In this paper interfacial edge crack problems are considered by the application of the finite element method. The stress intensity factors are accurately determined from the ratio of crack-tip-stress value between the...In this paper interfacial edge crack problems are considered by the application of the finite element method. The stress intensity factors are accurately determined from the ratio of crack-tip-stress value between the target given unknown and reference problems. The reference problem is chosen to produce the singular stress fields proportional to those of the given unknown problem. Here the original proportional method is improved through utilizing very refined meshes and post-processing technique of linear extrapolation. The results for a double-edge interface crack in a bonded strip are newly obtained and compared with those of a single-edge interface crack for different forms of combination of material. It is found that the stress intensity factors should be compared in the three different zones of relative crack lengths. Different from the case of a cracked homogeneous strip, the results for the double edge interface cracks are found to possibly be bigger than those for a single edge interface crack under the same relative crack length.展开更多
In this communication we propose a method to implement an all-optical astable multivibrator using the non-linear material based switches and logic gates. The scheme can operate in real time. The delay time can achieve...In this communication we propose a method to implement an all-optical astable multivibrator using the non-linear material based switches and logic gates. The scheme can operate in real time. The delay time can achieve ps(pico-second). The pulse duration can be made very low and may cross the THz easily by selecting proper material and laser source.展开更多
Fly ash （FA） and ground granulated blast-furnace slag （GGBFS） were added to improve the performances of regenerated binding materials （RBM） which refer to dehydrated phases with rebinding ability of waste harden...Fly ash （FA） and ground granulated blast-furnace slag （GGBFS） were added to improve the performances of regenerated binding materials （RBM） which refer to dehydrated phases with rebinding ability of waste hardened cement paste. Flowability tests, compressive strength tests, SEM, TG-DSC, and non-evaporable water content tests were employed to study the performances of the combined binding materials and the interactions between RBM, FA, and GGBFS. Results show that adding FA or GGBFS can improve the workability of RBM paste, and GGBFS has positive effects on strength of RBM. Pozzolanic reactions happen between RBM, FA, and GGBFS. And the activation effect of RBM to FA and GGBFS is superior to that of P.O grade-32.5 cement, especially at earlier ages, because of the high reactive f-CaO existing in RBM. On the advantages of the synergetic effects of RBM and pozzolanic admixtures such as FA and GGBFS, new combined binding materials can be prepared by blending them together.展开更多
Based on a shallow roadway with weakly cemented soft strata in western China, this paper studies the range and degree of plastic zones in soft strata roadways with weak cementation. Geological radars were used to moni...Based on a shallow roadway with weakly cemented soft strata in western China, this paper studies the range and degree of plastic zones in soft strata roadways with weak cementation. Geological radars were used to monitor the loose range and level of surrounding rocks. A mechanical model of weakly cemented roadway was established, including granular material based on the measured results. The model was then used to determine the plastic zone radium. The predicted results agree well with measured results which provide valuable theoretical references for the analysis of surrounding rock stability and support reinforcing design of weakly cemented roadways. Finally, a combined supporting scheme of whole section bolting and grouting was proposed based on the original supporting scheme. It is proved that this support plan can effectively control the deformation and plastic zone expansion of the roadway surrounding rock and thus ensure the long-term stable and safe mining.展开更多
Vibrational power flow on combined plates with a change in mass and stiffness or with viscoelastic damping layer used widely in engineering is studied. The expressions of flexural displacement and other physical quan...Vibrational power flow on combined plates with a change in mass and stiffness or with viscoelastic damping layer used widely in engineering is studied. The expressions of flexural displacement and other physical quantities are obtained using Laplace transformation and transfer matrix approach, then influences of changes in mass and stiffness of discontinuous material and the free damping layer on the input power flow and the transmitted power flow are discussed. The conclusions provide theory basis for structural optimization design and reducing noise and vibration展开更多
By introducing piezoelectric materials into hydrogel oral dressings,a microelectric field could be generated under stress stimulation,thus facilitating oral wound healing.However,to adapt to the moist and dynamic envi...By introducing piezoelectric materials into hydrogel oral dressings,a microelectric field could be generated under stress stimulation,thus facilitating oral wound healing.However,to adapt to the moist and dynamic environment of the oral cavity,traditional"step-by-step"synthesis often requires the combination of materials with different functionalities.Given the property differences between these materials,this strategy typically involves complex experimental procedures and unnecessary energy consumption.In this study,with the concept of"integrated construction",we innovatively proposed a dual-step photo-induced method and successfully fabricated composite hydrogels with excellent performance.We introduced abundant oxygen vacancies into ZnO,leveraging the enhanced interface dynamics to achieve sustained photo-induced effect.With a double-network polymer framework as a template,this method could achieve the photo-induced spontaneous in-situ synthesis of polydopamine(PDA)within hydrogel without any extra special experimental conditions and complex operation procedures.We conducted a thorough analysis of the mechanism underlying this photo-induced method and applied the as-prepared hydrogel for the treatment of oral wounds,which significantly accelerated the healing process due to the outstanding comprehensive performance of hydrogel.These results suggest novel ideas and theoretical support for the facile construction of high-performance hydrogels based on photodynamic principles,demonstrating immense potential for future applications in wound dressings.展开更多
