Huge quantities of zinc leaching residues(ZLRs) generated from zinc production are dumped continuously around the world and pose a potential environmental threat because of their considerable amounts of entrained heav...Huge quantities of zinc leaching residues(ZLRs) generated from zinc production are dumped continuously around the world and pose a potential environmental threat because of their considerable amounts of entrained heavy metals(mainly lead). Most ZLRs have not been properly treated and the valuable metals in them have not yet been effectively recovered. Herein, the deep cleaning of a ZLR and recovery of valuable metals via a hydrometallurgical route were investigated. The cleaning process consists of two essential stages: acid leaching followed by calcium chloride leaching. The optimum conditions for extracting zinc, copper, and indium by acid leaching were a sulfuric acid concentration of 200 g·L^(-1), a liquid/solid ratio of 4:1(m L/g), a leaching time of 2 h, and a temperature of 90°C. For lead and silver extractions, the optimum conditions were a calcium chloride concentration of 400 g·L^(-1), a pH value of 1.0, a leaching time of 1 h, and a temperature of 30°C. After calcium chloride leaching, silver and lead were extracted out and the lead was finally recovered as electrolytic lead by electrowinning. The anglesite phase, which poses the greatest potential environmental hazard, was removed from the ZLR after deep cleaning, thus reducing the cost of environmental management of ZLRs. The treatment of chlorine and spent electrolyte generated in the process was discussed.展开更多
Niclosamide,an oral antihelminthic drug,has been used to treat tapeworm infection for about 50 years.Niclosamide is also used as a molluscicide for water treatment in schistosomiasis control programs.Recently,several ...Niclosamide,an oral antihelminthic drug,has been used to treat tapeworm infection for about 50 years.Niclosamide is also used as a molluscicide for water treatment in schistosomiasis control programs.Recently,several groups have independently discovered that niclosamide is also active against cancer cells,but its precise mechanism of antitumor action is not fully understood.Evidence supports that niclosamide targets multiple signaling pathways (NF-κB,Wnt/β-catenin,Notch,ROS,mTORC1,and Stat3),most of which are closely involved with cancer stem cells.The exciting advances in elucidating the antitumor activity and the molecular targets of this drug will be discussed.A method for synthesizing a phosphate pro-drug of niclosamide is provided.Given its potential antitumor activity,clinical trials for niclosamide and its derivatives are warranted for cancer treatment.展开更多
The Cu_2MoS_4 nanoparticles were prepared using a relatively simple and convenient solid-phase process, which was applied for the first time. The crystalline structure, morphology, and optical properties of Cu_2MoS_4 ...The Cu_2MoS_4 nanoparticles were prepared using a relatively simple and convenient solid-phase process, which was applied for the first time. The crystalline structure, morphology, and optical properties of Cu_2MoS_4 nanoparticles were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, and UV-vis spectrophotometry. Cu_2MoS_4 nanoparticles having a band gap of 1.66 eV exhibits good photocatalytic activity in the degradation of methylene blue, which indicates that this simple process may be critical to facilitate the cheap production of photocatalysts.展开更多
In this study,we prepared Ti/IrO2–ZrO2 electrodes with different ZrO2 contents using zirconium-n-butoxide(C16H36O4Zr)and chloroiridic acid(H2IrCl6)via a sol–gel route.To explore the effect of ZrO2 content on the sur...In this study,we prepared Ti/IrO2–ZrO2 electrodes with different ZrO2 contents using zirconium-n-butoxide(C16H36O4Zr)and chloroiridic acid(H2IrCl6)via a sol–gel route.To explore the effect of ZrO2 content on the surface properties and electrochemical behavior of electrodes,we performed physical characterizations and electrochemical measurements.The obtained results revealed that the binary oxide coating was composed of rutile IrO2,amorphous ZrO2,and an IrO2–ZrO2 solid solution.The IrO2–ZrO2 binary oxide coatings exhibited cracked structures with flat regions.A slight incorporation of ZrO2 promoted the crystallization of the active component IrO2.However,the crystallization of IrO2 was hindered when the added ZrO2 content was greater than 30at%.The appropriate incorporation of ZrO2 enhanced the electrocatalytic performance of the pure IrO2 coating.The Ti/70at%IrO2–30at%ZrO2 electrode,with its large active surface area,improved electrocatalytic activity,long service lifetime,and especially,lower cost,is the most effective for promoting oxygen evolution in sulfuric acid solution.展开更多
