基于SPH方法的大块煤冲击破碎数值模拟

为研究大块煤在钎杆冲击下的破碎效果,引入RHT混凝土本构模型材料来模拟大块硬煤（压缩强度35 MPa）,并基于光滑质点流体动力学（SPH）方法建立了钎杆冲击大块煤的三维仿真模型。分析比较了大块在静压、纯冲击和冲压组合作用下的破坏程度,以及平头和圆锥形钎杆冲击效果的差异。仿真结果表明：平头钎杆在30 MPa压力、15 m/s速度或是其组合作用下,均无法使大块产生有效破坏;平头钎杆在200 m/s的超高速下可使大块产生彻体破坏,但实现钎杆高速运动困难;圆锥钎杆在30 MPa压力和15 m/s速度的冲压作用下,使大块产生了较大范围的锥形失效,远高于常规液压破碎锤的单次冲击破坏程度。锥形钎杆、高压高速是破碎硬质大块煤的一种有效方法,可在较少作用次数下实现破碎,验证了低频重载破碎大块的可行性。     

高压大流量安全阀试验装置研究

大流量安全阀保护立柱不受高压破坏,是液压支架重要原件之一。为了测试液压支架安全阀的动态特性,设计了一种以蓄能器为动力源的高压大流量安全阀试验装置,介绍了其工作原理,以及测控系统。经试验表明,以蓄能器代替大流量泵,可实现快速加载,为安全阀提供大流量阶跃信号,该试验系统可满足大流量安全阀的动态特性测试要求。     

辽宁省重力场特征与矿产预测

以辽宁省重力场为研究对象,通过对草河掌一八里甸岩体的重力二维反演以及大台沟铁矿重磁场特征分析,论述了重力异常解释在推断成矿有利部位方面的方法技术应用,认为重力梯度带附近为多金属矿产成矿有利部位,重磁同源异常为“鞍山式”铁矿的成矿标志之一。     

大断面方坯轧制折叠缺陷的产生原因及控制

大断面方坯一般用于锻造,生产中经常发生的直线裂缝状缺陷直接影响锻件的表面质量、根据直线裂缝状缺陷的形貌特点,分析缺陷产生原因,并在生产中验证分析结果,最终寻找出控制缺陷的措施。研究表明,在连续立轧过程中,钢坯在孔型中立轧压下量过大会导致明显双鼓变形凸起,此双鼓变形凸起在随后的平轧中容易形成直线裂缝状的折叠缺陷。通过优化轧制规程和清理方式,可以减轻甚至避免此缺陷。     

大型矿山变压器设计方案的比选

对大型矿山变压器的选择进行了方案的比较,通过4个方案的比选,选出了技术经济指标最优的方案。     

Traditional 'air-dried' fermented sausages from Central Germany

Traditional varieties of fermented pork sausages from Central Germany are different from related meat products in various aspects. First, they are prepared from “warm” pork immediately after slaughter. The meat is then minced, mixed with spices and minimal amounts of sugars, salt and nitrate, and the stuffed sausages ripen for a minimum of 6-8 weeks at temperatures below 15 °C. Second, surface mould growth during ripening is regularly removed or suppressed. The manufacturing methods require a minimum of investments and labour and reflect the socio-economic situation in the manufacturing area. The sausages have a good record of safety, and a preliminary risk assessment indicates that pathogens are kept under sufficient control by the extended ripening at low temperatures. Small-scale (artisanal) manufacture of these products is only possible with a flexible interpretation of the hygienic principles set up in current legislation.     

低压降高效换热器复合强化传热试验研究

大小孔折流板与圆弧波纹管都是近几年提出的降低换热器壳程压降和提高传热效果的结构元件。针对大小孔折流板和圆弧波纹管的特点,提出了将两者相结合的低压降高效换热器,并试验研究该换热器的流动和传热性能。结果表明,换热器具有较低的壳程压降和良好综合传热能力。与光管的普通弓形折流板换热器相比,相同流量下,大孔直径为φ26mm的圆弧切线波纹管与大小孔折流板复合结构换热器的壳程板间压降可降低64％,虽然孔径较大时壳程膜传热系数有所下降,但总传热系数有明显提高。若以单位压降的传热系数来评判,圆弧切线波纹管与大小孔折流板复合结构换热器的强化传热性能要远高于普通弓形折流板换热器,最高值可达普通弓形折流板换热器的2．87倍。     

超精密大尺寸光学玻璃平面磨床的研制

光学玻璃广泛应用于激光技术、光电通讯、航空航天以及国防工业等领域。上海机床厂有限公司开发了超精密大尺寸光学玻璃平面磨床,对该磨床的结构及相关技术进行了介绍。     

Design schemes and comparison research of the end-effector of large space manipulator

The end-effector of the large space manipulator is employed to assist the manipulator in handling and manipulating large payloads on orbit.Currently,there are few researches about the end-effector,and the existing end-effectors have some disadvantages,such as poor misalignment tolerance capability and complex mechanical components.According to the end positioning errors and the residual vibration characters of the large space manipulators,two basic performance requirements of the end-effector which include the capabilities of misalignment tolerance and soft capture are proposed.And the end-effector should accommodate the following misalignments of the mechanical interface.The translation misalignments in axial and radial directions and the angular misalignments in roll,pitch and yaw are ±100 mm,100 mm,±10°,±15°,±15°,respectively.Seven end-effector schemes are presented and the capabilities of misalignment tolerance and soft capture are analyzed elementarily.The three fingers-three petals end-effector and the steel cable-snared end-effector are the most feasible schemes among the seven schemes,and they are designed in detail.The capabilities of misalignment tolerance and soft capture are validated and evaluated,through the experiment on the micro-gravity simulating device and the dynamic analysis in ADAMS software.The results show that the misalignment tolerance capabilities of these two schemes could satisfy the requirement.And the translation misalignment tolerances in axial and radial directions and the angular misalignment tolerances in roll,pitch and yaw of the steel cable-snared end-effector are 30mm,15mm,6°,3° and 3° larger than those of the three fingers-three petals end-effector,respectively.And the contact force of the steel cable-snared end-effector is smaller and smoother than that of the three fingers-three petals end-effector.The end-effector schemes and research methods are beneficial to the developments of the large space manipulator end-effctor and the space docking mechanism.     

动态车辆超载预检系统的设计与实现

为了实时的检测出动态车辆是否超载,设计出了一种动态车辆超载预检测系统。系统硬件平台以工控机为核心处理单元,以LED大屏幕为显示单元,用高精度多通道数据采集卡PCI-1716完成数据采集。软件设计以C++作为编程语言,以Visu-al C++6.0作为前台开发工具,设计了一套高效、稳定的软件系统,实现了对硬件设备控制、数据采集、数据处理、数据显示、数据通信以及数据存储等功能。实验结果表明,系统运行稳定可靠,能够准确检测出超限车辆,实现了对超载车辆的实时检测。