White body-color （Y, Gd）BxV1-xO4-x ：Eu^3＋ phosphors were prepared by coprecipitation reaction. Under VUV excitation at 147 nm, the red emission colorimetric purity of （Y, Gd） BxV1-xO4-x： Eu^3＋ phosphor is much...White body-color （Y, Gd）BxV1-xO4-x ：Eu^3＋ phosphors were prepared by coprecipitation reaction. Under VUV excitation at 147 nm, the red emission colorimetric purity of （Y, Gd） BxV1-xO4-x： Eu^3＋ phosphor is much better than that of commercial PDP （plasma display panels） phosphor （Y, Gd）BO3：Eu^3＋ . But its relative emission intensity is only about 90% of the commercial phosphor.展开更多
The energy transfer phenomenon of Ce→Gd→Tb via Gd sublattice and its depandence has been investigated in GdxY-1-xP5O14:Ce,Tb.The fluorescent and excitation spectra of Gdp5O14,Gdp5O14:Ce,Gdp5O14:Tb and GdxY-1xP5O14:C...The energy transfer phenomenon of Ce→Gd→Tb via Gd sublattice and its depandence has been investigated in GdxY-1-xP5O14:Ce,Tb.The fluorescent and excitation spectra of Gdp5O14,Gdp5O14:Ce,Gdp5O14:Tb and GdxY-1xP5O14:Ce,Tb and absorption spectrum of Gdp5O14 have been studied.The results show that as x is larger than 0.7.the energy transfer from Ce3+ via Gd3+to Tb3+ is obvious.The main reason for the energy transfer of Ce→Gd→Tb being efficient in the region x>0.7 is that the spectral overlap between Ce3+ emission spectrum and Gd3+ absorption spectrum increases and the structure changes from monoclinic Ⅱ(C2/c) layer structure(x<0.7) to monoclinic I(P21/c) ribbon structure.展开更多
Preparation, structure and spectral properties of rare earth pentaphosphates Gd_xY_(1-x)P_5O_(14): Ce, Tb have been investigated. When x>0. 7, the pentaphosphates belong to monoclinic crystal system Ⅰ with space g...Preparation, structure and spectral properties of rare earth pentaphosphates Gd_xY_(1-x)P_5O_(14): Ce, Tb have been investigated. When x>0. 7, the pentaphosphates belong to monoclinic crystal system Ⅰ with space group P2_1/c (C). When x≤0. 7. they belong to monoclinic crystal system Ⅱ with C2/c (C). The fluorescent and excitation spectra of Gdp_5O_(14), GdP_5O_(14): Ce. GdP_5O_(14) : Tb and Gd_xY_(1-x)P_5O_(14) : Ce, Tb have been studied and the energy transfer phenomenon from Ce(3+)→Gd(3+)→Tb(3+) by the medium of Gd(3+) sublattice has been determined.展开更多
Magnetic refrigeration is a revolutionary, efficient, environmentally friendly cooling technology, which is on the threshold of commercialization. The magnetic rare earth materials are utilized as the magnetic refrige...Magnetic refrigeration is a revolutionary, efficient, environmentally friendly cooling technology, which is on the threshold of commercialization. The magnetic rare earth materials are utilized as the magnetic refrigerants in most cooling devices, and for many cooling application the Nd2Fe14B permanent magnets are employed as the source of the magnetic field. The status of the near room temperature magnetic cooling was reviewed.展开更多
Nitrogen(N)deficiency causes early leaf senescence,resulting in accelerated whole-plant maturation and severely reduced crop yield.However,the molecular mechanisms underlying N-deficiency-induced early leaf senescence...Nitrogen(N)deficiency causes early leaf senescence,resulting in accelerated whole-plant maturation and severely reduced crop yield.However,the molecular mechanisms underlying N-deficiency-induced early leaf senescence remain unclear,even in the model species Arabidopsis thaliana.In this study,we identified Growth,Development and Splicing 1(GDS1),a previously reported transcription factor,as a new regulator of nitrate(NO3)signaling by a yeast-one-hybrid screen using a NO3enhancer fragment from the promoter of NRT2.1.We showed that GDS1 promotes NO3 signaling,absorption and assimilation by affecting the expression of multiple NO3 regulatory genes,including Nitrate Regulatory Gene2(NRG2).Interestingly,we observedthat gds1mutants show early leaf senescence as well as reduced NO3-contentand Nuptake under N-deficient conditions.Further analyses indicated that GDS1 binds to the promoters of several senescence-related genes,including Phytochrome-lnteracting Transcription Factors 4 and 5(PIF4 and PIF5)and represses their expression.Interestingly,we found that N deficiency decreases GDS1 protein accumulation,and GDS1 could interact with Anaphase Promoting Complex Subunit 10(APC10).Genetic and biochemical experiments demonstrated that Anaphase Promoting Complex or Cyclosome(APC/C)promotes the ubiquitination and degradation of GDS1 under N deficiency,resulting in loss of PIF4 and PiF5 repression and consequent early leaf senescence.Furthermore,we discovered that overexpression of GDS1 could delay leaf senescence and improve seed yield and N-use efficiency(NUE)in Arabidopsis.In summary,our study uncovers a molecular framework illustrating a new mechanism underlying low-N-induced early leaf senescence and provides potential targets for genetic improvement of crop varieties with increased yield and NUE.展开更多
文摘White body-color （Y, Gd）BxV1-xO4-x ：Eu^3＋ phosphors were prepared by coprecipitation reaction. Under VUV excitation at 147 nm, the red emission colorimetric purity of （Y, Gd） BxV1-xO4-x： Eu^3＋ phosphor is much better than that of commercial PDP （plasma display panels） phosphor （Y, Gd）BO3：Eu^3＋ . But its relative emission intensity is only about 90% of the commercial phosphor.
