Biomass Productivity of Taiwania flousiana Plantation and Successive Rotation Plantation of Cunninghamia lanceolata in Cutover Forest Land of C.Lanceolata

[Objectives] The aim was to reveal the accumulation characteristics and differences of biomass productivity of Taiwania flousiana plantation and successive rotation plantation of Cunninghamia lanceolata .[Methods] The biomass and productivity of the 23-year-old T. flousiana plantation and successive rotation plantation of C. lanceolata were studied at Nandan Shankou Forestry Farm of Guangxi., China.[Results] There were differences in the biomass distribution of different organs of T. flousiana plantation and successive rotation plantation of C.lanceolata. The biomass for the T. flousiana plantation was distributed in the order of stem 〉 branch 〉 leaves 〉 bark, and the successive rotation plantations of C. lanceolata was stem〉 root 〉 branch 〉 bark 〉 leaves. The biomass of tree layer of 23-years-old T. flousiana plantation and successive rotation plantations were 195.21 and 136.82 t/hm^2, respectively, including 113.32 and 87.91 t/hm^2 of economic biomass （stem）. The annual net productivity of tree layer of the 2 plantations were 8.49 and 5.95 t/（hm^2·a）, respectively, including 5.14 and 3.82 t/（hm^2·a） of stem. Therefore, T. flousiana plantation has higher biomass accumulation ability than that of successive rotation plantations of C.lanceolata, and can be used as an excellent substitute tree species for the regeneration of C.lanceolata cutover plantation.[Conclusions]

NIR regeneration and visible luminescence modification in photochromic glass:A novel encryption and 3D optical storage medium

Photochromic glass shows great promise for 3D optical information encryption and storage applications.The formation of Ag nanoclusters by light irradiation has been a significant development in the field of photochromic glass research.However,extending this approach to other metal nanoclusters remains a challenge.In this study,we present a pioneering method for crafting photochromic glass with reliably adjustable dual-mode luminescence in both the NIR and visible spectra.This was achieved by leveraging bimetallic clusters of bismuth,resulting in a distinct and novel photochromic glass.When rare-earth-doped,bismuth-based glass is irradiated with a 473 nm laser,and it undergoes a color transformation from yellow to red,accompanied by visible and broad NIR luminescence.This phenomenon is attributed to the formation of laserinduced(Bi^(+),Bi^(0))nanoclusters.We achieved reversible manipulation of the NIR luminescence of these nanoclusters and visible rare-earth luminescence by alternating exposure to a 473 nm laser and thermal stimulation.Information patterns can be inscribed and erased on a glass surface or in 3D space,and the readout is enabled by modulating visible and NIR luminescence.This study introduces a pioneering strategy for designing photochromic glasses with extensive NIR luminescence and significant potential for applications in highcapacity information encryption,optical data storage,optical communication,and NIR imaging.The exploration of bimetallic cluster formation in Bi represents a vital contribution to the advancement of multifunctional glass systems with augmented optical functionalities and versatile applications.

Reversible 3D optical data storage and information encryption in photo-modulated transparent glass medium

Transparent glass has been identified as a vital medium for three-dimensional(3D)optical information storage and multi-level encryption.However,it has remained a challenge for directly writing 3D patterning inside a transparent glass using semiconductor blue laser instead of high-cost femtosecond laser.Here,we demonstrate that rare earth ions doped transparent glass can be used as 3D optical information storage and data encryption medium based on their reversible transmittance and photoluminescence manipulation.The color of tungsten phosphate glass doped with rare earth ions change reversibly from light yellow to blue upon alternating 473 nm laser illumination and temperature stimulation,resulting in the reversible luminescence modulation.The information data could be repeatedly written and erased in arbitrary 3D space of transparent glass,not only showing the ability of the excellent reproducibility and storage capacity,but also opening opportunities in information security.The present work expands the application fields of luminescent glass,and it is conducive to develop a novel 3D data storage and information encryption media.

Large reversible upconversion luminescence modification and 3D optical information storage in femtosecond laser irradiation-subjected photochromic glass

Fast response,high luminescence contrast,three-dimensional(3D)storage,and nondestructive reading are key factors for the optical storage application of photochromic materials.Femtosecond(fs)laser direct writing technology with multiphoton nonlinear absorption is becoming a useful tool for microprocessing functional units in the 3D space of glass owing to its remarkable advantages,such as a fast processing speed and high processing accuracy.Herein,the photochromism of transparent glass codoped with rare-earth ions was investigated under 800-nm fs laser irradiation,affording a fast response.The photochromic glass achieves an upconversion luminescence(UCL)modification of 92%.The photochromic glass can be bleached back to its original color using heat treatment.The transmittance and UCL modification show excellent reproducibility under alternating stimulations between 800-nm fs laser irradiation and heat treatment.The data can be written in the interior of the transparent photochromic glass using 800-nm fs laser irradiation,facilitating 3D information storage.These results suggest that the 800-nm fs laser irradiation-subjected photochromic glass is an ideal optical data storage medium.

