Reaction characteristics of magnesium production under argon flow by silicothermic reduction and numerical simulation of argon entrainment process

In this study, the reaction characteristics of reduction of calcined dolomite with ferrosilicon under argon flow to produce magnesium were studied by conducting experiments Pidgeon pellets were used to study the effect of reduced temperature, argon flow, and reduced time on the conversion of calcined dolomite reduction by ferrosilicon. The results show that the conversion significantly increases with the increase in the reduction temperature and reduction time. The conversion first increases and then decreases with the increase in argon flow. The highest conversion was obtained when the argon flow rate was 3 L·min^(-1), and a nearly spherical shape, nanoscale magnesium powder was obtained. Then the characters of the circulating argon entrainment process were numerically studied by ANSYS Fluent 17. A physical model of multilayer pellet arrangement was established, and a numerical calculation model of chemical reaction, radiation, heat conduction, and convection heat transfer was constructed. This confirms that high-temperature argon can effectively strengthen the heat exchange between pellets, improve the heat transfer efficiency, and facilitate the pellets to react quickly. When the conversion is 80%, the production efficiency increased by about 28.6%. In addition, the magnesium production efficiency showed an increase tendency with the increase of the argon inlet flow rate.

Revolutionizing the Life Sciences by Developing a Holographic Digital Mannequin

1.The need to develop a holographic digital mannequin Life processes,including high intelligence,self-organization,and homeostasis,are characterized by the biological organism in the form of self-renewal,self-replication and self-regulation,metabolism,self-repair,and self-reproduction,which are all processes of multisystem coordinated movement[1].Research in the field of life sciences is not limited to the use of advanced observational methods to reveal microscopic structures at the subcellular or molecular level.Discoveries based on these methods alone cannot characterize the dynamic processes of life at the microscopic and molecular level[2].

碳模板诱导生长Fe-N_x活性位点（英文）

能源危机和环境恶化是当今社会面临的巨大挑战.燃料电池作为一种高效、清洁的发电装置,受到了社会各界特别是新能源行业的高度关注.尤其是,日本丰田推出Mirai燃料电池汽车量产上市计划,把燃料电池及其关键技术发展推向了一个新的发展纪元.然而,制约燃料电池走向大规模商业化的核心问题依然是其综合性能不具竞争力.其中,氧电极的缓慢动力学以及贵金属Pt的有限资源、高昂成本等是关键所在,因此,亟待实现高性能非贵金属催化剂的突破.近年来,大量研究表明,Fe-N_x掺杂的碳催化剂具有极大的代Pt潜力,研究者们尝试各种手段进行开发,如:调控Fe化合物及N前驱体的类型与添加量,改变温度、压力等合成条件,采用轴向配位体连接、共价接枝、球磨等非热解路线,构建核壳、有序介孔碳、阵列、类石墨烯薄片、多孔碳等碳纳米结构,制备石墨烯/碳纳米管、石墨烯/碳黑、碳纳米带/碳纳米管、碳纳米颗粒/碳纤维、碳球/碳纳米管/石墨烯等复合材料,进行酸洗、造孔、二次加热等后处理,调控不同类型Fe物种相生成等.此外,EXAFS及M?sbauer等谱学技术已经证实Fe-N_x特别是Fe-N_4为强活性位点.因此,有待提出合理策略以促进非贵金属碳催化剂中Fe-N_x强活性位点的高密度掺杂.本文提出了一种碳模板诱导Fe-N_x活性位点生长的方法即通过高温热解含有Fe盐的三聚氰胺前驱体混合物,成功制备了Fe-N_x掺杂的碳催化剂,并结合多种表征技术证实了碳模板对制备碳催化剂结构组成及电化学性能的影响.形貌结果说明,碳模板的引入有利于Fe、N化合物的均匀吸附以至于Fe基纳米颗粒的均一成核,促使竹状碳纳米管在碳模板表面以及中间均一生长;氮气吸脱附及孔径分布曲线显示,引入碳模板形成的复合材料较单一的碳纳米管和碳黑材料具有提高的比表面积和总孔体积,说明复合材料中存在两种单体的有效协同;M?sbauer、XPS及XRD测试数据证实,碳模板可以调控Fe、N两种元素的耦合方式,能够抑制金属Fe和Fe碳化物等非活性Fe物种的生成、诱导Fe-N4和其它Fe氮化物等强活性Fe-N_x物种的生长.电化学测试数据表明,复合材料具有提升的面积活性和质量活性,且TOF值明显提高,说明碳模板的引入增强了Fe-N_x位点的本征活性;此外,复合材料的氧还原过程为高效的4e–途径。

