异形件加工中步进电机的控制研究

加工异形件时最主要的工作就是对步进电机的控制,我们在加工异形件时选用AT89C51单片机对步进电机进行控制。在实验中单片机主要控制换相顺序、步进电机的速度及步进电机的位置。本文通过介绍在异形件加工过程中使用步进电机带动执行机构运行,设计出异形件加工时的硬件驱动和软件驱动,保证加工异形件是的质量和效率。在实际应用中,该系统运行稳定、可靠,设计简单实用。     

考虑质量风险的养老服务供应链契约研究

服务质量是养老服务的重要因素。针对我国养老问题,结合养老服务供应链思想,通过建立单集成商、多合作性提供商的质量风险模型,研究集成商和提供商之间不同质量激励合同对服务质量和供应链收益等要素的影响,探讨了合同成立的潜在条件,并分析了合同内变量之间存在的潜在关系。发现在满足一定条件时,适当的激励系数会使得提供商产生合作关系、提高风险防范水平并增加供应链各部分收益。对供应链风险环境下有效激励合同的建立提供一定理论依据。     

基于城镇地籍数据三维建模的城镇低效用地调查研究

［目的］文章以江西省某县中心城区为例，利用城镇地籍数据构建一种快速调查低效用地的方法，为实现城镇用地粗放低效利用向精明高效利用转变。［方法］首先根据建筑物三维属性开展城镇三维建模； 然后结合GIS三维可视化、空间分析等方法识别低效用地； 最后采用单因子评价法进行低效用地类型判定。［结果］（1）Ⅰ类低效用地的分布与城镇建设程度有关，主要分布在建设程度弱的区域； （2）Ⅱ类低效用地受布局混乱影响，造成周边建设用地割裂，影响土地的综合利用； （3）Ⅲ类低效用地大部分远离城镇中心区域，“粗放式”的土地利用模式导致土地利用强度不达标。［结论］盘活城镇低效用地是现实需要，基于城镇地籍数据三维建模的低效用地调查方法，减少了内、外业工作量，提高了调查效率与可视化程度，为城镇低效用地调查提供一种新技术与方法，有助于增强城镇核心功能，实现土地集约节约利用。     

单片机系统CPU抗干扰技术实践与研究

本篇阐述了单片机系统CPU抗干扰的技术,根据本人在学习和工作中的实践和心得,从硬件技术方面进行论述以完成“无扰动恢复系统”抗干扰的功能。     

用爱烘干你潮湿的心——浅谈单亲家庭高职生的心理问题及调适

在学生群体中,单亲家庭高职生的心理教育最难收到成效,究其原因,由于这类学生的心理产生了一定程度的扭曲,且由于这种扭曲具有复杂性、封闭性和持久性等特点,本文就谈谈单亲家庭高职生的心理问题及对策。     

探讨青海地区油气田单井的经济效益的提高

油气田单井效益的高低直接影响到油气开采企业效益的好坏。近年来,青海油气田多井低产矛盾日益突出,稳产难度日益加大的等严峻考验,面对困难青海油田积极用科学的发展观为指导以以提高单井产量为中心,努力排解、解决提高油气田单井的经济效益所与遇到的任何问题。本文就青海地区油气田的特点及提高单井经济效益的方法进行报道。     

基于RBF的单神经元自适应PID控制在单螺杆挤出机中的应用

在塑料挤出生产行业,单螺杆挤出机的应用非常广泛。对于精密挤出行业,挤出机的速度调节对于整个生产的质量有着重要影响,传统的挤出机速度控制通常采用PID算法实现。文章介绍了通过基于RBF的单神经元自适应PID控制实现了挤出机速度控制的精度高,动态特性好,具有较好的自适应性和鲁棒性等特点。     

单中心聚烯烃催化剂的化学负载

本文介绍了近几年国内外在单中心聚烯烃催化剂负载化方面的研究进展.     

The WTO,the Doha Round Impasse,PTAs, and FTAs/RTAs

Beginning in 2001, the Doha Rounds afforded World Trade Organization (WTO) members the opportunity to develop equitable trade rules between the developed and developing member states. The WTO has been successful in advancing multilateral international trade; however, since the Doha Rounds stalemate, it has witnessed the development of more than 300 Preferential Trade Agreements (PTAs) and over 500 Free Trade Agreements (FTAs). This article attempts to answer two questions: (1) has the failure of the Doha Rounds contributed to the proliferation of PTAs and FTAs, and (2) are these agreements threatening the regulatory authority of the WTO, which, in turn, reduces its ability to effectively promote and govern free trade, and its mission?     

An evaluation of the management of the Finnish employment service

This paper analyses the efficiency of the Finnish Employment Service's management in selecting unemployed individuals who are offered a job. The database used considers short-term unemployed individuals who face the same labour market conditions in 1996. Duration analysis with a Weibull model has been performed in order to study the determinants of the transition probability from unemployment into employment and the impact of receiving job offers through the Employment Service (ES). In order to carry this out, it has been taken into account that the reception of such job offers may be endogenous because the ES selects the individuals who will receive the offers. The empirical results suggest that the decisions made by the ES are adequate in the sense that they increase the benefit of society, compared with a random assignment of the vacancies offered through the ES. Moreover, the effects of the other determinants depend on whether the individual receives offers. The results also point out that individuals who receive no offers through the ES are more likely, as time passes by, to be discouraged in searching for a job than those who do.