Non-bonding modulations between single atomic cerium and monodispersed selenium sites towards efficient oxygen reduction

Currently,dual atomic catalysts(DACs)with neighboring active sites for oxygen reduction reaction(ORR)still meet lots of challenges in the synthesis,especially the construction of atomic pairs of elements from different blocks of the periodic table.Herein,a“rare earth(Ce)-metalloid(Se)”non-bonding heteronuclear diatomic electrocatalyst has been constructed for ORR by rational coordination and carbon support defect engineering.Encouraging,the optimized Ce-Se diatomic catalysts(Ce-Se DAs/NC)displayed a half-wave potential of 0.886 V vs.reversible hydrogen electrode(RHE)and excellent stability,which surpass those of separate Ce or Se single atoms and most single/dual atomic catalysts ever reported.In addition,a primary zinc-air battery constructed using Ce-Se DAs/NC delivers a higher peak power density(209.2 mW·cm^(−2))and specific capacity(786.4 mAh·gZn^(−1))than state-of-the-art noble metal catalysts Pt/C.Theoretical calculations reveal that the Ce-Se DAs/NC has improved the electroactivity of the Ce-N_(4)region due to the electron transfer towards the nearby Se specific activity(SA)sites.Meanwhile,the more electron-rich Se sites promote the adsorptions of key intermediates,which results in the optimal performances of ORR on Ce-Se DAs/NC.This work provides new perspectives on electronic structure modulations via non-bonded long-range coordination micro-environment engineering in DACs for efficient electrocatalysis.

Electroacupuncture improves neuropathic pain Adenosine, adenosine 5'-triphosphate disodium and their receptors perhaps change simultaneously

Applying a stimulating current to acupoints through acupuncture needles–known as electroacupuncture–has the potential to produce analgesic effects in human subjects and experimental animals. When acupuncture was applied in a rat model, adenosine 5-triphosphate disodium in the extracellular space was broken down into adenosine, which in turn inhibited pain transmission by means of an adenosine A1 receptor-dependent process. Direct injection of an adenosine A1 receptor agonist enhanced the analgesic effect of acupuncture. The analgesic effect of acupuncture appears to be mediated by activation of A1 receptors located on ascending nerves. In neuropathic pain, there is upregulation of P2X purinoceptor 3 （P2X3） receptor expression in dorsal root ganglion neurons. Conversely, the onset of mechanical hyperalgesia was diminished and established hyperalgesia was significantly reversed when P2X3 receptor expression was downregulated. The pathways upon which electroacupuncture appear to act are interwoven with pain pathways, and electroacupuncture stimuli converge with impulses originating from painful areas. Electroacupuncture may act via purinergic A1 and P2X3 receptors simultaneously to induce an analgesic effect on neuropathic pain.

Stable all-solid-state Li-Te battery with Li_(3)TbBr_(6) superionic conductor

Rare-earth(RE)halide solid electrolytes(HSEs)have been an emerging research area due to their good electrochemical and mechanical properties for all-solid-state lithium batteries(ASSBs).However,only very limited types of HSEs have been reported with high performance.In this work,tens of grams of RE-HSE Li_(3)TbBr_(6)(LTbB)was synthesized by a vacuum evaporationassisted method.The as-prepared LTbB displays a high ionic conductivity of 1.7 mS·cm^(-1),a wide electrochemical window,and good formability.Accordingly,the assembled solid lithium-tellurium(Li-Te)battery based on the LTbB HSE exhibits excellent cycling stability up to 600 cycles,which is superior to most previous reports.The processes and the chemicals during the discharge/charge of Li-Te batteries have been studied by various in situ and ex situ characterizations.Theoretical calculations have demonstrated the dominant conductivity contributions of the direct[octahedral]-[octahedral]([Oct]-[Oct])pathway for Li ion migrations in the electrolyte.The Tb sites guarantee efficient electron transfer while the Li 2s orbitals are not affected during migration,leading to a low activation barrier.Therefore,this successful fabrication and application of LTbB have offered a highly competitive solution for solid electrolytes in ASSBs,indicating the great potential of RE-based HSEs in energy devices.

