The Macao Science Satellite-1(MSS-1)is the first space science satellite jointly developed on the Chinese mainland and in Macao region.It comprises two satellites,named MSS-1A and MSS-1B,and holds considerable importa...The Macao Science Satellite-1(MSS-1)is the first space science satellite jointly developed on the Chinese mainland and in Macao region.It comprises two satellites,named MSS-1A and MSS-1B,and holds considerable importance in China’s space exploration endeavors.Among these,MSS-1A is the world’s first high-precision scientific satellite dedicated to exploring the geomagnetic field and space environment at low latitudes.Equipped with two high-precision vector magnetometers and one scalar magnetometer,which are integrally installed on a highly stable nonmagnetic optical bench,the MSS-1A enables simultaneous high-precision measurements of both the Earth’s vector magnetic field and its scalar components.Its design integrates several state-of-the-art technologies,including arc-second-level thermal stability control,nonmagnetic thermal control for the optical bench,and ultra-high magnetic cleanliness control.These innovations effectively minimize magnetic interference originating from the satellite itself,thereby substantially improving the precision of geomagnetic field measurements and establishing a robust technical foundation for future magnetic survey satellite constellations.展开更多
Since 2011,the Chinese Academy of Sciences(CAS)has implemented the Strategic Priority Program on Space Science(SPP).A series of scientific satellites have been developed and launched,such as Dark Matter Particle Explo...Since 2011,the Chinese Academy of Sciences(CAS)has implemented the Strategic Priority Program on Space Science(SPP).A series of scientific satellites have been developed and launched,such as Dark Matter Particle Explorer(DAMPE),Quantum Experiments at Space Scale(QUESS),Advanced Space-based Solar Observatory(ASO-S),Einstein Probe(EP),and significant scientific outcomes have been achieved.In order to plan the future space science missions in China,CAS has organized the Chinese space science community to conduct medium and long-term development strategy studies,and summarized the major scientific frontiers of space science as“One Black,Two Dark,Three Origins and Five Characterizations”.Five main scientific themes have been identified for China’s future breakthroughs,including the Extreme Universe,Space-Time Ripples,the Panoramic View of the Sun and Earth,the Habitable Planets,and Biological&Physical Science in Space.Space science satellite missions to be implemented before 2030 are proposed accordingly.展开更多
In 2024,the Chinese Meridian Project(CMP)completed its construction,deploying 282 instruments across 31 stations.This achievement not only provides a robust foundation but also serves as a reference template for the I...In 2024,the Chinese Meridian Project(CMP)completed its construction,deploying 282 instruments across 31 stations.This achievement not only provides a robust foundation but also serves as a reference template for the International Meridian Circle Program(IMCP).The IMCP aims to integrate and establish a comprehensive network of ground-based monitoring stations designed to track the propagation of space weather events from the Sun to Earth.Additionally,it monitors various disturbances generated within the Earth system that impact geospace.Over the past two years,significant progress has been made on the IMCP.In particular,the second phase of construction for the China-Brazil Joint Laboratory for Space Weather has been completed,and the North Pole and Southeast Asia networks are under active construction.The 2024 IMCP joint observation campaign was successfully conducted.To facilitate these developments,the scientific program committee of IMCP was established,following the success of 2023 IMCP workshop and the space weather school,which was co-hosted with the Asia-Pacific Space Cooperation Organization(APSCO)and sponsored by Chinese Academy of Sciences(CAS)and Scientific Committee on Solar-Terrestrial Physics(SCOSTEP).Preparations are now underway for the 2024 workshop in collaboration with the National Institute for Space Research(INPE)in Brazil.展开更多
The National Space Science Center of the Chinese Academy of Sciences(NSSC,CAS),as the leading institute responsible for the overall management of scientific satellite missions in China,is China’s gateway to space sci...The National Space Science Center of the Chinese Academy of Sciences(NSSC,CAS),as the leading institute responsible for the overall management of scientific satellite missions in China,is China’s gateway to space science.NSSC is the cradle of China’s first artificial satellite“Dongfanghong-1”(DFH-1).In the course of more than 60 years’development,NSSC has led the implementation of“Double Star Program”,the first science-driven space mission in China,and successively implemented a fleet of scientific missions under the Strategic Priority Program on Space Science(Phase I and II),such as the Dark Matter Particle Explorer(DAMPE,or Wukong),the Quantum Experiments at Space Scale(QUESS,or Micius),the Hard X-ray Modulation Telescope(HXMT,or Insight),the Taiji-1,the Advanced space-based Solar Observatory(ASO-S,or Kuafu)and the Einstein Probe(EP).Currently,the space science satellite series has been established,yielding substantial scientific output.For the future,the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE),a China-ESA joint mission,will be launched in 2025.In addition,the newly released National Mid-and Long-term Program for Space Science Development in China(2024-2050),the first of its kind at the national level,has identified five key scientific themes.A fleet of future scientific missions revolving these themes will deepen mankind’s scientific understanding of the universe.展开更多
The article briefly reviews the development history of space science in China,from the preparation period in the 1950s and 1960s,the first science mission Double Star Program(DSP),to the current Strategic Priority Pro...The article briefly reviews the development history of space science in China,from the preparation period in the 1950s and 1960s,the first science mission Double Star Program(DSP),to the current Strategic Priority Program(SPP)on space science of the Chinese Academy of Sciences(CAS).Both science objectives and payload technologies of the missions are addressed.The key management issues,such as longterm planning and the maximization of science output,are also mentioned.In addition,it also stresses the importance of international cooperation in space science.展开更多
The joint European Space Agency and Chinese Academy of Sciences Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission will explore global dynamics of the magnetosphere under varying solar wind and interplane...The joint European Space Agency and Chinese Academy of Sciences Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission will explore global dynamics of the magnetosphere under varying solar wind and interplanetary magnetic field conditions,and simultaneously monitor the auroral response of the Northern Hemisphere ionosphere.Combining these large-scale responses with medium and fine-scale measurements at a variety of cadences by additional ground-based and space-based instruments will enable a much greater scientific impact beyond the original goals of the SMILE mission.Here,we describe current community efforts to prepare for SMILE,and the benefits and context various experiments that have explicitly expressed support for SMILE can offer.A dedicated group of international scientists representing many different experiment types and geographical locations,the Ground-based and Additional Science Working Group,is facilitating these efforts.Preparations include constructing an online SMILE Data Fusion Facility,the discussion of particular or special modes for experiments such as coherent and incoherent scatter radar,and the consideration of particular observing strategies and spacecraft conjunctions.We anticipate growing interest and community engagement with the SMILE mission,and we welcome novel ideas and insights from the solar-terrestrial community.展开更多
