K2O·CaO·4B2O3·12H2O∶Nd3+的合成及发光性能

以CaCl2、K2B4O7和Nd2O3为原料,采用易于工业化、无污染的水溶液法反应合成碱-碱土金属硼酸盐K2O·CaO·4B2O3·12H2O∶Nd3+晶体,利用X射线衍射、红外光谱、扫描电镜、荧光分光度计等现代分析测试手段,对所合成晶体进行了分析和表征.结果表明,所制备的K2O·CaO·4B2O3·12H2O∶Nd3...     

立方纳米结构ZnGa_2O_4的制备及光催化性质

首先采用水热法在FTO衬底上制备出α-GaOOH纳米柱阵列,再以α-GaOOH纳米柱/FTO结构作为前驱体进行水热反应,经溶解再结晶过程,α-GaOOH纳米柱可转变为边长约为500 nm的ZnGa_2O_4纳米立方块。在模拟太阳光源辐照下的一系列光催化实验结果表明:样品对亚甲基蓝具有较强的吸附作用和较高的光催化活性,对罗丹明B、刚果红的吸附能力和光催化作用都很弱,对甲基橙只有较弱的光催化作用;H_2O_2可以作为电子捕捉剂和供氧剂,促进样品的导带电子参与活性自由基的形成,使样品对染料表现出持续较高的光催化活性。     

新型FED荧光粉MSi2N2O2∶Eu2+(M=Sr,Ba)的发光性能

采用高温固相法合成了一系列新型绿色FED(Field Emission Display)荧光粉MSi2N2O2∶Eu2+(M=Sr,Ba),研究了该荧光粉在不同电压和电流密度下的发光特性.在电子束激发下,SrSi2N2O2:Eu2+的发射主峰位于541 nm,属于黄绿光发射;BaSi2N2O2∶Eu2+的发射主峰位于4...     

氧化反应调控的金纳米簇“关-开”型荧光探针检测过氧化氢和葡萄糖

基于过氧化氢（H₂O₂）氧化单巯基（—S）为双巯基（S—S）,抑制金纳米簇（AuNCs）荧光猝灭,建立了一种灵敏的荧光传感方法用于过氧化氢和葡萄糖（Glu）的检测。DNA为模板合成的金纳米簇作为荧光探针,荧光强度高、稳定且合成简单快速。加入半胱氨酸（Cys）,半胱氨酸上的单巯基可以与金纳米簇发生化学键合反应形成稳定的Au—S键,破坏金纳米簇的结构,导致金纳米簇荧光强度猝灭。但当体系中存在过氧化氢时,将单巯基半胱氨酸氧化成双巯基的胱氨酸。双巯基的胱氨酸不能与金纳米簇发生键合作用,金纳米簇在471 nm处发射出强烈的荧光信号。葡萄糖可以在葡萄糖氧化酶（Gox）的作用下产生过氧化氢,利用该方法进一步开展了对葡萄糖的检测。以金纳米簇荧光强度的变化值F/F₀为纵坐标,过氧化氢或葡萄糖浓度为横坐标,实现了对过氧化氢和葡萄糖的灵敏检测,线性范围分别为10~100和10~200 μmol·L-1,检测下限分别为2.8和3.1 μmol·L-1。选择4种其他糖类化合物和5种金属离子作为干扰物质,均不会抑制半胱氨酸对金纳米簇的荧光猝灭效应,表明该方法具有很好的选择性。用该方法成功检测了胎牛血清样品中的葡萄糖,加标回收率为94.5%~112.7%。此外,该方法可拓展到其他基于酶催化产生过氧化氢体系的分析物检测,如胆固醇、辣根过氧化物酶等,为过氧化氢相关反应的分析提供了一种通用、简便的方法,在临床诊断、食品科学和环境分析等领域具有潜在的应用价值。     

