中性载体PVC膜钡离子选择电极的研制

钡离子选择电极的研制已有较多报导,吴国梁等作过有关综述。以聚氧乙烯醇类化合物为活性物制备钡离子选择电极的文献也有几篇。Levins利用 Igepal-Co-880与Ba~(2+)的络合物和四苯硼酸根形成魄盐为活性物,溶子对硝基乙基苯内,制成液膜钡离子电极。Jaber 等作了改进,研究了溶剂的影响,以 Autarox—Co—880Ba·2 TPB 为活性物,邻硝基苯辛醚或邻硝基二苯醚为增塑剂,制成了 PVC 膜钡离子电极,指出采用亲脂     

PVC膜电极对表面活性剂响应的实验研究

在广泛使用表面活性剂的今天,将聚合物离子选择电极用于测量表面活性剂,是一个有实用价值的课题,可望实现对环保工程中的监控和工业流程中的质量控制.人们曾对此进行了大量的工作,但对有些问题的看法至今尚无定论.为此,我们研制了几种膜电极,分别对Cl~-,Ba~(2+)和一系列阴离子、非离子表面活性剂进行测试,比较了各自响应规律的异同点,并从理论上对响应机理进行了探讨.     

离子选择性电极膜溶度积常数的估算

本文用多次标准添加法,由在线的PC—1500A袖珍计算机采集和用单纯形法处理数据,获得了CI~-、F~-和Ca~(2+)离子选择性电极膜的表观溶度积常数。经电势误差分析,结果是满意的。本法也适用于其它离子选择性电极。     

Gran线性滴定法测定硅

本文以氟离子选择电极为指示电极,利用 Gran 线性滴定法测定硅酸盐等矿石中的硅,用柠檬酸盐和抗坏血酸隐蔽 Fe~(3+)、Al~(3+)、Ca~(2+)、Mg~(2+)、Cu~(2+)、Mn~(2+)等干扰离子,利用计算机处理分析数据,方法简便、快速、准确。     

氟电极法测定Pb2+、Cd2+对植物细胞质膜透性的影响

以植物叶片为试验体系,测量它们在水溶液中不同浸泡时间的外渗液中 F~-离子浓度,并测量其相应的电导率,结果说明,植物细胞外渗 F~-离子浓度与总离子浓度成正比关系,因而 F~-离子选择性电极法可作为测量植物细胞质膜透性的一种方法,还试验了用 F~-离子选择性电极法测量 pb~(2+)、Cd~(2+)对植物细胞质膜透性的影响,实验结果表明,10~(-5)mol/L、10~(-4)mol/L 的 pb~(2+)、Cd~(2+)对 F~-离子选择性电极无干扰,而 pb~(2+)、Cd~(2+)在10~(-5)mol/L、10~(-4)mol/L 时就能使植物细胞质膜透性显著增大,表现出对植物细胞有一定的伤害作用,但不同植物对 Pb~(2)、Cd~(2+)重金属的抗性有些差别。     

银片涂PVC膜钾离子选择电极的研制与应用

本文允绍了一种用银片作基体电极的PVC膜钾离子选择性电极。该电极较其他钾电极对铵离子的选择性要好,K_(K~+)~(Pot),NH_4~+为5.5×10~(-4),在0.5mol/L 醋酸铵介质中,电极对钾离子在5.0×10~(-5)—1.0×10~(-1)mol/L 范围内符合能斯特关系,斜率为65mv/PK(25℃),检测下限为1×10~(-5)mol/L。电极的稳定性和选择性能良好,能很好地应用于土壤中速效钾的测定。     

（P—Cl）TPPMnCl修饰的玻炭电极上分子氧的电催化还原

已知 Fe~(2+)、Mn~(2+)、Cr~(2+)、Co~(2+)等的配合物能够与分子氧反应,并催化分子氧的还原.当高价态的卟啉铁和卟啉锰经电化学方法还原成二价的卟啉铁和卟啉锰时,它们可以与O_2发生轴向配位反应。本文制备了(P-Cl)TPPMnCl 修饰的玻炭电极,研究了该电极表面进行的分子氧的电催化还原反应的机理,并研究了各种轴向配体对催化性能的影响。一、实验一、仪器和试剂79—1型伏安分析仪(河南电分析仪器厂)3086型 X—Y 函数记录仪(四川仪表厂)P-1型金相试样抛光机(上海电光器件厂)三电极系统:工作电极为(P-Cl)TPPMaCl 修饰的玻炭电极;参比电极为 Ag/AgCl     

PVC膜钯离子选择电极的研制

迄今为止,有关钯离子选择电极的报导仅有Sclbona等研制的季胺盐缔合物液膜电极和蒋德华等研制的季胺盐缔合物PVC膜电极。前者线性范围仅一个数量级(10~(-1)～10~(-2)M)。本文发现在含氧酸体系中,将丁基罗丹明B与PdI_3~-络阴离子生成的缔合物作活性物质,可制得性能良好的PVC膜钯离子选择电极。本文研究了电极的制作、性能及初步应     

干扰素免疫电极的研究

用溴化氰在醋酸纤维素膜上固定了马抗人γ干扰素抗体,该抗体膜在37℃下与样品液温育反应1h后,置于一碘离子选择电极端部而构成抗体电极,另一个碘离子选择电极与空白膜组装成参比电极.测量了电极在0.1mmol KI+4.4mmol H_2O_2+0.1mol磷酸盐缓冲液pH5.0中的响应,结果表明电极电位与样品中γ干扰素浓度呈曲线关系.抗体膜可重复使用6d以上.还介绍了过氧化物酶标记的γ干扰素制备方法和电极响应线性化方法.     

