基于响应面法的锌-铁-锰合金脉冲电沉积工艺优化

[目的]采用脉冲电沉积法在Q235钢表面制备Zn-Fe-Mn合金,以提高低碳钢的耐蚀性。[方法]先通过单因素实验研究了不同因素对Zn-Fe-Mn合金镀层耐蚀性的影响,然后以主要影响因素──pH、电流密度和温度为因子,镀层在3.5%Na Cl溶液中的腐蚀电流密度为响应值,采用响应面法对电沉积工艺进行优化,并建立了各因子与腐蚀电流密度之间的回归模型。[结果]电沉积Zn-Fe-Mn合金的较优工艺参数为:脉冲频率1000 Hz,占空比0.2,pH 6.0,电流密度62.60 mA/cm^(2),温度29℃,时间30 min。在较优条件下所得Zn-Fe-Mn合金镀层的实测腐蚀电流密度为2.26μA/cm^(2),与模型预测值仅相差1.80%。[结论]本文建立的回归模型可靠,可用于Zn-Fe-Mn合金电沉积工艺参数的优化,为开发高性能镀层提供理论支持。

碱性锌酸盐体系锌-铁-二氧化钛复合电镀工艺的研究

通过在碱性锌铁合金电镀液中加入适量钛白粉,制得锌-铁-二氧化钛复合电镀层。介绍了镀液中各组分的作用及操作条件。研究了镀液中的氧化锌、氯化亚铁、二氧化钛、配合剂和添加剂的含量以及阴极电流密度、温度和搅拌等对复合镀层中铁和二氧化钛含量的影响,优选出最佳镀液组成及操作条件。结果表明,复合电镀过程中,二氧化钛与铁的沉积互相促进,具有协同效应。

偶氮氯膦-Ⅲ光度法测定锌-铁-稀土合金中稀土含量

pH在2～4的酸性介质中，采用分光光度法，用草酸掩蔽干扰金属离子，以偶氮氯膦-Ⅲ为显色剂，在680nm波长处测量吸光度．结果表明，稀土含量在0～55μg／mL之间时符合比尔定律，加标回收试验显示该法准确可靠．

清远市铁山脚-寨仔铜铅锌多金属矿普查区找矿潜力

普查区岩体接触带长5km,物化探异常强度高,范围广,矽卡岩、大理岩化角岩化遍布,已知矿点有观音山铁铜矿床点、寨仔铁矿点、老虎头铅锌矿点,综合条件指示区域具有较好的成矿热源和成矿物质来源,具有较好的热液型多金属矿找矿前景。

综合地球物理方法在蒙古国中戈壁省某铁-锌多金属矿区勘查中的应用

采用高精度磁法与双频激电法相结合的方式对蒙古国中戈壁省某铁-锌多金属矿区进行地球物理勘查评价,圈定出多个低磁、高视幅频率、低视电阻率异常区,经工程验证该异常由多个铁-锌金属矿体引起,矿体赋存于花岗岩与大理岩接触交代所形成的矽卡岩带内,矿床成因类型为接触交代矽卡岩型,矿床规模为中型。该矿区研究结果表明,高精度磁法与双频激电法的联合应用,可以快速圈定深部铁锌多金属矿化异常体,并为后期探矿工程部署提供依据,是寻找同类型矿床的有效方法之一。

氧化镍-铁酸锌复合薄膜／锡掺杂玻璃光波导传感元件的制备及其对硫化氢气体的气敏性

用溶胶-凝胶法制成了NiO掺杂的ZnFe2O4溶胶,并用浸渍提拉法将其固定在锡掺杂玻璃光波导表面,研制了NiO-ZnFe2O4复合薄膜/锡掺杂玻璃光波导气敏元件,并对无机有毒气体进行了检测。实验结果表明,在室温下,该传感元件对H2S气体具有一定的选择性响应,而对相同浓度的其它无机气体的响应相对较小,能够检测到1.0×10-9(体积比)的H2S气体,其响应和恢复时间分别是6和8 s。该元件具有灵敏度高、响应-恢复快、可逆性和重复性好、容易制备,在室温下便于操作等特点。

焦磷酸盐电镀锌-镍-铁三元合金

锌-镍-铁三元合金电镀工艺是在焦磷酸钾溶液中进行。镀层以锌为主,其成分为85%Zn,10%Ni,5%Fe。镀层外观银白、致密,抛光性能良好。锌-镍-铁三元合金镀液是以焦磷酸钾为主络盐,镀液呈微碱性(p H约为8.8)不含毒性,有利于环保。

