In this work,we used time-sliced ion velocity imaging to study the photodissociation dynamics of Mg O at 193 nm.Three dissociation pathways are found through the speed and angular distributions of magnesium.One pathwa...In this work,we used time-sliced ion velocity imaging to study the photodissociation dynamics of Mg O at 193 nm.Three dissociation pathways are found through the speed and angular distributions of magnesium.One pathway is the one-photon excitation of Mg O(X^(1)∑^(+))to Mg O(G^(1)Π)followed by spin-orbit coupling between the G^(1)Π,3^(3)Πand ^(1^(5))Πstates,and finally dissociated to the Mg(^(3)Pu)+O(^(3)Pg)along the 1^(5)Πsurface.The other two pathways are one-photon absorption of Mg O(A^(1)Π)state to Mg O(G^(1)Π)and Mg O(4^(1)Π)state to dissociate into Mg(^(3)P_(u))+O(^(3)P_(g))and Mg(^(1)S_(g))+O(^(1)S_(g)),respectively.The anisotropy parameters of the dissociation pathways are related to the lifetime of the vibrational energy levels and the coupling of rotational and vibronic spin-orbit states.The total kinetic energy analysis gives D0(Mg-O)=21645±50 cm^(-1).展开更多
Photodissociation dynamics of dichlorodifluoromethane (CF2Cl2) around 235 nm has been studied using the time-sliced velocity map imaging technology in combination with the resonance enhanced multi-photon ionization te...Photodissociation dynamics of dichlorodifluoromethane (CF2Cl2) around 235 nm has been studied using the time-sliced velocity map imaging technology in combination with the resonance enhanced multi-photon ionization technology. By measuring the raw images of chlorine atoms which are formed via one-photon dissociation of CF2Cl2, the speed and angular distributions can be directly obtained. The speed distribution of excited-state chlorine atoms consists of high translation energy (ET) and low ET components, which are related to direct dissociation on 3Q0 state and predissociation on the ground state induced by internal conversion, respectively. The speed distribution of ground-state chlorine atoms also consists of high ET and low ET components which are related to predissociation between 3Q0 and 1Q1 states and predissociation on the ground state induced by internal conversion, respectively. Radical dissociation channel is confirmed, nevertheless, secondary dissociation and three-body dissociation channels are excluded.展开更多
We report a newly constructed laser ablation crossed molecular beam apparatus, equipped with time-sliced velocity map imaging technique, to study state-to-state metal atom reaction dynamics. Supersonic metal atomic be...We report a newly constructed laser ablation crossed molecular beam apparatus, equipped with time-sliced velocity map imaging technique, to study state-to-state metal atom reaction dynamics. Supersonic metal atomic beam is generated by laser vaporization of metal rod, and free expansion design without gas flow channel has been employed to obtain a good quality of metal atomic beam. We have chosen the crossed-beam reaction Al＋O2 to test the performance of the new apparatus. Two-rotational-states selected AIO（X^2∑＋, v=0, N and N＋I4） products can be imaged via P（N） and R（N＋14） branches of the Av=l band at the same wavelength, during （1＋1） resonance-enhanced multi-photon ionization through the AIO（D2E＋） intermediate state. In our experiment at 244.145 nm for simultaneous transitions of P（15） and R（29） branch, two rings in slice image were clearly distinguishable, corresponding to the AiO（v=0, N=IS） and AIO（v=0, N=29） states respectively. The energy difference between the two rotational levels is 403 cm^-1. The success of two states resolved in our apparatus suggests a better collisional energy resolution compared with the recent research study [J. Chem. Phys. 140, 214304 （2014）].展开更多
One of the themes of modern molecular reac tion dynamics is to charac terize elementary chemical reactions from“quan tum state to quan tum stat e”,and the study of molecular reaction dynamics in excited states can h...One of the themes of modern molecular reac tion dynamics is to charac terize elementary chemical reactions from“quan tum state to quan tum stat e”,and the study of molecular reaction dynamics in excited states can help test the validi ty of modern chemical t heories and provide met hods to cont rol chemical reactions.The subject of this review is to describe the recent experimental techniques used to study the reaction dynamics of metal atoms in the gas phase.Through these techniques,information such as the internal energy distribution and angular distribution of the nascent products or the three-dimensional stereodynamic reactivity can be obtained.In addition,by preparing metal at oms wi th specific exci ted elec tronic states or orbi tal arrangemen ts,information about the reactivity of the electronic states enriches the relevant understanding of the electron transfer mechanism in metal reaction dynamics.展开更多
