Study on Electrodeposition of Ho-Co Alloy in Dimethylsulfoxide

Ｎｏｗｒａｒｅｅａｒｔｈｓ ｉｒｏｎａｌｌｏｙｓａｒｅｐｒｏｄｕｃｅｄｍａｉｎｌｙｂｙｖａｃｕｕｍｅｖａｐｏｒａｔｉｏｎ ,ｃａｔｈｏｄｅｓｐｕｔ ｔｅｒｉｎｇｏｒｉｏｎｐｌａｔｉｎｇ ,ｗｈｅｒｅｔｈｅｃｏｓｔｉｓｈｉｇｈａｎｄｔｈｅｔｅｃｈｎｏｌｏｇｙｉｓｃｏｍｐｌｉｃａｔｅｄ .Ｅｌｅｃｔｒｏｄｅ ｐｏｓｉｔｉｏｎｍａｙｂｅａｃｏｍｐａｒａｔｉｖｅｌｙｇｏｏｄｗａｙｆｏｒｉｔｓｌｏｗｃｏｓｔａｎｄｓｉｍｐｌｅｔｅｃｈｎｏｌｏｇｙ .Ｈｏｗｅｖｅｒｉｔｉｓｄｉｆｆｉｃｕｌｔｔｏｅｌｅｃｔｒｏｄｅｐｏｓ…     

采用磁控溅射法在细菌纤维素膜上制备高性能的铟锡氧化物薄膜

Microbial cellulose (MC) membranes produced by Acetobacter xylinum NUST4.1, were used as flexible substrates for the fabrication of transparent indium tin oxide (ITO) electrodes. Transparent and conductive ITO thin films were deposited on MC membrane at room temperature using radio frequency (RF) magnetron sputtering. The optimum ITO deposition conditions were achieved by examining crystalline structure, surface morphology and optoelectrical characteristics with X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and UV spectroscopy. The sheet resistance of the samples was measured with a four-point probe and the resistivity of the film was calculated. The results reveal that the preferred orientation of the deposited ITO crystals is strongly dependent upon with oxygen content (O2/Ar, volume ratio) in the sputtering chamber. And the ITO crystalline structure directly determines the conductivity of ITO-deposited films. High conductive [sheet resistance～120Ω.square-1(Ω.sq-1)] and transparent (above 76%)ITO rilms(240 nm thick) were Obtained with a moderate sputtering power (about 60 W) and with an oxygen flow rate of 0.25ml·min-1(sccm) during the deposition. These results show that the ITO-MC electrodes can find their potential application in optoelectrical devices.     

铁矾渣微波硫酸化焙烧水浸液的深度除铁

采用微波低温硫酸化焙烧-水浸和针铁矿除铁方法将Zn、Cu等富集到浸出液中,Pb和Ag富集到浸出渣中,使有价金属得到清洁的回收利用.研究了上述工艺中浸出液除铁的优化工艺条件,探究了反应体系的pH值、浸出液单次滴加量、浸出液的铁含量等因素对除铁效果的影响,并采用X射线衍射分析、扫描电子显微镜观察等手段对得到的沉淀渣进行了表征.研究获得的优化实验条件为:以200 mL的0.01 mol·L^-1ZnSO₄溶液为底液,晶种添加量为20 g·L^-1,除铁体系pH值控制在3左右,温度90℃,每隔5 min滴加3 mL水浸液(保持反应体系中铁的浓度<1 g·L^-1).在此条件下,除铁后溶液残铁量仅为0.065 g·L^-1,去除率可达99.3%,达到了深度除铁效果.除铁过程中,Zn的损失率仅为4.1%.     