BACKGROUND Gallbladder squamous cell carcinoma(GBSCC)is a rare subtype of malignancy and accounts for only 2%-3%of gallbladder malignancies.Due to its rapid development,most patients with GBSCC initially present with ...BACKGROUND Gallbladder squamous cell carcinoma(GBSCC)is a rare subtype of malignancy and accounts for only 2%-3%of gallbladder malignancies.Due to its rapid development,most patients with GBSCC initially present with an advanced stage of the disease and hence a poor prognosis.The clinicopathological and biological features of SCC remain to be fully elucidated,owing to its uncommon occurrence.The majority of currently available data only described individual case reports or series analyses of trivial cases.CASE SUMMARY A 64-year-old man was admitted for progressively poor abdominal distension and pain.Liver computed tomography(CT)showed infiltration of gallbladder carcinoma into the adjacent liver,and enlarged retroperitoneal lymph nodes.The patient underwent radical cholecystectomy.Part of the mass was grey and soft,and the neoplastic section showed a purulent-necrotic lesion.Hematoxylin and eosin staining revealed a moderately differentiated SCC.Immunohistochemical studies showed strong staining of the tumor for AE1/3 and CK5/6.Staining for CK19,CK7,and CAM5.2 was positive in the cytoplasm.Systemic chemotherapy was not administered because of the patient’s poor physical condition.After five months,CT and magnetic resonance cholangiopancreatography showed multiple metastases in the liver and abdominal cavity.CONCLUSION Squamous components of GBSCC may explain the complex biological behavior,and CD109 may be involved in the pathogenesis.展开更多
The recycling of spent LiFePO_(4)batteries has received extensive attention due to its environmental impact and economic benefit.In the pretreatment process of spent LiFePO_(4)batteries,the separation of active materi...The recycling of spent LiFePO_(4)batteries has received extensive attention due to its environmental impact and economic benefit.In the pretreatment process of spent LiFePO_(4)batteries,the separation of active materials and current collectors determines the difficulty of the re-covery process and product quality.In this work,a facile and efficient pretreatment process is first proposed.After only freezing the electrode pieces and immersing them in boiling water,LiFePO_(4)materials were peeled from the Al foil.Then,after roasting under an inert atmosphere and sieving,all the cathode and anode active materials were easily and efficiently separated from the Al and Cu foils.The active materials were subjected to acid leaching,and the leaching solution was further used to prepare FePO_(4)and Li_(2)CO_(3).Finally,the battery-grade FePO_(4)and Li_(2)CO_(3)were used to re-synthesize LiFePO_(4)/C via the carbon thermal reduction method.The discharge capacities of re-synthesized LiFePO_(4)/C cathode were 144.2,139.0,133.2,125.5,and 110.5 mA·h·g−1 at rates of 0.1,0.5,1,2,and 5 C,which satisfies the requirement for middle-end LiFePO_(4)batteries.The whole process is environmental and has great potential for industrial-scale recycling of spent lithium-ion batteries.展开更多
Currently, the majority of copper tailings are not effectively developed. Worldwide, large amounts of copper tailings generated from copper production are continuously dumped, posing a potential environmental threat. ...Currently, the majority of copper tailings are not effectively developed. Worldwide, large amounts of copper tailings generated from copper production are continuously dumped, posing a potential environmental threat. Herein, the recovery of iron from copper tailings via low-temperature direct reduction and magnetic separation was conducted; process optimization was carried out, and the corresponding mineralogy was investigated. The reduction time, reduction temperature, reducing agent (coal), calcium chloride additive, grinding time, and magnetic field intensity were examined for process optimization. Mineralogical analyses of the sample, reduced pellets, and magnetic concentrate under various conditions were performed by X-ray diffraction, optical microscopy, and scanning electron microscopy-energy-dispersive X-ray spectrometry to elucidate the iron reduction and growth mechanisms. The results indicated that the optimum parameters of iron recovery include a reduction temperature of 1150A degrees C, a reduction time of 120 min, a coal dosage of 25%, a calcium chloride dosage of 2.5%, a magnetic field intensity of 100 mT, and a grinding time of 1 min. Under these conditions, the iron grade in the magnetic concentrate was greater than 90%, with an iron recovery ratio greater than 95%.展开更多
