In recent years,Remotely Operated Vehicles(ROVs)have played an increasingly important role in the construc-tion and monitoring of underwater pile foundations.However,due to the open frame structure of such vehicles,a ...In recent years,Remotely Operated Vehicles(ROVs)have played an increasingly important role in the construc-tion and monitoring of underwater pile foundations.However,due to the open frame structure of such vehicles,a gap of knowledge still exists with regard to their hydrodynamic behavior.In this study,the hydrodynamic stability of such vehicles is investigated numerically by means of a multiple reference frame method.The hydrodynamic characteristics of the ROV when it moves horizontally and upward in the vertical plane are examined.It is found that there is interference between the horizontal and vertical thrusters of the ROV.There is also interference between the propeller thrust and drag(or lift).The effect of the vertical thrusters can increase the horizontal thrust by about 5%.The horizontal thrusters create a low-pressure area below the body,which can make vertical drag experienced by the ROV significantly higher.展开更多
This study aims to investigate the primary carbides precipitation in H13 steel solidified at relatively high cooling rates,ranging from 300 to 6,000℃·min^-1,based on in situ observations with a high temperature ...This study aims to investigate the primary carbides precipitation in H13 steel solidified at relatively high cooling rates,ranging from 300 to 6,000℃·min^-1,based on in situ observations with a high temperature confocal laser scanning microscope.In the cooling rate range investigated,the solidification microstructure becomes more refined as cooling rate increases and the relationship between the secondary dendrite arm spacing(SDAS),λ2,and cooling rate,.T,can be expressed asλ2=128.45.T-0.124.Regardless of cooling rates,two kinds of primary carbides,i.e.,the Mo-Cr-rich and V-rich carbides,are precipitated along the interdendritic region and most of them are the Mo-Cr-rich carbides.The morphology of Mo-Cr-rich carbide is not obviously influenced by the cooling rate,but that of V-rich carbide is obviously affected.The increasing cooling rate markedly refines the primary carbides and reduces their volume fractions,but their precipitations cannot be inhibited even when the cooling rate is increased to 6,000℃·min^-1.Besides,the segregation ratios(SRs)of the carbides forming elements are not obviously affected by the cooling rate.However,compared with the conventionally cast ingot,the SDAS and primary carbides in the steel solidified at the investigated cooling rates are much finer,morphologies of the carbides have changed significantly,and SRs of the carbides forming elements are markedly greater.The variation of primary carbide characteristics with cooling rate is mainly due to the change in SDAS.展开更多
Platinum(Pt)is a critical raw material for automotive catalytic converters due to its high-temperature stability,corrosion resistance and catalytic activity,whereas its limited primary resources and uneven distributio...Platinum(Pt)is a critical raw material for automotive catalytic converters due to its high-temperature stability,corrosion resistance and catalytic activity,whereas its limited primary resources and uneven distribution make it hard to meet the growing demand of platinum.Spent automotive catalyst(SAC)is currently the most important secondary resource of platinum,of which the platinum content is much higher than that of the primary platinum resources.The recovery process of platinum from spent automobile catalyst mainly consists of pretreatment followed by enrichment and refining,involving pyro-and hydrometallurgical techniques,among which enrichment and refining processes are extremely important for platinum recovery from spent automobile catalyst.This paper provides an overview of the technologies for platinum recovery from spent automotive catalyst.The emphasis is placed on the processes of enrichment and refining based on hydrometallurgical techniques.Future directions of research and development of platinum recovery from spent automobile catalyst are also proposed.展开更多
