An improved large eddy simulation using a dynamic second-order sub-grid-scale （SGS） stress model has been developed to model the governing equations of dense turbulent particle-liquid two-phase flows in a rotating c...An improved large eddy simulation using a dynamic second-order sub-grid-scale （SGS） stress model has been developed to model the governing equations of dense turbulent particle-liquid two-phase flows in a rotating coordinate system, and continuity is conserved by a mass-weighted method to solve the filtered governing equations. In the cur- rent second-order SGS model, the SGS stress is a function of both the resolved strain-rate and rotation-rate tensors, and the model parameters are obtained from the dimensional consistency and the invariants of the strain-rate and the rotation-rate tensors. In the numerical calculation, the finite volume method is used to discretize the governing equations with a staggered grid system. The SIMPLEC algorithm is applied for the solution of the discretized governing equations. Body- fitted coordinates are used to simulate the two-phase flows in complex geometries. Finally the second-order dynamic SGS model is successfully applied to simulate the dense turbu-lent particle-liquid two-phase flows in a centrifugal impeller. The predicted pressure and velocity distributions are in good agreement with experimental results.展开更多
High-fidelity two-qubit gates are essential for the realization of large-scale quantum computation and simulation.Tunable coupler design is used to reduce the problem of parasitic coupling and frequency crowding in ma...High-fidelity two-qubit gates are essential for the realization of large-scale quantum computation and simulation.Tunable coupler design is used to reduce the problem of parasitic coupling and frequency crowding in manyqubit systems and thus thought to be advantageous. Here we design an extensible 5-qubit system in which center transmon qubit can couple to every four near-neighboring qubits via a capacitive tunable coupler and experimentally demonstrate high-fidelity controlled-phase(CZ) gate by manipulating central qubit and one nearneighboring qubit. Speckle purity benchmarking and cross entropy benchmarking are used to assess the purity fidelity and the fidelity of the CZ gate. The average purity fidelity of the CZ gate is 99.69±0.04% and the average fidelity of the CZ gate is 99.65±0.04%, which means that the control error is about 0.04%. Our work is helpful for resolving many challenges in implementation of large-scale quantum systems.展开更多
The development of high-fidelity two-qubit quantum gates is essential for digital quantum computing.Here,we propose and realize an all-microwave parametric controlled-Z(CZ)gates by coupling strength modulation in a su...The development of high-fidelity two-qubit quantum gates is essential for digital quantum computing.Here,we propose and realize an all-microwave parametric controlled-Z(CZ)gates by coupling strength modulation in a superconducting Transmon qubit system with tunable couplers.After optimizing the design of the tunable coupler together with the control pulse numerically,we experimentally realized a 100 ns CZ gate with high fidelity of 99.38%±0.34%and the control error being 0.1%.We note that our CZ gates are not affected by pulse distortion and do not need pulse correction,providing a solution for the real-time pulse generation in a dynamic quantum feedback circuit.With the expectation of utilizing our all-microwave control scheme to reduce the number of control lines through frequency multiplexing in the future,our scheme draws a blueprint for the high-integrable quantum hardware design.展开更多
Optical frequency combs(OFCs)have great potential in communications,especially in dense wavelength-division multiplexing.However,the size of traditional OFCs based on conventional optical microcavities or dispersion f...Optical frequency combs(OFCs)have great potential in communications,especially in dense wavelength-division multiplexing.However,the size of traditional OFCs based on conventional optical microcavities or dispersion fibers is at least tens of micrometers,far larger than that of nanoscale electronic chips.Therefore,reducing the size of OFCs to match electronic chips is of necessity.Here,for the first time to our knowledge,we introduce surface plasmon polaritons(SPPs)to the construction of OFCs to realize a miniature device.The thickness of our device is reduced below 1μm.Though the presence of SPPs may induce ohmic and scattering loss,the threshold of the device is obtained as 9μW,comparable to the conventional device.Interestingly,the response time is 13.2 ps,much faster than the optical counterparts.This work provides a feasible strategy for the miniaturization of OFCs.展开更多
