Vacancy defect MoSeTe embedded in N and F co-doped carbon skeleton for high performance sodium ion batteries and hybrid capacitors

Sodium-ion batteries(SIBs) and hybrid capacitors(SIHCs) have garnered significant attention in energy storage due to their inherent advantages,including high energy density,cost-effectiveness,and enhanced safety.However,developing high-performance anode materials to improve sodium storage performa nce still remains a major challenge.Here,a facile one-pot method has been developed to fabricate a hybrid of MoSeTe nanosheets implanted within the N,F co-doped honeycomb carbon skeleton(MoSeTe/N,F@C).Experimental results demonstrate that the incorporation of large-sized Te atoms into MoSeTe nanosheets enlarges the layer spacing and creates abundant anion vacancies,which effectively facilitate the insertion/extraction of Na^(+) and provide numerous ion adsorption sites for rapid surface capacitive behavior.Additionally,the heteroatoms N,F co-doped honeycomb carbon skeleton with a highly conductive network can restrain the volume expansion and boost reaction kinetics within the electrode.As anticipated,the MoSeTe/N,F@C anode exhibits high reversible capacities along with exceptional cycle stability.When coupled with Na_(3)V_(2)(PO_(4))_(3)@C(NVPF@C) to form SIB full cells,the anode delivers a reversible specific capacity of 126 mA h g^(-1) after 100 cycles at 0.1 A g^(-1).Furthermore,when combined with AC to form SIHC full cells,the anode demonstrates excellent cycling stability with a reversible specific capacity of50 mA h g^(-1) keeping over 3700 cycles at 1.0 A g^(-1).In situ XRD,ex situ TEM characterization,and theoretical calculations(DFT) further confirm the reversibility of sodium storage in MoSeTe/N,F@C anode materials during electrochemical reactions,highlighting their potential for widespread practical application.This work provides new insights into the promising utilization of advanced transition metal dichalcogenides as anode materials for Na^(+)-based energy storage devices.

Optimal design of Er/Yb co-doped fiber amplifiers with an Yb-band fiber Bragg grating

In this paper, Er/Yb co-doped fiber amplifiers(EYDFAs) with an Yb-band fiber Bragg grating(FBG) at the pump end to improve the performance of the amplifier is systematically studied. The influence of the reflectivity and center wavelength of the FBG along with the gain-fiber length on the performance of an EYDFA are numerically analyzed. The results show that the wavelength of the FBG has critical influence on the efficiency of the EYDFA,whereas the requirement to its reflectivity is relaxed. It is an effective and promising way to improve the efficiency of a high-power pumped EYDFA by introducing a suitable Yb-band FBG at the pump end. Based on the analysis of the underlying principles, suggestions for the practical design and possible further improvement strategies are also proposed.

Rate equation model analysis on the infrared and upconversion emission of Er/Yb co-doped borate-silicate glass

Er/Yb co-doped borate-silicate glasses with various Yb concentrations were fabricated by high-temperature solid-reaction method.The photoluminescence spectra around 1.55 μm and the visible upconversion spectra were measured.The radiative lifetime of Er-4I13/2,com-pared with the measured one,was obtained by Judd-Ofelt theory based on the absorption spectra.A rate equation model for Er/Yb co-doped system has been established based on the data obtained from the measurements,including the absorption and emissio...

