Self-assembled S-scheme In_(2.77)S_(4)/K^(+)-doped g-C_(3)N_(4)photocatalyst with selective O_(2) reduction pathway for efficient H_(2)O_(2) production using water and air

The development of an efficient artificial H_(2)O_(2) photosynthesis system is a challenging work using H_(2)O and O_(2) as starting materials.Herein,3D In_(2.77)S_(4) nanoflower precursor was in-situ deposited on K^(+)-doped g-C_(3)N_(4)(KCN)nanosheets using a solvothermal method,then In_(2.77)S_(4)/KCN(IS/KCN)het-erojunction with an intimate interface was obtained after a calcination process.The investigation shows that the photocatalytic H_(2)O_(2) production rate of 50IS/KCN can reach up to 1.36 mmol g^(-1)h^(-1)without any sacrificial reagents under visible light irradiation,which is 9.2 times and 4.1 times higher than that of KCN and In_(2.77)S_(4)/respectively.The enhanced activity of the above composite can be mainly attributed to the S-scheme charge transfer route between KCN and In_(2.77)S_(4) according to density functional theory calculations,electron paramagnetic resonance and free radical capture tests,leading to an expanded light response range and rapid charge separation at their interface,as well as preserving the active electrons and holes for H_(2)O_(2) production.Besides,the unique 3D nanostructure and surface hydrophobicity of IS/KCN facilitate the diffusion and transportation of O_(2) around the active centers,the energy barriers of O_(2) protonation and H_(2)O_(2) desorption steps are ef-fectively reduced over the composite.In addition,this system also exhibits excellent light harvesting ability and stability.This work provides a potential strategy to explore a sustainable H_(2)O_(2) photo-synthesis pathway through the design of heterojunctions with intimate interfaces and desired reac-tion thermodynamics and kinetics.

First-Principles Investigation of Charge Transfer Mechanism of B-Doped 3C-SiC Semiconductor Material

This study delves into the charge transfer mechanism of boron (B)-doped 3C-SiC through first-principles investigations. We explore the effects of B doping on the electronic properties of 3C-SiC, focusing on a 12.5% impurity concentration. Our comprehensive analysis encompasses structural properties, electronic band structures, and charge density distributions. The optimized lattice constant and band gap energy of 3C-SiC were found to be 4.373 Å and 1.36 eV respectively, which is in agreement with previous research (Bui, 2012;Muchiri et al., 2018). Our results show that B doping narrows the band gap, enhances electrical conductivity, and influences charge transfer interactions. The charge density analysis reveals substantial interactions between B dopants and surrounding carbon atoms. This work not only enhances our understanding of the material’s electronic properties, but also highlights the importance of charge density analysis for characterizing charge transfer mechanisms and their implications in the 3C-SiC semiconductors.

双酚A通过上调Apoa 1基因的表达抑制TM3细胞睾酮合成

旨在从脂质代谢的角度探讨载脂蛋白A1(apolipoprotein A1,Apoa 1)是否介导了双酚A(bisphenol A,BPA)暴露所致小鼠睾丸间质细胞株(TM3)睾酮合成的降低。将TM3细胞随机分为不同浓度的BPA暴露剂量(0、5、10、20、40、60、80μmol·L^(-1))组,0μmol·L^(-1)BPA为对照组(CON)。给予相应剂量处理24 h后,运用CCK-8法检测TM3细胞活力,确定BPA最适染毒剂量;通过ELISA检测TM3细胞培养上清液睾酮(testosterone,T)含量;利用RT-qPCR检测TM3细胞脂质代谢相关基因Apoa1、Apoa 2(apolipoprotein A2)、Apoc 3(apolipoprotein C3)的mRNA表达水平;运用Western blot和免疫荧光方法检测APOA1蛋白表达水平;采用油红O染色观察细胞内脂滴累积情况。结果表明,20μmol·L^(-1)BPA处理24 h对TM3细胞活力无显著影响,40μmol·L^(-1)BPA处理24 h后,TM3细胞活力受到极显著抑制(P<0.01);此外,20μmol·L^(-1)BPA处理TM3细胞24 h后,培养上清液中睾酮含量极显著低于对照组(P<0.01),Apoa 1基因的mRNA表达水平及蛋白表达量极显著升高(P<0.001),但Apoa 2和Apoc 3基因的mRNA表达水平无显著变化;与对照组相比,20μmol·L^(-1)BPA处理24 h,TM3细胞的脂滴累积量极显著降低(P<0.0001)。综上,BPA可通过上调Apoa 1基因的表达水平,增强胆固醇逆向转运(reverse cholesterol transport,RCT),引起TM3细胞内的脂滴含量减少,导致TM3细胞的睾酮合成分泌降低。