Male infertility can result from impaired sperm motility caused by multiple morphological abnormalities of the flagella(MMAF).Distinct projections encircling the central microtubules of the spermatozoal axoneme play p...Male infertility can result from impaired sperm motility caused by multiple morphological abnormalities of the flagella(MMAF).Distinct projections encircling the central microtubules of the spermatozoal axoneme play pivotal roles in flagellar bending and spermatozoal movement.Mammalian sperm-associated antigen 17(SPAG17)encodes a conserved axonemal protein of cilia and flagella,forming part of the C1a projection of the central apparatus,with functions related to ciliary/flagellar motility,skeletal growth,and male fertility.This study investigated two novel homozygous SPAG17 mutations(M1:NM_206996.2,c.829+1G>T,p.Asp212_Glu276del;and M2:c.2120del,p.Leu707*)identified in four infertile patients from two consanguineous Pakistani families.These patients displayed the MMAF phenotype confirmed by Papanicolaou staining and scanning electron microscopy assays of spermatozoa.Quantitative real-time polymerase chain reaction(PCR)of patients’spermatozoa also revealed a significant decrease in SPAG17 mRNA expression,and immunofluorescence staining showed the absence of SPAG17 protein signals along the flagella.However,no apparent ciliary-related symptoms or skeletal malformations were observed in the chest X-rays of any of the patients.Transmission electron microscopy of axoneme cross-sections from the patients showed incomplete C1a projection and a higher frequency of missing microtubule doublets 1 and 9 compared with those from fertile controls.Immunofluorescence staining and Western blot analyses of spermatogenesis-associated protein 17(SPATA17),a component of the C1a projection,and sperm-associated antigen 6(SPAG6),a marker of the spring layer,revealed disrupted expression of both proteins in the patients’spermatozoa.Altogether,these findings demonstrated that SPAG17 maintains the integrity of spermatozoal flagellar axoneme,expanding the phenotypic spectrum of SPAG17 mutations in humans.展开更多
Atmospheric chemistry research and atmospheric measurement techniques have mutually promoted each other and developed rapidly in China in recent years.Cavity-based absorption spectroscopy,which uses a high-finesse cav...Atmospheric chemistry research and atmospheric measurement techniques have mutually promoted each other and developed rapidly in China in recent years.Cavity-based absorption spectroscopy,which uses a high-finesse cavity to achieve very long absorption path-length,thereby achieving ultra-high detection sensitivity,plays an extremely important role in atmospheric chemistry research.Based on the Beer–Lambert law,this technology has the unique advantages of being non-destructive,chemical-free,and highly selective.It does not require any sample preparation and can quantitatively analyze atmospheric trace gases in real time and in situ.In this paper,we review the following:(1)key technological advances in different cavity-based absorption spectroscopy techniques,including cavity ring-down spectroscopy,cavityenhanced absorption spectroscopy,cavity attenuated phase shift spectroscopy,and their extensions;and(2)applications of these techniques in the detection of atmospheric reactive species,such as total peroxy radical,formaldehyde,and reactive nitrogen(e.g.,NOx,HONO,peroxy nitrates,and alkyl nitrates).The review systematically introduces cavity-based absorption spectroscopy techniques and their applications in atmospheric chemistry,which will help promote further communication and cooperation in the fields of laser spectroscopy and atmospheric chemistry.展开更多
Alzheimer’s disease is a neurodegenerative disease resulting from deficits in synaptic transmission and homeostasis.The Alzheimer’s disease brain tends to be hyperexcitable and hypersynchronized,thereby causing neur...Alzheimer’s disease is a neurodegenerative disease resulting from deficits in synaptic transmission and homeostasis.The Alzheimer’s disease brain tends to be hyperexcitable and hypersynchronized,thereby causing neurodegeneration and ultimately disrupting the operational abilities in daily life,leaving patients incapacitated.Repetitive transcranial magnetic stimulation is a cost-effective,neuro-modulatory technique used for multiple neurological conditions.Over the past two decades,it has been widely used to predict cognitive decline;identify pathophysiological markers;promote neuroplasticity;and assess brain excitability,plasticity,and connectivity.It has also been applied to patients with dementia,because it can yield facilitatory effects on cognition and promote brain recovery after a neurological insult.However,its therapeutic effectiveness at the molecular and synaptic levels has not been elucidated because of a limited number of studies.This study aimed to characterize the neurobiological changes following repetitive transcranial magnetic stimulation treatment,evaluate its effects on synaptic plasticity,and identify the associated mechanisms.This review essentially focuses on changes in the pathology,amyloidogenesis,and clearance pathways,given that amyloid deposition is a major hypothesis in the pathogenesis of Alzheimer’s disease.Apoptotic mechanisms associated with repetitive transcranial magnetic stimulation procedures and different pathways mediating gene transcription,which are closely related to the neural regeneration process,are also highlighted.Finally,we discuss the outcomes of animal studies in which neuroplasticity is modulated and assessed at the structural and functional levels by using repetitive transcranial magnetic stimulation,with the aim to highlight future directions for better clinical translations.展开更多
Morphological alterations in dendritic spines have been linked to changes in functional communication between neurons that affect learning and memory.Kinesin-4 KIF21A helps organize the microtubule-actin network at th...Morphological alterations in dendritic spines have been linked to changes in functional communication between neurons that affect learning and memory.Kinesin-4 KIF21A helps organize the microtubule-actin network at the cell cortex by interacting with KANK1;however,whether KIF21A modulates dendritic structure and function in neurons remains unknown.In this study,we found that KIF21A was distributed in a subset of dendritic spines,and that these KIF21A-positive spines were larger and more structurally plastic than KIF21A-negative spines.Furthermore,the interaction between KIF21A and KANK1 was found to be critical for dendritic spine morphogenesis and synaptic plasticity.Knockdown of either KIF21A or KANK1 inhibited dendritic spine morphogenesis and dendritic branching,and these deficits were fully rescued by coexpressing full-length KIF21A or KANK1,but not by proteins with mutations disrupting direct binding between KIF21A and KANK1 or binding between KANK1 and talin1.Knocking down KIF21A in the hippocampus of rats inhibited the amplitudes of long-term potentiation induced by high-frequency stimulation and negatively impacted the animals’cognitive abilities.Taken together,our findings demonstrate the function of KIF21A in modulating spine morphology and provide insight into its role in synaptic function.展开更多
Physical and chemical processes observed in the mesosphere and thermosphere above the Earth’s low latitudes are complex and highly interrelated to activity in the low-latitude ionosphere.Metallic sodium detected by l...Physical and chemical processes observed in the mesosphere and thermosphere above the Earth’s low latitudes are complex and highly interrelated to activity in the low-latitude ionosphere.Metallic sodium detected by lidar can yield clues to dynamic and chemical processes in these spatial layers above the Earth’s atmosphere.This paper is based on sodium layer data collected at two low-latitude stations,one in the northern hemisphere and one in the southern.The low-latitude sodium layer exhibits conspicuous seasonal variations in shape,density,and altitude;these variations are similar between Earth’s hemispheres:sodium layer density at both stations reaches its seasonal maximum in autumn and minimum in summer.However,maximal Na density over Brazil is greater than that over Hainan.Nocturnal variations of Na density above the two low-latitude stations are also similar;at both,maxima are observed before sunrise.Some variations of the Na layer over Brazil that differ from those observed in the northern hemisphere may be related to the South Atlantic Magnetic Anomaly(SAMA)or fountain effect.We suggest that low-latitude Na layer data may provide useful additional evidence that could significantly improve the low-latitude part of the WACCM-Na model.展开更多
