细结晶NHN基点火头药剂的性能研究

以细结晶NHN为点火头药剂,分别以聚乙烯醇(PVA)胶、羟丙基甲基纤维素胶以及赛璐珞无水乙醇胶为黏结剂,探究不同黏结剂对点火头发火性能和机械性能的影响;并在此基础上,尝试掺杂Fe₂O₃、Zr等添加剂以提高点火头药剂的性能。结果表明：以PVA胶为黏结剂的点火头表现出更好的点火性能、更高的机械强度;掺杂Zr后,点火头发火时火焰明亮刺眼,说明Zr参与点火过程,放出热量,增加了点火能力。     

汽车安全气囊用电点火药电感度研究

用电点火管的0.01%发火电流I_0.01%和99.99%发火电流I_99.99%表征汽车安全气囊用电点火药的电感度。研究了共沉淀物中苦味酸钾（KP）与高氯酸钾(KClO₄）质量比对电点火管1.2 A、2 ms和0.4 A、10 s发火性能的影响。实验结果表明,KP与KClO₄质量比为4.0∶6.0的共沉淀物,满足美国汽车行业USCAR—28标准规定的电点火管的功能指标。筛选了氟橡胶为电点火药的黏合剂,石墨为电点火药的惰性添加剂,并通过升降法测试了优化配方的电感度,I_0.01%=0.458 A、I_99.99%=0.851 A,满足电点火管的安全性和可靠性指标。共沉淀物中KP与KClO₄质量比为4.0∶6.0,外加质量分数3%的氟橡胶和适量石墨,可制备一种能满足汽车安全气囊用电点火管安全性和可靠性要求的电点火药。     

模板法制备多孔核/壳结构的Fe2O3/Al纳米铝热薄膜

通过聚苯乙烯(PS)胶晶球模板法制备出三维有序大孔(3DOM)α-Fe₂O₃薄膜骨架, 再利用磁控溅射将Al沉积到3DOM α-Fe₂O₃骨架上得到核/壳结构的Fe₂O₃/Al纳米铝热复合薄膜。扫描电镜(SEM)测试结果表明: 纳米Al均匀地附着在α-Fe₂O₃骨架表面, 骨架孔结构由原先的近圆形转变为Al沉积后的类菱形, 孔壁的厚度从32 nm增加到100 nm; 采用X射线能谱(EDS)对Fe₂O₃/Al纳米铝热薄膜的元素含量进行了分析; 由差示扫描量热法(DSC)分析显示铝热薄膜在490℃开始反应, 经历固-固和固-液两个反应阶段, 总放热量达到1374.7 J/g; 使用激光点火器对铝热薄膜进行点火, 薄膜飞溅出火花并伴有明亮刺眼的亮光, 整个发火时间达2.6 ms, 显示其能被点火并发生自蔓延反应, 可作为一种理想的点火材料。     

高稳定性(EDA)(FA)2[Pb3I10]层状钙钛矿薄膜的制备与表征

为了提高钙钛矿太阳能电池在潮湿环境中的稳定性, 采用一步法, 通过在DMF中混合(EDA)I₂、(FA)I和PbI₂, 将乙二胺离子引入钙钛矿晶格, 成功制备了一种具有较高稳定性的二维片层状的钙钛矿结构薄膜。通过原位掠入射X射线衍射(GIXRD)、X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见吸收光谱(UV-Vis)和原子力显微镜(AFM)等方法检测分析(EDA)(FA)₂[Pb₃I₁₀]在低湿度及高湿度环境下的结构、形貌以及光学性能变化。结果表明: 制备的 (EDA)(FA)₂[Pb₃I₁₀]薄膜在相同湿度环境下比当前广泛应用于钙钛矿太阳能电池的甲胺铅碘薄膜(CH₃NH₃PbI₃)稳定性更高; 薄膜的光学带隙约为1.67 eV, 与太阳能电池最佳带隙比较接近。另外, (EDA)(FA)₂[Pb₃I₁₀]薄膜在可见光范围吸光性能较好; 薄膜的粗糙度很小, 适合制备太阳能电池, 而且, 成本较硅基太阳能电池低廉, 在分子水平较CH₃NH₃PbI₃的可调谐性更大, 使钙钛矿太阳能电池在未来大面积应用成为可能。     