Fabrication of Gd_(2)O_(3)-doped CeO_(2)thin films through DC reactive sputtering and their application in solid oxide fuel cells

Physical vapor deposition(PVD)can be used to produce high-quality Gd_(2)O_(3)-doped CeO2(GDC)films.Among various PVD methods,reactive sputtering provides unique benefits,such as high deposition rates and easy upscaling for industrial applications.GDC thin films were successfully fabricated through reactive sputtering using a Gd_(0.2)Ce_(0.8)(at%)metallic target,and their application in solid oxide fuel cells,such as buffer layers between yttria-stabilized zirconia(YSZ)/La0.6Sr0.4Co0.2Fe0.8O_(3−δ)and as sublayers in the steel/coating system,was evaluated.First,the direct current(DC)reactive-sputtering behavior of the GdCe metallic target was determined.Then,the GDC films were deposited on NiO-YSZ/YSZ half-cells to investigate the influence of oxygen flow rate on the quality of annealed GDC films.The results demonstrated that reactive sputtering can be used to prepare thin and dense GDC buffer layers without high-temperature sintering.Furthermore,the cells with a sputtered GDC buffer layer showed better electrochemical performance than those with a screen-printed GDC buffer layer.In addition,the insertion of a GDC sublayer between the SUS441 interconnects and the Mn-Co spinel coatings contributed to the reduction of the oxidation rate for SUS441 at operating temperatures,according to the area-specific resistance tests.

Lu_(2)O_(3):Yb,Tm/MC540纳米材料的制备及研究

以水热反应及后续的高温煅烧过程为合成手段,成功制备了Lu_(2)O_(3):Yb,Tm纳米材料。XRD结果显示所得样品为纯Lu2O3晶相。且SEM结果表明所得样品由不规则形状组成,粒径在100nm左右。随后通过搅拌吸附过程负载部花青(MC540)光敏剂,得到Lu_(2)O_(3):Yb,Tm/MC540纳米材料。然后以肺癌细胞(A-549细胞)为模型,研究了Lu_(2)O_(3):Yb,Tm/MC540纳米材料的抗肿瘤活性。结果表明,在650nm的红光照射下,上述材料对肺癌A-549细胞具有明显的光动力杀伤疗效。

Tm^(3+)高掺杂的NaYF_(4)纳米颗粒制备与发光性能研究

为了研究Tm^(3+)高掺杂浓度下NaYF_(4)纳米颗粒的上转换发光性能,采用热分解法合成了六方相的NaYF_(4)∶Yb^(3+)/Tm^(3+)(20%/8%)纳米颗粒,并用X射线衍射对其结构进行了表征,用透射电子显微镜对其形貌和大小进行了表征.通过搭建上转换光谱测试系统,研究了在980 nm激光激发下NaYF_(4)∶Yb^(3+)/Tm^(3+)纳米颗粒的上转换发光光谱,并分析了其发光机制.通过计算475,513,650,744,805 nm处发光强度与激发光功率间的依赖关系,证明了其上转换发光过程为双光子过程.

