At the township level,combining Voronoi diagram and breaking point theory,this paper divides township grade system and its scope of influence in Dafang County of Guizhou Province,and discusses the grade system from sm...At the township level,combining Voronoi diagram and breaking point theory,this paper divides township grade system and its scope of influence in Dafang County of Guizhou Province,and discusses the grade system from small scale perspective.Results show that Dafang County takes Dafang Town as the center,Dashi Town in the north and Shachang Township in the east as auxiliary part,Sanyuan Township,Zhuyuan Township,Babao Township,Pudi Township,Lihua Township,and Dingxin Township as cooperative part,to drive development of 36 townships in Dafang County.Thus,it basically reflects township grade of Dafang County,accords with current development situation,provides certain reference value for system planning and economic zoning of small scale regions,and it is able to improve the accuracy of scope division by completing attribute data and revision of many methods.展开更多
Objective:To evaluate the methodological quality of the systematic reviews(SRs)of acupuncture and moxibustion for chronic constipation and rate the evidence bodies of their Meta-analysis.Methods:We searched MEDLINE,EM...Objective:To evaluate the methodological quality of the systematic reviews(SRs)of acupuncture and moxibustion for chronic constipation and rate the evidence bodies of their Meta-analysis.Methods:We searched MEDLINE,EMBASE,Chinese Biomedical Literature Database(CBM),the China National Knowledge Infrastructure(CNKI),the VIP Database and the WanFang Database.Systematic Aseviews and Meta-analysis of all Randomized Controlled Trials(RCTs)of acupuncture and moxibustion for chronic constipation were included.Data from the included studies were extracted by two independent reviewers and were re-evaluated with AMSTAR 2 and Grades of Recommendation,Assessment,Development,and Evaluation(GRADE).Results:We included 12 SRs/Meta-analysis with only one conducted outside China.Evaluated with AMSTAR 2,methodology of one SR was of medium quality,methodologies of 7 SRs were of low quality,and methodologies of 4 SRs were of critical low quality.Among 54 outcome measures screened from included SRs,7 outcome measures introduced evidence bodies of moderate quality,22 outcome measures were of low quality and 25 outcome measures were of very low quality.No high level of quality was awarded to any evidence body.Conclusion:Overall,the quality level of SR/Meta-analysis of acupuncture/moxibustion for chronic constipation is low.The SRs/Meta-analysis of acupuncture/moxibustion for chronic constipation can be used for guideline formulation and clinical decision making by taking into account the experience of clinical experts,patients'preference,medical policies and other factors.展开更多
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
With the continuous advancement of the internationalization of higher education in China,the Grade Point Average(GPA)has become a primary indicator for evaluating academic performance in universities,playing a positiv...With the continuous advancement of the internationalization of higher education in China,the Grade Point Average(GPA)has become a primary indicator for evaluating academic performance in universities,playing a positive role in educational management.However,as it is closely tied to students’immediate interests,such as awards,exemptions from entrance exams for postgraduate recommendations,and domestic or international further education,certain new issues have emerged in its practical application.These problems have hindered the effective functioning of the GPA system,attracting widespread attention.This paper examines the origin,connotation,and theoretical assumptions of the GPA system,discusses its positive functions and existing challenges,and proposes recommendations for further improving academic evaluation.展开更多
Purpose:This study aims to address the lack of a unified grading framework in Chinese reading by proposing a comprehensive model integrating linguistic complexity and reading experience,to evaluate the difficulty leve...Purpose:This study aims to address the lack of a unified grading framework in Chinese reading by proposing a comprehensive model integrating linguistic complexity and reading experience,to evaluate the difficulty level of Chinese books.Design/methodology/approach:We utilized the Probabilistic Fuzzy Linguistic Technique(PFLT)for subjective indicators related to reading experience.Combined with collected objective indicators data,the Entropy Weight Method(EWM)is used for objective weight allocation,and Tomada De Decisão Interativa Multicritério(TODIM)is applied for multi-criteria decision-making.Findings:The results demonstrate that the proposed framework significantly enhances the alignment between text complexity and reader engagement,achieving a high consistency with authoritative benchmarks.Research limitations:The study may be limited by the scope of subjective and objective indicators used;further validation with more diverse data sources could strengthen generalizability.Practical implications:This approach shows promise in advancing the standardization and objectivity of Chinese reading grading systems,with potential applications in educational and publishing contexts.Originality/value:This study offers a structured evaluation model that incorporates both linguistic complexity and experiential factors,providing a novel and comprehensive method for assessing Chinese text difficulty.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
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
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
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
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
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
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
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
