铁基二氧化铅电极电解法制臭氧研究

以自制铁基二氧化铅电极作阳极,以石墨电极作阴极,探讨在不同电流强度和不同电解液条件下进行电解产生臭氧的最佳条件.     

浅谈一种微型低压臭氧发生器

电解式臭氧发生器是通过电解水而产生臭氧,微型低压臭氧发生器所述的是用智能低压电路控制,采用新型PEM膜、电极材料电解纯净水得到臭氧,并使用独特的结构设计,能使臭氧含量自动控制在国际公认的标准值内,同时智能的电路设计可自动显示臭氧发生器的运行情况,由于使用直流低电压电解方式,工作时不会产生电磁波和噪音,与其它精密仪器、家用电器共同工作时,不会造成干扰,具有制造成本低、使用简单的特点。     

铅合金阳极电解二氧化锰的研究(Ⅰ)——电解条件的确定及成品的理化性能

作者用正交试验法探索铅合金阳极电解制备二氧化锰电流效率较高的电解条件。然后按这些条件进行电解,获得一定量的成品。对产品进行放电试验,再根据放电性能提出用铅合金阳极电解制备二氧化锰的较优惠工艺条件。文中列出试样及对照样品的理化特性数据。     

软锰矿粒子电极处理SMP模拟废水实验研究

将软锰矿粒子电极引入三维电极系统处理钻井废水中难降解有机物。考察电解质和相关运行条件对CODCr去除率和活性氯生成量的影响。实验表明:Na Cl作支持电解质时CODCr去除率明显优于Na2SO4,电解产生的活性氯能进一步促进有机物的氧化降解。软锰矿粒子电极能显著提高活性氯的生成量和电流效率。以Na Cl为电解质,在电导率3600μs/cm、p H值7.0、粒子电极投加量80 g、电流强度0.9 A、曝气600 m L/min、电解40 min的实验条件下电解SMP模拟废水,CODCr去除率可达61.50%。     

ABS塑料基二氧化铅电极的制造,性能及其应用

在ABS塑料基体上用沉积二氧化铅的方法制造出了二氧化铅电极,这在国内尚未见报道。本文作者还对电极的阳极特性、二氧化铅腐蚀速率、沉积层与塑料表面结合力等性能,以及该电极在湿法电解炼铅、电解制取臭氧和高氯酸钠等方面的应用进行了研究,取得了有实际应用价值的结果。     

改性钛基二氧化铅电极制备及性能

为提高Ti/Pb O2电极的导电性能和电催化活性,通过涂覆法在钛板基体上裹覆萘酚-碳纳米管膜作为底层并通过电沉积法制备Pb O2改性电极;通过单因素变量法,研究了p H、电流强度、电解时间等因素对该电极电催化氧化苯酚模拟废水性能影响,并进行动力学分析。结果表明:改性电极导电性能增强,在最佳条件p H=6,I=1 A下降解1 h,苯酚去除率达到46. 2%,但反应产热,电能消耗增加;反应符合一级动力学方程。     

国外撷英

日本东京都工业技术研究所研制成一套高效分解高浓度三氯乙烯的设备.该设备可完全分解2300ppm高浓度三氯乙烯.整套分解设备由动力装置、提供混合气体的气泵、控制混合气体流量的流量计、气化有害物质的气化器、分解已气化有害物质的放电电解箱和洗涤已分解气体、使其无害化的碱性洗涤柱组成.该设备采用一对面积各为70mm~2×70mm~2的电极,两根电极相距3mm,其中一根电极用钛制成,另一个电极是层叠陶瓷的铜电极.混合气体进入两个电极之间时,三氯乙烯和臭氧发生化学反应,三氯乙烯分解成氯化氢和二氧化碳.在6kV高压电下约产生7.2g/m~3臭氧,以0.5L/min的流速进入该设备的空气蒸发了有害的有机化合物,化合物在通过该分解设备时,在臭氧的氧化作用和放电电解下被分解,2300ppm三氯乙烯被完全分解,     

ZrO_2电极表征及对4-氯酚电化学降解应用

采用浸渍法以氧氯化锆修饰颗粒活性炭,获得Zr-GAC.用扫描电子显微镜、X射线衍射仪和比表面仪对等方法对修饰活性炭性能进行表征,结果表明:氧氯化锆负载在活性炭上为ZrO_2.以苯酚为去除目标,研究了Zr-GAC在电化学氧化处理4-氯酚模拟废水过程,实验结果表明:ZrGAC三维电极对4-氯酚具有降解作用,粒子电极投加量10 g,电解质硫酸钠浓度2 g/L、板间距4 cm,电流强度1 A,电解500 mg/L4-氯酚模拟废水300 ml,电解180 min时,4-氯酚去除率可达98.5%,降解过程中产生4-氯邻苯二酚、苯酚、对苯二酚、苯醌、反丁烯二酸、草酸.     