基于转录组学探讨Calpeptin在睾丸间质细胞系TM3中的作用机制

目的:探究Calpeptin对睾丸间质细胞(TM3)的分子调控及其机制。方法:选取对数生长期的TM3细胞分为空白对照组、Calpeptin处理组(浓度为10μmol/L),处理20min后收集细胞提取总RNA,在进行RNA质量检测后上机执行测序程序,获得mRNA表达谱。通过生物信息学技术,分析Calpeptin处理后的信号通路变化以及通路内基因的表达水平。此外应用实时荧光定量PCR(qRT-PCR)对选取的差异表达mRNA进行验证。结果:经转录组学测序分析,发现Calpeptin处理后共有63个差异表达基因,其中包括38个显著上调基因和25个显著下调基因,KEGG通路分析揭示,这些差异基因主要富集于甲状旁腺激素的合成与分泌、IL-17信号通路、Apelin信号通路、昼夜节律干扰、醛固酮的合成和分泌等相关经典通路。并通过qRT-PCR对其中12个差异mRNA基因进行表达量的验证。结论:Calpeptin能够导致TM3细胞中mRNA差异表达,这一作用可能与调控激素合成、分泌及炎症反应等过程密切相关。

Upconversion Luminescence Properties of Ho^(3+),Tm^(3+),Yb^(3+) Co-Doped Nanocrystal NaYF_4 Synthesized by Hydrothermal Method

Nanocrystal of upconversion （UC） phosphor Ho^3＋, Tm^3＋ , and Yb^3＋ co-doped NaYF4 was prepared by the hydrothermal method in the presence of the complexing agent EDTA. Under 980 nm diode laser excitation, the impact of different concentrations of Ho^3＋ ion on the UC luminescence intensity was discussed. The law of luminescence intensity versus pump power shows that the 474 nm blue emission, 538 nm green emission, and 642 nm red emission are all due to the two-photon process, while the 450 nm blue emission is a three-photon process. The UC mechanism and processes were also analyzed. The sample was characterized by transmission electron microscopy （TEM） and X-ray diffraction （XRD）. The result shows that Ho^3＋ ,Tm^3＋ , and Yb^3＋ co-doped NaYF4 prepared by the hydrothermal method exhibits a hexagonal nanocrystal.

Tm^(3+)-doped tellurite glass with Yb^(3+) energy sensitized for broadband amplifier at 1400–1700 nm bands

A kind of novel experiment was disclosed as it possessed two bands of fluorescence emission at 1.4 and 1.6 μm, which were perfectly complimentary to the current C band of optic communication. The fluorescence was based on energy transfer and up-conversion processes between Tm^3＋ and Yb^3＋ under direct pumping of 975 nm LD. The spectra and lifetimes of Tm^3＋ fluorescence in the tellurite glass were described. The corresponding fluorescence characteristics and energy migration process were analyzed by the method of lifetime and intensity comparison. The mechanism of the up-conversion based IR fluorescence was presented upon analyzing the multi-photon pumping process. The potential advantages of Tm^3＋/Yb^3＋ co-doped tellurite glass as amplifier material were concluded.

2 μm mid-infrared optical spectra of Tm3+-doped germanium gallate glasses

Glasses with the composition of 65GeO212Ga2O3-10BaO-8Li2O-5La2O3(molar ratio) doped with 1.526 wt.%, 3.006 wt.%, 5.836 wt.%, 11.028 wt.%, and 15.678 wt.% Tm2O3, respectively, were fabricated by conventional melting method. According to the absorption spectra and the Judd-Ofelt theory, the J-O strength parameters (Ω2,Ω4, Ω6) were calculated, with which the radiative transition probabilities,branching ratios and radiative lifetimes were obtained. The infrared emission spectra (with 808 nm LD excitation) at～1.47 and～1.8 μm of various concentrations of Tm3+-doped glasses were studied. The emission intensity at～1.8 μm reached to the maximum when the Tm2O3-doping concentration was near to be～3.006 wt.% (1.0 mol.%), and then decreased as doping concentration increased further. The mechanism of the fluorescence intensity change was explained with the cross-relaxation effect and the concentration quenching effect of Tm3+. Meanwhile, according to McCumber theory, the absorption and emission cross-sections corresponding to the 3F4→3H6 transitions of Tm3+ at 1.8 μm was obtained. For Tm3+-doped germanate glasses, the maximum emission cross-section reached a value higher than that re-ported for fluorozircoaluminate glasses. It is expected to be a favorable candidate host for～2.0 μm mid-inflated laser because the glass shows favorable optical spectra.

