富含氧空位的由多金属氧簇辅助的银基异质结用于高效电催化固氮

目前工业产氨主要依赖传统的Haber-Bosch工艺,然而该工艺条件苛刻,需要高温(350-550℃)和高压(150-250bar),每年消耗全球能源供应的2%,同时排放4.5亿吨二氧化碳(占全球总排放量的1.6%).近年来,科研工作者致力于开发高效率、高选择性的固氮电催化剂,但是由于析氢反应的强烈竞争,目前已报道的氮还原催化剂仍然受到低法拉第效率和低氨产率的限制.因此,开发活性位点丰富、氮气吸附能力强、催化性能优异的氮还原电催化剂成为当务之急.贵金属催化剂由于其纳米结构中富含活性位点,并且金属表界面处具有较好的导电性,因此表现出较高的法拉第效率.而分子催化剂因可调的电子结构和明确的构效关系引起了广泛关注.多金属氧簇是一种典型的金属聚阴离子团簇,由氧原子连接的含氧多面体组成,且具备优异的氧化还原性能.因此,本课题组尝试将多金属氧簇分子引入到氮还原催化剂中,并探究其催化机理.本文选取了一个多金属氧簇为前驱体,在溶剂、还原剂和诱导剂共存时,通过一锅法合成了富含氧空位的AgPW_(11)/Ag纳米方块电催化剂.实验结果表明,富含氧空位的AgPW_(11)/Ag异质结催化剂在-0.2 V(vs.RHE)电位时表现出高达46.02±1.03μg h^(-1)mg^(-1)_(cat).的氨产率和34.07±0.16%的法拉第效率,催化反应能够稳定运行32h且性能未见衰减,显著优于银催化剂.随后系统地研究了AgPW_(11)/Ag催化剂的氮还原活性位点,发现异质结中的银单质为催化反应提供了高导电性的支持,而催化剂中的银氧簇具有较好的电子得失能力,有利于促进氮还原反应中的六电子转移过程.丰富的氧空位利于吸附氮气,也能协同提升AgPW_(11)/Ag对电化学氮还原的催化活性.密度泛函理论计算结果表明,在还原后的银氧簇中,银原子d轨道与氮气π*轨道之间的强相互作用激活了吸附的氮气,促进了第一个质子化过程:*N_(2)向*N-NH的转化(电化学决速步).综上,本工作建立了异质结催化剂的催化性能与其分子结构之间的构效关系,为开发多金属氧簇及其衍生物作为电催化剂提供了依据和思路.

氧化苦参碱对小鼠皮肤屏障功能障碍的修复作用研究

探讨氧化苦参碱(OMT)乳膏对小鼠皮肤屏障功能的修复作用。将70只雄性ICR小鼠随机分为7组,除正常组小鼠外,采用胶带粘贴法模拟机械损伤,复制皮肤屏障功能障碍小鼠模型。造模后经皮连续给药5天,拍摄照片并测定造模区域的经表皮失水量(TEWL)。实验结束后,HE染色观察皮肤组织形态学变化,酶联免疫吸附法(ELISA)检测皮肤组织中肿瘤坏死因子α(TNF-α)、白细胞介素-8(IL-8)的含量,通过实时定量PCR(RT-qPCR)检测紧密连接蛋白(ZO-1)、丝聚蛋白(FLG)、水通道蛋白3(AQP3)mRNA的表达量,通过Western blot检测屏障相关蛋白如封闭蛋白(OCC)、FLG、紧密连接蛋白(Claudin)的表达量。结果显示,与模型组相比,OMT各剂量组均能降低皮肤TEWL,减轻炎症浸润,改善皮肤病理状态,同时高剂组皮肤组织中TNF-α等炎症因子的含量显著降低(P<0.05),ZO-1、FLG m RNA及OCC、FLG、Claudin蛋白的表达显著升高(P<0.05)。因此,OMT具有修复皮肤屏障功能的作用。

