The phase transformation of galena in H_(2)SO_(4)-Fe_(2)(SO_(4))_(3) system under oxygen pressure was investigated.Results indicated that the critical conditions for the phase transformation of galena into lead jarosi...The phase transformation of galena in H_(2)SO_(4)-Fe_(2)(SO_(4))_(3) system under oxygen pressure was investigated.Results indicated that the critical conditions for the phase transformation of galena into lead jarosite(Pb-J)were 130℃,30 g/L H_(2)SO_(4),15 g/L Fe^(3+),and an oxygen partial pressure of 0.4 MPa.Furthermore,increased Fe^(3+)concentration and oxygen partial pressure did not enhance jarosite formation.Conversely,lowering the temperature and increasing the H_(2)SO_(4) concentration facilitated PbSO_(4) formation and inhibited its further conversion to Pb-J.Additionally,the effects of potassium sulfate,sodium sulfate,and high concentrations of zinc sulfate on the phase transformation of galena were examined through leaching tests,XRD,SEM-EDS,and FT-IR analyses.All three sulfates inhibited the conversion of galena to Pb-J.Among these,potassium sulfate prevented Pb-J formation and converted it more thoroughly into potassium jarosite.However,high concentrations of zinc sulfate facilitated the crystallization of both PbSO_(4) and Pb-J,which altered the morphology of the product.Zinc ions coprecipitated with Pb-J,thereby integrating into the product.展开更多
To address the current situation where many small enterprises lack efficient management of customer data, this paper proposes a design and implementation plan of a customer relationship management (CRM) system based o...To address the current situation where many small enterprises lack efficient management of customer data, this paper proposes a design and implementation plan of a customer relationship management (CRM) system based on email service. It aims to solve the problems of data dispersion, untimely update and information redundancy in customer management of small and medium-sized enterprises. The system includes four core functional modules: historical email analysis, lead pool management, customer management and email archiving. Through email mining and web crawler technology, the system can extract potential customer information from historical emails and enrich lead data;the lead pool management module supports lead information maintenance, status tracking and conversion of high-value leads;the customer management module realizes the maintenance and dynamic tracking of customer information;the email management module provides the archiving of emails and attachments and the structured storage of basic email information. The system provides automated and intelligent customer information management, improves the work efficiency of sales staff, and provides an efficient customer relationship management solution for enterprises.展开更多
To present an advanced device scheme of high-performance optoelectronic synapses,herein,we demonstrated the electrically-and/or optically-drivable multifaceted synaptic capabilities on the 2D semiconductor channel-bas...To present an advanced device scheme of high-performance optoelectronic synapses,herein,we demonstrated the electrically-and/or optically-drivable multifaceted synaptic capabilities on the 2D semiconductor channel-based ferroelectric field-effect transistor(FeFET)architecture.The device was fabricated in the form of the MoS_(2)/PZT FeFET,and its synaptic weights were effectively controlled by dual stimuli(i.e.,both electrical and optical pulses simultaneously)as well as single stimuli(i.e.,either electrical or optical pulses alone).This could be attributed to the electrical pulse-tunable strong ferroelectric polarization in PbZrxTi_(1−x)O_(3)(PZT)as well as the polarization field-enhanced persistent photoconductivity effect in MoS_(2).Additionally,it was confirmed that the proposed device possesses substantial activity,achieving approximately 95%pattern recognition accuracy.The results substantiate the great potential of the 2D semiconductor channel-based FeFET device as a high-performance optoelectronic synaptic platform,marking a pivotal stride towards the realization of advanced neuromorphic computing systems.展开更多
A kind of management system for electric vehicle (EV) battery series was developed. The system can predict residual capacity for EV battery series and mileages. The system can determine if it is necessary for the batt...A kind of management system for electric vehicle (EV) battery series was developed. The system can predict residual capacity for EV battery series and mileages. The system can determine if it is necessary for the battery series to be charged. The system can determine which battery is necessary to be updated for the reason of damage or aging. The system can display the total voltage of battery series, extreme voltage and temperature of every battery in the series. The system can display the accumulative discharge for every battery in the series. The system can alarm when both total or extreme voltage is at low level, or temperature of a battery in the series is at high level. The system provided with a microprocessor as key part can collect and record signal of charging and discharging current, total voltage, extreme voltage and temperature for every battery. The mathematical model of residual capacity for EV lead acid batteries was discussed in details. The system operates well in the laboratory and meets the requirement.展开更多
