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1.
电沉积条件对锌镀层织构的影响 总被引:14,自引:1,他引:14
采用XRD方法研究添加剂,络合剂,以及电流密度对锌酸盐镀锌层的织构和晶粒尺寸的影响,结果表明,添加剂AA-1的存在有利于(101)晶面取向;而DIE则使镀层转变为110择优;两种添加剂同时存在下,可在一定的电流密度范围内获得高择优取向的锌镀层,而当又有络合剂TEA和EDTA同时存在时,则可在更宽广的电流密度范围内制得日 粒细密、表面光亮、择优系数TC(110)在985以上的高择优取向锌沉积层。 相似文献
2.
络合滴定法测定低压流体输送用镀锌焊接钢管镀锌层重量 总被引:2,自引:0,他引:2
介绍了利用络合滴定法测定低压流体输送用镀锌焊风管镀锌层重量的方法,试样用稀硫酸溶解,在PH1.5 ̄2.0的弱酸性介质中,以磺基水杨酸钠为指标剂,用EDTA滴定铁,调PH为5.5,以PAN为指示剂,用EDTA滴定锌,由EDTA用量求出锌的重量,用GB/T3091-93方法比较,试验结果满意。 相似文献
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1—(5—溴—2—吡啶偶氮)—2—萘酚—6—磺酸作指示剂络合滴定连续测定铜和锌 总被引:9,自引:1,他引:9
对5-Br-PAN-S作指示剂络合滴定连续测定铜和锌进行了研究,在pH6.0的乙酸乙酸的钠介质中,以5-Br-PAN-S作指示剂,EDTA为滴定剂连续测定铜和锌,滴定终点颜色变化敏锐,准确度高,铜和锌量各在0~20mg范围内与EDTA用量成正比,铜,锌比例在1:10~10:1范围内相互无影响,方法用于合金中铜,锌的连续测定,结果满意。 相似文献
4.
Nafion化学修饰圆盘顶富集—石墨炉原子吸收联用法对牛血超氧化物… 总被引:4,自引:0,他引:4
本文研究了Nafion化学修饰钨丝圆盘预富集-石墨炉原子吸收方法测定牛血超氧化物歧化酶中淳离态Cu^2+及Zn^2+的方法,并用GFAAS法直接测定SOD中铜、锌的总量,证实了牛血SOD中金属辅基铜、锌原子个数比为1:1;初步探讨了一定浓度的牛血SOD中Cu^2+,Zn^2+的表观离解平衡常数,为提高SOD的活性和稳定性的研究,提供了一种有效的方法。 相似文献
5.
水溶性新显色剂5-Br-PADN-S的制备与分析特性的研究及其用于锌的测定 总被引:3,自引:0,他引:3
报道了水溶性 1-(5-溴-2-吡啶偶氮)-2,7-萘二酚-6-磺酸(5-Br-PADN-S)的制备方法及其分析特性。研究了此试剂与锌(Ⅱ)等金属离子在水溶液中直接测定的显色反应,在pH 10.0~11.4 的Na2B4O7~NaOH 缓冲溶液中,5-Br-PADN-S与锌(Ⅱ)形成2∶1 的紫色配合物,最大吸收波长位于542 nm ,表观摩尔吸光系数ε542= 6.38×104 L/(m ol·cm ),锌量在0~20 m g/10 L范围内符合比耳定律。在掩蔽剂的存在下,用于人发、奶粉及矿石等试样中锌的测定,结果与AAS法一致。 相似文献
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低碳烷烃合成芳烃的研究:Ⅱ.Zn—HZSM—5催化剂上丙烷的转化 总被引:6,自引:0,他引:6
对ZSM-5型高硅沸石进行了锌改性,制备了不同锌含量的Zn/HZSM-5催化剂。以丙烯为原料,在反应温度470 ̄550℃,空速1 ̄7h^-1条件下反应,并考察了催化剂的稳定性。结果表明,Zn/HZSM-5较HZSM-5在原料转化率变化不大的情况下,芳烃选择性有较大提高,液体产物收率明显增加。氨TPD和吡啶吸附红外光谱表明,Zn/HZSM-5较HZSM-5总酸量低,L酸量多,B酸量少。丙烷在线热重分 相似文献
8.
