The construction of a new beamline,BL10U1,was completed at the Shanghai synchrotron radiation facility in 2020.This multipurpose beamline was designed to provide X-ray scattering techniques such as ultra-small-angle X...The construction of a new beamline,BL10U1,was completed at the Shanghai synchrotron radiation facility in 2020.This multipurpose beamline was designed to provide X-ray scattering techniques such as ultra-small-angle X-ray scattering(USAXS),small-angle X-ray scattering(SAXS),wide-angle X-ray scattering,and microfocus SAXS(μSAXS)for a broad user community.To realize fast time-resolved USAXS experiments,the beamline adopted an in-vacuum undulator with a total length of 1.6 m as the photon source.An in-house cryogenic-cooled double multilayer monochromator was installed to deliver a photon flux of approximately 10^(13) photons/s at a photon energy of 10 keV.The three-year successful operation of this beamline demonstrated that the monochromator operated smoothly,as expected.BL10U1 has three end stations in succession:USAXS end station,μSAXS end station,and end station for industrial applications.The minimum scattering vector q~0.0042 nm^(-1) at 10 keV can be achieved at the USAXS end station equipped with a 28 m-long and 1.8 m-diameter vacuum flight tube.At theμSAXS end station,a beam spot of less than 10×8μm was achieved for micro-SAXS experiments.In contrast,in situ experimental instruments up to 5 m high and 8 m wide can be mounted at the industrial application end station,which offers industrial scientists the opportunity to use their large industrial equipment.BL10U1 opens up a new capability to investigate phenomena such as non-equilibrium and dynamic processes of materials with a wide length scale from angstroms to micrometers with millisecond time resolution.In this paper,we also report beamline design considerations and commissioning results.展开更多
X-ray photon correlation spectroscopy(XPCS)has emerged as a powerful tool for probing the nanoscale dynamics of soft condensed matter and strongly correlated materials owing to its high spatial resolution and penetrat...X-ray photon correlation spectroscopy(XPCS)has emerged as a powerful tool for probing the nanoscale dynamics of soft condensed matter and strongly correlated materials owing to its high spatial resolution and penetration capabilities.This technique requires high brilliance and beam coherence,which are not directly available at modern synchrotron beamlines in China.To facilitate future XPCS experiments,we modified the optical setup of the newly commissioned BL10U1 USAXS beamline at the Shanghai Synchrotron Radiation Facility(SSRF).Subsequently,we performed XPCS measurements on silica suspensions in glycerol,which were opaque owing to their high concentrations.Images were collected using a high frame rate area detector.A comprehensive analysis was performed,yielding correlation functions and several key dynamic parameters.All the results were consistent with the theory of Brownian motion and demonstrated the feasibility of XPCS at SSRF.Finally,by carefully optimizing the setup and analyzing the algorithms,we achieved a time resolution of 2 ms,which enabled the characterization of millisecond dynamics in opaque systems.展开更多
OBJECTIVE To evalu ate the role of resting magnetocardiography in identifying seve re coronary artery stenosis in patients with suspected coronary artery disease.METHODS A total of 513 patients with angina symptoms we...OBJECTIVE To evalu ate the role of resting magnetocardiography in identifying seve re coronary artery stenosis in patients with suspected coronary artery disease.METHODS A total of 513 patients with angina symptoms were included and divided into two groups based on the extent of coronary artery disease determined by angiography:the non-severe coronary stenusis group(<70% stenosis) and the severe coronary stenosis group(≥70% stenosis).The diagnostic model was constructed using magnetic field map(MFM) parameters,either individually or in combination with clinical indicators.The performance of the models was evaluated using receiver operating characteristic curves,accuracy,sensitivity,specificity,positive predictive value(PPV) and ne gative predictive value(NPV).Calibration plots and decision curve analysis were performed to investigate the clinical utility and performance of the models,respectively.RESULTS