目的:系统评价培土生金中药联合西医常规疗法治疗支气管哮喘缓解期肺脾两虚证的疗效以及证据质量,为临床决策及疾病指南制订提供循证依据。方法:检索中国知网(CNKI)、万方数据库(Wangfang)、Pubmed、Web of Science等8大中英文数据库,由...目的:系统评价培土生金中药联合西医常规疗法治疗支气管哮喘缓解期肺脾两虚证的疗效以及证据质量,为临床决策及疾病指南制订提供循证依据。方法:检索中国知网(CNKI)、万方数据库(Wangfang)、Pubmed、Web of Science等8大中英文数据库,由2名研究者独立进行文献筛选、信息提取、偏倚风险评估及方法学质量评价,并对纳入研究的总有效率、中医证候积分、第一秒用力呼气容积(FEV1)、第一秒用力呼气容积/用力肺活量(FEV1/FVC)、哮喘控制测试(ACT)评分等结局指标进行Meta分析,最终依照GRADE评估证据质量。结果:共纳入14项研究,合计1263例患者。结果显示:(1)培土生金中药联合常规西医疗法可有效改善患者总有效率,降低患者中医证候积分,改善患者FEV1水平、FEV1/FVC及ACT评分。(2)总有效率证据质量较优,可信度高,其余指标证据质量较低,尚待更多高质量的研究支持以提升证据级别。结论:培土生金中药联合西医常规疗法治疗支气管哮喘缓解期肺脾两虚证优于单用西医常规治疗,且在总有效率上证据质量较高,具有一定的循证学意义。展开更多
This study presents a systematic investigation of high-efficiency flexible copper indium gallium selenide(CIGS)thin-film solar cells fabricated using an optimized three-stage co-evaporation process.The research focuse...This study presents a systematic investigation of high-efficiency flexible copper indium gallium selenide(CIGS)thin-film solar cells fabricated using an optimized three-stage co-evaporation process.The research focuses on two key innovations:(1)NaF pre-deposition for controlled alkali metal doping and(2)active regulation of In/Ga evaporation timing during the initial growth stage to precisely engineer the Ga/(Ga+In)(GGI)ratio gradient throughout the absorber layer depth.Through comprehensive characterization of structural properties,elemental distributions,and device performance,we demonstrate that the synergistic combination of Na doping and tailored Ga grading effectively addresses critical challenges in flexible CIGS devices,including back-surface Ga accumulation and non-ideal bandgap profiles.Our results reveal that this dual optimization strategy significantly enhances charge carrier mobility and collection efficiency,ultimately leading to substantial improvements in overall solar cell performance.The findings establish a robust materials engineering approach for developing high-performance flexible photovoltaic devices through precise control of compositional gradients and defect passivation.展开更多
Functionally graded cellular structures(FGCSs)have a multitude of applications to a wide range of industries.Utilising the ever-progressing technology of additive manufacturing(AM),FGCSs can be applied to control mate...Functionally graded cellular structures(FGCSs)have a multitude of applications to a wide range of industries.Utilising the ever-progressing technology of additive manufacturing(AM),FGCSs can be applied to control material grading and achieve the desired mechanical properties.The current study explores the design and optimisation of FGCSs for AM,with a focus on improving the compression and impact performance of below knee(BK)prosthetic limbs made of thermoplastic polyurethane(TPU).A multiscale research methodology integrating topology optimization(TO),finite element analysis(FEA),and design of experiments(Do E)was adopted to optimise lattice structures in terms of stiffness and lightweight properties.Two-unit cell designs were considered in the study:Schwarz P gyroid and body-centered cubic(BCC).Response surface methodology(RSM)was implemented to analyse the effect of minimum and maximum cell wall thickness,cell size,and unit cell type on the mechanical performance of TPU FGCS structures.The results indicated that a Schwarz P FGCS structure with cell size,minimum and maximum cell wall thickness of 6,0.9 and 2.8 mm,respectively,could be optimal for a compromise between performance and weight.In this optimized case,stiffness and volume fraction values of 684 N/mm and 0.64 were obtained,respectively.The study also presents a proof-of-concept design for a BK prosthetic damper,highlighting the potential of FGCSs to enhance patient comfort,reduce manufacturing costs,and enable personalised designs through 3D scanning and AM.The obtained results could be a step forward towards the incorporation of AM technologies in prosthetics,offering a pathway to lightweight,cost-effective,and functionally tailored solutions.展开更多
Thermomagnetic generation(TMG),a heat-to-electricity conversion technology based on the thermomagnetic effect,offers high reliability and broad adaptability to diverse heat sources.By exploiting the temperature-depend...Thermomagnetic generation(TMG),a heat-to-electricity conversion technology based on the thermomagnetic effect,offers high reliability and broad adaptability to diverse heat sources.By exploiting the temperature-dependent magnetization of thermomagnetic materials,TMG converts thermal energy into electrical energy through cyclic changes in magnetic flux based on Faraday's law.The performance of TMG systems is largely governed by the intrinsic properties of the working materials and the design of device architecture.Ideal TMG materials exhibit sharp and reversible magnetization transitions near the operating temperature,low thermal hysteresis,and high thermal conductivity.Device configurations can be broadly categorized into active and passive systems:active TMG devices rely on controlled thermal cycling and optimized magnetic circuits for enhanced output,whereas passive devices utilize self-actuated mechanical motion to generate electricity.In this topical review,we provide a comprehensive overview of recent advances in TMG materials and device configurations.Furthermore,we discuss future development trends and offer perspectives on experimental strategies to advance this field.展开更多
