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A Discusion on Limited Load-Carrying Capacity of Rectangular Plates
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作者 Li Changchun Shi Depei Wang Bocheng Associate Professor, Department of Naval Architecture and Ocean Engineering, Jiao Tong University,Shanghai 200030Engineer, Shangsha Shipyard, Shangsha 410013 《China Ocean Engineering》 SCIE EI 1996年第4期401-408,共8页
The elastic-plastic method is often used in designing the inner flat bulkhead plates of submarines, and the upper structure of ships and drilling platforms. Such bulkhead plates can bear the load only once. For the im... The elastic-plastic method is often used in designing the inner flat bulkhead plates of submarines, and the upper structure of ships and drilling platforms. Such bulkhead plates can bear the load only once. For the improvement of the load-carrying capacity or the reduction of the weight of plates, the yield line analytical method is employed in this paper to design the bulkhead plate to improve economy and increase the effiective load. Besides, a further sutdy of this method has been made theoretically and experimentally, and the data of the limited load-carrying capacity of the plate have been obtained. Furthermore, the safety coefficients for such a method are presented, which can be used as reference for related departments and staffs. 展开更多
关键词 elastic-plastic design limited load-carrying capacity yield line analytical method safety coefficient
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Boundary slippage for generating hydrodynamic load-carrying capacity
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作者 张勇斌 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2008年第9期1155-1164,共10页
Boundary slippage is used to generate the load-carrying capacity of the hydrodynamic contact between two parallel plane surfaces. In the fluid inlet zone, the fluidcontact interfacial shear strength on a stationary su... Boundary slippage is used to generate the load-carrying capacity of the hydrodynamic contact between two parallel plane surfaces. In the fluid inlet zone, the fluidcontact interfacial shear strength on a stationary surface is set at low to generate boundary slippage there, while in the fluid outlet zone the fluid-contact interfacial shear strength on the stationary surface is set at high enough to prevent the occurrence of boundary slippage. The fluid-contact interfacial shear strength on the entire moving surface is set at high enough to prevent boundary slippage on the moving surface. These hydrodynamic contact configurations are analyzed to generate the pronounced load-carrying capacity. The optimum ratio of the outlet zone width to the inlet zone width for the maximum load-carrying capacity of the whole contact is found to be 0.5. 展开更多
关键词 hydrodynamic contact load-carrying capacity boundary slippage
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Using a GIS to Assessment the Load-Carrying Capacity of Soil Case of Berhoum Area, Hodna Basin, (Eastern Algeria) 被引量:1
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作者 Amar Guettouche Farid Kaoua 《Journal of Geographic Information System》 2013年第5期492-497,共6页
The concept of load-carrying capacity of the soil can be evaluated by two main components: permissible stress and permissible depth;and therefore, running it begins its assessment that allows an outline of exploitatio... The concept of load-carrying capacity of the soil can be evaluated by two main components: permissible stress and permissible depth;and therefore, running it begins its assessment that allows an outline of exploitation. Nevertheless, the assessment of the load-carrying capacity made the object of several works of research and many models, based on the multi-criteria analysis, have been established. This work examines the contribution of GIS approach to assessment load-carrying capacity of the soil. This one has been finished in two practicums: 1) Assessment of the capacity of soil by a multi-criteria approach, using the Weighted Sum Model (WSM);2) It brought to use the GIS approach to evaluate and spatialize degree of soil bearing stresses resulting from the buildings, as well as load distribution. The method has been applied to the Berhoum area of Hodna Basin, in eastern Algeria, where each is characterized by its various natural properties and density of equipment. Final results are better in the classification of the degree of load-carrying capacity possible in each site. This results in allowing exploiters to program their optimal designs for the rational management of the area. 展开更多
关键词 load-carrying capacity WSM GIS Berhoum Hodna Basin’s Algeria
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Contact Force Distribution and Static Load-carrying Capacity of Large Size Double Row Four-point Contact Ball Bearing 被引量:7
