The effect of plasma and charged particle interaction with spacecraft in a low Earth orbit(LEO)environment leads to ion focusing and the formation of an ion void in the downstream region as a result of charging.Simula...The effect of plasma and charged particle interaction with spacecraft in a low Earth orbit(LEO)environment leads to ion focusing and the formation of an ion void in the downstream region as a result of charging.Simulations and investigations using a fixed potential imposed on the spacecraft showed the nonsignificance of geophysical parameter changes to ion focusing.Variation of the temperature ratio(T_(r))contributed only to local ion focusing and manifested as two-ion streamers dispersed at the upper and lower edges of the spacecraft-the outermost layers of the satellite structure at the top and bottom,respectively.A simulation involving changing the ambient plasma density(N_(p))also showed the formation of local ion focusing,in which ions were more concentrated as the density increased.Furthermore,auroral electron density(N_(ae))variation had no clear impact on ion focusing,as indicated by static two-ion structures in the wake field.However,variation of the object potential(ϕ)strongly affected ion focusing formation,leading to distortion of the initial ion void region behind the spacecraft.The formation of ion focusing in this study was subject to the electric field produced by the object potential and the ambipolar electric field resulting from plasma expansion in the downstream region.展开更多
Given the scarcity of Satellite Frequency and Orbit(SFO)resources,it holds paramount importance to establish a comprehensive knowledge graph of SFO field(SFO-KG)and employ knowledge reasoning technology to automatical...Given the scarcity of Satellite Frequency and Orbit(SFO)resources,it holds paramount importance to establish a comprehensive knowledge graph of SFO field(SFO-KG)and employ knowledge reasoning technology to automatically mine available SFO resources.An essential aspect of constructing SFO-KG is the extraction of Chinese entity relations.Unfortunately,there is currently no publicly available Chinese SFO entity Relation Extraction(RE)dataset.Moreover,publicly available SFO text data contain numerous NA(representing for“No Answer”)relation category sentences that resemble other relation sentences and pose challenges in accurate classification,resulting in low recall and precision for the NA relation category in entity RE.Consequently,this issue adversely affects both the accuracy of constructing the knowledge graph and the efficiency of RE processes.To address these challenges,this paper proposes a method for extracting Chinese SFO text entity relations based on dynamic integrated learning.This method includes the construction of a manually annotated Chinese SFO entity RE dataset and a classifier combining features of SFO resource data.The proposed approach combines integrated learning and pre-training models,specifically utilizing Bidirectional Encoder Representation from Transformers(BERT).In addition,it incorporates one-class classification,attention mechanisms,and dynamic feedback mechanisms to improve the performance of the RE model.Experimental results show that the proposed method outperforms the traditional methods in terms of F1 value when extracting entity relations from both balanced and long-tailed datasets.展开更多
Unraveling the essence of electronic structure effected by d-d orbital coupling of transition metal and methanol oxidation reaction(MOR)performance can fundamentally guide high efficient catalyst design.Herein,density...Unraveling the essence of electronic structure effected by d-d orbital coupling of transition metal and methanol oxidation reaction(MOR)performance can fundamentally guide high efficient catalyst design.Herein,density functional theory(DFT)calculations were performed at first to study the d–d orbital interaction of metallic Pt Pd Cu,revealing that the incorporation of Pd and Cu atoms into Pt system can enhance d-d electron interaction via capturing antibonding orbital electrons of Pt to fill the surrounding Pd and Cu atoms.Under the theoretical guidance,Pt Pd Cu medium entropy alloy aerogels(Pt Pd Cu MEAAs)catalysts have been designed and systematically screened for MOR under acid,alkaline and neutral electrolyte.Furthermore,DFT calculation and in-situ fourier transform infrared spectroscopy analysis indicate that Pt Pd Cu MEAAs follow the direct pathway via formate as the reactive intermediate to be directly oxidized to CO_(2).For practical direct methanol fuel cells(DMFCs),the Pt Pd Cu MEAAs-integrated ultra-thin catalyst layer(4–5μm thickness)as anode exhibits higher peak power density of 35 m W/cm^(2) than commercial Pt/C of 20 m W/cm^(2)(~40μm thickness)under the similar noble metal loading and an impressive stability retention at a 50-m A/cm^(2) constant current for 10 h.This work clearly proves that optimizing the intermediate adsorption capacity via d-d orbital coupling is an effective strategy to design highly efficient catalysts for DMFCs.展开更多
By introducing noncanonical vortex pairs to partially coherent beams, spatial correlation singularity (SCS) and orbital angular momenta (OAM) of the resulting beams are studied using the Fraunhofer diffraction integra...By introducing noncanonical vortex pairs to partially coherent beams, spatial correlation singularity (SCS) and orbital angular momenta (OAM) of the resulting beams are studied using the Fraunhofer diffraction integral. The effect of noncanonical strength, off-axis distance and vortex sign on spatial correlation singularities in far field is stressed. Furthermore, far-field OAM spectra and densities are also investigated, and the OAM detection and crosstalk probabilities are discussed. The results show that the number of dislocations of SCS always equals the sum of absolute values of topological charges for canonical or noncanonical vortex pairs. Although the sum of the product of each OAM mode and its power weight equals the algebraic sum of topological charges for canonical vortex pairs, the relationship no longer holds in the noncanonical case except for opposite-charge vortex pairs. The changes of off-axis distance, noncanonical strength or coherence length can lead to a more dominant power in adjacent mode than that in center detection mode, which also indicates that crosstalk probabilities of adjacent modes exceed the center detection probability. This work may provide potential applications in OAM-based optical communication, imaging, sensing and computing.展开更多
