Design of ZnSe-CoSe heterostructure decorated in hollow N-doped carbon nanocage with generous adsorption and catalysis sites for the reversibly fast kinetics of polysulfide conversion

Although lithium-sulfur batteries(Li SBs)are regarded as one of the most promising candidates for the next-generation energy storage system,the actual industrial application is hindered by the sluggish solid–liquid phase conversion kinetics,severe shuttle effect,and low sulfur loadings.Herein,a zeolitic imidazolate framework(ZIF)derived heterogeneous ZnSe-CoSe nanoparticles encapsulated in hollow N-doped carbon nanocage(ZnSe-CoSe-HNC)was designed by etching with tannic acid as a multifunctional electrocatalyst to boost the polysulfide conversion kinetics in LiSBs.The hollow structure in ZIF ensures large inner voids for sulfur and buffering volume expansions.Abundant exposed ZnSe-CoSe heterogeneous interfaces serve as bifunctional adsorption-catalytic centers to accelerate the conversion kinetics and alleviate the shuttle effect.Together with the highly conductive framework,the ZnSe-CoSeHNC/S cathode exhibits a high initial reversible capacity of 1305.3 m A h g-1at 0.2 C,high-rate capability,and reliable cycling stability under high sulfur loading and lean electrolyte(maintaining at 745 m A h g-1after 200 cycles with a high sulfur loading of 6.4 mg cm-2and a low electrolyte/sulfur ratio of 6μL mg^(-1)).Theoretical calculations have demonstrated the heterostructures of ZnSe-CoSe offer higher binding energy to lithium polysulfides than that of ZnSe or CoSe,facilitating the electron transfer to lithium polysulfides.This work provides a novel heterostructure with superior catalytic ability and hollow conductive architecture,paving the way for the practical application of functional sulfur electrodes.

Insight into fouling behavior of poly(vinylidene fluoride)(PVDF)hollow fiber membranes caused by dextran with different pore size distributions

Membrane fouling is the key problem that occurs in membrane process for water treatment. However, how membrane microstructure influences the fouling behavior is still not clear. In this study, fouling behavior caused by dextran was deeply and systematically investigated by employing four poly(vinylidene fluoride)(PVDF)membranes with different pore sizes, ranging from 24 to 94 nm. The extent of fouling by dextran was accurately characterized by pore reduction, flux decline, and the change of critical flux. The result shows that membrane with the smallest pore size of 24 nm experienced the smallest fouling rate and the lowest fouling extent. As the membrane pore size increased, the critical flux ranges were 105-114, 63-73, 38-44 and 34-43 L·m^(-2)·h^(-1),respectively. The critical flux and fouling resistances indicated that the fouling propensity increases with the increase of membrane pore size. Two pilot membrane modules with mean pore size of 25 nm and 60 nm were applied in membrane filtration of surface water treatment. The results showed that serious irreversible membrane fouling occurred on the membrane with pore size of 60 nm at the permeate flux of40.5 L·m^(-2)·h^(-1).On the other hand, membrane with pore size of 25 nm exhibited much better anti-fouling performance when permeate flux was set to 40.5,48 and 60 L·m^(-2)·h^(-1).

Meta-analysis of cognitive function in Chinese first-episode schizophrenia: MATRICS Consensus Cognitive Battery (MCCB) profile of impairment

