具有不同形貌和择优取向的MxWO3·xH2O粉晶的制备与表征

采用沉淀结合渗析的方法，以钨酸钠、钨酸铵为原料，制备了不同形貌、具有择优取向的M_xWO₃·xH₂O(M=Na⁺，NH₄⁺，x<1)粉晶，利用SEM、XRD、TG、IR、XPS等手段对粉体进行表征，考察了不同渗析时间和焙烧温度对粉晶形貌、晶化程度及结构转变的影响。结果表明，长时间渗析后粉体的晶化程度明显提高，并沿(010)晶面方向择优生长，形貌由不规则形变为梭形和蝴蝶形。经空气气氛400 ℃焙烧后，Na_xWO₃·xH₂O和(NH₄)_xWO₃·xH₂O粉晶均转变为沿(200)晶面方向择优生长的立方青铜相，且形貌也发生改变。     

Synthesis of Strontium Carbonate by the Induction of Microbiology

Spherical strontium carbonate was synthesized by the induction of microbial bacillus pasteurii at ambient temperature with strontium chloride and urea as the raw materials. The phase composition, particle size and morphology of the product were studied by XRD and SEM. The results indicated that the strontium carbonate synthesized by the induction of microbial bacillus pasteurii was of good dispersion and uniform particle size. The spherical strontium carbonate particles obtained by adding different control agents were constructed by numerous flakes or olive-shaped nano-particles. The products were orthorhombic according to their XRD patterns.     

异烟酸在碱性溶液中金电极上的现场表面增强振动光谱研究

应用表面增强红外吸收光谱法、循环伏安法和微分电容法研究了0.1 mol•L^－1 KClO₄和0.1 mol•L^－1 KCl碱性化溶液(pH 10)中, 异烟酸(INA)在Au电极表面的吸附取向和结构. 结果表明: －0.5～0.2 V (vs. SCE)间INA阴离子(INA^－)通过其羧酸根上的两个氧原子垂直吸附在Au电极表面; 特性吸附Cl^－对上述吸附结构无实质影响. 进一步的表面增强拉曼光谱的测试表明即使在－0.8～－0.5 V, 极少量吸附的INA^－很可能仍维持上述基本构型.     

Nafion? / TiO2复合膜的质子传导性能研究

Nafion^® / TiO₂ composite membranes were prepared by in-situ chemical reaction method using Ti(OC₄H₉)₄ and Nafion^® 117 as raw materials. The membranes were characterized by UV, FTIR-ATR and XRD, respectively. Methanol permeability and water uptake were investigated as a function of TiO₂ contents. The conductivity of the membranes was measured under water vapor pressure (2.644 7 kPa) or in dry atmospheres. The XRD results showed that the titanium dioxide in Nafion^® membranes were crystallized in anatase phase with an average crystaline diameter of 3.0 nm. The water uptake of the composite membranes was larger than that of the pure Nafion^® membrane when the TiO₂ loading was within 14wt%. The methanol permeability of the membrane decreased as the TiO₂ loading increased. The addition of 3wt% TiO₂ to Nafion^® membranes improved the conductivity in dry measurement conditions. The proton conductivity of the composite membrane increased greatly after the hydrothermal treatment at 160 ℃ for 2 hours.     

A Nanospherical Metal–Organic Framework UiO-66 for Solid-Phase Microextraction of Polycyclic Aromatic Hydrocarbons

Polycyclic aromatic hydrocarbons are a low content, but highly toxic organic pollutant in the environment. Because of their great threat to the health and survival of humans and other creatures, it is necessary to have a very simple and convenient as well as highly sensitive method to detect them. Based on previous studies, a nanospherical metal–organic framework UiO-66 was re-applied as the solid-phase microextraction coating and the extraction performance of polycyclic aromatic hydrocarbons was investigated. Scanning electron microscope and X-ray diffraction were used to characterize the extraction material. The extraction conditions were optimized factor by factor, and the analytical method was established with broad linear ranges (0.03–50 and 0.10–50 µg L^?1), excellent correlation coefficients (0.9955–0.9993) and low limits of detection (0.01–0.03 µg L^?1). The analytical method was applied to detect polycyclic aromatic hydrocarbons in rainwater and lake water, and satisfactory results were obtained. Compared with previous reports, this method had wider linear range, lower limit of detection and longer service life.     

