Electrical Characterization of Individual Cesium Lead Halide Perovskite Nanowires Using Conductive AFM

Perovskite nanostructures have attracted much attention in recent years due to their suitability for a variety of applications such as photovoltaics, light-emitting diodes (LEDs), nanometer-size lasing, and more. These uses rely on the conductive properties of these nanostructures. However, electrical characterization of individual, thin perovskite nanowires has not yet been reported. Here, conductive atomic force microscopy characterization of individual cesium lead halide nanowires is presented. Clear differences are observed in the conductivity of nanowires containing only bromide and nanowires containing a mixture of bromide and iodide. The differences are attributed to a higher density of crystalline defects, deeper trap states, and higher inherent conductivity for nanowires with mixed bromide–iodide content.     

中药口服液提取工艺的分析

对中药口服液提取工艺进行了简单的分析讨论。其中,重点对现有的中药口服液提取工艺方法进行了探讨,并由此思考了水提醇沉法的优化改进,仅供参考。     

Status and initial experiments of DRAGON-V facility for lithium-lead blanket technologies of hydrogen fusion reactors

A dual-coolant integrated experimental facility named DRAGON-V has been developed at the Institute of Nuclear Energy Safety Technology, Hefei Institute of Physical Science, Chinese Academy of Sciences, for the key technology research and performance evaluation of candidate liquid lithium-lead (PbLi) blanket of hydrogen fusion reactors. The loop is composed of a material test sub-loop and thermal-hydraulic test sub-loop, the design parameters are PbLi inventory 20 tons, PbLi temperature up to 550 °C, the maximum PbLi flow rate up to 40 kg/s. A novel cold trap system is designed to remove the suspended and crystalized impurities in PbLi fluid with three cooling zones and cross row arrangement of rod bundle filter elements. The paper describes the loop itself and its major components, initial loop testing, flow and measurement diagnostics and current experiments. The obtained test results of the loop and its components have demonstrated that the new facility is fully functioning and ready for experimental studies of material corrosion with/without a magnetic field, magnetohydrodynamic (MHD) effect, purification, heat and mass transfer phenomena in PbLi flows and can also be used in mock-up testing in conditions relevant to fusion applications.     

分子筛负载有机磷酸酯成核体系对聚丙烯性能的影响研究

采用溶液浸渍法制备了不同分子筛负载有机磷酸酯（MBP）成核体系，研究其对等规聚丙烯（iPP）结晶性能和力学性能的影响，并通过扫描电子显微镜观察不同分子筛对MBP的分散情况，进而揭示不同分子筛负载MBP对iPP成核性能提升差异的原因。结果表明，B类分子筛?1和B类分子筛-2负载MBP对iPP性能影响有限。而A类分子筛-1和A类分子筛-2负载MBP成核体系对iPP的性能提升明显：不仅促使iPP的结晶温度分别提高了10 ℃和6 ℃；也在促使iPP的弯曲模量分别提高29.9 %和13.0 %的同时，使得其冲击强度分别提升8 %和7 %，起到了有效的刚韧平衡的作用。成核体系的SEM结果表明，A类分子筛-1的加入能有效分散MBP，从而促使其在iPP当中发挥成核性能；而B类分子筛?1本身团聚严重，无法很好地分散MBP，因此无法发挥提升iPP成核性能的作用。     

Dynamic behavior of droplet transport on realistic gas diffusion layer with inertial effect via a unified lattice Boltzmann method

The dynamic behavior of liquid droplets on a reconstructed real gas diffusion layer (GDL) surface with the inertial effect produced by the three dimensional (3D) flow channel is investigated using an improved pseudopotential multiphase model within the unified lattice Boltzmann model (ULBM) framework, which can realize thermodynamic consistency and tunable surface tension. The microstructure of the GDL (Toray-090) including carbon fibers and polytetrafluoroethylene (PTFE) is reconstructed by a stochastic and mixed-wettability model. The critical force formulation for the Cassie-Wenzel transition of a droplet on GDL surface is derived. The effects of inertia and contact angles on the liquid droplet transport process on a reconstructed real GDL surface with a 3D flow channel are investigated. The results show the normalized center-of-mass coordinate X may enter the channel wall area or fluctuate around the initial position. With increased inertia applied on the droplet, the normalized center-of-mass coordinate Y grows faster and the normalized center-of-mass coordinate Z decreases. It is found by the ULBM for the first time that the liquid droplet is pushed back into the GDL by inertial effect. With the increase of inertia and the decrease of contact angle of GDL, both the droplet penetration depth in GDL and the droplet invasion fraction increase. The droplet invasion fraction in GDL is up to 30%.     

