RIGOROUS PROOF FOR CHARACTERISTICS OF PRACTICABLE MAGNETIC POTENTIOMETERS AND THEIR APPLICATION

The characters of practicable magnetic potentiometers have not been rigorously proved. This paper deduced a mathematical description of mutual inductance of the cylindricalmagneticpotentiometerwithfinite turns crosssection and verifies that M is independent of the position with respect to the primary circuit and is unaffected by stray fields of current not linked with them. Using these features, a novel device is designed to measure ACcurrent of the measuring range 0~4 000 A. The experimental result shows the measuring error is less than 1%.The device holds various advantages: such as the fixed number of turns of the primary winding, low cost, small size and weight. This paper pointed out that if the device is used to measure the nonsinusoidal signal, an integrator can increase the accuracy.

ATMP对钙、镁离子阻垢作用机理的配位化学研究

采用电位滴定方法,运用先进的配位常数计算程序,通过恰当配位化学模型的建立,研究了水溶液中氨基三亚甲基膦酸(ATMP)自身的解离以及与Ca2+、Mg2+离子间的配位化学作用,测定了相应的解离常数和配合物稳定常数,并得到了各配合物物种在不同pH条件下的形态分布,从溶液配位化学的角度对ATMP的阻垢作用机理进行了讨论。

四种阻垢剂与Mg^(2+)之间的配位化学作用研究

本文采用酸碱电位滴定分析方法,运用先进的数据处理程序-BEST程序,通过建立恰当的配位化学模式,研究了水溶液中四种阻垢剂:氨基三甲叉磷酸(ATMP)、2-磷基-1,4-丁三酸(PBTCA)、聚丙烯酸(PAA,MW=2000)、马丙共聚物(PMAAA,MW =3000)自身的解离以及与Mg2+离子间的配位化学作用,得到相应的配合物稳定常数,作出各种配合物在不同pH值下形态分布图,并对阻垢机理的解释提供一定的理论基础。

两点电位滴定法测定食盐中碘含量的研究

提出了用两点电位滴定法测定食盐中碘的新方法,该法只需在终点附近记录两次滴定数据即可计算滴定的化学计量点。实验结果表明:该法操作方便,数据处理简单,精密度与准确度均较高,分析速度较国标法有较大提高。

测定苯甲酸钠含量的新方法

目的建立用两点电位滴定法直接测定苯甲酸钠含量的方法。方法只需在化学计量点后适当位置测定两组滴定数据,即可确定化学计量点。结果平均偏差0.063,平均回收率为99.61%,RSD=0.21%(n=3)。结论所用方法简便、快速、准确,测定结果与药典法基本一致。

西门子Siregraph CF机维修实例

我院的西门子Siregraph CF X线机1998年购买使用,经过十来年的使用,设备相对比较旧,故障发生率较高,我们将多年来维修此机的一些有关点片系统片盒不识片的故障做些介绍。此机片盒的大小规格是通过两个绕着钢丝绳的电位器Format Sensing 3PT10、3PT11(3PT10对应Width、3PT11对应Height)的不同的阻值决定的,而电位器Format Sensing 3PT10、3PT11电缆线是绕在一个伸缩的曲臂上,片盒的更换和点片时的曝光,都需要曲臂的运动,在每天的使用中,这个曲臂就需要做无数次的伸缩运动,所以曲臂上的电缆线就极易折断。在这些故障中,大部分都可以利用替代的配件就可以修复机器,避免了向厂家订购配件的麻烦,同时也降低了维修成本。

Development of Flexible Spherical Actuator with 3D Coordinate Measuring Device

Rehabilitation devices help to recover the physical abilities of patients. This study aims to develop a portable rehabilitation device that is safe to use when?patients are holding it by hands. In a previous study, to realize a home rehabilitation device, a flexible spherical actuator that can provide motion to patients was developed. In this study, to measure the relative position between both handling stages, a 3D coordinate measuring device using three wire-type linear potentiometers and an embedded controller was proposed and tested. In this paper, the spherical actuator with built-in 3D coordinate measuring device is described. The measuring method and experimental results obtained are also presented. The tracking position control of the actuator using the measuring device was carried out. As a result, the position of the handling stages can be successfully controlled using the feedback signal from the tested?measuring device.