Vapor pressure of lead and lead chlorides from FeOT？CaO？SiO2？Al2O3 slag system was measured by using Knudsen effusion method. The results suggest that the vapor pressures of lead and lead chlorides increase with in...Vapor pressure of lead and lead chlorides from FeOT？CaO？SiO2？Al2O3 slag system was measured by using Knudsen effusion method. The results suggest that the vapor pressures of lead and lead chlorides increase with increasing temperature. For the slag systems without chlorine, the logarithm of vapor pressure （lnp） shows highly linear dependency on the reciprocal of temperature （1/T）, and higher vapor pressure is observed in the condition where more metallic lead vapor is formed. In this case, the vapor pressure of lead increases with increasing slag basicity （w（CaO）/w（SiO2））, increasing FeO content andw（Fe2＋）/w（Fe3＋） ratio. For the case of slag system with chlorine addition, the total pressures of PbCl2 and PbCl increase with decreasing basicity and FeO content of slag.展开更多
In order to let the supplier make more reasonable supply decisions,an integrated continuous replenishment policy for the vendor-managed inventory system is presented,which considers the quantity-based shipment consoli...In order to let the supplier make more reasonable supply decisions,an integrated continuous replenishment policy for the vendor-managed inventory system is presented,which considers the quantity-based shipment consolidation and stock replenishment with lead time.Then the system cost is analyzed and a mathematical model is built.Since the model is rather complex,the bounds of the optimal policy are first attained,then the problem is solved by a heuristic algorithm.Through experiments the relationship between the order lead time and the corresponding integrated policy is discussed,and the influence on the system cost is also analyzed.The results reveal that the lead time's influence on the system is more serious with the increase of the order lead time,the integrated policy with the order lead time is more reasonable and the optimal policy can minimize the total system cost.Finally,the parameter sensitivity of the model is analyzed.展开更多
According to the ion and molecule coexistence theory, a thermodynamic model of lead oxide activity in PbO-CaO-SiO2-FeO-Fe2O3 slag system was established at the temperature of 1273-1733 K. The activities of Pb O in sla...According to the ion and molecule coexistence theory, a thermodynamic model of lead oxide activity in PbO-CaO-SiO2-FeO-Fe2O3 slag system was established at the temperature of 1273-1733 K. The activities of Pb O in slag were calculated, and their equal activity curves were plotted. The influences of slag basicity Q, iron oxide rate R and temperature T on activity NPb O and activity coefficient γPbO were also investigated. Results show that the calculated values of γPb O are in good agreement with the reported experimental data, showing that the model can wholly embody the slag structural characteristics. NPbO departures positively from Raoult values, and increases with increasing Pb O content in slag but changes little with T. γPbO increases with increasing Q, and goes through the maximum with increasing R for basic slag（Q0.3）. Results can be applied to the thermodynamic research and operational optimization of modern lead smelting technologies.展开更多
China’s shipbuilding industry maintained the world’s largest market share in terms of three major indicators for the 16th consecutive year in 2025,according to data released by the Ministry of Industry and Informati...China’s shipbuilding industry maintained the world’s largest market share in terms of three major indicators for the 16th consecutive year in 2025,according to data released by the Ministry of Industry and Information Technology on 1 February.展开更多
Lead-halide perovskite solar cells(PSCs)have rapidly achieved certified efficiencies>27%,rivaling silicon photovoltaics.However,their commercialization is hindered by intrinsic material challenges:poor operational ...Lead-halide perovskite solar cells(PSCs)have rapidly achieved certified efficiencies>27%,rivaling silicon photovoltaics.However,their commercialization is hindered by intrinsic material challenges:poor operational stability under moisture,heat,and light;toxic lead leakage from degraded films.Metal-organic frameworks(MOFs),with their unique framework structure,large specific surface area,high heavy metal capturing capacity,and tunable conductivity,offer promising solutions to these issues.Recent studies have integrated MOFs into PSCs architectures to enhance performance and durability.This comprehensive review begins with an in-depth discussion of the structure,optical properties,electrical characteristics,and stability of MOFs,as well as their theoretical compatibility with perovskites.Subsequently,it provides a detailed analysis of how MOFs enhance charge carrier transport,promote perovskite crystallinity,improve device stability,and suppress lead leakage in PSCs.In summary,this review examines the research progress and potential of integrating MOFs with perovskites to address the critical PSCs challenges of efficiency,instability,and toxicity.展开更多
