Recent years have witnessed transformative changes brought about by artificial intelligence(AI)techniques with billions of parameters for the realization of high accuracy,proposing high demand for the advanced and AI ...Recent years have witnessed transformative changes brought about by artificial intelligence(AI)techniques with billions of parameters for the realization of high accuracy,proposing high demand for the advanced and AI chip to solve these AI tasks efficiently and powerfully.Rapid progress has been made in the field of advanced chips recently,such as the development of photonic computing,the advancement of the quantum processors,the boost of the biomimetic chips,and so on.Designs tactics of the advanced chips can be conducted with elaborated consideration of materials,algorithms,models,architectures,and so on.Though a few reviews present the development of the chips from their unique aspects,reviews in the view of the latest design for advanced and AI chips are few.Here,the newest development is systematically reviewed in the field of advanced chips.First,background and mechanisms are summarized,and subsequently most important considerations for co-design of the software and hardware are illustrated.Next,strategies are summed up to obtain advanced and AI chips with high excellent performance by taking the important information processing steps into consideration,after which the design thought for the advanced chips in the future is proposed.Finally,some perspectives are put forward.展开更多
The current global economic and trade landscape is undergoing profound changes.Since the outbreak of the China-US trade friction in 2018,the United States has systematically promoted the“de-Sinicizat ion”strategy in...The current global economic and trade landscape is undergoing profound changes.Since the outbreak of the China-US trade friction in 2018,the United States has systematically promoted the“de-Sinicizat ion”strategy in the supply chain through measures such as imposing tariffs,exercising technology blockades,and setting up industrial subsidy barriers.Chinese products,including automot ive par ts and elect ronic equipment,have been significantly impacted.展开更多
We present a compact cold atom platform where an optical grating chip and planar coil chip are placed inside a compact vacuum chamber to create a magneto-optical trap.This approach significantly reduces the system vol...We present a compact cold atom platform where an optical grating chip and planar coil chip are placed inside a compact vacuum chamber to create a magneto-optical trap.This approach significantly reduces the system volume to about 20×20×20 cm^(3) compared to conventional vacuum systems and offers greater flexibility in accessing the trapped atoms.We demonstrate the trapping of 3×10^(5) cold rubidium atoms at a temperature of 100μK in a vacuum pressure below 10^(−7) mbar.The simplified optical geometry,low power consumption,and high degree of integration make this a promising platform for portable and versatile cold-atom devices in quantum sensing,timing,and information processing.展开更多
Vibration detection using sensors with both wide working frequency range,good sensitivity,and other good performances is a topic of great interest in fields such as inertial navigation,deep-sea fishing boat engines co...Vibration detection using sensors with both wide working frequency range,good sensitivity,and other good performances is a topic of great interest in fields such as inertial navigation,deep-sea fishing boat engines condition monitoring,seismic monitoring,attitude,and heading reference system,etc.This paper investigates two 6H-SIC MEMS diaphragms,one triangular and the other square,used in a fiber optic Fabry–Perot(FP)accelerometer in an experimental scenario.The triangular chip shows a wide working frequency range of 630 Hz–5300 Hz,a natural frequency of 44.3 k Hz,and a mechanical sensitivity of 0.154 nm/g.An optimal structure of the square chip used in a probe such as a fiber optic FP accelerometer also shows a wide working frequency range of 120 Hz–2300 Hz;a good sensitivity of 31.5 m V/g,a resonance frequency of7873 Hz,an accuracy of 0.96%F.S.,a frequency measurement error of 1.15%,and an excellent linearity of 0.9995.展开更多
