Discussion on the application prospect of the transient electromagnetic method based on the dual launcher and mine advanced detection

The dual transmitter implements the equivalent anti-magnetic flux transient electromagnetic method, which can effectively reduce the scope of the transient electromagnetic detection blind area. However, this method is rarely reported in the detection of pipelines in urban geophysical exploration and the application of coal mines. Based on this, this paper realizes the equivalent anti-magnetic flux transient electromagnetic method based on the dual launcher. The suppression effect of this method on the blind area is analyzed by physical simulation. And the detection experiment of underground pipelines is carried out outdoors. The results show that the dual launcher can significantly reduce the turn-off time, thereby effectively reducing the impact of the blind area on the detection results, and the pipeline detection results verify the device’s effectiveness. Finally, based on the ground experimental results, the application prospect of mine advanced detection is discussed. Compared with other detection fields, the formation of blind areas is mainly caused by the equipment. If the dual launcher can be used to reduce the blind area, the accuracy of advanced detection can be improved more effectively. The above research results are of great significance for improving the detection accuracy of the underground transient electromagnetic method.

Dissolution of antibiotics mycelium in ionic liquids:Performance and mechanism

Antibiotics mycelium, byproduct of pharmaceutical industry, contains high percentage of proteins, polysaccharides and lipids, while, the low solubility in traditional solvents limits its utilization. The dissolution process of penicillin mycelium was investigated using ionic liquids(ILs) as solvent. Quantitative correlation of solubility and ILs structure and dissolution mechanism were determined. About 91.45% of penicillin mycelium was dissolved in 1-butyl-3-methylimidazolium acetate([Bmim]Ac) under the condition of 120.0 ℃ and [Bmim]Ac/mycelium(m/m) ratio of 3.90:1. Synergistic effect of ILs and DMSO was confirmed with the DMSO/[Bmim]Ac(v/m) ratio in the range of 0.0-1.0. At 25.0 ℃, the dissolution of penicillin mycelium increased from 69.74% to94.50%, with the ratio of DMSO to [Bmim]Ac(v/m) as 1:1. The room temperature dissolution of mycelium provides a novel and energy-saving process for its high-valued utilization. The NMR and FT-IR spectra showed that hydrogen bonds are the dominant driving force for the dissolution in ILs. Quantitative study on the effects of anions and cations of ILs on dissolution using Kamlet-Taft model showed that there was a linearly positive correlation between solubility of penicillin mycelium and(3 parameter of the ILs. The solubility of mycelium increased with increasing hydrogen bond accepting ability of anions and donating ability of cations.

Development trend and prospect of solid phase extraction technology

Solid phase extraction is widely used in sample pretreatment,concentration and analysis processes due to high selectivity and suitability for low concentration sample system.In this review,we systematically summarized and discussed the development trends of solid phase extraction by bibliometrics method.By analyzing papers output scale,the research and development direction of solid phase extraction technology is prospected.We also give an overview on current strategies of novel solid phase extraction from the separation medium and separation technology.The paper aims to describe the global research profile and the development trends of solid phase extraction,to help researchers to accurately grasp the research trend and to provide support for scientific research institutions to formulate scientific policies and strategic plans.Furthermore,the prospect of the development and application of solid phase extraction is also discussed.

Three-liquid-phase extraction and separation of V(V) and Cr(VI) from acidic leach solutions of high-chromium vanadium–titanium magnetite