Lithium is critical for economic growth since it is the primary component of batteries.Na^(+)is one of the main impurity ions in solution during the separation and enrichment of Li^(+).According to the size-matching e...Lithium is critical for economic growth since it is the primary component of batteries.Na^(+)is one of the main impurity ions in solution during the separation and enrichment of Li^(+).According to the size-matching effect between the cavities of crown ethers and Li+,crown ethers can selectively adsorb Li^(+).Herein,1,8-dihydroxyl-4,4,5,5-tetramethylbenzo-14-crown-4 was synthesized and used to extract lithium from a Li^(+)/Na^(+)mixed solution.Density functional theory(DFT)was used to explore the properties of complexes with M062X.The results show that the interactions between crown ethers and metal ions are due to electrostatic attraction.Hydroxyl functional groups can synergistically extract Li^(+)/Na^(+)from solutions with the oxygen atom in the crown ether ring.The stability of the complex is also enhanced by van der Waals interactions between the butyrate acid root and crown ether.1,8-dihydroxyl-4,4,5,5-tetramethylbenzo-14-crown-4 has a stronger interaction with lithium butyrate than with sodium butyrate for most conformations.The adsorption selectivity for Li+is proportional to the number of ether oxygen atoms that interact with Li^(+).The Li^(+)extraction efficiency increases from 3.93%to 20.93%in lithium hydroxide solution with the presence of butyrate acid root.When the butyrate acid root is added to the mixed Li^(+)/Na^(+)solution,the Li^(+)extraction efficiency increases from 6.54%to 31.20%,while the Li^(+)/Na^(+)separation coefficient decreases from33.25 to 1.32.展开更多
The research and application of responsive materials have long been hampered by their complicated designs and tedious construction processes.Besides,many current responsive materials show retard or weak responsiveness...The research and application of responsive materials have long been hampered by their complicated designs and tedious construction processes.Besides,many current responsive materials show retard or weak responsiveness.In this study,responsive hybrid poly(vinyl alcohol)hydrogel membranes with embedded poly(N-isopropylacrylamide-acrylic acid)microgels as valves were constructed by simple mixing and subsequent freezing-thawing process.In the structure of the membranes,the matrix poly(vinyl alcohol)chains thread through and entangle with the microgels,and the microgels are firmly constrained within the hybrid hydrogel network.The fast and sharp temperature responsiveness of the embedded microgels was largely retained and endowed the hydrogel membrane with excellent temperature and pH responsiveness.Moreover,the hydrogel membrane showed excellent fatigue resistance in both temperature and pH-responsive flux examination.This study presented the great potential of these hybrid hydrogel membranes in biomedical applications and provided a new strategy for the future design and construction of responsive biomaterials.展开更多
HIV-1 infection-induced cGAS–STING–TBK1–IRF3 signaling activates innate immunity to produce type I interferon(IFN).The HIV-1 nonstructural protein viral infectivity factor(Vif)is essential in HIV-1 replication,as i...HIV-1 infection-induced cGAS–STING–TBK1–IRF3 signaling activates innate immunity to produce type I interferon(IFN).The HIV-1 nonstructural protein viral infectivity factor(Vif)is essential in HIV-1 replication,as it degrades the host restriction factor APOBEC3G.However,whether and how it regulates the host immune response remains to be determined.In this study,we found that Vif inhibited the production of type I IFN to promote immune evasion.HIV-1 infection induced the activation of the host tyrosine kinase FRK,which subsequently phosphorylated the immunoreceptor tyrosine-based inhibitory motif(ITIM)of Vif and enhanced the interaction between Vif and the cellular tyrosine phosphatase SHP-1 to inhibit type I IFN.Mechanistically,the association of Vif with SHP-1 facilitated SHP-1 recruitment to STING and inhibited the K63-linked ubiquitination of STING at Lys337 by dephosphorylating STING at Tyr162.However,the FRK inhibitor D-65495 counteracted the phosphorylation of Vif to block the immune evasion of HIV-1 and antagonize infection.These findings reveal a previously unknown mechanism through which HIV-1 evades antiviral immunity via the ITIM-containing protein to inhibit the posttranslational modification of STING.These results provide a molecular basis for the development of new therapeutic strategies to treat HIV-1 infection.展开更多
In order to take full advantage of the secondary resources,in this paper,we reported a template-free process to prepare porous Co microfibers from spent lithiumion batteries(LIBs).First,the waste LiCoO_(2) powders wer...In order to take full advantage of the secondary resources,in this paper,we reported a template-free process to prepare porous Co microfibers from spent lithiumion batteries(LIBs).First,the waste LiCoO_(2) powders were leached by oxalic acid at a suitable temperature,and rodlike cobalt oxalate powders were obtained.Second,the porous Co microfibers were prepared by using the cobalt oxalate as precursors through a thermal decomposition at420 ℃ under nitrogen atmosphere.The prepared Co microfibers possess diameters of 1-2 μm,and each microfiber consists of small particles with size of100-200 nm.The Co microfibers(25 wt%)/paraffin composite exhibited excellent microwave absorption performance.When the sample thickness is 4.5 mm,the reflection losses reach-36.14 and-38.20 dB at 4.16 and 17.60 GHz,respectively,and the effective bandwidth reaches up to 5.52 GHz.This indicates that the Co microfibers can be used as a promising microwave absorber.Therefore,this paper demonstrates a novel process to make a high value-added product through recycling from the spent lithium-ion batteries.In addition,it is advantageous to eliminate the hazard of spent lithium-ion batteries and electromagnetic radiation to environment and human health.展开更多
