Manas River,the largest inland river to the north of the Tianshan Mountains,provides important water resources for human production and living.The seasonal snow cover and snowmelt play essential roles in the regulatio...Manas River,the largest inland river to the north of the Tianshan Mountains,provides important water resources for human production and living.The seasonal snow cover and snowmelt play essential roles in the regulation of spring runoff in the Manas River Basin（MRB）.Snow cover is one of the most significant input parameters for obtaining accurate simulations and predictions of spring runoff.Therefore,it is especially important to extract snow-covered area correctly in the MRB.In this study,we qualitatively and quantitatively analyzed the uncertainties of snow cover extraction caused by the terrain factors and land cover types using TM and DEM data,along with the Per（the ratio of the difference between snow-covered area extracted by the Normalized Difference Snow Index（NDSI） method and visual interpretation method to the actual snow-covered area） and roughness.The results indicated that the difference of snow-covered area extracted by the two methods was primarily reflected in the snow boundary and shadowy areas.The value of Per varied significantly in different elevation zones.That is,the value generally presented a normal distribution with the increase of elevation.The peak value of Per occurred in the elevation zone of 3,700–4,200 m.Aspects caused the uncertainties of snow cover extraction with the order of sunny slope〉semi-shady and semi-sunny slope〉shady slope,due to the differences in solar radiation received by each aspect.Regarding the influences of various land cover types on snow cover extraction in the study area,bare rock was more influential on snow cover extraction than grassland.Moreover,shrub had the weakest impact on snow cover extraction.展开更多
Recent experimental data for anomalous magnetic moments strongly indicates the existence of new physics beyond the Standard Model.Energetic μ^(+) bunches are relevant to μ^(+) rare decay,spin rotation,resonance and ...Recent experimental data for anomalous magnetic moments strongly indicates the existence of new physics beyond the Standard Model.Energetic μ^(+) bunches are relevant to μ^(+) rare decay,spin rotation,resonance and relaxation(μSR)technology,future muon colliders,and neutrino factories.In this paper,we propose prompt μ^(+) acceleration in a nonlinear toroidal wakefield driven by a shaped steep-rising-front Laguerre–Gaussian(LG)laser pulse.An analytical model is described,which shows that a μ^(+) beam can be focused by an electron cylinder at the centerline of a toroidal bubble and accelerated by the front part of the longitudinal wakefield.A shaped LG laser with a short rise time can push plasma electrons,generating a higher-density electron sheath at the front of the bubble,which can enhance the acceleration field.The acceleration field driven by the shaped steep-rising-front LG laser pulse is about four times greater than that driven by a normal LG laser pulse.Our simulation results show that a 300 MeV μ^(+) bunch can be accelerated to 2 GeV and its transverse size is focused from an initial value of w_(0)=5μm to w=2μm in the toroidal bubble driven by the shaped steep-rising-front LG laser pulse with a normalized amplitude of a=22.展开更多
Four challenging and unusual retinal cases:(I)11-year follow-up for retinal hemangioblastoma with von Hippel-Lindau(VHL)disease;(II)treatment for central serous chorioretinopathy(CSC)-observation,half does photodynami...Four challenging and unusual retinal cases:(I)11-year follow-up for retinal hemangioblastoma with von Hippel-Lindau(VHL)disease;(II)treatment for central serous chorioretinopathy(CSC)-observation,half does photodynamic therapy(PDT)or micropulse laser photocoagulation;(III)diagnosis and treatment for a child with optic nerve defect;(IV)the optional treatment for retinal detachment(RD)with iridolenticular choroidal coloboma,were presented and discussed by three international retinal specialists at a retinal clinical round in Fundus Diseases Center of Zhongshan Ophthalmic Center(ZOC).The discussion helps us a better understanding of the pathogenesis and managements of these four retinal diseases and their association with systemic conditions.展开更多
The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 3...The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.展开更多
Background:TP53 mutations and homologous recombination deficiency(HRD)occur frequently in breast cancer.However,the characteristics of TP53 pathogenic mutations in breast cancer patients with/without HRD are not clear...Background:TP53 mutations and homologous recombination deficiency(HRD)occur frequently in breast cancer.However,the characteristics of TP53 pathogenic mutations in breast cancer patients with/without HRD are not clear.Methods:Clinical next-generation sequencing(NGS)of both tumor and paired blood DNA from 119 breast cancer patients(BRCA-119 cohort)was performed with a 520-gene panel.Mutations,tumor mutation burden(TMB),and genomic HRD scores were assessed from NGS data.NGS data from 47 breast cancer patients in the HRD test cohort were analyzed for further verification.Results:All TP53 pathogenic mutations in patients had somatic origin,which was associated with the protein expression of estrogen receptor and progestogen receptor.Compared to patients without TP53 pathologic mutations,patients with TP53 pathologic mutations had higher levels of HRD scores and different genomic alterations.The frequency of TP53 pathologic mutation was higher in the HRDhigh group(HRD score≥42)relative to that in the HRD-low group(HRD score<42).TP53 has different mutational characteristics between the HRD-low and HRD-high groups.TP53-specific mutation subgroups had diverse genomic features and TMB.Notably,TP53 pathogenic mutations predicted the HRD status of breast cancer patients with an area under the curve(AUC)of 0.61.TP53-specific mutations,namely HRD-low mutation,HRD-high mutation,and HRD common mutation,predicted the HRD status of breast cancer patients with AUC values of 0.32,0.72,and 0.58,respectively.Interestingly,TP53 HRD-high mutation and HRD common mutation combinations showed the highest AUC values(0.80)in predicting HRD status.Conclusions:TP53-specific mutation combinations predict the HRD status of patients,indicating that TP53 pathogenic mutations could serve as a potential biomarker for poly-ADP-ribose polymerase(PARP)inhibitors in breast cancer patients.展开更多
