Ce(Ⅳ)、Th(Ⅳ)与四偏磷酸钠配合物的合成及性质

本文用沉淀外示体积法,电导滴定和pH滴定法研究了Ce(Ⅳ)、Th(Ⅳ)与四偏磷酸钠(Na_4P_4O_(12)·4H_2O)的配合反应,合成了固体配合物Na_4[Ce(P_4O_(12))_2]·4H_2O和Na_1Th(P_1O(?)4H_2O。讨论了配体、配合物的红外光谱,X—Ray粉末衍射及热谱性能。     

磷酸盐基质点阵中Ce~(3 )→Tb~(3 )的转移

在具有不同结构类型的各种磷酸液盐中,特别在新化合物 Na_3Ln(PO_4)_2:Ce,Tb;NaxSr_(3-2)xlnx(PO_4)_3:Ce,Tb 和 KCaLn(PO_4)_2:Ce,Tb 中,已经表明将发生 Ce~(3 )→Tb~(3 )的转移。     

W-Ce复合缓蚀剂对X80管线钢的缓蚀性能及机理研究

为了研究Na_2WO_4·2H_2O、Ce(NO_3)_3·6H_2O单一缓蚀剂以及Na2WO_4·2H_2O-Ce(NO_3)_3·6H_2O(简写为:W-Ce)复合缓蚀剂对X80管线钢的缓蚀作用,采用失重法计算钢试样在不含和含有不同缓蚀剂的中性Na Cl介质中的缓蚀效率,结合SEM表征确定出,在35℃恒温条件下,780 mg·L~(-1)Na_2WO_4·2H_2O与660 mg·L~(-1)Ce(NO_3)_3·6H_2O复配得到的W-Ce复合缓蚀剂具有最高的缓蚀效率,达99.01%。根据EDS分析和多酸配合物的理论,探究了W-Ce复合缓蚀剂的缓蚀机理和模型。最终认为,W-Ce复合缓蚀剂对X80钢片的缓蚀作用,主要是通过Ce~(3+)和WO_4~(2-)形成的杂多酸[Ce(WO_4)_3]_n~(3-)与钢片表面的Fe配位吸附作用,形成一层缓蚀膜,从而隔绝腐蚀介质,产生了优良的抑制腐蚀效果。     

用结晶—重结晶法制备高纯硝酸铈

研究了高纯硝酸铈的结晶法制备及重结晶法纯化除杂,采用正交回归试验法考察了硝酸铈结晶过程中料液初始酸度、结晶温度、陈化时间对产品质量的影响,以及母液回收利用情况。结果表明:采用结晶—重结晶法可以获得高纯硝酸铈产品,其中非稀土杂质质量分数小于1.5×10-5;确定了洁净硝酸铈制备工艺条件。热分解机制研究结果表明,硝酸铈的组成为Ce(NO_3)_3·6H_2O。     

Effect of Eu~(3+) contents on structure and luminescence properties of Na_3Bi_(2–x)(PO_4)_3:xEu~(3+) and Na_3Bi_(1–x)(PO_4)_2:xEu~(3+) phosphors

A series of Na_3Bi_(2–x)(PO_4)_3:xEu~(3+) and Na_3Bi_(1–x)(PO_4)_2:xEu~(3+) phosphors were successfully synthesized by solid-state method.The structure and luminescence properties were carefully investigated.The excitation spectra presented an obvious excitation band,and the peak was located at 396 nm,which matched well with the popular emissions from near-UV light-emitting diode chips.With the phase of Na_3Bi_(2–x)(PO_4)_3:xEu~(3+) changing to that of Na_3Bi_(1–x)(PO_4)_2:xEu~(3+),the intensity of magnetic dipole transition(~5D_0→F_1) at 598 nm became stronger than that of electric dipole transition(~5D_0→~7F_2) at 621 nm.Under 396 nm excitation,the chromaticity coordinates and the decay curves of the entitled phosphors were also investigated.Based on all experiments without concentration quenching,we could control the luminescence intensity of the material by adjusting the doping amount of the active ions.All results indicated that Na_3Bi_(2–x)(PO_4)_3:xEu~(3+) and Na_3Bi_(1–x)(PO_4)_2:xEu~(3+) phosphors have potential application as red phosphors in near UV chip-based white light emitting diodes.     