Pr,Yb,Ho:GdScO_(3)晶体生长及光谱性能

2.7-3.0μm波段激光在很多领域具有重要应用,为探索和发展该波段新型晶体材料,本文采用提拉法生长出Pr,Yb,Ho:GdScO_(3)晶体,通过共掺入Pr3+离子以达到衰减Ho^(3+):^(5)I_(7)能级寿命的目的.采用X射线衍射测试得到了晶体的粉末衍射数据,测量了拉曼光谱,并对晶体的拉曼振动峰进行指认,对Pr,Yb,Ho:GdScO_(3)晶体的透过光谱、发射光谱和荧光寿命进行表征.Yb^(3+)的最强吸收峰在966 nm,吸收峰半峰宽为90 nm;2.7-3.0μm波段最强发射峰在2850 nm,半峰宽为70 nm;Ho^(3+):^(5)I_(6)和^(5)I_(7)能级寿命分别为1094μs和56μs.与Yb,Ho:GdScO_(3)晶体相比,Yb^(3+)的吸收峰和2.7-3.0μm的发射峰半峰宽明显展宽,同时下能级寿命显著减小,计算表明Ho^(3+):^(5)I_(7)与Pr^(3+):^(3)F_(2)+^(3)H_(6)能级之间能实现高效的能量传递.以上结果表明Pr,Yb,Ho:GdScO_(3)晶体是性能更优异的2.7-3.0μm波段激光材料.

水平定向结晶法生长浓度渐变Yb∶YAG激光晶体及光谱性能研究

本文采用水平定向结晶(HDC)法成功生长出180 mm×81 mm×16 mm的浓度渐变Yb∶YAG激光晶体,从放肩部位和尾部分别获取了尺寸为40 mm×40 mm×7 mm、70 mm×70 mm×7 mm的Yb∶YAG激光晶体板条各两件。采用632 nm激光、偏光应力仪对晶体板条的光学性质进行检测,实验结果发现靠近晶坯自由表面的板条内部通透,无散射光路,应力较小且分布均匀,表明该晶体板条具有优异的光学质量。进一步测试分析了晶体板条不同位置处的吸收光谱,根据935 nm波长处的吸收系数计算出Yb^(3+)的掺杂浓度,发现40 mm×40 mm×7 mm的激光晶体板条中Yb^(3+)掺杂浓度沿晶体生长方向逐步增加,浓度梯度约为0.42%/cm;而70 mm×70 mm×7 mm的激光晶体板条中Yb^(3+)掺杂浓度几乎保持不变,约为4.50%。

谷子SiNF-YB亚家族基因的单倍型与功能分析

谷子属于短日照植物,是我国北方重要的杂粮作物,随着对谷子的深入研究,越来越多与逆境相关的转录因子被发现,其中NF-Y家族便是一类可以与启动子中CCAAT-box相结合的转录因子,包括3个亚家族NF-YA、NF-YB、NF-YC。本研究针对谷子SiNF-YB亚家族的14个基因进行研究,通过亚细胞定位分析,发现该亚家族中除了SiNF-YB8和SiNF-YB15其余成员主要定位于细胞核中。顺式作用元件分析显示,在各成员启动子区域包含大量与非生物胁迫响应以及光周期相关的顺式作用元件。单倍型分析显示,SiNF-YB4是一个与耐旱有很强相关性的基因,有3种单倍型,其中H003是优异的抗旱单倍型;SiNF-YB12是一个与抽穗有很强相关性的基因,有H001和H002两种单倍型。转录组数据分析显示,抗旱和敏旱品种干旱处理前后,SiNF-YB5在根部的表达量存在显著性差异;在长日照与短日照条件下,SiNF-YB4在春谷和夏谷中的表达量存在显著差异。本研究结果为后续进一步探究谷子SiNF-YB亚家族基因的功能提供了重要的理论依据,同时为培育抽穗期与环境相适应的谷子抗旱品种奠定基础。

棒状结构NaGdF_(4):Yb^(3+),Er^(3+)上转换发光性能的研究

以乙二胺四乙酸二钠(EDTD-2Na)为螯合剂,采用水热法合成了棒状结构的NaGdF_(4):Yb^(3+),Er^(3+)纳米粉末。分别借助X射线衍射(XRD)、荧光光谱仪(PL)和扫描显微镜(SEM)对其晶体结构、发光强度和表面形貌进行分析和表征。探究了稀土前驱体、水热温度和水热时间的实验条件对NaGdF_(4):Yb^(3+),Er^(3+)纳米粉末上转换发光强度的影响;研究了氟源和钠源对NaGdF_(4):Yb^(3+),Er^(3+)晶体形貌和上转换发光强度的改善;同时,采用煅烧处理的方法,进一步探究样品的形貌和发光强度收到的影响。实验结果表明NH4F与NaOH作为氟源和钠源及200℃煅烧1 h得到的棒状结构NaGdF_(4):Yb^(3+),Er^(3+)的发光强度最好,色坐标(CIE)绿色发光强度从84%提升到94.88%。

