Friction stir welding (FSW) of aluminum alloys is currently utilized in several modern industries. The joints must have sufficient elastic?plastic response and formability levels similar to that of the base metal. In ...Friction stir welding (FSW) of aluminum alloys is currently utilized in several modern industries. The joints must have sufficient elastic?plastic response and formability levels similar to that of the base metal. In this work, double-sided FSW of AA6061 sheet was compared with its conventional single-sided one. An adjustable tool with different pin lengths (50%?95% of the sheet thickness) was used to perform the double-sided welds. Macro- and micro-structures, strength, and hardness of the joints were investigated to determine the optimum pin penetration depth. The best results were obtained for a double-sided joint made by a pin length equal to 65% of the sheet thickness, which showed an increase of 41% in the ultimate tensile strength compared with the single-sided joint.展开更多
Currently,conventional single-sided friction stir welding is primarily suitable for joining thin plate aluminum alloys,and its application to thick plates is still challenging in terms of welding efficiency and joint ...Currently,conventional single-sided friction stir welding is primarily suitable for joining thin plate aluminum alloys,and its application to thick plates is still challenging in terms of welding efficiency and joint mechanical properties.Simultaneous double-sided friction stir welding(SDS-FSW)is a high-efficiency joining technique specifically developed for welding thick plates.However,there is little research on the influence of SDS-FSW process parameters on the joint mechanical properties.In this study,a 12 mm thick AA6061-T6 aluminum alloy and dual robot welding equipment are used to conduct SDS-FSW experiments exploring the influence of rotational speedωand welding speed v on the mechanical properties and microstructure.The results show that when the welding parameters areω=800 r/min and v=60–80 mm/min,smooth and defect-free thick plate aluminum alloy SDS-FSW joints can be obtained,and the macroscopic morphology of the joints is distributed in a“dumbbell”shape.The grain size in the weld nugget zone increases with increasing welding heat input.The microhardness distribution in the joint displays a“W”shape,and the hardness value of the weld nugget zone can reach 67%to 86%of that of the base metal(BM).The junction between the thermo-mechanically affected zone and the heat affected zone is the weakest region of the joint,with the lowest hardness being approximately 51%of that of the BM.When the welding parameters areω=800 r/min and v=140 mm/min,the SDS-FSW joint has the highest tensile strength,reaching 78.43%of the BM strength and exhibiting ductile fracture characteristics.This research indicates that acceptable weld strength in thick aluminum alloys can be achieved via the SDS-FSW joining mechanism,highlighting its significant potential for industrial applications.展开更多
The double-sided lapping process is extensively employed in the manufacturing of wafers,optical windows,and seal rings due to its high efficiency and ability to achieve precise flatness.However,limited research has ex...The double-sided lapping process is extensively employed in the manufacturing of wafers,optical windows,and seal rings due to its high efficiency and ability to achieve precise flatness.However,limited research has explored the thickness uniformity among different workpieces after double-sided lapping,and the underlying mechanism remains unclear.To address the demand for higher precision,this paper first analyzed the relative kinematic model between the workpiece and the lapping plate to clarify the causes of thickness variations among workpieces after double-sided lapping.Subsequently,a finite element method(FEM)model was developed to account for the pressure distribution on the workpiece surfaces at the initial stage of the process.The results indicate that the number of workpieces influences the final thickness variation.Then,various sets of thin copper plates with different thicknesses were lapped,and the findings revealed that five copper plates processed simultaneously exhibited more uniform thickness compared to the three plates.The experimental results align well with the theoretical analysis.Ultimately,a thickness variation of less than 6μm was achieved on five copper plates measuringΦ100×2.9 mm.This study presents a comprehensive analysis of the mechanisms influencing thickness uniformity in the double-sided lapping process and provides practical guidelines for optimizing the process to achieve stringent precision standards in industrial applications.展开更多
Bio-magnesium(Mg)alloys exhibit excellent biocompatibility and biodegradability,making them highly promising for implant applications.However,their limited strength-ductility balance remains a critical challenge restr...Bio-magnesium(Mg)alloys exhibit excellent biocompatibility and biodegradability,making them highly promising for implant applications.However,their limited strength-ductility balance remains a critical challenge restricting widespread use.In this study,ultra-fine-grained and homogeneous Mg alloys were fabricated using double-sided friction stir processing(DS-FSP)with liquid CO_(2) rapid cooling,leading to a significant enhancement in the strength-ductility synergy of the stirred zone.The results demonstrate that DS-FSP samples exhibit simultaneous improvements in ultimate tensile strength(UTS)and elongation,reaching 334.1±15 MPa and 28.2±7.3%,respectively.Compared to the non-uniform fine-grained microstructure obtained through single-sided friction stir processing,DS-FSP generates a uniform ultra-fine-grained structure,fundamentally altering the fracture behavior and mechanisms of Mg alloys.The DS-FSP samples exhibit irregular fracture patterns due to variations in basal slip system activation among different grains.In contrast,single-sided friction stir processing samples,characterized by a fine-grained yet heterogeneous microstructure,display flat shear fractures dominated by high-density dislocation initiation induced by twin formation,with fracture propagation dictated by the non-uniform texture.By achieving an ultra-fine grain size and homogeneous texture,DS-FSP effectively modifies the fracture mechanisms,thereby enhancing the strength-ductility balance of bio-magnesium alloys.展开更多
The influence of laser parameters on are beharior of laser-TIC, dauble-side welding was investigated by utilizing CCD sensor and intage processing methods. It was found that are images had an obvious transformation fr...The influence of laser parameters on are beharior of laser-TIC, dauble-side welding was investigated by utilizing CCD sensor and intage processing methods. It was found that are images had an obvious transformation from laser preheating to laser plasma ejected from the keyhole bottom, resulting in the phenomena of arc column convergence and arc root constrictian. The attraction phenomenon of the laser and the arc is also found in laser-TIG double-side welding. More noteworthy is that the behavior of arc attraction or constriction became much obvious at a lower current or laser plasma ejected from the keyhole bottom. The decrease in arc voltage had a certain relation u＇ith the improvement of arc stabilio.展开更多
A new high efficiency welding method, double-sided double arc welding with double powers （DSAW-D）, is developed for thick plate of low alloy high strength steel in this study. It is well known that the thermal cycle...A new high efficiency welding method, double-sided double arc welding with double powers （DSAW-D）, is developed for thick plate of low alloy high strength steel in this study. It is well known that the thermal cycles have an important influence on the microstructure, shape, stress, distortion and mechanical property. The DSA W-D method can control the temperature field on a wide range by regulating the distance between two arcs, improve the microstructure and prevent hot and cold cracking of high strength steel. But at present, the effect of arc distance on the temperature field and shape is not clear. Therefore, the paper researches the effect of arc distance on the temperature field and weld pool during DSAW-D using finite element method. The transient temperature field of different arc distance in DSAW-D is calculated. To verify the numerical results, the temperature is measured by the thermo-couple and the calculated results agree approximately with experimental data. Farther, the thermal property and mutual effect of double-sided arcs are investigated. The temperature distributions and weld pool profile at different arc distances are obtained. The results show that arc distance is a very important factor to affect the heat process.展开更多