高浓度电解液被认为是一种很有前景的拓宽电解液电化学稳定窗口和提高水系电池电化学性能的方法.但是高浓度电解液也存在高成本、高粘度、低电导率等棘手问题.因为特殊的Grotthuss机制,质子电池能够在低浓度电解液中获得足够的动力学性...高浓度电解液被认为是一种很有前景的拓宽电解液电化学稳定窗口和提高水系电池电化学性能的方法.但是高浓度电解液也存在高成本、高粘度、低电导率等棘手问题.因为特殊的Grotthuss机制,质子电池能够在低浓度电解液中获得足够的动力学性能.基于此,我们采用罕见的超低浓度硫酸电解液(0.01 mol L^(-1))助力K~+预嵌的VO(KVO,KVO)电化学稳定性.在50 mA g^(-1)的低电流密度下,KVO电极具有129 mA h g^(-1)的比容量;在1 A g^(-1)的电流密度下,循环20,000圈的容量保持率为78%.超低浓度电解液策略为开拓耐用的、低成本的水系能源存储系统提供了一种新的路径.展开更多
Metagenomic binning is the process of sorting genome or contig sequences obtained by metagenomic sequencing of environmental DNA or genetically heterogeneous groups of organisms into categories representing the indivi...Metagenomic binning is the process of sorting genome or contig sequences obtained by metagenomic sequencing of environmental DNA or genetically heterogeneous groups of organisms into categories representing the individual species or genetically homogenous groups (e.g., strains) from which they originated (Rasheed and Rangwala, 2013). Conventionally, whole-genome sequencing of single species requires culture and isolation of microorganisms.展开更多
In the present work,both computational and experimentalmethods are employed to study the two-phase flow occurring in a model pump sump.The twofluid model of the two-phase flow has been applied to the simulation of the...In the present work,both computational and experimentalmethods are employed to study the two-phase flow occurring in a model pump sump.The twofluid model of the two-phase flow has been applied to the simulation of the threedimensional cavitating flow.The governing equations of the two-phase cavitating flow are derived from the kinetic theory based on the Boltzmann equation.The isotropic RNG k−ε−kca turbulence model of two-phase flows in the form of cavity number instead of the formof cavity phase volume fraction is developed.The RNG k−ε−kca turbulence model,that is the RNG k−εturbulence model for the liquid phase combined with the kca model for the cavity phase,is employed to close the governing turbulent equations of the two-phase flow.The computation of the cavitating flow through a model pump sump has been carried out with this model in three-dimensional spaces.The calculated results have been compared with the data of the PIV experiment.Good qualitative agreement has been achievedwhich exhibits the reliability of the numerical simulation model.展开更多
基金the National Natural Science Foundation of China(50779069 and 90510007)the Start-up Scientific Research Foundation of China Agricultural University(2006021)the Beijing Natural Science Foundation(3071002).
文摘An improved large eddy simulation using a dynamic second-order sub-grid-scale （SGS） stress model has been developed to model the governing equations of dense turbulent particle-liquid two-phase flows in a rotating coordinate system, and continuity is conserved by a mass-weighted method to solve the filtered governing equations. In the cur- rent second-order SGS model, the SGS stress is a function of both the resolved strain-rate and rotation-rate tensors, and the model parameters are obtained from the dimensional consistency and the invariants of the strain-rate and the rotation-rate tensors. In the numerical calculation, the finite volume method is used to discretize the governing equations with a staggered grid system. The SIMPLEC algorithm is applied for the solution of the discretized governing equations. Body- fitted coordinates are used to simulate the two-phase flows in complex geometries. Finally the second-order dynamic SGS model is successfully applied to simulate the dense turbu-lent particle-liquid two-phase flows in a centrifugal impeller. The predicted pressure and velocity distributions are in good agreement with experimental results.
