Rapid growth of angle-confined large-domain graphene bicrystals

In the chemical vapor deposition growth of large-area graphene polycrystalline thin films,the coalescence of randomly oriented graphene domains results in a high density of uncertain grain boundaries (GBs).The structures and properties of various GBs are highly dependent on the misorientation angles between the graphene domains,which can significantly affect the performance of the graphene films and impede their industrial applications.Graphene bicrystals with a specific type of GB can be synthesized via the controllable growth of graphene domains with a predefined lattice orientation.Although the bicrystal has been widely investigated for traditional bulk materials,no successful synthesis strategy has been presented for growing two-dimensional graphene bicrystals.In this study, we demonstrate a simple approach for growing well-aligned large-domain graphene bicrystals with a confined tilt angle of 30° on a facilely recrystallized single-crystal Cu (100) substrate.Control of the density of the GBs with a misorientation angle of 30° was realized via the controllable rapid growth of subcentimeter graphene domains with the assistance of a cooperative catalytic surface-passivation treatment.The large-area production of graphene bicrystals consisting of the sole specific GBs with a tunable density provides a new material platform for fundamental studies and practical applications.     

A novel de-rusting method with molten salt precleaning and laser cleaning for the recycling of steel parts

Clean Technologies and Environmental Policy - Steel parts are a kind of high recovery value product for which de-rusting is the primary step in the recycling process. Laser cleaning is a popular...     

Nanoindentation measurement of core–skin interphase viscoelastic properties in a sandwich glass composite

Mechanics of Time-Dependent Materials - Debonding at the core–skin interphase region is one of the primary failure modes in core sandwich composites under shear loads. As a result, the...     

IE理论在营业厅固网业务流程优化中的应用

针对营业厅固网业务服务流程繁琐、服务不及时、客户长时间排队等待的现状,基于工业工程(IE)理论,重新定义IE理论图表技术符号,应用“5W1H”提问技术分析现状,确定需要优化的项目;应用“ECRS”4大原则优化固网业务流程。以某市营业厅固网业务流程为例,优化后客户平均移动距离由69 m缩短至34 m、高峰期平均停留时间由58 min缩短至29 min,说明使用该方法优化固网业务流程效果明显。这对于提高客户满意度、提升服务质量和效率以及企业竞争实力具有指导作用。     

Water-Soluble,Alanine-Modified Fullerene C60 Promotes the Proliferation and Neuronal Differentiation of Neural Stem Cells

As carbon-based nanomaterials, water-soluble C₆₀ derivatives have potential applications in various fields of biomedicine. In this study, a water-soluble fullerene C₆₀ derivative bearing alanine residues (Ala-C₆₀) was synthesized. The effects of Ala-C₆₀ on neural stem cells (NSCs) as seed cells were explored. Ala-C₆₀ can promote the proliferation of NSCs, induce NSCs to differentiate into neurons, and inhibit the migration of NSCs. Most importantly, the Ala-C₆₀ can significantly increase the cell viability of NSCs treated with hydrogen peroxide (H₂O₂). The glutathioneperoxidase (GSH-Px) and superoxide dismutase (SOD) activities and glutathione (GSH) content increased significantly in NSCs treated even by 20 μM Ala-C₆₀. These findings strongly indicate that Ala-C₆₀ has high potential to be applied as a scaffold with NSCs for regeneration in nerve tissue engineering for diseases related to the nervous system.     

Characteristics of evolution of mining-induced stress field in the longwall panel:insights from physical modeling

The evolution of mining-induced stress field in longwall panel is closely related to the fracture field and the breaking characteristics of strata.Few laborator...     

Influence of residual chirality on the conformation and enzymatic degradation of glycopolypeptide based biomaterials

Science China Technological Sciences - Glycopolypeptides as analogs of glycoproteins or glycosaminoglycans represent attractive building blocks for the construction of biomimetic biomaterials....     

ARGET ATRP合成大分子偶联剂PMMA-b-PTMSPMA及其对玻璃表面的接枝

以电子转移再生催化剂的原子转移自由基聚合(ARGET ATRP)成功合成了大分子硅烷偶联剂即聚甲基丙烯酸甲酯-b-3-甲基丙烯酰氧基丙基三甲氧基硅烷(PMMA-b-PTMSPMA)。利用所制得的大分子偶联剂对玻璃表面进行了接枝改性,对改性后的玻璃表面形态及疏水性能进行了研究。结果表明,以CuBr2/PMDETA络合物为催化体系,溴化铜(CuBr2)用量为n(CuBr2)/n(单体)=5×10-4时,PMMA段以辛酸亚锡(Sn(EH)2)为还原剂,PTMSPMA段以铜(Cu)为还原剂,用ARGET ATRP两步法成功制备了嵌段共聚物PMMA-b-PTMSPMA。采用"接枝到(graft onto)"方法,在温和的条件下,在玻璃表面接枝上了大分子偶联剂。玻璃表面的接触角可从30°提高到65°,提高了玻璃表面的疏水性。