文摘The energy transfer phenomenon of Ce→Gd→Tb via Gd sublattice and its depandence has been investigated in GdxY-1-xP5O14:Ce,Tb.The fluorescent and excitation spectra of Gdp5O14,Gdp5O14:Ce,Gdp5O14:Tb and GdxY-1xP5O14:Ce,Tb and absorption spectrum of Gdp5O14 have been studied.The results show that as x is larger than 0.7.the energy transfer from Ce3+ via Gd3+to Tb3+ is obvious.The main reason for the energy transfer of Ce→Gd→Tb being efficient in the region x>0.7 is that the spectral overlap between Ce3+ emission spectrum and Gd3+ absorption spectrum increases and the structure changes from monoclinic Ⅱ(C2/c) layer structure(x<0.7) to monoclinic I(P21/c) ribbon structure.
文摘Preparation, structure and spectral properties of rare earth pentaphosphates Gd_xY_(1-x)P_5O_(14): Ce, Tb have been investigated. When x>0. 7, the pentaphosphates belong to monoclinic crystal system Ⅰ with space group P2_1/c (C). When x≤0. 7. they belong to monoclinic crystal system Ⅱ with C2/c (C). The fluorescent and excitation spectra of Gdp_5O_(14), GdP_5O_(14): Ce. GdP_5O_(14) : Tb and Gd_xY_(1-x)P_5O_(14) : Ce, Tb have been studied and the energy transfer phenomenon from Ce(3+)→Gd(3+)→Tb(3+) by the medium of Gd(3+) sublattice has been determined.
基金Project supported bythe U.S .Department of Energy ,Office of Basic Energy Sciences , Materials Science and Engineering Division and Astronautics Corporation of America , Milwaukee , Wisconsin
文摘Magnetic refrigeration is a revolutionary, efficient, environmentally friendly cooling technology, which is on the threshold of commercialization. The magnetic rare earth materials are utilized as the magnetic refrigerants in most cooling devices, and for many cooling application the Nd2Fe14B permanent magnets are employed as the source of the magnetic field. The status of the near room temperature magnetic cooling was reviewed.
基金supported by grants from the National Natural Science Foundation of China(grant no.31970270)Y.W.,the Taishan Scholar Foundation to Y.W.,the National Research and Development Program of China(2021YFF1000401)+1 种基金Y.W.,and the National Natural Science Foundation of China(grant no.32200228)the Natural Science Foundation of Shandong Province(grant no.ZR2020QC028)to H.F.
文摘Nitrogen(N)deficiency causes early leaf senescence,resulting in accelerated whole-plant maturation and severely reduced crop yield.However,the molecular mechanisms underlying N-deficiency-induced early leaf senescence remain unclear,even in the model species Arabidopsis thaliana.In this study,we identified Growth,Development and Splicing 1(GDS1),a previously reported transcription factor,as a new regulator of nitrate(NO3)signaling by a yeast-one-hybrid screen using a NO3enhancer fragment from the promoter of NRT2.1.We showed that GDS1 promotes NO3 signaling,absorption and assimilation by affecting the expression of multiple NO3 regulatory genes,including Nitrate Regulatory Gene2(NRG2).Interestingly,we observedthat gds1mutants show early leaf senescence as well as reduced NO3-contentand Nuptake under N-deficient conditions.Further analyses indicated that GDS1 binds to the promoters of several senescence-related genes,including Phytochrome-lnteracting Transcription Factors 4 and 5(PIF4 and PIF5)and represses their expression.Interestingly,we found that N deficiency decreases GDS1 protein accumulation,and GDS1 could interact with Anaphase Promoting Complex Subunit 10(APC10).Genetic and biochemical experiments demonstrated that Anaphase Promoting Complex or Cyclosome(APC/C)promotes the ubiquitination and degradation of GDS1 under N deficiency,resulting in loss of PIF4 and PiF5 repression and consequent early leaf senescence.Furthermore,we discovered that overexpression of GDS1 could delay leaf senescence and improve seed yield and N-use efficiency(NUE)in Arabidopsis.In summary,our study uncovers a molecular framework illustrating a new mechanism underlying low-N-induced early leaf senescence and provides potential targets for genetic improvement of crop varieties with increased yield and NUE.