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作者 Yan-shuang WANG Qian-qian YUAN 《Defence Technology(防务技术)》 SCIE EI CAS 2013年第4期229-236,共8页
Clearance not only affects the startup torque,rotation precision and stiffness of bearing,but also affects the load distribution,load-carrying capacity and life of bearing.A computational model in which the clearance ... Clearance not only affects the startup torque,rotation precision and stiffness of bearing,but also affects the load distribution,load-carrying capacity and life of bearing.A computational model in which the clearance of bearing is first included is presented for determining the contact force distribution and static load-carrying capacity of a double row four-point contact ball bearing which is subjected to the combined radial,axial and overturning moment loadings.The relation between the negative axial clearance and the contact force distribution is analyzed.The static load-carrying capacity curves are established,and the effects of the changes in negative axial clearance,curvature radius coefficient of raceway groove and initial contact angle on the static load-carrying capacity are analyzed.The results show that,with the increase in the absolute value of negative clearance,the maximum contact load decreases first and then increases.The clearance values in the range of 0.2 mme0 mm have little effect on the static load-carrying capacity of bearing.With the increase in the curvature radius coefficient of raceway groove and the decrease in the initial contact angle,the static load capacity of bearing decreases. 展开更多
关键词 四点接触球轴承 承载能力 接触力 静态 双排 大尺寸 轴向游隙 轴向间隙
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Lateral load-carrying capacity analyses of composite shear walls with double steel plates and filled concrete with binding bars 被引量:1
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作者 周德源 刘凌飞 朱立猛 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第8期2083-2091,共9页
A method is developed to predict the lateral load-carrying capacity of composite shear walls with double steel plates and filled concrete with binding bars(SCBs). Nonlinear finite element models of SCBs were establish... A method is developed to predict the lateral load-carrying capacity of composite shear walls with double steel plates and filled concrete with binding bars(SCBs). Nonlinear finite element models of SCBs were established by using the finite element tool, Abaqus. Tie constraints were used to connect the binding bars and the steel plates. Surface-to-surface contact provided by the Abaqus was used to simulate the interaction between the steel plate and the core concrete. The established models could predict the lateral load-carrying capacity of SCBs with a reasonable degree of accuracy. A calculation method was developed by superposition principle to predict the lateral load-carrying capacity of SCBs for the engineering application. The concrete confined by steel plates and binding bars is under multi-axial compression; therefore, its shear strength was calculated by using the Guo-Wang concrete failure criterion. The shear strength of the steel plates of SCBs was calculated by using the von Mises yielding criterion without considering buckling. Results of the developed method are in good agreement with the testing and finite element results. 展开更多
关键词 钢筋混凝土剪力墙 填充复合材料 承载力分析 复合剪力墙 钢板 有限元模型 侧向 承载能力
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A comparison study on structure-function relationship of polysaccharides obtained from sea buckthorn berries using different methods:antioxidant and bile acid-binding capacity 被引量:4
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作者 Qiaoyun Li Zuman Dou +5 位作者 Qingfei Duan Chun Chen Ruihai Liu Yueming Jiang Bao Yang Xiong Fu 《Food Science and Human Wellness》 SCIE CSCD 2024年第1期494-505,共12页
In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic... In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic(HRP-U),acid(HRP-C)and alkali(HRP-A)assisted extraction methods were investigated.The results demonstrated that extraction methods had significant effects on extraction yield,monosaccharide composition,molecular weight,particle size,triple-helical structure,and surface morphology of HRPs except for the major linkage bands.Thermogravimetric analysis showed that HRP-U with filamentous reticular microstructure exhibited better thermal stability.The HRP-A with the lowest molecular weight and highest arabinose content possessed the best antioxidant activities.Moreover,the rheological analysis indicated that HRPs with higher galacturonic acid content and molecular weight showed higher viscosity and stronger crosslinking network(HRP-C,HRP-W and HRP-U),which exhibited stronger bile acid binding capacity.The present findings provide scientific evidence in the preparation technology of sea buckthorn polysaccharides with good antioxidant and bile acid binding capacity which are related to the structure affected by the extraction methods. 展开更多
