BACKGROUND Hemophagocytic lymphohistiocytosis(HLH)is a severe hyperinflammatory reaction,which is rare and life-threatening.According to the pathogen,HLH is divided into genetic and acquired.The most common form of ac...BACKGROUND Hemophagocytic lymphohistiocytosis(HLH)is a severe hyperinflammatory reaction,which is rare and life-threatening.According to the pathogen,HLH is divided into genetic and acquired.The most common form of acquired HLH is infection-associated HLH,of which Herpes viruses,particularly Epstein-Barr virus(EBV),are the leading infectious triggers.However,it is difficult to distinguish between simple infection with EBV and EBV-induced infectionassociated HLH since both can destroy the whole-body system,particularly the liver,thereby increasing the difficulty of diagnosis and treatment.CASE SUMMARY This paper elaborates a case about EBV-induced infection-associated HLH and acute liver injury,aiming to propose clinical guides for the early detection and treatment of patients with EBV-induced infection-associated HLH.The patient was categorized as acquired hemophagocytic syndrome in adults.After the ganciclovir antiviral treatment combined with meropenem antibacterial therapy and methylprednisolone inhibition to inflammatory response,gamma globulin enhanced immunotherapy,the patient recovered.CONCLUSION From the diagnosis and treatment of this patient,attention should be paid to routine EBV detection and a further comprehensive understanding of the disease as well as early recognition and early initiation are keys to patients’survival.展开更多
Following publication of the original article,the authors observed that both Fig.5 and Fig.4 depict the same image.Figure 5 was inaccurately referenced and displayed.The correct Fig.5 is copied below:The original arti...Following publication of the original article,the authors observed that both Fig.5 and Fig.4 depict the same image.Figure 5 was inaccurately referenced and displayed.The correct Fig.5 is copied below:The original article has been updated.展开更多
To provide a reliable and comprehensive data reference for core geometry design of graphite-moderated and low-enriched uranium fueled molten salt reactors,the influences of geometric parameters on the temperature coef...To provide a reliable and comprehensive data reference for core geometry design of graphite-moderated and low-enriched uranium fueled molten salt reactors,the influences of geometric parameters on the temperature coefficient of reactivity(TCR)at an assembly level were characterized.A four-factor formula was introduced to explain how different reactivity coefficients behave in terms of the fuel salt volume fraction and assembly size.The results show that the fuel salt temperature coefficient(FSTC)is always negative owing to a more negative fuel salt density coefficient in the over-moderated region or a more negative Doppler coefficient in the under-moderated region.Depending on the fuel salt channel spacing,the graphite moderator temperature coefficient(MTC)can be negative or positive.Furthermore,an assembly with a smaller fuel salt channel spacing is more likely to exhibit a negative MTC.As the fuel salt volume fraction increases,the negative FSTC first weakens and then increases,owing to the fuel salt density effect gradually weakening from negative to positive feedback and then decreasing.Meanwhile,the MTC weakens as the thermal utilization coefficient caused by the graphite temperature effect deteriorates.Thus,the negative TCR first weakens and then strengthens,mainly because of the change in the fuel salt density coefficient.As the assembly size increases,the magnitude of the FSTC decreases monotonously owing to a monotonously weakened fuel salt Doppler coefficient,whereas the MTC changes from gradually weakened negative feedback to gradually enhanced positive feedback.Then,the negative TCR weakens.Therefore,to achieve a proper negative TCR,particularly a negative MTC,an assembly with a smaller fuel salt channel spacing in the under-moderated region is strongly recommended.展开更多