In the severe coronary stenosis group,QR_MCTDd,S_MDp,and TT_(MA)C_(50) were significantly higher than those in the non-severe coronary stenosis group(10,46±10.66 vs,5.11±6.07,P <0.001;7.2±8.64 vs.4.68±6.95,P=0.003;0.32±57.29 vs.0.26±57.29,P <0.001).While,QR_MV_(amp),R_(MA),and T_(MA) in the severe coronary stenosis group were lower(0.23±0.16 vs.0.28±0.16,P<0.001;55.06±48.68 vs.59.24±53.01,P<0.001;51.67±39.32 vs. 60.45±51.33,P <0.001).Seven MFM parameters were integrated into the model,resulting in an area under the curve of 0.810(95% CI:0.765-0.855).The sensitivity,specificity,PPV,NPV,and accurecy were 71.7%,80.4%,93.3%,42.8 %,and 73.5%;respectevely.The combined model exhibited an area under the curve of 0.845(95% CI:0.798-0.892).The sensitivity,specificity,PPV,NPV,and accuracy were 84.3%,73.8%,92.6%,54.6%,and 82.1%;respectively.Calibration curves demonstrate d excellent agreement between the nomogram prediction and actual observation.The decision curve analysis showed that the c ombine d model provided greater net benefit compared to the magnetocardingraphy model.CONCLUSIONS The novel quantitative MFM parameters,whether used individually or in combination with clinical indicators,have been shown to effectively pre dict the risk of severe coronary stenosis in patients presenting with angina-like symptoms.Magnetocardiography,an emerging non-invasive diagnostic tool,warrants further exploration for its potential in diagnosing coronary heart disease.展开更多
As the research proposed reservoirs after impact on the surrounding ecological fragile areas of groundwater level and scope, through the proposed reservoir area and its surrounding data collecting, hydrogeology survey...As the research proposed reservoirs after impact on the surrounding ecological fragile areas of groundwater level and scope, through the proposed reservoir area and its surrounding data collecting, hydrogeology survey and related test, for Modflow system simulation platform, through to the boundary conditions, initial conditions and source sink term and related hydrogeological parameters, the model identification and verification, The model of hydrogeological parameters in the study area is constructed. The simulation results show that the groundwater depth near the reservoir area will be higher than the critical value (1.8 m) of secondary salinization of soil. At the same time, according to the investigation and experiment, if the reservoir does not do seepage treatment, the water infiltration in the reservoir will aggravate the environmental hydrogeological problems in the ecologically fragile area.展开更多
OBJECTIVE To assess the safety and effectiveness of intravascular lithotripsy(IVL)treatment for de novo coronary lesion involving severely calcified vessels in a Chinese population.METHODS The Clinical Trial of the Sh...OBJECTIVE To assess the safety and effectiveness of intravascular lithotripsy(IVL)treatment for de novo coronary lesion involving severely calcified vessels in a Chinese population.METHODS The Clinical Trial of the ShOckwave Coronary IVL System Used to Treat CalcIfied Coronary ArtEries(SOLSTICE)was a prospective,single-arm,multicentre trial.According to the inclusion criteria,patients with severely calcified lesions were enrolled in the study.IVL was used to perform calcium modification prior to stent implantation.The primary safety endpoint was freedom from major adverse cardiac events(MACEs)at 30 days.The primary effectiveness endpoint was procedural success,defined as successful stent delivery with residual stenosis<50% by core lab assessment without in-hospital MACEs.The morphological changes of calcium modification were assessed by optical coherence tomography(OCT)before and after IVL treatment.RESULTS Patients(n=20)were enrolled at three sites in China.Severe calcification by core lab assessment was present in all lesions,with a mean calcium angle and thickness of 300±51°and 0.99±0.12 mm(by OCT),respectively.The 30-day MACE rate was 5%.Both primary safety and effectiveness endpoints were achieved in 95% of patients.The final in-stent diameter stenosis was 13.1%±5.7% with no patient had a residual stenosis<50%after stenting.No serious angiographic complications(severe dissection grade D or worse,perforation,abrupt closure,slow flow/no-reflow)observed at any time during the procedure.OCT imaging demonstrated visible multiplane calcium fracture in 80% of lesions with a mean stent expansion of 95.62%±13.33% at the site of maximum calcification and minimum stent area(MSA)of 5.34±1.64 mm^(2).CONCLUSIONS The initial coronary IVL experience for Chinese operators resulted in high procedural success and low angiographic complications consistent with prior IVL studies,reflecting the relative ease of use of IVL technology.展开更多