Ab initio molecular dynamics simulation reveals the influence of entropy effect on Co@BEA zeolite-catalyzed dehydrogenation of ethane

The C–H bond activation in alkane dehydrogenation reactions is a key step in determining the reaction rate.To understand the impact of entropy,we performed ab initio static and molecular dynamics free energy simulations of ethane dehydrogenation over Co@BEA zeolite at different temperatures.AIMD simulations showed that a sharp decrease in free energy barrier as temperature increased.Our analysis of the temperature dependence of activation free energies uncovered an unusual entropic effect accompanying the reaction.The unique spatial structures around the Co active site at different temperatures influenced both the extent of charge transfer in the transition state and the arrangement of 3d orbital energy levels.We provided explanations consistent with the principles of thermodynamics and statistical physics.The insights gained at the atomic level have offered a fresh interpretation of the intricate long-range interplay between local chemical reactions and extensive chemical environments.

Facile preparation of Fe-Beta zeolite-supported transition metal oxide catalysts and their catalytic performance for the simultaneous removal of NO_(x)and soot

Diesel engine exhaust comprises nitrogen oxides(NOx)and soot particles,which cause serious air pollution.However,owing to the contradictory nature of NO_(x)reduction and soot oxidation,a trade-off exists in the simultaneous removal of NO_(x)and soot.Consequently,catalytic technology has become a hot research topic.This study prepared MOδ/Fe-Beta(M=Fe,Co,Ni,Mn,Cu)catalysts through incipient wetness impregnation using Fe-Beta as the support and explored the catalytic performance of the above catalysts.The results exhibited the good performance of the prepared catalysts.The introduction of Mn resulted in a lower peak temperature of soot combustion for the catalyst,and slightly decreased deNOx performance of Fe-Beta.The soot combustion temperature was as low as 422℃,and the temperature window for 80%NO conversion was 164-423℃.The interaction between MnOd and zeolite can regulate the acid sites and produce sufficient active oxygen species for the catalyst.The catalytic activity of the MnOδ/Fe-Beta catalyst is due to its strong redox property,the appropriate number of acid sites,and sufficient number of active oxygen species.In addition,the catalyst had good stability and water and sulfur resistance,therefore it had great potential for future application in the simultaneous removal of NO_(x)and soot from diesel engine exhaust.

Performance enhancement and active sites identification of Cu-Cd bimetallic oxide derived catalysts for electrochemical CO_(2) reduction

The development of earth-abundant electrocatalysts with high performance for electrochemical CO_(2)reduction(ECR)is of great significance.Cu-based catalysts have been widely investigated for ECR due to their unique ability to generate various carbonaceous products,but directing selectivity toward one certain product and identifying the real active sites during ECR are still full of challenge.Here,after the incorporation of CdO into CuO,the Cu_(0.5)Cd_(0.5)-O catalyst achieves a 10.3-fold enhancement for CO selectivity in comparison with CuO,and a CO faradic efficiency nearly 90%with a current density around20 mA cm^(-2)could maintain at least 60 h.Interestingly,a wide CO/H_(2)ratio(0.07-10)is reached on Cu_(x)Cd_(1-x)-O catalysts by varying the Cu/Cd ratio,demonstrating the potential of syngas production using such catalysts.The results of ex situ XRD,XPS,and in situ Raman reveal that the real active sites of Cu_(0.5)Cd_(0.5)-O catalysts for CO production during ECR reaction are the reconstructed mixed phases of CuCd alloy and CdCO_(3).In situ FTIR and theoretical calculations further implicate the presence of Cd related species promotes the CO desorption and inhibits the H_(2)evolution,thus leading to an enhanced CO generation.