The China Spallation Neutron Source is an accelerator-based user facility for neutron,proton,muon applications and so on.The designed proton beam power is 100 kW for the first phase.Overall,the scope of accelerator co...The China Spallation Neutron Source is an accelerator-based user facility for neutron,proton,muon applications and so on.The designed proton beam power is 100 kW for the first phase.Overall,the scope of accelerator control system covers four parts,the global systems,the device layer local controls and remote controls,the high-level applications and services and the integration of conventional facilities.The principle guideline is to adopt as many as possible matured technologies and commercial products in the design and implementation.The control system is based on Experimental Physics and Industrial Control System.VME64x bus is chosen for timing system and fast protection system.PLCs and embedded industrial computers are used in the device layer slow controls.Control System Studio is adopted as the high-level applications.Blade server-based virtualization platform is deployed for the computer system.The accelerator control system was completed in September 2017 and then transited to routine operations.The design,implementation and operation of the accelerator control system are described in this paper.展开更多
基金the financial supports from the National Natural Science Foundation of China(Nos.51704011,51904003)the Joint Funds of the National Natural Science Foundation of China(No.U1703130)。
基金supported by the Major Special Science and Technology Project(2019B10076)of“Ningbo Science and Technology Innovation 2025”.
文摘In recent years,Remotely Operated Vehicles(ROVs)have played an increasingly important role in the construc-tion and monitoring of underwater pile foundations.However,due to the open frame structure of such vehicles,a gap of knowledge still exists with regard to their hydrodynamic behavior.In this study,the hydrodynamic stability of such vehicles is investigated numerically by means of a multiple reference frame method.The hydrodynamic characteristics of the ROV when it moves horizontally and upward in the vertical plane are examined.It is found that there is interference between the horizontal and vertical thrusters of the ROV.There is also interference between the propeller thrust and drag(or lift).The effect of the vertical thrusters can increase the horizontal thrust by about 5%.The horizontal thrusters create a low-pressure area below the body,which can make vertical drag experienced by the ROV significantly higher.
基金the National Natural Science Foundation of China(Grant No.51904146)the Doctor Start-up Fund of Liaoning Province(Grant No.2019-BS-125)the National Key Laboratory of Marine Engineering of China(Grant No.SKLMEA-USTL-201707)。
文摘This study aims to investigate the primary carbides precipitation in H13 steel solidified at relatively high cooling rates,ranging from 300 to 6,000℃·min^-1,based on in situ observations with a high temperature confocal laser scanning microscope.In the cooling rate range investigated,the solidification microstructure becomes more refined as cooling rate increases and the relationship between the secondary dendrite arm spacing(SDAS),λ2,and cooling rate,.T,can be expressed asλ2=128.45.T-0.124.Regardless of cooling rates,two kinds of primary carbides,i.e.,the Mo-Cr-rich and V-rich carbides,are precipitated along the interdendritic region and most of them are the Mo-Cr-rich carbides.The morphology of Mo-Cr-rich carbide is not obviously influenced by the cooling rate,but that of V-rich carbide is obviously affected.The increasing cooling rate markedly refines the primary carbides and reduces their volume fractions,but their precipitations cannot be inhibited even when the cooling rate is increased to 6,000℃·min^-1.Besides,the segregation ratios(SRs)of the carbides forming elements are not obviously affected by the cooling rate.However,compared with the conventionally cast ingot,the SDAS and primary carbides in the steel solidified at the investigated cooling rates are much finer,morphologies of the carbides have changed significantly,and SRs of the carbides forming elements are markedly greater.The variation of primary carbide characteristics with cooling rate is mainly due to the change in SDAS.