For hypersonic air-breathing vehicles,the V-shaped leading edges(VSLEs)of supersonic combustion ramjet(scramjet)inlets experience complex shock interactions and intense aerodynamic loads.This paper provides a comprehe...For hypersonic air-breathing vehicles,the V-shaped leading edges(VSLEs)of supersonic combustion ramjet(scramjet)inlets experience complex shock interactions and intense aerodynamic loads.This paper provides a comprehensive review of flow characteristics at the crotch of VSLEs,with particular focus on the transition of shock interaction types and the variation of wall heat flux under different freestream Mach numbers and geometric configurations.The mechanisms governing shock transition,unsteady oscillations,hysteresis,and three-dimensional effects in VSLE flows are first examined.Subsequently,thermal protection strategies aimed at mitigating extreme heating loads are reviewed,emphasizing their relevance to practical engineering applications.Special attention is given to recent studies addressing thermochemical nonequilibrium effects on VSLE shock interactions,and the limitations of current research are critically assessed.Finally,perspectives for future investigations into hypersonic VSLE shock interactions are outlined,highlighting opportunities for advancing design and thermal management strategies.展开更多
Filamentous fungi are able to accumulate significant amount of metals from their environment. The potential of fungal biomass as agents for biosorption of heavy metals from contaminated sediments is currently receivin...Filamentous fungi are able to accumulate significant amount of metals from their environment. The potential of fungal biomass as agents for biosorption of heavy metals from contaminated sediments is currently receiving attention. In the present study, a total of 41 isolates of filamentous fungi obtained from the sediment of the Langat River, Selangor, Malaysia were screened for their tolerance and uptake capability of copper （Cu） and lead （Pb）. The isolates were identified as Aspergillus niger, A. fumigatus, Trichoderma asperellum, Penicillium simplicissimurn and P. janthinellum. A. niger and P. simplicissimum, were able to survive at 1000 mg/L of Cu（Ⅱ） concentration on Potato Dextrose Agar （PDA） while for Pb, only A. niger survived at 5000 mg/L concentration. The results showed that A. niger, P. simplicissimum and T. asperellum have a better uptake capacity for Pb compared to Cu and the findings indicated promising biosorption of Cu and Pb by these filamentous fungi from aqueous solution. The present study was also determined the maximum removal of Cu（Ⅱ） and Pb（Ⅱ） that was performed by A. niger. The metal removal which occurred at Cu（Ⅱ） 200 mg/L was （20.910 ＋ 0.581） mg/g and at 250 mg/L of PbⅡ） was （54.046 ± 0.328） mg/g.展开更多
[Objective] The aim was to seek effective soil remediation technologies suitable for soils slightly or moderately polluted. [Method] In-situ leaching-immobi- lization was used to research remediation soil and vegetabl...[Objective] The aim was to seek effective soil remediation technologies suitable for soils slightly or moderately polluted. [Method] In-situ leaching-immobi- lization was used to research remediation soil and vegetable contaminated by lead in vegetable bases in Chongqing. [Result] By tartaric acid-based leaching-sodium sulphide-based immobilization, vegetable Pb reduction rate was 46.4%, soil Pb reduction rate was 8.45% and Pb immobilization rate was 9.3% in deeper horizons. EDTA leaching did reduce lead content in vegetables, but reduced vegetable yield simultaneously. [Conclusion] The coupling remediation technology brought heavy metal contents down in vegetables without affecting productions. Therefore, it guarantees vegetable safety and reduces vegetable farmer＇s economic loss. It is a remediation technology suitable for soils slightly or moderately contaminated by heavy metals.展开更多
This paper deals with a study on SnPb and lead-free soldered joint reliability of PLCC devices with different lead counts under three kinds of temperature cycle profiles, which is based on non-linear finite element me...This paper deals with a study on SnPb and lead-free soldered joint reliability of PLCC devices with different lead counts under three kinds of temperature cycle profiles, which is based on non-linear finite element method. By analyzing the stress of soldered joints, it is found that the largest stress is at the area between the soldered joints and the leads, and analysis results indicate that the yon Mises stress at the location slightly increases with the increase of lead counts. For PLCC with 84 leads the soldered joints was modeled for three typical loading （273 -398 K, 218 -398 K and 198 -398 K） in order to study the influence of acceleration factors on the reliability of soldered joints. And the estimation of equivalent plastic strain of three different lead-free solder alloys （ Sn3.8AG0. 7Cu, Sn3.5Ag and Sn37Pb ） was also carried out.展开更多
