Carbon steel seamless steel pipe is a kind of long steel with hollow
section and no joints around. The steel pipe has a hollow cross-section
and is widely used as a pipeline for conveying fluids, such as pipelines
for conveying oil, natural gas, gas, water and some solid materials. carbon steel black pipe,seamless carbon steel pipe,low carbon steel pipe,carbon steel welded pipe Shandong Fengbao Metal Products CO.,LTD. , https://www.fbsteelpipes.com
Compared with solid steel such as round steel, steel pipe has the same
bending and torsional strength and is lighter in weight. It is a kind of
economic cross-section steel, widely used in the manufacture of
structural parts and mechanical parts, such as oil drill pipe,
automobile transmission shaft, bicycle frame and steel scaffolding used
in construction.
The manufacture of ring parts with steel pipes
can improve the utilization rate of materials, simplify the
manufacturing process, save materials and processing time, such as
rolling bearing rings, jack sleeves, etc., which have been widely used
to manufacture steel pipes.
Steel pipe is an indispensable
material for all kinds of conventional weapons, and the barrel and
barrel are made of steel pipe. Steel pipes can be divided into round
pipes and special-shaped pipes according to the different shapes of the
cross-sectional area. Because the circular surface volume is the largest
under the condition of equal circumference, more fluid can be
transported with circular tubes. In addition, when the annular section
is subjected to internal or external radial pressure, the force is more
uniform, so the vast majority of steel pipes are round pipes.
The use of steel pipe to manufacture ring parts can improve the
utilization rate of materials, simplify the manufacturing process, save
materials and processing hours, such as rolling bearing rings, jack
sleeves, etc., currently has been widely used to manufacture steel pipes
Progress in research on controllable single-layer graphene films on insulating substrates
[ Instrument Network Instrument Development ] Chemical vapor deposition (CVD) is one of the effective methods for growing large-area high-quality graphene. In the CVD growth of graphene, it is necessary to use a metal catalyst. Graphene needs to be transferred to construct an electrical device, which is incompatible with current semiconductor processing processes, and the transfer causes graphene wrinkles, breakage, and electrical properties. If the metal-free catalytic growth of graphene can be realized on an insulating substrate, the electrical device can be directly constructed without transferring. However, unlike the self-limiting growth mode on most metal substrates, CVD growth of graphene on an insulating substrate is often accompanied by shortcomings such as slow growth rate and repeated nucleation, resulting in graphite with poor uniformity and uncertainty. Alkene film. Therefore, the preparation of a large-area uniform single-layer graphene film directly on an insulating substrate has a profound influence on the docking of the semiconductor industry and the acceleration of the industrial application of graphene.
Under the support of the National Natural Science Foundation of China and the Chinese Academy of Sciences Pilot Project, the Key Laboratory of Organic Solids of the Institute of Chemistry of the Chinese Academy of Sciences has long been committed to the research of CVD controllable graphene and has made a series of progress (Adv. Mater. 2015). , 27, 2821-2837; Adv. Mater.2015, 27, 4195-4199; Adv. Mater. 2016, 28, 4956-4975; Adv. Mater. Interfaces 2016, 3, 1600347; J. Mater. Chem. C 2016 , 4, 7464-7471; Mater. Horiz. 2016, 3, 568; Chem. Mater. 2017, 29, 1022-1027; Nat. Commun. 2017, 8, 14029; Carbon 2017, 121, 1-9; Adv. Mater. Interfaces 2018, 5, 1800347; Angew. Chem. Int. Ed. 2018, 57, 192-197; Mater. Horiz. 2018, 5, 1021-1034; Chem. Mater. 2019, 31, 1231; Adv. Mater Technol. 2019, 4, 1800572; Diamond Relat. Mater. 2019, 91, 112-118; Small Methods 2019, 31, 2507).
Recently, researchers have adopted a new precursor regulation strategy to successfully inhibit the secondary nucleation of graphene, thereby directly growing a large area of ​​high-quality uniform single-layer graphene film on the insulating substrate. Through the study of the growth mechanism of graphene, it is known that the hydroxylation of the surface of the silica substrate weakens the bond between the edge of the graphene and the substrate, thereby realizing the growth of graphene dominated by primary nucleation. Field-effect transistor (FET) device test results show that the prepared uniform single-layer graphene film has excellent electrical properties, and the mobility is up to 3800 cm2 V-1 s-1, which is a graphene thin film device grown on an insulating substrate. The highest performance value. This method of preparing high-quality graphene films on an insulating substrate without any complicated transfer process makes the application of graphene in the field of integrated electronics and optoelectronics one step further. In this work, the researchers and Xu Zhiping, a professor of engineering mechanics at Tsinghua University, conducted a close collaborative study on the growth mechanism of graphene. The relevant research results were published in the American Chemical Society (J. Am. Chem. Soc). , 2019, 141, 11004-11008), the authors of the correspondence are Yu Gui and Xu Zhiping, the first author is Wang Huaping.