最新刊期
卷 65 ， 期 4 ， 2026
- 摘要：The year 2025 marked the passing of two towering figures of twentieth-century mathematical physics, Rodney Baxter and Chen-Ning Yang. Yang reshaped modern physics through the introduction of non-abelian gauge theory and, independently, through the consistency conditions that later became known as the Yang-Baxter equation. Baxter transformed those conditions into a systematic theory of exact solvability in statistical mechanics and quantum integrable systems.This article is written in memory of Baxter and Yang, whose work revealed how local consistency principles generate global mathematical structure. We review the Yang-Mills formulation of gauge theory, its mass obstruction and resolution via symmetry breaking, and the geometric framework it engendered, including instantons, Donaldson-Floer theory, magnetic monopoles, and Hitchin systems. In parallel, we trace the emergence of the Yang-Baxter equation from factorised scattering to solvable lattice models, quantum groups, and Chern-Simons theory. Rather than presenting two separate narratives, gauge theory and integrability are presented as complementary manifestations of a shared coherence principle - an ongoing journey from gauge symmetry toward mathematical unity.关键词：Yang-Mills theory;Yang-Baxter equation;gauge theory;quantum groups;mirror symmetry66|58|0更新时间：2026-07-24
Invited review
- 摘要：Let
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Laser frequency stabilization experiment with fast and slow feedback based on optical frequency comb
摘要：A highly stable laser source is a fundamental requirement for precision spectroscopy and quantum state manipulation in ion-trap experiments. To meet the demand for laser frequency stability in precision measurements with ytterbium ions， this work presents the design and implementation of a fast-slow feedback laser frequency stabilization scheme referenced to an optical frequency comb. The system extracts frequency error information by detecting the beat signal between a continuous-wave laser and a comb tooth of the optical frequency comb， and employs a dual-loop feedback architecture： a slow feedback loop compensates for long-term frequency drifts of the laser， while a fast feedback loop provides high-bandwidth frequency tuning based on an acousto-optic modulator（AOM）. To mitigate the impact of the AOM diffraction-angle variation with driving frequency on optical path stability，a double-frequency-shifting optical configuration based on the AOM is designed and implemented. Experimental results show that， after locking the 934 nm laser to the optical frequency comb， the beat note linewidth is compressed to the Hz level， and the center frequency fluctuation is reduced to ±3.6 mHz in 3 hours. The relative instability of the system reaches - 摘要：This paper proposes a domain adaptation detection framework based on self-supervised visual representations， integrating general object detection with prototype library matching techniques. By leveraging the pre-trained features of DINOv3 for matching and screening， the proposed method can localize and distinguish target vehicles under few-shot conditions without the need for fine-tuning. First， a data augmentation front-end module based on multi-view synthesis is constructed to generate multi-angle samples. This aligns with overhead surveillance scenes， compensating for viewpoint deficiency in cross-domain settings. Subsequently， an inter-class clustering and prototype matching method is designed. By mining data modalities via clustering algorithms， a real-world prototype library encompassing various morphologies is constructed to address the issue of large intra-class variations. Building upon this， a joint global and local representation is introduced， which integrates semantic and textural details from different network layers to achieve fine-grained discrimination of target vehicles. Experimental results demonstrate that under few-shot conditions， the proposed method effectively overcomes the degradation in detection performance caused by viewpoint domain shift. Compared with traditional approaches， it improves the detection recall rate and significantly reduces false positives triggered by non-target vehicles， validating the effectiveness and robustness of the proposed domain adaptation framework in special vehicle monitoring scenarios..关键词：special transport vehicle;self-supervised visual model;domain adaptive detection53|43|0更新时间：2026-07-24