Background Compromised neurocognition is a core feature of schizophrenia. With increasing studies researching cognitive function of Chinese patients with first-episode schizophrenia (FES) using MATRICS Consensus Cognitive Battery (MCCB), it is not clear about the level and pattern of cognitive impairment among this population. Aim To provide a meta-analysis systematically analysing studies of neurocognitive function using MCCB in Chinese patients with FES. Methods An independent literature search of both Chinese and English databases up to 13 March 2019 was conducted by two reviewers. Standardised mean difference (SMD) was calculated using the random effects model to evaluate the effect size. Results 56 studies (FES=3167, healthy controls (HC)=3017) were included and analysed. No study was rated as 'high quality' according to Strengthening the Reporting of Observational Studies in Epidemiology. Compared with HCs, Chinese patients with FES showed impairment with large effect size in overall cognition (SMD=-1.60,95% Cl -1.82 to -1.38,厂=67%) and all seven cognitive domains, with the SMD ranging from -0.87 to -1.41. In nine MCCB subtests, patients with FES showed significant difference in Symbol Coding (SMD=-1.90), Trail Making Test (TMT)(SMD=-1.36), Continuous Performance Test-Identical Pairs (SMD=-1.33), Hopkins Verbal Learning Test (SMD=-1.24), Brief Visuospatial Memory Test (SMD=-1.18), Mazes (SMD=-1.16), Category Fluency (SMD=-1.01), Spatial Span (SMD=-0.69) and Mayer-Salovey-Caruso Emotional Intelligence Test (SMD=-0.38). Conclusions Our meta-analysis demonstrates that Chinese patients with FES show neurocognitive deficits across all seven MCCB cognitive domains and all nine subtests, particularly in two neurocognitive domains: speed of processing and attention/vigilance, with the least impairment shown in social cognition. Symbol Coding and TMT may be the most sensitive tests to detect cognitive deficit in Chinese patients with FES.

促进物理化学在线教学质量的实践

在疫情特殊时期,立足以学生的学习为中心,依托物理化学国家精品MOOC、利用“慕课堂+QQ群+腾讯会议”网络技术,构建了“五步法”在线教学模式,即“导学助力→MOOC自学→在线评测→及时反馈→讨论进阶”。充分发挥教师的主导作用,采用多样化的在线教学交互策略,激励、引导学生参与教学全过程,有效保障了在线教学质量。

Research Status and Strategies for Cognitive Function in Schizophrenia

Cognition is divided into neurocognition and social cognition,both of which are interconnected with each other and yet are mutually independent.Neurocognition,which is based on neuroanatomical structures,function connections,neuroelectrophysiology and molecular biology,is the basis of the human brain and the reflection of

Effect of O_2/CH_4ratio on the optimal specific-energy-input (SEI) for oxidative reforming of biogas in a plasma-shade reactor

In a novel plasma-shade reactor for oxidative reforming of biogas(CH4/CO2=3/2),the effects of specific-energy-input (SEI) on CH4 and CO2 conversions and energy cost of syngas were investigated at O2/CH4ratios ranged from 0.42 to 0.67.At each of O2/CH4 ratios,V-shape profiles of energy cost of syngas increasing with SEI were observed,reaching the lowest value at the optimal SEI(Opt-SEI).With the increase of O2/CH4 ratio,the Opt-SEI decreased significantly.Moreover,at the Opt-SEI,O2 and CH4 conversions and dry-basis concentration of syngas increased and energy cost of syngas decreased greatly with the increase of O2/CH4 ratio.

Clinical Observation of Zhuang Medicine Yangxue Xiaozheng Decoction in Treating the Combined Endometriosis of Dampness and Blood Stasis in Guangxi

Objective:To explore the clinical effects of Zhuang Medicine Yangxue Xiaozheng Decoction in treating the combined Ems of dampness and blood stasis in Guangxi;Methods:100 patients with endometriosis treated in Lili Clinic of Famous Doctor,Guangxi International Zhuang Medicine Hospital from Mach 2016 to May 2017 were chosen as the research object.According to the random grouping method,patients were randomly divided into the treatment group(The Zhuang Medicine Yangxue Xiaozheng Decoction(ZYF)Group)and the control group(Chinese patent medicine SanJieZhenTongJiaoNang(SJZT)group with 50 cases in each group.After treatment,the TCM syndrome score,changes in pelvic mass size,hepatocyte growth factor(HGP)levels,and clinical effects before and after treatment were evaluated.Results:After two courses of treatment,the total effective rate of patients in the ZYF group was 88%,which were significantly better than 70%of the SJZT group.The difference was statistically significant(P<0.05).Conclusion:With a significant effect on patients with the combined Ems of dampness and blood stasis in Guangxi,Zhuang Medicine Yangxue Xiaozheng Decoction can improve the uterine cavity mass and reduce serum HGP level.