A new method by liquid–liquid–liquid three phase system, consisting of acidified primary amine N1923(abbreviated as A-N1923), poly(ethylene glycol)(PEG) and (NH_4)_2SO_4 aqueous solution, was suggested for the separation and simultaneous extraction of V(V) and Cr(VI) from the acidic leach solutions of highchromium vanadium–titanium magnetite. Experimental results indicated that V(V) and Cr(VI) could be selectively enriched into the A-N1923 organic top phase and PEG-rich middle phase, respectively, while Al(III)and other co-existing impurity ions, such as Si(IV), Fe(III), Ti(IV), Mg(II) and Ca(II) in acidic leach solutions,could be enriched in the(NH_4)_2SO_4 bottom aqueous phase. During the process for extraction and separation of V(V) and Cr(VI), almost all of impurity ions could be removed. The separation factors between V(V) and Cr(VI) could reach 630 and 908, respectively in the organic top phase and PEG middle phase, and yields of recovered V(V) and Cr(VI) in the top phase and middle phase respectively were all above 90%.Various effects including aqueous p H, A-N1923 concentration, PEG added amount and(NH_4)_2SO_4 concentration on three-phase partitioning of V(V) and Cr(VI) were discussed. It was found that the partition of Cr(VI) into the PEG-rich middle phase was driven by hydrophobic interaction, while extraction of V(V) by A-N1923 resulted of anion exchange between NO_3^- and H_2V_(10)O_(28)^(-4). Stripping of V(V) and Cr(VI) from the top organic phase and the middle PEG-rich phase were achieved by mixing respectively with NaNO_3 aqueous solutions and Na OH-((NH_4)_2SO_4 solutions. The present work highlights a new approach for the extraction and purification of V and Cr from the complex multi-metal co-existing acidic leach solutions of high-chromium vanadium–titanium magnetite.

Grouping separation of mixed rare earths from their coexisting aqueous solutions by liquid-column elution

A new approach was proposed for grouping separation of 14 lanthanide rare-earth ions from their coexisting mixed aqueous solutions, by performing liquid-column elution using the aqueous solution containing 14 lanthanide rare-earth ions as the stationary phase and the dispersed organic oil droplets containing P507 extractant as the mobile phase. It was revealed that 14 lanthanide rare-earth ions could be separated into four groups, according to the lanthanide tetrad effect, respectively eluting out from the liquid column at different time in a certain order. Various effects including the saponification degree of P507, the concentration of P507 in organic phase, the length and inner diameter of the extraction column on the performance of grouping separation of rare-earth ions were discussed. The changes of the mass transfer coefficients were also investigated. The separation efficiency of the four groups of rareearth elements(REEs) was evaluated based on the elution resolution, Rs, of the elution peaks of La(Ⅲ),Gd(Ⅲ), Ho(Ⅲ) and Lu(Ⅲ), the four representative elements respectively from each of the four groups of REEs. Experimental results demonstrated that the separation of REEs by liquid-column elution mainly depended on the competitive adsorption of different rare-earth groups onto the surface of ascending P507 oil droplets. The affinity of different rare-earth groups with P507 extractant and a limited adsorption capacity of P507 molecules at the surface of the oil droplets ascending in liquid column play the important role. The present work highlights a promising technique for grouping separation of multiple lanthanide elements co-existing complex systems.

A novel constant interfacial area cell for determining the extraction kinetics of Er(Ⅲ) from chloride medium

A novel constant interfacial area cell(NCIAC),by spatially separating the agitation from liquid flow circulation of organic and aqueous two phases,was suggested to obtain detailed kinetic data for Er(Ⅲ) extraction from chloride medium by 2-ethyl-hexyl-phosphonic acid mono-(2-ethylhexyl) ester(EHEHPA).Different from the traditional Lewis cell and the constant interfacial area cell with laminar flow,the concentrations of Er(Ⅲ) in organic and aqueous two phases were uniform,and the stability of the interfacial area between the two phases could be controlled effectively.Therefore,the special requirements for the design of agitators in the traditional Lewis cell and the constant interfacial area cell for minimizing the influence of diffusion resistance could be avoided.Experimental results indicated that the extraction kinetics was mainly affected by the aqueous flow rate,interfacial area between organic and aqueous two phases,and the aqueous p H values.An extraction kinetic equation was suggested based on the experimental data.

