8 research outputs found
Design and Implementation of JiangBin Community Police Work System Based on Web
随着城市的发展,流动人口以及暂住人口等不断的增多,这些人口都具有高流动性,给基层警务系统带来极大的管理难度。基层警务人员通过使用现代社区警务系统来满足不断变化的社区管理需求。现代社区警务系统通过使用现代化信息化技术,规范化服务手段,达到了社区警务服务的电子化,流程化。现代社区警务系统通过管理社区的人口信息、房屋信息、车辆信息、场所信息来实现警务的社区化,并通过与区、街道、市之间共享这些基础信息来达到统一协同管理。现代社区警务系统之间市局来保证基础数据的访问和共享,使得社区管理的边界大大的扩展,提高社区民警的服务质量和工作效率,节约行政成本。 本文借鉴了软件工程的开发思想,开发并实现了一套适用...With the development of the city, the floating population and the floating population, the population is highly mobile, which brings great difficulty to the police system. Grass - roots police officers meet the changing needs of community management through the use of modern community police work system. Modern community police work system through the use of modern information technology, standard...学位:工程硕士院系专业:软件学院_工程硕士(软件工程)学号:X201323177
Determination of 19 Organophosphorous Pesticides Residues in Milk Drink and Milk Powder by Gas Chromatography-Negative Chemical Ionization-Mass Spectrometry
将气相色谱-负离子化学源质谱法(GC-NCIMS)应用于牛奶饮品和奶粉中19种有机磷农药残留的同时分析。牛奶饮品和奶粉经乙腈提取剂超声提取、Florisil硅藻土和中性氧化铝双净化剂同时净化及正己烷-乙酸乙酯(体积比1∶1)混合洗脱剂洗脱后,以三苯基磷酸酯为内标物,采用GC-NCI MS的选择离子监测方式(SIM)定性与定量分析。当牛奶饮品和奶粉的加标浓度水平为20、100、500μg/kg时,平均加标回收率为64.5%~129%,相对标准偏差为2%~20%;除喹硫磷的方法检出限(MDL)为2.4μg/kg外,其余18种有机磷农药的MDL均小于1.0μg/kg;线性范围为10~500μg/kg,相关系数均大于0.9988,此分析方法成功地应用于牛奶饮品和奶粉中多种痕量有机磷农药残留的分析。A rapid method was developed for the determination of 19 organophosphorous pesticides residues in commercial milk drink and milk powder.Under optimized conditions,the pesticides were extracted from milk drink or milk powder with acetonitrile in an ultrasonic bath and cleaned up on a Florisil and neutral alumina column,and were determined by gas chromatography with negative chemical ionization mass spectrometric detection in the selected ion monitoring mode with triphenyl phosphate as internal standard.The recoveries for all the pesticides studied ranged from 64.5% to 129% with a relative standard deviation range of 2%-20%.The detection limit of the method was less than 1.0 μg/kg for most of the pesticides except for the quinolphos.The linear ranges of the calibration curves ranged from 10 μg/kg to 500 μg/kg with correlation coefficients of 0.998 8.The proposed method was successfully applied to the analysis of these compounds in milk drink and milk powder
Determination of Five Polybrominated Diphenyl Ether Residues in Deep-Sea Fish Oil Using Gas Chromatography-Negative Chemical Ionization/Mass Spectrometry
建立了气相色谱-负离子化学电离质谱法(GC-NCI/MS)同时分析深海鱼油食品中5种多溴联苯醚残留的分析方法。深海鱼油食品用正己烷超声提取、中性与酸性硅胶色谱柱净化和正己烷洗脱后,以PCB103为内标物,采用GC-NCI/MS的选择离子监测方式(SIM)分析;同时探讨了5种多溴联苯醚的NCI/MS特征离子的断裂机理。当空白深海鱼油食品的加标浓度为20.0和100.0μg/kg时,加标回收率为88.6%-111.3%,相对标准偏差为3.8%-13.5%,方法的检测限为0.77-1.34μg/kg,线性范围为1.0-500.0μg/kg,相关系数均大于0.999 2。此方法已成功地应用于深海鱼油食品中5种痕量多溴联苯醚残留的同时分析。Polybrominated diphenyl ethers(PBDEs) are a kind of brominated flame retardants(BFRs),which refer to compounds used in some plastics to impede or even suppress the combustion process.As the emission or disposal of plastics,PBDE residues have been found in both environment and biota.In this work,an analytical method was developed for the simultaneous determination of 5 PBDE residues in deep-sea fish oil.PBDEs were extracted from deep-sea fish oil with n-hexane,cleaned up on a silical gel column,and determined by using gas chromatography-negative chemical ionization/mass spectrometry(GC-NCI/MS) in the selected ion-monitoring(SIM) mode,with PCB103 as the internal standard.Meanwhile,the characteristic ion and fragmentation mechanism of some PBDEs in NCI/MS were evaluated.Recovery studies were performed at 20.0 and 100.0 μg/kg fortification levels for each PBDE,and the recoveries ranged from 88.6% to 111.3% with relative standard deviations between 3.8% and 13.5% for different PBDEs.The limits of detection(LOD) were from 0.77 to 1.34 μg/kg for different PBDEs.The developed method was linear over the range assayed,1.0-500.0 μg/kg,with correlation coefficients larger than 0.999 2.The developed method has also been successfully applied to the determination of PBDEs in several deep-sea fish oil samples and the three most abundant PBDEs(PBDE-47,PBDE-99 and PBDE-100) were found
激发态~(17)Ne双质子2p发射的实验
<正>在中国科学院近代物理研究所放射性束流装置RIBLL上完成了17Ne+197Au的实验,采用硅条探测器与CsI(Tl)+PIN探测器阵列进行运动学完全测量,研究了17Ne双质子发射的机制。实验选
The Influence of Exercise in Low-Temperature Environment on the Physiological Functions of Human Body
Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024*
Determination of the number of ψ(3686) events taken at BESIII
The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^