A novel and fast three-dimensional reconstruction method for a Compton camera and its performance in radionuclide imaging is proposed and analyzed in this study. The conical surface sampling back-projection method wit...A novel and fast three-dimensional reconstruction method for a Compton camera and its performance in radionuclide imaging is proposed and analyzed in this study. The conical surface sampling back-projection method with scattering angle correction(CSS-BP-SC) can quickly perform the back-projection process of the Compton cone and can be used to precompute the list-mode maximum likelihood expectation maximization(LM-MLEM). A dedicated parallel architecture was designed for the graphics processing unit acceleration of the back-projection and iteration stage of the CSS-BP-SC-based LM-MLEM. The imaging results of the two-point source Monte Carlo(MC) simulation demonstrate that by analyzing the full width at half maximum along the three coordinate axes, the CSS-BP-SC-based LM-MLEM can obtain imaging results comparable to those of the traditional reconstruction algorithm, that is, the simple back-projection-based LM-MLEM. The imaging results of the mouse phantom MC simulation and experiment demonstrate that the reconstruction results obtained by the proposed method sufficiently coincide with the set radioactivity distribution, and the speed increased by more than 664 times compared to the traditional reconstruction algorithm in the mouse phantom experiment. The proposed method will further advance the imaging applications of Compton cameras.展开更多
In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric s...In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric stress in the quartz particles under dynamic heating in a heterogeneous plasma flow was determined by a two-stage approximation approach.The effect of the presence of vacuoles in natural quartz on the particle thermobaric destruction conditions was studied.It was found that the equivalent thermal and baric stresses in quartz particles may significantly increase in the presence of vacuoles within a small gas volume fraction.The influence of the regime and energetic working conditions of an RF inductively coupled plasma torch system on the particle thermobaric destruction conditions was examined,and a recommendation was given to promote the degree of thermobaric destruction of quartz particles,which is of substantial importance for improving the overall enrichment efficiency of quartz concentrates.展开更多
With the development of satellite communication,in order to solve the problems of shortage of on-board resources and refinement of delay requirements to improve the communication performance of satellite optical netwo...With the development of satellite communication,in order to solve the problems of shortage of on-board resources and refinement of delay requirements to improve the communication performance of satellite optical networks,this paper proposes a bee colony optimization algorithm for routing and wavelength assignment based on directional guidance(DBCO-RWA)in satellite optical networks.In D-BCORWA,directional guidance based on relative position and link load is defined,and then the link cost function in the path search stage is established based on the directional guidance factor.Finally,feasible solutions are expanded in the global optimization stage.The wavelength utilization,communication success probability,blocking rate,communication hops and convergence characteristic are simulated.The results show that the performance of the proposed algorithm is improved compared with existing algorithms.展开更多