A Study on Measurement of Forest Soil Redox Potential

Redox potential has principal influences on formation and attribute of soils and it is necessary to research the measurement of soil redox potential. The self-made potentiometer and two indigenous FJA-5 potentiometers were employed to measure the Eh values of fir forest soils in situ, which lied in Savage Sea Beauty Spot in Sichuan Province. Simultaneously fresh soils in situ were collected and made into suspensions with various soil-water ratios and standing time to measure Eh values. The results demonstrated that the total tendency of Eh values measured by the self-made potentiometer was gradually falling with soil-water ratios increasing and standing time prolonging. There is a great difference between Eh values measured in laboratory and in situ. Only in situ may the measured Eh values show realistic oxidation-reduction conditions and formation characteristics of forest soil. The self-made potentiometer has a preferable performance than indigenous FJA-5 potentiometers and it can be applied to measuring forest soil Eh in situ.

水和废水中氯离子的自动电位滴定

采用自动电位滴定法测定水和废水中的氯离子,研究了酸度和介质及各种离子对测定的影响。实验结果表明,本法具有高选择性,而且操作手续简便快捷,分析结果准确可靠。

电镀废水中硫氰酸根离子含量的自动电位滴定

研究了用自动电位滴定测定硫氰酸根离子的条件和方法。实验结果表明,选用银电极为指示电极,217型双液接电极为参比电极,在硝酸介质中滴定硫氰酸根离子,方法具有高选择性;应用于电镀废水分析,方法简便快捷,在4min内能打印出分析结果。

氰化镀银溶液中银含量的自动电位滴定

采用自动电位滴定法测定氰化镀银溶液中的银含量,研究了各种条件对测定的影响。实验结果表明,本法简便、快捷。分析结果准确可靠。

铜电极电位滴定法测定氢氧化镁

以HG/T3607—2000为基础,研究了用Metrohm798MPTTitrino全自动电位滴定仪测定氢氧化镁中镁离子质量分数的方法,铜电极为指示电极,银/氯化银为参比电极。与人工滴定比较,具有操作简便、分析速度快、终点判断准确的特点,受环境及溶液温度的影响小。并用基准氧化镁对该方法进行了验证。

酸性镀铜液中氯离子的自动电位滴定

采用自动电位滴定法测定酸性镀铜液中的氯离子,研究了镀液中各种成分对测定的影响。实验结果表明,本法简便、快捷。分析结果准确可靠。

镀镍溶液中总镍含量的自动电位滴定

采用自动电位滴定法测定镀镍溶液中总镍含量,研究了镀液中各种成分对测定的影响。实验结果表明,与常规的以紫脲酸铵为指示剂的EDTA滴定法相比,本法能在4 min内打印出分析结果,更为简便快捷。

光亮镍镀液中硼酸含量的自动电位滴定

研究了光亮镍镀液中硼酸含量自动电位滴定的条件和方法。实验结果表明,用柠檬酸钾作掩蔽剂,防止Ni^(2+)的沉淀和其它重金属离子的干扰;加入丙三醇溶液,以pH复合电极为指示电极,进行自动电位滴定来测定硼酸,方法简便快捷,分析结果准确可靠。