A multi-effect distillation technology for seawater desalination driven by tidal energy and low grade energy is presented.In the system,tidal energy is utilized to supply power instead of coventional electric pumps du...A multi-effect distillation technology for seawater desalination driven by tidal energy and low grade energy is presented.In the system,tidal energy is utilized to supply power instead of coventional electric pumps during the operation,resulting in the decrease of dependence on steady electric power supply and a reduction in the running costs.According to the technological principle,a testing unit is designed and built.The effects of the feed seawater temperature and the heat source temperature on the unit performance are tested and analyzed.The experimental results show that the fresh water output is 27 kg/h when the heating water temperature is 65 ℃ and the absolute pressure is 25 kPa.The experimental and theoretical analysis results indicate that the appropriate heating water temperature is a key factor in ensuring the steady operation of the system.展开更多
The 3-dimensional couple equations of magneto-electro-elastic structures are derived under Hamiltonian system based on the Hamilton principle. The problem of single sort of variables is converted into the problem of d...The 3-dimensional couple equations of magneto-electro-elastic structures are derived under Hamiltonian system based on the Hamilton principle. The problem of single sort of variables is converted into the problem of double sorts of variables, and the Hamilton canonical equations are established. The 3-dimensional problem of magneto-electro-elastic structure which is investigated in Euclidean space commonly is converted into symplectic system. At the same time the Lagrange system is converted into Hamiltonian system. As an example, the dynamic characteristics of the simply supported functionally graded magneto-electro-elastic material （FGMM） plate and pipe are investigated. Finally, the problem is solved by symplectic algorithm. The results show that the physical quantities of displacement, electric potential and magnetic potential etc. change continuously at the interfaces between layers under the transverse pressure while some other physical quantities such as the stress, electric and magnetic displacement are not continuous. The dynamic stiffness is increased by the piezoelectric effect while decreased by the piezomagnetic effect.展开更多
The thermal stresses relaxation of Ni/NiFe2O4 system functionally graded cermet inert anode for aluminum electrolysis was optimally designed. The transient thermal stresses of the inert anode under complex boundary co...The thermal stresses relaxation of Ni/NiFe2O4 system functionally graded cermet inert anode for aluminum electrolysis was optimally designed. The transient thermal stresses of the inert anode under complex boundary condition during high-temp （955℃） electrolysis were calculated using the finite-element software ANSYS, the influence of different parameters on the distribution of the thermal stresses were analyzed. The results showed that, during the process of thermal shock, the thermal hoop tensile stress on the surface of the anode is very large, which is possibly the major cause of anode crack; when the radius of the anode is between 0.05-0.15m, a range that can be realized by recent manufacturing technology, the optimum composition distribution exponent p is 0.25; The hoop tensile stresses reduce with the decrease of anode scale and also decrease with the decrease of the convection coefficient between the electrolyte and the anode.展开更多
BACKGROUND Hepatocellular carcinoma(HCC)is a frequent cause of cancer related death globally.Neutrophil to lymphocyte ratio(NLR)and albumin bilirubin(ALBI)grade are emerging prognostic indicators in HCC.AIM To study p...BACKGROUND Hepatocellular carcinoma(HCC)is a frequent cause of cancer related death globally.Neutrophil to lymphocyte ratio(NLR)and albumin bilirubin(ALBI)grade are emerging prognostic indicators in HCC.AIM To study published literature of NLR and ALBI over the last five years,and to validate NLR and ALBI locally in our centre as indicators of HCC survival.METHODS A systematic review of the published literature on PubMed of NLR and ALBI in HCC over the last five years.The search followed the guidelines of the preferred reporting items for systematic reviews and meta-analyses.Additionally,we also investigated HCC cases between December 2013 and December 2018 in our centre.RESULTS There were 54 studies describing the relation between HCC and NLR and 95 studies describing the relation between HCC and ALBI grade over the last five years.Our local cohort of patients showed NLR to have a significant negative relationship to survival(P=0.011).There was also significant inverse relationship between the size of the largest HCC nodule and survival(P=0.009).Median survival with alpha fetoprotein(AFP)<10 KU/L was 20 mo and with AFP>10 KU/L was 5 mo.We found that AFP was inversely related to survival,this relationship was not statically significant(P=0.132).Mean survival for ALBI grade 1 was 37.7 mo,ALBI grade 2 was 13.4 months and ALBI grade 3 was 4.5mo.ALBI grades performed better than Child Turcotte Pugh score in detecting death from HCC.CONCLUSION NLR and ALBI grade in HCC predict survival better than the conventional alpha fetoprotein.ALBI grade performs better than Child Turcotte Pugh score.These markers are done as part of routine clinical care and in cases of normal alpha fetoprotein,these markers could give a better understanding of the patient disease progression.NLR and ALBI grade could have a role in modified easier to learn staging and prognostic systems for HCC.展开更多
基金Supported the Project for Revision of Overall Land Use Plan for Dafang County(Guizhou University[2009]HT1226)Construction of Graphics Library for Dafang County([2011]1201)
文摘At the township level,combining Voronoi diagram and breaking point theory,this paper divides township grade system and its scope of influence in Dafang County of Guizhou Province,and discusses the grade system from small scale perspective.Results show that Dafang County takes Dafang Town as the center,Dashi Town in the north and Shachang Township in the east as auxiliary part,Sanyuan Township,Zhuyuan Township,Babao Township,Pudi Township,Lihua Township,and Dingxin Township as cooperative part,to drive development of 36 townships in Dafang County.Thus,it basically reflects township grade of Dafang County,accords with current development situation,provides certain reference value for system planning and economic zoning of small scale regions,and it is able to improve the accuracy of scope division by completing attribute data and revision of many methods.
