比分析.结果表明:顶管在良好泥浆套中顶进时,管壁接触压力整体分布较均匀,注浆时呈突然增大变化,停顶后逐渐恢复正常水平;管道环向钢筋以受压为主、应力不大,其变化由管道轴向偏移和注浆控制,测试阶段管道受力状态以偏心受压为主;管壁接触压力实测值与按规程计算的设计值相比,管顶处相近、管侧处实测值略大、管底处实测值较小,规程的土压力分布模式用于管道设计计算偏于保守.     

固定直径的树的Harary指数

图G的Harary指数定义为图中所有点对的反距离之和.给出了固定直径的树的Harary指数的第二大值,并刻画了对应的极图.