Influence of ion species on extraction characteristicsof mixed ion beams

The spatial distributions of different kinds of ions are usually not completely the same in the process of extracting.In order to study the reason for the different characteristics of ion extraction, a simplified simulation model of Cu+ andCr+ ions extraction process was established by 2D3V (two-dimensional in space and three- dimensional in velocity space)particle-in-cell (PIC) method. The effects of different extraction voltages from 0 V to 500 V on the density distribution ofCu+ and Cr+ ions and the change of plasma emission surface were analyzed. On the basis of this model, the ion densitydistribution characteristics of Cu+ ions mixed with Li+, Mg+, K+, Fe+, Y+, Ag+, Xe+, Au+, and Pb+ ions respectivelyunder 200-V extraction voltage are further simulated, and it is revealed that the atomic mass of the ions is the key reason fordifferent ion density distributions when different kinds of ions are mixed and extracted, which provides support for furtherunderstanding of ion extraction characteristics.

Highly selective extraction of aromatics from aliphatics by using metal chloride-based ionic liquids

The separation of aromatics from aliphatics is essential for achieving maximum exploitation of oil resources in the petrochemical industry.In this study,a series of metal chloride-based ionic liquids were prepared and their performances in the separation of 1,2,3,4-tetrahydronaphthalene(tetralin)/dodecane and tetralin/decalin systems were studied.Among these ionic liquids,1-ethyl-3-methylimidazolium tetrachloroferrate([EMIM][FeCl_(4)])with the highest selectivity was used as the extractant.Density functional theory calculations showed that[EMIM][FeCl_(4)]interacted more strongly with tetralin than with dodecane and decalin.Energy decomposition analysis of[EMIM][FeCl_(4)]-tetralin indicated that electrostatics and dispersion played essential roles,and induction cannot be neglected.The van der Waals forces was a main effect in[EMIM][FeCl_(4)]-tetralin by independent gradient model analysis.The tetralin distribution coefficient and selectivity were 0.8 and 110,respectively,with 10%(mol)tetralin in the initial tetralin/dodecane system,and 0.67 and 19.5,respectively,with 10%(mol)tetralin in the initial tetralin/decalin system.The selectivity increased with decreasing alkyl chain length of the extractant.The influence of the extraction temperature,extractant dosage,and initial concentrations of the system components on the separation performance were studied.Recycling experiments showed that the regenerated[EMIM][FeCl_(4)]could be used repeatedly.

Influence of extraction voltage on electron and ion behavior characteristics

The characteristics of the extracted ion current have a significant impact on the design and testing of ion source performance.In this paper,a 2D in space and 3D in velocity space particle in cell(2D3V PIC)method is utilized to simulate plasma motion and ion extraction characteristics under various initial plasma velocity distributions and extraction voltages in a Cartesian coordinate system.The plasma density is of the order of 10^(15)m^(-3)-10^(16)m^(-3)and the extraction voltage is of the order of 100 V-1000 V.The study investigates the impact of various extraction voltages on the velocity and density distributions of electrons and positive ions,and analyzes the influence of different initial plasma velocity distributions on the extraction current.The simulation results reveal that the main reason for the variation of extraction current is the spacecharge force formed by the relative aggregation of positive and negative net charges.This lays the foundation for a deeper understanding of extraction beam characteristics.

Feature extraction and learning approaches for cancellable biometrics:A survey

Biometric recognition is a widely used technology for user authentication.In the application of this technology,biometric security and recognition accuracy are two important issues that should be considered.In terms of biometric security,cancellable biometrics is an effective technique for protecting biometric data.Regarding recognition accuracy,feature representation plays a significant role in the performance and reliability of cancellable biometric systems.How to design good feature representations for cancellable biometrics is a challenging topic that has attracted a great deal of attention from the computer vision community,especially from researchers of cancellable biometrics.Feature extraction and learning in cancellable biometrics is to find suitable feature representations with a view to achieving satisfactory recognition performance,while the privacy of biometric data is protected.This survey informs the progress,trend and challenges of feature extraction and learning for cancellable biometrics,thus shedding light on the latest developments and future research of this area.