China's requisition-compensation balance strategy has dramatically reshaped cropland spatial patterns,drawing multidisciplinary research attention.However,existing studies predominantly emphasize horizontal distri...China's requisition-compensation balance strategy has dramatically reshaped cropland spatial patterns,drawing multidisciplinary research attention.However,existing studies predominantly emphasize horizontal distribution,overlooking the significant influence of slope gradient on cropland spatial patterns.This paper proposes a slope location quotient(SLQ)index that reflects the relative advantage of cropland distribution and explores the slope grade difference of cropland spatial patterns in China at the county scale.The analysis adopts 30-m resolution digital elevation model with land cover data,taking 2672 counties with cropland ratio>1%as study units.The temporal scope covers 1990 and 2020,with slope gradients categorized into five grades:0°~2°,2°~6°,6°~15°,15°~25°,and 25°~90°.Results show that:1)The inverse correlation between cropland area and slope gradient remained stable throughout the study period,with the variation in cropland area frequency across slope grades being less than 1%.2)The spatial patterns of SLQ in 1990 and 2020 both transited stepwise with slope gradient,while≤2°and>6°slopes exhibited opposing patterns.3)The mean absolute variation of SLQ during 1990-2020 increased with slope gradient(R2=0.926,p<0.01).Particularly for slope grades>15°,the mean absolute variation reached 0.26(for 15°~25°)and 0.43(for 25°~90°),respectively,and displayed a distinct southward-increasing and northwarddecreasing pattern.This study offers novel slopegradient perspectives for analyzing cropland spatial patterns.To enhance cropland protection benefits,reversing the steep cropland SLQ surge in southern China is recommended.展开更多
Automated grading of dandruff severity is a clinically significant but challenging task due to the inherent ordinal nature of severity levels and the high prevalence of label noise from subjective expert annotations.S...Automated grading of dandruff severity is a clinically significant but challenging task due to the inherent ordinal nature of severity levels and the high prevalence of label noise from subjective expert annotations.Standard classification methods fail to address these dual challenges,limiting their real-world performance.In this paper,a novel,three-phase training framework is proposed that learns a robust ordinal classifier directly from noisy labels.The approach synergistically combines a rank-based ordinal regression backbone with a cooperative,semi-supervised learning strategy to dynamically partition the data into clean and noisy subsets.A hybrid training objective is then employed,applying a supervised ordinal loss to the clean set.The noisy set is simultaneously trained using a dualobjective that combines a semi-supervised ordinal loss with a parallel,label-agnostic contrastive loss.This design allows themodel to learn fromthe entire noisy subset while using contrastive learning to mitigate the risk of error propagation frompotentially corrupt supervision.Extensive experiments on a new,large-scale,multi-site clinical dataset validate our approach.Themethod achieves state-of-the-art performance with 80.71%accuracy and a 76.86%F1-score,significantly outperforming existing approaches,including a 2.26%improvement over the strongest baseline method.This work provides not only a robust solution for a practical medical imaging problem but also a generalizable framework for other tasks plagued by noisy ordinal labels.展开更多
When micro/nano-scale gradient coatings are subject to large thermal gradients or high heat fluxes,the spatial size effect cannot be ignored.It is important to understand how the size effect influences the thermal fra...When micro/nano-scale gradient coatings are subject to large thermal gradients or high heat fluxes,the spatial size effect cannot be ignored.It is important to understand how the size effect influences the thermal fracture behavior of functionally graded coating/substrate structures.This study aims at analyzing the transient thermal fracture behavior of collinear interface cracks in functionally graded coating/substrate structures based on the nonlocal dual-phase-lag heat conduction model.By means of integral transform techniques,the mixed boundary problem is transformed into a set of singular integral equations,which are solved by the Chebyshev polynomials.The effects of the nonlocal parameter,coating thickness,crack spacing,and non-homogeneous parameters on the temperature and stress intensity factors(SIFs)are examined.The numerical results show that these parameters play an essential role in controlling the thermal fracture behavior of the structures,especially at micro/nano-scales.展开更多
We used hydrodynamic simulations and shock wave propagation theories to analyze the behavior of shock waves within Ti/Pt periodically modulated graded structures and their integration layers.The effects of the total n...We used hydrodynamic simulations and shock wave propagation theories to analyze the behavior of shock waves within Ti/Pt periodically modulated graded structures and their integration layers.The effects of the total number of periodic layers,the total thickness of graded materials and loading velocity on the integration layer thickness and behavior of pressure-strain rate were systematically investigated.The results reveal that,by adjusting the total number of periodically modulated layers,the total thickness of graded materials and loading velocity the pressure amplitudes of the reflected compressive and rarefaction waves at different interfaces of Ti/Pt periodically modulated graded materials can be precisely controlled.Furthermore,empirical structural design criteria for Ti/Pt periodically modulated graded materials are established.The thickness ratio variation between adjacent Ti/Pt layers in the periodic structure must exceed 0.32.After the collaborative design of the integration layer,Ti/Pt periodically modulated graded materials can achieve a controllable loading function with pressures ranging from 1.4 to 144 GPa and strain rates from 3.8×10^(4) to 1.7×10^(7) s^(–1).The outcomes of this research provide a theoretical and simulation basis for the optimized design of periodically modulated graded materials to be utilized in ramp compression experiments.展开更多