LncRNA LOC103694972 promotes fibrosis of NRK-49F cells by regulating STAT3-dependent Smad/CTGF pathway via targeting miR-29c-3p

Background:Renalfibrosis is an important process in the development of chronic kidney disease.Understanding the pathogenesis andfinding effective treatments for renalfibrosis is crucial.This study aims to investigate whether a newly discovered long non-coding RNA(lncRNA)called LOC103694972 could be a potential target for treatingfibrosis of NRK-49F cells.Methods:LncRNA Chip was used to identify differentially expressed lncRNAs between TGF-β1-induced NRK-49F cells and normal cells.The dual-luciferase assay confirmed the binding between miR-29c-3p and signal transducer and activator of transcription(STAT3),as well as between miR-29c-3p and lncRNA LOC103694972.Si-LOC103694972 and miR-29c-3p mimic were then transfected into TGF-β1-induced NRK-49F cells.Results:The study found that LOC103694972 was highly expressed in TGF-β1-induced NRK-49F cells.These cells exhibited increased cell length and activity compared to the control group.The expression levels of Collagen I,α-Smooth muscle actin(α-SMA),and tissue inhibitor of metalloproteinase(TIMP-1)were increased,while matrix Metalloproteinase 2(MMP2)and matrix Metalloproteinase 9(MMP9)expression was decreased.However,transfection with si-LOC103694972 and miR-29c-3p mimics restored cell morphology and reduced cell viability.This led to a decrease in the levels of Collagen I,α-SMA,and TIMP-1,as well as an increase in MMP2 and MMP9 expression.Additionally,TGF-β1-induced NRK-49F cells transfected with miR-29c-3p mimics activated the STAT3-Smad3/CTGF pathway.Conclusion:Based on thesefindings,lncRNA LOC103694972 shows promise as a target for treating renalfibrosis.It negatively regulates miR-29c-3p and activates the STAT3-Smad3/CTGF pathway.

Analysis of a Rare Heavy Rain Weather Process in Autumn in Ulanqab City

Based on the conventional observation data and NCEP/NCAR reanalysis data,the circulation situation,influencing systems and causes of the heavy rain during September 20-21,2010 in Ulanqab City were analyzed from the evolution process of weather circulation situation and the changes of various physical quantity fields.The results show that there was an obvious frontal zone between 45-52°N,which brought strong cold air.The transport of warm and humid air outside the subtropical high and typhoon was the main water vapor source of the strong precipitation,and the southwest jet at 700 hPa transported abundant water vapor.There was a broad inverted trough to the south of 45°N,with a central value of 1000.0 hPa.Ulanqab City was on the top of the inverted trough,stable and less moved,which was conducive to the occurrence of systematic heavy precipitation.The rainstorm was a strong precipitation process caused by the intersection of cold air brought by the southward movement of the upper frontal zone and warm and humid air outside the subtropical high.After the precipitation,the invasion of strong cold air brought frost and cold wave weather to Ulanqab City.

Analysis of Characteristics of Snow Accumulation and Its Meteorological Influencing Factors during a Snowstorm Process in Ulanqab City

Based on the data of national observation stations of CMISS system,artificial encrypted observation data of snow depth,ERA5 reanalysis data,the snowfall process in Ulanqab City from March 17 to 19,2022 was analyzed.It is found that the influencing system of the snowfall process was upper-air trough combined with ground inverted trough.Snowfall was not proportional to snow depth,and the relationship between the maximum snow depth and total snowfall varied in different value intervals.A large intensity of snowfall was a necessary condition for the formation of abundant accumulated snow when ground temperature was higher than 0℃.After the formation of accumulated snow,ground temperature changed less,and it was easy to produce accumulated snow as ground temperature was lower.The lower the temperature,the more conducive to the generation of accumulated snow.

Collision and Deadlock Avoidance in Multi-Robot Systems Based on Glued Nodes

Dear editor,In this letter,we would like to discuss a method to avoid collisions and deadlocks in multi-robot systems based on a new concept of glued nodes.In terms of collision and deadlock avoidance,many methods are based on zone control which has two disadvantages.First,unless all nodes are collision-free,the roadmap must be divided into disjoint zones,which increases the difficulty of applying the methods.Moreover,each zone should be able to accommodate a robot,which leads to imprecision and waste of space.This letter proposes the concept of glued nodes,which can dynamically determine the mutual influence between nodes based on the real-time sizes and paths of the robots.Based on the glued nodes,this letter proposes a collision and deadlock avoidance algorithm,which can be applied to multi-robot systems with variable-sized robots and roadmaps with any structure.The experimental results indicate that the method proposed in this letter is effective and efficient.

