Two methods for separating the magnetospheric solar wind charge exchange soft X-ray emission from the diffuse X-ray background

Solar wind charge exchange(SWCX)is the process of solar wind high-valence ions exchanging charges with neutral components and generating soft X-rays.Recently,detecting the SWCX emission from the magnetosphere is proposed as a new technique to study the magnetosphere using panoramic soft X-ray imaging.To better prepare for the data analysis of upcoming magnetospheric soft X-ray imaging missions,this paper compares the magnetospheric SWCX emission obtained by two methods in an XMM-Newton observation,during which the solar wind changed dramatically.The two methods differ in the data used to fit the diffuse X-ray background(DXB)parameters in spectral analysis.The method adding data from the ROSAT All-Sky Survey(RASS)is called the RASS method.The method using the quiet observation data is called the Quiet method,where quiet observations usually refer to observations made by the same satellite with the same target but under weaker solar wind conditions.Results show that the spectral compositions of magnetospheric SWCX emission obtained by the two methods are very similar,and the changes in intensity over time are highly consistent,although the intensity obtained by the RASS method is about 2.68±0.56 keV cm^(-2)s^(-1)sr^(-1)higher than that obtained by the Quiet method.Since the DXB intensity obtained by the RASS method is about 2.84±0.74 keV cm^(-2)s^(-1)sr^(-1)lower than that obtained by the Quiet method,and the linear correlation coefficient between the difference of SWCX and DXB obtained by the two methods in diffe rent energy band is close to-1,the diffe rences in magnetospheric SWCX can be fully attributed to the diffe rences in the fitted DXB.The difference between the two methods is most significant when the energy is less than 0.7 keV,which is also the main energy band of SWCX emission.In addition,the difference between the two methods is not related to the SWCX intensity and,to some extent,to solar wind conditions,because SWCX intensity typically va ries with the solar wind.In summary,both methods are robust and reliable,and should be considered based on the best available options.

Global hybrid simulations of soft X-ray emissions in the Earth’s magnetosheath

Earth’s magnetopause is a thin boundary separating the shocked solar wind plasma from the magnetospheric plasmas,and it is also the boundary of the solar wind energy transport to the magnetosphere.Soft X-ray imaging allows investigation of the large-scale magnetopause by providing a two-dimensional(2-D)global view from a satellite.By performing 3-D global hybrid-particle-in-cell(hybrid-PIC)simulations,we obtain soft X-ray images of Earth’s magnetopause under different solar wind conditions,such as different plasma densities and directions of the southward interplanetary magnetic field.In all cases,magnetic reconnection occurs at low latitude magnetopause.The soft X-ray images observed by a hypothetical satellite are shown,with all of the following identified:the boundary of the magnetopause,the cusps,and the magnetosheath.Local X-ray emissivity in the magnetosheath is characterized by large amplitude fluctuations(up to 160%);however,the maximum line-of-sight-integrated X-ray intensity matches the tangent directions of the magnetopause well,indicating that these fluctuations have limited impact on identifying the magnetopause boundary in the X-ray images.Moreover,the magnetopause boundary can be identified using multiple viewing geometries.We also find that solar wind conditions have little effect on the magnetopause identification.The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission will provide X-ray images of the magnetopause for the first time,and our global hybrid-PIC simulation results can help better understand the 2-D X-ray images of the magnetopause from a 3-D perspective,with particle kinetic effects considered.

Tomographic reconstruction of the Earth’s magnetosheath from multiple spacecraft:a theoretical study

Following our earlier work on tomographic reconstruction of the magnetosheath soft X-ray emissions with superposed epoch analysis of many images recorded from a single spacecraft we now explore the instantaneous reconstruction of the magnetosheath and magnetopause using a few images recorded simultaneously from a few spacecraft.This work is motivated by the prospect of possibly having two or three soft X-ray imagers in space in the coming years,and that many phenomena which occur at the magnetopause boundary,such as reconnection events and pressure pulse responses,do not lend themselves as well to superposed epoch analysis.If the reconstruction is successful-which we demonstrate in this paper that it can be-this collection of imagers can be used to reconstruct the magnetosheath and magnetopause from a single image from each spacecraft,allowing for high time resolution reconstructions.In this paper we explore the reconstruction using,two,three,and four spacecraft.We show that the location of the subsolar point of the magnetopause can be determined with just two satellites,and that volume emissions of soft X-rays,and the shape of the boundary,can be reconstructed using three or more satellites.