The in-flight heating process of cerium dioxide(CeO_(2))powders was investigated through experiments and numerical simulations.In the experiment,CeO_(2)powder(average size of 30μm)was injected into radio-frequency(RF...The in-flight heating process of cerium dioxide(CeO_(2))powders was investigated through experiments and numerical simulations.In the experiment,CeO_(2)powder(average size of 30μm)was injected into radio-frequency(RF)argon plasma,and the temperatures were measured using a DPV-2000 monitor.A model combining the electromagnetism,thermal flow,and heat transfer characteristics of powder during in-flight heating in argon plasma was proposed.The melting processes of CeO_(2)powders of different diameters,with and without thermal resistance effect,were investigated.Results show that the heating process of CeO_(2)powder particles consists of three main stages,one of which is relevant to a dimensionless parameter known as the Biot number.When the Biot value≥0.1,thermal resistance increases significantly,especially for the larger powders.The predicted temperature of the particles at the outlet(1800–2880 K)is in good agreement with the experimental result.展开更多
Rechargeable Zn/Sn-air batteries have received considerable attention as promising energy storage devices.However,the electrochemical performance of these batteries is significantly constrained by the sluggish electro...Rechargeable Zn/Sn-air batteries have received considerable attention as promising energy storage devices.However,the electrochemical performance of these batteries is significantly constrained by the sluggish electrocatalytic reaction kinetics at the cathode.The integration of light energy into Zn/Sn-air batteries is a promising strategy for enhancing their performance.However,the photothermal and photoelectric effects generate heat in the battery under prolonged solar irradiation,leading to air cathode instability.This paper presents the first design and synthesis of Ni_(2)-1,5-diamino-4,8-dihydroxyanthraquinone(Ni_(2)DDA),an electronically conductiveπ-d conjugated metal-organic framework(MOF).Ni_(2)DDA exhibits both photoelectric and photothermal effects,with an optical band gap of~1.14 eV.Under illumination,Ni_(2)DDA achieves excellent oxygen evolution reaction performance(with an overpotential of 245 mV vs.reversible hydrogen electrode at 10 mA cm^(−2))and photothermal stability.These properties result from the synergy between the photoelectric and photothermal effects of Ni_(2)DDA.Upon integration into Zn/Sn-air batteries,Ni_(2)DDA ensures excellent cycling stability under light and exhibits remarkable performance in high-temperature environments up to 80℃.This study experimentally confirms the stable operation of photo-assisted Zn/Sn-air batteries under high-temperature conditions for the first time and provides novel insights into the application of electronically conductive MOFs in photoelectrocatalysis and photothermal catalysis.展开更多
Beam-tracking simulations have been extensively utilized in the study of collective beam instabilities in circular accelerators.Traditionally,many simulation codes have relied on central processing unit(CPU)-based met...Beam-tracking simulations have been extensively utilized in the study of collective beam instabilities in circular accelerators.Traditionally,many simulation codes have relied on central processing unit(CPU)-based methods,tracking on a single CPU core,or parallelizing the computation across multiple cores via the message passing interface(MPI).Although these approaches work well for single-bunch tracking,scaling them to multiple bunches significantly increases the computational load,which often necessitates the use of a dedicated multi-CPU cluster.To address this challenge,alternative methods leveraging General-Purpose computing on Graphics Processing Units(GPGPU)have been proposed,enabling tracking studies on a standalone desktop personal computer(PC).However,frequent CPU-GPU interactions,including data transfers and synchronization operations during tracking,can introduce communication overheads,potentially reducing the overall effectiveness of GPU-based computations.In this study,we propose a novel approach that eliminates this overhead by performing the entire tracking simulation process exclusively on the GPU,thereby enabling the simultaneous processing of all bunches and their macro-particles.Specifically,we introduce MBTRACK2-CUDA,a Compute Unified Device Architecture(CUDA)ported version of MBTRACK2,which facilitates efficient tracking of single-and multi-bunch collective effects by leveraging the full GPU-resident computation.展开更多
Fe_(3)Sn_(2),a ferromagnetic metal with a kagome lattice,serves as an ideal platform for exploring topological electronic states and Berry curvature due to its unique band structure.However,systematic reports on the t...Fe_(3)Sn_(2),a ferromagnetic metal with a kagome lattice,serves as an ideal platform for exploring topological electronic states and Berry curvature due to its unique band structure.However,systematic reports on the transport properties of Fe_(3)Sn_(2)nanosheets remain scarce.We present temperature-dependent transport property measurements of Fe_(3)Sn_(2)nanosheets synthesized via chemical vapor deposition on Si/SiO_(2)substrates.The samples exhibit a robust anomalous Hall effect from 40 K to 300 K,along with a magnetoresistance sign reversal at 40 K at high magnetic fields,indicating a spin reorientation from in-plane to out-of-plane.Notably,a sharp crossover in the dominant transport contribution from electrons to holes near 200 K is observed,accompanied by distinct anomalous Hall behaviors in the two regimes,indicating a temperature-induced Lifshitz transition within the multi-band system.This divergence is potentially linked to a topological reconstruction of the Fermi surface across the transition.Our findings highlight the tunability of topological transport in two-dimensional kagome magnets and provide new insights into the interplay between band topology,dimensionality and magnetic order.展开更多
The effect of adding hydroxycinnamic acids(caffeic acid,sinapic acid,p-coumaric acid and chlorogenic acid)in Cabernet Sauvignon dry red wine before and after fermentation was investigated,taking into account the color...The effect of adding hydroxycinnamic acids(caffeic acid,sinapic acid,p-coumaric acid and chlorogenic acid)in Cabernet Sauvignon dry red wine before and after fermentation was investigated,taking into account the color parameters,anthocyanin content,and overall polyphenol levels in the wine samples.The copigmentation effect of malvidin-3-Oglucoside and sinapic acid was further explored in model solution and through theoretical calculations.The results indicated that the addition of hydroxycinnamic acids significantly enhanced the wine's color with sinapic acid(before the fermentation)showing the most pronounced color protection effect.Compared to control samples,the addition of hydroxycinnamic acids resulted in a 36%increase in total phenolic content and a 28% increase in total anthocyanin content.Thermodynamic analysis revealed that the interaction between sinapic acid and malvidin-3-O-glucoside was spontaneous and exothermic.Theoretical studies identified hydrogen bonding(HB)and dispersion forces as the main primary stabilizing forces,with the carboxyl group of sinapic acid playing a critical role while the anthocyanin backbone also influenced the interaction.展开更多
