All boron-based 2D material as anode material in Li-ion batteries

To design the high-energy-density Li-ion batteries, the anode materials with high specific capacity haveattracted much attention. In this work, we adopt the first principles calculations to investigate the pos-sibility of a new two dimensional boron material, named Be, as anode material for Li-ion batteries. Thecalculated results show that the maximum theoretical specific capacity of Bc is 1653mAh g-1 （LiBl.s）.Additionally, the energy barriers of Li ion and Li vacancy diffusion are 330 meV and 110 meV, respec-tively, which imply fast charge and discharge ability for B6 as an anode material. The theoretical findingsreported in this work suggest that BG is a potential candidate as anode material of high-energy-density Li-ion batteries.

Preparation and combustion properties of laminated sticks of B-CuO and B-Bi_(2)O_(3)

To explore the composite process of B-CuO and B-Bi_(2)O_(3) two-component laminated sticks,obtain the corresponding sticks with good printing effect,and explore the energy release behavior.In this study,boron,copper oxide,and bismuth trioxide powders were dispersed in the dispersed phase (DMF) using F_(2602) as a binder,and the construction of two-component B-CuO,B-Bi_(2)O_(3),three-component microcomposite,and three-component macro-composite sticks were realized with the help of double nozzle direct ink writing (DIW) technique respectively.The resulting sticks were ignited by a nichrome wire energized with a direct current,and a high-speed camera system was used to record the combustion behavior of the sticks,mark the flame position,and calculate the rate of ignition.The results showed that the B-CuO stick burning rate (42.11 mm·s^(-1)) was much higher than that of B-Bi_(2)O_(3)(17.84 mm·s^(-1)).The formulation with the highest CuO content (ω_(CuO)=58.7%) in the microscale composite of the sticks also had the fastest burning rate of 60.59 mm·s^(-1),as the CuO content decreased (ω_(CuO)=43.5%,29.3%),its burning rate decreased to 34.78 mm·s^(-1),37.97 mm·s^(-1).The stick with the highest copper oxide content(ω_(CuO)=60%) also possessed the highest burning rate (48.84 mm·s^(-1)) in the macro-composite sticks,and the burning rates of the macro-composite sticks with component spacing of 0.1 mm,0.2 mm,and 0.5 mm were 43.34 mm·s^(-1),48.84 mm·s^(-1),and 40.76 mm·s^(-1).

卡腰对导爆管雷管延时精度的影响

通过改变雷管的卡腰尺寸和卡腰位置来探究卡腰对雷管延时精度的具体影响。试验研究表明,卡腰工艺会影响延期体的燃烧速度和燃烧稳定性,对于相同的延期体结构,卡腰尺寸越大,燃烧速度越快,气体堵塞效应越小,燃烧越稳定,雷管延时精度越高;当其他所有条件一致,雷管的卡腰位置由延期体上端移到延期体底端时,延期体的燃速变慢,受气体压力影响更小,燃烧更稳定,雷管延时精度更高;此外,当卡腰尺寸或卡腰位置变化时,药芯直径的大小会影响雷管延时精度的改变幅度。

A high propylene productivity over B2O3/SiO2@honeycomb cordierite catalyst for oxidative dehydrogenation of propane

Boron-based metal-free catalysts for oxidative dehydrogenation of propane(ODHP)have drawn great attention in both academia and industry due to their impressive activity and olefin selectivity.Herein,the SiO2 and B2O3 sequentially coated honeycomb cordierite catalyst is designed by a two-step wash-coat method with different B2O3 loadings(0.1%–10%)and calcination temperatures(600,700,800℃).SiO2 obtained by TEOS hydrolysis acts as a media layer to bridge the cordierite substrate and boron oxide via abundant Si\\OH groups.The welldeveloped straight channels of honeycomb cordierite make it possible to carry out the reactor under high gas hourly space velocity(GHSV)and the thin wash-coated B2O3 layer can effectively facilitate the pore diffusion on the catalyst.The prepared B2O3/SiO2@HC monolithic catalyst exhibits good catalytic performance at low boron oxide loading and achieves excellent propylene selectivity(86.0%),olefin selectivity(97.6%,propylene and ethylene)and negligible CO2(0.1%)at 16.9%propane conversion under high GHSV of 345,600 ml·(g B2O3)^-1·h^-1,leading to a high propylene space time yield of 15.7 g C3H6·(g B2O3)^-1·h^-1 by suppressing the overoxidation.The obtained results strongly indicate that the boron-based monolithic catalyst can be properly fabricated to warrant the high activity and high throughput with its high gas/surface ratio and straight channels.

Electrospinning synthesis of porous boron-doped silica nanofibers for oxidative dehydrogenation of light alkanes

The discovery of the high activity and selectivity of boron-based catalysts for oxidative dehydrogenation(ODH)of alkanes to olefins has attracted significant attention in the exploration of a new method for the synthesis of highly active and selective catalysts.Herein,we describe the synthesis of porous boron-doped silica nanofibers(PBSNs)100-150 nm in diameter by electrospinning and the study of their catalytic performance.The electrospinning synthesis of the catalyst ensures the uniform dispersion and stability of the boron species on the open silica fiber framework.The one-dimensional nanofibers with open pore structures not only prevented diffusion limitation but also guaranteed high catalytic activity at high weight hourly space velocity(WHSV)in the ODH of alkanes.Compared to other supported boron oxide catalysts,PBSN catalysts showed higher olefin selectivity and stability.The presence of Si-OH groups in silica-supported boron catalysts may cause low propylene selectivity during the ODH of propane.When the ODH conversion of ethane reached 44.3%,the selectivity and productivity of ethylene were 84%and 44.2%g_(cat)^(-1)s^(-1),respectively.In the case of propane ODH,the conversion,selectivity of olefins,and productivity of propylene are 19.2%,90%,and 76.6 jimol g_(cat)^(-1)s^(-1),respectively.No significant variations in the conversion and product selectivity occurred during 20 h of operation at a high WHSV of 84.6 h^(-1).Transient analysis and kinetic experiments indicated that the activation of O2 was influenced by alkanes during the ODH reaction.

Boron based hypergolic ionic liquids:A review

The advance of space technology is deeply affected by the breakthrough of high-performance fuels.Hypergolic ionic liquids(HILs)are one of the most potential fuels for bipropellant systems.However,high viscosity value and low specific impulse of traditional N-based HILs limit their application.Recently,boron-based HILs with low viscosity become the new candidates,and their derivatives are also found to promote the hypergolicity as additives in HILs.Here,the synthesis,physical chemical properties and thermal performance of boron-based HILs and HILadditive system are reviewed.