The cemented tailings backfill(CTB)with initial defects is more prone to destabilization damage under the influence of various unfavorable factors during the mining process.In order to investigate its influence on the...The cemented tailings backfill(CTB)with initial defects is more prone to destabilization damage under the influence of various unfavorable factors during the mining process.In order to investigate its influence on the stability of underground mining engineering,this paper simulates the generation of different degrees of initial defects inside the CTB by adding different contents of air-entraining agent(AEA),investigates the acoustic emission RA/AF eigenvalues of CTB with different contents of AEA under uniaxial compression,and adopts various denoising algorithms(e.g.,moving average smoothing,median filtering,and outlier detection)to improve the accuracy of the data.The variance and autocorrelation coefficients of RA/AF parameters were analyzed in conjunction with the critical slowing down(CSD)theory.The results show that the acoustic emission RA/AF values can be used to characterize the progressive damage evolution of CTB.The denoising algorithm processed the AE signals to reduce the effects of extraneous noise and anomalous spikes.Changes in the variance curves provide clear precursor information,while abrupt changes in the autocorrelation coefficient can be used as an auxiliary localization warning signal.The phenomenon of dramatic increase in the variance and autocorrelation coefficient curves during the compression-tightening stage,which is influenced by the initial defects,can lead to false warnings.As the initial defects of the CTB increase,its instability precursor time and instability time are prolonged,the peak stress decreases,and the time difference between the CTB and the instability damage is smaller.The results provide a new method for real-time monitoring and early warning of CTB instability damage.展开更多
In this research, it used advanced oxidation processes for the recovery, detoxification and mineralization of wastewater mainly contaminated by antibiotics （ciprofloxacin）. These processes can be used alone or in co...In this research, it used advanced oxidation processes for the recovery, detoxification and mineralization of wastewater mainly contaminated by antibiotics （ciprofloxacin）. These processes can be used alone or in combination with each other or by complementing traditional methods, even allowing the disinfection of bacterial and viral inactivation. With the use of experimental systems UV/H202/O3, UV/H202, it can achieve total mineralization of the compound. Ciprofloxacin solutions used at 50, 100, 200, 300, 400 and 500 ppm, degraded to 100% of antibiotics and by a microbiological method show that the loss of biological activity is inversely proportional to the time of irradiation.展开更多
Phthalic acid esters(PAEs)are a group of compounds widespread in the environment.To investigate the occurrence and accumulation characteristics of PAEs,surface water samples were collected from the Three Gorges Reserv...Phthalic acid esters(PAEs)are a group of compounds widespread in the environment.To investigate the occurrence and accumulation characteristics of PAEs,surface water samples were collected from the Three Gorges Reservoir area,China.The total concentrations of∑_(11)analyzed PAEs(11PAEs)in the collected water samples ranging from 197.7 to 1,409.3 ng/L(mean±IQR:583.1±308.4 ng/L).While DEHP was the most frequently detected PAE,DnBP and DnNP were the most predominant PAEs in the analyzed water samples with a mean contribution of 63.3%of the∑_(11)PAEs.The concentrations of the∑_(11)PAEs in the water samples from the upper reaches of the Yangtze River were significantly higher than those from themiddle reaches.To better understand the transport and fate of the PAEs,seven detected PAEs were modeled by Quantitative Water Air Sediment Interaction(QWASI).The simulated and measured values were close for most PAEs,and differences are within one order of magnitude even for the worst one.For all simulated PAEs,water and particle inflow were main sources in the reservoir,whereas water outflow and degradation in water were important removal pathways.The contribution ratios of different sources/losses varied fromPAEs,depending on their properties.The calculated risk quotients of DnNP in the Three Gorges Reservoir area whether based onmonitoring or simulating results were all far exceeded the safety threshold value,implying the occurrence of this PAE compound may cause potential adverse effects for the aquatic ecology of the Three Gorges Reservoir area.展开更多
A critical challenge hindering the practical application of lithium–oxygen batteries(LOBs)is the inevitable problems associated with liquid electrolytes,such as evaporation and safety problems.Our study addresses the...A critical challenge hindering the practical application of lithium–oxygen batteries(LOBs)is the inevitable problems associated with liquid electrolytes,such as evaporation and safety problems.Our study addresses these problems by proposing a modified polyrotaxane(mPR)-based solid polymer electrolyte(SPE)design that simultaneously mitigates solvent-related problems and improves conductivity.mPR-SPE exhibits high ion conductivity(2.8×10^(−3)S cm^(−1)at 25℃)through aligned ion conduction pathways and provides electrode protection ability through hydrophobic chain dispersion.Integrating this mPR-SPE into solid-state LOBs resulted in stable potentials over 300 cycles.In situ Raman spectroscopy reveals the presence of an LiO_(2)intermediate alongside Li_(2)O_(2)during oxygen reactions.Ex situ X-ray diffraction confirm the ability of the SPE to hinder the permeation of oxygen and moisture,as demonstrated by the air permeability tests.The present study suggests that maintaining a low residual solvent while achieving high ionic conductivity is crucial for restricting the sub-reactions of solid-state LOBs.展开更多
