Surface Analysis of Chemical Stripping Titanium Alloy Oxide Films

The chemical stripping method of titanium alloy oxide films was studied. An environment friendly solution hydrogen peroxide and sodium hydroxide without hydrofluoric acid or fluoride were used to strip the oxide films. The morphologies of the surface and cross-section of the oxide films before and after the films stripping were characterized by using scanning electron microscopy （SEM）. The microstructure and chemical compositions of the oxide films before and after the films stripping were investigated by using Raman spectroscopy （Raman） and X-ray photoelectron spectroscopy （XPS）. It was shown that the thickness of the oxide film was in the range of 5-6 μm. The oxide films were stripped for 2 to 8 min in the solution. Moreover, the effect of the stripping time on the efficiency of the film stripping was investigated, and the optimum stripping time was between 6-8 min. When the stripping solution completely dissolved the whole film, the α/β microstructure of the titanium alloy Ti-10V-2Fe-3Al was partly revealed. The stripping mechanism was discussed in terms of the dissolution of film delamination. The hydrogen peroxide had a significant effect on the dissolution of the titanium alloy anodic oxide film. The feasibility of the dissolution reaction also was evaluated.

Repassivation Behaviour of UNS S32101 and UNS S30403 Stainless Steels after Cathodic Stripping of the Native Passive Film in a CO₂-Saturated Oilfield Brine

Repassivation behaviour of the passive film formed on lean duplex stainless steel UNS S32101 and austenitic stainless steel UNS S30403 in a CO2-saturated oilfield environment has been studied. The native passive film on the alloys was thinned/removed by stepping the potential of the alloy to ﹣850 mV/Ag/AgCl for 30 minutes. Potentiostatic measurements were then taken at potentials of ﹣200, ﹣100, 0, 100 and 200 mV versus Ag/AgCl. Results show that the passive film repassivates at potentials of ﹣200 and ﹣100 mV and 0 mV for both alloys at 50°C. The current density however continues to rise for potentials of 100 and 200 mV. This shows that both alloys are susceptible to pitting at potentials above 100 mV at the test temperature of 50°C.

Determination of the Antiretroviral Drug Zidovudine in Diluted Alkaline Electrolyte by Adsorptive Stripping Voltammetry at the Mercury Film Electrode

This paper describes a stripping method for the determination of zidovudine at the submicromolar concentration levels. This method is based on the controlled adsorptive accumulation of zidovudine at the thin-film mercury electrode, followed by a linear-sweep stripping voltammetry measurement of the surface species. Optimal experimental conditions include a NaOH solution of 2.0 × 10–3 mol●L–1 (sup-porting electrolyte), an accumulation potential of –0.30 V and a scan rate of 100 mV?s–1. The response of zidovudine is linear over the concentration range 0.01 - 0.08 ppm. After an accumulation time of 5 minutes, the detection limit was found to be 0.67 ppb (2.5 × 10–9 mol●L–1). More convenient methods to measure zidovudine concentration in the presence of the didanosine, acyclovir, nevirapine, lamivudine, and efavirenz, were also investigated. The presence of zidovudine together with ATP or ssDNA demonstrates the utility of this method.

Effect of phosphorus content on interfacial heat transfer and film deposition behavior during the high-temperature simulation of strip casting

The interfacial wettability and heat transfer behavior are crucial in the strip casting of high phosphorus-containing steel.A hightemperature simulation of strip casting was conducted using the droplet solidification technique with the aims to reveal the effects of phosphorus content on interfacial wettability,deposited film,and interfacial heat transfer behavior.Results showed that when the phosphorus content increased from 0.014wt%to 0.406wt%,the mushy zone enlarged,the complete solidification temperature delayed from1518.3 to 1459.4℃,the final contact angle decreased from 118.4°to 102.8°,indicating improved interfacial contact,and the maximum heat flux increased from 6.9 to 9.2 MW/m2.Increasing the phosphorus content from 0.081wt%to 0.406wt%also accelerated the film deposition rate from 1.57 to 1.73μm per test,resulting in a thickened naturally deposited film with increased thermal resistance that advanced the transition point of heat transfer from the fifth experiment to the third experiment.