An open quantum battery(QB)model of a single qubit system charging in a coherent auxiliary bath(CAB)consisting of a series of independent coherent ancillae is considered.According to the collision charging protocol we...An open quantum battery(QB)model of a single qubit system charging in a coherent auxiliary bath(CAB)consisting of a series of independent coherent ancillae is considered.According to the collision charging protocol we derive a quantum master equation and obtain the analytical solution of QB in a steady state.We find that the full charging capacity(or the maximal extractable work(MEW))of QB,in the weak QB-ancilla coupling limit,is positively correlated with the coherence magnitude of ancilla.Combining with the numerical simulations we compare with the charging properties of QB at finite coupling strength,such as the MEW,average charging power and the charging efficiency,when considering the bath to be a thermal auxiliary bath(TAB)and a CAB,respectively.We find that when the QB with CAB,in the weak coupling regime,is in fully charging,both its capacity and charging efficiency can go beyond its classical counterpart,and they increase with the increase of coherence magnitude of ancilla.In addition,the MEW of QB in the regime of relative strong coupling and strong coherent magnitude shows the oscillatory behavior with the charging time increasing,and the first peak value can even be larger than the full charging MEW of QB.This also leads to a much larger average charging power than that of QB with TAB in a short-time charging process.These features suggest that with the help of quantum coherence of CAB it becomes feasible to switch the charging schemes between the long-time slow charging protocol with large capacity and high efficiency and the short-time rapid charging protocol with highly charging power only by adjusting the coupling strength of QB-ancilla.This work clearly demonstrates that the quantum coherence of bath can not only serve as the role of“fuel”of QB to be utilized to improve the QB's charging performance but also provide an alternative way to integrate the different charging protocols into a single QB.展开更多
切沟体积是表征切沟侵蚀量、输水输沙能力的重要参数。笔者以冀西北山盆地区典型流域切沟为研究对象,使用Riegl三维激光扫描仪获取切沟点云数据,构建高分辨率DEM,提取切沟形态参数,分析切沟断面特征,构建并验证适宜的切沟体积估算模型...切沟体积是表征切沟侵蚀量、输水输沙能力的重要参数。笔者以冀西北山盆地区典型流域切沟为研究对象,使用Riegl三维激光扫描仪获取切沟点云数据,构建高分辨率DEM,提取切沟形态参数,分析切沟断面特征,构建并验证适宜的切沟体积估算模型。结果表明:1)切沟间的发育不均衡,不同切沟沟长、面积和体积相差较大,但同一参数在各个断面位置的参数值差别较小;2)面积、沟长和沟深与体积呈显著的正相关,相关系数较高,分别为0.949、0.870和0.814;3)基于V-L关系、V-A关系和V(A,D)关系建立对应的线性回归方程,其决定系数R 2分别为0.7706、0.9159和0.9748,模型验证结果显示,V(A,D)关系模型V=0.04653 A 1.499+24.08 D 1.916-44.26在预测冀西北山盆地区切沟体积上更有优势。研究结果可为大空间尺度切沟侵蚀定量模拟及制图提供理论和技术支持,为水土保持工程提供科学理论依据。展开更多
基金This work was supported by the National Key R&D Program of China(No.2020YFA0405802)the Shanghai Large Scientific Facilities Center.
文摘The construction of a new beamline,BL10U1,was completed at the Shanghai synchrotron radiation facility in 2020.This multipurpose beamline was designed to provide X-ray scattering techniques such as ultra-small-angle X-ray scattering(USAXS),small-angle X-ray scattering(SAXS),wide-angle X-ray scattering,and microfocus SAXS(μSAXS)for a broad user community.To realize fast time-resolved USAXS experiments,the beamline adopted an in-vacuum undulator with a total length of 1.6 m as the photon source.An in-house cryogenic-cooled double multilayer monochromator was installed to deliver a photon flux of approximately 10^(13) photons/s at a photon energy of 10 keV.The three-year successful operation of this beamline demonstrated that the monochromator operated smoothly,as expected.BL10U1 has three end stations in succession:USAXS end station,μSAXS end station,and end station for industrial applications.The minimum scattering vector q~0.0042 nm^(-1) at 10 keV can be achieved at the USAXS end station equipped with a 28 m-long and 1.8 m-diameter vacuum flight tube.At theμSAXS end station,a beam spot of less than 10×8μm was achieved for micro-SAXS experiments.In contrast,in situ experimental instruments up to 5 m high and 8 m wide can be mounted at the industrial application end station,which offers industrial scientists the opportunity to use their large industrial equipment.BL10U1 opens up a new capability to investigate phenomena such as non-equilibrium and dynamic processes of materials with a wide length scale from angstroms to micrometers with millisecond time resolution.In this paper,we also report beamline design considerations and commissioning results.
基金This work was supported by National Natural Science Foundation of China(No.12075304)Natural Science Foundation of Shanghai(No.22ZR1442100)National Key Research and Development Program of China(No.2022YFB3503904).