The preparation of ferronickel alloy from the nickel laterite ore with low Co and high MgO contents was studied by using a pre-reduction-smelting method. The effects of reduction time, calcination temperature, quantit...The preparation of ferronickel alloy from the nickel laterite ore with low Co and high MgO contents was studied by using a pre-reduction-smelting method. The effects of reduction time, calcination temperature, quantity of reductant and calcium oxide (CaO), and pellet diameter on the reduction ratio of Fe and on the pellet strength were investigated. The results show that, for a roasting temperature > 800 A degrees C, a roasting time > 30 min, 1.5wt% added anthracite coal, 5wt% added CaO, and a pellet size of similar to 10 mm, the reduction ratio of Fe exceeds 70% and the compressive strength of the pellets exceeds 10 kg per pellet. Reduction smelting experiments were performed by varying the smelting time, temperature, quantity of reductant and CaO, and reduction ratio of Fe in the pellets. Optimal conditions for the reduction smelting process are as follows: smelting time, 30-45 min; smelting temperature, 1550A degrees C; quantity of reductant, 4wt%-5wt%; and quantity of CaO, 5wt%; leading to an Fe reduction ratio of 75% in the pellets. In addition, the mineral composition of the raw ore and that during the reduction process were investigated by process mineralogy.展开更多
Monodispersed copper oxalate paxticles with flaky morphology were prepared via a simple one-pot synthesis method. Scanning electron microscope (SEM), X-ray diffraction (XRD), and fourier tza^sform infraJced (FTIR...Monodispersed copper oxalate paxticles with flaky morphology were prepared via a simple one-pot synthesis method. Scanning electron microscope (SEM), X-ray diffraction (XRD), and fourier tza^sform infraJced (FTIR) spectra were used to characterize paxticle mor- phology, size, phase composition, and functional groups. It was found that the presence of ethylenediaminetetzaacetic acid (EDTA) and the solution pH value had strong influence on the morphological and size evolution of the precipitated particles. On the basis of controlled re- lease of copper ions from a Cu2+-EDTA complex and Weimazn's law, a stzategy for the controlled synthesis of monodispersed copper oxa- late paxticles was designed by refemng to the basic mode of the St0ber method. The inherent nature of crystallization to form the flaky solid in the early stage of precipitation as well as the driving force of the long-lasting low supersaturation in the growth stage was proposed to ex- plain the size and morphological evolution of the copper oxalate precipitates. Thermodynamic equilibrium concentrations of copper(II) spe- cies in the Cu(II)-EDTA-oxalate-H20 solution system were calculated to help explain the possible formation mechaNsm of copper oxalate precipitates.展开更多
Abdominal magnetic resonance imaging(MRI)and computed tomography(CT)are commonly used for disease screening,diagnosis,and treatment guidance.However,abdominal MRI has disadvantages including slow speed and vulnerabili...Abdominal magnetic resonance imaging(MRI)and computed tomography(CT)are commonly used for disease screening,diagnosis,and treatment guidance.However,abdominal MRI has disadvantages including slow speed and vulnerability to motions,while CT suffers from problems of radiation.It has been reported that deep learning reconstruction can solve such problems while maintaining good image quality.Recently,deep learning-based image reconstruction has become a hot topic in the field of medical imaging.This study reviews the latest research on deep learning reconstruction in abdominal imaging,including the widely used convolutional neural network,generative adversarial network,and recurrent neural network.展开更多
