An improved model to calculate the length of the mixing chamber of the ejector was proposed on the basis of the Fano flow model,and a method to optimize the structures of the mixing chamber and diffuser of the ejector...An improved model to calculate the length of the mixing chamber of the ejector was proposed on the basis of the Fano flow model,and a method to optimize the structures of the mixing chamber and diffuser of the ejector was put forward.The accuracy of the model was verified by comparing the theoretical results calculated using the model to experimental data reported in literature.Variations in the length of the mixing chamber L_(m) and length of the diffuser L_(d) with respect to variations in the outlet temperature of the ejector T_(c),outlet pressure of the ejector p_(c),and the expansion ratio of the pressure of the primary flow to that of the secondary flow p_(g)/p_(e) were investigated.Moreover,variations in L_(m) and L_(d) with respect to variations in the ratio of the diameter of the throat of the motive nozzle to the diameter of the mixing chamber d_(g0)/d_(c3) and ratio of the outlet diameter of the diffuser to the diameter of themixing chamber d_(c)/d_(c3) were investigated.The distribution of flow fields in the ejector was simulated.Increasing L_(m) and d_(c3) reduced T_(c) and p_(c).Moreover,reducing p_(g)/p_(e) or d_(g0)/d_(c3) reduced T_(c) and p_(c).The length of the mixed section L_(m2),which was determined on the basis of the Fano flow model,increased as pg increased and decreased as d_(c3) increased.The mixing length L_(m1),which was considered the primary flow expansion,showed the opposite trend with that of L_(m2).Moreover,Ld increased as p_(g)/p_(e) and d_(c)/d_(c3) increased.When the value of d_(c) was 1.8 to 2.0 times as high as that of dc3,the semi-cone angle of the diffuser ranged between 6°and 12°.At a constant dc/dc3,decreasing T_(c) and pc increased Ld.展开更多
Benefiting from their large molar extinction coefficient,high carrier mobility,narrow and tunable emissions,inorganic metal halide perovskites(IMHPs) demonstrate great potential in various optoelectrical devices inclu...Benefiting from their large molar extinction coefficient,high carrier mobility,narrow and tunable emissions,inorganic metal halide perovskites(IMHPs) demonstrate great potential in various optoelectrical devices including solar cells,light emitting diodes and photodetectors in the past few years.Metal ions doping,well-known as a modification method of semiconductors,has been extensively applied in IMHPs as well.Diverse metal ions have been doped in IMHPs including alkali metals,alkali earth metals,transition metals and lanthanide metals,which either improve their optical performances or induce intriguing brand-new properties.Among them,lanthanide metals feature plentiful energy levels and stable optical properties and are one of the most noteworthy species.Here we review recent progress in lanthanide ions doped IMHPs.We summarize Yb,Eu or Er ions singly doping in detail,which was the most investigated species in IMHPs.Other lanthanide ions are also reviewed synoptically.Furthermore,we introduce lanthanide ions multi-doped IMHPs and at last we put forward several potential development directions.As the interests in lanthanide ions doped IMHPs rise,researchers have made some achievements in the field.Still though,there are more unexplored issues.Although there are review articles focusing on metal ions doped IMHPs or lanthanide ions doped perovskites,this review aims to provide an overall introduction of lanthanide ions doped IMHPs.This review may help researchers learn about lanthanide ions doped IMHPs and is to inspire researchers to make further promotion in this field.展开更多
A type of multifunctional erbium(Er^(3+))and ytterbium(Yb^(3+))codoped NaY(WO4)2 phosphors,with simultaneous photon upconversion,photon quantum cutting,and luminescence ratiometric temperature sensing abilities,have b...A type of multifunctional erbium(Er^(3+))and ytterbium(Yb^(3+))codoped NaY(WO4)2 phosphors,with simultaneous photon upconversion,photon quantum cutting,and luminescence ratiometric temperature sensing abilities,have been developed,opening up new possibilities for high-performance silicon solar cells.展开更多