Analysis of the joint detection capability of the SMILE satellite and EISCAT-3D radar

The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)satellite is a small magnetosphere–ionosphere link explorer developed cooperatively between China and Europe.It pioneers the use of X-ray imaging technology to perform large-scale imaging of the Earth’s magnetosheath and polar cusp regions.It uses a high-precision ultraviolet imager to image the overall configuration of the aurora and monitor changes in the source of solar wind in real time,using in situ detection instruments to improve human understanding of the relationship between solar activity and changes in the Earth’s magnetic field.The SMILE satellite is scheduled to launch in 2025.The European Incoherent Scatter Sciences Association(EISCAT)-3D radar is a new generation of European incoherent scatter radar constructed by EISCAT and is the most advanced ground-based ionospheric experimental device in the high-latitude polar region.It has multibeam and multidirectional quasi-real-time three-dimensional(3D)imaging capabilities,continuous monitoring and operation capabilities,and multiple-baseline interferometry capabilities.Joint detection by the SMILE satellite and the EISCAT-3D radar is of great significance for revealing the coupling process of the solar wind–magnetosphere–ionosphere.Therefore,we performed an analysis of the joint detection capability of the SMILE satellite and EISCAT-3D,analyzed the period during which the two can perform joint detection,and defined the key scientific problems that can be solved by joint detection.In addition,we developed Web-based software to search for and visualize the joint detection period of the SMILE satellite and EISCAT-3D radar,which lays the foundation for subsequent joint detection experiments and scientific research.

Deformations at Earth’s dayside magnetopause during quasi-radial IMF conditions:Global kinetic simulations and Soft X-ray Imaging

The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)is a joint mission of the European Space Agency(ESA)and the Chinese Academy of Sciences(CAS).Primary goals are investigating the dynamic response of the Earth's magnetosphere to the solar wind(SW)impact via simultaneous in situ magnetosheath plasma and magnetic field measurements,X-Ray images of the magnetosheath and magnetic cusps,and UV images of global auroral distributions.Magnetopause deformations associated with magnetosheath high speed jets(HSJs)under a quasi-parallel interplanetary magnetic field condition are studied using a threedimensional(3-D)global hybrid simulation.Soft X-ray intensity calculated based on both physical quantities of solar wind proton and oxygen ions is compared.We obtain key findings concerning deformations at the magnetopause:(1)Magnetopause deformations are highly coherent with the magnetosheath HSJs generated at the quasi-parallel region of the bow shock,(2)X-ray intensities estimated using solar wind h+and self-consistentO7+ions are consistent with each other,(3)Visual spacecraft are employed to check the discrimination ability for capturing magnetopause deformations on Lunar and polar orbits,respectively.The SMILE spacecraft on the polar orbit could be expected to provide opportunities for capturing the global geometry of the magnetopause in the equatorial plane.A striking point is that SMILE has the potential to capture small-scale magnetopause deformations and magnetosheath transients,such as HSJs,at medium altitudes on its orbit.Simulation results also demonstrate that a lunar based imager(e.g.,Lunar Environment heliospheric X-ray Imager,LEXI)is expected to observe a localized brightening of the magnetosheath during HSJ events in the meridian plane.These preliminary results might contribute to the pre-studies for the SMILE and LEXI missions by providing qualitative and quantitative soft X-ray estimates of dayside kinetic processes.

Accelerating the practical application of MOFs for hydrogen storage-from performance-driven to application-oriented

Metal–organic frameworks(MOFs)are highly promising porous materials known for their exceptional porosity,extensive surface area,and customizable pore structures,making them an ideal solution for hydrogen storage.However,most MOFs research remains confined to the laboratory,lacking practical applications.To address this,the author proposes a shift towards practical applications,the creation of a comprehensive MOFs database,alignment of synthesis with practical considerations,and diversification of MOFs applications.These steps are crucial for harnessing the full potential of MOFs in real-world energy challenges.

High performance photodegradation resistant PVA@TiO_(2)/carboxyl-PES self-healing reactive ultrafiltration membrane