关键词 Sea buckthorn Extraction method STRUCTURE Rheological properties Antioxidant activity Bile acid binding capacity
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Insight into the capacity degradation and structural evolution of single-crystal Ni-rich cathodes
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作者 Xiaodong Zhang Jiao Lin +5 位作者 Ersha Fan Qingrong Huang Su Ma Renjie Chen Feng Wu Li Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期68-76,I0003,共10页
Single-crystal Ni-rich cathodes are a promising candidate for high-energy lithium-ion batteries due to their higher structural and cycling stability than polycrystalline materials.However,the phase evolution and capac... Single-crystal Ni-rich cathodes are a promising candidate for high-energy lithium-ion batteries due to their higher structural and cycling stability than polycrystalline materials.However,the phase evolution and capacity degradation of these single-crystal cathodes during continuous lithation/delithation cycling remains unclear.Understanding the mapping relationship between the macroscopic electrochemical properties and the material physicochemical properties is crucial.Here,we investigate the correlation between the physical-chemical characteristics,phase transition,and capacity decay using capacity differential curve feature identification and in-situ X-ray spectroscopic imaging.We systematically clarify the dominant mechanism of phase evolution in aging cycling.Appropriately high cut-off voltages can mitigate the slow kinetic and electrochemical properties of single-crystal cathodes.We also find that second-order differential capacity discharge characteristic curves can be used to identify the crystal structure disorder of Ni-rich cathodes.These findings constitute a step forward in elucidating the correlation between the electrochemical extrinsic properties and the physicochemical intrinsic properties and provide new perspectives for failure analysis of layered electrode materials. 展开更多
关键词 Single-crystal cathodes capacity decay Phase transition Differential capacity analysis
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Effect of Trimetazidine on Functional Capacity in Patient with Ischaemic Cardiomyopathy (TOFCAPI)
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作者 Mohsin Ahmed Golam Morshed +7 位作者 Mahmood Hasan Khan Md. Arifur Rahman Muhammed Aminur Razzaque Shariful Islam Sayeedur Rahman Khan Chowdhury Md. Kudrat-E-Khuda Salahuddin Anis Shiblee Md. Habibur Rahman 《International Journal of Clinical Medicine》 CAS 2024年第2期55-67,共13页
Objective: This study aimed to evaluate the efficacy of trimetazidine on exercise capacity via a six-minute walk test in patients with ischaemic cardiomyopathy and also evaluate the effect of trimetazidine on left ven... Objective: This study aimed to evaluate the efficacy of trimetazidine on exercise capacity via a six-minute walk test in patients with ischaemic cardiomyopathy and also evaluate the effect of trimetazidine on left ventricular function via echocardiography in the same population. Methods: This prospective observational study, conducted at the National Institute of Cardiovascular Diseases in Dhaka, Bangladesh, enrolled 200 patients with ischaemic cardiomyopathy and a depressed left ventricular ejection fraction (LVEF Results: In this study (n = 200) of ischaemic cardiomyopathy patients, the mean age was 58 years, with 76% of the patients being male. All study subjects received GDMT (Guideline-Directed Medical Therapy) for angina and heart failure. Those who received the modified released form of trimetazidine developed lesions during the 1st and 2nd follow-ups, during which the LVEF, LVIDd, and six-minute walk distance significantly improved (p Conclusion: The findings of the present study demonstrated that the addition of modified-release trimetazidine to GDMT can improve exercise capacity and left ventricular function in patients with ischaemic cardiomyopathy. 展开更多
关键词 BANGLADESH Heart Failure Exercise capacity TRIMETAZIDINE Ischaemic Cardiomyopathy
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Functional Capacity of Patients with Venous Thromboembolic Disease Six to Twelve Months after Treatment
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作者 Hamadou Bâ Chris-Nadège Nganou-Gnindjio +3 位作者 Alexis Noé S. Guiakam Kemnang Yemele Honore Danwe Dieudonné Guy S. Wafeu 《World Journal of Cardiovascular Diseases》 CAS 2024年第2期88-98,共11页