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.

Frequency Up-conversion Luminescence Properties and Mechanism of Tm^(3+) /Er^(3+)/Yb^(3+) Co-doped Oxyfluorogermanate Glasses

Oxyfluoride glasses were developed with composition 60GeO 2 ·10AlF 3 ·25BaF 2 ·（1.95-x）GdF 3 · 3YbF 3 ·0.05TmF 3 ·xErF 3 （x=0.02,0.05,0.08,0.11,0.14,0.17）in mole percent.Intense blue（476 nm）,green（524 and 546 nm）and red（658 nm）emissions which identified from the 1G 4 →3H 6 transition of Tm3＋and the（2H 11/2 ,4S 3/2 ）→4I 15/2 ,4F 9/2 →4I 15/2 transitions of Er3＋,respectively,were simultaneously observed under 980 nm excitation at room temperature.The results show that multicolor luminescence including white light can be adjustably tuned by changing doping concentrations of Er3＋ion or the excitation power.In addition,the energy transfer processes among Tm3＋,Er3＋and Yb3＋ions,and up-conversion mechanisms are discussed.

Upconversion Luminescence of Er^(3+), Tm^(3+) and Yb^(3+)Co-doped Gd_3Ga_5O_(12) Nanocrystals

A series of Er3＋, Tm3＋ and Yb3＋ doped Gd3Ga5O12 nanocrystals were prepared by a combustion method. The X-ray diffraction （XRD）, field emission scanning electron microscope （FESEM） and upconversion （UC） emission spectra were used to characterize the samples. The results of XRD indicate that Gd3Ga5O12：Er3＋, Tm3＋, Yb3＋ nanocrystals with cubic phase can be obtained. Under the excitation of a 980 nm laser, the different rare earth ions doped Gd3Ga5O12 nanoerystals show upconversion luminescence involving the green emission attributed to the ^2H11/2→^4I15/2, 4^S3/2→^4I15/2 transitions of Er3＋ ions, respectively, the red emissions assigned to the ^4F9/2→^4I15/2 transitions of Er3＋ ions and the ^1G4→^3F4 as well as 3F2,3→^3H6 transitions of Tm3＋ ions, respectively, the blue emission attributed to ^1G4→^3H6 transitions of Tm3＋ ions, and the near-infrared assigned to the ^3H4→^3H6 transitions of Tm3＋ ions. The CIE coordinates for the samples are calculated. The dependence of their upconversion luminescence properties on Yb3＋ ion concentration is investieated.

Spectroscopy and Energy Transfer in Yb^(3+) and Tm^(3+) Co-doped Gd_3Ga_5O_(12) Crystal

Yb3＋/Tm3＋ co-doped Gd3Ga5O12 single crystal with a dimension of Φ30mm×20mm was grown successfully by Czochralski method.The absorption spectrum was recorded at room temperature and used to calculate the absorption cross-section.Based on the Judd-Ofelt（J-O） theory,we obtained the three intensity parameters and spectral parameters of this crystal,such as the line strengths,oscillator strengths,radiative probabilities and radiative lifetimes as well as the fluorescent branching ratios.Room temperature fluorescence spectra and luminescence decay curves were recorded.The energy transfer between Yb3＋-Tm3＋ was observed and the mechanism was discussed.The stimulated emission cross-section of the 3F4→3H6 transition was calculated by the Füchtbauer-Ladenburg（F-L） equation.The potential laser gains for this transition were also investigated.This crystal is promising as a tunable infrared laser crystal at 2.0 μm.

