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1.
用于电渗控制的新型毛细管电泳装置   总被引:2,自引:0,他引:2  
朱英  陈义 《分析化学》1998,26(4):373-377
提出了一种可利用径向电场控制电渗的新型毛细管电泳装置,着重讨论了其工作原理,电渗控制方法及相关结果。该装置不仅能方便地实现电渗的电场控制,而且通过略加改进,还能与商品仪器兼容。  相似文献   

2.
介绍DX-2000I型离子色谱仪改进的要点。改进后,该仪器具有DX-300型离子色谱仪的功能,能满足大亚湾核电站生产控制的需要。  相似文献   

3.
凝固点降低法测定摩尔质量实验的改进   总被引:2,自引:0,他引:2  
针对过冷程度控制,对搅拌装置作了改进:上端带鼓气球(捆紧)的玻璃弯管通过鼓气搅拌。改进后,搅拌方便简单、速度易控制、过冷现象明显、最高温度易观察、数据准确、满足了实验的要求。  相似文献   

4.
硝基苯催化加氢制对氨基苯酚的合成工艺研究进展   总被引:6,自引:0,他引:6  
介绍了硝基苯在酸性介质中一步加氢重排的反应机理及模型。以提高对氨基苯酚产率和纯度为宗旨,在大量文献调研的基础上提出了控制副反应的几种方法,并讨论了改进对氨基苯酚产量和纯度的可能途径。引用文献22篇。  相似文献   

5.
激光在电化学中的应用(I)   总被引:1,自引:0,他引:1  
任斌  田中群 《电化学》1996,2(1):9-15
本文是激光在电化学中应用的综述第一部分,简要介绍激光电化学的特点,历史和有关实验装置,综述激光在电沉积,电聚合,电极材料改进,表面刻蚀,电化学吸脱剂,控制电化学反应,光电化学开关与信息存储等方面的应用。  相似文献   

6.
胡跃华 《大学化学》1991,6(4):41-41
国内物理化学实验用气泡最大压力法测定溶液表面张力的装置不足之处是:毛细管内的气泡很难以单个方式出现,常常是连串产生,造成压力计内液面连续跳动,液面高度差难以读准(本实验的关键是要测准压力计差△h),对数据处理引入较大误差。针对上述不足,我对原装置进行了改进:将装置中的滴液漏斗换成注射器,通过控制抽气速度快慢来控制毛细管内气泡产生,改进后的装置如图所示。用改进的装置优点在于:(1)能够很好地控制毛细管内产生单个气泡,使得压力计中液面不会连续跳动;(2)气泡的产生和读数能同步进行,做到每产生一个气泡读一次数,能十分准确读出压力差  相似文献   

7.
(TbDy)Fe2基定向凝固磁致伸缩合金的性能与组织和成分的关系   总被引:11,自引:1,他引:11  
制备(TbDy)Fe2基磁致伸缩合金的过程中,采用改进的Bridgman技术使(TbDy)Fe2基相形成沿〈110〉晶向取向生长的组织,控制Fe/(Tb+Dy)=190~195(原子比)以防止(TbDy)Fe3相出现,控制Dy/Tb≈070/030以减小(TbDy)Fe2相的磁晶各向异性,控制氧含量低于05mg·g-1以保证晶体的稳定性等技术措施,获得了最高磁致伸缩应变(80kA·m-1)达1500×10-6的产品。晶体直径为6~30mm,最大长度达300mm。  相似文献   

8.
表面活性剂碱度测定方法的改进和验证   总被引:1,自引:0,他引:1  
表面活性剂碱度的检测主要依照国标GB/T 7378-1996中的方法,使用手动滴定、依据指示剂来判断滴定终点.本文基于全自动电位滴定仪对国标方法进行了改进和验证,建立了表面活性剂碱度测定的光度滴定法和电位滴定法,并对两种改进方法进行了验证.改进后的方法分别根据光度电极和电位电极的突跃点来判断滴定终点,判断更准确,与国标方法的结果相一致,重复性RSD≤3.0%.在国标方法基础上改进的光度滴定法和电位滴定法,滴定体积控制精确、自动化程度高、重复性和准确性好,可作为国标方法的改进方法用于实际检测.  相似文献   