排液滴定法快速测定球团矿体积

介绍一种通过排液滴定快速测定球团矿体积的新方法。该方法基于体积排液原理，滴定控制精度，经过大量试验验证准确可行，设备、试剂、程序简单，数据直观，便于复查核对，精度高，耗时短，单次测定仅需30 min即可完成。应用后可将球团矿相对自由膨胀指数的测定时间缩短3 h以上，弥补了GB/T 13240—1991《铁矿球团相对自由膨胀指数的测定方法》中推荐的球团矿体积测定方法的不足。     

Xylene Isomerization in the Liquid Phase Using Large‐Pore Zeolites

Three large‐pore zeolites, Beta with Si/Al ratios of 25 and 35 and Mordenite with an Si/Al ratio of 30, were studied in the conversion of o‐xylene at 493 K. Maximum conversion was achieved by the catalyst with the highest Si/Al ratio due to faster diffusion of the isomer inside the zeolite channels because of the lower acidity of the solid even with larger crystal size. A kinetic study was then carried out over this catalyst between 473 and 513 K in a batch reactor in the liquid phase. The activation energies obtained do not indicate the presence of diffusional constraints towards any isomer. Finally, the kinetic model obtained was simulated in a fixed‐bed reactor and compared to ZSM‐5 in the temperature range from 493 to 533 K. An increment in p‐xylene production of 20 % on average was obtained.     

Effect of CaO on the liquid/spinel/matte/gas equilibria in the Si–Fe–O–Cu–S system at controlled P(SO2) 0.3 and 0.6 atm

Herein the phase equilibria in the Si–Fe–Ca–O–S–Cu system in equilibrium with matte at controlled P(SO₂) of 0.3 and 0.6 atm and fixed matte grade of 72 wt % Cu were experimentally investigated in the spinel primary phase field. The high-temperature equilibrations were realized in spinel substrate and the sample after quenching were characterized using Electron Probe Micro-analysis (EPMA). The effect of CaO on the liquidus temperature of slags was quantified with varying CaO content from 0 to 6 wt %. It was found that, the presence of CaO increased the liquidus temperature of slags and moreover, the increment effect got enhanced with increasing CaO content in the present range. The influence of P(SO₂) was further clarified and it was found that, the equilibrium SiO₂ content in the liquid phase, at the same temperature, remarkably increased with increasing P(SO₂). The present study will not only deepen the understanding of the equilibration in the present liquid/spinel/matte/gas system, but also provide useful guidance for the industrial operations.     

N–TiO2 crystal seeds incorporated in amorphous matrix for enhanced solar hydrogen generation: Experimental & first-principles analysis

We present here a combined study on the photoelectrochemical activity of highly active Nitrogen doped titanium dioxide thin-film using experiments and First principle density (DFT) based calculation. Hybridization of N 2p with O 2p and localized valence band upshifting leads to the reduction in band-gap of N–TiO₂. To validate theoretical findings, the role of nitrogen in TiO₂ is revisited with a focus on partial crystallinity. The best-case photoelectrode, nanostructured partially crystalline nitrogen-doped titanium dioxide (PCNDTO) offered photocurrent density of 24.3 mA/cm² at 1 V versus saturated calomel electrode (SCE). The absence of well-defined peaks and long-range order in XRD pattern and Raman spectrum respectively suggests partially crystallinity. High-resolution transmission electron microscopy (HR-TEM) images confirm the presence of TiO₂ crystals in the amorphous matrix. High photoelectrochemical response can be attributed to the abundance of hydroxyl groups, high electrochemical active surface area, reduced charge transfer resistance, and reduced charge carrier recombination rate.