Direct epitaxial growthⅢ–Ⅴquantum dot(QD)structures on CMOS-compatible silicon substrates is considered as one of the most promising approaches to achieve low-cost and high-yield Si-based lasers for silicon photoni...Direct epitaxial growthⅢ–Ⅴquantum dot(QD)structures on CMOS-compatible silicon substrates is considered as one of the most promising approaches to achieve low-cost and high-yield Si-based lasers for silicon photonic integration.However,epitaxial growth ofⅢ–Ⅴmaterials on Si encounters the following three major challenges:high density of threading dislocations,antiphase boundaries and thermal cracks,which significantly degrade the crystal quality and potential device performance.In this review,we will focus on some recent results related to InAs/GaAs quantum dot lasers on Si(001)substrates byⅢ–Ⅴ/Ⅳhybrid epitaxial growth via(111)-faceted Si hollow structures.Moreover,by using the step-graded epitaxial growth process the emission wavelength of InAs QDs can be extended from O-band to C/L-band.High-performance InAs/GaAs QD microdisk lasers with sub-milliwatts threshold on Si(001)substrates are fabricated and characterized.The above results pave a promising path towards the on-chip lasers for optical interconnect applications.展开更多
Mobile edge computing has shown its potential in serving emerging latency-sensitive mobile applications in ultra-dense 5G networks via offloading computation workloads from the remote cloud data center to the nearby n...Mobile edge computing has shown its potential in serving emerging latency-sensitive mobile applications in ultra-dense 5G networks via offloading computation workloads from the remote cloud data center to the nearby network edge.However,current computation offloading studies in the heterogeneous edge environment face multifaceted challenges:Dependencies among computational tasks,resource competition among multiple users,and diverse long-term objectives.Mobile applications typically consist of several functionalities,and one huge category of the applications can be viewed as a series of sequential tasks.In this study,we first proposed a novel multiuser computation offloading framework for long-term sequential tasks.Then,we presented a comprehensive analysis of the task offloading process in the framework and formally defined the multiuser sequential task offloading problem.Moreover,we decoupled the long-term offloading problem into multiple single time slot offloading problems and proposed a novel adaptive method to solve them.We further showed the substantial performance advantage of our proposed method on the basis of extensive experiments.展开更多
In this work,magnesium silicate-based sulfonated polystyrene sphere composites(SPS/MgSi)were synthesized by one-step(SMD1)and two-step(SMD2)methods.For SMD1,MgSi particles were densely assembled on the surface of SPS,...In this work,magnesium silicate-based sulfonated polystyrene sphere composites(SPS/MgSi)were synthesized by one-step(SMD1)and two-step(SMD2)methods.For SMD1,MgSi particles were densely assembled on the surface of SPS,assisted by complexation between Fe^3+and hydroxyl phenol.For SMD2,SPS/SiO2 was firstly obtained by the same method as SMD1,and then SPS/SiO2 was transformed directly to SPS/MgSi under hydrothermal conditions.Therefore,MgSi obtained by the two-step method had an interwoven structure.Compared to SPS,MgSi and SMD1,SMD2 presented a larger specific surface area and more negative surface charges.Therefore,SMD2 showed superior adsorption performance toward CIP with concentrations of 5,10 and 50 mg/L,and for 50 mg/L,the equilibrium adsorption capacity could reach 329.7 mg/g.The adsorption process is fast and can be described by the pseudo-second-order kinetic model.The relationship between pH value and Zeta potential demonstrated that electrostatic interaction dominated the adsorption process.In addition,competitive adsorption showed that the effect of Na^+was negligible but the effect of Ca^2+was dependent on its concentration.Humid acid(HA)could slightly promote the absorption of CIP by SMD2.After five rounds of adsorption-desorption,the equilibrium adsorption capacity of SMD2 still remained at 288.6 mg/L for 50 mg/L CIP.Notably,SMD2 presented likewise superior adsorption capacity for CIP with concentrations of 10 and 50 mg/L in Minjiang source water.All the results indicated that this synthesis method is universal and that SMD2 has potential as an adsorbent for CIP removal from aquatic environments.展开更多
Semiconductor mode-locked lasers(MLLs)can provide coherent optical frequency combs(OFCs)with high repetition rates and output power,which have been recognized as potential multi-wavelength sources used in optical comm...Semiconductor mode-locked lasers(MLLs)can provide coherent optical frequency combs(OFCs)with high repetition rates and output power,which have been recognized as potential multi-wavelength sources used in optical communication field due to their compactness,high-efficiency,and low-cost properties.In this article,we have reviewed recent development of semiconductor MLL-based frequency comb generation.Different approaches of semiconductor MLLs for OFC generation are synoptically summarized based on various material platforms.The representative progress of III-V semiconductor MLLs on III-V platform and especially on Si substrates is both discussed for the applications in integrated silicon photonics.展开更多
基金financial support was provided by the National Natural Science Foundation of China (Nos. 61635011, 11574356, 11434010, 61804177 and 11804382)National Key Research and Development Program of China (Nos. 2016YFA0300600 and 2016YFA0301700)+1 种基金Key Research Program of Frontier Sciences, CAS (No. QYZDB-SSW-JSC009)Ting Wang was supported by the Youth Innovation Promotion Association of CAS (No. 2018011)
文摘Direct epitaxial growthⅢ–Ⅴquantum dot(QD)structures on CMOS-compatible silicon substrates is considered as one of the most promising approaches to achieve low-cost and high-yield Si-based lasers for silicon photonic integration.However,epitaxial growth ofⅢ–Ⅴmaterials on Si encounters the following three major challenges:high density of threading dislocations,antiphase boundaries and thermal cracks,which significantly degrade the crystal quality and potential device performance.In this review,we will focus on some recent results related to InAs/GaAs quantum dot lasers on Si(001)substrates byⅢ–Ⅴ/Ⅳhybrid epitaxial growth via(111)-faceted Si hollow structures.Moreover,by using the step-graded epitaxial growth process the emission wavelength of InAs QDs can be extended from O-band to C/L-band.High-performance InAs/GaAs QD microdisk lasers with sub-milliwatts threshold on Si(001)substrates are fabricated and characterized.The above results pave a promising path towards the on-chip lasers for optical interconnect applications.