目的建立超高效液相色谱-四极杆-静电场轨道阱高分辨质谱法(ultra performance liquid chromatography quadrupole electrostatic field orbital trap high-resolution mass spectrometry,UPLC-Q-Orbitrap HRMS)筛查保健食品原料中30种...目的建立超高效液相色谱-四极杆-静电场轨道阱高分辨质谱法(ultra performance liquid chromatography quadrupole electrostatic field orbital trap high-resolution mass spectrometry,UPLC-Q-Orbitrap HRMS)筛查保健食品原料中30种植物生长调节剂的方法。方法样品经QuEChERS法提取和净化后,在一级母离子全扫描及数据依赖的二级子离子(Full MS/dd-MS2)模式下同时采集正负离子数据。样品检测结果经自建的植物生长调节剂高分辨质谱数据库进行筛查,筛查出的化合物以母离子精确质量数的峰面积进行定量,保留时间和二级碎片离子进行定性确证。结果30种植物生长调节剂的一级母离子的质量偏差绝对值均低于3 ppm,在相应线性范围内线性关系良好(r2≥0.999),方法检出限为0.2~34.0μg/kg,3类不同样品(党参、巴戟天、金银花)中30种植物生长调节剂的平均回收率分别为68.5%~110.1%、65.8%~105.6%和64.7%~106.5%,相对标准偏差(relative standard deviations,RSDs)分别为1.5%~9.2%、1.3%~9.6%和1.4%~10.7%。结论该方法前处理简单、净化效果好、高效、准确,适用于保健食品原料中植物生长调节剂的快速筛查检测。展开更多
Surface chemistry plays a critical role in the fields of electrochemistry,heterogeneous catalysis,adsorption,etc.[1–4].The representative D-band center theory reported through Hammer and Nørskov in surface chemi...Surface chemistry plays a critical role in the fields of electrochemistry,heterogeneous catalysis,adsorption,etc.[1–4].The representative D-band center theory reported through Hammer and Nørskov in surface chemistry has been widely used in early studies to predict adsorption strength[5,6].Generally,the adsorption strength of active sites correlates inversely with the downward shift of the D-band center(εd)relative to the Fermi level,as lower-energy positioning increases anti-bonding orbital occupancy,weakening surface interactions(Fig.1(a)).展开更多
To address uncertainties in satellite orbit error prediction,this study proposes a novel ensemble learning-based orbit prediction method specifically designed for the BeiDou navigation satellite system(BDS).Building o...To address uncertainties in satellite orbit error prediction,this study proposes a novel ensemble learning-based orbit prediction method specifically designed for the BeiDou navigation satellite system(BDS).Building on ephemeris data and perturbation corrections,two new models are proposed:attention-enhanced BPNN(AEBP)and Transformer-ResNet-BiLSTM(TR-BiLSTM).These models effectively capture both local and global dependencies in satellite orbit data.To further enhance prediction accuracy and stability,the outputs of these two models were integrated using the gradient boosting decision tree(GBDT)ensemble learning method,which was optimized through a grid search.The main contribution of this approach is the synergistic combination of deep learning models and GBDT,which significantly improves both the accuracy and robustness of satellite orbit predictions.This model was validated using broadcast ephemeris data from the BDS-3 MEO and inclined geosynchronous orbit(IGSO)satellites.The results show that the proposed method achieves an error correction rate of 65.4%.This ensemble learning-based approach offers a highly effective solution for high-precision and stable satellite orbit predictions.展开更多
AIM:To describe the clinical manifestations,imaging features and surgical treatments in 5 cases of extraocular muscle(EOM)dysplasia presenting as orbital spaceoccupying lesions(SOL).METHODS:Records from the 5 cases wi...AIM:To describe the clinical manifestations,imaging features and surgical treatments in 5 cases of extraocular muscle(EOM)dysplasia presenting as orbital spaceoccupying lesions(SOL).METHODS:Records from the 5 cases with EOM dysplasia between 2004 and 2016 were retrospectively reviewed and clinical data were recorded including family history,age at onset,age at surgery,visual acuity,cycloplegic refraction,ocular alignment and motility,stereoacuity,exophthalmos,anterior segment and fundus,orbital computed tomography(CT)or magnetic resonance imaging(MRI)scan,surgical methods and final outcomes.RESULTS:All 5 cases(1 male,4 females)were unilateral(3 right,2 left eyes).The average age was 5.4y(range 4-6y)with no family history.Patients had unilateral strabismus(horizontal and vertical),restricted eye movement,and eyelid changes(abnormal fissures,lagophthalmos,and/or entropion)in the affected eye.None had proptosis;1 had 2-mm enophthalmos.Orbital CT/MRI showed irregular,ill-defined masses in EOM.Two anterior orbitotomies and 3 strabismus surgeries were performed,and pathology confirmed EOM dysplasia.After surgery,horizontal deviations,which ranged from exotropia(XT)10 prism diopter(PD)to esotropia(ET)10 PD(average 6 PD),decreased by an average of 18 PD,while vertical deviations,which ranged from 4 PD to 20 PD(mean 9.8 PD),decreased by an average of 23.2 PD.CONCLUSION:SOL from EOM dysplasia is non-familial and typically presenting unilaterally characterized by an irregular,diffusely infiltrating mass within the EOM.EOM involvement causes strabismus,restricted eye movement,eyelid changes,and enophthalmos likely due to cicatricial processes.展开更多
In this paper,the problem of brake orbits with minimal period estimates are considered for the first-order Hamiltonian systems with anisotropic growth,i.e.,the Hamiltonian functions may have super-quadratic,sub-quadra...In this paper,the problem of brake orbits with minimal period estimates are considered for the first-order Hamiltonian systems with anisotropic growth,i.e.,the Hamiltonian functions may have super-quadratic,sub-quadratic and quadratic behaviors simultaneously in different variable components.展开更多