酸性镀铜液中硫酸含量的自动电位滴定

研究了用自动电位滴定法测定酸性镀铜液中硫酸含量的条件和方法。实验结果表明,与用甲基橙为指示剂的手动滴定法相比,提高了分析的准确度和精密度,而且分析操作简便快捷。

尿素和氨态氮肥中全量氮测定的新方法

提出了一个用气提-自动电位滴定测定尿素和氨态氮肥中全量氮测定的新方法。研究了各种因素对气提和自动电位滴定的影响。实验结果表明,与常规的蒸馏滴定法相比,本法具有八大优点:①节能:节约电能80%以上;②减排:免除了蒸馏时大量冷却水的排放;③降耗:降低了分析试剂的消耗;④增效:分析速度提高了一倍以上;⑤安全:免除了蒸馏法的高温作业;⑥省力:免除了手工滴定之操作劳动;⑦省费:比蒸馏法降低成本4倍以上;⑧准确:免除了手工滴定的观测误差,提高了方法的准确度和精密度。

碱性铜锡合金镀液中氰化亚铜含量的自动电位滴定

研究了用自动电位滴定测定碱性铜锡合金镀液中氰化亚铜的条件和方法。实验结果表明,与以淀粉为指示剂的硫代硫酸钠滴定法相比,节约了化学试剂的消耗,提高了分析的准确度和精密度,而且方法简便快捷,能在4min以内打印出分析结果。

Effects of Bentonite,Hydrogel and Biochar Amendments on Soil Hydraulic Properties from Saturation to Oven Dryness

Effects of hydrogel, bentonite, and biochar as soil amendments on soil hydraulic properties and improving water availability from saturation to oven dryness were investigated. Soils were mixed with hydrogel (0.10%, 0.25%, and 0.50%), bentonite (0.5%, 1.0%, and 2.5%), and biochar (1.0%, 2.5%, and 5.0%) as soil amendments (weight:weight). Three methods (extended multistep outflow (XMSO), evaporation (EVA), and WP4 dewpoint potentiometer) were used to measure soil hydraulic properties from saturation to oven dryness. The cumulative XMSO results were more uniform across all the applied pressure steps for the amended soils. The EVA exhibited a shorter linear decrease during the first evaporation stage and a lower evaporation rate during the second evaporation stage. The WP4 results also exhibited that soil amendments increased the soil water content of the amended soils at low matric potentials. The results of soil water retention curves revealed that the unamended soil retained less water at any matric potential compared to the amended soils. Soil hydraulic conductivity decreased with increasing amount of soil amendments. The saturated hydraulic conductivity was higher for the unamended soil than the soils amended w计h 2.5% bentonite, 0.50% hydrogel, and 5.0% biochar by 11, 3, and 18 times, respectively. These results suggested that soil amendments improved soil water retentivity, which confirmed the appropriateness of these soil amendments for potential use in sandy soil improvements. However, field experiments and economical perception studies should be considered for further investigation.

Enzyme-loaded liposome with biocatalytic precipitation for potentiometric immunoassay of thyroid-stimulating hormone in thyroid carcinoma

A simple and feasible potentiometric immunosensing platform based on enzymatic biocatalytic precipitation technique was designed for the sensitive detection of thyroid-stimulating hormone(TSH;a typical kind of biomarkers for thyroid carcinoma),using horseradish peroxidase(HRP)-loaded liposome for the signal amplification.To construct such an assay system,a sandwich-type immunoreaction was readily carried out on monoclonal anti-TSH capture antibody-coated electrode by using polyclonal antiTSH secondary antibody-conjugated HRP-loaded liposome.Accompanying the formation of sandwichtype immunocomplex,the carried liposome was lysed through the added Triton X-100 to release the entrapped HRP molecules,which catalyzed the oxidation of 4-chloro-1-naphthol to produce an insoluble and uncharged organic precipitation on the electrode surface,thereby causing the change of the local electrical potential.Two labeling protocols with and without the liposome were investigated for detection of target TSH,improved analytical features were achieved with HRP-entrapped liposome.Under optimal conditions,the potentiometric immunosensor had good responses for TSH detection within the linear range of 0.01-30 p IU/mL at a detection limit of 0.0067 p IU/mL.Good reproducibility,high specificity and long-time stability were acquired during the assay procedure.Importantly,a wellmatched accuracy between the potentiometric immunosensor and commercial human TSH ELISA kit was gave for the analysis of human serum samples.