对于磁约束聚变实验装置,磁探针诊断是一种基础又非常重要的研究等离子体磁涨落的诊断.中国首台准环对称仿星器(Chinese First Quasi-axisymmetric Stellarator,CFQS)实验运行的第1阶段(也称为CFQST准环对称仿星器)的物理实验研究需要...对于磁约束聚变实验装置,磁探针诊断是一种基础又非常重要的研究等离子体磁涨落的诊断.中国首台准环对称仿星器(Chinese First Quasi-axisymmetric Stellarator,CFQS)实验运行的第1阶段(也称为CFQST准环对称仿星器)的物理实验研究需要磁探针诊断提供相应的等离子体磁涨落测量.本文报道了在CFQST准环对称仿星器上新研制的高频磁探针阵列诊断,其由8个相同的三维高频磁探针组成,每个高频磁探针可以同时测量极向、径向及环向3个方向的磁涨落信号;优化的空间布置使得高频磁探针阵列可以用于研究磁涨落的极向和环向传播特征,其最高环向模数分辨相比于低频磁探针阵列的n=±6提高至n=±16.本文将简要介绍高频磁探针阵列诊断的机械系统、信号传输线、采集与控制系统等主要子系统及在研制各系统过程中克服的挑战,以及对高频磁探针的有效面积标定和原位频率响应标定的研究结果,CFQS-T高频磁探针每个测量方向的共振频率均大于400 k Hz,满足测量50—300 k Hz高频磁涨落的设计需求.初步的应用研究显示高频磁探针阵列诊断可用于低频和高频磁涨落的时频谱、极向和环向传播分析,值得注意的是,本文首次报道了对CFQS-T上高频磁涨落的测量分析结果.高频磁探针阵列诊断的成功研制有助于CFQS-T深入开展等离子体电磁涨落的相关研究.展开更多
Magnetization,specific heat,and muon spin relaxation(μSR)experiments have been carried out on the Cr-based nitride superconductor La_(3)Cr_(10-x)N_(11),which exhibits a number of unconventional superconducting proper...Magnetization,specific heat,and muon spin relaxation(μSR)experiments have been carried out on the Cr-based nitride superconductor La_(3)Cr_(10-x)N_(11),which exhibits a number of unconventional superconducting properties.The susceptibilityχ(T)shows nearly perfect superconducting diamagnetism(4πχ(T=0)≈-1)and a remarkably high upper critical fieldμ_(0)Hc_(2)=11.2 T.The specific heat displays activated exponential behavior exp(-Δ0/kBT),together with a large and field-dependent residual Sommerfeld coefficient.Transverse-field muon spin relaxation(μSR)measurements suggest s+s-wave or p-wave pairing symmetry,ruling out single s-wave pairing.Zero-fieldμSR yields no statistically significant evidence for time reversal symmetry breaking(TRSB),and places an upper bound of 1.5(1.3)ms-1 on any TRSB-induced muon relaxation rate at T=0.Our results suggest that the unconventional superconductivity in Ln_(3)Cr_(10-x)N_(11),Ln=La and Pr,is mainly due to Cr 3d electrons and is similar in both compounds,whereas Pr 4f electrons are primarily responsible for the TRSB superconductivity observed in Pr_(3)Cr_(10-x)N_(11).展开更多
The magnetic fields and dynamical processes in the solar polar regions play a crucial role in the solar magnetic cycle and in supplying mass and energy to the fast solar wind,ultimately being vital in controlling sola...The magnetic fields and dynamical processes in the solar polar regions play a crucial role in the solar magnetic cycle and in supplying mass and energy to the fast solar wind,ultimately being vital in controlling solar activities and driving space weather.Despite numerous efforts to explore these regions,to date no imaging observations of the Sun's poles have been achieved from vantage points out of the ecliptic plane,leaving their behavior and evolution poorly understood.This observation gap has left three top-level scientific questions unanswered:How does the solar dynamo work and drive the solar magnetic cycle?What drives the fast solar wind?How do space weather processes globally originate from the Sun and propagate throughout the solar system?The Solar Polarorbit Observatory(SPO)mission,a solar polar exploration spacecraft,is proposed to address these three unanswered scientific questions by imaging the Sun's poles from high heliolatitudes.In order to achieve its scientific goals,SPO will carry six remote-sensing and four in-situ instruments to measure the vector magnetic fields and Doppler velocity fields in the photosphere,to observe the Sun in the extreme ultraviolet,X-ray,and radio wavelengths,to image the corona and the heliosphere up to 45 R_(s),and to perform in-situ detection of magnetic fields,and low-and high-energy particles in the solar wind.The SPO mission is capable of providing critical vector magnetic fields and Doppler velocities of the polar regions to advance our understanding of the origin of the solar magnetic cycle,providing unprecedented imaging observations of the solar poles alongside in-situ measurements of charged particles and magnetic fields from high heliolatitudes to unveil the mass and energy supply that drive the fast solar wind,and providing observational constraints for improving our ability to model and predict the three-dimensional(3D)structures and propagation of space weather events.展开更多
《2020年中国智能物联网(AIoT)白皮书》显示,随着我国5G网络的迅猛发展,大容量低价格的IoT(Internet of Things)传感器设备快速普及,数据呈爆发性增长,图像处理在物联网的诸多领域(如智慧城市、智慧交通、智慧医疗等)得到了广泛应用。...《2020年中国智能物联网(AIoT)白皮书》显示,随着我国5G网络的迅猛发展,大容量低价格的IoT(Internet of Things)传感器设备快速普及,数据呈爆发性增长,图像处理在物联网的诸多领域(如智慧城市、智慧交通、智慧医疗等)得到了广泛应用。在这些领域研究中,科研人员往往相对轻视数据收集过程中的实际问题,如天气变化、季节迁移、昼夜交替等时间变化带来的图像数据退化,以及随着物体移动、叠加、模糊、部分遮挡等诸多空间变化带来的噪声问题。其中,以雨天为代表的复杂天气下的图像模糊问题非常常见,也最具挑战。因此,文中对数据收集过程中的上述实际问题进行了系统性的调查,归类和总结了复杂天气下的图像去雨算法。与此同时,鉴于此类算法的执行需要消耗大量GPU计算资源,文中通过利用Amazon EC2云服务器中G4和P3系列的GPU实例对综述的各种去雨算法的处理时长和去雨效果进行了定量化评估,并阐述了各类去雨算法的特点和在云物联网应用中的最新趋势。展开更多
When a pico satellite is under normal operational condi- tions, whether it is extended or unscented, a conventional Kalman filter gives sufficiently good estimation results. However, if the measurements are not reliab...When a pico satellite is under normal operational condi- tions, whether it is extended or unscented, a conventional Kalman filter gives sufficiently good estimation results. However, if the measurements are not reliable because of any kind of malfunc- tions in the estimation system, the Kalman filter gives inaccurate results and diverges by time. This study compares two different robust Kalman filtering algorithms, robust extended Kalman filter （REKF） and robust unscented Kalman filter （RUKF）, for the case of measurement malfunctions. In both filters, by the use of de- fined variables named as the measurement noise scale factor, the faulty measurements are taken into the consideration with a small weight, and the estimations are corrected without affecting the characteristic of the accurate ones. The proposed robust Kalman filters are applied for the attitude estimation process of a pico satel- lite, and the results are compared.展开更多
