车辆远程监控系统的设计与实现

文章提出了一种具有实时安全预警功能的车辆远程监控系统,包括车载数据采集端、手机客户端以及监控中心.汽车车载数据采集终端可实时采集到车辆的位置信息、速度和加速度信息并通过3G无线通信网络将这些数据发送到监控中心数据服务器.监控中心接收到所有车辆传来的数据,并将信息发送到用户车的手机客户端上,手机客户端通过本车的数据和周边车辆的数据计算出本车是否处于安全状态,如不安全手机客户端则会预警,提醒驾驶员采取措施避免事故的发生.     

路灯智能监控管理系统

分析了在我国实现路灯管理的遥测、遥信、遥控、遥调自动化系统的必要性、可行性及对节能、减少交通事故的重要性和社会经济效益,提出了实现系统的技术方案。     

8098单片机多路高速数据采集系统

针对电力系统实时监测的需要，讨论了如何利用８０９８单片机建立多路高速数据采集系统。为此介绍了８０９８单片机的主要性能，指出了其应用于数据采集系统的优点，并就数据采集系统中的软硬件设计问题作了简明阐述。     

Compositional characteristics and aromatic profile of date palm seeds from seven varieties grown in Tunisia

This paper reports a discrimination study based on the physico‐chemical characteristics, fatty acids and profile of volatile compounds of the seeds from seven date palm varieties (Phoenix dactylifera L.) grown in Tunisia. Date seeds contained 10.49–14.76% moisture; 6.28–11.2% fat (on a dry weight basis); 2.67–12.85% protein; 0.91–6.06% reducing sugar; 0.61–2.98% sucrose and 0.97–1.17% ash. Gas liquid chromatography revealed that the oil fraction of the date palm seeds contained eighteen fatty acids, with oleic acid (30.77–42.50%) and lauric acid (18.51–27.48%) as the main unsaturated and saturated ones. Volatile profile showed differences among varieties. In total, forty‐five compounds were identified, mainly alcohols, aldehydes and unsaturated hydrocarbons ones. This study provides evidence that the seeds of date may be a potential source of valuable nutrients with interesting functionality.     

Minimizing the weighted sum of maximum earliness and maximum tardiness costs on a single machine with periodic preventive maintenance

We consider the problem of scheduling a set of jobs on a single machine against a common and restrictive due date. In particular, we are interested in the problem of minimizing the weighted sum of maximum earliness and maximum tardiness costs. This kind of objective function is related to the just-in-time environment where penalties, such as storage cost and additional charges for late delivery, should be avoided. First we present a mixed integer linear model for the problem without availability constraints and we prove that this model can be reduced to a polynomial-time model. Secondly, we suppose that the machine undergoes a periodic preventive maintenance. We present then a second mixed integer linear model to solve the problem to optimality. Although the latter problem can be solved to optimality for small instances, we show that the problem reduces to the one-dimensional bin packing problem. Computational results show that the proposed algorithm best fit decreasing performs well.     

Strengthening of AISI 2205 duplex stainless steel by strain ageing

In this study, static strain ageing behavior of commercially available and solution heat treated duplex stainless steel was investigated and the effect of static strain ageing on the mechanical properties was also determined in detail. Some of as-received duplex stainless steel test specimens were pre-strained in tension by 5% and then aged at 100 °C, 200 °C, 300 °C, 400 °C, 500 °C and 600 °C for 30 min in furnace. Some of duplex stainless steel test specimens were solution heat treated at 1050 °C for 30 min, water quenched and then pre-strained for 5% in tension shortly after the solution heat treatment.In order to identify the effect of static strain ageing on the mechanical properties, the tensile strength, the change in the strength due to ageing (ΔY), elongation fracture and hardness were determined. The test results showed that the mechanical properties were affected by static strain ageing mechanism which was applied at different temperatures for same time interval.     

CBR strength of reinforced soil with natural fibres and considering environmental conditions

This paper investigates the effect of including randomly spaced palm fibres in a soil matrix. The fibres in date palm have special properties such as low costs, plenitude in the region, durability, lightweight, high tension capacity and relative strength against deterioration. Thus, it is possible to use the palm fibres as an alternative low-cost natural material for soil reinforcement. As the objective of this research was to mix the soil and date palm fibres to use in the construction of soil roads, especially village road, we discuss the influence of date palm fibres on CBR (California Bearing Ratio) strength of fine sand. CBR tests were conducted under dry and submerged conditions. The durability of fibres was also investigated using the plain fibres and fibres coated with bitumen. Some samples were soaked for several months before being loaded. The results show that the addition of palm fibres increases the CBR strength of the sand specimens significantly. It is also seen that the sliding strength controls the failure of the specimens rather than the rupture strength.     

需量结算用户抄表结算异常情况分析

最大需量的计算是否准确,对于采用最大需量计算基本电费的企业用户来说至关重要。影响最大需量准确性的因素包括最大需量设置周期、抄表例日的调整、最大需量记录装置是否准确等。通过对最大需量计算中产生问题的具体分析、探讨,明确了影响最大需量计算准确性的几种因素,并从管理和技术方面提出相关建议,以期对准确计算最大需量用户的电费提供借鉴。     

“断零”的危害和防范

阐述三相四线配电回路中中性线中断("断零")引发的诸多电气危害,介绍国际上和国内对防"断零"危害的不同措施。作者赞同国际电工标准采取多种措施避免"断零"的发生,从根本上杜绝"断零"引发诸多电气危害的对策。对我国有关规范以过欠压防护电器防范"断零"的规定提出质疑。