欧洲葡萄NF-YB3基因克隆与表达分析

为探究VvNF-YB3基因在葡萄生长发育和响应非生物胁迫过程中的功能,以无核白为试材,克隆得到了VvNF-YB3基因编码区序列,全长为624 bp,编码207个氨基酸,蛋白质等电点6.31,不稳定指数27.66,总平均疏水指数-0.738,为一酸性、稳定的亲水蛋白。通过生物信息学分析发现,VvNF-YB3基因位于10号染色体,含有1个内含子,编码蛋白质存在1个CBFD_NFYB_HMF结构域,与河岸葡萄NF-YB3相似性最高。VvNF-YB3的二级结构中α-螺旋和无规则卷曲占比较高,三级结构为单体的螺旋-卷曲-螺旋,启动子中包含响应激素和胁迫的多个顺式作用元件。VvNF-YB3基因在葡萄的叶片、卷须、花、幼果和茎中均表达,且在成熟的叶片中表达量最高。PEG模拟的干旱、低温和高温胁迫均可影响VvNF-YB3基因的表达,VvNF-YB3为一胁迫响应基因。VvNF-YB3的互作蛋白大多是核因子Y家族的亚基,ERF、bHLH、ARF等27个转录因子可能调控VvNF-YB3基因的表达。由此推测,VvNF-YB3基因可能通过受到上游转录因子的调控并与其他NF-Y蛋白互作响应各种环境胁迫。

Ultralong nitrogen/sulfur Co-doped carbon nano-hollowsphere chains with encapsulated cobalt nanoparticles for highly efficient oxygen electrocatalysis

The development of simple and effective strategies to prepare electrocatalysts,which possess unique and stable structures comprised of metal/nonmetallic atoms for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),is currently an urgent issue.Herein,an efficient bifunctional electrocatalyst featured by ultralong N,S-doped carbon nano-hollow-sphere chains about 1300 nm with encapsulated Co nanoparticles(Co-CNHSCs)is developed.The multifunctional catalytic properties of Co together with the heteroatom-induced charge redistribution(i.e.,modulating the electronic structure of the active site)result in superior catalytic activities toward OER and ORR in alkaline media.The optimized catalyst Co-CNHSC-3 displays an outstanding electrocatalytic ability for ORR and OER,a high specific capacity of 1023.6 mAh gZn^(-1),and excellent reversibility after 80 h at 10mA cm^(-2)in a Zn-air battery system.This work presents a new strategy for the design and synthesis of efficient multifunctional carbon-based catalysts for energy storage and conversion devices.

宽温区Yb∶YAG板条激光模块热畸变仿真研究

本文对不同冷却温度下的Yb:YAG晶体板条激光模块高功率运转时的温度场、应力场及对应的热畸变进行了仿真分析研究。结果显示,随着冷却温度从300 K降低至77K,板条的温度梯度热应力与应变都明显降低。当冷却温度为77 K时,最大主应力为4.14 MPa,仅为常温时的15.6%,最大主应变为3.82×10^(-5),仅为常温时的6%。为了分析Yb:YAG晶体板条激光模块不同冷却温度下输出激光的光束质量,以确定其最佳运转温度,我们采用光线追迹的方法,对单程通过板条的1030 nm探测光进行仿真。可以看到,当冷却温度为77 K时,远场光斑能量更为集中,且探测光光程差的PV值为0.7941μm,仅为300 K时的59.6%。模拟结果表明低温运转有利于Yb:YAG晶体板条激光模块产生高功率高光束质量激光输出,这为高功率高光束质量Yb:YAG晶体板条激光的设计工作奠定了基础。