Online identification and extraction method of regional large-scale adjustable load-aggregation characteristics

This article introduces the concept of load aggregation,which involves a comprehensive analysis of loads to acquire their external characteristics for the purpose of modeling and analyzing power systems.The online identification method is a computer-involved approach for data collection,processing,and system identification,commonly used for adaptive control and prediction.This paper proposes a method for dynamically aggregating large-scale adjustable loads to support high proportions of new energy integration,aiming to study the aggregation characteristics of regional large-scale adjustable loads using online identification techniques and feature extraction methods.The experiment selected 300 central air conditioners as the research subject and analyzed their regulation characteristics,economic efficiency,and comfort.The experimental results show that as the adjustment time of the air conditioner increases from 5 minutes to 35 minutes,the stable adjustment quantity during the adjustment period decreases from 28.46 to 3.57,indicating that air conditioning loads can be controlled over a long period and have better adjustment effects in the short term.Overall,the experimental results of this paper demonstrate that analyzing the aggregation characteristics of regional large-scale adjustable loads using online identification techniques and feature extraction algorithms is effective.

Noise‐tolerant matched filter scheme supplemented with neural dynamics algorithm for sea island extraction

Achieving high‐precision extraction of sea islands from high‐resolution satellite remote sensing images is crucial for effective resource development and sustainable management.Unfortunately,achieving such accuracy for sea island extraction presents significant challenges due to the presence of extensive background interference.A more widely applicable noise‐tolerant matched filter(NTMF)scheme is proposed for sea island extraction based on the MF scheme.The NTMF scheme effectively suppresses the background interference,leading to more accurate and robust sea island extraction.To further enhance the accuracy and robustness of the NTMF scheme,a neural dynamics algorithm is supplemented that adds an error integration feedback term to counter noise interference during internal computer operations in practical applications.Several comparative experiments were conducted on various remote sensing images of sea islands under different noisy working conditions to demonstrate the superiority of the proposed neural dynamics algorithm‐assisted NTMF scheme.These experiments confirm the ad-vantages of using the NTMF scheme for sea island extraction with the assistance of neural dynamics algorithm.

Experimental investigation on coal pore-fracture variation and fractal characteristics synergistically affected by solvents for improving clean gas extraction

Chemical solvents instead of pure water being as hydraulic fracturing fluid could effectively increase permeability and improve clean methane extraction efficiency.However,pore-fracture variation features of lean coal synergistically affected by solvents have not been fully understood.Ultrasonic testing,nuclear magnetic resonance analysis,liquid phase mass spectrometry was adopted to comprehensively analyze pore-fracture change characteristics of lean coal treated by combined solvent(NMP and CS_(2)).Meanwhile,quantitative characterization of above changing properties was conducted using geometric fractal theory.Relationship model between permeability,fractal dimension and porosity were established.Results indicate that the end face fractures of coal are well developed after CS2and combined solvent treatments,of which,end face box-counting fractal dimensions range from 1.1227 to 1.4767.Maximum decreases in ultrasonic longitudinal wave velocity of coal affected by NMP,CS_(2)and combined solvent are 2.700%,20.521%,22.454%,respectively.Solvent treatments could lead to increasing amount of both mesopores and macropores.Decrease ratio of fractal dimension Dsis 0.259%–2.159%,while permeability increases ratio of NMR ranges from 0.1904 to 6.4486.Meanwhile,combined solvent could dissolve coal polar and non-polar small molecules and expand flow space.Results could provide reference for solvent selection and parameter optimization of permeability-enhancement technology.

Characteristics and mechanism of Ni^(2+)and Cd^(2+)adsorption by recovered perlite from agar extraction residue

Ni^(2+)and Cd^(2+)in wastewater accumulated through the ecological chain and could jeopardize human health.Adsorption of Ni^(2+)and Cd^(2+)from wastewater using recovered perlite was an important way to solve the problem of resource utilization of solid waste from agar production.Our previous study confirmed that recovered perlite from agar extraction residue had better pore size and specific surface area than commercial perlite.However,the adsorption efficiency and adsorption mechanism of recovered perlite were the main factors limiting its adsorption application.The adsorption process of Ni^(2+)and Cd^(2+)by recovered perlite in aqueous solution was described by the pseudo-second-order kinetic equation,and the relevant adsorption mechanism was mainly chemisorption.Compared with commercial perlite,the adsorption removal rate of Ni^(2+)and Cd^(2+)by enzymatic recovered perlite could reach 92.9%and 89.2%,respectively,and were improved by 12.63%and 13.03%.Langmuir isothermal adsorption model could better describe the isothermal adsorption process of recovered perlite on heavy metal Ni^(2+)and Cd^(2+),and the relevant adsorption mechanism was mainly monolayer adsorption.The X-ray photoelectron spectroscopy(XPS)results indicated that the decrease of Si—O Si^(2+)hydroxyl coordination bond and the increase of C—Si bond might make the binding effect of recovered perlite with heavy metals stronger.The competitive adsorption of Ni^(2+)and Cd^(2+)by recovered perlite was still dominated by chemisorption and monolayer adsorption.This study was expected to provide a theoretical basis and technical support for the removal of Ni^(2+)and Cd^(2+)from wastewater using recovered perlite from seaweed residue.