- 摘要：With the advantages of high power density， galvanic isolation， and soft-switching capability， the dual-active-bridge （DAB） DC-DC converter has been widely used in modern DC microgrids and renewable-energy systems. However， when a DAB converter supplies a constant power load （CPL）， the load exhibits negative incremental impedance， which can drive the system poles into the right-half plane， thereby causing oscillations and instability. To address this issue， this paper proposes an active-damping-based improved active disturbance rejection control strategy， developed from the reduced-order averaged model of the DAB converter and the equivalent CPL model. A shunt virtual admittance is designed at the DAB output to actively compensate the negative impedance introduced by the CPL. On this basis， the linear extended state observer （LESO） and the linear active disturbance rejection control （LADRC） structure are reconfigured to simultaneously mitigate the adverse effects of negative impedance and enhance robustness. Experimental results show that， compared with conventional PI control and standard LADRC， the proposed method effectively suppresses output-voltage oscillations， shortens the settling time， and improves system stability.关键词：dual active bridge;constant power load;active damping;active disturbance rejection control75|61|0更新时间：2026-07-24
- 摘要：Existing low-strain-rate dynamic loading devices are generally characterized by complex structures and high costs， while pulse loading modes other than compression remain underdeveloped. To address these issues， this paper proposes four novel low-strain-rate pulse loading devices， which cover tensile， compressive， tensile-compressive mixed， and impact loading modes. Their working principles are systematically elaborated， the pulse loading performance of the four types of devices is verified through experiments， and the regulation laws of pulse waveforms are analyzed and summarized. The results demonstrate that： 1） All four devices can achieve the corresponding pulse loading； the amplitude of the output tensile pulse is proportional to the falling height of the weight， and the pulse width is proportional to the elasticity of the thin string； 2） The amplitudes of the output compressive and tensile-compressive mixed pulses of the four devices are proportional to the exciter voltage， while the pulse width is inversely proportional to the operating frequency； 3） The impact pulse velocity output by the four devices is proportional to the spring compression amount. This research enriches the types of low-strain-rate dynamic loading devices and provides a low-cost， precise， and adjustable experimental method for research in related fields.关键词：low strain rate;dynamic loading;pulse loading device;loading performance;pulse waveform regulation71|51|0更新时间：2026-07-24
- 摘要：This paper proposes an interface-traction-based equilibrium finite element method combined with dual analysis theory to achieve high-precision stress solutions and strict a posteriori error estimation for finite sliding contact problems. First， the principle of minimum complementary energy for contact problems is derived within the framework of finite sliding. By introducing contact constraints， the problem is transformed into a quadratic programming problem. Subsequently，an traction-based equilibrium element is constructed using the macro-element technique and substituted into the principle of minimum complementary energy. Consequently，a high-precision equilibrium stress field that strictly satisfies the equilibrium equations is obtained. By combining the equilibrium stress field obtained from this method with the compatible displacement field from standard finite elements， the constitutive relation error （CRE） for contact problems can be derived and calculated. It is proven that this CRE serves as a strict upper bound for the discretization error. Finally， the proposed method is numerically verified through typical multi-body contact benchmarks， demonstrating its effectiveness in terms of solution accuracy， convergence， and discretization error estimation.关键词：finite-slip contact problem;equilibrium finite element;complementary energy principle;local search algorithm;dual analysis222|377|0更新时间：2026-07-24
- 摘要：To address the performance degradation of fault diagnosis in spacecraft attitude control systems under conditions of scarce fault samples and imbalanced data distribution， this paper proposes a fault diagnosis method integrating time-series image encoding and deep learning. First， a Wasserstein Generative Adversarial Network with gradient penalty （WGAN-GP） is employed to augment fault time-series samples and balance the training set distribution. Subsequently， three encoding methods—Gramian Angular Summation Field， Markov Transition Field， and Recurrence Plot—are utilized to convert time-series signals into two-dimensional images. Then， a two-dimensional convolutional neural network is constructed to extract and classify fault features. Experimental results demonstrate that the proposed method significantly improves diagnostic accuracy under varying sample imbalance ratios， validating its effectiveness and robustness in imbalanced sample scenarios.关键词：spacecraft attitude control system;fault diagnosis;time-series image encoding;generative adversarial network;convolutional neural network271|560|0更新时间：2026-07-24
