基于碳点的小型自校正比率荧光光纤铬(VI)传感器

荧光比率传感探针检测方法能够克服环境(如样品基质、猝灭剂等)和仪器等外部因素影响, 得到更加可靠的检测结 果。 本文合成用于组成比率型荧光纳米探针的两种荧光碳点(CDs), 在 365 nm 紫外光的激发下, 这两种碳点分别在 440 nm 和 570 nm 处具有荧光发射峰, 且对 Cr(VI)具有相反的响应。 通过水凝胶将比率荧光探针包覆在设计的光纤尖端上, 能够实 现 Cr(VI)浓度的在线检测。 利用飞秒激光微加工系统制作的齿形光纤结构, 有利于荧光探针的激发和传感器荧光的收集。 为进一步降低传感器成本、缩减传感器体积, 采用低成本的 LED 灯珠作为激发光源。 采用比率荧光探针包覆, 克服 LED 灯珠 光源稳定性差的缺点, 使传感器可以实现自校正。 实验表明,即使光源强度波动较大, 该传感器连续 7 次测量的相对标准偏差 (RSD)仅为 3. 1% 。 在 0~ 200 μM 范围内, 该传感器对 Cr(VI)具有良好的线性关系, 检出限(LOD)为 0. 9 μM。 该传感器能够 应用于实际样品中 Cr(VI)的检测, 说明该传感器的具有实用性和可靠性。     

二苯碳酰二肼分光光度法测定磁性材料中的铬(Ⅵ)

在硫酸介质中,二苯碳酰二肼可与铬(VI)发生显色反应生成紫红色的络合物,该络合物在540 nm波长处有最大吸收峰,由此建立测定磁性材料中铬(VI)含量的分光光度分析方法。本文对测定波长、显色pH值、显色剂用量以及显色时间等实验条件进行优化,在最佳实验条件下,络合物在540nm处的吸光度值与铬(VI)的浓度在0～0.3mg/L范围内呈良好的线性关系,其线性方程为A=0.839C-0.0048(c∶mg/L),相关系数r=0.9999;检出限为3.85×10~(-4)mg/L,回收率为94%～105%。采用碱浸煮方法提取磁性材料中的铬(VI),并用该方法对样品中铬(VI)的含量进行测定,并与SGS测得的结果进行对比。结果表明,该法的测定结果与SGS测得的结果相一致。该方法具有操作简便、快捷的优点,用于磁性材料中铬(VI)的测定,所得结果令人满意。     

聚乙二醇-二苯偶氮羰酰肼萃取分光光度法测定原油中的铬(VI)

研究了铬(VI)-二苯偶氮羰酰肼(DPCO)-聚乙二醇(PEG)体系的萃取行为和显色条件。在pH值为2.0的盐酸-氯化钾缓冲溶液中,络合物中的铬(VI)可被PEG相全部萃取,在PEG相中络合物的最大吸收峰位于550nm处,铬(VI)含量在0~25μg/10mL范围内符合比尔定律,表观摩尔吸收系数ε550=3.13×104L·mol-1·cm-1。人工合成样品中铬(VI)的平均回收率为96.84%。采用该方法测定了辽河原油和沙特原油中的铬(VI),其相对标准偏差分别为2.7%和2.8%,平均回收率分别为99.17%和96.64%。实验证明,该方法具有操作简便、分析速度快、精密度好的优点,是集萃取和显色为一体的测定原油中铬(VI)的较好方法。     

流动注射分光光度法测定水中痕量六价铬的研究

研究建立了测定水中痕量六价铬的流动注射光度方法.在酸溶液中,六价铬与二苯基碳酰二肼(DPC)形成红色螯合物的显色反应,其最大吸收峰在540nm处;本方法的线性范围为2.0-400.0μg/L(r＞0.999),检出限为0.3μg/L,在50.0和100.0μg/L时的相对标准偏差(RSD)分别为1.18%、0.91%,加标回收率为93.0%-105.0%,测定频率60样/h.本方法简单、灵敏度高、分析速度快.应用本法成功地进行了地表水中Cr(VI)的测定,获得满意结果.     

