Models to describe the damage and fracture behaviors of the interface between the fuel foil and cladding in UMo/Zr monolithic fuel plates were established and numerically implemented.The effects of the interfacial coh...Models to describe the damage and fracture behaviors of the interface between the fuel foil and cladding in UMo/Zr monolithic fuel plates were established and numerically implemented.The effects of the interfacial cohesive strength and cohesive energy on the irradiationinduced thermal-mechanical behaviors of fuel plates were investigated.The results indicated that for heterogeneously irradiated fuel plates:(1)interfacial damage and failure were predicted to be initiated near the fuel foil corner with higher fission densities,accompanied by the formation of a large gap after interface failure,which was consistent with some experimental observations;high tensile stresses in the fuel foil occurred near the edges of the failed interface,attributed to through-thickness cracking of the fuel foil,as found in some post-irradiation examinations;(2)the cohesive strength and cohesive energy of the interface both influenced the in-pile evolution behaviors of fuel plates;a lower cohesive strength or cohesive energy resulted in faster interfacial damage;(3)after interface fracture,the thickness of the whole plate increased to a greater degree(by~20%)than that of the samples without interfacial damage,which was attributed to the locally enhanced Mises stresses and the nearby creep deformations around the cracked interface.This study provided a theoretical basis for assessing failure in fuel elements.展开更多
BACKGROUND Hilar cholangiocarcinoma(HC)is a good adaptation certificate of hepatic arterectomy,and hepatic arterectomy is conductive to the radical resection of cholangiocarcinoma,which simplifies the operation and he...BACKGROUND Hilar cholangiocarcinoma(HC)is a good adaptation certificate of hepatic arterectomy,and hepatic arterectomy is conductive to the radical resection of cholangiocarcinoma,which simplifies the operation and helps with a combined resection of the peripheral portal tissue.With continuous development of surgical techniques,especially microsurgical technique,vascular invasion is no longer a contraindication to surgery in the past 10 years.However,hepatic artery reconstruction after hepatic arterectomy has been performed to treat liver tumor in many centers with better results,but it is rarely applied in advanced HC.AIM To determine the prognosis of patients with advanced HC after hepatic artery resection and reconstruction.METHODS A total of 98 patients with HC who underwent radical operation in our hospital were selected for this retrospective analysis.According to whether the patients underwent hepatic artery resection and reconstruction or not,they were divided into reconstruction(n=40)and control(n=58)groups.The traumatic indices,surgical resection margin,liver function tests before and after the operation,and surgical complications were compared between the two groups.RESULTS Operation time,blood loss,hospital stay,and gastrointestinal function recovery time were higher in the reconstruction group than in the control group(P<0.05);The R0 resection rates were 90.00%and 72.41%in the reconstruction and control groups,respectively(P<0.05).Serum alanine aminotransferase was lower in the reconstruction group on day one and three postoperatively,whereas serum aspartate aminotransferase was lower on the third day(P<0.05).Preoperatively,the Karnofsky performance status scores were similar between the groups(P>0.05),but was higher in the reconstruction group(P<0.05)two weeks postoperatively.There was no difference in the complication rate between the two groups(27.50%vs 32.67%,P>0.05).Two-year survival rate(42.50%vs 39.66%)and two-year survival time(22.0 mo vs 23.0 mo)were similar between the groups(P>0.05).CONCLUSION Radical surgery combined with reconstruction after hepatic artery resection improves R0 resection rate and reduces postoperative liver injury in advanced HC.However,the operation is difficult and the effect on survival time is not clear.展开更多
pH dependent uorescence emission of a thioxanthone-based probe has been re-ported recently.The potential deter-minant factors of pH dependence may provide important clues to design novel thioxanthone-based probes in t...pH dependent uorescence emission of a thioxanthone-based probe has been re-ported recently.The potential deter-minant factors of pH dependence may provide important clues to design novel thioxanthone-based probes in the fu-ture.pH dependence of photochemical kinetics of thioxanthone itself was inves-tigated in this work using nanosecond time-resolved laser ash photolysis.The nanosecond time-resolved transient absorption spectra and kinetics of TX in aqueous acetonitrile were recorded,as well as for a model reaction system including TX with diphenylamine(DPA)as a co-initiator.Besides the well-known absorption peak of ^(3)TX*,other peaks at 417,518,673 and 780 nm,have been reliably attributed to major intermediates in the overall reaction between TX and DPA with photolysis,which has been con rmed to occur along a multistep process.In the strong acidic solution(pH≈3.0),TX and protonated TX ions(TXH^(+))coexist due to protonated equilibrium.Consequently,high proton concentration promotes the predominant decay pathway after photolysis from electron transfer to proton affnity.Subsequently,the di erent primary products,^(3)TXH^(+*)or TX^(·-),proceed di erent secondary reaction channels.In addition,within the wide pH range from weak acid(pH=5.0)to alkaline solution(pH=13.0),the overall reaction mechanism and rates do not show visible changes.展开更多
A light-induced,nickel-catalyzed three-component arylsulfonation of 1,3-enynes in the absence of photocatalyst is reported.This methodology exhibited mild conditions,broad scope and high efficiency,and its synthetic u...A light-induced,nickel-catalyzed three-component arylsulfonation of 1,3-enynes in the absence of photocatalyst is reported.This methodology exhibited mild conditions,broad scope and high efficiency,and its synthetic utility has been demonstrated by a concise total synthesis of sulfone-containing drug molecule.Detailed mechanistic studies indicated that this light induced nickel catalysis is autopromoted by in situ produced allene,which plays a key role as co-ligand in the photoactive excited state Ni(Ⅰ)species for the LMCT process.The detailed elucidation of this light-induced nickel catalytic cycle may shed some lights on the exploitation of new catalytic activity and establishment of novel methods.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12132005,11772095,12102094)the Foundation from Science and Technology on Reactor System Design Technology Laboratory。
文摘Models to describe the damage and fracture behaviors of the interface between the fuel foil and cladding in UMo/Zr monolithic fuel plates were established and numerically implemented.The effects of the interfacial cohesive strength and cohesive energy on the irradiationinduced thermal-mechanical behaviors of fuel plates were investigated.The results indicated that for heterogeneously irradiated fuel plates:(1)interfacial damage and failure were predicted to be initiated near the fuel foil corner with higher fission densities,accompanied by the formation of a large gap after interface failure,which was consistent with some experimental observations;high tensile stresses in the fuel foil occurred near the edges of the failed interface,attributed to through-thickness cracking of the fuel foil,as found in some post-irradiation examinations;(2)the cohesive strength and cohesive energy of the interface both influenced the in-pile evolution behaviors of fuel plates;a lower cohesive strength or cohesive energy resulted in faster interfacial damage;(3)after interface fracture,the thickness of the whole plate increased to a greater degree(by~20%)than that of the samples without interfacial damage,which was attributed to the locally enhanced Mises stresses and the nearby creep deformations around the cracked interface.This study provided a theoretical basis for assessing failure in fuel elements.
