Determination of pesticide residues in food matrices using the QuEChERS methodology

The determination of pesticide residues in food matrices is a formidable challenge mainly because of the small quantities of analytes and large amounts of interfering substances which can be co-extracted with analytes and, in most cases, adversely affect the results of an analysis. However, safety concerns require that pesticides of the wide range of chemical properties (including acidic, basic and neutral) should be monitored. Because of the wide variety of food matrices, the sample must initially be cleaned up before final analysis. That is why the analytical chemist is faced with the need to devise new methodologies for determining such residues to be determined in a single analytical run. To accomplish the goal, QuEChERS methodology has been developed. It is a streamlined and effective extraction and cleanup approach for the analysis of diverse analyte residues in food matrices. So far, there have been achieved promising results by liquid or gas chromatography analysis, including pesticides, but also acrylamide, pharmaceuticals and veterinary drugs.     

销毁废旧弹药的技术探讨

近些年,某市收缴了一些民用爆炸物品和战争年代遗留下的军用爆炸物品。这些爆炸物品的存在对人民的生命财产安全构成了极大的威胁。针对这些爆炸物品的特点,进行了销毁方法设计;介绍了其销毁流程;确定了销毁参数;并进行爆破振动安全校核和安全技术措施的制定,销毁取得圆满成功。     

拆除爆破安全技术的探讨与应用

结合工程爆破实践经验和爆破理论,分析了拆除爆破中飞石、振动、冲击波、噪音与污染等有害因素的产生原因、计算依据和防护技术。针对具体的工程情况,只要采取有效的安全措施,可以将拆除爆破的危害控制到最低程度,取得较好的爆破效果。     

广播电视播控中心UPS系统可靠性提升与实现

广东广播电视台通过采用串联热备份方式对单机UPS系统增加冗余提高可靠性,在系统设置和现场测试通过后,热备份UPS顺利地接入在线运行的配电系统,并且提供扩建的缩编、上载机房的负荷用电,克服串联热备份UPS空载运行导致电池组无法放电影响寿命的缺点,最终,不仅实现了播出配电系统可靠性升级,也充分发挥了热备份UPS的用途。     

辽宁省小型水库安全度汛信息管理系统研究与实现

为转变辽宁省小型水库报汛模式,提高报汛效率及可靠性,在现有短信报汛工作基础上,综合运用云计算、大数据、移动互联网等技术,采用基于云MAS短信报汛技术,Android和IOS 2种手机App开发框架,"一级部署、三级应用"等研究方法,开发面向省、市、县各级工作及管理用户的统一框架的小型水库安全度汛信息管理系统,主要包括度汛信息管理系统和智能手机报汛巡检App 2个部分,包含水库报汛、巡查监管等10余项功能模块.经过2 a多的汛期运行,该成果在实际防汛工作中发挥重要作用,已经成为全省小型水库报汛不可替代的重要手段.实践检验表明:小型水库安全度汛信息管理系统的研究与实践工作是非常必要的,可实现从短信报汛向智能手机报汛的转变,有效提高全省小型水库报汛水平,为其他类似地区水库报汛工作提供借鉴意义.     

基于SSL＆SET协议的在线支付模型探究

电子支付是电子商务交易活动中的一个重要环节,涉及到用户与商家和银行等多个部门的信息交互。如何实现安全、可靠、方便的电子支付,是电子商务发展中迫切需要解决的问题。本文对两种占主流地位的安全交易协议SSL和SET进行了比较,在此基础上,提出一种基于SSL＆SET的在线安全支付模型,并对其特色进行了分析和论证。     

论监理工程师的安全责任

在充分研究国内外建设工程相关法律法规、合同文本及实际案例的基础上,详细分析了监理工程师承担安全责任的原因,总结了监理工程师对建设工程的安全承担责任的前提条件,并针对性地提出了监理企业和监理工程师避免安全责任的具体措施。     

大型低温液体贮存站贮罐设计选型论证(续)

运用热力学第一定律对低温液体在贮存、运输转注过程中的热力学特性进行了分析,定量分析、计算了低温液体节流过程的节流汽化率值,提出了减少节流过程所形成的汽化率的有效途径;论证了在大型低温液体贮存站贮罐设计选型时,应根据不同的低温液体液源、液体品质和操作工况等条件进行设计选型;论证了除合理地选择正确的低温液体贮罐结构形式外,还应高度重视低温液体贮罐的安全泄放设计,以确保低温液体贮存站的安全性能、使用性能和技术经济性能均处于最佳状态。     

切丝机维护模式刀辊低速自动旋转功能监控系统设计

切丝机是烟草制丝线主要设备。本文介绍运用艾默生CT驱动器的STO(Safe Torque Off)禁止力矩输出技术实现刀辊维护模式下的安全低速驱动。     

Safe system approach to reducing serious injury risk in motorcyclist collisions with fixed hazards

Collisions with fixed objects in the roadway environment account for a substantial proportion of motorcyclist fatalities. Many studies have identified individual roadway environment and/or motorcyclist characteristics that are associated with the severity of the injury outcome, including the presence of roadside barriers, helmet use, alcohol use and speeding. However, no studies have reported the cumulative benefit of such characteristics on motorcycling safety. The safe system approach recognises that the system must work as a whole to reduce the net injury risk to road users to an acceptable level, including the four system cornerstone areas of roadways, speeds, vehicles and people. The aim of the present paper is to consider these cornerstone areas concomitantly, and quantitatively assess the serious injury risk of motorcyclists in fixed object collisions using this holistic approach. A total of 1006 Australian and 15,727 (weighted) United States motorcyclist-fixed object collisions were collected retrospectively, and the serious injury risks associated with roadside barriers, helmet use, alcohol use and speeding were assessed both individually and concomitantly. The results indicate that if safety efforts are made in each of the safe system cornerstone areas, the combined effect is to substantially reduce the serious injury risk of fixed hazards to motorcyclists. The holistic approach is shown to reduce the serious injury risk considerably more than each of the safety efforts considered individually. These results promote the use of a safe system approach to motorcycling safety.