Electromechanical Transient Modeling Analysis of Large-Scale New Energy Grid Connection

The synchronous virtual machine uses inverter power to imitate the performance of the conventional synchronous machine.It also has the same inertia,damping,frequency,voltage regulation,and other external performance as the generator.It is the key technology to realize new energy grid connections’stable and reliable operation.This project studies a dynamic simulation model of an extensive new energy power system based on the virtual synchronous motor.A new energy storage method is proposed.The mathematical energy storage model is established by combining the fixed rotor model of a synchronous virtual machine with the charge-discharge power,state of charge,operation efficiency,dead zone,and inverter constraint.The rapid conversion of energy storage devices absorbs the excess instantaneous kinetic energy caused by interference.The branch transient of the critical cut set in the system can be confined to a limited area.Thus,the virtual synchronizer’s kinetic and potential energy can be efficiently converted into an instantaneous state.The simulation of power system analysis software package(PSASP)verifies the correctness of the theory and algorithm in this paper.This paper provides a theoretical basis for improving the transient stability of new energy-connected power grids.

The mechanisms of melanogenesis inhibition by glabridin:molecular docking,PKA/MITF and MAPK/MITF pathways

Glabridin is the main ingredient of hydrophobic fraction in licorice extract and has been shown to have anti-melanogenesis activity in skins.However,the underlying mechanism(s)remain not completely understood.The aim of this study is thus to elucidate the possible mechanisms related to the melanogenesis suppression by glabridin in cultured B16 murine melanoma cells and in UVA radiation induced hyperpigmentation model of BALB/c mice as well.Molecular docking simulations revealed that between catalytic core residues and the compound.The treatment by glabridin significantly downregulated both transcriptional and/or protein expression of melanogenesis-related factors including melanocyte stimulating hormone receptor(MC1R),microphthalmia-associated transcription factor(MITF),tyrosinase(TYR),TYR-related protein-1(TRP-1)and TRP-2 in B16 cells.Both PKA/MITF and MAPK/MITF signaling pathways were found to be involved in the suppression of melanogenesis by glabridin in B16 cells.Also in vivo glabridin therapy significantly reduced hyperpigmentation,epidermal thickening,roughness and inflammation induced by frequent UVA exposure in mice skins,thus beneficial for skin healthcare.These data further look insights into the molecular mechanisms of melanogenesis suppression by glabridin,rationalizing the application of the natural compound for skin healthcare.

Review of Design and Control Optimization of Axial Flux PMSM in Renewable-energy Applications

Axial flux permanent magnet synchronous motors(AFPMSMs)have been widely used in wind-power generation,electric vehicles,aircraft,and other renewable-energy applications owing to their high power density,operating efficiency,and integrability.To facilitate comprehensive research on AFPMSM,this article reviews the developments in the research on the design and control optimization of AFPMSMs.First,the basic topologies of AFPMSMs are introduced and classified.Second,the key points of the design optimization of core and coreless AFPMSMs are summarized from the aspects of parameter design,structure design,and material optimization.Third,because efficiency improvement is an issue that needs to be addressed when AFPMSMs are applied to electric or other vehicles,the development status of efficiency-optimization control strategies is reviewed.Moreover,control strategies proposed to suppress torque ripple caused by the small inductance of disc coreless permanent magnet synchronous motors(DCPMSMs)are summarized.An overview of the rotor-synchronization control strategies for disc contra-rotating permanent magnet synchronous motors(CRPMSMs)is presented.Finally,the current difficulties and development trends revealed in this review are discussed.