Functionally graded material(FGM)plates are widely used in various engineering structures owing to their tailor-made mechanical properties,whereas cracked homogeneous plates constitute a canonical setting in fracture ...Functionally graded material(FGM)plates are widely used in various engineering structures owing to their tailor-made mechanical properties,whereas cracked homogeneous plates constitute a canonical setting in fracture mechanics analysis.These two classes of problems respectively embody material non-uniformity and geometric discontinuity,thereby imposing more stringent requirements on numerical methods in terms of high-order field continuity and accurate defect representation.Based on the classical Kirchhoff-Love plate theory,a numerical manifold method(MLS-NMM)incorporating moving least squares(MLS)interpolation is developed for bending analysis of FGM plates and fracture simulation of homogeneous plates with defects.The method constructs an H^(2)-regular approximation with high-order continuous weighting functions and,combined with the separation of mathematical and physical covers,establishes a unified framework that accurately handles material gradients and cracks without mesh reconstruction.For the crack tip,a singular physical cover incorporating the Williams asymptotic field is introduced to achieve local enrichment,enabling the natural capture of displacement discontinuity and stress singularity.Stress intensity factors are extracted using the interaction integral method,and the dimensionless J-integral shows a maximum relative error below 1.2%compared with the reference solution.Numerical results indicate that MLS-NMM exhibits excellent convergence performance:using 676 mathematical nodes,the nondimensional central deflection of both FGM and homogeneous plates agrees with reference solutions with a maximum relative error below 0.81%,and no shear locking occurs.A systematic analysis reveals that for a simply supported on all four edges(SSSS)FGM square plate with a/h=10,the nondimensional central deflection increases by 212%as the gradient index nrises from 0 to 5.For a homogeneous plate containing a central crack with c/a=0.6,the nondimensional central deflection increases by approximately 46%compared with the intact plate.Under weak boundary constraints(e.g.,SFSF),the deformation is markedly amplified,with the deflection reaching more than three times that under strong constraints(SCSC).The proposed method provides an efficient,reconstruction-free numerical tool for high-accuracy bending and fracture analyses of FGM and cracked thin-plate structures.展开更多
To the Editor,Artificial intelligence(AI)usage has been increasing.Many fields have implemented the use of AI and Large LanguageModels(LLMs),especially in medicine.Furthermore,manypatients have increasingly been using...To the Editor,Artificial intelligence(AI)usage has been increasing.Many fields have implemented the use of AI and Large LanguageModels(LLMs),especially in medicine.Furthermore,manypatients have increasingly been using AI;often,they will prompt AI with questions before even stepping into a physi-cian's office.The question lies in whether the information produced by AI is reliable and if this information is concise and easy to read across all patient populations.展开更多
Sandwich functionally graded(FG)auxetic beams are extensively utilized in aerospace,automotive,and biomedical industries due to their excellent strength-toweight ratio,impact resistance,and tunable mechanical properti...Sandwich functionally graded(FG)auxetic beams are extensively utilized in aerospace,automotive,and biomedical industries due to their excellent strength-toweight ratio,impact resistance,and tunable mechanical properties.The integration of FG materials with auxetic structures enhances their adaptability in advanced engineering applications.However,understanding their dynamic behavior under external excitations is essential for optimal design and structural reliability.Nonlinear interactions in such structures pose significant challenges in vibration analysis,necessitating robust analytical methods.This study presents a closed-form solution for the nonlinear forced vibration analysis of sandwich FG auxetic beams,offering an accurate and efficient method for predicting their dynamic response.The beam consists of two FG face sheets with material properties varying through the thickness and a re-entrant honeycomb auxetic core with an adjustable Poisson's ratio.The governing nonlinear equations of motion are derived using the first-order shear deformation theory(FSDT),the modified Gibson model,and the von Kármán relations,formulated through Hamilton's principle.A closed-form solution is obtained via the Galerkin method and multiple-scale technique.The results demonstrate that FG layers enable control of the overweight and dynamic response amplitude,with positive power law indexes reducing weight.Comparisons with finite element results confirm the accuracy of the proposed formulation.展开更多