铁氧化物在热浸镀锌时对铁—锌反应的抑制作用的研究

研究在４５０℃下，分别以Ｚｎ－Ａｌ（０．２０％）（质量分数）和纯Ｚｎ为镀液，均一氧化层对镀锌反应的影响。研究发现，铁氧化物在纯Ｚｎ镀液中起到抑制Ｆｅ－Ｚｎ晶簇形成的作用，这与以Ａｌ－Ｚｎ为镀液，在钢界面形成的Ｆｅ２Ａｌ５层所起的作用类似。铁氧化物在纯锌镀液中的抑制作用是暂时性的，因为氧化层会有裂缝或其它损伤，成为Ｚｎ液的扩散通道。

Pyrite depression in marmatite flotation by sodium glycerine-xanthate

The depression of pyrite in marmatite flotation by sodium glycerine-xanthate （SGX） was investigated through microflotation, zeta potential and adsorption measurements. The flotation tests of mineral show that in the presence of SGX, marmatite can be activated by Cu^2＋ and shows good flotability, while pyrite cannot be activated and therefore shows poor flotability. At the pH value range from 4 to 11, the flotation selectivity between marmatite and pyrite is obvious when the SGX concentration is below 50 mg/L. The depression mechanism of SGX on sulfide minerals is discussed based on zeta potential and adsorption isotherm. Zeta potential measurement demonstrates that in the presence of Cu^2＋, SGX can strongly adsorb on the surface of pyrite, while it cannot adsorb on the surface of marmatite. The results of adsorption isotherms show that the adsorption density of SGX on pyrite is greater.

Element distribution of high iron-bearing zinc calcine in high gradient magnetic field

High gradient magnetic separation was conducted in order to separate insoluble zinc ferrite from zinc calcine before acid leaching of hydrometallurgical process. Chemical composition and structural characterization of zinc calcine were studied via inductively coupled plasma （ICP）, X-ray diffraction （XRD）, Mossbauer spectra, scanning electron microscopy （SEM） and laser particle analysis （LPA）. The parameters of magnetic separation which affect the distribution of zinc ferrite and undesired elements, such as calcium, sulfur and lead in magnetic concentrate were investigated. The results of high gradient magnetic separation indicate that more than 85% of zinc ferrite is distributed into magnetic concentrate from the zinc calcine under the magnetic induction of 0.70 T. In addition, about 60% of calcium and 40% of sulfur distribute in non magnetic phases of tailings during magnetic separation process. Most of lead distributes uniformly along the zinc calcine in superfine particle size.

Zn-Ca-Fe氧化物催化水解微晶纤维素

以尿素为沉淀剂制备了一系列复合金属沉淀物,将其在高温条件下煅烧获得一系列复合金属氧化物固体催化剂,并将其用于催化微晶纤维素的水解反应;考察了反应温度、反应时间、搅拌转速、催化剂用量和微晶纤维素用量对反应的影响。实验结果表明,在反应温度160℃、反应时间20 h、搅拌转速400 r/mnin、微晶纤维素2.0 g、Zn-Ca-Fe氧化物0.9 g和H_2O 200 mL的条件下,微晶纤维素的转化率高达42.56%,葡萄糖的收率为69.20%,且微晶纤维素水解液为中性溶液。在相同反应条件下,Zn-Ca-Fe氧化物可重复使用5次,其催化活性无明显降低。

Effects of Iron-zinc Combined Application on Yield and Quality of Tobacco

[Objective] This study aimed to improve the yield and quality of tobacco. [Method] Different proportion combinations of zinc sulfate and iron sulfate were applied to Jiyan 9, and its agronomic traits, field natural incidence, economic characters and chemical composition were compared among different treatments. [Result] Iron-zinc combined application improved the yield and quality of tobacco. Among all the treatments, Treatment 2 （FeSO4 15 kg/hm2 ＋ ZnSO4 10 kg/hm2） and Treatment 5 （FeSO4 15 kg/hm2 ＋ ZnSO4 15 kg/hm2） were the best. [Conclusion] This study will provide a theoretical basis for the improvement of yield and quality of tobacco.