简易构筑Bi2Mo3O12@Bi2O2CO3异质结增强光催化脱除NO性能及其转化过程（英文）

电荷分离及转移是影响光催化效率的重要因素之一.本文采用简易的水热焙烧法,设计并构筑了Bi2Mo3O12@Bi2O2CO3(BMO@BOC)异质结,促进了光生载流子的分离与迁移,并优化了异质结构中的BMO与BOC的组分比例,其中BMO@BOC-1样品展现了最高的光催化脱除NO效率(~35%),且具有优异的循环稳定性.SEM与TEM结果表明,BMO@BOC-1样品是由超薄纳米片构成,可以提供丰富的反应活性位点,从而促进光催化反应的发生.HRTEM,XRD及Raman充分证明已成功合成不同组分比例的BMO@BOC异质结.同时, Raman与XPS结果表明, BMO@BOC异质结由Bi, O,C及Mo组成, XPS图谱中拟合峰位置的偏移是由异质结组分不同所致.值得注意的是, UV-visDRS结果表明,BMO@BOC-4具有最好的光谱吸收性能,但它与BMO@BOC-2和BMO@BOC-1样品的吸收带边相近,而PL结果则表明BMO@BOC-1具有更好的电荷分离性能,以及合适的组分比例,在一定程度上可以促进光吸收,并能最大限度的促进光生载流子的分离.BMO@BOC-1样品的ESR测试结果说明,·OH与·O2-的含量随着光照时间的延长而增加,证实了它们是光催化NO氧化的活性中间物种.另外,光催反应机制的研究在高效光催化剂的研发及其商业化应用中具有深远意义.本文还利用原位红外实时动态监测手段,采用"连续流测试法"与"间歇流测试法"直观动态地研究了BMO@BOC异质结催化剂表面光催化NO脱除反应过程.结果表明,在开灯前的吸附阶段于催化剂表面形成了NO-, NO2-以及NO2等中间产物,开灯后的氧化阶段出现终产物(NO3-).进一步深入分析,中间产物NO-和NO2-在氧化阶段会被氧化活性物种进一步氧化成NO3-,而中间产物NO2可能作为一种毒副产物影响NO的完全氧化.综上所述,本文将为理解NO氧化过程提供直观且动态的研究方法,对光催化技术的发展具有重要的指导意义.

Active corrosion protection of super-hydrophobic corrosion inhibitor intercalated Mg-Al layered double hydroxide coating on AZ31 magnesium alloy

Magnesium alloys,the advanced lightweight structural materials,have been successfully applied in the manufacturing field.Unfortunately,their poor corrosion resistance restrains the potential wide applications.In this work,anti-corrosion coatings were fabricated via the insitu growth of the corrosion inhibitors intercalated magnesium-aluminum layered double hydroxide(Mg-Al LDH)on AZ31 magnesium alloy and then post-sealing it by a super-hydrophobic coating.SEM,XRD,EDS,FTIR,XPS and contact angle test were conducted to analyze physical/chemical features of these coatings.Potentiodynamic polarization curves and electrochemical impedance spectroscopy were recorded to assess the anti-corrosion performance of prepared coatings.Surprisingly,Mg-Al LDH with molybdate intercalation and lauric acid modification achieves the excellent corrosion inhibition performance(99.99%)due to the multicomponent synergistic effect such as the physical protection of Mg-Al LDH,the corrosion inhibition of molybdate and super-hydrophobic properties of lauric acid.This work presents a scientific perspective and novel design philosophy to fabricate the efficient anti-corrosion coating to protect magnesium alloys and then expand their potential applications in other field.

Anion intercalated layered-double-hydroxide structure for efficient photocatalytic NO remove

Due to the easily controllable interlayer anions, metal cation composition proportion and thickness, which is beneficial to modify surface chemical state and tune bandgap, layered double hydroxides(LDHs) have great promising potential for photocatalytic applications. In this study,we have successfully synthesized the ZnAl–LDH intercalated the single anion between ZnAl cationic interlayer without anionic impurities by using a facile calcining and reconstructing routes. The electron structure and surface chemical state of the prepared products have been investigated by combining the DFT calculation and experimental characterization methods. UV–vis DRS was used to certify the light absorption of the prepared products, and we performed the DFT calculation to demonstrate the density of state and activation of reactant. These results suggested that the ZnAl–LDH–CO3 possessed the more proper band structure and superior ability to activate NO and O2 for accelerating the photocatalytic NO oxidation activity. Moreover, the in situ DRIFTS with dynamically monitoring intermediates and products over the ZnAl–LDH–CO3 was adopted to declare the photocatalytic NO oxidized process during the photocatalytic reaction process. This work illustrated the influence of different interlayer anions to the electron structure and surface chemical state of ZnAl–LDH structure through the experimental verification combined DFT calculation and the photocatalytic NO oxidized process via in situ DRIFTS analyzing, which would provide a novel way to design and fabricate the efficient photocatalysis, and understand the reaction process.