Developmental and reproductive toxicity(DART)endpoint entails a toxicological assessment of all developmental stages and reproductive cycles of an organism.In silico tools to predict DART will provide a method to asse...Developmental and reproductive toxicity(DART)endpoint entails a toxicological assessment of all developmental stages and reproductive cycles of an organism.In silico tools to predict DART will provide a method to assess this complex toxicity endpoint and will be valuable for screening emerging pollutants as well as for m anaging new chemicals in China.Currently,there are few published DART prediction models in China,but many related research and development projects are in progress.In 2013,WU et al.published an expert rule-based DART decision tree(DT).This DT relies on known chemical structures linked to DART to forecast DART potential of a given chemical.Within this procedure,an accurate DART data interpretation is the foundation of building and expanding the DT.This paper excerpted case studies demonstrating DART data curation and interpretation of four chemicals(including 8-hydroxyquinoline,3,5,6-trichloro-2-pyridinol,thiacloprid,and imidacloprid)to expand the existing DART DT.Chemicals were first selected from the database of Solid Waste and Chemicals Management Center,Ministry of Ecology and Environment(MEESCC)in China.The structures of these 4 chemicals were analyzed and preliminarily grouped by chemists based on core structural features,functional groups,receptor binding property,metabolism,and possible mode of actions.Then,the DART conclusion was derived by collecting chemical information,searching,integrating,and interpreting DART data by the toxicologists.Finally,these chemicals were classified into either an existing category or a new category via integrating their chemical features,DART conclusions,and biological properties.The results showed that 8-hydroxyquinoline impacted estrous cyclicity,s exual organ weights,and embryonal development,and 3,5,6-trichloro-2-pyridinol caused central nervous system(CNS)malformations,which were added to an existing subcategory 8e(aromatic compounds with multi-halogen and nitro groups)of the DT.Thiacloprid caused dystocia and fetal skeletal malformation,and imidacloprid disrupted the endocrine system and male fertility.They both contain 2-chloro-5-methylpyridine substituted imidazolidine c yclic ring,which were expected to create a new category of neonicotinoids.The current work delineates a t ransparent process of curating toxicological data for the purpose of DART data interpretation.In the presence of sufficient related structures and DART data,the DT can be expanded by iteratively adding chemicals within the a pplicable domain of each category or subcategory.This DT can potentially serve as a tool for screening emerging pollutants and assessing new chemicals in China.展开更多
With the acceleration of the energy transition,new synthetic routes for converting alkanes into highvalue products are emerging.However,the thermal safety of these new routes may not have been fully considered,potenti...With the acceleration of the energy transition,new synthetic routes for converting alkanes into highvalue products are emerging.However,the thermal safety of these new routes may not have been fully considered,potentially leading to dangers during the optimization of reaction conditions.This study reports,for the first time,a reactor explosion incident during the experiment of a new synthetic route for adipic acid:nitric acid oxidation of n-hexane.Differential scanning calorimetry(DSC),accelerating rate calorimetry(ARC),and corrective calculations were used to investigate the cause of the explosion.The results indicate that the polyparaphenol(PPL) liner material,which was used for the first time in the experiment,is unlikely to react with the system and cause the explosion.When the nitric acid concentration is increased from 3.7 mol·L^(-1) to 5.4 mol·L^(-1),the thermal stability of the system decreases,and the heat release surpasses the chemical explosion threshold(1000 J·g^(-1)).The maximum self-heat rate(d T/dtmax) increases by at least 7 times,and the maximum pressure rise rate(dp/dtmax)increases by at least 11 times.This led to the actual pressure in the reactor increasing from 4.96 MPa to at least 11.09 MPa,which far exceeded the rated pressure(3 MPa) and reached the rupture pressure(3.5to 4 times their rated pressure),resulting in the explosion.This study aims to provide a warning regarding the safety of new synthetic routes involving the nitric acid-organic systems,particularly the conversion of alkanes,to prevent the recurrence of similar incidents.展开更多
Flood regulation service(FRS)stands as one of the key benefits that people get from the ecosystem.Under the influence of climate change and human activities,the relationship between supply and demand of FRS would incr...Flood regulation service(FRS)stands as one of the key benefits that people get from the ecosystem.Under the influence of climate change and human activities,the relationship between supply and demand of FRS would increasingly affect regional flood risk and sustainable development.However,there was currently a lack of systematic study on the future supply-demand relationship of FRS in the flood-vulnerable area undergoing rapidly development in China.This study integrated the Scenario Model Intercomparison Project(ScenarioMIP)with the Shared Socioeconomic Pathways(SSPs)datasets and climate model data to quantify the supply-demand ratio(SDR)of FRS in the Yangtze River Delta(YRD),China from 2020 to 2050.Trend analyses were conducted using linear regres-sion,Theil-Sen median estimation,and Hurst exponent analysis,while key drivers of SDR changes were identified and quantified through the Lindeman-Merenda-Gold(LMG)method between 2021 and 2050.Results show that the supply of FRS in the YRD was generally insufficient to meet the demand.The imbalanced subbasins covered 88.24%of the total study area,with 34.48%of this imbal-anced area concentrated in the Southeastern Basin in China.During 2021 and 2050,the imbalance of FRS supply-demand relationship would largely aggravate in the YRD,of which the aggravated area would account for 77.23%.Under different scenarios,the SDR for FRS would decrease significantly,with rates ranging from-5.45×10^(-4) to-2.06×10^(-4)(P<0.05).Especially,the decline rate of SDR in the YRD Basin(DeltaB)reached 2.92 times that the average of YRD.Human activities were the primary factors that exacerbated the imbalance in FRS supply-demand relationship,of which the relative contribution rate exceeds 75%.Particular attention should be direc-ted toward critical regions like the Southeast Basin in China(SEB)and DeltaB where substantial aggravation of supply-demand imbal-ances of FRS is projected.展开更多
