Ladder Time Stepwise Inertia Coordinated Control Method of Multiple Wind Farms to Suppress System Frequency Secondary Drop

Currently,both regulated and deregulated power trading exist in China’s power system,which has caused imbalanced funds in the electricity market.In this paper,a simulation analysis of the electricity market with wind energy resources is conducted,and the calculation methods of unbalanced funds are investigated systematically.In detail,the calculation formulas of unbalanced funds are illustrated based on their definition,and a two-track electricity market clearing model is established.Firstly,the concept of the dual-track system is explained,and the specific calculation formulas of various types of unbalanced funds are provided.Next,considering the renewable energy consumption,the market clearing model based on DC power flow is constructed and solved;by combining fitting methods of mid-and long-term curves,the unbalanced funds are calculated based on clearing results and formulas.

PpTCP18 is upregulated by lncRNA5 and controls branch number in peach (Prunus persica) through positive feedback regulation of strigolactone biosynthesis

Branch number is an important agronomic trait in peach(Prunus persica)trees because plant architecture affects fruit yield and quality.Although breeders can select varieties with different tree architecture,the biological mechanisms underlying architecture remain largely unclear.In this study,a pillar peach(‘Zhaoshouhong’)and a standard peach(‘Okubo’)were compared.‘Zhaoshouhong’was found to have significantly fewer secondary branches than‘Okubo’.Treatment with the synthetic strigolactone(SL)GR24 decreased branch number.Transcriptome analysis indicated that PpTCP18(a homologous gene of Arabidopsis thaliana BRC1)expression was negatively correlated with strigolactone synthesis gene expression,indicating that PpTCP18 may play an important role in peach branching.Yeast one-hybrid,electrophoretic mobility shift,dual-luciferase assays and PpTCP18-knockdown in peach leaf buds indicated that PpTCP18 could increase expression of PpLBO1,PpMAX1,and PpMAX4.Furthermore,transgenic Arabidopsis plants overexpressing PpTCP18 clearly exhibited reduced primary rosette-leaf branches.Moreover,lncRNA sequencing and transient expression analysis revealed that lncRNA5 targeted PpTCP18,significantly increasing PpTCP18 expression.These results provide insights into the mRNA and lncRNA network in the peach SL signaling pathway and indicate that PpTCP18,a transcription factor downstream of SL signaling,is involved in positive feedback regulation of SL biosynthesis.This role of PpTCP18 may represent a novel mechanism in peach branching regulation.Our study improves current understanding of the mechanisms underlying peach branching and provides theoretical support for genetic improvement of peach tree architecture.

苯并噁嗪树脂改性研究进展

苯并噁嗪树脂(PBZ)是一类杂环单体热开环聚合材料,具有优异的热稳定性、高的拉伸强度和良好的耐化学性,在航空复合材料、共混物和电子电路板等许多领域得到应用。文中概述了不同结构苯并噁嗪单体的研究进展,详细论述了苯并噁嗪树脂改性的研究现状,对苯并噁嗪共聚物、苯并噁嗪-聚合物合金、苯并噁嗪纳米复合材料、纤维-苯并噁嗪复合材料等方面进行了总结。指出了PBZ树脂存在加工温度高,经典的PBZ脆性大的缺点以及产生的原因,最后对苯并噁嗪树脂的研究方向进行了展望。

Combination of iTRAQ proteomics and RNA-seq transcriptomics reveals multiple levels of regulation in phytoplasma-infected Ziziphus jujuba Mill

