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寒区隧道围岩-喷层界面增黏与抗冻试验研究

岩石力学与工程学报 2024年第6期43卷 1383-1396页

作者：刘慧徐海南任建喜申艳军贾海梁奚家米唐丽云郁金捷魏尧西安科技大学建筑与土木工程学院陕西西安710054 长安大学地质工程与测绘学院陕西西安710054 长安大学黄土科学全国重点实验室陕西西安710054 中交第一公路勘察设计研究院有限公司高寒高海拔地区道路工程安全与健康国家重点实验室陕西西安710065

寒区隧道普遍受到冻融作用影响,易发生沿着混凝土衬砌结构与围岩界面损伤与脱黏现象,严重影响隧道工程施工质量与安全运营。为提升隧道围岩-喷层界面黏结强度与抗冻性能,将围岩-喷层界面简化为岩石-混凝土二元体,研制适用于提升围岩-喷... 详细信息

寒区隧道普遍受到冻融作用影响,易发生沿着混凝土衬砌结构与围岩界面损伤与脱黏现象,严重影响隧道工程施工质量与安全运营。为提升隧道围岩-喷层界面黏结强度与抗冻性能,将围岩-喷层界面简化为岩石-混凝土二元体,研制适用于提升围岩-喷层界面黏结性与抗冻性的水泥基界面剂,并开展水泥基界面剂喷涂前后的砂岩-混凝土界面黏结强度及抗冻性能对比试验。试验结果表明:(1)冻融作用产生的岩石-混凝土界面中与硅氧四面体平行的主链破裂,是导致岩石-混凝土界面黏结性能降低的核心原因;(2)通过试验适配研制,提出适用于提升寒区隧道喷层界面黏结性与抗冻性的水泥基界面剂最优配合比为∶水泥∶水∶硅微粉∶硅烷偶联剂∶高分子胶凝材料(水性丙烯酸酯腹膜胶+竹材液化酚醛树脂)=10∶4.4∶0.8∶0.2∶1∶0.5;(3)因水泥基界面剂的高分子水化作用,喷层界面产生的“树根桩”效应扩大了岩石与混凝土接触面的栓堵程度,同时,硅烷偶联剂的化学键合作用提升了界面间的机械咬合力,二者耦合增强作用提高岩石-混凝土界面的黏结剪切强度和劈裂强度。通过对比试验发现,在冻融30次后,采用水泥基界面剂处理后,岩石-混凝土界面剪切强度较未处理试样可提升109%,黏结劈裂强度则提升了78%;(4)水泥基界面剂中硅氧烷水解缩合作用产生的硅氧键吸附在岩石-混凝土界面形成的疏水层,抑制了界面富水区扩展;而联合反应生成的硅凝胶发生相变释放热量,减少了岩石-混凝土界面冻融损伤,可抑制岩石-混凝土界面裂纹萌生与扩展。(5)研制的水泥基界面剂本身具有良好的抗冻性,特别是在-10℃~10℃的冻融环境中可高效发挥提升围岩-喷层界面黏结性及抗冻性的功能。研究为寒区隧道围岩-喷层界面增黏与抗冻处理提供了一种新的解决方案。

关键词：隧道工程岩石-混凝土水泥基界面剂冻融循环黏结强度抗冻性

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330 MW循环流化床锅炉深度调峰技术

发电技术 2024年第2期45卷 199-206页

作者：张思海李超然万广亮刘印学徐海楠黄中杨海瑞国能宁东第一发电有限公司宁夏回族自治区银川市750408 电力系统及发电设备控制和仿真国家重点实验室(清华大学能源与动力工程系) 北京市海淀区100084

为推进“双碳”政策的实施,消纳波动性较强的新能源并网发电,当前对火电机组的深度调峰要求越来越高。循环流化床(circulating fluidized bed,CFB)锅炉机组在深度调峰低负荷运行工况有着先天优势,但实现20%以下的超低负荷运行依然面临... 详细信息

为推进“双碳”政策的实施,消纳波动性较强的新能源并网发电,当前对火电机组的深度调峰要求越来越高。循环流化床(circulating fluidized bed,CFB)锅炉机组在深度调峰低负荷运行工况有着先天优势,但实现20%以下的超低负荷运行依然面临众多的困难,如炉内流化的稳定性、氮氧化物的排放及炉内局部超温带来的安全性等问题。以某330 MW CFB锅炉的深度调峰技术应用为例,介绍了输煤筛分破碎系统、风帽节流圈、下二次风管等机组部件的改造,并配合烟气再循环等技术应用,成功实现了18%的超低负荷深度调峰运行,同时也很好地控制了NOx的排放。最后总结了CFB机组超低负荷深度调峰技术的关键点和难点,对深度调峰运行带来的潜在问题进行了分析,并提出了相应的解决措施。研究结果具有重要的工程借鉴作用。

