线性乘积和规划已出现在工程实践和管理科学等领域,是一类NP-难问题。针对该问题目标函数的特殊结构,将其重构为一个D.C.(difference of convex functions)规划问题。再利用凹函数的凸包络,构造出了一种D.C.松弛问题,并将其分解为两个...线性乘积和规划已出现在工程实践和管理科学等领域,是一类NP-难问题。针对该问题目标函数的特殊结构,将其重构为一个D.C.(difference of convex functions)规划问题。再利用凹函数的凸包络,构造出了一种D.C.松弛问题,并将其分解为两个凸子问题。然后将该D.C.松弛与超矩形的标准二分法相结合,设计了新的分支定界算法,并分析了其理论收敛性和计算复杂度。最后,借助大量数值实验验证了该算法的有效性。展开更多
The bulge test is a widely utilized method for assessing the mechanical properties of thin films,including metals,polymers,and semiconductors.However,as film thickness diminishes to nanometer scales,boundary condition...The bulge test is a widely utilized method for assessing the mechanical properties of thin films,including metals,polymers,and semiconductors.However,as film thickness diminishes to nanometer scales,boundary conditions dominated by weak van der Waals forces significantly impact mechanical responses.Instead of sample fracture,interfacial shear deformation and delamination become the primary deformation modes,thereby challenging the applicability of conventional bulge models.To accommodate the interfacial effect,a modified mechanical model based on the bulge test has been proposed.This review summarizes recent advancements in the bulge test to highlight the potential challenges and opportunities for future research.展开更多
Subsurface rocks,as complex porous media,exhibit multiscale pore structures and intricate physical properties.Digital rock physics technology has become increasingly influential in the study of subsurface rock propert...Subsurface rocks,as complex porous media,exhibit multiscale pore structures and intricate physical properties.Digital rock physics technology has become increasingly influential in the study of subsurface rock properties.Given the multiscale characteristics of rock pore structures,direct three-dimensional imaging at sub-micrometer and nanometer scales is typically infeasible.This study introduces a method for reconstructing porous media using multidimensional data,which combines one-dimensional pore structure parameters with two-dimensional images to reconstruct three-dimensional models.The pore network model(PNM)is stochastically reconstructed using one-dimensional parameters,and a generative adversarial network(GAN)is utilized to equip the PNM with pore morphologies derived from two-dimensional images.The digital rocks generated by this method possess excellent controllability.Using Berea sandstone and Grosmont carbonate samples,we performed digital rock reconstructions based on PNM extracted by the maximum ball algorithm and compared them with stochastically reconstructed PNM.Pore structure parameters,permeability,and formation factors were calculated.The results show that the generated samples exhibit good consistency with real samples in terms of pore morphology,pore structure,and physical properties.Furthermore,our method effectively supplements the micropores not captured in CT images,demonstrating its potential in multiscale carbonate samples.Thus,the proposed reconstruction method is promising for advancing porous media property research.展开更多
The use of additive manufacturing techniques in the development of unconventional materials can help reduce the environmental impact of traditional construction materials.In this paper,the properties of a 3D-printed b...The use of additive manufacturing techniques in the development of unconventional materials can help reduce the environmental impact of traditional construction materials.In this paper,the properties of a 3D-printed biocomposite were evaluated.Biofilaments obtained by mixing pulverized bamboo fibers with polylactic acid(PLA)resin were extruded during the manufacturing process.To assess the effect of incorporating plant fibers,an analysis was conducted on the morphology,elemental chemical composition,crystallinity index,principal functional groups,thermal stability,surface roughness,microhardness,density,tensile strength,elastic modulus,and strain percentage of reinforced samples.The results were comparedwith those obtained from the characterization of standard PLAfilaments(unreinforced).The fused deposition modeling(FDM)technique was employed to print biocomposite specimens.Additionally,the influence of the printing parameters(infill density,build orientation,and layer thickness)on the physical,tribological,andmechanical properties of the biocomposites was analyzed.These results were compared with those obtained for specimens printed with pure PLA.The findings indicate that incorporating 10%vegetable filler into PLA filaments enhanced the strength and stiffness of the biocomposite under axial loads.Finally,the strength of the biocomposite subjected to axial loads was compared with the standardized values for wood-plastic composites,demonstrating the feasibility of its use for non-structural purposes in civil construction.展开更多
本文是D.C.隶属函数模糊集及其应用系列研究的第二部分。指出在实际问题中普遍选用的三角形、半三角形、梯形、半梯形、高斯型、柯西型、S形、Z形、π形隶属函数模糊集等均为D.C.隶属函数模糊集,建立了D.C.隶属函数模糊集对模糊集的万...本文是D.C.隶属函数模糊集及其应用系列研究的第二部分。指出在实际问题中普遍选用的三角形、半三角形、梯形、半梯形、高斯型、柯西型、S形、Z形、π形隶属函数模糊集等均为D.C.隶属函数模糊集,建立了D.C.隶属函数模糊集对模糊集的万有逼近性。探讨了D.C.隶属函数模糊集与模糊数之间的关系,给出了用D.C.隶属函数模糊集逼近模糊数的-εC e llina逼近形式,得到模糊数与D.C.函数之间的一个对应算子,指出了用模糊数表示D.C.函数的问题。展开更多