无隔膜电解合成乙醛酸研究

研究了无隔膜电解草酸法生产乙醛酸的工艺,使用性能优良的新型阳极材料钽铱电极,并对电解工艺进行了优化。结果表明：在电解温度为20℃,电流密度为350A／m^2,使用钽铱电极,电解草酸饱和溶液8h后,乙醛酸产率达81％,该法具有装置简单、耗电低、电解液不受污染、阳极材料使用寿命长、产品纯度高等优点。     

汞膜电极阳极解析法在海水分析中的应用——Ⅰ.海水中痕量铜的测定

本工作提出用铂球镀银沾汞的汞膜电极阳极解析法测定海水中痕量铜,对电极的制备、性能及测定灵敏度等作了探讨. 在0.1N乙二胺与0.1N乙二胺硫酸盐的去铜海水底液中,应用汞膜电极在外加电压为1.0伏特F电解浓集15—20分钟,在一0.4至-0.1伏特间进行阳极溶出,成功地测定了浓度为10~(-6)—10~(-8)M的铜,回收误差为10％左右.     

Mn2+掺杂不锈钢基β-PbO2电极制备及电催化性能

在硝酸铅镀液中添加Mn(NO3)2,直流电沉积方法制备不锈钢基β-PbO2电极.利用SEM、EDS表征电极的形貌和Mn含量,阳极极化曲线和动力学参数表征电极的电催化活性.结果表明:Mn(NO3)2的添加量为6g/L时,表面形貌为颗粒状,排列紧凑,其电催化活性最好.掺杂Mn2+制备的不锈钢基β-PbO2电极与Pb-(1%)Ag合金阳极相比,槽电压降低,电流效率提高.     

Electrochemical migration behaviors of lead-free 64Sn-35Bi-1Ag solder on FR-4 PCB board plated with Cu

Electrochemical migration (ECM) characteristic is a new reliability failure. A parallel surfacial electrode system coupling with scanning electron microscope (SEM), energy dispersive X-ray analysis (EDAX), and X-ray Diffraction (XRD) technologies is designed to research ECM behavior of 64Sn-35Bi-1Ag (SBA) solder in 3.5 g/L NaCl solution and compare to that of Sn37Pb and Sn-3.0Ag-0.5Cu (SAC) solders. Results show that SBA solder is more susceptible to ECM failure than Sn37Pb solder, which is more difficult than SAC solder. The affected factors of ECM are given as follows: the solder compositions, the loaded electric field, ECM time, etc. The electrochemical reaction mechanism of ECM process is achieved. EDAX and XRD analyses show that the main contents on dendrites of SBA solder after ECM test are Sn, hardly any Bi, a little Ag, which illustrates that the order of ion migration capacity is shown as follows: Sn Ag Bi.     

稀土Ce掺杂铝合金阳极的结构和电化学性能

通过向Al-5Zn-0．05In-0．1Sn铝舍金基体中添加不同量的稀土元素Ce，制得一系列含稀土Ce的合金。采用扫描电镜和能谱分析，研究稀土对铝合金阳极微观组织的影响，并进行将稀土铝舍金用作铝空气电池阳极的电化学性能测试。研究结果表明：当Ce的含量不大于0．5％时，细化枝晶的效果较好；添加稀土元素Ce，铝舍金阳极的自腐蚀电位负移，放电稳定性和放电电压提高；当以50mA／cm^2的电流密度恒流放电时，Ce含量为0．3％的舍金放电性能最好，放电电压为1．118V，放电时间达到13h；添加稀土元素Ce能改善铝舍金阳极的耐腐蚀性能。     

无铅焊料Sn-9Zn—xLa的制备及性能

采用粉末冶金技术成功制备了La含量为x(其中x=0.1%～0.5%)的无铅焊料Sn-9Zn-xLa,应用DTA,SEM,XRD等技术分析了焊料的熔点,形貌,微结构,成分,焊料与Cu基板的粘附性等性能,并获得这些性能随La添加量而变化的规律.研究表明:添加微量稀土元素La能较大程度的改善无铅焊料润湿等方面的性能,Sn-9Zn-xLa有望替代传统PbSn合金,成为微电子器件封装焊接材料.     

Ameliorating mechanical properties and reducing anisotropy of as-extruded Mg-1.0Sn-0.5Ca alloy via Al addition

Effects of Al addition to a Mg–Sn–Ca ternary alloy on its microstructure and tensile properties after extrusion were studied via extrusion of Mg-1.0Sn-0.5Ca-xAl (x ​= ​0, 0.8, 2.4 ​wt%) sheets and analysis of the extruded materials. The results showed that Al addition not only refined the grain size (from 9.8 ​± ​0.7 ​μm to 8.3 ​± ​0.4 ​μm and 7.6 ​± ​0.5 ​μm) but also accelerated the generation of more second phase (from 0.98 to 1.72 and 4.32%). Except for the CaMgSn and Mg₂Ca in Mg-1.0Sn-0.5Ca alloy, new phase (Mg, Al)₂Ca appeared after Al addition. The addition of Al into Mg–Sn–Ca alloy induced the textural variation from an initially ED-split double-peaked texture to a weakened texture, i.e., divergent elliptical texture, due to the effect of particle stimulated nucleation. This eventually contributed to the improvement of mechanical anisotropy as well as the higher Hc value and n-value. For the strain hardening behavior when tension along the TD, the prolonged stage Ⅱ of Al-modified alloys was closely connected with the additional TD textural components, accelerating the activation of more basal slip. The decreased θⅢ0 in stage Ⅲ of Al-modified alloys is beneficial to the grain refinement and the emergence of more second phase.     