The molten salt reactor(MSR), as one of the Generation Ⅳ advanced nuclear systems, has attracted a worldwide interest due to its excellent performances in safety, economics, sustainability, and proliferation resistan...The molten salt reactor(MSR), as one of the Generation Ⅳ advanced nuclear systems, has attracted a worldwide interest due to its excellent performances in safety, economics, sustainability, and proliferation resistance. The aim of this work is to provide and evaluate possible solutions to fissile 233 U production and further the fuel transition to thorium fuel cycle in a thermal MSR by using plutonium partitioned from light water reactors spent fuel. By using an in-house developed tool, a breeding and burning(B&B) scenario is first introduced and analyzed from the aspects of the evolution of main nuclides, net 233 U production, spectrum shift, and temperature feedback coefficient. It can be concluded that such a Th/Pu to Th/^(233)U transition can be accomplished by employing a relatively fast fuel reprocessing with a cycle time less than 60 days. At the equilibrium state, the reactor can achieve a conversion ratio of about 0.996 for the 60-day reprocessing period(RP) case and about 1.047 for the 10-day RP case.The results also show that it is difficult to accomplish such a fuel transition with limited reprocessing(RP is 180 days),and the reactor operates as a converter and burns the plutonium with the help of thorium. Meanwhile, a prebreeding and burning(PB&B) scenario is also analyzed briefly with respect to the net 233 U production and evolution of main nuclides. One can find that it is more efficient to produce 233 U under this scenario, resulting in a double time varying from about 1.96 years for the 10-day RP case to about 6.15 years for the 180-day RP case.展开更多
With respect to a liquid-fueled molten salt reactor(MSR),the temperature coefficient of reactivity mainly includes the moderator temperature coefficient(MTC)and the fuel salt temperature coefficient(FSTC).The FSTC is ...With respect to a liquid-fueled molten salt reactor(MSR),the temperature coefficient of reactivity mainly includes the moderator temperature coefficient(MTC)and the fuel salt temperature coefficient(FSTC).The FSTC is typically divided into the Doppler coefficient and the density coefficient.In order to compensate for the potentially positive MTC,the FSTC should be sufficiently negative,and this is mostly optimized in terms of the geometry aspect in pioneering studies.However,the properties of fuel salt also directly influence the FSTC.Thus,the effects of different fuel salt compositions including the^(235)U enrichment,heavy metal proportion in salt phase(HM proportion),and the^7Li enrichment on FSTC are investigated from the viewpoint of the essential six-factor formula.The analysis is based on an undermoderated MSR.With respect to the Doppler coefficient,the temperature coefficient of the fast fission factors(a_T(ξ))is positive and those of the resonance escape probability(a_T(p)),thermal reproduction factor(a_T(g)),thermal utilization factor(a_T(f)),and total non-leakage probability(a_T(λ))are negative.With respect to the density coefficient,a_T(p)and a_T(g)are positive,while the others are negative.The results indicate that the effects of the^(235)U enrichment and HM on FSTC are mainly reflected in a_T(e)and a_T(p),which are the dominant factors when the neutron spectrum is relatively hard.Furthermore,the^7Li enrichment influences FSTC by a_T(f)and a_T(λ),which are the key factors in a relative soft spectrum.In order to obtain a more negative FSTC for an under-moderated MSR,the possible positive density coefficient,especially its a_T(p),should be suppressed.Thus,a lower^(235)U enrichment(albeit higher than a certain value,5 wt%in this article)along with a lower HM proportion and/or a higher^7Li enrichment are recommended.The analyses provide an approach to achieve a more suitable fuel salt composition with a sufficiently negative FSTC.展开更多
With the analysis on regulating system in 200 MW steam turbine, the necessity of appending the fast-opening function to the original system is set forth and a new type of fast-opening mechanism is devised. The mathema...With the analysis on regulating system in 200 MW steam turbine, the necessity of appending the fast-opening function to the original system is set forth and a new type of fast-opening mechanism is devised. The mathematical model of system is built up. With the use of AMESIM software, the displacement curve of the piston, the force curve of the cartridge valve spool, the pressure curve and the flux curve in the regulation process are obtained