Preparation and characterization of composite microspheres of nano zinc ferrite/poly(D,L-lactide-co-alanine)

Magnetic nano zinc ferrite fliuds were synthesized using an improved liquid phase chemical method, which would be used to replace tradditional iron oxides magnetic material. A novel copolymer （PLAA） with D, L-lactide （D, L-LA） and alanine was synthesized using stannous octoate as initiator. Magnetic polymer microspheres were fabricated with nano zinc ferrite fluid coated with alanine modified poly lactide. These as-prepared zinc ferrite fluids, modified poly lactide and magnetic composites, were characterized with X-ray diffraction diffractometer, FT-IR spectrometer, nuclear magnetic resonance spectrometer, scanning electron microscope, transmission electron microscope, vibrating sample magnetometer, and thermogravimetric analyzer. The results demonstrate that the as-prepared zinc ferrite is spinel type of ZnFe2O4 nano crystals with particle size of 20-45 nm and magnetization of 32×10^-3 A.m2. Alanine is copolymerized with lactide, and the prepared composite magnetic microsphere is coated with the modified polylactide, with mass fraction of 45.5% of PLA, particle size ranging from 80-300 nm, and magnetization of 10.6×10^-3 A·m^2, which suggests ZnFe2O4 enjoys a stable magnetization after being coated by polymer.

Electroplated super-hydrophobic Zn−Fe coating for corrosion protection on magnesium alloy

A superhydrophobic Zn−Fe alloy coating was prepared on the surface of a reactive magnesium alloy using a simple,low-cost,eco-friendly method.Firstly,the Zn−Fe coating was obtained in a neutral glycerol Zn−Fe plating solution,which is green,compositionally stable,and non-corrosive to the equipment.And then the superhydrophobic surface with a flower-like microstructure was obtained by grafting myristic acid onto the Zn−Fe coating via a chelation reaction.The water contact angle was>150°and the rolling angle was 3°−4°.The corrosion rate of the two groups of superhydrophobic magnesium alloy samples with electrodeposition time of 30 and 50 min,respectively,was reduced by about 87%compared to that of the bare magnesium alloy.The prepared superhydrophobic coatings exhibit high performance in self-cleaning,abrasion resistance,and corrosion resistance.

Fe-Zn糖蛋白的提取工艺

以荆门的蚂蟥蚯蚓为原料,将其清洗后加缓冲液匀浆,然后经提取、离心、脱脂、脱色、喷雾干燥后得到一种棕黄色超细粉末.经检测,证实其主要成分为Fe-Zn糖蛋白.

Effect of dephytinization on bioavailability of iron,calcium and zinc from infant cereals assessed in the Caco-2 cell model

AIM： To test the effect of the dephytinization of three different commercial infant cereals on iron, calcium, and zinc bioavailability by estimating the uptake, retention, and transport by Caco-2 cells. METHODS： Both dephytinized （by adding an exogenous phytase） and non-dephytinized infant cereals were digested using an in vitro digestion protocol adapted to the gastrointestinal conditions of infants younger than 6 too. Mineral cell retention, transport, and uptake from infant cereals were measured using the soluble fraction of the simulated digestion and the Caco-2 cells. RESULTS： Dephytinization of infant cereals significantly increased （P 〈 0.05） the cell uptake efficiency （from 0.66%-6.05% to 3.93%-13%）, retention （from 6.04%-16.68% to 14.75%-20.14%） and transport efficiency （from 0.14%-2.21% to 1.47%-6.02%）, of iron, and the uptake efficiency （from 5.0%-35.4% to 7.3%-41.6%） and retention （from 4.05%-20.53% to 14.45%-61.3%） of zinc, whereas calcium only cell uptake showed a significant increase （P 〈 0.05） after removing phytate from most of the samples analyzed. A positive relationship （P 〈 0.05） between mineral solubility and the cell uptake and transport efficiencies was observed. CONCLUSION： Removing phytate from infant cereals had a beneficial effect on iron and zinc bioavailability when infant cereals were reconstituted with water. Since in developing countries cereal-based complementary foods for infants are usually consumed mixed with water, exogenous phytase additions could improve the nutritional value of this weaning food.