Iron and steel industry is one of the main sources of air pollution emissions in China.The sintering process is an important link in the blast furnace ironmaking process,but it is also accompanied by a large number of...Iron and steel industry is one of the main sources of air pollution emissions in China.The sintering process is an important link in the blast furnace ironmaking process,but it is also accompanied by a large number of pollutants.Under the background of ultra-low emissions,iron and steel enterprises urgently need to upgrade their existing processes to address the existing process in practical application problems.In this study,a steel group in Gansu Province was taken as an example.By comparing and analyzing the pollutant emission characteristics before and after the ultra-low emission retrofit,the collaborative control effect of the combined process on SO_(2),NO_(x),particulate matter,and dioxins after the new retrofit was systematically evaluated.The results show that after the retrofit,the concentrations of particulate matter,SO_(2) and NO_(x) have dropped to near-zero levels,and the dioxin removal efficiency has reached 98.87%,with all indicators being better than the national ultra-low emission standards.The study confirms that the optimal combination of multi-pollutant collaborative treatment technologies is the key to achieving efficient emission reduction,among which selective catalytic reduction technology has a particularly significant synergistic removal effect on NO_(x) and dioxins.This study provides an important technical reference and practical basis for the ultra-low emission retrofit of the steel industry,and has important guiding significance for promoting the green retrofit of the industry.Its ultra-low emission retrofit is of great significance for achieving green and low-carbon development.展开更多
Benzalkonium chloride(BAC)is widely employed as a broad-spectrum biocide and has emerged as a significant environmental pollutant.Polymyxin B(PB)serves as the last-line defense for the treatment of Gram-negative patho...Benzalkonium chloride(BAC)is widely employed as a broad-spectrum biocide and has emerged as a significant environmental pollutant.Polymyxin B(PB)serves as the last-line defense for the treatment of Gram-negative pathogens.Previous studies reported that BAC-adapted Pseudomonas aeruginosa increased the tolerance to PB.Herein,we present the novel finding that the combination of BAC and PB exhibited synergistic antibacterial effects against P.aeruginosa.Time-killing assay demonstrated a significant reduction in bacterial cell viability.Scanning electron microscopy,zeta potential analysis,hydrophobicity measurements,and fluorescence probe analyses collectively revealed severe disruption of the cell envelope and membrane potential induced by the combination of BAC and PB.Transcriptomic analysis revealed that the BAC-PB combination notably downreg-ulated the expression of genes involved in lipid A modification and cell envelope production,including phoPQ,pmrAB,bamABCDE,lptABCDEG,lolB,yidC,and murJ.Additionally,the combination group exhibited augmented production of reactive oxygen species and diminished ATP synthesis.The expression of the genes associated with substance metabolism and energy generation was significantly impeded.This study provides significant implica-tions for the interactions of biocides and antibiotics on Gram-negative pathogens,while also addressing antibiotic resistance and developing the external treatment strategy for Pseudomonas-infected wounds and burns.展开更多
[Objectives]To explore the control mode of farmland drainage pollutants and investigate the effects of ecological ditch and wetland on reducing farmland drainage pollutants in Hetao Irrigation District.[Methods]Based ...[Objectives]To explore the control mode of farmland drainage pollutants and investigate the effects of ecological ditch and wetland on reducing farmland drainage pollutants in Hetao Irrigation District.[Methods]Based on the demonstration construction project of the ecological ditch-constructed wetland system in the Hetao Irrigation District,an experimental study was conducted from July to September 2023 to investigate the interception and purification effects of ecological ditches,constructed wetlands,and the combined ecological ditch-constructed wetland system on farmland drainage pollutants.Key water quality parameters measured included total nitrogen(TN)concentration and total phosphorus(TP)concentration.[Results]Different treatment modes of ecological ditches and constructed wetlands have a certain removal effect on nitrogen and phosphorus pollutants in water bodies.The ecological ditches treated with Astragalus laxmannii,Melilotus officinalis,Medicago sativa,bio-ball substrate,and bio-sheet substrate showed reduction efficiencies for TN and TP of 21.09% and 23.84%,12.06% and 26.67%,20.08% and 34.15%,23.65% and 20.56%,and 19.92% and 25.83%,respectively.The emergent plant area showed reduction efficiencies of 24.28%for TN and 17.89%for TP,while the submerged plant area achieved a reduction efficiency of 10.21%for both TN and TP.Among the different treatment modes,the ecological ditch with M.sativa performed better in TP removal,whereas the bio-ball substrate treatment mode showed higher effectiveness in TN removal.In addition,the emergent plant area exhibited better TP removal performance,while the submerged plant area was more effective in TN removal.The combined system of ecological ditch and constructed wetland achieved removal rates of 37.55% for TN and 11.47% for TP.It effectively facilitates the step-by-step interception and adsorption purification of pollutants,thereby showing significant removal and purification effects on nitrogen and phosphorus contaminants.This contributes to mitigating agricultural non-point source pollution.[Conclusions]The combined ecological ditch-constructed wetland system serves dual functions of agricultural drainage and pollutant interception and purification.It reduces the pollution load of farmland drainage on receiving water bodies to some extent and mitigates agricultural non-point source pollution.Therefore,it is a relatively suitable technology for managing agricultural non-point source pollution in the Hetao Irrigation District.展开更多
Inflammatory bowel disease(IBD),which includes Crohn’s disease(CD)and ulcerative colitis(UC),is a chronic inflammatory condition affecting the gastrointestinal tract.The global incidence and prevalence of IBD continu...Inflammatory bowel disease(IBD),which includes Crohn’s disease(CD)and ulcerative colitis(UC),is a chronic inflammatory condition affecting the gastrointestinal tract.The global incidence and prevalence of IBD continue to increase.While multiple clinical treatments exist,conventional therapies frequently present limitations and adverse effects.Natural polysaccharides(PSs)have emerged as a significant focus of research interest due to their therapeutic potential and applications in functional foods and health products.This review synthesizes current understanding of IBD pathophysiology and the mechanisms by which natural PSs counter IBD,including their capacity to restore immune homeostasis and intestinal barrier function,modulate gut microbiota and metabolites,reduce oxidative stress,and address irregularities in autophagy and endoplasmic reticulum stress(ERS).The review examines the structure-activity relationships of PSs demonstrating anti-IBD effects and identifies promising therapeutic products.The discussion encompasses pharmacokinetics,safety evaluations,and clinical applications of these compounds.This comprehensive review establishes a theoretical foundation for developing natural PS-based therapeutic approaches for IBD management.展开更多
Lattice materials have demonstrated promising potential in engineering applications owing to their exceptional lightweight,high specific strength,and tunable mechanical properties.However,the traditional homogenizatio...Lattice materials have demonstrated promising potential in engineering applications owing to their exceptional lightweight,high specific strength,and tunable mechanical properties.However,the traditional homogenization methods based on the classical elasticity theory struggle to accurately describe the non-classical mechanical behaviors of lattice materials,especially when dealing with complex unit-cell geometries featured by non-symmetric configurations or non-single central node connections.In response to this limitation,this study establishes a generalized homogenization model based on the micropolar theory framework,employing Hill's boundary conditions to precisely predict the equivalent moduli of complex lattice materials.By introducing the independent rotational degree of freedom(DOF)characteristic of the micropolar theory,the proposed model successfully overcomes the limitation of conventional methods in accurately describing the asymmetric deformation and scale effects.We initially calculate the constitutive relations of two-dimensional(2D)cross-shaped multi-node chiral lattices and subsequently extend the method to three-dimensional(3D)lattices,successfully predicting the mechanical properties of both traditional and eccentric body-centered cubic(BCC)lattices.The theoretical model is validated through the finite element numerical verification which shows excellent consistency with the theoretical predictions.A further parametric study investigates the influence of geometric parameters,revealing the underlying size-effect mechanism.This paper provides a reliable theoretical tool for the design and property optimization of complex lattice materials.展开更多