To study the influence of roll casting process parameters on temperature and thermal-stress fields for the AZ31 magnesium alloy sheets,three-dimensional geometric and 3D finite element models for roll casting were est...To study the influence of roll casting process parameters on temperature and thermal-stress fields for the AZ31 magnesium alloy sheets,three-dimensional geometric and 3D finite element models for roll casting were established based on the symmetry of roll casting by ANSYS software.Meshing method and smart-sizing algorithm were used to divide finite element mesh in ANSYS software.A series of researches on the temperature and stress distributions during solidification process with different process parameters were done by 3D finite element method.The temperatures of both the liquid-solid two-phase zone and liquid phase zone were elevated with increasing pouring temperature.With the heat transfer coefficient increasing,the two-phase region for liquid-solid becomes smaller.With the pouring temperature increasing and the increase of casting speed,the length of two-phase zone rises.The optimized of process parameters（casting speed 2 m/min,pouring temperature 640 ℃ and heat transfer coefficient 15 kW/（m2·℃） with the water pouring at roller exit was used to produce magnesium alloy AZ31 sheet,and equiaxed grains with the average grain size of 50 μm were achieved after roll casting.The simulation results give better understanding of the temperature variation in phase transformation zone and the formation mechanism of hot cracks in plates during roll casting and help to design the optimized process parameters of roll casting for Mg alloy.展开更多
多发性骨髓瘤(multiple myeloma,MM)是一种不可治愈的血液系统恶性肿瘤,尽管新型蛋白酶体抑制剂、免疫调节剂及CD38单抗等药物的应用显著延长了患者的生存时间,但复发耐药仍难以避免。细胞免疫治疗,特别是嵌合抗原受体(chimeric antigen...多发性骨髓瘤(multiple myeloma,MM)是一种不可治愈的血液系统恶性肿瘤,尽管新型蛋白酶体抑制剂、免疫调节剂及CD38单抗等药物的应用显著延长了患者的生存时间,但复发耐药仍难以避免。细胞免疫治疗,特别是嵌合抗原受体(chimeric antigen receptor,CAR)T细胞疗法的快速发展,极大程度的改变了复发/难治性(relapsed/refractory,R/R)MM患者的治疗现状。FDA目前已批准了2款靶向B细胞成熟抗原(B cell maturation antigen,BCMA)的CAR-T细胞产品,使其用于既往接受过4线及以上治疗的R/R MM患者。随着临床研究的不断深入,靶向GPRC5D(G protein-coupled receptor C class Group 5 member D,G蛋白偶联受体C类第5组成员D)的CAR-T细胞治疗也显示出其独特的优势。除了应用于难治复发的患者,多项临床试验支持CAR-T在MM中治疗线数的前移。本文就CAR-T细胞治疗在MM中开展的关键性临床研究展开综述,旨在为临床应用提供参考。展开更多
文摘线性乘积和规划已出现在工程实践和管理科学等领域,是一类NP-难问题。针对该问题目标函数的特殊结构,将其重构为一个D.C.(difference of convex functions)规划问题。再利用凹函数的凸包络,构造出了一种D.C.松弛问题,并将其分解为两个凸子问题。然后将该D.C.松弛与超矩形的标准二分法相结合,设计了新的分支定界算法,并分析了其理论收敛性和计算复杂度。最后,借助大量数值实验验证了该算法的有效性。
基金supported by the National Natural Science Foundation of China(Grant Nos.22072031,12372107,11832010,and 11890682)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB36000000).
文摘The bulge test is a widely utilized method for assessing the mechanical properties of thin films,including metals,polymers,and semiconductors.However,as film thickness diminishes to nanometer scales,boundary conditions dominated by weak van der Waals forces significantly impact mechanical responses.Instead of sample fracture,interfacial shear deformation and delamination become the primary deformation modes,thereby challenging the applicability of conventional bulge models.To accommodate the interfacial effect,a modified mechanical model based on the bulge test has been proposed.This review summarizes recent advancements in the bulge test to highlight the potential challenges and opportunities for future research.
基金supported by the Shandong Provincial Natural Science Foundation(ZR2024MD116)National Natural Science Foundation of China(Grant Nos.42174143,42004098)Technology Innovation Leading Program of Shaanxi(No.2024 ZC-YYDP-27).
文摘Subsurface rocks,as complex porous media,exhibit multiscale pore structures and intricate physical properties.Digital rock physics technology has become increasingly influential in the study of subsurface rock properties.Given the multiscale characteristics of rock pore structures,direct three-dimensional imaging at sub-micrometer and nanometer scales is typically infeasible.This study introduces a method for reconstructing porous media using multidimensional data,which combines one-dimensional pore structure parameters with two-dimensional images to reconstruct three-dimensional models.The pore network model(PNM)is stochastically reconstructed using one-dimensional parameters,and a generative adversarial network(GAN)is utilized to equip the PNM with pore morphologies derived from two-dimensional images.The digital rocks generated by this method possess excellent controllability.Using Berea sandstone and Grosmont carbonate samples,we performed digital rock reconstructions based on PNM extracted by the maximum ball algorithm and compared them with stochastically reconstructed PNM.Pore structure parameters,permeability,and formation factors were calculated.The results show that the generated samples exhibit good consistency with real samples in terms of pore morphology,pore structure,and physical properties.Furthermore,our method effectively supplements the micropores not captured in CT images,demonstrating its potential in multiscale carbonate samples.Thus,the proposed reconstruction method is promising for advancing porous media property research.