9.
柏冬 《化学教育》2002,23(7):72-72
该文阐述了水蒸气蒸馏实验装置的特点、改进的依据,并提出了两种新的改进实验方法,对其效果及装置的特点进行了分析。  相似文献   

10.
质量控制在化学检测试验中有着重要的作用,其目的之一是对实验室中的误差进行控制,使数据在允许范围内,从而确保检测结果的准确性和有效性[1]。质量控制分为内部质量控制与外部质量控制。内部质量控制是实验室控制质量风险、寻求改进机会的重要切入点[2-3]。  相似文献   

11.
介绍了一种用于有毒有害气体报警器计量检定用手持控制终端的设计。通过对手持终端的软件、电源系统、无线通信系统和主控系统的研发,实现了无线控制报警器检定的操作,并可在手持终端上显示报警器的相关参数以及检定结果等内容。该手持终端提高了检定效率,避免了有害气体对检定人员的侵袭。  相似文献   

12.
观察肺泡灌洗在高血压脑出血并病发肺感染中的应用。方法选择GCS评分4—8分的高血压脑出血并病发肺感染患者58例,随机分为实验组和对照组,每组各29例,两组患者均给予基础治疗,实验组在基础治疗的基础上施行肺泡灌洗,对照组未施行肺泡罐洗,观察比较两组的治疗效果。结果实验组有25例肺部感染控制,控制时间9.1d,对照组19例肺部感染控制,控制时间15.2d,实验组肺部感染控制率明显高于对照组,且控制时间明显短于对照组,两组相比差异均具有统计学意义(P〈0.05)。肺泡灌洗能有效控制高血压脑出血并病发的肺部感染,提高存活率,减少治疗时间,提高患者生活质量,且无严重并发症。  相似文献   

13.
Eleven elements in hepatocyte of mice fed with zinc deficient diet and those fed with control diet were determined by INAA. Zinc concentration, especially, in cytosolic fraction of zinc deficient mice was lower than that of control ones. On the other hand, cobalt concentrations in all fractions of zinc deficient mice were higher than those of control ones. However, when SDS-PAGE was performed for cytosolic fraction of hepatic cells, the positions and the number of the protein bands on gel developed for zinc deficient mice were not different from those for control ones.  相似文献   

14.
采用深珠光印字烟用接装纸作为质控样品,用微波消解处理质控样品,以电感耦合等离子体质谱法(ICP–MS)对样品的铬、砷、铅含量进行定值,并进行不确定度评定。利用方差分析评价均匀性,ADF检验评价稳定性。经F检验表明在95%的置信区间,制备的烟用接装纸质控样品均匀性良好;经ADF检验表明,各元素在1%的显著水平下稳定可靠,样品稳定性良好。将烟用接装纸质控样品用于质控,并绘制Levy–Jennings质控图,质控效果良好。  相似文献   

15.
为探讨经过重复性"饥饿/再投喂"方式处理后大鼠摄取高脂食物时有关体质量控制与能量平衡调节的瘦素(leptin)和神经肽Y(NPY)的表达变化,设计"重复性饥饿1 d/再投喂基础饲料1 d,持续6周"的饲喂方式处理动物模型,6周后改为每天喂以高脂饲料(高脂模型组),另设高脂对照组和基础对照组,喂养至12周,测定了血脂水平...  相似文献   

16.
The paper addresses an approach to robust stabilization of chemical continuous stirred tank reactors. State feedback was used for the stabilization and the feedback controller was designed using the robust model-based predictive control algorithm in which the symmetric constraints on input and output variables are taken into account. The known strategy was modified by adding integral action to the controller. Parameters of robust feedback controllers with and without integral action were found as solutions of a constrained optimization problem solved on the infinite prediction horizon. The possibility to stabilize chemical reactors with uncertainty using the robust model-based predictive control has been verified by simulations and compared with the optimal linear quadratic control and the model-based predictive control. The obtained results confirm that the robust model-based predictive control provides better results than other approaches.  相似文献   

