Thermoelectric(TE)materials have been considered as a strong candidate for recovering the waste heat from industry and vehicles due to the ability to convert heat directly into electricity.Recently,multinary diamond-l...Thermoelectric(TE)materials have been considered as a strong candidate for recovering the waste heat from industry and vehicles due to the ability to convert heat directly into electricity.Recently,multinary diamond-like chalcogenides(MDLCs),such as Cu In Te_2,Cu_2Sn Se_3,Cu_3Sb Se_4,Cu_2ZnSnSe_4,etc.,are eco-friendly Pb-free TE materials with relatively large Seebeck coefficient and low thermal conductivity and have aroused intensive research as a popular theme in the TE field.In this review,we summarize the TE performance and device development of MDLCs.The features of crystalline and electronic structure are first analyzed,and then the strategies that have emerged to enhance the TE figure of merits of these materials are illustrated in detail.The final part of this review describes the advance in TE device research for MDLCs.In the outlook,the challenges and future directions are also discussed to promote the further development of MDLCs TE materials.展开更多
BACKGROUND Severe acute pancreatitis(SAP)is a common condition in the intensive care unit(ICU)and has a high mortality.Early evaluation of the severity and prognosis is very important for SAP therapy.Recently,red bloo...BACKGROUND Severe acute pancreatitis(SAP)is a common condition in the intensive care unit(ICU)and has a high mortality.Early evaluation of the severity and prognosis is very important for SAP therapy.Recently,red blood cell distribution(RDW)was associated with mortality of sepsis patients and could be used as a predictor of prognosis.Similarly,RDW may be associated with the prognosis of SAP patients and be used as a prognostic indicator for SAP patients.AIM To investigate the prognostic value of RDW for SAP patients.METHODS We retrospectively enrolled SAP patients admitted to the ICU of the First Affiliated Hospital of China Medical University from June 2015 to June 2017.According to the prognosis at 90 d,SAP patients were divided into a survival group and a non-survival group.RDW was extracted from a routine blood test.Demographic parameters and RDW were recorded and compared between the two groups.The receiver operator characteristic(ROC)curve was constructed and Cox regression analysis was performed to investigate the prognostic value of RDW for SAP patients.RESULTS In this retrospective cohort study,42 SAP patients were enrolled,of whom 22 survived(survival group)and 20 died(non-survival group).The baseline parameters were comparable between the two groups.The coefficient of variation of RDW(RDW-CV),standard deviation of RDW(RDW-SD),Acute Physiology and Chronic Health Evaluation II(APACHE II)score,and Sequential Organ Failure Assessment(SOFA)score were significantly higher in the non-survival group than in the survival group(P<0.05).The RDW-CV and RDW-SD were significantly correlated with the APACHE II score and SOFA score,respectively.The areas under the ROC curves(AUCs)of RDW-CV and RDW-SD were all greater than those of the APACHE II score and SOFA score,among which,the AUC of RDW-SD was the greatest.The results demonstrated that RDW had better prognostic value for predicting the mortality of SAP patients.When the RDW-SD was greater than 45.5,the sensitivity for predicting prognosis was 77.8%and the specificity was 70.8%.Both RDW-CV and RDW-SD could be used as independent risk factors to predict the mortality of SAP patients in multivariate logistic regression analysis and univariate Cox proportional hazards regression analysis,similar to the APACHE II and SOFA scores.CONCLUSION The RDW is greater in the non-surviving SAP patients than in the surviving patients.RDW is significantly correlated with the APACHE II and SOFA scores.RDW has better prognostic value for SAP patients than the APACHE II and SOFA scores and could easily be used by clinicians for the treatment of SAP patients.展开更多
GeTe is an excellent mid-temperature thermoelectric material with high dimensionless figure of merit(ZT)values at temperatures over 600 K.Its near-room-temperature performance is less studied due to the intrinsic high...GeTe is an excellent mid-temperature thermoelectric material with high dimensionless figure of merit(ZT)values at temperatures over 600 K.Its near-room-temperature performance is less studied due to the intrinsic high carrier concentration.Here,we successfully enhance the Seebeck coefficient of GeTe from~30 to 220μV·K^(−1) at 300 K,which is achieved by AgInSe2 alloying and Bi doping.It is demonstrated that Bi doping helps to optimize the Seebeck coefficient without deteriorating the intrinsic electrical transport properties of the matrix.A high room-temperature power factor(PF)of~11μW·cm^(−1)·K^(−2) is achieved for a wide range of Bi-doped samples.The simultaneously introduced abundant point defects cause mass and strain fluctuations,which decrease the lattice thermal conductivity(κ_(L))to a low value of 0.6 W·m^(−1)·K^(−1) at 300 K.Due to the synergetic effects of Bi doping in AgInSe2-alloyed GeTe,a high room-temperature ZT value of 0.46 is obtained together with a high ZT value of 1.1 at 523 K.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51372064 and 61704044)the Key Project of the Natural Science Foundation of Hebei Province,China(Grant No.E2017201227)
文摘Thermoelectric(TE)materials have been considered as a strong candidate for recovering the waste heat from industry and vehicles due to the ability to convert heat directly into electricity.Recently,multinary diamond-like chalcogenides(MDLCs),such as Cu In Te_2,Cu_2Sn Se_3,Cu_3Sb Se_4,Cu_2ZnSnSe_4,etc.,are eco-friendly Pb-free TE materials with relatively large Seebeck coefficient and low thermal conductivity and have aroused intensive research as a popular theme in the TE field.In this review,we summarize the TE performance and device development of MDLCs.The features of crystalline and electronic structure are first analyzed,and then the strategies that have emerged to enhance the TE figure of merits of these materials are illustrated in detail.The final part of this review describes the advance in TE device research for MDLCs.In the outlook,the challenges and future directions are also discussed to promote the further development of MDLCs TE materials.