Reversible multiplexing for optical information recording, erasing, and reading-out in photochromic BaMgSiO4:Bi3+ luminescence ceramics

Optical data storage technology has many advantages over the traditional solid-state and magnetic storage technology,such as low cost,multi-dimensional storage,and rewritable capability.Therefore,the optical data storage technology has been in increasing demand for optical storage media.Herein,the photochromic and photoluminescence properties of BaMgSiO4:Bi^3+ceramics were investigated.The BaMgSiO4:Bi^3+ceramics showed reversible photochromism from gray to pink upon alternating the 254 nm ultraviolet light and 532 nm laser irradiation.This is caused by the electron trapping and de-trapping in the oxygen vacancies of the BaMgSiO4:Bi^3+host.This reversible behavior of photochromism was applied to fabricate different patterns on the surface of the BaMgSiO4:Bi^3+ceramics,which exhibited the reversible dual-mode optical information recording and erasing abilities.The photoluminescence reversible modulation of the BaMgSiO4:Bi^3+ceramics was obtained through the photochromic phenomenon.This modification behavior of luminescence could be applied to read-out the recording information in the BaMgSiO4:Bi^3+ceramics.The coloration and bleaching of BaMgSiO4:Bi^3+ceramics were dependent on the time of light stimulation,which facilitated multiplexing encoding.This photoluminescence and photochromism multiplexing of the BaMgSiO4:Bi^3+ceramics enhanced the optical data storage capability.

Intense single-band red upconversion emission in BiOCl:Er3+ layered semiconductor via co-doping Ho3+

Exploring a new tuning way to facilely realize single-band red emission in trivalent rare-earth ions(RE3+) doped upconversion(UC) materials is still desirable.In this work,the intense single-band red emission is achieved by co-doping only Ho3+in the BiOCl:Er3+ under 1550 nm excitation.In the BiOCl layered host,co-doping Ho3+can further enhance the red emission and simultaneously suppress the green emission of Er3+,and thus obviously improve the red-to-green(R/G) ratio.It is found that Ho3+does not se rve as ene rgy trapping through the 5 I6 state as in traditional UC materials but acts as ET bridge(4 S3/2,2 H11/2(Er3+)→5 F4,5 S2(Ho3+)→4 F9/2(Er3+)).The tuning mechanism of Ho3+is discussed in detail and further confirms through a comparative experiment.Our research gives an unusual perspective to tune the UC behavior of Er3+through co-doping Ho3+,which might be inspiring for achievement of single-band red UC emission.

Reply to Comment on"Reversible 3D optical data storage and information encryption in photomodulated transparent glass medium

Dear Editor,Tungsten-based photochromic materials are well known,suchastungsten-phosphateglasses,tungsten-telluriteglasses,andtungsten-borateglasses'.Photoluminescence glasses exhibit a wide range of application in the fields of display,lighting,laser and optical thermometry,et al.Combination of photochromic and luminescence can extend the application of luminescence materials2-7.Our focus is not on the development of new photochromic materials,but on the control of luminescence through photochromic reaction,especially achieved the real complex threedimensional patterns using laser directly writing technology in photo-modulated transparent glass.In our work2,the three-dimensional optical data storage and information encryption application of photochromic glass with luminescence was obtained.

Preparation and upconversion luminescence modification of YbPO4:Er3+inverse opal heterostructure

Photonic crystal heterostructures composed of YbPO4：Er^（3＋） inverse opal and polystyrene opal were prepared via a template-assisted process, which exhibited two photonic band gaps. The microstructure,phase and optical properties of photonic crystal heterostructures were investigated by x-ray diffraction,scanning electron microscopy, fluorescence spectroscopy, absorption spectroscopy, fluorescence lifetime,etc. The upconversion emission suppression caused by single photonic band gap from the following YbPO4：Er^（3＋） inverse opal or the upper opal was observed. The upconversion luminescence was strongly suppressed due to the two photonic band gap overlapping effect caused by the following YbPO4：Er^（3＋） inverse opal or the upper opal. The modified mechanisms of upconversion luminescence were discussed by the upconversion luminescence lifetime of YbPO4：Er^（3＋） photonic crystal heterostructures. The results demonstrated the modified upconversion luminescence is attributed to the photon trapping caused by Bragg reflection of photonic crystal heterostructures.

Color tunable and white light emitting via energy transfer in single-phase BiOCl:Er^(3+),Sm^(3+) phosphors for WLEDs

BiOCl crystal shows potential as efficient optical host due to its special layered structure. Here,the luminescence properties of the Er^3＋/Sm^3＋ co-doped BiOCl phosphors as single-phase phosphors were reported. Upon near ultraviolet excitation（NUV, 380 nm corresponding the ^4 I15/2→ ^4 G11/2 transition of Er^3＋ ions）, the phosphors exhibit the efficient characteristic emissions of Er^3＋ and Sm^3＋ ions simultaneously. The energy transfer（ET） from Er^3＋ to Sm^3＋ ions in the layered crystals has been validated by the variation of emission intensities and decay lifetimes respectively, which is ascribed to be a dipoledipole interaction. By virtue of the ET behavior and increasing Sm^3＋ ion concentration, the enhancing emission intensity of Sm^3＋ and the tunability of emission color from yellowish-green（0.318, 0.420） to white（0.343, 0.347） are realized. The results of our work indicate that the Er^3＋/Sm^3＋ co-doped BiOCI phosphor has a promising application serving as single component white emitting phosphors for NUV excited WLEDs.