The occurrence of ultrafiltration(UF)membrane fouling frequently hampers the sustainable advancement of UF technology.Reactive self-cleaning UF membranes can effectively alleviate the problem of membrane fouling.Nevertheless,the self-cleaning process may accelerate membrane aging.Addressing these concerns,we present an innovative design concept for composite self-healing materials based on self-cleaning UF membranes.To begin,TiO_(2)nanoparticles were incorporated into the polymer molecular structure via molecular design,resulting in the synthesis of TiO_(2)/carboxyl-polyether sulfone(PES)hybrid materials.Subsequently,the nonsolvent-induced phase inversion technique was employed to prepare a novel of UF membrane.Lastly,a polyvinyl alcohol(PVA)hydrogel coating was applied to the hybrid UF membrane surface to create PVA@TiO_(2)/carboxyl-PES self-healing reactive UF membranes.By establishing a covalent bond,the TiO_(2)nanoparticles were effectively and uniformly dispersed within the UF membrane,leading to exceptional self-cleaning properties.Furthermore,the water-absorbing and swelling properties of PVA hydrogel,along with its capacity to form hydrogen bonds with water molecules,resulted in UF membranes with improved hydrophilicity and active self-healing abilities.The results demonstrated that the water contact angle of PVA@5%TiO_(2)/carboxyl-PES UF membrane was 43.1°.Following a 1-h exposure to simulated solar exposure,the water flux recovery ratio increased from 48.16%to 81.03%.Moreover,even after undergoing five cycles of 12-h simulated sunlight exposure,the UF membranes exhibited a consistent retention rate of over 97%,thus fully demonstrating their exceptional self-cleaning,antifouling,and selfhealing capabilities.We anticipate that the self-healing reactive UF membrane system will serve as a pioneering and comprehensive solution for the self-cleaning antifouling challenges encountered in UF membranes while also effectively mitigating the aging effects of reactive UF membranes.

Evidence of guide field magnetic reconnection in flapping current sheets

Based on current sheet flapping motion on 27 August 2018 in the dusk flank magnetotail,as recorded by instruments aboard Magnetospheric Multiscale(MMS)spacecraft,we present the first study of guide field reconnection observed in the flux rope embedded in kink-like flapping current sheets near the dusk-side flank of the magnetotail.Unlike more common magnetotail reconnections,which are symmetric,these asymmetric small-scale(λ_(i)~650 km)reconnections were found in the highly twisted current sheet when the direction normal to the sheet changes from the Z direction into the Y direction.The unique feature of this unusual reconnection is that the reconnection jets are along the Z direction-different from outflow in the X direction,which is the more usual situation.This vertical reconnection jet is parallel or antiparallel to the up-and-down motion of the tail’s current sheet.The normalized reconnection rate R is estimated to be~0.1.Our results indicate that such asymmetric reconnections can significantly enlarge current sheet flapping,with large oscillation amplitudes.This letter presents direct evidence of guide field reconnection in a highly twisted current sheet,characterized by enlarged current sheet flapping as a consequence of the reconnection outflow.

The payloads of planetary physics research onboard China’s First Mars Mission (Tianwen-1)

Mars is not only our nearby but also the most Earth-like planetary neighbor.Scientific exploration of Mars is thus of crucial value to our understanding of the solar system.The existence of abundant evidence for the former presence of water on Mars demands further exploration for signs of life on our sister planet,and investigations that could shed light on conditions favorable to the origin of life.For nearly 60 years,humans have conducted orbitally-based remote sensing and in-situ surface exploration of Mars,leading to many significant scientific discoveries.But much remains to be done before we can be sure that we truly and fully understand Mars.Key research topics include the history of water on Mars and how that history relates to the planet’s habitable environment-past,present,and future;the distribution and evolution of waterbearing and evaporative salt minerals on the planet’s surface;the history of volcanic activity on Mars;the Martian magnetic field and its effect on the escape of water and atmosphere from the planet;interactions between the solar wind and the Martian atmosphere and ionosphere;atmospheric characteristics and climate change on Mars;and so on(Li CL et al.,2018;Liu JJ et al.,2018).Based on the above scientific questions about life,climate,and geology on Mars,the international planetary science community has formulated ambitious Mars exploration programs.

大型LNG储罐外罐涂漆工艺及质量控制

我国大型液化天然气(LNG)储罐多建造在沿海地带,储罐外罐长期处于高湿度、高氯化物浓度环境,腐蚀介质主要是大气中氯化物、二氧化碳,对钢筋混凝土、预应力混凝土中钢筋具有强腐蚀作用。所以,必须采用防腐涂料对外罐混凝土进行隔离保护,防止附近海水及空气中的氯离子等腐蚀介质对混凝土结构造成破坏。文章介绍了LNG储罐外罐涂装工艺及质量控制。

The first attempt for closure of the patent foramen ovale under guidance of teleoperation ultrasonic robot:a case report

Patent foramen ovale(PFO)is a remnant of normal fetal anatomy,which occurs in about 20%–25%of cases.Patients with PFO are at increased risk for migraine,acute limb ischemia secondary to emboli and cryptogenic(no other identifiable cause)stroke.The traditional approach has been to use a fluoroscopically guided blocking device,but this is contraindicated in patients with severe allergies to contrast media or inability to undergo angiography.With the advancements in technology,ultrasonic robotic systems have become available for medical procedures.In the current study,we reported a case of using the ultrasonic robotic teleoperation system to achieve closure of PFO at the Chinese PLA General Hospital,Beijing,China.