某些变价元素络合吸附电流在催化体系中的增敏研究和应用

在含EDTA、溴代苯羟乙酸(Br-BHA)的硫-磷混酸介质中,变价元素,钼(VI)-钨(VI)-Br-BHA络合物分别产生不太灵敏的极谱电流。加入NaClO_3后,产生灵敏催化电流[比在苯羟乙酸(BHA)体系分别增敏2.3倍和3倍],峰电位(Ep)分别移至-0.44V和-0.78V。系统研究了10余种易质子化有机染料和8种阳离子表面活性剂对上述催化电流进一步增敏效应,其中以亚甲蓝(MB)为最佳。无NaClO_3时,加入MB,原络合电流略有所降低,E_D无明显变化。但当加入NaClO_3后,极谱催化电流得到进一步增敏,Ep分别为-0.43V和-0.83V。钼(VI)、钨(VI)测定的线性范围分别为2×10~(-9)～4×10~(-7)和5×10~(-10)～2×10~(-8)mlo/L,检出限分别为1×10~(-9)和3×10~(-10)mol/L。大多共存离子(阳离子44种,阴离子10种)不干扰测定,[Mo(VI)]:[W(VI)]或反之,为1:25000互不干扰。方法已用于合金、纯铁等样品中钼、钨的同时直接测定,结果满意。文中对络合物组分比、电流特性、电极反应机理、增敏可能的规律和机理等进行了详细的研究,并计算了一系列有关常数和参、函数。     

流动注射在线离子交换分离富集火焰原子吸收光谱法测定水中Cr（Ⅲ）和Cr（Ⅵ）

优化了流动注射离子交换分离富集火焰原子吸收光谱法测定水样中Cr(Ⅲ）和Cr(Ⅵ)的实验条件和流路参数等。方法简便、快速。Cr(Ⅲ)和Cr(Ⅵ)的检出限（3σ）分别为5.4ng/mL和0.83ng/mL。测定50ng/mLCr(Ⅲ)和Cr(Ⅵ)的精密度RSD（n=7)分别为2.8%和4.3%，分析速率为25个样／h。     

铬铁中氧化锰、氧化铬的连续测定

铬铁中氧化锰及氧化铬采用Na2O2熔融试样测定直接氧化了Mn(Ⅱ)与Cr(Ⅲ),同时分离出锰,在一定的酸度范围内测定MnO的含量,调整滤液酸度,测定Cr2O3的含量,达到了锰、铬连续测定的目的。     

快速消解分光光度法测量COD_(Cr)与传统方法的对比实验

作者进行环保行业标准快速消解分光光度测定法、COD_(Cr)的国家标准滴定法以及2h消解分光光度法在不同生活污水及工业废水样品的对比重复实验的研究。根据实验结果统计分析得出:快速消解分光光度法COD_(Cr)检测可以在各种监测现场代替实验室国标滴定法,以更快的速度、更少的二次污染来测定水质COD_(Cr)。     

直读光谱法测定2(1/4)Cr1Mo(1/4)V中Cr不确定度

针对制造加氢反应器用材料2(1/4)Cr1Mo(1/4)V,采用火花放电直读光谱法测定Cr元素,依据JJF 1059.1-2012测量不确定度评定与表示技术规程,分析ARL4460型号直读光谱仪测量Cr元素含量不确定度的主要来源,对测量结果的不确定度进行评定。     

洋河酒厂新视觉形象识别系统全面导入推广

近日,洋河酒厂对企业原有的视觉形象识别系统作了调整,全面导入推广新的视觉形象识别系统(VI),以更好地体现洋河企业文化和发展理念。2006年5月26日,该公司专门出台了《江苏洋河酒厂股份有限公司视觉识别系统(VI)管理办法》(简称《管理办法》),以保证公司新的(VI)顺利导入实施,建立洋河独特的品牌文化,提高洋河品牌竞争力,促进公司整体VI建设。按《管理办法》要求,洋河酒厂专门成立了VI管理委员会,负责VI规范文件的制定及日常工作的决策、规范活动的组织、实施、督促与检查。董事长、党委书记杨廷栋任主任,总经理张雨柏任执行主任。管…     

用虚拟仪器技术实现的CT校验仪

虚拟仪器主要是用软件来实现各种仪器,它的主要特点是灵活,多功能、一机多用及高性能价格比。本文将虚拟仪器技术应用于电流互感器的检测,利用ＬａｂＶＩＥＷ提供的开发平台,研制出基于虚拟仪器的电流互感器准确度校验仪,通过对实际的电流互感器进行检测实验,结果说明虚拟校验仪可以代替传统的校验仪,而且比之功能更多。     

Development of electrolyte filtration system for ECM taking into account removal of chromium (VI) ions