- 摘要：Based on the theory of fractional-order viscoelastic mechanics and classical elements， a constitutive model has been established that can accurately characterize the creep and dynamic mechanical behavior of polymers. In response to the damage evolution characteristics during the material rheological process， a damage variable considering time effects is introduced to construct a damage-involved fractional-order constitutive relationship， effectively representing the mechanical response of the material in complex nonlinear processes such as stress relaxation and accelerated creep. To verify the reliability of the model， a dynamic mechanical analysis model was built based on the fractional-order Poynting-Thomson model， and comparative validation was conducted through dynamic mechanical experiments. The results show that the hysteresis loop curves fitted by the model are highly consistent with the experimental data， demonstrating the effectiveness of fractional derivatives in describing the dynamic mechanical properties of polymers.关键词：viscoelastic materials;fractional constitutive model;creep damage;relaxation;dynamic mechanical behavior49|54|0更新时间：2026-07-24
- 摘要：In pressurized water reactors，these rods are commonly constrained by spacer grids，forming a multi-span beam configuration characterized by multiple elastic supports. Concurrently，the flow channels housing the fuel rods experience turbulence induced by axial flow interacting with the spacer grids，leading to increased excitation forces on the fuel rod surfaces compared to pure axial flow conditions. Based on the transfer matrix method（TMM） and the anisotropy of fuel rod stiffness， a multi-elastic constraint model of fuel rod bending vibration was established.. Additionally，the mode superposition method（MSM） is utilized to simulate and investigate the vibration response of fuel rods subjected to axial flow by applying segmented harmonic excitations. A comparative assessment of various elastic constraint failure scenarios is also performed. Finally，the method’s accuracy is verified.关键词：vibration characteristic;multiple constraints;fuel rod;TMM;MSM234|320|0更新时间：2026-07-24
- 摘要：The shape of sand particles affects the physical and mechanical properties of sand， thereby influencing its engineering behavior. To investigate the influence of soil particle shape on its internal structure and particle motion characteristics， the creep process of sands with different particle shapes under varying stresses was simulated based on the discrete element method in the study. The results reveal that the micro-scopic of non-spherical particles to creep is quite different from that of spherical particles. The flatter particle shape leads to higher sample strength and more volumetric contraction. The particle shape affects the distribution of contact force during creep， which makes it more comparable to the distribution of contact force in the shearing process. In terms of particle alignment， the flatter the particles， the more they tend to be distributed in the direction perpendicular to the major external loading （i.e.， the horizontal direction） during creep. During shearing， particle shape changes the contribution of internal particle contact motion to overall specimen deformation normal contact deformation produces dilatancy while tangential contact deformation generates contraction， contrary to its contribution in spherical particle motion. The contribution of inter-particle contact motion to the volumetric strain during creep is closely related to the strain characteristics at the onset of creep. In other words， the contribution of the interparticle contact motion in creep depends on the initial state of creep and is a continuation of the deformation from that state. This study provides a theoretical basis for predicting long-term stability and deformation in geotechnical foundations.关键词：particle shape;creep deformation;internal structure of soil;particle motion characteristic55|411|0更新时间：2026-07-24
- 摘要：The upper reaches of the Hanjiang River are located in the north-south climatic transition zone of China， where sedimentary sequences are crucial for revealing the evolution history of the East Asian monsoon. This study examined the Mituosi profile in the upper Hanjiang River. Chromaticity parameters were systematically measured and integrated with magnetic susceptibility and grain size to assess their paleoclimatic significance and reconstruct the Holocene climate evolution. The results show that lightness L* is negatively correlated with Fe2O3 content （R=-0.83）. Influenced by organic matter content， L* values are lowest in the paleosol layer （average 48.41）， reflecting strong pedogenesis. Redness a* exhibits a significant positive correlation with Fe₂O₃ content （R=0.77）， reaching peak value in the paleosol layer （average 4.99）. This reflects the enrichment of iron oxides under warm and humid conditions. Yellowness b* and hue angle h* display maximum values in the cold-dry Malan loess unit and decline in the paleosol layer. Conversely， the a*/b* ratio shows