类石墨桥膜的发火可靠性研究

以相同工艺制作类石墨桥膜点火桥,对其进行蘸药等处理，形成点火头结构;升降法试验得到不同激发条件下50%发火时的电流或电压，并验证其发火可靠性；测试点火头的响应状态，得到裸桥状态下类石墨桥膜对不同能量输入的响应。以相同方式制作桥丝式点火头，得到发火参数与电压、电流特性。涂覆有150目下叠氮肼镍(NHA)的类石墨桥膜，99%恒流发火电流为325.65 mA；99%恒压发火电压为2.43 V；在电容47 μF条件下99%脉冲发火电压为10.45 V。同样蘸药的桥丝式点火头，99%恒流发火电流为89.61 mA；在电容47 μF条件下99%脉冲发火电压为4.72 V。对比发现，类石墨桥膜点火头在使用钝感药剂时可满足0.99（0.90置信度下）可靠度要求。     

HfO2铁电薄膜基MFIS存储结构中的高κ介电晶籽层效应研究:铁电正交相生长和界面电荷注入抑制(英文)

HfO₂基材料铁电场效应晶体管(FeFET)商业化应用面临的一个重要挑战是其疲劳特性差.本文提出,在基于金属-铁电-绝缘层-半导体(MFIS)栅叠层结构的FeFET中研发合适的高κ界面晶籽层(SL)以大幅度提升其疲劳性能.我们在ZrO₂, HfO₂,(HfO₂)_0.75(Al₂O₃)_0.25 (HAO)和Al₂O₃等典型的高κ介电SL上制备了Hf_0.5Zr_0.5O₂ (HZO)铁电薄膜,系统研究了HZO薄膜的微观结构、铁电性及其MFIS器件的存储特性.首先,揭示了HZO薄膜中铁电正交相的形核和生长不仅受高κ介电SL表面能的影响,而且其微观结构对HZO中正交相的形成也起到重要作用.其次,澄清了高κ介电晶籽层对MFIS结构存储特性的影响,通过精确计算的MFIS结构的界面层电场,对MFIS结构的存储特性做出了合...     

一步溶剂热法制备铋-氧化铋-溴氧化铋三元复合物及其可见光驱动催化降解亚甲基蓝

构建表面等离子体共振(SPR)、氧空位、异质结是提升半导体光催化剂催化活性的有效方式之一。本文通过改变Bi(NO₃)₃与KBr的摩尔比，采用一步溶剂热法合成了具有SPR效应和氧空位的Bi-Bi₂O₃-BiOBr三元异质结复合材料。利用XRD、电子顺磁共振(EPR)、XPS、SEM、TEM、UV-vis等手段对所得产物的晶相、元素组成和微观形貌进行表征分析，考察Bi(NO₃)₃与KBr的摩尔比对三元复合物可见光驱动光催化降解亚甲基蓝(MB)活性的影响。结果表明：Bi-Bi₂O₃-BiOBr的催化活性依赖于Bi(NO₃)₃与KBr的摩尔比，但高于纯Bi₂O₃和BiOBr。Bi(NO₃)₃与KBr摩尔比为2∶1制备的2∶1-Bi-Bi₂O₃-Bi...     

α籽晶促进低温反应溅射沉积α-Al2O3薄膜

分别使用反应溅射Al+α-Al₂O₃(15% α-Al₂O₃,质量分数)复合靶和在金箔基体表面预植α-Al₂O₃籽晶,促进α-Al₂O₃薄膜的低温沉积。使用扫描电子显微镜(SEM)、掠入射X射线衍射(GIXRD)和能谱仪(EDS)等方法表征薄膜样品的表面形貌、相结构和元素组成。结果表明,在射频反应溅射Al+α-Al₂O₃复合靶、沉积温度为560℃条件下能在Si(100)基体上沉积出化学计量比的单相α-Al₂O₃薄膜;使用射频反应溅射Al靶、沉积温度为500℃条件下能在预植α-Al₂O₃籽晶(籽晶密度为10⁶/cm²)的金箔表面沉积出化学计量比的单相α-Al₂O₃薄膜。两种研究方案的结果均表明,α-Al₂O₃籽晶能促进低温沉积单相α-Al₂O₃薄膜。     

孤立Pt位点于Pt-Sn、Pt-Zn配位的PtSnZn有序金属间化合物选择性催化丙烷脱氢（英文）

随着页岩气的大规模开采,丙烷脱氢制丙烯日益重要.在本文中我们以Al₂O ₃为载体,结合强静电吸附法和程序升温还原法合成了～0.9 nm PtSnZn有序金属间化合物团簇(PtSnZn/Al₂O₃).PtSnZn金属间化合物的结构形成主要受动力学控制,Pt原子被Sn和Zn完全孤立,形成Pt-Sn和Pt-Zn原子对.PtSnZn/Al₂O₃在丙烷脱氢反应中表现出优异的催化性能,丙烯选择性高达～100%,并且在长周期稳定性测试中丙烷转化率维持在40%以上.Pt Sn Zn/Al₂O ₃的丙烷脱氢催化性能远远优于Pt/Al₂O₃、PtSn/Al₂O₃和PtZn/Al₂O₃催化剂.实验结果和理论计算表明Sn 5p和Zn 4s与Pt 5d轨道的杂化使得Pt d带中心远离费米能级(-2.81 eV...     