基金supported by the National Natural Science Foundation of China (Nos.61972272,62172291,62072321,and U1905211)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (No.21KJA520008)+2 种基金the Open Project Program of the State Key Laboratory of Mathematical Engineering and Advanced Computing (No.2019A04)the Postgraduate Research&Practice Innovation Program of Jiangsu Province (No.SJCX211344)the Provincial Key Laboratory for Computer Information Processing Technology (No.KJS1740).
文摘Mobile edge computing has shown its potential in serving emerging latency-sensitive mobile applications in ultra-dense 5G networks via offloading computation workloads from the remote cloud data center to the nearby network edge.However,current computation offloading studies in the heterogeneous edge environment face multifaceted challenges:Dependencies among computational tasks,resource competition among multiple users,and diverse long-term objectives.Mobile applications typically consist of several functionalities,and one huge category of the applications can be viewed as a series of sequential tasks.In this study,we first proposed a novel multiuser computation offloading framework for long-term sequential tasks.Then,we presented a comprehensive analysis of the task offloading process in the framework and formally defined the multiuser sequential task offloading problem.Moreover,we decoupled the long-term offloading problem into multiple single time slot offloading problems and proposed a novel adaptive method to solve them.We further showed the substantial performance advantage of our proposed method on the basis of extensive experiments.
基金This work was supported by the National Natural Science Foundation of China(Nos.21577018 and 21477128)and the National Science Foundation of Fujian Province(No.2016J01223).
文摘In this work,magnesium silicate-based sulfonated polystyrene sphere composites(SPS/MgSi)were synthesized by one-step(SMD1)and two-step(SMD2)methods.For SMD1,MgSi particles were densely assembled on the surface of SPS,assisted by complexation between Fe^3+and hydroxyl phenol.For SMD2,SPS/SiO2 was firstly obtained by the same method as SMD1,and then SPS/SiO2 was transformed directly to SPS/MgSi under hydrothermal conditions.Therefore,MgSi obtained by the two-step method had an interwoven structure.Compared to SPS,MgSi and SMD1,SMD2 presented a larger specific surface area and more negative surface charges.Therefore,SMD2 showed superior adsorption performance toward CIP with concentrations of 5,10 and 50 mg/L,and for 50 mg/L,the equilibrium adsorption capacity could reach 329.7 mg/g.The adsorption process is fast and can be described by the pseudo-second-order kinetic model.The relationship between pH value and Zeta potential demonstrated that electrostatic interaction dominated the adsorption process.In addition,competitive adsorption showed that the effect of Na^+was negligible but the effect of Ca^2+was dependent on its concentration.Humid acid(HA)could slightly promote the absorption of CIP by SMD2.After five rounds of adsorption-desorption,the equilibrium adsorption capacity of SMD2 still remained at 288.6 mg/L for 50 mg/L CIP.Notably,SMD2 presented likewise superior adsorption capacity for CIP with concentrations of 10 and 50 mg/L in Minjiang source water.All the results indicated that this synthesis method is universal and that SMD2 has potential as an adsorbent for CIP removal from aquatic environments.
基金supported by the National Natural Science Foundation of China(61975230 and 62008308)the National Key Research and Development Program of China(2021YFB2800400)Ting Wang was supported by the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2018011)。
文摘Semiconductor mode-locked lasers(MLLs)can provide coherent optical frequency combs(OFCs)with high repetition rates and output power,which have been recognized as potential multi-wavelength sources used in optical communication field due to their compactness,high-efficiency,and low-cost properties.In this article,we have reviewed recent development of semiconductor MLL-based frequency comb generation.Different approaches of semiconductor MLLs for OFC generation are synoptically summarized based on various material platforms.The representative progress of III-V semiconductor MLLs on III-V platform and especially on Si substrates is both discussed for the applications in integrated silicon photonics.