羟苄唑PVC膜电极及PVC膜石墨棒电极的研究

羟苄唑是治疗急性出血性结膜炎的药物,其PVC膜电极的研制及应用尚未见报导。作者据以前工作,以羟苄唑—四苯硼离子缔合物为活性物质研制成羟苄唑PVC膜电极(Ⅰ)及PVC膜石墨棒电极(Ⅱ)。经测试,(Ⅰ)的能斯特响应范围为1.0×10~(-2)—4.0×10~(-5)M,检测下限为5.6×10~(-6)M;对羟苄唑的回收率为100.2—105.1％(Ⅱ)的能斯特响应范围为1.0×10~(-2)M—4.3×10~(-5)M,检测下限为8.9×10~(-5)M,回收率为98.6—     

中性载体PVC膜pH电极的制备与应用

研制了中性载体三辛胺ＰＶＣ膜ｐＨ电极,其响应的ｐＨ线性范围为２．５～１２．３,斜率５３．６ｍＶ／ｐＨ,并用于水样和含Ｆ离子水样ｐＨ测定。     

用直接实验设计方法优化聚丙烯腈基膜的制备条件

以聚丙烯腈为聚合物,磷酸或聚乙二醇-600为添加剂,N-甲基吡咯烷酮为溶剂,采用L-S相转换法制备PAN超滤膜。利用计算机直接实验设计方法设计制膜的配方,用Statistic Analytic System(SAS)统计软件对膜的水通量、牛血清蛋白截留率和平均孔径进行回归分析,得出影响PAN基底膜性能的主要因素,并且优化了PAN基膜制备的工艺条件。实验结果表明,PAN浓度、添加剂种类和添加剂浓度是PAN基膜性能的主要影响因素;在一定的浓度范围内,以适当的PAN浓度和添加剂浓度均可制备出渗透性能较好的PAN超滤膜;SAS统计软件对PAN基膜的截留率和平均孔径的预测值与实验值吻合较好。     

Perchlorate selective membrane electrodes based on synthesized platinum(II) complexes for low-level concentration measurements

Three synthesized platinum(II) complexes, [PtR₂(NN)] (R = Me, p-MeC₆H₄ and p-MeOC₆H₄; NN = 2,2′-bipyridyl), were studied to characterize their ability as an anion carrier in a PVC membrane electrode. The polymeric membrane electrodes (PME) and also coated glassy carbon electrodes (CGCE) prepared with [Pt(p-MeOC₆H₄)₂(NN)] showed excellent response characteristics to perchlorate ions. The electrodes exhibited Nernstian responses to ClO₄⁻ ions over a wide concentration range from 5 × 10⁻⁷ to 4.0 × 10⁻¹ M for PME and 1.5 × 10⁻⁷ to 2.7 × 10⁻¹ M for CGCE with low detection limits (4.0 × 10⁻⁷ M for PME and 1.0 × 10⁻⁷ M for CGCE). The electrodes possess fast response time, satisfactory reproducibility, appropriate lifetime and, most importantly, good selectivity toward ClO₄⁻ relative to a variety of other common anions. The potentiometric response of the electrodes is independent of the pH of the test solution in the pH range 2.5–9.5. The proposed sensors were used in potentiometric determination of perchlorate ions in mineral water, urine samples and also samples containing interfering anions. The interaction of the ionophore with perchlorate ions was shown by UV–vis spectroscopy.     

Rapid fabrication of nanoparticles array on polycarbonate membrane based on positive dielectrophoresis

We report here a rapid formation of island arrays with nanoparticles on and within polycarbonate (PC) membrane based on positive dielectrophoresis (p-DEP). For the fabrication of the patterning device, PC membranes with 10 μm thickness and 100, 200 or 400 nm pore size were sandwiched by an upper bare ITO substrate and a lower disk array ITO electrode which was defined by insulation layer of negative photoresist. A suspension of 190 nm diameter polymethylmethacrylate (PMMA) particles containing rhodamine 6G (R6G) fluorescent molecules was introduced into the device between the upper ITO and the PC membrane. AC electric signal (typically 20 Vpp, 70 kHz) was then applied to the ITO, resulting in the formation of island patterns with high electric fields gradient regions on and in the PC membrane. Particles patterns with island shape were assembled on membrane within 1 s after applying AC electric field. The electrodes can be used repeatedly as the template of subsequent patterning. Although, particles islands were only formed on the PC membrane with 100 and 200 nm diameter pores, the particles penetrated the membrane with 400 nm pores to form patterns on the back surface. Since the strong electric fields were formed at the edges of disks, particles on the back surface were the projection of the disk array of ITO to form ring shapes. The unique structure with particles was explained based on the simulation of electric field distribution. The present proposal offers a procedure to fabricate particle arrays with extremely simple, rapid and highly reproducible manner.     