Background High energy photon source(HEPS)is the fourth-generation light source,which uses a large number of highperformance insertion devices to generate synchrotron radiation.The control system is an important part ...Background High energy photon source(HEPS)is the fourth-generation light source,which uses a large number of highperformance insertion devices to generate synchrotron radiation.The control system is an important part of the insertion device(ID).Purpose Cryogenic permanent magnet undulator(CPMU)is one kind of IDs that works in liquid nitrogen temperature and ultra-high vacuum environment,and its control system is more difficult and complex than in-air ID.The design of the control system for CPMU will be introduced in detail.Method The sub-systems include high-precision magnetic gap control,safety protection,measurement and compensation of magnetic gap at cryogenic temperature and cryogenic temperature monitoring.Mature,reliable,stable technical schemes are designed to meet the technical specifications of sub-systems.Results The experiment results show that the magnetic gap motion accuracy can be controlled within 0.2–0.3μm under the step size of 1μm.The safety protection system has been tested in turn,and the predetermined protection can be achieved.The average value of magnetic gap cold contraction is 1.512 mm measured by optical micrometer,and the compensation is realized by software.The average temperature of the main magnet structure measured by the temperature sensors is 81.0 K,and the temperature gradient is 0.7 K/m.The temperature monitoring is reliable and stable.Conclusion The CPMU control system which is based on EPICS has been successfully applied to the CPMU prototype,and the test results have met the design specifications.展开更多
Introduction A novel type of pure permanent cryogenic Delta–Knot Undulator was developed at IHEP to supply a high flux of full adjustable polarization synchrotron radiation with low on-axis power density.This prototy...Introduction A novel type of pure permanent cryogenic Delta–Knot Undulator was developed at IHEP to supply a high flux of full adjustable polarization synchrotron radiation with low on-axis power density.This prototype was an active attempt and early exploration for future APPLE–Knot undulator,which will be used at high energy photon source(HEPS).Materials and methods There are several challenges to develop a cryogenic delta undulator,such as the complicated structure,the influence of large magnetic force,and the magnetic measurement difficulty due to the very small gap.In this paper,the mechanical design for overcoming these difficulties will be presented in detail.Conclusion A special hall measuring system is developed,and the preliminary results agree with the theoretical results.This undulator prototype will provide valuable experience for angle magnetization technology,intricate magnetic attraction structure design,and magnetic field measurement under closed small space.展开更多
Purpose More undulators are required of HEPS in future.The efficiency of traditional Hall-probe measurement method is relatively low,which is difficult to meet the measurement needs of large quantities of undulators.I...Purpose More undulators are required of HEPS in future.The efficiency of traditional Hall-probe measurement method is relatively low,which is difficult to meet the measurement needs of large quantities of undulators.In order to improve debugging efficiency,the pulsed-wire method is required further improvement.Methods A pulsed-wire method is an effective method to achieve magnetic field distribution through narrow aperture of undulator.The pulsed-wire method works by sending a square current pulse through the wire,which will induce an interaction with the magnetic field due to the Lorentz force.This force causes the wire to be displaced,and this displacement travels along the wire in both directions as an acoustic wave.Measurement of the displacement in the wire over time using a motion detector yields the first or second integrals of the magnetic field.Results The accuracy and repeatability are the important requirements.The repeatability of the first field integral of the pulsed-wire system is better than 1‰which meets the design requirements.Conclusions This paper illustrates the effectiveness of pulsed-wire system by test results.Through comparison,the accuracy of the system is proved.It provides a new important measurement system for undulators in future.展开更多
基金funded by the National Natural Science Foundation of China (91025001)the Key Project of the National Science and Technology (E0405/1112/05)
文摘Manas River,the largest inland river to the north of the Tianshan Mountains,provides important water resources for human production and living.The seasonal snow cover and snowmelt play essential roles in the regulation of spring runoff in the Manas River Basin（MRB）.Snow cover is one of the most significant input parameters for obtaining accurate simulations and predictions of spring runoff.Therefore,it is especially important to extract snow-covered area correctly in the MRB.In this study,we qualitatively and quantitatively analyzed the uncertainties of snow cover extraction caused by the terrain factors and land cover types using TM and DEM data,along with the Per（the ratio of the difference between snow-covered area extracted by the Normalized Difference Snow Index（NDSI） method and visual interpretation method to the actual snow-covered area） and roughness.The results indicated that the difference of snow-covered area extracted by the two methods was primarily reflected in the snow boundary and shadowy areas.The value of Per varied significantly in different elevation zones.That is,the value generally presented a normal distribution with the increase of elevation.The peak value of Per occurred in the elevation zone of 3,700–4,200 m.Aspects caused the uncertainties of snow cover extraction with the order of sunny slope〉semi-shady and semi-sunny slope〉shady slope,due to the differences in solar radiation received by each aspect.Regarding the influences of various land cover types on snow cover extraction in the study area,bare rock was more influential on snow cover extraction than grassland.Moreover,shrub had the weakest impact on snow cover extraction.
