近紫外光激发的颜色可调Sr_2SiO_4:Gd~(3+),Tb~(3+),Eu~(3+)荧光粉的制备及其发光性能研究

采用液相沉淀法制备了近紫外光激发的颜色可调Sr_2SiO_4:0.06Gd~(3+),0.06Tb~(3+)、Sr_2SiO_4:0.06Gd~(3+),0.06Eu~(3+)和Sr_2SiO_4:0.06Gd~(3+),0.03Tb~(3+),0.03Eu~(3+)荧光粉,利用XRD、SEM、荧光光谱以及色坐标分析研究了所制备荧光粉的结构、形貌和发光性能。XRD分析表明,Sr_2SiO_4:0.06Gd~(3+),0.06Tb~(3+)、Sr_2SiO_4:0.06Gd~(3+),0.06Eu~(3+)和Sr_2SiO_4:0.06Gd~(3+),0.03Tb~(3+),0.03Eu~(3+)荧光粉样品属单斜晶系。荧光光谱分析表明,Sr_2SiO_4:Gd~(3+),Tb~(3+),Eu~(3+)的激发光谱包括200~300nm的宽带吸收峰和Tb~(3+)、Eu~(3+)的系列吸收峰。在243nm、354nm紫外光激发下,Sr_2SiO_4:0.06Gd~(3+),0.06Tb~(3+)的发射光谱由Tb~(3+)的~5D_4→~7F6(490nm,蓝绿光)、~5D_4→~7F_5(548nm,绿光)和~5D_4→~7F4(588nm,黄光)跃迁发射峰组成。在243nm、364nm紫外光激发下,Sr_2SiO_4:0.06Gd~(3+),0.06Eu~(3+)的发射光谱由Eu~(3+)的~5D_0→~7F_1(591nm,橙光)、~5D_0→~7F2(614nm,红光)、~5D_0→~7F_3(652nm,红光)跃迁发射峰组成。在243nm、252nm、364nm紫外光激发下,Sr_2SiO_4:0.06Gd~(3+),0.03Tb~(3+),0.03Eu~(3+)的发射光谱由Tb~(3+)的~5D_4→~7F_6(490nm,蓝绿光)、~5D_4→~7F_5 (548nm,绿光)、~5D_4→~7F_4(588nm,黄光)和Eu~(3+)的~5D_0→~7F_1(591nm,橙光)、~5D_0→~7F_2(614nm,红光)、~5D_0→~7F_3(652nm,红光)跃迁发射峰组成。色坐标分析表明,Sr_2SiO_4:0.06Gd~(3+),0.03Tb~(3+),0.03Eu~(3+)是很好的近紫外光激发的三色发光荧光粉。     

白色荧光粉Ba_2B_2O_5:Ce~(3+),Mn~(2+)的发光性能及能量传递

采用高温固相法制备了系列荧光粉Ba_2B_2O_5:Ce~(3+),Mn~(2+),研究了材料的发光性能。结果表明:Ba_2B_2O_5:Ce~(3+),Mn~(2+)在250~400 nm范围内有较强的吸收,且Ce~(3+)到Mn~(2+)存在能量传递,当Mn~(2+)掺杂量合适时,材料发射白色光。Ce~(3+)到Mn~(2+)的能量传递机理为电偶极–电偶极相互作用,利用浓度猝灭方法计算得到了能量传递的临界距离为1.33 nm。测得Ba_2B_2O_5:0.03Ce~(3+),0.07Mn~(2+)的色坐标为(0.309,0.292),色温为6 036 K。当测试温度为150℃时,材料的发射强度仍可以保持为室温时的80.0%。表明Ba_2B_2O_5:Ce~(3+),Mn~(2+)在紫外基白光LEDs领域有一定的潜在应用价值。     