关键词：火电机组循环流化床(CFB)锅炉深度调峰超低排放烟气再循环

Wharton’s jelly MSC-derived extracellular vehicles-loaded hyaluronic acid-alginate adhesives for treatment of osteoarthritis

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Journal of Materials Science & Technology 2023年第11期142卷 240-252页

作者： Yanhong Zhao Xige Zhao hainan xu Yi Xing Tengling Wu xun Sun Mingjie Kuang Xinlong Ma Wenguang Liu Qiang Yang School and Hospital of Stomatology Tianjin Medical UniversityTianjin 300070China School of Materials Science and Engineering Tianjin Key Laboratory of Composite and Functional MaterialsTianjin UniversityTianjin 300350China Department of Spine Surgery Tianjin HospitalTianjin UniversityTianjin 300211China Laboratory of Molecular Signaling and Stem Cells Therapy Molecular Laboratory for Gene Therapy and Tooth RegenerationBeijing Key Laboratory of Tooth Regeneration and Function ReconstructionCapital Medical University School of StomatologyBeijing 100050China Department of Orthopedics the Provincial Hospital Affiliated to Shandong UniversityShandong 250014China

The repair of cartilage injury caused by osteoarthritis(OA)has long plagued *** stem cell(MSC)-derived small extracellular vesicles(sEVs)show great potential in cartilage regeneration and immunoregulation to realise cell-free ***,unprotected sEVs are prone to be washed away by the flow of fluids and degraded in *** this work,we successfully revealed that human Wharton’s jelly of umbilical cord-derived MSC(hWJMSC)sEVs promote proliferation,inhibit apoptosis,and attenuate the inflammation of chondrocytes in *** light of the long period required for cartilage regeneration,we synthesised an injectable and adhesive aldehyded sodium alginate crosslinked acylhydrazide-modified hyaluronic acid(ALG-CHO/HHA)hydrogel loaded with sEVs to boost the reparative effect of the *** hydrogel-bearing sEVs was injected into cartilage defects where they adhered to the cartilage *** this configuration,the sEVs were delivered in a sustainable manner with the degradation of the hydrogel at the injury sites,thus contributing to highly efficient cartilage repair by regulating the regenerative and immune *** ALG-CHO/HHA-sEV platform meets the clinical demand for long-lasting repair with a single ***,this work provides a new idea and theoretical basis for the clinical application of sEVs in the treatment of OA.

关键词： Extracellular vesicles Hydrogel Osteoarthritis Cartilage regeneration

Advanced electrocatalysts with unusual active sites for electrochemical water splitting

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InfoMat 2024年第1期6卷 65-82页

作者： hainan Sun Xiaomin xu Hyunseung Kim Zongping Shao WooChul Jung Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology(KAIST)DaejeonRepublic of Korea WA School of Mines:Minerals Energy and Chemical Engineering(WASM-MECE) Curtin UniversityPerthWestern AustraliaAustralia

Electrochemical water splitting represents a promising technology for green hydrogen *** design advanced electrocatalysts,it is crucial to identify their active sites and interpret the relationship between their structures and *** extensively studied as electrocatalysts include noble-metal-based(e.g.,Ru,Ir,and Pt)and non-noble-metal-based(e.g.,3d transition metals)***,advancements in characterization techniques and theoretical calculations have revealed novel and unusual active *** present review highlights the latest achievements in the discovery and identification of various unconventional active sites for electrochemical water splitting,with a focus on state-of-the-art strategies for determining true active sites and establishing structure–activity ***,we discuss the remaining challenges and future perspectives for the development of next-generation electrocatalysts with unusual active *** presenting a fresh perspective on the unconventional reaction sites involved in electrochemical water splitting,this review aims to provide valuable guidance for the future study of electrocatalysts in industrial applications.

关键词： electrochemical water splitting hydrogen evolution reaction oxygen evolution reaction structure–activity relationship unusual active sites

Seroprevalence and infection attack rate of COVID-19 in Indian cities

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Infectious Disease Modelling 2022年第2期7卷 25-32页

作者： Yiming Fei hainan xu Xingyue Zhang Salihu S.Musa Shi Zhao Daihai He Department of Math and Stats The Hang Seng UniversityHong KongChina Department of Math and Stats McMaster UniversityCanada Department of Applied Mathematics The Hong Kong Polytechnic UniversityHong KongChina Department of Mathematics Kano University of Science and TechnologyWudilNigeria JC School of Public Health and Primary Care Chinese University of Hong KongHong KongChina CUHK Shenzhen Research Institute ShenzhenChina

Objectives:Serological surveys were used to infer the infection attack rate in different *** sensitivity of the testing assay,Abbott,drops fast over time since infection which makes the serological data difficult to *** this work,we aim to solve this ***:We collect longitudinal serological data of Abbott to construct a sensitive decay *** use the reported COVID-19 deaths to infer the infections,and use the decay function to simulate the seroprevalence and match to the reported seroprevalence in 12 Indian ***:Our model simulated seroprevalence matchs the reported seroprevalence in most of the 12 Indian *** obtain reasonable infection attack rate and infection fatality rate for most of the 12 Indian ***:Using both reported COVID-19 deaths data and serological survey data,we infer the infection attack rate and infection fatality rate with increased confidence.

