Prunus sunhangii: A new species of Prunus from central China

A new species of Rosaceae from Central China, Prunus sunhangii D. G. Zhang & T. Deng, sp. nov., is described and illustrated. The new species is placed in Prunus subgenus Cerasus by flower and fruit characteristics. It is most similar to Prunus cerasoides, but differs by having longitudinally 2-lobed apical petals, an acuminate leaf apex, 17—25 stamens, white petals, dark black drupes, brown hypanthium, and different phenology. The phylogenetic placement of this species was assessed based on morphological and molecular data. Molecular analysis(cp DNA + ITS) corroborated its placement in subgenus Cerasus,specifically Prunus section Serrula.

MOF-derived Zn-Co-Ni sulfides with hollow nanosword arrays for high-efficiency overall water and urea electrolysis

Water electrolysis is a promising technology to produce hydrogen but it was severely restricted by the slow oxygen evolution reaction(OER).Herein,we firstly reported an advanced electrocatalyst of MOF-derived hollow Zn-Co-Ni sulfides(ZnS@Co_(9)S_(8)@Ni_(3)S_(2)-1/2,abbreviated as ZCNS-1/2)nanosword arrays(NSAs)with remarkable hydrogen evolution reaction(HER),OER and corresponding water electrolysis performance.To reach a current density of 10 mA cm^(-2),the cell voltage of assembled ZCNS-1/2//ZCNS-1/2 for urea electrolysis(1.314 V)is 208 mV lower than that for water electrolysis(1.522 V)and stably catalyzed for over 15 h,substantially outperforming the most reported water and urea electrolysis electrocatalysts.Density functional theory calculations and experimental result clearly reveal that the properties of large electrochemical active surface area(ECSA)caused by hollow NSAs and fast charge transfer resulted from the Co_(9)S_(8)@Ni_(3)S_(2) heterostructure endow the ZCNS-1/2 electrode with an enhanced electrocatalytic performance.

PEDOT:PSS:From conductive polymers to sensors

PEDOT:PSS conductive polymers have received tremendous attention over the last two decades owing to their high conductivity,ease of processing,and biocompatibility.As a flexible versatile material,PEDOT:PSS can be developed into various forms and has had a significant impact on emerging sensing applications.This review covers the development of PEDOT:PSS from material to physical sensors.We focus on the morphology of PEDOT:PSS in the forms of aqueous dispersions,solid films,and hydrogels.Manufacturing processes are summarized,including coating,printing,and lithography,and there is particular emphasis on nanoimprinting lithography that enables the production of PEDOT:PSS nanowires with superior sensing performance.Applications to various physical sensors,for humidity,temperature,pressure,and strain,are demonstrated.Finally,we discuss the challenges and propose new directions for the development of PEDOT:PSS.

A new presentation of the Indian Ocean shallow overturning circulation from a vertical perspective

The calculation of the meridional overturning streamfunction in the southern Indian Ocean is biased by the Indonesian Throughflow.Therefore,this study applies the vertical overturning streamfunction to diagnose the shallow overturning circulation in the Indian Ocean.Using the Ocean General Circulation Model for the Earth simulator output,improvements with the vertical overturning streamfunction compared with the meridional overturning streamfunction are explored.The results show that the vertical overturning streamfunction smoothly connects the shallow overturning circulations of the northern Indian Ocean and the southern Indian Ocean with the whole cycle of the subtropical cell and the cross-equatorial cell.The vertical overturning streamfunction shows a much cleaner shallow overturning circulation,which is underestimated by the meridional overturning streamfunction.It shows that the shallow overturning circulation has a magnitude of~13 Sv(1 Sv≡106 m 3 s−1),of which the subtropical cell accounts for~8 Sv.In addition,the vertical overturning streamfunction captures a clockwise overturning cell in the upper 600 m layer between 30°S and 34°S.This cell has a magnitude of about−5 Sv and probably corresponds to the wind-forced subtropical gyre.Therefore,the vertical overturning streamfunction provides a new approach for estimating the shallow overturning circulation in the Indian Ocean.

Plasmon Bi in-situ anchored on BiOCl nanosheets assembled microspheres towards optimized photothermal-photocatalytic performance

Interface engineering is of great importance to improve the photocatalytic performance.Herein,in-situ formation plasmon Bi/BiOCl nanosheets assembled heterojunction microspheres are fabricated via facile reductive solvothermal approach.The aldehyde group in the DMF structure is used to exert the weak reducing property of the solvent and thus strip out the metal Bi in BiOCl.The metal Bi is anchored on surface of BiOCl firmly due to in-situ formation engineered interface,which could realize efficient charge transfer channel.The resultant Bi/BiOCl heterojunctions assemblies with narrow bandgap of 3.05 eV and mesoporous structure extend the photoresponse to visible light region and could provide sufficient surface active sites.The visible-light-driven photocatalytic degradation of high-toxic norfloxacin for Bi/BiOCl heterojunctions is up to 95.5%within 20 min,representing several times that of pristine BiOCl nanosheets and the physical mixture.It is attributed to the in-situ formation of Bi/BiOCl heterojunctions and surface plasmon resonance(SPR)effect of plasmon Bi promoting charge transfer,and the obvious photothermal effect promoting the photocatalytic reaction,which are verified by experimental and density functional theory(DFT)calculations.This strategy provides ideal perspectives for fabricating metal/semiconductor heterojunctions photocatalysts with high-performance.