The aim of this study is to present a new understanding for the selective lithium recovery from spent lithium-ion batteries(LIBs)via sulfation roasting.The composition of roasting products and reaction behavior of imp...The aim of this study is to present a new understanding for the selective lithium recovery from spent lithium-ion batteries(LIBs)via sulfation roasting.The composition of roasting products and reaction behavior of impurity elements were analyzed through thermodynamic calculations.Then,the effects of sulfuric acid dosage,roasting temperature,roasting time,and impurity elements were assessed on the leaching efficiency of valuable metals.Characterization methods such as X-ray diffraction(XRD),scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS),and X-ray photoelectron spectroscopy(XPS)were employed to analyze the phase transformation mechanism during roasting process.The results indicate that after sulfation roasting(n(H_(2)SO_(4)):n(Li)=0.5,550℃,2 h),94%lithium can be selectively recovered by water leaching and more than 95%Ni,Co,and Mn can be leached through acid leaching without the addition of reduction agent.During the sulfation roasting process,the lithium in LiNi_(x)Mn_(y)Co_zO_(2)is mainly converted to Li_(2)SO_(4),while the Ni,Co and Mn are first transformed to sulfate and then converted into oxide form.In addition,impurity elements such as Al and F will combine with lithium to form LiF and LiAlO_(2),which will reduce the leaching rate of lithium.These results provide a new understanding on the mechanisms of phase conversion during sulfation roasting and reveal the influence of impurity elements for the lithium recovery from spent LIBs.展开更多
The pressure nitric acid leaching of alkali-pre- treated low-grade limonitic laterite, as well as removing impurity AI(III) and preparing intermediate product of nickel/cobalt sulphide from leaching liquor were inve...The pressure nitric acid leaching of alkali-pre- treated low-grade limonitic laterite, as well as removing impurity AI(III) and preparing intermediate product of nickel/cobalt sulphide from leaching liquor were investi- gated. After pretreatment, iron exists in the form of amorphous iron oxides, while nickel is adsorbed on the surface of iron oxides in the form of nickel oxide. The preferable pressure leaching conditions are determined as follows: leaching temperature of 458 K, leaching duration of 60 min, initial acidity of nitric acid of 1.90 mol.L-~ and liquid to solid ratio of 3:1 (volume to mass ratio). Under these conditions, the leaching efficiencies of Ni, Co and A1 are 95 %, 88 % and 55 %, respectively, and that of Fe is less than 1%. The loss rates of Ni and Co are 1.8 % and 1.5 %, respectively, during the step of removing impurity AI(III). The sulphide precipitation process produces the interim production of nickel/cobalt sulphides, recovering greater than 99 % of Ni and Co in the purified solution. The iron-rich (〉60 %) pressure leaching residue with low Cr, S can be further reclaimed as the raw materials for iron making.展开更多
基金Project(2017M610766)supported by China Postdoctoral Science FoundationProject(FRF-BD-17-010A)supported by the Fundamental Research Funds for the Central Universities,China
基金financially supported by the National Natural Science Foundation of China (Nos. 52034002, U1802253, 51974025)the Fundamental Research Funds for the Central Universities, China (No. FRF-MP-20-04)
基金financially supported by the National Natural Science Foundation of China (Nos. U1302274 and 51674026)the Fundamental Research Funds for the Central Universities (No. 230201606500078)the Yunnan Technical Innovation and Personnel Training Program
文摘Huge quantities of zinc leaching residues(ZLRs) generated from zinc production are dumped continuously around the world and pose a potential environmental threat because of their considerable amounts of entrained heavy metals(mainly lead). Most ZLRs have not been properly treated and the valuable metals in them have not yet been effectively recovered. Herein, the deep cleaning of a ZLR and recovery of valuable metals via a hydrometallurgical route were investigated. The cleaning process consists of two essential stages: acid leaching followed by calcium chloride leaching. The optimum conditions for extracting zinc, copper, and indium by acid leaching were a sulfuric acid concentration of 200 g·L^(-1), a liquid/solid ratio of 4:1(m L/g), a leaching time of 2 h, and a temperature of 90°C. For lead and silver extractions, the optimum conditions were a calcium chloride concentration of 400 g·L^(-1), a pH value of 1.0, a leaching time of 1 h, and a temperature of 30°C. After calcium chloride leaching, silver and lead were extracted out and the lead was finally recovered as electrolytic lead by electrowinning. The anglesite phase, which poses the greatest potential environmental hazard, was removed from the ZLR after deep cleaning, thus reducing the cost of environmental management of ZLRs. The treatment of chlorine and spent electrolyte generated in the process was discussed.