Atmospheric rivers(ARs)are an important component of the hydrological cycle linking moisture sources in lower latitudes to the Antarctic surface mass balance.We investigate AR signatures in the atmospheric vertical pr...Atmospheric rivers(ARs)are an important component of the hydrological cycle linking moisture sources in lower latitudes to the Antarctic surface mass balance.We investigate AR signatures in the atmospheric vertical profiles at the Dronning Maud Land coast,East Antarctica,using regular and extra radiosonde measurements conducted during the Year of Polar Prediction Special Observing Period November 2018 to February 2019.Prominent AR events affecting the locations of Neumayer and Syowa cause a strong increase in specific humidity extending through the mid-troposphere and a strong low-level jet(LLJ).At Neumayer,the peak in the moisture inversion(up to 4 g kg^?1)is observed between 800 and 900 hPa,while the LLJ(up to 32 m s^?1)is concentrated below 900 hPa.At Syowa the increase in humidity is less pronounced and peaks near the surface,while there is a substantial increase in wind speed(up to 40 m s?1)between 825 and 925 hPa.Moisture transport(MT)within the vertical profile during the ARs attains a maximum of 100 g kg?1 m s?1 at both locations,and is captured by both ERA-Interim and ERA5 reanalysis data at Neumayer,but is strongly underestimated at Syowa.Composites of the enhanced MT events during 2009?19 show that these events represent an extreme state of the lower-tropospheric profile compared to its median values with respect to temperature,humidity,wind speed and,consequently,MT.High temporal-and vertical-resolution radiosonde observations are important for understanding the contribution of these rare events to the total MT towards Antarctica and improving their representation in models.展开更多
Cyclones with strong winds can make the Southern Ocean and the Antarctic a dangerous environment.Accurate weather forecasts are essential for safe shipping in the Southern Ocean and observational and logistical operat...Cyclones with strong winds can make the Southern Ocean and the Antarctic a dangerous environment.Accurate weather forecasts are essential for safe shipping in the Southern Ocean and observational and logistical operations at Antarctic research stations.This study investigated the impact of additional radiosonde observations from Research Vessel"Shirase"over the Southern Ocean and Dome Fuji Station in Antarctica on reanalysis data and forecast experiments using an ensemble data assimilation system comprising the Atmospheric General Circulation Model for the Earth Simulator and the Local Ensemble Transform Kalman Filter Experimental Ensemble Reanalysis,version 2.A 63-member ensemble forecast experiment was conducted focusing on an unusually strong Antarctic cyclonic event.Reanalysis data with(observing system experiment)and without(control)additional radiosonde data were used as initial values.The observing system experiment correctly captured the central pressure of the cyclone,which led to the reliable prediction of the strong winds and moisture transport near the coast.Conversely,the control experiment predicted lower wind speeds because it failed to forecast the central pressure of the cyclone adequately.Differences were found in cyclone predictions of operational forecast systems with and without assimilation of radiosonde observations from Dome Fuji Station.展开更多
In the present study, we aimed to evaluate the pathways contributing to ATP release from mouse astrocytes during hypoosmotic stress. We first examined the expression of mRNAs for proteins constituting possible ATP- re...In the present study, we aimed to evaluate the pathways contributing to ATP release from mouse astrocytes during hypoosmotic stress. We first examined the expression of mRNAs for proteins constituting possible ATP- releasing pathways that have been suggested over the past several years. In RT-PCR analysis using both control and osmotically swollen astrocytes, amplification of cDNA fragments of expected size was seen for connexins （Cx32, Cx37, Cx43）, pannexin 1 （Pxl）, the P2X7 receptor, MRP1 and MDR1, but not CFTR. Inhibitors of exocytotic vesicular release, gap junction hemi-channels, CFTR, MRP1, MDR1, the P2X7 receptor, and volume-sensitive outwardly rectifying chloride channels had no significant effects on the massive ATP release from astrocytes. In contrast, the hypotonicity-induced ATP release from astrocytes was most effectively inhibited by gadolinium （50 μM）, an inhibitor of the maxi-anion channel, which has recently been shown to serve as a pathway for ATP release from several other cell types. Thus, we propose that the maxi-anion channel constitutes a major pathway for swelling-induced ATP release from cultured mouse astrocytes as well.展开更多
We have isolated a recessive rice mutant, designated as indeterminate growth （ing）, which displays creeping and apparent heterochronic phenotypes in the vegetative period with lanky and winding culms. Rough mapping ...We have isolated a recessive rice mutant, designated as indeterminate growth （ing）, which displays creeping and apparent heterochronic phenotypes in the vegetative period with lanky and winding culms. Rough mapping and subsequent molecular characterization revealed that the ing mutant carries a large deletion, which corresponds to a 103 kb region in the Nipponbare genome, containing nine annotated genes on chromosome 3. Of these annotated genes, the SLR1 gene encoding a DELLA protein is the only one that is well characterized in its function, and its null mutation, which is caused by a single base deletion in the middle of the intronless SLR1 gene, confers a slender phenotype that bears close resemblance to the ing mutant phenotype. The primary cause of the ing mutant phenotype is the deletion of the SLR1 gene, and the ing mutant appears to be the first characterized mutant having the entire SLR1 sequence deleted. Our results also suggest that the deleted region of 103 kb does not contain an indispensable gene, whose dysfunction must result in a lethal phenotype.展开更多