文摘X-ray photon correlation spectroscopy(XPCS)has emerged as a powerful tool for probing the nanoscale dynamics of soft condensed matter and strongly correlated materials owing to its high spatial resolution and penetration capabilities.This technique requires high brilliance and beam coherence,which are not directly available at modern synchrotron beamlines in China.To facilitate future XPCS experiments,we modified the optical setup of the newly commissioned BL10U1 USAXS beamline at the Shanghai Synchrotron Radiation Facility(SSRF).Subsequently,we performed XPCS measurements on silica suspensions in glycerol,which were opaque owing to their high concentrations.Images were collected using a high frame rate area detector.A comprehensive analysis was performed,yielding correlation functions and several key dynamic parameters.All the results were consistent with the theory of Brownian motion and demonstrated the feasibility of XPCS at SSRF.Finally,by carefully optimizing the setup and analyzing the algorithms,we achieved a time resolution of 2 ms,which enabled the characterization of millisecond dynamics in opaque systems.
基金supported by the National Key Research and Development Program (No.2022YFC2407001)。
文摘OBJECTIVE To evalu ate the role of resting magnetocardiography in identifying seve re coronary artery stenosis in patients with suspected coronary artery disease.METHODS A total of 513 patients with angina symptoms were included and divided into two groups based on the extent of coronary artery disease determined by angiography:the non-severe coronary stenusis group(<70% stenosis) and the severe coronary stenosis group(≥70% stenosis).The diagnostic model was constructed using magnetic field map(MFM) parameters,either individually or in combination with clinical indicators.The performance of the models was evaluated using receiver operating characteristic curves,accuracy,sensitivity,specificity,positive predictive value(PPV) and ne gative predictive value(NPV).Calibration plots and decision curve analysis were performed to investigate the clinical utility and performance of the models,respectively.RESULTS In the severe coronary stenosis group,QR_MCTDd,S_MDp,and TT_(MA)C_(50) were significantly higher than those in the non-severe coronary stenosis group(10,46±10.66 vs,5.11±6.07,P <0.001;7.2±8.64 vs.4.68±6.95,P=0.003;0.32±57.29 vs.0.26±57.29,P <0.001).While,QR_MV_(amp),R_(MA),and T_(MA) in the severe coronary stenosis group were lower(0.23±0.16 vs.0.28±0.16,P<0.001;55.06±48.68 vs.59.24±53.01,P<0.001;51.67±39.32 vs. 60.45±51.33,P <0.001).Seven MFM parameters were integrated into the model,resulting in an area under the curve of 0.810(95% CI:0.765-0.855).The sensitivity,specificity,PPV,NPV,and accurecy were 71.7%,80.4%,93.3%,42.8 %,and 73.5%;respectevely.The combined model exhibited an area under the curve of 0.845(95% CI:0.798-0.892).The sensitivity,specificity,PPV,NPV,and accuracy were 84.3%,73.8%,92.6%,54.6%,and 82.1%;respectively.Calibration curves demonstrate d excellent agreement between the nomogram prediction and actual observation.The decision curve analysis showed that the c ombine d model provided greater net benefit compared to the magnetocardingraphy model.CONCLUSIONS The novel quantitative MFM parameters,whether used individually or in combination with clinical indicators,have been shown to effectively pre dict the risk of severe coronary stenosis in patients presenting with angina-like symptoms.Magnetocardiography,an emerging non-invasive diagnostic tool,warrants further exploration for its potential in diagnosing coronary heart disease.
文摘As the research proposed reservoirs after impact on the surrounding ecological fragile areas of groundwater level and scope, through the proposed reservoir area and its surrounding data collecting, hydrogeology survey and related test, for Modflow system simulation platform, through to the boundary conditions, initial conditions and source sink term and related hydrogeological parameters, the model identification and verification, The model of hydrogeological parameters in the study area is constructed. The simulation results show that the groundwater depth near the reservoir area will be higher than the critical value (1.8 m) of secondary salinization of soil. At the same time, according to the investigation and experiment, if the reservoir does not do seepage treatment, the water infiltration in the reservoir will aggravate the environmental hydrogeological problems in the ecologically fragile area.