铈(Ⅲ)盐与邻菲啰啉单氮氧化物形成配合物的研究

本实验合成出Ce(PhenNO)_4(ClO_4)_3·H_2O和Ce(PhenNO)_2·(NO_3)_3两种配合物。通过元素分析、红外光谱、紫外光谱、热谱、摩尔电导及溶解性,对它们的性质进行了研究。     

Ce掺杂Cu_2O(Ce/Cu_2O)薄膜的制备及其光电性能

用NaAc与Cu(Ac)_2为反应体系,采用电沉积法,在ITO上制备了Ce掺杂的Cu_2O(Ce/Cu_2O)薄膜。探讨了Cu(Ac)_2浓度、沉积温度、沉积时间、沉积电压和溶液pH等制备条件对Cu_2O样品光电性能的影响及Ce掺杂量对Cu_2O薄膜光电性能的影响。结果表明,当反应液中含0.04 mol/L Cu(Ac)_2、0.02 mol/L NaAc、0.0064 mmol/L CTAB、0.008 mol/L Ce(NO_3)_3、溶液pH为5.5、沉积温度为50℃时,在1.4 V电压下沉积40 min,即可制备形貌较好、光电压达0.3239 V的Ce/Cu_2O薄膜,Ce的掺杂有着比单纯Cu_2O薄膜更高的光电性能。UV-vis、XRD、SEM和EDS等表征结果显示,Ce的掺杂使得Cu_2O薄膜紫外吸收峰发生蓝移、抑制了Cu_2O微晶的生长、使薄膜的形貌变为叶脉较宽的星型枝叶状,样品中Ce元素质量分数和原子分数分别为22.63%和8.78%。     

1,6-双(1′-苯基-3′-甲基-5′-氧代吡唑-4′-基) 己二酮与UO_2(Ⅱ),Th(Ⅳ)及Ce(Ⅳ)的配合物合成及性质

本文用电导滴定和pH滴定法研究了乙醇—水液溶中UO_2(Ⅱ),Th(Ⅳ)及Ce(Ⅳ)与1,6—双(1′苯基-3′-甲基-5′-氧代吡唑-4′-基)已二酮的配合反应。合成了固态配合物:UO_2L·H_2O,ThL_2·2H_2O和Ce_2L_3(NO_3)_2·4H_2O,研究了它们的UV,IR,~1HNMR,荧光光谱及热稳定性。     

磷酸三钠对高钛高炉渣制备微晶泡沫玻璃的影响

以高钛型高炉渣和废玻璃粉为主要原料,碳酸钙为发泡剂,硼砂为助熔剂,采用"一步法"烧结在900℃低温下制备了微晶泡沫玻璃。借助DSC、XRD、SEM等分析测试手段,研究了磷酸三钠(Na_3PO_4·12H_2O)添加量对制备微晶泡沫玻璃的影响。结果表明,在不同的磷酸三钠添加量(0%～10%,质量分数)下,微晶泡沫玻璃的主要物相变化不显著,均为透辉石Ca(Mg, Al)(Si, Al)2O6,富铁普通辉石Ca(Mg, Fe)(Si, Fe)_2O_6以及普通辉石CaMgSi_2O_6;随着Na_3PO_4·12H2O含量增加,微晶泡沫玻璃抗压强度和导热系数减小,体积密度和吸水率先减小后增大。当磷酸三钠添加量为6%时,微晶泡沫玻璃具有最优的综合性能。     

Eu(Ⅲ)-β-NPA-HTTA二元、三元配合物的合成和光谱研究

为了获得高光效、高稳定性能的发光材料,探讨β-萘甲酸(β-NPA)化合物在发光材料方面的应用,合成了Eu(Ⅲ)与β-NPA及2-噻吩甲酰三氟丙酮(HTTA)形成的二元、三元荧光配合物。对所合成的配合物利用元素分析、紫外可见光谱、红外光谱、荧光光谱等手段进行了表征。对稀土配合物的结构与发光性能之间的关系进行了探讨。表征结构表明,两个配合物的组成分别为Eu(β-NPA)_3·3H_2O和Eu(β-NPA)(TTA)_2·2H_2O;紫外光谱研究表明,β-NPA与铕离子配位后整个体系的共轭程度增大,使得配合物的紫外吸收能力增强;荧光光谱研究显示,与铕离子反应后的配合物的配体β-NPA、2-HTTA能将吸收的能量有效地传递给铕离子,从而使配合物发射出强的铕离子的特征荧光,且两个配合物Eu(β-NPA)_3·3H_2O,Eu(β-NPA)(TTA)_2·2H_2O均以~5D_0→~7F_2跃迁的荧光发射最强。得到了两种高效的红色荧光配合物Eu(β-NPA)_3·3H_2O,Eu(β-NPA)(TTA)_2·2H_2O,它们可望成为制备鲜艳红色发光材料的侯选。     