It is widely known that the hypervelocity impact of orbital debris can cause serious damage to spacecraft,and enhancing the impact resistance is the great concern of spacecraft shield design.This paper provides a comp...It is widely known that the hypervelocity impact of orbital debris can cause serious damage to spacecraft,and enhancing the impact resistance is the great concern of spacecraft shield design.This paper provides a comprehensive overview of advances in the development of bumper materials for spacecraft shield applications.In particular,the protective mechanism and process of the bumper using different materials against hypervelocity impact are reviewed and discussed.The advantages and disadvantages of each material used in shield were discussed,and the performance under hypervelocity impact was given according to the specific configuration.This review provides the useful reference and basis for researchers and engineers to create bumper materials for spacecraft shield applications,and the contemporary challenges and future directions for bumper materials for spacecraft shield were presented.展开更多
The hybridization between oxygen 2p and transition-metal 3d states largely determines the electronic structure near the Fermi level and related functionalities of transition-metal oxides(TMOs).Considerable efforts hav...The hybridization between oxygen 2p and transition-metal 3d states largely determines the electronic structure near the Fermi level and related functionalities of transition-metal oxides(TMOs).Considerable efforts have been made to manipulate the p-d hybridization in TMOs by tailoring the spatial orbital overlap via structural engineering.Here,we demonstrate enhanced p-d hybridization in Ba^(2+)-doped LaNiO_(3)epitaxial films by simultaneously modifying both the spatial and energetic overlaps between the O-2p and Ni-3d orbitals.Combining x-ray absorption spectroscopy and firstprinciples calculations,we reveal that the enhanced hybridization stems from the synergistic effects of a reduced chargetransfer energy due to hole injection and an increased spatial orbital overlap due to straightening of Ni-O-Ni bonds.We further show that the enhanced p-d hybridization can be utilized to promote the oxygen evolution activity of LaNiO_(3).This work sheds new insights into the fine-tuning of the electronic structures of TMOs for enhanced functionalities.展开更多
The factors controlling dust activity and humidity in Central Asia and their relationships remain controversial,partly due to a lack of high-resolution geological records for the mid-to-late last glaciation.In this st...The factors controlling dust activity and humidity in Central Asia and their relationships remain controversial,partly due to a lack of high-resolution geological records for the mid-to-late last glaciation.In this study,we established an optically stimulated luminescence chronology for the QSHA profile in the Yili Basin,a region influenced by westerlies.Grain size and trace element data were used as paleoclimatic indicators.We investigated the relationships among Central Asian dust activity,humidity,and westerlies strength on orbital to millennial scale from 37.4 ka to 11.6 ka.Our study reveals that,on orbital timescales,humidity is positively correlated with westerlies strength which controlled by precession.Dust activity is controlled by Siberian High which was regulated by Northern Hemisphere high-latitude temperature.Their responses to low-latitude and high-latitude forcing mechanisms respectively and present an opposite relationship.On millennial timescales,humidity and westerlies strength are positively correlated.During Marine Isotope Stage(MIS)2,humidity and dust activity show synchronous fluctuations,while during MIS 3,they exhibit an inverse relationship.Westerlies strength regulated humidity,which subsequently controlled glacial activity in the Tianshan Mountains,influencing dust activity in Central Asia.Additionally,the QSHA profile recorded seven Dansgaard-Oeschger(D-O)events on millennial timescales,indicating a potential link between Central Asian dust activity and high-latitude temperature variations in the Northern Hemisphere.Our findings provide new insights into dust and humidity interaction during the last glaciation periods in Central Asia and contribute to understanding global dust and hydrological cycles.展开更多
Orbital disorders include conditions originating from the orbital bones,surrounding tissues,and post-orbital septum.They also include systemic ailments affecting the orbit.Different clinical symptoms make up the compl...Orbital disorders include conditions originating from the orbital bones,surrounding tissues,and post-orbital septum.They also include systemic ailments affecting the orbit.Different clinical symptoms make up the complex range of orbital disorders.Because these disorders mostly impact the orbital area instead of the intraocular compartment,there is little diagnostic usefulness for typical ophthalmic visual tests.As such,the vital instruments for diagnosing and evaluating orbital illnesses have become ophthalmic imaging modalities,including ocular ultrasonography(B-scan),computed tomography(CT),and magnetic resonance imaging(MRI).One way to improve the precision and promptness of diagnosing orbital diseases is to standardize the functioning of widely used imaging equipment and define the radiological features of orbital abnormalities.Such programs are crucial for the care of patients with orbital disorders since they considerably reduce the number of misdiagnoses and missed diagnoses in these individuals.The underlying concepts,operational techniques,and normal and pathological imaging findings associated with common diagnostic tools for orbital illnesses are all thoroughly reviewed in this guideline.The objective is to improve primary healthcare settings’diagnostic competence in the field of orbital pathology and to standardize procedures for diagnosing orbital disorders.展开更多
