A fluorescent supramolecular polymer network with an excellent triple-stimuli responsive property based on metal-ligand coordination and host-vip interactions has been constructed from a terpyridine-monofunctionaliz...A fluorescent supramolecular polymer network with an excellent triple-stimuli responsive property based on metal-ligand coordination and host-vip interactions has been constructed from a terpyridine-monofunctionalized leaning tower[6]arene,a tetraphenylethylene AIEgen,and a bridging coordination ion(Zn^2+).Addition of competitive binding agents,trifluoroacetic acid,and/or pillar[5]arene can break the metal coordination and/or host-vip inclusion complexation,and thermal heating can weaken the non-covalent interactions in the supramolecular polymer gel,all leading to the gel-to-sol transition.展开更多
This paper presents a study on the design strategy of leaning-type arch bridges.The main characteristics of leaning-type arch bridges are first introduced;Kunshan Yufeng Bridge is taken as an example to discuss differ...This paper presents a study on the design strategy of leaning-type arch bridges.The main characteristics of leaning-type arch bridges are first introduced;Kunshan Yufeng Bridge is taken as an example to discuss different aspects of a design strategy,which includes self-system optimization,selection of beam length and bridge deck position,and other aspects.This paper can be used as a reference to further improve and develop bridge design.展开更多
The production of high-purity n-hexane under mild conditions is of great significance in both the petrochemical industry and synthetic chemistry.Here,we report an easy-to-operate and energy-efficient n-hexane purifica...The production of high-purity n-hexane under mild conditions is of great significance in both the petrochemical industry and synthetic chemistry.Here,we report an easy-to-operate and energy-efficient n-hexane purification strategy using nonporous adaptive crystals of perethylated leaning pillar[6]arene(EtLP6).Adaptive EtLP6 crystals preferentially absorb n-hexane over other branched or cyclic C6 alkanes with similar boiling points.This selectivity arises from the different thermodynamic stabilities and variabilities of EtLP6 crystalloids loaded with n-hexane and other C6 alkanes.Moreover,the reversible transformations between the nonporous vip-free and n-hexane-containing structures make the EtLP6 crystals highly recyclable.展开更多
There are two kinds of people on earth today,Just two kinds of people,no more,I say.Not the good and the bad,for ’tis well understoodThe good are half bad and the bad are half good.Not the happy and sad,
The transverse rupture strength(TRS)is a key mechanical property for brittle Ti(C,N)-based cermets.However,the complicated structure with the ceramics hard phase and the metal binder phase makes it challenging to asce...The transverse rupture strength(TRS)is a key mechanical property for brittle Ti(C,N)-based cermets.However,the complicated structure with the ceramics hard phase and the metal binder phase makes it challenging to ascertain the essential impact on the TRS.To fundamentally understand the fracture in this system,herein,we present a theoretical model to investigate the essential TRS including friction stress at the phase boundary and Peierls stress of dislocations based on the first-principles method,in which the strain-stress method and Peierls-Nabarro method are employed.The traditional application of this method is analyzing the contributions to the yield strength(YS)in the constitution equation.In this article,we present a transformation of the TRS calculation into YS calculation in terms of some basic mechanical theories,thereby extending the applicability of this method to the calculation of TRS.And,the numerical valuations with good linear fit between the experimental TRS and calculated TRS including intrinsic strength,Hall-Petch effect,as well as dislocation density hardening provide solid evidence for the accuracy of our deductions and theoretical model.Finally,it is evident that the brittle components in cermets are not typically the ceramic phase itself.Our methodology illuminates a novel yet effective approach for analyzing fracture in Ti(C,N)-based cermets,which may be extended to other brittle materials in future.展开更多
利用格上LWE(Leaning With Error)困难性假设,将保密地比较两个数是否相等转化为判断对随机串加密后的解密是否正确,有效地解决了数和集合关系的判定、求集合交集和集合相等安全多方计算问题,并利用模拟范例证明该协议在半诚实模型下是...利用格上LWE(Leaning With Error)困难性假设,将保密地比较两个数是否相等转化为判断对随机串加密后的解密是否正确,有效地解决了数和集合关系的判定、求集合交集和集合相等安全多方计算问题,并利用模拟范例证明该协议在半诚实模型下是安全的。与传统的基于数论的协议相比,该方案由于不需要模指数运算,因而具有较低的计算复杂度,同时因其基于格中困难问题,因而能抵抗量子攻击。展开更多