Dynamic solidification of Sn-38.1% Pb eutectic alloy within ultrasonic field

The dynamic solidification of Sn-38.1% Pb eutectic alloy within an ultrasonic field is investigated at a frequency of 35 kHz.As the sample height H is reduced,the effect of ultrasound on macrosegregation becomes more prominent,and the volume fraction of spherical eutectic cells increases correspondingly.When H equals the wavelength λ in liquid alloy,the introduction of ultrasound enlarges the distribution region of the primary (Sn) phase,but reduces the domains of the Sn-Pb eutectic and primary (Pb) phases.Meanwhile,a "dendritic-equiaxed" structural transition occurs in the primary (Sn) phase,and its grain size is significantly reduced within the ultrasonic field.Once H decreases to λ/2 and λ/4,the ultrasonic field promotes crystal nucleation and suppresses further undercooling of the bulk liquid alloy.Theoretical analyses indicate that the local high pressure induced by the cavitation effect and the stirring effect due to acoustic streaming are the main factors dominating the eutectic growth mechanism during dynamic solidification.     

无汞碱锰电池锌负极的研究（Ⅱ）

在碱性锌锰电池负极铜集电体表面用化学方法分别沉积致密的铟、锌、锡单层和锌铟、锡、铟、锌锡双层金属。用动态析氢实验表征,发现沉积单、双层金属的集电体在含锌粉的7．0mol/L KOH溶液体系中的析氢量比无沉积层的铜集电体析氢量要小,其中沉积锌铟、锡铟双层的析氢量最小,与用循环伏安和极化曲线方法测试金属集电体的电化学行为的结果一致。在相同的条件下,将沉积不同镀层的集电体装配成电池进行放电,实验结果表明：集电体表面化学沉积铟、锌、锡单层或锌铟、锡铟、锌锡双层金属用来生产无汞碱锰电池的放电性能均超过这类电池的国家行业标准QB1185－01中的要求。     

时效处理对Sn-Ag-Cu-Bi无铅钎料显微组织和力学性能的影响

主要研究了时效处理对Sn-3Ag-0.5Cu、Sn-3Ag-0.5Cu-1Bi、Sn-3Ag-0.5Cu-3Bi无铅钎料显微组织和力学性能的影响,并根据试验结果讨论了Bi元素的作用.试验结果表明Bi的加入提高了钎料的抗拉强度,但降低了其延伸率.通过在不同温度下时效处理,在含Bi的钎料中,Bi在Sn基体中析出,而含Bi的钎料表现出相对稳定的力学性能.这可归因于Bi的固溶强化与弥散强化作用的转化.     

Generation of sodium hypochlorite (NaOCl) from sodium chloride solution using C/PbO2 and Pb/PbO2 electrodes

Two modified electrodes (Pb/PbO₂ and C/PbO₂) were prepared by electrodepositing a lead oxide layer on lead and carbon substrates. These modified electrodes were used as anodes for the generation of sodium hypochlorite (NaOCl) from sodium chloride solution. Different operating conditions and factors affecting the treatment process of NaOCl generation, including current density, pH values, conductive electrolytes, and electrolysis time, were studied and optimized. By comparison the C/PbO₂ electrode shows a higher efficiency than the Pb/PbO₂ electrode for the generation of NaOCl.     

^7Be and ^210pb radioactivity and implications on sources of surface ozone at Mt. Waliguan

Beryllium-7 (^7Be) and lead-210 (^210Pb) radioactivity in aerosols collected, from October 2002 to January 2004 at Mt. Waliguan, by the Global Atmospheric Watch (GAW) Station, Qinghai Province is presented. The data were analyzed together with simultaneously measured surface ozone concentrations. We found that short time variations of ^7Be and ^210Pb were linked to alternations of synoptic weather around the Mt. Waliguan region. ^210Pb showed the lowest concentration in summer while ^7Be showed no obvious seasonal changes. Relatively high ^7Be and ^210Pb radioactivity was observed at Mt. Waliguan when compared with the observations at other mountain sites in other parts of the world. Surface ozone and ^7Be showed a consistent seasonal variation. Surface ozone correlated fairly well with ^7Be/^210Pb ratio. This suggested that vertical transport from higher altitudes of the atmosphere has predominant effects on the budget of surface ozone at Mt. Waliguan.