纳米MnS空心球的制备与表征

以适量的月桂酸硫脲咪唑啉季铵盐（SUDEI）为表面活性剂，采用溶剂热法在N-N二甲基甲酰胺（DMF）／乙醇中160℃反应12h，制备出了单分散的直径约300nm左右的纳米MnS空心球，并采用TEM、SEM观察其形貌；X射线衍射测试其晶体形态；IR、EDS测试其结构组成。讨论了不同溶剂体系对其形貌的影响，得出在VDMF：∨乙醇=3：1时，填充度为8C％，Mn^2＋与月桂酸硫脲咪唑啉季铵盐（SUDEI）的摩尔比为1：3．5时分散性最好。     

L-胱氨酸辅助合成Bi_2S_3纳米片状球和花状结构(英文)

以硝酸铋[Bi(NO)3·5H2O]和L-胱氨酸为反应原料,采用溶剂热法制备出Bi2S3纳米片状球和花状结构。L-胱氨酸(一种非常普遍和实用的氨基酸)作为硫源,在实验过程中不释放出刺激性气味(H2S)。利用X-射线衍射(XRD)、扫描电子显微镜(SEM)对所合成的产物的晶型结构、组成和表面形貌等进行了表征。结果表明:所合成的产物为典型的Bi2S3正交结构;在170°C条件下反应12h,以DMF为溶剂能够得到Bi2S3纳米片状球和花状结构。根据实验结果,对所合成Bi2S3的可能形成机理进行了简单探讨。     

硫化铋纳米棒的制备与表征

以L-胱氨酸为硫源,采用溶剂热法在不同的溶剂中反应,制备出硫化铋(Bi2S3)纳米薄片和纳米棒,采用X射线衍射(XRD)仪、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等分别对所合成的Bi2S3晶型结构、表面形貌进行表征。结果表明,所合成的Bi2S3为典型的Bi2S3正交结构。以DMF为溶剂,在160℃下反应5d,得到了长为4000～8000nm、宽为200～300nm的正交相Bi2S3纳米棒。根据实验结果对所合成的Bi2S3的形成机制进行简单探讨。     

溶剂热合成γ-AlOOE

用Al2（SO4）3、尿素和一种新型咪唑啉型表面活性剂-二（2-十一烷基-1-甲酰胺乙基咪唑啉）己二胺季铵盐（SUAEIHDI）为原料，以H2O／DMF、H2O／乙醇为分散介质，在150、190℃条件下，溶剂热合成了γ-AlOOH。主要讨论了溶剂和表面活性剂的协同作用、表面活性剂加入量、溶剂种类、反应温度对粒子大小和形貌的影响。     

浸渍提拉法合成Bi4Ti3O12基复合薄膜及其光催化性能

以TiO2、Bi4Ti3O12为原材料,采用浸渍-提拉法制备复合薄膜,研究了材料合成工艺对复合薄膜微观形貌、相结构及光催化性能的影响。XRD研究结果表明,合成的复合薄膜材料中含有正交相Bi4Ti3O12和锐钛矿TiO2两种晶相,Bi4Ti3O12沿垂直于玻璃基片的<001>方向取向生长。TiO2溶胶的浓度,Bi4Ti3O12的用量,以及表面活性剂的用量,拉膜次数对复合薄膜的成型有明显的影响,当TiO2溶胶的浓度为3mol/L、TiO2溶胶和Bi4Ti3O12质量比为10:1、表面活性剂的质量分数为3%、拉膜次数为3次的时候,合成的Bi4Ti3O12/TiO2复合薄膜较均匀且具有较优异的光催化性能。     

Bi2Te3片式阵列的制备及生成机理

以Bi（NO3）3和Te为反应物，在乙二胺四乙酸二钠（EDTA-2Na）、N，N-二甲基甲酰胺（DMF）与乙醇组成的混合溶剂以及过量强碱KOH的作用下，通过溶剂热反应，制得Bi2Te3热电材料的片式阵列纳米结构。利用XRD、SEM、EDX对产物的物相、形貌及成分进行了表征和研究。通过实验研究推断这种BizTe，片式阵列的形成过程可能是一个络合-成核-生长-脱离-组装的过程。     

溶剂热合成γ-AlOOH

用Al2(SO4)3、尿素和一种新型咪唑啉型表面活性剂-二(2-十一烷基-1-甲酰胺乙基咪唑啉)己二胺季铵盐(SUAEIHDI)为原料,以H2O/DMF、H2O/乙醇为分散介质,在150、190 ℃条件下,溶剂热合成了γ-AlOOH.主要讨论了溶剂和表面活性剂的协同作用、表面活性剂加入量、溶剂种类、反应温度对粒子大小和形貌的影响.     

PZT均分散纳米粉体的制备

以钛酸四丁酯、醋酸铅、氧氯化锆为主要原料，以自制的表面活性剂2-十一烷基-1-二硫脲乙基咪唑啉季铵盐（SUDEI）为表面修饰剂，以乙二醇做溶剂，制备出PZT溶胶，并将其作为前躯体，进行微波处理。对本实验制得的PZT样品用扫描电子显微镜观察PZT粉体的形貌和分散状况，用TG表征样品的热行为，用XRD分析确定其晶型，用EDS确定了样品的表面成分组成。实验数据表明以该方法制备的粉为粒度均匀，分散性好的纳米级PZT粉体，粒径尺寸为50～70nm。     

反应时间对溶剂热法制备Bi_2Se_3纳米片的影响

以BiCl3和Se粉为原料,二甘醇(DEG)作为溶剂,Na2SO3作为还原剂,碱性条件,在160℃的反应温度下,利用溶剂热法成功地合成Bi2Se3纳米片,并研究不同反应时间(20,22,24h)作用下所得产物结构形貌的变化。利用XRD和SEM对所合成产物的晶相结构及表面形貌进行表征。结果显示:在不同反应时间下所合成的粉体均为纯物相(均为六方晶相)的纳米片状Bi2Se3,且反应22h条件下所得产物形貌为大小均一、分散性良好的六边形片状结构,其厚度为10～50nm。并分析片状结构Bi2Se3的形成机制。     

表面活性剂对Si3N4注射成型的影响

就硬脂酸（SA）及硅烷KH570两种不同的表面活性剂对注射成型各阶段的影响进行了研究。实验证明：硬脂酸在降低原始粉料混合粘度时所起的作用明显；硅烷KH570在降低经过表面氧化处理的Si3N4粉料混合粘度时作用效果明显；不同表面活性剂及不同用量对脱脂效果影响不大；但随着表面活性剂用量增加，烧结体密度逐渐减少，同样硬度也逐渐减少。但当溶剂脱脂应用于脱脂阶段时，烧结体性质在密度、硬度方面都有所提高，表面活性剂的影响不再呈明显的规律性。     

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.     

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。     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.