Myelination is an essential feature of the vertebrate nervous system that provides electrical insulation to axons,thereby facilitating the transmission of nerve impulses.Deficiencies in myelination in diseases such as...Myelination is an essential feature of the vertebrate nervous system that provides electrical insulation to axons,thereby facilitating the transmission of nerve impulses.Deficiencies in myelination in diseases such as multiple sclerosis（MS）lead to serious neurological disorders.展开更多
An impurity powder dropper was installed in the 21 st campaign of the Large Helical Device experiment(Oct.2019–Feb.2020)under a collaboration between the National Institute for Fusion Science and the Princeton Plasma...An impurity powder dropper was installed in the 21 st campaign of the Large Helical Device experiment(Oct.2019–Feb.2020)under a collaboration between the National Institute for Fusion Science and the Princeton Plasma Physics Laboratory for the purposes of real-time wall conditioning and edge plasma control.In order to assess the effective injection of the impurity powders,spectroscopic diagnostics were applied to observe line emission from the injected impurity.Thus,extreme-ultraviolet(EUV)and vacuum-ultraviolet(VUV)emission spectra were analyzed to summarize observable impurity lines with B and BN powder injection.Emission lines released from B and N ions were identified in the EUV wavelength range of 5–300Ameasured using two grazing incidence flat-field EUV spectrometers and in the VUV wavelength range of 300–2400Ameasured using three normal incidence 20 cm VUV spectrometers.BI–BV and NIII–NVII emission lines were identified in the discharges with the B and BN powder injection,respectively.Useful B and N emission lines which have large intensities and are isolated from other lines were successfully identified as follows:BI(1825.89,1826.40)A(blended),BII 1362.46A,BIII(677.00,677.14,677.16)A(blended),BIV 60.31A,BV 48.59A,NIII(989.79,991.51,991.58)A(blended),NIV765.15A,NV(209.27,209.31)A(blended),NVI 1896.80A,and NVII 24.78A.Applications of the line identifications to the advanced spectroscopic diagnostics were demonstrated,such as the vertical profile measurements for the BV and NVII lines using a space-resolved EUV spectrometer and the ion temperature measurement for the BII line using a normal incidence 3 m VUV spectrometer.展开更多
Shot-integrated measurement of the triton burnup ratio has been performed in the Large Helical Device. It was reported that the triton burnup ratio, defined as total DT neutron yield divided by total DD neutron yield,...Shot-integrated measurement of the triton burnup ratio has been performed in the Large Helical Device. It was reported that the triton burnup ratio, defined as total DT neutron yield divided by total DD neutron yield, increases significantly in inward shifted configurations. To understand the magnetic configuration dependence of the triton burnup ratio, the first orbit loss fraction of 1 MeV tritons is evaluated by means of the Lorentz orbit code for various magnetic configurations. The first orbit loss of 1 MeV tritons is seen at t of less than 10-5 s and loss points of the triton are concentrated on the side of the helical coil case where the magnetic field is relatively weak. The significant decrease of the first orbit loss fraction by 15% is obtained with the inward shift of the magnetic axis position from 3.90 to 3.55 m. It is found that the decrease of first orbit loss is due to the reduction of the first orbit loss of transition and helically trapped tritons.展开更多
A two-point model is used to investigate the characteristics of scrape-off layer(SOL)plasma with the field line tracing method in the experimental advanced superconducting tokamak.The profiles of plasma density,temper...A two-point model is used to investigate the characteristics of scrape-off layer(SOL)plasma with the field line tracing method in the experimental advanced superconducting tokamak.The profiles of plasma density,temperature and particle flux on the divertor target calculated by the model are in reasonable agreement with experimental observation.Moreover,the profiles of plasma parameters on the divertor target strongly depend on the SOL magnetic topology or the equilibrium configuration from the modeling.展开更多
In order to understand the mechanism by which the resonant magnetic perturbation (RMP)mitigates or suppresses the edge-localized mode (ELM),the topological study of the edge magnetic field in ELM mitigation or suppres...In order to understand the mechanism by which the resonant magnetic perturbation (RMP)mitigates or suppresses the edge-localized mode (ELM),the topological study of the edge magnetic field in ELM mitigation or suppression phase is a critical issue.To model the three-dimensional magnetic field topology superposed RMP on Experimental Advanced Superconducting Tokamak,a numerical model using the field line tracing method for both vacuum and ideal plasma response approximations is proposed.Using the numerical model,the topological change and the penetration depth of the stochastic field lines in the edge magnetic field are studied in an RMP experiment.Comparing profiles of minimum9 on edge stochastic field lines and the particle flux pattem,the ideal plasma response changes the field line penetration depth while remaining similar profile relative to vacuum approximation.To mitigate and suppress ELM strongly,the deep penetration of RMP fields and topological changes of the edge magnetic field is a key from our modeling.展开更多