本文对用于原子吸收光谱分析的在线液-液萃取流路系统进行了研究,采用了一种新型、适用、简便的相分隔器和相分离器,并用该流路系统对矿石、人发中的Cu(FAAS)以及矿石中痕量Au进行了测定(GFAAS)。在水相和有机相的流量比为25:1,采样频率为20h ̄(-1)时,用FAAS法测定Cu的RSD为1.9%(n=10)、DL(3σ)为1.0μg.L ̄(-1);用GFAAS法测定Au的RSD为4.9%,n=10、DL(3σ)为0.08μg.L ̄(-1) 。 相似文献
9.
低碳烷烃合成芳烃的研究 总被引:2,自引:0,他引:2
对ZSM-5型高硅沸石进行了锌改性,制备了不同锌含量的Zn/HZSM-5催化剂。以丙烷为原料,在反应温度470~550℃,空速1~7h ̄(-1)条件下反应,并考察了催化剂的稳定性。结果表明,Zn/HZSM-5较HZSM-5在原料转化率变化不大的情况下,芳烃选择性有较大提高,液体产物收率明显增加。氨TPD和吡啶陡吸附红外光谱表明,Zn/HZSM-5较HZSM-5总酸量低,L酸量多,B酸量少。丙烷在线热重分析表明,Zn/HZSM-5积炭初速度较HZSM-5低一半,H_2化学吸附表明,Zn/HZSM-5的吸氢量是0.45mmolH2/gZn,相当于每mg锌可吸附2.71×10 ̄(17)个氢分子。 相似文献
10.
在线流动注射液—液萃取系统在原子吸收光谱法中的研究及应用 总被引:10,自引:0,他引:10
本对用于原子吸收光谱分析的在线液-液萃取流路系统进行了研究,采用了一种新型、适用、简便的相分隔器和相分离器,并用该流路系统对矿石、人发中的Cu(FAAS)以及矿石中痕量Au进行了测定(GFAAS)。在水相和有机相的流量比为25:1,采样频率为20h^-1时,用FAAS法测定Cu的RSD为1.9%(n=10)、DL(3σ)为1.0μg·L^-1;用GFAAS法测定Au的RSD为4.9%,n=10、 相似文献
11.
A. I. Andrukhiv A. A. Bachaev I. V. Skobeleva 《Russian Journal of Applied Chemistry》2013,86(10):1483-1492
Effect of Tsinkamin-02 additive on characteristics of electrolytically fabricated zinc electrode for backup power sources was studied. Its influence on how a zinc powder is formed, deposition process parameters (current efficiency by zinc, cathodic polarization), and utilization factor of the active substance of the negative electrode in a nickel-zinc power source discharged in a high-intensity mode was determined. The component concentrations of the electrolyte used to deposit the zinc powder were optimized. An explanation was suggested for the mechanism of Tsinkamin-02 action. 相似文献
12.
Effect of Tsinkamin-02 additive on characteristics of electrolytically fabricated zinc electrode for backup power sources was studied. Its influence on how a zinc powder is formed, deposition process parameters (current efficiency by zinc, cathodic polarization), and utilization factor of the active substance of the negative electrode in a nickel-zinc power source discharged in a high-intensity mode was determined. The component concentrations of the electrolyte used to deposit the zinc powder were optimized. An explanation was suggested for the mechanism of Tsinkamin-02 action. 相似文献
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研究了聚羧酸盐分散剂(SD-819)和聚萘磺酸盐分散剂(SD-661)在水溶液中的表面性能;同时考察了分散剂添加量对500 g/L扑草净水悬浮剂(SC)中的吸附、Zeta电势和流变性能等的影响.结果表明,与分散剂SD-661相比,分散剂SD-819水溶液中的表面张力(γcmc)小,临界胶束浓度(cmc)和胶束生成自由能(ΔGmic)低,吸附量大,制备出的扑草净SC黏度低,流动性好,触变性优良.结果表明,聚羧酸盐分散剂更适用于高浓度扑草净SC的制备. 相似文献
16.