Jujube witches’broom(JWB)is caused by infection with a phytoplasma.A multi-omics approach was taken during graft infection of jujube by JWB-infected scion through the analysis of the plant transcriptome,proteome and phytohormone levels.A high number of differentially expressed genes(DEGs)were identified 37 weeks after grafting(WAG),followed by observation of typical symptoms of JWB at 48 WAG.At 37 WAG,the majority of the upregulated DEGs and differentially expressed proteins(DEPs)were related to flavonoid biosynthesis,phenylalanine metabolism and phenylpropanoid biosynthesis.Two of the four upregulated proteins were similar to jasmonate-induced protein-like.Among the downregulated genes,the two most populated GO terms were plant–pathogen interaction and plant hormone signal transduction(mainly for tryptophan metabolism).Moreover,phytoplasma infection resulted in reduced auxin content and increased jasmonate content,indicating that auxin and jasmonic acid have important roles in regulating jujube responses during the first and second stages of phytoplasma infection.At 48 WAG,the two largest groups of upregulated genes were involved in phenylpropanoid biosynthesis and flavonoid biosynthesis.Both genes and proteins involved in carbon metabolism and carbon fixation in photosynthetic organisms were downregulated,indicating that photosynthesis was affected by the third stage of phytoplasma infection.

Overexpression of peach NAC25 promotes anthocyanin biosynthesis in poplar shoots

Anthocyanins,a categories of metabolites derived from flavonoid biosynthesis pathway,are responsible for the red color of peach.Anthocyanin metabolism is modulated by a complicated regulatory network.In this study,our results demonstrated that PpNAC25 was a component of anthocyanin regulatory network in peach.PpNAC25 showed a closed relationship with the well-known ripening-related gene NOR(no-ripening)and was highly expressed in peach fruit.Overexpression of PpNAC25 in poplar resulted in a redder shoot tips compared with EV control.PpNAC25 overexpression upregulated the anthocyanin biosynthetic and transportation genes in transcript levels and then increased anthocyanin contents.In Y1H and Luc/Ren assay,PpNAC25 bound to the promoter of the anthocyanin-activator PpMYB10.1 and PpMYB10.2 and activated its transcript.Moreover,PpNAC25 formed a heterodimer with PpNAC1,an anthocyanin-regulator.Our researches provide evidence that PpNAC25 may be a positive regulator of anthocyanin biosynthesis in peach fruit.

Hybrid hydrovoltaic electricity generation driven by water evaporation

Water evaporation is a ubiquitous natural process exploiting thermal energy from ambient environment.Hydrovoltaic technologies emerged in recent years offer one prospective route to generate electricity from water evaporation,which has long been overlooked.Herein,we developed a hybrid hydrovoltaic generator driven by natural water evaporation,integrating an“evaporation motor”with an evaporation-electricity device and a droplet-electricity device.A rotary motion of the“evaporation motor”relies on phase change of ethanol driven by water-evaporation induced temperature gradient.This motion enables the evaporation-electricity device to work under a beneficial water-film operation mode to produce output of~4 V and~0.2μA,as well as propels the droplet-electricity device to convert mechanical energy into pulsed output of~100 V and~0.2 mA.As different types of hydrovoltaic devices require distinctive stimuli,it was challenging to make them work simultaneously,especially under one single driving force.We here for the first time empower two types of hydrovoltaic devices solely by omnipresent water evaporation.Therefore,this work presents a new pathway to exploiting water evaporation-associated ambient thermal energy and provides insights on developing hybrid hydrovoltaic generators.

Osteogenic and antibacterial dual functions of a novel levofloxacin loaded mesoporous silica microspheres/nano-hydroxyapatite/ polyurethane composite scaffold