Modern battlefields exhibit high dynamism,where traditional static weighting methods in combat effectiveness assessment fail to capture real-time changes in indicator values,leading to limited assessment accuracy—esp...Modern battlefields exhibit high dynamism,where traditional static weighting methods in combat effectiveness assessment fail to capture real-time changes in indicator values,leading to limited assessment accuracy—especially critical in scenarios like sudden electronic warfare or degraded command,where static weights cannot reflect the operational value decay or surge of key indicators.To address this issue,this study proposes a dynamic adaptive weightingmethod for evaluation indicators based onG1-CRITIC-PIVW.First,theG1(Sequential Relationship Analysis Method)subjective weighting method—translates expert knowledge into indicator importance rankings—leverages expert knowledge to quantify the relative importance of indicators via sequential relationship ranking,while the CRITIC(Criteria Importance Through Intercriteria Correlation)objective weighting method—derives weights from data characteristics by integrating variability and inter-correlations—calculates weights by integrating indicator variability and inter-indicator correlations,ensuring data-driven objectivity.These two sets of weights are then fused using a deviation coefficient optimization model,minimizing the squared deviation from a reference weight and adjusting the fusion coefficient via Spearman’s rank correlation to resolve potential conflicts between subjective and objective judgments.Subsequently,the PIVW(Punishment-Incentive VariableWeight)theory—adapts weights to realtime indicator performance via penalty/incentive rules—is applied for dynamic adjustment.Scenario-specific penalty λ_(1) and incentive λ_(2) thresholds are set based on operational priorities and indicator volatility,penalizing indicators with values below λ_(1) and incentivizing those exceeding λ_(2) to reflect real-time indicator performance.Experimental validation was conducted using an Air Defense and Anti-Missile(ADAM)system effectiveness assessment framework,with data covering 7 indicators across 3 combat scenarios.Results show that compared to static weighting methods,the proposed method reduces MAE(Mean Absolute Error)by 15%-20% and weighted decision error rate by 84.2%,effectively reducing overestimation/underestimation of combat effectiveness in dynamic scenarios;compared to Entropy-TOPSIS,it lowers MAE by 12% while achieving a weighted Kendall’sτconsistency coefficient of 0.85,ensuring higher alignment with expert judgment.This method enhances the accuracy and scenario adaptability of effectiveness assessment,providing reliable decision support for dynamic battlefield environments.展开更多
AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 group...AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 groups:Group A(implanted with the SN6CWS),Group B(implanted with the MI60),and Group C(implanted with the Aspira-aA).ELP measurements were obtained with swept-source optical coherence tomography(SS-OCT)at 1d,1wk,1mo,and 3mo postoperatively.Subjective refraction assessments were conducted at 1wk,1mo,and 3mo following surgery.RESULTS:The study included 189 eyes of 150 cataract patients(66 males).There were 77 eyes in Group A,55 eyes in Group B,and 57 eyes in Group C.The root mean square of the ELP(ELPRMS)within the initial 3mo was significantly lower for Group A than for Groups B and C.Refractive changes within Group A were not significant across the time points of 1wk,1mo,and 3mo.Conversely,both Group B and Group C demonstrated statistically significant shifts toward hyperopia from 1wk to 3mo postsurgery.CONCLUSION:Among the three IOLs examined,the SN6CWS IOL showes the greatest stability during the first 3mo postoperatively.Between 1wk and 3mo after surgery,notable hyperopic shifts are evident in eyes implanted with the MI60 and Aspira-aA IOLs,whereas refractive outcomes remain relatively constant in eyes implanted with SN6CWS IOLs.展开更多
The Stern-Gerlach(SG)experiment is a fundamental experiment for revealing the existence of“spin”.In this experiment,beams of silver atoms are sent through inhomogeneous magnetic fields to observe their deflection.Th...The Stern-Gerlach(SG)experiment is a fundamental experiment for revealing the existence of“spin”.In this experiment,beams of silver atoms are sent through inhomogeneous magnetic fields to observe their deflection.Thus,the conventional SG experiment can be viewed as a magnetic-type spin effect.In this work,we successfully generalize the SG effect from magnetic-type to electric-type by solving Dirac's equation with a potential barrier,revealing an extraordinary spin effect.Beams of Dirac particles can be regarded as matter waves.Based on Dirac's equation,we obtain the explicit forms of the incident,reflected,and transmitted waves.The electric-type SG effect shows that the reflected and transmitted waves can exhibit notable spatial shifts,which depend on the spin direction and the incident angle of the wave.The electrictype SG effect has potential applications for separating Dirac particles with different spin directions and for estimating the spin direction of Dirac particles.Some discussions related to the interaction between spin and the electric field are also presented.展开更多
Aerodynamic performances of axial compressors are significantly affected by variation of Reynolds number in aero-engines.In the design and analysis of compressors,previous correction methods for cascades and stages ha...Aerodynamic performances of axial compressors are significantly affected by variation of Reynolds number in aero-engines.In the design and analysis of compressors,previous correction methods for cascades and stages have difficulties in predicting comprehensively Reynolds number effects on airfoils,matching and characteristics curves.This study proposes Re-correction models for loss,deviation angle and endwall blockage based on classical theories and cascade tests,and loss and deviation models show good agreement in test data of NACA65 and C4 cascades.Throughflow method considering Reynolds number effects is developed by integrating the correction models into a verified Streamline Curvature(SLC)tool.A three-stage axial compressor is investigated through SLC and CFD methods from design Reynolds number(Red=2106)to low Re=4104,and the numerical methods are validated with test data of characteristic curves and spanwise distributions at Red.With Re reduction,SLC method with correction models well predicts variation in overall performances compared with CFD calculations and Wassell's model.Streamwise and spanwise matching such as total pressure and loss distributions in SLC predictions are basically consistent with those in CFD results at near-stall points under design and low Reynolds numbers.SLC and CFD methods share similar detections of stall risks in the third stage(Stg3),and their analyses of diffusion processes deviate to some extent due to different predictions in separated endwall flow.The correction models can be adopted to consider Reynolds number effects in through-flow design and analysis of axial compressors.展开更多
基金The support of Iran National Science Foundation (INSF) (Grant No. 91051732)
文摘Friction stir welding (FSW) of aluminum alloys is currently utilized in several modern industries. The joints must have sufficient elastic?plastic response and formability levels similar to that of the base metal. In this work, double-sided FSW of AA6061 sheet was compared with its conventional single-sided one. An adjustable tool with different pin lengths (50%?95% of the sheet thickness) was used to perform the double-sided welds. Macro- and micro-structures, strength, and hardness of the joints were investigated to determine the optimum pin penetration depth. The best results were obtained for a double-sided joint made by a pin length equal to 65% of the sheet thickness, which showed an increase of 41% in the ultimate tensile strength compared with the single-sided joint.