Kinetics and the difference for extraction of praseodymium and neodymium from nitrate aqueous solution by [A336][NO_3] using the single drop technique

The kinetics and the difference for Pr(Ⅲ)and Nd(Ⅲ)extraction from nitrate aqueous solution using trialkylmethylammonium nitrate([A336][NO3])as extractant were investigated by the single drop technique.The dependence of the extraction rate of Pr(Ⅲ)and Nd(Ⅲ)on the concentrations of free Pr(Ⅲ)and Nd(Ⅲ)ions,the concentrations of Na NO3 and H+in aqueous solutions,and the concentrations of[A336][NO3]in kerosene solutions were discussed and the corresponding extraction rate equations for Pr(Ⅲ)and Nd(Ⅲ)were obtained.These equations demonstrated that the reaction rate constant of Pr(Ⅲ)with[A336][NO3]was double than that of Nd(Ⅲ).The effect of the addition of diethylenetriaminepentaacetic acid(DTPA)on the difference in the extraction rate of Pr(Ⅲ)and Nd(Ⅲ)by[A336][NO3]was also investigated.It was revealed that the difference in the complex formation rates of Pr(Ⅲ)and Nd(Ⅲ)with DTPA made a significant impact on the difference in the extraction rates of Pr(Ⅲ)and Nd(Ⅲ)with[A336][NO3].The ratio of extraction rates of Pr(Ⅲ)to Nd(Ⅲ)with[A336][NO3]was in proportion to the ratio of complex formation rates of Pr(Ⅲ)to Nd(Ⅲ)with DTPA.The extraction rate difference for Pr(Ⅲ)and Nd(Ⅲ)with[A336][NO3]increased due to a higher complex formation rate constant of DTPA with the free and un-complexed Nd(Ⅲ)ions in the aqueous nitrate solution than that with Pr(Ⅲ)ions.Therefore,the addition of DTPA in the aqueous nitrate solution is an effective method to intensify the separation of Pr(Ⅲ)and Nd(Ⅲ)in kinetics.The study on the extraction mechanism indicated that both the extraction of Pr(Ⅲ)and Nd(Ⅲ)by[A336][NO3]were diffusion controlled,and the reactions obeyed SN2 mechanism.The present work highlights a possible approach to strengthen the kinetic separation of Pr(Ⅲ)and Nd(Ⅲ).

Novel magnetic carbon supported molybdenum disulfide catalyst and its application in residue upgrading

A novel hybrid material consisted of carbon covered Fe_(3)O_(4)nanoparticles and MoS_(2)nanoflower(FCM)was designed and prepared by micelle-assisted hydrothermal methods.Multiple techniques,including X-Ray diffraction(XRD),high-resolution transmission electron microscopy(HRTEM)and X-ray photoelectron spectroscopy(XPS)were employed to characterize it.The results show that FCM has a flower-like morphology with a 330 nm Fe_(3)O_(4)core as well as 70 nm highly crystalline MoS_(2)shell.FCM is superparamagnetic with a saturation magnetization of 35 emu g-1.Then hydrocracking of Canadian bitumen residue(CBR)was applied to estimate its catalytic activity.The results show that FCM exhibits superior catalytic hydrocracking activity compared to bulk MoS_(2)and commercial oil-dispersed Mo(CO)6 by the same Mo loading.Further measurement by elemental analysis,XPS and XRD reveals that the MoS_(2)nanoflower with abundant catalytic active sites and covered carbon layer with anti-coke ability donate to the superior upgrading performance.Besides,the catalysts can be easily recovered by the external magnetic field.This work provides a novel kind magnetic nanocatalyst which is potential for slurry-phase hydrocracking applications.■2020,Institute of Process Engineering,Chinese Academy of Sciences.Publishing services by Elsevier B.V.on behalf of KeAi Communications Co.,Ltd.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).

Mild stir-assisted membrane dispersion for enhancing propionic acid extraction

Mild stir-assisted membrane dispersion extraction(MDE) method was employed to enhance propionic acid(HA)extraction and compared to the mechanical stirred extraction(MSE) method. Triocylamine(TOA) and tributyl phosphate(TBP) were chosen as model extractant to extract HA. Firstly, droplet size and the size distribution of organic phase were analyzed, and then the effects of phase ratio, extractant and HA concentration on extraction performance were investigated. Comparing the two extraction methods, the results show mild stir-assisted MDE method reduced the mass transfer equilibrium time compared to MSE method. The mass transfer mechanism was explored by analyzing mass transfer resistance. Mild stir-assisted MDE had less total mass transfer resistance than MSE. When the extractant concentration was 40%, the extraction process was controlled by organic phase mass transfer process with HA volume fraction was 1% and controlled by both of reaction process and organic phase mass transfer process when HA concentration increased to 5%. This work may provide a new type of extraction method for the recovery of organic carboxylic acid.