文摘OBJECTIVE To assess the safety and effectiveness of intravascular lithotripsy(IVL)treatment for de novo coronary lesion involving severely calcified vessels in a Chinese population.METHODS The Clinical Trial of the ShOckwave Coronary IVL System Used to Treat CalcIfied Coronary ArtEries(SOLSTICE)was a prospective,single-arm,multicentre trial.According to the inclusion criteria,patients with severely calcified lesions were enrolled in the study.IVL was used to perform calcium modification prior to stent implantation.The primary safety endpoint was freedom from major adverse cardiac events(MACEs)at 30 days.The primary effectiveness endpoint was procedural success,defined as successful stent delivery with residual stenosis<50% by core lab assessment without in-hospital MACEs.The morphological changes of calcium modification were assessed by optical coherence tomography(OCT)before and after IVL treatment.RESULTS Patients(n=20)were enrolled at three sites in China.Severe calcification by core lab assessment was present in all lesions,with a mean calcium angle and thickness of 300±51°and 0.99±0.12 mm(by OCT),respectively.The 30-day MACE rate was 5%.Both primary safety and effectiveness endpoints were achieved in 95% of patients.The final in-stent diameter stenosis was 13.1%±5.7% with no patient had a residual stenosis<50%after stenting.No serious angiographic complications(severe dissection grade D or worse,perforation,abrupt closure,slow flow/no-reflow)observed at any time during the procedure.OCT imaging demonstrated visible multiplane calcium fracture in 80% of lesions with a mean stent expansion of 95.62%±13.33% at the site of maximum calcification and minimum stent area(MSA)of 5.34±1.64 mm^(2).CONCLUSIONS The initial coronary IVL experience for Chinese operators resulted in high procedural success and low angiographic complications consistent with prior IVL studies,reflecting the relative ease of use of IVL technology.
基金supported by the National Natural Science Foundation of China (No. 12220101005)Natural Science Foundation of Jiangsu Province (No. BK20220132)+2 种基金Primary Research and Development Plan of Jiangsu Province (No. BE2019002-3)Fundamental Research Funds for Central Universities (No. NG2022004)the Foundation of the Graduate Innovation Center in NUAA (No. xcxjh20210613)。
文摘A novel and fast three-dimensional reconstruction method for a Compton camera and its performance in radionuclide imaging is proposed and analyzed in this study. The conical surface sampling back-projection method with scattering angle correction(CSS-BP-SC) can quickly perform the back-projection process of the Compton cone and can be used to precompute the list-mode maximum likelihood expectation maximization(LM-MLEM). A dedicated parallel architecture was designed for the graphics processing unit acceleration of the back-projection and iteration stage of the CSS-BP-SC-based LM-MLEM. The imaging results of the two-point source Monte Carlo(MC) simulation demonstrate that by analyzing the full width at half maximum along the three coordinate axes, the CSS-BP-SC-based LM-MLEM can obtain imaging results comparable to those of the traditional reconstruction algorithm, that is, the simple back-projection-based LM-MLEM. The imaging results of the mouse phantom MC simulation and experiment demonstrate that the reconstruction results obtained by the proposed method sufficiently coincide with the set radioactivity distribution, and the speed increased by more than 664 times compared to the traditional reconstruction algorithm in the mouse phantom experiment. The proposed method will further advance the imaging applications of Compton cameras.
基金supported by National Natural Science Foundation of China(Nos.52202460,52177128)National Key R&D Program of China(Nos.2020YFC2201100,2021YFC2202804)+2 种基金China Postdoctoral Science Foundation(Nos.2021M690392,2021TQ0036)Science Foundation for Youth Scholars of the Beijing Institute of TechnologyAdvanced Space Propulsion Laboratory of BICE and the Beijing Engineering Research Centre of Efficient and Green Aerospace Propulsion Technology(No.LabASP-2021-04)。
文摘In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric stress in the quartz particles under dynamic heating in a heterogeneous plasma flow was determined by a two-stage approximation approach.The effect of the presence of vacuoles in natural quartz on the particle thermobaric destruction conditions was studied.It was found that the equivalent thermal and baric stresses in quartz particles may significantly increase in the presence of vacuoles within a small gas volume fraction.The influence of the regime and energetic working conditions of an RF inductively coupled plasma torch system on the particle thermobaric destruction conditions was examined,and a recommendation was given to promote the degree of thermobaric destruction of quartz particles,which is of substantial importance for improving the overall enrichment efficiency of quartz concentrates.