Background: Venous thromboembolism (VTE) is among the leading causes of hospital-related disability-adjusted life years lost. We aimed to determine the prevalence and determinants of functional capacity impairment six... Background: Venous thromboembolism (VTE) is among the leading causes of hospital-related disability-adjusted life years lost. We aimed to determine the prevalence and determinants of functional capacity impairment six to twelve months after an acute VTE event. Methods: This was a cross-sectional study conducted between January and April 2021 in two referral hospitals of Yaoundé, including consenting adult patients admitted to these hospitals six to twelve months ago for VTE. We excluded dead patients and those with any comorbidity or symptoms limiting physical activity. The functional outcome was assessed with the six-minute walk test. Functional capacity impairment was defined as walking distance lower than the expected value. Results: We included 27 cases in this study with a mean age of 53.2 ± 14.4 years. The prevalence of functional capacity impairment was 29.6% (95% CI: 14.8 - 48.1). Factors associated with poor functional outcome were obesity (OR: 59.5;95% CI: 4.6 - 767.2;p - 207.4;p = 0.017), massive PE (OR: 30;95% CI: 2.5 - 354;p = 0.004), and poor adherence to treatment (OR: 30.3;95% CI: 2.5 - 333.3;p = 0.004). Conclusion: Functional capacity impairment is common in the medium-term after VTE and factors associated with this poor outcome are obesity, the severity of the VTE, and poor adherence to treatment. 展开更多
关键词 Functional capacity Venous Thromboembolism Six-Minute Walk Test Cameroon
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Effect of speed humps on instantaneous traffic emissions in a microscopic model with limited deceleration capacity
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作者 胡宇晨 李启朗 +2 位作者 刘军 王君霞 汪秉宏 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期413-420,共8页
As a common transportation facility, speed humps can control the speed of vehicles on special road sections to reduce traffic risks. At the same time, they also cause instantaneous traffic emissions. Based on the clas... As a common transportation facility, speed humps can control the speed of vehicles on special road sections to reduce traffic risks. At the same time, they also cause instantaneous traffic emissions. Based on the classic instantaneous traffic emission model and the limited deceleration capacity microscopic traffic flow model with slow-to-start rules, this paper has investigated the impact of speed humps on traffic flow and the instantaneous emissions of vehicle pollutants in a single lane situation. The numerical simulation results have shown that speed humps have significant effects on traffic flow and traffic emissions. In a free-flow region, the increase of speed humps leads to the continuous rise of CO_(2), NO_(X) and PM emissions. Within some density ranges, one finds that these pollutant emissions can evolve into some higher values under some random seeds. Under other random seeds, they can evolve into some lower values. In a wide moving jam region, the emission values of these pollutants sometimes appear as continuous or intermittent phenomenon. Compared to the refined Na Sch model, the present model has lower instantaneous emissions such as CO_(2), NO_(X) and PM and higher volatile organic components(VOC) emissions. Compared to the limited deceleration capacity model without slow-to-start rules, the present model also has lower instantaneous emissions such as CO_(2), NO_(X) and PM and higher VOC emissions in a wide moving jam region. These results can also be confirmed or explained by the statistical values of vehicle velocity and acceleration. 展开更多
关键词 traffic emissions speed humps slow-to-start rules deceleration capacity
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A comparative study of data-driven battery capacity estimation based on partial charging curves
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作者 Chuanping Lin Jun Xu +5 位作者 Delong Jiang Jiayang Hou Ying Liang Xianggong Zhang Enhu Li Xuesong Mei 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期409-420,I0010,共13页
With its generality and practicality, the combination of partial charging curves and machine learning(ML) for battery capacity estimation has attracted widespread attention. However, a clear classification,fair compar... With its generality and practicality, the combination of partial charging curves and machine learning(ML) for battery capacity estimation has attracted widespread attention. However, a clear classification,fair comparison, and performance rationalization of these methods are lacking, due to the scattered existing studies. To address these issues, we develop 20 capacity estimation methods from three perspectives:charging sequence construction, input forms, and ML models. 22,582 charging curves are generated from 44 cells with different battery chemistry and operating conditions to validate the performance. Through comprehensive and unbiased comparison, the long short-term memory(LSTM) based neural network exhibits the best accuracy and robustness. Across all 6503 tested samples, the mean absolute percentage error(MAPE) for capacity estimation using LSTM is 0.61%, with a maximum error of only 3.94%. Even with the addition of 3 m V voltage noise or the extension of sampling intervals to 60 s, the average MAPE remains below 2%. Furthermore, the charging sequences are provided with physical explanations related to battery degradation to enhance confidence in their application. Recommendations for using other competitive methods are also presented. This work provides valuable insights and guidance for estimating battery capacity based on partial charging curves. 展开更多