The accurate mechanical analysis of thick-walled pressure vessel structures composed of advanced materials,such as hyperelastic and functionally graded materials(FGMs),is critical for ensuring their safety and optimiz...The accurate mechanical analysis of thick-walled pressure vessel structures composed of advanced materials,such as hyperelastic and functionally graded materials(FGMs),is critical for ensuring their safety and optimizing their design.However,conventional numerical methods can face challenges with the non-linearities inherent in hyperelasticity and the complex spatial variations in FGMs.This paper presents a novel hybrid numerical approach combining Physics-Informed Neural Networks(PINNs)with Finite Element Method(FEM)derived data for the robust analysis of thick-walled,axisymmetric,heterogeneous,hyperelastic pressure vessels with elliptical geometries.A PINN framework incorporating neo-Hookean constitutive relations is developed in MATLAB.To enhance training efficiency and accuracy,the PINN’s loss function is augmented with displacement data obtained from high-fidelity FEM simulations performed in ANSYS.The methodology is rigorously validated by comparing PINN-predicted displacement and von Mises stress fields against ANSYS benchmarks for various scenarios of FGMconfigurations(with material properties varying according to a power law)subjected to internal and external pressurization.The results demonstrate excellent agreement between the proposed hybrid PINN-FEMapproach and conventional FEMsolutions across all test cases,accurately capturing complex deformation patterns and stress concentrations.This study highlights the potential of data-augmented PINNs as an effective and accurate computational tool for tackling complex solid mechanics problems involving non-linearmaterials and significant heterogeneity,offering a promising avenue for future research in engineering design and analysis.展开更多
With the reform booming in teaching fields,the author carried out Graded English teaching in her teaching classroom and achieved favorable efficiency.In this paper,the author mainly discusses the specific grading of e...With the reform booming in teaching fields,the author carried out Graded English teaching in her teaching classroom and achieved favorable efficiency.In this paper,the author mainly discusses the specific grading of exercise after class in implementing graded teaching,taking for example Section A,Unit 6(Go for it! SB for Grade Eight,Volume A,by People's Education Press and Thomson Learning,2004,2nded).展开更多
With the reform booming in teaching fields,the author carried out Graded English teaching in her teaching classroom and achieved favorable efficiency.In this paper,the author mainly discusses the specific grading of t...With the reform booming in teaching fields,the author carried out Graded English teaching in her teaching classroom and achieved favorable efficiency.In this paper,the author mainly discusses the specific grading of teaching objectives in implementing graded teaching.展开更多
Purpose:To evaluate the effect of competency-based management in improving nurse and patient satisfaction.Methods:According to the competency-based management objectives and principles,821 nurses were classified into ...Purpose:To evaluate the effect of competency-based management in improving nurse and patient satisfaction.Methods:According to the competency-based management objectives and principles,821 nurses were classified into different levels based on clear nurse qualifications and post responsibilities.According to the different levels of nursing staff and training plans with different emphases,the goal was for the nursing staff to gradually achieve the corresponding level.Targeted training programs for different levels of nurses were formulated to enable nurses to gradually increase their competency levels.Results:After implementation of competency-based management,nurse job satisfaction and patient satisfaction increased significantly(P<0.01).Additionally,the reported nurse job burnout decreased(P<0.01).Conclusion:Competency-based management can promote nurses’enthusiasm,reduce job burnout,improve job satisfaction,as well as improve patient satisfaction.展开更多
We performed this study to investigate pathological upgrading from biopsy to prostatectomy and clinicopathological factors associated with grade group(GG)upgrading in patients with International Society of Urological ...We performed this study to investigate pathological upgrading from biopsy to prostatectomy and clinicopathological factors associated with grade group(GG)upgrading in patients with International Society of Urological Pathology(ISUP)GG 1 and 2 prostate cancer(PCa)in a Chinese cohort.We included patients diagnosed with PCa with ISUP GG 1 and 2 at biopsy,who underwent RP at our institution.Pre-and postoperative clinical variables were examined.Univariate and multivariate logistic regression analyses were conducted to identify independent factors associated with GG upgrading.Patients in GG upgraded group had higher total prostatespecific antigen(tPSA;median:14.43 ng ml^(−1) vs 10.52 ng ml^(−1),P=0.001)and PSA density(PSAD;median:0.45 ng ml^(−2) vs 0.27 ng ml^(−2),P<0.001)than those in GG nonupgraded group.Patients in upgraded group had a higher ratio for Prostate ImagingReporting and Data System(PI-RADS)score>3(86.4%vs 67.9%,P<0.001).Those with GG 1 in biopsy were more likely to experience GG upgrading after RP than those with GG 2(71 vs 54,P=0.016).Independent preoperative factors predicting GG upgrading were PI-RADS score>3(odds ratio[OR]:2.471,95%confidence interval[CI]:1.132–5.393;P=0.023),higher PSAD(P=0.001),and GG in biopsy(OR:0.241,95%CI:0.123–0.471;P<0.001).The histopathological analyses of RP specimens revealed that perineural invasion(PNI;OR:1.839,95%CI:1.027–3.490;P=0.041)was identified as an independent factor associated with GG upgrading.Our results revealed that GG in the biopsy,PSAD,PI-RADS score>3,and PNI were independent factors of GG upgrading.These factors should be considered for patients with ISUP grade≤2 PCa.展开更多
The SHIFT-G technology of inverse catalyst loading is used to optimize the catalyst grading in the residue hydrotreating unit. The results, taken from pilot tests and commercial units, have showed that the optimized c...The SHIFT-G technology of inverse catalyst loading is used to optimize the catalyst grading in the residue hydrotreating unit. The results, taken from pilot tests and commercial units, have showed that the optimized catalyst grading system can reasonably distribute the reaction load, effectively improve the prop- erties of hydrotreated products, prolong the operating cycle and promote economic benefits.展开更多
