电视机自动增益控制电路动态特性测量

本文提出一种电视机自动增益控制电路动态特性简易测量方法.按照此法,只需在待测电视机前加一级可调衰减器,就能用常用电子仪器测出自动增益控制电路的动态特性,并以此为依据改善电视机相关电路的性能.     

An economic model for the quality selection problem

The object of an economic model for the quality selection problem is to select the best parameter value for an input quality characteristic (X) so that the quality loss incurred on an output quality characteristic (Y) is minimized. The relation function between Y and X is assumed to be known throughout the article. In the work of Taguchi's experimentations, the selection of best parameter values is solved by two-step optimization when Y is adjustable. In the article, it is further extended to the case where Y is non-adjustable. An economic quality selection model with a general relation function is proposed based on a Taylor-series method for both adjustable and non-adjustable cases. A special case of a quality selection model with a quadratic relation function is also studied. A circuit example provided by Taguchi is presented to illustrate the use of this model.     

双螺杆泵Ω形对称型螺杆流场数值分析

由于螺杆泵几何结构及流体流动状态较为复杂,其压力分布和速度等特性很难用数学解析法来分析计算。本文利用参数化设计模块建立双螺杆泵Q形对称型螺杆三维模型,构建双螺杆流道的流场分析模型,运用有限元分析方法得出了双螺杆泵流道内压力场和速度场分布规律。结果表明：流体在流道中的流速分布具有规律性,整个流道的流场速度高低交替变化,在螺杆与衬套间隙处的流动为层流,螺旋面接触区内的流动为复杂的湍流,离螺杆啮合区近的螺旋槽内易发生涡流。本研究结果对于了解双螺杆泵螺杆工况下的性能情况具有重要的参考价值。     

双螺旋加料器输送机理的研究

本文在正位移输送机理的基础上，提出了双螺旋加料器理论输出量模型，并讨论了对其有影响的几个重要因素。     

对CA6140车床进给系统新的思考

本文在深入分析了ＣＡ６１４０车床进给系统的基础上，提出了用“三轴滑移公用齿轮机构”代替原机床“双轴滑移公用齿轮机构”的总体设想。改进后的机床在进给机构方面不仅能原设计的不足，又能改善其综合功能，获得较好的效果。     

Analysis of the Market‐Based Adjustable Outsourcing Contract under Uncertainties

The market‐based adjustable contract for customized goods or services has emerged in outsourcing practices. Its objective is to minimize the operational risks inherent in today's volatile environment of operations. Our research reveals several important properties of this contract through a continuous‐time analytical approach. Specifically, we consider the determination of this contract between two risk‐averse firms through a Nash bargaining process. We derive the optimal adjusting mechanism analytically and extensively analyze the application boundary of the market‐based adjustable outsourcing contract. We conclude by discussing implications for practice and research.     

考虑柔性和间隙的螺旋引纬机构仿真分析

为了提高引纬机构的稳定性和精度,将柔性构件和间隙的影响考虑在内,联合ANSYS和ADAMS建立螺旋引纬机构的刚柔耦合模型,通过ADAMS进行动力学仿真,在刚性系统和刚柔耦合系统中分别分析了旋转铰间隙对剑杆输出特性曲线的影响。在对仿真数据的观察中发现了相当比例的噪声信号,为了消除噪声信号的影响,利用统计学中上下四分位数和中位数来识别替换异常值;在综合考虑间隙和柔性构件的影响时,利用减噪后的加速度曲线与理想刚体系统下的数据的偏差值得到一个新的曲线,该曲线在固定区间内做高频波动,呈现出类似周期性声波信号的特点。结果表明旋转铰间隙是影响剑杆稳定性和精度的主要因素,柔性构件和间隙的综合作用产生了趋向于周期性的碰撞影响。依据研 究结果可以进一步对原刚体模型下设计的引纬机构进行优化设计。     

“螺丝揭顶”坟墓葬俗的民俗学研究——以武陵文化区渝东南酉水流域瓦乡话、土家语、苗语地区为例

武陵文化区酉水流域"螺丝揭顶"坟墓葬式是少数民族葬俗,是原始社会历史文化的遗留,其水生、土养、岫居、岩葬、石柩、遮阳、龙坛、吉穴、安魂、孝亲等丧葬内涵明显,在中国水乡蚌壳仙女等民间文学中有体现,是水乡稻作民族葬俗模式在山区的遗留,有对水乡生活的留恋,是历史上移民文化的遗存,是对人类生命礼仪、南方民族尊尊亲贤等优雅风尚的最高赞颂,有丰富的民族、历史文化、艺术、宗教因素,是中国南方民族丧葬文化的精品。