This paper proposes a novel impulsive thrust strategy guided by optimal continuous thrust strategy to address two-player orbital pursuit-evasion game under impulsive thrust control.The strategy seeks to enhance the in...This paper proposes a novel impulsive thrust strategy guided by optimal continuous thrust strategy to address two-player orbital pursuit-evasion game under impulsive thrust control.The strategy seeks to enhance the interpretability of impulsive thrust strategy by integrating it within the framework of differential game in traditional continuous systems.First,this paper introduces an impulse-like constraint,with periodical changes in thrust amplitude,to characterize the impulsive thrust control.Then,the game with the impulse-like constraint is converted into the two-point boundary value problem,which is solved by the combined shooting and deep learning method proposed in this paper.Deep learning and numerical optimization are employed to obtain the guesses for unknown terminal adjoint variables and the game terminal time.Subsequently,the accurate values are solved by the shooting method to yield the optimal continuous thrust strategy with the impulse-like constraint.Finally,the shooting method is iteratively employed at each impulse decision moment to derive the impulsive thrust strategy guided by the optimal continuous thrust strategy.Numerical examples demonstrate the convergence of the combined shooting and deep learning method,even if the strongly nonlinear impulse-like constraint is introduced.The effect of the impulsive thrust strategy guided by the optimal continuous thrust strategy is also discussed.展开更多
This study aimed to investigate the impact of administration routes in establishing the Adriamycin(ADR)-induced chronic kidney disease(CKD)model.Using BALB/c mice,we compared the effects of conventional tail-vein inje...This study aimed to investigate the impact of administration routes in establishing the Adriamycin(ADR)-induced chronic kidney disease(CKD)model.Using BALB/c mice,we compared the effects of conventional tail-vein injection(TV10,10 mg/kg)to those of retro-orbital sinus(orbital vein)injection(OV10,10 mg/kg;OV8,8 mg/kg).The re-sults indicated that the OV10 group exhibited CKD pathology similar to the TV10 group,with both groups demonstrating significantly higher urinary albumin/creatinine ratio(p<0.05),tubular injury(p<0.05),and degree of renal fibrosis(p<0.05)than the OV8 group.No significant differences were observed between the OV10 and TV10 groups in urinary albumin/creatinine ratio,tubular injury,and degree of renal fibrosis.These findings demonstrated that retro-orbital administration of 10 mg/kg ADR in-duces comparable effects to conventional tail-vein administration.This technique's technical simplicity may improve experimental efficiency,reproducibility,and animal welfare in CKD research.In conclusion,this study validates the utility of retro-orbital injection in CKD model establishment,demonstrating its potential to standardize and improve the reliability of future CKD research protocols.展开更多
It is known that monotone recurrence relations can induce a class of twist homeomorphisms on the high-dimensional cylinder,which is an extension of the class of monotone twist maps on the annulus or two-dimensional cy...It is known that monotone recurrence relations can induce a class of twist homeomorphisms on the high-dimensional cylinder,which is an extension of the class of monotone twist maps on the annulus or two-dimensional cylinder.By constructing a bounded solution of the monotone recurrence relation,the main conclusion in this paper is acquired:The induced homeomorphism has Birkhoff orbits provided there is a compact forward-invariant set.Therefore,it generalizes Angenent's results in low-dimensional cases.展开更多
AIM:To evaluate the efficacy of combined orbital radiation and periorbital triamcinolone acetonide injection for patients with Graves’orbitopathy(GO)who experienced treatment failure with glucocorticoid pulse therapy...AIM:To evaluate the efficacy of combined orbital radiation and periorbital triamcinolone acetonide injection for patients with Graves’orbitopathy(GO)who experienced treatment failure with glucocorticoid pulse therapy(GPT).METHODS:A total of 57 eligible patients(35.09%males,mean age of 51.19±11.90y)were included in this case-series study.The medical information collected during each visit was evaluated and analyzed.RESULTS:Significant improvement was observed in patients six months after radiation therapy.Both the clinical activity score and the efficacy score showed substantial improvement(P<0.001).Furthermore,there was significant resolution of extraocular muscle inflammation on magnetic resonance imaging at three and six months after radiation therapy.The initial high signal intensity ratio(SIR)max was found to be associated with greater improvement in SIR sum(P<0.001,B=2.002,95%CI:1.377 to 2.628),while the presence of sight-threatening stage or moderate to severe diplopia negatively influenced the improvement of SIR sum(P=0.045,0.008,0.006;B=-1.966,-1.478,-0.997;95%CI:-3.886 to-0.045,-2.552 to-0.403,-1.694 to-0.300;respectively).CONCLUSION:The combination therapy demonstrates significant effectiveness in treating patients with GO who experienced severe ocular inflammation and have previous GPT failure.Noticeable improvement is observed as early as one month after initiating radiation therapy,and patients with more severe inflammatory states showes greater benefit from the treatment.展开更多
文摘The effect of plasma and charged particle interaction with spacecraft in a low Earth orbit(LEO)environment leads to ion focusing and the formation of an ion void in the downstream region as a result of charging.Simulations and investigations using a fixed potential imposed on the spacecraft showed the nonsignificance of geophysical parameter changes to ion focusing.Variation of the temperature ratio(T_(r))contributed only to local ion focusing and manifested as two-ion streamers dispersed at the upper and lower edges of the spacecraft-the outermost layers of the satellite structure at the top and bottom,respectively.A simulation involving changing the ambient plasma density(N_(p))also showed the formation of local ion focusing,in which ions were more concentrated as the density increased.Furthermore,auroral electron density(N_(ae))variation had no clear impact on ion focusing,as indicated by static two-ion structures in the wake field.However,variation of the object potential(ϕ)strongly affected ion focusing formation,leading to distortion of the initial ion void region behind the spacecraft.The formation of ion focusing in this study was subject to the electric field produced by the object potential and the ambipolar electric field resulting from plasma expansion in the downstream region.
