The development of Pd-based bimetallic nanoalloys (NAs) with abundant active sites for achieving highly efficient electrocatalysis in alcohol oxidation deserves continuous attention. Herein, we utilized a facile visible-light-assisted liquid-phase method involving adjusting reaction time to generate active sites, successfully synthesizing one-dimensional (1D) PdAg NAs rich in defects. The optimized 1D PdAg NA exhibits remarkable electrochemical activity, stability, and antipoisonous properties in glycerol oxidation reaction (GOR) and ethanol oxidation reaction (EOR), far exceeding pure Pd and commercial Pd/C catalysts. Notably, compared to glycerol oxidation (1496 mA mg-1 Pd and 4.13 mA cm-2), the optimized PdAg NA demonstrated higher mass activity (2990 mA mg-1 Pd) and specific activity (7.86 mA cm-2) in ethanol oxidation. In summary, this work may provide a strategy for designing low-cost electrocatalysts enriched with defects, thereby promoting the development of high-performance alcohol oxidation reactions.

Pd-Ag bimetallic catalysts containing different molar ratios of Pd/Ag (30/70, 50/50, and 70/30) were prepared using a facile visible-light-assisted liquid-phase method. The samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, energy-dispersive X-ray spectros-copy, transmission electron microscopy, high-resolution transmission electron microscopy, high-angle annular dark-field scanning transmission electron microscopy, selected-area electron diffraction, and inductively coupled plasma optical emission spectroscopy. Cyclic voltammetry and chronoamperometry measurements were used to evaluate their electrocatalytic properties toward the methanol oxidation reaction (MOR) in alkaline media. The alloyed Pd50Ag50 nanowire network with the optimized molar ratio, which had abundant defects (grain boundaries, lattice dislocations, lattice expansion, and distortion), provided more active sites for the MOR under alkaline conditions. The onset potential of the MOR on the Pd50Ag50-loaded glassy carbon electrode (GCE) was more negative than those on the Pd30Ag70, Pd70Ag30, and pure Pd electrodes. The Pd50Ag50 catalyst showed the best catalytic activity (2853 mA mgPd  1/6.85 mA cmPd  2) compared with those of the pure Pd catalyst (320 mA mgPd  1/2.68 mA cmPd  2) and other samples. This sample also exhibited a high tolerance (ib/if = 0.19) to the poisoning species and long stability (only lost 7.64 % after 500 cycles). The alloyed Pd50Ag50 network is a promising catalyst for the MOR. This work may be extended to construct advanced Pd-M (M = other metals) catalysts for fuel cell applications by surface defect engineering.

为进一步研究风云三号(FY-3B)土壤水分降尺度获取高分辨率土壤水分的方法,使其更适用于农业、水文、生态等区域尺度的应用要求,以MODIS为数据源,青藏高原那曲地区为研究区,利用表观热惯量模型(apparent thermal inertia,ATI)与温度植被指数(temperature vegetation index,TVI)模型在不同植被覆盖度下适用的特点,构建综合ATI与TVI的土壤水分反演模型;结合低分辨率FY-3B土壤水分产品,利用土壤水分降尺度方法,获取高分辨率下土壤水分反演模型系数,并得到高分辨率土壤水分.通过与地面观测数据对比,降尺度后土壤水分与实测数据的R2在0.4以上,RMSE在0.055～0.103 cm3/cm3之间,表明降尺度后的土壤水分能够较好地反映区域土壤水分的空间分布与变化.

