Synergistic extraction of rare earth by mixtures of 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester and di-（2-ethylhexyl） phosphoric acid from sulfuric acid medium

The extraction of Nd^3＋ and Sm^3＋, including the extraction and stripping capability as well as the separation effect of Nd^3＋ or Sm^3＋, from a sulfuric acid medium, by mixtures of di-（2-ethylhexyl） phosphoric acid （HDEHP, H2A2（0）） and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester （HEH/EHP, H2L2（0）） were studied. The distribution ratios and synergistic coefficients of Nd^3＋ and Sm^3＋ in different acidities were also determined. A synergistic extractive effect was found when HDEHP and HEH/EHP were used as mixed extractants for Sm^3＋ or Nd^3＋. The chemical compositions of the extracted complex were determined as Nd.（HA2）2-HL2 and Sm.（HA2）2-HL2. The extraction equilibrium constants, enthalpy change, and entropy change of the extraction reaction were also determined.     

改性膨润土对苯酚和苯胺吸附规律的影响

目的为了更有效地处理有机废水中的苯酚和苯胺,同时开发新型、高效和价廉的吸附剂.方法采用自制的改性膨润土作为吸附剂进行吸附实验,研究了在不同的pH值、吸附温度、初始质量浓度和吸附时间等条件下,改性膨润土吸附苯酚和苯胺单组分溶液的规律.结果改性膨润土对苯酚和苯胺的吸附量随着pH值的升高呈现下降的趋势;随着初始质量浓度的升高,吸附量呈现减小的趋势;随着吸附温度的升高,吸附量呈现下降的趋势;改性膨润土对苯酚的饱和吸附量约为2.1 mg/g,对苯胺的饱和吸附量约为3.7 mg/g.结论试验所得改性膨润土对苯酚和苯胺的吸附规律,可以为改性膨润土在水处理中的应用提供参考.     

Influence of fuels on the morphology of undoped Y3Al5O12 and photoluminescence of Y3Al5O12:Eu prepared by a combustion method

Undoped and Eu-doped yttrium aluminum garnet nano-powders were prepared by a facile combustion method with citric acid/ethylene diamine tetraacetic acid (EDTA) as fuels and nitrates as oxidizers. The precursors and powders calcined at 1030 °C were investigated using thermogravimetric (TG), differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscope (SEM), and Brunauer-Emmett-Teller (BET) surface area measurements. It was found that the powders could be indexed with a garnet structure. The grains were in shape of hemispherical with sizes between 60 nm and 100 nm. With decreasing the citric acid/EDTA ratio, the crystallite size decreased steadily and the specific surface area increased. Investigations of photoluminescence (PL) revealed that as-synthesized YAG:Eu³⁺ phosphor samples exhibited an orange emission band with a main peak at 591 nm under the excitation of 394 nm. As citric acid amounts increased, the quality of crystallinity became higher and the luminescent properties were monotonously enhanced.     

考虑浸泡水温影响的泥质粉砂岩破坏过程声发射特征试验研究

高地温水工隧洞、深部矿山工程中温度的变化对地下岩体的物理力学性质具有重要影响,目前不同水温浸泡下岩石破裂相关研究较少。本文将泥质粉砂岩置于自然干燥以及28℃(常温)、40℃、50℃、70℃、100℃共五种不同温度的水中浸泡至饱和,然后开展单轴压缩试验,研究了泥质粉砂岩的物理力学及声发射特征。研究结果表明:温度对泥质粉砂岩含水的影响存在一个临界转换点(本研究为40℃),当温度在28~40℃时,岩石含水能力被"弱化",当温度大于40℃时,泥质粉砂岩含水能力被"增强"。在28~100℃中,温度对泥质粉砂岩物理力学性质起"增强"作用,表现为弹性模量增加,刚度提升。当水温从28℃升高到40℃,声发射时域活动性增强,水温从40℃提高到100℃时,声发射时域活动性减弱。声发射能量b值和熵值曲线较好地体现了裂纹演化规律,水温越高,在形成主裂纹过程中,伴生裂纹出现的概率越低。     

