斜投影-不展开薄层色谱法对废木料液化产物乙酰丙酸的过程分析

采用多波长薄层色谱扫描法,不经过传统的薄层色谱展开步骤实现混合体系的快速定量。废木料液化过程产物为混合体系,分别将不同液化反应时间点所取样品点样于硅胶板上。仅对液化过程终点的样本点进行一次展开,分离斜投影建模所需的反射光谱,切割出目标产物(乙酰丙酸)和背景光谱,构造斜投影算子;对其他液化过程中的样品点不展开,采集混合光谱,经斜投影算法分离出其中的目标产物纯光谱,从而实现定量。将该方法的定量结果与高效液相色谱法的定量结果对比,得到两种方法测定乙酰丙酸的相对误差小于3.27%,表明两种方法具有良好的一致性。     

无机化学中的一题多解

无机化学计算中采取一题多解可开拓学生的思维,加深对化学基本原理的理解和掌握,有利于巩固和提高所学知识,并加以灵活运用,做到触类旁通。文章以无机化学教学中化学平衡、电极电势2类问题的计算给予说明。     

Amphiphilic ABC Triblock Terpolymer Templating for Mesoporous Silica

Self-assembled triblock terpolymers have attracted intense attention in recent years because of their abundant variety of assembly mesostructure. We reported the synthesis of mesoporous silica materials with the am- phiphilic ABC triblock terpolymer polyethylene-poly（ethylene oxide）-polycaprolactone（PE-PEO-PCL） as a template and tetraethoxysilane（TEOS） as a silica source. Increasing the hydrophilic head group（PEO） led to the decrease of packing parameter g, which gave rise to the mesophase transformation from a cylindrical two-dimensional hexagonal P6mm structure to a cage-type face centered cubic closed-packing mesostructure. This new templating route provided a new insight into the template factor governed inorganic-organic self-assembly mesophases.     

New Half-sandwich Zirconium（IV） Complexes Containing Salicylaldimine Ligands： Synthesis,Characterizations and Catalytic Properties

Two new half-sandwich zirconium（IV） complexes bearing salicylaldimine ligands of the type Cp＊Zr[2-tBu-4-R-6-（CH=NiPr）C6H2O]C12[R=H（1）, tBu（2）] were prepared by the reaction of Cp＊ZrC13 with the corresponding lithium of salicylaldimine ligands 2-tBu-4-R-6-（CH=NiPr）C6H2OLi[R=H（LiLa）, tBu（LiLb）]. Com- plexes 1 and 2 were characterized by 1H NMR, BC NMR spectroscopy and elemental analysis. When activated with AliBu3 and Ph3CB（C6F5）4, both complexes 1 and 2 exhibited reasonable catalytic activities for ethylene polymeriza- tion, producing polyethylenes with moderate molecular weight. Complexes 1 and 2 also exhibited reasonable catalyt- ic activities for ethylene copolymerization with 1-hexene, producing poly（ethylene-co-l-hexene）s with moderate molecular weight and reasonable 1-hexene content.     

含FEC电解液的锂离子电池低温性能研究

研究含FEC溶剂电解液(FEC+EMC,EC,PC)的低温性能及其与磷酸铁锂正极或中间相碳微球(MCMB)负极的匹配.该电解液具有较高的低温电导率,FEC可在1.6 V与负极反应成膜,有效地提高负极稳定性.红外测试发现,FEC可抑制其它电解液溶剂在负极成膜过程中的分解,在常温(20℃)和低温(-20℃)下形成的SEI膜阻抗均较低.电化学测试表明,以该电解液装配的锂离子电池(电极)具有较高的低温放电容量和倍率性能.     