基金Ministry of Science and Technology of the People's Republic of China,"Development of International Clinical Practice Guideline,Technical Operation Standard and Service Standard of Acupuncture and Moxibustion".Granting number:2019YFC1712200。
文摘Objective:To evaluate the methodological quality of the systematic reviews(SRs)of acupuncture and moxibustion for chronic constipation and rate the evidence bodies of their Meta-analysis.Methods:We searched MEDLINE,EMBASE,Chinese Biomedical Literature Database(CBM),the China National Knowledge Infrastructure(CNKI),the VIP Database and the WanFang Database.Systematic Aseviews and Meta-analysis of all Randomized Controlled Trials(RCTs)of acupuncture and moxibustion for chronic constipation were included.Data from the included studies were extracted by two independent reviewers and were re-evaluated with AMSTAR 2 and Grades of Recommendation,Assessment,Development,and Evaluation(GRADE).Results:We included 12 SRs/Meta-analysis with only one conducted outside China.Evaluated with AMSTAR 2,methodology of one SR was of medium quality,methodologies of 7 SRs were of low quality,and methodologies of 4 SRs were of critical low quality.Among 54 outcome measures screened from included SRs,7 outcome measures introduced evidence bodies of moderate quality,22 outcome measures were of low quality and 25 outcome measures were of very low quality.No high level of quality was awarded to any evidence body.Conclusion:Overall,the quality level of SR/Meta-analysis of acupuncture/moxibustion for chronic constipation is low.The SRs/Meta-analysis of acupuncture/moxibustion for chronic constipation can be used for guideline formulation and clinical decision making by taking into account the experience of clinical experts,patients'preference,medical policies and other factors.
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。
文摘With the continuous advancement of the internationalization of higher education in China,the Grade Point Average(GPA)has become a primary indicator for evaluating academic performance in universities,playing a positive role in educational management.However,as it is closely tied to students’immediate interests,such as awards,exemptions from entrance exams for postgraduate recommendations,and domestic or international further education,certain new issues have emerged in its practical application.These problems have hindered the effective functioning of the GPA system,attracting widespread attention.This paper examines the origin,connotation,and theoretical assumptions of the GPA system,discusses its positive functions and existing challenges,and proposes recommendations for further improving academic evaluation.
基金supported by the Humanities and Social Sciences Cultivation Fund Project of the USST(Grant No.24SKPY04)the China Youth and Children Research Association(Grant No.2023B18).
文摘Purpose:This study aims to address the lack of a unified grading framework in Chinese reading by proposing a comprehensive model integrating linguistic complexity and reading experience,to evaluate the difficulty level of Chinese books.Design/methodology/approach:We utilized the Probabilistic Fuzzy Linguistic Technique(PFLT)for subjective indicators related to reading experience.Combined with collected objective indicators data,the Entropy Weight Method(EWM)is used for objective weight allocation,and Tomada De Decisão Interativa Multicritério(TODIM)is applied for multi-criteria decision-making.Findings:The results demonstrate that the proposed framework significantly enhances the alignment between text complexity and reader engagement,achieving a high consistency with authoritative benchmarks.Research limitations:The study may be limited by the scope of subjective and objective indicators used;further validation with more diverse data sources could strengthen generalizability.Practical implications:This approach shows promise in advancing the standardization and objectivity of Chinese reading grading systems,with potential applications in educational and publishing contexts.Originality/value:This study offers a structured evaluation model that incorporates both linguistic complexity and experiential factors,providing a novel and comprehensive method for assessing Chinese text difficulty.