The pseudocapacitance mechanism of graphene/CoAl LDH and its derivatives:Are all the modifications beneficial?

Cobalt-Aluminum layered double hydroxide(CoAl LDH) is a hopeful electrode material due to the advantage of easy modifiability for preparing LDH-based derivatives.However,there is short of modification methods to prepare the Co-based derivatives from CoAl LDH and also short of an intuitive perspective to analyze the pseudocapacitance mechanism of CoAl LDH and its derivatives.Herein,Graphene/CoAl LDH and its derivatives including Graphene/CoS,Graphene/CoS-1,Graphene/CoOOH,Graphene/CoP were prepared by reasonably using alkali etching treatment,sulfofication and phosphorization.The specific capacitance of Graphene/CoAl LDH,Graphene/CoS,Graphene/CoS-1,Graphene/CoOOH,Graphene/CoP at1 A g^(-1) are 260.7,371.3,440.8,61.4 and 122.2 F g^(-1),especially.The pseudocapacitance mechanism of Graphene/CoAl LDH and its derivatives was analyzed.Due to the positive effect of sulfofication on the electrical conductivity of GO and cobalt sulfide,the Graphene/CoS and Graphene/CoS-1 exhibit the optimal electrochemical performance and superior rate capability.In addition,due to the repulsion effect between Graphene and OH-,the Graphene/CoAl LDH exhibits optimal cycling stability of 224.1% capacitance retention after 20000 cycles.Besides,the reason of terrible specific capacitance of Graphene/CoOOH is that the presence of H bond in interlayer of CoOOH inhibits the interaction between Co3+ and OHspecies.Hence,not all modifications will increase the specific capacitance of the electrode materials.Overall,this work provides us with a detailed analysis of the electrochemical mechanism and correlation of CoAl LDH and its derivatives from the perspective of crystal structure and composition.

RNA-Seq analysis reveals the growth and photosynthetic responses of rapeseed(Brassica napus L.)under red and blue LEDs with supplemental yellow,green,or white light

Compound light is required for plant growth and development,but the response mechanisms of plants are undercharacterized and not fully understood.The present study was undertaken to evaluate the effect of supplemental light(green light,G;white light,W;yellow light,Y)added to red–blue light(RB)and sole W on the growth and photosynthesis of rapeseed seedlings.The results revealed that supplemental G/W improved the growth and photosynthesis of seedlings,but supplemental Y significantly reduced the photosynthetic rate and palisade tissue layer.Sole W caused similar responses in terms of growth,leaf development,oxidative damage,and antioxidant capability as supplemental Y.In total,449,367,813,and 751 differentially expressed genes(DEGs)were identified under supplemental G,Y,and W and sole W,respectively,compared to RB.The DEGs under different lights were closely associated with pathways such as light stimulus and high-light response,root growth,leaf development,photosynthesis,photosynthesis-antenna proteins,carbohydrate synthesis and degradation,secondary metabolism,plant hormones,and antioxidant capacity,which contributed to the distinct growth and photosynthesis under different treatments.Our results suggest that Y is more likely substituted by other wavelengths to achieve certain effects similar to those of supplemental Y,while G has a more distinctive effect on rapeseed.Taken together,supplementation RB with G/W promotes the growth of rapeseed seedlings in a controlled environment.

Compulsive malposition of birnessite slab in 2D-Parallel birnessite on β-MnO_(2) networks for enhanced pseudocapacitance performances

High electrochemically active bimessite is always desirable pseudocapacitive material for supercapacitor.Here,two-dimensional(2D)compulsive malposition parallel bimessite standing on β-MnO_(2) interconnected networks have been designed.Due to the retrition of β-MnO_(2),compulsi ve malposition,slippage of MnO6 slab,occured in bimessite resulting in weaken bi nding force between bimessi te slab and interlayer cations,which enhanced their electrochemical performances.Additionally,the electrical conductivity of the structure was largely promoted by the 2D charge transfer route and double-exchange mechanism in bimessite,also leading to desirable electro-chemical properties.Based on the fraction of as-prepared nanostructure,the par all bimessite exhibited good pseudocapacitance performance(660 F g^(-1))with high rate capability.In addition,the asymmetrice supercapacitor assembled by reduced graphene oxide(RGO)and as-prepared nanostructure,which respectively served as the negative and positive eletrode,delivered an energy density of 33.1 Wh kg^(-1) and a mad mum power density of 64.0 kW kg^(-1) with excellent cyeling stability(95.8% after 10000 cycles).Finally,the study opens new avenwes for synthesizing high eletrochemically actiwe bimessite structure for high-performance energy storage devices.