Green Fabrication of Freestanding Piezoceramic Films for Energy Harvesting and Virus Detection

Most electronics such as sensors,actuators and energy harvesters need piezoceramic films to interconvert mechanical and electrical energy.Transferring the ceramic films from their growth substrates for assembling electronic devices commonly requires chemical or physical etching,which comes at the sacrifice of the substrate materials,film cracks,and environmental contamination.Here,we introduce a van der Waals stripping method to fabricate large-area and freestanding piezoceramic thin films in a simple,green,and cost-effective manner.The introduction of the quasi van der Waals epitaxial platinum layer enables the capillary force of water to drive the separation process of the film and substrate interface.The fabricated lead-free film,Ba_(0.85)Ca_(0.15)Zr_(0.1)Ti_(0.9)O_(3)(BCZT),shows a high piezoelectric coefficient d_(33)=209±10 pm V−1 and outstanding flexibility of maximum strain 2%.The freestanding feature enables a wide application scenario,including micro energy harvesting,and covid-19 spike protein detection.We further conduct a life cycle analysis and quantify the low energy consumption and low pollution of the water-based stripping film method.

Determination of Soil Base－Suluble Se by Anodic Stripping Voltammetry with Aurum Thin－Film Electrode

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Electrochemical Characteristics and Applications of Boron-Doped Polycrystalline Diamond Film Electrodes

The elcetrochemical characteristics of boron doped polycrystalline diamond thin film (BDF) electrode 4×4 mm 2 in size were studied using cyclic voltammetry and potentiostatic method. The diamond electrode exhibits adequate electrochemical activity and its response current changes linearly with K 3Fe(CN) 6 concentrations. The response current is proportional to the square root of the scan rate, reflecting mass transport controlled by planar diffusion. Stable mass transport can be quickly established within 4s. The BDF electrode provides good resolving power for the determination of lead and cadmium and gives satisfactory results in the analysis of pure water sample.

Optical and electronic performances of CVD diamond film andits applications in radiation detectors

The outstanding properties of CVD diamond film such as electronic, optical, thermal and mechanical and the high radiation hardness have made it an ideal candidate material for radiation detectors in severe environments. Fabrication of ＇detector grade＇ CVD diamond films and development of CVD diamond detectors have been leading edge subjects. Micro-strip gas chamber （MSGC） fabricated on CVD diamond substrate would overcome the charge-up effect and the substrate instability, which has been a hotspot in the research of gas detectors.

Determination of Hypoxanthine in the Presence of Copper by Adsorptive Stripping Voltammetry

A stripping method for the determination of hypoxanthine in the presence of copper at the submicromolar concentration levels is described. The method is based on controlled adsorptive accumulation of hypoxanthine-copper at the thin-film mercury electrode followed by a fast linear scan voltammetric measurement of the surface species. Optimum experimental conditions were found to be the use of 1.0 × 10﹣3 mol·L﹣1 NaOH solution as electrolyte supporting, an accumulation potential of ﹣0.50 V and a linear scan rate of 200 mV·s﹣1. The response of hypoxanthine-copper is linear over the concentration ranges of 10 - 60 ppb. For an accumulation time of 30 minutes, the detection limit was found to be 250 ppt (1.8 × 10﹣9 mol·L﹣1). Adequate conditions for measuring the hypoxanthine in the presence of metal ions, xanthine, uric acid and other nitrogenated bases were also investigated. The utility of the method is demonstrated by the presence of hypoxanthine associated in ATP or ssDNA.

Preparation of dendritic bismuth film electrodes and their application for detection of trace Pb(Ⅱ)and Cd(Ⅱ)

In this paper,dendritic Bi film electrodes with porous structure had successfully been prepared on glassy carbon electrode using a constant current electrolysis method based on hydrogen bubble dynamic templates.The electrode prepared using a large applied current density showed an increased internal electroactive area and a significantly improved electrochemical performance.The analytical utility of the prepared dendritic Bi film electrodes for the determination of Pb(Ⅱ)and Cd(Ⅱ)in the range of 5–50 μg·L^(-1)were presented in combination with square wave stripping voltammetry in model solution.Compared with non-porous Bi film electrode,the dendritic Bi film electrode exhibited higher sensitivity and lower detection limit.The prepared Bi film electrode with dendritic structure was also successfully applied to real water sample analysis.

Design and experiment of nail tooth picking up device for strip type residual film recycling and baling machine

In order to solve the problem of residual film pollution caused by large area of cotton mulched planting in Xinjiang,a strip type residual film recycling and baling machine was designed,which can complete mulching film picking up,impurities separation,baling and other operations.The picking up device,as the key part of residual film recycling machine,was designed and analyzed.The kinematics of the pick-up nail tooth was analyzed,and its motion equation,motion trajectory and the conditions for completing the film pick-up were determined.And the key parameters were determined by analyzing the conditions of no missing picking and the stress of the residual film.According to the Box-Benhnken test design principle,field experiments were carried out with the forward speed of machine,the pickup speed ratio and the number of auxiliary film removing mechanisms as the key experimental factors,and the residual film pickup rate,the cotton stalk content and the residual film winding rate as the operation performance indexes of the picking up device.The mathematical models between the experimental factors and indexes were established,and the effect of each factor was analyzed.Through multi-objective parameter optimization and field experiment,the optimal combination of operation parameters was obtained as follows:the forward speed of machine of 1.67 m/s,the pickup speed ratio of 1.13,and the number of auxiliary film removing mechanisms of 6.Under this parameter combination,the pickup rate of residual film was 88.9%,the cotton stalk content in recycled residual film of 3.9%,and the residual film winding rate of 1.5%.The absolute error with the theoretical value was less than 0.6%.The research results show that the picking up device has stable operation performance and good residual film recycling effect,which meets the design and practical operation requirements.