Dear Editor,The Hans Chinese(HC)ethnic group,comprising approximately 1.4 billion individuals,represents the largest workforce globally.Historically,HC has been predominantly isolated from other ethnic groups for over...Dear Editor,The Hans Chinese(HC)ethnic group,comprising approximately 1.4 billion individuals,represents the largest workforce globally.Historically,HC has been predominantly isolated from other ethnic groups for over 3 millennia,resulting in distinct genetic and physiological characteristics[1,2].Consequently,the energy required to maintain essential functions,represented by the basal metabolic rate(BMR),cannot be accurately assessed in HC with algorithms developed for European-American(EA)populations,even when controlling for diff erences in body size[3].Notably,the widely used Harris-Benedict equation tends to overestimate BMR,relative to measured BMR via indirect calorimetry,in more than 50%of HC individuals[3].Hence,HC generally expends less energy than EA under basal(resting)conditions.This raises an important question:does HC require lower energy expenditure than EA for equivalent external work?Th e present aimed to address this inquiry,while adjusting for key confounding factors such as age,sex,physical activity,aerobic capacity,BMR,and body composition.展开更多
Lithium-sulfur batteries(LSBs)hold significant promise as advanced energy storage systems due to their high energy density,low cost,and environmental advantages.However,despite recent advancements,their practical ener...Lithium-sulfur batteries(LSBs)hold significant promise as advanced energy storage systems due to their high energy density,low cost,and environmental advantages.However,despite recent advancements,their practical energy density still falls short of the levels required for commercial viability.The energy density is critically dependent on both sulfur loading and the amount of electrolyte used.Highsulfur loading coupled with lean electrolyte conditions presents several challenges,including the insulating nature of sulfur and Li_(2)S,insufficient electrolyte absorption,degradation of the cathode structure,severe lithium polysulfide shuttling,slow redox reaction kinetics,and instability of the Li metal anode.MXenes-based materials,with their metallic conductivity,large polar surfaces,and abundant active sites,have been identified as promising electrocatalysts to improve the redox reactions in LSBs.This review focuses on the significance and challenges associated with high-sulfur loading and lean electrolytes in LSBs,highlighting recent advancements in MXenes-based electrocatalysts aimed at optimizing sulfur cathodes and lithium anodes.It provides a comprehensive discussion on MXenes as both active materials and substrates in LSBs,with the goal of enhancing understanding of the regulatory mechanisms that govern sulfur conversion reactions and lithium plating/stripping behavior.Finally,the review explores future opportunities for MXenes-based electrocatalysts,paving the way for the practical application of LSBs.展开更多
Over the past few years,the Cu element has attracted much attention in duplex stainless steels.It undoubtedly holds advantageous in regulating the two-phase proportion and austenite stability and is also one of the cr...Over the past few years,the Cu element has attracted much attention in duplex stainless steels.It undoubtedly holds advantageous in regulating the two-phase proportion and austenite stability and is also one of the crucial factors affecting the corrosion resistance.However,the systematic research on the impact of Cu addition to lean duplex stainless steels remains insufficient.In this study,a novel Cu-alloyed Mn-N-type 20Cr lean duplex stainless steel was developed and the effect of Cu on the strain hardening capacity and corrosion resistance was analyzed.The results show that the Cu addition increases the volume fraction and stability of the austenite,retards the martensitic transformation,and extends the transformation-induced plasticity effect to a wider strain range.Compared to the Cu-free steel,the plasticity of Cu-containing steel can be increased by~26%.Additionally,the addition of Cu redistributes the Cr and N elements in the ferrite and austenite phases,thereby improving the corrosion resistance of the lean duplex stainless steel.展开更多
Objective:To evaluate the application value of lean management in the management of flexible endoscopes.Methods:From January to December 2023,routine management was implemented,and 200 flexible endoscopes used for exa...Objective:To evaluate the application value of lean management in the management of flexible endoscopes.Methods:From January to December 2023,routine management was implemented,and 200 flexible endoscopes used for examination and treatment were included in the control group;from January to December 2024,lean management was implemented,and 200 flexible endoscopes used for examination and treatment were included in the observation group.The average daily usage frequency,management effectiveness,and failure rate of flexible endoscopes were compared between the two groups.Results:The average daily usage frequency of flexible endoscopes in the observation group was higher than that in the control group(P<0.05);the 3S retrieval rate and spot-check qualification rate of endoscopes in the observation group were higher than those in the control group(P<0.05);the failure rate of flexible endoscopes in the observation group was lower than that in the control group(P<0.05).Conclusion:Implementing lean management during the management of flexible endoscopes can improve the efficiency of endoscope retrieval,increase the average daily usage frequency of flexible endoscopes,and reduce endoscope failures.展开更多