Stability of penicillin G in ionic liquid [Bmim]PF_6

The extraction of penicillin G by ionic liquid[Bmim]PF_6 has exhibited promising prospect.The stability of penicillin G is crucial for developing a green ionic liquid-based extraction technology.In this work,the stability of penicillin G in[Bmim]PF_6 was systematically investigated.The results showed the stability of penicillin G was significantly influenced by pH and temperature.It tended to be more stable when pH value increased from 1.5 to 4.0 and the temperature gradually decreased.The half-life(t_(1/2))of penicillin G in[Bmim]PF_6 was 17.7 h in the optimal technological condition(pH 2.0 and 10°C),which is enough for the requirement of extraction technology.The reaction of penicillin G in[Bmim]PF_6 followed the first order kinetics in the pH range 2.0–4.0.Three isomers of penicillin G were found through rearrangement at pH 2.0,and their structures were not affected by temperature.

Interfacial engineering of transition-metal sulfides heterostructures with built-in electric-field effects for enhanced oxygen evolution reaction

Developing highly efficient,durable,and non-noble electrocatalysts for the sluggish anodic oxygen evolution reaction(OER)is the pivotal for meeting the practical demand in water splitting.However,the current transition-metal electrocatalysts still suffer from low activity and durability on account of poor interfacial reaction kinetics.In this work,a facile solid-state synthesis strategy is developed to construct transition-metal sulfides heterostructures(denoted as MS_(2)/NiS_(2),M=Mo or W)for boosting OER electrocatalysis.As a result,MoS2/NiS2 and WS2/NiS2 show lower overpotentials of 300 mV and 320 mV to achieve the current density of 10 mA·cm^(-2),and smaller Tafel slopes of 60 mV.dec^(-1) and 83 mV.dec^(-1)in 1 mol·L^(-1) KOH,respectively,in comparison with the single MoS2,WS2,NiS2,as well as even the benchmark RuO2.The experiments reveal that the designed heterostructures have strong electronic interactions and spontaneously develop a built-in electric field at the heterointerface with uneven charge distribution based on the difference of band structures,which promote interfacial charge transfer,improve absorptivity of OH-,and modulate the energy level more comparable to the OER.Thus,the designed transition-metal sulfides heterostructures exhibit a remarkably high electrocatalytic activity for OER.This study provides a simple strategy to manipulate the heterostructure interface via an energy level engineering method for OER and can be extended to fabricate other heterostructures for various energy-related applications.

Overview of Trends in Global Single Cell Research Based on Bibliometric Analysis and LDA Model(2009–2019)

Purpose:This article aims to describe the global research profile and the development trends of single cell research from the perspective of bibliometric analysis and semantic mining.Design/methodology/approach:The literatures on single cell research were extracted from Clarivate Analytic’s Web of Science Core Collection between 2009 and 2019.Firstly,bibliometric analyses were performed with Thomson Data Analyzer(TDA).Secondly,topic identification and evolution trends of single cell research was conducted through the LDA topic model.Thirdly,taking the post-discretized method which is used for topic evolution analysis for reference,the topics were also be dispersed to countries to detect the spatial distribution.Findings:The publication of single cell research shows significantly increasing tendency in the last decade.The topics of single cell research field can be divided into three categories,which respectively refers to single cell research methods,mechanism of biological process,and clinical application of single cell technologies.The different trends of these categories indicate that technological innovation drives the development of applied research.The continuous and rapid growth of the topic strength in the field of cancer diagnosis and treatment indicates that this research topic has received extensive attention in recent years.The topic distributions of some countries are relatively balanced,while for the other countries,several topics show significant superiority.Research limitations:The analyzed data of this study only contain those were included in the Web of Science Core Collection.Practical implications:This study provides insights into the research progress regarding single cell field and identifies the most concerned topics which reflect potential opportunities and challenges.The national topic distribution analysis based on the post-discretized analysis method extends topic analysis from time dimension to space dimension.Originality/value:This paper combines bibliometric analysis and LDA model to analyze the evolution trends of single cell research field.The method of extending post-discretized analysis from time dimension to space dimension is distinctive and insightful.