Environmental contribution to needle variation among natural populations of Pinus tabuliformis

Variations in the phenotypic characteristics of conifer needles is a consequence of genetic evolution that has been widely used in geographic variation and ecological studies.Although many studies are based on an in situ sampling strategy and generally realize the contribution of environmental effects to variation in needle traits,it is still uncertain which needle traits are most influenced by genetic effects and which are most influenced by the environment.Using both a common garden experiment to eliminate environmental heterogeneity and an in situ sampling strategy,we compared 18 Pinus tabuliformis needle traits among 10 geographical populations.Using both sampling strategies,we found significant differences in needle traits among populations and among individuals within populations.Differences in the‘‘among-population’’variance component between the two sampling strategies revealed the environmental contribution among natural populations for each trait.The among-population variance in the following traits exceeded 8%:needle length,number of stomata within 2 mm(NS2),number of stomatal lines on the planar side,number of resin canals(RCN)and the resin canal area(RCA).For the stability of needle traits,NS2,RCN,RCA,ratio of the vascular bundle area to the RCA(VBA/RCA),and MA/RCA differed significantly in more than five provenance changes between the common garden populations and natural populations,which may be susceptible to environmental effects.Conversely,the crosssectional area,mesophyll area(MA),MA/(VBA+RCA),and MA/VBA were phenotypically stable.Geographic variation patterns and systematic relation of needle traits differed between the two sampling strategies,suggesting that in situ sampling results may reflect environmental effects and deviate statistical parameters for genetic study.Future studies of genetic evolution in the context of geographic variation should be based on appropriate sampling strategies and stable phenotypic traits.

Variations in electrical impedance and phase angle among seedlings of Pinus densata and parental species in Pinus tabuliformis habitat environment

Electrical impedance （El） and phase angle （PHI） parameters in AC impedance spectroscopy are important electrical parameters in the study of medical pathology. However, little is known about their application in variation and genetic relationship studies of forest trees. In order to test whether impedance parameters could be used in genetic relationship analysis among conifer species, E1 and PHI were measured in a seedling experiment test composed of Pinus tabuliformis, Pinus yunnanensis, and Pinus densata in a habitat of Pinus tabuliformis. The results showed that variations in both EI and PHI among species were sig- nificant in different electric frequencies, and the EI and PHI values measured in the two populations of P. densata were between the two parental species, P. yunnanensis and P. tabuliformis. These results show that these two impedance parameters could reflect the genetic relationship among pine species. This was the first time using the two AC impedance spectroscopy parameters to test the genetic relationship analysis between tree species, and would be a hopeful novelreference methodology for future studies in evolution and genetic variation of tree species.

Insights into high-efficient removal of tetracycline by a codoped mesoporous carbon adsorbent

Adsorbents with simple preparation and high surface area have become increasingly prevalent for the removal of organic contaminants.Herein,a carbon nanoplate codoped by Co and N elements with abundant ordered mesoporous(Co/N-MCs)was applied as an adsorbent for tetracycline removal.Taking integrated advantages of ordered mesopores on carbon-based structures and N-doping inducing the strengthenedπ–πdispersion and generation of pyridinic N,as well as cobaltic nanoparticles embedded in carbon nanoplates,the Co/N-MCs was tailored for high efficiently absorbing tetracycline viaπ-πinteraction,Lewis acid-base interaction,metal complexation and electrostatic attraction.The Co/N-MCs had the advantages of high surface area,porous structure,plenty adsorption sites,and easy separation.As such,the as-prepared Co/N-MCs adsorbents significantly enhanced tetracycline removal performance with a maximum adsorption capacity of 344.83 mg·g^(-1) at pH 6 and good reusability,which was finally applied to removal tetracycline from tap water sample.Furthermore,the adsorption process towards tetracycline hydrochloride could be well attributed to the pseudo-second-order kinetic and Langmuir isotherm models.Compared with traditional carbon-based adsorbents,it owns a simpler synthesis method and a higher adsorption capacity,as well as it is a promising candidate for water purification.