文摘Given the scarcity of Satellite Frequency and Orbit(SFO)resources,it holds paramount importance to establish a comprehensive knowledge graph of SFO field(SFO-KG)and employ knowledge reasoning technology to automatically mine available SFO resources.An essential aspect of constructing SFO-KG is the extraction of Chinese entity relations.Unfortunately,there is currently no publicly available Chinese SFO entity Relation Extraction(RE)dataset.Moreover,publicly available SFO text data contain numerous NA(representing for“No Answer”)relation category sentences that resemble other relation sentences and pose challenges in accurate classification,resulting in low recall and precision for the NA relation category in entity RE.Consequently,this issue adversely affects both the accuracy of constructing the knowledge graph and the efficiency of RE processes.To address these challenges,this paper proposes a method for extracting Chinese SFO text entity relations based on dynamic integrated learning.This method includes the construction of a manually annotated Chinese SFO entity RE dataset and a classifier combining features of SFO resource data.The proposed approach combines integrated learning and pre-training models,specifically utilizing Bidirectional Encoder Representation from Transformers(BERT).In addition,it incorporates one-class classification,attention mechanisms,and dynamic feedback mechanisms to improve the performance of the RE model.Experimental results show that the proposed method outperforms the traditional methods in terms of F1 value when extracting entity relations from both balanced and long-tailed datasets.
基金financially supported by the National Natural Science Foundation of China(Nos.52073214 and 22075211)Guangxi Natural Science Fund for Distinguished Young Scholars(No.2024GXNSFFA010008)+5 种基金Natural Science Foundation of Shandong Province(Nos.ZR2023MB049 and ZR2021QB129)China Postdoctoral Science Foundation(No.2020M670483)Science Foundation of Weifang University(No.2023BS11)supported by the open research fund of the Laboratory of Xinjiang Native Medicinal and Edible Plant Resources Chemistry at Kashi Universitysupported by the Tianhe Qingsuo Open Research Fund of TSYS in 2022 and NSCC-TJNankai University Large-scale Instrument Experimental Technology R&D Project(No.21NKSYJS09)。
文摘Unraveling the essence of electronic structure effected by d-d orbital coupling of transition metal and methanol oxidation reaction(MOR)performance can fundamentally guide high efficient catalyst design.Herein,density functional theory(DFT)calculations were performed at first to study the d–d orbital interaction of metallic Pt Pd Cu,revealing that the incorporation of Pd and Cu atoms into Pt system can enhance d-d electron interaction via capturing antibonding orbital electrons of Pt to fill the surrounding Pd and Cu atoms.Under the theoretical guidance,Pt Pd Cu medium entropy alloy aerogels(Pt Pd Cu MEAAs)catalysts have been designed and systematically screened for MOR under acid,alkaline and neutral electrolyte.Furthermore,DFT calculation and in-situ fourier transform infrared spectroscopy analysis indicate that Pt Pd Cu MEAAs follow the direct pathway via formate as the reactive intermediate to be directly oxidized to CO_(2).For practical direct methanol fuel cells(DMFCs),the Pt Pd Cu MEAAs-integrated ultra-thin catalyst layer(4–5μm thickness)as anode exhibits higher peak power density of 35 m W/cm^(2) than commercial Pt/C of 20 m W/cm^(2)(~40μm thickness)under the similar noble metal loading and an impressive stability retention at a 50-m A/cm^(2) constant current for 10 h.This work clearly proves that optimizing the intermediate adsorption capacity via d-d orbital coupling is an effective strategy to design highly efficient catalysts for DMFCs.
