Stress represents a critical determinant of dynamic hazards in underground coal mining operations.Heterogeneous geological features substantially influence stress distribution and magnitude throughout mining environme...Stress represents a critical determinant of dynamic hazards in underground coal mining operations.Heterogeneous geological features substantially influence stress distribution and magnitude throughout mining environments.To investigate the mechanical evolution and failure mechanisms of heterogeneous stratified composite coal-rock(CCR)under mining-induced stresses,three-point bending tests(TPBT)and numerical simulations are conducted on CCR specimens with varying homogeneity indices.Results show a significant positive correlation between CCR fracture strength and the homogeneity index(φ).Higher φ values are associated with more uniform displacement discontinuity zones during the fracturing process.Initial loading is observed to induce compressive strain at the upper coal-rock interface(UI),while tensile strain predominated at both the lower interface(LI)and boundary(LB).Interface strain magnitudes followed the pattern LB>LI>UI,with stability inversely proportional to strain intensity.As φ increases,interfacial stability is reduced,damage severity is amplified,and the critical strain energy release rate is elevated.These variations are primarily governed by the homogeneity-dependent redistribution of particle zones and the downward migration of resistant interfaces.These findings enhance our understanding of fracture propagation in heterogeneous CCR under mining stresses,thereby contributing to improved hazard forecasting and control strategies in coal mine composite roof systems.展开更多
随着数智时代的到来,图形用户界面(graphical user interface,GUI)的外观专利申请量逐年递增。文章立足交互设计流程,将交互设计中的低保真原型、高保真原型以及占位符概念引入专利制度体系内,对GUI外观专利部分案例进行分类讨论,厘清...随着数智时代的到来,图形用户界面(graphical user interface,GUI)的外观专利申请量逐年递增。文章立足交互设计流程,将交互设计中的低保真原型、高保真原型以及占位符概念引入专利制度体系内,对GUI外观专利部分案例进行分类讨论,厘清了专利制度下“内容画面”概念与设计领域占位符概念的差异。针对低保真原型与高保真原型在现行法律制度下的提交方式,分别提出以下建议:对于低保真原型,应当判定其是否为纯图文排版、是否缺乏设计高度;若排除上述两种情形,应考虑加入参考图及简要说明,以保证GUI的清楚表达。对于高保真原型,应当判断其设计特征是否相对固定,从而确定其是否需要采取半透明遮罩层与参考图结合的模式提交。展开更多
移动应用是近10年来兴起的新型计算模式,深刻地影响人民的生活方式.移动应用主要以图形用户界面(graphical user interface,GUI)方式交互,而对其进行人工测试需要消耗大量人力和物力.为此,研究者提出针对移动应用GUI的测试自动生成技术...移动应用是近10年来兴起的新型计算模式,深刻地影响人民的生活方式.移动应用主要以图形用户界面(graphical user interface,GUI)方式交互,而对其进行人工测试需要消耗大量人力和物力.为此,研究者提出针对移动应用GUI的测试自动生成技术以提升测试效率并检测潜在缺陷.收集了145篇相关论文,系统地梳理、分析和总结现有工作.提出了“测试生成器-测试环境”研究框架,将该领域的研究按照所属模块进行分类.特别地,依据测试生成器所基于的方法,将现有方法大致分为基于随机、基于启发式搜索、基于模型、基于机器学习和基于测试迁移这5个类别.此外,还从缺陷类别和测试动作等其他分类维度梳理现有方法.收集了该领域中较有影响力的数据集和开源工具.最后,总结当前面临的挑战并展望未来的研究方向.展开更多
The scaled suction caisson repre sents an innovative design featuring a bio-inspired sidewall modeled after snake skin,commonly utilized in offshore mooring platforms.In comparison with traditional suction caissons,th...The scaled suction caisson repre sents an innovative design featuring a bio-inspired sidewall modeled after snake skin,commonly utilized in offshore mooring platforms.In comparison with traditional suction caissons,this bio-inspired design demonstrates reduced penetration resistance and enhanced pull-out capacity due to the anisotropic shear behaviors of its sidewall.To investigate the shear behavior of the bio-inspired sidewall under pull-out load,direct shear tests were conducted between the bio-inspired surface and sand.The research demonstrates that the interface shear strength of the bio-inspired surface significantly surpasses that of the smooth surface due to interlocking effects.Additionally,the interface shear strength correlates with the aspect ratio of the bio-inspired surface,shear angle,and particle diameter distribution,with values increasing as the uniformity coefficient Cudecreases,while initially increasing and subsequently decreasing with increases in both aspect ratio and shear angle.The ratio between the interface friction angleδand internal friction angle δs defines the interface effect factor k.For the bio-inspired surface,the interface effect factor k varies with shear angleβ,ranging from 0.9 to 1.12.The peak value occurs at a shear angleβof 60°,substantially exceeding that of the smooth surface.A method for calculating the relative roughness RN is employed to evaluate the interface roughness of the bio-inspired surface,taking into account scale dimension and particle diameter distribution effects.展开更多
