다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Materials with good flexibility and high conductivity that can provide electromagnetic interference (EMI) shielding with minimal thickness are highly desirable, especially if they can be easily processed into films. Two-dimensional metal carbides and nitrides, known as MXenes, combine metallic conductivity and hydrophilic surfaces. Here, we demonstrate the potential of several MXenes and their polymer composites for EMI shielding. A 45-micrometer-thick Ti3C2Tx film exhibited EMI shielding effectiveness of 92 decibels (>50 decibels for a 2.5-micrometer film), which is the highest among synthetic materials of comparable thickness produced to date. This performance originates from the excellent electrical conductivity of Ti3C2Tx films (4600 Siemens per centimeter) and multiple internal reflections from Ti3C2Tx flakes in free-standing films. The mechanical flexibility and easy coating capability offered by MXenes and their composites enable them to shield surfaces of any shape while providing high EMI shielding efficiency.

Electromagnetic interference shielding with 2D transition metal carbides (MXenes)

Metal Oxides and Oxysalts as Anode Materials for Li Ion Batteries

Conductometric semiconducting metal oxide gas sensors have been widely used and investigated in the detection of gases. Investigations have indicated that the gas sensing process is strongly related to surface reactions, so one of the important parameters of gas sensors, the sensitivity of the metal oxide based materials, will change with the factors influencing the surface reactions, such as chemical components, surface-modification and microstructures of sensing layers, temperature and humidity. In this brief review, attention will be focused on changes of sensitivity of conductometric semiconducting metal oxide gas sensors due to the five factors mentioned above.

Metal oxide gas sensors: Sensitivity and influencing factors

We developed two-step solution-phase reactions to form hybrid materials of Mn3O4 nanoparticles on reduced graphene oxide (RGO) sheets for lithium ion battery applications. Mn3O4 nanoparticles grown selectively on RGO sheets over free particle growth in solution allowed for the electrically insulating Mn3O4 nanoparticles wired up to a current collector through the underlying conducting graphene network. The Mn3O4 nanoparticles formed on RGO show a high specific capacity up to ~900mAh/g near its theoretical capacity with good rate capability and cycling stability, owing to the intimate interactions between the graphene substrates and the Mn3O4 nanoparticles grown atop. The Mn3O4/RGO hybrid could be a promising candidate material for high-capacity, low-cost, and environmentally friendly anode for lithium ion batteries. Our growth-on-graphene approach should offer a new technique for design and synthesis of battery electrodes based on highly insulating materials.

Mn3O4-Graphene Hybrid as a High Capacity Anode Material for Lithium Ion Batteries

Ternary WSe2@CNTs/Co3O4 nanocomposites for highly efficient multi-band microwave absorption

The invention discloses a preparation method of a lead-free piezoelectric thick film with sodium bismuth titanate and potassium sodium niobate spin-coated alternately. A simple and easy-to-control process method is provided based on a sol-gel method and comprises the steps of: respectively preparing stable BNT and KNN sol, plating the KNN sol on a (Pt/TiO2/Ti/SiO2/Si) substrate at the revolving speed of 3200r/min for 30 seconds, drying a wet film at 200 DEG C, keeping the temperature for 10 minutes at a muffle furnace which is heated to 500 DEG C at a speed of 4 DEG C per minute, coating a BNT film on a second layer, repeating the steps three times under the same heat treatment conditions, i.e. alternately spin-coating six layers, and annealing for 10 minutes at 700 DEG C to finally obtain the KNN-BNT thick film with the thickness of 4 micrometers. The prepared thick film has the advantages of uniform grains, tight arrangement, smooth surface and no cracking.

Preparation method of lead-free piezoelectric thick film with sodium bismuth titanate and potassium sodium niobate spin-coated alternately

Microwave absorbing characteristics of composites filled with carbon nanotubes (CNTs), including the laminar composite with different thickness, is investigated in detail. The filler used for the absorbent is CNTs and the matrix is polyester. The absorbing curves display obvious absorbability, which measuring frequency-band extend from 8~18 GHz. But comparative experiments show that the absorbing level is lower than nature graphite under the condition of specifically thickness. The further test shows that there exists relative strength peak at 25 GHz

Investigation on Potential Microwave Absorbability of Polyester-composites Filled with Carbon Nanotubes

Multiple nonlinear dielectric resonance of ultra-long silver trimolybdate nanowires

The effective microwave absorption materials could contribute to alleviating the electromagnetic wave pollution. However, conventional microwave absorption materials usually suffer from insufficient absorption intensity and the narrow effective absorption bandwidth. Herein, BiFeO3/BaFe7(MnTi)2.5O19 composites are proposed to address these issues through offering synergetic electromagnetic properties and proper electromagnetic properties. BiFeO3 combined with BaFe7(MnTi)2.5O19 exhibits dielectric multiple relaxation behaviors, strong ferromagnetic resonance and electromagnetic matching, ensuring increased multi-band microwave absorption. Accordingly, the minimum reflection loss (RL) of the composite with volume ratio of 1.5:1 reaches − 48 dB, and the bandwidth less than − 10 dB covers multi-frequencies at C, X and Ku band. These results suggest that BiFeO3/BaFe7(MnTi)2.5O19 composite could be a promising microwave absorption material in imaging, healthcare, information safety and military fields.

Mao-Sheng Cao

Papers

Ternary WSe2@CNTs/Co3O4 nanocomposites for highly efficient multi-band microwave absorption

Preparation method of lead-free piezoelectric thick film with sodium bismuth titanate and potassium sodium niobate spin-coated alternately

Investigation on Potential Microwave Absorbability of Polyester-composites Filled with Carbon Nanotubes

Multiple nonlinear dielectric resonance of ultra-long silver trimolybdate nanowires

The synergetic electromagnetic properties and enhanced microwave absorption of BiFeO 3 /BaFe 7 (MnTi) 2.5 O 19 composite