New Supramolecular Networks Based on Paratungstate with N-Donor Bridging Ligands

Three new supramolecular networks based on paratungstate and N-donor bridging ligands, [H₂bpmp]_2.5H[H₂W₁₂O₄₀]2H₂O(1), [H₂(bpp)]₂[H(py―CH₃)]_0.25[H(py―C₂H₅)]_0.25H_1.5[H₂W₁₂O₄₀]·4H₂O(2) and [H₂pip]₃[H₂W₁₂O₄₀](3)[bpmp=N,N'-bis(4-pyridylmethyl)piperazine; bpp=1,3-bis(4-pyridyl)propane; py=pyridine; pip=piperazine] were prepared by the hydrothermal synthesis and characterized by elemental analysis, infrared(IR), thermogravimetric(TG) analysis and single-crystal X-ray diffraction(XRD). All the compounds show high-dimen- sional supramolecular networks based on [H₂W₁₂O₄₀]^6- and the protonated N-donor ligands via the N―H···O―W hydrogen bonds and/or π···π stacking interactions. Their luminescent properties were investigated.     

Hydrothermal Synthesis and Dielectric Characterization of a Double Perovskite Ba2FeSbO6

A double perovskite oxide Ba₂FeSbO₆ was hydrothermally synthesized and structurally characterized by X-ray diffraction. This solid compound shows a single phase and has a trigonal structure with space group R m and cell parameters of a=0.57261 nm and c=1.40244 nm. The dielectric constant and loss tangent of the solid measured in a frequency range from 100 Hz to 1 MHz at temperatures from 313 K to 513 K reveal a relaxation process of frequency dependence of the real part(ε') of dielectric constant and dielectric loss tand. The frequency dependence of electrical property led to the framework of conductivity and electric modulus formalisms. The scaling behavior of imaginary part of electric modulus suggests that the relaxation describes the single mechanism at various temperatures. The variation tendency of the alternating current impedance indicates the thermally activated conduction process follows Jonsche’s power law.     

pH值对金刚石表面化学镀镍的影响

本文以金刚石颗粒表面化学镀的方法镀覆镍金属层为背景,通过X射线衍射(XRD)、扫描电镜(SEN)等测试手段研究了pH值对镀层的组织、形貌及镀速的影响.结果表明:当镀液的pH值低于10.5时,镀速几乎为零,反应不能发生;pH值在10.5 ～ 12时,镀速随pH值的增加而增大,且镀速增加较快,XRD图谱中有镍峰存在,镍峰随pH值的增加而增强,基体有裸露现象;当pH值在13左右时,镀速较为稳定,镍衍射峰较强,镀层较为均匀,无裸露现象;pH值接近14时,镀层较为粗糙,且有脱落现象.在pH值等于13的条件下二次化学镀,基体表面得到的镀层厚度大约为1.5 μm,镀层致密度较好,且包覆严实.     

纳米非晶碳薄膜的制备及其场致电子发射特性

采用微波等离子体增强化学气相沉积(MPECVD)法,在涂有FeCl3的硅衬底上制备出了纳米非晶碳薄膜.通 过SEM、XRD和拉曼光谱分析了薄膜材料的形貌和结构.并研究了薄膜材料的场发射特性.结果表明:薄膜的开启电场仅为0.39 V/μm;当电场强度为1.85 V/μm时,电流密度高达3.06 mA/cm2;且场发射点均匀、密集、稳定.迭代法计算表明薄膜材料的功函数为3.1 eV,发射点密度约为1.7×105个/cm2.这些均表明该薄膜是一种性能优良的场发射阴极材料.     

舰船单轴旋转激光捷联惯导系统动态初始对准

初始对准的时间和精度是舰船惯导系统的重要指标。针对在不同情况下惯导系统启动的实际工程需求,提出了单轴旋转激光捷联惯导系统的初始对准方案。研究了系统在动基座情况下进行粗对准方法。建立了单轴旋转惯导系统的误差模型,使用卡尔曼滤波的方法实现了系统精对准过程。分别对惯导系统三种不同动态启动条件,设计了不同的对准方案。数字仿真结果表明,经过6h的初始对准,垂向陀螺常值漂移的对准误差在设定值的5.2%以内,垂向加表零偏的对准误差在设定值的1.8%以内。