Chen Jiayong:Pioneer in hydrometallurgy and chemical engineering disciplines

Dr.Chen Jiayong(Chia-Yung)was born on Feb.17,1922 in a prestigous intellectual clan at Jintang County,Sichuan Province,China.After receiving early education at the Chengdu County Middle School(now Chengdu 7th School),he was admitted as an undergraduate student to the Department of Chemical Engineering,the National Central University at the city of Chongqing from 1939 through 1943 during the Anti-Japanese War.After graduation,he continued to work as a teaching assistant for both the inorganic and organic chemistry courses.

磁性Fe3O4@SiO2颗粒结构对其吸附DNA的影响

采用共沉淀法和水热法制备了不同结构的超顺磁性Fe3O4@SiO2纳米颗粒,对其进行表征,研究了其吸附DNA的性能及磁分离性能.结果表明,20-750nm范围内粒径较大的颗粒与DNA结合时可提供更多单位平面结合位点,使结合的稳定性和结合几率增加,DNA结合量提高.不同核-壳结构的Fe3O4@SiO2纳米颗粒的磁分离响应时间不同,内核大小相近时,壳层厚度增加会导致颗粒在磁场中受到的磁力与阻力的比值减小,磁响应时间增加,DNA回收率降低.粒径约为200nm的Fe3O4@SiO2纳米颗粒用于纯化全血中DNA最好,提取率为95.2%,磁响应时间为10s.

绿色分离技术发展态势与展望

进入21世纪以来,绿色分离技术不断创新,新型绿色分离技术不断涌现,应用领域逐步拓展。本工作对绿色分离技术领域论文的产出规模、学术影响力、学科布局、国际合作等相关指标进行了文献计量分析,并对各项绿色分离技术进行比较分析,同时比较了中国与世界相关国家的研究实力,旨在了解中国与世界绿色分离技术的发展态势,为制定绿色分离技术发展战略和学科政策、科研工作者选择科研方向、企业投资决策等提供有益的参考。要点:(1)对绿色分离技术领域论文的产出规模、国际合作等相关指标进行了文献计量分析。(2)对各国绿色分离技术的特点进行比较分析,分析了中国与世界相关国家研究实力的差距。(3)从学科发展和产业战略需求两个方面展望了中国绿色分离技术的发展。

Enhanced separation of praseodymium and neodymium by kinetic“push and pull”system of[A336][NO3]-DTPA in a column extractor

A new approach was suggested in present work for improving the separation between Pr(Ⅲ) and Nd(Ⅲ)by a so-called kinetic "push and pull" system consisting of [A336][NO3] and DTPA in a column extractor.It is revealed that,when organic extractant [A336][NO3] is continuously pumped into the column extractor in the form of dispersed oil droplets and at the same time DTPA was injected into the aqueous feed solution whet the extraction was just started,the separatiot factor of Pr(Ⅲ) to Nd(Ⅲ),βPr/Nd,increased obviously with the time,and could even achieve 21.7.Such an amazing increase in βPr/Nd value might be due to the extraction rate of Pr(Ⅲ) by [A336][NO3] oil droplets being faster than that of Nd(Ⅲ),while the complexing rate of Nd(Ⅲ) with DTPA in the aqueous solutions being faster than that of Pr(III).The opposite order of the two rates for Pr(Ⅲ) and Nd(Ⅲ) result in their kinetic "push and pull" separation.In contrast,the βPr/Nd value in traditional thermodynamic separation reported in previous literatures is only around 5 or even less,even though using the same extractant [A336][NO3] and DTPA but by previously adding DTPA into the aqueous feed solutions for pre-complexing of Pr(Ⅲ) and Nd(Ⅲ).Various effects from the pH and addition amount of DTPA aqueous solutions,LiNO3 concentrations in initial aqueous feed solutions,the initial concentration ratios of Pr(Ⅲ) to Nd(Ⅲ) ions,the initial pH of aqueous feed solutions,and the concentrations of [A336][NO3] in organic phases,on the kinetic separatiot of Pr(Ⅲ) and Nd(Ⅲ) are discussed.The present work highlights a promising approach for separation of rare earths or other targets with extreme similarity in physicochemical properties.