红色荧光粉Ba_3La_6(SiO_4)_6:Eu~(3+)的制备与发光性能

采用高温固相法合成了Eu~(3+)激活的Ba_3La_6(SiO_4)_6红色荧光粉并对其发光性质进行了研究。XRD谱显示,合成样品为纯相Ba_3La_6(SiO_4)_6晶体。样品的激发光谱由一系列宽谱组成,峰值分别位于300、364、384、395、416和466nm,其激发主峰位于395nm。在395nm激发下,荧光粉在619nm(~5D_0→~7F_2)处有很强的发射。研究了不同Eu~(3+)掺杂浓度对样品发射光谱的影响。结果显示,随Eu~(3+)掺杂量的增大,发光强度先增大后减小。Eu~(3+)掺杂摩尔分数为13%时,出现浓度淬灭,其浓度淬灭机理为电偶极-电偶极相互作用。研究了不同Bi~(3+)掺杂量对Ba_3La_6(SiO_4)_6:Eu~(3+)发射光谱及色坐标的影响。Bi~(3+)掺杂样品中存在Bi~(3+)→Eu~(3+)的能量传递。     

钙钛矿型GdAlO_3:RE~(3+)(RE=Eu/Er-Yb)和LaAlO_3:Eu~(3+)发光粉的结构和发光性能

采用溶胶凝胶-燃烧法,柠檬酸为络合剂合成出系列GdAlO_3∶Eu~(3+)和LaAlO_3∶Eu~(3+)荧光粉及GdAlO_3∶Er~(3+), Yb~(3+)上转换发光粉。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、荧光光谱和上转换发光光谱对样品的结构、形貌和发光性能进行了研究。XRD分析表明:1000℃热处理获得具有正交结构的GdAlO_3∶Eu~(3+)荧光粉和GdAlO_3∶Er~(3+),Yb~(3+)上转换发光粉及具有六方结构的LaAlO_3∶Eu~(3+)荧光粉。柠檬酸比例和热处理温度对发光粉晶粒尺寸和晶相的形成有影响。荧光光谱研究表明:荧光粉的主发射峰来自于Eu~(3+)离子的~5D_0→~7F_2跃迁。柠檬酸比例及基质阳离子影响Eu~(3+)离子的局域对称环境。GdAlO_3∶Er~(3+),Yb~(3+)上转换发光粉在980 nm红外光激发下,发射来自于Er~(3+)离子~2H_(11/2)、~4S_(3/2)到~4I_(15/2)跃迁和~4F_(9/2)到~4I_(15/2)跃迁。计算并比较了GdAlO_3∶Eu~(3+),LaAlO_3∶Eu~(3+)和GdAlO_3∶Er~(3+),Yb~(3+)样品的色坐标。     

近紫外激发Ba_2ZnW_(1-x)Mo_xO_6:Eu~(3+),Li~+红色荧光粉的制备及其荧光性能

通过高温固相法制备了系列Ba_2ZnW_(1-x)Mo_xO_6:Eu~(3+),Li~+红色荧光粉,研究了Mo~(6+)离子掺杂对样品的晶体结构以及荧光性能的影响。结果表明:部分Mo~(6+)离子取代W~(6+)离子后,样品的激发波长发生红移,最大激发波长从316 nm转移到373 nm,使得样品能有效地被近紫外光(350～420 nm)激发。Ba_2ZnW_(0.6)Mo_(0.4)O_6:Eu~(3+),Li~+在373 nm波长的激发下,所得的荧光强度最强。Eu~(3+)离子的特征跃迁仍以~5D_0→~7F_1(598 nm)跃迁为主,但~5D_0→~7F_2(615 nm)跃迁得以加强。通过其发射光谱计算所得色坐标为(0.6385,0.3611),接近标准红色色坐标。Ba_2ZnW_(0.6)Mo_(0.4)O_6:Eu~(3+)Li~+作为红色荧光粉在被近紫外激发的白光LED中具有很好的应用前景。     