Quantum state protection from finite-temperature thermal noise with application to controlled quantum teleportation

We propose a quantum state protection scheme via quantum feedforward control combined with environment-assisted measurement to protect arbitrary unknown initial states from the finite-temperature thermal noise(FTTN).The main strategy is to transfer the quantum system to a noise-robust state by weak measurement and feedforward control before the noise channel.Then we apply the environment-assisted measurement on the noise channel to select our desired damped states that are invertible to the initial state.After the noise channel,the reversal operations are applied to restore the initial state.We consider the protection of a single-qubit system,derive the analytical expressions of the success probability and the fidelity,and analyze the influence of key parameters on the performance of the proposed scheme.Unlike previous studies,there is no trade-off between the fidelity and the success probability in the proposed scheme;hence one could maximize them separately.Simulation results show that the proposed scheme can greatly improve the fidelity of the quantum state with a certain success probability.Moreover,the proposed scheme is successfully applied to improving the fidelity of controlled quantum teleportation through two independent FTTN channels from the perspective of protecting the shared entanglement.

公务员职业生涯规划探究:以警察为分析对象

警察职业生涯规划将培养警察贯穿于职业生涯全过程,将警察个性化发展规划与警察队伍的科学管理相结合,将警察个人潜能开发、职业素养提升与警务人才队伍建设相结合,通过政策引导与制度创新实现警察职业生涯规划的良性互动。职业生涯规划的核心议题包括分析警察职业周期阶段特征及需求,搭建组织管理与职业发展的匹配模型,注重警察内职业生涯的成长,设计多元化职业发展通道,并提供相应的制度与组织保证。

Advanced Space-based Solar Observatory(ASO-S):an overview

The Advanced Space-based Solar Observatory(ASO-S)is a mission proposed for the 25 th solar maximum by the Chinese solar community.The scientific objectives are to study the relationships between the solar magnetic field,solar flares and coronal mass ejections(CMEs).Three payloads are deployed:the Full-disk vector Magneto Graph(FMG),the Lyman-αSolar Telescope(LST)and the Hard X-ray Imager(HXI).ASO-S will perform the first simultaneous observations of the photospheric vector magnetic field,non-thermal imaging of solar flares,and the initiation and early propagation of CMEs on a single platform.ASO-S is scheduled to be launched into a 720 km Sun-synchronous orbit in 2022.This paper presents an overview of the mission till the end of Phase-B and the beginning of Phase-C.

A first attempt of inferior vena cava filter successfully guided by a mixed-reality system: a case report

Pulmonary embolism(PE)is one of the fatal heart attacks,and lower limbs deep vein thrombosis(DVT)is the most common reason for PE.Inferior vena cava filter(IVCF)implantation is a most prevention for PE.But it may carry a high risk of injury because of the radiation and contrast agent.Patients with nephrotic syndrome(NS)or some other renal diseases may prone to thrombosis due to the excretion of protein C and protein S overmuch.So,it is necessary to develop a new therapy without contrast agent.Mixed-reality(MR)is a new technology as a guidance of inferior vena cava filter implantation exposed under no X-ray and required no contrast agent.

MicroRNA-29a attenuates angiotensin-Ⅱ induced-left ventricular remodeling by inhibiting collagen,TGF-β and SMAD2/3 expression

Background Left ventricular(LV)remodeling is the most common target organ damage in hypertension.Previously,our study found that plasma microRNA-29a(miR-29a)level was associated with the LV remodeling in hypertensive patients.However,the causal relationship between miR-29a and LV remodeling remains unknown.Thus,the aim of this study was to investigate the regulation mechanism of miR-29a in LV remodeling.Methods&Results Overexpression and knockdown miR-29a mice were generated by tail-intravenous injection of miR-29a-mimic and inhibitor lentivirus for one week respectively.Then the mice were subjected to angiotensin-II(AngII)induced LV remodeling by subcutaneous AngII capsule osmotic pumping into AngII for four weeks.AngII-induced LV remodeling mice as the model group(n=9).Age-matched male SPF C57/BL6J mice(6–8 weeks old)were treated with the pumping of saline as a vehicle(n=6).In vivo,overexpression miR-29a ameliorated AngII-induced LV remodeling,while knockdown miR-29a deteriorated LV remodeling.Simultaneously,we observed that overexpression miR-29a mice inhibited but knockdown miR-29a mice increased cardiac cross-sectional area,indicating that miR-29a has an antagonistic effect on cardiac hypertrophy.Further studies found that overexpression miR-29a inhibited the content of the LV collagen including collagen I and III.Moreover,the expression of transforming growth factor-β(TGF-β)and phosphorylated SMAD2/3 decreased with the down-regulation of collagen I and III in overexpression miR-29a mice.Conclusions Our finding indicates that overexpression miR-29a attenuates LV remodeling by inhibiting collagen deposition,TGF-β,and phosphorylated SMAD2/3 expression.Thus,intervention miR-29a may be a therapeutic target for attenuating LV remodeling.