Current efficiency improvement of Zn-Fe alloy electrodeposition by hydrogen inhibitor

In order to inhibit hydrogen evolution and enhance current efficiency of Zn-Fe alloy electrodeposition from alkaline zincate solution, hydrogen inhibitors composed of the sulfur group elements were optimized on the basis of atom structures analysis. The effects of hydrogen inhibitor on the current efficiency of Zn-Fe alloy electroplating and their electrochemical behaviors were studied. The results indicate that hydrogen inhibitor can increase the current efficiency of Zn-Fe alloy electroplating evidently, from 63.28% without hydrogen inhibitor up to 83.54% with a hydrogen inhibitor at a volume fraction of 2.0%, while it has a minor influence on that of pure Zn plating, which maintains at 80%. The optimum volume fraction of hydrogen inhibitor is 2.0%.

Highly selective acetone sensor based on ternary Au/Fe_2O_3-ZnO synthesized via co-precipitation and microwave irradiation

Ternary Au/Fe2O3-ZnO gas-sensing materials were synthesized by combining co-precipitation and microwave irradiation process.The as-prepared Au/Fe2O3-ZnO was characterized with X-ray diffractometer and scanning electron microscope,and its gas-sensing performance was measured using a gas-sensor analysis system.The results show that the as-prepared products consist of hexagonal wurtzite ZnO,face-centered cubic gold nanoparticles and orthorhombic Fe2O3crystallines.The Au/Fe2O3-ZnO based sensor has a very high selectivity to ethanol and acetone,and also has high sensitivity(154)at a low working temperature(270°C)and an extremely fast response(1s)against acetone.It is found that the selectivity can be adjusted by Fe2O3content added in the ternary materials.It possesses a worth looking forward prospect to practical applications in acetone detecting and administrating field.

Effects of short-term application of low-dose growth hormone on trace element metabolism and blood glucose in surgical patients

AIM： To investigate the effects of short-term application of low-dose growth hormone on trace element metabolism and blood glucose in surgical patients METHODS： A total of 48 consecutive patients undergoing abdominal operations were randomized to receive either subcutaneous rhGH （0.15 IU/kg） or placebo （menstruum） injections daily for 7 d after surgery. The two groups had similar nutrition intake. Blood, feces, urine and drain samples were collected to measure zincum, cuprum and ferrum as well as glucose levels. Accumulative intake, excretion and balance of zincum, cuprum and ferrum, apparent absorption （AA） and apparent utilization （AU） of zincum, cuprum and ferrum, blood glucose levels and adverse events were estimated. RESULTS： There were no differences in accumulative intake and drain excretion between the two groups. The feces excretion and accumulative excretion of cuprum were lower in the rhGH group （P 〈 0.05）. The urinary excretion of zincum, cuprum and ferrum was all significantly decreased in the rhGH group （P 〈 0.05） and the accumulative balance of zincum, cuprum and ferrum was improved compared with the placebo group （P 〈 0.05）. AA of cuprum in the rhGH group was almost twice as much as the placebo group （P 〈 0.05）, and AU of zincum, cuprum and ferrum was all improved in the rhGH group （P 〈 0.05）. The mean blood glucose level was significantly higher in the rhGH group than in the placebo group from d 3 to d 6 after operation （P 〈 0.05）.improves the retention of zincum, cuprum and ferrum and decreases the excretion of zincum, cuprum and ferrum, improves the balance of zincum, cuprum and ferrum, and promotes the AA and AU of zincum, cuprum and ferrum, rhGH can be well tolerated without significant adverse effects and the blood glucose level can be well controlled.

Synthesis of Ni-Zn ferrite and its microstructure and magnetic properties

Nanometer Ni0.5Zn0.5Fe2O4 powders with spinel phase were prepared by the hydrothermal method using purified FeSO4 solution from sodium jarosite＇s slag as materials. The results show that the spinel phase of Ni0.5Zn0.5Fe2O4 powders begins to form at a relatively low temperature （130 ℃） and a shorter holding time （1 h） when pH=8. The crystallization kinetics equation at 200℃ is ln[-ln（1-x）] =-0.78＋0.951n t. The growth activation energy of Ni0.5Zn0.5Fe2O4 grains is 41.6 kJ/moL in hydrothermal synthesis process. With the increase of sintering temperature, the density and diameter shrinkage of ferrite circulus increase, whereas its pores decrease. The results of magnetic measurements show that saturation magnetic flux density Bs increases and the coercivity Hc decreases with the increase of their sintering temperature. Magnetic parameters of all the investigated samples satisfy the character demand of high Bs, low Br and low Hc of soft magnetic ferrite materials.