Up-conversion photoluminescence characteristics of Yb^(3+):Er^(3+):Tm^(3+) co-doped borosilicate glasses

Yb^3＋：Er^3＋：Tm^3＋co-doped borosilicate glasses are prepared. Their strong up-conversion photoluminescence spectra in a range from ultra-violet to near-infrared, which are excited by a 978-nm laser diode, are measured, and the mechanisms of energy transfer among Yb^3＋ Er^3＋ and Tm^3＋ ions are discussed. The results show that there is an unexpected wavelength at 900-nm emission from Yb^3＋ Stark splitting levels to pump Tm^3＋ ions and there exists an optimum pump power. The concentration of the Tm^3＋ dopant gives rise to a prominent effect on the intensity of visible and near-infrared emissions for the yb^3＋：Er^3＋：Tm^3＋ co-doped borosilicate glasses.

Yb^(3+)和Tm^(3+)共掺透明磷酸盐微晶盐玻璃上转换发光性能

采用熔融冷却法制备了掺杂不同比例Yb^(3+)和Tm^(3+)的磷酸盐玻璃,通过在630℃保温1 h得到透明的微晶玻璃,对样品进行XRD测试,表明析出的晶体为Na_(3.6)Y_(1.8)(PO_(4))_(3),通过Jade6.0计算和TEM分析,其晶粒尺寸均在20~40 nm之间,小于可见光波长,透过率光谱表明,经过热处理之后微晶玻璃仍保持70%以上的透过率。研究了前驱体玻璃和微晶玻璃在980 nm LD泵浦下的上转换荧光光谱,微晶玻璃的上转换效率明显高于前驱体玻璃,在上转换荧光光谱中,475 nm处发射强烈的上转换蓝光,654 nm处发射微弱的红光,795 nm处发射较弱的红外光。随着Yb^(3+)掺杂浓度的增加其上转换效率先增大后减小,Yb^(3+)的掺杂浓度为0.9%时,产生浓度猝灭现象。通过分析上转发光强度与激光器泵浦功率之间的关系,在Yb^(3+)和Tm^(3+)共掺的磷酸盐微晶玻璃中,上转换蓝光、红光和红外光的发射均为双光子过程。解释了Yb^(3+)和Tm^(3+)在磷酸盐微晶玻璃中的上转换发光机制。利用CIE1931计算,可知Yb^(3+)和Tm^(3+)共掺磷酸盐微晶玻璃的上转换发光色度坐标落在了蓝光区域,有望用在光学储存、全色显示、蓝色防伪、蓝光激光玻璃等领域。

K_(3)ScF_(6)∶Tm^(3+),Yb^(3+)/CdS光催化复合材料的制备及其光催化性能研究

上转换材料与光催化剂复合可以产生吸收光谱“红移”的效果,对提高光催化剂的降解效率具有重要意义。为了提高CdS对近红外光的利用率,通过高温固相反应法合成了冰晶石结构上转换发光材料K_(3)ScF_(6)∶Tm^(3+),Yb^(3+),并采用高能球磨法将其与CdS复合制备出一种新型光催化复合材料K_(3)ScF_(6)∶Tm^(3+),Yb^(3+)/CdS。采用X射线粉末衍射(XRD)、场发射扫描电镜(SEM)、荧光光谱(PL)和紫外-可见漫反射吸收光谱对其成分、结构和性能进行了系统表征。同时,对不同复合比例下制备的复合催化剂对罗丹明B(RhB)的光降解效率和K_(3)ScF_(6)∶Tm^(3+),Yb^(3+)/CdS光催化复合材料的光催化机理进行了研究。结果表明,K_(3)ScF_(6)∶Tm^(3+),Yb^(3+)和CdS的最佳复合比为3.6∶1,上转换发光材料K_(3)ScF_(6)∶Tm^(3+),Yb^(3+)的引入协同促进了CdS的光催化作用,光催化过程中·OH与·O^(2-)均参与了对RhB的降解,并且·OH起主要作用。此外,在最佳复合比下,经过80 min,K_(3)ScF_(6)∶Tm^(3+),Yb^(3+)/CdS样品降解率达到99.9%,与未复合的CdS相比,降解率提高了近50倍。所有结果表明K_(3)ScF_(6)∶Tm^(3+),Yb^(3+)/CdS光催化复合材料在光催化领域具有潜在的应用价值。