基金Supported by National Key R&D program of China(Grant No.2019YFA0709004)。
文摘Currently,conventional single-sided friction stir welding is primarily suitable for joining thin plate aluminum alloys,and its application to thick plates is still challenging in terms of welding efficiency and joint mechanical properties.Simultaneous double-sided friction stir welding(SDS-FSW)is a high-efficiency joining technique specifically developed for welding thick plates.However,there is little research on the influence of SDS-FSW process parameters on the joint mechanical properties.In this study,a 12 mm thick AA6061-T6 aluminum alloy and dual robot welding equipment are used to conduct SDS-FSW experiments exploring the influence of rotational speedωand welding speed v on the mechanical properties and microstructure.The results show that when the welding parameters areω=800 r/min and v=60–80 mm/min,smooth and defect-free thick plate aluminum alloy SDS-FSW joints can be obtained,and the macroscopic morphology of the joints is distributed in a“dumbbell”shape.The grain size in the weld nugget zone increases with increasing welding heat input.The microhardness distribution in the joint displays a“W”shape,and the hardness value of the weld nugget zone can reach 67%to 86%of that of the base metal(BM).The junction between the thermo-mechanically affected zone and the heat affected zone is the weakest region of the joint,with the lowest hardness being approximately 51%of that of the BM.When the welding parameters areω=800 r/min and v=140 mm/min,the SDS-FSW joint has the highest tensile strength,reaching 78.43%of the BM strength and exhibiting ductile fracture characteristics.This research indicates that acceptable weld strength in thick aluminum alloys can be achieved via the SDS-FSW joining mechanism,highlighting its significant potential for industrial applications.
基金Supported by the Liaoning Provincial Natural Science Foundation(Grant No.2023-MSBA-008)Unveiling and Commanding Program of Liaoning Province(Grant No.2022JH1/10800080)the Fundamental Research Funds for the Central Universities(Grant No.DUT24MS008).
文摘The double-sided lapping process is extensively employed in the manufacturing of wafers,optical windows,and seal rings due to its high efficiency and ability to achieve precise flatness.However,limited research has explored the thickness uniformity among different workpieces after double-sided lapping,and the underlying mechanism remains unclear.To address the demand for higher precision,this paper first analyzed the relative kinematic model between the workpiece and the lapping plate to clarify the causes of thickness variations among workpieces after double-sided lapping.Subsequently,a finite element method(FEM)model was developed to account for the pressure distribution on the workpiece surfaces at the initial stage of the process.The results indicate that the number of workpieces influences the final thickness variation.Then,various sets of thin copper plates with different thicknesses were lapped,and the findings revealed that five copper plates processed simultaneously exhibited more uniform thickness compared to the three plates.The experimental results align well with the theoretical analysis.Ultimately,a thickness variation of less than 6μm was achieved on five copper plates measuringΦ100×2.9 mm.This study presents a comprehensive analysis of the mechanisms influencing thickness uniformity in the double-sided lapping process and provides practical guidelines for optimizing the process to achieve stringent precision standards in industrial applications.
基金financial support from the National Key Research and Development Program of China(2021YFC2400703)Zhengzhou City Major Special Project for Collaborative InnovationChina Scholarship Council。
文摘Bio-magnesium(Mg)alloys exhibit excellent biocompatibility and biodegradability,making them highly promising for implant applications.However,their limited strength-ductility balance remains a critical challenge restricting widespread use.In this study,ultra-fine-grained and homogeneous Mg alloys were fabricated using double-sided friction stir processing(DS-FSP)with liquid CO_(2) rapid cooling,leading to a significant enhancement in the strength-ductility synergy of the stirred zone.The results demonstrate that DS-FSP samples exhibit simultaneous improvements in ultimate tensile strength(UTS)and elongation,reaching 334.1±15 MPa and 28.2±7.3%,respectively.Compared to the non-uniform fine-grained microstructure obtained through single-sided friction stir processing,DS-FSP generates a uniform ultra-fine-grained structure,fundamentally altering the fracture behavior and mechanisms of Mg alloys.The DS-FSP samples exhibit irregular fracture patterns due to variations in basal slip system activation among different grains.In contrast,single-sided friction stir processing samples,characterized by a fine-grained yet heterogeneous microstructure,display flat shear fractures dominated by high-density dislocation initiation induced by twin formation,with fracture propagation dictated by the non-uniform texture.By achieving an ultra-fine grain size and homogeneous texture,DS-FSP effectively modifies the fracture mechanisms,thereby enhancing the strength-ductility balance of bio-magnesium alloys.
文摘The influence of laser parameters on are beharior of laser-TIC, dauble-side welding was investigated by utilizing CCD sensor and intage processing methods. It was found that are images had an obvious transformation from laser preheating to laser plasma ejected from the keyhole bottom, resulting in the phenomena of arc column convergence and arc root constrictian. The attraction phenomenon of the laser and the arc is also found in laser-TIG double-side welding. More noteworthy is that the behavior of arc attraction or constriction became much obvious at a lower current or laser plasma ejected from the keyhole bottom. The decrease in arc voltage had a certain relation u＇ith the improvement of arc stabilio.
基金This work was supported by National Natural Science Foundation of China, No 50675046, 50775053.
文摘A new high efficiency welding method, double-sided double arc welding with double powers （DSAW-D）, is developed for thick plate of low alloy high strength steel in this study. It is well known that the thermal cycles have an important influence on the microstructure, shape, stress, distortion and mechanical property. The DSA W-D method can control the temperature field on a wide range by regulating the distance between two arcs, improve the microstructure and prevent hot and cold cracking of high strength steel. But at present, the effect of arc distance on the temperature field and shape is not clear. Therefore, the paper researches the effect of arc distance on the temperature field and weld pool during DSAW-D using finite element method. The transient temperature field of different arc distance in DSAW-D is calculated. To verify the numerical results, the temperature is measured by the thermo-couple and the calculated results agree approximately with experimental data. Farther, the thermal property and mutual effect of double-sided arcs are investigated. The temperature distributions and weld pool profile at different arc distances are obtained. The results show that arc distance is a very important factor to affect the heat process.
