Multi-site occupancies and dependent photoluminescence of Ca_(9)Mg_(1.5)(PO_(4))_(7):Eu^(2+) phosphors:A bifunctional platform for optical thermometer and plant growth lighting

Herein,we demonstrate an optical thermometer based on single Eu^(2+)doped Ca_(9)Mg_(1.5)(PO_4)_7 phosphors,which were prepared by traditional solid-state reaction technique under a reduction atmosphere.Considerations on the bond length obtained by the crystal structure refinement and the dependent photoluminescence performances allow to assign the two distinct emission bands to Eu^(2+)ions occupied Cal-Ca3 and Mg2 sites.Moreover,the blue and red emitting bands perfectly match with the photosynthetic action spectrum,which can enhance the indoor plant photosynthesis.The optimal doping content of Eu^(2+)ions in this Ca_(9)Mg_(1.5)(PO_(4))_(7)system is 3 mol%.The corresponding concentration quenching effect is verified as dipole-dipole interaction with the critical distance of 3.315 nm.Furthermore,by exploiting the fluorescence intensity technique,the optical thermal resistance properties of Ca_(9)Mg_(1.5)(PO_4)_7:Eu^(2+)are identified based on the temperature dependent emission spectra in a range of 303-523 K.In detail,the maximum absolute and relative sensitivity S_(a)and S_(r)of Ca_9Mg_(1.5)(PO_(4))_(7):Eu^(2+)thermometer are as high as 0.637%/K and 0.3155 K^(-1),respectively.Consequently,the Eu^(2+)doped Ca_(9)Mg_(1.5)(PO_(4))_(7)phosphors establish a bifunctional platfo rm for both optical the rmometer and plant growth lighting via multi-site occupancies.

Arbuscular mycorrhizal symbiosis facilitates apricot seedling(Prunus sibirica L.)growth and photosynthesis in northwest China

Arbuscular mycorrhizal(AM)fungi can successfully enhance photosynthesis(P_(n))and plants growth in agricultural or grassland ecosystems.However,how the symbionts affect species restoration in sunlight-intensive areas remains largely unexplored.Therefore,this study’s objective was to assess the effect of AM fungi on apricot seedling physiology,within a specific time period,in northwest China.In 2010,an experimental field was established in Shaanxi Province,northwest China.The experimental treatments included two AM fungi inoculation levels(0 or 100 g of AM fungal inoculum per seedling),three shade levels(1900,1100,and 550µmol m^(−2) s^(−1)),and three ages(1,3,and 5 years)of transplantation.We examined growth,Pn,and morphological indicators of apricot(Prunus sibirica L.)seedling performances in 2011,2013,and 2015.The colonization rate in mycorrhizal seedlings with similar amounts of shade is higher than the corresponding controls.The mycorrhizal seedling biomass is significantly higher than the corresponding non-mycorrhizal seedling biomass.Generally,P_(n),stomatal conductance(G_(s)),transpiration rate(T_(r)),and water use efficiency are also significantly higher in the mycorrhizal seedlings.Moreover,mycorrhizal seedlings with light shade(LS)have the highest Pn.WUE is increased in non-mycorrhizal seedlings because of the reduction in T_(r),while T_(r) is increased in mycorrhizal seedlings with shade.There is a significant increase in the N,P,and K fractions detected in roots compared with shoots.This means that LS had apparent benefits for mycorrhizal seedlings.Our results also indicate that AM fungi,combined with LS,exert a positive effect on apricot behavior.

A novel Li^(+)-doped MgLuGaO_(4)phosphor with stable white-light emission and long persistent luminescence

In recent years,white persistent luminescence materials have received extensive attention due to the potential application of white light in the field of plant growth lighting.The white persistent luminescence materials synthesized by traditional methods either have strict requirements on the concentration of doped ions or cannot produce white light continuously and stably due to different decay rates of various emission centers,which limits their further application.In our work,we successfully synthesized a novel Li^(+)-doped MgLuGaO_(4)phosphor with stable white-light emission and long persistent luminescence.The broadband emission of MgLuGaO_(4):Li^(+)is mainly located at 350-650 nm,which has no change at different decay time,showing stable white-light emission.The persistent luminescence intensity is increased by 3.8 times and the persistent luminescence time is extended from 24 h to more than 36 h by doping Li+ions.Stable white-light and long persistent luminescence emission make it promising to be used in plant growth lighting.