文摘BACKGROUND Hilar cholangiocarcinoma(HC)is a good adaptation certificate of hepatic arterectomy,and hepatic arterectomy is conductive to the radical resection of cholangiocarcinoma,which simplifies the operation and helps with a combined resection of the peripheral portal tissue.With continuous development of surgical techniques,especially microsurgical technique,vascular invasion is no longer a contraindication to surgery in the past 10 years.However,hepatic artery reconstruction after hepatic arterectomy has been performed to treat liver tumor in many centers with better results,but it is rarely applied in advanced HC.AIM To determine the prognosis of patients with advanced HC after hepatic artery resection and reconstruction.METHODS A total of 98 patients with HC who underwent radical operation in our hospital were selected for this retrospective analysis.According to whether the patients underwent hepatic artery resection and reconstruction or not,they were divided into reconstruction(n=40)and control(n=58)groups.The traumatic indices,surgical resection margin,liver function tests before and after the operation,and surgical complications were compared between the two groups.RESULTS Operation time,blood loss,hospital stay,and gastrointestinal function recovery time were higher in the reconstruction group than in the control group(P<0.05);The R0 resection rates were 90.00%and 72.41%in the reconstruction and control groups,respectively(P<0.05).Serum alanine aminotransferase was lower in the reconstruction group on day one and three postoperatively,whereas serum aspartate aminotransferase was lower on the third day(P<0.05).Preoperatively,the Karnofsky performance status scores were similar between the groups(P>0.05),but was higher in the reconstruction group(P<0.05)two weeks postoperatively.There was no difference in the complication rate between the two groups(27.50%vs 32.67%,P>0.05).Two-year survival rate(42.50%vs 39.66%)and two-year survival time(22.0 mo vs 23.0 mo)were similar between the groups(P>0.05).CONCLUSION Radical surgery combined with reconstruction after hepatic artery resection improves R0 resection rate and reduces postoperative liver injury in advanced HC.However,the operation is difficult and the effect on survival time is not clear.
基金This work was supported by the Educational Com-mission of Anhui Province of China(No.KJ2018A0491 and KJ2019A0736)the National Natural Science Foun-dation of China(No.21873089)the Natural Science Foundation of Anhui Province(No.1908085MB50).
文摘pH dependent uorescence emission of a thioxanthone-based probe has been re-ported recently.The potential deter-minant factors of pH dependence may provide important clues to design novel thioxanthone-based probes in the fu-ture.pH dependence of photochemical kinetics of thioxanthone itself was inves-tigated in this work using nanosecond time-resolved laser ash photolysis.The nanosecond time-resolved transient absorption spectra and kinetics of TX in aqueous acetonitrile were recorded,as well as for a model reaction system including TX with diphenylamine(DPA)as a co-initiator.Besides the well-known absorption peak of ^(3)TX*,other peaks at 417,518,673 and 780 nm,have been reliably attributed to major intermediates in the overall reaction between TX and DPA with photolysis,which has been con rmed to occur along a multistep process.In the strong acidic solution(pH≈3.0),TX and protonated TX ions(TXH^(+))coexist due to protonated equilibrium.Consequently,high proton concentration promotes the predominant decay pathway after photolysis from electron transfer to proton affnity.Subsequently,the di erent primary products,^(3)TXH^(+*)or TX^(·-),proceed di erent secondary reaction channels.In addition,within the wide pH range from weak acid(pH=5.0)to alkaline solution(pH=13.0),the overall reaction mechanism and rates do not show visible changes.
基金supported by the National Science Foundation of China(21602213,21971228)。
文摘A light-induced,nickel-catalyzed three-component arylsulfonation of 1,3-enynes in the absence of photocatalyst is reported.This methodology exhibited mild conditions,broad scope and high efficiency,and its synthetic utility has been demonstrated by a concise total synthesis of sulfone-containing drug molecule.Detailed mechanistic studies indicated that this light induced nickel catalysis is autopromoted by in situ produced allene,which plays a key role as co-ligand in the photoactive excited state Ni(Ⅰ)species for the LMCT process.The detailed elucidation of this light-induced nickel catalytic cycle may shed some lights on the exploitation of new catalytic activity and establishment of novel methods.