The interface between concrete and soil-rock mixture(SRM-concrete interface)under freeze-thaw cycles is very prone to creep damage,threatening the long-term stability of the superstructure in cold regions.However,ther...The interface between concrete and soil-rock mixture(SRM-concrete interface)under freeze-thaw cycles is very prone to creep damage,threatening the long-term stability of the superstructure in cold regions.However,there is no study concerning the characteristics of the nonlinear accelerated creep stage using the existing creep model in SRM-concrete interface.Therefore,shear creep tests were conducted to study the creep displacement and failure modes at the SRM-concrete interface under varying rock contents(15%-65%)and freeze-thaw cycles(0-20 iterations).A modified Burgers viscoelastic-plastic constitutive model is proposed to illustrate the creep failure characteristics of SRM-concrete interface induced by freeze-thaw cycles,which contains a hardening and loosening component.Results reveal a notable decrease in creep deformation correlating with increased rock content at SRM-concrete interface.Notably,the resistance of SRM-concrete interface to shear creep behavior peaks after five freeze-thaw cycles.This modified creep model accurately describes the nonlinear hardening and loosening creep behavior at the SRM-concrete interface,offering a substantial theoretical foundation for studying the longterm deformation and service life of superstructures in cold regions.展开更多
In this paper, by means of effective testing practices, main strategies of integration testing for GUI software, including differentiating strategy for distinguished system, strategy of personnel organization, increme...In this paper, by means of effective testing practices, main strategies of integration testing for GUI software, including differentiating strategy for distinguished system, strategy of personnel organization, incremental testing strategy based on baseline version, testing strategy of circulating loop through the whole life, and the strategy of test suite construction, were briefly investigated. Moreover, for the code analysis, the FTA (Fault Tree analysis) is proposed to deal with the software change in regression testing. For test suite constructing, the constructing methods for baseline version and the incremental change are deeply discussed, in which main points focus on the testing strategy based on “Sheet/Form”, the “Grey-box approach” for integration testing process, and the application of the improved STD (State Transform Diagram) in state testing. At the same time, the suite construction of integration testing for two types, including small scale program and large scale software, is analyzed and discussed in detail. For testing execution, the specific method based on “Cross-testing” is investigated. Concurrently, by a lot of examples, all results of testing activity indicate that these strategies and methods are useful and fitted to integration testing for GUI software.展开更多
Radiation-induced acoustic computed tomography(RACT)is an evolving biomedical imaging modality that aims to reconstruct the radiation energy deposition in tissues.Traditional backprojection(BP)reconstructions carry no...Radiation-induced acoustic computed tomography(RACT)is an evolving biomedical imaging modality that aims to reconstruct the radiation energy deposition in tissues.Traditional backprojection(BP)reconstructions carry noisy and limited-view artifacts.Model-based algorithms have been demonstrated to overcome the drawbacks of BPs.However,model-based algorithms are relatively more complex to develop and computationally demanding.Furthermore,while a plethora of novel algorithms has been developed over the past decade,most of these algorithms are either not accessible,readily available,or hard to implement for researchers who are not well versed in programming.We developed a user-friendly MATLAB-based graphical user interface(GUI;RACT2D)that facilitates back-projection and model-based image reconstructions for twodimensional RACT problems.We included numerical and experimental X-ray-induced acoustic datasets to demonstrate the capabilities of the GUI.The developed algorithms support parallel computing for evaluating reconstructions using the cores of the computer,thus further accelerating the reconstruction speed.We also share the MATLAB-based codes for evaluating RACT reconstructions,which users with MATLAB programming expertise can further modify to suit their needs.The shared GUI and codes can be of interest to researchers across the globe and assist them in e±cient evaluation of improved RACT reconstructions.展开更多