The operational state of distillation columns significantly impacts product quality and production efficiency.However,due to the complex operation and diverse influencing factors,ensuring the safety and efficient oper...The operational state of distillation columns significantly impacts product quality and production efficiency.However,due to the complex operation and diverse influencing factors,ensuring the safety and efficient operation of the distillation columns becomes paramount.This research combines passive acoustic monitoring with artificial intelligence techniques,proposed a technology based on residual network(ResNet),which involves the transformation of the acoustic signals emitted by three distillation columns under different operating states.The acoustic signals were initially in one-dimensional waveform format and then converted into two-dimensional Mel-Frequency Cepstral Coefficients spectrogram database using fast Fourier transform.Ultimately,this database was employed to train a ResNet for the purpose of identifying the operational states of the distillation columns.Through this approach,the operational states of distillation columns were monitored.Various faults,including flooding,entrainment,dry-tray,etc.,were diagnosed with an accuracy of 98.91%.Moreover,an intermediate transitional state between normal operation and fault was identified and accurately recognized by the proposed method.Under the transitional state,the acoustic signals achieved an accuracy of 97.85%on the ResNet,which enables early warnings before faults occur,enhancing the safety of chemical production processes.The approach presents a powerful tool for the monitoring and diagnosis of chemical equipment,particularly distillation columns,ensuring the safety and efficiency.展开更多
Mine water pollution caused by improper discharge of industrial wastewater,waste liquid and waste residue into minedout areas is a new form of pollution occurred in China in recent years.This kind of pollution is buri...Mine water pollution caused by improper discharge of industrial wastewater,waste liquid and waste residue into minedout areas is a new form of pollution occurred in China in recent years.This kind of pollution is buried deeply,and it is difficult to control,dispose and repair.Deep contaminated mine water from abandoned mining areas may even enter the ocean,posing a great threat to marine ecosystems.In this study,using a water pollution incident occurred in a coal field at a depth of 80 m in Shandong Province,China,in 2015,as an example,the methods of engineering block disposal and groundwater remediation are reported,and the remediation effects are tested and evaluated by in-situ chemical detection and geophysical surveys.The test results showed that engineering blocking measures such as cut-off walls can obviously block the DNAPL diffusion process in mine water,but the blocking effect on organic pollutants dissolved in water was limited.It can slow down the diffusion process of organic gas.The presence of mining tunnels and mined-out areas in the contaminated zone enhances the diffusion speed of various pollutants,especially during the remediation process when pollutants rapidly spread throughout the entire contaminated area.Groundwater circulation extraction and oxidation methods have a significant degradation effect on pollutants like dichloromethane,but they may generate a large amount of secondary gaseous pollutants.These gaseous pollutants may migrate to the shallow subsurface through structures such as faults,leading to secondary subsurface contamination.When designing remediation plans,it is crucial to strike a balance between blocking and guiding in the context of both blocking and restoration projects for achieving effective remediation.展开更多
Recombinant E. coli BL 21 was cultivated in high cell density to produce human-like collagen. The effects of the feeding of nitrogen source, controlled by an auto on/off-feeding mode with two different cycles of 0.5mi...Recombinant E. coli BL 21 was cultivated in high cell density to produce human-like collagen. The effects of the feeding of nitrogen source, controlled by an auto on/off-feeding mode with two different cycles of 0.5min and 4min intervals, oxygen-enrichment methods and inducement strength on the cell yield and human-like collagen production were investigated. The studies showed that nitrogen source feeding in fast cycle could result in higher human-like collagen production than that in slow cycle; and the feedback regulation of glucose, increase of the pressure of fermentation bioreactor, and supply of oxygen-enriched air could all increase cell yield and human-like collagen production. The effects of inducement strength on protein expression were found important. When OD600 reached 90-100, the cultivation temperature was increased to 42℃ to begin induction for 2-3 h, and then shifted to 39℃ for 5-6h induction, the cell density and human-like collagen production could reach 96g·L-1 [DCW (dry cell mass)] and 19.8% (g·g-1 DCW) respectively.展开更多
This is an overview of the development of process systems engineering (PSE) in a smaller world. Two different spatio-temporal scopes are identified for microscale and nanoscale process systems. The features and challe...This is an overview of the development of process systems engineering (PSE) in a smaller world. Two different spatio-temporal scopes are identified for microscale and nanoscale process systems. The features and challenges for each scale are reviewed, and different methodologies used by them discussed. Comparison of these two new areas with traditional process systems engineering is described. If microscale PSE could be considered as an extension of traditional PSE, nanoscale PSE should be accepted as a new discipline which has looser connection with the extant core of chemical engineering. Since "molecular factories" is the next frontier of processing scale, nanoscale PSE will be the new theory to handle the design, simulation and operation of those active processing systems.展开更多
Ce （Ⅳ） nitrato complexes were adsorbed on two anion exchangers based on polyvinyl pyridine （PVP） and quatemized PVP incorporated into porous silica matrix. The effect of nitric acid concentration （0.5～6 mol...Ce （Ⅳ） nitrato complexes were adsorbed on two anion exchangers based on polyvinyl pyridine （PVP） and quatemized PVP incorporated into porous silica matrix. The effect of nitric acid concentration （0.5～6 mol·L^-1） and temperature （278 ～318 K） on Ce（ Ⅳ ） sorption efficiency was investigated. Sorption increased with increasing nitric acid concentration, indicating that [Ce（NO3）6]^2- complex is the main adsorbed Ce（Ⅳ） species. Oxidation of sorbents by adsorbed Ce （ Ⅳ ） species resulting in Ce （ Ⅲ ） release to the solution was observed. Pyridine based anion exchangers exhibited higher oxidation stability compared to the commercial strong base anion exchanger. Ce（ Ⅳ ） reduction was temperature dependent and obeyed pseudo-first-order reaction kinetics. Column separation of Ce （ Ⅳ ） from La （ Ⅲ ） and Y （ Ⅲ ） was carried out from 6 mol·L^-1 nitric acid with PVP based anion exchanger. Reasonable Ce （Ⅳ） breakthrough capacity （0.7 mol·kg^-1 PVP） was achieved. No remarkable decrease of capacity was observed within 3 consequent runs. In contrast, Ce （Ⅲ） leakage due to reduction decreased and breakthrough capacity slightly increased. This effect was more pronounced with increasing temperature. Regeneration with 0.1 mol·L^- 1 nitric acid was successful （recovery 100% ± 4% ） and Ce solution of high purity （ 〉 99.97% ） with respect to La and Y content was gained.展开更多