Atomically dispersed indium and cerium sites for selectively electroreduction of CO_(2)to formate

Currently,single-atom combo catalysts(SACCs)for carbon dioxide reduction reaction(CO_(2)RR)to the formation of HCOOH are still very limited,especially the lanthanide-based SACCs.In this work,the novel SACCs with atomically dispersed In and Ce active sites were successfully prepared on the nitrogen-doped carbon matrix(InCe/CN).Both aberration-corrected high-angle annular dark-field scanning transmission electron microscopy(AC-HAADF-STEM)images and the extended X-ray absorption fine structure(EXAFS)spectra proved the well-isolated In and Ce atoms.The as-prepared InCe/CN shows a high Faradaic efficiency(FE)(77%)and current density of HCOOH formation(j_(HCOOH))at-1.35 V vs.reversible hydrogen electrode(RHE),much higher than the single atom catalysts.Theoretical calculations have indicated that the introduced Ce single atom sites not only significantly promote electron transfer but also optimize the In-5p orbitals towards higher selectivity towards the HCOOH formation.This work innovatively extends the design of SACCs towards the main group and Ln metals for more applications.

The first chiral cerium halide towards circularly-polarized luminescence in the UV region

Chiral organic-inorganic hybrid metal halides(OIHMHs)have attracted broader scientific community recently in spin lightemitting diodes,and circularly polarized light-emitting diodes.However,the emission peaks of the reported chiral OIHMHs mainly locate in the visible region,and chiral OIHMH with ultraviolet(UV)circularly polarized luminescence(CPL)has been rarely reported.To fill this gap,cerium,a unique rare-earth(RE)element with tunable luminescence from UV to the visible region owing to the 4 f-related electronic transition,was introduced to construct the first RE-based chiral OIHMHs,R/S-MCC.The chirality is successfully transferred from the chiral organic cations to the inorganic cerium chloride framework in R/S-MCC,as confirmed by the single crystal structures,circular dichroism,and CPL.The emission spectra of R/S-MCC are in the UV region,originating from the characteristic d-f transition of Ce^(3+),which making the Ce-based metal halides are ideal candidates towards CPL light sources in the UV region.Notably,R-and S-MCC are the first RE-based OIHMHs,also the first chiral metalhalides with UV CPL.Our work opens a new avenue for the development of the chiral OIHMH family towards RE-based chiral OIHMH.The RE-based chiral metal halides couple the unique and superior optical,electrical,magnetic,and spintronic properties of RE elements with chirality could accelerate the development of chiral optoelectronics and spintronics toward real applications.

Recent advances on rare earths in solid lithium ion conductors

Solid lithium-ion-conducting material is the key component in the fabrication of next-gene ration all solid state lithium ion batteries(LIBs)which would exhibit superior safety and performance compared with the currently widely used ones that resort to essentially inflammable and volatile organic solvents.To date,great efforts have been made in developing solid conductors with high lithium ion conductivity,such as polymers and inorganic materials.Rare earths play a very important role in this area and have attracted extensive interest since the recent decades for their unique properties in the realm of solidstate inorganic lithium-ion-conducting electrolyte materials.In this introduction,we focus on the role of rare earths in solid conductors for lithium ion,especially in a few most studied systems such as perovskites,garnets,silicates,borohydride and the recently reported halides in which rare earths act as a key framing component.Besides,the effect of rare earths as dopants is also discussed in some recently studied systems.Valence,coordination,and size are the most important factors that influence the crystal structure and property of these lithium ion conductors.The aim of this review is to highlight the great potentials of these unique elements of rare earths,and to help improve the performance of existing materials and explore new applications in the development of new LIBs with high performances.