Porous garnet as filler of solid polymer electrolytes to enhance the performance of solid-state lithium batteries

In order to enhance the ionic conductivity of solid polymer electrolytes(SPEs)and their structural rigidity against lithium dendrite during lithium-ion battery(LIB)cycling,we propose porous garnet Li6.4La3Zr2Al0.2O12(LLZO),as the filler to SPEs.The porous LLZO with interlinked grains was synthesized via a resol-assisted cationic coordinative co-assembly approach.The porous structure of LLZO with high specific surface area facilitates the interaction between polymer and filler and provides sufficient entrance for Li^(+)migration into the LLZO phase.Furthermore,the interconnection of LLZO grains forms continuous inorganic pathways for fast Li^(+)migration,which avoid the multiple diffusion for Li^(+)in interface.As a result,the SPEs with porous LLZO(SPE-PL)show a high ionic conductive of 0.73 mS·cm^(-1) at 30℃ and lithium-ion transference number of 0.40.The porous LLZO with uniformly dispersed pores also acts as an ion distributor to regulate ionic flux.The lithium-symmetrical batteries assembled with SPE-PL show a highly stable Li plating/stripping cycling for nearly 3000 h at 0.1 mA·cm^(-2).The corresponding Li/LiFePO_(4) batteries also exhibit excellent cyclic performance with capacity retention of 75%after nearly 500 cycles.This work brings new insights into the design of conductive fillers and the optimization of SPEs.

Recent advances in vacancy engineering for reliable lithiumsulfur batteries

The high-energy-density and low-cost features endow lithium-sulfur batteries with broad application prospects.However,many drawbacks,especially the detrimental shuttle effect,have hindered the further development of LSBs.In response,a lot of new structures have been applied to suppress the shuttle effect and promote the development of LSBs.Recently,vacancy engineering has gained the attention of researchers due to its unique electronic structure.This review aims to analyze the application of vacancy engineering in LSBs.Firstly,the electrochemistry of LSBs has been systematically discussed and the existing challenges as well as improvement tactics of LSBs have also been presented.Subsequently,the preparation methods and characterization technologies of various vacancies are summarized,including oxygen vacancies,sulfur vacancies,selenium vacancies,other anion vacancies,cation vacancies,etc.The latest applications of vacancy engineering in LSBs are also summarized in this review.Finally,some prospects and insights for further investigation and practical application of vacancy engineering in LSBs are put forward.

A homogenous solid polymer electrolyte prepared by facile spray drying method is used for room-temperature solid lithium metal batteries

The aggregation of inorganic particles with high mass ratio will form a heterogeneous electric field in the solid polymer electrolytes(SPEs),which is difficult to be compatible with lithium anode,leading to inadequate ionic conductivity.Herein,a facile spray drying method is adopted to increase the mass ratio of inorganic particles and solve the aggregation problems of fillers simultaneously.The polyvinylidene fluoride(PVDF)with lithium bis(trifluoromethanesulfonyl)imide(LiTFSI)covers the surface of each Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)granules during the nebulization process,then forming flat solid electrolytes via layer-by-layer deposition.Characterized by the atomic force microscope,the obtained solid electrolytes achieve a homogenous dispersion of Young’s modulus and surface electric field.As a result,the as-prepared SPEs present high tensile strength of 7.1 MPa,high ionic conductivity of 1.86×10^(−4)S·cm^(−1)at room temperature,and wide electrochemical window up to 5.0 V,demonstrating increased mechanical strength and uniform lithium-ion migration channels for SPEs.Thanks to the as-prepared SPEs,the lithiumsymmetrical cells show a highly stable Li plating/stripping cycling for over 1,000 h at 0.1 mA·cm^(−2).The corresponding Li/LCoO_(2)batteries also present good rate capability and excellent cyclic performance with capacity retention of 80%after 100 cycles at room temperature.