基金supported in part by the National Key R&D Program of China(No.2018YFA0404802)National Natural Science Foundation of China(No.11875319)+2 种基金the Hunan Provincial Science and Technology Program(No.2020RC4020)Innovation Project of IHEP(Nos.542017IHEPZZBS11820,542018IHEPZZBS12427)the CAS Center for Excellence in Particle Physics(CCEPP),the Meritocracy Research Funds of China West Normal University(No.17YC504)。
文摘Recent experimental data for anomalous magnetic moments strongly indicates the existence of new physics beyond the Standard Model.Energetic μ^(+) bunches are relevant to μ^(+) rare decay,spin rotation,resonance and relaxation(μSR)technology,future muon colliders,and neutrino factories.In this paper,we propose prompt μ^(+) acceleration in a nonlinear toroidal wakefield driven by a shaped steep-rising-front Laguerre–Gaussian(LG)laser pulse.An analytical model is described,which shows that a μ^(+) beam can be focused by an electron cylinder at the centerline of a toroidal bubble and accelerated by the front part of the longitudinal wakefield.A shaped LG laser with a short rise time can push plasma electrons,generating a higher-density electron sheath at the front of the bubble,which can enhance the acceleration field.The acceleration field driven by the shaped steep-rising-front LG laser pulse is about four times greater than that driven by a normal LG laser pulse.Our simulation results show that a 300 MeV μ^(+) bunch can be accelerated to 2 GeV and its transverse size is focused from an initial value of w_(0)=5μm to w=2μm in the toroidal bubble driven by the shaped steep-rising-front LG laser pulse with a normalized amplitude of a=22.
文摘Four challenging and unusual retinal cases:(I)11-year follow-up for retinal hemangioblastoma with von Hippel-Lindau(VHL)disease;(II)treatment for central serous chorioretinopathy(CSC)-observation,half does photodynamic therapy(PDT)or micropulse laser photocoagulation;(III)diagnosis and treatment for a child with optic nerve defect;(IV)the optional treatment for retinal detachment(RD)with iridolenticular choroidal coloboma,were presented and discussed by three international retinal specialists at a retinal clinical round in Fundus Diseases Center of Zhongshan Ophthalmic Center(ZOC).The discussion helps us a better understanding of the pathogenesis and managements of these four retinal diseases and their association with systemic conditions.
基金support from diverse funding sources,including the National Key Program for S&T Research and Development of the Ministry of Science and Technology(MOST),Yifang Wang's Science Studio of the Ten Thousand Talents Project,the CAS Key Foreign Cooperation Grant,the National Natural Science Foundation of China(NSFC)Beijing Municipal Science&Technology Commission,the CAS Focused Science Grant,the IHEP Innovation Grant,the CAS Lead Special Training Programthe CAS Center for Excellence in Particle Physics,the CAS International Partnership Program,and the CAS/SAFEA International Partnership Program for Creative Research Teams.
文摘The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.
基金funding from the National Natural Science Foundation of China(Grants No.82203435,82203703,82203141,and 82102865)Guangdong Basic and Applied Basic Research Foundation(Grant No.2021A1515111138)+1 种基金Guangzhou Science and Technology Plan Project Support(Grant No.2023A04J2103)the China Postdoctoral Science Foundation(Grants No.2022M713576 and 2022T150757).