Chinese Customers' WTP for Legal Digital Music Downloading

This study is to examine the effects of some significant factors on consumers' willingness to pay( WTP) for digital music via the moderating variables of music affinity and the deterrence effect of the legislation. Based on 517 Chinese respondents with access to digital music,using the multiple liner regression model,this study indicates that free ideology,perceived benefits of free downloading,perceived benefits of paid downloading,subjective norm,habit strength have direct influence on WTP,and music affinity and the deterrence effect of the legislation have moderating effects. This study contributes theoretically to research on Chinese consumers' WTP for digital music and offers practical recommendations for the digital music charging system setup.

Introduction of Environmental Protection Concept in Textile Major Education

The textile industry is a pillar industry of the national economy,and it is also a polluting industry.Green environmental protection has become the development trend of the textile industry,which requires the joint efforts of the government,enterprises and practitioners.Strengthening the environmental protection education of textile students has important significance for the implementation of sustainable development strategy of textile industry.Tertiary education is a very good platform for the implementation of environmental protection education for textile students,and it is also a critical period for students to strengthen the concept of environmental protection education.Students’environmental protection awareness may take measures to cultivate such as integrating environmental protection courses into major training programs,practice teaching of environmental protection,applying for training programs of college students’innovation and entrepreneurship,participating in research projects,etc.

Pathway toward carbon-neutral power systems in China

At the General Debate of the United Nations General Assembly conducted in September 2020,President Xi Jinping proposed that China will strive to achieve carbon neutrality before 2060.A recent study using highresolution modeling pioneered in issuing optimized pathways for achieving carbonneutral electrical systems in China by midcentury with negative CO_(2) abatement costs[1].As the world’s largest energy producer and consumer,China requires a total investment of over one hundred trillion fixed assets to realize carbon neutrality,which will become an important engine for the green recovery of the global economy in the postpandemic era.Presently,however,China’s national toplevel plan for the transition pathway toward a carbonneutral electrical system remains unclear and the local goals and plans of emission reduction lack coordination.

NF-κB in biology and targeted therapy:new insights and translational implications

NF-κB signaling has been discovered for nearly 40 years.Initially,NF-κB signaling was identified as a pivotal pathway in mediating inflammatory responses.However,with extensive and in-depth investigations,researchers have discovered that its role can be expanded to a variety of signaling mechanisms,biological processes,human diseases,and treatment options.In this review,we first scrutinize the research process of NF-κB signaling,and summarize the composition,activation,and regulatory mechanism of NF-κB signaling.We investigate the interaction of NF-κB signaling with other important pathways,including PI3K/AKT,MAPK,JAK-STAT,TGF-β,Wnt,Notch,Hedgehog,and TLR signaling.The physiological and pathological states of NF-κB signaling,as well as its intricate involvement in inflammation,immune regulation,and tumor microenvironment,are also explicated.Additionally,we illustrate how NF-κB signaling is involved in a variety of human diseases,including cancers,inflammatory and autoimmune diseases,cardiovascular diseases,metabolic diseases,neurological diseases,and covID-19.Further,we discuss the therapeutic approaches targeting NF-κB signaling,including IKK inhibitors,monoclonal antibodies,proteasome inhibitors,nuclear translocation inhibitors,DNA binding inhibitors,TKls,non-coding RNAs,immunotherapy,and CAR-T.Finally,we provide an outlook for research in the field of NF-κB signaling.We hope to present a stereoscopic,comprehensive NF-κB signaling that will inform future research and clinical practice.