Electro-oxidation of Ce （ Ⅲ ） to Ce （ Ⅳ ） in parallel plate flow type electrolyzer divided with cation exchange membrane was carried out in nitric acid media at carbon felt anode under galvanostatic conditions. ...Electro-oxidation of Ce （ Ⅲ ） to Ce （ Ⅳ ） in parallel plate flow type electrolyzer divided with cation exchange membrane was carried out in nitric acid media at carbon felt anode under galvanostatic conditions. Carbon felt was used as an anode for its high specific surface area and high oxygen evolution overpotential. Pt coated Ti plates were used as cathode and anode current feeder. The oxidation of 1 mol· L^-1 Ce（ Ⅲ ） solution in 2 mol· L^- 1 HNO3 was proceeding with a high current efficiency （92%） until about 80% of Ce（ Ⅲ ） was oxidized. Then, oxygen evolution, accompanied by terminal voltage jump, took place, lowering current efficiency. Ce（ Ⅲ ） was oxidized up to 90% with current efficiency of 62%. In this mode, strong carbon felt anode oxidation was observed. The wear out of carbon felt was 46% in six consequent runs （6 h of operation）. After each run, carbon felt surface had to be renewed with slightly alkaline solution to remove carbon oxidation products and ensure regular operational conditions. When anode surface was blocked, oxygen evolution took place from the beginning of electrolysis due to higher actual current density. The wear out of carbon felt anode could be minimized by means of oxygen evolution prevention. In the case when electrolysis had been stopped before oxygen evolution started （at Ce（ Ⅳ ） conversion of about 80% ）, the wear out of anode was less than 2% during 6 consequent runs （4 h of operation）.展开更多
Because of the good thermal stability and superior carrier transport characteristics of formamidinium lead trihalide perovskite HC(NH_2)_2 PbX_3(FAPbX_3), it has been considered to be a better optoelectronic material ...Because of the good thermal stability and superior carrier transport characteristics of formamidinium lead trihalide perovskite HC(NH_2)_2 PbX_3(FAPbX_3), it has been considered to be a better optoelectronic material than conventional CH_3NH_3-PbX_3(MAPbX_3). Herein, we fabricated a FAPbBr_3 microcrystal-based photodetector that exhibited a good responsivity of 4000 A W-1 and external quantum efficiency up to 106% under one-photon excitation, corresponding to the detectivity greater than 1014 Jones. The responsivity is two orders of magnitude higher than that of previously reported formamidinium perovskite photodetectors. Furthermore, the FAPbBr_3 photodetector's responsivity to two-photon absorption with an 800-nm excitation source can reach 0.07 A W^(-1), which is four orders of magnitude higher than that of its MAPbBr_3 counterparts. The response time of this photodetector is less than 1 ms.This study provides solid evidence that FAPbBr_3 can be an excellent candidate for highly sensitive and fast photodetectors.展开更多
The title compound N-（2-ethoxyphenyl）-3-oxobenzo[d]isothiazole-2（3H）-carboxa-mide（C16H14N2O3S,Mr = 314.35） has been synthesized and structurally characterized by IR,1H NMR and single-crystal X-ray diffraction.Th...The title compound N-（2-ethoxyphenyl）-3-oxobenzo[d]isothiazole-2（3H）-carboxa-mide（C16H14N2O3S,Mr = 314.35） has been synthesized and structurally characterized by IR,1H NMR and single-crystal X-ray diffraction.The crystal belongs to triclinic,space group P with a = 4.6395（15）,b = 8.689（3）（A°）, c=17.917（7）（A°）α=87.763（9）,β = 84.625（9）,γ = 82.344（9）°,V = 712.4（4）（A°）^3,Z = 2,Dc = 1.465 Mg·m^-3,λ（MoKa） = 0.71073,F（000） = 328,μ（MoKa） = 0.242 mm-1,the final R = 0.038 and wR = 0.089.A total of 3702 unique reflections were collected,of which 2762 with I 〉 2σ（I） were observed.X-ray analysis revealed that the benzisothiazolone ring and benzene moieties were essentially planar,and three intramolecular hydrogen bonds N（2）-H（2N）…O（1）,N（2）-H（2N）…O（3） and C（10）-H（10）…O（2） were observed.The preliminary biologi-cal test showed that the title compound had antifungal and antibacteria activities against Bacillus subtilis（CMCC63003）,Aeromonas hydrophila（ATCC7966）,Staphylococcus aureus（ATCC6538）,Escherichia coli（JM103）,Blastomyces albicans,Gloeosporium papaya P.Henn,Colletotrichum gloeosporioides Penz and Botryodiplodia theobromae.展开更多
AIM： To determine whether increased blood flow of the liver can cause oxidative stress and hepatocyte damage, and to elaborate methods suitable for measuring the antioxidant defence during hepatic surgery on rat mode...AIM： To determine whether increased blood flow of the liver can cause oxidative stress and hepatocyte damage, and to elaborate methods suitable for measuring the antioxidant defence during hepatic surgery on rat model.METHODS： In nembutal narcosis, the left lateral and the medial lobes of the liver were clipped for 45 rain to make the total blood supply flow through the other lobes. Total antioxidant status, glutathione peroxidase and superoxide dysmutase activity, as well as the concentrations of diene conjugates and free sulphydril groups, H-donating ability and reducing power of the liver samples were determined. Chemiluminescent intensity of the liver was also measured. Metal ions （Al, Ca, Cu, Fe, Mg, Mn, Zn） and P and S concentrations of the liver were determined with an inductively coupled plasma optical emission spectrometer and Se content was measured by cathodic stripping voltammetry.RESULTS： Glutathione peroxidase and superoxide dysmutase activities of the liver decreased significantly in the hyperemia group compared to those observed in the sham operated group. The level of total antioxidant status was also significantly lower in the hyperemia group. H-donating ability, reducing power and free sulphydril group concentration showed the same tendency. A significant correlation （P〈0.05） was found between the changes in non-specific antioxidant activities. This pointed to simultaneous activity of the antioxidant defence system. Al, Cu, Mn, Zn, and S were lower in the hyperemia group than in the sham operated group when the levels of Ca, Fe, Mg, Se and P ions were higher during hyperemia.CONCLUSION： Oxidative stress is one of the main factors for the injury of intact liver lobes during ischaemia-reperfusion.展开更多