高指数晶面和梯度组成的PtCu_(3)@Pt_(3)Cu@Pt纳米枝晶氧还原电催化剂性能

燃料电池作为一种清洁、高效的能量转换装置,其大规模应用受到阴极氧还原反应(ORR)动力学缓慢以及铂资源稀缺和价格高昂等的极大制约.尽管研究人员在过去几十年中付出了巨大努力,但研制高效、耐用的低Pt合金催化剂仍亟待突破.近年的研究表明,Pt的一些高指数晶面能够表现出比Pt(111)晶面更高的ORR活性,尤其是Pt(332),Pt(331)和Pt(554)等.同时,合金化能够通过电子与几何效应减弱含氧物种在Pt表面的吸附能,提升Pt合金催化剂的ORR活性.因此,高指数晶面和合金化的结合将是设计开发高性能电催化剂的有效手段.本文提出一种气氛调控的液相合成方法,通过在油胺中加热还原Pt化合物和Cu化合物,不添加其它保护剂,仅通过反应气氛的调控,成功制备了不同形貌的Pt-Cu合金纳米结构(纳米多脚、纳米凹立方体、纳米枝晶).通过反应前期引入氧化性气氛随后切换为惰性气氛的调控策略,合成具有高指数晶面的具有纳米枝晶结构的PtCu3合金;进一步对其进行电化学去合金化形成富Pt壳层,既保持其纳米枝晶形貌和高指数晶面,又形成具有梯度组成的PtCu_(3)@Pt_(3)Cu@Pt纳米枝晶.相比而言,全程惰性气氛下生长得到纳米多脚结构,全程氧化性气氛下生长则得到纳米凹立方体.电化学测试结果表明,在0.1 M HClO4电解液中,PtCu_(3)@Pt_(3)Cu@Pt纳米枝晶展现出较高的ORR活性,在0.9 V(vs.RHE)处的Pt质量活性和面积活性高达1.55 A mgPt^(-1)和2.4 mA cmPt^(-2),分别为商业Pt/C催化剂的14倍和24倍;此外,PtCu_(3)@Pt_(3)Cu@Pt纳米枝晶具有良好的电化学稳定性能,经0.7~1.1 V(vs.RHE)电势范围内循环5000圈,其催化活性保持稳定.DFT计算表明,Cu合金效应和高指数晶面结构共同增强了Pt的ORR活性,其中PtCu_(3)@Pt_(3)Cu@Pt纳米枝晶高指数晶面台阶位点的氧结合能接近最优值,从而表现出火山顶点附近的ORR活性.

Recent advances and prospects of asymmetric non-fullerene small molecule acceptors for polymer solar cells

Recently,polymer solar cells developed very fast due to the application of non-fullerence acceptors.Substituting asymmetric small molecules for symmetric small molecule acceptors in the photoactive layer is a strategy to improve the performance of polymer solar cells.The asymmetric design of the molecule is very beneficial for exciton dissociation and charge transport and will also fine-tune the molecular energy level to adjust the open-circuit voltage(Voc)further.The influence on the absorption range and absorption intensity will cause the short-circuit current density(Jsc)to change,resulting in higher device performance.The effect on molecular aggregation and molecular stacking of asymmetric structures can directly change the microscopic morphology,phase separation size,and the active layer's crystallinity.Very recently,thanks to the ingenious design of active layer materials and the optimization of devices,asymmetric non-fullerene polymer solar cells(A-NF-PSCs)have achieved remarkable development.In this review,we have summarized the latest developments in asymmetric small molecule acceptors(A-NF-SMAs)with the acceptor-donor-acceptor(A-D-A)and/or acceptor-donor-acceptor-donor-acceptor(A-D-A-D-A)structures,and the advantages of asymmetric small molecules are explored from the aspects of charge transport,molecular energy level and active layer accumulation morphology.