(Pr0.9La0.1)2(Ni0.74Cu0.21Ga0.05)O4+δ纳米纤维阴极的制备及电化学性质

采用静电纺丝法制备了(Pr_(0.9)La_(0.1))_2(Ni_(0.74)Cu_(0.21)Ga_(0.05))O_(4+δ)(PLNCG)氧化物纳米纤维。利用热重-差热分析(TG-DTA)、X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)和扫描电子显微镜(SEM)对材料的物相及微观形貌进行分析。研究表明950℃煅烧5 h得到平均直径420 nm、形貌均一的PLNCG氧化物纤维;1 000℃烧结2 h得到紧密附着在Ce_(0.9)Gd_(0.1)O_(2-δ)(CGO)电解质上的网状结构纤维阴极。电化学阻抗谱(EIS)测试结果表明纳米纤维阴极具有比粉体阴极更优越的性能。700℃的极化电阻(RP)为0.134Ω·cm~2,比同组分的粉末阴极减少32%(RP=0.197Ω·cm~2)。以纤维阴极构筑的电解质支撑单电池Ni-CGO/CGO/PLNCG在700℃的最大输出功率密度为231 m W·cm-2。氧分压测试结果表明阴极反应的速率控制步骤为电荷转移过程。     

柚皮苷与人血清白蛋白相互作用的研究

用荧光、紫外光谱、分子对接研究了柚皮苷与人血清白蛋白(HSA)在pH=7.40的Tris-HCl缓冲溶液中相互作用的情况。结果表明,柚皮苷对人血清白蛋白的内源荧光有明显的猝灭作用,猝灭过程为动态猝灭。根据Stern-Volmer方程计算得到柚皮苷与HSA在293、298和310 K下的结合常数分别为2.472×105、2.210×105和1.392×104L·mol-1,结合位点数约为1。由实验计算出热力学参数焓变ΔH为-16.8 kJ·mol-1,ΔS为46.0 J·mol-1·K-1,推断出柚皮苷与人血清白蛋白之间主要靠疏水作用和静电引力结合,与分子模拟的结果相同。同时采用同步荧光技术考察了柚皮苷对HSA构象的影响。     

菜花状纳米氧化锌的溶剂热合成及气敏性能研究

以Zn(NO₃)₂·6H₂O和NaOH为原料,采用溶剂热合成技术制备了菜花状氧化锌纳米粉体,采用X射线衍射仪、扫描电镜和X-射线光电子能谱仪等对产物的物相、微观形貌和表面元素状态进行了表征,结果表明产物属于六方晶系的ZnO,呈规则的菜花状,分散性好,粒径90～100 nm,粉体表面存在大量的吸附氧。用该粉体制成厚膜型旁热式气敏元件,测试结果发现：在加热电压为6 V时气敏元件对甲醇、乙醇、正丙醇、丙酮、苯和甲苯等还原性气体具有较高的灵敏度,特别是对正丙醇、丙酮有较好的选择性,可以检测浓度低至1 μL·L^-1的乙醇、正丙醇和丙酮。     

“宠物毒粮”中的假冒蛋白质——三聚氰胺

详细介绍了三聚氰胺的结构、制备和性质;从各个角度分析了它的毒性,分析了它对人和动物的危害。     

自动增益控制的自触发脉冲激光测距技术

文中提出了一种具有自动增益控制的自触发脉冲测距方案,不但减小脉冲信号上升沿 引起的测距误差,而且也减小由于信号幅度变化带来的漂移误差影响。实验结果表明:该激光脉冲测距系统在1m～10m的测距范围内,测距精度达到亚毫米级。