非离子表面活性剂体系层状液晶中硫化锌纳米颗粒的抗磨性

利用层状液晶中溶剂厚度的限定性,在ＴｒｉｔｏｎＸ－１００／Ｃ１０Ｈ２１ＯＨ／Ｈ２Ｏ体系层状液晶中,分别各以０．１ｍｏｌ／Ｌ的Ｚｎ（ＣＨ３ＣＯＯ）２和Ｎａ２Ｓ水溶液代替组分水制备出粒径约为１０ｎｍＺｎＳ颗粒,并对层状液晶中ＺｎＳ纳米颗粒的抗磨性能进行了研究,结果表明,ＺｎＳ纳米颗粒能提高ＴｒｉｔｏｎＸ－１０Ｃ１０Ｈ２１ＯＨ／Ｈ２Ｏ体系层状液晶的抗磨性,但对极压性能无影响。     

Microstructure and mechanical properties of ZrO2 (Y2O3)–Al2O3 nanocomposites prepared by spark plasma sintering

Zirconia (yttria)–alumina ceramic nanocomposites were fabricated from different powders by spark plasma sintering (SPS). One powder was a commercially available nanocomposite powder TZP-3Y20A, consisting of 3 mol% yttria-stabilized zirconia (3-YSZ) reinforced with 20 wt% alumina, and the other, used as a comparison, was a conventional mechanically mixed powder 3YSZ-20A, a blend made of 3 mol% yttria-stabilized zirconia powder ZrO₂ (3Y) and 20 wt% α-alumina powder. The effect of the sintering temperature on the densification, the sintering behavior, the mechanical properties and the microstructure of the composites was investigated. The results showed that the density increased with increasing sintering temperature, and thus, the mechanical properties were strengthened because of the increased densification. The nanocomposite powder TZP-3Y20A was easily sintered, and good mechanical properties were achieved as compared with the powder from the conventional mechanically mixed method, the maximum flexural strength and fracture toughness of which were 967 MPa and 5.27 MPa m^1/2, respectively.     

Preparation and properties of magnetic iron oxide nanotubes

Magnetite (Fe3O4) nanotubes were prepared by reducing synthesized hematite (α-Fe2O3) nanotubes in 5% H2+95% Ar atmosphere,and then maghemite (γ-Fe2O3) nanotubes were obtained by re-oxidizing the Fe3O4 nanotubes.The nanotube structure was kept from collapsing or sintering throughout the high temperature reducing and re-oxidizing processes.The coercivities of the Fe3O4 and γ-Fe2O3 nanotubes synthesized were found to be 340.22 Oe and 342.23 Oe,respectively,both higher than other nanostructures with the same phase and of similar size.Both adsorbed phosphate and the nanotube structure are considered responsible for this high coercivity.     

辛烷基苯酚聚氧乙烯醚与正癸醇层状液晶的结构及润滑性能研究

用小角Ｘ射线衍射和自旋标记电子自旋共振（ＥＳＲ）方法测定辛烷基苯酚聚氧乙烯醚与正癸醇体系层状液晶的结构。用高速环－块摩擦磨损试验机考察了不同组分含量的层状液晶对铝合金－钢摩擦副的润滑作用。结果表明：随着水含量的增加,层状液晶稳定性降低,润滑效果变差;随着辛烷基苯酚聚氧乙烯醚含量的增加,层状液晶的稳定性增加,润滑性能提高。     

爆轰法合成碳包覆纳米铜颗粒

以硝酸铜和柠檬酸制成的干凝胶为主要反应物,加入油酸有机碳源和黑索今炸药,在氮气保护气 氛下在爆炸容器中引爆,成功地合成了碳包覆纳米铜颗粒。分别采用X射线衍射、透射电镜对产物形貌特征 进行表征。结果表明,在爆轰产物中富含碳包覆纳米铜颗粒,产物呈圆球体,具有完好的核壳结构形貌,颗粒 粒径在10~40nm 之间,外层碳壳结构主要由无定型碳和石墨构成。并对爆轰法合成碳包覆纳米铜颗粒的 形成机理进行了分析。     

Vapour-diffusion assisted growth of oriented or-cobalt hydroxide thin films

Layered ,α-cobalt hydroxides Co(OH) 1.65Cl0.35.0.5H2O (1), Co(OH) 1.75(NO3)0.25.0.1H2O (2) with unique macro- and microscale morphologies have been synthesised by a low temperature, ammonia-controlled vapour-diffusion method. The materials have thin film morphologies and were characterized by X-ray powder diffraction (XRD) and field emission scanning electron microscopy (FESEM).     