Globally,approximately 10 million new tuberculosis(TB)cases are reported annually.Delayed diagnosis due to low detection rates is the primary cause of mortality.Although pathological examination is commonly used for d...Globally,approximately 10 million new tuberculosis(TB)cases are reported annually.Delayed diagnosis due to low detection rates is the primary cause of mortality.Although pathological examination is commonly used for diagnosing TB,5%-30%of cases remain undiagnosed,emphasizing the urgent need to establish quality control(QC)standards to reduce rates of misdiagnosis and missed diagnoses.To address this,we introduced a novel QC chip for detecting Mycobacterium tuberculosis(MTB).A quantitative pathological QC model was constructed by precisely and uniformly integrating MTB and HeLa cells into a photocurable hydrogel.This model was then sliced into uniform sections to create QC chips.It demonstrated that the QC chips exhibited no significant differences in intra-batch or inter-batch variation(coefficient of variation<5%),and remained stable at−80°C for one year.Furthermore,these chips were found to be 100%effective when tested with 240 clinical samples(200 with special staining and 40 with polymerase chain reaction).In addition to enhancing TB detection rates,this approach offers visualization,quantification,and sustainable production.Overall,this work provides a novel framework for developing QC chips for pathological testing,offering a reliable solution to enhance clinical diagnostic workflows.展开更多
The effect of Ce on ignition point of AZ91D magnesium alloy chips was studied. For the AZ91D and the AZ91D-xCe magnesium alloys, changing the sizes of the chips in the range of 58 - 270 μm has a limited influence on ...The effect of Ce on ignition point of AZ91D magnesium alloy chips was studied. For the AZ91D and the AZ91D-xCe magnesium alloys, changing the sizes of the chips in the range of 58 - 270 μm has a limited influence on ignition point, however, the shift of the content of Ce has much effect on ignition point. Increasing the Ce content, x from 0.15 to 0.25, the ignition point increases with increasing of Ce; however, x from 0.25 to 0.45, the ignition point decreases with increasing of Ce. By the addition of Ce of 0.25 %. the ignition point is raised by 43℃.展开更多
An accurate technique for measuring the frequency response of semiconductor laser diode chips is proposed and experimentally demonstrated.The effects of test jig parasites can be completely removed in the measurement ...An accurate technique for measuring the frequency response of semiconductor laser diode chips is proposed and experimentally demonstrated.The effects of test jig parasites can be completely removed in the measurement by a new calibration method.In theory,the measuring range of the measurement system is only determined by the measuring range of the instruments network analyzer and photo detector.Diodes' bandwidth of 7 5GHz and 10GHz is measured.The results reveal that the method is feasible and comparing with other method,it is more precise and easier to use.展开更多
The first example of the microfluidic chips(MFCs) consisting of centimeter-level 3D channels with highdensity and large-volume fabricated by femtosecond laser micromachining were utilized to develop a time-saving, eco...The first example of the microfluidic chips(MFCs) consisting of centimeter-level 3D channels with highdensity and large-volume fabricated by femtosecond laser micromachining were utilized to develop a time-saving, economical and hazardless flow synthesis process, and its advantages have been proved by in situ formation of aryldiazonium salts and subsequent borylation with bis(pinacolato)diboron. There are several important advantages in our 3D MFC-based flow synthesis technology, including the following:(1) the reaction temperature was altered from ice bath to room temperature;(2) the residence time was reduced by 10 times;(3) the yield was greatly improved, that is, several arylboronates were successfully obtained with higher yield compared to traditional batch process. Therefore, it can be envisioned that a novel, simplified flow synthetic protocol will be developed toward green organic synthesis via MFCs.展开更多
A series of novel red-emitting BaLiZn_(3)(BO_(3))_(3):Eu^(3+)phosphors were synthesized through the high temperature solid state reaction method.The phase composition,crystal structure,morphology and photo luminescenc...A series of novel red-emitting BaLiZn_(3)(BO_(3))_(3):Eu^(3+)phosphors were synthesized through the high temperature solid state reaction method.The phase composition,crystal structure,morphology and photo luminescence property of the BaLiZn_(3)(BO_(3))_(3):Eu^(3+)samples were systematically investigated.The phosphor can be efficiently excited by the near ultraviolet light(NUV)of 396 nm and blue light of 466 nm,and give out red light emission at 618 nm corresponding to the electric dipole transition(^(5)D_(0)→^(7)E_(2)).The optimal doping concentration of Eu^(3+)ions in BaLiZn_(3)(BO_(3))_(3)is determined to be about 3 mol%,and the concentration-quenching phenomenon arise from the electric dipole-dipole interaction.The temperature dependent luminescence behavior of BaLiZn_(3)(BO_(3))_(3):0.03 Eu^(3+)phosphor exhibits its good thermal stability,and the activation energy for thermal quenching characteristics is calculated to be 0.1844 eV.The decay lifetime of the BaLiZn_(3)(BO_(3))_(3):0.03 Eu^(3+)is measured to be 1.88 ms.These results suggest that the BaLiZn_(3)(BO_(3))_(3):Eu^(3+)phosphors have the potential application as a red component in white light emitting diodes(WLEDs)with NUV or blue chips.展开更多