Rationally designed hollow carbon nanospheres decorated with S,P co-doped NiSe_(2) nanoparticles for high-performance potassium-ion and lithium-ion batteries

Hollow nanostructures with external shells and inner voids have been proved to greatly shorten the transport distance of ions/electrons and buffer volume change,especially for the large-sized potassium-ions in secondary batteries.In this work,hollow carbon(HC) nanospheres embedded with S,P co-doped NiSe_(2)nanoparticles are fabricated by "drop and dry" and "dissolving and precipitation" processes to form Ni(OH)2nanocrystals followed by annealing with S and P dopants to form nanoparticles.The resultant S,P-NiSe_(2)/HC composite exhibits excellent cyclic performance with 131.6 mA h g^(-1)at1000 mA g^(-1)after 3000 cycles for K^(+)storage and a capacity of 417.1 mA h g^(-1)at 1000 mA g^(-1)after1000 cycles for Li^(+)storage.K-ion full cells are assembled and deliver superior cycling stability with a ca pacity of 72.5 mA h g^(-1)at 200 mA g^(-1)after 500 cycles.The hollow carbon shell with excellent electrical conductivity effectively promotes the transporta tion and tolerates large volume variation for both K^(+)and Li^(+).Density functional theory calculations confirm that the S and P co-doping NiSe_(2) enables stronger adsorption of K^(+)ions and higher electrical conductivity that contributes to the improved electrochemical performance.

Nitrogen and phosphorus co-doped activated carbon induces high density Cu^(+)active center for acetylene hydrochlorination

This work aims to solve the problems of low reaction activity of Cu-based catalysts and agglomeration of active centers in acetylene hydrochlorination.Cu-based catalysts supported by NAP co-doped activated carbon(AC)with different content(mCu-xNP/AC)were manufactured and applied in the acetylene hydrochlorination reaction.It was found that the doping of carriers N and P induced the transformation of Cu^(2+)to Cu^(+),and the catalytic activity was markedly improved.Under the optimal reaction temperature of 220℃,the gas hourly space velocity(GHSV)of C_(2)H_(2)was 90 h^(-1)and V_(HCl):V_(C_(2)H_(2))was 1.15.The initial activity of the 5%Cu-30 NP/AC catalyst reached 95.59%.Through some characterization methods showed the addition of N and P improved the dispersion of Cu in carbon,which increased the ratio of Cu^+/Cu^(2+).The measurement results confirmed that the chemisorption capacity of mCu-xNP/AC for C_(2)H_(2)decreased slightly,and the chemisorption capacity for HCl increased significantly,which was the reason for the increased activity of the catalyst.The conclusion provides a reference for the development of acetylene hydrochlorination Cu catalyst.

Construction of N,O co-doped carbon anchored with Co nanoparticles as efficient catalyst for furfural hydrodeoxygenation in ethanol

Hydrodeoxygenation of furfural(FF)into 2-methylfuran(MF)is a significant biomass utilization route.However,designing efficient and stable non-noble metal catalyst is still a huge challenge.Herein,we reported the N,O co-doped carbon anchored with Co nanoparticles(Co-SFB)synthesized by employing the organic ligands with the target heteroatoms.Raman,electron paramagnetic resonance(EPR),electrochemical impedance spectroscopy(EIS),and X-ray photoelectron spectroscopy(XPS)characterizations showed that the co-doping of N and O heteroatoms in the carbon support endows Co-SFB with enriched lone pair electrons,fast electron transfer ability,and strong metal-support interaction.These electronic properties resulted in strong FF adsorption as well as lower apparent reaction activation energy.At last,the obtained N,O co-doped Co/C catalyst showed excellent catalytic activity(nearly 100 mol%FF conversion and 94.6 mol%MF yield)and stability for in-situ dehydrogenation of FF into MF.This N,O co-doping strategy for the synthesis of highly efficient catalytic materials with controllable electronic state will provide an excellent opportunity to better understand the structure-function relationship.