电极银浆用微纳米银粉的制备与性能研究

以硝酸银为前驱体, 抗坏血酸为还原剂, 单宁为分散剂, 采用液相化学还原法制备了微纳米超细银颗粒。通过X射线衍射仪、扫描电子显微镜、激光粒度分析仪、振实密度仪及太阳能性能测试仪等设备研究了反应物浓度、分散剂剂量、pH值等工艺参数对银颗粒形貌、平均粒径及振实密度的影响。结果表明, 当硝酸银浓度为0.1mol·L-1, 抗坏血酸浓度为0.1mol·L-1, 单宁浓度为0.01mol·L-1, pH值为1, 反应温度为25℃时, 能够获得分散性良好的球状银颗粒; 将平均粒径为1.16μm和0.66μm的两种银粉按照一定质量比进行混合, 制备得到的混合银粉最高振实密度可达到6.1g·mL-1; 通过研究基于不同振实密度银粉的银电极表面形貌和电池性能, 可以得出基于振实密度6.1g·mL-1混合银粉所制的银电极相对密度最好, 太阳能电池的光电转换效率最高, 达到17.16%。     

Emission enhancement and color modulation of Tm(Ho)/Yb codoped Gd_2(MoO_4)_3 thin films via the use of multilayered structure

The multilayered structure thin films(Gd_2(MoO_4)_3:Ho(Tm)/Yb@Gd_2(MoO_4)_3:Yb)) were prepared through sol-gel and spin-coating method,while the average thinness was nearly 140 nm.We investigated the up-conversion luminescence of Gd2(MoO_4)3:Ho(Tm)/Yb@Gd2(MoO_4)3:Yb thin films,The results show that the double-layer structured thin films are able to increase the emission intensity.The fluorescence enhancement factors of the luminescence from Gd2(MoO_4)3:Ho/Yb@Gd2(MoO_4)3:Yb thin films,located at540 and 662 nm,reach 7.5 and 4.3,respectively.And the enhancement factors of emissions located at450,475 and 650 nm(Gd_2(MoO_4)3:Tm/Yb@Gd_2(MoO_4)_3:Yb)) reach 9,2 and 2,respectively.The considerable enhancement is due to the suppression of surface quenching and energy harvesting via the Yb ions in the outer shell.In addition,the emission color of thin films can be modulated from yellow to blue via tuning the number of Gd2(MoO_4)3:Ho/Yb and Gd2(MoO_4)3:Tm/Yb layers,which provides a feasible strategy to tune the up-conversion emission color.     

NaYF4:Yb,Er材料的制备及其上转换发光性能

通过沉淀法制备Yb3+和Er3+共掺的NaYF4上转换发光材料,考察了主要制备工艺条件对材料上转换发光性能的影响,并探讨了其上转换发光的机理。利用x射线衍射(XRD)、透射电镜(TEM)、荧光光谱仪对样品进行了表征。结果表明,Yb3+和Er3+的掺杂浓度分别15%(摩尔分数,下同)、3%,焙烧温度为600℃时可得到发光性能较好的六方相NaYF4:Yb,Er上转换材料,其主要上转换途径是Yb3+和Er3+之间的能量转移,且Er3+的红、绿光发射均为双光子过程。     

Energy transfer in Tb~（3＋）,Yb~（3＋） codoped Lu_2O_3 near-infrared downconversion nanophosphors

Tb3+ and Yb3+ codoped Lu2O3 nanophosphors were synthesized by the reverse-strike co-precipitation method. The obtained Lu2O3:Tb3+,Yb3+ nanophosphors were characterized by X-ray diffraction (XRD) and photoluminescence (PL) spectra. The XRD results showed that all the prepared nanophosphors could be readily indexed to pure cubic phase of Lu2O3 and indicated good crystallinity. The Tb3+→Yb3+ energy transfer mechanisms in the UV-blue region in Lu2O3 nanophosphors were investigated. The experimental results showed that the strong visible emission around 543 nm from Tb3+ (5D4→7F5) and near-infrared (NIR) emission around 973 nm from Yb3+ (2F5/2→2F7/2) of Lu2O3:Tb3+,Yb3+ nanophosphors were observed under ultraviolet light excitation, respectively. Tb3+ could be effectively excited up to its 4f75d1 state and relaxed down to the 5D4 level, from which the energy was transferred cooperatively to two neighboring Yb3+. The Yb3+ concentration dependent luminescent properties and lifetimes of both the visible and NIR emissions were also studied. The lifetime of the visible emission decreased with the increase of Yb3+ concentration, verifying the efficient energy transfer from the Tb3+ to the Yb3+. Cooperative energy transfer (CET) from Tb3+ to Yb3+ was discussed as a possible mechanism for the near-infrared emission. When doped concentrations were 1 mol.% Tb3+ and 2 mol.% Yb3+, the intensity of NIR emission was the strongest.     