混凝- 膜分离集成工艺处理表面活性剂废水的研究

废水中的表面活性剂成分复杂、分子量小,若不经处理直接排入水体,将造成水体的富营养化。膜分离法处理废水存在膜易污染、清洗困难的问题。针对上述问题,文章提出采用混凝-膜分离集成工艺处理表面活性剂废水。首先,采用相转化法自制二氧化钛改性聚偏氟乙烯超滤膜,并通过扫描电子显微镜、傅里叶红外光谱、接触角测量仪测试膜的结构和性能;然后以十二烷基苯磺酸钠配制表面活性剂废水,以聚合氯化铝作为混凝剂,研究紫外光照强度、进水流量,溶液 pH值对集成工艺处理效果的影响。研究结果表明,改性膜表面具有致密分离层,断面呈指状孔和海绵状结构;傅里叶红外光谱表明聚乙二醇和二氧化钛的加入掩盖了部分聚偏氟乙烯晶型的红外吸收;二氧化钛改性膜具有更小的接触角;紫外光照强度和进水流量对混凝-膜分离工艺影响较小,溶液酸碱性对工艺影响较大,并且当溶液 pH值为4.5时集成工艺对表面活性剂废水处理效果最佳。混凝-膜分离集成工艺作为一种新型解决方案,在大规模、高效、低成本处理生活和工业废水中有望发挥重要作用。     

Amperometric biosensor for formic acid in air

The possibility of developing a simple, inexpensive and specific personal passive “real-time” air sampler incorporating a biosensor for formic acid was investigated. The sensor is based on the enzymatic reaction between formic acid and formate dehydrogenase (FDH) with nicotinamide adenine dinucleotide (NAD⁺) as a co-factor and Meldola's blue as mediator. An effective way to immobilise the enzyme, co-factor and Meldola's blue on screen-printed, disposable, electrodes was found to be in a mixture of glycerol and phosphate buffer covered with a gas-permeable membrane. Steady-state current was reached after 4–15 min and the limit of detection was calculated to be below 1 mg/m³. However, the response decreased by 50% after storage at −15°C for 1 day.     

微结构气体传感器的优化设计

利用SiO2相对于SiNx有更低的热导率,作为膜式微气体传感器的热绝缘和电绝缘层,而单晶Si适合通过各向异性腐蚀形成倒杯状结构来支撑SiO2膜。将膜式微气体传感器中的加热器和信号电极设计在一个平面上,以减小工艺复杂度,获得较高的加热效率。利用有限元分析工具ANSYS分析比较加热器和信号电极在不同宽度与间距时的温度分布。当设定加热器宽度为50μm,信号电极宽度50μm,加热器和信号电极间距为25μm,微气体传感器将获得更低的功耗和比较均匀的中心温度分布,有利于传感器整体性能的提高。     

MD5算法在农业数据消重中的应用

垂直搜索引擎的数据来源于各大相关网站。随着互联网用户越来越多,相互转载,重复发布的数据也越来越多,由于这些重复及相似数据的存在,严重影响了搜索引擎的检索结果。针对这一问题本文提出了一种解决方法,即利用MD5算法在数据处理阶段有效的消除冗余数据。结果表明该方法很好的提高了检索质量。     

What happens turning a 250-μm-thin piezo-stack sideways?

Usually when piezoelectric membrane actuators are mentioned, one classically thinks of a passive membrane with a piezoelectric actuator on top. In this paper omitting the passive membrane will be suggested. Therefore, the piezoelectric actuator will not be commonly designed as plate capacitor structure, such as that the piezoelectric material sitting between two plate electrodes. Rather will the actuation be caused by structured surface electrodes on only one side of the piezoelectric material, leaving the opposite side free of potential. Several surface electrode designs, starting with interdigital parallel structures, known from surface acoustic wave transducers, spiral and ring structures, ending with star-shaped structures, are tested. The main advantage of this actuation principle is that with the varying electrode design it became possible to also generate an upward movement, i.e., in the direction of electrode side of the membrane. This upward movement has not been achieved with any piezoelectric membrane actuator so far.     

阳离子药物通用电极的研究

本文研究了用四苯硼酸衍生物为载休的石墨内导PVC膜阳离子药物通用电极。探讨了定域体、电活性物质及增塑剂等与电极性能的关系,用正交试验法对四间氯苯硼酸钾(TMCIPBK)为载体的电极膜组进行了优化。确定了通用电极的活化条件,比较了十二种药物通用电极和相应专用电极的性能,研究了分配系数(P_分)和一阶分子连接性指数(~IX~V)与电极选择性系数(K~(pot))的相关性能,将所制电极用于药物分析,获得了满意的结果。