17.
The efficiency and palatability of two baits were studied to the control of crawling insects in urban areas: “Cockroach Kill Gel” for control of cockroaches and Faratox B for control of ants. Ionizing energy was used in producing the baits. It was concluded, that after irradiation the palatability of Faratox B improved and palatability of Cockroach Kill Gel did not change.  相似文献   

18.
目的探讨不同激光美容治疗技术的临床应用效果。方法选取2014年1月—2016年9月期间温州医科大学附属眼视光医院收治的48例色素暗沉病症和良性皮肤增生相关病症患者作为研究对象,随机分为对照组和观察组,各24例。两组患者均根据美容需求制定YAG激光治疗方案,对照组单纯采用YAG激光(Q一Switehing Nd:YAGLaser Deviee)技术治疗,观察组在对照组基础上增加强脉冲光治疗,观察两组患者治疗1个月后临床疗效、皮肤损伤程度及损伤愈合时间。结果观察组患者激光美容治疗,治疗总有效率为95.83%(23/24),显著高于对照组(79.17%,19/24),组间差异有统计学意义(P0.05)。观察组皮肤损伤愈合时间(11.36±5.69)d显著低于对照组(15.23±6.58)d,组间差异有统计学意义(P0.05)。观察组和对照组患者两组皮肤损伤程度比较,无显著差异P0.05,无统计学意义。结论 YAG激光联合强脉冲光技术应用于临床医学美容治疗效果较好,且缩短了患者恢复时间,该激光美容治疗技术临床应用可靠。  相似文献   

19.
A plan for internal quality control (IQC) was designed to monitor the quality of analytical results obtained from the simultaneous determination by ICP-MS of nine trace elements (As, Cd, Mo, Ni, Pb, U, V, W and Zr) in 1350 samples of human urine collected as part of an epidemiological study. Analytical performances, assessed during the method validation, were as follows: limit of quantification ranging from 0.002 μg/L (U) to 0.9 μg/L (Ni); recovery rates varying between 82 % (As) and 110 % (W); intermediate precision as relative standard deviation ranging from 2.5 % (Mo) to 14.2 % (V). Only for Zr, a significantly higher relative standard deviation was obtained. Initially, two commercially certified reference materials (CRMs) based on freeze-dried human urine and containing the elements of interest at suitable levels of concentration were used as control materials. However, due to considerations of reliability, convenience and cost, a control material based on fresh human urine was prepared in-house, evaluated by comparison with the CRMs and implemented for the IQC. The IQC strategy was as follows: at least one control material was analysed in each analytical session and one more control material was analysed after every ten urine samples. The central lines of the control charts were based on the assigned concentration values; the warning and action limits were set on a statistical basis, as two-times and three-times the value of the uncertainty of certified values or the observed standard deviation. At the end of the study, the data collected for the in-house control material were re-evaluated and confirmed its suitability for the purpose. The use of an in-house control material had important advantages: it was more representative of the test samples; its preparation did not involve additional steps, therefore, reducing the risk of contamination; the cost of implementing the IQC was also reduced. Some issues concerning the control charts for As and Mo were addressed and will be discussed.  相似文献   

20.
Automatic calculation of control charts for precision and accuracy of radioimmunoassay was reported by Faure, et al. Duplicate control samples independently measured was assumed to have a bivariate normal distribution. In this case they assumed that the correlation coefficient between each value of the pairs of control samples is zero. Our experience using this method revealed that a considerable number of assayed samples distributed outside the calculated control limits in case of "accuracy control". It was considered that this happened because in radioimmunoassay the between-assays precision is usually larger than the within-an-assay precision and there is a significant correlation between values of duplicates. We also found equal probability density did not make a true circle but a long circle. Therefore in the present paper we proposed for control charts of radioimmunoassay an equal probability long circle calculated by bivariate analysis of Mahalanobis' generalized distance. It was found that a Mahalanobis' long circle could explain the density distribution of radioimmunoassay with a reasonable percent of samples outside the calculated control limits. What happened here can be interpreted by a large between-assays variability shown by some commercial kits. This automatic calculation method could be applied not only for quality control but also for evaluation and comparison of radioimmunoassay system or commercial kits. Control survey could also be analyzed by such a method.  相似文献   

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