Deformation behavior of 1 Al containing Mg alloy has been investigated in the present study.After annealing,the Mg-1 Al alloy shows a typical basal texture.When compared to the pure Mg having a similar texture and gra...Deformation behavior of 1 Al containing Mg alloy has been investigated in the present study.After annealing,the Mg-1 Al alloy shows a typical basal texture.When compared to the pure Mg having a similar texture and grain size,the Mg-1 Al alloy shows much higher strength and larger elongation.Slip trace analyses of the tensile strained specimens show that non-basal slips such as pyramidal I and II slips can be easily activated at an early stage of deformation in the Mg-1 Al alloy and the grains in the Mg-1 Al alloy are seen to accommodate a larger degree of deformation than those in the pure Mg at a given strain.With increasing tensile strain,however,there is a strain localization along the initially formed slip lines of non-basal slips,forming surface steps without activating multiple slip lines.展开更多
This work investigates the effect of solid solution on ductility and on the activation of individual deformation mechanisms at moderate temperatures and at quasi-static strain rates in Mg-Zn and Mg-Al alloys. With tha...This work investigates the effect of solid solution on ductility and on the activation of individual deformation mechanisms at moderate temperatures and at quasi-static strain rates in Mg-Zn and Mg-Al alloys. With that aim, four solid solution Mg-Zn and Mg-Al binary alloy ingots containing 1 and 2 wt.% solute atoms were subjected to hot rolling and subsequent annealing to generate polycrystals with similar average grain size and basal-type texture for each composition. The activity of the different slip systems after tensile testing at 150°C and at 250°C was evaluated in pure Mg and in the alloys by EBSD-assisted slip trace analysis. In addition, segregation of Zn and Al atoms at grain boundaries during the thermo-mechanical processing was characterized by HAADF-STEM and EDX. It was found that while the addition of Al and Zn atoms to pure Mg does not lead to major changes in the mechanical strength at the investigated temperatures, it does enhance ductility significantly, especially at 250℃. Our results show that this increase in ductility cannot be attributed to a higher activation of non-basal systems in the alloys, as reported earlier, as the incidence of non-basal systems is indeed considerably higher in pure Mg. This work suggests, on the contrary, that the ductility increase may be attributed to the presence of a more homogenous basal activity in the alloys due to a lower degree of orientation clustering, to grain boundary solute segregation, and to a higher slip diffusivity at grain interiors.展开更多
[Objectives]This study was conducted to establish an ultra-high performance liquid chromatography-tandem mass spectrometry for the rapid extraction of sodium pentachlorophenoxide from animal-derived food.[Methods]The ...[Objectives]This study was conducted to establish an ultra-high performance liquid chromatography-tandem mass spectrometry for the rapid extraction of sodium pentachlorophenoxide from animal-derived food.[Methods]The samples were extracted with an acetonitrile water solution(8∶2),0.1 mol/L hydrochloric acid and a purification extraction bag with shaking.Centrifugation was performed to obtain supernatants,which were added to purification tubes containing PSA and C_(18) for purification,and then filtered with membranes for determination.Each test solution was separated by a ZORBAX Eclipse plus C_(18) column with acetonitrile and 5 mmol/L ammonium acetate as mobile phases,and determined with electrospray ionization and multiple reaction monitoring.[Results]The method had good linearity in the concentration range of 1.0-50 ng/ml,and the correlation coefficient was 0.9997.The limit of detection was 0.25μg/kg and the limit of quantification was 0.75μg/kg.The recovery was between 87.4%and 112.5%,and the RSD%was between 0.5%and 10.0%.[Conclusions]The method has simple operation and high sensitivity,and is suitable for trace detection of sodium pentachlorophenoxide in large quantities of animal-derived food.展开更多
Perfluoronaphthenes,with inert chemical and biological properties and ability to dissolve large amounts of oxygen,have received the most attention in medical applications.However,the excessive anion contained may caus...Perfluoronaphthenes,with inert chemical and biological properties and ability to dissolve large amounts of oxygen,have received the most attention in medical applications.However,the excessive anion contained may cause some side effects.Herein,liquid-liquid extraction technique with shaking and ultrasonic extraction was used for the trace analysis of five anions(F^(-),Cl^(-),NO_(3)^(-),PO_(4)^(3-),SO_(4)^(2-))in perfluorodecalin using water as green extractant.The optimum pretreatment technology and ion chromatography detection conditions were established.Good linearity was observed in each concentration range,and the linear correlation coefficient(R^(2))was better than 0.997.The limits of detection(S/N=3)of five anions from perfluorodecalin were 3.2,5.5,14.2,23.2 and 29.5μg/L,respectively.The established method with high sensitivity and accuracy has been successfully appliedfor the determination of five anions in three perfluorodecalin products,which provides a basis for further development of green detection and quality standard formulation in perfluorodecalin and other fluorocarbon solvents.展开更多