On 19 May 2022, an outbreak of 105 red sprites that occurred over South Asia was fortuitously recorded by two amateurs from a site in the southern Tibetan Plateau(TP), marking the highest number captured over a single...On 19 May 2022, an outbreak of 105 red sprites that occurred over South Asia was fortuitously recorded by two amateurs from a site in the southern Tibetan Plateau(TP), marking the highest number captured over a single thunderstorm in South Asia. Nearly half of these events involved dancing sprites, with an additional 16 uncommon secondary jets and at least four extremely rare green emissions called “ghosts” observed following the associated sprites. Due to the absence of the precise timing needed to identify parent lightning, a method based on satellite motion trajectories and star fields is proposed to infer video frame timestamps within an error of less than one second. After verifying 95 sprites from two videos, our method identified the parent lightning for 66 sprites(~70%). The sprite-producing strokes, mainly of positive polarity with peak currents exceeding +50 k A, occurred in the stratiform region of a mesoscale convective complex(MCC)that spanned the Ganges Plain to the southern TP, with a cloud area over 200 000 km2 and a minimum cloud-top black body temperature near 180 K. This observation confirms that thunderstorms in South Asia, akin to mesoscale convective systems(MCSs) in the Great Plains of the United States or coastal thunderstorms in Europe, can produce numerous sprites,including complex species. Our analysis bears important implications for characterizing thunderstorms above the southern TP and examining their physical and chemical effects on the adjacent regions, as well as the nature of the coupling between the troposphere and middle-upper atmosphere in this region.展开更多
Background:The forest musk deer,a rare fauna species found in China,is famous for its musk secretion which is used in selected Traditional Chinese medicines.However,over-hunting has led to musk deer becoming an endang...Background:The forest musk deer,a rare fauna species found in China,is famous for its musk secretion which is used in selected Traditional Chinese medicines.However,over-hunting has led to musk deer becoming an endangered species,and their survival is also greatly challenged by various high incidence and high mortality respiratory and intestinal diseases such as septic pneumonia and enteritis.Accumulating evidence has demonstrated that Akkermannia muciniphila(AKK)is a promising probiotic,and we wondered whether AKK could be used as a food additive in animal breeding pro-grammes to help prevent intestinal diseases.Methods:We isolated one AKK strain from musk deer feces(AKK-D)using an im-proved enrichment medium combined with real-time PCR.After confirmation by 16S rRNA gene sequencing,a series of in vitro tests was conducted to evaluate the probiotic effects of AKK-D by assessing its reproductive capability,simulated gas-trointestinal fluid tolerance,acid and bile salt resistance,self-aggregation ability,hy-drophobicity,antibiotic sensitivity,hemolysis,harmful metabolite production,biofilm formation ability,and bacterial adhesion to gastrointestinal mucosa.Results:The AKK-D strain has a probiotic function similar to that of the standard strain in humans(AKK-H).An in vivo study found that AKK-D significantly amelio-rated symptoms in the enterotoxigenic Escherichia coli(ETEC)-induced murine diar-rhea model.AKK-D improved organ damage,inhibited inflammatory responses,and improved intestinal barrier permeability.Additionally,AKK-D promoted the reconsti-tution and maintenance of the homeostasis of gut microflora,as indicated by the fact that AKK-D-treated mice showed a decrease in Bacteroidetes and an increase in the proportion of other beneficial bacteria like Muribaculaceae,Muribaculum,and unclas-sified f_Lachnospiaceae compared with the diarrhea model mice.Conclusion:Taken together,our data show that this novel AKK-D strain might be a potential probiotic for use in musk deer breeding,although further extensive system-atic research is still needed.展开更多
Objective Autism spectrum disorder(ASD)is a neurodevelopmental condition characterized by difficulties with communication and social interaction,restricted and repetitive behaviors.Previous studies have indicated that...Objective Autism spectrum disorder(ASD)is a neurodevelopmental condition characterized by difficulties with communication and social interaction,restricted and repetitive behaviors.Previous studies have indicated that individuals with ASD exhibit early and lifelong attention deficits,which are closely related to the core symptoms of ASD.Basic visual attention processes may provide a critical foundation for their social communication and interaction abilities.Therefore,this study explores the behavior of children with ASD in capturing attention to changes in topological properties.Methods Our study recruited twenty-seven ASD children diagnosed by professional clinicians according to DSM-5 and twenty-eight typically developing(TD)age-matched controls.In an attention capture task,we recorded the saccadic behaviors of children with ASD and TD in response to topological change(TC)and non-topological change(nTC)stimuli.Saccadic reaction time(SRT),visual search time(VS),and first fixation dwell time(FFDT)were used as indicators of attentional bias.Pearson correlation tests between the clinical assessment scales and attentional bias were conducted.Results This study found that TD children had significantly faster SRT(P<0.05)and VS(P<0.05)for the TC stimuli compared to the nTC stimuli,while the children with ASD did not exhibit significant differences in either measure(P>0.05).Additionally,ASD children demonstrated significantly less attention towards the TC targets(measured by FFDT),in comparison to TD children(P<0.05).Furthermore,ASD children exhibited a significant negative linear correlation between their attentional bias(measured by VS)and their scores on the compulsive subscale(P<0.05).Conclusion The results suggest that children with ASD have difficulty shifting their attention to objects with topological changes during change detection.This atypical attention may affect the child’s cognitive and behavioral development,thereby impacting their social communication and interaction.In sum,our findings indicate that difficulties in attentional capture by TC may be a key feature of ASD.展开更多
Solar activity plays an important role in influencing space weather,making it important to understand numerous aspects of spatial and temporal variations in the Sun's radiative output.High-performance deep learnin...Solar activity plays an important role in influencing space weather,making it important to understand numerous aspects of spatial and temporal variations in the Sun's radiative output.High-performance deep learning models and long-term observational records of sunspot relative numbers are essential for solar cycle forecasting.Using the multivariate time series of monthly sunspot relative numbers provided by the National Astronomical Observatory of Japan and two Informer-based models,we forecast the amplitude and timing of solar cycles 25 and 26.The main results are as follows:(1)The maximum amplitude of solar cycle 25 is higher than the previous solar cycle 24 and the following solar cycle 26,suggesting that the long-term oscillatory variation of sunspot magnetic fields is related to the roughly centennial Gleissberg cyclicity.(2)Solar cycles 25 and 26 exhibit a pronounced Gnevyshev gap,which might be caused by two non-coincident peaks resulting from solar magnetic flux transported by meridional circulation and mid-latitude diffusion in the convection zone.(3)Hemispheric prediction of sunspot activity reveals a significant northsouth asynchrony,with activity level of the Sun being more intense in the southern hemisphere.These results are consistent with expectations derived from precursor methods and dynamo theories,and further provide evidence for internal changes in solar magnetic field during the decay of the Modern Maximum.展开更多