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 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.
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.
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.
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.
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.
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.
基金The Key Basic Program of Science and Technology Commission of Shanghai Municipality(No.08110511700)the ShanghaiLeading Academic Discipline Program(No.S30503)
文摘A multi-effect distillation technology for seawater desalination driven by tidal energy and low grade energy is presented.In the system,tidal energy is utilized to supply power instead of coventional electric pumps during the operation,resulting in the decrease of dependence on steady electric power supply and a reduction in the running costs.According to the technological principle,a testing unit is designed and built.The effects of the feed seawater temperature and the heat source temperature on the unit performance are tested and analyzed.The experimental results show that the fresh water output is 27 kg/h when the heating water temperature is 65 ℃ and the absolute pressure is 25 kPa.The experimental and theoretical analysis results indicate that the appropriate heating water temperature is a key factor in ensuring the steady operation of the system.
文摘The 3-dimensional couple equations of magneto-electro-elastic structures are derived under Hamiltonian system based on the Hamilton principle. The problem of single sort of variables is converted into the problem of double sorts of variables, and the Hamilton canonical equations are established. The 3-dimensional problem of magneto-electro-elastic structure which is investigated in Euclidean space commonly is converted into symplectic system. At the same time the Lagrange system is converted into Hamiltonian system. As an example, the dynamic characteristics of the simply supported functionally graded magneto-electro-elastic material （FGMM） plate and pipe are investigated. Finally, the problem is solved by symplectic algorithm. The results show that the physical quantities of displacement, electric potential and magnetic potential etc. change continuously at the interfaces between layers under the transverse pressure while some other physical quantities such as the stress, electric and magnetic displacement are not continuous. The dynamic stiffness is increased by the piezoelectric effect while decreased by the piezomagnetic effect.
基金This work was supported by the National Basic Research Program of China(No.2005CB623703)National Natural Science Foundation(No.5047405I)+1 种基金Hunan Provincial Natural Science Foundation of China(No.03JJY3080)Trans-Century Excellent Persons Cultivation Project of Ministry of Education of China(in 2002).
文摘The thermal stresses relaxation of Ni/NiFe2O4 system functionally graded cermet inert anode for aluminum electrolysis was optimally designed. The transient thermal stresses of the inert anode under complex boundary condition during high-temp （955℃） electrolysis were calculated using the finite-element software ANSYS, the influence of different parameters on the distribution of the thermal stresses were analyzed. The results showed that, during the process of thermal shock, the thermal hoop tensile stress on the surface of the anode is very large, which is possibly the major cause of anode crack; when the radius of the anode is between 0.05-0.15m, a range that can be realized by recent manufacturing technology, the optimum composition distribution exponent p is 0.25; The hoop tensile stresses reduce with the decrease of anode scale and also decrease with the decrease of the convection coefficient between the electrolyte and the anode.
文摘BACKGROUND Hepatocellular carcinoma(HCC)is a frequent cause of cancer related death globally.Neutrophil to lymphocyte ratio(NLR)and albumin bilirubin(ALBI)grade are emerging prognostic indicators in HCC.AIM To study published literature of NLR and ALBI over the last five years,and to validate NLR and ALBI locally in our centre as indicators of HCC survival.METHODS A systematic review of the published literature on PubMed of NLR and ALBI in HCC over the last five years.The search followed the guidelines of the preferred reporting items for systematic reviews and meta-analyses.Additionally,we also investigated HCC cases between December 2013 and December 2018 in our centre.RESULTS There were 54 studies describing the relation between HCC and NLR and 95 studies describing the relation between HCC and ALBI grade over the last five years.Our local cohort of patients showed NLR to have a significant negative relationship to survival(P=0.011).There was also significant inverse relationship between the size of the largest HCC nodule and survival(P=0.009).Median survival with alpha fetoprotein(AFP)<10 KU/L was 20 mo and with AFP>10 KU/L was 5 mo.We found that AFP was inversely related to survival,this relationship was not statically significant(P=0.132).Mean survival for ALBI grade 1 was 37.7 mo,ALBI grade 2 was 13.4 months and ALBI grade 3 was 4.5mo.ALBI grades performed better than Child Turcotte Pugh score in detecting death from HCC.CONCLUSION NLR and ALBI grade in HCC predict survival better than the conventional alpha fetoprotein.ALBI grade performs better than Child Turcotte Pugh score.These markers are done as part of routine clinical care and in cases of normal alpha fetoprotein,these markers could give a better understanding of the patient disease progression.NLR and ALBI grade could have a role in modified easier to learn staging and prognostic systems for HCC.