This letter proposes a new tomographic reconstruction procedure based on the Laplacian eigenfunction(LEF) patterns, which are independent of the plasma cross-section and do not require the flux surface information. Th...This letter proposes a new tomographic reconstruction procedure based on the Laplacian eigenfunction(LEF) patterns, which are independent of the plasma cross-section and do not require the flux surface information. The process is benchmarked for the experimental data of Heliotron J plasma and the results are compared with the least-squares approximation by a Phillips–Tikhonov(PT)-type regularization, which is widely used as the standard technique for tomographic reconstruction. The reconstruction based on the LEF is found to be capable of determining the magnetic axis at different time locations efficiently in comparison with the PT-type regularization.展开更多
In the ELMy H-mode experiment,naturally occurring dust originating at the high-field side is clearly observed using the high-speed vacuum ultraviolet imaging system developed on the Experimental Advanced Superconducti...In the ELMy H-mode experiment,naturally occurring dust originating at the high-field side is clearly observed using the high-speed vacuum ultraviolet imaging system developed on the Experimental Advanced Superconducting Tokamak(EAST).The main ablation cloud shape is similar to the classical shape observed in pellet fueling experiments.However,during the dust penetration,an erupted secondary cloudlet with a bent‘cigar’shape is observed and moves upwards along the direction perpendicular to the magnetic field line,which is different to the obviation in the pellet fueling experiments.This may be due to the ion diamagnetic drift effect.The velocities of the secondary cloudlet are estimated to be 50–80 m s^(-1).In addition,a significant degradation of the plasma confinement is observed during the dust penetration.展开更多
Cytoplasmic inc lus ions containing the transactivation response element(TAR)DNAbinding protein-43(TDP-43)aggregates are hallmarks of neurodegenerative disorders,such as amyotrophic lateral sclerosis(ALS)and frontotem...Cytoplasmic inc lus ions containing the transactivation response element(TAR)DNAbinding protein-43(TDP-43)aggregates are hallmarks of neurodegenerative disorders,such as amyotrophic lateral sclerosis(ALS)and frontotemporal dementia(Arai et al.,2006;Neumann et al.,2006).Despite the well-recognized correlation between TDP-43 aggregation and neuronal degeneration,whether this relationship is causal has remained unclear.展开更多
The preparation for an experimental soft x-ray tomography study on the Heliotron J (H-J) machine is carried out,with the objectives of evaluating the capability of the current soft x-ray tomographic system in terms of...The preparation for an experimental soft x-ray tomography study on the Heliotron J (H-J) machine is carried out,with the objectives of evaluating the capability of the current soft x-ray tomographic system in terms of the identification of different mode structures and their poloidal rotation,and the axis shift with different plasma and machine parameters,and fixing the physics goals for the experimental study.These preparations were carried out via a simulated soft x-ray data set arising from different plasma conditions,such as magnetic islands,low beta and high beta.Soft x-ray tomography (SXT) is performed by the discrete pixel method including singular value decomposition and Phillips-Tikhonov regularization,to obtain clear and smooth images.The H-J soft x-ray tomography results from simulated soft x-rays for the equilibrium H-J plasma sensed the magnetic axis shift clearly and an estimate was also achieved.Successful reconstruction for mode structure m =1/n =1 was obtained along with the realization of the poloidal rotation of the structure.The reconstruction for the m =2/n =1 mode was not very clear for the current soft x-ray diagnostic design.Effective mode identification was not possible due to the lack of measurements.The SXT from the current soft x-ray diagnostic on H-J,the magnetic axis shift can be estimated and the m =1/n =1 mode can be studied.Study of higher poloidal modes is difficult with the current design.展开更多
We report the discovery of an extremely metal-poor（EMP） giant,LAMOST J110901.22＋075441.8, which exhibits a large excess of r-process elements with [Eu/Fe] ～ ＋1.16. The star is one of the newly discovered EMP star...We report the discovery of an extremely metal-poor（EMP） giant,LAMOST J110901.22＋075441.8, which exhibits a large excess of r-process elements with [Eu/Fe] ～ ＋1.16. The star is one of the newly discovered EMP stars identified from the LAMOST low-resolution spectroscopic survey and a highresolution follow-up observation with the Subaru Telescope. Stellar parameters and elemental abundances have been determined from the Subaru spectrum. Accurate abundances for a total of 23 elements including 11 neutron-capture elements from Sr through Dy have been derived for LAMOST J110901.22＋075441.8. The abundance pattern of LAMOST J110901.22＋075441.8 in the range of C through Zn is in line with the ＂normal＂ population of EMP halo stars, except that it shows a notable underabundance in carbon. The heavy element abundance pattern of LAMOST J110901.22＋075441.8 is in agreement with other well studied cool r-II metal-poor giants such as CS 22892-052 and CS 31082-001. The abundances of elements in the range from Ba through Dy match the scaled solar r-process pattern well.LAMOST J110901.22＋075441.8 provides the first detailed measurements of neutroncapture elements among r-II stars at such low metallicity with [Fe/H]-3.4, and exhibits similar behavior as other r-II stars in the abundance ratio of Zr/Eu as well as Sr/Eu and Ba/Eu.展开更多
文摘对于磁约束聚变实验装置,磁探针诊断是一种基础又非常重要的研究等离子体磁涨落的诊断.中国首台准环对称仿星器(Chinese First Quasi-axisymmetric Stellarator,CFQS)实验运行的第1阶段(也称为CFQST准环对称仿星器)的物理实验研究需要磁探针诊断提供相应的等离子体磁涨落测量.本文报道了在CFQST准环对称仿星器上新研制的高频磁探针阵列诊断,其由8个相同的三维高频磁探针组成,每个高频磁探针可以同时测量极向、径向及环向3个方向的磁涨落信号;优化的空间布置使得高频磁探针阵列可以用于研究磁涨落的极向和环向传播特征,其最高环向模数分辨相比于低频磁探针阵列的n=±6提高至n=±16.本文将简要介绍高频磁探针阵列诊断的机械系统、信号传输线、采集与控制系统等主要子系统及在研制各系统过程中克服的挑战,以及对高频磁探针的有效面积标定和原位频率响应标定的研究结果,CFQS-T高频磁探针每个测量方向的共振频率均大于400 k Hz,满足测量50—300 k Hz高频磁涨落的设计需求.初步的应用研究显示高频磁探针阵列诊断可用于低频和高频磁涨落的时频谱、极向和环向传播分析,值得注意的是,本文首次报道了对CFQS-T上高频磁涨落的测量分析结果.高频磁探针阵列诊断的成功研制有助于CFQS-T深入开展等离子体电磁涨落的相关研究.
