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]

基于光致变色效应的BaMgSiO4:Bi3+陶瓷的发光性质调控及信息的可逆写入、擦除和读出研究（英文）

光存储技术与传统固态存储和磁存储相比有许多优点,如成本低、可重复性存储.因此,光存储的需求正在持续增长.本文研究了铋掺杂的硅酸镁钡陶瓷的光致变色及光致发光现象.在紫外线(254 nm)和532 nm激光交替辐照下,实现了陶瓷在灰色与粉红色之间的可逆转变.研究证实MgSiO4:Bi^3+陶瓷的可逆光致变色来源于基质中的氧空位陷阱对电子的俘获和释放.基于可逆光致变色效应在陶瓷表面制作不同颜色的图案,实现了光信号的双模式存储和擦除.同时,在光致变色过程中实现了光致发光的可逆调控;通过这种可逆的发光调控行为,实现存储信息的读出;此外,变色和漂白的程度与光照射时间有关,因此可实现多通路编码存储,有望提高光存储容量.

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.

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.