顶空-气质联用测定水中24种挥发性有机物

本文采用顶空-气质联用技术分析水中24种挥发性有机物的含量.全扫描模式下,24种挥发性有机物的质量溶度在10400～400ug/L范围内与其峰面积呈线性关系,方法检出限在0.4～1.1 μg/L之间,在20μg/L、100μg/L、200 μg/L等3个浓度水平上进行加标回收实验,回收率在83.7～110之间,RSD(n=6)在0.78％～6.02％之间.SIM模式下,方法检出限在0.1～0.5μg/L之间,在6μg/L、12μg/L、20 μ g/L等3个浓度水平上进行加标回收实验,回收率在82.6％～104％之间,RSD(n=6)在0.6％～5.1％之间.检出限、精密度和准确度均获得满意的结果.     

我国及上海关于VOCs治理政策及现状分析

VOCs(volatile organic compounds)挥发性有机物是指常温下饱和蒸汽压大于133.32 Pa、常压下沸点在50～260℃之间的有机化合物。VOCs主要来源于工业废气、汽车尾气、涂装材料等,不仅污染环境而且危害人体健康,部分挥发性有机物会破坏臭氧层造成温室效应加重。挥发性有机物(VOCs)一词在中国第一次被官方提及是在1994年10月由生态环境保护部发布的《广东环境数据报告》中,2010年国务院办公厅转发了《环境保护部等部门关于推进大气污染联防联控工作改善区域空气质量指导意见的通知》,首次将VOCs治理提升到国家层面。此后,国家出台各种相关政策法律,以控制(VOCs)挥发性有机物的排放量及治理。文章对我国及上海市关于(VOCs)挥发性有机物治理的政策加以整理并分析。     

固相萃取-气相色谱质谱联用测定地表水中20种半挥发性有机物

应用全自动固相萃取仪富集水源水中20种半挥发性有机物。选用C18固相萃取柱富集,控制样品p H值≤2,加入适量氯化钠增加离子强度,选用二氯甲烷和乙酸乙酯为洗脱剂并优化固相萃取条件,用气相色谱质谱仪进行定性定量分析。结果表明,线性范围为0.5~5.0 mg/L,检出限在0.01~5.7μg/L范围内,相关系数0.996,加标回收率在28.5%~148.3%范围内,相对标准偏差(n=6)为0.6%~12.5%。有效地实现了大体积水样下20种半挥发有机物的全自动萃取过程,拥有良好回收率和稳定性。     

气相色谱-质谱法测定水中松节油的研究

研究了吹扫捕集/气相色谱-质谱法测定水中松节油的分析方法,研究表明:低浓度和高浓度标准系列的校准曲线均具有良好的线性关系,相关系数达到0.999,检出限为0.3μg/L,检出下限为1.2μg/L,平行重复测定6次,相对标准偏差0.6%～1.8%,加标回收率91.0%～100.2%。该方法简便、灵敏度高,可同时满足废水、地下水和地表水中松节油的测定。     

固相萃取-GC-ECD法检测地表水中的溴氰菊酯、腐霉利和氰戊菊酯残留量

建立固相萃取富集地表水中的溴氰菊酯、氰戊菊酯和腐霉利3种常用农药,气相色谱-电子捕获检测器法定量检测的分析方法。利用固相萃取技术,选择弗罗里硅柱对地表水样进行富集、净化;丙酮洗脱、正己烷定容后,上气相色谱仪(GC)检测,外标法定量。其结果是溴氰菊酯、氰戊菊酯和腐霉利在质量浓度1.0～500.0μg/L范围内具有良好的线性,相关系数R2均大于0.995,检出限如下:溴氰菊酯:0.23μg/L,氰戊菊酯:0.36μg/L和腐霉利0.24μg/L。加样回收率分别为102.4%、93.4%和94.2%,重复性与精密度(n=6)RSD在5.0%以内。该方法具有重复性好、快速、准确度高等特点,适用于地表水中溴氰菊酯、腐霉利和氰戊菊酯残留量的监测。     