基金the National Key R&D Program of China(Grant No.2017YFA0304300)the Chinese Academy of Sciences+6 种基金Anhui Initiative in Quantum Information TechnologiesTechnology Committee of Shanghai Municipalitythe National Natural Science Foundation of China(Grants Nos.11905217,11774326,and 11905294)the Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)the Natural Science Foundation of Shanghai(Grant No.19ZR1462700)the Key-Area Research and Development Program of Guangdong Provice(Grant No.2020B0303030001)the Youth Talent Lifting Project(Grant No.2020-JCJQ-QT-030)。
文摘High-fidelity two-qubit gates are essential for the realization of large-scale quantum computation and simulation.Tunable coupler design is used to reduce the problem of parasitic coupling and frequency crowding in manyqubit systems and thus thought to be advantageous. Here we design an extensible 5-qubit system in which center transmon qubit can couple to every four near-neighboring qubits via a capacitive tunable coupler and experimentally demonstrate high-fidelity controlled-phase(CZ) gate by manipulating central qubit and one nearneighboring qubit. Speckle purity benchmarking and cross entropy benchmarking are used to assess the purity fidelity and the fidelity of the CZ gate. The average purity fidelity of the CZ gate is 99.69±0.04% and the average fidelity of the CZ gate is 99.65±0.04%, which means that the control error is about 0.04%. Our work is helpful for resolving many challenges in implementation of large-scale quantum systems.
基金the USTC Center for Micro-and Nanoscale Research and Fabrication for supporting the sample fabricationQuantum CTek Co.,Ltd.for supporting the fabrication and the maintenance of room-temperature electronics+7 种基金supported by the National Key R&D Program of China(Grant No.2017YFA0304300)the Chinese Academy of Sciencesthe Anhui Initiative in Quantum Information Technologiesthe Technology Committee of Shanghai Municipalitythe National Natural Science Foundation of China(Grants No.11905217 and 11905294)the Natural Science Foundation of Shanghai(Grant No.19ZR1462700)he Key-Area Research and Development Program of Guangdong Province(Grant No.2020B0303030001)the China Postdoctoral Science Foundation。
文摘The development of high-fidelity two-qubit quantum gates is essential for digital quantum computing.Here,we propose and realize an all-microwave parametric controlled-Z(CZ)gates by coupling strength modulation in a superconducting Transmon qubit system with tunable couplers.After optimizing the design of the tunable coupler together with the control pulse numerically,we experimentally realized a 100 ns CZ gate with high fidelity of 99.38%±0.34%and the control error being 0.1%.We note that our CZ gates are not affected by pulse distortion and do not need pulse correction,providing a solution for the real-time pulse generation in a dynamic quantum feedback circuit.With the expectation of utilizing our all-microwave control scheme to reduce the number of control lines through frequency multiplexing in the future,our scheme draws a blueprint for the high-integrable quantum hardware design.
基金supported by Innovation Program for Quantum Science and Technology (2021ZD0300200)Shanghai Municipal Science and Technology Major Project (2019SHZDZX01)+13 种基金Special funds from Jinan Science and Technology Bureau and Jinan High Tech Zone Management Committeethe Chinese Academy of Sciences (CAS)Anhui Initiative in Quantum Information TechnologiesTechnology Committee of Shanghai MunicipalityNatural Science Foundation of Shandong Province (ZR202209080019)Key-Area Research and Development Program of Guangdong Provice (2020B0303030001)supported in part by the Japanese MEXT Quantum Leap Flagship Program (MEXT Q-LEAP,JPMXS0118069605)the support from the Youth Talent Lifting Project (2020-JCJQ-QT-030)the National Natural Science Foundation of China (12274464,and 11905294)China Postdoctoral Science Foundationthe Open Research Fund from State Key Laboratory of High Performance Computing of China (201901-01)supported by Shanghai Rising-Star Program (23QA1410000)the Youth Innovation Promotion Association of CAS (2022460)the support from THE XPLORER PRIZE。
基金National Key Research and Development Program of China(2018YFE0204000)Strategic Priority Research Program of the Chinese Academy of Sciences(XDB43000000)+2 种基金National Natural Science Foundation of China(21975245,51972300,62274155,U20A20206)Youth Innovation Promotion Association of the Chinese Academy of Sciences(2020114)Beijing Nova Program(2020117)。
文摘Optical frequency combs(OFCs)have great potential in communications,especially in dense wavelength-division multiplexing.However,the size of traditional OFCs based on conventional optical microcavities or dispersion fibers is at least tens of micrometers,far larger than that of nanoscale electronic chips.Therefore,reducing the size of OFCs to match electronic chips is of necessity.Here,for the first time to our knowledge,we introduce surface plasmon polaritons(SPPs)to the construction of OFCs to realize a miniature device.The thickness of our device is reduced below 1μm.Though the presence of SPPs may induce ohmic and scattering loss,the threshold of the device is obtained as 9μW,comparable to the conventional device.Interestingly,the response time is 13.2 ps,much faster than the optical counterparts.This work provides a feasible strategy for the miniaturization of OFCs.