One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet(MBC,Active Asteroid)311P/PANSTARRS.This paper outlines the scientific object...One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet(MBC,Active Asteroid)311P/PANSTARRS.This paper outlines the scientific objectives,measurement targets,and measurement requirements for the proposed Gas and Ion Analyzer(GIA).The GIA is designed for in-situ mass spectrometry of neutral gases and low-energy ions,such as hydrogen,carbon,and oxygen,in the vicinity of 311P.Ion sampling techniques are essential for the GIA's Time-of-Flight(TOF)mass analysis capabilities.In this paper,we present an enhanced ion sampling technique through the development of an ion attraction model and an ion source model.The ion attraction model demonstrates that adjusting attraction grid voltage can enhance the detection efficiency of low-energy ions and mitigate the repulsive force of ions during sampling,which is influenced by the satellite's surface positive charging.The ion source model simulates the processes of gas ionization and ion multiplication.Simulation results indicate that the GIA can achieve a lower pressure limit below 10-13Pa and possess a dynamic range exceeding 10~9.These performances ensure the generation of ions with stable and consistent current,which is crucial for high-resolution and broad dynamic range mass spectrometer analysis.Preliminary testing experiments have verified GIA's capability to detect gas compositions such as H2O and N2.In-situ measurements near 311P using GIA are expected to significantly contribute to our understanding of asteroid activity mechanisms,the evolution of the atmospheric and ionized environments of main-belt comets,the interactions with solar wind,and the origin of Earth's water.展开更多
In this paper,a linear optimization method(LOM)for the design of terahertz circuits is presented,aimed at enhancing the simulation efficacy and reducing the time of the circuit design workflow.This method enables the ...In this paper,a linear optimization method(LOM)for the design of terahertz circuits is presented,aimed at enhancing the simulation efficacy and reducing the time of the circuit design workflow.This method enables the rapid determination of optimal embedding impedance for diodes across a specific bandwidth to achieve maximum efficiency through harmonic balance simulations.By optimizing the linear matching circuit with the optimal embedding impedance,the method effectively segregates the simulation of the linear segments from the nonlinear segments in the frequency multiplier circuit,substantially improving the speed of simulations.The design of on-chip linear matching circuits adopts a modular circuit design strategy,incorporating fixed load resistors to simplify the matching challenge.Utilizing this approach,a 340 GHz frequency doubler was developed and measured.The results demonstrate that,across a bandwidth of 330 GHz to 342 GHz,the efficiency of the doubler remains above 10%,with an input power ranging from 98 mW to 141mW and an output power exceeding 13 mW.Notably,at an input power of 141 mW,a peak output power of 21.8 mW was achieved at 334 GHz,corresponding to an efficiency of 15.8%.展开更多
An atmospheric pressure plasma jet(APPJ)approach is developed to prepare platinum nanoparticles(PtNPs)under mild reaction conditions of lower temperatures and without adding chemical reagents.Optical Emission Spectros...An atmospheric pressure plasma jet(APPJ)approach is developed to prepare platinum nanoparticles(PtNPs)under mild reaction conditions of lower temperatures and without adding chemical reagents.Optical Emission Spectroscopy(OES)and X-ray Photoelectron Spectroscopy(XPS)tests revealed that the APPJ contains a large number of high-energy active particles,which can generate solvated electrons in liquid thereby promoting the rapid reduction of Pt(Ⅳ)ions into Pt(0)atoms,and these atoms gradually grow into nanoparticles.After 3 min of treatment,PtNPs exhibit excellent dispersibility with a particle size distribution ranging from 1.8 to 2.8 nm.After 5 min,the particle size increases,and aggregation occurs.The zeta potentials for the two situations were-56.0 mV and-12.5 mV respectively.The results indicate that the treatment time has a significant impact on the dispersion,particle size distribution,and sol stability of the nanoparticles.Furthermore,it reveals the formation mechanism of PtNPs prepared by APPJ,which involves the generation and expansion of nanocrystalline nuclei,and the construction of negatively charged colloidal particles.The overall mechanism highlights the importance of the plasma-liquid interaction in the synthesis of PtNPs,offering a new perspective on the controllable production of nanomaterials using plasma technology.展开更多
BACKGROUND Hepatocellular carcinoma(HCC)ranks among the most prevalent and deadly malignancies,characterized by a high recurrence rate.Regulator of chromosome condensation 1(RCC1)serves as a principal guanine nucleoti...BACKGROUND Hepatocellular carcinoma(HCC)ranks among the most prevalent and deadly malignancies,characterized by a high recurrence rate.Regulator of chromosome condensation 1(RCC1)serves as a principal guanine nucleotide exchange factor for ras-related nuclear protein guanosine triphosphatase(GTPase)and is implicated in various cancers.However,the role of RCC1 in HCC remains unex-plored.AIM To elucidate the functional significance and molecular mechanisms of RCC1 in HCC.METHODS Bioinformatics were to examine the expression levels of RCC1 in HCC and to assess its impact on the prognosis of this malignancy.The cell counting kit-8 assay and flow cytometry were utilized to evaluate the cell viability and cell cycle of HCC cells.Furthermore,quantitative reverse transcription and immunoblotting were to investigate the influence of RCC1 on cyclin associated proteins.RESULTS Bioinformatics analysis revealed that RCC1 was highly expressed in HCC and correlated with poor prognosis in HCC patients.Functional studies showed that RCC1 overexpression promoted the malignant phenotype of HCC cells,especially the proliferation of HCC cells,whereas RCC1 knockdown had the opposite effect.Mechanistically,we identied cell division cycle-associated(CDCA)8 as a downstream target of RCC1 in HCC.RCC1 overexpression markedly increased CDCA8 levels,consequently enhancing cell proliferation and survival in HCC cells.Additionally,we discovered that RCC1 contributed to the development and progression of HCC by activating the phosphoinositide 3-kinase/protein kinase B/cyclin-dependent kinase inhibitor 1a pathway through CDCA8.CONCLUSION Our study provides profound insights into the pivotal role of RCC1 in HCC and its potential as a therapeutic target.展开更多
We investigate the hole-doped Hubbard model on a honeycomb lattice using a fermionic projected entangled pair states(f PEPS)method.Our study reveals the presence of quasi-long-range order of Cooper pairs,characterized...We investigate the hole-doped Hubbard model on a honeycomb lattice using a fermionic projected entangled pair states(f PEPS)method.Our study reveals the presence of quasi-long-range order of Cooper pairs,characterized by powerlaw decay of correlation functions with exponents K>1.We further analyze the competing phases of superconductivity,specifically the antiferromagnetic(AFM)order and the charge density wave(CDW)order.Our results show that there are domain wall structures when the hole dopingδis small and the Coulomb parameter U is large.However,these structures disappear as we increase the hole dopingδor decrease U.Furthermore,for small hole doping,the system exhibits AFM order,which diminishes forδ>0.05.Conversely,as the doping level increases,the CDW order gradually decreases.Notably,a considerable CDW order persists even at higher doping levels.These findings suggest a progressive suppression of the AFM order and a growing prominence of the CDW order with increasingδ.展开更多
文摘The Macao Science Satellite-1(MSS-1)is the first space science satellite jointly developed on the Chinese mainland and in Macao region.It comprises two satellites,named MSS-1A and MSS-1B,and holds considerable importance in China’s space exploration endeavors.Among these,MSS-1A is the world’s first high-precision scientific satellite dedicated to exploring the geomagnetic field and space environment at low latitudes.Equipped with two high-precision vector magnetometers and one scalar magnetometer,which are integrally installed on a highly stable nonmagnetic optical bench,the MSS-1A enables simultaneous high-precision measurements of both the Earth’s vector magnetic field and its scalar components.Its design integrates several state-of-the-art technologies,including arc-second-level thermal stability control,nonmagnetic thermal control for the optical bench,and ultra-high magnetic cleanliness control.These innovations effectively minimize magnetic interference originating from the satellite itself,thereby substantially improving the precision of geomagnetic field measurements and establishing a robust technical foundation for future magnetic survey satellite constellations.