Green Approach to Corrosion Inhibition of Mild Steel by Lignin Sulfonate in Acidic Media

The inhibition effect of lignin sulfonate against corrosion for mild steel in acidic solution has been examined by means of FTIR(fourier transform infrared spectroscopy),FAA(flame atomic absorption)spectroscopy,SEM(scanning electron microscope),EDS(energy dispersive X-ray spectroscopy),and mass loss techniques.The results revealed that lignin is a beneficial inhibitor for mild steel corrosion in acidic medium.It has been further found that Langmuir adsorption isotherm is obeyed by the tested lignin′s adsorption over the surface of mild steel.The range of inhibition efficiency(IE)in 2mol·L~(-1) HCl was found to be 75.88%-87.88%for Reax 88 A,40.72%-60.32%for Reax 88 B,and 54.32%-63.03%for Reax 100 M,after immersed at 298 Kfor 24htime.     

Effect of Lanthanum on Expression of Recombinant Allophycocyanin Gene in Pichia Pastoris

The methylotrophic yeast ,Pichia pastorishasbeen developed to be an outstanding host for the pro-duction of foreign proteins since its alcohol oxidasepromoter was isolated and cloned ,and its transforma-tion was first reported in 1985[1 ,2].This organismh…     

What is the Effect of Critical Surface Tension of PbSO3 Thin Film?

This study focuses on the critical surface tension of lead sulfite (PbSO₃) crystalline thin film produced with chemical bath deposition on substrates (commercial glass).The PbSO₃ thin films were deposited at room temperature at different deposition times. The structural properties of the films were defined and examined according to X-ray diffraction (XRD) and the XRD results such as dislocation density, average grain size, and no. of crystallites per unit area. Atomic force microscopy was used to measure the film thickness and the surface properties. The critical surface tension of the PbSO₃ thin films was measured with an optical tensiometer instrument and calculated using the Zisman method. The results indicated that the critical surface tension of films changed in accordance with the average grain size and film thickness. The film thickness increased with deposition time and was inversely correlated with surface tension. The average grain size increased according to deposition time and was inversely correlated with surface tension.     

Effects of oxygen pressure on La_3Ga_5SiO_(14) thin films grown by pulsed laser deposition

La3Ga5SiO14 thin films were grown on Si(100) substrates by pulsed laser deposition at several oxygen pressures(5,10,and 20 Pa).The effects of oxygen pressure on the structural and morphological characteristics of the films were investigated using X-ray diffraction,atomic force microscopy,and scanning electron microscopy.X-ray diffraction results showed the intensity of lines from crystallites oriented along the(300) and(220) planes increased as the oxygen pressure was increased to 20 Pa.The deposited films ...     

CSP结晶器保护渣固态渣膜结构和矿相的分析

通过光学显微镜、扫描电镜及X射线衍射分析,研究了1537 mm×67 mm CSP连铸结晶器保护(%:34.6CaO,28.6SiO₂,8.8C,8.5F,8.6Na₂O)固态渣膜的结构、矿相组成和析晶率,分析结果表明,绝大多数固 态渣膜厚0.6~1.3mm, 呈三层结构：结晶层-玻璃层-结晶层,靠结晶器壁侧为0.10～0.14mm 厚的结晶层;CSP 固态渣膜的析晶率为40%～80%,结晶矿相主要为枪晶石(3CaO ·2SiO₂ ·CaF₂)和矿物Na₂O ·Al₂O₃ ·SiQ₂。通过 调整固态渣膜的厚度及枪晶石等矿物的析晶率,可达到控制渣膜传热,提高连铸坯表面质量的目的     