Lev/MSNs/n-HA/PU has been proved to be a novel scaffold material to treat bone defect caused by chronic osteomyelitis.We have previously identified that this material can effectively treat chronic osteomyelitis caused by Staphylococcus aureus in vivo.However,the potential mechanisms of antibacterial and osteogenic induction properties remain unclear.Thus,for osteogenesis property,immunohistochemistry,PCR,and Western blot were performed to detect the expression of osteogenic markers.Furthermore,flow cytometry and TUNEL were applied to analyze MC3T3-E1 proliferation and apoptosis.For antibacterial property,the material was co-cultivated with bacteria,bacterial colony forming units was counted and the release time of the effective levofloxacin was assayed by agar disc-diffusion test.Moreover,scanning electron microscope was applied to observe adhesion of bacteria.In terms of osteogenic induction,we found BMSCs adherently grew more prominently on Lev/MSNs/n-HA/PU.Lev/MSNs/n-HA/PU also enhanced the expression of osteogenic markers including OCN and COL1a1,as well as effectively promoted the transition from G1 phase to G2 phase.Furthermore,Lev/MSNs/n-HA/PU could reduce apoptosis of MC3T3-E1.Besides,both Lev/MSNs/n-HA/PU and n-HA/PU materials could inhibit bacterial colonies,while Lev/MSNs/n-HA/PU possessed a stronger antibacterial activities,and lower bacterial adhesion than n-HA/PU.These results illustrated that Lev/MSNs/n-HA/PU composite scaffold possess favorable compatibility in vitro,which induce osteogenic differentiation of MSCs,promote proliferation and differentiation of MC3T3-E1,and inhibit apoptosis.Moreover,clear in vitro antibacterial effect of Lev/MSNs/n-HA/PU was also observed.In summary,this study replenishes the potential of Lev/MSNs/n-HA/PU composite scaffold possess dual functions of anti-infection and enhanced osteogenesis for future clinical application.

The diameter factor of aligned membranes facilitates wound healing by promoting epithelialization in an immune way

Topographical properties,such as pattern and diameter,of biomaterials play important roles in influencing cell activities and manipulating the related immune response during wound healing.We prepared aligned electrospinning membranes with different fiber diameters,including 319±100 nm(A300),588±132 nm(A600),and 1048±130 nm(A1000),by adjusting the distance from the tip to the collector,the injection rate,and the concentration of the solution.The A300 membranes significantly improved cell proliferation and spreading and facilitated wound healing(epithelization and vascularization)with the regeneration of immature hair follicles compared to the other membranes.Transcriptomics revealed the underlying molecular mechanism that A300 could promote immune-related processes towards a pro-healing direction,significantly promoting keratinocyte migration and skin wound healing.All the results indicated that wound healing requires the active participation of the immune process,and that A300 was a potential candidate for guided skin regeneration applications.

A baicalin-loaded coaxial nanofiber scaffold regulated inflammation and osteoclast differentiation for vascularized bone regeneration

We demonstrate a simple,effective and feasible method to address the shrinkage of Poly(lactic-co-glycolic acid)(PLGA)through a core-shell structure fiber strategy.The results revealed that introducing size-stable poly-caprolactone(PCL)as the core fiber significantly improved the PLGA-based fibrous scaffold’s dimensional maintenance.We further utilized fish collagen to modify the PLGA shell layer(PFC)of coaxial fibers and loaded baicalin(BA)into the PCL core layer(PCL-BA)to endow fibrous scaffold with more functional biological cues.The PFC/PCL-BA fibrous scaffold promoted the osteogenic differentiation of bone mesenchymal stem cells and stimulated the RAW264.7 cells to polarize into a pro-reparative phenotype.Importantly,the in vivo study demonstrated that the PFC/PCL-BA scaffold could regulate inflammation and osteoclast differentiation,favor neovascularization and bone formation.This work tactfully combined PLGA and PCL to establish a drug release platform based on the core-shell fibrous scaffold for vascularized bone regeneration.

一种提升六方氮化硼抗氧化性的洁净干转移方法

六方氮化硼(h-BN)是一种具有出色热稳定性和化学惰性的二维材料,在苛刻条件下应用广泛.然而,表面金属催化剂会使其抗氧化性显著降低.对于通过化学气相沉积制备的样品,常规通过湿法蚀刻金属基底的转移方法不可避免地会引入金属残留.我们这里提出了一种针对铜表面生长的单层h-BN薄膜的洁净干转移方法.空气环境下界面氧插层和表面铜氧化导致界面粘附能量显著降低,因而h-BN薄膜可以从基底上被直接机械剥离开.与湿法转移制备的薄膜形成鲜明对比,干法转移得到的h-BN薄膜几乎没有金属(铁)污染,使其抗氧化性提高了50–100℃,甚至接近其本征性能.在干法转移的单层h-BN薄膜保护下,单层石墨烯在空气中的耐受温度提高到700℃,展示了这一干转移方法的优势.