We present a method and a tool for the verification of causal and temporal properties for embedded systems.We analyze trace streams resulting from the execution of virtual prototypes that combine simulated hardware an...We present a method and a tool for the verification of causal and temporal properties for embedded systems.We analyze trace streams resulting from the execution of virtual prototypes that combine simulated hardware and embedded software.The main originality lies in the use of logical clocks to abstract away irrelevant information from the trace.We propose a model-based approach that relies on domain specific languages(DSL).A first DSL,called TISL(trace item specification language),captures the relevant data structures.A second DSL,called STML(simulation trace mapping language),abstracts the simulation raw data into logical clocks,abstracting simulation data into relevant observation probes and thus reducing the trace streams size.The third DSL,called TPSL,defines a set of behavioral patterns that include widely used temporal properties.This is meant for users who are not familiar with temporal logics.Each pattern is transformed into an automata.All the automata are executed concurrently and each one raises an error if and when the related TPSL property is violated.The contribution is the integration of this pattern-based property specification language into the SimSoC virtual prototyping framework without requiring to recompile all the simulation models when the properties evolve.We illustrate our approach with experiments that show the possibility to use multi-core platforms to parallelize the simulation and verification processes,thus reducing the verification time.展开更多
As a highly powerful and sensitive tool,surface enhanced Raman scattering(SERs)has attracted extensive attention in quantification analysis.However,the strong dependence of SERS signal on the detailed local nanostruct...As a highly powerful and sensitive tool,surface enhanced Raman scattering(SERs)has attracted extensive attention in quantification analysis.However,the strong dependence of SERS signal on the detailed local nanostructure makes quantitative SERS analysis suffer from difficulties in controlling the uniformity of nanoscale hot spots and the inefficiency of placing the targeted molecules in prefabricated hot spots.展开更多
Extensive application of nuclear energy has caused widespread environmental uranium contamination.New detection approaches without complicated sample pretreatment and precision instruments are in demand for on-site an...Extensive application of nuclear energy has caused widespread environmental uranium contamination.New detection approaches without complicated sample pretreatment and precision instruments are in demand for on-site and in-time determination of uranyl ions in environmental monitoring, especially in an emergency situation. In this work, a simple and effective fluorescent sensor(Z)-N’-hydroxy-4-(1,2,2-triphenylvinyl)benzimidamide(TPE-A) with aggregation-induced emission(AIE) character was established and studied. It could realize to detect UO_(2)2+via quenching the fluorescence of its aggregation-induced emission, with good selectivity and sensitivity. Such strategy shows a wide linear range from 5.0 × 10^(-8)mol/L to 4.5 × 10^(-7)mol/L(R^(2)= 0.9988) with exceptional sensitivity reaching 4.7 × 10^(-9)mol/L, which is far below the limit for uranium in drinking water(30 μg/L, ca. 1.1 × 10-7mol/L) stipulated by the WHO.A response time less than four minutes make it rapid for uranyl ion measurement. It was applied for detection of uranyl ion in spiked river water samples with recoveries in the range of 98.7%-104.0%, comparable to those obtained by ICP-MS. With the advantages of portable apparatus, rapid detection process and high sensitivity, TPE-A can serve as a promising fluorescent sensor for the detection of UO_(2)2+in environmental water samples.展开更多
Although tension-compression(T-C)asymmetry in yield strength was rarely documented in coarse-grained face centered cubic(FCC)metals as critical resolved shear stress(CRSS)for dislocation slip differs little between te...Although tension-compression(T-C)asymmetry in yield strength was rarely documented in coarse-grained face centered cubic(FCC)metals as critical resolved shear stress(CRSS)for dislocation slip differs little between tension and compression,the T-C asymmetry in strength,i.e.,higher strength when loaded in compression than in tension,was reported in some FCC high entropy alloys(HEAs)due to twinning and phase transitions activated at high strain regimes in compression.In this paper,we demonstrate a reversed and atypical tension-compression asymmetry(tensile strength markedly exceeds compressive strength)in a non-equiatomic FCC Ni_(2)CoFeV_(0.5)Mo_(0.2) medium entropy alloy(MEA)under dynamic loading,wherein dislocation slip governs dynamic deformation without twins or phase transitions.The asymme-try can be primarily interpreted as higher CRSS and more hard slip modes(lower average Schmid factor)activated in grains under dynamic tension than compression.Besides,larger strain rate sensitivity in dy-namic tension overwhelmingly contributes to the higher flow stress,thanks to the occurrence of more immobile Lomer-locks,narrower spacing of planar slip bands and higher dislocation density.This finding may provide some insights into designing MEAs/HEAs with desired properties under extreme conditions such as blast,impact and crash.展开更多