Spectroscopic properties and mechanism of Tm^(3+)/Er^(3+)/Yb^(3+) co-doped oxyfluorogermanate glass ceramics containing BaF_2 nanocrystals

Transparent Tm^3＋/Er^3＋/yb^3＋ co-doped oxyfluorogermanate glass ceramics containing BaF2 nanocrystals are prepared. Under excitation of a 980-nm laser diode （LD）, compared with the glass before heat treatment, the Tm^3＋/Er^3＋/yb^3＋ co-doped oxyfluorogermanate glass ceramics can emit intense blue, green and red up-conversion luminescence and Stark- split peaks; X-ray diffraction （XRD） and transmission electron microscope （TEM） results show that BaF2 nanocrystals with an average diameter of 20 nm are precipitated from the glass matrix. Stark splitting of the up-conversion luminescence peaks in the glass ceramics indicates that Tm^3＋, Er^3＋ and （or） Yb^3＋ ions are incorporated into the BaF2 nanocrystals. The up-conversion luminescence intensities of Tm^3＋, Er^3＋ and the splitting degree of luminescence peaks in the glass ceramics increase significantly with the increase of heat treat temperature and heat treat time extension. In addition, the possible energy transfer process between rare earth ions and the up-conversion luminescence mechanism are also proposed.

基于稀土掺杂上转换纳米材料NaYF_(4):Yb,Er@TGA直接对金属离子进行定量分析的方法探究

目的:基于荧光猝灭或增强机制,构建稀土掺杂上转换纳米材料NaYF_(4):Yb,Er@TGA直接对金属离子进行定量分析的方法,实现对金属离子快速、准确、灵敏检测。方法:通过溶剂热法制备出性能优良的稀土掺杂上转换纳米材料NaYF_(4):Yb,Er@TGA,并对其进行表征;通过测量14种常见的金属离子对NaYF_(4):Yb,Er@TGA荧光强度的影响,筛选能够引起NaYF_(4):Yb,Er@TGA荧光强度增强或下降,且与金属离子浓度呈线性关系的金属离子类型,进而建立检测新方法。结果:金属离子Mg^(2+)、Fe^(3+)分别在浓度范围为0~7.00μg/mL、0~6.00μg/mL与NaYF_(4):Yb,Er@TGA的荧光强度呈现良好的线性关系,其标准曲线方程的线性系数分别为0.9924、0.9982,检出限分别为1.79μg/mL、1.30μg/mL,加标回收率分别为95.5%~98.8%、92.5%~97.8%,方法相对标准偏差分别为4.05%、8.18%。结论:该方法检测限低、准确度较高、精密度较好,有望用于实际样品中Mg^(2+)、Fe^(3+)定量分析。

Intense up-conversion emissions of yb3＋/Dy3＋ co-doped A12O3 nanopowders prepared by non-aqueous sol-gel method＊

yb3＋/Dy3＋ co-doped A1203 nanopowders have been prepared by the non-aqueous sol-gel method and their up- conversion photoluminescence spectra are measured under excitation by a 980-nm semiconductor laser. The results show that there are comparatively abundant spectra of up-conversion emissions centered at 378, 408, 527 and 543, and 663 nm, corresponding to 4C9/2→ 6H13/2, 4C9/2→ 6Hll/2, 4115/2 → 6H13/2, and 4F9/2 →6Hll/2 transitions of Dy3＋, respectively. Two-photon and three-photon processes are involved in ultraviolet, violet, green, and red up-conversion emissions. The energy transition between Yb3＋ and Dy3＋ is discussed.