Preparation and photoelectric properties of Ho^(3+)-doped titanium dioxide nanowire downconversion photoanode

Ho^3＋-doped titanium dioxide（TiO2：Ho^3＋） downconversion（DC） nanowires were synthesized through a simple hydrothermal method followed by a subsequent calcination process after being immersed in Ho（NO3）3 aqueous solution. Moreover, TiO2：Ho^3＋ nanowires（HTNWs） were used as the photoanode in dye-sensitized solar cells（DSSCs） to investigate their photoelectric properties. Scanning electron microscopy（SEM） and X-ray diffraction（XRD） were used to characterize the morphology and structure of the material, respectively. The photofluorescence and ultraviolet-visible absorption spectra of HTNWs reveal a DC from the near and middle ultraviolet light to visible light which matches the strong absorbed region of the N719 dye. Compared with the pure TNW photoanode, HTNWs DC photoanodes show greater photovoltaic efficiency. The photovoltaic conversion efficiency（η） of the DSSCs with HTNWs photoanode doped with 4% Ho2O3（mass fraction） is two times that with pure TNW photoanode. This enhancement could be attributed to HTNWs which could extend the spectral response range of DSSCs to the near and middle ultraviolet region and increase the short-circuit current density（Jsc） of DSSCs, thus leading to the enhancement of photovoltaic conversion efficiency.

Dy^(3+)/Tm^(3+)掺杂Na_(2)Gd(PO_(4))(WO_(4))的制备及发光性能研究

采用二次熔融的高温固相法合成了一系列Dy^(3+)/Tm^(3+)共掺钠-钆-磷钨酸盐(NGPW)荧光材料,研究了其光致发光特性和热稳定性,以及CIE与激发波长的映射关系。改变激发波长可以让NGPW∶2%Tm^(3+),xDy^(3+)(x=1%、2%、3%、4%、5%)荧光粉的颜色从蓝色-冷白色-暖白色-黄色连续变化。在356nm和363nm激发下,可实现白光发射。对共掺杂荧光粉的荧光衰减曲线进行表征,验证了该荧光粉中Dy^(3+)和Tm^(3+)之间存在能量转移。详细研究了能量传递效率和能量传递机理。NGPW∶2%Tm^(3+),xDy^(3+)荧光粉有望成为极具潜力的色彩可调的单组分荧光粉。

白光LED用YVO_(4)∶Tm^(3+)蓝色荧光粉的制备及发光性能

白光LED是指稀土掺杂的荧光粉被蓝光芯片或紫外芯片激发后获得各种室温发白光的器件。该种光致发光的实现方式是一种新型全固态照明光源,具有节能、环保及绿色照明等优点,被誉为第四代照明光源。对于现代设施农业,480~500nm之间的蓝光有一种调整植物节律的作用,对植物生长是有益的。蓝光在绿色植物的光合作用和光形态中起着重要的作用,绿色植物通过叶绿素、胡萝卜素、叶黄素和光敏素来捕获太阳光进行光合作用,适合植物生长的LED灯可提高光合作用效率,但传统的光源由于光质问题难以调节光波长,在这种情况下,需要将太阳光谱成分中380 nm以下的紫外光转换成蓝光,可提高作物光能利用率。所以,高光效、高热稳定性蓝色荧光粉已成为全光谱照明、光生态农业等领域的重要材料。蓝色荧光材料在近紫外(NUV)芯片激发的白光用发光二极管(W-LED)的制造中起重要作用。采用高温固相法制备YVO_(4)∶Tm^(3+)蓝色荧光粉,通过X射线衍射仪、扫描电子显微镜、荧光光谱仪等检测手段对样品的物相结构、表观形貌及发光性能进行表征分析。结果表明:通过高温固相法1100℃下煅烧2 h可以制备出YVO_(4)∶Tm^(3+)蓝色荧光粉,粉体呈2μm左右的球形,激发峰位于319 nm紫外区域,发射峰位于479 nm蓝光区域,样品色坐标位于(0.1044,0.1224),是一种有望应用于白光LED的蓝色荧光粉。