基金National Natural Science Foundation of China(11875039)Shanxi Scholarship Council of China(2023-033)+2 种基金Fundamental Research Program of Shanxi Province(202303021221071)China Baowu Low Carbon Metallurgical Innovation Foundation(2022)2023 Anhui Major Industrial Innovation Plan Project。
文摘The in-flight heating process of cerium dioxide(CeO_(2))powders was investigated through experiments and numerical simulations.In the experiment,CeO_(2)powder(average size of 30μm)was injected into radio-frequency(RF)argon plasma,and the temperatures were measured using a DPV-2000 monitor.A model combining the electromagnetism,thermal flow,and heat transfer characteristics of powder during in-flight heating in argon plasma was proposed.The melting processes of CeO_(2)powders of different diameters,with and without thermal resistance effect,were investigated.Results show that the heating process of CeO_(2)powder particles consists of three main stages,one of which is relevant to a dimensionless parameter known as the Biot number.When the Biot value≥0.1,thermal resistance increases significantly,especially for the larger powders.The predicted temperature of the particles at the outlet(1800–2880 K)is in good agreement with the experimental result.
基金supported by the National Natural Science Foundation of China(No.62464010)Spring City Plan-Special Program for Young Talents(K202005007)+2 种基金Yunnan Talents Support Plan for Young Talents(XDYC-QNRC-2022-0482)Yunnan Local Colleges Applied Basic Research Projects(202101BA070001-138)Frontier Research Team of Kunming University 2023.
文摘Rechargeable Zn/Sn-air batteries have received considerable attention as promising energy storage devices.However,the electrochemical performance of these batteries is significantly constrained by the sluggish electrocatalytic reaction kinetics at the cathode.The integration of light energy into Zn/Sn-air batteries is a promising strategy for enhancing their performance.However,the photothermal and photoelectric effects generate heat in the battery under prolonged solar irradiation,leading to air cathode instability.This paper presents the first design and synthesis of Ni_(2)-1,5-diamino-4,8-dihydroxyanthraquinone(Ni_(2)DDA),an electronically conductiveπ-d conjugated metal-organic framework(MOF).Ni_(2)DDA exhibits both photoelectric and photothermal effects,with an optical band gap of~1.14 eV.Under illumination,Ni_(2)DDA achieves excellent oxygen evolution reaction performance(with an overpotential of 245 mV vs.reversible hydrogen electrode at 10 mA cm^(−2))and photothermal stability.These properties result from the synergy between the photoelectric and photothermal effects of Ni_(2)DDA.Upon integration into Zn/Sn-air batteries,Ni_(2)DDA ensures excellent cycling stability under light and exhibits remarkable performance in high-temperature environments up to 80℃.This study experimentally confirms the stable operation of photo-assisted Zn/Sn-air batteries under high-temperature conditions for the first time and provides novel insights into the application of electronically conductive MOFs in photoelectrocatalysis and photothermal catalysis.
基金supported by the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(MSIT)(No.RS-2022-00143178)the Ministry of Education(MOE)(Nos.2022R1A6A3A13053896 and 2022R1F1A1074616),Republic of Korea.
文摘Beam-tracking simulations have been extensively utilized in the study of collective beam instabilities in circular accelerators.Traditionally,many simulation codes have relied on central processing unit(CPU)-based methods,tracking on a single CPU core,or parallelizing the computation across multiple cores via the message passing interface(MPI).Although these approaches work well for single-bunch tracking,scaling them to multiple bunches significantly increases the computational load,which often necessitates the use of a dedicated multi-CPU cluster.To address this challenge,alternative methods leveraging General-Purpose computing on Graphics Processing Units(GPGPU)have been proposed,enabling tracking studies on a standalone desktop personal computer(PC).However,frequent CPU-GPU interactions,including data transfers and synchronization operations during tracking,can introduce communication overheads,potentially reducing the overall effectiveness of GPU-based computations.In this study,we propose a novel approach that eliminates this overhead by performing the entire tracking simulation process exclusively on the GPU,thereby enabling the simultaneous processing of all bunches and their macro-particles.Specifically,we introduce MBTRACK2-CUDA,a Compute Unified Device Architecture(CUDA)ported version of MBTRACK2,which facilitates efficient tracking of single-and multi-bunch collective effects by leveraging the full GPU-resident computation.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2022YFA1403503,2022YFA1602802,2023YFA1607400,and 2024YFA1613200)Beijing Natural Science Foundation(Grant No.JQ23022)supported by the Synergetic Extreme Condition User Facility and the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302600)。
文摘Fe_(3)Sn_(2),a ferromagnetic metal with a kagome lattice,serves as an ideal platform for exploring topological electronic states and Berry curvature due to its unique band structure.However,systematic reports on the transport properties of Fe_(3)Sn_(2)nanosheets remain scarce.We present temperature-dependent transport property measurements of Fe_(3)Sn_(2)nanosheets synthesized via chemical vapor deposition on Si/SiO_(2)substrates.The samples exhibit a robust anomalous Hall effect from 40 K to 300 K,along with a magnetoresistance sign reversal at 40 K at high magnetic fields,indicating a spin reorientation from in-plane to out-of-plane.Notably,a sharp crossover in the dominant transport contribution from electrons to holes near 200 K is observed,accompanied by distinct anomalous Hall behaviors in the two regimes,indicating a temperature-induced Lifshitz transition within the multi-band system.This divergence is potentially linked to a topological reconstruction of the Fermi surface across the transition.Our findings highlight the tunability of topological transport in two-dimensional kagome magnets and provide new insights into the interplay between band topology,dimensionality and magnetic order.
基金supported by the Key R&D Program of Shaanxi Province,China(2024NC-YBXM-146)the Xi’an Agricultural Technology Research and Development Project,China(24NYGG0048)+1 种基金the Key R&D Program of Xianyang,China(L2024-ZDYF-ZDYF-NY-0028)the National Foreign Expert Project of China(G2023172002L)。
文摘The effect of adding hydroxycinnamic acids(caffeic acid,sinapic acid,p-coumaric acid and chlorogenic acid)in Cabernet Sauvignon dry red wine before and after fermentation was investigated,taking into account the color parameters,anthocyanin content,and overall polyphenol levels in the wine samples.The copigmentation effect of malvidin-3-Oglucoside and sinapic acid was further explored in model solution and through theoretical calculations.The results indicated that the addition of hydroxycinnamic acids significantly enhanced the wine's color with sinapic acid(before the fermentation)showing the most pronounced color protection effect.Compared to control samples,the addition of hydroxycinnamic acids resulted in a 36%increase in total phenolic content and a 28% increase in total anthocyanin content.Thermodynamic analysis revealed that the interaction between sinapic acid and malvidin-3-O-glucoside was spontaneous and exothermic.Theoretical studies identified hydrogen bonding(HB)and dispersion forces as the main primary stabilizing forces,with the carboxyl group of sinapic acid playing a critical role while the anthocyanin backbone also influenced the interaction.