关键词 Lithium-ion battery Partial charging curves capacity estimation DATA-DRIVEN Sampling frequency
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Prediction of Damping Capacity Demand in Seismic Base Isolators via Machine Learning
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作者 Ayla Ocak Umit Isıkdag +3 位作者 Gebrail Bekdas Sinan Melih Nigdeli Sanghun Kim ZongWoo Geem 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2899-2924,共26页
Base isolators used in buildings provide both a good acceleration reduction and structural vibration control structures.The base isolators may lose their damping capacity over time due to environmental or dynamic effe... Base isolators used in buildings provide both a good acceleration reduction and structural vibration control structures.The base isolators may lose their damping capacity over time due to environmental or dynamic effects.This deterioration of them requires the determination of the maintenance and repair needs and is important for the long-termisolator life.In this study,an artificial intelligence prediction model has been developed to determine the damage and maintenance-repair requirements of isolators as a result of environmental effects and dynamic factors over time.With the developed model,the required damping capacity of the isolator structure was estimated and compared with the previously placed isolator capacity,and the decrease in the damping property was tried to be determined.For this purpose,a data set was created by collecting the behavior of structures with single degrees of freedom(SDOF),different stiffness,damping ratio and natural period isolated from the foundation under far fault earthquakes.The data is divided into 5 different damping classes varying between 10%and 50%.Machine learning model was trained in damping classes with the data on the structure’s response to random seismic vibrations.As a result of the isolator behavior under randomly selected earthquakes,the recorded motion and structural acceleration of the structure against any seismic vibration were examined,and the decrease in the damping capacity was estimated on a class basis.The performance loss of the isolators,which are separated according to their damping properties,has been tried to be determined,and the reductions in the amounts to be taken into account have been determined by class.In the developed prediction model,using various supervised machine learning classification algorithms,the classification algorithm providing the highest precision for the model has been decided.When the results are examined,it has been determined that the damping of the isolator structure with the machine learning method is predicted successfully at a level exceeding 96%,and it is an effective method in deciding whether there is a decrease in the damping capacity. 展开更多
关键词 Vibration control base isolation machine learning damping capacity
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Battery pack capacity estimation for electric vehicles based on enhanced machine learning and field data
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作者 Qingguang Qi Wenxue Liu +3 位作者 Zhongwei Deng Jinwen Li Ziyou Song Xiaosong Hu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期605-618,共14页
Accurate capacity estimation is of great importance for the reliable state monitoring,timely maintenance,and second-life utilization of lithium-ion batteries.Despite numerous works on battery capacity estimation using... Accurate capacity estimation is of great importance for the reliable state monitoring,timely maintenance,and second-life utilization of lithium-ion batteries.Despite numerous works on battery capacity estimation using laboratory datasets,most of them are applied to battery cells and lack satisfactory fidelity when extended to real-world electric vehicle(EV)battery packs.The challenges intensify for large-sized EV battery packs,where unpredictable operating profiles and low-quality data acquisition hinder precise capacity estimation.To fill the gap,this study introduces a novel data-driven battery pack capacity estimation method grounded in field data.The proposed approach begins by determining labeled capacity through an innovative combination of the inverse ampere-hour integral,open circuit voltage-based,and resistance-based correction methods.Then,multiple health features are extracted from incremental capacity curves,voltage curves,equivalent circuit model parameters,and operating temperature to