Visualization of the electrocatalytic activity of three- dimensional MoSe2@reduced graphene oxide hybrid nanostructures for oxygen reduction reaction

Developments of nanostructured transition metal dichalcogenides （TMDs） materials as novel electrocatalyst candidates for oxygen reduction reaction （ORR） is a new strategy to promote the developments of non-precious metal ORR catalysts. In this work, a three-dimensional （3D） hybrid of rosebud-like MoSe2 nanostructures supported on reduced graphene oxide （rGO） nanosheets was successfully synthesized through a facile hydrothermal strategy. The prepared MoSe2@rGO hybrid nanostructure showed enhanced electrocatalytic activity for the ORR in alkaline medium compared to that of the pure MoSe2, rGO, and their simple physical mixture, which could benefit from the excellent oxygen adsorption ability of the abundantly exposed active edge sites of the ultrathin MoSe2 layers, the conductivity and aggregation-limiting effect of the rGO platform, as well as the unique 3D rosebud-like architecture of the hybrid material. The electrocatalytic activity of the MoSe2@rGO hybrid towards ORR was comparable to that of com- inertial Pt/C catalysts. And the promoted reaction was revealed to involve a nearly four-electron-dominated ORR process by analysis of the obtained Koutecky- Levich plots. The scanning electrochemical microscopy （SECM） technique, with the advantages of investigating of the local catalytic activity of samples with high spatial resolution and simultaneously evaluating activities of different catalysts in a single experiment, was further applied to investigate the local ORR electrocatalytic activity of MoSe2@rGO and compare it with those of other catalyst samples through applying different sample potentials. The excellent stability and methanol tolerance of the 3D nanostructured MoSe2@rGO hybrid against methanol further prove the 3D nanostructured MoSe2@rGO hybrid as a promising ORR electrocatalyst in alkaline solution for potential applications in fuel cells and metal-air batteries.

Crystalline/Amorphous Heterophase with Self-Assembled Hollow Structure for Highly Efficient Electrochemical Hydrogen Production

Heterophase nanomaterials composed of multiple phases have attracted increasing attention due to their enhanced performance in electrocatalytic field.Nevertheless,constructing two-dimensional(2D)crystalline/amorphous heterophase nanostructures with the samechemical composition remains a great challenge.Herein,we report the preparation of a 2D crystalline/amorphous heterophase of MoS2 nanosheets with the same elemental components via a facile solvothermal method.

Pitch-derived 3D amorphous carbon encapsulated sulfur-rich cathode for aqueous Zn-S batteries

Rechargeable aqueous zinc batteries have attracted much attention due to their high security, plentiful zinc resources, and environmental friendliness. However, it can only offer limited specific capacity and energy density based on ion insertion chemistry cathode. Herein, we design a low-cost and high-energy density aqueous Zn-S battery where the conversion cathode was fabricated by pitch-derived three-dimensional(3D) amorphous carbon encapsulated industrial-grade sulfur powder. The cost of the chemical substances for this aqueous Zn-S battery might be reduced to $9.38 per kW h based on the affordable cost of the raw ingredients. It is found that the PAC/S-60.33% cathode reveals excellent electrochemical performance, including a high reversible capacity(633.5 mAh g^(-1)at 0.5 A g^(-1)), high energy density(297.5 Wh kg^(-1)), an excellent rate capability(204.5 mAh g^(-1) at 5.5 A g^(-1)), as well as good cycling stability(180 mAh g^(-1)after 400 cycles at 5.0 A g^(-1)). Besides, the reaction mechanism of the cathode was investigated using ex-situ X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), and transmission electron microscope(TEM). It was demonstrated that the cathode undergoes a conversion reaction between S and Zn S. Furthermore, the discoveries also offer prospective possibilities to fabricate more secure and inexpensive battery systems.

Multiple discharges before leader inception in long air gaps under positive switching impulses

There are multiple corona bursts before leader inception when the rising rate of the applied voltage or electric field is not sufficiently high enough in long positive sparks.In existing studies,no attention has been paid to whether these corona bursts occur in the same location,and they are mostly considered directly as belonging to the same discharge.However,this paper presents that in a typical rod-plate long air gap,the multiple corona bursts before leader inception are distributed in at least two different locations,and the highest probability of three discharges occurs.Also,the discharge occurs with the highest probability in the time sequence‘tip-tip-side-tip-other side’of the electrode in the first five corona bursts.For each discharge,the first corona current is a single,double exponential pulse,while the following corona currents are mostly a superposition of multiple pulses.The above findings are mainly based on experiments in a 1.4 m air gap under positive switching impulses,in which the voltage,current,and high-speed images were recorded simultaneously.Finally,based on the experimental results,this paper discusses the effects brought by ignoring the multiple discharges on key parameters of leader inception and makes some suggestions to optimise long spark experiments.