based on simulation. The performances of three fast-opening systems composed of cartridge valves with different diameters are compared. Based on the analysis on factors that affect the execution time of fast-opening, the dead zone of the fast-opening system is put forward. To overcome the defect, dif- ferent operation modes are adopted for different zones. The result shows that with the increase of the valve diameter, the regulating time in the dead zone significantly exceeds the fast-opening time in the whole journey. Accordingly, the optimization operation tactic in the dead zone and the qualification conditions are brought forward. The fast-opening system composed of 32 mm cartridge valves is taken as an example with use of the tactic. The simulation result shows that the maximum regulating time is shortened by 509 ms.展开更多
The electrolysis of water into hydrogen and oxygen provides an effective means of storing electrical energy indirectly.The current challenge is to design an optimal catalyst that exhibits low overpotentials,long-term ...The electrolysis of water into hydrogen and oxygen provides an effective means of storing electrical energy indirectly.The current challenge is to design an optimal catalyst that exhibits low overpotentials,long-term stability,universal availability,and only uses inexpensive materials.Herein,a Co3O4nanoflower/stainless steel(P-Ov-CO_(3)O_(4)/SS) catalyst with both oxygen vacancies(Ovs) and phosphorus doping was perfectly prepared via a simple three-step method.The Ovs promoted charge transfer and accelerated the electrocatalysis,while P finely tuned the surface charge state.This resulted in numerous active sites for catalysis,and the synergistic effect of phosphorus doping and oxygen vacancies was finely demonstrated.The resultant electrocatalyst exhibited low hydrogen evolution overpotentials of 118 mV(-10 mA·cm^(-2)) and 242(-200 mA·cm^(-2)),as well as oxygen evolution overpotentials of 327 mV(100 mA·cm^(-2)) and 370 mV(200 mA·cm^(-2)),owing to the excellent synergistic effect of the Ovs and low-temperature phosphating.Moreover,P-Ov-Co_(3)O_(4)/SS//P-Ov-Co_(3)O_(4)/SS exhibited a low water splitting voltage of 1.681 V at 20 mA.cm-2.These findings will enable the synthesis of novel high-performance electrocatalysts for overall water splitting.展开更多
To optimize the temperature coefficient of reactivity(TCR)for a graphite-moderated and liquid-fueled molten salt reactor,the effects of fuel salt composition on the fuel salt temperature coefficient of reactivity(FSTC...To optimize the temperature coefficient of reactivity(TCR)for a graphite-moderated and liquid-fueled molten salt reactor,the effects of fuel salt composition on the fuel salt temperature coefficient of reactivity(FSTC)were investigated in our earlier work.In this study,we aim to provide a more comprehensive analysis of the TCR by considering the effects of the graphite-moderator temperature coefficient of reactivity(MTC).The effects of^235U enrichment and heavy metal(HM)proportion in the salt mixture on the MTC are investigated from the perspective of the six-factor formula based on a full-core model.For the MTC(labeled“αTM”),the temperature coefficient of the fast fission factors(αTM(ε))is positive,while those of the resonance escape probability(αTM(p)),the thermal reproduction factor(αTM(η)),the thermal utilization factor(αTM(f)),and the total non-leakage probability(αTM(A))are negative.The results reveal that the magnitudes ofαTM(ε)andαTM(p)for the MTC are similar.Thus,variations in the MTC with^235U enrichment for different HM proportions are mainly dependent onαTM(η),αTM(A),andαTM(f),but especially on the former two.To obtain a more negative MTC,a lower HM proportion and/or a lower 235U enrichment is recommended.Together with our previous studies on the FSTC,a relatively soft neutron spectrum could strengthen the TCR with a sufficiently negative MTC.展开更多