New Methodological Approach to Investigation of Kinetics of REE Extraction in Nonstationary Conditions

The influence of periodical oscillations of the temperature on extraction and stripping processes in the extraction systems was studied. Two extraction systems were investigated： （1） 6 mol · L^-1 NaNO3-Nd（NO3）3-Pr（NO3）3-TBP kerosene and （2） [Nd（NO3）3 · 3TBP] -[ Pr（NO3）3 · 3TBP] -kerosene - 0.1 mol · L^-1 HNO3. Mathematical modeling of the nonstationary membrane extraction has been enhanced by including the dependence of the extraction rate constants on temperature. The values of activation energy for direct and reverse extraction and stripping reactions of Pr and Nd were calculated from experimental temporal dependencies of metal concentration and temperature by solving the reverse kinetics problem using the proposed mathematical model, A series of experiments with periodical oscillations of the temperature on the extraction system for the separation of rare earth elements （REE） using bulk liquid membrane between two extractors were performed. The mathematical model adequately describes the experimental data. The optimization of the extraction process for separation of REE by liquid membrane, under the influence of periodical oscillation of the temperature, was made based on the extraction rate constants and activation energies. The optimal conditions of separation by liquid membrane were found： frequency and amplitude of thermal oscillations, liquid membrane flow rate, and optimal ratio between organic and aqueous phase in extractors.     

Synthesis of Y2O3 Nano-Powder from Yttrium Oxalate under Ambient Temperature

ThereareseveralprecipitationmethodsinthesynthesisofY2 O3 nano powdersuchascarbonatemethod ,ammoniumsaltmethodandoxyhydratemeth odetc .[1～ 5] ,buttheoxalateprecipitationmethodisconsideredtobethebestmethodinindustryandtheadvantagesofoxalicacidastheagentofp…     

氯化钕与甘氨酸配位反应的热化学研究

采用具有恒温环境的反应热量计,以2mol     

Effect of humidity on microstructure and properties of YBCO film prepared by TFA-MOD method

Epitaxial YBCO superconducting films were deposited on the single crystal LaAlO3. (001) substrate by metal organic deposition method. All YBCO films were fired at 820 ℃ in humidity range of 2.6%-19.7% atmosphere. Microstructure of YBCO thin films was ana-lyzed by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). Superconducting properties of YBCO films were measured by four-probe method. XRD results showed that the second phase (such as BaF2)and a-axis-oriented grains existed in the films prepared at 2.6% humidity condition; a-axis-oriented grains increased in the film prepared at higher than 4.2% humidity condition; almost pure c-axias-oriented grains existed in the films fired at 4.2% humidity condition. Morphologies of the YBCO films showed that all films had a smooth and crack-free surface. YBCO film prepared at 4.2% humidity condition showed Jc value of 3.3 MA/cm2 at 77 K in self-field.     

液氯化法浸金过程热力学

针对氯化物体系中金的浸出反应进行热力学计算,分别绘制出Au-Cl-H2O体系电位-pH图、lg[Au(Ⅲ)]-pH图、lg[Cl-]-pH图,并分析了金氯化浸出过程的热力学影响因素。电位-pH图中存在着金氯络合物的稳定区域,在pH为中性或弱酸性并保持氧化电位高于0.9 V的条件下,金将以AuCl4-的形态浸出。AuCl4-的稳定性很差,易受氯化物浓度、AuCl4-浓度等热力学因素的影响。加大氯化物浓度或降低AuCl4-浓度,在热力学上有利于金的浸出。在保证金尽可能浸出的角度来说,热力学上最佳条件为pH 3.5～7.8、氧化电位高于0.9 V、氯化物浓度高于1 mol.L-1,AuCl4-浓度1×10-5～1×10-4mol.L-1。     