SPE-液相色谱法测定工业废水中的DBP和DNOP

结合液相色谱定性定量分析的方法,建立固相萃取工业废水中的邻苯二甲酸二丁酯(DBP)和邻苯二甲酸二辛酯(DNOP)的测定。比较硅胶柱、C18、Qasis HLB和Si/PSA玻璃柱对DBP和DNOP萃取效率的影响。结果表明,Si/PSA玻璃柱回收率最稳定,Qasis HLB次之,C18的萃取效率较低。硅胶柱对DBP的萃取效率较高,但对DNOP的萃取效率低于80%。经水梯检测得出DBP和DNOP在0.1～4.0μg/mL质量范围内呈良好线性关系,相关系数均在0.9995以上,检出限均低于0.2μg/L。采用该方法分析5个实际工业废水样品发现所有水样中均有DBP检出,1个样品中检出DNOP,整体回收率在94.2%～101.2%。该法回收率稳定,抗干扰能力强,灵敏度高,适用工业废水中的DBP和DNOP检测。     

高效液相色谱-串联质谱法直接进样测定水中6种有机物

直接进样使用超高效液相色谱-串联质谱测定水中6种有机物(灭草松、2.4-滴、莠去津、微囊藻毒素-LR、呋喃丹、甲萘威)。该检测方法可同时测定水样中上述6种有机化合物的浓度,水样前处理简单,减少实验人员的劳动强度,提高检测效率,同时有机溶剂使用量较小,有利于保护环境和实验人员身体健康,加标回收率在86.9%～111.7%之间,相对标准偏差在4.0%～10.6%之间,检测方法的精密度和加标回收率均令人满意。     

气相色谱法测定地表水中环氧氯丙烷

建立吹扫捕集-气相色谱法测定地表水中环氧氯丙烷的方法并优化了吹扫条件。实验结果表明,该方法操作简便,环氧氯丙烷在4.00~50.0μg/L浓度范围内线性关系良好,方法检出限为0.81μg/L,实际水样加标回收率在94.2%~104.5%之间,可满足地表水中环氧氯丙烷的监测。     

沈阳市挥发性有机物综合治理工作的探索与实践

介绍了挥发性有机物(VOCs)的危害及沈阳市涉VOCs排放企业现状,论述“一厂一策”、环境影响后评价是VOCs治理的重要补救措施,源头替代、过程控制、末端治理和环境管理是严格控制企业VOCs排放的必然选择.三种举措的互相补充和不断完善,可减少企业VOCs的排放量,削减VOCs排放总量,减少PM2.5的排放和臭氧污染.     

龙潭湖甲藻水华应急处置的研究

为消除龙硿洞龙潭湖甲藻水华,选用二氧化氯、漂白粉和生石灰等安全、廉价、易得的常规消毒、除藻剂。检测结果表明,湖水中叶绿素由139.05μg/L降至3.60μg/L,减少97.4%,甲藻由11.1×106cells/L降至0cells/L,佩氏拟多甲藻(Peridiniopsis penardii)和颗粒直链藻极窄变种(Melosira granulate var.angustissima)均被漂白粉、二氧化氯杀死漂白,叶绿体被完全破坏,底泥样品悬浮后观察,均未检出活体拟多甲藻,甲藻水华被彻底消除。     

基于TOP-DOWN设计方法学的机车三维产品设计规范的研究

通过对信息化技术的研究,从分析大连机车车辆有限公司产品设计现状入手,针对机车行业的特点,提出了建立基于TOP-DOWN设计方法学的产品设计规范.通过设计规范的推广,使设计师可以实时地按照设计要求修改产品的结构,尽快完成新产品设计及现有产品的改型设计,同时实现设计师与工艺师之间的协同工作.     

计算机辅助工程技术在摩托车领域中的应用

本文论述了计算机辅助工程技术在摩托车设计及制造中的重要意义及其在我国摩托车领域中的应用状况。同时分析了CAD/CAE/CAPP/CAM/PDM/CIMS技术在今后的发展趋势     

基于MotoTron平台的发动机ECU快速原型开发

介绍了MotoTron快速原型开发平台的组成及特性,针对汽车发动机控制系统复杂的开发过程,在Matlab/Simulink环境下以图形化的语言和基于体系结构的软件构架,完成了系统建模、代码生成、ECU刷写、标定工作,实现了目标发动机的主要的控制性能。     

基于Web的水电站大坝巡检系统设计与开发

针对目前水电站大坝巡检系统存在的问题,对巡检对象作了详细剖析后进行了科学、合理的划分,并提出了可扩展的数据库构建模型,开发了基于Web的水电站大坝巡检系统.实践表明,该系统可有效提高工作效率.     