基金Supported by Consultation and Evaluation Program on Academic Divisions of the Chinese Academy of Sciences(2022-DX02-B-007)。
文摘Since 2011,the Chinese Academy of Sciences(CAS)has implemented the Strategic Priority Program on Space Science(SPP).A series of scientific satellites have been developed and launched,such as Dark Matter Particle Explorer(DAMPE),Quantum Experiments at Space Scale(QUESS),Advanced Space-based Solar Observatory(ASO-S),Einstein Probe(EP),and significant scientific outcomes have been achieved.In order to plan the future space science missions in China,CAS has organized the Chinese space science community to conduct medium and long-term development strategy studies,and summarized the major scientific frontiers of space science as“One Black,Two Dark,Three Origins and Five Characterizations”.Five main scientific themes have been identified for China’s future breakthroughs,including the Extreme Universe,Space-Time Ripples,the Panoramic View of the Sun and Earth,the Habitable Planets,and Biological&Physical Science in Space.Space science satellite missions to be implemented before 2030 are proposed accordingly.
基金Supported by International Meridian Circle Program Headquarters,China-Brazil Joint Laboratory for Space Weather(Y42347A99S)。
文摘In 2024,the Chinese Meridian Project(CMP)completed its construction,deploying 282 instruments across 31 stations.This achievement not only provides a robust foundation but also serves as a reference template for the International Meridian Circle Program(IMCP).The IMCP aims to integrate and establish a comprehensive network of ground-based monitoring stations designed to track the propagation of space weather events from the Sun to Earth.Additionally,it monitors various disturbances generated within the Earth system that impact geospace.Over the past two years,significant progress has been made on the IMCP.In particular,the second phase of construction for the China-Brazil Joint Laboratory for Space Weather has been completed,and the North Pole and Southeast Asia networks are under active construction.The 2024 IMCP joint observation campaign was successfully conducted.To facilitate these developments,the scientific program committee of IMCP was established,following the success of 2023 IMCP workshop and the space weather school,which was co-hosted with the Asia-Pacific Space Cooperation Organization(APSCO)and sponsored by Chinese Academy of Sciences(CAS)and Scientific Committee on Solar-Terrestrial Physics(SCOSTEP).Preparations are now underway for the 2024 workshop in collaboration with the National Institute for Space Research(INPE)in Brazil.
文摘The National Space Science Center of the Chinese Academy of Sciences(NSSC,CAS),as the leading institute responsible for the overall management of scientific satellite missions in China,is China’s gateway to space science.NSSC is the cradle of China’s first artificial satellite“Dongfanghong-1”(DFH-1).In the course of more than 60 years’development,NSSC has led the implementation of“Double Star Program”,the first science-driven space mission in China,and successively implemented a fleet of scientific missions under the Strategic Priority Program on Space Science(Phase I and II),such as the Dark Matter Particle Explorer(DAMPE,or Wukong),the Quantum Experiments at Space Scale(QUESS,or Micius),the Hard X-ray Modulation Telescope(HXMT,or Insight),the Taiji-1,the Advanced space-based Solar Observatory(ASO-S,or Kuafu)and the Einstein Probe(EP).Currently,the space science satellite series has been established,yielding substantial scientific output.For the future,the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE),a China-ESA joint mission,will be launched in 2025.In addition,the newly released National Mid-and Long-term Program for Space Science Development in China(2024-2050),the first of its kind at the national level,has identified five key scientific themes.A fleet of future scientific missions revolving these themes will deepen mankind’s scientific understanding of the universe.
文摘The article briefly reviews the development history of space science in China,from the preparation period in the 1950s and 1960s,the first science mission Double Star Program(DSP),to the current Strategic Priority Program(SPP)on space science of the Chinese Academy of Sciences(CAS).Both science objectives and payload technologies of the missions are addressed.The key management issues,such as longterm planning and the maximization of science output,are also mentioned.In addition,it also stresses the importance of international cooperation in space science.
基金supported by Royal Society grant DHFR1211068funded by UKSA+14 种基金STFCSTFC grant ST/M001083/1funded by STFC grant ST/W00089X/1supported by NERC grant NE/W003309/1(E3d)funded by NERC grant NE/V000748/1support from NERC grants NE/V015133/1,NE/R016038/1(BAS magnetometers),and grants NE/R01700X/1 and NE/R015848/1(EISCAT)supported by NERC grant NE/T000937/1NSFC grants 42174208 and 41821003supported by the Research Council of Norway grant 223252PRODEX arrangement 4000123238 from the European Space Agencysupport of the AUTUMN East-West magnetometer network by the Canadian Space Agencysupported by NASA’s Heliophysics U.S.Participating Investigator Programsupport from grant NSF AGS 2027210supported by grant Dnr:2020-00106 from the Swedish National Space Agencysupported by the German Research Foundation(DFG)under number KR 4375/2-1 within SPP"Dynamic Earth"。
文摘The joint European Space Agency and Chinese Academy of Sciences Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission will explore global dynamics of the magnetosphere under varying solar wind and interplanetary magnetic field conditions,and simultaneously monitor the auroral response of the Northern Hemisphere ionosphere.Combining these large-scale responses with medium and fine-scale measurements at a variety of cadences by additional ground-based and space-based instruments will enable a much greater scientific impact beyond the original goals of the SMILE mission.Here,we describe current community efforts to prepare for SMILE,and the benefits and context various experiments that have explicitly expressed support for SMILE can offer.A dedicated group of international scientists representing many different experiment types and geographical locations,the Ground-based and Additional Science Working Group,is facilitating these efforts.Preparations include constructing an online SMILE Data Fusion Facility,the discussion of particular or special modes for experiments such as coherent and incoherent scatter radar,and the consideration of particular observing strategies and spacecraft conjunctions.We anticipate growing interest and community engagement with the SMILE mission,and we welcome novel ideas and insights from the solar-terrestrial community.
基金supported by the National Natural Science Foundation of China(No.82171599 and No.32270901)the National Key Research and Developmental Program of China(2022YFC2702601 and 2022YFA0806303)the Global Select Project(DJKLX-2022010)of the Institute of Health and Medicine,Hefei Comprehensive National Science Center.