基金the National Key R&D Program of China(2017YFA0304300),the Chinese Academy of Sciences,Anhui Initiative in Quantum Information Technologies,Technology Committee of Shanghai Municipality,National Natural Science Foundation of China(11905217,11774326,and 11905294)‘Shang-hai Municipal Science and Technology Major Project(2019SHZDZX01)’Natural Science Foundation of Shanghai(19ZR1462700)‘Key-Area Research and Development Program of Guangdong Province(2020B0303030001)’the Youth Talent Lifting Project(2020-JCJQ-QT-030)。
基金supported by the National Natural Science Foundation of China(52102264)the Natural Science Foundation of Jiangsu Province(BK20200826)+2 种基金the Natural Science Foundation of Jiangsu Higher Education Institutions(20KJB430018)the Startup Foundation for Introducing Talent of NUIST(2020r023)Jiangsu Provincial Scientific Research and Practice Innovation Program(KYCX21_0991)。
文摘高浓度电解液被认为是一种很有前景的拓宽电解液电化学稳定窗口和提高水系电池电化学性能的方法.但是高浓度电解液也存在高成本、高粘度、低电导率等棘手问题.因为特殊的Grotthuss机制,质子电池能够在低浓度电解液中获得足够的动力学性能.基于此,我们采用罕见的超低浓度硫酸电解液(0.01 mol L^(-1))助力K~+预嵌的VO(KVO,KVO)电化学稳定性.在50 mA g^(-1)的低电流密度下,KVO电极具有129 mA h g^(-1)的比容量;在1 A g^(-1)的电流密度下,循环20,000圈的容量保持率为78%.超低浓度电解液策略为开拓耐用的、低成本的水系能源存储系统提供了一种新的路径.
基金supported by the grants from the National Key Research Program (2021YFA0910700)Shenzhen science and technology university stable support program (GXWD20201230155 427003-20200821222112001)+1 种基金Guangdong Key Area Research Program (2020B0101380001)Shenzhen Science and Technology Program (JCYJ20200109113201726)
文摘Metagenomic binning is the process of sorting genome or contig sequences obtained by metagenomic sequencing of environmental DNA or genetically heterogeneous groups of organisms into categories representing the individual species or genetically homogenous groups (e.g., strains) from which they originated (Rasheed and Rangwala, 2013). Conventionally, whole-genome sequencing of single species requires culture and isolation of microorganisms.
基金This research work was funded by the Chinese National Foundation of Natural Science(Nos.51076077,51176168,51249003 and 51076144)This work is also supported by Science Foundation of Zhejiang Sci-Tech University(ZSTU) under Grant No.11130032241201.
文摘In the present work,both computational and experimentalmethods are employed to study the two-phase flow occurring in a model pump sump.The twofluid model of the two-phase flow has been applied to the simulation of the threedimensional cavitating flow.The governing equations of the two-phase cavitating flow are derived from the kinetic theory based on the Boltzmann equation.The isotropic RNG k−ε−kca turbulence model of two-phase flows in the form of cavity number instead of the formof cavity phase volume fraction is developed.The RNG k−ε−kca turbulence model,that is the RNG k−εturbulence model for the liquid phase combined with the kca model for the cavity phase,is employed to close the governing turbulent equations of the two-phase flow.The computation of the cavitating flow through a model pump sump has been carried out with this model in three-dimensional spaces.The calculated results have been compared with the data of the PIV experiment.Good qualitative agreement has been achievedwhich exhibits the reliability of the numerical simulation model.
