Study on the removal of olefins from naphtha by clay loaded with trifluoromethanesulfonic acid

Journal of Porous Materials - In this work, a trifluoromethanesulfonic acid (TFOH) modified clay (TFOH-Clay) was developed for the removal of trace olefins in heavy naphtha. 5%TFOH-Clay can...     

Surface Modification of Co3O4 Nanosheets to Promote Peroxymonosulfate Activation for Degradation of Atrazine

Catalysis Letters - This study proposed a new facile route to rational creating oxygen-vacancy (Vo)-rich surface of Co3O4 nanosheets by acetic acid leaching. The acid leached Co3O4 nanosheets was...     

基于Massive MIMO及频谱叠加的5G SA网络上行优化方法

大规模多输入多输出(Multiple-Input Multiple-Output, MIMO)可以有效提升5G SA网络的上行链路数据传输速率以及可靠性。针对5G SA网络上行链路速率和覆盖不均衡的情况,提出了基于大规模MIMO的分组算法,将发送信号矢量进行分组,组内采用最大似然检测,组外采用基于正交三角分解(QR分解)的干扰消除检测,并且结合5G频谱的叠加策略,在降低算法复杂度的同时,有效提升网络覆盖和速率。通过5G SA现网实测,通过MIMO降低分组数量能够提升分组检测性能,结合上行低频段频谱叠加策略能够有效提升5G SA网络上行覆盖30%,提升5G SA网络上行平均速率40%~80%,特别是弱覆盖边缘的网络速率,最高可达600%。     

One-step preparation of the superhydrophobic Al alloy surface with enhanced corrosion and wear resistance

Corrosion and wear failures are bottlenecks for restricting applications and developments of Al-based functional materials. As a new lubrication technology, superhydrophobic preparation provides an effective way to settle Al alloy corrosion. The preparation methods of superhydrophobic Al alloys are mainly multistep strategies. In this study, superhydrophobic Al alloy, has been prepared by an efficient one-step electrochemical etching process. Meanwhile, its micromorphology has been observed by a scanning electron microscope. The wettability has been measured by video optical contact angle meter. The corrosion behavior has been tested by electrochemical workstation, and wear performance has been characterized by friction tester. The results show that the micro-nanoterraced concave–convex structure has been fabricated and an as-prepared surface exhibits excellent superhydrophobic behavior. Further electrochemical and tribological tests show that corrosion resistance and wear resistance have also been significantly improved. This study provides a new method to prepare wear-resistant and corrosion-resistant Al alloy for widening applications of multifunctional Al-based engineering materials.     

Far-red-emitting YAl3(BO3)4:Cr3+ phosphors with excellent thermal stability and high luminescent yield for plant growth LEDs

Phosphors-converted LEDs (pc-LEDs) are excellent artificial light sources for indoor plant cultivation, in which the far-red-emitting component (700−780 nm) plays an important role in regulating the photomorphogenesis of plants. Accordingly, highly efficient and thermally stable far-red-emitting phosphors are indispensable for developing high-performance plant cultivation pc-LEDs. Herein, far-red-emitting YAl₃(BO₃)₄:Cr³⁺ (YAB:Cr³⁺) phosphors were synthesized by solid-state reaction, and their photoluminescence characteristics, thermal quenching, quantum yield (QY), and application in pc-LEDs were systematically investigated. The YAB:Cr³⁺ phosphor has an intense broadband absorption to the blue light, simultaneously exhibiting the sharp-line ²E emission and the broadband ⁴ T₂ emission of Cr³⁺ with a QY of ~86.7%. The far-red broadband emissions of YAB:Cr³⁺ centered at ~735 nm show a high resemblance to the active-state (P_FR) absorption of plant phytochrome. Moreover, the YAB:Cr³⁺ phosphor shows the thermally enhanced luminescence at temperatures of 303−393 K and the near-zero thermal quenching up to 423 K. The anomalous thermal enhancement is attributed to the temperature-dependent repopulation between ²E and ⁴ T₂ states. Finally, a pc-LED device was fabricated with the YAB:Cr³⁺ phosphor and blue chip, exhibiting the light out power of ~50.6 mW and energy conversion efficiency of ~17.4% at 100 mA drive current, respectively. The exceptional PL features including suitable excitation/emission wavelengths, suppressed thermal quenching and high QY make YAB:Cr³⁺ phosphors very promising for applications in plant growth pc-LEDs.     

Stable Radicals with Protective Umbrellas Integrated on the Surface of 2D Layered Materials

Radicals are closely related to human life and health and have been widely used in biology, chemistry, functional materials, etc. However, the high reactivity, disorder, and short half-lives limit their wide applications. Therefore, it remains a great challenge to prepare stable and ordered radicals. Herein, radicals are prepared with protective umbrellas (diethylmethyleneamine, DEMA) that are integrated on the surface of 2D layered materials to isolate water and oxygen and enhance the stability of radicals. Taking 2D black phosphorus (BP) as an example: triethylamine reacts with dichloromethane to form quaternary ammonium salts with further Hoffmann elimination to produce DEMA radicals that could react with one electron of a lone pair electrons in P on the surface of BP to produce P radicals, which shows a prolonged half-life of 21 days at room temperature. First-principle calculations and electron paramagnetic resonance fitting confirm that the steric hindrance constructed by dense DEMA passivation layer acts as a protective umbrella and the 2D coupling of P radicals and other P atoms in 2D BP plane to enhance the stability and strong superexchange interaction of P radicals. Furthermore, it is a general strategy to produce stable radicals integrated on the 2D plane.