基金funded by the National Key Research and Development Program of China(Grant No.2022YFA1402203)the National Natural Science Foundations of China(Grant No.12174065)+1 种基金the Innovation Program for Quantum Science and Technology(Grant No.2024ZD0300104)the Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01).
文摘Magnetization,specific heat,and muon spin relaxation(μSR)experiments have been carried out on the Cr-based nitride superconductor La_(3)Cr_(10-x)N_(11),which exhibits a number of unconventional superconducting properties.The susceptibilityχ(T)shows nearly perfect superconducting diamagnetism(4πχ(T=0)≈-1)and a remarkably high upper critical fieldμ_(0)Hc_(2)=11.2 T.The specific heat displays activated exponential behavior exp(-Δ0/kBT),together with a large and field-dependent residual Sommerfeld coefficient.Transverse-field muon spin relaxation(μSR)measurements suggest s+s-wave or p-wave pairing symmetry,ruling out single s-wave pairing.Zero-fieldμSR yields no statistically significant evidence for time reversal symmetry breaking(TRSB),and places an upper bound of 1.5(1.3)ms-1 on any TRSB-induced muon relaxation rate at T=0.Our results suggest that the unconventional superconductivity in Ln_(3)Cr_(10-x)N_(11),Ln=La and Pr,is mainly due to Cr 3d electrons and is similar in both compounds,whereas Pr 4f electrons are primarily responsible for the TRSB superconductivity observed in Pr_(3)Cr_(10-x)N_(11).
文摘The magnetic fields and dynamical processes in the solar polar regions play a crucial role in the solar magnetic cycle and in supplying mass and energy to the fast solar wind,ultimately being vital in controlling solar activities and driving space weather.Despite numerous efforts to explore these regions,to date no imaging observations of the Sun's poles have been achieved from vantage points out of the ecliptic plane,leaving their behavior and evolution poorly understood.This observation gap has left three top-level scientific questions unanswered:How does the solar dynamo work and drive the solar magnetic cycle?What drives the fast solar wind?How do space weather processes globally originate from the Sun and propagate throughout the solar system?The Solar Polarorbit Observatory(SPO)mission,a solar polar exploration spacecraft,is proposed to address these three unanswered scientific questions by imaging the Sun's poles from high heliolatitudes.In order to achieve its scientific goals,SPO will carry six remote-sensing and four in-situ instruments to measure the vector magnetic fields and Doppler velocity fields in the photosphere,to observe the Sun in the extreme ultraviolet,X-ray,and radio wavelengths,to image the corona and the heliosphere up to 45 R_(s),and to perform in-situ detection of magnetic fields,and low-and high-energy particles in the solar wind.The SPO mission is capable of providing critical vector magnetic fields and Doppler velocities of the polar regions to advance our understanding of the origin of the solar magnetic cycle,providing unprecedented imaging observations of the solar poles alongside in-situ measurements of charged particles and magnetic fields from high heliolatitudes to unveil the mass and energy supply that drive the fast solar wind,and providing observational constraints for improving our ability to model and predict the three-dimensional(3D)structures and propagation of space weather events.
文摘《2020年中国智能物联网(AIoT)白皮书》显示,随着我国5G网络的迅猛发展,大容量低价格的IoT(Internet of Things)传感器设备快速普及,数据呈爆发性增长,图像处理在物联网的诸多领域(如智慧城市、智慧交通、智慧医疗等)得到了广泛应用。在这些领域研究中,科研人员往往相对轻视数据收集过程中的实际问题,如天气变化、季节迁移、昼夜交替等时间变化带来的图像数据退化,以及随着物体移动、叠加、模糊、部分遮挡等诸多空间变化带来的噪声问题。其中,以雨天为代表的复杂天气下的图像模糊问题非常常见,也最具挑战。因此,文中对数据收集过程中的上述实际问题进行了系统性的调查,归类和总结了复杂天气下的图像去雨算法。与此同时,鉴于此类算法的执行需要消耗大量GPU计算资源,文中通过利用Amazon EC2云服务器中G4和P3系列的GPU实例对综述的各种去雨算法的处理时长和去雨效果进行了定量化评估,并阐述了各类去雨算法的特点和在云物联网应用中的最新趋势。
文摘When a pico satellite is under normal operational condi- tions, whether it is extended or unscented, a conventional Kalman filter gives sufficiently good estimation results. However, if the measurements are not reliable because of any kind of malfunc- tions in the estimation system, the Kalman filter gives inaccurate results and diverges by time. This study compares two different robust Kalman filtering algorithms, robust extended Kalman filter （REKF） and robust unscented Kalman filter （RUKF）, for the case of measurement malfunctions. In both filters, by the use of de- fined variables named as the measurement noise scale factor, the faulty measurements are taken into the consideration with a small weight, and the estimations are corrected without affecting the characteristic of the accurate ones. The proposed robust Kalman filters are applied for the attitude estimation process of a pico satel- lite, and the results are compared.