Neutrophil extracellular traps induced by interleukin 8 via CXCR1/2 promote the progression of gastric carcinoma through transcription factor IIB-related factor 1 and cyclin

Neutrophils constitute a significant portion of the immune cells present within the tumor microenvironment.Evidence generated by our group has confirmed neutrophils to be an adverse independent prognostic factor affecting the disease-free survival of gastric carcinoma(GC)patients.1 Neutrophil extracellular traps(NETs),protein-covered DNA webs that interact with tumor cells in the tumor microenvironment,were detected in GC tissues and found to clinically associated with disease progression in our previous study.2 NETosis could be mediated by a series of agonists,such as interleukin 8(IL-8).3 However,the mechanism of IL-8 in the progression of GC occurs via NETs remains unclear.In this study,we identified that IL-8-mediated NETosis can promote the proliferation,migration,and invasion of GC cells in vitro,which can be abrogated by NET degradation through deoxyribonucleaseI(DNase I)or IL-8 suppression through neutralizing antibodies.Disruption of NETs by DNase I or blockade of the IL-8-CXC chemokine receptor 2(CXCR2)axis could result in growth retardation in mouse models.We also confirmed that NETs may influence the biological behavior of GC cells by up-regulating the expression of transcription factor IB-related factor 1(BRF1)and cyclin p21/p27.

首次在嫦娥五号月壤中鉴定出铁陨石碎片类型

Lunar soil preserves numerous fragments of meteorites impacting on the Moon,providing a unique opportunity to investigate the distribution of the types of projectiles over billions of years.Here we report the first discovery of an iron meteorite fragment from the Chang’e-5 lunar soil,which consists mainly of martensite(quenched from taenite),kamacite,and schreibersite,with a trace of pentlandite.The meteorite fragment is Ni-and P-rich,S-poor,and based on its mineral chemistry and bulk composition,can be classified into the IID-group,a rare and carbonaceous group of iron meteorite originating in the outer Solar System.This meteorite fragment experienced only limited partial melting followed by fast cooling,suggestive of efficient preservation of intact remnants of iron meteorites impacting on the porous lunar regolith.Alternatively,it is a relic of a low-velocity impact of submillimeter-sized metal grains originated from an IID-like iron meteorite.Our observations demonstrate that it is feasible to achieve the type distribution of meteorites impacting on the Moon via systematically analyzing a large number of metal grains separated from lunar soils,thus shedding light on the dynamic evolution of the Solar System.

Two haplotype-resolved,gap-free genome assemblies for Actinidia latifolia and Actinidia chinensis shed light on the regulatory mechanisms of vitamin C and sucrose metabolism in kiwifruit

Kiwifruit is a recently domesticated horticultural fruit crop with substantial economic and nutritional value,especially because of the high content of vitamin C in its fruit.In this study,we de novo assembled two telomere-to-telomere kiwifruit genomes from Actinidia chinensis var.‘Donghong’(DH)and Actinidia latifolia‘Kuoye’(KY),with total lengths of 608327852 and 640561626 bp for 29 chromosomes,respectively.With a burst of structural variants involving inversion,translocations,and duplications within 8.39 million years,the metabolite content of DH and KY exhibited differences in saccharides,lignans,and vitamins.A regulatory ERF098 transcription factor family has expanded in KY and Actinidia eriantha,both of which have ultra-high vitamin C content.With each assembly phased into two complete haplotypes,we identified allelic variations between two sets of haplotypes,leading to protein sequence variations in 26494 and 27773 gene loci and allele-specific expression of 4687 and 12238 homozygous gene pairs.Synchronized metabolome and transcriptome changes during DH fruit development revealed the same dynamic patterns in expression levels and metabolite contents;free fatty acids and flavonols accumulated in the early stages,but sugar substances and amino acids accumulated in the late stages.The AcSWEET9b gene that exhibits allelic dominance was further identified to positively correlate with high sucrose content in fruit.Compared with wild varieties and other Actinidia species,AcSWEET9b promoters were selected in red-flesh kiwifruits that have increased fruit sucrose content,providing a possible explanation on why red-flesh kiwifruits are sweeter.Collectively,these two gap-free kiwifruit genomes provide a valuable genetic resource for investigating domestication mechanisms and genome-based breeding of kiwifruit.