This study systematically investigated the Lean Blowoff(LBO)limits of Two-Dimensional(2D)bluff-body stabilized premixed flames by varying the air mass flow rate,inflowtemperature,bluff-body width,and fuel type.The dat...This study systematically investigated the Lean Blowoff(LBO)limits of Two-Dimensional(2D)bluff-body stabilized premixed flames by varying the air mass flow rate,inflowtemperature,bluff-body width,and fuel type.The data of LBO limits were analyzed and fittedaccording to the Damk?hler(Da)and Reynolds(Re)numbers,and the fitting accuracy of LBO datawas highly improved by a modified characteristic length simultaneously considering the length andwidth of the bluff body,which is usually neglected in the previous studies.Moreover,to our knowl-edge,this is the first time that simultaneous transverse and spanwise OH*-Chemiluminescence(CL)imaging has been performed to examine the three-dimensional behavior of the LBO process.The flame stability is heavily affected by the mass and energy transport between reactants andproducts in both directions,potentially leading to the flame pinch-off.The intensity and positionof the upstream flame after pinch-off are decisive to the occurrence of the following LBO.Whenthe upstream flame after pinch-off is weak and close to the bluff body,it cannot re-ignite thedownstream unburnt gas.Subsequently,a permanent downstream extinction occurs,and theLBO takes place.The results help understand the LBO mechanism of 2D bluff-body stabilizedflames.展开更多
As a creative and effective teaching method adopted by many countries, cooperative learning is one of the most widespread and fruitful areas in modern education theory. With the introduction of the concept of cooperat...As a creative and effective teaching method adopted by many countries, cooperative learning is one of the most widespread and fruitful areas in modern education theory. With the introduction of the concept of cooperative learning among College oral English teaching, students could undergo all-round training in English proficiency, cooperative ability, self-learning ability and sense of competition. This paper mainly focuses on how to make full use of cooperative leaning in College oral English teaching, and tries to verify that cooperative leaning is a practical and effective teaching mode which could enhance the College oral English classroom teaching quality.展开更多
基金the National Natural Science Foundation of China (No. 21871108) for financial support
文摘A fluorescent supramolecular polymer network with an excellent triple-stimuli responsive property based on metal-ligand coordination and host-vip interactions has been constructed from a terpyridine-monofunctionalized leaning tower[6]arene,a tetraphenylethylene AIEgen,and a bridging coordination ion(Zn^2+).Addition of competitive binding agents,trifluoroacetic acid,and/or pillar[5]arene can break the metal coordination and/or host-vip inclusion complexation,and thermal heating can weaken the non-covalent interactions in the supramolecular polymer gel,all leading to the gel-to-sol transition.
文摘This paper presents a study on the design strategy of leaning-type arch bridges.The main characteristics of leaning-type arch bridges are first introduced;Kunshan Yufeng Bridge is taken as an example to discuss different aspects of a design strategy,which includes self-system optimization,selection of beam length and bridge deck position,and other aspects.This paper can be used as a reference to further improve and develop bridge design.
基金the National Natural Science Foundation of China(21871108)Jilin Province-University Cooperative Construction Project-Special Funds for New Materials(SXGJSF2017-3)Jilin University Talents Cultivation Program for financial support.
文摘The production of high-purity n-hexane under mild conditions is of great significance in both the petrochemical industry and synthetic chemistry.Here,we report an easy-to-operate and energy-efficient n-hexane purification strategy using nonporous adaptive crystals of perethylated leaning pillar[6]arene(EtLP6).Adaptive EtLP6 crystals preferentially absorb n-hexane over other branched or cyclic C6 alkanes with similar boiling points.This selectivity arises from the different thermodynamic stabilities and variabilities of EtLP6 crystalloids loaded with n-hexane and other C6 alkanes.Moreover,the reversible transformations between the nonporous vip-free and n-hexane-containing structures make the EtLP6 crystals highly recyclable.