水稻突变体pe-1对弱光胁迫的响应机制

以γ射线诱变籼稻双科早(Oryza sativa subsp.indica cv.‘Shuangkezao’)获得的早熟鲜绿突变体pe-1为实验材料,在三叶期和分蘖期进行弱光胁迫,探讨pe-1与野生型在形态特征、非生物胁迫相关酶活性及其调控基因表达量、叶绿素含量、叶绿体合成与降解及光形态建成相关基因表达对弱光响应的差异。结果表明,与野生型相比,弱光胁迫后,pe-1叶片黄化程度显著降低,株高和叶面积显著增加;三叶期和分蘖期的叶片中不同叶绿素含量变化不同。此外,pe-1叶绿素含量增加,且其抗氧化应激反应相关酶过氧化氢酶(CAT)和过氧化物酶(POD)的活性及相关基因的表达量均高于野生型,表明在弱光胁迫下pe-1活性氧清除能力增强,适应能力更强。pe-1的光形态建成相关基因表达量高于野生型,表明弱光处理下pe-1的光接收能力更强。综上,pe-1突变体具有抵御弱光胁迫的潜力,该结果有助于耐弱光水稻品种的选育。

Mitochondrial flashes are interlinked with adaptive thermogenesis in brown adipocytes

Mitochondrial flash(mitoflash)is the electrochemical excitation of a single mitochondrion and plays diverse signaling roles in a variety of cells.From the viewpoint of bioenergetics,it represents the transient uncoupling of mitochondrial respiration from ATP synthesis.Brown adipose tissue(BAT)produces heat,primarily via mitochondrial uncoupled respiration.Here,we aim to illustrate the mitoflash activity in BAT thermogenesis.We show that BAT mitochondria undergo stochastic and intermittent mitoflashes at the levels of isolated mitochondria,cultured brown adipocytes,and even intact BAT.A BAT mitoflash contains multiple signals,including transient depolarization of mitochondrial membrane potential,transient matrix alkalization,and bursting production of reactive oxygen species.Importantly,thermogenic activation by b3-adrenergic stimulation dramatically augments mitoflash incidence,with mild effects on its unitary characteristics.Ablation of the thermogenic uncoupling protein 1(UCP1)showed little effect on mitoflash biogenesis during heat production.Collectively,our results suggest that mitoflash might constitute an elemental signaling activity of mitochondria to regulate BAT thermogenesis.

Interparticle energy transfer between NaNdF_(4) and NaYbF_(4) in self-assembled nanostructures

Forster resonance energy transfer(FRET)is a widely used spectroscopic technique.The development of donor-acceptor combinations is essential to advance this technique.To make the energy transfer efficiency independent of the external environment,we explored the potential of constructing donor—acceptor combinations with lanthanide ion-doped nanoparticles(LNPs),in which the 4f electrons of the lanthanide ions are shielded by the 5s and 6p electrons.Non-radiative energy transfer between LNPs was demonstrated in self-assembled nanostructures and core-shell structure of LNPs was used to control the distance between donor and acceptor in self-assembled nanostructures.The emission intensity ratio of donor and acceptor illustrates that the energy transfer efficiency decreases significantly with increasing distance and the effective energy transfer distance is 8.5 nm,showing the potential of using LNPs as donor-acceptor pairs in the construction of distance-dependent energy transfer system.

Flexible one-dimensional photonic crystal films composed of chalcogenide glass and water-soluble polymer for curvature sensing

Curvature sensing plays an important role in structural health monitoring,damage detection,real-time shape control,modification,etc.Developing curvature sensors with large measurement ranges,high sensitivity,and linearity remains a major challenge.In this study,a curvature sensor based on flexible one-dimensional photonic crystal(1D-PC)films was proposed.The flexible 1D-PC films composed of dense chalcogenide glass and water-soluble polymer materials were fabricated by solution processing.The flexible 1D-PC film curvature sensor has a wide measurement range of 33-133 m-1and a maximum sensitivity of0.26 nm/m^(-1).The shift of the transmission peak varies approximately linearly with the curvature in the entire measurement range.This kind of 1D-PC film curvature sensor provides a new idea for curvature sensing and measurement.