原位晶化法在铜网上快速合成Cu3(BTC)2基膜及其催化性能研究

在常温条件下, 采用原位晶化法在铜网载体上合成了包含Keggin型杂多酸H₃PMo₁₂O₄₀的Cu₃(BTC)₂(BTC= 1, 3, 5-均苯三甲酸)基金属-有机框架膜材料。利用XRD、FT-IR和SEM等方法对膜的结构、成分及形貌进行了表征。含磷钼杂多酸的Cu₃(BTC)₂基薄膜均匀地覆盖在铜丝表面上, 膜厚度约为8 μm, 晶体尺寸均一, 且融合生长。合成过程中, 经过预处理的铜网本身既是载体又是铜源。研究发现加入H₂O₂能有效地促进膜的合成。铜网负载的薄膜作为非均相催化剂, 在H₂O₂氧化降解罗丹明B的化学反应中表现出很高的催化活性, 反应100 min后, 降解率可达98%。膜催化剂重复使用三次, 均表现出较高的催化性能。     

Determination of the phase transition in Pb0.88Ln0.08Ti0.98Mn0.02O3 (Ln=La, Sm, Eu) piezoceramics based on the Stefan–Boltzmann law

A method for determination of the phase transition in piezoelectric ceramic based on the relationship expressed by the Stefan–Boltzmann law is reported, i.e., by means of the radiation that the piezoelectric ceramic emits when it is subjected to different temperatures. The experiment is performed in piezoelectric ceramic based on PbTiO₃ modified by the partial substitution of rare earths for Pb in the Pb_0.88(Ln)_0.08Ti_0.98Mn_0.02O₃ system (Ln=La, Sm, Eu). From the measured emitted radiation, the value of the emissivity is calculated for each type of piezoelectric ceramic.     

Characterization of A12O3, A12O3 + TiO2 Powder Mixture, and Coatings Prepared by Plasma Spraying

A1₂O₃ and its mixture with 3 wt% Ti0₂ powders were prepared by fusion and crushing methods. Al₂O₃ + 13 wt% TiO₂ and A1₂O₃ + 40 wt% TiO₂ powders were mixtures of fused AI₂O₃ + 3 wt% TiO₂ and 10 wt% and 37 wt% of TiO₂respectively. Chemical analysis of the powders showed that: approximately 1 wt% of impurities were present in each powder. True and tap densities were measured and are discussed for all powders. Powder size study showed narrow range of distribution of particle size in each powder. SEM study showed that the particles were in round and other irregular shapes in all the powders. A1₂O₃ was found to be in alpha phase and TiO₂ in rutile phase. All the powders were coated by plasma spraying at 16 kW. The density of the coatings were measured and are discussed. In the coatings, A1₂O₃ was in both alpha and gamma phases. In A1₂O₃ + 13 wt% TiO₂ and A1₂O₃ + 40 wt% TiO₂ coatings, the oxygen reduction from TiO₂ was observed.     

Lattice matching of D023 and D022 phases in Al-6at.%(Ti,V,Zr) systems

Composite quaternary alloys with 21–22 vol.% of Al₃M (M = Ti,V,Zr) were made by vacuum arc melting. Two inlermetallic phases were found in alloys: one is V rich D0₂₂-Al₃(Ti,V,Zr) and the other is Zr rich D0₂₃-Al₃(Ti,V,Zr). Measured lattice constants of precipitate phases were strongly dependent on the composition of transition elements in precipitates and generally obeyed Vegard's rule. The lattice misfits between Al₃M phases and the matrix did not change much in alloys while the lattice misfit between D0₂₂ and D0₂₃ Al₃M phases was found to decrease with an increase in Ti content implying that the interface between both phases became more smooth, hard to distinguish and separate. A geometrical model was made for the lattice matching between two, D0₂₂ and D0₂₃ Al₃M phases. Titanium has been found to act as a retarding element to separation into D0₂₃ and D0₂₂ phases and the pre-existing phase may have been L₁₂ or D0₂₃ phase.     

Processing, microstructure and properties of C40 Mo(Si,Al)2/Al2O3 composites

The C40 Mo(Si_0.75Al_0.25)₂/Al₂O₃ composites were prepared by spark plasma sintering (SPS) of mechanically alloyed (MA) powders. The Mo(Si_0.75Al_0.25)₂/0–20 vol.% Al₂O₃ materials, showing micron and submicron composite structure, possess a hardness of 13.9–14.6 GPa but a poor toughness of 1.78–1.80 MPa m^1/2. The addition of 30 vol.% Al₂O₃ leads to the formation of the micron C40 Mo(Si_0.75Al_0.25)₂/Al₂O₃ composite with an intergranular distribution of Al₂O₃, that results in a drop of the hardness to 10.2 GPa and an improvement of the toughness to 3.67 MPa m^1/2. The transition of the cleavage facets to the intergranular fracture with the addition of Al₂O₃ is assumed as the main toughening mechanism.     