神农架国家公园植物采集史及模式标本名录

本文基于标本及文献数据对神农架国家公园高等植物标本采集史进行简要概述。该地区有着近140年的标本采集历史,最早对神农架地区进行植物标本采集的是爱尔兰植物学家Augustine Henry。中国科学院武汉植物园标本馆(HIB)收藏了采自该地区的21,402份标本,居首位;其次为中国科学院植物研究所标本馆(PE)16,483份、华中农业大学博物馆(CCAU)1,851份。标本采集年份主要集中在1956–1959、1976–1981、1985–1987三个时间段,其中以1976年采集数量为最多。标本采集月份主要集中在4–11月,8月采集量最大。不同植物的标本数量两极分化严重,标本量多的如桦叶荚蒾(Viburnum betulifolium),高达295份,然而有612种植物的标本量仅1份,约2/3的植物标本量少于10份。因而,在今后的采集工作中我们应该将重心置于标本数量不足的物种和类群,而标本数量过剩的类群则应减少或停止采集;植物标本的采集过程应尽可能全覆盖,突出对高海拔、峡谷、石壁、无人区等特殊生境的调查。采集时间上应该注重春、冬二季。此外,我们对该地区的维管植物模式标本进行了考证,编制了《神农架国家公园维管植物模式标本名录》。该地区共有维管植物模式标本39种2变种3变型,隶属24科34属。对神农架国家公园维管植物模式标本的整理为履行联合国教科文组织世界遗产中心的要求及进一步开展神农架遗产的管理与保护提供了依据。

Highly stable aqueous phase black phosphorus quantum dots with enhanced fluorescence property

Black phosphorus quantum dots(BPQDs)are a kind of outstanding optical material due to the tunable band structure.However,their fluorescence property and stability are obviously weakened in the aqueous phase,which extremely restricts the development of BPQDs.Here,we propose a new method to prepare stable BPQDs in an aqueous solution directly with high absolute fluorescence quantum yield.Aqueous phase BPQDs are synthesized by liquid exfoliation and hydrothermal with NH_(2)-polyethylene glycol(PEG)-NH_(2) as the modification agent to protect the BPQDs,which have high stability more than six months.In addition,NH_(2)-PEG-NH_(2) is also a surface passivation agent to enhance the emission of BPQDs by forming P-N bonds,which is confirmed by an absolute fluorescent quantum yield of 11.5%.Moreover,BPQDs show excellent resistance to a strong acid environment and high ionic strengths except for Fe^(3+).Therefore,the BPQDs are a kind of highly selective and linear response fluorescence probe for Fe^(3+).Considering the good biocompatibility of BPQDs,they are employed as cell fluorescent label probes and show excellent fluorescence imaging contrast.Based on the unique structural stability and fluorescence performance in the aqueous phase,BPQDs are potential candidates for Fe^(3+)detection and optical bio-imaging.

导致狐狸重症腹泻疫情的新型犬冠状病毒的发现与鉴定

2019年末,中国东北地区狐狸群中暴发大规模疫情,发病狐狸表现出急性腹泻症状,并出现大量狐狸死亡.通过对该疫源地发病狐狸肛拭子、血液与发病组织的检测分析,获得了多条全长新型犬冠状病毒(CCoV)基因组序列,研究团队将该病毒命名为VuCCoV,并确认VuCCoV是引起该疫情的病原.进一步分析表明,VuCCoV基因组的4个结构基因(S,E,M,N)中的3个(E,M,N)与犬冠状病毒(CCoV)对应基因具有超过90%的核苷酸同一性,但S基因核苷酸序列表现出较大的差异.VuCCoV的RNA依赖的RNA聚合酶与蝙蝠冠状病毒PB025的对应蛋白仅存在2~3个氨基酸差异,系统进化分析提示VuCCoV很可能来源于蝙蝠.表面等离子体共振分析实验表明,VuCCoV刺突蛋白受体结合区(RBD)可与犬和狐狸的氨肽酶N(APN)结合,但不与人APN结合,假病毒感染及病毒分离培养实验进一步证实该VuCCoV不易感染人源细胞.蝙蝠等野生动物宿主的病毒跨物种传播对人类和家畜健康构成了显著威胁,VuCCoV的发现和溯源证实蝙蝠作为疫情出现的潜在驱动因素的重要性.积极监控蝙蝠及其他犬科动物中的病毒感染,发现、鉴定对人兽健康构成潜在威胁的新型冠状病毒并研究其进化变异特征与感染特性,对于防控新发人兽共患传染病、建设国家生物安q全体系具有重要意义.

皮凯蒂之问——观念、历史与不平等研究

不平等是经济学等社会科学学科的热点议题。托马斯·皮凯蒂持续关注这一领域。在《21世纪资本论》的基础上,他的近作《资本与意识形态》试图推进不平等研究。皮凯蒂认为,资本收益率超过经济增长率是经济不平等的根源,但分化的关键在于政治与意识形态的结合使得西方收入和受教育程度不高的底层失去改善其不平等境况的机会。在“皮凯蒂之问”的观念史考察中,西方学界的不平等探讨或排斥政治权力而放任资本权力,或批判资本权力而寄望政治权力,“单线批判”与“二元对立”使经济与社会科学在“富人经济学”和“穷人政治学”之间摇摆。中国“共同富裕”概念的出发点是共同体的福让,落脚点是对资本与权力的双线批判。可以此为契机,与全球“不平等”研究进行理论对话,明晰其对国际社会科学的意义。