文摘By introducing noncanonical vortex pairs to partially coherent beams, spatial correlation singularity (SCS) and orbital angular momenta (OAM) of the resulting beams are studied using the Fraunhofer diffraction integral. The effect of noncanonical strength, off-axis distance and vortex sign on spatial correlation singularities in far field is stressed. Furthermore, far-field OAM spectra and densities are also investigated, and the OAM detection and crosstalk probabilities are discussed. The results show that the number of dislocations of SCS always equals the sum of absolute values of topological charges for canonical or noncanonical vortex pairs. Although the sum of the product of each OAM mode and its power weight equals the algebraic sum of topological charges for canonical vortex pairs, the relationship no longer holds in the noncanonical case except for opposite-charge vortex pairs. The changes of off-axis distance, noncanonical strength or coherence length can lead to a more dominant power in adjacent mode than that in center detection mode, which also indicates that crosstalk probabilities of adjacent modes exceed the center detection probability. This work may provide potential applications in OAM-based optical communication, imaging, sensing and computing.
文摘目的建立超高效液相色谱-四极杆-静电场轨道阱高分辨质谱法(ultra performance liquid chromatography quadrupole electrostatic field orbital trap high-resolution mass spectrometry,UPLC-Q-Orbitrap HRMS)筛查保健食品原料中30种植物生长调节剂的方法。方法样品经QuEChERS法提取和净化后,在一级母离子全扫描及数据依赖的二级子离子(Full MS/dd-MS2)模式下同时采集正负离子数据。样品检测结果经自建的植物生长调节剂高分辨质谱数据库进行筛查,筛查出的化合物以母离子精确质量数的峰面积进行定量,保留时间和二级碎片离子进行定性确证。结果30种植物生长调节剂的一级母离子的质量偏差绝对值均低于3 ppm,在相应线性范围内线性关系良好(r2≥0.999),方法检出限为0.2~34.0μg/kg,3类不同样品(党参、巴戟天、金银花)中30种植物生长调节剂的平均回收率分别为68.5%~110.1%、65.8%~105.6%和64.7%~106.5%,相对标准偏差(relative standard deviations,RSDs)分别为1.5%~9.2%、1.3%~9.6%和1.4%~10.7%。结论该方法前处理简单、净化效果好、高效、准确,适用于保健食品原料中植物生长调节剂的快速筛查检测。
文摘Surface chemistry plays a critical role in the fields of electrochemistry,heterogeneous catalysis,adsorption,etc.[1–4].The representative D-band center theory reported through Hammer and Nørskov in surface chemistry has been widely used in early studies to predict adsorption strength[5,6].Generally,the adsorption strength of active sites correlates inversely with the downward shift of the D-band center(εd)relative to the Fermi level,as lower-energy positioning increases anti-bonding orbital occupancy,weakening surface interactions(Fig.1(a)).
基金funded by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA28040300)Project for Guangxi Science and Technology Base,and Talents(Grant No.GK AD22035957)+1 种基金the Informatization Plan of the Chinese Academy of Sciences(Grant No.CAS-WX2021SF-0304)the West Light Foundation of the ChineseAcademy of Sciences(Grant No.XAB2021YN19).
文摘To address uncertainties in satellite orbit error prediction,this study proposes a novel ensemble learning-based orbit prediction method specifically designed for the BeiDou navigation satellite system(BDS).Building on ephemeris data and perturbation corrections,two new models are proposed:attention-enhanced BPNN(AEBP)and Transformer-ResNet-BiLSTM(TR-BiLSTM).These models effectively capture both local and global dependencies in satellite orbit data.To further enhance prediction accuracy and stability,the outputs of these two models were integrated using the gradient boosting decision tree(GBDT)ensemble learning method,which was optimized through a grid search.The main contribution of this approach is the synergistic combination of deep learning models and GBDT,which significantly improves both the accuracy and robustness of satellite orbit predictions.This model was validated using broadcast ephemeris data from the BDS-3 MEO and inclined geosynchronous orbit(IGSO)satellites.The results show that the proposed method achieves an error correction rate of 65.4%.This ensemble learning-based approach offers a highly effective solution for high-precision and stable satellite orbit predictions.
基金Supported by the National Natural Science Foundation of China(No.81670885).
文摘AIM:To describe the clinical manifestations,imaging features and surgical treatments in 5 cases of extraocular muscle(EOM)dysplasia presenting as orbital spaceoccupying lesions(SOL).METHODS:Records from the 5 cases with EOM dysplasia between 2004 and 2016 were retrospectively reviewed and clinical data were recorded including family history,age at onset,age at surgery,visual acuity,cycloplegic refraction,ocular alignment and motility,stereoacuity,exophthalmos,anterior segment and fundus,orbital computed tomography(CT)or magnetic resonance imaging(MRI)scan,surgical methods and final outcomes.RESULTS:All 5 cases(1 male,4 females)were unilateral(3 right,2 left eyes).The average age was 5.4y(range 4-6y)with no family history.Patients had unilateral strabismus(horizontal and vertical),restricted eye movement,and eyelid changes(abnormal fissures,lagophthalmos,and/or entropion)in the affected eye.None had proptosis;1 had 2-mm enophthalmos.Orbital CT/MRI showed irregular,ill-defined masses in EOM.Two anterior orbitotomies and 3 strabismus surgeries were performed,and pathology confirmed EOM dysplasia.After surgery,horizontal deviations,which ranged from exotropia(XT)10 prism diopter(PD)to esotropia(ET)10 PD(average 6 PD),decreased by an average of 18 PD,while vertical deviations,which ranged from 4 PD to 20 PD(mean 9.8 PD),decreased by an average of 23.2 PD.CONCLUSION:SOL from EOM dysplasia is non-familial and typically presenting unilaterally characterized by an irregular,diffusely infiltrating mass within the EOM.EOM involvement causes strabismus,restricted eye movement,eyelid changes,and enophthalmos likely due to cicatricial processes.