Molecular modulating of cobalt phthalocyanines on aminofunctionalized carbon nanotubes for enhanced electrocatalytic CO_(2)conversion

Metal porphyrins and metal phthalocyanines(Pc)constitute a promising class of metal molecular catalysts(MMCs)for efficient CO_(2)-to-CO electrocatalytic conversion due to their well-defined molecular structures.How to adjust the local coordination and electronic environment of the metal center and enhance the molecular-level dispersion of the active components remains as great challenges for further improving the performance.Herein,a cobalt(II)Pc(CoPc)-COOH/carbon nanotube(CNT)-NH_(2)hybrid catalyst was rationally designed by clicking the CoPc-COOH molecules onto the surface of CNT-NH_(2)through amidation reaction.This novel hybrid catalyst exhibited the enhanced current density of 22.4 mA/cm2 and CO selectivity of 91%at−0.88 V vs.reversible hydrogen electrode(RHE)in the CO_(2)electroreduction,as compared with CoPc-COOH/CNT and CoPc/CNT samples.The superior activity was ascribed to the charge transfer induced by introduction of-COOH and-NH_(2)functional groups to CoPc and CNT,respectively,facilitating the active centers of CoI being generated at lower potentials,and leading to the highest turnover frequency(TOF)being obtained over the CoPc-COOH/CNT-NH_(2)hybrid catalyst.The inherent directivity and saturability of covalent bonds formed via the amidation reaction ensure not only a higher density of Co active centers,but also an improved stability for CO_(2)reduction reaction(CO_(2)RR).The present study represents an effective strategy for improving MMCs performance by molecular modulating of metal phthalocyanines on functionalized carbon substrates directed by click confinement chemistry.

适用于氢气低温制备与高效存储的催化新体系

氢气是一种具有极高能量密度的二次清洁能源,被认为最有可能替代现有的煤炭和石油等化石燃料作为未来人类社会赖以生存和发展的能源基础.以清洁、高效、无污染的氢循环代替目前对环境有严重威胁且日益枯竭的碳循环.在可预见的未来,全球主要国家将会加大氢能开发和利用的投入.尤其是伴随着我国能源体系的升级和新能源产业的快速发展,氢气作为高效的能量载体势必会成为未来清洁能源发展的主要方向之一.氢能应用循环主要包括3个环节,即(1)氢燃料的制备;(2)氢燃料的存储和输运;(3)氢燃料化学能到电能或其他形式能量的高效转变.结合国家能源战略及基础研究的需求,本研究团队近期在氢气的低温制备和存储方面取得了一定的研究成果.尤其是以α-MoC作为强相互作用载体制备的Au和Pt纳米催化剂,分别在低温水汽变换反应和液相甲醇水重整产氢反应方面取得了较为突出的研究成果.该研究成果为氢燃料的低温原位制备,氢燃料安全、高效的存储运输及大规模工业制氢过程的优化提供了新的思路.本文结合该领域近年来的国内外研究进展和本实验室的研究成果,简单介绍适用于工业化制氢过程的低温水汽变换过程和液相储氢新体系,并对未来该领域的发展提出一定的展望.

Highly active sites of low spin Fe^(Ⅱ)N_(4)species:The identification and the ORR performance

Over recent years,catalytic materials of Fe-N-C species have been recognized being active for oxygen reduction reaction(ORR).However,the identification of active site remains challenging as it generally involves a pyrolysis process and mixed components being obtained.Herein Fe_(3)C/C and Fe_(2)N/C samples were synthesized by temperature programmed reduction of Fe precursors in 15%CH_(4)/H_(2)and pure NH_(3),respectively.By acid leaching of Fe_(2)N/C sample,only single sites of FeN_(4)species were presented,providing an ideal model for identification of catalytic functions of the single sites of FeN_(4)in ORR.A correlation was conducted between the concentration of Fe^(Ⅱ)N_(4)in low spin state by Mossbauer spectra and the kinetic current density at 0.8 V in alkaline media,and such a structure-performance correlation assures the catalytic roles of low spin Fe^(Ⅱ)N_(4) species as highly active sites for the ORR.

