含镍和含钴介孔分子筛的稳定性和孔结构

以十六烷基三甲基溴化铵为模板剂,以硅酸钠、氯化镍、氯化钴等无机盐为原料,水热法合成出含Ni介孔分子筛和含Co介孔分子筛。采用XRD、FT-IR、TPR、TEM和比表面积孔径测定等方法对样品进行表征。结果表明:合成了长程有序性好的含Ni和含Co介孔分子筛;含Ni介孔分子筛的比表面积为753.3 m2/g,平均孔径为3.23 nm,750℃焙烧3 h,100℃水热处理5 d介孔结构仍然存在;含Co介孔分子筛的比表面积为744.1m2/g,平均孔径为4.44 nm,650℃焙烧后转变为虫蛀状介孔结构,750℃焙烧3 h后介孔有序性变得很差,100℃水热处理5 d后转变为虫蛀状结构。     

沉淀法合成纳米CeO2的晶粒生长动力学

以Ce(NO3)3·6HzO为铈源,(NH4)2CO3·H2O为沉淀剂,并加入一定量表面活性剂PEG4000,采用液相沉淀法制备前驱体Ce2(CO3)3·H2O,前驱体经热处理合成纳米CeO2.根据XRD线宽法研究了纳米CeO2热处理过程的晶粒生长动力学,结果表明随焙烧温度升高,CeO2晶粒尺寸显著增大;300℃下焙烧时间对CeO2晶粒尺寸影响不明显,700℃下CeO2晶粒随焙烧时间延长而长大,且焙烧初期粒径增长较快,超过180 min后增长速率变慢;700℃时CeO2晶粒生长指数为5,即符合5次方动力学方程,晶粒生长速率常数为1.986 5×104 nm5/min;由于纳米尺寸效应,使得CeO2晶粒生长活化能在低温区和高温区不同,低于400℃时为25.64 kJ/mol,高于400℃时为87.64 kJ/mol;认为热处理过程CeO2的晶粒生长为扩散生长机制.     

介孔Li3V2（PO4）3正极材料的研磨溶胶凝胶法合成和电化学性能（英文）

以V2O5·nH2O、LiOH·H2O、NH4H2PO4和蔗糖为原料,采用研磨溶胶凝胶技术制备了无定形Li3V2(PO4)3前驱体,再经过焙烧获得具有单斜结构的介孔Li3V2(PO4)3正极材料,并用XRD、SEM、TEM、比表面积和电化学性能测试来表征材料的性能。研究表明,在700°C下焙烧的样品具有良好的介孔结构、最大的比表面积(188cm2/g)和最小的孔径(9.3nm)。在0.2C倍率下,该介孔样品的首次放电容量达155.9mA·h/g,经过50次循环后其容量仍然可达154mA·h/g,表现出非常稳定的放电性能。     

介孔氧化锆材料的模板自组装法合成与表征

采用模板自组装的方法一步合成介孔氧化锆材料,并利用TG-DTA、SAXRD、N2吸附和HRTEM对材料进行表征。结果发现,经400℃焙烧后模板剂能够完全脱除;低角度XRD结果显示材料具有良好的介孔结构;N2吸附结果得到介孔氧化锆的孔径为3.7nm,比表面积为165.3m2/g。介孔氧化锆经不同温度焙烧后的XRD和HRTEM结果表明,600℃焙烧后仍能保持介孔结构,更高温度焙烧介孔结构被破坏;选区电子衍射显示在介孔孔壁上有部分的纳米晶生成。     

无压反应合成MCM-41硅基介孔材料

以水玻璃溶液为硅源,十六烷基三甲基溴化铵(CTAB)为模板剂,成功合成了MCM-41硅基介孔材料.并用XRD、TEM和N2吸附一脱附等方法对样品进行了表征.XRD分析表明:当m(CTAB)/n(Si)的比值为0.09,合成体系pH值为10～11,反应温度为85℃时,合成的样品微观结构好,长程有序化程度高.TEM和N2吸附一脱附的分析结果表明:样品具有六方有序结构的硅基介孔材料,其BET表面积为1027 m2/g,最可几孔径为2.88nm.     

介孔二氧化铈纳米材料的制备与性能

采用化学沉淀法制备了纳米氧化铈(CeO2)储氧材料,利用X射线衍射(XRD)分析考察了焙烧温度对氧化铈物相结构的影响;利用热重分析(TG)对沉淀物到氧化物转变过程进行了具体分析;通过储氧量(OSC)测定和氢气程序升温还原性(H2-TPR)测定及其织构性能测定(BET法)等不同手段对CeO2材料进行了表征。结果表明:采用沉淀法制备得到的纯CeO2材料属于纳米级介孔材料。该材料具有较好的抗高温老化性能,较强的氧化还原能力,较大的比表面积和孔容及合理的平均孔径。在1000℃高温焙烧后仍然保持立方萤石结构,虽然有所烧结,但仍能保持纳米晶粒和纳米孔结构。     