Two compounds,3-oxo-N-o-tolylbenzo[d]isothiazole-2（3H）-carboxamide （1） and N-（2-methoxyphenyl）-3-oxobenzo[d]isothiazole-2（3H）-carboxamide （2）,were synthesized from the initial compound benzo[d]isothiazol-3...Two compounds,3-oxo-N-o-tolylbenzo[d]isothiazole-2（3H）-carboxamide （1） and N-（2-methoxyphenyl）-3-oxobenzo[d]isothiazole-2（3H）-carboxamide （2）,were synthesized from the initial compound benzo[d]isothiazol-3（2H）-one （BIT） and characterized by 1 H NMR,IR and elemental analysis,respectively.The single crystals of compounds 1 and 2 were obtained and determined by X-ray diffraction analysis.The preliminary results of biological activity experiment show that some of the title compounds exhibited a favorable antimicrobial activity.展开更多
基金Projects(52374138,51764013)supported by the National Natural Science Foundation of ChinaProject(20204BCJ22005)supported by the Training Plan for Academic and Technical Leaders of Major Disciplines of Jiangxi Province,China+1 种基金Project(2019M652277)supported by the China Postdoctoral Science FoundationProject(20192ACBL21014)supported by the Natural Science Youth Foundation Key Projects of Jiangxi Province,China。
文摘The cemented tailings backfill(CTB)with initial defects is more prone to destabilization damage under the influence of various unfavorable factors during the mining process.In order to investigate its influence on the stability of underground mining engineering,this paper simulates the generation of different degrees of initial defects inside the CTB by adding different contents of air-entraining agent(AEA),investigates the acoustic emission RA/AF eigenvalues of CTB with different contents of AEA under uniaxial compression,and adopts various denoising algorithms(e.g.,moving average smoothing,median filtering,and outlier detection)to improve the accuracy of the data.The variance and autocorrelation coefficients of RA/AF parameters were analyzed in conjunction with the critical slowing down(CSD)theory.The results show that the acoustic emission RA/AF values can be used to characterize the progressive damage evolution of CTB.The denoising algorithm processed the AE signals to reduce the effects of extraneous noise and anomalous spikes.Changes in the variance curves provide clear precursor information,while abrupt changes in the autocorrelation coefficient can be used as an auxiliary localization warning signal.The phenomenon of dramatic increase in the variance and autocorrelation coefficient curves during the compression-tightening stage,which is influenced by the initial defects,can lead to false warnings.As the initial defects of the CTB increase,its instability precursor time and instability time are prolonged,the peak stress decreases,and the time difference between the CTB and the instability damage is smaller.The results provide a new method for real-time monitoring and early warning of CTB instability damage.
文摘In this research, it used advanced oxidation processes for the recovery, detoxification and mineralization of wastewater mainly contaminated by antibiotics （ciprofloxacin）. These processes can be used alone or in combination with each other or by complementing traditional methods, even allowing the disinfection of bacterial and viral inactivation. With the use of experimental systems UV/H202/O3, UV/H202, it can achieve total mineralization of the compound. Ciprofloxacin solutions used at 50, 100, 200, 300, 400 and 500 ppm, degraded to 100% of antibiotics and by a microbiological method show that the loss of biological activity is inversely proportional to the time of irradiation.
基金supported by the Innovation Fund of Nanjing Institute of Environmental Science,Ministry of Ecology and Environment,China(No.ZX2023QT003)the National Natural Science Foundation of China(No.22306130)+1 种基金Jiangsu Funding Program for Excellent Postdoctoral Talent(No.2022ZB789)the Ecological Environment Research Project of Jiangsu Province,China(No.2022014).
文摘Phthalic acid esters(PAEs)are a group of compounds widespread in the environment.To investigate the occurrence and accumulation characteristics of PAEs,surface water samples were collected from the Three Gorges Reservoir area,China.The total concentrations of∑_(11)analyzed PAEs(11PAEs)in the collected water samples ranging from 197.7 to 1,409.3 ng/L(mean±IQR:583.1±308.4 ng/L).While DEHP was the most frequently detected PAE,DnBP and DnNP were the most predominant PAEs in the analyzed water samples with a mean contribution of 63.3%of the∑_(11)PAEs.The concentrations of the∑_(11)PAEs in the water samples from the upper reaches of the Yangtze River were significantly higher than those from themiddle reaches.To better understand the transport and fate of the PAEs,seven detected PAEs were modeled by Quantitative Water Air Sediment Interaction(QWASI).The simulated and measured values were close for most PAEs,and differences are within one order of magnitude even for the worst one.For all simulated PAEs,water and particle inflow were main sources in the reservoir,whereas water outflow and degradation in water were important removal pathways.The contribution ratios of different sources/losses varied fromPAEs,depending on their properties.The calculated risk quotients of DnNP in the Three Gorges Reservoir area whether based onmonitoring or simulating results were all far exceeded the safety threshold value,implying the occurrence of this PAE compound may cause potential adverse effects for the aquatic ecology of the Three Gorges Reservoir area.
基金supported by a National Research Foundation of Korea(NRF)Grant funded by the Ministry of Science and ICT(2021R1A2C1014294,2022R1A2C3003319)the BK21 FOUR(Fostering Outstanding Universities for Research)through the National Research Foundation(NRF)of Korea.
文摘A critical challenge hindering the practical application of lithium–oxygen batteries(LOBs)is the inevitable problems associated with liquid electrolytes,such as evaporation and safety problems.Our study addresses these problems by proposing a modified polyrotaxane(mPR)-based solid polymer electrolyte(SPE)design that simultaneously mitigates solvent-related problems and improves conductivity.mPR-SPE exhibits high ion conductivity(2.8×10^(−3)S cm^(−1)at 25℃)through aligned ion conduction pathways and provides electrode protection ability through hydrophobic chain dispersion.Integrating this mPR-SPE into solid-state LOBs resulted in stable potentials over 300 cycles.In situ Raman spectroscopy reveals the presence of an LiO_(2)intermediate alongside Li_(2)O_(2)during oxygen reactions.Ex situ X-ray diffraction confirm the ability of the SPE to hinder the permeation of oxygen and moisture,as demonstrated by the air permeability tests.The present study suggests that maintaining a low residual solvent while achieving high ionic conductivity is crucial for restricting the sub-reactions of solid-state LOBs.