During the ECM process, the metal workpiece is dissolved and turns into sludge which contaminates the electrolyte. To realize precise ECM with high cost-effectiveness, an electrolyte treatment system which can realize reuse of the electrolyte and maintain the electrolyte quality constant is significantly important and essential. Especially, in the ECM of alloys containing a certain level of chromium, it is very likely chromium dissolves to the toxic carcinogen Cr(VI). Therefore, an electrolyte filtration system is required for removing not only the sludge but also residual toxic ions in the electrolyte for health and environment conservation reasons. In this study, activated carbon and scrap iron, which are low cost and easily available materials, were newly utilized to reduce and remove toxic Cr(VI) ions. Experiments clarified that use of activated carbon has no influence on the machining ability of NaNO₃ aqueous solution serving as the electrolyte. By adjusting the pH of the electrolyte to acidic, activated carbon can remove Cr(VI) from the NaNO₃ aqueous solution electrolyte to a concentration of less than 0.1 mg/L. On the other hand, scrap iron generated from metal cutting processes can be used to reduce Cr(VI) to non-toxic Cr(III). By mixing HNO₃ into the electrolyte solution, the reduction efficiency of scrap iron on Cr(VI) improves significantly.     

秦氏模型智能虚拟控件的实现

介绍了智能虚拟控件的模型要素，论述了智能虚拟控件的形成原理，讨论了智能虚拟控件的设计方法与优化准则，给出了智能虚拟控件的计算机表达方法。智能虚拟控件是对虚拟仪器的重要发展，它把仪器的功能、性能、控制关系等全部有机地融合于一个或几个部件之中。     

Tribological evaluation and tribochemistry of some dialkyldithiomalonamides and their Mo‐S complexes as EP additives

The reported use of molybdenum dithiocarbamates and molybdenum dithiophosphates as antiwear and EP additives has led to attempts by the authors to synthesise certain novel Mo‐S complexes, and evaluate their effectiveness. In the present paper, the synthesis of certain 1,5‐dialkyl‐2,4‐dithiomalonamides and their Mo‐S complexes, namely, bis(1,5‐dialkyl‐2,4‐dithiomalonamido)‐dioxo‐molybdenum (VI), and the tribological evaluation of their 0.5% w/v admixtures in paraffin oil by a four‐ball test are reported, and the results compared with a dioxo‐bis(N,N‐diethyldithiocarbamato)‐molybdenum(VI) reference additive. The additive, bis(1,5‐diethylhexyl‐2,4‐dithiomalonamido)‐dioxo‐molybdenum(VI), has been found to reduce significantly both coefficient of friction and wear‐scar values, and to give higher load wear index values and flash temperatures, and has been found to be equally effective with alloy steel balls of three different compositions. However, all the Mo‐S complexes afforded smaller wear‐scar diameters in a one‐hour wear test. The wear spots on the used steel ball specimens were subjected to SEM and AES surface analysis for understanding the additive‐metal interaction tribochemistry.     

A GREEN METHOD FOR THE DETERMINATION OF CHROMIUM(VI) AND IRON(III) IN WATER BY SEQUENTIAL INJECTION ANALYSIS AND SPECTROPHOTOMETRIC DETECTION

In this article, an organic-reagent-free method was described for the determination of Cr(VI) and Fe(III) by double-system double-wavelength sequential injection technique with a single sample injection. In this approach, the determination of Cr(VI) was based on the detection of a blue unstable intermediate compound resulting from the reaction of Cr(VI) with hydrogen peroxide, and the determination of Fe(III) was based on the color reaction of Fe(III) with thiocyanate in acidic medium. Sequential injection analysis (SIA) parameters, including spacer solution volume, aspiration order, aspiration volumes, flow rate, acid medium, solution acidity, and reagent concentrations, were optimized. The linear range for the determination was 3.0–60.0 μg mL^?1 for Cr(VI) and 1.0–40.0 μg mL^?1 for Fe(III), respectively. The limit of detection (LOD) was 0.6 μg mL^?1 for Cr(VI) and 0.2 μg mL^?1 for Fe(III), and the limit of quantitation (LOQ) was 2.0 μg mL^?1 for Cr(VI) and 0.67 μg mL^?1 for Fe(III). The total volume of the reagent consumed in each determination was only 0.11 mL. The proposed method was applied to the simultaneous determination of Cr(VI) and Fe(III) in electroplating wastewater and environmental waters. The results were in good agreement with those obtained by atomic absorption spectrometry. The recoveries were in the range of 97.5–101.1%.     