Arabidopsis Plants Having Defects in Nonsense-mediated mRNA Decay Factors UPF1, UPF2, and UPF3 Show Photoperiod-dependent Phenotypes in Development and Stress Responses

Nonsense-mediated mRNA decay （NMD） is an important mRNA quality surveillance pathway in all eukaryotes that eliminates aberrant mRNAs derived from various sources. Three NMD factor proteins, UPF1, UPF2, and UPF3 are required for the NMD process and were found to be also involved in certain stress responses in mammalian and yeast cells. Using Arabidopsis thaliana mutants of UPF1 and UPF3 and UPF2-silenced lines （irUPF2）, we examined the involvement of UPF1, UPF2, and UPF3 in development and in response to stresses, wounding and infection by Pseudomonas syringae pv. tomato strain DC3000. Under the long （16 h） photoperiod condition, Arabidopsis having a defect in NMD factors exhibited altered morphologies of various organs, disturbed homeostasis of wounding-induced jasmonic acid and pathogen-elicited salicylic acid, and abnormal wounding- and methyl jasmonate-induced changes in the transcript levels of two defense-related genes, LOX2 and VSP2. Importantly, when plants were cultivated under the short （10 h） photoperiod condition, mutants of UPF1 and UPF3 and irUPF2 showed smaller differences from the wild-type plants in growth and stress-induced responses. These data suggest a complex regulatory network, likely composed of light signaling and NMD factor-mediated pathways, in influencing plant development and adaption to environmental stresses.

Highly Enantioselective Hydrogenation of tetra-and tri-Substitutedα,β-Unsaturated Carboxylic Acids with oxa-Spiro Diphosphine Ligands

We herein present the design and synthesis of a structurally unique oxa-spirocyclic diphosphine ligand,termed as O-SDP.The diphosphine ligand O-SDP derived from oxa-spirocyclic diphenols(O-SPINOL)has a relatively larger bite angle compared with that of SDP,and O-SDP has been successfully applied in the ruthenium-catalyzed asymmetric hydrogenation ofα,β-unsaturated carboxylic acids under mild reaction conditions.High yields and enantioselectivities were generally achieved for a wide range of substrates(up to 99%yield and>99%ee),and many of the resulting products are key intermediates of important drugs such as Sacubitril,Artemisinin,and Paroxetine.

Discovery and development of ferrocene-based tetradentate ligands for Ir-catalysed asymmetric hydrogenation of ketone

The development of highly active and enantioselective ligands and catalysts for the asymmetric hydrogenation of ketone has been the goal of synthetic chemists for more than fifty years.Herein,a series of ferrocene-based tetradentate ligands were developed and applied in Ir-catalysed asymmetric hydrogenation of ketone.The hydrolytic ring-opening of the oxazoline moiety of ligand f-amphox leads to the accidental discovery of a highly efficient and enantioselective tetradentate ligand f-phamidol which showed extraordinarily high reactivity and enantioselectivity(up to 99%yield,up to>99%ee and up to 1,000,000 TON).In addition,two types of other tetradentate ligands f-phamida and f-phamide were also synthesized and evaluated.

Entity set expansion in knowledge graph:a heterogeneous information network perspective

Entity set expansion(ESE)aims to expand an entity seed set to obtain more entities which have common properties.ESE is important for many applications such as dictionary con-struction and query suggestion.Traditional ESE methods relied heavily on the text and Web information of entities.Recently,some ESE methods employed knowledge graphs(KGs)to extend entities.However,they failed to effectively and fficiently utilize the rich semantics contained in a KG and ignored the text information of entities in Wikipedia.In this paper,we model a KG as a heterogeneous information network(HIN)containing multiple types of objects and relations.Fine-grained multi-type meta paths are proposed to capture the hidden relation among seed entities in a KG and thus to retrieve candidate entities.Then we rank the entities according to the meta path based structural similarity.Furthermore,to utilize the text description of entities in Wikipedia,we propose an extended model CoMeSE++which combines both structural information revealed by a KG and text information in Wikipedia for ESE.Extensive experiments on real-world datasets demonstrate that our model achieves better performance by combining structural and textual information of entities.