文摘Male infertility can result from impaired sperm motility caused by multiple morphological abnormalities of the flagella(MMAF).Distinct projections encircling the central microtubules of the spermatozoal axoneme play pivotal roles in flagellar bending and spermatozoal movement.Mammalian sperm-associated antigen 17(SPAG17)encodes a conserved axonemal protein of cilia and flagella,forming part of the C1a projection of the central apparatus,with functions related to ciliary/flagellar motility,skeletal growth,and male fertility.This study investigated two novel homozygous SPAG17 mutations(M1:NM_206996.2,c.829+1G>T,p.Asp212_Glu276del;and M2:c.2120del,p.Leu707*)identified in four infertile patients from two consanguineous Pakistani families.These patients displayed the MMAF phenotype confirmed by Papanicolaou staining and scanning electron microscopy assays of spermatozoa.Quantitative real-time polymerase chain reaction(PCR)of patients’spermatozoa also revealed a significant decrease in SPAG17 mRNA expression,and immunofluorescence staining showed the absence of SPAG17 protein signals along the flagella.However,no apparent ciliary-related symptoms or skeletal malformations were observed in the chest X-rays of any of the patients.Transmission electron microscopy of axoneme cross-sections from the patients showed incomplete C1a projection and a higher frequency of missing microtubule doublets 1 and 9 compared with those from fertile controls.Immunofluorescence staining and Western blot analyses of spermatogenesis-associated protein 17(SPATA17),a component of the C1a projection,and sperm-associated antigen 6(SPAG6),a marker of the spring layer,revealed disrupted expression of both proteins in the patients’spermatozoa.Altogether,these findings demonstrated that SPAG17 maintains the integrity of spermatozoal flagellar axoneme,expanding the phenotypic spectrum of SPAG17 mutations in humans.
基金supported by the National Natural Science Foundation of China(Grant Nos.U21A2028,42022051,62275250,42030609,41627810,91644107,and 91544228).
文摘Atmospheric chemistry research and atmospheric measurement techniques have mutually promoted each other and developed rapidly in China in recent years.Cavity-based absorption spectroscopy,which uses a high-finesse cavity to achieve very long absorption path-length,thereby achieving ultra-high detection sensitivity,plays an extremely important role in atmospheric chemistry research.Based on the Beer–Lambert law,this technology has the unique advantages of being non-destructive,chemical-free,and highly selective.It does not require any sample preparation and can quantitatively analyze atmospheric trace gases in real time and in situ.In this paper,we review the following:(1)key technological advances in different cavity-based absorption spectroscopy techniques,including cavity ring-down spectroscopy,cavityenhanced absorption spectroscopy,cavity attenuated phase shift spectroscopy,and their extensions;and(2)applications of these techniques in the detection of atmospheric reactive species,such as total peroxy radical,formaldehyde,and reactive nitrogen(e.g.,NOx,HONO,peroxy nitrates,and alkyl nitrates).The review systematically introduces cavity-based absorption spectroscopy techniques and their applications in atmospheric chemistry,which will help promote further communication and cooperation in the fields of laser spectroscopy and atmospheric chemistry.
基金supported by the Hefei Comprehensive National Science Center Hefei Brain Project(to KW)the National Natural Science Foundation of China,Nos.31970979(to KW),82101498(to XW)the STI2030-Major Projects,No.2021ZD0201800(to PH).
文摘Alzheimer’s disease is a neurodegenerative disease resulting from deficits in synaptic transmission and homeostasis.The Alzheimer’s disease brain tends to be hyperexcitable and hypersynchronized,thereby causing neurodegeneration and ultimately disrupting the operational abilities in daily life,leaving patients incapacitated.Repetitive transcranial magnetic stimulation is a cost-effective,neuro-modulatory technique used for multiple neurological conditions.Over the past two decades,it has been widely used to predict cognitive decline;identify pathophysiological markers;promote neuroplasticity;and assess brain excitability,plasticity,and connectivity.It has also been applied to patients with dementia,because it can yield facilitatory effects on cognition and promote brain recovery after a neurological insult.However,its therapeutic effectiveness at the molecular and synaptic levels has not been elucidated because of a limited number of studies.This study aimed to characterize the neurobiological changes following repetitive transcranial magnetic stimulation treatment,evaluate its effects on synaptic plasticity,and identify the associated mechanisms.This review essentially focuses on changes in the pathology,amyloidogenesis,and clearance pathways,given that amyloid deposition is a major hypothesis in the pathogenesis of Alzheimer’s disease.Apoptotic mechanisms associated with repetitive transcranial magnetic stimulation procedures and different pathways mediating gene transcription,which are closely related to the neural regeneration process,are also highlighted.Finally,we discuss the outcomes of animal studies in which neuroplasticity is modulated and assessed at the structural and functional levels by using repetitive transcranial magnetic stimulation,with the aim to highlight future directions for better clinical translations.
基金supported by the National Key Research and Development Program of China,No.2021ZD0202503(to AHT)the National Natural Science Foundation of China,Nos.31872759(to AHT)and 32070707(to CF)+1 种基金Shenzhen Science and Technology Program,No.RCJC20210609104333007(to ZW)Shenzhen-Hong Kong Institute of Brain Science,Shenzhen Fundamental Research Institutions,No.2021SHIBS0002(to ZW).
文摘Morphological alterations in dendritic spines have been linked to changes in functional communication between neurons that affect learning and memory.Kinesin-4 KIF21A helps organize the microtubule-actin network at the cell cortex by interacting with KANK1;however,whether KIF21A modulates dendritic structure and function in neurons remains unknown.In this study,we found that KIF21A was distributed in a subset of dendritic spines,and that these KIF21A-positive spines were larger and more structurally plastic than KIF21A-negative spines.Furthermore,the interaction between KIF21A and KANK1 was found to be critical for dendritic spine morphogenesis and synaptic plasticity.Knockdown of either KIF21A or KANK1 inhibited dendritic spine morphogenesis and dendritic branching,and these deficits were fully rescued by coexpressing full-length KIF21A or KANK1,but not by proteins with mutations disrupting direct binding between KIF21A and KANK1 or binding between KANK1 and talin1.Knocking down KIF21A in the hippocampus of rats inhibited the amplitudes of long-term potentiation induced by high-frequency stimulation and negatively impacted the animals’cognitive abilities.Taken together,our findings demonstrate the function of KIF21A in modulating spine morphology and provide insight into its role in synaptic function.
基金supported by the NSFC (42374204, 42004143,42364012)the Project of Stable Support for Youth Team in Basic Research Field,Chinese Academy of Sciences (Grant No.YSBR-018)+3 种基金the Scientific Projects of Hainan Province(KJRC2023C05, ZDYF2021GXJS040)the Innovational Fund for Scientific and Technological Personnel of Hainan Provincethe Chinese Meridian ProjectPandeng Program of National Space Science Center,Chinese Academy of Sciences
文摘Physical and chemical processes observed in the mesosphere and thermosphere above the Earth’s low latitudes are complex and highly interrelated to activity in the low-latitude ionosphere.Metallic sodium detected by lidar can yield clues to dynamic and chemical processes in these spatial layers above the Earth’s atmosphere.This paper is based on sodium layer data collected at two low-latitude stations,one in the northern hemisphere and one in the southern.The low-latitude sodium layer exhibits conspicuous seasonal variations in shape,density,and altitude;these variations are similar between Earth’s hemispheres:sodium layer density at both stations reaches its seasonal maximum in autumn and minimum in summer.However,maximal Na density over Brazil is greater than that over Hainan.Nocturnal variations of Na density above the two low-latitude stations are also similar;at both,maxima are observed before sunrise.Some variations of the Na layer over Brazil that differ from those observed in the northern hemisphere may be related to the South Atlantic Magnetic Anomaly(SAMA)or fountain effect.We suggest that low-latitude Na layer data may provide useful additional evidence that could significantly improve the low-latitude part of the WACCM-Na model.