Nematode-induced trap formation regulated by the histone H3K4 methyltransferase AoSET1 in the nematode-trapping fungus Arthrobotrys oligospora

The methylation of lysine 4 of histone H3(H3K4),catalyzed by the histone methyltransferase KMT2/SET1,has been functionally identified in many pathogenic fungi but remains unexplored in nematode-trapping fungi(NTFs).Here,we report a regulatory mechanism of an H3K4-specific SET1 orthologue,AoSET1,in the typical nematode-trapping fungus Arthrobotrys oligospora.When the fungus is induced by the nematode,the expression of AoSET1 is up-regulated.Disruption of AoSet1 led to the abolishment of H3K4me.Consequently,the yield of traps and conidia ofΔAoSet1 was significantly lower than that of the WT strain,and the growth rate and pathogenicity were also compromised.Moreover,H3K4 trimethylation was enriched mainly in the promoter of two bZip transcription factor genes(AobZip129 and AobZip350)and ultimately up-regulated the expression level of these two transcription factor genes.In theΔAoSet1 and AoH3K4A strains,the H3^(K4)me modification level was significantly decreased at the promoter of transcription factor genes AobZip129 and AobZip350.These results suggest that AoSET1-mediated H3KEme serves as an epigenetic marker of the promoter region of the targeted transcription factor genes.Furthermore,we found that AobZip129 negatively regulates the formation of adhesive networks and the pathogenicity of downstream AoPABP1 and AoCPR1.Our findings confirm that the epigenetic regulatory mechanism plays a pivotal role in regulating trap formation and pathogenesis in NTFs,and provide novel insights into the mechanisms of interaction between NTFs and nematodes.

Dietary folic acid addition reduces abdominal fat deposition mediated by alterations in gut microbiota and SCFA production in broilers

Intensive selective breeding for high growth rate and body weight cause excess abdominal fat in broilers.Gut microbiota and folic acid were reported to regulate lipid metabolism.A total of 210 one-day-old broilers were divided into the control(folic acid at 1.3 mg/kg)and folic acid groups(folic acid at 13 mg/kg)to illustrate the effects of folic acid on growth performance,abdominal fat deposition,and gut microbiota,and the experiment lasted 28 d.Results revealed that dietary folic acid addition decreased abdominal fat percentage(P<0.05)and down-regulated genes expression related to cell proliferation and differentiation in abdominal fat including IGF1,EGF,C/EBPα,PPARγ,PLIN1,FABP4 and PCNA(P<0.05).Folic acid addition decreased caecal Firmicutes-to-Bacteroidetes ratio(P<0.01)and increased the proportions of Alistipes,Oscillospira,Ruminococcus,Clostridium,Dehalobacterium and Parabacteroides(P<0.05).Caecal acetic acid,and propionic acid contents were found to be higher under folic acid treatment(P<0.05),which were negatively related to genes expression associated with adipocyte proliferation and differentiation(P<0.05).Ruminococcus was positively correlated with caecal acetic acid content,and the same phenomenon was detected between propionic acid and Oscillospira and Ruminococcus(P<0.05).Acetic acid and Oscillospira were identified to be negatively associated with abdominal fat percentage(P<0.05).In conclusion,our data demonstrated that dietary supplementation of folic acid reduced fat deposition in broilers by inhibiting abdominal adipocyte proliferation and differentiation,which might be mediated by changes in gut microbiota and short chain fatty acid production.