基金supported in part by grants from National Natural Science Foundation of China for Distinguished Young Scholars(81025021)the National Basic Research Program of China(973Program grant2009CB825506)+2 种基金the Major Research Plan of the National Natural Science Foundation of China(90713036)the National High Technology Research and Development Program of China(863Program grant2008AA02Z420)the Fundamental Research Foundation for the Central Universities to Jing-Xuan Pan
文摘Niclosamide,an oral antihelminthic drug,has been used to treat tapeworm infection for about 50 years.Niclosamide is also used as a molluscicide for water treatment in schistosomiasis control programs.Recently,several groups have independently discovered that niclosamide is also active against cancer cells,but its precise mechanism of antitumor action is not fully understood.Evidence supports that niclosamide targets multiple signaling pathways (NF-κB,Wnt/β-catenin,Notch,ROS,mTORC1,and Stat3),most of which are closely involved with cancer stem cells.The exciting advances in elucidating the antitumor activity and the molecular targets of this drug will be discussed.A method for synthesizing a phosphate pro-drug of niclosamide is provided.Given its potential antitumor activity,clinical trials for niclosamide and its derivatives are warranted for cancer treatment.
基金financially supported by the Fundamental Research Funds for the Central Universities (No. FRF-BD-15-004A)
文摘The Cu_2MoS_4 nanoparticles were prepared using a relatively simple and convenient solid-phase process, which was applied for the first time. The crystalline structure, morphology, and optical properties of Cu_2MoS_4 nanoparticles were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, and UV-vis spectrophotometry. Cu_2MoS_4 nanoparticles having a band gap of 1.66 eV exhibits good photocatalytic activity in the degradation of methylene blue, which indicates that this simple process may be critical to facilitate the cheap production of photocatalysts.
基金financially supported by the National Natural Science Foundation of China (Nos. U1802253, 51974025 and 51674026)the Guangxi Innovation-Driven Development Project (No. AA18242042-1)+1 种基金the Beijing Natural Science Foundation of China (No. 2182040)the Fundamental Research Funds for the Central Universities (FRF22TT-19-001)
文摘In this study,we prepared Ti/IrO2–ZrO2 electrodes with different ZrO2 contents using zirconium-n-butoxide(C16H36O4Zr)and chloroiridic acid(H2IrCl6)via a sol–gel route.To explore the effect of ZrO2 content on the surface properties and electrochemical behavior of electrodes,we performed physical characterizations and electrochemical measurements.The obtained results revealed that the binary oxide coating was composed of rutile IrO2,amorphous ZrO2,and an IrO2–ZrO2 solid solution.The IrO2–ZrO2 binary oxide coatings exhibited cracked structures with flat regions.A slight incorporation of ZrO2 promoted the crystallization of the active component IrO2.However,the crystallization of IrO2 was hindered when the added ZrO2 content was greater than 30at%.The appropriate incorporation of ZrO2 enhanced the electrocatalytic performance of the pure IrO2 coating.The Ti/70at%IrO2–30at%ZrO2 electrode,with its large active surface area,improved electrocatalytic activity,long service lifetime,and especially,lower cost,is the most effective for promoting oxygen evolution in sulfuric acid solution.
基金the National Natural Science Foundation of China,No.81560053the Youth Science and Technology Innovation Leading Talents Project of Corps,No.2017CB004+1 种基金International Science and Technology Cooperation Promotion Plan of Shihezi University,No.GJHZ201805Xinjiang Production and Construction Corps Key Areas Innovation Team Project,No.2018CB002
文摘BACKGROUND Gallbladder squamous cell carcinoma(GBSCC)is a rare subtype of malignancy and accounts for only 2%-3%of gallbladder malignancies.Due to its rapid development,most patients with GBSCC initially present with an advanced stage of the disease and hence a poor prognosis.The clinicopathological and biological features of SCC remain to be fully elucidated,owing to its uncommon occurrence.The majority of currently available data only described individual case reports or series analyses of trivial cases.CASE SUMMARY A 64-year-old man was admitted for progressively poor abdominal distension and pain.Liver computed tomography(CT)showed infiltration of gallbladder carcinoma into the adjacent liver,and enlarged retroperitoneal lymph nodes.The patient underwent radical cholecystectomy.Part of the mass was grey and soft,and the neoplastic section showed a purulent-necrotic lesion.Hematoxylin and eosin staining revealed a moderately differentiated SCC.Immunohistochemical studies showed strong staining of the tumor for AE1/3 and CK5/6.Staining for CK19,CK7,and CAM5.2 was positive in the cytoplasm.Systemic chemotherapy was not administered because of the patient’s poor physical condition.After five months,CT and magnetic resonance cholangiopancreatography showed multiple metastases in the liver and abdominal cavity.CONCLUSION Squamous components of GBSCC may explain the complex biological behavior,and CD109 may be involved in the pathogenesis.