Al(OH)3对聚丙烯腈粉火焰传播特性影响研究

为研究Al(OH)₃粉体抑爆剂对聚丙烯腈（polyacrylonitrile, PAN）粉尘爆炸的抑制作用,利用透明管道爆炸传播测试系统,研究不同含量的Al(OH)₃对PAN粉尘爆炸火焰传播形态、温度等参数的影响,并采用扫描电镜、热重分析仪、傅里叶红外光谱仪研究Al(OH)₃抑制PAN粉尘爆炸的微观特征,总结出Al(OH)₃对PAN粉尘爆炸的抑制机理。测试结果表明,随着Al(OH)₃质量分数的增加,PAN粉尘爆燃的最大火焰传播距离和传播速度逐渐减小。同时压力监控及温度监控结果显示,随着Al(OH)₃质量分数的增加,PAN粉尘的最大爆炸压力及最大温度均逐渐减小,由此验证了Al(OH)₃对PAN粉尘爆炸的抑制作用,且60%质量比的Al(OH)₃的抑制效果最好。通过对PAN粉尘爆炸固态产物表征及热分析的研究,从物理和化学两个方面分析了Al(OH)₃对PAN粉尘火焰的抑制机理,物理抑制包括包覆、吸热降温、气体惰化3种方式,化学抑制主要通过消耗维持燃烧爆炸连锁反应的关键自由基?O和?OH减少了自由基?H、?OH与?O之间的放热反应。     

Water-bathing synthesis of high-surface-area zeolite P from diatomite

Zeolite P was synthesized for the first time via a novel water-bathing route at 90 C using scrubbed diatomite,sodium hydroxide,and aluminum hydroxide as precursor,with SiO 2/Al 2 O 3,SiO 2/Na 2 O,and H 2 O/Na 2 O molar ratios of 7.43,3.81,and 80.00,respectively.The as-fabricated samples were characterized by means of scanning electron microscopy,X-ray diffraction,and nitrogen adsorption measurements.This study showed that (i) treating the diatomite raw material with sodium hexametaphosphate could open the p...     

Functionalized TiO2@ZrO2@Y2O3 ：Eu3＋ core-multishell microspheres and their photoluminescence properties

TiO2@ZrO2@Y2O3 ：Eu3＋ composite particles with a core-multishell structure were synthesized through the combination of a layer-by-layer （LBL） self-assembly method and a sol-gel process. The obtained sam- ples were characterized with scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, X-ray photoelectron spectroscopy （XPS）, X-ray diffraction （XRD）, and fluorescence spectropho- tometry. The results showed that the composite particles had a core-multishell structure, spherical morphology, and a narrow size distribution. The presence of a ZrO2 layer on the TiO2 core can effec- tively prevent the reaction between the TiO2 core and a Y203 shell; the temperature for the reaction between the TiO2 core and the Y203 shell in the TiO2@ZrO2@Y2O3 ：Eu core-multishell phosphor can be elevated by 300 ℃ compared to that for TiO2@ZrO2：Eu. Upon excitation of the core-multishell particles in the ultraviolet （254 nm）, the Eu3＋ ion in the Y2O3 ：Eu3＋ shell shows its characteristic red emission （611 nm, 5D0→7F2）, and the photoluminescence （PL） intensity of the phosphor with the core-multishell structure was obviously greater than that of the core-shell TiO2@Y2O3 ：Eu phosphor.     

SYNTHESIS OF SnO2 NANOCRYSTALS BY SOLID STATE REACTION FOLLOWED BY CALCINATION

Nanocrystalline SnO2 was synthesized by direct mixing and grinding of SnCI4-5H2O and NaOH at room temperature, followed by calcination at different temperatures for different times in air. Product samples were characterized by X-ray diffraction and transmission electron microscope, revealing that the amorphous precursor SnO2 was transformed to crystals at 200℃ for 3h, and that the average particle size increased upon raising the calcining temperature or prolonging the calcining time. The mechanism of the phase transformation of the products is discussed.     