基金financially supported by the Natural Science Foundation of Anhui Province(No.2108085J26)the National Natural Science Foundation of China(Nos.51904003 and U1703130)+1 种基金the Key Research and Development Plan of Anhui Province(No.2022n07020004)the Open Foundation of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization(No.CNMRCUKF2208)。
文摘Platinum(Pt)is a critical raw material for automotive catalytic converters due to its high-temperature stability,corrosion resistance and catalytic activity,whereas its limited primary resources and uneven distribution make it hard to meet the growing demand of platinum.Spent automotive catalyst(SAC)is currently the most important secondary resource of platinum,of which the platinum content is much higher than that of the primary platinum resources.The recovery process of platinum from spent automobile catalyst mainly consists of pretreatment followed by enrichment and refining,involving pyro-and hydrometallurgical techniques,among which enrichment and refining processes are extremely important for platinum recovery from spent automobile catalyst.This paper provides an overview of the technologies for platinum recovery from spent automotive catalyst.The emphasis is placed on the processes of enrichment and refining based on hydrometallurgical techniques.Future directions of research and development of platinum recovery from spent automobile catalyst are also proposed.
基金financially supported by the National Natural Science Foundation of China(Nos.51704011,U1703130 and 51904003)。
文摘Lithium is critical for economic growth since it is the primary component of batteries.Na^(+)is one of the main impurity ions in solution during the separation and enrichment of Li^(+).According to the size-matching effect between the cavities of crown ethers and Li+,crown ethers can selectively adsorb Li^(+).Herein,1,8-dihydroxyl-4,4,5,5-tetramethylbenzo-14-crown-4 was synthesized and used to extract lithium from a Li^(+)/Na^(+)mixed solution.Density functional theory(DFT)was used to explore the properties of complexes with M062X.The results show that the interactions between crown ethers and metal ions are due to electrostatic attraction.Hydroxyl functional groups can synergistically extract Li^(+)/Na^(+)from solutions with the oxygen atom in the crown ether ring.The stability of the complex is also enhanced by van der Waals interactions between the butyrate acid root and crown ether.1,8-dihydroxyl-4,4,5,5-tetramethylbenzo-14-crown-4 has a stronger interaction with lithium butyrate than with sodium butyrate for most conformations.The adsorption selectivity for Li+is proportional to the number of ether oxygen atoms that interact with Li^(+).The Li^(+)extraction efficiency increases from 3.93%to 20.93%in lithium hydroxide solution with the presence of butyrate acid root.When the butyrate acid root is added to the mixed Li^(+)/Na^(+)solution,the Li^(+)extraction efficiency increases from 6.54%to 31.20%,while the Li^(+)/Na^(+)separation coefficient decreases from33.25 to 1.32.
基金supported by the National Natural Science Foundation of China(Nos.22275137 and 82202342)Natural Science Foundation of Tianjin Municipal Science and Technology Commission(No.21JCYBJC01810).
文摘The research and application of responsive materials have long been hampered by their complicated designs and tedious construction processes.Besides,many current responsive materials show retard or weak responsiveness.In this study,responsive hybrid poly(vinyl alcohol)hydrogel membranes with embedded poly(N-isopropylacrylamide-acrylic acid)microgels as valves were constructed by simple mixing and subsequent freezing-thawing process.In the structure of the membranes,the matrix poly(vinyl alcohol)chains thread through and entangle with the microgels,and the microgels are firmly constrained within the hybrid hydrogel network.The fast and sharp temperature responsiveness of the embedded microgels was largely retained and endowed the hydrogel membrane with excellent temperature and pH responsiveness.Moreover,the hydrogel membrane showed excellent fatigue resistance in both temperature and pH-responsive flux examination.This study presented the great potential of these hybrid hydrogel membranes in biomedical applications and provided a new strategy for the future design and construction of responsive biomaterials.
基金We thank Professor Zhemin Zheng for his kind advice and meaningful guidance in our research. This research is supported by funds from National Natural Science Foundation of Shaanxi Province, China （2004C1 15）.
文摘蚂蚱的二种， Calliptamus abbreviatus (Ikonn ) andShirakiacris shirakii (我。Bol ) ，在吉林省的喝的区域随机被收集，中国。由使用免疫组织化学的方法和统计分析，我们也就是在二只蚂蚱的精子发生的四个代表性的阶段观察了并且比较 c 工具包蛋白质的时间的表示：spermatogonia；主要精母细胞；第二等的精母细胞；并且成熟精子。结果证明有在各个的积极时间的表示精子发生上演的 c 工具包，但是有不同积极表示层次：(i)c 工具包蛋白质的弱积极表示在 spermatogonia 出现了，积极小粒更薄；(i i ) 强壮的积极表示 ofc 工具包蛋白质在主要精母细胞存在，积极小粒在所有发育阶段之中变得最大；(iii ) 积极表示呆在的 c 工具包在第二等的 spermatocytewhile 更强壮积极小粒变得更薄；(iv ) 在成熟精子有 c 工具包和更薄的积极小粒的强壮的积极表情，它在头和尾巴上散布了；最大的 c-kitpositive 小粒被发现了集中在睾丸的结束的(v) ；并且(vi )c 工具包的重要差别积极表示在在蚂蚱的二种之间的精子发生存在。Theresults 显示那 c 工具包蛋白质可以在精子发生起一个关键作用并且甚至在蚂蚱保留精子和授精的生理酌……
基金This work was supported by grants from the Program of Shanghai Academic Research Leader(21XD1402900)the Natural Science Foundation of Shanghai(21ZR1481400)+3 种基金the National Natural Science Foundation of China(31972900)the National Youth Talent Support Program(Ten Thousand Talent Program)the National Key Research and Development Program of China(2018YFC1705505)the National Megaproject on Key Infectious Diseases(2017ZX10202102).
