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Preparation of Laser Cladding Coating Undercooling Cu-based Alloy and Co on Non-equilibrium Solidification Structure

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Journal of Wuhan University of Technology(Materials Science) 2024年第2期39卷 463-472页

作者：田徐铭 CAO shichao HOU Kai HOU Xiaopeng WANG Hongfu 张煜 Department of Outpatient Xinzhou People’s HospitalXinzhou 034099China School of Mechanical Engineering North University of ChinaTaiyuan 030051China Department of Neurosurgery Xinzhou People’s HospitalXinzhou 034099China Department of Orthopedics Xinzhou People’s HospitalXinzhou 034099China

The effect of the gradient content of Co element on the solidification process of Cu-based alloy under deep under cooling conditions was explored.The non-equilibrium solidification structure of the under cooled alloy samples were analyzed.It is found that the rapidly solidified alloy has undergone twice grain refinement during the undercooling process.Characterization and significance of the maximum undercooling refinement structure of Cu60Ni35Co5 at T=253 K were analyzed.High-density defects were observed,such as dislocations,stacking faults networks,and twinning structures.The standard FCC diffraction pattern represents that it is still a single-phase structure.Based on the metallographic diagram,EBSD and TEM data analysis,it is illustrated that the occurrence of grain refinement under high undercooling is due to stress induced recrystallization.In addition,the laser cladding technology is used to coat Co-based alloy(Stellite12) coating on 304 stainless steel substrate;the microstructure of the coating cross-section was analyzed.It was found that the microstructure of the cross-section is presented as columnar crystals,planar crystals,and disordered growth direction,so that the coating has better hardness and wear resistance.By electrochemical corrosion of the substrate and coating,it can be seen that the Co and Cr elements present in the coating are more likely to form a dense passivation film,which improved the corrosion resistance of the coating.

关键词： non-equilibrium solidification structure undercooling recrystallization laser cladding coating

Adsorption of rubidium ion from aqueous solution by surface ion imprinted materials

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Chinese Journal of Chemical Engineering 2023年第2期54卷 1-10页

作者： Zhongqi Ren Jie Wang Hewei Zhang Fan Zhang shichao tian Zhiyong Zhou State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

A new type of rubidium ion-imprinted polymer has been synthesized by the surface-imprinting technique using methacrylic acid as the functional monomer,the rubidium ion as the template,methanol as the solvent,and silica as a carrier.Ethylene glycol dimethacrylate and 2,2-azobisisobutyronitrile were used as acrosslinker and an initiator,respectively.In addition,based on the macrocyclic effect of crown ethers,the 18-crown-6 ligand was introduced as a ligand to fix the template ions better.Scanning electron microscopy,zeta-potential analysis,Fourier transform infrared spectroscopy,thermogravimetric analysis,and X-ray photoelectron spectroscopy were performed to characterize the ion-imprinted polymer.The effects of the preparation and adsorption conditions on the adsorption performance of the rubidium ion-imprinted polymer were investigated.The results indicated that the rubidium ion-imprinted polymer has high selectivity and faster kinetics than other adsorbents,with an equilibrium adsorption capacity of 200.19 mg·g^(-1)at 298 K within 25 min.The sorption isotherm was well described by the Freundlich isotherm model,while the adsorption kinetics fitted the pseudo-second-order kinetic model.Consecutive adsorption-desorption experiments showed that the ion-imprinted polymer had good chemical stability and reusability.

关键词： Surface-imprinted material Adsorption Aqueous solution Silica Selectivity

Comprehensive treatment of latex wastewater and resource utilization of concentrated liquid

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Chinese Journal of Chemical Engineering 2023年第5期57卷 183-192页

作者： shichao tian Yuming Tu Rujie Li Yufan Du Zhiyong Zhou Fan Zhang Zhongqi Ren State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

Latex wastewater is a kind of refractory organic wastewater containing high concentrations of organics and ammonia nitrogen.In this work,the combined process of forward osmosis(FO)and reverse osmosis(RO)was designed to treat the latex wastewater in the whole process,achieving the water recovery rate of 99%and basically no waste discharge after the catalytic oxidation process.The turbidity of the latex wastewater was decreased to below 1 NTU by microfiltration pretreatment,and then using MgCl_2 worked as the draw solution for FO process to treat the latex wastewater.Different operation conditions including adding acid or scale inhibitor as the pretreatment methods were conducted to improve the treatment performance of the combined process.After the treatment of the whole process,the concentration of COD was less than 20 mg·L^(-1),the concentration of NH_3-N was less than 10 mg·L^(-1),and the concentration of TP was less than 0.5 mg·L^(-1)for the treated latex wastewater.The water quality met standards of industrial water reuse after the complete analysis of the treated latex wastewater,meanwhile,useful substances of L-Quebrachitol(L-Q)were successfully extracted from the concentrated solution.Therefore,the combined process of FO and RO could realize the efficient treatment and reuse of latex wastewater,which provided with some important guidance on the industrial application.