文摘Background:TP53 mutations and homologous recombination deficiency(HRD)occur frequently in breast cancer.However,the characteristics of TP53 pathogenic mutations in breast cancer patients with/without HRD are not clear.Methods:Clinical next-generation sequencing(NGS)of both tumor and paired blood DNA from 119 breast cancer patients(BRCA-119 cohort)was performed with a 520-gene panel.Mutations,tumor mutation burden(TMB),and genomic HRD scores were assessed from NGS data.NGS data from 47 breast cancer patients in the HRD test cohort were analyzed for further verification.Results:All TP53 pathogenic mutations in patients had somatic origin,which was associated with the protein expression of estrogen receptor and progestogen receptor.Compared to patients without TP53 pathologic mutations,patients with TP53 pathologic mutations had higher levels of HRD scores and different genomic alterations.The frequency of TP53 pathologic mutation was higher in the HRDhigh group(HRD score≥42)relative to that in the HRD-low group(HRD score<42).TP53 has different mutational characteristics between the HRD-low and HRD-high groups.TP53-specific mutation subgroups had diverse genomic features and TMB.Notably,TP53 pathogenic mutations predicted the HRD status of breast cancer patients with an area under the curve(AUC)of 0.61.TP53-specific mutations,namely HRD-low mutation,HRD-high mutation,and HRD common mutation,predicted the HRD status of breast cancer patients with AUC values of 0.32,0.72,and 0.58,respectively.Interestingly,TP53 HRD-high mutation and HRD common mutation combinations showed the highest AUC values(0.80)in predicting HRD status.Conclusions:TP53-specific mutation combinations predict the HRD status of patients,indicating that TP53 pathogenic mutations could serve as a potential biomarker for poly-ADP-ribose polymerase(PARP)inhibitors in breast cancer patients.
文摘Background High energy photon source(HEPS)is the fourth-generation light source,which uses a large number of highperformance insertion devices to generate synchrotron radiation.The control system is an important part of the insertion device(ID).Purpose Cryogenic permanent magnet undulator(CPMU)is one kind of IDs that works in liquid nitrogen temperature and ultra-high vacuum environment,and its control system is more difficult and complex than in-air ID.The design of the control system for CPMU will be introduced in detail.Method The sub-systems include high-precision magnetic gap control,safety protection,measurement and compensation of magnetic gap at cryogenic temperature and cryogenic temperature monitoring.Mature,reliable,stable technical schemes are designed to meet the technical specifications of sub-systems.Results The experiment results show that the magnetic gap motion accuracy can be controlled within 0.2–0.3μm under the step size of 1μm.The safety protection system has been tested in turn,and the predetermined protection can be achieved.The average value of magnetic gap cold contraction is 1.512 mm measured by optical micrometer,and the compensation is realized by software.The average temperature of the main magnet structure measured by the temperature sensors is 81.0 K,and the temperature gradient is 0.7 K/m.The temperature monitoring is reliable and stable.Conclusion The CPMU control system which is based on EPICS has been successfully applied to the CPMU prototype,and the test results have met the design specifications.
基金The Grant No.is 11675207.Project name:The Physical and Technical Study of Quasi-eriodic DELTA Undulator working at liquid nitrogen temperature.
文摘Introduction A novel type of pure permanent cryogenic Delta–Knot Undulator was developed at IHEP to supply a high flux of full adjustable polarization synchrotron radiation with low on-axis power density.This prototype was an active attempt and early exploration for future APPLE–Knot undulator,which will be used at high energy photon source(HEPS).Materials and methods There are several challenges to develop a cryogenic delta undulator,such as the complicated structure,the influence of large magnetic force,and the magnetic measurement difficulty due to the very small gap.In this paper,the mechanical design for overcoming these difficulties will be presented in detail.Conclusion A special hall measuring system is developed,and the preliminary results agree with the theoretical results.This undulator prototype will provide valuable experience for angle magnetization technology,intricate magnetic attraction structure design,and magnetic field measurement under closed small space.
文摘Purpose More undulators are required of HEPS in future.The efficiency of traditional Hall-probe measurement method is relatively low,which is difficult to meet the measurement needs of large quantities of undulators.In order to improve debugging efficiency,the pulsed-wire method is required further improvement.Methods A pulsed-wire method is an effective method to achieve magnetic field distribution through narrow aperture of undulator.The pulsed-wire method works by sending a square current pulse through the wire,which will induce an interaction with the magnetic field due to the Lorentz force.This force causes the wire to be displaced,and this displacement travels along the wire in both directions as an acoustic wave.Measurement of the displacement in the wire over time using a motion detector yields the first or second integrals of the magnetic field.Results The accuracy and repeatability are the important requirements.The repeatability of the first field integral of the pulsed-wire system is better than 1‰which meets the design requirements.Conclusions This paper illustrates the effectiveness of pulsed-wire system by test results.Through comparison,the accuracy of the system is proved.It provides a new important measurement system for undulators in future.