基金supported by the National Natural Science Foundation of China (Grant No.42394122)CAS Project of Stable Support for Youth Team in Basic Research Field (YSRR-018)+1 种基金the National Key R&D Program of China (2023YFC3007703)the Chinese Meridian Project, and the International Partnership Program of Chinese Academy of Sciences (183311KYSB20200003)。
文摘On 19 May 2022, an outbreak of 105 red sprites that occurred over South Asia was fortuitously recorded by two amateurs from a site in the southern Tibetan Plateau(TP), marking the highest number captured over a single thunderstorm in South Asia. Nearly half of these events involved dancing sprites, with an additional 16 uncommon secondary jets and at least four extremely rare green emissions called “ghosts” observed following the associated sprites. Due to the absence of the precise timing needed to identify parent lightning, a method based on satellite motion trajectories and star fields is proposed to infer video frame timestamps within an error of less than one second. After verifying 95 sprites from two videos, our method identified the parent lightning for 66 sprites(~70%). The sprite-producing strokes, mainly of positive polarity with peak currents exceeding +50 k A, occurred in the stratiform region of a mesoscale convective complex(MCC)that spanned the Ganges Plain to the southern TP, with a cloud area over 200 000 km2 and a minimum cloud-top black body temperature near 180 K. This observation confirms that thunderstorms in South Asia, akin to mesoscale convective systems(MCSs) in the Great Plains of the United States or coastal thunderstorms in Europe, can produce numerous sprites,including complex species. Our analysis bears important implications for characterizing thunderstorms above the southern TP and examining their physical and chemical effects on the adjacent regions, as well as the nature of the coupling between the troposphere and middle-upper atmosphere in this region.
基金This research was funded by Shaanxi Administration of Traditional Chinese Medicine Projects(2021-QYZL-01,2021-QYPT-001)Key R&D Project in Shaanxi Province(2023-YBSF-463)+1 种基金the Foundation of Science and Technology in Shaanxi Province(2020TD-050)the Fundamental Research Funds for the Central Universities(GK202205010).
文摘Background:The forest musk deer,a rare fauna species found in China,is famous for its musk secretion which is used in selected Traditional Chinese medicines.However,over-hunting has led to musk deer becoming an endangered species,and their survival is also greatly challenged by various high incidence and high mortality respiratory and intestinal diseases such as septic pneumonia and enteritis.Accumulating evidence has demonstrated that Akkermannia muciniphila(AKK)is a promising probiotic,and we wondered whether AKK could be used as a food additive in animal breeding pro-grammes to help prevent intestinal diseases.Methods:We isolated one AKK strain from musk deer feces(AKK-D)using an im-proved enrichment medium combined with real-time PCR.After confirmation by 16S rRNA gene sequencing,a series of in vitro tests was conducted to evaluate the probiotic effects of AKK-D by assessing its reproductive capability,simulated gas-trointestinal fluid tolerance,acid and bile salt resistance,self-aggregation ability,hy-drophobicity,antibiotic sensitivity,hemolysis,harmful metabolite production,biofilm formation ability,and bacterial adhesion to gastrointestinal mucosa.Results:The AKK-D strain has a probiotic function similar to that of the standard strain in humans(AKK-H).An in vivo study found that AKK-D significantly amelio-rated symptoms in the enterotoxigenic Escherichia coli(ETEC)-induced murine diar-rhea model.AKK-D improved organ damage,inhibited inflammatory responses,and improved intestinal barrier permeability.Additionally,AKK-D promoted the reconsti-tution and maintenance of the homeostasis of gut microflora,as indicated by the fact that AKK-D-treated mice showed a decrease in Bacteroidetes and an increase in the proportion of other beneficial bacteria like Muribaculaceae,Muribaculum,and unclas-sified f_Lachnospiaceae compared with the diarrhea model mice.Conclusion:Taken together,our data show that this novel AKK-D strain might be a potential probiotic for use in musk deer breeding,although further extensive system-atic research is still needed.
文摘Objective Autism spectrum disorder(ASD)is a neurodevelopmental condition characterized by difficulties with communication and social interaction,restricted and repetitive behaviors.Previous studies have indicated that individuals with ASD exhibit early and lifelong attention deficits,which are closely related to the core symptoms of ASD.Basic visual attention processes may provide a critical foundation for their social communication and interaction abilities.Therefore,this study explores the behavior of children with ASD in capturing attention to changes in topological properties.Methods Our study recruited twenty-seven ASD children diagnosed by professional clinicians according to DSM-5 and twenty-eight typically developing(TD)age-matched controls.In an attention capture task,we recorded the saccadic behaviors of children with ASD and TD in response to topological change(TC)and non-topological change(nTC)stimuli.Saccadic reaction time(SRT),visual search time(VS),and first fixation dwell time(FFDT)were used as indicators of attentional bias.Pearson correlation tests between the clinical assessment scales and attentional bias were conducted.Results This study found that TD children had significantly faster SRT(P<0.05)and VS(P<0.05)for the TC stimuli compared to the nTC stimuli,while the children with ASD did not exhibit significant differences in either measure(P>0.05).Additionally,ASD children demonstrated significantly less attention towards the TC targets(measured by FFDT),in comparison to TD children(P<0.05).Furthermore,ASD children exhibited a significant negative linear correlation between their attentional bias(measured by VS)and their scores on the compulsive subscale(P<0.05).Conclusion The results suggest that children with ASD have difficulty shifting their attention to objects with topological changes during change detection.This atypical attention may affect the child’s cognitive and behavioral development,thereby impacting their social communication and interaction.In sum,our findings indicate that difficulties in attentional capture by TC may be a key feature of ASD.
基金supported by the National Nature Science Foundation of China(12463009)the Yunnan Fundamental Research Projects(202301AV070007,202401AU070026)+2 种基金the"Yunnan Revitalization Talent Support Program"Innovation Team Project(202405AS350012)the Scientific Research Foundation Project of Yunnan Education Department(2023J0624,2024Y469)the GHfund A(202407016295)。
文摘Solar activity plays an important role in influencing space weather,making it important to understand numerous aspects of spatial and temporal variations in the Sun's radiative output.High-performance deep learning models and long-term observational records of sunspot relative numbers are essential for solar cycle forecasting.Using the multivariate time series of monthly sunspot relative numbers provided by the National Astronomical Observatory of Japan and two Informer-based models,we forecast the amplitude and timing of solar cycles 25 and 26.The main results are as follows:(1)The maximum amplitude of solar cycle 25 is higher than the previous solar cycle 24 and the following solar cycle 26,suggesting that the long-term oscillatory variation of sunspot magnetic fields is related to the roughly centennial Gleissberg cyclicity.(2)Solar cycles 25 and 26 exhibit a pronounced Gnevyshev gap,which might be caused by two non-coincident peaks resulting from solar magnetic flux transported by meridional circulation and mid-latitude diffusion in the convection zone.(3)Hemispheric prediction of sunspot activity reveals a significant northsouth asynchrony,with activity level of the Sun being more intense in the southern hemisphere.These results are consistent with expectations derived from precursor methods and dynamo theories,and further provide evidence for internal changes in solar magnetic field during the decay of the Modern Maximum.