Understanding frictional anisotropy,which refers to the variation in frictional resistance based on the shear direction,is crucial for optimizing the friction angle between a bio-inspired structure and the surrounding...Understanding frictional anisotropy,which refers to the variation in frictional resistance based on the shear direction,is crucial for optimizing the friction angle between a bio-inspired structure and the surrounding soil.Previous studies focused on estimating the interface frictional anisotropy mobilized by snakeskin-inspired textured surfaces and sand under monotonic shear loading conditions.However,there is a need to estimate interface frictional anisotropy under repetitive shear loads.In this study,a series of repetitive direct shear(DS)tests are performed with snakeskin-inspired textured surfaces under a constant vertical stress and two shear directions(cranial first half→caudal second half or caudal first half→cranial second half).The results show that(1)mobilized shear stress increases with the number of shearing cycles,(2)cranial shearing(shearing against the scales)consistently produces a higher shear resistance and less contractive behavior than caudal shearing(shearing along the scales),and(3)a higher scale height or smaller scale length of the surface yields a higher interface friction angle across all shearing cycles.Further analysis reveals that the gap between the cranial and caudal shear zones of the interface friction angle as a function of L/H(i.e.the ratio of scale length L to scale height H)continues to decrease as the number of shearing cycles approaches asymptotic values.The directional frictional resistance(DFR)decreases as the number of shearing cycles increases.Furthermore,the discussion covers the impact of initial relative density,vertical stress,and the number of shearing cycles on interface frictional anisotropy.展开更多
为研究工程水泥基复合材料(ECC)加固盐冻融损伤后普通混凝土(Salt-freeze-thaw-damaged Normal Concrete,SftdNC)界面的剪切性能,通过66组剪切试件试验,系统探究了盐冻融循环次数、界面粗糙度、ECC抗压强度等级、界面剂类型及ECC养护龄...为研究工程水泥基复合材料(ECC)加固盐冻融损伤后普通混凝土(Salt-freeze-thaw-damaged Normal Concrete,SftdNC)界面的剪切性能,通过66组剪切试件试验,系统探究了盐冻融循环次数、界面粗糙度、ECC抗压强度等级、界面剂类型及ECC养护龄期等参数对界面宏观剪切性能与微观黏结特性的影响机制。结果表明:ECC-SftdNC界面破坏模式呈现材料破坏、界面破坏和混合破坏3类特征。电镜扫描结果显示:ECC-SftdNC界面黏结机制主要源于化学结合与机械咬合协同作用,界面剂可有效填充微裂缝并改善界面过渡区。当盐冻融循环次数增至200时,界面剪切强度与剪切断裂能分别衰减68%和28%;界面粗糙度从1.5mm提升至6.5mm可使界面剪切强度提高92%。在界面剂类型对比中,粉煤灰改性水泥浆表现出最优增强效果,其剪切强度与断裂能分别提升54%和75%。基于塑性极限理论建立的ECC-SftdNC界面剪切强度计算模型与试验数据吻合良好。提出的多参数影响规律与理论模型,为寒区盐冻融损伤混凝土桥梁的ECC加固设计与工程应用提供了重要理论依据和技术支撑。展开更多
基金Project(2022YFC3004700)supported by the National Key Research and Development Plan Project,ChinaProject(52374241)supported by the Key Project of the National Natural Science Foundation of China+3 种基金Project(KYCX24_2924)supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province,ChinaProject(2024WLKXJ151)supported by the Graduate Innovation Program of China University of Mining and Technology,ChinaProject(GZC20241919)supported by the Postdoctoral Fellowship Program of China Postdoctoral Science FoundationProject(2024ZB451)supported by the Jiangsu Province Outstanding Postdoctoral Program,China。
摘要Stress represents a critical determinant of dynamic hazards in underground coal mining operations.Heterogeneous geological features substantially influence stress distribution and magnitude throughout mining environments.To investigate the mechanical evolution and failure mechanisms of heterogeneous stratified composite coal-rock(CCR)under mining-induced stresses,three-point bending tests(TPBT)and numerical simulations are conducted on CCR specimens with varying homogeneity indices.Results show a significant positive correlation between CCR fracture strength and the homogeneity index(φ).Higher φ values are associated with more uniform displacement discontinuity zones during the fracturing process.Initial loading is observed to induce compressive strain at the upper coal-rock interface(UI),while tensile strain predominated at both the lower interface(LI)and boundary(LB).Interface strain magnitudes followed the pattern LB>LI>UI,with stability inversely proportional to strain intensity.As φ increases,interfacial stability is reduced,damage severity is amplified,and the critical strain energy release rate is elevated.These variations are primarily governed by the homogeneity-dependent redistribution of particle zones and the downward migration of resistant interfaces.These findings enhance our understanding of fracture propagation in heterogeneous CCR under mining stresses,thereby contributing to improved hazard forecasting and control strategies in coal mine composite roof systems.
