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1.
为改善晶态V2O5(c-V2O5)正极材料实际容量较低、循环性能较差等问题,制备了空心球聚吡咯/V2O5复合材料。利用导电吡咯单体(Py)在中空型V2O5层间发生原位氧化聚合反应制备聚吡咯(PPy)/中空型V2O5复合材料(HS-PPy/V2O5)。采用X射线衍射仪(XRD)、扫描电镜(SEM)、透射电镜(TEM)对样品进行表征,采用恒流充放电测试和电化学阻抗(EIS)测试样品的电化学性能。结果表明,Py单体已插入中空型V2O5层间,与纯中空型V2O5相比,制备的HS-PPY/V2O5复合材料比容量虽然有所减小,但是循环稳定性有较大的提高。  相似文献   

2.
采用水溶液恒电流电化学聚合法在纯钛表面制备了聚吡咯/重组人骨形成蛋白涂层(Ti/PPy/rhBMP-2)。利用循环伏安扫描分析涂层氧化还原性质,^125I蛋白质标记法检测rhBMP-2掺杂量,表面粗糙度仪、扫描电子显微镜检测涂层微观形貌。通过对骨髓间充质干细胞(BMSCs)在Ti/PPy/rhBMP-2表面增殖、分化能力的检测,评价Ti/PPy/rhBMP-2对骨髓间充质干细胞增殖、分化的影响。结果表明,rhBMP-2能够以聚电解质阴离子方式稳定地掺杂于PPy结构中,并且所生成的涂层表面粗糙度高且结构疏松。Ti/PPy/rhBMP-2中掺杂固定的rhBMP-2依然保持着其骨诱导活性,能够促进BMSCs的增殖、分化。  相似文献   

3.
以La2O3、Cr(NO3)3·9H2O、Sr(NO3)2、Mn(NO3)2和柠檬酸为原料,用溶胶-凝胶法制备了La0.75Sr0.25Cr0.5Mn0.5O3粉体。使用DTA、XRD、SEM、FT-IR等对粉体及中间体进行了表征。结果表明,用此法制备的前驱体,经700℃焙烧2h即可制得粒度均匀的晶体,其平均粒径为4.87nm。以制得的粉体为气敏材料制备了管状NO2气体传感器,并测试了传感器的性能。结果表明,La0.75Sr0.25Cr0.5Mn0.5O3材料对NO2具有良好的敏感性能。在一定温度范围内,随着NO2浓度的升高,传感器电动势信号逐渐增大。在测试温度范围内,电动势与NO2浓度之间呈良好的线性关系。  相似文献   

4.
以Cu2O为氧源,采用内氧化法制备了Al2O3/Cu复合材料,通过电火花试验研究了该复合材料的电蚀特性,并进行了微观组织结构分析。结果表明,采用内氧化法制备的Al2O3/Cu复合材料,在铜基体中弥散分布着纳米级的Al2O3颗粒;在基本保证与紫铜相同加工速度的前提下,Al2O3/Cu复合材料工具电极的相对损耗和工件表面粗糙度均小于紫铜工具电极,且在试验范围内Al2O3/Cu复合材料工具电极损耗和工具表面粗糙度均随Al2O3含量的增加而降低。  相似文献   

5.
采用水溶液恒电流电化学聚合法在纯钛表面制备了PPy涂层(Ti/PPy)。利用傅里叶红外光谱、X射线光电子能谱测定表面化学成分。用扫描电子显微镜观察涂层微观形貌,接触角测量仪检测接触角并计算表面能。搭接剪切法测定涂层与基底间的结合强度。通过对成骨细胞在Ti/PPy表面附着、铺展以及增殖能力的检测,评价Ti/PPy对成骨细胞生长的影响。结果表明,Ti/PPy的表面能(59.5mJ/m^2)高于纯钛(47.0mJ/m^2),并且具有良好的结合强度(9.16±1.62)MPa。Ti/PPy与Ti一样具有良好的生物相容性,成骨细胞能够在Ti/PPy涂层表面完成附着、铺展以及增殖的生物功能。  相似文献   