Rapid and real-time mon itoring of food quality plays critical roles in the food industry and for the gen era I public health.Herei n,we specially synthesized a new perylene bisimide(PBI)derivative(PCB-EpE)composed of...Rapid and real-time mon itoring of food quality plays critical roles in the food industry and for the gen era I public health.Herei n,we specially synthesized a new perylene bisimide(PBI)derivative(PCB-EpE)composed of two PBI units and a rigid o-carborane linker,which was further employed in constructi ng a con ceptual fluoresce nt film sen sor for evaluati ng fish fresh ness.Photophysical studies indicate that PCB-EpE displays an open"Z-type"molecular configuration in chloroform and a closed"△-type"configuration in methyl cyclohexa ne.Comparatively,"Z-type"molecular configurati on possesses higher fluoresce nee qua ntum yield and is more sen sitive toward volatile basic nitrogen(VBN).展开更多
The relevance of the study is forensic expert activity in terms of forensic examinations have been so transformed that existing theoretical provisions do not already solve traditional problems in some fields;their sol...The relevance of the study is forensic expert activity in terms of forensic examinations have been so transformed that existing theoretical provisions do not already solve traditional problems in some fields;their solvation requires new approaches of both theoretical and practical nature.In this regard,the purpose of this study is to analyze the content of new innovative directions in forensic examinations,including criminalistic ones,and the possibility of their effective application in forensic expert activity.The methodological basis of the study is the dialectical method of scientific knowledge,which allowed the authors to consider the theoretical and scientific,and practical foundations of modem trends in forensic examinations,including criminalistic ones.It also helped to identify promising fields of examinations necessary for crime prevention.Therefore,authors singled out the following advanced fields:biometric and computer forensic analyses,polygraph,and odor and trace evidence analyses.The materials of the article are of practical value for forensic experts and criminologists,law enforcement agencies.展开更多
文摘Deformation behavior of 1 Al containing Mg alloy has been investigated in the present study.After annealing,the Mg-1 Al alloy shows a typical basal texture.When compared to the pure Mg having a similar texture and grain size,the Mg-1 Al alloy shows much higher strength and larger elongation.Slip trace analyses of the tensile strained specimens show that non-basal slips such as pyramidal I and II slips can be easily activated at an early stage of deformation in the Mg-1 Al alloy and the grains in the Mg-1 Al alloy are seen to accommodate a larger degree of deformation than those in the pure Mg at a given strain.With increasing tensile strain,however,there is a strain localization along the initially formed slip lines of non-basal slips,forming surface steps without activating multiple slip lines.
基金funding from the Madrid region under programme S2018/NMT4381-MAT4.0-CM projectFunding from projects PID2019111285RB-I00 and PID2020-118626RB-I00 awarded by the Spanish Ministry of Science, Innovation and Universitiesfinancial support from the China Scholarship Council (Grant no 201706050154)
文摘This work investigates the effect of solid solution on ductility and on the activation of individual deformation mechanisms at moderate temperatures and at quasi-static strain rates in Mg-Zn and Mg-Al alloys. With that aim, four solid solution Mg-Zn and Mg-Al binary alloy ingots containing 1 and 2 wt.% solute atoms were subjected to hot rolling and subsequent annealing to generate polycrystals with similar average grain size and basal-type texture for each composition. The activity of the different slip systems after tensile testing at 150°C and at 250°C was evaluated in pure Mg and in the alloys by EBSD-assisted slip trace analysis. In addition, segregation of Zn and Al atoms at grain boundaries during the thermo-mechanical processing was characterized by HAADF-STEM and EDX. It was found that while the addition of Al and Zn atoms to pure Mg does not lead to major changes in the mechanical strength at the investigated temperatures, it does enhance ductility significantly, especially at 250℃. Our results show that this increase in ductility cannot be attributed to a higher activation of non-basal systems in the alloys, as reported earlier, as the incidence of non-basal systems is indeed considerably higher in pure Mg. This work suggests, on the contrary, that the ductility increase may be attributed to the presence of a more homogenous basal activity in the alloys due to a lower degree of orientation clustering, to grain boundary solute segregation, and to a higher slip diffusivity at grain interiors.