Sunlight-controlled CO_(2) separation resulting from a biomass-based CO_(2) absorber

Renewable solid sorbents for CO_(2) capture and storage have shown great potentials for the sake of gaseous separation,tail gas treatment,environmental regulation and climate governance.However,current existed preparation and reusability of solid sorbents are generally subject to high energy consumption and complicated procedure.Herein,a light-controlled CO_(2) separation system with high working temperature resulting from natural sawdust combined with polyethyleneimine is fabricated,which involves low energy input and few operating sequences.This system shows a direct and ratiometric response to sunlight illumination by which CO_(2) can be reversibly adsorbed and released.This light-controlled CO_(2) separation process is prospective to become an attractive alternative to traditional alkaline CO_(2) collection method in terms of its convenience and low cost.As a practical demonstration,CO_(2) mixed with N_(2) is successfully separated through this light-controlled carbon capture and storage(CCS) system,which offers great promise for CO_(2) capture and enrichment with applicability across a wide range of scales.

Anti-apoptotic effects of recombinant human granulocyte colony-stimulating factor in focal cerebral ischemic rats

The neuroprotective effects of granulocyte colony-stimulating factor in cerebral ischemia/reperfusion injury are currently contentious. The present study examined the effects of subcutaneous injection of recombinant human granulocyte colony-stimulating factor （50 pg/kg） over 5 days in a model of cerebral ischemia/reperfusion with intraluminal filament occlusion in rats. The results indicated that recombinant human granulocyte colony-stimulating factor reduced brain infarct volume following cerebral ischemia/reperfusion injury in rats, down-regulated the expression of caspase-3 mRNA （a key protease for apoptosis in the cerebral ischemia zone）, lowered the rate of neuronal apoptosis in the cerebral ischemia zone, and notably ameliorated neurological function. These results indicate that recombinant human granulocyte colony-stimulating factor has anti-apoptotic effects on neurons following focal cerebral ischemia/reperfusion injury, and exerts neuroprotective effects.

Traumatic Middle Meningeal Artery Pseudoaneurysms Presenting with Intractable Epistaxis: A Rare Case Report and Review of Literature

Middle meningeal artery (MMA) pseudoaneurysms are very rare and are most often traumatic. They may present as an epidural or intraparenchymal hematoma. This study reports a rare case in which a patient suffered from intractable epistaxis because of a pseudoaneurysm in middle meningeal artery and skull base fracture after craniocerebra trauma. Pseudoaneurysm and the feeding artery were embolized by using Onyx-18 liquid embolic system. Complete cessation of bleeding was achieved in this case immediately after the endovascular therapies. In this study, clinical manifestation, diagnostic imaging and endovascular treatment are described. Formation mechanisms and the treatment of traumatic pseudoaneurysm of middle meningeal artery are discussed.

Benzothiadiazole-based materials for organic solar cells

The past few years have witnessed power conversion efficiency(PCE)of organic solar cells(OSCs)skyrocketing to the value of 20%due to the outstanding advantages of organic photoactive materials.The latter,which consist of donor and acceptor materials,indeed play important roles in OSCs,and particularly one building block has attracted considerable research attention,namely benzothiadiazole(BT).The diversity of OSCs based on the BT structure have indeed sprung up,and the progressive increase in PCE values is more than just eye-catching since it heralds a renewal and bright future of OSCs.This review analyzes significant studies that have led to these remarkable progresses and focuses on the most effective BT small-molecules and BT polymers for OSC reported in the last decades.The pivotal structure-property relationships,donor-acceptor matching criteria,and morphology control approaches are gathered and discussed in this paper.Lastly,we summarize the remaining challenges and offer a personal perspective on the future advance and improvement of OSCs.