We study the phot odissociation dynamics of CS2 in the ultraviolet region using the time-sliced velocity map ion imaging technique.The S(3 Pj)+CS(X1E+)product channels were observed and identified at four wavelengths ...We study the phot odissociation dynamics of CS2 in the ultraviolet region using the time-sliced velocity map ion imaging technique.The S(3 Pj)+CS(X1E+)product channels were observed and identified at four wavelengths of 201.36,203.10,204.85 and 206.61 nm.In the measured images of S(3Pj=2,1,0),the vibrational states of the CS(X1E+)co-products were partially resolved and the vibrational state distributions were determined.Moreover,the product total kinetic energy releases and the anisotropic parameters were derived.The relatively small anisotropic parameter values indicate that the S(3Pj=2丄0)+CS(X1E+)channels are very likely formed via the indirect predissociation process of CS2.The study of the S(3Pj=2,1;0)+CS(X1E+)channels,which come from the spin-orbit coupling dissociation process of CS2,shows that nonadiabatic process plays a role in the ultraviolet photodissociation of CS2.展开更多
The reaction dynamics of yttrium atoms with sulfur dioxide molecules at a high collision energy of 36 kcal/mol was studied using time-sliced velocity map ion imaging,crossed molecular beam and laser-ablation method.Th...The reaction dynamics of yttrium atoms with sulfur dioxide molecules at a high collision energy of 36 kcal/mol was studied using time-sliced velocity map ion imaging,crossed molecular beam and laser-ablation method.The product YO was detected via multiphoton ionization at various wavelengths in the region of 482-615 nm.The slice images of YO show a broad velocity distribution and forward-backward peaking angular distribution.The forward scattering signal is stronger than its backward distribution.This indicates that the reaction proceeds via an intermediate complex and the lifetime of the intermediate state is less than one rotational period.The formation of complex suggests that electron transfer occurs in the oxidation reaction.展开更多
The photodissociation dynamics of Al O at 193 nm is studied using time-sliced ion velocity mapping.Two dissociation channels are found through the speed and angular distributions of aluminum ions:one is one-photon dis...The photodissociation dynamics of Al O at 193 nm is studied using time-sliced ion velocity mapping.Two dissociation channels are found through the speed and angular distributions of aluminum ions:one is one-photon dissociation of the neutral AlO to generate Al(2 Pu)+O(3 Pg),and the other is two-photon ionization and then dissociation of AlO^+to generate Al^+(1 Sg)+O(3 Pg).Each dissociation channel includes the contribution of AlO in the vibrational states v=0-2.The anisotropy parameter of the neutral dissociation channel is more dependent on the vibration state of AlO than the ion dissociation channel.展开更多
Edge computing can alleviate the problem of insufficient computational resources for the user equipment,improve the network processing environment,and promote the user experience.Edge computing is well known as a pros...Edge computing can alleviate the problem of insufficient computational resources for the user equipment,improve the network processing environment,and promote the user experience.Edge computing is well known as a prospective method for the development of the Internet of Things(IoT).However,with the development of smart terminals,much more time is required for scheduling the terminal high-intensity upstream dataflow in the edge server than for scheduling that in the downstream dataflow.In this paper,we study the scheduling strategy for upstream dataflows in edge computing networks and introduce a three-tier edge computing network architecture.We propose a Time-Slicing Self-Adaptive Scheduling(TSAS)algorithm based on the hierarchical queue,which can reduce the queuing delay of the dataflow,improve the timeliness of dataflow processing and achieve an efficient and reasonable performance of dataflow scheduling.The experimental results show that the TSAS algorithm can reduce latency,minimize energy consumption,and increase system throughput.展开更多
基金supported by the National Natural Science Foundation of China(No.22073019 and No.21673047)the Shanghai Key Laboratory Foundation of Molecular Catalysis and Innovative Materialsthe Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning。
文摘In this work,we used time-sliced ion velocity imaging to study the photodissociation dynamics of Mg O at 193 nm.Three dissociation pathways are found through the speed and angular distributions of magnesium.One pathway is the one-photon excitation of Mg O(X^(1)∑^(+))to Mg O(G^(1)Π)followed by spin-orbit coupling between the G^(1)Π,3^(3)Πand ^(1^(5))Πstates,and finally dissociated to the Mg(^(3)Pu)+O(^(3)Pg)along the 1^(5)Πsurface.The other two pathways are one-photon absorption of Mg O(A^(1)Π)state to Mg O(G^(1)Π)and Mg O(4^(1)Π)state to dissociate into Mg(^(3)P_(u))+O(^(3)P_(g))and Mg(^(1)S_(g))+O(^(1)S_(g)),respectively.The anisotropy parameters of the dissociation pathways are related to the lifetime of the vibrational energy levels and the coupling of rotational and vibronic spin-orbit states.The total kinetic energy analysis gives D0(Mg-O)=21645±50 cm^(-1).