基金the financial support to CESAM (UID/AMB/ 50017/2019) through national funds and FCT grant CIRCNA/CAC/ 0273/2019National Institute of Polar Research (NIPR) Project Research No. KP302
文摘Atmospheric rivers(ARs)are an important component of the hydrological cycle linking moisture sources in lower latitudes to the Antarctic surface mass balance.We investigate AR signatures in the atmospheric vertical profiles at the Dronning Maud Land coast,East Antarctica,using regular and extra radiosonde measurements conducted during the Year of Polar Prediction Special Observing Period November 2018 to February 2019.Prominent AR events affecting the locations of Neumayer and Syowa cause a strong increase in specific humidity extending through the mid-troposphere and a strong low-level jet(LLJ).At Neumayer,the peak in the moisture inversion(up to 4 g kg^?1)is observed between 800 and 900 hPa,while the LLJ(up to 32 m s^?1)is concentrated below 900 hPa.At Syowa the increase in humidity is less pronounced and peaks near the surface,while there is a substantial increase in wind speed(up to 40 m s?1)between 825 and 925 hPa.Moisture transport(MT)within the vertical profile during the ARs attains a maximum of 100 g kg?1 m s?1 at both locations,and is captured by both ERA-Interim and ERA5 reanalysis data at Neumayer,but is strongly underestimated at Syowa.Composites of the enhanced MT events during 2009?19 show that these events represent an extreme state of the lower-tropospheric profile compared to its median values with respect to temperature,humidity,wind speed and,consequently,MT.High temporal-and vertical-resolution radiosonde observations are important for understanding the contribution of these rare events to the total MT towards Antarctica and improving their representation in models.
基金a Japan Society for the Promotion of Science(JSPS)Overseas Research Fellowship,JSPS Grants-in-Aid for Scientific Research(KAKENHI)(Grant Nos.19K14802 and 18H05053)。
文摘Cyclones with strong winds can make the Southern Ocean and the Antarctic a dangerous environment.Accurate weather forecasts are essential for safe shipping in the Southern Ocean and observational and logistical operations at Antarctic research stations.This study investigated the impact of additional radiosonde observations from Research Vessel"Shirase"over the Southern Ocean and Dome Fuji Station in Antarctica on reanalysis data and forecast experiments using an ensemble data assimilation system comprising the Atmospheric General Circulation Model for the Earth Simulator and the Local Ensemble Transform Kalman Filter Experimental Ensemble Reanalysis,version 2.A 63-member ensemble forecast experiment was conducted focusing on an unusually strong Antarctic cyclonic event.Reanalysis data with(observing system experiment)and without(control)additional radiosonde data were used as initial values.The observing system experiment correctly captured the central pressure of the cyclone,which led to the reliable prediction of the strong winds and moisture transport near the coast.Conversely,the control experiment predicted lower wind speeds because it failed to forecast the central pressure of the cyclone adequately.Differences were found in cyclone predictions of operational forecast systems with and without assimilation of radiosonde observations from Dome Fuji Station.
文摘In the present study, we aimed to evaluate the pathways contributing to ATP release from mouse astrocytes during hypoosmotic stress. We first examined the expression of mRNAs for proteins constituting possible ATP- releasing pathways that have been suggested over the past several years. In RT-PCR analysis using both control and osmotically swollen astrocytes, amplification of cDNA fragments of expected size was seen for connexins （Cx32, Cx37, Cx43）, pannexin 1 （Pxl）, the P2X7 receptor, MRP1 and MDR1, but not CFTR. Inhibitors of exocytotic vesicular release, gap junction hemi-channels, CFTR, MRP1, MDR1, the P2X7 receptor, and volume-sensitive outwardly rectifying chloride channels had no significant effects on the massive ATP release from astrocytes. In contrast, the hypotonicity-induced ATP release from astrocytes was most effectively inhibited by gadolinium （50 μM）, an inhibitor of the maxi-anion channel, which has recently been shown to serve as a pathway for ATP release from several other cell types. Thus, we propose that the maxi-anion channel constitutes a major pathway for swelling-induced ATP release from cultured mouse astrocytes as well.
基金supported by a grant from the Program for Promotion of Basic Research Activities for Innovative Biosciences(PROBRAIN to S.I.) from Bio-oriented Technology Research Advancement Institution(BRAIN) in Japangrants from the Ministry of Education,Culture,Sports, Science,and Technology of Japan(No.17207002 to S.I.and 22780007 to K.T.)+1 种基金supported by the Global COE Program(to H.K.and S.I.)the NIBB Cooperative Research Program(9-151 to H.K.and 9-153 to M.M.),and the Graduate University for Advanced Studies(Sokendai)
文摘We have isolated a recessive rice mutant, designated as indeterminate growth （ing）, which displays creeping and apparent heterochronic phenotypes in the vegetative period with lanky and winding culms. Rough mapping and subsequent molecular characterization revealed that the ing mutant carries a large deletion, which corresponds to a 103 kb region in the Nipponbare genome, containing nine annotated genes on chromosome 3. Of these annotated genes, the SLR1 gene encoding a DELLA protein is the only one that is well characterized in its function, and its null mutation, which is caused by a single base deletion in the middle of the intronless SLR1 gene, confers a slender phenotype that bears close resemblance to the ing mutant phenotype. The primary cause of the ing mutant phenotype is the deletion of the SLR1 gene, and the ing mutant appears to be the first characterized mutant having the entire SLR1 sequence deleted. Our results also suggest that the deleted region of 103 kb does not contain an indispensable gene, whose dysfunction must result in a lethal phenotype.