In order to illustrate the thermodynamic characteristics of arsenic during alkaline pressure oxidation leaching process oflead anode slime(NaNO3as oxidant;NaOH as alkaline reagent),theφ-pH diagrams of As-Na-H2O,N-H2O...In order to illustrate the thermodynamic characteristics of arsenic during alkaline pressure oxidation leaching process oflead anode slime(NaNO3as oxidant;NaOH as alkaline reagent),theφ-pH diagrams of As-Na-H2O,N-H2O,As-N-Na-H2Osystems at ionic mass concentration of0.1mol/kg and temperatures of298,373,423and473K were established according tothermodynamic calculation.The results show that the existence forms of arsenic are associated with pH value,which mainly exists inthe forms of H3AsO4,24H AsO-,24HAsO-,H2AsO2-and As2O3in lower pH region,while it mainly exists in the form of3AsO4-when pH>11.14.High alkali concentration and high temperature are advantageous to the arsenic leaching.The alkaline pressureoxidation leaching experiments display that the tendency of arsenic leaching rate confirms the thermodynamic analysis resultsobtained from theφ-pH diagrams of As-N-Na-H2O system,and the highest leaching rate of arsenic reaches95.85%at453K.展开更多
Rice grain size is an important trait that affects rice yield and quality, and thus the identification of genes related to grain size is of great significance for improving rice yield and quality. Many genes related t...Rice grain size is an important trait that affects rice yield and quality, and thus the identification of genes related to grain size is of great significance for improving rice yield and quality. Many genes related to grain size, such as DEP1(Huang et al., 2009),GW5(Liu et al., 2017).展开更多
Experimental studies on phase equilibria and liquidus temperature in the PbO-ZnO-CaO-SiO2-＂Fe2O3＂ system,with the mass ratios of CaO/SiO2=1-1.6 and Fe/SiO2= 1.3-1.7,and 40% PbO and 8% ZnO,were carried out between 12...Experimental studies on phase equilibria and liquidus temperature in the PbO-ZnO-CaO-SiO2-＂Fe2O3＂ system,with the mass ratios of CaO/SiO2=1-1.6 and Fe/SiO2= 1.3-1.7,and 40% PbO and 8% ZnO,were carried out between 1273 and 1573 K.Slags were equilibrated at 1273 to 1573 K and cooled rapidly by quenching.The XRD and SEM-EDS results showed that the slag compositions are in the franklinite primary phase field.Calcium and lead silicates are formed between 1373 and 1473 K.The Ca/Pb silicate and magnetoplumbite phases are partially formed by an incongruent reaction.The experimental and thermodynamical results showed that the liquidus increased by increasing CaO/SiO2 mass ratio and decreasing Fe/SiO2 mass ratio.展开更多
This paper proposes a numerical method to analyze the ice protection capability and predict the power requirements of a piezoelectric resonant de-icing system.The method is based on a coupled electro-mechanical finite...This paper proposes a numerical method to analyze the ice protection capability and predict the power requirements of a piezoelectric resonant de-icing system.The method is based on a coupled electro-mechanical finite element analysis which enables the fast computation of the modes of resonance of interest to de-ice curved surfaces and the estimation of the input voltage and current required for a given configuration(defined by its mode,actuator location,ice deposit,etc.).Eventually,the electric power to be supplied can be also assessed.The method is applied to a NACA 0024 leading edge equipped with piezoelectric actuators.First,two extension modes are analyzed and compared with respect to their efficiency and power requirements.Then,tests are carried out in an icing tunnel to verify the effectiveness of the piezoelectric ice protection system and the predictions of the maximal required power.The system allows de-icing the leading edge in less than 2 s for a glaze ice deposit.展开更多
Vaporization behavior （1163-1463 K） of lead in the slag system of FeO-CaO-SiO2-Al2O3 with CaC% was examined. A thermodynamic estimation with the principle of Gibbs free energy minimization showed that the major vapo...Vaporization behavior （1163-1463 K） of lead in the slag system of FeO-CaO-SiO2-Al2O3 with CaC% was examined. A thermodynamic estimation with the principle of Gibbs free energy minimization showed that the major vapor species from the sample of the FeO-CaO-SiO2-Al2O3 system＋PbO＋CaCl2 were metallic Pb, PbCl, PbCl2, and FeCl2, at the experimental temperature range. The experimental results show that the mole ratio of vaporized Cl in lead chlorides to vaporized Pb, simply expressed as Cl/Pb decreases with increasing temperature. The larger Cl/Pb means a larger ratio of gaseous PbCl2, since metallic Pb and PbCl vapors are formed in a similar reduction atmosphere. The evaporation is initially rapid and becomes steady after holding for 10 min. Gaseous PbCl2 is mainly formed during the heating period, and at the holding stage, it reacts with FeO to produce gaseous FeCl2 With regard to slag composition, FeO content and basicity significantly affect the evaporation of lead. High FeO content and high basicity promotes the formation of metallic Pb and PbCI, whereas, it prohibits PbCl2 evaporation.展开更多
In this study, we searched multiple databases for all relevant original articles (1996-2013). To investigate blood lead levels (BLL) and possible risk factors for lead exposure among children in China A total of 388 a...In this study, we searched multiple databases for all relevant original articles (1996-2013). To investigate blood lead levels (BLL) and possible risk factors for lead exposure among children in China A total of 388 articles met our inclusion criteria. The overall geometric mean (GM) BLL was 71 μg/L, and the prevalence of elevated BLL (EBLL, defined as BLL ≥100 μg/L) was 18.48% among children. The prevalence of EBLL remained significantly higher among boys. In children less than 6 years of age, there were significantly increasing trends in both BLL and prevalence of EBLL in an age-dependent manner. The ban on leaded gasoline significantly reduced the BLL as well as EBLL prevalence; however, children whose parents had lower educational levels or were exposed to lead in the workplace had a higher EBLL prevalence. Despite its decline over time, the average BLL among children in China remains higher than the average level most recently reported in the United States. Childhood lead poisoning remains a public health problem in China.展开更多