AZ91 Mg alloy recycled by a solid state process and equal channel angular pressing(ECAP)exhibited a superior strength. The mechanical properties of AZ91 Mg alloy recycled from machined chips by extrusion at 623 K and ...AZ91 Mg alloy recycled by a solid state process and equal channel angular pressing(ECAP)exhibited a superior strength. The mechanical properties of AZ91 Mg alloy recycled from machined chips by extrusion at 623 K and ECAP at 573 K and 623 K were compared with those of the reference alloy which was produced from an as-received AZ91 Mg alloy block under the same conditions as the recycled alloy.The recycled specimens show a higher strength at room temperature than the reference alloy.The improvement of the tensile properties is attributed not only to the small grain size,but also to the dispersed oxide contaminants.展开更多
In this study,carbon black(0,0.01,0.03 and 0.08 wt%)and AZ31(Mg-3Al-lZn)magnesium chips were used to fabricate carbon black-reinforced magnesium matrix composites with extrusion or a combination of extrusion and high-...In this study,carbon black(0,0.01,0.03 and 0.08 wt%)and AZ31(Mg-3Al-lZn)magnesium chips were used to fabricate carbon black-reinforced magnesium matrix composites with extrusion or a combination of extrusion and high-ratio differential speed rolling.After hot pressing at 693 K and extrusion at 623 K with an extrusion ratio of 22,the magnesium chips coated with carbon black were soundly bonded into a bulk composite material.The grain sizes of the extruded materials were similar with a size of 48.2-51.5|im despite the difference in the amount of carbon black.The yield strength and ultimate tensile strength increased from 177 to 191 MPa and from 240 to 265 MPa,respectively,as a result of the addition of 0.01%carbon black;however,a further increase in the strength was marginal with additional carbon black.The same trend was observed in the strain hardening behavior.The tensile elongation increased by to the addition of 0.01%carbon black(from 15.8%to 17.4%)due to the increased work hardening effect,but decreased with additional carbon black due to its agglomeration and poor dispersion at higher concentration.After high-ratio differential speed rolling(HRDSR)on the extruded materials and subsequent annealing,the AZ31 and AZ31 composites had a similar fine grain size of 16.3-17.9 p.m.The annealed HRDSR composites showed the best mechanical properties at a higher content of carbon black(0.03%)compared to that(0.01%)for the extruded composites.This resulted from the enhanced dispersion effect of the carbon black due to the high shear flow induced during the HRDSR process.The extruded composites exhibited the three distinct hardening stages(stage II,stage III and stage IV),while the annealed HRDSR composites mainly displayed the stage III hardening.The addition of carbon black increased the strain hardening rate at all the strain hardening stages in both of the extruded and annealed HRDSR materials.At the initial hardening stage,the strain hardening rates of the extruded composites were higher than those of the annealed HRDSR composites,but this became reversed at the later stage of hardening.Possible explanations for this observation were discussed.The strength analysis suggests that dislocation-carbon black interaction by Orowan strengthening and dislocation generation due to a difference in thermal expansion between matrix and carbon black are the major strengthening mechanisms.展开更多
The present paper is related to the conversion of Ti–6Al–4V chips into powder and investigates the usability of the produced powder in powder metallurgy applications. In this regard, a disc-milling process was appli...The present paper is related to the conversion of Ti–6Al–4V chips into powder and investigates the usability of the produced powder in powder metallurgy applications. In this regard, a disc-milling process was applied to Ti–6Al–4V chips and the obtained powder was subsequently compacted. The compacted samples were sintered by the sinter hot isostatic pressing (sinter-HIP) method at 1200°C under high vacuum, their mechanical properties and microstructure were investigated and compared with those of commercial powder compacts subjected to the same preparation processes. The results showed that the produced powder exhibits greater flowability and higher apparent density than the commercial powder. However, the sintered products prepared from the commercial powder exhibited a higher relative density, lower porosity, and, as a result, greater flexural strength compared with the sintered compacts prepared from the produced powder. In addition, transgranular fracture was greater in the sintered products of the commercial powder. The microstructural studies revealed that the sintered products made from both the commercial and the produced powders consisted of α- and β-phase but contained more α-phase. All of the examined properties were found to be substantially affected by the particle size of the powders.展开更多
