During the last two decades,we have witnessed great progress in research on thermoelectrics.There are two primary focuses.One is the fundamental understanding of electrical and thermal transport,enabled by the interpl...During the last two decades,we have witnessed great progress in research on thermoelectrics.There are two primary focuses.One is the fundamental understanding of electrical and thermal transport,enabled by the interplay of theory and experiment;the other is the substantial enhancement of the performance of various thermoelectric materials,through synergistic optimisation of those intercorrelated transport parameters.Here we review some of the successful strategies for tuning electrical and thermal transport.For electrical transport,we start from the classical but still very active strategy of tuning band degeneracy(or band convergence),then discuss the engineering of carrier scattering,and finally address the concept of conduction channels and conductive networks that emerge in complex thermoelectric materials.For thermal transport,we summarise the approaches for studying thermal transport based on phonon–phonon interactions valid for conventional solids,as well as some quantitative efforts for nanostructures.We also discuss the thermal transport in complex materials with chemical-bond hierarchy,in which a portion of the atoms(or subunits)are weakly bonded to the rest of the structure,leading to an intrinsic manifestation of part-crystalline part-liquid state at elevated temperatures.In this review,we provide a summary of achievements made in recent studies of thermoelectric transport properties,and demonstrate how they have led to improvements in thermoelectric performance by the integration of modern theory and experiment,and point out some challenges and possible directions.展开更多
On acid soils,the trivalent aluminium ion(Al3+)predominates and is very rhizotoxic to most plant species.For some native plant species adapted to acid soils including tea(Camellia sinensis),Al3+has been regarded as a ...On acid soils,the trivalent aluminium ion(Al3+)predominates and is very rhizotoxic to most plant species.For some native plant species adapted to acid soils including tea(Camellia sinensis),Al3+has been regarded as a beneficial mineral element.In this study,we discovered that Al3+is actually essential for tea root growth and development in all the tested varieties.Aluminum ion promoted new root growth in five representative tea varieties with dose-dependent responses to Al3+availability.In the absence of Al3+,the tea plants failed to generate new roots,and the root tips were damaged within 1 d of Al deprivation.Struc-tural analysis of root tips demonstrated that Al was required for root meristem development and activity.In situ morin@staining of Al3+in roots revealed that Al mainly localized to nuclei in root meristem cells,but then gradually moved to the cytosol when Al3+was subsequently withdrawn.This movement of Al3+from nuclei to cytosols was accompanied by exacerbated DNA damage,which suggests that the nuclear-targeted Al primarily acts to maintain DNA integrity.Taken together,these results provide novel evidence that Al3+is essential for root growth in tea plants through maintenance of DNA integrity in meristematic cells.展开更多
Starting from December 2019,Wuhan,China,encountered the first outbreak of coronavirus disease 2019(COVID-19)(1-2).The epidemic was successfully suppressed by strict containment so that the number of infected people wa...Starting from December 2019,Wuhan,China,encountered the first outbreak of coronavirus disease 2019(COVID-19)(1-2).The epidemic was successfully suppressed by strict containment so that the number of infected people was reduced to 0 on April 8,2020(3–4).After that,China experienced roughly 3 dozen outbreaks with local transmission caused by imported severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).展开更多
OBJECTIVE:To evaluate the effects of electric acupoint stimulation on gastrointestinal hormones and motility among geriatric postoperative patients with gastrointestinal tumors,and to explore an efficient and noninvas...OBJECTIVE:To evaluate the effects of electric acupoint stimulation on gastrointestinal hormones and motility among geriatric postoperative patients with gastrointestinal tumors,and to explore an efficient and noninvasive method for postoperative recovery of bowel functions.METHODS:Forty patients were randomly and evenly assigned into a regular nursing care group(RNC) and an acupoint electric stimulation group(AES).Patients in the RNC group received regular nursing care and patients in the AES group received regular nursing care plus electric stimulation of acupoints.The serum levels of gastrin(GAS),motilin(MOT),and cholecystokinin(CCK),and an electrogastrogram(EGG) of all the patients were evaluated on the first,third,and fifth day after surgery.The time to first flatus after surgery and the number of patients with side effects such as abdominal pain,abdominal distention,and diarrhea were recorded.RESULTS:There were significant differences between the two groups in GAS,MOT,EGG,time to first flatus,abdominal pain,abdominal distention,and diarrhea(P < 0.05).CONCLUSION:Electric stimulation on acupoints could increase levels of GAS and MOT,promote the recovery of gastrointestinal functions,and decrease complications among postoperative senile patients with gastrointestinal tumors.展开更多
基金supported by National Basic Research Program of China(973-program)under project number 2013CB632501National Natural Science Foundation of China under contract number 11234012+7 种基金the Key Research Program of Chinese Academy of Sciences(Grant No.KGZD-EW-T06)research grants(14DZ2261200 and 15JC1400301)from Science and Technology Commission of Shanghai MunicipalityInternational S&T Cooperation Program of China(2015DFA51050)supported by the U.S.Department of Energy,Office of Basic Energy Sciences under award number DE-SC-0008574supported by the Department of Energy through the S3TEC Energy Frontier Research Center award#DE-SC0001299/DE-FG02–09ER46577supported by the U.S.Department of Energy under corporate agreement DE-FC26-04NT42278by GM,and by National Science Foundation under award number 1235535support from Shanghai Institute of Materials Genome.
