Experimental and Numerical Studies of Multi-compartment Spreading Fire in a Full-Scale Steel Framed Building

Fire Technology - Fire dynamic characteristics in multi-compartments are still not very clear. This paper presents a spreading fire test in a full-scale two-storey steel framed building to...     

镍基高温合金GH202高温氧化后的微观组织演变

研究了镍基高温合金GH202在800~1100 ℃高温氧化后晶粒、碳化物和强化相的演变过程。采用透射电子显微镜、扫描电子显微镜和电子背散射衍射对其微观结构进行了表征。结果表明：镍基高温合金的硬度随氧化温度的升高而降低，1100 ℃氧化100 h后，硬度降低了43.5%。800和900 ℃氧化后晶粒生长速度较慢，而经900 ℃氧化后晶界碳化物析出显著增加。在1000和1100 ℃氧化后，晶粒尺寸明显增大。氧化过程中晶界迁移是由晶界两侧自由能差决定，温度越高，晶界向曲率中心迁移越快，大量细小晶粒被吞并形成了大晶粒。大块状碳化物（MC）分解成大量的碳原子，与Cr原子结合形成少量的富Cr颗粒状M₂₃C₆。在900 ℃氧化150 h后，M₂₃C₆演化为富Ti的M₆C。随着氧化温度的升高，碳化物在γ相中回熔。在800、900和1000 ℃氧化后，γ′相逐渐长大，在1100 ℃氧化100 h后，完全溶解于γ相。     

High-Performance All-Solid-State Supercapacitor Electrode Materials Using Freestanding Electrospun Carbon Nanofiber Mats of Polyacrylonitrile and Novolac Blends

Herein, this paper reports a facile method to prepare electrospun carbon nanofiber mats (ECNFMs) with high specific surface area and interconnected structure using polyacrylonitrile (PAN) as a precursor and novolac resin (NOC) as a polymer sacrificial pore-making agent. Without additional treatment, the prepared ECNFMs have a highly porous structure because NOC decomposes in a wider temperature range than most polymer activators. The NOC content in the PAN nanofibers shows important effects on porosity. The BET specific surface area of ECNFMs reaches a maximum of 1468 m² g⁻¹ when the precursor nanofibers contained 30 wt% NOC (ECNFM-3) after carbonization at 1000 °C. The supercapacitor device from ECNFM-3 electrode and all-solid-state electrolyte shows excellent cycling durability and high specific capacitance: ≈99.72% capacitance retention after 10 000 charge/discharge cycles and ≈320 mF cm⁻² at 0.25 mA cm⁻². Furthermore, it shows a large energy density of ≈11.1 $\mu$Wh cm⁻² under the power density of 500 mW m⁻². Activation of carbon nanofibers simply by the addition of NOC into precursor nanofibers can offer a handy way to prepare ECNFMs for high-performance all-solid-state supercapacitors and other potential applications.     

A techno-economic review of biomass gasification for production of chemicals

Gasification is a thermochemical process which can be used as a low-emission and highly efficient method to produce syngas and chemicals such as biomethanol and dimethyl ether (DME). In this paper, a review of technologies and methods for economic production of chemicals through gasification of biomass and other fuels has been carried out. A variety of techno-economic studies and analysis have been proposed in order to better understand the technical and economic assessments during the biomass gasification. Results showed that the methanol production cost for biomass (wood) is from 195 to 935 €/t, for waste residues is from 200 to 930 €/t, for coal is from 160 to 480 €/t, and for natural gas is from 90 to 290 €/t. It also concluded that fuel (wood) cost has positive linear relationship with ethanol production cost, meaning as the feedstock cost increases from 30 to 50 $/day-ton, the ethanol production cost enhances from 1.66 to 1.95 $/gal.     