To understand how differentially methylated genes（DMGs）might affect the pathogenesis of Kashin-Beck disease（KBD）.Genome-wide methylation profiling of whole blood from 12matched KBD and controls pairs was performed...To understand how differentially methylated genes（DMGs）might affect the pathogenesis of Kashin-Beck disease（KBD）.Genome-wide methylation profiling of whole blood from 12matched KBD and controls pairs was performed using a high-resolution Infinium 450 K methylation array.In total,97 CpG sites were differentially展开更多
Based on the mechanism of chip breaking and the principle of semi-solid thixomolding, the lathe process of AZ91D magnesium alloys chips used in semi-solid thixotropic injection molding process was studied. With three ...Based on the mechanism of chip breaking and the principle of semi-solid thixomolding, the lathe process of AZ91D magnesium alloys chips used in semi-solid thixotropic injection molding process was studied. With three kinds of turning tools, such as 31303C5, 31003C and 31303C, different chips were gotten. And by one tool with different lathe parameters, different chips were gotten. The results show that, under the needed condition of the thixotropic injection molding machine, the ideal chips are gotten and the size of magnesium alloy chips must be about 35mm, and the turning tool is chosen, whose chip breaker groove is narrower and the depth of cutting is more than 3mm as well as the amount of feed is larger than 0.3mm. The deformation occurs on the microstructure of the chips, and the residual stress is important to the later microstructure of semi-solid state in injection molding.展开更多
In this study,a novel method termed hydrothermal carbonized deposition on chips(HTCDC)is proposed to prepare aluminum alloy-amorphous carbon(Al/APC)composites.The influences of glucose concentration in hydrothermally ...In this study,a novel method termed hydrothermal carbonized deposition on chips(HTCDC)is proposed to prepare aluminum alloy-amorphous carbon(Al/APC)composites.The influences of glucose concentration in hydrothermally reaction on the microstructure and wear resistance of the Al/APC composites were thoroughly studied.Amorphous carbon was deposited by HTCDC onto Al–20Si chips as a supporter.The Al/APC composites were prepared by hot extrusion from the chips.The results indicated that a uniform carbon film was successfully synthesized on the surface of the chips,improving the wear resistance of the Al/APC composites.With increasing concentration of glucose solution,the size and the number of delamination on the wear surface and the coefficient of friction decreased,and the wear rate decreased at first and then increased.In addition,the dehydration and carbonization processes in the hydrothermal reaction of glucose were analyzed.A schematic model of the wear surface of the Al/APC composites was established and the wear mechanisms were discussed.展开更多
基金supported by the Hong Kong Polytechnic University(1-WZ1Y,1-W34U,4-YWER).
文摘Recent years have witnessed transformative changes brought about by artificial intelligence(AI)techniques with billions of parameters for the realization of high accuracy,proposing high demand for the advanced and AI chip to solve these AI tasks efficiently and powerfully.Rapid progress has been made in the field of advanced chips recently,such as the development of photonic computing,the advancement of the quantum processors,the boost of the biomimetic chips,and so on.Designs tactics of the advanced chips can be conducted with elaborated consideration of materials,algorithms,models,architectures,and so on.Though a few reviews present the development of the chips from their unique aspects,reviews in the view of the latest design for advanced and AI chips are few.Here,the newest development is systematically reviewed in the field of advanced chips.First,background and mechanisms are summarized,and subsequently most important considerations for co-design of the software and hardware are illustrated.Next,strategies are summed up to obtain advanced and AI chips with high excellent performance by taking the important information processing steps into consideration,after which the design thought for the advanced chips in the future is proposed.Finally,some perspectives are put forward.
文摘The current global economic and trade landscape is undergoing profound changes.Since the outbreak of the China-US trade friction in 2018,the United States has systematically promoted the“de-Sinicizat ion”strategy in the supply chain through measures such as imposing tariffs,exercising technology blockades,and setting up industrial subsidy barriers.Chinese products,including automot ive par ts and elect ronic equipment,have been significantly impacted.