文摘Developmental and reproductive toxicity(DART)endpoint entails a toxicological assessment of all developmental stages and reproductive cycles of an organism.In silico tools to predict DART will provide a method to assess this complex toxicity endpoint and will be valuable for screening emerging pollutants as well as for m anaging new chemicals in China.Currently,there are few published DART prediction models in China,but many related research and development projects are in progress.In 2013,WU et al.published an expert rule-based DART decision tree(DT).This DT relies on known chemical structures linked to DART to forecast DART potential of a given chemical.Within this procedure,an accurate DART data interpretation is the foundation of building and expanding the DT.This paper excerpted case studies demonstrating DART data curation and interpretation of four chemicals(including 8-hydroxyquinoline,3,5,6-trichloro-2-pyridinol,thiacloprid,and imidacloprid)to expand the existing DART DT.Chemicals were first selected from the database of Solid Waste and Chemicals Management Center,Ministry of Ecology and Environment(MEESCC)in China.The structures of these 4 chemicals were analyzed and preliminarily grouped by chemists based on core structural features,functional groups,receptor binding property,metabolism,and possible mode of actions.Then,the DART conclusion was derived by collecting chemical information,searching,integrating,and interpreting DART data by the toxicologists.Finally,these chemicals were classified into either an existing category or a new category via integrating their chemical features,DART conclusions,and biological properties.The results showed that 8-hydroxyquinoline impacted estrous cyclicity,s exual organ weights,and embryonal development,and 3,5,6-trichloro-2-pyridinol caused central nervous system(CNS)malformations,which were added to an existing subcategory 8e(aromatic compounds with multi-halogen and nitro groups)of the DT.Thiacloprid caused dystocia and fetal skeletal malformation,and imidacloprid disrupted the endocrine system and male fertility.They both contain 2-chloro-5-methylpyridine substituted imidazolidine c yclic ring,which were expected to create a new category of neonicotinoids.The current work delineates a t ransparent process of curating toxicological data for the purpose of DART data interpretation.In the presence of sufficient related structures and DART data,the DT can be expanded by iteratively adding chemicals within the a pplicable domain of each category or subcategory.This DT can potentially serve as a tool for screening emerging pollutants and assessing new chemicals in China.
基金supported by the Opening Project of Shanghai Key Laboratory of Crime Scene Evidence (2024XCWZK04)。
文摘With the acceleration of the energy transition,new synthetic routes for converting alkanes into highvalue products are emerging.However,the thermal safety of these new routes may not have been fully considered,potentially leading to dangers during the optimization of reaction conditions.This study reports,for the first time,a reactor explosion incident during the experiment of a new synthetic route for adipic acid:nitric acid oxidation of n-hexane.Differential scanning calorimetry(DSC),accelerating rate calorimetry(ARC),and corrective calculations were used to investigate the cause of the explosion.The results indicate that the polyparaphenol(PPL) liner material,which was used for the first time in the experiment,is unlikely to react with the system and cause the explosion.When the nitric acid concentration is increased from 3.7 mol·L^(-1) to 5.4 mol·L^(-1),the thermal stability of the system decreases,and the heat release surpasses the chemical explosion threshold(1000 J·g^(-1)).The maximum self-heat rate(d T/dtmax) increases by at least 7 times,and the maximum pressure rise rate(dp/dtmax)increases by at least 11 times.This led to the actual pressure in the reactor increasing from 4.96 MPa to at least 11.09 MPa,which far exceeded the rated pressure(3 MPa) and reached the rupture pressure(3.5to 4 times their rated pressure),resulting in the explosion.This study aims to provide a warning regarding the safety of new synthetic routes involving the nitric acid-organic systems,particularly the conversion of alkanes,to prevent the recurrence of similar incidents.
基金Under the auspices of National Natural Science Foundation of China(No.42101251)。
文摘Flood regulation service(FRS)stands as one of the key benefits that people get from the ecosystem.Under the influence of climate change and human activities,the relationship between supply and demand of FRS would increasingly affect regional flood risk and sustainable development.However,there was currently a lack of systematic study on the future supply-demand relationship of FRS in the flood-vulnerable area undergoing rapidly development in China.This study integrated the Scenario Model Intercomparison Project(ScenarioMIP)with the Shared Socioeconomic Pathways(SSPs)datasets and climate model data to quantify the supply-demand ratio(SDR)of FRS in the Yangtze River Delta(YRD),China from 2020 to 2050.Trend analyses were conducted using linear regres-sion,Theil-Sen median estimation,and Hurst exponent analysis,while key drivers of SDR changes were identified and quantified through the Lindeman-Merenda-Gold(LMG)method between 2021 and 2050.Results show that the supply of FRS in the YRD was generally insufficient to meet the demand.The imbalanced subbasins covered 88.24%of the total study area,with 34.48%of this imbal-anced area concentrated in the Southeastern Basin in China.During 2021 and 2050,the imbalance of FRS supply-demand relationship would largely aggravate in the YRD,of which the aggravated area would account for 77.23%.Under different scenarios,the SDR for FRS would decrease significantly,with rates ranging from-5.45×10^(-4) to-2.06×10^(-4)(P<0.05).Especially,the decline rate of SDR in the YRD Basin(DeltaB)reached 2.92 times that the average of YRD.Human activities were the primary factors that exacerbated the imbalance in FRS supply-demand relationship,of which the relative contribution rate exceeds 75%.Particular attention should be direc-ted toward critical regions like the Southeast Basin in China(SEB)and DeltaB where substantial aggravation of supply-demand imbal-ances of FRS is projected.
基金the National Natural Science Foundation of China(22308079)the Natural Science Foundation of Hebei Province,China(B2022202008,B2023202025)the Science and Technology Project of Hebei Education Department,China(BJK2022037).