氢氧混合气体爆轰波的真实化学反应模型数值模拟

采用高精度的ENO格式和基于基元化学反应的真实化学反应模型求解氢氧混合气体一维爆轰波的精细结构。采用直接起爆方法得到稳定传播的爆轰波 ,计算的爆轰波阵面参数和实验相当符合。对爆轰波反应区化学反应的研究表明 ,参与反应的不同组分具有不同类型的变化特征。网格尺寸影响的研究表明 ,计算结果的精度随着网格尺寸的增加而增加 ,并能保持较好的收敛性。移动网格研究结果表明 ,网格运动速度和爆轰速度接近时 ,两者的相互作用对计算结果产生一定影响。     

PHASE STRUCTURE OF W-DOPED NANO-TiO2 PRODUCED BY SOL-GEL METHOD

With Ti（OBu）4 as precursor, and HAc as complexing agent, pure and W-doped TiO2 gelatins were prepared by a sol-gel method. During the process of gel formation, metal ions were dispersed in the porous TiO2 matrix. Then, powders of nano-TiO2 and W-doped nano-TiO2 were prepared by drying, grinding and heat treatment at different temperatures. The grain size and structure of the samples, pure TiO2 and W-doped, and treated at different temperatures were studied by X-ray diffraction （XRD）, Beckman Coulter Sorption Analysis and TEM. Results showed that, with increasing temperature, the TiO2 transformed from anatase to rutile and the grain size increased. This transformation and grain growth of TiO2 could be retarded by doping with W.     

Comparison of schemes for preparing magnetic Fe3O4 nanoparticles

Magnetic Fe3O4 nanoparticles were prepared by means of coprecipitation using NH3·H2O in water and in alcohol, and using NaOH in water. A series of instruments such as SEM, TEM, HRTEM, FT-IR, XRD and VSM were used to characterize the properties of the magnetic nanoparticles.was the longest. The process using NaOH in water was the simplest and the reaction time was the shortest, but the particle characteristics were inferior to those of the other two methods. The mean size of magnetic Fe3O4 nanoparticles prepared by coprecipitation in alcohol was the smallest among the three, but the nanoparticles aggregated severely. The magnetic Fe3O4 nanoparticles were coated with oleic acid using saturated sodium coated successfully and thoroughly.     

Synthesis of iron oxide nanoparticles via sonochemical method and their characterization

Preparation of iron oxide ( -Fe 2 O 3 ) nanoparticles was carried out via a sonochemical process. The process parameters such as temperature, sonication time and power of ultrasonication play important roles in the size and morphology of the final products. The iron oxide nanoparticles were characterized by transmission electron microscopy, X-ray powder diffraction, and thermogravimetric and differential thermal analyses. From transmission electron microscopy observations, the size of the iron oxide nanopar...     

Controllable magnetic properties of cobalt ferrite particles derived from layered double hydroxide precursors

Cobalt ferrite CoxNi1-xFe2O4 (x=0, 0.5, 1) particles with controllable magnetic properties have been pre-pared by calcination of co-substituted NiFe2+Fe3+-layered double hydroxide (NiFe2+Fe3+-LDH) precursors prepared via a scalable method involving separate nucleation and aging steps (SNAS). Their structural and magnetic characteristics were investigated by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). Measurements of magnetic properties show that the saturation magnetization (Ms) and coercivity (Hc) of the calcined products increased with increasing cobalt content. The LDH precursor-based product obtained by calcination of a mixture of CoFe2+Fe3+-LDH and NiFe2+Fe3+-LDH powders with a Co/Ni molar ratio of 1:1, exhibits a moderate value of Ms and an increased value of Hc compared to the corresponding values for an Ni0.5Co0.5Fe2O4 material prepared by calcination of a Co0.5Ni0.5Fe2+Fe3+-LDH precursor, and a physical mixture of CoFe2O4 and NiFe2O4 with a Co/Ni molar ratio of 1 : 1. These results may provide a way to regulate magnetic anisotrupy of ferrite spinels by varying the composition of the LDH precursors.     