an opposite trend to h*， with a high value （average 0.39） in the paleosol layer. Significant correlations among chromaticity parameters and magnetic susceptibility， clay content， and the Rb/Sr ratio confirming their utility as reliable paleoclimate proxies. The record reveals a cold， dry early Holocene （11.5~8.0 ka BP） characterized by weak pedogenesis. This was followed by warm， humid mid-Holocene （8.0~3.1 ka BP）with strong pedogenesis， albeit interrupted by a significant cold-dry event at ~6.48 ka BP. The late Holocene （since ~3.1 ka BP） saw a return to cold， dry climates. These findings not only provide new evidence for paleoclimate reconstruction in the upper Hanjiang River but also enhance our understanding of climate dynamics in the north-south transition zone.关键词：paleoclimate reconstruction;chromaticity parameter;climate evolution;Holocene;upper Hanjiang river38|28|0更新时间：2026-07-24
- 摘要：Elevated structures at the block scale can hinder the diffusion of atmospheric particulate matter， leading to localized pollutant accumulation. To investigate the distribution characteristics of pollutant matter in these areas and their influencing factors， this study focused on the space under the East First Ring Elevated Expressway in Nanchang. Continuous field monitoring was conducted over 5 days， covering morning， afternoon， and evening rush hours at multiple locations （10 sites and 30 sampling points）. This was combined with numerical simulations using ANSYS Fluent to analyze the spatiotemporal distribution of PM2.5 and PM10 and their key influencing factors. The results indicated that： 1）Temporally， the particulate matter concentrations followed the order "afternoon rush hour> morning rush hour> evening rush hour"， and were significantly higher on weekdays than on weekends. 2） Spatially， high-concentration areas are primarily at intersections and zones directly beneath the bridge deck， while low-concentration areas are more prevalent at T-junctions and ramp spaces. Areas with higher concentrations typically featured wider bridge decks and roads. 3）Particulate matter concentration show significant positive correlations with relative humidity， traffic flow， and black globe temperature， and significant negative correlations with air temperature. 4）Numerical simulations reveal a significant positive correlation between concentration and wind speed at low wind speeds. The elevated bridge structure reduces wind speed underneath it， creating a stagnation zone for pollutants. Different configurations of the elevated bridges and surrounding buildings generated distinct wind fields， which in turn affect particulate matter concentration variation. This study provides a scientific basis for improving environmental quality and preventing health risks in the spaces under elevated highways.关键词：under-bridge space;particulate matter;spatio-temporal distribution;air flow field;Nanchang43|27|0更新时间：2026-07-24
- 摘要：Plague and cholera frequently occurred in Northeast-North China during the republic period of China， representing one of the most severe public health crises of the period. Using an epidemic database （1912-1949） and concurrent meteorological grid data， this study employed Mann-Kendall mutation tests and spatial auto-correlation analysis to compare the spatiotemporal distributions of the two diseases and to identify regional differentiation patterns in their climatic response mechanisms. The results showed that： 1） Temporally， both diseases exhibited consistent peak periods during 1917-1921， 1928-1935， and 1943-1947. 2） Their seasonal distributions were opposed： plague peaked in winter （34.9%）， whereas cholera was concentrated in summer and autumn （97.7%）. 3） Spatially， plague hotspots formed a high-value belt in eastern-central Inner Mongolia， dominated by natural foci attributes； cholera hotspots clustered in the Beijing-Tianjin urban agglomeration and the Northeast railway corridor， significantly influenced by transportation networks， population density， and water sanitation conditions. 4） Climatic responses showed that， plague was negatively correlated with temperature （65.69% of the study area） and precipitation （51.92%）， favoring cold-dry conditions. Conversely， cholera was positively correlated with temperature （64.89%） and precipitation （63.92%）， favoring warm-humid conditions. During years of abrupt climate change， plague was more sensitive to temperature shifts， whereas cholera was more sensitive to precipitation changes， revealing a marked differentiation in their climatic responses. This study provides historical references for differentiated risk management in modern epidemic prevention.关键词：plague;cholera;meteorological element;the republic period of China;Northeast-North China59|38|0更新时间：2026-07-24