Magnetically rotational reactor for absorbing benzene emissions by ionic liquids

A magnetically rotational reactor (MRR) has been developed and used in absorbing benzene emissions. The MRR has a permanent magnet core and uses magnetic ionic liquid [bmim]FeCl4 as absorbent. Benzene emissions were carried by N2 into the MRR and were absorbed by the magnetic ionic liquid. The rotation of the permanent magnet core provided impetus for the agitation of the magnetic ionic liquid, enhancing mass transfer and making benzene better dispersed in the absorbent. 0.68 g benzene emissions could be absorbed by a gram of [bmim]FeCl4, 0.27 and 0.40 g/g higher than that by [bmim]PF6 and [bmim]BF4, respectively. The absorption rate increased with increasing rotation rate of the permanent magnet.

Polystyrene microsphere-immobilized palladium(Ⅱ)porphyrin as mild,reusable,and highly efficient catalyst for Heck reaction

A novel Heck reaction catalyst consisting of a palladium(Ⅱ) complex of meso-tetra(phydroxyphenyl)porphyrin(MTP) and cross-linked chloromethylated polystyrene microspheres(PMs) was successfully prepared via covalent ether bonds between the chloride groups in the PMs and the hydroxyl groups in MTP.The catalyst was characterized using scanning electron microscopy,Fourier-transform infrared spectroscopy,and inductively coupled plasma atomic emission spectroscopy(ICP-AES).This polystyrene-supported palladium-complex was an efficient heterogeneous catalyst for cross-coupling of aryl iodides with ethyl acrylate.The reaction of iodobenzene and ethyl acrylate under N_2 at 100 ℃ and a catalyst concentration of 0.1%gave a gas chromatography product yield of 99.8%,which is much higher than that achieved using a free palladium(Ⅱ) complex of MTP as the catalyst(41.3%).The catalyst was recycled up to six times without significant loss of catalytic activity.These results suggest that the immobilized palladium(Ⅱ)-MTP catalyst has potential applications in synthetic and industrial chemistry.

Extraction kinetics and kinetic separation of La(Ⅲ),Gd(Ⅲ),Ho(Ⅲ) and Lu(Ⅲ) from chloride medium by HEHEHP

Acco rding to the tetrad-effect,14 elements of lanthanides can be divided into four groups.In our previous study,a new approach was proposed for the kinetic separation of four rare earth ions La(Ⅲ),Gd(Ⅲ),Ho(Ⅲ) and Lu(Ⅲ) coming from four groups.In that study,four rare-earth ions were kinetically separated from their coexisting mixed aqueous solutions,by performing liquid-column elution using the aqueous solution containing four lanthanide rare-earth ions as the stationary phase and the dispersed organic oil droplets containing HEHEHP(2-ethyl hexyl phosphonic acid mono 2-ethyl hexyl ester) extractant as the mobile phase.The study of extraction kinetics is very important for understanding the kinetic separation of rare earth ions,which was carried out in this paper.The extraction kinetics of La(Ⅲ),Gd(Ⅲ),Ho(Ⅲ) and Lu(Ⅲ) by HEHEHP diluted in heptane were investigated using single drop method.The different parameters affecting the extraction rate such as column length,specific interfacial area,rare earth ion concentration,extractant concentration,hydrogen ion concentration and temperature were separately studied and the rate equations are deduced.It is first order with respect to rare earth ion and HEHEHP concentrations,and negative first order with respect to hydrogen ion concentrations.The rate constants at 293.15 K are 10-6.23,10-5.73,10-5.58 and 10-5.43,respectively.The experimental results demonstrate that the extraction rate of La(Ⅲ), Gd(Ⅲ),Ho(Ⅲ) or Lu(Ⅲ) is diffusion-controlled,and the extraction reaction takes place at the interface rather than in the bulk phase.The extraction model was proposed.Besides,the kinetic separation of rare earth ions by HEHEHP oil drops was discussed.