基金Projects(2023AG05008,202302AB080012)supported by the Yunnan Major Scientific and Technological Program,ChinaProject(202405AC350015)supported by the Science and Technology Talent Programme of Yunnan Province,China。
文摘The phase transformation of galena in H_(2)SO_(4)-Fe_(2)(SO_(4))_(3) system under oxygen pressure was investigated.Results indicated that the critical conditions for the phase transformation of galena into lead jarosite(Pb-J)were 130℃,30 g/L H_(2)SO_(4),15 g/L Fe^(3+),and an oxygen partial pressure of 0.4 MPa.Furthermore,increased Fe^(3+)concentration and oxygen partial pressure did not enhance jarosite formation.Conversely,lowering the temperature and increasing the H_(2)SO_(4) concentration facilitated PbSO_(4) formation and inhibited its further conversion to Pb-J.Additionally,the effects of potassium sulfate,sodium sulfate,and high concentrations of zinc sulfate on the phase transformation of galena were examined through leaching tests,XRD,SEM-EDS,and FT-IR analyses.All three sulfates inhibited the conversion of galena to Pb-J.Among these,potassium sulfate prevented Pb-J formation and converted it more thoroughly into potassium jarosite.However,high concentrations of zinc sulfate facilitated the crystallization of both PbSO_(4) and Pb-J,which altered the morphology of the product.Zinc ions coprecipitated with Pb-J,thereby integrating into the product.
文摘To address the current situation where many small enterprises lack efficient management of customer data, this paper proposes a design and implementation plan of a customer relationship management (CRM) system based on email service. It aims to solve the problems of data dispersion, untimely update and information redundancy in customer management of small and medium-sized enterprises. The system includes four core functional modules: historical email analysis, lead pool management, customer management and email archiving. Through email mining and web crawler technology, the system can extract potential customer information from historical emails and enrich lead data;the lead pool management module supports lead information maintenance, status tracking and conversion of high-value leads;the customer management module realizes the maintenance and dynamic tracking of customer information;the email management module provides the archiving of emails and attachments and the structured storage of basic email information. The system provides automated and intelligent customer information management, improves the work efficiency of sales staff, and provides an efficient customer relationship management solution for enterprises.
基金supported by the National Research Foundation(NRF)of Korea through the Basic Science Research Programs(Nos.2019R1A2C1085448,2023R1A2C1005421,RS-2024-00356939)funded by the Korean Government.
文摘To present an advanced device scheme of high-performance optoelectronic synapses,herein,we demonstrated the electrically-and/or optically-drivable multifaceted synaptic capabilities on the 2D semiconductor channel-based ferroelectric field-effect transistor(FeFET)architecture.The device was fabricated in the form of the MoS_(2)/PZT FeFET,and its synaptic weights were effectively controlled by dual stimuli(i.e.,both electrical and optical pulses simultaneously)as well as single stimuli(i.e.,either electrical or optical pulses alone).This could be attributed to the electrical pulse-tunable strong ferroelectric polarization in PbZrxTi_(1−x)O_(3)(PZT)as well as the polarization field-enhanced persistent photoconductivity effect in MoS_(2).Additionally,it was confirmed that the proposed device possesses substantial activity,achieving approximately 95%pattern recognition accuracy.The results substantiate the great potential of the 2D semiconductor channel-based FeFET device as a high-performance optoelectronic synaptic platform,marking a pivotal stride towards the realization of advanced neuromorphic computing systems.
文摘A kind of management system for electric vehicle (EV) battery series was developed. The system can predict residual capacity for EV battery series and mileages. The system can determine if it is necessary for the battery series to be charged. The system can determine which battery is necessary to be updated for the reason of damage or aging. The system can display the total voltage of battery series, extreme voltage and temperature of every battery in the series. The system can display the accumulative discharge for every battery in the series. The system can alarm when both total or extreme voltage is at low level, or temperature of a battery in the series is at high level. The system provided with a microprocessor as key part can collect and record signal of charging and discharging current, total voltage, extreme voltage and temperature for every battery. The mathematical model of residual capacity for EV lead acid batteries was discussed in details. The system operates well in the laboratory and meets the requirement.