那曲地区作为我国"五大牧区"的重要组成部分,其地表温度的监测对农业、 环境、 气象等领域具有重要意义.为进一步分析FY-3B/VIRR地表温度遥感产品在那曲地区的适用性,利用第三极土壤水分和温度监测网络(Soil Moisture and Temperature Monitoring Network on the central TP,TP-SMTMN)地面观测数据,对2012年1月—2014年12月FY-3B/VIRR地表温度产品进行对比,并分析其地表温度分布变化特征.结果表明,FY-3B/VIRR地表温度与大多数地面观测站观测值的决定系数(R2)在0.5以上,FY-3B/VIRR地表温度值高于地面观测值,均方根误差(Root Mean Squard Error,RMSE)小于7 K.那曲地区地表温度南部较高,北部较低,整体呈现由北到南逐渐升高的格局;地表温度季节变化明显,夏季地表温度高于秋冬季;2012—2014年地表温度变化较小,中部地区变化较大.

Octyl(triphenylethynyl)silane monomer(OTPES) was synthesized with ethyl bromide, octyltrichlorosilane and phenylethylene by Grignard reaction. The molecular structure was confirmed by FTIR and NMR. The poly[octyl(triphenylethynyl)]silane resin(POTPES) was prepared by thermal polymerization and the corresponding thermal degradation behavior wasstudied by thermogravimetric analysis(TG) combining with model and model-free fitted methods. The dielectric property of resin was also studied by vector network analyzer. The results show that the melt point of OTPES was 50 °C and the processing window was over 236 °C. The resin degradation temperature of Td5 occurred over 433 °C and the char yield was over 60% at 800 °C. Based on Kissinger, Flynn-Wall-Ozawa, Coats-Redfern, Achar, Vyazovkin-Wight and Tang methods, the reaction activity(E) was 155.51, 152.97, 150.82, 146.02, 148.38 and 148.77 kJ/mol, respectively. Dielectric properties analysis displayed that the real part(ε′) and the imaginary part(ε″) of the relative complex permittivity of POTPES was 2.5 and 0.05, respectively, and the dielectric loss tangent was between 0.03 and 0.25. The reflection loss of resin was more than −2.85 dB in all range of 1–5 mm thicknesses and 2–18 GHz frequency, which indicated that POTPES resin was a real wave-transparent resin matrix.

Using palladium nitrate and silver nitrate as the metal precursor, ethanol and sodium citrate tribasic dehydrate as reducing agents and poly (vinyl pyrrolidone) (PVP) as a stabilizer and guiding agent, Pd-Ag alloy nanowires were synthesized via visible-light-assisted solution approach with a commercial incandescent lamp as light source. The morphologies, crystal structure and optical properties were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), power X-ray diffraction (PXRD), and UV-visible spectroscopy, respectively. The electrocatalytic properties of the Pd-Ag alloy nanowires modified glassy carbon electrode for ethanol oxidation were investigated by cyclic voltammetry and chronoamperometry. The Pd-Ag alloy nanowires exhibited much better electrocatalytic performance than Pd nanoparticles toward ethanol oxidation reaction in alkaline media in terms of the electrocatalytic activity, anti-poisoning ability and stability.

Sea anemone-like palladium (Pd)/polyaniline (PANI) nanocomposites were synthesized via visible-light-assisted swollen liquid crystals (SLCs) template method. The resulting samples were characterized by transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive spectrometer (EDS), x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), ultraviolet-visible (UV–vis) absorption spectroscopy and Fourier transform infrared (FT-IR) spectroscopy, respectively. The electrocatalytic properties of Pd/PANI nanocomposites modified glass carbon electrode (GCE) for methane oxidation were investigated by cycle voltammetry (CV) and chronoamperometry. Those dispersed sea anemone-like Pd/PANI nanocomposites had an average diameter of 320 nm. The obtained Pd nanoparticles with an average diameter of about 45 nm were uniformly distributed in PANI matrix. Sea anemone-like Pd/PANI nanocomposites exhibited excellent electrocatalytic activity and stability for oxidation of methane (CH4).