基金supported by the National Key R&D Program(Grant Nos.2021YFA1402004 and 2021YFF0603701)the National Natural Science Foundation of China(Grant Nos.12134014,U21A20433,U21A6006,and 92265108)+1 种基金the Fundamental Research Funds for the Central Universitiesthe University of Science and Technology of China(USTC)Research Funds of the Double First-Class Initiative。
文摘We present a compact cold atom platform where an optical grating chip and planar coil chip are placed inside a compact vacuum chamber to create a magneto-optical trap.This approach significantly reduces the system volume to about 20×20×20 cm^(3) compared to conventional vacuum systems and offers greater flexibility in accessing the trapped atoms.We demonstrate the trapping of 3×10^(5) cold rubidium atoms at a temperature of 100μK in a vacuum pressure below 10^(−7) mbar.The simplified optical geometry,low power consumption,and high degree of integration make this a promising platform for portable and versatile cold-atom devices in quantum sensing,timing,and information processing.
基金Project supported by the National Natural Science Foundation of China(Grant No.32473216)Ningbo Youth Science and Technology Innovation Leading Talent Project(Grant No.2023QL004)。
文摘Vibration detection using sensors with both wide working frequency range,good sensitivity,and other good performances is a topic of great interest in fields such as inertial navigation,deep-sea fishing boat engines condition monitoring,seismic monitoring,attitude,and heading reference system,etc.This paper investigates two 6H-SIC MEMS diaphragms,one triangular and the other square,used in a fiber optic Fabry–Perot(FP)accelerometer in an experimental scenario.The triangular chip shows a wide working frequency range of 630 Hz–5300 Hz,a natural frequency of 44.3 k Hz,and a mechanical sensitivity of 0.154 nm/g.An optimal structure of the square chip used in a probe such as a fiber optic FP accelerometer also shows a wide working frequency range of 120 Hz–2300 Hz;a good sensitivity of 31.5 m V/g,a resonance frequency of7873 Hz,an accuracy of 0.96%F.S.,a frequency measurement error of 1.15%,and an excellent linearity of 0.9995.
基金supported by the National Natural Science Foundation of China(Nos.52325504 and 52235007)the Basic Public Welfare Research Project of Zhejiang Province(No.LGY23H160089)the Science and Technology Plan Project of Taizhou City(No.24ywa08).
文摘Globally,approximately 10 million new tuberculosis(TB)cases are reported annually.Delayed diagnosis due to low detection rates is the primary cause of mortality.Although pathological examination is commonly used for diagnosing TB,5%-30%of cases remain undiagnosed,emphasizing the urgent need to establish quality control(QC)standards to reduce rates of misdiagnosis and missed diagnoses.To address this,we introduced a novel QC chip for detecting Mycobacterium tuberculosis(MTB).A quantitative pathological QC model was constructed by precisely and uniformly integrating MTB and HeLa cells into a photocurable hydrogel.This model was then sliced into uniform sections to create QC chips.It demonstrated that the QC chips exhibited no significant differences in intra-batch or inter-batch variation(coefficient of variation<5%),and remained stable at−80°C for one year.Furthermore,these chips were found to be 100%effective when tested with 240 clinical samples(200 with special staining and 40 with polymerase chain reaction).In addition to enhancing TB detection rates,this approach offers visualization,quantification,and sustainable production.Overall,this work provides a novel framework for developing QC chips for pathological testing,offering a reliable solution to enhance clinical diagnostic workflows.
文摘The effect of Ce on ignition point of AZ91D magnesium alloy chips was studied. For the AZ91D and the AZ91D-xCe magnesium alloys, changing the sizes of the chips in the range of 58 - 270 μm has a limited influence on ignition point, however, the shift of the content of Ce has much effect on ignition point. Increasing the Ce content, x from 0.15 to 0.25, the ignition point increases with increasing of Ce; however, x from 0.25 to 0.45, the ignition point decreases with increasing of Ce. By the addition of Ce of 0.25 %. the ignition point is raised by 43℃.
文摘An accurate technique for measuring the frequency response of semiconductor laser diode chips is proposed and experimentally demonstrated.The effects of test jig parasites can be completely removed in the measurement by a new calibration method.In theory,the measuring range of the measurement system is only determined by the measuring range of the instruments network analyzer and photo detector.Diodes' bandwidth of 7 5GHz and 10GHz is measured.The results reveal that the method is feasible and comparing with other method,it is more precise and easier to use.