改性粉煤灰的制备及从烟气中吸收SO_2试验研究

研究了对粉煤灰进行改性并用以从烟气中吸收SO_2,考察了温度、m(Ca(OH)_2)/m(Na_2SiO_3·9H_2O)、液固体积质量比对粉煤灰改性的影响。结果表明:在m(Ca(OH)_2)/m(Na_2SiO_3·9H_2O)=2/1、温度80℃条件下,对粉煤灰改性14h,干燥2h,所得改性粉煤灰对烟气中SO_2的吸收量达137.998mg/g,吸收效果较好。     

Preparation and Characterization of Red Emitting Phosphor Ba_xCa_(3-x)(PO_4)_2∶Ce, Mn

Preparation and Characterization of Red Emitting Phosphor Ba_xCa_(3-x)(PO_4)_2∶Ce, Mn     

A hydrometallurgical method of energy saving type for separation of rare earth elements from rare earth polishing powder wastes with middle fraction of ceria

This study described a hydrometallurgical method to investigate the separation of rare earth elements(REEs)from rare earth polishing powder wastes(REPPWs)containing large amounts of rare earth oxides with a major phase of CeO_2 and minor phases of La_2O_3,Pr_2O_3,and Nd_2O_3 using a process devised by the authors.The suggested approach consisted of five processes:the synthesis of NaR E(SO_4)_2·xH_2O from rare earth oxides in Na_2SO_4-H_2SO_4-H_2 O solutions(Process 1),the conversion of NaR E(SO_4)_2·xH_2O into RE(OH)_3 using NaO H(Process 2),and the oxidation of Ce(OH)_3 into Ce(OH)_4 using air with O_2 injection(Process 3),followed by Processes 4 and 5 for separation of REEs by acid leaching using HCl and H_2SO_4,respectively.To confirm the high yield of NaR E(SO_4)_2·xH_2O in Process 1,experiments were carried out under various Na_2SO_4 concentrations(0.4–2.5 mol/L),sulfuric acid concentrations(6–14 mol/L),and reaction temperatures(95–125 oC).In addition,the effect of the pH value on the separation of Ce(OH)_4 in HCl-H_2 O solutions with Ce(OH)_4,La-,Pr-,and Nd(OH)_3 in Process 4 was also investigated.On the basis of above results,the possibility of effective separation of REEs from REPPWs could be confirmed.     

6061铝合金表面稀土铈盐法处理工艺研究

采用稀土盐Ce(NO_3)_3·6H_2O作为主盐、H_2O_2为强氧化剂,研究出新型6061铝合金无铬转化工艺,并通过抗蚀性能测试、转化膜膜厚测试等方法对其转化后的耐腐蚀性能进行分析。结果表明,最佳成膜工艺参数,Ce(NO_3)_3·6H_2O浓度为15g·L~(-1);H_2O_2浓度为4m L·L~(-1);处理温度为35℃,处理时间为10 min;pH为3.5。稀土铈转化膜的生成可以显著降低6061铝合金的腐蚀速率,提高金属基体的耐腐蚀性能。     

(NH_4)_2〔Ce(NO_3)_6〕的制备及其水溶性研究

着重讨论水溶性较大的(NH_4)_2 〔Ce(NO_3)_6〕络合物制备过程中酸度、硝酸铵量、温度等对其合成的影响,并用(NH_4)_2 〔Ce(NO_3)_6〕-NH_6NO_3-H_2O的罗什布相图说明硝酸高铈铵在硝酸铵的水溶液中的溶解度变化。     

Synthesis,photoluminescence properties and thermal investigation by TG-MS of RE(DAS)_3·xH_2O(RE=Eu~(3+),Tb~(3+))