邛崃石窟摩崖造像的彩绘颜料分析与研究

四川省邛崃市地处成都平原,是成都地区发现的摩崖造像规模最大,分布最集中的地区。由于潮湿、半露天的保存环境,造像遭到严重破坏,缺少相关的科学分析研究。本文选用邛崃地区内花置寺摩崖造像、临邛镇磐陀寺摩崖造像和大同乡石笋山摩崖造像三处共12件彩绘颜料样品,通过超景深显微观察、X射线荧光分析、X射线衍射和显微激光拉曼光谱综合分析,获取彩绘颜料信息。结果表明红色颜料为赤铁矿[Fe₂O₃]和铅丹[Pb₃O₄];绿色颜料为砷酸铜[Cu(AsO₃)(OH)·2H₂O]和过硫酸三铜钠钾[KNaCu₃O(SO₄)₃];白色颜料为石膏[CaSO₄];黄色颜料为黄赭石[Fe₂O₃];黑色颜料为铅丹[Pb₃O₄]的变化产物,蓝色颜料为青金石[Na₆Ca₂Al₆Si₆O₂₄(SO₄)₂]。值得注意的是绿色颜料的分析结果,其中检出的砷酸铜类物质在近年中国西南地区彩绘分析中较常见,结合文献调研判断其为近现代人工合成颜料巴黎绿的变化产物,进而推测此处有近现代重绘可能。另外,首次检出过硫酸三铜钠钾成分的绿色颜料,丰富了古代彩绘颜料的分析实例,判断可能是某种绿色含铜矿物的变化结果。四川地区环境湿润,一些不稳定的矿物颜料容易发生化学变化,有的产生变色,有的颜色变化不明显,但成分已产生新的物质。通过分析邛崃石窟彩绘颜料,获取四川地区摩崖造像所使用颜料的相关信息,为颜料复原提供科学依据,同时也有利于文物工作者展开针对性保护工作,为四川地区彩绘石窟的研究和保护提供参考。     

Sonochemical decolorization of acid black 210 in the presence of exfoliated graphite

The decolorization of acid black 210 by ultrasonic irradiation in the presence of exfoliated graphite was investigated. Low pH value and large exfoliation volume of exfoliated graphite favored the ultrasonic decolorization of acid black 210. The combination method of ultrasonic waves and exfoliated graphite achieved better results than either exfoliated graphite or ultrasound alone. Improved decolorization efficiency has been observed in the present system compared to the process using a combination of ultrasound and activated carbon. In the combination method of ultrasonic waves and exfoliated graphite, approximately 99.5% of acid black 210 was removed using 0.8 g/l exfoliated graphite at a pH of 1 within 120 min at 51 degrees C.     

Effect of various sono-oxidation parameters on the removal of aqueous 2,4-dinitrophenol

The influences of ultrasonic output intensity, solution pH, H₂O₂ concentration and the addition of Fenton reagent on the degradation of 2,4-dinitrophenol (DNP) under ultrasonic irradiation were investigated. It was observed that the degradation of DNP fitted pseudo-first-order dynamics under our experimental conditions. Increasing the ultrasonic output intensity increased the degradation efficiency of DNP and low pH favored the ultrasonic degradation of DNP. The addition of H₂O₂ enhanced the ultrasonic degradation efficiency of DNP. The further addition of Cu²⁺, however, hindered the degradation of DNP. In contrast, sono-oxidation treatment in combination with FeSO₄/H₂O₂ showed a synergistic effect for DNP degradation.     

杭锦2#土的光谱特征及非均相Fenton反应机理

杭锦2#土是内蒙古鄂尔多斯杭锦旗地区发现的层状含铁天然矿物,利用Ｘ射线衍射、吡啶吸附红外光谱及Ｘ射线光电子能谱技术对样品的性质进行了表征。X射线光电子能谱表明杭锦2#土骨架结构中Si和Al原子结合能与标准硅氧四面体和铝氧八面体中Si和Al结合能相比明显增加,表面存在Lewis酸位和Brönsted酸位,且杭锦2#土中铁物种以Fe(Ⅲ)和Fe(Ⅱ)形式存在于骨架结构中;非均相Fenton反应中杭锦2#土的Fe(Ⅱ)可与H₂O₂反应生成自由基(·OH)与Fe(Ⅲ),但反应速率慢且难以循环。酸活化后杭锦2#土中Si和Al的结合能进一步增加,铁物种部分转变为非结构铁并以Fe3+与Fe2+转移到样品表面;X射线光电子能谱、吡啶红外和氨气程序升温表征表明酸活化杭锦2#土表面Lewis酸位和Brönsted酸位增多;非均相Fenton反应中,酸活化杭锦2#土表面Fe3+与Fe2+可与H₂O₂循环反应,不断生成·OH并对甲基橙进行降解,且活化杭锦2#土表面Brönsted酸能够提供质子将H₂O₂包围,抑制其分解生成HO-₂并提供更多的·OH,Lewis酸能增加杭锦2#土表面吸附氧（O_ad）含量,而Fe2+可被O_ad氧化为Fe3+,促进Fe2+/Fe3+之间的循环,同时在氧化过程中电子转移到O_ad形成O·-₂,O·-₂能够与Brönsted酸提供的质子反应形成·OH,·OH与O·-₂均为氧化性自由基,能够提升活化杭锦2#土非均相Fenton反应活性。此外,X射线衍射表明酸活化使杭锦2#土中CO2-₃转化为对Fenton反应负面影响更小的SO2-₄进而提升其非均相Fenton反应活性。     