文摘[Objectives]This study was conducted to establish an ultra-high performance liquid chromatography-tandem mass spectrometry for the rapid extraction of sodium pentachlorophenoxide from animal-derived food.[Methods]The samples were extracted with an acetonitrile water solution(8∶2),0.1 mol/L hydrochloric acid and a purification extraction bag with shaking.Centrifugation was performed to obtain supernatants,which were added to purification tubes containing PSA and C_(18) for purification,and then filtered with membranes for determination.Each test solution was separated by a ZORBAX Eclipse plus C_(18) column with acetonitrile and 5 mmol/L ammonium acetate as mobile phases,and determined with electrospray ionization and multiple reaction monitoring.[Results]The method had good linearity in the concentration range of 1.0-50 ng/ml,and the correlation coefficient was 0.9997.The limit of detection was 0.25μg/kg and the limit of quantification was 0.75μg/kg.The recovery was between 87.4%and 112.5%,and the RSD%was between 0.5%and 10.0%.[Conclusions]The method has simple operation and high sensitivity,and is suitable for trace detection of sodium pentachlorophenoxide in large quantities of animal-derived food.
基金supported by the Zibo Key Scientific Research program(2019gy010020)the Jinan Customs Science and Technology Plan(2020JK012)
文摘Perfluoronaphthenes,with inert chemical and biological properties and ability to dissolve large amounts of oxygen,have received the most attention in medical applications.However,the excessive anion contained may cause some side effects.Herein,liquid-liquid extraction technique with shaking and ultrasonic extraction was used for the trace analysis of five anions(F^(-),Cl^(-),NO_(3)^(-),PO_(4)^(3-),SO_(4)^(2-))in perfluorodecalin using water as green extractant.The optimum pretreatment technology and ion chromatography detection conditions were established.Good linearity was observed in each concentration range,and the linear correlation coefficient(R^(2))was better than 0.997.The limits of detection(S/N=3)of five anions from perfluorodecalin were 3.2,5.5,14.2,23.2 and 29.5μg/L,respectively.The established method with high sensitivity and accuracy has been successfully appliedfor the determination of five anions in three perfluorodecalin products,which provides a basis for further development of green detection and quality standard formulation in perfluorodecalin and other fluorocarbon solvents.
基金supported by the Sino-European LIAM A Laboratory and by the INRIA Sophia Antipolis Research Center.
文摘We present a method and a tool for the verification of causal and temporal properties for embedded systems.We analyze trace streams resulting from the execution of virtual prototypes that combine simulated hardware and embedded software.The main originality lies in the use of logical clocks to abstract away irrelevant information from the trace.We propose a model-based approach that relies on domain specific languages(DSL).A first DSL,called TISL(trace item specification language),captures the relevant data structures.A second DSL,called STML(simulation trace mapping language),abstracts the simulation raw data into logical clocks,abstracting simulation data into relevant observation probes and thus reducing the trace streams size.The third DSL,called TPSL,defines a set of behavioral patterns that include widely used temporal properties.This is meant for users who are not familiar with temporal logics.Each pattern is transformed into an automata.All the automata are executed concurrently and each one raises an error if and when the related TPSL property is violated.The contribution is the integration of this pattern-based property specification language into the SimSoC virtual prototyping framework without requiring to recompile all the simulation models when the properties evolve.We illustrate our approach with experiments that show the possibility to use multi-core platforms to parallelize the simulation and verification processes,thus reducing the verification time.
基金The authors greatly appreciate the financial support from NSFC(22022402,21974051 for L.Zhang,and 21635003,21811540027 for Y.Tian)Innovation Program of Shanghai Municipal Education Commission(No.201701070005E00020)for Y.Tian.
文摘As a highly powerful and sensitive tool,surface enhanced Raman scattering(SERs)has attracted extensive attention in quantification analysis.However,the strong dependence of SERS signal on the detailed local nanostructure makes quantitative SERS analysis suffer from difficulties in controlling the uniformity of nanoscale hot spots and the inefficiency of placing the targeted molecules in prefabricated hot spots.