红树林沉积物中天然多聚有机物厌氧降解菌多样性与细菌新类群分离

【目的】红树林沉积物中有机物丰富,通过研究认识参与难降解天然有机多聚物的微生物降解过程及其环境作用,并获得新颖的难培养厌氧微生物。【方法】对漳州九龙江河口红树林沉积物中降解纤维素、几丁质和木质素的厌氧细菌定向富集和平板分离纯化,并对其多样性进行分析。【结果】共筛选分离获得202株厌氧细菌(82株专性厌氧细菌,120株兼性厌氧细菌),包括4个疑似新属(Lachnotalea sp.MCCC 1A16036、Varunaivibrio sp.MCCC 1A15903、Clostridium sp.MCCC 1A15884、Caminicella sp.MCCC 1A17445)和4个疑似新种(Sunxiuqinia sp.MCCC 1A15904、Pseudodesulfovibrio sp.MCCC 1A16040、Pseudodesulfovibrio sp.MCCC 1A16038、Mangrovibacterium lignilyticum MCCC 1A15882)。不同天然有机多聚物富集菌群分离到的优势可培养细菌主要属于变形菌门、拟杆菌门和厚壁菌门,但种群略有差异。在纤维素和几丁质富集菌群中,变形菌门和拟杆菌门菌株是纤维素和几丁质富集菌群的优势菌群,拟杆菌门的Prolixibacter bellariivorans、Mangrovibacterium lignilyticum和变形菌门的Desulfovibrio salexigenes、Vibrio alginolyticus分别在纤维素和几丁质富集菌群可培养细菌中占绝对优势。但降解实验表明,放线菌门细菌Demequina salsinemoris MCCC 1A15890和Brevibacterium celere MCCC 1A17451对纤维素降解活性最高。梭杆菌门细菌Propionigenium maris MCCC 1A15874和Ilyobacter polytropus MCCC 1A15889对几丁质降解活性最高。在木质素富集菌群中,拟杆菌门的Mangrovibacterium lignilyticum和厚壁菌门的Clostridium amygdalinum都具有较高的相对丰度。变形菌门细菌Desulfomicrobium apsheronum MCCC 1A15932和拟杆菌门细菌Mangrovibacterium lignilyticum MCCC 1A15882对木质素降解效果显著。【结论】红树林沉积物中存在丰富多样且新颖的厌氧难培养细菌,且多数具有纤维素、几丁质或木质素厌氧降解能力。该研究结果为探究红树林沉积物原位环境天然有机多聚物碳的生物地球化学循环机制提供了相关理论基础和纯培养微生物资源。

氧化铈纳米粒子的抗菌机理及应用（英文）

纳米材料因其特殊的抗菌机理,在抗菌领域得到了广泛应用.氧化铈纳米粒子是重要的抗菌材料之一,具有对正常细胞毒性低,且抗菌机理基于可逆价态转化的优势.目前已有许多关于氧化铈纳米粒子抗菌活性的研究报道,但系统性探究其抗菌机理的文章则极为少见.本文首先系统性地探究了氧化铈纳米粒子可能的抗菌机理,即静电相互作用在抗菌过程中发挥重要作用,此外抗菌过程还伴随活性氧物种的产生和纳米粒子对细菌的机械损伤.其次,本文分析了氧化铈纳米粒子抗菌效果的影响因素,并总结了不同研究中氧化铈纳米粒子对大肠杆菌和金黄葡萄球菌的抗菌效果.最后提出了氧化铈纳米粒子可能的应用前景.本文将有利于对氧化铈纳米粒子抗菌机理的深入理解,并为该类材料在未来的设计和应用提供借鉴.