关键词： COVID-19 Pandemic Seroprevalence Attack rate Mathematical modelling

Application of CRISPR/Cas12i.3 for targeted mutagenesis in broomcorn millet(Panicum miliaceum L.)

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Journal of Integrative Plant Biology 2024年第8期66卷 1544-1547页

作者： Yuhe Bai Shengnan Liu Yan Bai Zhisong xu hainan Zhao Haiming Zhao Jinsheng Lai Ya Liu Weibin Song State Key Laboratory of Maize Bio-breeding Key Laboratory of Genome Editing Research and ApplicationMinistry of Agriculture and Rural AffairsDepartment of Plant Genetics and BreedingNational Maize Improvement CenterCollege of Agronomy and BiotechnologyChina Agricultural UniversityBeijing 100193China National Agricultural Technology Extension&Service Center Beijing 100125China Beijing Key Laboratory of Maize DNA Fingerprinting and Molecular Breeding Beijing Academy of Agriculture and Forestry SciencesBeijing 100097China

As the global human population continues to grow and is predicted to reach 10 billion by 2050,the demand for food volume and quality raises a tremendous challenge(OECD/FAO,2017).The worldwide arable land area is decre... 详细信息

关键词： arable continue raise

Effect of ischemic postconditioning on the response of apoptotic factors and cardiac function in patients with STEMI receiving percutaneous coronary intervention

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China Medical Abstracts(Internal Medicine) 2021年第4期38卷 214-215页

作者： xu hainan Dept Cardiol Changsha Centr HospAffil South China UnivChangsha 410004

Objective Patients with ST-elevation myocardial infarction(STEMI) were subjected to administer ischemic post-conditioning (IPOC) before conducting emergency treatment with percutaneous intervention(PCI).

关键词： STEMI percutaneous ischemic

曲面结构经编多轴向玻璃纤维复合材料制备及弯曲性能

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复合材料学报 2023年第8期40卷 4506-4516页

作者：徐海南刘策杨金伟高晓平内蒙古工业大学轻工与纺织学院呼和浩特010080

分别以双轴向和四轴向经编玻璃纤维织物为增强体,基于真空辅助树脂传递模塑成型工艺制备平板和曲面结构复合材料试样。实验测试复合材料弯曲性能和准静态压痕特性,实验测试不同铺层结构试样沿不同方向(0°和90°)的弯曲性能。在此基础上... 详细信息

分别以双轴向和四轴向经编玻璃纤维织物为增强体,基于真空辅助树脂传递模塑成型工艺制备平板和曲面结构复合材料试样。实验测试复合材料弯曲性能和准静态压痕特性,实验测试不同铺层结构试样沿不同方向(0°和90°)的弯曲性能。在此基础上,分析增强体铺层结构、曲率半径对曲面结构复合材料准静态压痕特性的影响。结果表明:双轴向经编玻璃纤维复合材料试样沿0°和90°方向当量弯曲强度分别比四轴向编玻璃纤维复合材料增加94.74%、98.37%,四轴向经编玻璃纤维复合材料试样沿0°和90°方向的最大断裂应变分别是双轴向经编玻璃纤维复合材料试样的1.9倍和2.4倍。当双轴向复合材料曲率半径为260 mm、四轴向复合材料曲率半径为150 mm时,承载能力最优;当双轴向复合材料曲率半径为150 mm、四轴向复合材料曲率半径为80 mm时,应变特性最优。实验结果为曲面结构玻璃纤维复合材料在各类室外建筑穹顶构件的应用提供借鉴。

关键词：多轴向经编复合材料曲面结构真空辅助成型工艺弯曲强度应变特性

无人机倾斜摄影结合BIM技术在公路设计中的应用

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北方交通 2022年第5期 61-63页

作者：徐海楠辽宁省公路勘测设计公司沈阳市110006

介绍了倾斜摄影测量建模的关键技术,以及倾斜摄影技术与BIM技术在公路设计中的联合应用方法,探讨了二者结合的应用前景,可为相关技术人员提供一定的参考。

关键词：无人机抢险任务倾斜摄影 BIM DEM