Al2O3包覆Li1.2Mn0.54Ni0.13Co0.13O2富锂正极材料的电化学性能

用溶胶凝胶法制备了Li_1.2Mn_0.54Ni_0.13Co_0.13O₂富锂锰基正极材料,用均匀沉淀法对其进行不同比例Al₂O₃的表面包覆改性,并对其进行XRD、TEM表征和电化学性能分析。结果表明,包覆后的材料保持了原来的层状结构,Al₂O₃均匀地包覆在材料颗粒表面形成纳米级包覆层。在0.1C、2.0~4.8 V条件下Al₂O₃包覆量(质量分数)为0.7%的正极材料首次放电容量为251.3 mAh/g,首次库仑效率达到76.1%,100次循环后容量保持率达92.9%。包覆Al₂O₃抑制了循环过程中的电压衰减,适量的Al₂O₃包覆使正极材料的电化学性能提高。     

Rietveld refinement and spectroscopic studies of sodium lead fluoroapatite lacunaire synthesized by hydrothermal method

The structure of NaPb₉(PO₄)₆F(H₂O)_0.33, isostructural with apatite, was determined by X-ray powder diffraction methods and the result of Rietveld refinement is P6₃/m, a = 9.76396(8) Å and c = 7.27520(9) Å. The final refinement led to R_F = 5.4%, R_B = 6.6%. In the tunnel, the water molecule (O_w) and F⁻ ions appear to be located in 2b and 4e sites, with occupancies of 0.028(6) and 0.075(8), respectively. In the M(1) and M(2) sites the occupancies of Pb and Na are 0.282(3)/0.051(3) and 0.467(5)/0.033(5), respectively. The formula assigned to the compound is [Pb_3.38(4)Na_0.62(4)](1)[Pb_5.60(6)Na_0.40(6)](2)(PO₄)₆F_0.90(10)(H₂O)_0.33(7)□_0.77(17), where □ = vacancy. The assignment of the observed frequencies in the Raman and infrared spectra is discussed on the basis of a unit-cell group analysis and by comparison with fluor and chloroapatite analogs. The result of ³¹P and ²³Na magic angle spinning-nuclear magnetic resonance (MAS-NMR) spectroscopies confirmed the structural results.     

二次化学共沉淀法制备片状钡铁氧体的形成历程及磁性能研究

采用二次化学共沉淀法制备出六角或近六角片状BaFe₁₂O₁₉,其颗粒径向尺寸和径厚比分别为0.4-2μm和4-20。通过XRD、FTIR、TG/DTA及SEM/EDS分析技术研究了片状BaFe₁₂O₁₉的形成历程。结果表明:前驱体为非晶态BaCO₃、低结晶态Fe（OH）₃和晶态α-Fe₂O₃包覆原料BaFe₁₂O₁₉复合物;前驱体在焙烧过程中经过Fe（OH）₃脱水、BaCO₃分解反应、中间相α-Fe₂O₃和BaO反应得到终产物BaFe₁₂O₁₉。基于形成历程,六角片状BaFe₁₂O₁₉较原料BaFe₁₂O₁₉表现出显著提高的颗粒径向尺寸和径厚比、较高的纯度和略低的结晶有序程度,进而表现出明显提高的矫顽力、略低的饱和磁化强度和剩余磁化强度。     

ZrO2增韧Al2O3颗粒增强Fe45复合材料拉伸断裂的有限元-离散元耦合方法仿真ZrO2增韧Al2O3颗粒增强Fe45复合材料拉伸断裂的有限元-离散元耦合方法仿真

采用有限元-离散元耦合方法（FEM-DEM方法）,进行了氧化锆增韧氧化铝颗粒增强Fe45复合材料（ZrO₂-Al₂O₃/Fe45）轴对称代表体元模型的拉伸断裂仿真分析。分析了FEM-DEM模型对单元尺寸的敏感性,结果表明采用,二阶实体单元加双零厚度内聚力单元的FEM-DEM模型降低了计算结果对单元尺寸的敏感性。ZrO₂-Al₂O₃/Fe45复合材料拉伸断裂的模拟结果表明,颗粒形状对裂纹的扩展会产生较大影响,复合材料的开裂首先在垂直于拉力方向的界面处发生,界面裂纹扩展至基体应力集中处之后基体发生开裂,裂纹由开裂的界面和基体裂纹共同组成。