Objective To identify reliable reference genes（RGs） for normalization of real-time PCR（RT-q PCR） data in Codonopsis pilosula. Methods The expression profiles of 10 candidate RGs（GAPDH, ACT, α-TUB, β-TUB, UBQ, C...Objective To identify reliable reference genes（RGs） for normalization of real-time PCR（RT-q PCR） data in Codonopsis pilosula. Methods The expression profiles of 10 candidate RGs（GAPDH, ACT, α-TUB, β-TUB, UBQ, CYP, EF-1α, NAC, F-box and PP2A） were examined in C. pilosula during the phenological period. The raw materials examined included roots, stems, leaves, and flower buds at flowering and boll-forming stages, five growth stages of untreated and treated roots with plant growth retardant. The best-suited RGs were accessed using ge Norm, NormF inder, Best Keeper, and Ref Finder algorithms. Results The best-ranked references genes differed across the samples. GAPDH and PP2A were the most suitable for expression analysis in untreated tissues while GAPDH, α-TUB, and PP2A were ranked as the three most stably expressed genes in untreated roots, while NAC and CYP were the most stably expressed genes in stressed（i.e., treated） roots. The expression of UGPase, a key enzyme for CPP biosynthesis, was determined to further validate the selected RGs. Conclusion A total of 10 RGs can be used as reference genes of C. pilosula, however the appropriate one should be used as it may chance.展开更多
The effects of substituting Co for Fe on the microstructure and stress rupture properties of K4750 alloy were studied.The microstructure of the alloy without Co(K4750 alloy)and the alloy containing Co(K4750-Co alloy)w...The effects of substituting Co for Fe on the microstructure and stress rupture properties of K4750 alloy were studied.The microstructure of the alloy without Co(K4750 alloy)and the alloy containing Co(K4750-Co alloy)were analyzed.Substitution of Co for Fe inhibited the decomposition of MC carbide and the precipitation ofηphase during long-term aging treatment.In K4750-Co alloy,the morphology of MC carbide at the grain boundary(GB)remained dispersed blocky shape and noηphase was observed after aging at 750℃ for 3000 h.However,in K4750 alloy,almost all the MC carbides at GBs broke down into granular M23C6 carbide and needle-likeηphase.The addition of cobalt could delay the decomposition of MC carbides,which accordingly restricted the elemental supply for the formation ofηphase.The stress rupture tests were conducted on two alloys at 750℃/430 MPa.When Co is substituted for Fe in K4750 alloy,the stress rupture life increased from 164.10 to 264.67 h after standard heat treatment.This was mainly attributed to increased concentration of Al,Ti and Nb inγ’phase in K4750-Co alloy,which further enhanced the strengthening effect ofγ’phase.After aging at 750℃ for 3000 h,substitution of Co for Fe can also cause the stress rupture life at 750℃/430 MPa to increase from 48.72 to 208.18 h.The reason was mainly because MC carbide degradation andηphase precipitation in K4750 alloy,which promoted the initiation and propagation of micro-crack during stress rupture testing.展开更多
Polymerizing the narrow bandgap small-molecule architecture with a conjugated linking unit(or called the polymerized small molecule acceptors(PSMAs))is a promising strategy to design polymer acceptors for efficient al...Polymerizing the narrow bandgap small-molecule architecture with a conjugated linking unit(or called the polymerized small molecule acceptors(PSMAs))is a promising strategy to design polymer acceptors for efficient all polymer solar cells(all-PSCs).Currently,the fused-ring-based small molecule acceptors(SMAs)are preferred monomers to design efficient PSMAs,leaving the challenge of reducing the materials cost.In this work,we firstly employ nonfused-core SMA with simple synthetic procedures to design PSMAs(namely PBTI-H,PBTI-F and PBTI-Cl)to address this issue.Relative to the fused-ring based counterparts,these three PSMAs exhibit much higher figure-of-merit value.Additionally,a power-conversion efficiency of 8.80%is achieved in the PBTI-Cl-based all-PSC.The results offer an attractive approach to design low-cost PSMAs for efficient all-PSCs.展开更多
基金Supported by the National Natural Science Foundation of China,No.82174189Talents Training Program of Seventh People’s Hospital of Shanghai University of Traditional Chinese Medicine,No.JCR2022-01+3 种基金TCM Specialist Disease Alliance Construction Project of Shanghai Municipal Health Commission,No.ZY(2021-2023)-0302Talent Training Project of Senior Master of Chinese Medicine of Shanghai Pudong,No.PDZY-2022-0601Project of Introducing Senior Talents of Chinese Medicine of Shanghai Pudong,No.PDZY-2022-0701Talents Training Program of the Seventh People’s Hospital,Shanghai University of Traditional Chinese Medicine,No.QMX2021-04.