Si(100)衬底上CeO2薄膜的脉冲激光制备及性能研究

用CeO2陶瓷靶材,使用脉冲激光沉积(PLD)技术在Si(100)衬底上制备了CeO2薄膜.研究了衬底温度、沉积氧压对薄膜性能的影响,实验制备出了高度(111)取向的CeO2薄膜.使用X射线衍射(XRD)、反射式高能电子衍射(RHEED)对薄膜进行晶体结构的表征.结果表明:随着衬底温度的增加,薄膜中的残余宏观应力(拉应力)及微观应力逐渐减小,薄膜结晶质量不断提高,而沉积氧压对此影响较小.RHEED图像显示使用PLD方法在Si衬底上沉积的薄膜具备较高的结晶性及原子级平整的表面.使用原子力显微镜(AFM)对样品进行表面粗糙度分析,发现不同温度下生长的薄膜均具有光滑的表面,方均根粗糙度(RMS)均在0.4 nm以下.使用Keithley 4200半导体测试仪、椭偏仪对薄膜进行电性能及光学性能分析,发现衬底温度对薄膜的电学性能有显著影响,并且CeO2薄膜结晶状态与电学性能有直接的联系.     

氧化铝赤泥盐酸浸出稀土元素研究

在用盐酸浸出氧化铝赤泥提取氧化钪的过程中,稀土元素镧,铈,钕也一同浸出,进入到浸出液中。研究了拜耳法赤泥盐酸浸出稀土元素镧,铈,钕的过程。研究了浸出温度、酸度、液固比和浸出时间对稀土元素浸出率的影响。研究结果表明,影响稀土浸出率的因素依次是浸出温度,盐酸浓度,配料液固比,和浸出时间。当接近沸点109℃浸出时,镧、铈、钕浸出率提高最快。盐酸酸度在4～5 mol.L-1时,浸出率升高较快,5～7 mol.L-1时,缓慢提高,当超过7 mol.L-1时,镧、铈、钕的浸出率基本不变化。当液固比为4.0时,镧、铈、钕元素的浸出率较低,仅为60%～75%之间,当液固比提高到5.0时,稀土元素的浸出率升高较快。随着浸出时间的延长,氧化稀土的浸出率从60～180 min时,缓慢提高,在180 min时达到最大值,超过180 min后,变化不大。在温度为沸点(109℃),液固比6.0,时间180 min。盐酸浓度7 mol.L-1的条件下浸出,赤泥中La,Ce,Nd的浸出率能达到95%以上。     

D302-Ⅱ树脂吸附铼的性能研究及应用

针对地浸采铀浸出液低含量铼的回收,研究了D302-Ⅱ弱碱性阴离子交换树脂吸附和解吸铼的性能和机制。通过静态试验考察温度、酸度、时间对树脂吸附的影响;通过动态试验考察了溶液酸度和流速的影响,并进行了解吸剂及其浓度影响试验、抗干扰试验及树脂再生的试验;用地浸采铀浸出液通过D302-Ⅱ树脂,进行模拟回收铼试验。结果表明,D302-Ⅱ树脂对铼的吸附速率快,吸附反应速率常数k=1.6×10-3s-1,半交换期t1/2=433 s。吸附酸度在pH 2.0～5.0范围内,有利于铼的吸附。吸附平衡服从Freundish吸附等温式,吸附反应放热,反应可在常温下进行。动态上柱酸度选择为pH 2.0～5.0,流速1～2 ml.min-1,铼的吸附率可达95%以上;洗脱液选择NH4OH,25倍树脂床体积的3 mol.L-1NH4OH溶液可将铼洗脱完全。地浸采铀浸出液中的共存离子不影响铼的吸附和解吸,0.5 mol.L-1H2SO4溶液可使树脂再生。树脂对铼的静态和动态吸附容量分别为166和162 mg.g-1干树脂,对浓度低至0.03 mg.L-1铼溶液吸附和解吸,回收率可达96%～102%,表明该树脂有较好的应用前景。