文摘The operational state of distillation columns significantly impacts product quality and production efficiency.However,due to the complex operation and diverse influencing factors,ensuring the safety and efficient operation of the distillation columns becomes paramount.This research combines passive acoustic monitoring with artificial intelligence techniques,proposed a technology based on residual network(ResNet),which involves the transformation of the acoustic signals emitted by three distillation columns under different operating states.The acoustic signals were initially in one-dimensional waveform format and then converted into two-dimensional Mel-Frequency Cepstral Coefficients spectrogram database using fast Fourier transform.Ultimately,this database was employed to train a ResNet for the purpose of identifying the operational states of the distillation columns.Through this approach,the operational states of distillation columns were monitored.Various faults,including flooding,entrainment,dry-tray,etc.,were diagnosed with an accuracy of 98.91%.Moreover,an intermediate transitional state between normal operation and fault was identified and accurately recognized by the proposed method.Under the transitional state,the acoustic signals achieved an accuracy of 97.85%on the ResNet,which enables early warnings before faults occur,enhancing the safety of chemical production processes.The approach presents a powerful tool for the monitoring and diagnosis of chemical equipment,particularly distillation columns,ensuring the safety and efficiency.
基金supported by the Polluted Site Remediation Project of Gao Village,Puji Street,Zhangqiu District,Jinan City,Shandong Provincefinancially supported by the National Natural Science Foundation of China(Nos.42072331,U1906209)the Taishan Scholar Foundation(No.tstp20230626)。
文摘Mine water pollution caused by improper discharge of industrial wastewater,waste liquid and waste residue into minedout areas is a new form of pollution occurred in China in recent years.This kind of pollution is buried deeply,and it is difficult to control,dispose and repair.Deep contaminated mine water from abandoned mining areas may even enter the ocean,posing a great threat to marine ecosystems.In this study,using a water pollution incident occurred in a coal field at a depth of 80 m in Shandong Province,China,in 2015,as an example,the methods of engineering block disposal and groundwater remediation are reported,and the remediation effects are tested and evaluated by in-situ chemical detection and geophysical surveys.The test results showed that engineering blocking measures such as cut-off walls can obviously block the DNAPL diffusion process in mine water,but the blocking effect on organic pollutants dissolved in water was limited.It can slow down the diffusion process of organic gas.The presence of mining tunnels and mined-out areas in the contaminated zone enhances the diffusion speed of various pollutants,especially during the remediation process when pollutants rapidly spread throughout the entire contaminated area.Groundwater circulation extraction and oxidation methods have a significant degradation effect on pollutants like dichloromethane,but they may generate a large amount of secondary gaseous pollutants.These gaseous pollutants may migrate to the shallow subsurface through structures such as faults,leading to secondary subsurface contamination.When designing remediation plans,it is crucial to strike a balance between blocking and guiding in the context of both blocking and restoration projects for achieving effective remediation.
基金Supported by the National Science and Technology Key Funds (2003DA901A32)the National Nature Science Foundation (No. 20476085).
文摘Recombinant E. coli BL 21 was cultivated in high cell density to produce human-like collagen. The effects of the feeding of nitrogen source, controlled by an auto on/off-feeding mode with two different cycles of 0.5min and 4min intervals, oxygen-enrichment methods and inducement strength on the cell yield and human-like collagen production were investigated. The studies showed that nitrogen source feeding in fast cycle could result in higher human-like collagen production than that in slow cycle; and the feedback regulation of glucose, increase of the pressure of fermentation bioreactor, and supply of oxygen-enriched air could all increase cell yield and human-like collagen production. The effects of inducement strength on protein expression were found important. When OD600 reached 90-100, the cultivation temperature was increased to 42℃ to begin induction for 2-3 h, and then shifted to 39℃ for 5-6h induction, the cell density and human-like collagen production could reach 96g·L-1 [DCW (dry cell mass)] and 19.8% (g·g-1 DCW) respectively.
文摘This is an overview of the development of process systems engineering (PSE) in a smaller world. Two different spatio-temporal scopes are identified for microscale and nanoscale process systems. The features and challenges for each scale are reviewed, and different methodologies used by them discussed. Comparison of these two new areas with traditional process systems engineering is described. If microscale PSE could be considered as an extension of traditional PSE, nanoscale PSE should be accepted as a new discipline which has looser connection with the extant core of chemical engineering. Since "molecular factories" is the next frontier of processing scale, nanoscale PSE will be the new theory to handle the design, simulation and operation of those active processing systems.
基金Project supported bythe Japan Societyfor the Promotion of Science (JSPS)
文摘Ce （Ⅳ） nitrato complexes were adsorbed on two anion exchangers based on polyvinyl pyridine （PVP） and quatemized PVP incorporated into porous silica matrix. The effect of nitric acid concentration （0.5～6 mol·L^-1） and temperature （278 ～318 K） on Ce（ Ⅳ ） sorption efficiency was investigated. Sorption increased with increasing nitric acid concentration, indicating that [Ce（NO3）6]^2- complex is the main adsorbed Ce（Ⅳ） species. Oxidation of sorbents by adsorbed Ce （ Ⅳ ） species resulting in Ce （ Ⅲ ） release to the solution was observed. Pyridine based anion exchangers exhibited higher oxidation stability compared to the commercial strong base anion exchanger. Ce（ Ⅳ ） reduction was temperature dependent and obeyed pseudo-first-order reaction kinetics. Column separation of Ce （ Ⅳ ） from La （ Ⅲ ） and Y （ Ⅲ ） was carried out from 6 mol·L^-1 nitric acid with PVP based anion exchanger. Reasonable Ce （Ⅳ） breakthrough capacity （0.7 mol·kg^-1 PVP） was achieved. No remarkable decrease of capacity was observed within 3 consequent runs. In contrast, Ce （Ⅲ） leakage due to reduction decreased and breakthrough capacity slightly increased. This effect was more pronounced with increasing temperature. Regeneration with 0.1 mol·L^- 1 nitric acid was successful （recovery 100% ± 4% ） and Ce solution of high purity （ 〉 99.97% ） with respect to La and Y content was gained.