The removal of MO molecules from aqueous solution by the combination of ultrasound/adsorption/photocatalysis

Methyl orange (MO) molecules had been removed from aqueous solution by nano-TiO(2)/exfoliated graphite composites with the combination of ultrasound/adsorption/photocatalysis. The experimental results had showed that nano-TiO(2)/exfoliated graphite composites provided with the adsorptive capability of exfoliated graphite and the photocatalysis capability of nano-TiO(2) synchronously. It had been proved that the removal ratios related to the adsorption and photocatalysis capability of the composites and were influenced by US and UV irradiation, the reaction times, the reaction temperatures, the initial pH values, the dosages and the initial MO solution concentrations. Moreover, it had been illuminated that the combination was very effective and useful on removing MO molecules from aqueous solution.     

Performance and reliability improvement of La_2O_3/Al_2O_3 nanolaminates using ultraviolet ozone post treatment

La-based binary or ternary compounds have recently attracted a great deal of attention as a potential candidate to replace the currently used Hf-based dielectrics in future transistor and capacitor devices for sub-22 generation. However, the hygroscopic nature of La₂O₃ hampers its application as dielectrics in electron devices. To cope with this challenge, ultraviolet (UV) ozone post treatment is proposed to suppress the moisture absorption in the H₂O-based atomic layer deposition (ALD) La₂O₃/Al₂O₃ nanolaminates which is related to the residual hydroxyl/hydrogen groups after annealing. The x-ray photoelectron spectroscopy (XPS) and conductive atomic force microscopy (AFM) results indicate that the moisture absorption of the H₂O-based ALD La₂O₃/Al₂O₃ nanolaminates is efficiently suppressed after 600 ℃ annealing, and the electrical characteristics are greatly improved.     

Er3+/Yb3+共掺碲酸盐玻璃陶瓷的光谱性质

利用熔融淬火法在900℃下成功制备出原料比为60TeO2 -10CaF2 -25 H3 BO3-1 Er2 O3-4Yb2 O3的Er3+/Yb3+共掺杂透明玻璃陶瓷.利用XRD和TEM验证了玻璃陶瓷中存在Er2Te5O13纳米微晶,并由Raman测试得知其声子能量为886 cm-1.分别测量了其上转换和下转换发射谱,...     

Synthesis and characterization of NiMn2O4 nanoparticles using gelatin as organic precursor

Nanoparticles of NiMn₂O₄ were successfully obtained by mixing gelatin and inorganic salts NiCl₂·6H₂O and MnCl₂·4H₂O in aqueous solution. The mixture has been synthesized at different temperatures and resulted in NiMn₂O₄ nanoparticles with crystallites size in the range of 14–44 nm, as inferred from X-ray powder diffraction (XRPD) data. We have also observed that both the average crystallite size and the unit cell parameters increase with increasing synthesis temperature. Magnetic measurements confirmed the presence of a magnetic transition near 110 K.     

Ln2Sn2O7：Er3+纳米晶的制备及发光性能研究

采用溶胶-凝胶法合成Ln₂Sn₂O₇:Er³⁺(Ln=La,Gd,Y)纳米晶。通过X射线衍射和场发射扫描电子显微镜测试了样品的晶体结构和形貌,同时对样品的上转换发光性能进行了测试。结果表明:在980 nm连续激发光的激发下,样品主要表现为绿光发射。发射中心在528,549 nm的绿光和672 nm处的红光发射分别对应Er³⁺离子的⁴S_3/2→⁴I_15/2、²H_11/2→⁴I_15/2和 ⁴F_9/2→⁴I_15/2跃迁。以La₂Sn₂O₇:Er³⁺纳米晶为例,Er³⁺离子的摩尔分数为7%、退火温度为1 150℃是其制备的最佳条件,此时其各个发射峰的强度最高。对La₂Sn₂O₇:Er³⁺的发光强度与激发功率关系的研究表明,其绿光和红光发射均为双光子过程。激发光吸收和能量转移是La₂Sn₂O₇:Er³⁺纳米晶上转换发光的主要机制。     

