新建隧道近接既有隧道爆破施工减振措施研究

隧道爆破施工容易造成邻近建筑物的振动破坏,爆破所引起的振动速度和位移需要严格控制在安全规程允许范围内。以毕浦隧道爆破施工为背景,结合数值模拟和现场监测,提出了在隧道施工过程中采用两种方法进行减振,并进行了研究。研究结果表明:微差爆破的减振率为22.553%,设置单排、双排和三排减振孔平均减振率分别为20.955%,41.212%和61.157%,减振效果更明显,均可达到规范要求。

Bio-inspired synthesis of nanomaterials and smart structures for electrochemical energy storage and conversion

Traditional synthetic methodologies are confronted with great challenges to fabricate complex nanomaterials with delicate design,high efficiency and excellent sustainability.During the past decade,bio-inspired synthesis has been extensively applied as an effective and efficient strategy for the fabrication of nanomaterials and nanostructures.Mimicking electrode materials at nanoscale in the aspect of either structure or functionality has been receiving surging interest because of their incomparable advantages and outperforming properties.In this review,we summarize the recent progresses on bio-inspired synthesis of nanomaterials and smart structures in the field of energy storage and conversion.Firstly,an overall introduction of bio-inspired synthetic strategies will be presented,with focus on the biotemplates and bio-resources.Following that,a library of complex mimicking structures featured by high-order,hierarchical porosity,or bionic function are introduced,with discussion on their chemical and physical properties associated with the structure.The enhanced electrochemical properties such as energy density,cycling stability,etc.in different electrochemical systems will be also discussed.At last,we will expand the perspectives regarding the advantages and limitations of bioinspired strategy and possible solutions in the future.

Catholyte engineering to release the capacity of iodide for high-energy-density iodine-based redox flow batteries

Due to the high solubility,high reversibility,and low cost of iodide,iodine-based redox flow batteries(RFBs)are considered to have great potential for upscaling energy storage.However,their further development has been limited by the low capacity of I−as one-third of the I−is used to form I3−(I2I−)during the charging process.Herein,we have demonstrated that the pseudohalide ion,thiocyanate(SCN−),is a promising complexing agent for catholyte of iodinebased RFBs to free up the I−by forming iodine-thiocyanate ions([I2SCN]−)instead of I3−,unlocking the capacity of iodide.Applying this strategy,we have demonstrated iodine-based RFBs with full utilization of iodide to achieve high capacity and high energy density.Both the zinc/iodine RFB and polysulfide/iodine RFB with SCN−complex agent achieve their theoretical capacity of around 160 A h Lposolyte^(−1)(6.0MI−in catholyte).Therefore,the zinc/iodine RFB delivers a high energy density of 221.34Wh Lposolyte^(−1),and the polysulfide/iodine RFB achieves a highenergy density of 165.62Wh Lposolyte^(−1).It is believed that this effective catholyte engineering can be further generalized to other iodine-based RFBs,offering new opportunities to unlock the capacity of iodide and achieve high energy density for energy storage.

Involvement and therapeutic implications of airway epithelial barrier dysfunction in type 2 inflammation of asthma

Type 2 inflammation is a complex immune response and primary mechanism for several common allergic diseases including allergic rhinitis,allergic asthma,atopic dermatitis,and chronic rhinosinusitis with nasal polyps.It is the predominant type of immune response against helminths to prevent their tissue infiltration and induce their expulsion.Recent studies suggest that epithelial barrier dysfunction contributes to the development of type 2 inflammation in asthma,which may partly explain the increasing prevalence of asthma in China and around the globe.The epithelial barrier hypothesis has recently been proposed and has received great interest from the scientific community.The development of leaky epithelial barriers leads to microbial dysbiosis and the translocation of bacteria to inter-and sub-epithelial areas and the development of epithelial tissue inflammation.Accordingly,preventing the impairment and promoting the restoration of a deteriorated airway epithelial barrier represents a promising strategy for the treatment of asthma.This review introduces the interaction between type 2 inflammation and the airway epithelial barrier in asthma,the structure and molecular composition of the airway epithelial barrier,and the assessment of epithelial barrier integrity.The role of airway epithelial barrier disruption in the pathogenesis of asthma will be discussed.In addition,the possible mechanisms underlying the airway epithelial barrier dysfunction induced by allergens and environmental pollutants,and current treatments to restore the airway epithelial barrier are reviewed.

Large scale preparation of 20 cm×20 cm graphene modified carbon felt for high performance vanadium redox flow battery

Vanadium redox flow batteries(VRFBs)are widely applied in energy storage systems(e.g.,wind energy,solar energy),while the poor activity of commonly used carbon-based electrode limits their large-scale application.In this study,the graphene modified carbon felt(G/CF)with a large area of 20 cm×20 cm has been successfully prepared by a chemical vapor deposition(CVD)strategy,achieving outstanding electrocatalytic redox reversibility of the VRFBs.The decorating graphene can provide abundant active sites for the vanadium redox reactions.Compared with the pristine carbon felt(CF)electrode,the G/CF composite electrode possesses more defective sites on surface,which enhances activity toward VO^(2+)/VO^(2+)couple and electrochemical performances.For instance,such G/CF electrode delivered remarkable voltage efficiency(VE)of 88.4%and energy efficiency(EE)of 86.4%at 100 mA·cm^(-2),much higher than CF electrode by 2.1%and 3.78%,respectively.The long-term cycling stability of G/CF electrode was further investigated and a high retention value of 47.6%can be achieved over 600 cycles.It is demonstrated that this work develops a promising and effective strategy to synthesize the large size of carbon electrode with high performances for the next-generation VRFBs.