Object:To determine the extent and impact of upgrading and downgrading among men who underwent radical prostatectomy(RP)according to new grade groupings and to identify predictors of upgrading from biopsy grade Group ...Object:To determine the extent and impact of upgrading and downgrading among men who underwent radical prostatectomy(RP)according to new grade groupings and to identify predictors of upgrading from biopsy grade Group Ⅰ and Ⅱ,and downgrading to grade Group I,in a community setting.Methods:Study participants included 2279 men with non-metastatic prostate cancer diagnosed 2006-2015 who underwent prostatectomy,from the multi-institutional South Australia Prostate Cancer Clinical Outcomes Collaborative registry.Extent of up-or down-grading was assessed by comparing biopsy and prostatectomy grade groupings.Risk of biochemical recurrence(BCR)with upgrading was assessed using multivariable competing risk regression.Binomial logistic regression was used to identify pre-treatment predictors of upgrading from grade Groups Ⅰ and Ⅱ,and risk group reclassification among men with low risk disease.Results:Upgrading occurred in 35%of cases,while downgrading occurred in 13%of cases.Sixty percent with grade Group I disease were upgraded following prostatectomy.Upgrading from grade Group I was associated with greater risk of BCR compared with concordant grading(Hazard ratio:3.1,95%confidence interval:1.7-6.0).Older age,higher prostate-specific antigen levels(PSA),fewer biopsy cores,higher number of positive cores and more recent diagnosis predicted upgrading from grade Group Ⅰ,while higher PSA and clinical stage predicted upgrading from grade Group Ⅱ.No clinical risk factors for reclassification were identified.Conclusion:Biopsy sampling errors may play an important role in upgrading from grade Group I.Improved clinical assessment of grade is needed to encourage greater uptake of active surveillance.展开更多
文摘目的:系统评价培土生金中药联合西医常规疗法治疗支气管哮喘缓解期肺脾两虚证的疗效以及证据质量,为临床决策及疾病指南制订提供循证依据。方法:检索中国知网(CNKI)、万方数据库(Wangfang)、Pubmed、Web of Science等8大中英文数据库,由2名研究者独立进行文献筛选、信息提取、偏倚风险评估及方法学质量评价,并对纳入研究的总有效率、中医证候积分、第一秒用力呼气容积(FEV1)、第一秒用力呼气容积/用力肺活量(FEV1/FVC)、哮喘控制测试(ACT)评分等结局指标进行Meta分析,最终依照GRADE评估证据质量。结果:共纳入14项研究,合计1263例患者。结果显示:(1)培土生金中药联合常规西医疗法可有效改善患者总有效率,降低患者中医证候积分,改善患者FEV1水平、FEV1/FVC及ACT评分。(2)总有效率证据质量较优,可信度高,其余指标证据质量较低,尚待更多高质量的研究支持以提升证据级别。结论:培土生金中药联合西医常规疗法治疗支气管哮喘缓解期肺脾两虚证优于单用西医常规治疗,且在总有效率上证据质量较高,具有一定的循证学意义。
基金supported by the National Key Research and Development Program of China(Grant No.2024YFB4205300)the National Natural Science Foundation of China(Grant No.52173243)+2 种基金the Natural Science Foundation of Guangdong Province(Grant No.2021A1515011409)Shenzhen&Hong Kong Joint Research Program(Grant No.SGDX20201103095605015)SIAT-CUHK Joint Laboratory of Photovoltaic Solar Energy.
文摘This study presents a systematic investigation of high-efficiency flexible copper indium gallium selenide(CIGS)thin-film solar cells fabricated using an optimized three-stage co-evaporation process.The research focuses on two key innovations:(1)NaF pre-deposition for controlled alkali metal doping and(2)active regulation of In/Ga evaporation timing during the initial growth stage to precisely engineer the Ga/(Ga+In)(GGI)ratio gradient throughout the absorber layer depth.Through comprehensive characterization of structural properties,elemental distributions,and device performance,we demonstrate that the synergistic combination of Na doping and tailored Ga grading effectively addresses critical challenges in flexible CIGS devices,including back-surface Ga accumulation and non-ideal bandgap profiles.Our results reveal that this dual optimization strategy significantly enhances charge carrier mobility and collection efficiency,ultimately leading to substantial improvements in overall solar cell performance.The findings establish a robust materials engineering approach for developing high-performance flexible photovoltaic devices through precise control of compositional gradients and defect passivation.
基金financially supported and funded by the Deanship of Scientific Research at Imam Mohammad Ibn Saud Islamic University(IMSIU)(No.IMSIU-DDRSP2503)。
文摘Functionally graded cellular structures(FGCSs)have a multitude of applications to a wide range of industries.Utilising the ever-progressing technology of additive manufacturing(AM),FGCSs can be applied to control material grading and achieve the desired mechanical properties.The current study explores the design and optimisation of FGCSs for AM,with a focus on improving the compression and impact performance of below knee(BK)prosthetic limbs made of thermoplastic polyurethane(TPU).A multiscale research methodology integrating topology optimization(TO),finite element analysis(FEA),and design of experiments(Do E)was adopted to optimise lattice structures in terms of stiffness and lightweight properties.Two-unit cell designs were considered in the study:Schwarz P gyroid and body-centered cubic(BCC).Response surface methodology(RSM)was implemented to analyse the effect of minimum and maximum cell wall thickness,cell size,and unit cell type on the mechanical performance of TPU FGCS structures.The results indicated that a Schwarz P FGCS structure with cell size,minimum and maximum cell wall thickness of 6,0.9 and 2.8 mm,respectively,could be optimal for a compromise between performance and weight.In this optimized case,stiffness and volume fraction values of 684 N/mm and 0.64 were obtained,respectively.The study also presents a proof-of-concept design for a BK prosthetic damper,highlighting the potential of FGCSs to enhance patient comfort,reduce manufacturing costs,and enable personalised designs through 3D scanning and AM.The obtained results could be a step forward towards the incorporation of AM technologies in prosthetics,offering a pathway to lightweight,cost-effective,and functionally tailored solutions.