Rare earth(Ⅲ) diphenyl-4-amine sulfonates(RE(DAS)_3·xH_2O,RE=Eu~(3+),Tb~(3+))phosphors were synthesized by precursor method from barium diphenyl-4-amine sulfonate and rare earth sulfates.FTIR,TG/DSC coupled to mass spectrometry(TG/DSC/MS),X-ray powder diffraction(XPD),scanning electron microscopy(SEM) and photo luminesce nce(PL) spectroscopy were utilized to structurally and morphologically characterize the samples.Thermal decomposition of Eu(DAS)_3·7H_2O and Tb(DAS)_3·2H_2O at 973 K under dynamic air atmosphere results in crystalline Eu_2O_2SO_4 and Tb_2O_2SO_4 materials,respectively.Accordingly,MS spectra reveal the liberation of thermal decomposition products of precursors,largely as CO_2,NO_2 and SO_2 gases.The diphenyl-4-amine sulfonate(DAS) ligand demonstrats a good stabilizing property for Eu~(3+) and Tb~(3+) ions.The Eu(DAS)_3·7H_2O and Tb(DAS)_3·2H_2O compounds display efficient red and green emissions,under UV excitation,arising from the ~5D_0→~7F_J(J=0-4) and ~5D_4→~7F_J(J=0-6) transitions of the Eu~(3+) and Tb~(3+) ions,respectively.     

湿法炼锌铁钒除铁工艺管路结晶的机理探讨

通过对湿法炼锌过程所涉及的三元体系M_2SO_4-ZnSO_4-H_2O(M=K,Na,NH4)溶解度相图的比较研究,发现在上述三元体系中,在一般的冶炼工艺条件下,复盐(如(NH_4)_2SO_4·ZnSO_4·6H_2O(s)、Na_2SO_4·ZnSO_4·4H_2O(s)、K_2SO_4·ZnSO_4·6H_2O(s)远比单盐(如ZnSO_4·7H_2O(s)、Na_2SO_4(s)、K_2SO_4(s))要容易析出得多。这些复盐在溶液中的溶解度均随着温度的降低而降低,是管路结晶的主要诱因。溶解度较小的((NH_4)_2SO_4·ZnSO_4·6H_2O(s)生成是导致黄铵铁钒除铁过程管路易结晶堵塞的主因。     

(NH_4)_2HPO_4-NH_3·H_2O-H_2O系APT溶解度研究

采用溶解平衡法研究了(NH_4)_2HPO_4-NH_3·H_2O-H_2O系APT的溶解性能。随着氨水浓度增大,APT溶解度由略微下降转为较快上升,溶液中磷钨杂多酸浓度大幅降低,而同多钨酸根和正钨酸根浓度大幅升高。相同磷酸氢二铵浓度下(NH_4)_2HPO_4-NH_3·H_2O-H_2O系APT溶解度远大于(NH_4)_2HPO_4-H_2O系。     

砷酸钙渣形成类型的热力学分析

Ca-As盐的形成发生于含砷溶液的钙盐沉淀及砷在地下水迁移的过程中。通过热力学计算,绘制了25℃时Ca~(2+)-AsO_4~(3-)-H_2O系热力学平衡图,并考察了Ca/As摩尔比对沉淀的物相组成及沉淀效果的影响。结果表明,在0pH14范围内,Ca~(2+)-AsO_4~(3-)-H_2O系可形成4种固体物相,分别为CaHAsO_4·H_2O(_s)、Ca_3(AsO_4)_2·4H_2O(_s)、Ca_5(AsO_4)_3OH和Ca_4(OH)_2(AsO_4)_2·4H_2O(_s)。当Ca/As2时,CaHAsO_4·H_2O(_s)和Ca_3(AsO_4)_2·4H_2O(_s)的稳定区随着pH的增大而缩小,Ca_5(AsO_4)_3OH的稳定区随pH增大而扩大。当Ca/As2时,Ca_4(OH)_2(AsO_4)_2·4H_2O_((s))才能形成。结合已有研究,认为要达到理想的脱砷效果,Ca/As应该大于2,且溶液中应该保持较高的游离钙浓度。     

硫酸高铈催化缩醛(酮)反应

本文研究了硫酸高铈(Ce(SO_4)_2·4H_2O)对缩醛(酮)反应的催化作用,系统地探讨了各反应因素对反应的影响,研究发现硫酸高铈具有较高的催化活性,并使后处理简化。