The role of bonding agents on the aging characteristics is one of the important research topics.Aging program of the prepared propellant samples was conducting as follows:Five samples,two free of bonding agents,and th...The role of bonding agents on the aging characteristics is one of the important research topics.Aging program of the prepared propellant samples was conducting as follows:Five samples,two free of bonding agents,and three containing an aziridine based bonding agents(MAPO,HX-752,MAT4),four samples based on different bonding and curing agents all were aged at 70 ℃.The prepared bonding agent "MAT4" gave remarkable improvements and resulted in highly stable mechanical properties comparing with HX-752 or MAPO.The selected bonding agents family inhibited the rate of decomposition of the propellants during the aging periods and supported the propellant matrix against decomposition at the elevated temperatures.展开更多
Applications of HIP technique on W-Cu composites are studied and developed. TheCuinfiltrated W composites without nickel can be densified easily by HIP processing at the tempera-ture below the melting point of copper....Applications of HIP technique on W-Cu composites are studied and developed. TheCuinfiltrated W composites without nickel can be densified easily by HIP processing at the tempera-ture below the melting point of copper. The relative density of W-Cu composites increases from 96%-97% to nearly full dense for the materials in which copper contents are more than 30 percent inweight and improves to near 99 percent for W-Cu20 composites. The properties of W-Cu materials ,such as strength, hardness and electrical conductivity, and the homogeneity of properties are im-proved significantly. The diffusion bonding of W-Cu to W-Cu or Cu by HIP processing is also stud-ied. The bonding strength is in correspondence with that of matrix. It is possible to produce largedimension W-Cu workpieces and (W-Cu)-Cu complex layer materials in commercial scale.展开更多
A novel single-crystalline Si/poly-CoSi_(2)/SiO_(2)/Sub-Si structure has been successfully formed by silicon wafer bonding technique.The surface energy of the as-bonded wafers at room temperature is about 70erg/cm^(2)...A novel single-crystalline Si/poly-CoSi_(2)/SiO_(2)/Sub-Si structure has been successfully formed by silicon wafer bonding technique.The surface energy of the as-bonded wafers at room temperature is about 70erg/cm^(2).Annealing at 800°C for 30min does not only strengthen the bond to about 1100erg/cm^(2),but also employs solid phase reaction of sputtered cobalt to form a buried poly-crystalline CoSi_(2)layer with a resistivity of approximately 160μΩ.cm.Two bond processes has been compared.The quality of the sputtered Si-SiO_(2)bonding is better than that of the sputtered Si-Si bonding.展开更多
The Conference of the Parties(COP26 and 27)placed significant emphasis on climate financing policies with the objective of achieving net zero emissions and carbon neutrality.However,studies on the implementation of th...The Conference of the Parties(COP26 and 27)placed significant emphasis on climate financing policies with the objective of achieving net zero emissions and carbon neutrality.However,studies on the implementation of this policy proposition are limited.To address this gap in the literature,this study employs machine learning techniques,specifically natural language processing(NLP),to examine 77 climate bond(CB)policies from 32 countries within the context of climate financing.The findings indicate that“sustainability”and“carbon emissions control”are the most outlined policy objectives in these CB policies.Additionally,the study highlights that most CB funds are invested toward energy projects(i.e.,renewable,clean,and efficient initiatives).However,there has been a notable shift in the allocation of CB funds from climate-friendly energy projects to the construction sector between 2015 and 2019.This shift raises concerns about the potential redirection of funds from climate-focused investments to the real estate industry,potentially leading to the greenwashing of climate funds.Furthermore,policy sentiment analysis revealed that a minority of policies hold skeptical views on climate change,which may negatively influence climate actions.Thus,the findings highlight that the effective implementation of CB policies depends on policy goals,objectives,and sentiments.Finally,this study contributes to the literature by employing NLP techniques to understand policy sentiments in climate financing.展开更多
Ti_(3)SiC_(2) ceramic and SUS430 ferritic stainless steel were welded by the transient liquid phase(TLP)diffusion bonding method using an Al interlayer at 850-1050℃ in vacuum.The evolution of phase and morphology at ...Ti_(3)SiC_(2) ceramic and SUS430 ferritic stainless steel were welded by the transient liquid phase(TLP)diffusion bonding method using an Al interlayer at 850-1050℃ in vacuum.The evolution of phase and morphology at the interface and bonding strength were systematically investigated.The results show that Ti_(3)SiC_(2) and SUS430 were well bonded at 900-950℃.Three reaction zones were observed at the interface.At the joint interface area adjacent to alloy,the alloy completely reacted with liquid Al to form Al_(86)Fe_(14).At Ti_(3)SiC_(2)/Al interface,Ti and Si diffused outward from Ti_(3)SiC_(2) into the molten Al to form Fe_(3)Al+Al_(5)FeSi+TiAl_(3) zone.Adjacent to Ti_(3)SiC_(2) matrix,Ti_(3)Si(Al)C_(2)+TiCx zone was formed by the loss of Si.The evolution mechanism of TLP-bonded joints was discussed based on the interface microstructure and product phases.In addition,the tensile strength of the joint increased with increasing bonding temperature.The corresponding maximum value of 59.7 MPa was obtained from SUS430/Al(10μm)/Ti_(3)SiC_(2) joint prepared at 950℃.展开更多
文摘The role of bonding agents on the aging characteristics is one of the important research topics.Aging program of the prepared propellant samples was conducting as follows:Five samples,two free of bonding agents,and three containing an aziridine based bonding agents(MAPO,HX-752,MAT4),four samples based on different bonding and curing agents all were aged at 70 ℃.The prepared bonding agent "MAT4" gave remarkable improvements and resulted in highly stable mechanical properties comparing with HX-752 or MAPO.The selected bonding agents family inhibited the rate of decomposition of the propellants during the aging periods and supported the propellant matrix against decomposition at the elevated temperatures.