文摘During the last two decades,we have witnessed great progress in research on thermoelectrics.There are two primary focuses.One is the fundamental understanding of electrical and thermal transport,enabled by the interplay of theory and experiment;the other is the substantial enhancement of the performance of various thermoelectric materials,through synergistic optimisation of those intercorrelated transport parameters.Here we review some of the successful strategies for tuning electrical and thermal transport.For electrical transport,we start from the classical but still very active strategy of tuning band degeneracy(or band convergence),then discuss the engineering of carrier scattering,and finally address the concept of conduction channels and conductive networks that emerge in complex thermoelectric materials.For thermal transport,we summarise the approaches for studying thermal transport based on phonon–phonon interactions valid for conventional solids,as well as some quantitative efforts for nanostructures.We also discuss the thermal transport in complex materials with chemical-bond hierarchy,in which a portion of the atoms(or subunits)are weakly bonded to the rest of the structure,leading to an intrinsic manifestation of part-crystalline part-liquid state at elevated temperatures.In this review,we provide a summary of achievements made in recent studies of thermoelectric transport properties,and demonstrate how they have led to improvements in thermoelectric performance by the integration of modern theory and experiment,and point out some challenges and possible directions.
基金This research was financially supported by the National Natural Science Foundation of China(31701989)MOA Modern Agricultural Talents Support Project and the Natural Science Foundation of Fujian Province in China(2017J01602).
文摘On acid soils,the trivalent aluminium ion(Al3+)predominates and is very rhizotoxic to most plant species.For some native plant species adapted to acid soils including tea(Camellia sinensis),Al3+has been regarded as a beneficial mineral element.In this study,we discovered that Al3+is actually essential for tea root growth and development in all the tested varieties.Aluminum ion promoted new root growth in five representative tea varieties with dose-dependent responses to Al3+availability.In the absence of Al3+,the tea plants failed to generate new roots,and the root tips were damaged within 1 d of Al deprivation.Struc-tural analysis of root tips demonstrated that Al was required for root meristem development and activity.In situ morin@staining of Al3+in roots revealed that Al mainly localized to nuclei in root meristem cells,but then gradually moved to the cytosol when Al3+was subsequently withdrawn.This movement of Al3+from nuclei to cytosols was accompanied by exacerbated DNA damage,which suggests that the nuclear-targeted Al primarily acts to maintain DNA integrity.Taken together,these results provide novel evidence that Al3+is essential for root growth in tea plants through maintenance of DNA integrity in meristematic cells.
基金Supported by the National Natural Science Foundation(grant number 71934002)of the People’s Republic of China.
文摘Starting from December 2019,Wuhan,China,encountered the first outbreak of coronavirus disease 2019(COVID-19)(1-2).The epidemic was successfully suppressed by strict containment so that the number of infected people was reduced to 0 on April 8,2020(3–4).After that,China experienced roughly 3 dozen outbreaks with local transmission caused by imported severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).
基金Supported by the National Natural Science Foundation Project of China(Transcutaneous Electrical Acupoint Stimulation Prevents the Deep Vein Thrombosis:the Role of Endothelium Modulation,No.81202750)
文摘OBJECTIVE:To evaluate the effects of electric acupoint stimulation on gastrointestinal hormones and motility among geriatric postoperative patients with gastrointestinal tumors,and to explore an efficient and noninvasive method for postoperative recovery of bowel functions.METHODS:Forty patients were randomly and evenly assigned into a regular nursing care group(RNC) and an acupoint electric stimulation group(AES).Patients in the RNC group received regular nursing care and patients in the AES group received regular nursing care plus electric stimulation of acupoints.The serum levels of gastrin(GAS),motilin(MOT),and cholecystokinin(CCK),and an electrogastrogram(EGG) of all the patients were evaluated on the first,third,and fifth day after surgery.The time to first flatus after surgery and the number of patients with side effects such as abdominal pain,abdominal distention,and diarrhea were recorded.RESULTS:There were significant differences between the two groups in GAS,MOT,EGG,time to first flatus,abdominal pain,abdominal distention,and diarrhea(P < 0.05).CONCLUSION:Electric stimulation on acupoints could increase levels of GAS and MOT,promote the recovery of gastrointestinal functions,and decrease complications among postoperative senile patients with gastrointestinal tumors.