Synthesis of MoX2 (X =Se or S) monolayers with high-concentration 1T'phase on 4H/fcc-Au nanorods for hydrogen evolution

Controlled synthesis of transition metal dichalcogenide (TMD) monolayers with unusual crystal phases has attracted increasing attention due to their promising applications in electrocatalysis.However,the facile and large-scale preparation of TMD monolayers with high-concentration unusual crystal phase still remains a challenge.Herein,we report the synthesis of MoX2 (X =Se or S) monolayers with high-concentration semimetallic 1T'phase by using the 4H/face-centered cubic (fcc)-Au nanorod as template to form the 4H/fcc-Au@MoX2 nanocomposite.The concentrations of 1T'phase in the prepared MoSe2 and MoS2 monolayers are up to 86% and 81%,respectively.As a proof-of-concept application,the obtained Au@MoS2 nanocomposite is used for the electrocatalytic hydrogen evolution reaction (HER) in acid medium,exhibiting excellent performance with a low overpotential of 178 mV at the current density of 10 mNcm^2,a small Tafel slope of 43.3 mV/dec,and excellent HER stability.This work paves a way for direct synthesis of TMD monolayers with high-concentration of unusual crystal phase for the electrocatalytic application.

Ultrathin lanthanide oxides nanomaterials： synthesis, properties and applications

Over the past decade, ultrathin lanthanide oxides(Ln_2O_3, Ln = La to Lu) nanomaterials have been intensively studied in the fields of rare earth materials science. This unique class of nanomaterials has shown many unprecedented properties(big surface area, high surface effect, physical and chemical activities) and is thus being explored for numerous promising applications. In this review, a brief introduction of ultrathin Ln_2O_3 nanomaterials was given and their unique advantages were highlighted. Then, the typical synthetic methodologies were summarized and compared(thermal decomposition, solvothermal, soft template, co-precipition and microwave etc.). Due to the high surface effect, some promising applications of ultrathin Ln_2O_3 nanomaterials, such as drug delivery and catalysis of CO oxidation, were reviewed. Finally, on the basis of current achievements on ultrathin Ln_2O_3 nanomaterials, personal perspectives and challenges on future research directions were proposed.

CeO_(2)with diverse morphologies-supported IrOx nanocatalysts for efficient oxygen evolution reaction—Commemorating the 100th anniversary of the birth of Academician Guangxian Xu

IrOx-based catalysts are considered the most promising candidates for oxygen evolution reaction(OER)due to their high efficiency.However,improving their intrinsic catalytic activity is essential for practical application.In this work,CeO_(2)with three different morphologies(rod,cube,octahedron)and supported IrOx nanoparticles were fabricated,and they display morphology-dependent OER activity.The IrOx/CeO_(2)-rod shows the highest activity;the catalysts have a catalytic activity sequence of rod>cube>octahedron.A plausible mechanism was proposed:the CeO_(2)support with different morphologies modulates the electronic structure of IrOx by the synergistic interaction promoted by oxygen vacancies between the active component and the support,thereby altering the catalytic activity of the IrOx/CeO_(2)catalyst.

All in one theranostic nanoplatform enables efficient anti-tumor peptide I delivery for triple-modal imaging guided cancer therapy

Developing a reliable system to efficiently and safely deliver peptide drugs into tumor tissues still remains a great challenge since the instability of peptide drugs and low ability to traverse the cell membrane. Herein, we constructed a multifunctional nanoplatform based on porous europium/gadolinium (Eu/Gd)-doped NaLa(MoO4)2 nanoparticles (NLM NPs) to deliver antitumor peptide of B-cell lymphoma/leukemia-2-like protein 11 (BIM) for cancer therapy. The porous NLM NPs exhibited inherent photoluminescent, magnetic and X-ray absorbable properties, which enable them for triple-modal bioimaging, including fluorescence, magnetic resonance imaging (MRI) and computed tomography (CT). This triple-modal bioimaging can contribute to monitoring NLM NPs biodistribution and guiding therapy in vitro and in vivo. Furthermore, the NLM NPs showed negligible cytotoxicity in vitro and tissue toxicity in vivo. Importantly, NLM NPs could load the antitumor peptide of BIM and efficiently improve the resistance of peptide drugs to proteolysis. The BIM peptide was efficiently delivered into the tumor cells by NLM NPs, which can inhibit the growth and promote the apoptosis of cancer cells in vitro, significantly inhibit the tumor growth in vivo. Notably, NLM-BIM theranostic nanoplatform exhibits low systemic toxicity and fewer side effects in vivo. The NLM NPs can serve as a promising multifunctional peptide delivery nanoplatform for multi-modal bioimaging and cancer therapy.