文摘BACKGROUND Hemophagocytic lymphohistiocytosis(HLH)is a severe hyperinflammatory reaction,which is rare and life-threatening.According to the pathogen,HLH is divided into genetic and acquired.The most common form of acquired HLH is infection-associated HLH,of which Herpes viruses,particularly Epstein-Barr virus(EBV),are the leading infectious triggers.However,it is difficult to distinguish between simple infection with EBV and EBV-induced infectionassociated HLH since both can destroy the whole-body system,particularly the liver,thereby increasing the difficulty of diagnosis and treatment.CASE SUMMARY This paper elaborates a case about EBV-induced infection-associated HLH and acute liver injury,aiming to propose clinical guides for the early detection and treatment of patients with EBV-induced infection-associated HLH.The patient was categorized as acquired hemophagocytic syndrome in adults.After the ganciclovir antiviral treatment combined with meropenem antibacterial therapy and methylprednisolone inhibition to inflammatory response,gamma globulin enhanced immunotherapy,the patient recovered.CONCLUSION From the diagnosis and treatment of this patient,attention should be paid to routine EBV detection and a further comprehensive understanding of the disease as well as early recognition and early initiation are keys to patients’survival.
文摘Following publication of the original article,the authors observed that both Fig.5 and Fig.4 depict the same image.Figure 5 was inaccurately referenced and displayed.The correct Fig.5 is copied below:The original article has been updated.
基金supported by the Youth Innovation Promotion Association CAS (No.2022258)the National Natural Science Foundation of China (No.12175300)+1 种基金the Chinese TMSR Strategic Pioneer Science and Technology Project (No.XDA02010000)the Young Potential Program of Shanghai Institute of Applied Physics,Chinese Academy of Sciences (No.E1550510)。
文摘To provide a reliable and comprehensive data reference for core geometry design of graphite-moderated and low-enriched uranium fueled molten salt reactors,the influences of geometric parameters on the temperature coefficient of reactivity(TCR)at an assembly level were characterized.A four-factor formula was introduced to explain how different reactivity coefficients behave in terms of the fuel salt volume fraction and assembly size.The results show that the fuel salt temperature coefficient(FSTC)is always negative owing to a more negative fuel salt density coefficient in the over-moderated region or a more negative Doppler coefficient in the under-moderated region.Depending on the fuel salt channel spacing,the graphite moderator temperature coefficient(MTC)can be negative or positive.Furthermore,an assembly with a smaller fuel salt channel spacing is more likely to exhibit a negative MTC.As the fuel salt volume fraction increases,the negative FSTC first weakens and then increases,owing to the fuel salt density effect gradually weakening from negative to positive feedback and then decreasing.Meanwhile,the MTC weakens as the thermal utilization coefficient caused by the graphite temperature effect deteriorates.Thus,the negative TCR first weakens and then strengthens,mainly because of the change in the fuel salt density coefficient.As the assembly size increases,the magnitude of the FSTC decreases monotonously owing to a monotonously weakened fuel salt Doppler coefficient,whereas the MTC changes from gradually weakened negative feedback to gradually enhanced positive feedback.Then,the negative TCR weakens.Therefore,to achieve a proper negative TCR,particularly a negative MTC,an assembly with a smaller fuel salt channel spacing in the under-moderated region is strongly recommended.