Electrospinning/3D printing-integrated porous scaffold guides oral tissue regeneration in beagles

The combined use of guided tissue/bone regeneration(GTR/GBR)membranes and bone filling grafts represents a classical therapy for guiding the regeneration and functional reconstruction of oral soft and hard tissues.Nevertheless,due to its displacement and poor mechanical support,bone meal is not suitable for implantation in the case of insufficient cortical bone support and large dimensional defects.The combination of GTR/GBR membrane with a three-dimensional(3D)porous scaffold may offer a resolution for the repair and functional reconstruction of large soft and hard tissue defects.In this study,a novel integrated gradient biodegradable porous scaffold was prepared by bonding a poly(lactic-co-glycolic acid)(PLGA)/fish collagen(FC)electrospun membrane(PFC)to a 3D-printed PLGA/nano-hydroxyapatite(HA)(PHA)scaffold.The consistency of the composition(PLGA)ensured strong interfacial bonding between the upper fibrous membrane and the lower 3D scaffold.In vitro cell experiments showed that the PFC membrane(upper layer)effectively prevented the unwanted migration of L929 cells.Further in vivo investigations with an oral soft and hard tissue defect model in beagles revealed that the integrated scaffold effectively guided the regeneration of defective oral tissues.These results suggest that the designed integrated scaffold has great potential for guiding the regeneration and reconstruction of large oral soft and hard tissues.

Construction and Properties of Simvastatin and Calcium Phosphate Dual-Loaded Coaxial Fibrous Membranes with Osteogenic and Angiogenic Functions

The ideal Guided Bone Regeneration(GBR)membrane is required to have good biocompatibility,space maintenance ability,appropriate degradation rate,and preferably can guide the regeneration of vascularized bone tissue.In this study,Simvastatin(SIM)and calcium Phosphate(CaP)were encapsulated in a Polycaprolactone(PCL)/Chitosan(CS)core-shell structural fibrous membranes via coaxial electrospinning technology.The results showed that loaded SIM in the core of the core-shell structure fibrous membranes could sustainably release the drug for more than two months and upregulate the angiogenic marker of Bone Mesenchymal Stem Cells(BMSCs).Adding a certain amount of CaP to the shell layer provided more sites for the mineralization and synergistic with SIM to promote osteogenic differentiation of BMSCs in vitro.The intramuscular implantation experiments in rabbits suggested a normal early inflammation and enhanced vascularization induced by the SIM-loaded fibrous membranes.This study proposed an effective strategy to prepare a dual-loaded core-shell fibrous membrane for guided vascularized bone tissue regeneration.

Portable and flexible water-evaporation-generator based on hydrogel

Electricity from clean and renewable resources is a promising solution to address the growing energy crisis.Water,an abundant and widely distributed substance on the planet,contains tremendous energy[1,2].Recently,it was demonstrated that electricity can be generated directly through the interaction between water and nanostructured materials,termed as the hydrovoltaic effect[3],facilitating energy harvesting from water.In particular,it was found that the natural evaporation of water can sustainably generate an electric voltage of up to 1 V across a carbon black film[4].

Oxygen-suppressed selective growth of monolayer hexagonal boron nitride on copper twin crystals

Controlled growth of hexagonal boron nitride （h-BN） with desired properties is essential for its wide range of applications. Here, we systematically carried out the chemical vapor deposition of monolayer h-BN on Cu twin crystals. It was found that h-BN nucleated and grew preferentially and simultaneously on the narrow twin crystal strips present in the Cu substrates. The density functional theory calculations revealed that the introduction of oxygen could effidently ~ne the selectivity. This is because of the reduction in the dehydrogenation barrier of the precursor molecules by the introduction of oxygen. Our findings throw light on the direct growth of functional h-BN nanoribbons on nano-twinned crystal strips and switching of the growth behavior of h-BN films by oxygen.