文摘HIV-1 infection-induced cGAS–STING–TBK1–IRF3 signaling activates innate immunity to produce type I interferon(IFN).The HIV-1 nonstructural protein viral infectivity factor(Vif)is essential in HIV-1 replication,as it degrades the host restriction factor APOBEC3G.However,whether and how it regulates the host immune response remains to be determined.In this study,we found that Vif inhibited the production of type I IFN to promote immune evasion.HIV-1 infection induced the activation of the host tyrosine kinase FRK,which subsequently phosphorylated the immunoreceptor tyrosine-based inhibitory motif(ITIM)of Vif and enhanced the interaction between Vif and the cellular tyrosine phosphatase SHP-1 to inhibit type I IFN.Mechanistically,the association of Vif with SHP-1 facilitated SHP-1 recruitment to STING and inhibited the K63-linked ubiquitination of STING at Lys337 by dephosphorylating STING at Tyr162.However,the FRK inhibitor D-65495 counteracted the phosphorylation of Vif to block the immune evasion of HIV-1 and antagonize infection.These findings reveal a previously unknown mechanism through which HIV-1 evades antiviral immunity via the ITIM-containing protein to inhibit the posttranslational modification of STING.These results provide a molecular basis for the development of new therapeutic strategies to treat HIV-1 infection.
基金financially supported by the National Natural Science Foundation of China (Nos.51604005 and U1703130)the Universities Natural Science Research Project of Education Department of Anhui Province (No.KJ2020A0224)the Open Fund of Anhui Province Key Laboratory of Metallurgical Engineering & Resources Recycling (No.SKF19-01)。
文摘In order to take full advantage of the secondary resources,in this paper,we reported a template-free process to prepare porous Co microfibers from spent lithiumion batteries(LIBs).First,the waste LiCoO_(2) powders were leached by oxalic acid at a suitable temperature,and rodlike cobalt oxalate powders were obtained.Second,the porous Co microfibers were prepared by using the cobalt oxalate as precursors through a thermal decomposition at420 ℃ under nitrogen atmosphere.The prepared Co microfibers possess diameters of 1-2 μm,and each microfiber consists of small particles with size of100-200 nm.The Co microfibers(25 wt%)/paraffin composite exhibited excellent microwave absorption performance.When the sample thickness is 4.5 mm,the reflection losses reach-36.14 and-38.20 dB at 4.16 and 17.60 GHz,respectively,and the effective bandwidth reaches up to 5.52 GHz.This indicates that the Co microfibers can be used as a promising microwave absorber.Therefore,this paper demonstrates a novel process to make a high value-added product through recycling from the spent lithium-ion batteries.In addition,it is advantageous to eliminate the hazard of spent lithium-ion batteries and electromagnetic radiation to environment and human health.
文摘The China Spallation Neutron Source is an accelerator-based user facility for neutron,proton,muon applications and so on.The designed proton beam power is 100 kW for the first phase.Overall,the scope of accelerator control system covers four parts,the global systems,the device layer local controls and remote controls,the high-level applications and services and the integration of conventional facilities.The principle guideline is to adopt as many as possible matured technologies and commercial products in the design and implementation.The control system is based on Experimental Physics and Industrial Control System.VME64x bus is chosen for timing system and fast protection system.PLCs and embedded industrial computers are used in the device layer slow controls.Control System Studio is adopted as the high-level applications.Blade server-based virtualization platform is deployed for the computer system.The accelerator control system was completed in September 2017 and then transited to routine operations.The design,implementation and operation of the accelerator control system are described in this paper.