thoroughly characterize battery aging behavior.A feature selection procedure is performed to determine the optimal feature set based on the Pearson correlation coefficient.Moreover,a convolutional neural network and bidirectional gated recurrent unit,enhanced by an attention mechanism,are employed to estimate the battery pack capacity in real-world EV applications.Finally,the proposed method is validated with a field dataset from two EVs,covering approximately 35,000 kilometers.The results demonstrate that the proposed method exhibits better estimation performance with an error of less than 1.1%compared to existing methods.This work shows great potential for accurate large-sized EV battery pack capacity estimation based on field data,which provides significant insights into reliable labeled capacity calculation,effective features extraction,and machine learning-enabled health diagnosis. 展开更多
关键词 Electricvehicle Lithium-ion battery pack capacity estimation Machine learning Field data
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Durable K-ion batteries with 100% capacity retention up to 40,000 cycles
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作者 Xianlu Lu Zhao Liang +6 位作者 Zhi Fang Dongdong Zhang Yapeng Zheng Qiao Liu Dingfa Fu Jie Teng Weiyou Yang 《Carbon Energy》 SCIE EI CAS CSCD 2024年第5期201-212,共12页
Currently,the major challenge in terms of research on K-ion batteries is to ensure that they possess satisfactory cycle stability and specific capacity,especially in terms of the intrinsically sluggish kinetics induce... Currently,the major challenge in terms of research on K-ion batteries is to ensure that they possess satisfactory cycle stability and specific capacity,especially in terms of the intrinsically sluggish kinetics induced by the large radius of K+ions.Here,we explore high-performance K-ion half/full batteries with high rate capability,high specific capacity,and extremely durable cycle stability based on carbon nanosheets with tailored N dopants,which can alleviate the change of volume,increase electronic conductivity,and enhance the K+ion adsorption.The as-assembled K-ion half-batteries show an excellent rate capability of 468 mA h g^(−1) at 100 mA g^(−1),which is superior to those of most carbon materials reported to date.Moreover,the as-assembled half-cells have an outstanding life span,running 40,000 cycles over 8 months with a specific capacity retention of 100%at a high current density of 2000 mA g^(−1),and the target full cells deliver a high reversible specific capacity of 146 mA h g^(−1) after 2000 cycles over 2 months,with a specific capacity retention of 113%at a high current density of 500 mA g^(−1),both of which are state of the art in the field of K-ion batteries.This study might provide some insights into and potential avenues for exploration of advanced K-ion batteries with durable stability for practical applications. 展开更多
关键词 carbon nanosheet cycle stability K-ion batteries rate performance specific capacity
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Theoretical Analysis on Deflection and Bearing Capacity of Prestressed Bamboo-Steel Composite Beams
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作者 Qifeng Shan Ming Mao Yushun Li 《Journal of Renewable Materials》 EI CAS 2024年第1期149-166,共18页
A theoretical analysis of upward deflection and midspan deflection of prestressed bamboo-steel composite beams is presented in this study.The deflection analysis considers the influences of interface slippage and shea... A theoretical analysis of upward deflection and midspan deflection of prestressed bamboo-steel composite beams is presented in this study.The deflection analysis considers the influences of interface slippage and shear deformation.Furthermore,the calculation model for flexural capacity is proposed considering the two stages of loading.The theoretical results are verified with 8 specimens considering different prestressed load levels,load schemes,and prestress schemes.The results indicate that the proposed theoretical analysis provides a feasible prediction of the deflection and bearing capacity of bamboo-steel composite beams.For deflection analysis,the method considering the slippage and shear deformation provides better accuracy.The theoretical method for bearing capacity matches well with the test results,and the relative errors in the serviceability limit state and ultimate limit state are 4.95%and 5.85%,respectively,which meet the accuracy requirements of the engineered application. 展开更多
关键词 Bamboo scrimber composite beam PRESTRESS DEFLECTION bearing capacity
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Regulating intramolecular hydrogen bonds of p-phenylenediimidazole-based small-molecule compounds towards the enhanced lithium storage capacity
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作者 Liping Zheng Bei Wang +7 位作者 Jianze Zhang Wenjie Zhou Jiayi Ren Huige Ma Rui Li Chengming Li Mingjun Hu Jun Yang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第9期406-413,共8页