SpeciatedIsotopeDilutionMassSpectrometry(SIDMS):AnOverviewandAplicationsbyChevronEnergyTechnologyCompany

The field of elemental speciation has grown over the years, although the focus has shifted considerably throughout this time period-from developing hyphenated techniques (e.g. GC-ICP-MS, HPLC-ICP-MS, SFC-ICP-MS) to today’s challenge o identification of new element species using molecular mass spectrometry (e.g. electrospray ionization mass spectrometry (ES-MS)) and Speciated Isotope Mass Spectrometry (SIDMS). The fundamental theory of SIDMS in environmental systems is established and documented. In nature, an element may exist in different chemical forms (species) that are characterized by oxidation state and/or molecular structure. The toxicity and bioavailability of some elements is often directly related to the chemical form (i.e. species), for example trivalent Chromiun (Cr III) is essential for glucose metabolism in animals whereas hexavalent Chromium (Cr VI) is carcinogenic. Many other elements, such as mercury, arsenic, tin, lead and selenium, display similar “inter-species” toxicit differences. The different molecular forms of arsenic can in fact exercise different toxicity and it has long been recognized that not all arsenic compounds are toxic. Hence, it became necessary to identify the molecular form of arsenic in food and drink (i.e. the speciation of arsenic). Obviously, it is of concern to have available sensitive and accurate analytical method for qualitative and quantitative elemental speciation in any given sample.     

裂纹转子系统虚拟状态监测

裂纹转子系统的状态监测一直倍受关注。但由于裂纹转子自身较强的非线性特征,早期裂纹故障的监测与诊断很难在工程实际中实现。本文针对单盘横向裂纹Jeffcott转子系统,以虚拟仪器技术构建了状态监测框架,借助谐波小波变换方法,实现对系统虚拟监测的响应分析。结果表明,借助虚拟仪器可以很简单直接地实现裂纹转子系统的状态监测,其谐波小波分析结果能清晰地解释裂纹故障对系统的影响。     

火焰原子吸收光谱法中湿法消解和干灰化前处理法测定三七中总铅和铬含量的比较

利用火焰原子吸收光谱法中常用的消解方法(湿法消解法和干灰化法)对文山中草药三七中总铅和铬含量进行测定研究,通过比较不同前处理方法的检测结果、试剂消耗量、所用时间,找出每种方法的优劣。干灰化法时间短;湿法消解耗费时间长,酸用量大,其溶出率相对干灰化法低。本研究对三七中总铅和铬含量测定的方法选择有一定意义。     

A novel virtual instrument for power quality surveillance based in higher-order statistics and case-based reasoning

This paper presents the performance results of a Virtual Instrument (VI) based in Case-Based Reasoning (CBR), conceived to online monitor the power-quality. The PC-based instrument receives data through a DAQ board and a differential probe, while maintaining economy by eliminating the extra network construction and hardware. Being flexible, presents an user-friendly interface and a large data storage capacity, since it uses the hard disk. The computational guts of the instrument are based in third and fourth-order statistics (along with the variance), which enhance detection capability and reject noise influence. A time-domain sliding window sweeps the register under test and offers a time-variation pattern which reflects the deviation of the statistical estimator with respect to the steady state. This three-valued time-series comprises variance, skewness and kurtosis evolution, and constitutes a triple input to the innovative CBR module, which in turn is capable of distinguishing electrical anomalies among five categories (the sixth is reserved to the healthy signal): non-50 Hz, 50-Hz-asymmetrical, 50-symmetrical non-sinusoidal, swell and sag. Online surveillance tests developed over the local electrical network show acceptable accuracy (96%).     

铬盐工人尿液中Cr的形态分析及铬盐急性暴露监测研究

The chromium species in urine of chromate workers were determined using ion-pair reversed-phase HPLC-ICP-MS hyphenated technique (IPRPC-ICP-MS). Our results showed a significant relationship (n＝32, p＜0.01) between the urinary Cr(VI) and the individual airborne exposure levels of chromate workers, indicating that the urinary Cr(VI) level could be used as a convenient and suitable monitor for acute Cr(VI) occupational exposure. The addition of chelating agent of Cr(VI) (tetraethylammonium, TEA), could significantly enhance the stability of urinary Cr(VI) during sample storage. Meanwhile, the pH values had no significant effects on the Cr(VI) stability when samples were stored at －20℃ or －80℃.