Design method of extractant for liquid-liquid extraction based on elements and chemical bonds

In the petrochemical industry process, the relative volatility between the components to be separated is close to one or the azeotrope that systems are difficult to separate. Liquid-liquid extraction is a common and effective separation method, and selecting an extraction agent is the key to extraction technology research. In this paper, a design method of extractants based on elements and chemical bonds was proposed. A knowledge-based molecular design method was adopted to pre-select elements and chemical bond groups. The molecules were automatically synthesized according to specific combination rules to avoid the problem of “combination explosion” of molecules. The target properties of the extractant were set, and the extractant meeting the requirements was selected by predicting the correlation physical properties of the generated molecules. Based on the separation performance of the extractant in liquid-liquid extraction and the relative importance of each index, the fuzzy comprehensive evaluation membership function was established, the analytic hierarchy process determined the mass ratio of each index, and the consistency test results were passed. The results of case study based on quantum chemical analysis demonstrated that effective determination of extractants for the analysis of benzene-cyclohexane systems. The results unanimously prove that the method has important theoretical significance and application value.

Kinetics of cerium(Ⅳ) and fluoride extraction from sulfuric solutions using bifunctional ionic liquid extractant(Bif-ILE)[A336][P204]

The extraction kinetics of Ce（Ⅳ） and Ce（Ⅳ）-F^- mixture systems from sulfuric solutions to n-heptane solution containing Bif-ILE[A336][P204]（[trialkylmethylammonium][di-2-ethylhewanxylphosphinate]） with a constant interfacial area cell with laminar flow were studied,just to elucidate the extraction mechanism and the mass transfer models.The data were analyzed in terms of pseudo-first-order constants.The effects of stirring speed,specific interfacial area and temperature on the extraction rate in both systems were discussed,suggesting that the extractions were mixed bulk phases-interfacial control process.Supported by the experimental data,the corresponding rate equations for Ce（Ⅳ） extraction system and Ce（Ⅳ）-F^- mixture extraction system were obtained.The experimental results indicated the rate-controlling step.The kinetics model was deduced from the rate-controlling step and consistent with the rate equation.

ZIF-67/CS对阳离子染料孔雀石绿的吸附性能研究

针对传统吸附剂与水相分离困难的问题,设计并制备了一种环境友好、成本低廉的壳聚糖复合材料ZIF-67/CS。针对吸附剂对孔雀石绿(MG)污染物的吸附性能,考察了污染物浓度、接触时间、吸附剂用量、pH和离子强度对其吸附性能的影响。利用XRD、SEM、FT-IR、TG等对其结构、形貌及热稳定性进行了表征。结果表明,在吸附实验中,303.15 K时ZIF-67/CS对MG的吸附等温线符合Temkin等温吸附模型;吸附动力学拟合结果表明,ZIF-67/CS对MG的吸附行为符合拟二级吸附动力学模型;吸附热力学结果表明吸附过程是自发的、吸热的。ZIF-67/CS对MG的吸附是一个复杂的化学吸附过程,主要由速率决定。

基于MCS-SBL算法的配电网故障定位方法

配电网拓扑结构复杂,传统方法往往需要大量测点信息且难以实现快速有效的故障定位,本文提出基于少量测点信息的故障定位方法。首先,利用等效原理建立一个欠定的故障节点电压方程;其次,利用多重测量向量模型的贝叶斯压缩感知算法求解方程,根据重构稀疏电流矩阵的非零元素位置求解故障区域,实现故障定位;最后,在IEEE33节点配电系统上进行仿真实验,结果表明,所提方法仅需要少量测点的故障前后正序电压分量便可有效定位故障,计算速度较快,并且基本不受故障类型、过渡电阻的影响,同时适用于单故障和多重故障的场景,具有较强的抗噪能力。

PVA/CS多孔复合材料的制备及其对甲基橙的吸附性能研究

现阶段随着印染行业迅速发展,在为大众提供更多选择的同时,也导致污染问题日益严重。印染行业生产过程中,不可避免使用颜料和染料为其产品上色,此过程中会有污染物产生。目前,关于染料治理的研究得到重点关注。本文以聚乙烯醇/壳聚糖(PVA/CS)这一多孔复合材料为基础,探究该材料制备工艺,并通过实验,证明其对酸性染料的吸附性能。最终结果表明:制备的PVA/CS多孔复合材料,具备吸附酸性染料的功能,尤其是吸附甲基橙这一纺织工业常用染料效果良好。