文摘There are two kinds of people on earth today,Just two kinds of people,no more,I say.Not the good and the bad,for ’tis well understoodThe good are half bad and the bad are half good.Not the happy and sad,
基金financially supported by the National Key R&D Program of China(no.2022YFB3706600)the Central Fund to Guide Local Scientific and Technological Development,China(no.20231ZDH04044).
文摘The transverse rupture strength(TRS)is a key mechanical property for brittle Ti(C,N)-based cermets.However,the complicated structure with the ceramics hard phase and the metal binder phase makes it challenging to ascertain the essential impact on the TRS.To fundamentally understand the fracture in this system,herein,we present a theoretical model to investigate the essential TRS including friction stress at the phase boundary and Peierls stress of dislocations based on the first-principles method,in which the strain-stress method and Peierls-Nabarro method are employed.The traditional application of this method is analyzing the contributions to the yield strength(YS)in the constitution equation.In this article,we present a transformation of the TRS calculation into YS calculation in terms of some basic mechanical theories,thereby extending the applicability of this method to the calculation of TRS.And,the numerical valuations with good linear fit between the experimental TRS and calculated TRS including intrinsic strength,Hall-Petch effect,as well as dislocation density hardening provide solid evidence for the accuracy of our deductions and theoretical model.Finally,it is evident that the brittle components in cermets are not typically the ceramic phase itself.Our methodology illuminates a novel yet effective approach for analyzing fracture in Ti(C,N)-based cermets,which may be extended to other brittle materials in future.
文摘利用格上LWE(Leaning With Error)困难性假设,将保密地比较两个数是否相等转化为判断对随机串加密后的解密是否正确,有效地解决了数和集合关系的判定、求集合交集和集合相等安全多方计算问题,并利用模拟范例证明该协议在半诚实模型下是安全的。与传统的基于数论的协议相比,该方案由于不需要模指数运算,因而具有较低的计算复杂度,同时因其基于格中困难问题,因而能抵抗量子攻击。
基金supported by the Research Grant Council of Hong Kong-Early Career Scheme(106210224)and the Seed Fund(104006024).
文摘Dear Editor,The Hans Chinese(HC)ethnic group,comprising approximately 1.4 billion individuals,represents the largest workforce globally.Historically,HC has been predominantly isolated from other ethnic groups for over 3 millennia,resulting in distinct genetic and physiological characteristics[1,2].Consequently,the energy required to maintain essential functions,represented by the basal metabolic rate(BMR),cannot be accurately assessed in HC with algorithms developed for European-American(EA)populations,even when controlling for diff erences in body size[3].Notably,the widely used Harris-Benedict equation tends to overestimate BMR,relative to measured BMR via indirect calorimetry,in more than 50%of HC individuals[3].Hence,HC generally expends less energy than EA under basal(resting)conditions.This raises an important question:does HC require lower energy expenditure than EA for equivalent external work?Th e present aimed to address this inquiry,while adjusting for key confounding factors such as age,sex,physical activity,aerobic capacity,BMR,and body composition.
基金supported by the Research Funding of Hangzhou International Innovation Institute of Beihang University(Grant No.2024KQ102 and 2024KQ131)the National Natural Science Foundation of China(Grant No.524B2020,51925202,U22A20141,52432004,U23A20575,52472183,and 22379039).
文摘Lithium-sulfur batteries(LSBs)hold significant promise as advanced energy storage systems due to their high energy density,low cost,and environmental advantages.However,despite recent advancements,their practical energy density still falls short of the levels required for commercial viability.The energy density is critically dependent on both sulfur loading and the amount of electrolyte used.Highsulfur loading coupled with lean electrolyte conditions presents several challenges,including the insulating nature of sulfur and Li_(2)S,insufficient electrolyte absorption,degradation of the cathode structure,severe lithium polysulfide shuttling,slow redox reaction kinetics,and instability of the Li metal anode.MXenes-based materials,with their metallic conductivity,large polar surfaces,and abundant active sites,have been identified as promising electrocatalysts to improve the redox reactions in LSBs.This review focuses on the significance and challenges associated with high-sulfur loading and lean electrolytes in LSBs,highlighting recent advancements in MXenes-based electrocatalysts aimed at optimizing sulfur cathodes and lithium anodes.It provides a comprehensive discussion on MXenes as both active materials and substrates in LSBs,with the goal of enhancing understanding of the regulatory mechanisms that govern sulfur conversion reactions and lithium plating/stripping behavior.Finally,the review explores future opportunities for MXenes-based electrocatalysts,paving the way for the practical application of LSBs.