The highly conserved target of rapamycin(TOR)pathway plays an important role in aging across species.Previous studies have established that inhibition of the TOR complex 1(TORC1)significantly extends lifespan in Caeno...The highly conserved target of rapamycin(TOR)pathway plays an important role in aging across species.Previous studies have established that inhibition of the TOR complex 1(TORC1)significantly extends lifespan in Caenorhabditis elegans.However,it has not been clear whether TORC1 perturbation affects aging in a spatiotemporal manner.Here,we apply the auxin-inducible degradation tool to knock down endogenous DAF-15,the C.elegans ortholog of regulatory associated protein of TOR(Raptor),to characterize its roles in aging.Global or tissue-specific inhibition of DAF-15 during development results in various growth defects,whereas neuron-specific knockdown of DAF-15 during adulthood significantly extends lifespan and healthspan.The neuronal DAF-15 deficiency-induced longevity requires the intestinal activities of DAF-16/FOXO and PHA-4/FOXA transcription factors,as well as the AAK-2/AMP-activated protein kinaseαcatalytic subunit.Transcriptome profiling reveals that the neuronal DAF-15 knockdown promotes the expression of genes involved in protection.These findings define the tissue-specific roles of TORC1 in healthy aging and highlight the importance of neuronal modulation of aging.展开更多
The bioaccumulation of mercury(Hg)in aquatic ecosystem poses a potential health risk to human being and aquatic organism.Bioaccumulations by plankton represent a crucial process of Hg transfer from water to aquatic fo...The bioaccumulation of mercury(Hg)in aquatic ecosystem poses a potential health risk to human being and aquatic organism.Bioaccumulations by plankton represent a crucial process of Hg transfer from water to aquatic food chain.However,the current understanding of major factors affecting Hg accumulation by plankton is inadequate.In this study,a data set of 89 aquatic ecosystems worldwide,including inland water,nearshore water and open sea,was established.Key factors influencing plankton Hg bioaccumulation(i.e.,plankton species,cell sizes and biomasses)were discussed.The results indicated that total Hg(THg)and methylmercury(MeHg)concentrations in plankton in inland waters were significantly higher than those in nearshore waters and open seas.Bioaccumulation factors for the logarithm of THg and MeHg of phytoplankton were 2.4–6.0 and 2.6–6.7 L/kg,respectively,in all aquatic ecosystems.They could be further biomagnified by a factor of 2.1–15.1 and 5.3–28.2 from phytoplankton to zooplankton.Higher MeHg concentrations were observed with the increases of cell size for both phyto-and zooplankton.A contrasting trend was observed between the plankton biomasses and BAF_(MeHg),with a positive relationship for zooplankton and a negative relationship for phytoplankton.Plankton physiologic traits impose constraints on the rates of nutrients and contaminants obtaining process from water.Nowadays,many aquatic ecosystems are facing rapid shifts in nutrient compositions.We suggested that these potential influences on the growth and composition of plankton should be incorporated in future aquatic Hg modeling and ecological risk assessments.展开更多
文摘An improved model to calculate the length of the mixing chamber of the ejector was proposed on the basis of the Fano flow model,and a method to optimize the structures of the mixing chamber and diffuser of the ejector was put forward.The accuracy of the model was verified by comparing the theoretical results calculated using the model to experimental data reported in literature.Variations in the length of the mixing chamber L_(m) and length of the diffuser L_(d) with respect to variations in the outlet temperature of the ejector T_(c),outlet pressure of the ejector p_(c),and the expansion ratio of the pressure of the primary flow to that of the secondary flow p_(g)/p_(e) were investigated.Moreover,variations in L_(m) and L_(d) with respect to variations in the ratio of the diameter of the throat of the motive nozzle to the diameter of the mixing chamber d_(g0)/d_(c3) and ratio of the outlet diameter of the diffuser to the diameter of themixing chamber d_(c)/d_(c3) were investigated.The distribution of flow fields in the ejector was simulated.Increasing L_(m) and d_(c3) reduced T_(c) and p_(c).Moreover,reducing p_(g)/p_(e) or d_(g0)/d_(c3) reduced T_(c) and p_(c).The length of the mixed section L_(m2),which was determined on the basis of the Fano flow model,increased as pg increased and decreased as d_(c3) increased.The mixing length L_(m1),which was considered the primary flow expansion,showed the opposite trend with that of L_(m2).Moreover,Ld increased as p_(g)/p_(e) and d_(c)/d_(c3) increased.When the value of d_(c) was 1.8 to 2.0 times as high as that of dc3,the semi-cone angle of the diffuser ranged between 6°and 12°.At a constant dc/dc3,decreasing T_(c) and pc increased Ld.