Ion Exchange Induced Efficient N-Type Thermoelectrics in Solid-State

High-performance n-type solid-state ionic thermoelectrics (SS i-TEs) for low-grade heat harvesting are highly desired and challenging. Here, the design and synthesis of an efficient n-type mixed conductor via ion pair modulation is demonstrated, which consists of biguanide hydrochloride (MfmCl) and a poly(3,4-ethylenedioxythiophene) (PEDOT): poly(styrenesulfonate) (PSS) polymeric complex in a solid film. Theoretical calculations and nano/microstructure characterization reveal that the binding preference of ion pairs offers energetically favorable ion exchange in the matrix, which induces not only tightly bound Mfm PSS species but also favorable anion diffusion channels. Consequently, an enhanced ionic conductivity of 1.40 S m⁻¹ with a record highest negative thermopower of −46.97 mV K⁻¹ is achieved for the n-type mixed conductor thus far.     

In Situ Conversion Reaction Triggered Alloy@Antiperovskite Hybrid Layers for Lithiophilic and Robust Lithium/Garnet Interfaces

Garnet-type electrolytes demonstrate promising prospects in the field of solid-state lithium batteries owing to their superior ionic conductivity and high (electro)chemical stability toward Li metal, whereas the critical issue of Li dendrite growth and even infiltration throughout garnets limits their practical applications. Herein, a hybrid interlayer consisting of Li₃Bi alloy embedded in antiperovskite-type Li₃OCl matrix is in situ constructed at Li/Li_6.75La₃Zr_1.75Ta_0.25O₁₂ interface by taking the conversion reaction of BiOCl with Li metal. The lithiophilic nature of such interlayer enables an intimate contact of garnet against Li metal, guaranteeing a dramatically reduced interfacial resistance of 27 Ω cm². In addition, the inside electron-conducting Li₃Bi nanoparticles homogenize the interfacial potential distribution, while the outside ion-conducting Li₃OCl matrix with a bandgap of 5.06 eV blocks electron tunneling from Li bulk. Profiting from such synergistic effect, the resultant Li symmetric cell displays a high critical current density of 1.1 mA cm⁻², along with an ultralong cycling life of 1000 h at 0.5 mA cm⁻². Furthermore, the corresponding solid LiNi_0.6Co_0.2Mn_0.2O₂/Li cell delivers a high cycling stability for 150 times accompanied by a capacity retention of 82%. This study puts forward a potential solution for construction of functional layers at Li/garnet interfaces by making use of in situ conversion reaction.     

高钛渣作为光催化村料降解邻硝基酚的实验研究

通过以高钛渣为光催化材料降解邻硝基酚溶液的实验,研究了反应时间、添加强氧化剂H2O2、外加电场、溶液pH值对其光催化性能的影响.结果表明高钛渣对邻硝基酚具有较好的光催化效果.邻硝基酚的降解率随反应时间的增加而增大.强氧化剂H2O2能提高光催化材料降解率,在100 ml含3 mg的邻硝基酚溶液中,H2O2加入量为2 ml时最佳,光催化剂的光催化性能因外加电场的存在而有所提高,外加电场达到20 V后,其光催化性能显著提高.光催化效果最佳的pH值为6.     

一种自焙炭块的导热系数

利用激光脉冲法、铜卡量热计法和浸渍法分别测定了不同石墨化度的自焙炭块的热扩散系数α、恒压比热容ｃｐ和体积密度Ｄｂ,并据λ＝Ｄｂｃｐα求出２００～１１００℃该炭块的导热系数λ。结果表明：原始自焙炭块的λ值随温度升高而增大,这可能是由于测试过程中石墨化度随温度升高而明显增加,且λ值与石墨化度成正比所致;恒温下,λ值随石墨化度增加而增大;在石墨化度较高时,λ值随温度升高而稍有降低。当石墨化度在０．７以上时,国产自焙炭块的λ值接近美国ＵＣＡＲ炭砖的值