Power transformer fault diagnosis considering data imbalance and data set fusion

Improving the accuracy of transformer dissolved gas analysis is always an important demand for power companies.However,the requirement for large numbers of fault samples becomes an obstacle to this demand.This article creatively uses a large number of health data,which is much easier to obtain by power companies,to improve diagnosis accuracy.Comprehensive investigations from the view of both data set and methodology to deal with this problem are presented.A data set consists of 9595 health samples and 993 fault samples is used for analysis.The characteristics of the data set and the influence of the health data on diagnostic accuracy are discussed.The performance of many state‐of‐art algorithms that handle the imbalanced prob-lem is evaluated.Meanwhile,an efficient fault diagnosis algorithm named self‐paced ensemble(SPE)is presented.In SPE,classification hardness is proposed to include the data characteristic in the classification.This method can guarantee the diversity of the data set and keep high performance.According to the experiment results,the superior of SPE is confirmed and also proves that involving more health samples can improve transformer diagnosis when fault data are limited.

Rare-earth-incorporated low-dimensional chalcogenides: Dry-method syntheses and applications

Chalcogenide thin films incorporating rare-earth (RE) elements with applicationsin optics, electronics, and magnetics have received considerable attention.Aiming at growing pure chalcogenides, dry-method syntheses have beendeveloped. In this review, we summarize the progress thus far on lowdimensionalRE-based chalcogenides (RECs), covering fabrication methods,structures, and applications. This review also provides the summary and perspectivesof the challenges of fabrication and opportunities on the applicationof RECs in the future.

Cerium ions crosslinked sodium alginate-carboxymethyl chitosan spheres with antibacterial activity for wound healing

For wound healing,wound infection caused by bacteria is one of the important reasons that delay wound healing process.Therefore,it is very meaningful to develop a multifunctional wound dressing with antibacterial capability to accelerate wound healing.Sodium alginate(SA)and carboxymethyl chitosan(CMCS)are the most commonly used compositions in wound dressing,but their poor stability inhibits the further applications.Introducing CMCS and using cerium ions(Ce^(3+))to crosslink CMCS and SA to form SA-CMCS hybrid spheres by electrostatic spray method,can not only improve the stability of SA hydrogels,but also endow the spheres with excelle nt antibacterial properties due to the characteristics of Ce^(3+).The gradual release of Ce^(3+)from the SA-CMCS spheres can effectively inhibit the growth of Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli).Combining the wound healing promotion ability of SA and CMCS,this kind of wound dressing can not only avoid wound infection caused by bacteria effectively,but also accelerate wound healing,thus it is an easily prepared material with potential applications in skin defect repair.

Near room-temperature ferromagnetism in air-stable twodimensional Cr_(1−x)Te grown by chemical vapor deposition

Identifying air-stable two-dimensional(2D)ferromagnetism with high Curie temperature(T_(c))is highly desirable for its potential applications in next-generation spintronics.However,most of the work reported so far mainly focuses on promoting one specific key factor of 2D ferromagnetism(T_(c)or air stability),rather than comprehensive promotion of both of them.Herein,ultrathin Cr_(1-x)Te crystals grown by chemical vapor deposition(CVD)show thickness-dependent T_(c)up to 285 K.The out-of-plane ferromagnetic order is well preserved down to atomically thin limit(2.0 nm),as evidenced by anomalous Hall effect observed in non-encapsulated samples.Besides,the CVD-grown Cr_(1-x)Te nanosheets present excellent ambient stability,with no apparent change in surface roughness or electrical transport properties after exposure to air for months.Our work provides an alternative platform for investigation of intrinsic 2D ferromagnetism and development of innovative spintronic devices.