An efficient CuZr-based metallic glasses electrode material for electrocatalytic degradation of azo dyes

Metallic glasses have received a lot of attention on wastewater treatment due to their unique atomic structure,and the use of metallic glasses as electrodes has produced unexpected electrocatalytic degradation effects for many pollutants through combining with electrochemical technology.However,it still is a formidable challenge to find a metallic glass electrode material with both efficient and clean for the catalytic degradation of pollutants.In this work,the Cu_(55)Zr_(45)metallic glassy ribbons are used as an electrode to degrade azo dyes and show the excellent degradation effect,which can reach 95.6%within 40 min.In the degradation process,almost no additives are produced and Cu_(55)Zr_(45)metallic glassy ribbons have excellent effects under different pH conditions.Meanwhile,it exhibits good stability for degradation efficiency during the 8 cycle degradation tests of the amorphous alloy electrode.When the copper nanoparticles are exposed on the surface of the ribbons,the oxidized copper obtained synergistically produce activated radicals is the primary degradation mechanism,where the auxiliary degradation mechanisms include electron transfer and the promotion of active chlorine.This research develops a new type of electrode material for wastewater treatment,and the economy and high efficiency of Cu55Zr45metallic glass endow it the expandable functional applications.

Oxygen reduction electrocatalysis:From conventional to single-atomic platinum-based catalysts for proton exchange membrane fuel cells

Platinum(Pt)-based materials are still the most efficient and practical catalysts to drive the sluggish kinetics of cathodic oxygen reduction reaction(ORR)in proton exchange membrane fuel cells(PEMFCs).However,their catalysis and stability performance still need to be further improved in terms of corrosion of both carbon support and Pt catalyst particles as well as Pt loading reduction.Based on the developed synthetic strategies of alloying/nanostructuring Pt particles and modifying/innovating supports in developing conventional Pt-based catalysts,Pt single-atom catalysts(Pt SACs)as the recently burgeoning hot materials with a potential to achieve the maximum utilization of Pt are comprehensively reviewed in this paper.The design thoughts and synthesis of various isolated,alloyed,and nanoparticlecontained Pt SACs are summarized.The single-atomic Pt coordinating with non-metals and alloying with metals as well as the metal-support interactions of Pt single-atoms with carbon/non-carbon supports are emphasized in terms of the ORR activity and stability of the catalysts.To advance further research and development of Pt SACs for viable implementation in PEMFCs,various technical challenges and several potential research directions are outlined.

Structural plasticity-based hydrogel optical Willshaw model for one-shot on-the-fly edge learning

Autonomous one-shot on-the-fly learning copes with the high privacy,small dataset,and in-stream data at the edge.Implementing such learning on digital hardware suffers from the well-known von-Neumann and scaling bottlenecks.The optical neural networks featuring large parallelism,low latency,and high efficiency offer a promising solution.However,ex-situ training of conventional optical networks,where optical path configuration and deep learning model optimization are separated,incurs hardware,energy and time overheads,and defeats the advantages in edge learning.Here,we introduced a bio-inspired material-algorithm co-design to construct a hydrogel-based optical Willshaw model(HOWM),manifesting Hebbian-rule-based structural plasticity for simultaneous optical path configuration and deep learning model optimization thanks to the underlying opto-chemical reactions.We first employed the HOWM as an all optical in-sensor AI processor for one-shot pattern classification,association and denoising.We then leveraged HOWM to function as a ternary content addressable memory(TCAM)of an optical memory augmented neural network(MANN)for one-shot learning the Omniglot dataset.The HOWM empowered one-shot on-the-fly edge learning leads to 1000boost of energy efficiency and 10boost of speed,which paves the way for the next-generation autonomous,efficient,and affordable smart edge systems.

Ultrathin-shell epitaxial Ag@Au core-shell nanowires for high-performance and chemically-stable electronic, optical, and mechanical devices