关键词： Latex wastewater Resource utilization Forward osmosis Reverse osmosis Concentrated liquid

Highly selective and green recovery of lithium ions from lithium iron phosphate powders with ozone

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Frontiers of Chemical Science and Engineering 2023年第6期17卷 749-758页

作者： Ruiqi Li Kang Li Wei Wang Fan Zhang shichao tian Zhongqi Ren Zhiyong Zhou State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

Since lithium iron phosphate cathode material does not contain high-value metals other than lithium,it is therefore necessary to strike a balance between recovery efficiency and economic benefits in the recycling of waste lithium iron phosphate cathode materials.Here,we describe a selective recovery process that can achieve economically efficient recovery and an acceptable lithium leaching yield.Adjusting the acid concentration and amount of oxidant enables selective recovery of lithium ions.Iron is retained in the leaching residue as iron phosphate,which is easy to recycle.The effects of factors such as acid concentration,acid dosage,amount of oxidant,and reaction temperature on the leaching of lithium and iron are comprehensively explored,and the mechanism of selective leaching is clarified.This process greatly reduces the cost of processing equipment and chemicals.This increases the potential industrial use of this process and enables the green and efficient recycling of waste lithium iron phosphate cathode materials in the future.

关键词： lithium iron phosphate powder stoichiometric number selective leaching lithium recovery

Preparation of sodium alginate gel microspheres catalysts and its high catalytic performance for treatment of ciprofloxacin wastewater

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Chinese Journal of Chemical Engineering 2023年第11期63卷 158-170页

作者： Gaoyan Shao Jianjie Chen Yuming Tu Feng Liu Zhiyong Zhou shichao tian Zhongqi Ren State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

The discharge of the antibiotic wastewater has increased dramatically in our country with the development of medical science and wide application of antibiotic,resulting in serious harm to human body and ecological environment.In this work,ciprofloxacin(CIP)was selected as one of typical antibiotics and heterogeneous Fenton-like catalysts were prepared for the treatment of ciprofloxacin wastewater.The sodium alginate(SA)gel microspheres catalysts were prepared by polymerization method using double metal ions of Fe^(3+)and Mn^(2+)as cross-linking agents.Preparation conditions such as metal ions concentration,mass fraction of SA,polymerization temperature and dual-metal ions as crosslinking agent were optimized.Moreover,the effects of operating conditions such as initial concentration of CIP,pH value and catalyst dosage on CIP removal were studied.The kinetic equation showed that the effect of the initial concentration of CIP on the degradation rate was in line with second-order kinetics,and the effects of catalyst dosage and pH value on the degradation rate of CIP were in line with first-order kinetics.The SA gel microspheres catalysts prepared by dual-metal ions exhibited a high CIP removal and showed a good reusability after six recycles.The SA gel microspheres catalysts with an easy recovery performance provided an economical and efficient method for the removal of antibiotics in the future.

关键词： Sodium alginate gel microspheres Heterogeneous Fenton-like catalysts Dual-metal ions Hydroxyl radical Ciprofloxacin wastewater

Enrichment of nervonic acid in Acer truncatum Bunge oil by combination of two-stage molecular distillation,one-stage urea complexation and five-stage solvent crystallization

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中国化学工程学报:英文版 2023年第7期59卷 61-71页

作者： Yingxi Gao Jiayi Shi Jie Wang Fan Zhang shichao tian Zhiyong Zhou Zhongqi Ren State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

Nervonic acid is the world’s first and only potent substance that can repair damaged nerve fibers and promote nerve cell regeneration with high nutritional value.The wide variety of fatty acids in plant oils and fats with similar structures makes the large-scale separation and purification of high-purity nervonic acid very difficult.A new combined process of molecular distillation,urea inclusion and solvent crystallization was established to prepare high-purity nervonic acid with the mixed fatty acids obtained after saponification and acidification of Acer truncatum Bunge oil as raw materials.First,according to the difference in the mean free path of fatty acids,molecular distillation was used to separate and remove C16 saturated fatty acid of palmitic acid and four C18-C20 fatty acids of stearic,oleic,linoleic,and linolenic acids.The content of C16-C20 fatty acids decreased from 72.92% to 19.22% after two-stage molecular distillation processes,in which the contents of saturated fatty acid of palmitic acid decreased to about 0.5%.Then,according to the difference in carbon chain length and saturation of fatty acid,the contents of C22-C24 saturated fatty acids of tetracosanoic and docosanoic acids decreased to 0.21% and 0.07% by urea inclusion with urea/free fatty acid preparation by saponification(SPOMFs)ratio as 0.6.In addition,all saturated fatty acids were basically separated.Finally,according to the difference in the solubility of fatty acids in solvents,the C18-C20 unsaturated fatty acids of oleic,linoleic,and linolenic acids and C22 unsaturated fatty acid of erucic acid were removed by solvent crystallization.The content of C18-C20 unsaturated fatty acids decreased to less than 5% with pentanol as the solvent after the first stage solvent crystallization.The content of erucic acid decreased to 3.47% with anhydrous ethanol as the solvent after the second to fifth stage solvent crystallization.The combined process of molecular distillation,urea inclusion and low temperature crystallization innovatively adopted