基于CLIL 4Cs框架的高中英语教材对比分析

教材分析是教材编写的重要板块和教师教学的基本前提。文章采用内容分析法,基于CLIL模式下的4Cs课程框架,从内容、语言、文化和认知四个维度,对比分析人教版和外研社版高中英语教材的特点与差异。研究发现:两版教材单元主题所涉及的学科类型大体一致,人教版涉及民族学最多,外研社版涉及社会学和地理学最多;人教版教材不同语言知识与技能种类所占比重差异小,两版教材都偏重于语篇知识的学习与理解性技能的训练;两版教材文本所涉及的文化地域分布不均衡,人教版中本族语文化和目的语文化比例较多,外研社版中目的语文化和其他文化比例较多;两版教材体现的认知思维培养差异不显著,均侧重于低层次认知思维的培养,在高层次认知思维培养中,人教版侧重于分析思维的培养,外研社版侧重于评价思维的培养。基于上述研究结果,文章对高中英语教材编写和英语教学提出相应参考建议。

用于碳酸盐岩储层裂缝检测的GWO-CS-BP算法及应用研究

碳酸盐岩储层中的裂隙是油气的运移通道和储集空间,对于油气勘探、开发和评价都具有重要的指导意义。针对研究区碳酸盐岩储层裂缝检测的难题,提出灰狼布谷鸟优化BP算法(GWO-CS-BP),该算法是将GWO-CS(grey wolf-cuckoo search algorithm)与BP(back propagation)相结合形成的裂隙检测方法。将含裂缝信息的相干、曲率、倾角、方位角和构型张量等属性作为GWO-CS-BP神经网络的输入数据,在工区地质资料约束下根据测井数据获得裂缝发育水平评价指标,进而对研究区裂缝发育水平进行评价并划分等级。研究区碳酸盐岩储层裂缝发育水平检测结果表明,GWO-CS-BP算法能够综合各属性特点对研究区的裂缝发育水平特征进行二次误差控制,获得裂缝发育水平评价指标f s并将研究区裂缝发育水平划分为3个等级及4个裂缝存在区域。其中,当研究区裂缝发育水平参数的值适中时,即f s的值大于4.0且小于5.8时,C区域最有利于油气的聚集,高产井的分布数量较多。利用GWO-CS-BP算法对研究区的裂缝发育水平进行了精细评价,并得出裂隙发育水平参数f s,实现了GWO-CS算法改进的BP神经网络在裂缝检测中的有效应用。

Recovery of Li_(2)CO_(3)and FePO_(4)from spent LiFePO_(4)by coupling technics of isomorphic substitution leaching and solvent extraction

Efficient and low-cost recycling of spent lithium iron phosphate(LiFePO_(4),LFP)batteries has become an inevitable trend.In this study,an integrated closed-loop recycling strategy including isomorphic substitution leaching and solvent extraction process for spent LFP was proposed.An inexpensive FeCl_(3)was used as leaching agent to directly substitute Fe^(2+)from LFP.99%of Li can be rapidly leached in just 30 min,accompanied by 98%of FePO_(4)precipitated in lixivium.The tri-n-butyl phosphate(TBP)-sulfonated kerosene(SK)system was applied to extract Li from lixivium through a twelve-stage countercurrent process containing synchronous extraction and stepwise stripping of Li^(+)and Fe^(3+).80.81%of Li can be selectively enriched in stripping liquor containing 3.059 mol·L^(-1)of Li^(+)under optimal conditions.And the Fe stripping liquor was recovered for LFP re-leaching,of which,Fe^(2+)was oxidized to Fe^(3+)by appropriate H_(2)O_(2).Raffinate and lixivium were concentrated and entered into extraction process to accomplished closeloop recycling process.Overall,the results suggest that more than 99%of Li was recovered.FeCl_(3)holding in solution was directly regenerated without any pollutant emission.The sustainable mothed would be an alternative candidate for total element recycling of spent LFP batteries with industrial potential.

