Microstructure developed in the surface layer of Ti-6Al-4V alloy after sliding wear in vacuum

Microstructural changes in the surface layer of Ti-6Al-4V alloy after sliding wear in vacuum have been studied by means of scanning and transmission electron microscopy (SEM and TEM). The wear rates of Ti-6Al-4V alloy in vacuum were measured under different sliding velocities and loads. The experimental results showed that a severely deformed layer with a grain size of 50–100 nm and thickness about 70 μm was formed underneath the worn surface. Under the slower sliding velocities, the substructure of the layer had a high dislocation density, while under higher sliding velocities, twins were found to exist in the substructure. A process by which the deformed layer formed has been proposed and the deformation of materials at the contacting spots of the Ti-6Al-4V sample is discussed.     

有限单元法在地下工程围护结构传热中的应用

分析总结现有地下工程围护结构传热研究不足的基础上,对实际贴壁式和离壁式衬砌地下工程围护结构进行合理的物理数学简化,建立了热传递过程的数学模型.该数学模型中详细考察了不同的边界条件.有限单元法对复杂区域具有良好的适应性,论述了有限单元法在地下工程维护结构传热中的应用.     

Architecture engineering of hierarchically porous chitosan/vacuum-stripped graphene scaffold as bioanode for high performance microbial fuel cell

The bioanode is the defining feature of microbial fuel cell (MFC) technology and often limits its performance. In the current work, we report the engineering of a novel hierarchically porous architecture as an efficient bioanode, consisting of biocompatible chitosan and vacuum-stripped graphene (CHI/VSG). With the hierarchical pores and unique VSG, an optimized bioanode delivered a remarkable maximum power density of 1530 mW m(-2) in a mediator-less MFC, 78 times higher than a carbon cloth anode.     

氯化聚乙烯对氯丁橡胶与甲基丙烯酸甲酯接枝共聚反应的影响

研究了高氯氯化聚乙烯(HCPE)对氯丁橡胶与甲基丙烯酸甲酯接枝共聚及其反应产物的影响。结果表明,HCPE能加快聚合速率,提高转化率、接枝效率和接枝度。含HCPE的产物,含有较高分子量的级份,分子量分布较宽,树脂相的分布比较均匀,并具有较好的机械性能和较高的粘接强度。     

Effect of ligand passivation on morphology,optical and photoresponse properties of CdS colloidal quantum dots thin film

In the present report, cadmium sulfide (CdS) colloidal quantum dots (CQDs) with average diameter of 6 nm were synthesized by using oleylamine as ligand and solvent. The insulating oleylamine ligands form barriers around the CdS CQDs to decrease carrier mobility. In order to remove the ligands and improve the photoelectrical properties of the closed-packed film, ethanedithiol, mercaptopropionic acid and cetyltrimethylammonium bromide (CTAB) were applied for solid state ligand exchange. CTAB treated film had the fastest 3 dB bandwidth of 144.7 Hz and yielded the highest detectivity of 1.37 × 10⁸ Jones. The excellent properties of ligand passivation have important application in nanocrystals based electronic and optoelectronic devices.     

Therapy for cerebral ischemic injury with erythropoietin-containing nanoparticles

In this study we prepared nanocarrier of erythropoietin (EPO) and the curative effect of the EPO-containing nanoparticles for periventricular leukomalacia (PVL) model was validated. It was demonstrated that EPO-containing nanoparticles can ameliorate drug-induced liquefaction caused by hypoxia. EPO-containing nanomedicine may open new therapeutic strategies in hypoxia cure.     

Evaluation of the passivation effect and the first-principles calculation on surface termination of germanium detector

The point-contact high-purity germanium detector (HPGe) has the advantages of low background, low energy threshold, and high energy resolution and can be applie...     

The characteristics of waves around an entrance of a lagoon in South China Sea

The characteristics of the waves around a lagoon entrance in South China Sea were observed during the past one and half years based on the wave measurements.The...     

烟煤型等离子点火燃烧系统在广州珠江电厂的应用

介绍广州珠江发电厂烟煤型等离子点火燃烧系统应用情况和效果,以及该点火燃烧系统的构成和工作原理;从阳极与阴极使用抗氧化材料、复合结构、燃烧器的设计和风粉在线监测系统等方面分析了技术特点,总结了运行操作及运行中的注意事项.