黄色荧光粉Sr8ZnLu(PO4)7:Eu2+,Mn2+的制备与发光性能研究

采用高温固相法制备新型黄色荧光粉Sr_8ZnLu(PO_4)_7:Eu~(2+), Mn~(2+)。分别通过X射线衍射,扫描电镜和荧光光谱研究了材料的物相结构,形貌和发光性能。单掺Eu~(2+)样品在250～450 nm范围内出现宽峰吸收,预示着该材料可被近紫外芯片有效激发。Eu~(2+)发射光谱峰值位于520 nm,发光猝灭的机理被确定为偶极-偶极相互作用。在Eu~(2+)-Mn~(2+)共掺样品中荧光粉展现400～700 nm范围可调的宽峰发射。研究表明Sr_8ZnLu(PO_4)_7:Eu~(2+), Mn~(2+)黄色荧光粉在近紫外芯片激活的白光LED领域有潜在应用。     

BaAl_2O_4:Eu直接白色荧光粉的制备及其发光性能

采用高温固相法,通过控制反应温度和Eu~(3+)掺杂量,制备Ba Al_2O_4:Eu直接白色荧光粉。以电荷补偿模型为基础讨论了自还原机理。当合成温度为1 200℃、Eu~(3+)掺杂量为12%(摩尔分数)时,荧光粉颜色趋近于白光,色坐标位于(0.36,0.38)。通过X射线光电子能谱、发射和激发光谱以及漫反射光谱,研究了Ba Al_2O_4:Eu荧光粉的发光性能。结果表明:荧光粉中存在2个发光中心,分别与Ba的2种格位相对应。Eu2+和Eu~(3+)共存于基质中,说明Eu~(3+)在空气中发生自还原反应。主峰位于500 nm处的发射宽谱符合Eu2+的4f 65d–4f 7跃迁,596、619、655以及709 nm处的发射峰分别对应Eu~(3+)的4f–4f中5d0–7fJ(J=1,2,3,4)特征发射跃迁,发射峰以619 nm处的5d0–7f2电偶极跃迁为主。     

Eu~(3+)、Gd~(3+)共掺杂Sr_2SiO_4荧光粉的液相沉淀合成及能量转移发光性能

采用液相沉淀法合成了钆单掺杂、铕单掺杂、钆-铕共掺杂的硅酸锶发光材料。用X-射线衍射(XRD)对其结构表征。利用荧光光谱(PL)方法对合成的样品进行发光性能表征。研究结果表明:在250nm紫外光为激发波长时,Eu~(3+)单掺杂Sr_2SiO_4∶0.04Eu~(3+)的发光光谱出现Eu~(3+)的5D0→7F1(584nm)、5D0→7F2(614nm)、5D0→7F3(626nm)跃迁发光峰,钆-铕共掺杂Sr_2SiO_4∶x Gd3+,0.04Eu~(3+)发光体系中,主要表现为Eu~(3+)离子的特征发射。探讨了在硅酸锶发光体中Gd~(3+)→Eu~(3+)能量传递的机理,主要为电偶极-电偶极相互作用。当改变Eu~(3+)离子的掺杂浓度时,样品表现为Eu~(3+)离子的特征发射,此时材料发橙色光。保持Gd~(3+)、Eu~(3+)离子掺杂浓度不变,K+作为电荷补偿剂,对材料发光强度影响很小。     

燃烧法合成掺铕磷酸钙荧光材料

采用燃烧法合成掺铕磷酸钙发光材料,采用XRD和荧光光谱对其结构和荧光性质进行表征。结果表明:掺杂Eu~(3+)后未改变Ca_3(PO_4)_2的晶相结构;荧光粉样品在激发主峰位于394 nm处,归属于Eu~(3+)的~7F_0→~5L_6跃迁,发射主峰位于616 nm处,归属于Eu~(3+)的~5D_0→~7F_2电偶极跃迁;当Eu~(3+)掺杂浓度为10%时,得到Ca_(2.9)(PO_4)_2:0.1Eu~(3+)发光材料的发光强度不但是最强的,而且发出的色光与红光最为接近,是一类潜在的近紫外激发的红光发射荧光粉。     