基金supported by the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (No.17KJB150005 and No.17KJD510001)the Natural Science Foundation of Changzhou Institute of Technology (No.YN1507 and No.YN1611)+1 种基金Undergraduate Training Program for Innovation of Changzhou Institute of Technology (No.2017276Y)the National Natural Science Foundation of China (No.21273212)
文摘Photodissociation dynamics of dichlorodifluoromethane (CF2Cl2) around 235 nm has been studied using the time-sliced velocity map imaging technology in combination with the resonance enhanced multi-photon ionization technology. By measuring the raw images of chlorine atoms which are formed via one-photon dissociation of CF2Cl2, the speed and angular distributions can be directly obtained. The speed distribution of excited-state chlorine atoms consists of high translation energy (ET) and low ET components, which are related to direct dissociation on 3Q0 state and predissociation on the ground state induced by internal conversion, respectively. The speed distribution of ground-state chlorine atoms also consists of high ET and low ET components which are related to predissociation between 3Q0 and 1Q1 states and predissociation on the ground state induced by internal conversion, respectively. Radical dissociation channel is confirmed, nevertheless, secondary dissociation and three-body dissociation channels are excluded.
基金We are indebted to Prof. Kopin Liu （IAMS, Taipei） for stimulating discussions on going experiments, to Prof. Ming-fei Zhou and Assoc. Prof. Guan-jun Wang （Fudan University, Shanghai） for assistance in building machine, to Prof. Uzi. Even （Tel Aviv University, Tel Aviv） for discussions oil E1 valve employnmnt in laser ablation, and to Prof. Xue-ming Yang＇s group （DICP, Dalian） for new Iaser system. This work was supported by the National Natural Science Foundation of China （No.21322309） and the Program for Professor of Special Appointment （Eastern Scholar） at Shanghai Institutions of Higher Learning.
文摘We report a newly constructed laser ablation crossed molecular beam apparatus, equipped with time-sliced velocity map imaging technique, to study state-to-state metal atom reaction dynamics. Supersonic metal atomic beam is generated by laser vaporization of metal rod, and free expansion design without gas flow channel has been employed to obtain a good quality of metal atomic beam. We have chosen the crossed-beam reaction Al＋O2 to test the performance of the new apparatus. Two-rotational-states selected AIO（X^2∑＋, v=0, N and N＋I4） products can be imaged via P（N） and R（N＋14） branches of the Av=l band at the same wavelength, during （1＋1） resonance-enhanced multi-photon ionization through the AIO（D2E＋） intermediate state. In our experiment at 244.145 nm for simultaneous transitions of P（15） and R（29） branch, two rings in slice image were clearly distinguishable, corresponding to the AiO（v=0, N=IS） and AIO（v=0, N=29） states respectively. The energy difference between the two rotational levels is 403 cm^-1. The success of two states resolved in our apparatus suggests a better collisional energy resolution compared with the recent research study [J. Chem. Phys. 140, 214304 （2014）].
基金The work was supported by the National Natural Science Foundation of China(No.21673047 and No.22073019)the Shanghai Key Laboratory Foundation of Molecular Catalysis and Innovative Materialsthe Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning.
文摘One of the themes of modern molecular reac tion dynamics is to charac terize elementary chemical reactions from“quan tum state to quan tum stat e”,and the study of molecular reaction dynamics in excited states can help test the validi ty of modern chemical t heories and provide met hods to cont rol chemical reactions.The subject of this review is to describe the recent experimental techniques used to study the reaction dynamics of metal atoms in the gas phase.Through these techniques,information such as the internal energy distribution and angular distribution of the nascent products or the three-dimensional stereodynamic reactivity can be obtained.In addition,by preparing metal at oms wi th specific exci ted elec tronic states or orbi tal arrangemen ts,information about the reactivity of the electronic states enriches the relevant understanding of the electron transfer mechanism in metal reaction dynamics.
基金This work was supported by the National Key R&D Program of China(No.2017YFF0104500)the National Natural Science Foundation of China(No.21590802 and No.21473173)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB17000000).