基金a derivative product of the project INV-ING-3788 financed by the Vicerectory of Research of the Universidad Militar Nueva Granada,validity 2023.
文摘The use of additive manufacturing techniques in the development of unconventional materials can help reduce the environmental impact of traditional construction materials.In this paper,the properties of a 3D-printed biocomposite were evaluated.Biofilaments obtained by mixing pulverized bamboo fibers with polylactic acid(PLA)resin were extruded during the manufacturing process.To assess the effect of incorporating plant fibers,an analysis was conducted on the morphology,elemental chemical composition,crystallinity index,principal functional groups,thermal stability,surface roughness,microhardness,density,tensile strength,elastic modulus,and strain percentage of reinforced samples.The results were comparedwith those obtained from the characterization of standard PLAfilaments(unreinforced).The fused deposition modeling(FDM)technique was employed to print biocomposite specimens.Additionally,the influence of the printing parameters(infill density,build orientation,and layer thickness)on the physical,tribological,andmechanical properties of the biocomposites was analyzed.These results were compared with those obtained for specimens printed with pure PLA.The findings indicate that incorporating 10%vegetable filler into PLA filaments enhanced the strength and stiffness of the biocomposite under axial loads.Finally,the strength of the biocomposite subjected to axial loads was compared with the standardized values for wood-plastic composites,demonstrating the feasibility of its use for non-structural purposes in civil construction.
文摘本文是D.C.隶属函数模糊集及其应用系列研究的第二部分。指出在实际问题中普遍选用的三角形、半三角形、梯形、半梯形、高斯型、柯西型、S形、Z形、π形隶属函数模糊集等均为D.C.隶属函数模糊集,建立了D.C.隶属函数模糊集对模糊集的万有逼近性。探讨了D.C.隶属函数模糊集与模糊数之间的关系,给出了用D.C.隶属函数模糊集逼近模糊数的-εC e llina逼近形式,得到模糊数与D.C.函数之间的一个对应算子,指出了用模糊数表示D.C.函数的问题。
基金Project(CSTC 2010BB4301) supported by Natural Science Foundation Project of Chongqing,ChinaProject supported by the Open Fund for Key Laboratory of Manufacture and Test Techniques for Automobile Parts of Ministry of Education Chongqing University of Technology,2003,China
文摘To study the influence of roll casting process parameters on temperature and thermal-stress fields for the AZ31 magnesium alloy sheets,three-dimensional geometric and 3D finite element models for roll casting were established based on the symmetry of roll casting by ANSYS software.Meshing method and smart-sizing algorithm were used to divide finite element mesh in ANSYS software.A series of researches on the temperature and stress distributions during solidification process with different process parameters were done by 3D finite element method.The temperatures of both the liquid-solid two-phase zone and liquid phase zone were elevated with increasing pouring temperature.With the heat transfer coefficient increasing,the two-phase region for liquid-solid becomes smaller.With the pouring temperature increasing and the increase of casting speed,the length of two-phase zone rises.The optimized of process parameters（casting speed 2 m/min,pouring temperature 640 ℃ and heat transfer coefficient 15 kW/（m2·℃） with the water pouring at roller exit was used to produce magnesium alloy AZ31 sheet,and equiaxed grains with the average grain size of 50 μm were achieved after roll casting.The simulation results give better understanding of the temperature variation in phase transformation zone and the formation mechanism of hot cracks in plates during roll casting and help to design the optimized process parameters of roll casting for Mg alloy.
文摘多发性骨髓瘤(multiple myeloma,MM)是一种不可治愈的血液系统恶性肿瘤,尽管新型蛋白酶体抑制剂、免疫调节剂及CD38单抗等药物的应用显著延长了患者的生存时间,但复发耐药仍难以避免。细胞免疫治疗,特别是嵌合抗原受体(chimeric antigen receptor,CAR)T细胞疗法的快速发展,极大程度的改变了复发/难治性(relapsed/refractory,R/R)MM患者的治疗现状。FDA目前已批准了2款靶向B细胞成熟抗原(B cell maturation antigen,BCMA)的CAR-T细胞产品,使其用于既往接受过4线及以上治疗的R/R MM患者。随着临床研究的不断深入,靶向GPRC5D(G protein-coupled receptor C class Group 5 member D,G蛋白偶联受体C类第5组成员D)的CAR-T细胞治疗也显示出其独特的优势。除了应用于难治复发的患者,多项临床试验支持CAR-T在MM中治疗线数的前移。本文就CAR-T细胞治疗在MM中开展的关键性临床研究展开综述,旨在为临床应用提供参考。