Silver nanowires (AgNWs) hold great promise for applications in wearable electronics, flexible solar cells, chemical and biological sensors, photonic/plasmonic circuits, and scanning probe microscopy (SPM) due to their unique plasmonic, mechanical, and electronic properties. However, the lifetime, reliability, and operating conditions of AgNW-based devices are significantly restricted by their poor chemical stability, limiting their commercial potentials. Therefore, it is crucial to create a reliable oxidation barrier on AgNWs that provides long-term chemical stability to various optical, electrical, and mechanical devices while maintaining their high performance. Here we report a room-temperature solution-phase approach to grow an ultra-thin, epitaxial gold coating on AgNWs to effectively shield the Ag surface from environmental oxidation. The Ag@Au core-shell nanowires (Ag@Au NWs) remain stable in air for over six months, under elevated temperature and humidity (80 °C and 100% humidity) for twelve weeks, in physiological buffer solutions for three weeks, and can survive overnight treatment of an oxidative solution (2% H2O2). The Ag@Au core-shell NWs demonstrated comparable performance as pristine AgNWs in various electronic, optical, and mechanical devices, such as transparent mesh electrodes, surface-enhanced Raman spectroscopy (SERS) substrates, plasmonic waveguides, plasmonic nanofocusing probes, and high-aspect-ratio, high-resolution atomic force microscopy (AFM) probes. These Au@Ag core-shell NWs offer a universal solution towards chemically-stable AgNW-based devices without compromising material property or device performance.

Advanced Noncarbon Materials as Catalyst Supports and Non‑noble Electrocatalysts for Fuel Cells and Metal–Air Batteries

Electrochemical energy systems such as fuel cells and metal–air batteries can be used as clean power sources in the field of electric transportation and possess great potential in the reduction of various energy and environmental issues.In these systems,the oxygen reduction reaction(ORR)at the cathode is the rate-determining factor for overall system performance,and up to now,platinum group metals supported on carbon materials,especially Pt,remain the highest performing and the most practical ORR electrocatalysts.However,corresponding carbonaceous catalyst supports are extremely susceptible to corrosion under electrochemical operation,and therefore,the extensive exploration of alternative stable materials for ORR electrocatalysts with both high electrochemical stability and catalytic performance is essential.Here,noncarbon materials with high corrosion resistance have been explored to substitute traditional carbon supports or even act directly as low-cost non-noble metal electrocatalysts,and based on this,this review will present a comprehensive overview and deep analysis of the recent progress in noncarbon materials,including metals,oxides,nitrides,carbides,sulfides,and so on.Overall,general attributes associated with noncarbon materials include high corrosion resistance,strong metal–support interaction,and impressive porous structure retention.However,major drawbacks include low electrical conductivity,insufficient chemical stability in acidic or alkaline media,and poor electrochemical stability at ORR electrode potentials.To overcome these challenges,this review will also summarize efficient strategies such as combining with highly conductive materials,introducing dopants and forming vacancies to result in promising electrocatalytic ORR performances.Finally,this review will propose possible research directions to facilitate future research and development toward the practical application of noncarbon-based ORR electrocatalysts.

2021年度催化与表界面化学基金项目评审综述

本文总结了2021年度国家自然科学基金委员会化学科学部催化与表界面化学学科(B02)各类项目的申请、受理及评审情况.同时,通过统计并分析2018年学科重组以来四年的项目申请和资助、科学问题属性、学科代码和分类评审情况,提出了项目评审与管理和学科发展方面的一些建议与思考.

Evaluation of SARS-CoV-2-Neutralizing Nanobody Using Virus Receptor Binding Domain-Administered Model Mice

Due to the rapid spread of coronavirus disease 2019(COVID-19),there is an urgent requirement for the development of additional diagnostic tools for further analysis of the disease.The isolated nanobody Nb11-59 binds to the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)reeptor-binding domain[RBD]with high afinity to neutralize the virus and block the angiotensin-converting enzyme 2-(ACE2-)RBD interaction.Here,we introduce a novel nanobody-based radiotracer named^(68)Ga-Nb1159.The radiotracer retained high affinity for the RBD and showed reliable radiochemical characteristics both in vitro and in vivo.Predinical positron emission tomography(PET)studies of Ga-Nb1159 in mice revealed is rapid dearance from circulation and robust uptake into the renal and urinary systems.Fortunately,^(68)Ga-Nb1159 could speifcally reveal the distribution of the RBD in mice.This sudy also helped to evaluate the pharmacodynamic efects of the neutralizing nanobody.Moreover,^(68)Ga-Nb1159 may be a promising l0ol lo explore the distribution of the RBD and improve the understanding of the virus.In particular,this study identified a novel molecular radioagent and established a reliable evaluation method for speifially investigating the RBD through noninvasive and visual PET technology.