基于零声子线泵浦的高效率Yb∶YAG薄片激光器

高功率激光器在工业应用领域的需求不断增长,提高光-光转化效率是降低其生产制造成本的关键途径。针对提高激光器光-光转化效率所面临的增益介质的热负荷问题,利用锁定波长的969 nm“零声子线”泵浦、自主研制的高性能Yb∶YAG薄片晶体和48冲程泵浦系统等,搭建了高效的连续Yb∶YAG薄片激光器系统,实现了最高输出功率373 W,光-光转化效率可达73.37%。其优异性能为后续开展千瓦级超快Yb∶YAG薄片激光器研究奠定了基础。

Optical temperature sensor based on up-conversion fluorescence emission in Yb^(3+):Er^(3+) co-doped ceramics glass

yb^3＋：Er^3＋ co-doped oxy-fluoride ceramics glass has been prepared. The mechanism of up-conversion emissions about Er^3＋ was discussed, and the temperature properties of green up-conversion fluorescence between 303 and 823 K were investigated. The results show that the sensitivity of this sample reaches its maximum value, about 0.0047 K^-1, when the temperature is 383 K, indicating that this kind of sample can be used as high temperature and high sensitivity optical temperature sensor.

Gd-Sc(Yb)-YSZ陶瓷涂层的隔热性能及抗CMAS热腐蚀性能研究

采用两步水热法制备了组成分别为Zr_(0.87)Y_(0.07)Gd_(0.02)Sc_(0.04)O_(1.94)(Gd-Sc-YSZ)和Zr_(0.87)Y_(0.08)Gd_(0.03)Yb_(0.02)O_(1.94)(Gd-Yb-YSZ)的两种含有半空心球的陶瓷粉末。将上述陶瓷粉末造粒并通过大气等离子喷涂在渗铝涂层表面分别制备两种陶瓷层,组成了陶瓷层/渗铝层/NiCrAlY/DZ40M热障涂层,并分别测试了这两种热障涂层和传统YSZ涂层在热源温度1050℃和1400℃下的隔热温度及在1250℃下的抗CMAS热腐蚀性能。结果表明:Gd-Yb-YSZ和Gd-Sc-YSZ两种涂层在1400℃保温6h后其表面完好且没有脱落,两种涂层主要由亚稳四方相(t'-ZrO_(2))组成,这说明这两种涂层均有望在1400℃长期使用,在此高温条件下渗铝层对陶瓷层在NiCrAlY合金表面的黏结稳定性具有关键作用。在1050℃和1400℃热源条件下,相比于YSZ涂层,Gd-Yb-YSZ、Gd-Sc-YSZ涂层的隔热温度更高,且其热导率仅为YSZ涂层的0.35~0.5倍,即通过掺杂Gd、Yb、Sc,YSZ涂层的隔热效果显著提升。YSZ涂层经历1250℃的CMAS热腐蚀1h后发生边缘脱落,Gd-Yb-YSZ涂层在6h后仅中央变粗糙,而Gd-Sc-YSZ涂层6h后仍完好无损。Gd-Sc-YSZ和Gd-Yb-YSZ涂层的抗CMAS热腐蚀性能远优于YSZ涂层,特别是Gd-Sc-YSZ涂层。

YB45包装机商标纸内舌微量弯曲装置的设计

目的解决YB45硬盒包装机在生产过程中出现的商标纸内舌插盖导致小盒盖打不开的问题。方法根据YB45包装机自身的结构特点,对商标纸内舌涂胶装置及折叠装置进行改进,设计一种小盒商标纸内舌微量弯曲装置。此装置可以对商标纸内舌部位进行微量弯曲,内舌弯曲后的小盒商标纸在折叠过程中能有效防止烟包小盒插盖。结果使用商标纸内舌微量弯曲装置后,小盒插盖的数量由改进前的5.3盒/月降至0盒/月;机车效率由改进前的96.3%增至96.9%;质量得分由改进前的97.9分增长为98.5分。结论商标纸内舌微量弯曲装置能有效解决YB45硬盒包装机生产过程中出现的小盒插盖问题,有效保障了YB45包装机小盒包装的产品质量,同时也提升了机车效率。