基金supported by the Key Research and Development Program of Gansu Province(22YF7FA070)the National Natural Science Foundation of China(22406076,22466026)the Basic Research Project of Yunnan Province(202301BE070001-017,202401CF070139,202401AS070085)。
文摘Iron and steel industry is one of the main sources of air pollution emissions in China.The sintering process is an important link in the blast furnace ironmaking process,but it is also accompanied by a large number of pollutants.Under the background of ultra-low emissions,iron and steel enterprises urgently need to upgrade their existing processes to address the existing process in practical application problems.In this study,a steel group in Gansu Province was taken as an example.By comparing and analyzing the pollutant emission characteristics before and after the ultra-low emission retrofit,the collaborative control effect of the combined process on SO_(2),NO_(x),particulate matter,and dioxins after the new retrofit was systematically evaluated.The results show that after the retrofit,the concentrations of particulate matter,SO_(2) and NO_(x) have dropped to near-zero levels,and the dioxin removal efficiency has reached 98.87%,with all indicators being better than the national ultra-low emission standards.The study confirms that the optimal combination of multi-pollutant collaborative treatment technologies is the key to achieving efficient emission reduction,among which selective catalytic reduction technology has a particularly significant synergistic removal effect on NO_(x) and dioxins.This study provides an important technical reference and practical basis for the ultra-low emission retrofit of the steel industry,and has important guiding significance for promoting the green retrofit of the industry.Its ultra-low emission retrofit is of great significance for achieving green and low-carbon development.
基金supported by the National Natural Science Foundation of China(No.32170121).
文摘Benzalkonium chloride(BAC)is widely employed as a broad-spectrum biocide and has emerged as a significant environmental pollutant.Polymyxin B(PB)serves as the last-line defense for the treatment of Gram-negative pathogens.Previous studies reported that BAC-adapted Pseudomonas aeruginosa increased the tolerance to PB.Herein,we present the novel finding that the combination of BAC and PB exhibited synergistic antibacterial effects against P.aeruginosa.Time-killing assay demonstrated a significant reduction in bacterial cell viability.Scanning electron microscopy,zeta potential analysis,hydrophobicity measurements,and fluorescence probe analyses collectively revealed severe disruption of the cell envelope and membrane potential induced by the combination of BAC and PB.Transcriptomic analysis revealed that the BAC-PB combination notably downreg-ulated the expression of genes involved in lipid A modification and cell envelope production,including phoPQ,pmrAB,bamABCDE,lptABCDEG,lolB,yidC,and murJ.Additionally,the combination group exhibited augmented production of reactive oxygen species and diminished ATP synthesis.The expression of the genes associated with substance metabolism and energy generation was significantly impeded.This study provides significant implica-tions for the interactions of biocides and antibiotics on Gram-negative pathogens,while also addressing antibiotic resistance and developing the external treatment strategy for Pseudomonas-infected wounds and burns.
基金Supported by Special Fund Project for the Transformation of Scientific and Technological Achievements in Inner Mongolia Autonomous Region(2021CG0013)Bayannur City Science and Technology Plan Project(K202014)+1 种基金Inner Mongolia Autonomous Region Science and Technology Plan Project(2022YFHH0088)Research Special Project of the Education Department of Inner Mongolia Autonomous Region(STAQZX202320).
文摘[Objectives]To explore the control mode of farmland drainage pollutants and investigate the effects of ecological ditch and wetland on reducing farmland drainage pollutants in Hetao Irrigation District.[Methods]Based on the demonstration construction project of the ecological ditch-constructed wetland system in the Hetao Irrigation District,an experimental study was conducted from July to September 2023 to investigate the interception and purification effects of ecological ditches,constructed wetlands,and the combined ecological ditch-constructed wetland system on farmland drainage pollutants.Key water quality parameters measured included total nitrogen(TN)concentration and total phosphorus(TP)concentration.[Results]Different treatment modes of ecological ditches and constructed wetlands have a certain removal effect on nitrogen and phosphorus pollutants in water bodies.The ecological ditches treated with Astragalus laxmannii,Melilotus officinalis,Medicago sativa,bio-ball substrate,and bio-sheet substrate showed reduction efficiencies for TN and TP of 21.09% and 23.84%,12.06% and 26.67%,20.08% and 34.15%,23.65% and 20.56%,and 19.92% and 25.83%,respectively.The emergent plant area showed reduction efficiencies of 24.28%for TN and 17.89%for TP,while the submerged plant area achieved a reduction efficiency of 10.21%for both TN and TP.Among the different treatment modes,the ecological ditch with M.sativa performed better in TP removal,whereas the bio-ball substrate treatment mode showed higher effectiveness in TN removal.In addition,the emergent plant area exhibited better TP removal performance,while the submerged plant area was more effective in TN removal.The combined system of ecological ditch and constructed wetland achieved removal rates of 37.55% for TN and 11.47% for TP.It effectively facilitates the step-by-step interception and adsorption purification of pollutants,thereby showing significant removal and purification effects on nitrogen and phosphorus contaminants.This contributes to mitigating agricultural non-point source pollution.[Conclusions]The combined ecological ditch-constructed wetland system serves dual functions of agricultural drainage and pollutant interception and purification.It reduces the pollution load of farmland drainage on receiving water bodies to some extent and mitigates agricultural non-point source pollution.Therefore,it is a relatively suitable technology for managing agricultural non-point source pollution in the Hetao Irrigation District.
基金supported by the National Natural Science Foundation of China(Nos.82003977,82274134 and 82274139)the National Key Research and Development Plan(No.2017YFC1702200)+1 种基金the Key Research and Development Program of Zhejiang Province(No.2020C04020)the Science and Technology Program of Zhejiang Province(No.2025C02183).
文摘Inflammatory bowel disease(IBD),which includes Crohn’s disease(CD)and ulcerative colitis(UC),is a chronic inflammatory condition affecting the gastrointestinal tract.The global incidence and prevalence of IBD continue to increase.While multiple clinical treatments exist,conventional therapies frequently present limitations and adverse effects.Natural polysaccharides(PSs)have emerged as a significant focus of research interest due to their therapeutic potential and applications in functional foods and health products.This review synthesizes current understanding of IBD pathophysiology and the mechanisms by which natural PSs counter IBD,including their capacity to restore immune homeostasis and intestinal barrier function,modulate gut microbiota and metabolites,reduce oxidative stress,and address irregularities in autophagy and endoplasmic reticulum stress(ERS).The review examines the structure-activity relationships of PSs demonstrating anti-IBD effects and identifies promising therapeutic products.The discussion encompasses pharmacokinetics,safety evaluations,and clinical applications of these compounds.This comprehensive review establishes a theoretical foundation for developing natural PS-based therapeutic approaches for IBD management.
基金Project supported by the National Natural Science Foundation of China(No.12472077)the supports from Shanghai Gaofeng Project for University Academic Program Development,Fundamental Research Funds for the Central Universities(No.22120240353).