微波条件下杂原子MCM-41介孔分子筛的合成

以十六烷基三甲基溴化铵（CTAB）为模板剂,硅酸钠、氯化镍、氯化钴和氯化铜为原料,通过微波辐射法合成纯硅MCM-41和Ni（Co、Cu）MCM-41介孔分子筛。采用X射线衍射、透射电子显微镜、Fourier变换红外光谱和比表面积孔径分析等测试手段对所合成的介孔分子筛进行表征。考察了分别将杂原子Ni、Co和Cu引入MCM-41介孔分子筛对其介孔有序性、比表面积及孔径大小的影响。结果表明：在微波条件下可以合成出纯硅MCM-41和掺杂Ni（Co、Cu）MCM-41介孔分子筛,样品经550℃焙烧后模板剂被有效去除,合成样品的介孔结构没有被破坏;杂原子Ni（或Co、Cu）引入纯硅MCM-41介孔分子筛后,其比表面积和平均孔径均增大,且介孔有序性变好。     

低温燃烧合成Ce_(0.8)Nd_(0.2)O_(1.9)固溶体纳米粉末

采用低温燃烧合成工艺在甘氨酸-硝酸盐体系中制备出Ce0.8Nd0.2O1.9固溶体纳米粉末,重点考察了甘氨酸与硝酸盐的配比(G/N)以及焙烧温度对粉末特性的影响。通过热重-差示扫描量热分析(TG-DSC)得知,燃烧反应的点火温度为257℃。利用X射线衍射(XRD)、透射电镜(TEM)、比表面积仪(BET)及傅里叶红外光谱(FTIR)等手段对粉末的结构、形貌、成分、尺寸及比表面积进行了分析。结果表明:燃烧反应后直接得到萤石型结构的单相固溶体,晶粒尺寸为8nm~12nm之间,比表面积为38m2/g~47m2/g;晶粒尺寸随焙烧温度升高而增加,在800℃下焙烧1h后,可以去除反应残留物质,并使获得的晶形更加完整。     

热处理条件对介孔Al_2O_3结构性质的影响

以氯化铝和氨水反应制得拟薄姆石为前驱体,研究了拟薄姆石前驱体热处理性质,考察了焙烧温度对介孔Al_2O_3微观结构的影响,通过焙烧升温速率调控了γ-Al_2O_3表面酸碱性,借助XRD、SEM、BET及NH3/CO2-TPD等手段对焙烧产物晶相组成、微观形貌、孔结构及表面酸碱性进行分析表征。结果表明,焙烧温度对介孔Al_2O_3晶相组成、微观形貌、孔结构影响较大。随焙烧温度升高,Al_2O_3结晶度逐渐增大,且焙烧温度不同,Al_2O_3晶型不同,焙烧温度为600℃时制得了比表面积240.23 m~2·g~(-1),介孔孔容0.602 cm3·g~(-1),平均孔径10.71 nm的纳米球形介孔γ-Al_2O_3。升温速率对600℃焙烧制得γ-Al_2O_3表面酸碱性质具有较大影响,焙烧升温速率越快,表面酸碱强度越强。升温速率为5℃·min~(-1)时,表面具有最大弱酸(0.342 mmol·g~(-1))和弱碱量(0.322 mmol·g~(-1))。     

离心喷雾条件对CeWTi脱硝催化剂性能的影响

以离心喷雾干燥技术为基础,采用浸渍法制备了CeO2-WO3/TiO2(CeWTi)脱硝催化剂,研究了制备过程中离心喷雾温度对喷雾速率及催化剂粉体形貌、粒度、比表面积和脱硝性能的影响,分析了喷雾温度影响的机制.结果表明,CeWTi催化剂的离心喷雾速率、粒度均随离心喷雾温度的升高而显著增大,但其焙烧前粉体的粒度却无显著变化,仅为1μm左右.这是由于喷雾干燥后主要形成Ce(NO3)3·4H2O和Ti(W)O2的团聚体,并未形成Ce-W-Ti-O的固溶体.因此,在测试粒度时由于Ce(NO3)3·4H2O的溶解,测得粒度不是喷雾粉体的实际粒度,而是钛钨粉的粒度.     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

THERMODYNAMICS STUDY ON THE DECOMPOSITION OF CHROMITE WITH KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

INFLUENCE OF HEAT TREATMENT ON DAMPING BEHAVIOUR OF THE MAGNESIUM WROUGHT ALLOY AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

A STUDY OF TEMPERATURE-DEPENDENT VALENCE BOND STRUCTURE OF TITANIUM

On the basis of energy and shape method for the determination of the valence bond (VB) structures of crystal, the valence bond structure of titanium is redetermined at room temperature and calculated in the whole temperature range of 0-1943K. The outer shell electronic distribution of Ti is e_c~(2.9907) · (s_c~(0.4980) d_c~(2.4927)) ef1.0093 in crystal. The temperature dependences of the VB structures of hcp and bcc phases are the same. The VB structures of hcp and bcc phases monotonically increase or decrease with the increase in temperature, but show discontinuous changes at the phase-transformation temperature 1155K.