This book delves into the pain ted sculptures of the Tang and Song dynasties in Qinglian Temple and the Yuhuang Temple in Zezhou County,Jincheng City,Shanxi Provinee.The author not only describes in detail the histori...This book delves into the pain ted sculptures of the Tang and Song dynasties in Qinglian Temple and the Yuhuang Temple in Zezhou County,Jincheng City,Shanxi Provinee.The author not only describes in detail the historical background and artistic characteristics of these pain ted sculptures but also combines historical materials with inscription records,and puts forward unique insights into the imaging age and ide ntity of certain painted sculptures.展开更多
Human fingers have fingerprints and mechanoreceptors for biometric information encryption and tactile perception.Ideally,electronic skin(e-skin)integrates identity information and tactile sensing,but this remains chal...Human fingers have fingerprints and mechanoreceptors for biometric information encryption and tactile perception.Ideally,electronic skin(e-skin)integrates identity information and tactile sensing,but this remains challenging.Research on encryption and tactile sensing rarely overlaps.Here,we report using magnetization structures and combinations of magnetic materials to achieve two types of functions:6n×n invisible secure encryption is achieved through a n×n dipole magnetic array,and multipole magnets are used to achieve decoupling of pressure at various positions and sliding in different directions.The sliding distance ranges from 0 to 2.5 mm,with speeds between 5 and 25 mm/s.This study is based on flexible magnetic films,which have the potential to be used in wearable devices.The magnetic ring and signal detection modules verify the prospects of this fundamental principle in human-computer interaction(HCI)and demonstrate its applications in user identity recognition and tactile interaction.展开更多
Organic solar cells(OSCs)have demonstrated over 19%power conversion efficiency(PCE)with the help of material innovation and device optimization.Co-working with newly designed materials,traditional solvent additives,1-...Organic solar cells(OSCs)have demonstrated over 19%power conversion efficiency(PCE)with the help of material innovation and device optimization.Co-working with newly designed materials,traditional solvent additives,1-chloronaphthalene(CN),and 1,8-diodooctane(DIO)are still powerful in morphology modulation towards satisfying efficiencies.Here,we chose recently reported high-performance polymer donors(PM6&D18-Fu)and small molecular acceptors(Y6&L8-BO)as active layer materials and processed them by different conditions(CN or DIO or none).Based on corresponding 12 groups of device results,and their film morphology characterizations(both ex-situ and in-situ ones),the property-performance relationships are revealed case by case.It is thereby supposed to be taken as a successful attempt to demonstrate the importance and complexity of donor-acceptoradditive interaction,since the device performance and physics analyses are also tightly combined with morphology variation.Furthermore,ternary blend construction for PCE improvement provides an approaching 19%level and showcases the potential of understanding-guided-optimization(UGO)in the future of OSCs.展开更多
Although the power conversion efficiency of organic solar cells(OSCs)has been rapidly improved,there is still a lot of room for designing and developing new materials and their combinations to approach the efficiency ...Although the power conversion efficiency of organic solar cells(OSCs)has been rapidly improved,there is still a lot of room for designing and developing new materials and their combinations to approach the efficiency limit.In this work,we establish a database of~100 bulk heterojunction OSCs composed of representative donors and acceptors reported in the literature,and train machine learning models to identify the efficiency potential of donor-acceptor combinations.We find that the fully connected neural network achieves a Pearson coefficient of up to 0.88 for predicting the efficiency of OSCs with different combinations of donors and acceptors.We use sure independence screening and sparsifying method with feature analysis to analyze and evaluate the performance of OSCs.To prove the reliability and viability of the predictive model,we introduce the theoretical efficiency limits and confidence tests into the process,which provides a simple but reliable solution to quickly analyze and evaluate the potential of OSC materials and material combinations.展开更多
文摘In this paper interfacial edge crack problems are considered by the application of the finite element method. The stress intensity factors are accurately determined from the ratio of crack-tip-stress value between the target given unknown and reference problems. The reference problem is chosen to produce the singular stress fields proportional to those of the given unknown problem. Here the original proportional method is improved through utilizing very refined meshes and post-processing technique of linear extrapolation. The results for a double-edge interface crack in a bonded strip are newly obtained and compared with those of a single-edge interface crack for different forms of combination of material. It is found that the stress intensity factors should be compared in the three different zones of relative crack lengths. Different from the case of a cracked homogeneous strip, the results for the double edge interface cracks are found to possibly be bigger than those for a single edge interface crack under the same relative crack length.