基金Project supported by the Japan Oil,Gas and Metals National Corporation(JOGMEC)Project(51474021)supported by the National Natural Science Foundation of China
文摘Vapor pressure of lead and lead chlorides from FeOT？CaO？SiO2？Al2O3 slag system was measured by using Knudsen effusion method. The results suggest that the vapor pressures of lead and lead chlorides increase with increasing temperature. For the slag systems without chlorine, the logarithm of vapor pressure （lnp） shows highly linear dependency on the reciprocal of temperature （1/T）, and higher vapor pressure is observed in the condition where more metallic lead vapor is formed. In this case, the vapor pressure of lead increases with increasing slag basicity （w（CaO）/w（SiO2））, increasing FeO content andw（Fe2＋）/w（Fe3＋） ratio. For the case of slag system with chlorine addition, the total pressures of PbCl2 and PbCl increase with decreasing basicity and FeO content of slag.
基金The National Key Technology R&D Program of China during the 11 th Five-Year Plan Period(No.2006BAH02A06)
文摘In order to let the supplier make more reasonable supply decisions,an integrated continuous replenishment policy for the vendor-managed inventory system is presented,which considers the quantity-based shipment consolidation and stock replenishment with lead time.Then the system cost is analyzed and a mathematical model is built.Since the model is rather complex,the bounds of the optimal policy are first attained,then the problem is solved by a heuristic algorithm.Through experiments the relationship between the order lead time and the corresponding integrated policy is discussed,and the influence on the system cost is also analyzed.The results reveal that the lead time's influence on the system is more serious with the increase of the order lead time,the integrated policy with the order lead time is more reasonable and the optimal policy can minimize the total system cost.Finally,the parameter sensitivity of the model is analyzed.
基金Project(2013BAB03B05)supported by the National Key Technology R&D Program of China during the 12th Five-Year Plan Period,ChinaProject(20133BCB23018)supported by the Foundation for Young Scientist(Jinggang Star)of Jiangxi Province,ChinaProject(2012ZBAB206002)supported by the Natural Science Foundation of Jiangxi Province,China
文摘According to the ion and molecule coexistence theory, a thermodynamic model of lead oxide activity in PbO-CaO-SiO2-FeO-Fe2O3 slag system was established at the temperature of 1273-1733 K. The activities of Pb O in slag were calculated, and their equal activity curves were plotted. The influences of slag basicity Q, iron oxide rate R and temperature T on activity NPb O and activity coefficient γPbO were also investigated. Results show that the calculated values of γPb O are in good agreement with the reported experimental data, showing that the model can wholly embody the slag structural characteristics. NPbO departures positively from Raoult values, and increases with increasing Pb O content in slag but changes little with T. γPbO increases with increasing Q, and goes through the maximum with increasing R for basic slag（Q0.3）. Results can be applied to the thermodynamic research and operational optimization of modern lead smelting technologies.
文摘China’s shipbuilding industry maintained the world’s largest market share in terms of three major indicators for the 16th consecutive year in 2025,according to data released by the Ministry of Industry and Information Technology on 1 February.
基金financially supported by the National Natural Science foundation of China(grants nos.52272176)。
文摘Lead-halide perovskite solar cells(PSCs)have rapidly achieved certified efficiencies>27%,rivaling silicon photovoltaics.However,their commercialization is hindered by intrinsic material challenges:poor operational stability under moisture,heat,and light;toxic lead leakage from degraded films.Metal-organic frameworks(MOFs),with their unique framework structure,large specific surface area,high heavy metal capturing capacity,and tunable conductivity,offer promising solutions to these issues.Recent studies have integrated MOFs into PSCs architectures to enhance performance and durability.This comprehensive review begins with an in-depth discussion of the structure,optical properties,electrical characteristics,and stability of MOFs,as well as their theoretical compatibility with perovskites.Subsequently,it provides a detailed analysis of how MOFs enhance charge carrier transport,promote perovskite crystallinity,improve device stability,and suppress lead leakage in PSCs.In summary,this review examines the research progress and potential of integrating MOFs with perovskites to address the critical PSCs challenges of efficiency,instability,and toxicity.
基金funded by the Research Fund of National Key Laboratory of Aerospace Physics in Fluids,grant number 2024-APF-KFZD-01Guangdong Basic and Applied Basic Research Foundation,grant number 2025A1515012081+1 种基金National Natural Science Foundation of China,grant number 12002193Shandong Provincial Natural Science Foundation,China,grant number ZR2019QA018.