“Sea-island” structure silver/polyaniline (Ag/PANI) nanocomposites were synthesized through sonication of an aqueous solution with silver nitrate and aniline at the temperature of 20 ± 1°C under nitrogen atmosphere. The nanocomposites were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet–visible absorption spectroscopy, field emission scanning electron microscopy, and energy dispersive spectrometry, respectively. Furthermore, Ag/PANI nanocomposites were immobilized on the surface of glassy carbon electrode (GCE) and electroactivity behavior was investigated by cyclic voltammetry and differential pulse voltammetry. The obtained sea-island structured Ag/PANI nanocomposite-modified GCE showed high electrocatalytic activity for the oxidation of l-tyrosine.

采用微乳液聚合法,以十二烷基磺酸钠为乳化剂、过硫酸铵为引发剂、盐酸为质子掺杂酸、苯胺为原料制得酸掺杂聚苯胺.运用傅里叶变换红外光谱仪对聚苯胺的结构进行表征,探究浓盐酸掺杂量对聚苯胺电导率的影响,以及聚苯胺流变性能和热分解动力学研究.结果表明,掺杂酸量对电导率有明显影响,当浓盐酸掺杂量为6.5mL时,聚苯胺具有良好的电导率,平均电导率为1.360S/cm;聚苯胺的热分解反应平均活化能为93.66kJ/mol.

Diphenyldiphenylethynylsilane monomer (DPDPES) was synthesized with ethyl bromide, diphenyldichlorosilane and phenylacetylene by Grignard reaction. The molecular structure was characterized by FTIR and H-1-NMR spectroscopy. The polymer of polydiphenyl (diphenylethynyl) silane (PDPDPES) was also prepared by thermal polymerization. Non-isothermal thermal decomposition process of PDPDPES was studied with TG-DTG technology via model method to get thermal decomposition function and the corresponding mechanism which was further verified by model-free method. Results show that the apparent activation energy and the pre-exponential factor are about E-a = 245. 37kJ/mol and lgA=13. 78s(-1) obtained by six different kinetic methods, respectively. The mechanism of functions are f(alpha) = 10/23 . (1-alpha) . [-ln(1-alpha)](-1.3) and g(alpha) = H ln(1-alpha)(2.3).

A facile visible-light-assisted method has been demonstrated to synthesize palladium (Pd) nanoparticles (NPs) with single-crystalline multiple-twinned structures by reduction of PdCl2. The structures and electrochemical properties of Pd NPs were investigated by high resolution transmission electron microscopy (HRTEM), UV-visible spectroscopy, and cyclic voltammetry (CV). The results show that the formation of different nanostructures depends on the control of reduction rate. Unlike multiple-twinned Pd NPs, single-crystalline Pd NPs exhibit surface plasmon resonance (SPR) peaks in the visible region. By comparison of the electrochemical parameters in the oxidation process of Pd NPs with single-crystalline and multiple-twinned structures, multiple-twinned Pd NPs exhibit the better electrocatalytic activity and anti-poisoning capability for ethanol oxidation.

结合多年教学经验,通过分析《高分子化学》在高分子专业人才培养中的重要地位以及目前教学过程中存在的问题,总结了四点教学心得.

以苯胺、硝酸银为原料,在氮气氛围保护且不加氧化剂的稀硝酸溶液中,超声辐射合成Ag/PANI纳米复合材料.利用XRD、FT-IR、FESEM、EDS分别对产物的结构和形貌进行表征,并对Ag/PANI纳米复合材料修饰玻碳电极在电化学中对酪氨酸的电催化氧化情况进行研究.结果表明,Ag纳米粒子聚集体直径为(50±1)nm,均匀分布在PANI基体中,Ag/PANI纳米复合材料修饰电极对酪氨酸有较高的电催化活性.

On the basis of previous work and literature research,the necessity of porous polysulfone microspheres was summarized,and a reasonable experimental method was proposed. The main factors,including emulsion type,emulsifier,temperature,volume of water phase and oil / water ration,were determined through analyzing the complexity of fabricating porous polysulfone microspheres. Finally orthogonal scheme of it was designed by choosing different level of each factor.