文摘Electro-oxidation of Ce （ Ⅲ ） to Ce （ Ⅳ ） in parallel plate flow type electrolyzer divided with cation exchange membrane was carried out in nitric acid media at carbon felt anode under galvanostatic conditions. Carbon felt was used as an anode for its high specific surface area and high oxygen evolution overpotential. Pt coated Ti plates were used as cathode and anode current feeder. The oxidation of 1 mol· L^-1 Ce（ Ⅲ ） solution in 2 mol· L^- 1 HNO3 was proceeding with a high current efficiency （92%） until about 80% of Ce（ Ⅲ ） was oxidized. Then, oxygen evolution, accompanied by terminal voltage jump, took place, lowering current efficiency. Ce（ Ⅲ ） was oxidized up to 90% with current efficiency of 62%. In this mode, strong carbon felt anode oxidation was observed. The wear out of carbon felt was 46% in six consequent runs （6 h of operation）. After each run, carbon felt surface had to be renewed with slightly alkaline solution to remove carbon oxidation products and ensure regular operational conditions. When anode surface was blocked, oxygen evolution took place from the beginning of electrolysis due to higher actual current density. The wear out of carbon felt anode could be minimized by means of oxygen evolution prevention. In the case when electrolysis had been stopped before oxygen evolution started （at Ce（ Ⅳ ） conversion of about 80% ）, the wear out of anode was less than 2% during 6 consequent runs （4 h of operation）.
基金the National Key R@D Program of China (Grant 2017YFA0204800)the National Natural Science Foundation of China (Grant Nos: 21533010, 21321091, 21525315, 91333116 and 21173169) for their financial supports
文摘Because of the good thermal stability and superior carrier transport characteristics of formamidinium lead trihalide perovskite HC(NH_2)_2 PbX_3(FAPbX_3), it has been considered to be a better optoelectronic material than conventional CH_3NH_3-PbX_3(MAPbX_3). Herein, we fabricated a FAPbBr_3 microcrystal-based photodetector that exhibited a good responsivity of 4000 A W-1 and external quantum efficiency up to 106% under one-photon excitation, corresponding to the detectivity greater than 1014 Jones. The responsivity is two orders of magnitude higher than that of previously reported formamidinium perovskite photodetectors. Furthermore, the FAPbBr_3 photodetector's responsivity to two-photon absorption with an 800-nm excitation source can reach 0.07 A W^(-1), which is four orders of magnitude higher than that of its MAPbBr_3 counterparts. The response time of this photodetector is less than 1 ms.This study provides solid evidence that FAPbBr_3 can be an excellent candidate for highly sensitive and fast photodetectors.
基金Supported by the National Natural Science Foundation of China (No. 20962007)
文摘The title compound N-（2-ethoxyphenyl）-3-oxobenzo[d]isothiazole-2（3H）-carboxa-mide（C16H14N2O3S,Mr = 314.35） has been synthesized and structurally characterized by IR,1H NMR and single-crystal X-ray diffraction.The crystal belongs to triclinic,space group P with a = 4.6395（15）,b = 8.689（3）（A°）, c=17.917（7）（A°）α=87.763（9）,β = 84.625（9）,γ = 82.344（9）°,V = 712.4（4）（A°）^3,Z = 2,Dc = 1.465 Mg·m^-3,λ（MoKa） = 0.71073,F（000） = 328,μ（MoKa） = 0.242 mm-1,the final R = 0.038 and wR = 0.089.A total of 3702 unique reflections were collected,of which 2762 with I 〉 2σ（I） were observed.X-ray analysis revealed that the benzisothiazolone ring and benzene moieties were essentially planar,and three intramolecular hydrogen bonds N（2）-H（2N）…O（1）,N（2）-H（2N）…O（3） and C（10）-H（10）…O（2） were observed.The preliminary biologi-cal test showed that the title compound had antifungal and antibacteria activities against Bacillus subtilis（CMCC63003）,Aeromonas hydrophila（ATCC7966）,Staphylococcus aureus（ATCC6538）,Escherichia coli（JM103）,Blastomyces albicans,Gloeosporium papaya P.Henn,Colletotrichum gloeosporioides Penz and Botryodiplodia theobromae.
基金Supported by the Ph.D.Programme of the Semmelweis University No 2/1,ETT 002/2003 Project 1A 005/2004,1B 047/2004 NKFP Projects
文摘AIM： To determine whether increased blood flow of the liver can cause oxidative stress and hepatocyte damage, and to elaborate methods suitable for measuring the antioxidant defence during hepatic surgery on rat model.METHODS： In nembutal narcosis, the left lateral and the medial lobes of the liver were clipped for 45 rain to make the total blood supply flow through the other lobes. Total antioxidant status, glutathione peroxidase and superoxide dysmutase activity, as well as the concentrations of diene conjugates and free sulphydril groups, H-donating ability and reducing power of the liver samples were determined. Chemiluminescent intensity of the liver was also measured. Metal ions （Al, Ca, Cu, Fe, Mg, Mn, Zn） and P and S concentrations of the liver were determined with an inductively coupled plasma optical emission spectrometer and Se content was measured by cathodic stripping voltammetry.RESULTS： Glutathione peroxidase and superoxide dysmutase activities of the liver decreased significantly in the hyperemia group compared to those observed in the sham operated group. The level of total antioxidant status was also significantly lower in the hyperemia group. H-donating ability, reducing power and free sulphydril group concentration showed the same tendency. A significant correlation （P〈0.05） was found between the changes in non-specific antioxidant activities. This pointed to simultaneous activity of the antioxidant defence system. Al, Cu, Mn, Zn, and S were lower in the hyperemia group than in the sham operated group when the levels of Ca, Fe, Mg, Se and P ions were higher during hyperemia.CONCLUSION： Oxidative stress is one of the main factors for the injury of intact liver lobes during ischaemia-reperfusion.
基金Supported by the National Natural Science Foundation of China (No. 20962007)the Creative Talents Plan of Hainan University 211 Project
文摘Two compounds,3-oxo-N-o-tolylbenzo[d]isothiazole-2（3H）-carboxamide （1） and N-（2-methoxyphenyl）-3-oxobenzo[d]isothiazole-2（3H）-carboxamide （2）,were synthesized from the initial compound benzo[d]isothiazol-3（2H）-one （BIT） and characterized by 1 H NMR,IR and elemental analysis,respectively.The single crystals of compounds 1 and 2 were obtained and determined by X-ray diffraction analysis.The preliminary results of biological activity experiment show that some of the title compounds exhibited a favorable antimicrobial activity.