基金supported by the Chinese TMSR Strategic Pioneer Science and Technology Project(No.XDA02010000)the National Natural Science Foundation of China(No.91326201)the Frontier Science Key Program of the Chinese Academy of Sciences(No.QYZDY-SSW-JSC016)
文摘The molten salt reactor(MSR), as one of the Generation Ⅳ advanced nuclear systems, has attracted a worldwide interest due to its excellent performances in safety, economics, sustainability, and proliferation resistance. The aim of this work is to provide and evaluate possible solutions to fissile 233 U production and further the fuel transition to thorium fuel cycle in a thermal MSR by using plutonium partitioned from light water reactors spent fuel. By using an in-house developed tool, a breeding and burning(B&B) scenario is first introduced and analyzed from the aspects of the evolution of main nuclides, net 233 U production, spectrum shift, and temperature feedback coefficient. It can be concluded that such a Th/Pu to Th/^(233)U transition can be accomplished by employing a relatively fast fuel reprocessing with a cycle time less than 60 days. At the equilibrium state, the reactor can achieve a conversion ratio of about 0.996 for the 60-day reprocessing period(RP) case and about 1.047 for the 10-day RP case.The results also show that it is difficult to accomplish such a fuel transition with limited reprocessing(RP is 180 days),and the reactor operates as a converter and burns the plutonium with the help of thorium. Meanwhile, a prebreeding and burning(PB&B) scenario is also analyzed briefly with respect to the net 233 U production and evolution of main nuclides. One can find that it is more efficient to produce 233 U under this scenario, resulting in a double time varying from about 1.96 years for the 10-day RP case to about 6.15 years for the 180-day RP case.
基金supported by the Chinese TMSR Strategic Pioneer Science and Technology Project(No.XDA02010000)the Frontier Science Key Program of the Chinese Academy of Sciences(No.QYZDY-SSW-JSC016)
文摘With respect to a liquid-fueled molten salt reactor(MSR),the temperature coefficient of reactivity mainly includes the moderator temperature coefficient(MTC)and the fuel salt temperature coefficient(FSTC).The FSTC is typically divided into the Doppler coefficient and the density coefficient.In order to compensate for the potentially positive MTC,the FSTC should be sufficiently negative,and this is mostly optimized in terms of the geometry aspect in pioneering studies.However,the properties of fuel salt also directly influence the FSTC.Thus,the effects of different fuel salt compositions including the^(235)U enrichment,heavy metal proportion in salt phase(HM proportion),and the^7Li enrichment on FSTC are investigated from the viewpoint of the essential six-factor formula.The analysis is based on an undermoderated MSR.With respect to the Doppler coefficient,the temperature coefficient of the fast fission factors(a_T(ξ))is positive and those of the resonance escape probability(a_T(p)),thermal reproduction factor(a_T(g)),thermal utilization factor(a_T(f)),and total non-leakage probability(a_T(λ))are negative.With respect to the density coefficient,a_T(p)and a_T(g)are positive,while the others are negative.The results indicate that the effects of the^(235)U enrichment and HM on FSTC are mainly reflected in a_T(e)and a_T(p),which are the dominant factors when the neutron spectrum is relatively hard.Furthermore,the^7Li enrichment influences FSTC by a_T(f)and a_T(λ),which are the key factors in a relative soft spectrum.In order to obtain a more negative FSTC for an under-moderated MSR,the possible positive density coefficient,especially its a_T(p),should be suppressed.Thus,a lower^(235)U enrichment(albeit higher than a certain value,5 wt%in this article)along with a lower HM proportion and/or a higher^7Li enrichment are recommended.The analyses provide an approach to achieve a more suitable fuel salt composition with a sufficiently negative FSTC.