基金Supported by Health and Birth Control Committee of Liaoning Province,China
文摘BACKGROUND Severe acute pancreatitis(SAP)is a common condition in the intensive care unit(ICU)and has a high mortality.Early evaluation of the severity and prognosis is very important for SAP therapy.Recently,red blood cell distribution(RDW)was associated with mortality of sepsis patients and could be used as a predictor of prognosis.Similarly,RDW may be associated with the prognosis of SAP patients and be used as a prognostic indicator for SAP patients.AIM To investigate the prognostic value of RDW for SAP patients.METHODS We retrospectively enrolled SAP patients admitted to the ICU of the First Affiliated Hospital of China Medical University from June 2015 to June 2017.According to the prognosis at 90 d,SAP patients were divided into a survival group and a non-survival group.RDW was extracted from a routine blood test.Demographic parameters and RDW were recorded and compared between the two groups.The receiver operator characteristic(ROC)curve was constructed and Cox regression analysis was performed to investigate the prognostic value of RDW for SAP patients.RESULTS In this retrospective cohort study,42 SAP patients were enrolled,of whom 22 survived(survival group)and 20 died(non-survival group).The baseline parameters were comparable between the two groups.The coefficient of variation of RDW(RDW-CV),standard deviation of RDW(RDW-SD),Acute Physiology and Chronic Health Evaluation II(APACHE II)score,and Sequential Organ Failure Assessment(SOFA)score were significantly higher in the non-survival group than in the survival group(P<0.05).The RDW-CV and RDW-SD were significantly correlated with the APACHE II score and SOFA score,respectively.The areas under the ROC curves(AUCs)of RDW-CV and RDW-SD were all greater than those of the APACHE II score and SOFA score,among which,the AUC of RDW-SD was the greatest.The results demonstrated that RDW had better prognostic value for predicting the mortality of SAP patients.When the RDW-SD was greater than 45.5,the sensitivity for predicting prognosis was 77.8%and the specificity was 70.8%.Both RDW-CV and RDW-SD could be used as independent risk factors to predict the mortality of SAP patients in multivariate logistic regression analysis and univariate Cox proportional hazards regression analysis,similar to the APACHE II and SOFA scores.CONCLUSION The RDW is greater in the non-surviving SAP patients than in the surviving patients.RDW is significantly correlated with the APACHE II and SOFA scores.RDW has better prognostic value for SAP patients than the APACHE II and SOFA scores and could easily be used by clinicians for the treatment of SAP patients.
基金This work was supported by grants from Young foundation of Peking Union Medical College （No. 3332016107）, Nature Science Foundation of Jiangsu （No. BK20160153）, Innovation Research on Critical Diseases （No. 2016ZX320014）.
基金financially supported by the Singapore MOE AcRF Tier 2(Nos.2018-T2-1-010)Singapore A*STAR project(A19D9a0096 and SC25/21-102419)+3 种基金Singapore MOE Tier 1 RG128/21.Q.Zhu and A.Suwardi acknowledge Agency for Science,Technology and Research(A*STAR)Singapore Career Development Fund(CDF)(No.C210112022)the Sustainable Hybrid Lighting System for Controlled Environment Agriculture Program(No.A19D9a0096)support from S&T Program of Hebei(No.206Z4403G)。
文摘GeTe is an excellent mid-temperature thermoelectric material with high dimensionless figure of merit(ZT)values at temperatures over 600 K.Its near-room-temperature performance is less studied due to the intrinsic high carrier concentration.Here,we successfully enhance the Seebeck coefficient of GeTe from~30 to 220μV·K^(−1) at 300 K,which is achieved by AgInSe2 alloying and Bi doping.It is demonstrated that Bi doping helps to optimize the Seebeck coefficient without deteriorating the intrinsic electrical transport properties of the matrix.A high room-temperature power factor(PF)of~11μW·cm^(−1)·K^(−2) is achieved for a wide range of Bi-doped samples.The simultaneously introduced abundant point defects cause mass and strain fluctuations,which decrease the lattice thermal conductivity(κ_(L))to a low value of 0.6 W·m^(−1)·K^(−1) at 300 K.Due to the synergetic effects of Bi doping in AgInSe2-alloyed GeTe,a high room-temperature ZT value of 0.46 is obtained together with a high ZT value of 1.1 at 523 K.