惰性气体对C3H8可燃下极限的影响

为探究CO₂、N₂和Ar对C₃H₈可燃下极限的影响,在5 L爆炸容器中测定了C₃H₈在O₂/CO₂、O₂/Ar、O₂/N₂三种气氛下的可燃下极限。首先分析了稀释气浓度、稀释气种类和氧气浓度对C₃H₈的可燃下极限的影响。结果表明,在O₂/CO₂气氛下,稀释气浓度变化对C₃H₈的可燃下极限影响最大,对O₂/Ar的影响次之,对O₂/N₂的影响最小。在相同稀释气浓度条件下,CO₂对C₃H₈可燃下极限的影响最大,N₂的影响次之,Ar的影响最小。随着O₂浓度的上升,O₂/CO₂气氛的可燃下极限出现较为明显的下降,O₂/N₂和O₂/Ar的氛围的可燃下极限平缓上升。通过建立能量平衡方程分析了稀释气的比热和辐射效应对可燃下极限的影响。结果表明,混合气比热的改变是C₃H₈可燃下极限改变的主要原因,辐射热损失是影响可燃下极限的重要因素。     

爆轰法合成纳米CeO粉末*2

爆轰合成过程中采用Ce(NO₃)₃·6H₂O制备的可爆药剂,并利用X射线衍射仪(XRD)和透射电子显微镜(TEM)对合成的纳米CeO₂粉末进行了检测,研究了起爆方式对于合成产物结晶化度、粒径和形貌的影响。结果表明,采用Ce(NO₃)₃·6H₂O制备的可爆药剂,可以合成立方晶系的球形纳米CeO₂; 提高可爆药剂的爆速,可有效降低纳米CeO₂的粒径,得到球形化更好的纳米粒子。     

固-固掺杂结构声子晶体中弹性波的缺陷模

为了研究弹性波在固-固掺杂结构声子晶体中缺陷模的特性,推导出弹性波斜入射固-固掺杂结构声子晶体的转移矩阵。利用它计算了固-固掺杂结构声子晶体中弹性波的透射系数,得到由于掺杂在禁带的中间出现了多条缺陷模透射峰带,缺陷模透射峰带随杂质厚度的变化呈周期性地出现,在同一缺陷模透射峰带上缺陷模的频率随杂质厚度增加近似呈线性减少。缺陷模的这些特征可以作为设计声子晶体滤波器的理论依据。     

Converting industrial waste contact masses into effective multicomponent copper-based catalysts for the Rochow process

In this work, we report a simple and inexpensive approach to synthesize effective multicomponent Cu–Cu₂O–CuO catalysts for the Rochow process from industrial waste contact masses (WCMs). WCMs from the organosilane industry were treated with acid followed by reduction with metallic iron powder. The obtained copper powder was then subjected to controlled oxidation in air at different temperatures, followed by ball milling. The orthogonal array approach was applied to optimize this process, and the stirring speed and pH were found to significantly affect the leaching ratio and copper yield, respectively. When used for the Rochow process, the optimized ternary Cu–Cu₂O–CuO catalyst greatly enhanced the dimethyldichlorosilane selectivity and Si conversion compared with Cu–Cu₂O–CuO catalysts prepared without ball milling, bare Cu catalysts, and Cu–Cu₂O–CuO catalysts with different compositions. This could be attributed to their small particle size and the strong synergistic effect among the multiple components in the catalyst with the optimized composition.     

基于仿真与量纲分析的不同药量TNT内爆下多舱室结构毁伤规律研究

利用流固耦合算法，模拟了不同药量TNT内爆下大尺寸多舱室结构的毁伤效应。将各舱室划分为爆炸舱、共面邻舱、共边界邻舱和共点邻舱，再划分内爆下多舱室结构的毁伤等级。通过量纲分析，研究了内爆载荷下舱壁的变形失效规律，推导了内爆下多舱室结构的无量纲毁伤数，该毁伤数考虑了内爆载荷、材料性能和作用空间等因素，最后给出快速毁伤预测方法。研究结果表明:（1）内爆下多舱室结构的毁伤特点主要表现为舱壁挠曲变形、舱壁中心冲切失效、舱壁边界撕裂；（2）舱壁挠曲变形的挠厚比δ/H和固定边界撕裂的裂缝长厚比l/H均与药量-单舱室容积比m/V有明显线性关系；（3）提出的无量纲毁伤数和快速预测方法能够反映内爆下多舱室结构的毁伤情况，可为舰船毁伤研究提供参考。