印刷线路板环保型退膜液的设计开发及性能研究

为了提高印刷线路板退膜液的环保性,通过试验研究确定了以无机碱为主体的环保型退膜液配方:无机碱NaOH 0.5 mol/L,碎膜剂二乙二醇单丁醚10 mL/L,表面活性剂醇类R 5 mL/L,护锡剂柠檬酸钾1 g/L,其余为纯水。该退膜液无色透明,状态稳定,在温度50℃的条件下进行退膜,退膜时间在50~70 s以内,膜碎大小为5~10 mm,锡厚变量均值低于0.5μm,氨氮值为4.632 mg/L。将该退膜液与同产线产品进行对比,发现两者退膜性能极为接近,而环保型退膜液具有更低的氨氮值和化学需氧量(COD)值,在满足生产需求的同时也能有很好的环保性,从而降低了退膜废液的处理成本。

Enhanced optical transmission through a nanoslit by coupling light between periodic strips and metal film

Surface plasmon resonance （SPR） is obtained by exciting the surface plasmon （SP） at the metal and dielectric interface, which can greatly enhance the extraordinary optical transmission （EOT） through a nanoslit milled in the metal film. We present a structure with a 50-nm-wide silver nanoslit for EOT by coupling light into the dielectric interlayer between periodic strips and a metal film. When the period of the metallic strips is equal to the wavelength of the SPR, the transmission efficiency of 187.6 through the nanoslit is enhanced. The metallic strip width over the nanoslit is optimized to improve transmission efficiency, and the maximal efficiency of 204.3 is achieved.

基于模板剥离法制备高性能钙钛矿单晶薄膜光电探测器

近年来,杂化钙钛矿半导体材料由于其带隙可调、吸收系数高、载流子迁移率高、成本低廉等诸多优点,在光电器件领域备受青睐,如太阳能电池、电致发光器件、光电探测器等。其中,钙钛矿单晶薄膜因其无晶界、杂质和缺陷含量低等特点,展现出更为优异的光学、电学特性,成为制备高性能光电器件的理想材料体系。然而,钙钛矿单晶薄膜常采用空间限域法直接生长在空穴传输层上,不可避免地将导致界面缺陷和载流子层间输运等问题,严重制约了钙钛矿单晶薄膜光电探测器的性能。为此,本文通过引入模板剥离法工艺技术,在钙钛矿单晶薄膜两侧分别蒸镀功能层材料,制备了结构为Cu/BCP/C_(60)/MAPbBr_(3)/MoO_(3)/Ag的钙钛矿单晶薄膜光电探测器。基于模板剥离法,两侧蒸镀的功能层与钙钛矿单晶薄膜接触紧密,将有效改善载流子的注入和传输;同时,优化的器件结构以及考虑能带匹配等因素可实现高灵敏、响应快速的钙钛矿单晶薄膜光电探测器。改进后器件的开关比高达3.1×10^(3),响应度可达7.15 A/W,探测率为5.39×10^(12)Jones,外量子效率达到1794%。该工作为进一步改善和提升钙钛矿单晶薄膜光电探测器的探测性能提供了一种可行性技术方案。

In-plane Uniaxial Anisotropy and Magnetization Reversal Mechanism of FeCo Films by Strip Pattern

Strip-like Fe Co films were patterned by a traditional lithograph process from intrinsically isotropic continuous Fe Co films. The strip-patterned Fe Co film shows a strong in-plane uniaxial magnetic anisotropy with easy axis along the length direction of the strip. The angular dependences of remanence ratio, switching field, and coercivity indicate that the magnetization reversal mechanism of the strip-patterned Fe Co film is coherent rotation and domain wall depinning when the applied field is near the hard axis and easy axis, respectively. The consistency of the experimental hysteresis loops of the strip-patterned Fe Co film and calculated hysteresis loops with a simple in-plane uniaxial anisotropy model indicates that the strip-patterned Fe Co film behaves as a single domain. The absence of the domain wall and the strong in-plane anisotropy field make the strip-patterned Fe Co films have much potential for high-frequency application.