采用微乳液聚合法,以十二烷基磺酸钠为乳化剂(SDS)、过硫酸铵为引发剂(APS)、苯乙烯为原料合成了聚苯乙烯(PS).运用静电纺丝工艺对聚苯乙烯进行纺丝,探究纺丝液、纺丝电压、外加磁场和聚苯乙烯摩尔质量对聚苯乙烯纺丝纤维可纺性影响.运用扫描电子显微镜(SEM)对聚苯乙烯纺丝纤维的形貌进行表征,结果表明,一定范围内的纺丝液浓度、纺丝电压、外加磁场和聚苯乙烯摩尔质量均对纺丝纤维结构产生重要影响.

Using palladium chloride (PdCl2) as the palladium precursor, ethanol as reducing agent and poly (vinyl pyrrolidone) (PVP) as a stabilizer and guiding agent, palladium (Pd) multiply twinned particles (MTPs) were synthesized via photothermally assisted solution approach with visible light from a commercial energy -saving lamp as light source. The morphologies, crystal structure, optical properties and the stability of Pd MTPs were characterized by high resolution transmission electron microscopy (HRTEM), fast Fourier transformation (FFT), powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), UV -Visible spectroscopy and Fourier transform infrared (FT-IR) spectroscopy, respectively. The electrocatalytic properties of the Pd MTPs modified glassy carbon electrode for ethanol oxidation were investigated by cyclic voltammetry. The results showed that the formation of Pd MTPs depends on the coordination interaction of light and thermal effects. Surface plasmon resonance (SPR) peak of Pd MTPs is located at the visible region. This material exhibits remarkable electrocatalytic activity and anti -poisoning faculty for the ethanol oxidation.

以甲基三氯硅烷、苯乙炔为原料,通过格利雅反应成功制备甲基三苯乙炔基硅烷单体(MTPES).采用傅里叶红外光谱(FT-IR)、核磁氢谱(1H-NMR)表征其分子结构,并采用非等温差示扫描量热法(DSC)结合四种常见的固化动力学分析(Kissinger、Ozawa、Flynn-Wall-Ozawa、Friedman)获得了MTPES的动力学参数和固化机理.实验结果表明,MTPES单体的熔点为130℃,固化过程符合自催化反应模型,固化表观活化能为112.58kJ/mol,指前因子lnA为21.22s-1,反应级数n、m分别为1.20、0.56.

在没有氮气保护的作用下,以N,N'-亚甲基双丙烯酰胺(NMBA)为交联剂,以过硫酸铵(APS)为引发剂,采用静置热聚合法合成2-丙烯酰胺基-2-甲基丙磺酸(AMPS)/丙烯酰胺(AM)/羧甲基纤维素钠(CMC)三元共聚高吸水树脂.研究了反应条件对树脂吸水率的影响,并借助FT-IR、TG-DTA和偏光对树脂的分子结构、热稳定性和表面形态进行了分析.实验结果表明:所得树脂的最佳反应条件为:n(AM)∶n(AMPS)=1∶1、ω(APS) =0.45％、ω(CMC)=9％、ω(NMBA)=0.085％和pH=1.2,在此条件下合成的高吸水树脂室温下最大吸蒸馏水倍率为909g/g.

The rheological properties of phenyl(triphenylethynyl)silane(PTPES), vinyl(triphenylethynyl)silane(VTPES), diphenyl(diphenylethynyl)silane(BPBPES) three monomers and their polymers(TSAR) were studied by rheometer. At the same time, the degradation reaction kinetics of TSAR was analyzed and the degradation mechanism was also proposed by kinetic theory. The results show that three monomers have an excellent processability with beyond 150 ℃ process window by rheological analysis. Char yield obtained by TG was about 70% at 800℃. The reaction order was 4 and reaction activation energy was E=131.2 kJ/mol by 8 different kinetic analysis methods.