Co_(78)Si_(8)B_(14)metallic glass:A highly efficient and ultra-sustainable Fenton-like catalyst in degrading wastewater under universal pH conditions

Overcoming the pH limitation and increasing the catalyst reusability remain pressing demands for metal-lic glass(MG)in wastewater remediation.Herein,Co_(78)Si_(8)B_(14)MG ribbons are used to degrade dye wastew-ater by activating hydrogen peroxide(H_(2)O_(2))as Fenton-like catalysts.The Co-based MG catalysts exhibit high degradation efficiency under both acidic and alkaline conditions,and the kinetic reaction rate at pH 10(0.176 min^(−1)) and pH 4(0.089 min^(−1)) is 5.9 and 1.2 times higher than that of the extensively studied Fe-based MG catalysts,respectively.Impressively,the Co-based MG catalysts can be reused up to 20-60 times at universal pH conditions,demonstrating fairly good reusability.The newly discovered Co-based MG catalysts do not follow the classical Fenton reactions with H_(2)O^(2) the way Fe-based MGs do.In an acid environment,hydroxyl radicals play a dominant role in the degradation,while in an alkaline environ-ment,the effect of hydroxyl radicals is weakened,and Co^(3+) ions exert a relatively major function on the degradation.The excellent performance in catalytic activity and reusability at universal pH conditions of the Co-based MGs will inspire the development of MGs in wastewater treatment.

Noncovalent conformational locks in organic semiconductors

Highly planar conformation is considered to be one of the most important properties for high performance organic semiconductors. Among all kinds strategies for designing highly performing materials, noncovalent conformational locks(NCLs)have been widely used to increase the planarity and rigidity for π-conjugated systems. This review summarizes π-conjugated small molecules and polymers by employing various NCLs for controlling molecular conformation in the past two years. The optoelectronic properties of the conjugated materials, together with their applications on organic field-effect transistors(OFETs)and organic photovoltaics(OPVs) are discussed. Besides, the outlook and challenges in this field are also presented. It is obvious that NCLs play an important role in the design and synthesis of high-performance organic semiconductors.

Regioisomerism effect(RIE) on optimizing ultralong organic phosphorescence lifetimes

Organic phosphorescence materials demonstrate potential optoelectronic applications due to their remarkably ultralong organic phosphorescence(UOP)lifetime and abundant optical characteristics prior to the fluorescence materials.For a better insight into the intrinsic relationship among regioisomeric molecules,crystalline interactions,and phosphorescence properties,three crystalline dicarbazol-9-yl pyrazine-based regioisomers with para-,meta-and ortho-convergent substitutions(p-DCzP,m-DCzP,and o-DCzP)were designed and presented gradually increased UOP lifetimes prolonging from 63.14,127.93 to 350.46 ms,respectively,due to the regioisomerism effect(RIE)which would be an effective strategy for better understanding of structure-property of UOP materials.

Green strategy of scaleably synthesizing copper nanocomposites with remarkable catalytic activity for wastewater treatment

The functional copper nanocomposites(Cu NCs)have received increasing attention in the environmental catalysis application for wastewater treatment due to their superior catalytic activity and reactivity.However,overcoming the pH limitations towards the neutral and alkaline wastewater remains a tricky challenge.In this work,we demonstrate a green strategy to synthesize Cu NCs with coexistence of active Cu,Cu_(2)O and ZrO_(2)by self-propagating combustion of metallic glassy ribbons,which exhibit the extremely superior catalytic performance for degradation reaction,providing full conversion of organic dyes completely to the environmental friendly small species(efficiency>99%)under acidic,neutral and alkaline conditions.Compared with all other catalysts developed thus far,the novel Cu NCs catalysts with more active sites present much enhanced catalytic capability of degradation efficiency without the use of any chemical reagents for neutral and alkaline organic dye solutions.The possible decomposition pathways of organic dyes for different p H systems were systematically investigated.More importantly,the two kinds of catalytic mechanism related to high reactivity of nanoscale Cu/Cu_(2)O and strong oxidizing capability of activated·OH/·O_(2)^(-)radicals can also be successfully confirmed under different pH conditions.The green synthetic approach can be extended to design the various M-based nanocomposites(M=Fe,Co,Ni,Ag,Pd)as efficient catalysts for the functional applications of many chemical reactions.