植物磷脂酸的特性及其在ABA诱导气孔运动中的作用

磷脂酸(PA)是应答多种生理过程的第二信使,其作为一个脂质信号快速积累从而响应多种环境。PA主要通过磷脂酶D (PLD)和磷脂酶C/甘油二酯激酶(PLC/DGK)途径产生。基于PLDs的生化特性、激活机制以及在不同类型胁迫下被激活的特定同种型的差异,不同类型胁迫下会产生特定分子种组成的PA。PA在多种环境下起信号转导作用,在调节气孔运动中,PA的作用模式主要是通过与多种蛋白结合,激活或抑制这些蛋白的活性,进而执行其信使功能。该文主要综述PA的生化特性以及信号途径中PA互作蛋白的研究进展,并提出PA研究中亟待解决的问题及今后的重点研究方向。

经纵裂-透明隔间腔入路胼胝体切开术前对透明隔腔的MRI评估

目的探讨采用透明隔腔(CSP)的术前MRI分型评估经纵裂-透明隔间腔(CSPV)入路行胼胝体切开术的可行性。方法回顾性描述性研究。纳入上海仁济医院功能神经外科2014年1月—2020年12月耐药性癫痫患者31例,其中男21例、女10例,年龄2~31(15.3±7.3)岁,病程0.5~29(10.0±6.5)年。患者术前均行颅脑常规和/或薄层MR扫描,观察CSP形态并进行影像学分型。均采用经纵裂-CSPV入路行胼胝体切开术,术中对比观察术前MRI不同CSP分型患者手术操作特点及完成情况。结果 (1)31例中,术前MRI观察到CSP者29例,其中间隙型(Ⅱ型)28例、透明隔囊肿(Ⅳ型)1例;另外2例MRI未观察到CSP,为闭合型(Ⅰ型)。(2)29例术前MRI观察到CSP者,术中均探查到达CSP,并顺利分离两侧透明隔小叶:1例Ⅳ型CSP患者切开胼胝体即可到达CSPV,操作最为容易;28例Ⅱ型CSP患者,因CSP体积较小,定位有一定难度,但经仔细辨认均能到达,再向后分离两侧透明隔小叶没有困难。而2例Ⅰ型CSP患者术中未能分离出CSPV,改行经侧脑室入路完成手术。结论通过对CSP的术前MRI观察及影像学分型,可预估术中CSPV的分离难度,进而判断经纵裂-CSPV入路胼胝体切开术的可操作性。术前MRI观察到CSP存在,可以作为选择经纵裂-CSPV入路行胼胝体切开术的一个影像学指标,而Ⅰ型CSP患者不宜采用该入路。

CO_(2)加氢耦合芳胺和硝基芳烃N-烷基化催化剂研究进展

N-烷基芳胺用途广泛,是石油化工、橡胶产业、染料制备、药物研发和精细化学品合成等领域的重要中间体.传统的N-烷基芳胺合成往往存在原料价格较高、反应设备腐蚀和易于造成环境污染等问题.近年来,以储量丰富的温室气体CO_(2)作为C1资源,将CO_(2)加氢与芳胺或硝基芳烃N-烷基化耦合制备N-烷基芳胺的催化剂研究取得显著进展.本文综述了CO_(2)加氢耦合芳胺和硝基芳胺N-烷基化催化剂研究进展,重点介绍CO_(2)加氢与苯胺、甲基苯胺和硝基苯N-烷基化耦合的均相和多相催化剂构效关联、影响因素以及催化反应机理,并对该领域的催化剂研发前景进行了展望.

Symptom network topological features predict the effectiveness of herbal treatment for pediatric cough

Pediatric cough is a heterogeneous condition in terms of symptoms and the underlying disease mechanisms.Symptom phenotypes hold complicated interactions between each other to form an intricate network structure.This study aims to investigate whether the network structure of pediatric cough symptoms is associated with the prognosis and outcome of patients.A total of 384 cases were derived from the electronic medical records of a highly experienced traditional Chinese medicine (TCM) physician.The data were divided into two groups according to the therapeutic effect,namely,an invalid group (group A with 40 cases of poor efficacy) and a valid group (group B with 344 cases of good efficacy).Several well-established analysis methods,namely,statistical test,correlation analysis,and complex network analysis,were used to analyze the data.This study reports that symptom networks of patients with pediatric cough are related to the effectiveness of treatment: a dense network of symptoms is associated with great difficulty in treatment.Interventions with the most different symptoms in the symptom network may have improved therapeutic effects.