基金Project (No. NCET-04-0545) supported by the "New Century Elitist Supporting Plan" Fund Project of Education Ministry of China
文摘With the analysis on regulating system in 200 MW steam turbine, the necessity of appending the fast-opening function to the original system is set forth and a new type of fast-opening mechanism is devised. The mathematical model of system is built up. With the use of AMESIM software, the displacement curve of the piston, the force curve of the cartridge valve spool, the pressure curve and the flux curve in the regulation process are obtained based on simulation. The performances of three fast-opening systems composed of cartridge valves with different diameters are compared. Based on the analysis on factors that affect the execution time of fast-opening, the dead zone of the fast-opening system is put forward. To overcome the defect, dif- ferent operation modes are adopted for different zones. The result shows that with the increase of the valve diameter, the regulating time in the dead zone significantly exceeds the fast-opening time in the whole journey. Accordingly, the optimization operation tactic in the dead zone and the qualification conditions are brought forward. The fast-opening system composed of 32 mm cartridge valves is taken as an example with use of the tactic. The simulation result shows that the maximum regulating time is shortened by 509 ms.
基金supported by the National Natural Science Foundation of China (22065015)Key Research Program of Jiangxi Province of China (20202BBEL53023)the Natural Science Foundation of Jiangxi Province (Grant Nos. 20212BAB203015 and 20212BCJL23053)。
文摘The electrolysis of water into hydrogen and oxygen provides an effective means of storing electrical energy indirectly.The current challenge is to design an optimal catalyst that exhibits low overpotentials,long-term stability,universal availability,and only uses inexpensive materials.Herein,a Co3O4nanoflower/stainless steel(P-Ov-CO_(3)O_(4)/SS) catalyst with both oxygen vacancies(Ovs) and phosphorus doping was perfectly prepared via a simple three-step method.The Ovs promoted charge transfer and accelerated the electrocatalysis,while P finely tuned the surface charge state.This resulted in numerous active sites for catalysis,and the synergistic effect of phosphorus doping and oxygen vacancies was finely demonstrated.The resultant electrocatalyst exhibited low hydrogen evolution overpotentials of 118 mV(-10 mA·cm^(-2)) and 242(-200 mA·cm^(-2)),as well as oxygen evolution overpotentials of 327 mV(100 mA·cm^(-2)) and 370 mV(200 mA·cm^(-2)),owing to the excellent synergistic effect of the Ovs and low-temperature phosphating.Moreover,P-Ov-Co_(3)O_(4)/SS//P-Ov-Co_(3)O_(4)/SS exhibited a low water splitting voltage of 1.681 V at 20 mA.cm-2.These findings will enable the synthesis of novel high-performance electrocatalysts for overall water splitting.
基金supported by the Chinese TMSR Strategic Pioneer Science and Technology Project(No.XDA02010000)the Frontier Science Key Program of the Chinese Academy of Sciences(No.QYZDY-SSW-JSC016)
文摘To optimize the temperature coefficient of reactivity(TCR)for a graphite-moderated and liquid-fueled molten salt reactor,the effects of fuel salt composition on the fuel salt temperature coefficient of reactivity(FSTC)were investigated in our earlier work.In this study,we aim to provide a more comprehensive analysis of the TCR by considering the effects of the graphite-moderator temperature coefficient of reactivity(MTC).The effects of^235U enrichment and heavy metal(HM)proportion in the salt mixture on the MTC are investigated from the perspective of the six-factor formula based on a full-core model.For the MTC(labeled“αTM”),the temperature coefficient of the fast fission factors(αTM(ε))is positive,while those of the resonance escape probability(αTM(p)),the thermal reproduction factor(αTM(η)),the thermal utilization factor(αTM(f)),and the total non-leakage probability(αTM(A))are negative.The results reveal that the magnitudes ofαTM(ε)andαTM(p)for the MTC are similar.Thus,variations in the MTC with^235U enrichment for different HM proportions are mainly dependent onαTM(η),αTM(A),andαTM(f),but especially on the former two.To obtain a more negative MTC,a lower HM proportion and/or a lower 235U enrichment is recommended.Together with our previous studies on the FSTC,a relatively soft neutron spectrum could strengthen the TCR with a sufficiently negative MTC.