Si~(4+)掺杂对橙红色荧光粉NaBaSi_xP_(1-x)O_4:Eu~(3+)结构和发光性能的影响

采用高温固相法合成了一系列NaBaSi_xP_(1-x)O_4:Eu~(3+)橙红色荧光粉。表征了荧光粉的晶体结构和发光性能。考察了煅烧温度和Si~(4+)掺杂量对荧光粉结构和发光性能的影响。结果表明:掺杂Si~(4+)对荧光粉的晶型没有明显影响,但是导致了晶格膨胀。750℃煅烧时基质已形成NaBaPO_4相,晶型为六方晶系,荧光粉发射峰强度最强。激发光谱由200~280 nm的宽带和310~500 nm的一系列尖峰组成,分别对应于O~(2–)→Eu~(3+)电荷迁移带和Eu~(3+)的f→f能级跃迁吸收,最强激发峰位于393 nm左右,与近紫外LED芯片的发射光谱匹配。在393 nm近紫外光激发下,最强发射峰和次强发射峰分别位于红光616 nm和橙光591 nm附近,分别属于Eu~(3+)的~5D_0→~7F_2和~5D_0→~7F_1特征跃迁。NaBa_(0.92)Si_xP_(1–x)O_4:0.08Eu~(3+)中Si~(4+)的最佳掺杂量为0.02 mol,Na Ba_(0.92)Si_(0.02)P_(0.98)O_4:0.08Eu~(3+)样品在616和591 nm附近的发射强度比单掺杂Eu~(3+)的样品分别提高了66.6%和63.6%。     

Fe~(3 )、Zn~(2 )、Mn~(2 )、Cu~(2 )、Ca~(2 )、Mg~(2 )等离子共存体系中Ca~(2 )、Mg~(2 )的测定

叙述了Fe3 、Zn2 、Mn2 、Cu2 、Ca2 、Mg2 等离子共存体系中采用六次甲基四胺 -铜试剂沉淀除去Fe3 、Zn2 、Mn2 、Cu2 等干扰离子 ,用EDTA滴定钙镁的方法 ,该方法钙的回收率在 99.7%～ 10 0 .3 % ;镁的回收率在 10 0 .0 %～ 10 0 .4% ,标准偏差为 0 .0 2 2。     

Ag(I)(Et(2)PCH(2)CH(2)PPh(2))(2)]NO(3): An Antimitochondrial Silver Complex

The silver(I) complex [Ag(eppe)(2)]NO(3) (eppe = Et(2)PCH(2)CH(2)PPh(2)) is shown by X-ray crystallography to be tetrahedral with Ag - PEt(2) and Ag - P Ph(2) bond lengths of 2.482 and 2.518 A, respectively. The complex is selectively antimitochondrial and inhibits the growth of a number of yeast strains in non-fermentable media at concentrations as low as 2.5 muMu and induces the mitochondrial mutation petite The effect is largely reversed by the presence of aspirin. The complex is shown to be stable in the cell culture media and in the presence of glutathione, but readily reacts with disulfides of oxidized glutathione and serum albumin. Surprisingly, neither [Au(eppe)(2)]Cl nor [Au(eppe)(2)]Cl (dppe = Ph(2)PCH(2)CH(2)PPh(2)) showed any mitochondrial selectivity in the same screening protocol.     

Interaction of [Rh(2)(O(2)CCH(3))(4)(H(2)O)(2)] and [Rh(2)(O(2)CCH(OH)Ph)(2)(phen)(2)(H(2)O)(2)](O(2)C-CH(OH)Ph)(2) With Sulfhydryl Compounds and Ceruloplasmin

The interaction of binuclear rhodium(II) complexes [Rh(2)(OOCCH(3))(4)(H(2)O)(2)], [Rh(2){OOCCH(OH)Ph}(2)(phen)(2)(H(2)O)(2)] {OOCCH(OH)Ph}(2), [Rh(2)(OOCCH(3))(2)(bpy)(2)(H(2)O)(2)](OOCCH(3))(2) and [Rh(2)Cl(2)(OOCMe)(2)(bpy)(2)](3H(2)O) with ceruloplasmin, cysteine, glutathione and coenzyme A have been investigated using. UV-Vis and CD spectroscopies. The complexes containing phen or bpy at pH = 7.4 and 4.0 are readily reduced with sulfhydryl compounds, while rhodium(II) acetate is relatively stable in these conditions. Complex [Rh(2){OOCCH(OH)Ph}(2)(phen)(2)(H(2)O)(2)] strongly changes structure of ceruloplasmin leading to the decrease of of alpha-helix content and loss of oxidase activity.     