基金supported by the National Natural Science Foundation of China(Grant Nos.52171169 and 52101210)the National Key Research and Development Program of China(Grant No.2021YFB3501204)+3 种基金the State Key Laboratory for Advanced Metals and Materials(Grant No.2023-ZD01)USTB Concept Verification Funding Project(Grant No.GNYZ-2024-6)Fundamental Research Funds for the Central Universities(Grant No.FRF-TP-24-004A)USTB Research Center for International People-to-people Exchange in Science,Technology and Civilization(Grant Nos.2024KFZD001 and 2024KFYB004)。
文摘Thermomagnetic generation(TMG),a heat-to-electricity conversion technology based on the thermomagnetic effect,offers high reliability and broad adaptability to diverse heat sources.By exploiting the temperature-dependent magnetization of thermomagnetic materials,TMG converts thermal energy into electrical energy through cyclic changes in magnetic flux based on Faraday's law.The performance of TMG systems is largely governed by the intrinsic properties of the working materials and the design of device architecture.Ideal TMG materials exhibit sharp and reversible magnetization transitions near the operating temperature,low thermal hysteresis,and high thermal conductivity.Device configurations can be broadly categorized into active and passive systems:active TMG devices rely on controlled thermal cycling and optimized magnetic circuits for enhanced output,whereas passive devices utilize self-actuated mechanical motion to generate electricity.In this topical review,we provide a comprehensive overview of recent advances in TMG materials and device configurations.Furthermore,we discuss future development trends and offer perspectives on experimental strategies to advance this field.
基金supported by the project of the National Natural Science Foundation of China entitled“Distribution and change characteristics of construction land on slope gradient in mountainous cities of southern China”(No.41961039)。
文摘China's requisition-compensation balance strategy has dramatically reshaped cropland spatial patterns,drawing multidisciplinary research attention.However,existing studies predominantly emphasize horizontal distribution,overlooking the significant influence of slope gradient on cropland spatial patterns.This paper proposes a slope location quotient(SLQ)index that reflects the relative advantage of cropland distribution and explores the slope grade difference of cropland spatial patterns in China at the county scale.The analysis adopts 30-m resolution digital elevation model with land cover data,taking 2672 counties with cropland ratio>1%as study units.The temporal scope covers 1990 and 2020,with slope gradients categorized into five grades:0°~2°,2°~6°,6°~15°,15°~25°,and 25°~90°.Results show that:1)The inverse correlation between cropland area and slope gradient remained stable throughout the study period,with the variation in cropland area frequency across slope grades being less than 1%.2)The spatial patterns of SLQ in 1990 and 2020 both transited stepwise with slope gradient,while≤2°and>6°slopes exhibited opposing patterns.3)The mean absolute variation of SLQ during 1990-2020 increased with slope gradient(R2=0.926,p<0.01).Particularly for slope grades>15°,the mean absolute variation reached 0.26(for 15°~25°)and 0.43(for 25°~90°),respectively,and displayed a distinct southward-increasing and northwarddecreasing pattern.This study offers novel slopegradient perspectives for analyzing cropland spatial patterns.To enhance cropland protection benefits,reversing the steep cropland SLQ surge in southern China is recommended.
文摘Automated grading of dandruff severity is a clinically significant but challenging task due to the inherent ordinal nature of severity levels and the high prevalence of label noise from subjective expert annotations.Standard classification methods fail to address these dual challenges,limiting their real-world performance.In this paper,a novel,three-phase training framework is proposed that learns a robust ordinal classifier directly from noisy labels.The approach synergistically combines a rank-based ordinal regression backbone with a cooperative,semi-supervised learning strategy to dynamically partition the data into clean and noisy subsets.A hybrid training objective is then employed,applying a supervised ordinal loss to the clean set.The noisy set is simultaneously trained using a dualobjective that combines a semi-supervised ordinal loss with a parallel,label-agnostic contrastive loss.This design allows themodel to learn fromthe entire noisy subset while using contrastive learning to mitigate the risk of error propagation frompotentially corrupt supervision.Extensive experiments on a new,large-scale,multi-site clinical dataset validate our approach.Themethod achieves state-of-the-art performance with 80.71%accuracy and a 76.86%F1-score,significantly outperforming existing approaches,including a 2.26%improvement over the strongest baseline method.This work provides not only a robust solution for a practical medical imaging problem but also a generalizable framework for other tasks plagued by noisy ordinal labels.
基金Project supported by the Natural Science Foundation of Shandong Province of China(No.ZR2024MA085)the Fundamental Research Funds for Central Universities of China(No.27RA2515008)。
文摘When micro/nano-scale gradient coatings are subject to large thermal gradients or high heat fluxes,the spatial size effect cannot be ignored.It is important to understand how the size effect influences the thermal fracture behavior of functionally graded coating/substrate structures.This study aims at analyzing the transient thermal fracture behavior of collinear interface cracks in functionally graded coating/substrate structures based on the nonlocal dual-phase-lag heat conduction model.By means of integral transform techniques,the mixed boundary problem is transformed into a set of singular integral equations,which are solved by the Chebyshev polynomials.The effects of the nonlocal parameter,coating thickness,crack spacing,and non-homogeneous parameters on the temperature and stress intensity factors(SIFs)are examined.The numerical results show that these parameters play an essential role in controlling the thermal fracture behavior of the structures,especially at micro/nano-scales.
基金Funded by the Guangdong Major Project of Basic and Applied Basic Research(No.2021B0301030001)the Foundation of National Key Laboratory of Shock Wave and Detonation Physics(No.JCKYS2022212004)。
文摘We used hydrodynamic simulations and shock wave propagation theories to analyze the behavior of shock waves within Ti/Pt periodically modulated graded structures and their integration layers.The effects of the total number of periodic layers,the total thickness of graded materials and loading velocity on the integration layer thickness and behavior of pressure-strain rate were systematically investigated.The results reveal that,by adjusting the total number of periodically modulated layers,the total thickness of graded materials and loading velocity the pressure amplitudes of the reflected compressive and rarefaction waves at different interfaces of Ti/Pt periodically modulated graded materials can be precisely controlled.Furthermore,empirical structural design criteria for Ti/Pt periodically modulated graded materials are established.The thickness ratio variation between adjacent Ti/Pt layers in the periodic structure must exceed 0.32.After the collaborative design of the integration layer,Ti/Pt periodically modulated graded materials can achieve a controllable loading function with pressures ranging from 1.4 to 144 GPa and strain rates from 3.8×10^(4) to 1.7×10^(7) s^(–1).The outcomes of this research provide a theoretical and simulation basis for the optimized design of periodically modulated graded materials to be utilized in ramp compression experiments.