文摘In this communication we propose a method to implement an all-optical astable multivibrator using the non-linear material based switches and logic gates. The scheme can operate in real time. The delay time can achieve ps(pico-second). The pulse duration can be made very low and may cross the THz easily by selecting proper material and laser source.
基金Funded by the National Science Foundation of China(No. 50508034)
文摘Fly ash （FA） and ground granulated blast-furnace slag （GGBFS） were added to improve the performances of regenerated binding materials （RBM） which refer to dehydrated phases with rebinding ability of waste hardened cement paste. Flowability tests, compressive strength tests, SEM, TG-DSC, and non-evaporable water content tests were employed to study the performances of the combined binding materials and the interactions between RBM, FA, and GGBFS. Results show that adding FA or GGBFS can improve the workability of RBM paste, and GGBFS has positive effects on strength of RBM. Pozzolanic reactions happen between RBM, FA, and GGBFS. And the activation effect of RBM to FA and GGBFS is superior to that of P.O grade-32.5 cement, especially at earlier ages, because of the high reactive f-CaO existing in RBM. On the advantages of the synergetic effects of RBM and pozzolanic admixtures such as FA and GGBFS, new combined binding materials can be prepared by blending them together.
基金provided by the National 973 Programs(No.2014CB046905)the National Natural Science Foundation of China(Nos.51274191 and 51404245)+1 种基金the Doctoral Fund of Ministry of Education(No.20130095110018)China Postdoctoral Science Foundation(No.2014M551699)
文摘Based on a shallow roadway with weakly cemented soft strata in western China, this paper studies the range and degree of plastic zones in soft strata roadways with weak cementation. Geological radars were used to monitor the loose range and level of surrounding rocks. A mechanical model of weakly cemented roadway was established, including granular material based on the measured results. The model was then used to determine the plastic zone radium. The predicted results agree well with measured results which provide valuable theoretical references for the analysis of surrounding rock stability and support reinforcing design of weakly cemented roadways. Finally, a combined supporting scheme of whole section bolting and grouting was proposed based on the original supporting scheme. It is proved that this support plan can effectively control the deformation and plastic zone expansion of the roadway surrounding rock and thus ensure the long-term stable and safe mining.
文摘Vibrational power flow on combined plates with a change in mass and stiffness or with viscoelastic damping layer used widely in engineering is studied. The expressions of flexural displacement and other physical quantities are obtained using Laplace transformation and transfer matrix approach, then influences of changes in mass and stiffness of discontinuous material and the free damping layer on the input power flow and the transmitted power flow are discussed. The conclusions provide theory basis for structural optimization design and reducing noise and vibration
基金supported by the National Key R&D Program of China(2021YFB2012601)National Natural Science Foundation of China(No.U2230108)+2 种基金Shanghai Science and Technology Innovation Action Medical Innovation Research Project(23Y11910100)Shanghai Stomatological Hospital Institutional Project(Grant No.SSH-2022-02,SHH-2022-YJ-07,SSH-2023-02)Medical Engineering Integration Project of Fudan University.
文摘By introducing piezoelectric materials into hydrogel oral dressings,a microelectric field could be generated under stress stimulation,thus facilitating oral wound healing.However,to adapt to the moist and dynamic environment of the oral cavity,traditional"step-by-step"synthesis often requires the combination of materials with different functionalities.Given the property differences between these materials,this strategy typically involves complex experimental procedures and unnecessary energy consumption.In this study,with the concept of"integrated construction",we innovatively proposed a dual-step photo-induced method and successfully fabricated composite hydrogels with excellent performance.We introduced abundant oxygen vacancies into ZnO,leveraging the enhanced interface dynamics to achieve sustained photo-induced effect.With a double-network polymer framework as a template,this method could achieve the photo-induced spontaneous in-situ synthesis of polydopamine(PDA)within hydrogel without any extra special experimental conditions and complex operation procedures.We conducted a thorough analysis of the mechanism underlying this photo-induced method and applied the as-prepared hydrogel for the treatment of oral wounds,which significantly accelerated the healing process due to the outstanding comprehensive performance of hydrogel.These results suggest novel ideas and theoretical support for the facile construction of high-performance hydrogels based on photodynamic principles,demonstrating immense potential for future applications in wound dressings.