基金Supported by the National Natural Science Foundation of China(42474239,41204128)China National Space Administration(Pre-research project on Civil Aerospace Technologies No.D010301)Strategic Priority Research Program of the Chinese Academy of Sciences(XDA17010303)。
文摘One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet(MBC,Active Asteroid)311P/PANSTARRS.This paper outlines the scientific objectives,measurement targets,and measurement requirements for the proposed Gas and Ion Analyzer(GIA).The GIA is designed for in-situ mass spectrometry of neutral gases and low-energy ions,such as hydrogen,carbon,and oxygen,in the vicinity of 311P.Ion sampling techniques are essential for the GIA's Time-of-Flight(TOF)mass analysis capabilities.In this paper,we present an enhanced ion sampling technique through the development of an ion attraction model and an ion source model.The ion attraction model demonstrates that adjusting attraction grid voltage can enhance the detection efficiency of low-energy ions and mitigate the repulsive force of ions during sampling,which is influenced by the satellite's surface positive charging.The ion source model simulates the processes of gas ionization and ion multiplication.Simulation results indicate that the GIA can achieve a lower pressure limit below 10-13Pa and possess a dynamic range exceeding 10~9.These performances ensure the generation of ions with stable and consistent current,which is crucial for high-resolution and broad dynamic range mass spectrometer analysis.Preliminary testing experiments have verified GIA's capability to detect gas compositions such as H2O and N2.In-situ measurements near 311P using GIA are expected to significantly contribute to our understanding of asteroid activity mechanisms,the evolution of the atmospheric and ionized environments of main-belt comets,the interactions with solar wind,and the origin of Earth's water.
基金Supported by the Beijing Municipal Science&Technology Commission(Z211100004421012),the Key Reaserch and Development Pro⁃gram of China(2022YFF0605902)。
文摘In this paper,a linear optimization method(LOM)for the design of terahertz circuits is presented,aimed at enhancing the simulation efficacy and reducing the time of the circuit design workflow.This method enables the rapid determination of optimal embedding impedance for diodes across a specific bandwidth to achieve maximum efficiency through harmonic balance simulations.By optimizing the linear matching circuit with the optimal embedding impedance,the method effectively segregates the simulation of the linear segments from the nonlinear segments in the frequency multiplier circuit,substantially improving the speed of simulations.The design of on-chip linear matching circuits adopts a modular circuit design strategy,incorporating fixed load resistors to simplify the matching challenge.Utilizing this approach,a 340 GHz frequency doubler was developed and measured.The results demonstrate that,across a bandwidth of 330 GHz to 342 GHz,the efficiency of the doubler remains above 10%,with an input power ranging from 98 mW to 141mW and an output power exceeding 13 mW.Notably,at an input power of 141 mW,a peak output power of 21.8 mW was achieved at 334 GHz,corresponding to an efficiency of 15.8%.
基金partially supported by Natural Science Research Project of Anhui Educational Committee (Nos.KJ2021A1168,KJ2021A1169 and 2024AH050620)University Synergy Innovation Program of Anhui Province (No.GXXT-2022-026)University-Industry Cooperation Practical Education Base Project (No.2022xqjdx04)。
文摘An atmospheric pressure plasma jet(APPJ)approach is developed to prepare platinum nanoparticles(PtNPs)under mild reaction conditions of lower temperatures and without adding chemical reagents.Optical Emission Spectroscopy(OES)and X-ray Photoelectron Spectroscopy(XPS)tests revealed that the APPJ contains a large number of high-energy active particles,which can generate solvated electrons in liquid thereby promoting the rapid reduction of Pt(Ⅳ)ions into Pt(0)atoms,and these atoms gradually grow into nanoparticles.After 3 min of treatment,PtNPs exhibit excellent dispersibility with a particle size distribution ranging from 1.8 to 2.8 nm.After 5 min,the particle size increases,and aggregation occurs.The zeta potentials for the two situations were-56.0 mV and-12.5 mV respectively.The results indicate that the treatment time has a significant impact on the dispersion,particle size distribution,and sol stability of the nanoparticles.Furthermore,it reveals the formation mechanism of PtNPs prepared by APPJ,which involves the generation and expansion of nanocrystalline nuclei,and the construction of negatively charged colloidal particles.The overall mechanism highlights the importance of the plasma-liquid interaction in the synthesis of PtNPs,offering a new perspective on the controllable production of nanomaterials using plasma technology.
基金Supported by the National Natural Science Foundation of China,No.82002940 and No.82203336Shaanxi Natural Science Foundation,No.2023-JC-YB-166.
文摘BACKGROUND Hepatocellular carcinoma(HCC)ranks among the most prevalent and deadly malignancies,characterized by a high recurrence rate.Regulator of chromosome condensation 1(RCC1)serves as a principal guanine nucleotide exchange factor for ras-related nuclear protein guanosine triphosphatase(GTPase)and is implicated in various cancers.However,the role of RCC1 in HCC remains unex-plored.AIM To elucidate the functional significance and molecular mechanisms of RCC1 in HCC.METHODS Bioinformatics were to examine the expression levels of RCC1 in HCC and to assess its impact on the prognosis of this malignancy.The cell counting kit-8 assay and flow cytometry were utilized to evaluate the cell viability and cell cycle of HCC cells.Furthermore,quantitative reverse transcription and immunoblotting were to investigate the influence of RCC1 on cyclin associated proteins.RESULTS Bioinformatics analysis revealed that RCC1 was highly expressed in HCC and correlated with poor prognosis in HCC patients.Functional studies showed that RCC1 overexpression promoted the malignant phenotype of HCC cells,especially the proliferation of HCC cells,whereas RCC1 knockdown had the opposite effect.Mechanistically,we identied cell division cycle-associated(CDCA)8 as a downstream target of RCC1 in HCC.RCC1 overexpression markedly increased CDCA8 levels,consequently enhancing cell proliferation and survival in HCC cells.Additionally,we discovered that RCC1 contributed to the development and progression of HCC by activating the phosphoinositide 3-kinase/protein kinase B/cyclin-dependent kinase inhibitor 1a pathway through CDCA8.CONCLUSION Our study provides profound insights into the pivotal role of RCC1 in HCC and its potential as a therapeutic target.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12134012 and 12104433)。
文摘We investigate the hole-doped Hubbard model on a honeycomb lattice using a fermionic projected entangled pair states(f PEPS)method.Our study reveals the presence of quasi-long-range order of Cooper pairs,characterized by powerlaw decay of correlation functions with exponents K>1.We further analyze the competing phases of superconductivity,specifically the antiferromagnetic(AFM)order and the charge density wave(CDW)order.Our results show that there are domain wall structures when the hole dopingδis small and the Coulomb parameter U is large.However,these structures disappear as we increase the hole dopingδor decrease U.Furthermore,for small hole doping,the system exhibits AFM order,which diminishes forδ>0.05.Conversely,as the doping level increases,the CDW order gradually decreases.Notably,a considerable CDW order persists even at higher doping levels.These findings suggest a progressive suppression of the AFM order and a growing prominence of the CDW order with increasingδ.