基金supported by Beijing Natural Science Foundation(L233025)。
文摘Functionally graded material(FGM)plates are widely used in various engineering structures owing to their tailor-made mechanical properties,whereas cracked homogeneous plates constitute a canonical setting in fracture mechanics analysis.These two classes of problems respectively embody material non-uniformity and geometric discontinuity,thereby imposing more stringent requirements on numerical methods in terms of high-order field continuity and accurate defect representation.Based on the classical Kirchhoff-Love plate theory,a numerical manifold method(MLS-NMM)incorporating moving least squares(MLS)interpolation is developed for bending analysis of FGM plates and fracture simulation of homogeneous plates with defects.The method constructs an H^(2)-regular approximation with high-order continuous weighting functions and,combined with the separation of mathematical and physical covers,establishes a unified framework that accurately handles material gradients and cracks without mesh reconstruction.For the crack tip,a singular physical cover incorporating the Williams asymptotic field is introduced to achieve local enrichment,enabling the natural capture of displacement discontinuity and stress singularity.Stress intensity factors are extracted using the interaction integral method,and the dimensionless J-integral shows a maximum relative error below 1.2%compared with the reference solution.Numerical results indicate that MLS-NMM exhibits excellent convergence performance:using 676 mathematical nodes,the nondimensional central deflection of both FGM and homogeneous plates agrees with reference solutions with a maximum relative error below 0.81%,and no shear locking occurs.A systematic analysis reveals that for a simply supported on all four edges(SSSS)FGM square plate with a/h=10,the nondimensional central deflection increases by 212%as the gradient index nrises from 0 to 5.For a homogeneous plate containing a central crack with c/a=0.6,the nondimensional central deflection increases by approximately 46%compared with the intact plate.Under weak boundary constraints(e.g.,SFSF),the deformation is markedly amplified,with the deflection reaching more than three times that under strong constraints(SCSC).The proposed method provides an efficient,reconstruction-free numerical tool for high-accuracy bending and fracture analyses of FGM and cracked thin-plate structures.
文摘To the Editor,Artificial intelligence(AI)usage has been increasing.Many fields have implemented the use of AI and Large LanguageModels(LLMs),especially in medicine.Furthermore,manypatients have increasingly been using AI;often,they will prompt AI with questions before even stepping into a physi-cian's office.The question lies in whether the information produced by AI is reliable and if this information is concise and easy to read across all patient populations.
文摘Sandwich functionally graded(FG)auxetic beams are extensively utilized in aerospace,automotive,and biomedical industries due to their excellent strength-toweight ratio,impact resistance,and tunable mechanical properties.The integration of FG materials with auxetic structures enhances their adaptability in advanced engineering applications.However,understanding their dynamic behavior under external excitations is essential for optimal design and structural reliability.Nonlinear interactions in such structures pose significant challenges in vibration analysis,necessitating robust analytical methods.This study presents a closed-form solution for the nonlinear forced vibration analysis of sandwich FG auxetic beams,offering an accurate and efficient method for predicting their dynamic response.The beam consists of two FG face sheets with material properties varying through the thickness and a re-entrant honeycomb auxetic core with an adjustable Poisson's ratio.The governing nonlinear equations of motion are derived using the first-order shear deformation theory(FSDT),the modified Gibson model,and the von Kármán relations,formulated through Hamilton's principle.A closed-form solution is obtained via the Galerkin method and multiple-scale technique.The results demonstrate that FG layers enable control of the overweight and dynamic response amplitude,with positive power law indexes reducing weight.Comparisons with finite element results confirm the accuracy of the proposed formulation.
文摘The accurate mechanical analysis of thick-walled pressure vessel structures composed of advanced materials,such as hyperelastic and functionally graded materials(FGMs),is critical for ensuring their safety and optimizing their design.However,conventional numerical methods can face challenges with the non-linearities inherent in hyperelasticity and the complex spatial variations in FGMs.This paper presents a novel hybrid numerical approach combining Physics-Informed Neural Networks(PINNs)with Finite Element Method(FEM)derived data for the robust analysis of thick-walled,axisymmetric,heterogeneous,hyperelastic pressure vessels with elliptical geometries.A PINN framework incorporating neo-Hookean constitutive relations is developed in MATLAB.To enhance training efficiency and accuracy,the PINN’s loss function is augmented with displacement data obtained from high-fidelity FEM simulations performed in ANSYS.The methodology is rigorously validated by comparing PINN-predicted displacement and von Mises stress fields against ANSYS benchmarks for various scenarios of FGMconfigurations(with material properties varying according to a power law)subjected to internal and external pressurization.The results demonstrate excellent agreement between the proposed hybrid PINN-FEMapproach and conventional FEMsolutions across all test cases,accurately capturing complex deformation patterns and stress concentrations.This study highlights the potential of data-augmented PINNs as an effective and accurate computational tool for tackling complex solid mechanics problems involving non-linearmaterials and significant heterogeneity,offering a promising avenue for future research in engineering design and analysis.