基金supported by the Shanghai Municipal Science and Technology Major Project (“Beyond Limits manufacture”)。
文摘The first example of the microfluidic chips(MFCs) consisting of centimeter-level 3D channels with highdensity and large-volume fabricated by femtosecond laser micromachining were utilized to develop a time-saving, economical and hazardless flow synthesis process, and its advantages have been proved by in situ formation of aryldiazonium salts and subsequent borylation with bis(pinacolato)diboron. There are several important advantages in our 3D MFC-based flow synthesis technology, including the following:(1) the reaction temperature was altered from ice bath to room temperature;(2) the residence time was reduced by 10 times;(3) the yield was greatly improved, that is, several arylboronates were successfully obtained with higher yield compared to traditional batch process. Therefore, it can be envisioned that a novel, simplified flow synthetic protocol will be developed toward green organic synthesis via MFCs.
基金Project supported by the National Key R&D Program of China(2019YFA0709101)National Natural Science Foundation of China(52072364,51902305)the Fund for Creative Research Groups(21221061)。
文摘A series of novel red-emitting BaLiZn_(3)(BO_(3))_(3):Eu^(3+)phosphors were synthesized through the high temperature solid state reaction method.The phase composition,crystal structure,morphology and photo luminescence property of the BaLiZn_(3)(BO_(3))_(3):Eu^(3+)samples were systematically investigated.The phosphor can be efficiently excited by the near ultraviolet light(NUV)of 396 nm and blue light of 466 nm,and give out red light emission at 618 nm corresponding to the electric dipole transition(^(5)D_(0)→^(7)E_(2)).The optimal doping concentration of Eu^(3+)ions in BaLiZn_(3)(BO_(3))_(3)is determined to be about 3 mol%,and the concentration-quenching phenomenon arise from the electric dipole-dipole interaction.The temperature dependent luminescence behavior of BaLiZn_(3)(BO_(3))_(3):0.03 Eu^(3+)phosphor exhibits its good thermal stability,and the activation energy for thermal quenching characteristics is calculated to be 0.1844 eV.The decay lifetime of the BaLiZn_(3)(BO_(3))_(3):0.03 Eu^(3+)is measured to be 1.88 ms.These results suggest that the BaLiZn_(3)(BO_(3))_(3):Eu^(3+)phosphors have the potential application as a red component in white light emitting diodes(WLEDs)with NUV or blue chips.
基金Projects(50201005,50571031)supported by the National Natural Science Foundation of ChinaProject(2009DFA51830)supported by the Ministry of Science and Technology,China
文摘AZ91 Mg alloy recycled by a solid state process and equal channel angular pressing(ECAP)exhibited a superior strength. The mechanical properties of AZ91 Mg alloy recycled from machined chips by extrusion at 623 K and ECAP at 573 K and 623 K were compared with those of the reference alloy which was produced from an as-received AZ91 Mg alloy block under the same conditions as the recycled alloy.The recycled specimens show a higher strength at room temperature than the reference alloy.The improvement of the tensile properties is attributed not only to the small grain size,but also to the dispersed oxide contaminants.
基金This research was financially supported by the Basic Research Laboratory Program through the National Research Foundation of Korea funded by the Ministry of Education,Science and Technology(Project No.NRF2020-000000).