基金National Key Technology Research and Development Program of Ministry of Science and Technology of China(2011BAI07B07)National Natural Science Foundation of China(81072987)+1 种基金Top Science and Technology Innovation Teams of Higher Learning Institutions of Shanxi Province(201401)Fund for Shanxi Key Subjects Construction(FSKSC)(201612)
文摘Objective To identify reliable reference genes（RGs） for normalization of real-time PCR（RT-q PCR） data in Codonopsis pilosula. Methods The expression profiles of 10 candidate RGs（GAPDH, ACT, α-TUB, β-TUB, UBQ, CYP, EF-1α, NAC, F-box and PP2A） were examined in C. pilosula during the phenological period. The raw materials examined included roots, stems, leaves, and flower buds at flowering and boll-forming stages, five growth stages of untreated and treated roots with plant growth retardant. The best-suited RGs were accessed using ge Norm, NormF inder, Best Keeper, and Ref Finder algorithms. Results The best-ranked references genes differed across the samples. GAPDH and PP2A were the most suitable for expression analysis in untreated tissues while GAPDH, α-TUB, and PP2A were ranked as the three most stably expressed genes in untreated roots, while NAC and CYP were the most stably expressed genes in stressed（i.e., treated） roots. The expression of UGPase, a key enzyme for CPP biosynthesis, was determined to further validate the selected RGs. Conclusion A total of 10 RGs can be used as reference genes of C. pilosula, however the appropriate one should be used as it may chance.
文摘The effects of substituting Co for Fe on the microstructure and stress rupture properties of K4750 alloy were studied.The microstructure of the alloy without Co(K4750 alloy)and the alloy containing Co(K4750-Co alloy)were analyzed.Substitution of Co for Fe inhibited the decomposition of MC carbide and the precipitation ofηphase during long-term aging treatment.In K4750-Co alloy,the morphology of MC carbide at the grain boundary(GB)remained dispersed blocky shape and noηphase was observed after aging at 750℃ for 3000 h.However,in K4750 alloy,almost all the MC carbides at GBs broke down into granular M23C6 carbide and needle-likeηphase.The addition of cobalt could delay the decomposition of MC carbides,which accordingly restricted the elemental supply for the formation ofηphase.The stress rupture tests were conducted on two alloys at 750℃/430 MPa.When Co is substituted for Fe in K4750 alloy,the stress rupture life increased from 164.10 to 264.67 h after standard heat treatment.This was mainly attributed to increased concentration of Al,Ti and Nb inγ’phase in K4750-Co alloy,which further enhanced the strengthening effect ofγ’phase.After aging at 750℃ for 3000 h,substitution of Co for Fe can also cause the stress rupture life at 750℃/430 MPa to increase from 48.72 to 208.18 h.The reason was mainly because MC carbide degradation andηphase precipitation in K4750 alloy,which promoted the initiation and propagation of micro-crack during stress rupture testing.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.22022509,51873140 and 51820105003)Jiangsu Provincial Natural Science Foundation(No.BK20190095)+1 种基金Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.21KJA150006)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),and Collaborative Innovation Center of Suzhou Nano Science and Technology.
文摘Polymerizing the narrow bandgap small-molecule architecture with a conjugated linking unit(or called the polymerized small molecule acceptors(PSMAs))is a promising strategy to design polymer acceptors for efficient all polymer solar cells(all-PSCs).Currently,the fused-ring-based small molecule acceptors(SMAs)are preferred monomers to design efficient PSMAs,leaving the challenge of reducing the materials cost.In this work,we firstly employ nonfused-core SMA with simple synthetic procedures to design PSMAs(namely PBTI-H,PBTI-F and PBTI-Cl)to address this issue.Relative to the fused-ring based counterparts,these three PSMAs exhibit much higher figure-of-merit value.Additionally,a power-conversion efficiency of 8.80%is achieved in the PBTI-Cl-based all-PSC.The results offer an attractive approach to design low-cost PSMAs for efficient all-PSCs.