文摘This book delves into the pain ted sculptures of the Tang and Song dynasties in Qinglian Temple and the Yuhuang Temple in Zezhou County,Jincheng City,Shanxi Provinee.The author not only describes in detail the historical background and artistic characteristics of these pain ted sculptures but also combines historical materials with inscription records,and puts forward unique insights into the imaging age and ide ntity of certain painted sculptures.
基金supported by the National Natural Science Foundation of China(No.52105072,62304023)the National Key Research and DevelopmentProgram ofChina(No.2022YFC3802302,2023YFB3507300).
文摘Human fingers have fingerprints and mechanoreceptors for biometric information encryption and tactile perception.Ideally,electronic skin(e-skin)integrates identity information and tactile sensing,but this remains challenging.Research on encryption and tactile sensing rarely overlaps.Here,we report using magnetization structures and combinations of magnetic materials to achieve two types of functions:6n×n invisible secure encryption is achieved through a n×n dipole magnetic array,and multipole magnets are used to achieve decoupling of pressure at various positions and sliding in different directions.The sliding distance ranges from 0 to 2.5 mm,with speeds between 5 and 25 mm/s.This study is based on flexible magnetic films,which have the potential to be used in wearable devices.The magnetic ring and signal detection modules verify the prospects of this fundamental principle in human-computer interaction(HCI)and demonstrate its applications in user identity recognition and tactile interaction.
基金Research Grants Council of Hong Kong,Grant/Award Numbers:15221320,C5037-18GRGC Senior Research Fellowship Scheme,Grant/Award Number:SRFS2223-5S01+5 种基金Shenzhen Science and Technology Innovation Commission,Grant/Award Number:JCYJ20200109105003940Hong Kong Polytechnic University Internal Research Funds:Sir Sze-yuen Chung Endowed Professorship Fund,Grant/Award Number:8-8480RISE(Q-CDBK),Grant/Award Numbers:G-SAC5,1-YW4CGuangdong-Hong Kong-Macao Joint Laboratory for Photonic-Thermal-Electrical Energy Materials and Devices,Grant/Award Number:2019B121205001Guangdong Basic and Applied Basic Research Foundation,Grant/Award Numbers:2022A1515010875,2021A1515110017Natural Science Foundation of Top Talent of SZTU。
文摘Organic solar cells(OSCs)have demonstrated over 19%power conversion efficiency(PCE)with the help of material innovation and device optimization.Co-working with newly designed materials,traditional solvent additives,1-chloronaphthalene(CN),and 1,8-diodooctane(DIO)are still powerful in morphology modulation towards satisfying efficiencies.Here,we chose recently reported high-performance polymer donors(PM6&D18-Fu)and small molecular acceptors(Y6&L8-BO)as active layer materials and processed them by different conditions(CN or DIO or none).Based on corresponding 12 groups of device results,and their film morphology characterizations(both ex-situ and in-situ ones),the property-performance relationships are revealed case by case.It is thereby supposed to be taken as a successful attempt to demonstrate the importance and complexity of donor-acceptoradditive interaction,since the device performance and physics analyses are also tightly combined with morphology variation.Furthermore,ternary blend construction for PCE improvement provides an approaching 19%level and showcases the potential of understanding-guided-optimization(UGO)in the future of OSCs.
基金supported by the Natural Science Foundation of China(52394273,52373179 and 22005102)the Program for Science and Technology Development of Dongguan(2019622163009)+2 种基金the Dongguan Innovative Research Team Program(No.2018607201002)the Guangdong Provincial Training Program of Innovation and Entrepreneurship for Undergraduates(grant No.S202010561186)the TCL science and technology innovation fund,and the Fund of Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates(2023B1212060003).
文摘Although the power conversion efficiency of organic solar cells(OSCs)has been rapidly improved,there is still a lot of room for designing and developing new materials and their combinations to approach the efficiency limit.In this work,we establish a database of~100 bulk heterojunction OSCs composed of representative donors and acceptors reported in the literature,and train machine learning models to identify the efficiency potential of donor-acceptor combinations.We find that the fully connected neural network achieves a Pearson coefficient of up to 0.88 for predicting the efficiency of OSCs with different combinations of donors and acceptors.We use sure independence screening and sparsifying method with feature analysis to analyze and evaluate the performance of OSCs.To prove the reliability and viability of the predictive model,we introduce the theoretical efficiency limits and confidence tests into the process,which provides a simple but reliable solution to quickly analyze and evaluate the potential of OSC materials and material combinations.