基金This work was financially supported by the Key-Area Research and Development Program of Guangdong Province,China(No.2020B090919003)the National Natural Science Foundation of China(Nos.51834008,51874040,and U1802253)the Fundamental Research Funds for the Central Universities(No.FRF-TP-18-020A3).
文摘The recycling of spent LiFePO_(4)batteries has received extensive attention due to its environmental impact and economic benefit.In the pretreatment process of spent LiFePO_(4)batteries,the separation of active materials and current collectors determines the difficulty of the re-covery process and product quality.In this work,a facile and efficient pretreatment process is first proposed.After only freezing the electrode pieces and immersing them in boiling water,LiFePO_(4)materials were peeled from the Al foil.Then,after roasting under an inert atmosphere and sieving,all the cathode and anode active materials were easily and efficiently separated from the Al and Cu foils.The active materials were subjected to acid leaching,and the leaching solution was further used to prepare FePO_(4)and Li_(2)CO_(3).Finally,the battery-grade FePO_(4)and Li_(2)CO_(3)were used to re-synthesize LiFePO_(4)/C via the carbon thermal reduction method.The discharge capacities of re-synthesized LiFePO_(4)/C cathode were 144.2,139.0,133.2,125.5,and 110.5 mA·h·g−1 at rates of 0.1,0.5,1,2,and 5 C,which satisfies the requirement for middle-end LiFePO_(4)batteries.The whole process is environmental and has great potential for industrial-scale recycling of spent lithium-ion batteries.
基金financially supported by the National Natural Science Foundation of China (No. 51674026)
文摘Currently, the majority of copper tailings are not effectively developed. Worldwide, large amounts of copper tailings generated from copper production are continuously dumped, posing a potential environmental threat. Herein, the recovery of iron from copper tailings via low-temperature direct reduction and magnetic separation was conducted; process optimization was carried out, and the corresponding mineralogy was investigated. The reduction time, reduction temperature, reducing agent (coal), calcium chloride additive, grinding time, and magnetic field intensity were examined for process optimization. Mineralogical analyses of the sample, reduced pellets, and magnetic concentrate under various conditions were performed by X-ray diffraction, optical microscopy, and scanning electron microscopy-energy-dispersive X-ray spectrometry to elucidate the iron reduction and growth mechanisms. The results indicated that the optimum parameters of iron recovery include a reduction temperature of 1150A degrees C, a reduction time of 120 min, a coal dosage of 25%, a calcium chloride dosage of 2.5%, a magnetic field intensity of 100 mT, and a grinding time of 1 min. Under these conditions, the iron grade in the magnetic concentrate was greater than 90%, with an iron recovery ratio greater than 95%.
基金financially supported by the National Natural Science Foundation of China(Nos.U1302274 and 51274044)
文摘The preparation of ferronickel alloy from the nickel laterite ore with low Co and high MgO contents was studied by using a pre-reduction-smelting method. The effects of reduction time, calcination temperature, quantity of reductant and calcium oxide (CaO), and pellet diameter on the reduction ratio of Fe and on the pellet strength were investigated. The results show that, for a roasting temperature > 800 A degrees C, a roasting time > 30 min, 1.5wt% added anthracite coal, 5wt% added CaO, and a pellet size of similar to 10 mm, the reduction ratio of Fe exceeds 70% and the compressive strength of the pellets exceeds 10 kg per pellet. Reduction smelting experiments were performed by varying the smelting time, temperature, quantity of reductant and CaO, and reduction ratio of Fe in the pellets. Optimal conditions for the reduction smelting process are as follows: smelting time, 30-45 min; smelting temperature, 1550A degrees C; quantity of reductant, 4wt%-5wt%; and quantity of CaO, 5wt%; leading to an Fe reduction ratio of 75% in the pellets. In addition, the mineral composition of the raw ore and that during the reduction process were investigated by process mineralogy.