The use of redox-active organic electrode materials in energy storage is restricted due to their inferior solvent resistance,abysmal conductivity,and the resultant low practical capacity.To address these issues,a clas... The use of redox-active organic electrode materials in energy storage is restricted due to their inferior solvent resistance,abysmal conductivity,and the resultant low practical capacity.To address these issues,a class of bipolar p-phenylenediimidazole-based small-molecule compounds are designed and fabricated.Theπ-conjugated backbone of these small molecules allows for electron delocalization on a big conjugation plane,endowing them with good conductivity and reaction reversibility.Furthermore,when the para-positions of phenylene are occupied by hydroxyl groups,as-formed intramolecular hydrogen bonds(N–H…O)between phenolic hydroxyl groups and the–NH groups of imidazole rings further enhance the structural planarity,resulting in higherπ-conjugation degree and better conductivity,and thus higher utilization of active sites and electrode capacity,proved by both experimental results and theoretical calculations.The optimized composite electrode DBNQ@rGO-45 shows a high specific capacity(∼308 mA h g^(−1)at 100 mA g^(−1))and a long cycling stability(112.9 mA h g^(−1)after 6000 cycles at 2000 mA g^(−1)).The significantly better electrochemical properties for hydroxyl group-containing compounds than those without hydroxyl groups attributed to intramolecular hydrogen bond-induced conjugation enhancement will inspire the structure design of organic electrodes for better energy storage. 展开更多
关键词 Bipolar P-phenylenedimidazole Intramolecular hydrogenbonds Planarity and conjugationd egree High capacity
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MOF-derived porous graphitic carbon with optimized plateau capacity and rate capability for high performance lithium-ion capacitors
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作者 Ge Chu Chaohui Wang +2 位作者 Zhewei Yang Lin Qin Xin Fan 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第2期395-404,共10页
The development of anode materials with high rate capability and long charge-discharge plateau is the key to improve per-formance of lithium-ion capacitors(LICs).Herein,the porous graphitic carbon(PGC-1300)derived fro... The development of anode materials with high rate capability and long charge-discharge plateau is the key to improve per-formance of lithium-ion capacitors(LICs).Herein,the porous graphitic carbon(PGC-1300)derived from a new triply interpenetrated co-balt metal-organic framework(Co-MOF)was prepared through the facile and robust carbonization at 1300°C and washing by HCl solu-tion.The as-prepared PGC-1300 featured an optimized graphitization degree and porous framework,which not only contributes to high plateau capacity(105.0 mAh·g^(−1)below 0.2 V at 0.05 A·g^(−1)),but also supplies more convenient pathways for ions and increases the rate capability(128.5 mAh·g^(−1)at 3.2 A·g^(−1)).According to the kinetics analyses,it can be found that diffusion regulated surface induced capa-citive process and Li-ions intercalation process are coexisted for lithium-ion storage.Additionally,LIC PGC-1300//AC constructed with pre-lithiated PGC-1300 anode and activated carbon(AC)cathode exhibited an increased energy density of 102.8 Wh·kg^(−1),a power dens-ity of 6017.1 W·kg^(−1),together with the excellent cyclic stability(91.6%retention after 10000 cycles at 1.0 A·g^(−1)). 展开更多
关键词 metal-organic framework porous graphitic carbon optimized plateau capacity kinetic analysis lithium-ion capacitor
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Effective Capacity of URLLC over Parallel Fading Channels with Imperfect Channel State Information
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作者 Peng Hongsen Tao Meixia 《China Communications》 SCIE CSCD 2024年第5期45-63,共19页
This paper investigates the effective capacity of a point-to-point ultra-reliable low latency communication(URLLC)transmission over multiple parallel sub-channels at finite blocklength(FBL)with imperfect channel state... This paper investigates the effective capacity of a point-to-point ultra-reliable low latency communication(URLLC)transmission over multiple parallel sub-channels at finite blocklength(FBL)with imperfect channel state information(CSI).Based on reasonable assumptions and approximations,we derive the effective capacity as a function of the pilot length,decoding error probability,transmit power and the sub-channel number.Then we reveal significant impact of the above parameters on the effective capacity.A closed-form lower bound of the effective capacity is derived and an alternating optimization based algorithm is proposed to find the optimal pilot length and decoding error probability.Simulation results validate our theoretical analysis and show that the closedform lower bound is very tight.In addition,through the simulations of the optimized effective capacity,insights for pilot length and decoding error probability optimization are provided to evaluate the optimal parameters in realistic systems. 展开更多