摘要随着数智时代的到来,图形用户界面(graphical user interface,GUI)的外观专利申请量逐年递增。文章立足交互设计流程,将交互设计中的低保真原型、高保真原型以及占位符概念引入专利制度体系内,对GUI外观专利部分案例进行分类讨论,厘清了专利制度下“内容画面”概念与设计领域占位符概念的差异。针对低保真原型与高保真原型在现行法律制度下的提交方式,分别提出以下建议:对于低保真原型,应当判定其是否为纯图文排版、是否缺乏设计高度;若排除上述两种情形,应考虑加入参考图及简要说明,以保证GUI的清楚表达。对于高保真原型,应当判断其设计特征是否相对固定,从而确定其是否需要采取半透明遮罩层与参考图结合的模式提交。
摘要移动应用是近10年来兴起的新型计算模式,深刻地影响人民的生活方式.移动应用主要以图形用户界面(graphical user interface,GUI)方式交互,而对其进行人工测试需要消耗大量人力和物力.为此,研究者提出针对移动应用GUI的测试自动生成技术以提升测试效率并检测潜在缺陷.收集了145篇相关论文,系统地梳理、分析和总结现有工作.提出了“测试生成器-测试环境”研究框架,将该领域的研究按照所属模块进行分类.特别地,依据测试生成器所基于的方法,将现有方法大致分为基于随机、基于启发式搜索、基于模型、基于机器学习和基于测试迁移这5个类别.此外,还从缺陷类别和测试动作等其他分类维度梳理现有方法.收集了该领域中较有影响力的数据集和开源工具.最后,总结当前面临的挑战并展望未来的研究方向.
基金supported by the National Natural Science Foundation of China(Grant Nos.52371301 and 52471289)。
摘要The scaled suction caisson repre sents an innovative design featuring a bio-inspired sidewall modeled after snake skin,commonly utilized in offshore mooring platforms.In comparison with traditional suction caissons,this bio-inspired design demonstrates reduced penetration resistance and enhanced pull-out capacity due to the anisotropic shear behaviors of its sidewall.To investigate the shear behavior of the bio-inspired sidewall under pull-out load,direct shear tests were conducted between the bio-inspired surface and sand.The research demonstrates that the interface shear strength of the bio-inspired surface significantly surpasses that of the smooth surface due to interlocking effects.Additionally,the interface shear strength correlates with the aspect ratio of the bio-inspired surface,shear angle,and particle diameter distribution,with values increasing as the uniformity coefficient Cudecreases,while initially increasing and subsequently decreasing with increases in both aspect ratio and shear angle.The ratio between the interface friction angleδand internal friction angle δs defines the interface effect factor k.For the bio-inspired surface,the interface effect factor k varies with shear angleβ,ranging from 0.9 to 1.12.The peak value occurs at a shear angleβof 60°,substantially exceeding that of the smooth surface.A method for calculating the relative roughness RN is employed to evaluate the interface roughness of the bio-inspired surface,taking into account scale dimension and particle diameter distribution effects.
基金The National Natural Science Foundation of China(Grant No.42271144,Grant No.42071100)the Project of Shaanxi Province Qinchuangyuan"scientists&engineers"team construction(Grant No.2022KXJ-086)the Project of Application Fundamental Research of China Communications Construction(Grant No.2022-ZJKJ-PTJS07)。
摘要The interface between concrete and soil-rock mixture(SRM-concrete interface)under freeze-thaw cycles is very prone to creep damage,threatening the long-term stability of the superstructure in cold regions.However,there is no study concerning the characteristics of the nonlinear accelerated creep stage using the existing creep model in SRM-concrete interface.Therefore,shear creep tests were conducted to study the creep displacement and failure modes at the SRM-concrete interface under varying rock contents(15%-65%)and freeze-thaw cycles(0-20 iterations).A modified Burgers viscoelastic-plastic constitutive model is proposed to illustrate the creep failure characteristics of SRM-concrete interface induced by freeze-thaw cycles,which contains a hardening and loosening component.Results reveal a notable decrease in creep deformation correlating with increased rock content at SRM-concrete interface.Notably,the resistance of SRM-concrete interface to shear creep behavior peaks after five freeze-thaw cycles.This modified creep model accurately describes the nonlinear hardening and loosening creep behavior at the SRM-concrete interface,offering a substantial theoretical foundation for studying the longterm deformation and service life of superstructures in cold regions.
