Structure and Mechanical Performance of Nitrogen Doped Diamond-like Carbon Films

Nitrogen doped diamond-like carbon （DLC：N） films were prepared by electron cyclotron resonance chemical vapor deposition （ECR-CVD） on polycrystalline Si chips. Film thickness is about 50 nm. Auger electron spectroscopy （AES） was used to evaluate nitrogen content, and increasing N2 flow improved N content from 0 to 7.6%. Raman and X-ray photoelectron spectroscopy （XPS） analysis results reveal CN-sp^3C and N-sp^2C structure. With increasing the N2 flow, sp^3C decreases from 73.74% down to 42.66%, and so does N-sp^3C from 68.04% down to 20.23%. The hardness decreases from 29.18 GPa down to 19.74 GPa, and the Young＇s modulus from 193.03 GPa down to 144.52 GPa.

Analysis of Consumer Behavior in the Context of the Digital Economy

Under the condition that the digital economy model has penetrated into the consumption field,the consumer market environment is improving,the consumption structure is upgrading,the consumption content is diversified,and the consumer behavior is showing new epoch-making characteristics.But at the same time,there are also some problems,such as consumer privacy disclosure,and price discrimination based on consumer behavior.The future development of consumer economy needs the joint efforts of the government,the market and consumers to establish a new cycle of the economic system from top to bottom.

Space-and frequency-division multiplexing in photonic second-order topological insulators

Higher-order topological insulators,originally proposed in quantum condensed matters,have provided a new avenue for localizing and transmitting light in photonic devices.Nontrivial band topology in crystals with certain symmetries can host robust topological edge states and lower dimensional topological corner states(TCS),making them a promising platform for photonics applications.Here,we have designed several types of TCS with only two specific C6v-symmetric photonic crystals with various seamless splicing boundaries,where all the supposed TCS with diverse electromagnetic characteristics are visualized via numerical simulations and experimental measurements.More interestingly,we have observed that those TCS overlapping in spectral and spatial space tend to interweaved,inducing spectrum division.Meanwhile,the equivalent corners appear to have TCS with a phase difference,which is critical for directional activation of pseudospin dependence.Our findings demonstrate that coupled TCS with phase difference at different nanocavities can be selectively excited by a chiral source,which indicates that the TCS at this time have pseudospin-dependent properties.We further design a specific splicing structure to prevent coupling between adjacent TCS.This work provides a flexible approach for space-and frequency-division multiplexing in photonic devices.

Nucleon effective mass splitting and density-dependent symmetry energy effects on elliptic flow in heavy ion collisions at Elab= 0.09 ~ 1.5 GeV/nucleon

By incorporating an iso spin-dependent form of the momentum-dependent potential in the ultra-relativistic quantum molecular dynamics(UrQMD)model,we systematically investigate effects of the neutron-proton effective mass splitting m*n-p=m*n-m*p/m and the density-dependent nuclear symmetry energy Esym(ρ)on the elliptic flow v2 in197Au+197 Au collisions at beam energies from 0.09 to 1.5 GeV/nucleon.It is found that at higher beam energies(≥0.25 GeV/nucleon)with the approximately 75 MeV difference in slopes of the two different Esym(ρ),and the variation of m*n-p ranging from-0.03 to 0.03 at saturation density with isospin asymmetryδ=(ρn-ρp)/ρ-0.2,the Esym(ρ)has a stronger influence on the difference in v2 between neutrons and protons,i.e.,v2n-v2p,than m*n-p has.Meanwhile,at lower beam energies(≤0.25 GeV/nucleon),v2n-v2p is sensitive to both the Esym(ρ)and the m*n-p.Moreover,the influence of m*n-p on v2n-v2p is more evident with the parameters of this study when using the soft,rather than stiff,symmetry energy.