基金supported in part by the National Key Research and Development Program of China under Grant 2021YFB2900604in part by the National Natural Science Foundation of China(NSFC)under Grant U22B2033,61975234,61875230。
文摘With the development of satellite communication,in order to solve the problems of shortage of on-board resources and refinement of delay requirements to improve the communication performance of satellite optical networks,this paper proposes a bee colony optimization algorithm for routing and wavelength assignment based on directional guidance(DBCO-RWA)in satellite optical networks.In D-BCORWA,directional guidance based on relative position and link load is defined,and then the link cost function in the path search stage is established based on the directional guidance factor.Finally,feasible solutions are expanded in the global optimization stage.The wavelength utilization,communication success probability,blocking rate,communication hops and convergence characteristic are simulated.The results show that the performance of the proposed algorithm is improved compared with existing algorithms.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.11775019 and 62173213)the Natural Science Foundation of Shandong Province,China (Grant No.ZR2011FL009)the Shandong Provincial Science and Technology Support Program of Youth Innovation Team in Colleges (Grant Nos.2019KJN041 and 2020KJN005)。
文摘An open quantum battery(QB)model of a single qubit system charging in a coherent auxiliary bath(CAB)consisting of a series of independent coherent ancillae is considered.According to the collision charging protocol we derive a quantum master equation and obtain the analytical solution of QB in a steady state.We find that the full charging capacity(or the maximal extractable work(MEW))of QB,in the weak QB-ancilla coupling limit,is positively correlated with the coherence magnitude of ancilla.Combining with the numerical simulations we compare with the charging properties of QB at finite coupling strength,such as the MEW,average charging power and the charging efficiency,when considering the bath to be a thermal auxiliary bath(TAB)and a CAB,respectively.We find that when the QB with CAB,in the weak coupling regime,is in fully charging,both its capacity and charging efficiency can go beyond its classical counterpart,and they increase with the increase of coherence magnitude of ancilla.In addition,the MEW of QB in the regime of relative strong coupling and strong coherent magnitude shows the oscillatory behavior with the charging time increasing,and the first peak value can even be larger than the full charging MEW of QB.This also leads to a much larger average charging power than that of QB with TAB in a short-time charging process.These features suggest that with the help of quantum coherence of CAB it becomes feasible to switch the charging schemes between the long-time slow charging protocol with large capacity and high efficiency and the short-time rapid charging protocol with highly charging power only by adjusting the coupling strength of QB-ancilla.This work clearly demonstrates that the quantum coherence of bath can not only serve as the role of“fuel”of QB to be utilized to improve the QB's charging performance but also provide an alternative way to integrate the different charging protocols into a single QB.
文摘切沟体积是表征切沟侵蚀量、输水输沙能力的重要参数。笔者以冀西北山盆地区典型流域切沟为研究对象,使用Riegl三维激光扫描仪获取切沟点云数据,构建高分辨率DEM,提取切沟形态参数,分析切沟断面特征,构建并验证适宜的切沟体积估算模型。结果表明:1)切沟间的发育不均衡,不同切沟沟长、面积和体积相差较大,但同一参数在各个断面位置的参数值差别较小;2)面积、沟长和沟深与体积呈显著的正相关,相关系数较高,分别为0.949、0.870和0.814;3)基于V-L关系、V-A关系和V(A,D)关系建立对应的线性回归方程,其决定系数R 2分别为0.7706、0.9159和0.9748,模型验证结果显示,V(A,D)关系模型V=0.04653 A 1.499+24.08 D 1.916-44.26在预测冀西北山盆地区切沟体积上更有优势。研究结果可为大空间尺度切沟侵蚀定量模拟及制图提供理论和技术支持,为水土保持工程提供科学理论依据。