文摘Myelination is an essential feature of the vertebrate nervous system that provides electrical insulation to axons,thereby facilitating the transmission of nerve impulses.Deficiencies in myelination in diseases such as multiple sclerosis（MS）lead to serious neurological disorders.
基金supported by the Post-CUP programJSPSCAS Bilateral Joint Research Projects,‘Control of wall recycling on metallic plasma facing materials in fusionreactor,’2019–2022,(No.GJHZ201984)+2 种基金US Department of Energy(No.DE-AC02-09CH11466)with Princeton Universitythe LHD project financial support(Nos.ULPP010,ULFF022)JSPS KAKENHI(Nos.17K14426,20K03896)。
文摘An impurity powder dropper was installed in the 21 st campaign of the Large Helical Device experiment(Oct.2019–Feb.2020)under a collaboration between the National Institute for Fusion Science and the Princeton Plasma Physics Laboratory for the purposes of real-time wall conditioning and edge plasma control.In order to assess the effective injection of the impurity powders,spectroscopic diagnostics were applied to observe line emission from the injected impurity.Thus,extreme-ultraviolet(EUV)and vacuum-ultraviolet(VUV)emission spectra were analyzed to summarize observable impurity lines with B and BN powder injection.Emission lines released from B and N ions were identified in the EUV wavelength range of 5–300Ameasured using two grazing incidence flat-field EUV spectrometers and in the VUV wavelength range of 300–2400Ameasured using three normal incidence 20 cm VUV spectrometers.BI–BV and NIII–NVII emission lines were identified in the discharges with the B and BN powder injection,respectively.Useful B and N emission lines which have large intensities and are isolated from other lines were successfully identified as follows:BI(1825.89,1826.40)A(blended),BII 1362.46A,BIII(677.00,677.14,677.16)A(blended),BIV 60.31A,BV 48.59A,NIII(989.79,991.51,991.58)A(blended),NIV765.15A,NV(209.27,209.31)A(blended),NVI 1896.80A,and NVII 24.78A.Applications of the line identifications to the advanced spectroscopic diagnostics were demonstrated,such as the vertical profile measurements for the BV and NVII lines using a space-resolved EUV spectrometer and the ion temperature measurement for the BII line using a normal incidence 3 m VUV spectrometer.
基金supported partly by LHD project budgets (ULHH003 and ULHH034)
文摘Shot-integrated measurement of the triton burnup ratio has been performed in the Large Helical Device. It was reported that the triton burnup ratio, defined as total DT neutron yield divided by total DD neutron yield, increases significantly in inward shifted configurations. To understand the magnetic configuration dependence of the triton burnup ratio, the first orbit loss fraction of 1 MeV tritons is evaluated by means of the Lorentz orbit code for various magnetic configurations. The first orbit loss of 1 MeV tritons is seen at t of less than 10-5 s and loss points of the triton are concentrated on the side of the helical coil case where the magnetic field is relatively weak. The significant decrease of the first orbit loss fraction by 15% is obtained with the inward shift of the magnetic axis position from 3.90 to 3.55 m. It is found that the decrease of first orbit loss is due to the reduction of the first orbit loss of transition and helically trapped tritons.
基金JSPS-CAS Bilateral Joint Research Projects,‘Control of wall recycling on metallic plasma facing materials in fusion reactor’supported by the NIFS Collaboration Research Program (Nos.NIFS18KNST130 and NIFS20KNST171)supported by ‘PLADy S’,JSPS Core-to-Core Program,A. Advanced Research Networks
文摘A two-point model is used to investigate the characteristics of scrape-off layer(SOL)plasma with the field line tracing method in the experimental advanced superconducting tokamak.The profiles of plasma density,temperature and particle flux on the divertor target calculated by the model are in reasonable agreement with experimental observation.Moreover,the profiles of plasma parameters on the divertor target strongly depend on the SOL magnetic topology or the equilibrium configuration from the modeling.
基金National Key R&D Program of China (No. 2017YFE0301100)National Natural Science Foundation of China (No. 51828101)+3 种基金the KC Wong Educa-tion Foundationthe China Scholarship Councilthe NIFS (National Institute for Fusion Science) Collaborative Research Program (NIFS16KNTT042)JSPS (the Japan Society for the Promotion of Science) Grant-in-aid for Sci-entific Research (B) 18H01202.
文摘In order to understand the mechanism by which the resonant magnetic perturbation (RMP)mitigates or suppresses the edge-localized mode (ELM),the topological study of the edge magnetic field in ELM mitigation or suppression phase is a critical issue.To model the three-dimensional magnetic field topology superposed RMP on Experimental Advanced Superconducting Tokamak,a numerical model using the field line tracing method for both vacuum and ideal plasma response approximations is proposed.Using the numerical model,the topological change and the penetration depth of the stochastic field lines in the edge magnetic field are studied in an RMP experiment.Comparing profiles of minimum9 on edge stochastic field lines and the particle flux pattem,the ideal plasma response changes the field line penetration depth while remaining similar profile relative to vacuum approximation.To mitigate and suppress ELM strongly,the deep penetration of RMP fields and topological changes of the edge magnetic field is a key from our modeling.