Eu3+掺杂5Li2O-1Nb2O5-5TiO2发光陶瓷的制备及性能研究

以Li₂CO₃、Nb₂O₅、TiO₂和Eu₂O₃为原料,采用固相法制备Eu³⁺掺杂的5Li₂CO₃-1Nb₂O₅-5TiO₂（LNT）发光介质陶瓷。通过密度、XRD和荧光光谱测试,对0.2%（质量分数）Eu₂O₃掺杂的陶瓷片进行性能表征。结果表明：1 120℃烧结致密的陶瓷片,其晶相结构为“M-相”与Li₂TiO₃两相复合构成;在400 nm的近紫外光激发下,样品有较强的橙光（592 nm）和红光（615 nm）发射,分别属于Eu³⁺的⁵D₀→⁷F₁的磁偶极跃迁和⁵D₀→⁷F₂的电偶极跃迁。     

Fe3O4磁性纳米颗粒的催化性能研究进展

综述了国内外这一领域科研工作者的研究成果,以紫外光谱（UV）和电化学传感器为主要手段阐述了Fe₃O₄MNPs对H₂O₂的催化作用并对Fe₃O₄MNPs利用其催化性质在H₂O₂的检测领域的进一步发展和应用进行了展望。     

磷酸二氢根离子对香豆肼化合物的高选择性荧光增强

设计合成了荧光探针N,N-二.乙基氨基香豆素-3-肼基-2,4-二硝基苯肼(DC).光谱滴定实验显示,H2PO4-与DC能够以1∶1的化学计量比形成配合物.进一步的实验发现,和相同含量的DC溶液相比,该配合物溶液的相对光致荧光强度显著增强,同时伴有紫外吸收光谱红移,溶液颜色由橙黄色迅速变为紫色.其它阴离子,如F-、NO...     

等离子体放电活化生理盐水杀菌应用研究

等离子体中含有多种活性物种可实现高效安全杀菌,活性物种与生物体相互作用多在水环境下进行.因此等离子体与水的相互作用过程研究掀起了等离子体生物杀菌的新浪潮.本文采用水中阵列放电产生等离子体活化生理盐水,利用所产生的活化生理盐水对大肠杆菌开展了杀菌消毒研究,当等离子体放电时间达到120 s时产生的活化生理盐水与大肠杆菌混合后可使大肠杆菌的存活效率降至0.001%.通过紫外-可见吸收光谱测量及化学氧化还原沉降滴定表明放电电荷及激发态氧化性活性物种与水溶液相互作用,转化为活化生理盐水中长寿命相对稳定存在的H_2O_2和O_3等氧化性物种,与大肠杆菌作用并主导主要杀菌效果.     

Study of influence of metal ions on CdTe/H2O2 chemiluminescence

Water-soluble CdTe nanocrystals (NCs) were synthesized and applied to study the effect of metal ions on chemiluminescence (CL) of the CdTe/H₂O₂ system. The effects of experimental factors, such as pH, particle sizes of CdTe and reagent concentration, on kinetics curve and CL intensity of the CdTe/H₂O₂ system were examined. The results showed that under the optimal conditions Ba²⁺, Ca²⁺, Fe²⁺, Pb²⁺ and Cu²⁺ enhanced the CL intensity, and Cr³⁺, Ni²⁺, Zn²⁺ and Ag⁺ inhibited the CL intensity.     

超声波和紫外光协同降解酸性橙Ⅱ水溶液的机理研究

以含有多个苯环的典型偶氮染料-酸性橙Ⅱ为研究对象,研究了超声波和紫外光分别辐照及共同辐照下的降解现象。酸性橙Ⅱ水溶液在超声波及紫外光分别辐照下均发生显著降解,反应过程符合准一级反应动力学规律。在超声波和紫外光共同辐照下,反应过程也符合准一级反应动力学规律,同时酸性橙Ⅱ水溶液降解呈现显著的声光协同效应,即同一辐照时间内超声波和紫外光共同辐照下酸性橙Ⅱ的降解率大于超声波和紫外光单独辐照下各自降解率之和。动力学分析结果表明,该协同效应可归因于紫外光对超声空化过程中产生的过氧化氢的裂解作用。      

新生MnO2对酸性媒介黑T的吸附

以化学法合成的新生MnO2为吸附剂，对水中酸性媒介黑T（染料之一）进行了吸附脱色研究，并探讨了影响吸附的因素。结果表明，酸性媒介黑T的脱色率达95%。且PH是影响染料脱色的主要因素。