文摘Lattice materials have demonstrated promising potential in engineering applications owing to their exceptional lightweight,high specific strength,and tunable mechanical properties.However,the traditional homogenization methods based on the classical elasticity theory struggle to accurately describe the non-classical mechanical behaviors of lattice materials,especially when dealing with complex unit-cell geometries featured by non-symmetric configurations or non-single central node connections.In response to this limitation,this study establishes a generalized homogenization model based on the micropolar theory framework,employing Hill's boundary conditions to precisely predict the equivalent moduli of complex lattice materials.By introducing the independent rotational degree of freedom(DOF)characteristic of the micropolar theory,the proposed model successfully overcomes the limitation of conventional methods in accurately describing the asymmetric deformation and scale effects.We initially calculate the constitutive relations of two-dimensional(2D)cross-shaped multi-node chiral lattices and subsequently extend the method to three-dimensional(3D)lattices,successfully predicting the mechanical properties of both traditional and eccentric body-centered cubic(BCC)lattices.The theoretical model is validated through the finite element numerical verification which shows excellent consistency with the theoretical predictions.A further parametric study investigates the influence of geometric parameters,revealing the underlying size-effect mechanism.This paper provides a reliable theoretical tool for the design and property optimization of complex lattice materials.
基金funded by the National Natural Science Foundation of China(NSFC)under Grant Number 72071209.
文摘Modern battlefields exhibit high dynamism,where traditional static weighting methods in combat effectiveness assessment fail to capture real-time changes in indicator values,leading to limited assessment accuracy—especially critical in scenarios like sudden electronic warfare or degraded command,where static weights cannot reflect the operational value decay or surge of key indicators.To address this issue,this study proposes a dynamic adaptive weightingmethod for evaluation indicators based onG1-CRITIC-PIVW.First,theG1(Sequential Relationship Analysis Method)subjective weighting method—translates expert knowledge into indicator importance rankings—leverages expert knowledge to quantify the relative importance of indicators via sequential relationship ranking,while the CRITIC(Criteria Importance Through Intercriteria Correlation)objective weighting method—derives weights from data characteristics by integrating variability and inter-correlations—calculates weights by integrating indicator variability and inter-indicator correlations,ensuring data-driven objectivity.These two sets of weights are then fused using a deviation coefficient optimization model,minimizing the squared deviation from a reference weight and adjusting the fusion coefficient via Spearman’s rank correlation to resolve potential conflicts between subjective and objective judgments.Subsequently,the PIVW(Punishment-Incentive VariableWeight)theory—adapts weights to realtime indicator performance via penalty/incentive rules—is applied for dynamic adjustment.Scenario-specific penalty λ_(1) and incentive λ_(2) thresholds are set based on operational priorities and indicator volatility,penalizing indicators with values below λ_(1) and incentivizing those exceeding λ_(2) to reflect real-time indicator performance.Experimental validation was conducted using an Air Defense and Anti-Missile(ADAM)system effectiveness assessment framework,with data covering 7 indicators across 3 combat scenarios.Results show that compared to static weighting methods,the proposed method reduces MAE(Mean Absolute Error)by 15%-20% and weighted decision error rate by 84.2%,effectively reducing overestimation/underestimation of combat effectiveness in dynamic scenarios;compared to Entropy-TOPSIS,it lowers MAE by 12% while achieving a weighted Kendall’sτconsistency coefficient of 0.85,ensuring higher alignment with expert judgment.This method enhances the accuracy and scenario adaptability of effectiveness assessment,providing reliable decision support for dynamic battlefield environments.
基金Supported by the Zhejiang Medical Health Science and Technology Project(No.2021KY217)the Basic Public Welfare Research Project of Wenzhou Municipal Science and Technology Bureau(No.2024Y1221).
文摘AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 groups:Group A(implanted with the SN6CWS),Group B(implanted with the MI60),and Group C(implanted with the Aspira-aA).ELP measurements were obtained with swept-source optical coherence tomography(SS-OCT)at 1d,1wk,1mo,and 3mo postoperatively.Subjective refraction assessments were conducted at 1wk,1mo,and 3mo following surgery.RESULTS:The study included 189 eyes of 150 cataract patients(66 males).There were 77 eyes in Group A,55 eyes in Group B,and 57 eyes in Group C.The root mean square of the ELP(ELPRMS)within the initial 3mo was significantly lower for Group A than for Groups B and C.Refractive changes within Group A were not significant across the time points of 1wk,1mo,and 3mo.Conversely,both Group B and Group C demonstrated statistically significant shifts toward hyperopia from 1wk to 3mo postsurgery.CONCLUSION:Among the three IOLs examined,the SN6CWS IOL showes the greatest stability during the first 3mo postoperatively.Between 1wk and 3mo after surgery,notable hyperopic shifts are evident in eyes implanted with the MI60 and Aspira-aA IOLs,whereas refractive outcomes remain relatively constant in eyes implanted with SN6CWS IOLs.
基金supported by the Quantum Science and Technology-National Science and Technology Major Project of China(Grant No.2024ZD0301000)the National Natural Science Foundation of China(Grant No.12275136)。
文摘The Stern-Gerlach(SG)experiment is a fundamental experiment for revealing the existence of“spin”.In this experiment,beams of silver atoms are sent through inhomogeneous magnetic fields to observe their deflection.Thus,the conventional SG experiment can be viewed as a magnetic-type spin effect.In this work,we successfully generalize the SG effect from magnetic-type to electric-type by solving Dirac's equation with a potential barrier,revealing an extraordinary spin effect.Beams of Dirac particles can be regarded as matter waves.Based on Dirac's equation,we obtain the explicit forms of the incident,reflected,and transmitted waves.The electric-type SG effect shows that the reflected and transmitted waves can exhibit notable spatial shifts,which depend on the spin direction and the incident angle of the wave.The electrictype SG effect has potential applications for separating Dirac particles with different spin directions and for estimating the spin direction of Dirac particles.Some discussions related to the interaction between spin and the electric field are also presented.
基金supported by the National Science and Tech-nology Major Project of China(Nos.2017-II-0007-0021 and J2019-II-0017-0038)。
文摘Aerodynamic performances of axial compressors are significantly affected by variation of Reynolds number in aero-engines.In the design and analysis of compressors,previous correction methods for cascades and stages have difficulties in predicting comprehensively Reynolds number effects on airfoils,matching and characteristics curves.This study proposes Re-correction models for loss,deviation angle and endwall blockage based on classical theories and cascade tests,and loss and deviation models show good agreement in test data of NACA65 and C4 cascades.Throughflow method considering Reynolds number effects is developed by integrating the correction models into a verified Streamline Curvature(SLC)tool.A three-stage axial compressor is investigated through SLC and CFD methods from design Reynolds number(Red=2106)to low Re=4104,and the numerical methods are validated with test data of characteristic curves and spanwise distributions at Red.With Re reduction,SLC method with correction models well predicts variation in overall performances compared with CFD calculations and Wassell's model.Streamwise and spanwise matching such as total pressure and loss distributions in SLC predictions are basically consistent with those in CFD results at near-stall points under design and low Reynolds numbers.SLC and CFD methods share similar detections of stall risks in the third stage(Stg3),and their analyses of diffusion processes deviate to some extent due to different predictions in separated endwall flow.The correction models can be adopted to consider Reynolds number effects in through-flow design and analysis of axial compressors.