Determination of trace Pb(Ⅱ), Cd(Ⅱ) and Zn(Ⅱ) using differential pulse stripping voltammetry without Hg modification

In this work,we reported a simultaneous determination approach for Pb(II),Cd(II)and Zn(II)atμg L 1concentration levels using differential pulse stripping voltammetry on a bismuth film electrode(BiFE).The BiFE could be prepared in situ when the sample solution contained a suitable amount of Bi(NO)3,and its analytical performance was evaluated for the simultaneous determination of Pb(II),Cd(II)and Zn(II)in solutions.The determination limits were found to be 0.19μg L 1for Zn(II),and0.28μg L 1for Pb(II)and Cd(II),with a preconcentration time of 300 s.The BiFE approach was successfully applied to determine Pb(II),Cd(II)and Zn(II)in tea leaf and infusion samples,and the results were in agreement with those obtained using an atomic absorption spectrometry approach.Without Hg usage,the in situ preparation for BiFE supplied a green and acceptability sensitive method for the determination of the heavy metal ions.

铝基覆铜板表面感光膜退除工艺

以2 g/L氢氧化钠(Na OH)为主要退膜反应剂,12 mL/L氨水和6 mL/L乙醇胺为加速剂,0.2~1.0 g/L 358DR为铝面保护剂,退除铝基覆铜板表面的感光膜。通过单因素实验研究了退膜温度、时间和铝面保护剂浓度对退膜效果和铝面情况的影响。结果表明,在铝面保护剂358DR质量浓度为0.8 g/L、温度为40℃的条件下,20 s能够将感光膜完全退除,并且铝面没有被攻击。该退膜工艺用于实际产线时的退膜效果甚至优于小试结果。

不同覆盖时期和方式对旱地马铃薯土壤水热及产量的影响

于2018-2019年连续两年定位试验,设置秸秆带状秋覆盖(FSM)、黑膜大垄秋覆盖(FPM)、秸秆带状春覆盖(SSM)、黑膜大垄春覆盖(SPM)和不覆盖露地平作(CK)5个处理,研究不同覆盖时期和覆盖方式对旱地马铃薯土壤水热及产量的影响。结果表明:秸秆带状覆盖和黑膜大垄覆盖能显著提高马铃薯全生育期0~200 cm土层平均贮水量,秋覆盖大于春覆盖,与CK相比,秸秆带状覆盖和地膜覆盖分别平均提高马铃薯全生育期0~200 cm土层平均贮水量5.8%、8.6%;秸秆带状覆盖具有普遍的降温效应,而地膜覆盖存在普遍的增温效应,FSM和SSM处理0~25 cm土层平均温度分别较CK降低0.8℃和0.5℃,FPM和SPM处理分别增加0.5℃和0.6℃,秋覆盖降温幅度大于春覆盖,秋覆盖增温幅度小于春覆盖;秸秆带状覆盖和地膜覆盖均能显著提高马铃薯产量4.8%~7.6%、水分利用效率13.5%~22.6%,增产效应秋覆盖优于春覆盖。此外,秸秆带状覆盖显著提高纯经济收益和产投比且秋覆盖提高幅度大于春覆盖。因此,秸秆带状覆盖栽培技术是一种增产高、绿色可持续发展的栽培模式,适宜于西北半干旱雨养区秸秆资源较为富余地区推广应用。

秸秆带状覆盖种植马铃薯农田土壤温度及其气温响应特征

【目的】为探明西北半干旱雨养区秸秆带状覆盖马铃薯田地温变化特征。【方法】于2014~2015年在西北半干旱雨养区,设秸秆带状覆盖(SM)、地膜大垄(PMP)、全膜双垄沟(PMF)和露地平作(CK)4个处理。【结果】不同处理在各生育时期、各土层土壤温度存在显著差异,各层次土壤温度日变化随气温呈正弦函数变化,土壤温度随气温的变化滞后2 h左右;无论平水年,还是丰水年,秸秆覆盖马铃薯各生育时期均出现降温效应,地膜覆盖则表现为增温效应,与CK相比,秸秆覆盖全生育期0~25 cm土层土壤温度平均降低0.8~1.4℃,PMP、PMF分别提高1.6~2.3℃、1.0~1.1℃;秸秆覆盖可延长苗期-成熟生育天数,较CK延长6~7 d,较覆膜延长8 d;同时,秸秆覆盖降低日振幅,土壤温差较CK降低1.9℃,增加马铃薯膨大~成熟期土壤有效积温。【结论】秸秆带状覆盖有效调控地温变化,有利于马铃薯生长。