文摘In this study,carbon black(0,0.01,0.03 and 0.08 wt%)and AZ31(Mg-3Al-lZn)magnesium chips were used to fabricate carbon black-reinforced magnesium matrix composites with extrusion or a combination of extrusion and high-ratio differential speed rolling.After hot pressing at 693 K and extrusion at 623 K with an extrusion ratio of 22,the magnesium chips coated with carbon black were soundly bonded into a bulk composite material.The grain sizes of the extruded materials were similar with a size of 48.2-51.5|im despite the difference in the amount of carbon black.The yield strength and ultimate tensile strength increased from 177 to 191 MPa and from 240 to 265 MPa,respectively,as a result of the addition of 0.01%carbon black;however,a further increase in the strength was marginal with additional carbon black.The same trend was observed in the strain hardening behavior.The tensile elongation increased by to the addition of 0.01%carbon black(from 15.8%to 17.4%)due to the increased work hardening effect,but decreased with additional carbon black due to its agglomeration and poor dispersion at higher concentration.After high-ratio differential speed rolling(HRDSR)on the extruded materials and subsequent annealing,the AZ31 and AZ31 composites had a similar fine grain size of 16.3-17.9 p.m.The annealed HRDSR composites showed the best mechanical properties at a higher content of carbon black(0.03%)compared to that(0.01%)for the extruded composites.This resulted from the enhanced dispersion effect of the carbon black due to the high shear flow induced during the HRDSR process.The extruded composites exhibited the three distinct hardening stages(stage II,stage III and stage IV),while the annealed HRDSR composites mainly displayed the stage III hardening.The addition of carbon black increased the strain hardening rate at all the strain hardening stages in both of the extruded and annealed HRDSR materials.At the initial hardening stage,the strain hardening rates of the extruded composites were higher than those of the annealed HRDSR composites,but this became reversed at the later stage of hardening.Possible explanations for this observation were discussed.The strength analysis suggests that dislocation-carbon black interaction by Orowan strengthening and dislocation generation due to a difference in thermal expansion between matrix and carbon black are the major strengthening mechanisms.
基金financially supported by Faculty Member Training Program funded by Council of Higher Education Turkey [OYP-05276-DR-12]
文摘The present paper is related to the conversion of Ti–6Al–4V chips into powder and investigates the usability of the produced powder in powder metallurgy applications. In this regard, a disc-milling process was applied to Ti–6Al–4V chips and the obtained powder was subsequently compacted. The compacted samples were sintered by the sinter hot isostatic pressing (sinter-HIP) method at 1200°C under high vacuum, their mechanical properties and microstructure were investigated and compared with those of commercial powder compacts subjected to the same preparation processes. The results showed that the produced powder exhibits greater flowability and higher apparent density than the commercial powder. However, the sintered products prepared from the commercial powder exhibited a higher relative density, lower porosity, and, as a result, greater flexural strength compared with the sintered compacts prepared from the produced powder. In addition, transgranular fracture was greater in the sintered products of the commercial powder. The microstructural studies revealed that the sintered products made from both the commercial and the produced powders consisted of α- and β-phase but contained more α-phase. All of the examined properties were found to be substantially affected by the particle size of the powders.
基金supported by grants from the National Natural Science Foundation of China(No.81273007)
文摘To understand how differentially methylated genes（DMGs）might affect the pathogenesis of Kashin-Beck disease（KBD）.Genome-wide methylation profiling of whole blood from 12matched KBD and controls pairs was performed using a high-resolution Infinium 450 K methylation array.In total,97 CpG sites were differentially
文摘Based on the mechanism of chip breaking and the principle of semi-solid thixomolding, the lathe process of AZ91D magnesium alloys chips used in semi-solid thixotropic injection molding process was studied. With three kinds of turning tools, such as 31303C5, 31003C and 31303C, different chips were gotten. And by one tool with different lathe parameters, different chips were gotten. The results show that, under the needed condition of the thixotropic injection molding machine, the ideal chips are gotten and the size of magnesium alloy chips must be about 35mm, and the turning tool is chosen, whose chip breaker groove is narrower and the depth of cutting is more than 3mm as well as the amount of feed is larger than 0.3mm. The deformation occurs on the microstructure of the chips, and the residual stress is important to the later microstructure of semi-solid state in injection molding.
基金financially supported by the National Natural Science Foundation of China(Nos.51704087 and 51574100)the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(No.UNPYSCT-2016033)。
文摘In this study,a novel method termed hydrothermal carbonized deposition on chips(HTCDC)is proposed to prepare aluminum alloy-amorphous carbon(Al/APC)composites.The influences of glucose concentration in hydrothermally reaction on the microstructure and wear resistance of the Al/APC composites were thoroughly studied.Amorphous carbon was deposited by HTCDC onto Al–20Si chips as a supporter.The Al/APC composites were prepared by hot extrusion from the chips.The results indicated that a uniform carbon film was successfully synthesized on the surface of the chips,improving the wear resistance of the Al/APC composites.With increasing concentration of glucose solution,the size and the number of delamination on the wear surface and the coefficient of friction decreased,and the wear rate decreased at first and then increased.In addition,the dehydration and carbonization processes in the hydrothermal reaction of glucose were analyzed.A schematic model of the wear surface of the Al/APC composites was established and the wear mechanisms were discussed.