Copper (2+), Zinc (2+), and Nickel (2+) Uptake by Activated Sludge

Abstract

This paper reports the results obtained on copper, zinc, and nickel uptake by activated sludge in a completely mixed unit. Removal of these heavy metals from wastewater occurs by uptake and by precipitation, the latter being particularly important in the cases of copper and zinc. The amount of heavy metal taken up by the microorganisms at equilibrium varies with influent concentration for the three metals studied. The values obtained range from 2.3 mg/g VSS for copper at 1 mg/L in the influent to 57.4 mg/g VSS for nickel at influent 25 mg/L. Soluble metal removal from wastewater increases in percentage with influent concentration, being higher for copper and lower for nickel. Experiments with mixtures of these metals have also been carried out.     

氨噻肟酸与AE—活性酯

我国氨噻肟酸的总产量为300-400t/a,产品大部分用于生产AE-活性酯,部分直接出口。在氨噻肟酸生产中如何对反应过程进行实时监控,利用液氯替代价格较高同时危险性较大的液溴,以及如何控制氨噻肟酸产物中顺反异构体的比例、阻止二聚体的生成是今后有待解决的问题;在AE-活性酯的生产中,利用价格较低的原料代替昂贵的三苯基膦将对降低生产成本起到决定性的作用。     

H(2)O(2) in CO(2): sustainable production and green reactions

Hydrogen peroxide is a "green" oxidant whose relatively high cost has prevented it from being applied to commodity chemical processing. Interestingly, those attributes of the current H(2)O(2) process that contribute to the high cost also contribute to its nonsustainable features. We have consequently explored the generation of hydrogen peroxide both by the AQ route and directly from hydrogen and oxygen using liquid CO(2) as the solvent, because CO(2) provides some unique advantages to H(2)O(2) synthesis.     

N（2—甲苯基）—2—（2—甲苯氧乙酰基）氨基脲的合成

以固体氢氧化的钠作催化剂,用Ｎ－（２－甲苯基）三氯乙酰胺与２－本氧乙酰肼反应,合成一种新的氨基脲。     

A new binuclear Cr(III) citrate anion: Synthesis,characterization and crystal structure of [Cr(CO(NH2)2)6]2[Cr2(CO(NH2)2)2(C6H4O7)2]3

The new anion [Cr₂(CO(NH₂)₂)₂(C₆H₄O₇)₂]^2 − has been isolated in the complex [Cr(CO(NH₂)₂)₆]₂[Cr₂(CO(NH₂)₂)₂(C₆H₄O₇)₂]₃. The crystals of this complex were obtained by a one-pot synthetic method using 1:1 molar ratio of hexaureachromium(III) chloride and trisodium citrate in aqueous medium. It was characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction analysis. The compound crystallizes in space group R‾3 of the trigonal system with three formula units in a cell of dimensions a = b = 24.7461(4) Å, c = 13.7204(3) Å and γ = 120°. The crystal structure comprises the columns consisting of [Cr(CO(NH₂)₂)₆]^3 + cations surrounded by a cylinder of complex anions, [Cr₂(CO(NH₂)₂)₂(C₆H₄O₇)₂]^2 − which are packed in a honeycomb-like manner. This supramolecular architecture is formed and stabilized by inter- and intramolecular NH⋯O hydrogen bonds.     

2-(2-氯苄基)-2-(1-氯环丙基)环氧乙烷的合成

报道了丙硫菌唑中间体2-(2-氯苄基)-2-(1-氯环丙基)环氧乙烷的合成方法。以1-氯-N,N-二甲基环丙基甲酰胺和邻氯氯苄为原料,经格氏反应制备2-氯苄基-(1-氯环丙基)酮;后者再与硫叶立德试剂反应得到相应的环氧化物。