关键词： Nervonic acid Acer truncatum Bunge Molecular distillation Urea complexation Solvent crystallization

Extractive desulfurization of model fuels with a nitrogen-containing heterocyclic ionic liquid

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Frontiers of Chemical Science and Engineering 2022年第12期16卷 1735-1742页

作者： Guojia Yu Dongyu Jin Xinyu Li Fan Zhang shichao tian Yixin Qu Zhiyong Zhou Zhongqi Ren College of Chemical Engineering Beijing University of Chemical TechnologyBeijing 100029China

A nitrogen-containing ionic liquid was synthesized using an aromatic nitrogen-containing heterocyclic and an amino acid,and applied to the extractive desulfurization process to remove benzothiophene,dibenzothiophene,and 4,6-dimethyldibenzothiphene from a model fuel oil.Chemical characterizations and simulation using Gaussian 09 software confirmed the rationality of an ionic liquid structure.Classification of non-covalent interactions between the ionic liquid and the three sulfur-containing contaminants was studied by reduced density gradient analysis.The viscosity of the ionic liquid was adjusted by addition of polyethylene glycol.Under extraction conditions of the volume of ionic liquid to oil as 1:1 and temperature as room temperature,the desulfurization selectivity of ionic liquid followed the order of 4,6-dimethyldibenzothiphene(15 min)

关键词： extractive desulfurization nitrogen-containing heterocyclic ionic liquid reduced density gradient analysis desulfurization selectivity

Application of an optical nitrate profiler to high-and low-turbidity coastal shelf waters

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Acta Oceanologica Sinica 2023年第1期42卷 103-108页

作者： Yanpei Zhuang Yangjie Li Xizhen Liu shichao tian Bin Wang Zhongqiang Ji Haiyan Jin Jianfang Chen Polar and Marine Research Institute Jimei UniversityXiamen361000China Key Laboratory of Marine Ecosystem Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou310012China Marine Monitoring and Forecasting Center of Zhejiang Province Hangzhou310000China Institute for Geology University of HamburgHamburg20000Germany State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou310012China

Here,we report the results of high-resolution nitrate measurements using an optical nitrate profiler(in situ ultraviolet spectrophotometer,ISUS)along transect across a high-turbidity shelf(East China Sea)and a low-turbidity shelf(Chukchi Sea).The ISUS-measured nitrate concentrations closely reproduced the results measured by conventional bottle methods in low-turbidity waters.However,for high-turbidity waters of the East China Sea(salinity<30),a correction factor of 1.19 was required to match the standard bottle measurements.The high-resolution ISUS data revealed subtle spatial variability(e.g.,a subsurface nitrate minimum)that may have been missed if based solely on bottle results.Four main structures of the nitracline on the East China Sea are apparent from the ISUS nitrate profile.High-resolution nitrate data are important for studying nitrate budgets and nutrient dynamics on continental shelves.

关键词： high-resolution nitrate measurements in situ ultraviolet spectrophotometer(ISUS) nutrient dynamics nitracline East China Sea Chukchi Sea

高效背结异质结太阳电池硼掺杂非晶硅发射极研究

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人工晶体学报 2024年第1期53卷 132-137页

作者：宿世超赵晓霞田宏波王伟宗军国家电投集团新能源科技有限公司南昌330096 国家电投集团科学技术研究院有限公司北京102209

晶硅/非晶硅异质结(HJT)太阳电池由于具有高开压、高转换效率和低温度系数等优点而备受关注,其中硼掺杂p型非晶硅(p-a-Si∶H)发射极是高转换效率电池中不可忽视的重要部分,改变其硼掺杂浓度,可以调节p-layer薄膜的电学特性,从而直接影... 详细信息

晶硅/非晶硅异质结(HJT)太阳电池由于具有高开压、高转换效率和低温度系数等优点而备受关注,其中硼掺杂p型非晶硅(p-a-Si∶H)发射极是高转换效率电池中不可忽视的重要部分,改变其硼掺杂浓度,可以调节p-layer薄膜的电学特性,从而直接影响电池转换效率。本文采用等离子体增强化学气相沉积(PECVD)设备制备HJT太阳电池,通过改变B_(2)H_(6)的掺杂浓度,对电池中p-a-Si∶H层进行优化,使HJT电池获得0.75%的相对效率提升。进一步地,将发射极设置为梯度掺杂的双层结构,经过优化,少子寿命(@Δn=5×10^(15)cm^(-3))和隐开路电压(@1-Sun)分别提升400μs和3 mV,最终具有梯度掺杂发射极的电池其平均效率相对提升2.03%,主要表现为FF和Voc的明显增加,实现了高效HJT电池p型发射极的工艺优化。

关键词： HJT太阳电池硼掺杂非晶硅发射极暗电导率掺杂浓度梯度掺杂