基金supported by the NSFC(12301138)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(2021L377)+1 种基金the Doctoral Scientific Research Foundation of Shanxi Datong University(2018-B-15)The second author’s work was supported by the NSFC(12171108).
文摘In this paper,the problem of brake orbits with minimal period estimates are considered for the first-order Hamiltonian systems with anisotropic growth,i.e.,the Hamiltonian functions may have super-quadratic,sub-quadratic and quadratic behaviors simultaneously in different variable components.
基金supported by National Natural Science Foundation of China(Grant Nos.12202068,12202087)China National Space Administration Preliminary Research Project(Grant Nos.KJSP2023020201,KJSP2020010402).
文摘It is widely known that the hypervelocity impact of orbital debris can cause serious damage to spacecraft,and enhancing the impact resistance is the great concern of spacecraft shield design.This paper provides a comprehensive overview of advances in the development of bumper materials for spacecraft shield applications.In particular,the protective mechanism and process of the bumper using different materials against hypervelocity impact are reviewed and discussed.The advantages and disadvantages of each material used in shield were discussed,and the performance under hypervelocity impact was given according to the specific configuration.This review provides the useful reference and basis for researchers and engineers to create bumper materials for spacecraft shield applications,and the contemporary challenges and future directions for bumper materials for spacecraft shield were presented.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1402902)the National Natural Science Foundation of China(Grant Nos.12374179,12074119,12374145,051B22001,12104157,12134003,and 12304218)the Shanghai Pujiang Program(Grant No.23PJ1402200).
文摘The hybridization between oxygen 2p and transition-metal 3d states largely determines the electronic structure near the Fermi level and related functionalities of transition-metal oxides(TMOs).Considerable efforts have been made to manipulate the p-d hybridization in TMOs by tailoring the spatial orbital overlap via structural engineering.Here,we demonstrate enhanced p-d hybridization in Ba^(2+)-doped LaNiO_(3)epitaxial films by simultaneously modifying both the spatial and energetic overlaps between the O-2p and Ni-3d orbitals.Combining x-ray absorption spectroscopy and firstprinciples calculations,we reveal that the enhanced hybridization stems from the synergistic effects of a reduced chargetransfer energy due to hole injection and an increased spatial orbital overlap due to straightening of Ni-O-Ni bonds.We further show that the enhanced p-d hybridization can be utilized to promote the oxygen evolution activity of LaNiO_(3).This work sheds new insights into the fine-tuning of the electronic structures of TMOs for enhanced functionalities.
基金supported by the Natural Science Foundation of China(Grant Nos.42372220,42172207)the Youth Innovation Promotion Association Chinese Academy of Sciences(Grant No.Y2022102)+1 种基金the Science and Technology Innovation Project of Laoshan Laboratory(Grant No.LSKJ202203300)the International Partnership Program of the Chinese Academy of Sciences.
文摘The factors controlling dust activity and humidity in Central Asia and their relationships remain controversial,partly due to a lack of high-resolution geological records for the mid-to-late last glaciation.In this study,we established an optically stimulated luminescence chronology for the QSHA profile in the Yili Basin,a region influenced by westerlies.Grain size and trace element data were used as paleoclimatic indicators.We investigated the relationships among Central Asian dust activity,humidity,and westerlies strength on orbital to millennial scale from 37.4 ka to 11.6 ka.Our study reveals that,on orbital timescales,humidity is positively correlated with westerlies strength which controlled by precession.Dust activity is controlled by Siberian High which was regulated by Northern Hemisphere high-latitude temperature.Their responses to low-latitude and high-latitude forcing mechanisms respectively and present an opposite relationship.On millennial timescales,humidity and westerlies strength are positively correlated.During Marine Isotope Stage(MIS)2,humidity and dust activity show synchronous fluctuations,while during MIS 3,they exhibit an inverse relationship.Westerlies strength regulated humidity,which subsequently controlled glacial activity in the Tianshan Mountains,influencing dust activity in Central Asia.Additionally,the QSHA profile recorded seven Dansgaard-Oeschger(D-O)events on millennial timescales,indicating a potential link between Central Asian dust activity and high-latitude temperature variations in the Northern Hemisphere.Our findings provide new insights into dust and humidity interaction during the last glaciation periods in Central Asia and contribute to understanding global dust and hydrological cycles.
基金Supported by National Natural Science Foundation of China(No.82160195)Key R&D Program of Jiangxi Province(No.20223BBH80014).