基金supported by the Jilin Scientific and Technological Development Program(No.YDZJ202201ZYTS669)the National Natural Science Foundation of China(Nos.51974032,52174355,51874043 and 51604034).
文摘Over the past few years,the Cu element has attracted much attention in duplex stainless steels.It undoubtedly holds advantageous in regulating the two-phase proportion and austenite stability and is also one of the crucial factors affecting the corrosion resistance.However,the systematic research on the impact of Cu addition to lean duplex stainless steels remains insufficient.In this study,a novel Cu-alloyed Mn-N-type 20Cr lean duplex stainless steel was developed and the effect of Cu on the strain hardening capacity and corrosion resistance was analyzed.The results show that the Cu addition increases the volume fraction and stability of the austenite,retards the martensitic transformation,and extends the transformation-induced plasticity effect to a wider strain range.Compared to the Cu-free steel,the plasticity of Cu-containing steel can be increased by~26%.Additionally,the addition of Cu redistributes the Cr and N elements in the ferrite and austenite phases,thereby improving the corrosion resistance of the lean duplex stainless steel.
文摘Objective:To evaluate the application value of lean management in the management of flexible endoscopes.Methods:From January to December 2023,routine management was implemented,and 200 flexible endoscopes used for examination and treatment were included in the control group;from January to December 2024,lean management was implemented,and 200 flexible endoscopes used for examination and treatment were included in the observation group.The average daily usage frequency,management effectiveness,and failure rate of flexible endoscopes were compared between the two groups.Results:The average daily usage frequency of flexible endoscopes in the observation group was higher than that in the control group(P<0.05);the 3S retrieval rate and spot-check qualification rate of endoscopes in the observation group were higher than those in the control group(P<0.05);the failure rate of flexible endoscopes in the observation group was lower than that in the control group(P<0.05).Conclusion:Implementing lean management during the management of flexible endoscopes can improve the efficiency of endoscope retrieval,increase the average daily usage frequency of flexible endoscopes,and reduce endoscope failures.
基金the financial support of the National Natural Science Foundation of China(Nos.U2141221 and 52076136)the National Science and Technology Major Project,China(Nos.J2019-Ⅲ-0004-0047 and Y2022-Ⅲ-0001-0010)+1 种基金the Center for Basic Science of Aero Engines and Gas Turbines Project,China(No.P2022-B-Ⅱ019-001)the Natural Science Foundation of Shanghai,China(Nos.22ZR1467900 and 23ZR1481400)。
文摘This study systematically investigated the Lean Blowoff(LBO)limits of Two-Dimensional(2D)bluff-body stabilized premixed flames by varying the air mass flow rate,inflowtemperature,bluff-body width,and fuel type.The data of LBO limits were analyzed and fittedaccording to the Damk?hler(Da)and Reynolds(Re)numbers,and the fitting accuracy of LBO datawas highly improved by a modified characteristic length simultaneously considering the length andwidth of the bluff body,which is usually neglected in the previous studies.Moreover,to our knowl-edge,this is the first time that simultaneous transverse and spanwise OH*-Chemiluminescence(CL)imaging has been performed to examine the three-dimensional behavior of the LBO process.The flame stability is heavily affected by the mass and energy transport between reactants andproducts in both directions,potentially leading to the flame pinch-off.The intensity and positionof the upstream flame after pinch-off are decisive to the occurrence of the following LBO.Whenthe upstream flame after pinch-off is weak and close to the bluff body,it cannot re-ignite thedownstream unburnt gas.Subsequently,a permanent downstream extinction occurs,and theLBO takes place.The results help understand the LBO mechanism of 2D bluff-body stabilizedflames.
文摘As a creative and effective teaching method adopted by many countries, cooperative learning is one of the most widespread and fruitful areas in modern education theory. With the introduction of the concept of cooperative learning among College oral English teaching, students could undergo all-round training in English proficiency, cooperative ability, self-learning ability and sense of competition. This paper mainly focuses on how to make full use of cooperative leaning in College oral English teaching, and tries to verify that cooperative leaning is a practical and effective teaching mode which could enhance the College oral English classroom teaching quality.