负径向电场对带电粒子俘获率影响的数值模拟

本文采用数值方法求解Grad-Shafranov方程反演EAST典型长脉冲放电实验(炮号33068)的平衡位形和磁场分布，进而结合粒子在托卡马克电磁场中的运动方程，模拟氘离子在负径向电场存在时的运动轨迹，并统计不同负径向电场下的氘离子俘获率。结果表明：随负径向电场的增大，氘离子轨迹由扩张通行轨迹向外翻香蕉轨迹再向内翻香蕉轨迹，最后向压缩通行轨迹演变；氘离子俘获率随负径向电场的增大而减小，氘离子初始速度越小，其变化越大。     

Interaction of IL-22/IL-22R1 promotes cell proliferation and suppresses apoptosis of colorectal cancer via phosphorylation of STAT3

Interleukin-22 (IL-22) is a member of IL-10 cytokine family which is expressed in activated T cells predominantly and in activated natural killer cells at lower levels. Previous studies have demonstrated the link between elevated levels of IL-22 and disease severity of psoriasis, Crohn’s disease, rheumatoid arthritis and interstitial lung diseases. However, the function of IL-22 in the development and progression of colorectal cancer (CRC) remains elusive. In this study, we first evaluated the IL-22/IL-22R1 level in CRC patients, and found that tumor tissues have more active expression of IL-22 and IL-22R1 than normal tissues, presenting correlation with the degree of differentiation of tumor tissues. Subsequently, Caspase and cell viability assays were performed on SW-480 cell line which expresses high level of IL-22R1 to examine if the supplementation of IL-22 has an impact on apoptosis and proliferation. In comparison with treatment of 5-FU, supplementation of IL-22 promoted cell proliferation and ameliorated apoptosis. To unveil signal transduction upon activation of IL-22R, we examined the phosphorylation of STAT3 in SW-480 cell line following supplementation of IL-22. The treatment of IL-22 also increased the level of p-Akt, an essential component in PI3K/Akt pathway. Although the link between STAT3 phosphorylation and PI3K/ Akt activation remains to be explored, our study revealed the mechanism underlying the effects of IL-22R activation on apoptosis as well as tumor differentiation, indicating the prognostic value of IL-22/IL-22R.     

Carborane and cyanine conjugated galactose targeted amphiphilic copolymers for potential near infrared imaging-guided boron neutron capture therapy (BNCT)

Near infrared fluorescent galactose targeted glycopolymer containing m-carborane has been synthesized through ring open and atom transfer radical polymerization, followed by post-functionalization with a cyanine NIR dye. The copolymer could self-assemble into micelles which work as a potential agent for imaging-guided boron neutron capture therapy. The NIR micelles revealed no cytotoxicity for HepG2 cells. An enhanced and fast endocytosis due to the specific interaction between the HepG2 cells and the glycopolymer could be traced by fluorescence microscopy, and the bioimaging makes it possible to trace the nanoparticles and provides information where and when the neutron irradiation should be triggered.     

Hemodynamic Forces Regulate Cardiac Regeneration-Responsive Enhancer Activity during Ventricle Regeneration

Cardiac regenerative capacity varies widely among vertebrates. Zebrafish can robustly regenerate injured hearts and are excellent models to study the mechanisms of heart regeneration. Recent studies have shown that enhancers are able to respond to injury and regulate the regeneration process. However, the mechanisms to activate these regeneration-responsive enhancers (RREs) remain poorly understood. Here, we utilized transient and transgenic analysis combined with a larval zebrafish ventricle ablation model to explore the activation and regulation of a representative RRE. lepb-linked enhancer sequence (LEN) directed enhanced green fluorescent protein (EGFP) expression in response to larval ventricle regeneration and such activation was attenuated by hemodynamic force alteration and mechanosensation pathway modulation. Further analysis revealed that Notch signaling influenced the endocardial LEN activity as well as endogenous lepb expression. Altogether, our work has established zebrafish models for rapid characterization of cardiac RREs in vivo and provides novel insights on the regulation of LEN by hemodynamic forces and other signaling pathways during heart regeneration.     

同步硝化反硝化脱氮的关键因素探讨

结合近年来国内外的研究成果,主要讨论了三个关键因子对同步硝化反硝化(SND)脱氮的影响,并为影响SND的研究提出今后的方向。