基于步进电机控制的伺服钻孔机设计

采用高性能的STC89C516RD+单片机,控制步进电机完成点动、快进、工进以及精确定位的任务。定位系统是通过设定原点和精确控制脉冲数来实现的。解决了钻头在刚性材料表面上不能精确定位以及金属屑不易排出去的难题。与传统的手动钻孔机相比,该伺服钻孔机控制方便、精度高、生产效率高。     

成渝高速公路SDH光纤通信传输系统设计

根据四川成都一重庆（简称成渝）高速公路的实际情况，完成了对成渝高速公路SDH（同步数字系列）光纤通信传输系统的设计。通过对所设计系统进行的初步测试表明，设计方案合理可行，具有较高的实际工程指导意义。     

环状压电超声电机的多频率驱动分析与实验

针对压电超声电机的多频率驱动问题进行研究,设计并制作了利用定子内圆周面驱动的环状压电超声电机,明确了利用行波驱动电机转子的机理。通过有限元计算给出了电机定子所用弯曲模态的振型与位移云图。以计算结果为基础,分析了电机所用的压电陶瓷片的极化分区与定子弯曲模态激发之间的关系,得出了所用的压电陶瓷片能够实现电机多频率转动的结论。完成了所研制的超声电机的多频率驱动实验。实验结果表明,电机能够实现在多频率点的转动。依据本文分析思路,可以对其他结构形式的超声电机的多频率驱动问题进行研究。     

春花鱼鳞册初探

发现于天柱县的"春花鱼鳞册"在新出的清水江文书中具有重要的价值,对鱼鳞册所载"田主"身份的考察,结合清水江地区典田、借贷文契的特点,显示永佃制在当地耕地经营中已普遍存在。尽管鱼鳞册登载的耕地面积、范围看来不大,但对于了解清水江山地背景下耕地地权分配的状况,仍有一定的参考价值。     

浅谈汽车广告

文章通过分析成功的汽车广告的诉求主题、表现策略，指出：抓住时代需求，消费者心理需求，有的放矢的决定诉求主题和表现策略才是广告的成功之道。     

日本雇佣制度的变迁——兼职员工的现状分析

上世纪九十年代后,随着日本泡沫经济的破灭,一度被日本人引以自豪的终身雇佣制开始渐渐失去光芒。根据2005年日本厚生劳动省统计,日本兼职员工已经接近员工总数1/4,今后还有继续增加的趋势。本文仅从日本企业的兼职员工不断增加的现状入手,着重分析产生这种现象的原因。希望通过对日本兼职员工现状的分析并找出其变化的原因,为中国政府和企业制定政策提供一定的指导。     

“大陆台商”的非植根性状态与植根性趋势——基于新经济社会学视角的审视

常住大陆台商已经形成沟通两岸的特殊群体,这一群体从在大陆出现时持续至今的非植根状态一直值得各界关注.目前,该群体正从非根植状态向根植性状态转变.这一转变将对两岸关系产生重要影响.从新经济社会学角度研究台商这一社会群体,对研究台商的社会作用有着重要的战略意义.     

The Calibration for Two-Phase Randomized Response Estimator

This article presents the calibration procedure of the two-phase randomized response (RR) technique for surveying the sensitive characteristic. When the sampling scheme is two-phase or double sampling, auxiliary information known from the entire population can be used, but the auxiliary information should be information available from both the first and second phases of the sample. If there is auxiliary information available from both the first and second phases, then we can improve the ordinary two-phase RR estimator by incorporating this information in the estimation procedure. In this article, we used the new two-step Newton's method for computing unknown constants in the calibration procedure and compared the efficiency of the proposed estimator through some numerical study.     

改革户籍制度是化解农村干群矛盾的有效途径

户籍制度把农业户口和非农业户口严格区分开来,形成了城乡分割的二元结构;城乡壁垒限制了农民的流动,是导致干群矛盾的制度性原因之一。走城乡一体化的道路,逐步撤消城乡壁垒,保证农民的自由流动,有利于化解干群矛盾,从根本上解决农村社会问题。     

Real-time reliability evaluation of two-phase Wiener degradation process

Reliability modeling and evaluation for the two-phase Wiener degradation process are studied. For many devices, the degradation rates could possibly increase or decrease in a non smooth manner at some point in time due to the change of degradation mechanism. A two-phase Wiener degradation process with an unobserved change point is used to model the degradation process. And we assume that the change point varies randomly from device to device. Furthermore, we integrate historical data and up-to-date observation data to improve the degradation modeling and evaluation based on Bayesian method. The change point between the two phases was obtained based on the Akaike information criterion (AIC) and the criterion of the residual sum of squares. Finally, a real example of liquid coupling devices (LCDs) and a numeric example are discussed to demonstrate the effectiveness of the proposed method. The results show that the proposed method is effective and efficient.