表面改性Fe/CS调控CO加氢产物分布研究

CO加氢经费托合成制取高附加值化学品是实现煤炭清洁高效利用的重要途径之一,研发高效催化剂是实现产物分布定向调控、提高目标产物选择性并抑制C1副产物生成的关键。催化剂表面性质对CO的吸附活化、加氢活性和产物分布具有重要影响。以无水葡萄糖为碳源、乙二醇为溶剂,采用溶剂热法制得碳载体,经H_(2)O_(2)、NH_(3)•H_(2)O表面改性和掺氮处理后,采用浸渍法分别制备了5Fe/CS-H_(2)O_(2)、5Fe/CS-NH_(3)•H_(2)O和5Fe/CS-N催化剂,探究了表面改性对费托合成产物分布的影响。采用XRD、SEM、TEM、N_(2)吸/脱附、TG-DTG、FT-IR、Zeta电位、XPS和拉曼光谱等对样品进行了表征。结果表明,不同表面改性方式对催化剂表面物化性质和催化性能影响显著。H_(2)O_(2)改性增加了催化剂表面—OH的数量,增强了表面亲水性,促进了Fe在载体上的分散,催化剂的热稳定性提高。在300℃、1.5MPa、空速为1000h^(-1)和n(H_(2)):n(CO)=2的条件下进行CO加氢反应活性测试结果表明,改性后的催化剂显著抑制了CH4的生成,提高了低碳烯烃选择性,从5Fe/CS的24.39%分别提高到5Fe/CS-NH_(3)•H_(2)O的34.94%、5Fe/CS-N的37.63%以及5Fe/CS-H_(2)O_(2)的43.57%。通过表面改性和掺氮处理调控催化剂表面性质实现了对产物分布的优化。

Cs/O沉积Na_(2)KSb光电阴极表面的第一性原理研究

Na_(2)KSb光电阴极在光电倍增管、图像增强器、真空电子源等领域具有重要应用.为指导高灵敏度Na_(2)KSb光电阴极的制备,采用第一性原理计算方法,研究不同表面取向和原子终止面的Na_(2)KSb表面模型,获得稳定且最有利于电子发射的表面结构.基于该表面进一步研究了不同覆盖度下的Cs原子沉积和Cs/O原子共沉积对Na_(2)KSb表面电子结构和光学性质的影响.对比表面能、吸附能和吸附前后的功函数结果表明,Na_(2)KSb(111)K表面具有优越的电子发射能力以及良好的稳定性.当Na_(2)KSb(111)K表面吸附2/4单层的Cs原子和1/4单层O原子时,获得最大功函数下降量0.16 eV.表面吸附Cs/O原子有利于电荷往表面上方转移,并产生电荷累积,能形成有效表面偶极矩.通过分析能带结构和态密度,发现吸附Cs原子对导带底存在额外的能带贡献,且引入O原子吸附后价带发生上移.此外,吸附Cs/O原子有利于增强表面近红外光吸收,但是会导致表面紫外和可见光吸收变差.

The extraction of aromatics using N-methylpyrrolidone: Liquid-liquidequilibrium determination and mechanism exploration

LLE data of cyclooctane/3-methylpentane + benzene/toluene + N-methylpyrrolidone (NMP) at 298.15 Kand 313.15 K under a pressure of 101.3 kPa were measured in this work. The Othmer-Tobias and Handequations were adopted to validate the reliability of LLE data, where the correlation coefficients (R2) wereclose to unity, indicating the high reliability of the experimental data. The experimental data were analyzed using the distribution coefficient (D) and separation factor (S), and the effect of NMP extracting benzene and toluene from aromatics was explored. Meanwhile, the reason for the different extractionefficiencies of benzene and toluene using NMP was analyzed by quantum chemical calculations. TheNRTL and UNIQUAC thermodynamic models were used to correlate the liquid–liquid equilibrium data,and the relevant binary interaction parameters were obtained. The calculated root mean square deviation(RMSD) were all less than 0.0063, indicating that the obtained binary interaction parameters can be usedto simulate and calculate the extraction of aromatics using NMP.

基于绿色低共熔溶剂CS-1的TATB新型纯化方法与机理

为了解决TATB因溶解性差不适用于常规纯化方法的问题,采用反萃取技术,选用对TATB具有良好溶解性的新型绿色低共熔溶剂(CS-1),以水为反萃取剂,进行了TATB的纯化;对比了该法与其它纯化方法的不同,系统优化了该法中反萃取剂加入量、洗涤次数及干燥方式等条件对TATB的纯化影响,构建了纯度为(99.7±0.2)%,回收率为92.5%的TATB高效分离与绿色纯化方法。研究同时采用光谱过程监测和理论计算模拟,基于CS-1溶剂的TATB纯化动力学,探讨了基于氢键竞争和络合物解离的TATB纯化机制。