基金performed under the auspices of the NIFS Bilateral Collaboration Research Program (NIFS10KUHL037)partly supported by Grant-in-aid for Scientific Research (B) 18H01202 from the Japan Society for the Promotion of Science (JSPS) and JSPS-CAS Joint Research Program, Grant number JPJSBP120197202supported by JSPS Core-to-Core Program A. Advanced Research Networks,'PLADyS'。
文摘This letter proposes a new tomographic reconstruction procedure based on the Laplacian eigenfunction(LEF) patterns, which are independent of the plasma cross-section and do not require the flux surface information. The process is benchmarked for the experimental data of Heliotron J plasma and the results are compared with the least-squares approximation by a Phillips–Tikhonov(PT)-type regularization, which is widely used as the standard technique for tomographic reconstruction. The reconstruction based on the LEF is found to be capable of determining the magnetic axis at different time locations efficiently in comparison with the PT-type regularization.
基金supported in part by the National Key R&D Program of China(Nos.2019YFE03080200,2022YFE03030001 and2022YFE03050003)National Natural Science Foundation of China(Nos.11975271,12075284,12075283 and 12175277)+1 种基金the Chinese Academy of President’s International Fellowship Initiative(No.2021VMA0022)the Post-CUP program,JSPS-CAS Bilateral Joint Research Projects,‘Control of wall recycling on metallic plasma facing materials in fusion reactor’,2019–2022,(No.GJHZ201984)。
文摘In the ELMy H-mode experiment,naturally occurring dust originating at the high-field side is clearly observed using the high-speed vacuum ultraviolet imaging system developed on the Experimental Advanced Superconducting Tokamak(EAST).The main ablation cloud shape is similar to the classical shape observed in pellet fueling experiments.However,during the dust penetration,an erupted secondary cloudlet with a bent‘cigar’shape is observed and moves upwards along the direction perpendicular to the magnetic field line,which is different to the obviation in the pellet fueling experiments.This may be due to the ion diamagnetic drift effect.The velocities of the secondary cloudlet are estimated to be 50–80 m s^(-1).In addition,a significant degradation of the plasma confinement is observed during the dust penetration.
文摘Cytoplasmic inc lus ions containing the transactivation response element(TAR)DNAbinding protein-43(TDP-43)aggregates are hallmarks of neurodegenerative disorders,such as amyotrophic lateral sclerosis(ALS)and frontotemporal dementia(Arai et al.,2006;Neumann et al.,2006).Despite the well-recognized correlation between TDP-43 aggregation and neuronal degeneration,whether this relationship is causal has remained unclear.
文摘The preparation for an experimental soft x-ray tomography study on the Heliotron J (H-J) machine is carried out,with the objectives of evaluating the capability of the current soft x-ray tomographic system in terms of the identification of different mode structures and their poloidal rotation,and the axis shift with different plasma and machine parameters,and fixing the physics goals for the experimental study.These preparations were carried out via a simulated soft x-ray data set arising from different plasma conditions,such as magnetic islands,low beta and high beta.Soft x-ray tomography (SXT) is performed by the discrete pixel method including singular value decomposition and Phillips-Tikhonov regularization,to obtain clear and smooth images.The H-J soft x-ray tomography results from simulated soft x-rays for the equilibrium H-J plasma sensed the magnetic axis shift clearly and an estimate was also achieved.Successful reconstruction for mode structure m =1/n =1 was obtained along with the realization of the poloidal rotation of the structure.The reconstruction for the m =2/n =1 mode was not very clear for the current soft x-ray diagnostic design.Effective mode identification was not possible due to the lack of measurements.The SXT from the current soft x-ray diagnostic on H-J,the magnetic axis shift can be estimated and the m =1/n =1 mode can be studied.Study of higher poloidal modes is difficult with the current design.
基金the paper.H.N.L.and G.Z.acknowledge supports by the National Natural Science Foundation of China (Grant Nos.11103030, 11233004 and 11390371)W.A.and T.S.are supported by the JSPS Grant-in-Aid for Scientific Research (S: 23224004)+1 种基金S.H.is supported by the JSPS Grant-in-Aid for Scientific Research (c:26400231)N.C.acknowledges support from Sonderforschungsbereich 881 "The Milky Way System" (subproject A4) of the German Research Foundation (DFG)
文摘We report the discovery of an extremely metal-poor（EMP） giant,LAMOST J110901.22＋075441.8, which exhibits a large excess of r-process elements with [Eu/Fe] ～ ＋1.16. The star is one of the newly discovered EMP stars identified from the LAMOST low-resolution spectroscopic survey and a highresolution follow-up observation with the Subaru Telescope. Stellar parameters and elemental abundances have been determined from the Subaru spectrum. Accurate abundances for a total of 23 elements including 11 neutron-capture elements from Sr through Dy have been derived for LAMOST J110901.22＋075441.8. The abundance pattern of LAMOST J110901.22＋075441.8 in the range of C through Zn is in line with the ＂normal＂ population of EMP halo stars, except that it shows a notable underabundance in carbon. The heavy element abundance pattern of LAMOST J110901.22＋075441.8 is in agreement with other well studied cool r-II metal-poor giants such as CS 22892-052 and CS 31082-001. The abundances of elements in the range from Ba through Dy match the scaled solar r-process pattern well.LAMOST J110901.22＋075441.8 provides the first detailed measurements of neutroncapture elements among r-II stars at such low metallicity with [Fe/H]-3.4, and exhibits similar behavior as other r-II stars in the abundance ratio of Zr/Eu as well as Sr/Eu and Ba/Eu.