Growth of Ni/Mo/Cu on carbon fiber paper: An efficient electrocatalyst for hydrogen evolution reaction

The exploration of efficient catalysts toward hydrogen evolution reaction (HER) is still an urgent task. In this paper, Ni/Mo/Cu/C and Ni/Mo/C electrode were obtained by conventional pulse voltammetry, which acted as cathode in microbial electrolysis cells (MECs). The prepared samples are analyzed using SEM, XRD, XPS and electrochemical analysis techniques. Results indicated that the Ni/Mo/Cu coating has a rough and globular structure and presents high current density, a lower Tafel slope of 23.9 mV/dec than 30 mV/dec of Pt, which exceeds the electrochemical activity of Pt electrode. Its remarkably enhanced electrocatalytic activity is attributed to the high surface area, high conductivity as well as synergistic interaction among Ni, Mo and Cu.     

钱塘江风暴潮预报系统研制

基于C/S与B/S相结合的架构研制了钱塘江风暴潮预报系统,以二维天文潮、风暴潮耦合实时预报模型为核心,通过台风参数输入可迅速预报钱塘江河口台风暴潮的潮位过程、最高潮位及其潮位时刻等特征值.多次台风运行验证结果表明,该系统具有风暴潮预报、信息查询、方案比较等功能,且运行稳定、操作方便快捷、预报精度较高,可供借鉴.     

Testing of a sodium/nickel chloride (ZEBRA) battery for electric propulsion of ships and vehicles

One of the promising future batteries for electric propulsion of vehicles and ships is the sodium/nickel chloride or ZEBRA (Zero Emission Battery Research Activities) battery. Despite some disadvantages with respect to the high temperature, the advantages with respect to specific energy and energy density are such that, especially in applications where the battery is used on a more or less continuous basis (e.g., in delivery vans and taxies) it is an interesting candidate battery. Another interesting application is on board of ships, like submarines or future electrical surface ships with electric propulsion. In 1995 a 2 year feasibility study, including experimental testing of a 10 kW h battery, was completed. This investigated the naval applicability of the sodium/sulphur battery, which is also a high temperature battery. Here the limited, experimentally proven, life-time of the batteries of about 1.5 years and this made naval application almost impossible. A paper about this study was presented at the 19th International Power Sources Symposium held at Brighton, England, in April 1995 [R.A.A. Schillemans, C.E. Kluiters, Sodium/sulphur batteries for naval applications, in: A. Attewell, T. Keily (Eds.), Power Sources 15, International Power Sources Symposium Committee, Crowborough UK, 1995. p. 421.]. Because of the more or less comparable specifications on specific energy and the more promising results of the life-time and field tests with sodium/nickel chloride batteries, a ZEBRA battery from AEG Anglo Batteries has been tested for naval applications. This was done by simulating the charge and discharge as it occurs in practice for the applications investigated. With respect to the electrical ship application (investigated for the Royal Netherlands Navy) the power versus time taken from the battery was simulated as well as the charge procedures. The same can be done for the vehicle application: in this case typical drive cycles for a van or taxi are translated to power versus time taken from the battery. The results of the tests for application of the battery in naval ships are very promising.     

Beneficial effect of carbon–PVA colloid additives for lead–acid batteries

Based on the previous success of adding ultra-fine carbon–PVA (polyvinyl alcohol) colloid solution to restore performance of weak batteries, a large scale test programme of practical batteries including those used in forklift, golf cart, taxi cab, truck and bus applications from 150 companies was carried out. More than 95% of the tested batteries exhibited excellent recovery in performance parameters including the specific gravity (S.G.), voltage and operation time (Ah capacity). The work reported here includes basic research studies to understand better the beneficial action of the carbon–PVA colloid additive.     

Development of a hybrid battery system for an implantable biomedical device, especially a defibrillator/cardioverter (ICD)

An implantable defibrillator battery has to provide pulse power capabilities as well as high energy density. Low self-discharge rates are mandatory and a way to check the remaining available capacity is necessary. These requirements are accomplished by a system consisting of a lithium/manganese dioxide 6 V battery, plus a lithium/iodine-cell. The use of a high rate 6 V double-cell design in combination with a high energy density cell reduces the total volume required by the power source within an implantable defibrillator. The design features and performance data of the hybrid system are described.     

气缸-活塞组材料、公差以及表面强化工艺的匹配(一)

气缸 -活塞组使用寿命不长的问题 ,从摩擦学的角度出发 ,较详细地介绍了这组摩擦副实现材料的选配、形位公差及表面强化匹配要求的具体做法和基本数据 ,以供有关技术人员参考