There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

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

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

비만아 부모의 돌봄 경험: q 방법론

Physical Review B

Molecular dynamics simulations with Tersoff potentials were used to study the tensile and compressive mechanical behavior of SiC nanowires with torsion strain. The simulation results show that small torsion strain does not affect the mechanical behavior of SiC nanowires. However, large torsion strain induces the decrease of the critical stress. With large torsion strain, the collapse occurs in the nanowires before tensile failure and compressive buckling, and deformation zone occurs in the collapsed part.

Simulation on the effects of torsion strain on the mechanical properties of SiC nanowires under tensile and compressive loading

The invention belongs to the technical field of preparation of inorganic materials and particularly relates to a bowknot-shaped CeO2 nano material and a preparation method thereof. The CeO2 nano material consists of a plurality of layers of nanorods which are 140-220 nm in length and 45-55 nm in diameter, the length of a bowknot is 4-6 [mu]m in length, a bowknot-shaped CeO2 nano material has the formation ratio of larger than 90%, and a secondary rod-like structure is obvious. As cerium nitrate hexahydrate is taken as a cerium source, PVP is used together as a surfactant, and the special raw material reagent combination is subjected to hydro-thermal treatment and annealing treatment to obtain the bowknot-shaped CeO2 nano material consisting of the multi-layered nanorods. The bowknot-shapedCeO2 nano material is low in preparation cost and environmentally friendly because no strong acid or alkali is adopted. The specially-shaped nano structure can be used in such fields as catalysts, oxygen storage materials, fuel cells, super-capacitors, gas sensors, electronic ceramics and the like.

Bowknot-shaped CeO2 nano material and preparation method thereof

We investigate the interaction between the laser and energetic materials with different defects. The three-dimensional models of triaminotrinitrobenzene (TATB) explosives containing spherical pores, craters, and cracks are established, respectively. The laser ignition process of TATB is simulated with three-dimensional finite difference time domain (3D-FDTD) method to study the electromagnetic field distribution surrounding these defects with 355 nm laser incidence. It indicates that the larger defects in the TATB energetic materials have the stronger electric field modulations to initial incident laser for all the three defects, which is easier to lead to the generation of hot spots. Furthermore, TATB materials with spherical pore defects and crater defects are easier to form hot spots than those with narrow crack defects.

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Defects-Induced Hot Spots in TATB

The invention belongs to the technical field of preparation of inorganic materials, and particularly relates to a method for directly preparing nickel hydroxide/basic cobalt carbonate Ni(OH)2/Co2(CO3)(OH)2 composite electrode material on a current collector. The material can be directly used as an electrode of a supercapacitor, and has high specific capacity and excellent cycling stability. Firstly, nickel hydroxide nanoparticle layers are deposited and grown on the inner surface and the outer surface of the current collector, so that the firmness of the surfaces of an active material and thecurrent collector is improved, a crystal seed material is provided for the composite material grown on the current collector by a hydrothermal process in the second step, and meanwhile, the stabilityof the composite material on the surface of a framework structure of the current collector is ensured; and then in the second hydrothermal reaction synthesis process, the proportion between Ni ions and Co ions is strictly controlled for enabling the finally synthesized composite material to be uniformly distributed on the surfaces of nickel hydroxide nanoparticles of frameworks inside and outsidea current collector sheet, a spherical structure is presented, and spheres are tightly connected, so that the specific capacity of the capacitor can be effectively expanded.

Method for preparing nickel hydroxide/basic cobalt carbonate composite material on current collector

The invention belongs to the technical field of preparation of inorganic materials, and specifically relates to a Ce(1-x)ZrxO2 nanosheet material and a preparation method thereof. The preparation method comprises the following steps: preparing a mixed solution by adopting cerium nitrate, zirconium nitrate dihydrate and sodium nitrate; then sequentially adding ammonium hydroxide and hydrogen peroxide, thus obtaining sol; carrying out hydrothermal treatment, thus obtaining the Ce(1-x)ZrxO2 nanosheet material which is ultrathin and porous. A solid solution structure is formed by a prepared zirconium ion modified cerium oxide material, the prepared zirconium ion modified cerium oxide material is in a nanosheet morphology of which the thickness is 6 to 12nm, mesopores of which the sizes are 1.9 to 2.5nm are formed in a nanosheet, the specific surface area is greater than 180m /g, and the pore volume is greater than 0.50cm /g; Zr ions are uniformly distributed in crystal lattices of cerium dioxide, and the solid solution structure is formed; industrial large-scale production can be easily carried out, high-temperature roasting treatment is not required, the energy is saved, a surfactant or strong acid and strong base are not required, and a preparation process is environmentally friendly.

Zhijie Li

Papers

Simulation on the effects of torsion strain on the mechanical properties of SiC nanowires under tensile and compressive loading

Bowknot-shaped CeO2 nano material and preparation method thereof

Defects-Induced Hot Spots in TATB

Method for preparing nickel hydroxide/basic cobalt carbonate composite material on current collector

Ce(1-x)ZrxO2 nanosheet material and preparation method thereof