文摘With the reform booming in teaching fields,the author carried out Graded English teaching in her teaching classroom and achieved favorable efficiency.In this paper,the author mainly discusses the specific grading of exercise after class in implementing graded teaching,taking for example Section A,Unit 6(Go for it! SB for Grade Eight,Volume A,by People's Education Press and Thomson Learning,2004,2nded).
文摘With the reform booming in teaching fields,the author carried out Graded English teaching in her teaching classroom and achieved favorable efficiency.In this paper,the author mainly discusses the specific grading of teaching objectives in implementing graded teaching.
基金funded by a grant from the Liaocheng Science and Technology Development Plans(No.2012-193).
文摘Purpose:To evaluate the effect of competency-based management in improving nurse and patient satisfaction.Methods:According to the competency-based management objectives and principles,821 nurses were classified into different levels based on clear nurse qualifications and post responsibilities.According to the different levels of nursing staff and training plans with different emphases,the goal was for the nursing staff to gradually achieve the corresponding level.Targeted training programs for different levels of nurses were formulated to enable nurses to gradually increase their competency levels.Results:After implementation of competency-based management,nurse job satisfaction and patient satisfaction increased significantly(P<0.01).Additionally,the reported nurse job burnout decreased(P<0.01).Conclusion:Competency-based management can promote nurses’enthusiasm,reduce job burnout,improve job satisfaction,as well as improve patient satisfaction.
文摘We performed this study to investigate pathological upgrading from biopsy to prostatectomy and clinicopathological factors associated with grade group(GG)upgrading in patients with International Society of Urological Pathology(ISUP)GG 1 and 2 prostate cancer(PCa)in a Chinese cohort.We included patients diagnosed with PCa with ISUP GG 1 and 2 at biopsy,who underwent RP at our institution.Pre-and postoperative clinical variables were examined.Univariate and multivariate logistic regression analyses were conducted to identify independent factors associated with GG upgrading.Patients in GG upgraded group had higher total prostatespecific antigen(tPSA;median:14.43 ng ml^(−1) vs 10.52 ng ml^(−1),P=0.001)and PSA density(PSAD;median:0.45 ng ml^(−2) vs 0.27 ng ml^(−2),P<0.001)than those in GG nonupgraded group.Patients in upgraded group had a higher ratio for Prostate ImagingReporting and Data System(PI-RADS)score>3(86.4%vs 67.9%,P<0.001).Those with GG 1 in biopsy were more likely to experience GG upgrading after RP than those with GG 2(71 vs 54,P=0.016).Independent preoperative factors predicting GG upgrading were PI-RADS score>3(odds ratio[OR]:2.471,95%confidence interval[CI]:1.132–5.393;P=0.023),higher PSAD(P=0.001),and GG in biopsy(OR:0.241,95%CI:0.123–0.471;P<0.001).The histopathological analyses of RP specimens revealed that perineural invasion(PNI;OR:1.839,95%CI:1.027–3.490;P=0.041)was identified as an independent factor associated with GG upgrading.Our results revealed that GG in the biopsy,PSAD,PI-RADS score>3,and PNI were independent factors of GG upgrading.These factors should be considered for patients with ISUP grade≤2 PCa.
文摘The SHIFT-G technology of inverse catalyst loading is used to optimize the catalyst grading in the residue hydrotreating unit. The results, taken from pilot tests and commercial units, have showed that the optimized catalyst grading system can reasonably distribute the reaction load, effectively improve the prop- erties of hydrotreated products, prolong the operating cycle and promote economic benefits.
基金This project was funded by the Movember Foundation as part of their Australian and New Zealand prostate cancer outcomes registry initiative(PCOR-ANZ)which aims to develop a binational clinical registry for outcomes monitoring and research to inform practice and improve outcomes for men with prostate cancer.Dr.Beckmann is supported by an NHMRC Early Career Researcher Fellowship.
文摘Object:To determine the extent and impact of upgrading and downgrading among men who underwent radical prostatectomy(RP)according to new grade groupings and to identify predictors of upgrading from biopsy grade Group Ⅰ and Ⅱ,and downgrading to grade Group I,in a community setting.Methods:Study participants included 2279 men with non-metastatic prostate cancer diagnosed 2006-2015 who underwent prostatectomy,from the multi-institutional South Australia Prostate Cancer Clinical Outcomes Collaborative registry.Extent of up-or down-grading was assessed by comparing biopsy and prostatectomy grade groupings.Risk of biochemical recurrence(BCR)with upgrading was assessed using multivariable competing risk regression.Binomial logistic regression was used to identify pre-treatment predictors of upgrading from grade Groups Ⅰ and Ⅱ,and risk group reclassification among men with low risk disease.Results:Upgrading occurred in 35%of cases,while downgrading occurred in 13%of cases.Sixty percent with grade Group I disease were upgraded following prostatectomy.Upgrading from grade Group I was associated with greater risk of BCR compared with concordant grading(Hazard ratio:3.1,95%confidence interval:1.7-6.0).Older age,higher prostate-specific antigen levels(PSA),fewer biopsy cores,higher number of positive cores and more recent diagnosis predicted upgrading from grade Group Ⅰ,while higher PSA and clinical stage predicted upgrading from grade Group Ⅱ.No clinical risk factors for reclassification were identified.Conclusion:Biopsy sampling errors may play an important role in upgrading from grade Group I.Improved clinical assessment of grade is needed to encourage greater uptake of active surveillance.