Tianwen-1 MINPA observations in the solar wind

The Mars Ion and Neutral Particle Analyzer(MINPA)is one of the three scientific instruments onboard the Tianwen-1 orbiter to investigate the Martian space environment.During Tianwen-1’s transfer orbit to Mars,the MINPA was switched on to measure the solar wind ions.Here,we present the first results of the MINPA observations in the solar wind.During cruise,nearly half of the MINPA ion field-of-view(FOV)was blocked by the lander capsule;thus only the solar-wind ions with azimuthal speeds pointing towards the unblocked FOV sectors could be detected.We perform a detailed comparison of the MINPA’s solar wind observations with data from Earth-based missions when MINPA reached its count-rate peak,finding a general consistency of the ion moments between them.The blocking effect due to the lander is evaluated quantitatively under varying solar-wind velocity conditions.Despite the blocking effect,the MINPA’s solar wind measurements during the transfer orbit suggest a good performance.

Development and application of a multi-physics and multi-scale coupling program for lead-cooled fast reactor

In this study,a multi-physics and multi-scale coupling program,Fluent/KMC-sub/NDK,was developed based on the user-defined functions(UDF)of Fluent,in which the KMC-sub-code is a sub-channel thermal-hydraulic code and the NDK code is a neutron diffusion code.The coupling program framework adopts the"master-slave"mode,in which Fluent is the master program while NDK and KMC-sub are coupled internally and compiled into the dynamic link library(DLL)as slave codes.The domain decomposition method was adopted,in which the reactor core was simulated by NDK and KMC-sub,while the rest of the primary loop was simulated using Fluent.A simulation of the reactor shutdown process of M2LFR-1000 was carried out using the coupling program,and the code-to-code verification was performed with ATHLET,demonstrating a good agreement,with absolute deviation was smaller than 0.2%.The results show an obvious thermal stratification phenomenon during the shutdown process,which occurs 10 s after shutdown,and the change in thermal stratification phenomena is also captured by the coupling program.At the same time,the change in the neutron flux density distribution of the reactor was also obtained.

Effect of Combined Application of Organic Fertilizer and Chemical Fertilizer in Different Ratios on Growth,Yield and Quality of Fluecured Tobacco

The effect of different ratio of organic and inorganic fertilizers on the growth and the yield and quality of flue-cured tobacco was studied.Using randomized blocks design,the data of the test materials K326 were analyzed by using variance analysis,significance test and other methods.The release efficiency of organic fertilizer in the soil was slower,and the effect of organic fertilizer on the growth of tobacco plants was worse than that of chemical fertilizers,and under 25% organic fertilizer + 75% chemical fertilizer treatment,the quality of the fluecured tobacco was good.Under the treatment of 50% organic fertilizer + 50% chemical fertilizer,the production of flue-cured tobacco was high and the ratio of first-class tobacco was high.It is suggested that the organic fertilizer application ratio should be 25%-50% in the agricultural production.

A new inversion method for reconstruction of plasmaspheric He^(+)density from EUV images

The Computer Tomography(CT)method is used for remote sensing the Earth’s plasmasphere.One challenge for image reconstruction is insufficient projection data,mainly caused by limited projection angles.In this study,we apply the Algebraic Reconstruction Technique(ART)and the minimization of the image Total Variation(TV)method,with a combination of priori knowledge of north–south symmetry,to reconstruct plasmaspheric He+density from simulated EUV images.The results demonstrate that incorporating priori assumption can be particularly useful when the projection data is insufficient.This method has good performance even with a projection angle of less than 150 degrees.The method of our study is expected to have applications in the Soft X-ray Imager(SXI)reconstruction for the Solar wind–Magnetosphere–Ionosphere Link Explorer(SMILE)mission.