文摘We study the phot odissociation dynamics of CS2 in the ultraviolet region using the time-sliced velocity map ion imaging technique.The S(3 Pj)+CS(X1E+)product channels were observed and identified at four wavelengths of 201.36,203.10,204.85 and 206.61 nm.In the measured images of S(3Pj=2,1,0),the vibrational states of the CS(X1E+)co-products were partially resolved and the vibrational state distributions were determined.Moreover,the product total kinetic energy releases and the anisotropic parameters were derived.The relatively small anisotropic parameter values indicate that the S(3Pj=2丄0)+CS(X1E+)channels are very likely formed via the indirect predissociation process of CS2.The study of the S(3Pj=2,1;0)+CS(X1E+)channels,which come from the spin-orbit coupling dissociation process of CS2,shows that nonadiabatic process plays a role in the ultraviolet photodissociation of CS2.
基金supported by the National Natural Science Foundation of China (No.21673047,No.21327901and No.21573047)the Shanghai Key Laboratory Foundation of Molecular Catalysis and Innovative Materialsthe Program for Professor of Special Appointment(Eastern Scholar) at Shanghai Institutions of Higher Learning.
文摘The reaction dynamics of yttrium atoms with sulfur dioxide molecules at a high collision energy of 36 kcal/mol was studied using time-sliced velocity map ion imaging,crossed molecular beam and laser-ablation method.The product YO was detected via multiphoton ionization at various wavelengths in the region of 482-615 nm.The slice images of YO show a broad velocity distribution and forward-backward peaking angular distribution.The forward scattering signal is stronger than its backward distribution.This indicates that the reaction proceeds via an intermediate complex and the lifetime of the intermediate state is less than one rotational period.The formation of complex suggests that electron transfer occurs in the oxidation reaction.
基金supported by the National Natural Science Foundation of China(No.21673047,No.21327901,No.21573047)the Shanghai Key Laboratory Foundation of Molecular Catalysis and Innovative Materialsthe Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning。
文摘The photodissociation dynamics of Al O at 193 nm is studied using time-sliced ion velocity mapping.Two dissociation channels are found through the speed and angular distributions of aluminum ions:one is one-photon dissociation of the neutral AlO to generate Al(2 Pu)+O(3 Pg),and the other is two-photon ionization and then dissociation of AlO^+to generate Al^+(1 Sg)+O(3 Pg).Each dissociation channel includes the contribution of AlO in the vibrational states v=0-2.The anisotropy parameter of the neutral dissociation channel is more dependent on the vibration state of AlO than the ion dissociation channel.
基金The experimental work is supported by the National Natural Science Foundation of China(No.22241304,No.22225303)the National Natural Science Foundation of China(NSFC Center for Chemical Dynamics,No.22288201)+3 种基金the Scientific Instrument Developing Project of the Chinese Academy of Sciences(No.GJJSTD20220001)the Innovation Program for Quantum Science and Technology(No.2021ZD0303304)Xueming Yang also thanks the Guangdong Science and Technology Program(No.2019ZT08L455 and No.2019JC01X091)the Shenzhen Science and Technology Program(No.ZDSYS20200421111001787).
基金supported by the National Natural Science Foundation of China(21073187,21273212,21173205)National Key Basic Research Program of China(973)(2010CB923302)+1 种基金100 Talents Program of Chinese Academy of SciencesKnowledge Innovation Program of Chinese Academy of Sciences,and USTC-NSRL Joint Funds,China(KY2340000021)~~
基金This work were supported in part by the National Natural Science Foundation of China(No.61572191)Natural Science Foundation of Hunan Province(Nos.2022JJ30398,2022JJ40277 and 2022JJ40278)Scientific Research Fund of Hunan Provincial Education Department(No.17A130).
文摘Edge computing can alleviate the problem of insufficient computational resources for the user equipment,improve the network processing environment,and promote the user experience.Edge computing is well known as a prospective method for the development of the Internet of Things(IoT).However,with the development of smart terminals,much more time is required for scheduling the terminal high-intensity upstream dataflow in the edge server than for scheduling that in the downstream dataflow.In this paper,we study the scheduling strategy for upstream dataflows in edge computing networks and introduce a three-tier edge computing network architecture.We propose a Time-Slicing Self-Adaptive Scheduling(TSAS)algorithm based on the hierarchical queue,which can reduce the queuing delay of the dataflow,improve the timeliness of dataflow processing and achieve an efficient and reasonable performance of dataflow scheduling.The experimental results show that the TSAS algorithm can reduce latency,minimize energy consumption,and increase system throughput.