A Lipid Droplet-Associated GFP Reporter-Based Screen Identifies New Fat Storage Regulators in C.elegans

Fat storage disorders including obesity are pandemic human health problems. As a genetically amenable model organism, Caeno- rhabditis elegans has often been used to explore the molecular mechanisms of fat storage regulation. Dye staining of fixed animals and stimulated Raman scattering （SRS） microscopy methods have been used successfully to study fat storage, but a genetic screening system that takes full advantage of C. elegans transparency to perform live imaging of fluorescent protein reporters has not yet been reported. Here, we investigated the tissue-specific expression of the GFP fusion of Perilipin 1 （PLIN1）, a Drosophila lipid droplet-associated protein, in C. elegans. Our results indicate that PLINI：：GFP labels lipid droplets and can be used as a fat storage indicator in live worms. Through an RNAi screen, we further identified several previously uncharacterized new fat storage regulators.

小鼠CDP-二酰基甘油合成酶-2(Cds2)肝脏特异性敲除导致线粒体功能受损并快速发展为非酒精性肝炎及肝纤维化

非酒精性脂肪性肝病(NAFLD)包括单纯脂肪浸润和非酒精性脂肪性肝炎(NASH),继续发展可导致更为严重的肝纤维化、肝硬化和肝癌等.诱导肝脏从单纯脂肪浸润发展成NASH的机制还不是特别清楚.本研究构建了肝脏特异敲除CDP-二酰基甘油合成酶-2(Cds2)小鼠,并发现该小鼠快速产生肝脏脂肪大量储积、肝炎和肝纤维化等一系列肝脏病变.CDS2定位在线粒体相关内质网膜(MAM)上,敲除Cds2会导致线粒体功能受损和线粒体磷脂酰乙醇胺含量下降.肝脏过表达线粒体磷脂酰乙醇胺合成酶(Pisd)会增加线粒体磷脂酰乙醇胺含量,并减轻肝脏Cds2敲除小鼠肝损伤的表型.另外,过表达Cds2可以抵抗高脂喂食诱导的脂肪肝和肥胖.本研究揭示了小鼠肝脏Cds2生理功能,即Cds2可以调节线粒体磷脂含量和线粒体功能并继而影响NASH的快速发生.

Cost-Effective Membrane and Advanced Electrode for Stable Polysulfide-Ferricyanide Flow Battery

Based on inexpensive,safe,and environmentally friendly active redox species,neutral polysulfide-ferrocyanide redox flow batteries(PFRFBs)have attracted much attention for large-scale energy storage.However,the development of PFRFBs is undermined by the expensive commercial membrane materials as well as the sluggish polysulfide redox reactions.This work attempts to solve these critical problems by combining the economical membrane with the highly catalytic electrode.In specific,K^(+)-exchanged sulfonated polyether ether ketone(SPEEK-K)membranes have been investigated in PFRFBs to replace the costly Nafion membrane.SPEEK-K with optimized degree of sulfonation enables the PFRFB high average coulombic efficiency of 99.80%and superior energy efficiency of 90.42%at a current density of 20mAcm^(-2).Meanwhile,to overcome the kinetic limitations of polysulfide redox reactions,a CuS-modified carbon felt electrode is demonstrated with excellent catalytic performance,enabling the PFRFB higher and more stable energy efficiency over cycling.The combination of the cost-effective membrane with the catalytic electrode in one cell leads to a capacity retention of 99.54%after 1180 cycles and an outstanding power density(up to 223mWcm^(-2)).The significant enhancements of electrochemical performance at reduced capital cost will make the PFRFB more promising for large-scale energy storage systems.

Reduced phosphatidylcholine synthesis suppresses the embryonic lethality of seipin deficiency

Seipin plays a vital role in lipid droplet homeostasis,and its deficiency causes congenital generalized lipodystrophy type II in humans.It is not known whether the physiological defects are all caused by cellular lipid droplet defects.Loss-of-function mutation of seip-1,the Caenorhabditis elegans seipin ortholog,causes embryonic lethality and lipid droplet abnormality.We uncover nhr-114 and spin-4 as two suppressors of seip-1 embryonic lethality.Mechanistically,nhr-114 and spin-4 act in the“B12-one-carbon cycle-phosphatidylcholine(PC)”axis,and reducing PC synthesis suppresses the embryonic lethality of seip-1 mutants.Conversely,PC deficiency enhances the lipid droplet abnormality of seip-1 mutants.The suppression of seip-1 embryonic lethality by PC reduction requires polyunsaturated fatty acid.In addition,the suppression is enhanced by the knockdown of phospholipid scramblase epg-3.Therefore,seipin and PC exhibit opposite actions in embryogenesis,while they function similarly in lipid droplet homeostasis.Our results demonstrate that seipin-mediated embryogenesis is independent of lipid droplet homeostasis.