文摘Orbital disorders include conditions originating from the orbital bones,surrounding tissues,and post-orbital septum.They also include systemic ailments affecting the orbit.Different clinical symptoms make up the complex range of orbital disorders.Because these disorders mostly impact the orbital area instead of the intraocular compartment,there is little diagnostic usefulness for typical ophthalmic visual tests.As such,the vital instruments for diagnosing and evaluating orbital illnesses have become ophthalmic imaging modalities,including ocular ultrasonography(B-scan),computed tomography(CT),and magnetic resonance imaging(MRI).One way to improve the precision and promptness of diagnosing orbital diseases is to standardize the functioning of widely used imaging equipment and define the radiological features of orbital abnormalities.Such programs are crucial for the care of patients with orbital disorders since they considerably reduce the number of misdiagnoses and missed diagnoses in these individuals.The underlying concepts,operational techniques,and normal and pathological imaging findings associated with common diagnostic tools for orbital illnesses are all thoroughly reviewed in this guideline.The objective is to improve primary healthcare settings’diagnostic competence in the field of orbital pathology and to standardize procedures for diagnosing orbital disorders.
基金funded by the National Natural Science Foundation of China(No.U21B6001)。
文摘This paper proposes a novel impulsive thrust strategy guided by optimal continuous thrust strategy to address two-player orbital pursuit-evasion game under impulsive thrust control.The strategy seeks to enhance the interpretability of impulsive thrust strategy by integrating it within the framework of differential game in traditional continuous systems.First,this paper introduces an impulse-like constraint,with periodical changes in thrust amplitude,to characterize the impulsive thrust control.Then,the game with the impulse-like constraint is converted into the two-point boundary value problem,which is solved by the combined shooting and deep learning method proposed in this paper.Deep learning and numerical optimization are employed to obtain the guesses for unknown terminal adjoint variables and the game terminal time.Subsequently,the accurate values are solved by the shooting method to yield the optimal continuous thrust strategy with the impulse-like constraint.Finally,the shooting method is iteratively employed at each impulse decision moment to derive the impulsive thrust strategy guided by the optimal continuous thrust strategy.Numerical examples demonstrate the convergence of the combined shooting and deep learning method,even if the strongly nonlinear impulse-like constraint is introduced.The effect of the impulsive thrust strategy guided by the optimal continuous thrust strategy is also discussed.
文摘This study aimed to investigate the impact of administration routes in establishing the Adriamycin(ADR)-induced chronic kidney disease(CKD)model.Using BALB/c mice,we compared the effects of conventional tail-vein injection(TV10,10 mg/kg)to those of retro-orbital sinus(orbital vein)injection(OV10,10 mg/kg;OV8,8 mg/kg).The re-sults indicated that the OV10 group exhibited CKD pathology similar to the TV10 group,with both groups demonstrating significantly higher urinary albumin/creatinine ratio(p<0.05),tubular injury(p<0.05),and degree of renal fibrosis(p<0.05)than the OV8 group.No significant differences were observed between the OV10 and TV10 groups in urinary albumin/creatinine ratio,tubular injury,and degree of renal fibrosis.These findings demonstrated that retro-orbital administration of 10 mg/kg ADR in-duces comparable effects to conventional tail-vein administration.This technique's technical simplicity may improve experimental efficiency,reproducibility,and animal welfare in CKD research.In conclusion,this study validates the utility of retro-orbital injection in CKD model establishment,demonstrating its potential to standardize and improve the reliability of future CKD research protocols.
基金Supported by the National Natural Science Foundation of China(12201446)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(22KJB110005)the Shuangchuang Program of Jiangsu Province(JSSCBS20220898)。
文摘It is known that monotone recurrence relations can induce a class of twist homeomorphisms on the high-dimensional cylinder,which is an extension of the class of monotone twist maps on the annulus or two-dimensional cylinder.By constructing a bounded solution of the monotone recurrence relation,the main conclusion in this paper is acquired:The induced homeomorphism has Birkhoff orbits provided there is a compact forward-invariant set.Therefore,it generalizes Angenent's results in low-dimensional cases.
基金Supported by the Sichuan Department of Science and Technology(No.2022JDKP0010).
文摘AIM:To evaluate the efficacy of combined orbital radiation and periorbital triamcinolone acetonide injection for patients with Graves’orbitopathy(GO)who experienced treatment failure with glucocorticoid pulse therapy(GPT).METHODS:A total of 57 eligible patients(35.09%males,mean age of 51.19±11.90y)were included in this case-series study.The medical information collected during each visit was evaluated and analyzed.RESULTS:Significant improvement was observed in patients six months after radiation therapy.Both the clinical activity score and the efficacy score showed substantial improvement(P<0.001).Furthermore,there was significant resolution of extraocular muscle inflammation on magnetic resonance imaging at three and six months after radiation therapy.The initial high signal intensity ratio(SIR)max was found to be associated with greater improvement in SIR sum(P<0.001,B=2.002,95%CI:1.377 to 2.628),while the presence of sight-threatening stage or moderate to severe diplopia negatively influenced the improvement of SIR sum(P=0.045,0.008,0.006;B=-1.966,-1.478,-0.997;95%CI:-3.886 to-0.045,-2.552 to-0.403,-1.694 to-0.300;respectively).CONCLUSION:The combination therapy demonstrates significant effectiveness in treating patients with GO who experienced severe ocular inflammation and have previous GPT failure.Noticeable improvement is observed as early as one month after initiating radiation therapy,and patients with more severe inflammatory states showes greater benefit from the treatment.