6.
采用液相包裹法对Al2O3微粉进行稀土Y2O3表面改性,用挤压铸造法制备表面经稀土Y2O3改性的Al2O3/Al复合材料,并对复合材料的显微组织及界面进行观察和分析。结果表明:表面经稀土Y2O3改性的Al2O3微粉能均匀的分布于基体中,界面润湿性得以改善,复合材料组织更加均匀。拉伸性能测试表明:改性粉体对Al合金拉伸性能增强效果明显。对复合材料界面进行TEM,HREM及电子衍射分析表明,界面结合良好,界面处有Y2Al生成。EDAX分析表明界面相是钇、铝含量很高的物相;XRD图谱中也显示出Y2Al的衍射峰。  相似文献   

7.
采用静电吸附的方法制备出氧化石墨烯/氧化铜纳米棒复合物,再利用原味聚合的方法在氧化石墨烯/氧化铜纳米棒(GO/CuO-NRs)复合物上原味聚合上吡咯单体。通过对复合材料进行XRD、TEM、SEM和FT-IR的表征,说明制备了聚吡咯/氧化石墨烯/氧化铜纳米棒(PPy/GO/CuO-NRs)复合材料,并对复合材料电极催化葡萄糖进行了研究。结果表明,复合材料对葡萄糖有良好的催化性能。  相似文献   

8.
利用球磨预分散-搅拌铸造法制备纳米Al2O3/2024复合材料,并对所制备的铝基复合材料进行了显微组织及力学性能的研究。结果表明,经球磨预分散后,纳米颗粒团聚现象明显消除,纳米Al2O3呈单颗粒分散于Al粉表面;复合粉体添加法有效避免了超细增强颗粒和基体润湿性差和分散性较差的问题,实现纳米Al2O3颗粒均匀弥散分布于基体合金中;纳米Al2O3颗粒的加入显著提高基体合金的力学性能。与传统搅拌铸造相比,所制备的Al2O3/2024复合材料的抗拉强度、屈服强度和显微硬度分别提高了58%、59%和16%。  相似文献   

9.
利用球磨预分散一搅拌铸造法制备纳米Al2O3/2024复合材料,并对所制备的铝基复合材料进行了显微组织及力学性能的研究.结果表明,经球磨预分散后,纳米颗粒团聚现象明显消除,纳米Al2O3呈单颗粒分散于Al粉表面;复合粉体添加法有效避免了超细增强颗粒和基体润湿性差和分散性较差的问题,实现纳米Al2O3颗粒均匀弥散分布于基体合金中;纳米Al2O3颗粒的加人显著提高基体合金的力学性能.与传统搅拌铸造相比,所制备的Al2O3/2024复合材料的抗拉强度、屈服强度和显微硬度分别提高了58%、59%和16%.  相似文献   

10.
以FeCl_3为氧化剂,植酸钠(IP_6)为掺杂剂,纳米SiO_2为分散介质,通过化学氧化法合成了具有核-壳结构的IP_6掺杂聚吡咯(PPy)/纳米SiO_2粒子。利用电感耦合等离子体原子发射光谱法考察了氧化剂和分散剂用量以及反应温度对掺杂率的影响。利用TEM、XRD和热重分析法(TG)对IP_6掺杂PPy/纳米SiO_2粒子的形貌、结构和热稳定性进行了表征。利用电化学阻抗(EIS)技术对IP_6掺杂PPy/纳米SiO_2/环氧树脂长效耐蚀复合涂层的耐蚀性进行了评价。结果表明:PPy均匀包覆在纳米SiO_2粒子表面,形成形貌规则且具有核-壳结构的稳定IP_6掺杂聚吡咯(PPy)/纳米SiO_2粒子。当n(Py)∶n(FeCl_3)=2∶1,m(SiO_2)∶m(Py)=1∶5,反应温度为-5℃时,制备的PPy/纳米SiO_2材料中IP_6掺杂率为98.53%。以IP_6掺杂PPy/纳米SiO_2粒子为功能成分,环氧树脂为成膜物质,制备的IP_6掺杂PPy/纳米SiO_2/环氧树脂长效耐蚀复合涂层对1.0mol/L HCl介质中的Q235钢腐蚀具有良好的抑制效果。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
吴玉梅  熊晓云  靳蓉  孙敬民  杨林  罗晓星 《金属学报》2005,10(10):1100-1103
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。  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

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