基金the financial support received from the National Natural Science Foundation of China (No. 21702193)China Academy of Engineering Physics (Nos. TP03201601, TP02201711 and JMJJ20190101)。
文摘Extensive application of nuclear energy has caused widespread environmental uranium contamination.New detection approaches without complicated sample pretreatment and precision instruments are in demand for on-site and in-time determination of uranyl ions in environmental monitoring, especially in an emergency situation. In this work, a simple and effective fluorescent sensor(Z)-N’-hydroxy-4-(1,2,2-triphenylvinyl)benzimidamide(TPE-A) with aggregation-induced emission(AIE) character was established and studied. It could realize to detect UO_(2)2+via quenching the fluorescence of its aggregation-induced emission, with good selectivity and sensitivity. Such strategy shows a wide linear range from 5.0 × 10^(-8)mol/L to 4.5 × 10^(-7)mol/L(R^(2)= 0.9988) with exceptional sensitivity reaching 4.7 × 10^(-9)mol/L, which is far below the limit for uranium in drinking water(30 μg/L, ca. 1.1 × 10-7mol/L) stipulated by the WHO.A response time less than four minutes make it rapid for uranyl ion measurement. It was applied for detection of uranyl ion in spiked river water samples with recoveries in the range of 98.7%-104.0%, comparable to those obtained by ICP-MS. With the advantages of portable apparatus, rapid detection process and high sensitivity, TPE-A can serve as a promising fluorescent sensor for the detection of UO_(2)2+in environmental water samples.
基金the National Key R&D Program of China(No.2017YFA0204403)the National Natural Science Foundation of China(Nos.51971112 and51225102)+2 种基金the Fundamental Research Funds for the Central Universities(No.30919011405)X.Chen would like to acknowledge the finan-cial support from the National Natural Science Foundation of China(Nos.52001165 and 51931003)the Natural Science Foundation of Jiangsu Province,China(No.BK20200475),and the Fundamen-tal Research Funds for the Central Universities(No.30921011215).
文摘Although tension-compression(T-C)asymmetry in yield strength was rarely documented in coarse-grained face centered cubic(FCC)metals as critical resolved shear stress(CRSS)for dislocation slip differs little between tension and compression,the T-C asymmetry in strength,i.e.,higher strength when loaded in compression than in tension,was reported in some FCC high entropy alloys(HEAs)due to twinning and phase transitions activated at high strain regimes in compression.In this paper,we demonstrate a reversed and atypical tension-compression asymmetry(tensile strength markedly exceeds compressive strength)in a non-equiatomic FCC Ni_(2)CoFeV_(0.5)Mo_(0.2) medium entropy alloy(MEA)under dynamic loading,wherein dislocation slip governs dynamic deformation without twins or phase transitions.The asymme-try can be primarily interpreted as higher CRSS and more hard slip modes(lower average Schmid factor)activated in grains under dynamic tension than compression.Besides,larger strain rate sensitivity in dy-namic tension overwhelmingly contributes to the higher flow stress,thanks to the occurrence of more immobile Lomer-locks,narrower spacing of planar slip bands and higher dislocation density.This finding may provide some insights into designing MEAs/HEAs with desired properties under extreme conditions such as blast,impact and crash.
基金We ack no wledge the fundi ng from the Nati onal Natural Science Foundation of China(21820102005),111 project(B14041)the Fun dame ntal Research Funds for the Cen tral Un iversities(GK202001005 and GK202003034)+1 种基金the Innovation Capability Support Program of Shaanxi(2021TD-18)the Youth Innova-tion Team of Shaanxi Universities.
文摘Rapid and real-time mon itoring of food quality plays critical roles in the food industry and for the gen era I public health.Herei n,we specially synthesized a new perylene bisimide(PBI)derivative(PCB-EpE)composed of two PBI units and a rigid o-carborane linker,which was further employed in constructi ng a con ceptual fluoresce nt film sen sor for evaluati ng fish fresh ness.Photophysical studies indicate that PCB-EpE displays an open"Z-type"molecular configuration in chloroform and a closed"△-type"configuration in methyl cyclohexa ne.Comparatively,"Z-type"molecular configurati on possesses higher fluoresce nee qua ntum yield and is more sen sitive toward volatile basic nitrogen(VBN).
文摘The relevance of the study is forensic expert activity in terms of forensic examinations have been so transformed that existing theoretical provisions do not already solve traditional problems in some fields;their solvation requires new approaches of both theoretical and practical nature.In this regard,the purpose of this study is to analyze the content of new innovative directions in forensic examinations,including criminalistic ones,and the possibility of their effective application in forensic expert activity.The methodological basis of the study is the dialectical method of scientific knowledge,which allowed the authors to consider the theoretical and scientific,and practical foundations of modem trends in forensic examinations,including criminalistic ones.It also helped to identify promising fields of examinations necessary for crime prevention.Therefore,authors singled out the following advanced fields:biometric and computer forensic analyses,polygraph,and odor and trace evidence analyses.The materials of the article are of practical value for forensic experts and criminologists,law enforcement agencies.