文摘For hypersonic air-breathing vehicles,the V-shaped leading edges(VSLEs)of supersonic combustion ramjet(scramjet)inlets experience complex shock interactions and intense aerodynamic loads.This paper provides a comprehensive review of flow characteristics at the crotch of VSLEs,with particular focus on the transition of shock interaction types and the variation of wall heat flux under different freestream Mach numbers and geometric configurations.The mechanisms governing shock transition,unsteady oscillations,hysteresis,and three-dimensional effects in VSLE flows are first examined.Subsequently,thermal protection strategies aimed at mitigating extreme heating loads are reviewed,emphasizing their relevance to practical engineering applications.Special attention is given to recent studies addressing thermochemical nonequilibrium effects on VSLE shock interactions,and the limitations of current research are critically assessed.Finally,perspectives for future investigations into hypersonic VSLE shock interactions are outlined,highlighting opportunities for advancing design and thermal management strategies.
基金UPM and the Fundamental Research Grant Scheme provided by Ministry of Higher Education under project no. 01-11-08-661FR for the financial support for some parts of this study
文摘Filamentous fungi are able to accumulate significant amount of metals from their environment. The potential of fungal biomass as agents for biosorption of heavy metals from contaminated sediments is currently receiving attention. In the present study, a total of 41 isolates of filamentous fungi obtained from the sediment of the Langat River, Selangor, Malaysia were screened for their tolerance and uptake capability of copper （Cu） and lead （Pb）. The isolates were identified as Aspergillus niger, A. fumigatus, Trichoderma asperellum, Penicillium simplicissimurn and P. janthinellum. A. niger and P. simplicissimum, were able to survive at 1000 mg/L of Cu（Ⅱ） concentration on Potato Dextrose Agar （PDA） while for Pb, only A. niger survived at 5000 mg/L concentration. The results showed that A. niger, P. simplicissimum and T. asperellum have a better uptake capacity for Pb compared to Cu and the findings indicated promising biosorption of Cu and Pb by these filamentous fungi from aqueous solution. The present study was also determined the maximum removal of Cu（Ⅱ） and Pb（Ⅱ） that was performed by A. niger. The metal removal which occurred at Cu（Ⅱ） 200 mg/L was （20.910 ＋ 0.581） mg/g and at 250 mg/L of PbⅡ） was （54.046 ± 0.328） mg/g.
基金Supported by Chongqing Key Technologies R&D Program(CSTC2011AC101)Technology Supporting Program in 2013 of Chongqing Agriculture Committee~~
文摘[Objective] The aim was to seek effective soil remediation technologies suitable for soils slightly or moderately polluted. [Method] In-situ leaching-immobi- lization was used to research remediation soil and vegetable contaminated by lead in vegetable bases in Chongqing. [Result] By tartaric acid-based leaching-sodium sulphide-based immobilization, vegetable Pb reduction rate was 46.4%, soil Pb reduction rate was 8.45% and Pb immobilization rate was 9.3% in deeper horizons. EDTA leaching did reduce lead content in vegetables, but reduced vegetable yield simultaneously. [Conclusion] The coupling remediation technology brought heavy metal contents down in vegetables without affecting productions. Therefore, it guarantees vegetable safety and reduces vegetable farmer＇s economic loss. It is a remediation technology suitable for soils slightly or moderately contaminated by heavy metals.
基金the Jiangsu General Colleges and Universities Postgraduate Scientific Research Innovative Plan under Grant No. CX07B_087zthe Six Kind Skilled Personnel Project of Jiangsu Province,under Grant No. 06-E-020
文摘This paper deals with a study on SnPb and lead-free soldered joint reliability of PLCC devices with different lead counts under three kinds of temperature cycle profiles, which is based on non-linear finite element method. By analyzing the stress of soldered joints, it is found that the largest stress is at the area between the soldered joints and the leads, and analysis results indicate that the yon Mises stress at the location slightly increases with the increase of lead counts. For PLCC with 84 leads the soldered joints was modeled for three typical loading （273 -398 K, 218 -398 K and 198 -398 K） in order to study the influence of acceleration factors on the reliability of soldered joints. And the estimation of equivalent plastic strain of three different lead-free solder alloys （ Sn3.8AG0. 7Cu, Sn3.5Ag and Sn37Pb ） was also carried out.
基金Project(51564031) supported by the National Natural Science Foundation of ChinaProject(0201352042) supported by the Cooperation between School and Enterprise of China
文摘In order to illustrate the thermodynamic characteristics of arsenic during alkaline pressure oxidation leaching process oflead anode slime(NaNO3as oxidant;NaOH as alkaline reagent),theφ-pH diagrams of As-Na-H2O,N-H2O,As-N-Na-H2Osystems at ionic mass concentration of0.1mol/kg and temperatures of298,373,423and473K were established according tothermodynamic calculation.The results show that the existence forms of arsenic are associated with pH value,which mainly exists inthe forms of H3AsO4,24H AsO-,24HAsO-,H2AsO2-and As2O3in lower pH region,while it mainly exists in the form of3AsO4-when pH>11.14.High alkali concentration and high temperature are advantageous to the arsenic leaching.The alkaline pressureoxidation leaching experiments display that the tendency of arsenic leaching rate confirms the thermodynamic analysis resultsobtained from theφ-pH diagrams of As-N-Na-H2O system,and the highest leaching rate of arsenic reaches95.85%at453K.