关键词 effective capacity finite blocklength regime imperfect CSI parallel fading channels URLLC
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Tensile Strain Capacity Prediction of Engineered Cementitious Composites (ECC) Using Soft Computing Techniques
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作者 Rabar H.Faraj Hemn Unis Ahmed +2 位作者 Hardi Saadullah Fathullah Alan Saeed Abdulrahman Farid Abed 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2925-2954,共30页
Plain concrete is strong in compression but brittle in tension,having a low tensile strain capacity that can significantly degrade the long-term performance of concrete structures,even when steel reinforcing is presen... Plain concrete is strong in compression but brittle in tension,having a low tensile strain capacity that can significantly degrade the long-term performance of concrete structures,even when steel reinforcing is present.In order to address these challenges,short polymer fibers are randomly dispersed in a cement-based matrix to forma highly ductile engineered cementitious composite(ECC).Thismaterial exhibits high ductility under tensile forces,with its tensile strain being several hundred times greater than conventional concrete.Since concrete is inherently weak in tension,the tensile strain capacity(TSC)has become one of the most extensively researched properties.As a result,developing a model to predict the TSC of the ECC and to optimize the mixture proportions becomes challenging.Meanwhile,the effort required for laboratory trial batches to determine the TSC is reduced.To achieve the research objectives,five distinct models,artificial neural network(ANN),nonlinear model(NLR),linear relationship model(LR),multi-logistic model(MLR),and M5P-tree model(M5P),are investigated and employed to predict the TSCof ECCmixtures containing fly ash.Data from115 mixtures are gathered and analyzed to develop a new model.The input variables include mixture proportions,fiber length and diameter,and the time required for curing the various mixtures.The model’s effectiveness is evaluated and verified based on statistical parameters such as R2,mean absolute error(MAE),scatter index(SI),root mean squared error(RMSE),and objective function(OBJ)value.Consequently,the ANN model outperforms the others in predicting the TSC of the ECC,with RMSE,MAE,OBJ,SI,and R2 values of 0.42%,0.3%,0.33%,0.135%,and 0.98,respectively. 展开更多
关键词 Engineered cementitious composites fly ash curing time tensile strain capacity MODELING
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Exogenous calcium enhances the physiological status and photosynthetic capacity of rose under drought stress
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作者 Xiaojuan Zhao Shang Lin +5 位作者 Shuang Yu Yichang Zhang Lin Su Lifang Geng Chenxia Cheng Xinqiang Jiang 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第3期853-865,共13页
Drought(water shortage)can substantially limit the yield and economic value of rose plants(Rosa spp.).Here,we characterized the effect of exogenous calcium(Ca^(2+))on the antioxidant system and photosynthesis-related ... Drought(water shortage)can substantially limit the yield and economic value of rose plants(Rosa spp.).Here,we characterized the effect of exogenous calcium(Ca^(2+))on the antioxidant system and photosynthesis-related properties of rose under polyethylene glycol 6000(PEG6000)-induced drought stress.Chlorophyll levels,as well as leaf and root biomass,were significantly reduced by drought;drought also had a major effect on the enzymatic antioxidant system and increased concentrations of reactive oxygen species.Application of exogenous Ca^(2+)increased the net photosynthetic rate and stomatal conductance of leaves,enhanced water-use efficiency,and increased the length and width of stomata following exposure to drought.Organ-specific physiological responses were observed under different concentrations of Ca^(2+).Application of 5 mmol·L^(-1)Ca^(2+)promoted photosynthesis and antioxidant activity in the leaves,and application of 10 mmol·L^(-1)Ca^(2+)promoted antioxidant activity in the roots.Application of exogenous Ca^(2+)greatly enhanced the phenotype and photosynthetic capacity of potted rose plants following exposure to drought stress.Overall,our findings indicate that the application of exogenous Ca^(2+)enhances the drought resistance of roses by promoting physiological adaptation and that it could be used to aid the cultivation of rose plants. 展开更多
关键词 Rosa hybrida L. Exogenous calcium Drought stress Physiological index Photosynthetic capacity
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