基金Project supported by the National Natural Science Foundation of China(52272270,51972084)the Young Scientist Workshop(Harbin Institute of Technology)(AUGA5710094420)the Fundamental Research Funds for the Central Universities,China(AUGA5710052614)。
文摘Benefiting from their large molar extinction coefficient,high carrier mobility,narrow and tunable emissions,inorganic metal halide perovskites(IMHPs) demonstrate great potential in various optoelectrical devices including solar cells,light emitting diodes and photodetectors in the past few years.Metal ions doping,well-known as a modification method of semiconductors,has been extensively applied in IMHPs as well.Diverse metal ions have been doped in IMHPs including alkali metals,alkali earth metals,transition metals and lanthanide metals,which either improve their optical performances or induce intriguing brand-new properties.Among them,lanthanide metals feature plentiful energy levels and stable optical properties and are one of the most noteworthy species.Here we review recent progress in lanthanide ions doped IMHPs.We summarize Yb,Eu or Er ions singly doping in detail,which was the most investigated species in IMHPs.Other lanthanide ions are also reviewed synoptically.Furthermore,we introduce lanthanide ions multi-doped IMHPs and at last we put forward several potential development directions.As the interests in lanthanide ions doped IMHPs rise,researchers have made some achievements in the field.Still though,there are more unexplored issues.Although there are review articles focusing on metal ions doped IMHPs or lanthanide ions doped perovskites,this review aims to provide an overall introduction of lanthanide ions doped IMHPs.This review may help researchers learn about lanthanide ions doped IMHPs and is to inspire researchers to make further promotion in this field.
基金the National Natural Science Foundation of China(52272270 and 51972084)the Fundamental Research Funds for the Central Universities,China(AUGA5710052614).
文摘A type of multifunctional erbium(Er^(3+))and ytterbium(Yb^(3+))codoped NaY(WO4)2 phosphors,with simultaneous photon upconversion,photon quantum cutting,and luminescence ratiometric temperature sensing abilities,have been developed,opening up new possibilities for high-performance silicon solar cells.
基金the National Key R&D Program of China(2021YFA0805802 to D.C.)the National Natural Science Foundation of China(31971092 and 32171156 to D.C.)Some strains were provided by the Caenorhabditis Genetics Center(CGC),which is funded by NIHOffice of Research Infrastructure Programs(P40 OD010440).
文摘The highly conserved target of rapamycin(TOR)pathway plays an important role in aging across species.Previous studies have established that inhibition of the TOR complex 1(TORC1)significantly extends lifespan in Caenorhabditis elegans.However,it has not been clear whether TORC1 perturbation affects aging in a spatiotemporal manner.Here,we apply the auxin-inducible degradation tool to knock down endogenous DAF-15,the C.elegans ortholog of regulatory associated protein of TOR(Raptor),to characterize its roles in aging.Global or tissue-specific inhibition of DAF-15 during development results in various growth defects,whereas neuron-specific knockdown of DAF-15 during adulthood significantly extends lifespan and healthspan.The neuronal DAF-15 deficiency-induced longevity requires the intestinal activities of DAF-16/FOXO and PHA-4/FOXA transcription factors,as well as the AAK-2/AMP-activated protein kinaseαcatalytic subunit.Transcriptome profiling reveals that the neuronal DAF-15 knockdown promotes the expression of genes involved in protection.These findings define the tissue-specific roles of TORC1 in healthy aging and highlight the importance of neuronal modulation of aging.
基金funded by National Natural Science Foundation of China(Grant Nos.41977324 and 41630748)the Natural Science Foundation of Tianjin(No.20JCYBJC01080).
文摘The bioaccumulation of mercury(Hg)in aquatic ecosystem poses a potential health risk to human being and aquatic organism.Bioaccumulations by plankton represent a crucial process of Hg transfer from water to aquatic food chain.However,the current understanding of major factors affecting Hg accumulation by plankton is inadequate.In this study,a data set of 89 aquatic ecosystems worldwide,including inland water,nearshore water and open sea,was established.Key factors influencing plankton Hg bioaccumulation(i.e.,plankton species,cell sizes and biomasses)were discussed.The results indicated that total Hg(THg)and methylmercury(MeHg)concentrations in plankton in inland waters were significantly higher than those in nearshore waters and open seas.Bioaccumulation factors for the logarithm of THg and MeHg of phytoplankton were 2.4–6.0 and 2.6–6.7 L/kg,respectively,in all aquatic ecosystems.They could be further biomagnified by a factor of 2.1–15.1 and 5.3–28.2 from phytoplankton to zooplankton.Higher MeHg concentrations were observed with the increases of cell size for both phyto-and zooplankton.A contrasting trend was observed between the plankton biomasses and BAF_(MeHg),with a positive relationship for zooplankton and a negative relationship for phytoplankton.Plankton physiologic traits impose constraints on the rates of nutrients and contaminants obtaining process from water.Nowadays,many aquatic ecosystems are facing rapid shifts in nutrient compositions.We suggested that these potential influences on the growth and composition of plankton should be incorporated in future aquatic Hg modeling and ecological risk assessments.