基金financially supported by the Special Fundamental Funds by Beijing Scientific Committee for the Project of New Functional Materials for Environmental Remediation(No.00012245)
文摘Monodispersed copper oxalate paxticles with flaky morphology were prepared via a simple one-pot synthesis method. Scanning electron microscope (SEM), X-ray diffraction (XRD), and fourier tza^sform infraJced (FTIR) spectra were used to characterize paxticle mor- phology, size, phase composition, and functional groups. It was found that the presence of ethylenediaminetetzaacetic acid (EDTA) and the solution pH value had strong influence on the morphological and size evolution of the precipitated particles. On the basis of controlled re- lease of copper ions from a Cu2+-EDTA complex and Weimazn's law, a stzategy for the controlled synthesis of monodispersed copper oxa- late paxticles was designed by refemng to the basic mode of the St0ber method. The inherent nature of crystallization to form the flaky solid in the early stage of precipitation as well as the driving force of the long-lasting low supersaturation in the growth stage was proposed to ex- plain the size and morphological evolution of the copper oxalate precipitates. Thermodynamic equilibrium concentrations of copper(II) spe- cies in the Cu(II)-EDTA-oxalate-H20 solution system were calculated to help explain the possible formation mechaNsm of copper oxalate precipitates.
基金National Natural Science Foundation of China,No.61902338 and No.62001120Shanghai Sailing Program,No.20YF1402400.
文摘Abdominal magnetic resonance imaging(MRI)and computed tomography(CT)are commonly used for disease screening,diagnosis,and treatment guidance.However,abdominal MRI has disadvantages including slow speed and vulnerability to motions,while CT suffers from problems of radiation.It has been reported that deep learning reconstruction can solve such problems while maintaining good image quality.Recently,deep learning-based image reconstruction has become a hot topic in the field of medical imaging.This study reviews the latest research on deep learning reconstruction in abdominal imaging,including the widely used convolutional neural network,generative adversarial network,and recurrent neural network.
基金financially supported by the Key R&D Program of Zhejiang(No.2022C03074)the National Natural Science Foundation of China(Nos.51834008 and 51874040)。
文摘The aim of this study is to present a new understanding for the selective lithium recovery from spent lithium-ion batteries(LIBs)via sulfation roasting.The composition of roasting products and reaction behavior of impurity elements were analyzed through thermodynamic calculations.Then,the effects of sulfuric acid dosage,roasting temperature,roasting time,and impurity elements were assessed on the leaching efficiency of valuable metals.Characterization methods such as X-ray diffraction(XRD),scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS),and X-ray photoelectron spectroscopy(XPS)were employed to analyze the phase transformation mechanism during roasting process.The results indicate that after sulfation roasting(n(H_(2)SO_(4)):n(Li)=0.5,550℃,2 h),94%lithium can be selectively recovered by water leaching and more than 95%Ni,Co,and Mn can be leached through acid leaching without the addition of reduction agent.During the sulfation roasting process,the lithium in LiNi_(x)Mn_(y)Co_zO_(2)is mainly converted to Li_(2)SO_(4),while the Ni,Co and Mn are first transformed to sulfate and then converted into oxide form.In addition,impurity elements such as Al and F will combine with lithium to form LiF and LiAlO_(2),which will reduce the leaching rate of lithium.These results provide a new understanding on the mechanisms of phase conversion during sulfation roasting and reveal the influence of impurity elements for the lithium recovery from spent LIBs.
基金financially supported by the National Natural Science Foundation of China (Nos. 51274044, 51304023, and U1302274)
文摘The pressure nitric acid leaching of alkali-pre- treated low-grade limonitic laterite, as well as removing impurity AI(III) and preparing intermediate product of nickel/cobalt sulphide from leaching liquor were investi- gated. After pretreatment, iron exists in the form of amorphous iron oxides, while nickel is adsorbed on the surface of iron oxides in the form of nickel oxide. The preferable pressure leaching conditions are determined as follows: leaching temperature of 458 K, leaching duration of 60 min, initial acidity of nitric acid of 1.90 mol.L-~ and liquid to solid ratio of 3:1 (volume to mass ratio). Under these conditions, the leaching efficiencies of Ni, Co and A1 are 95 %, 88 % and 55 %, respectively, and that of Fe is less than 1%. The loss rates of Ni and Co are 1.8 % and 1.5 %, respectively, during the step of removing impurity AI(III). The sulphide precipitation process produces the interim production of nickel/cobalt sulphides, recovering greater than 99 % of Ni and Co in the purified solution. The iron-rich (〉60 %) pressure leaching residue with low Cr, S can be further reclaimed as the raw materials for iron making.