基金supported by the grants from the National Key Research and Development Program of China (2016YFD0100406)the Rice Molecular Design Breeding (2016YFD0101801)+1 种基金the National Natural Science Foundation of China (91535102 and 31771760)the Open Research Fund of State Key Laboratory of Hybrid Rice (Hunan Hybrid Rice Research Center) (2016KF09)
文摘Rice grain size is an important trait that affects rice yield and quality, and thus the identification of genes related to grain size is of great significance for improving rice yield and quality. Many genes related to grain size, such as DEP1(Huang et al., 2009),GW5(Liu et al., 2017).
文摘Experimental studies on phase equilibria and liquidus temperature in the PbO-ZnO-CaO-SiO2-＂Fe2O3＂ system,with the mass ratios of CaO/SiO2=1-1.6 and Fe/SiO2= 1.3-1.7,and 40% PbO and 8% ZnO,were carried out between 1273 and 1573 K.Slags were equilibrated at 1273 to 1573 K and cooled rapidly by quenching.The XRD and SEM-EDS results showed that the slag compositions are in the franklinite primary phase field.Calcium and lead silicates are formed between 1373 and 1473 K.The Ca/Pb silicate and magnetoplumbite phases are partially formed by an incongruent reaction.The experimental and thermodynamical results showed that the liquidus increased by increasing CaO/SiO2 mass ratio and decreasing Fe/SiO2 mass ratio.
文摘This paper proposes a numerical method to analyze the ice protection capability and predict the power requirements of a piezoelectric resonant de-icing system.The method is based on a coupled electro-mechanical finite element analysis which enables the fast computation of the modes of resonance of interest to de-ice curved surfaces and the estimation of the input voltage and current required for a given configuration(defined by its mode,actuator location,ice deposit,etc.).Eventually,the electric power to be supplied can be also assessed.The method is applied to a NACA 0024 leading edge equipped with piezoelectric actuators.First,two extension modes are analyzed and compared with respect to their efficiency and power requirements.Then,tests are carried out in an icing tunnel to verify the effectiveness of the piezoelectric ice protection system and the predictions of the maximal required power.The system allows de-icing the leading edge in less than 2 s for a glaze ice deposit.
基金supported by the National Natural Science Foundation of China (No.50704004)
文摘Vaporization behavior （1163-1463 K） of lead in the slag system of FeO-CaO-SiO2-Al2O3 with CaC% was examined. A thermodynamic estimation with the principle of Gibbs free energy minimization showed that the major vapor species from the sample of the FeO-CaO-SiO2-Al2O3 system＋PbO＋CaCl2 were metallic Pb, PbCl, PbCl2, and FeCl2, at the experimental temperature range. The experimental results show that the mole ratio of vaporized Cl in lead chlorides to vaporized Pb, simply expressed as Cl/Pb decreases with increasing temperature. The larger Cl/Pb means a larger ratio of gaseous PbCl2, since metallic Pb and PbCl vapors are formed in a similar reduction atmosphere. The evaporation is initially rapid and becomes steady after holding for 10 min. Gaseous PbCl2 is mainly formed during the heating period, and at the holding stage, it reacts with FeO to produce gaseous FeCl2 With regard to slag composition, FeO content and basicity significantly affect the evaporation of lead. High FeO content and high basicity promotes the formation of metallic Pb and PbCI, whereas, it prohibits PbCl2 evaporation.
基金supported by The National Natural Science Foundation of China(No.81172628)the Fundamental Research Funds for the Central Universities(No.2014305020201)
文摘In this study, we searched multiple databases for all relevant original articles (1996-2013). To investigate blood lead levels (BLL) and possible risk factors for lead exposure among children in China A total of 388 articles met our inclusion criteria. The overall geometric mean (GM) BLL was 71 μg/L, and the prevalence of elevated BLL (EBLL, defined as BLL ≥100 μg/L) was 18.48% among children. The prevalence of EBLL remained significantly higher among boys. In children less than 6 years of age, there were significantly increasing trends in both BLL and prevalence of EBLL in an age-dependent manner. The ban on leaded gasoline significantly reduced the BLL as well as EBLL prevalence; however, children whose parents had lower educational levels or were exposed to lead in the workplace had a higher EBLL prevalence. Despite its decline over time, the average BLL among children in China remains higher than the average level most recently reported in the United States. Childhood lead poisoning remains a public health problem in China.