- 摘要：Investigating the niche characteristics of rare and endangered plant populations is crucial to understanding their endangered status and enhancing protection efficiency. Based on data from 166 20 m×20 m quadrats， this study examined the niche characteristics of 21 rare and endangered woody plant species in Guanshan National Nature Reserve， Jiangxi Province. The niche breadth of these 21 species was assessed using the Levins and Shannon indices， and their resource utilization differentiation was studied using the Schoener's niche similarity proportion （Cik） and Pianka's niche overlap index （Oik）. The results indicate that： 1） The species with the largest niche breadth was Tapiscia sinensis， followed by Taxus wallichiana var. mairei， Michelia chapensis， and Toona ciliata， while the species with the smallest niche breadth was Hibiscus paramutabilis. Linear regression analysis showed a significant positive correlation between niche breadth and importance value， and a significant negative correlation with the coefficient of variation of importance value. 2） Rare and endangered plants in Guanshan displayed considerable differences in resource utilization， with both the niche similarity proportion （Cik） and niche overlap index （Oik） being relatively low. The maximum values of Cik and Oik were observed for the species pair Toona ciliata and Amentotaxus argotaenia （Cik：0.44， Oik：0.53）， reflecting their similar resource utilization. 3） Linear regression analysis showed a significant positive correlation between the Oik and Cik values of species pairs and the mean niche breadth of the pairs， indicating that species with wider niche breadths have a higher probability of occupying similar ecological niches. These findings provide a scientific basis for optimizing the allocation of conservation and management resources and designing targeted conservation plans in the nature reserve.关键词：rare and endangered plant;ecological niche characteristic;species conservation335|251|0更新时间：2026-07-24
- 摘要：To investigate the chemical constituents of mulberry branches and their inhibitory activity against phosphodiesterase 4（PDE4）， various chromatographic techniques including normal phase silica gel， reversed phase silica gel， and gel were comprehensively utilized for the separation and purification of mulberry branches. The structures of the compounds were identified through spectral data such as NMR and MS， combined with literature comparison. Using tritiated 3'，5'-cyclic adenosine monophosphate（3H-cAMP） as the substrate， the PDE4 inhibitory activity of the compounds was determined in vitro using liquid scintillation counting. The results showed that eight compounds were isolated and identified from the ethyl acetate fraction of the mulberry branch ethanol extract， namely： Morusin（1）， Mornigrol E（2）， Mornigrol F（3）， Kuwanon C（4）， Moracin M-3'-O-β-D-glucopyranoside（5），cis-oxyreseratrol-4-O-β-D-glucopyranoside（6）， Steppogenin（7）， and Dihydromorin（8）. Compound 6 was isolated from mulberry plants for the first time. The isopentenyl flavonoids 1， 3， and 4 exhibited good PDE4 inhibitory activity， with half-inhibitory concentrations（IC50） values of（1.02±0.20），（0.50±0.07）， and（0.38±0.06） μmol/L， respectively， indicating their potential as lead compounds for PDE4 inhibitors.关键词：Ramulus Mori;chemical constituents;phosphodiesterase-4;inhibitor377|308|0更新时间：2026-07-24
- 摘要：To achieve high-value utilization of titanium-bearing blast furnace slag（TBBFS），this study employed high-calcium content TBBFS as a calcium source，oxalic acid as an acid activator，and borax as a retarder to prepare slag-based calcium oxalate cement（COC）via an acid-base reaction. The effects of the mass ratio of TBBFS to oxalic acid［m（TBBFS）/m（OA）］and the retarder dosage on the mechanical properties and hydration process of COC were systematically investigated.The results showed that at a m（TBBFS）/m（OA） ratio of 6 and a retarder dosage of 0.5%，the prepared COC exhibited an initial setting time of 11.32 min and compressive strength of 27.05 MPa （28 d），demonstrating both favorable workability and mechanical performance.The main hydration products were identified as CaC2O4·2H2O and amorphous silicic acid/silica. The hardening mechanism involves a multi-step synergistic phase-formation process.First， the acidic environment created by the dissolution of oxalic acid promotes the release of Ca2+ and SiO42- ions from calcium silicate.These ions then react with oxalate（C2O42-） and hydrogen ions（H+） to form the primary binding phase（CaC2O4·2H2O）， while the resulting amorphous silicic acid or silica gel contributes to toughening and pore-filling.Meanwhile， chemically inert calcium titanate（CaTiO3）particles are uniformly distributed throughout the matrix，functioning as reinforcing micro-aggregates.This hierarchical composite structure achieves a synergistic enhancement in strength，toughness，and durability through the orderly formation and cooperative interaction of different phases at the microscale.关键词：Titania-rich blast furnace slag（TBBFS）;calcium oxalate cement;acid-base cement;hardening mechanism346|257|0更新时间：2026-07-24
Research articles
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