摘要In this paper, by means of effective testing practices, main strategies of integration testing for GUI software, including differentiating strategy for distinguished system, strategy of personnel organization, incremental testing strategy based on baseline version, testing strategy of circulating loop through the whole life, and the strategy of test suite construction, were briefly investigated. Moreover, for the code analysis, the FTA (Fault Tree analysis) is proposed to deal with the software change in regression testing. For test suite constructing, the constructing methods for baseline version and the incremental change are deeply discussed, in which main points focus on the testing strategy based on “Sheet/Form”, the “Grey-box approach” for integration testing process, and the application of the improved STD (State Transform Diagram) in state testing. At the same time, the suite construction of integration testing for two types, including small scale program and large scale software, is analyzed and discussed in detail. For testing execution, the specific method based on “Cross-testing” is investigated. Concurrently, by a lot of examples, all results of testing activity indicate that these strategies and methods are useful and fitted to integration testing for GUI software.
基金supported by the National Institute of Health (R37CA240806)and American Cancer Society (133697-RSG-19-110-01-CCE)support from UCI Chao Family Comprehensive Cancer Center (P30CA062203).
摘要Radiation-induced acoustic computed tomography(RACT)is an evolving biomedical imaging modality that aims to reconstruct the radiation energy deposition in tissues.Traditional backprojection(BP)reconstructions carry noisy and limited-view artifacts.Model-based algorithms have been demonstrated to overcome the drawbacks of BPs.However,model-based algorithms are relatively more complex to develop and computationally demanding.Furthermore,while a plethora of novel algorithms has been developed over the past decade,most of these algorithms are either not accessible,readily available,or hard to implement for researchers who are not well versed in programming.We developed a user-friendly MATLAB-based graphical user interface(GUI;RACT2D)that facilitates back-projection and model-based image reconstructions for twodimensional RACT problems.We included numerical and experimental X-ray-induced acoustic datasets to demonstrate the capabilities of the GUI.The developed algorithms support parallel computing for evaluating reconstructions using the cores of the computer,thus further accelerating the reconstruction speed.We also share the MATLAB-based codes for evaluating RACT reconstructions,which users with MATLAB programming expertise can further modify to suit their needs.The shared GUI and codes can be of interest to researchers across the globe and assist them in e±cient evaluation of improved RACT reconstructions.
基金the funding supported from the National Research Foundation of Korea(NRF)grant funded by the Korea Government MSIT(No.2021R1C1C1006003).
摘要Understanding frictional anisotropy,which refers to the variation in frictional resistance based on the shear direction,is crucial for optimizing the friction angle between a bio-inspired structure and the surrounding soil.Previous studies focused on estimating the interface frictional anisotropy mobilized by snakeskin-inspired textured surfaces and sand under monotonic shear loading conditions.However,there is a need to estimate interface frictional anisotropy under repetitive shear loads.In this study,a series of repetitive direct shear(DS)tests are performed with snakeskin-inspired textured surfaces under a constant vertical stress and two shear directions(cranial first half→caudal second half or caudal first half→cranial second half).The results show that(1)mobilized shear stress increases with the number of shearing cycles,(2)cranial shearing(shearing against the scales)consistently produces a higher shear resistance and less contractive behavior than caudal shearing(shearing along the scales),and(3)a higher scale height or smaller scale length of the surface yields a higher interface friction angle across all shearing cycles.Further analysis reveals that the gap between the cranial and caudal shear zones of the interface friction angle as a function of L/H(i.e.the ratio of scale length L to scale height H)continues to decrease as the number of shearing cycles approaches asymptotic values.The directional frictional resistance(DFR)decreases as the number of shearing cycles increases.Furthermore,the discussion covers the impact of initial relative density,vertical stress,and the number of shearing cycles on interface frictional anisotropy.
摘要为研究工程水泥基复合材料(ECC)加固盐冻融损伤后普通混凝土(Salt-freeze-thaw-damaged Normal Concrete,SftdNC)界面的剪切性能,通过66组剪切试件试验,系统探究了盐冻融循环次数、界面粗糙度、ECC抗压强度等级、界面剂类型及ECC养护龄期等参数对界面宏观剪切性能与微观黏结特性的影响机制。结果表明:ECC-SftdNC界面破坏模式呈现材料破坏、界面破坏和混合破坏3类特征。电镜扫描结果显示:ECC-SftdNC界面黏结机制主要源于化学结合与机械咬合协同作用,界面剂可有效填充微裂缝并改善界面过渡区。当盐冻融循环次数增至200时,界面剪切强度与剪切断裂能分别衰减68%和28%;界面粗糙度从1.5mm提升至6.5mm可使界面剪切强度提高92%。在界面剂类型对比中,粉煤灰改性水泥浆表现出最优增强效果,其剪切强度与断裂能分别提升54%和75%。基于塑性极限理论建立的ECC-SftdNC界面剪切强度计算模型与试验数据吻合良好。提出的多参数影响规律与理论模型,为寒区盐冻融损伤混凝土桥梁的ECC加固设计与工程应用提供了重要理论依据和技术支撑。