利用火焰原子吸收光谱法(FAAS),测定了硫酸铜、硫酸锌、膨润土、米糠、氧化锌、菜渣、盐等7种肉牛饲料添加剂中铅(Pb)元素的含量.各添加剂的加标回收率在98%-108%之间,相对标准偏差(RSD)小于1.3%,具有良好的准确度和精确度.结果表明,试验中所测的硫酸铜、硫酸锌、氧化锌添加剂中铅含量严重超出国家标准. 相似文献
17.
Adsorption mechanism and dispersion efficiency of three anionic additives [poly(acrylic acid), poly(styrene sulfonate) and HEDP] on zinc oxide 总被引:1,自引:0,他引:1
Dange C Phan TN André V Rieger J Persello J Foissy A 《Journal of colloid and interface science》2007,315(1):107-115
Adsorption on ZnO of sodium poly(acrylate) (PAA), sodium poly(styrene sulfonate) (PSS) and a monomer surfactant [hydroxyethylidene diphosphonate (HEDP)] was investigated in suspensions initially equilibrated at pH 7. Results demonstrate interplay in the adsorption mechanism between zinc complexation, salt precipitation, and ZnO dissolution. In the case of PAA, the adsorption isotherm exhibits a maximum attributed to the precipitation of zinc polyacrylate. PSS and HEDP formed high-affinity adsorption isotherms, but the plateau adsorption of HEDP was significantly lower than that of PSS. The adsorption isotherm of each additive is divided into two areas. At low additive concentration (high zinc/additive ratio), the total zinc concentration in the solution decreased and the pH increased upon addition. At a higher additive ratio, zinc concentration and pH increased with the organic concentration. The increase in pH is due to the displacement of hydroxyl ions from the surface and the increase in zinc concentration results from the dissolution of ZnO due to the complexation of zinc ions by the organics. The stability of the ZnO dispersions was investigated by measurement of the particle size distribution after addition of various amounts of polymers. The three additives stabilized the ZnO dispersions efficiently once full surface coverage was reached. 相似文献
18.
利用微计算机控制的电化学测试系统研究了低脆性镀锌添加剂DB对锌的电化学成核的影响。发现锌晶核的形成遵循连续成核机理。成核速度常数A与电极电位E的关系证明经典成核速度定律适用。饱和晶核数密度Vs和E的关系可经验地表示为Ns=N∞1-exp[-b(E-Ecr)]。E恒定不变时,A和Ns随DB浓度增大而减小。用异相成核理论解释了添加剂和过电位的不同效应。 相似文献
19.
Barbara Pacewska Iwona Wilińska Maria Bukowska 《Journal of Thermal Analysis and Calorimetry》2009,97(1):61-66
The aim of this work is to compare the influence of addition of waste aluminosilicate catalyst on the initial periods of hydration
of different cements, i.e. calcium aluminate cements of different composition and Portland cement, basing on the calorimetric
studies. Cement pastes containing up to 25 mass% of additive were studied, where the water/(cement+additive) ratio was 0.5.
An attempt was undertaken to explain the mechanism of action of introduced aluminosilicate in the system of hydrating cement,
particularly in the case of calcium aluminate cement pastes.
It was found that the presence of fine-grained additive caused in all studied cases the increase of the amount of released
heat in the first period after the addition of water. In the case of aluminate cements with aluminosilicate addition, a significant
reduction of induction time and faster precipitation of hydration products were observed compared to the reference sample
(without additive). In the experimental conditions, the additive caused the acceleration of aluminate cements hydration, and
the mechanism of its action is probably complex and can encompass: nucleative action of small grains and formation of new
chemical compounds. 相似文献
20.
Kazimierz Sykut Grazyna Dalmata Barbara Nowicka Jadwiga Saba 《Analytica chimica acta》1980,118(2):369-372
The “cap-pair” effect, which accelerates electrode processes, is shown to be useful in decreasing the effects of inhibitors on reduction processes. The determination of zinc in the presence of Tween-80 is used as an example. In the square-wave polarography of zinc at the 10-5 M level, addition of thiourea (10 g l-1) eliminates or greatly reduces the inhibitory action of Tween-80, thus allowing precise determinations. 相似文献