文摘Applications of HIP technique on W-Cu composites are studied and developed. TheCuinfiltrated W composites without nickel can be densified easily by HIP processing at the tempera-ture below the melting point of copper. The relative density of W-Cu composites increases from 96%-97% to nearly full dense for the materials in which copper contents are more than 30 percent inweight and improves to near 99 percent for W-Cu20 composites. The properties of W-Cu materials ,such as strength, hardness and electrical conductivity, and the homogeneity of properties are im-proved significantly. The diffusion bonding of W-Cu to W-Cu or Cu by HIP processing is also stud-ied. The bonding strength is in correspondence with that of matrix. It is possible to produce largedimension W-Cu workpieces and (W-Cu)-Cu complex layer materials in commercial scale.
基金Supported by the Science and Technology Development Foundation of Shanghai under Grant No.98JC14004.
文摘A novel single-crystalline Si/poly-CoSi_(2)/SiO_(2)/Sub-Si structure has been successfully formed by silicon wafer bonding technique.The surface energy of the as-bonded wafers at room temperature is about 70erg/cm^(2).Annealing at 800°C for 30min does not only strengthen the bond to about 1100erg/cm^(2),but also employs solid phase reaction of sputtered cobalt to form a buried poly-crystalline CoSi_(2)layer with a resistivity of approximately 160μΩ.cm.Two bond processes has been compared.The quality of the sputtered Si-SiO_(2)bonding is better than that of the sputtered Si-Si bonding.
基金supported by the funding of Belt and Road Research Institute,Xiamen University(No:1500-X2101200)National Natural Science Foundation of China(Key Program,No:72133003).
文摘The Conference of the Parties(COP26 and 27)placed significant emphasis on climate financing policies with the objective of achieving net zero emissions and carbon neutrality.However,studies on the implementation of this policy proposition are limited.To address this gap in the literature,this study employs machine learning techniques,specifically natural language processing(NLP),to examine 77 climate bond(CB)policies from 32 countries within the context of climate financing.The findings indicate that“sustainability”and“carbon emissions control”are the most outlined policy objectives in these CB policies.Additionally,the study highlights that most CB funds are invested toward energy projects(i.e.,renewable,clean,and efficient initiatives).However,there has been a notable shift in the allocation of CB funds from climate-friendly energy projects to the construction sector between 2015 and 2019.This shift raises concerns about the potential redirection of funds from climate-focused investments to the real estate industry,potentially leading to the greenwashing of climate funds.Furthermore,policy sentiment analysis revealed that a minority of policies hold skeptical views on climate change,which may negatively influence climate actions.Thus,the findings highlight that the effective implementation of CB policies depends on policy goals,objectives,and sentiments.Finally,this study contributes to the literature by employing NLP techniques to understand policy sentiments in climate financing.
基金supported by the National Natural Science Foundation of China(No.52001179)Natural Science Foundation of Shandong Province,China(No.ZR2020ME019).
文摘Ti_(3)SiC_(2) ceramic and SUS430 ferritic stainless steel were welded by the transient liquid phase(TLP)diffusion bonding method using an Al interlayer at 850-1050℃ in vacuum.The evolution of phase and morphology at the interface and bonding strength were systematically investigated.The results show that Ti_(3)SiC_(2) and SUS430 were well bonded at 900-950℃.Three reaction zones were observed at the interface.At the joint interface area adjacent to alloy,the alloy completely reacted with liquid Al to form Al_(86)Fe_(14).At Ti_(3)SiC_(2)/Al interface,Ti and Si diffused outward from Ti_(3)SiC_(2) into the molten Al to form Fe_(3)Al+Al_(5)FeSi+TiAl_(3) zone.Adjacent to Ti_(3)SiC_(2) matrix,Ti_(3)Si(Al)C_(2)+TiCx zone was formed by the loss of Si.The evolution mechanism of TLP-bonded joints was discussed based on the interface microstructure and product phases.In addition,the tensile strength of the joint increased with increasing bonding temperature.The corresponding maximum value of 59.7 MPa was obtained from SUS430/Al(10μm)/Ti_(3)SiC_(2) joint prepared at 950℃.
