检索结果-南通市图书馆

层状多孔氮化碳的光催化降解有机物及机理分析

在线全文

学校读者我要写书评

暂无评论

辽宁化工 2024年第6期53卷 879-885页

作者：郑帅陈浩马龙渤谢亮曾玉彬杨萍萍杜富滢中油(新疆)石油工程有限公司新疆克拉玛依834000 武汉大学动力与机械学院湖北武汉430072

石墨相氮化碳(g-C_(3)N_(4))因其合适的带隙结构、较好的光响应、稳定的物化属性、低廉的制备价格而备受关注,但是由于材料的比表面积较小、光生载流子分离效率较低,因而展现出较低的光催化活性。以尿素为前驱体合成氮化碳,通过调控合... 详细信息

石墨相氮化碳(g-C_(3)N_(4))因其合适的带隙结构、较好的光响应、稳定的物化属性、低廉的制备价格而备受关注,但是由于材料的比表面积较小、光生载流子分离效率较低,因而展现出较低的光催化活性。以尿素为前驱体合成氮化碳,通过调控合成过程中的温度和压力,通过一步煅烧法直接合成了质地轻薄、表面呈现层状多孔结构的氮化碳,g-C_(3)N_(4)的比表面积由原本的8.13 m^(2)·g^(-1)提高到了94.75m^(2)·g^(-1),且明显提高了材料的光生载流子分离效率。层状多孔氮化碳(L-CN)在6min之内对20mg·L^(-1)的罗丹明B的降解率达到100%,降解速度是体相g-C_(3)N_(4)的7.7倍,L-CN降解四环素的降解速度是体相g-C_(3)N_(4)的3.0倍,最大降解率达到85%。

关键词：光催化 g-C_(3)N_(4) 层状多孔罗丹明B 四环素

维普期刊数据库博看期刊

经导管主动脉瓣置换术后血小板变化特点及影响因素分析

在线全文

学校读者我要写书评

暂无评论

中国胸心血管外科临床杂志 2024年第6期31卷 832-837页

作者：李翔宇张海波杨芳宇郑帅孟斐王胜洵焦玉清李岳环吴凯胜沈经纶首都医科大学护理学院北京100069 首都医科大学附属北京安贞医院瓣膜外科中心北京100029

目的分析行经导管主动脉瓣置换术(transcatheter aortic valve implantation,TAVI)患者术后在院期间血小板变化特点及其影响因素。方法回顾性纳入2017年3月—2021年10月在北京安贞医院瓣膜外科中心行TAVI患者,根据患者术后血小板下降特... 详细信息

目的分析行经导管主动脉瓣置换术(transcatheter aortic valve implantation,TAVI)患者术后在院期间血小板变化特点及其影响因素。方法回顾性纳入2017年3月—2021年10月在北京安贞医院瓣膜外科中心行TAVI患者,根据患者术后血小板下降特点分为血小板变化自限性组和非自限性组。比较两组患者的术前一般资料、术前及术后超声资料、术中操作资料和术后在院期间抗血栓药物使用情况。结果最终纳入患者249例,自限性组175例(70.3%),其中男100例、女75例;非自限性组74例(29.7%),其中男43例、女31例,两组患者性别差异无统计学意义(P=0.863)。自限性组患者平均年龄为(73.11±8.88)岁,非自限性组为(71.54±10.39)岁,差异无统计学意义(P=0.231)。自限性组一般于术后第2 d发生血小板下降,并于术后第4 d达计数最低点,于术后第5~7 d恢复至基线水平;非自限性组血小板变化为单纯上升、下降或无规律波动。自限性组患者术前主动脉瓣狭窄程度更严重(P<0.001),且术中使用更多的体外循环辅助(P<0.001)。术后自限性组患者比非自限性组患者更易出现主动脉瓣瓣周漏(P=0.013)。结论TAVI术后患者血小板变化多呈自限性下降趋势,可能与患者术前主动脉瓣狭窄严重程度、术中使用体外循环装置、术后瓣周漏有关。

关键词：经导管主动脉瓣置换术主动脉瓣狭窄血小板影响因素

Geochemical characteristics of produced fluids from CBM wells and their indicative significance for gas accumulation in Daning-Jixian block,Ordos Basin

在线全文

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2023年第3期17卷 661-678页

作者： Taotao YAN Chao YANG shuai zheng Yadong BAI Wei CHEN Yanfei LIU Wenguang TIAN Shasha SUN Shangwen JIN Jiahang WANG Zhenxing LIU Huifang YAO College of Mining Engineering Taiyuan University of TechnologyTaiyuan 030024China Coal Reservoir Laboratory of National Engineering Research Center of CBM Development&Utilization China University of GeosciencesBeijing 100083China China Coal Geology Group Co. LtdBeijing 100043China Research Institute of Petroleum Exploration and Development(Northwest) PetroChinaLanzhou 730000China Beijing Furuibao Energy Technology Company Beijing 100176China PetroChina Research Institute of Petroleum Exploration and Development Beijing 100083China Engineering Institute of SINOPEC Shanghai Offshore Oil&Gas Company Shanghai 200120China Exploration and Development Research Institute of PetroChina Huabei Oilfield Company PetroChinaRenqiu 062552China

The Daning-Jixian block,the eastern edge of the Ordos Basin,is one of the most potential areas for CO_(2)geological storage,enhanced coalbed methane recovery(ECBM)exploration and production in China in recent *** ionic composition and total dissolved solids(TDS)of the produced water,coal organic matter maturity,molecular composition and carbon isotope characteristics of the produced gas were utilized to analyze the hydrogeological condition,CBM generation and migration characteristics in this *** CBM enrichment patterns and the geological impacts on gas well production characteristics were *** optimal area for CBM development and CO_(2)geological storage in the study area were also *** by the Xueguan reverse fault zone,the hydraulic unit in this area can be divided into two parts(i.e.,the recharge-runoff zone in the east and the weak runoff-stagnation zone in the west).The thermogenic gas is dominating CBM genesis in this *** biogenic gas replenishment is only distributed in the eastern margin area,where theδ13C1 value is less than the thermal simulation results as an influence of hydrodynamic ***,two models of CBM formation and accumulation were proposed,1)thermogenic CBM migrated by hydrodynamic and resorbed for preservation at impermeable fault boundaries;2)thermogenic CBM trapped by fault and accumulated by hydrodynamic in slope *** gas production performance,generally increased from east to west,is mainly dominated by hydrogeological ***,the west side of the fault zone is the enrichment and high-yield area for ECBM development and CO_(2)geological storage in the study area.

关键词： produced water and gas gas accumulation geochemical parameter CBM production CO_(2)geological storage Daning-Jixian block

Event-triggered distributed optimization for model-free multi-agent systems

在线全文

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2024年第2期25卷 214-224页

作者： Shanshan zheng shuai LIU Licheng WANG College of Science University of Shanghai for Science and TechnologyShanghai200093China College of Automation Engineering Shanghai University of Electric PowerShanghai200090China

In this paper,the distributed optimization problem is investigated for a class of general nonlinear model-free multi-agent *** dynamical model of each agent is unknown and only the input/output data are available.A model-free adaptive control method is employed,by which the original unknown nonlinear system is equivalently converted into a dynamic linearized *** event-triggered consensus scheme is developed to guarantee that the consensus error of the outputs of all agents is ***,by means of the distributed gradient descent method,a novel event-triggered model-free adaptive distributed optimization algorithm is put *** conditions are established to ensure the consensus and optimality of the addressed ***,simulation results are provided to validate the effectiveness of the proposed approach.

关键词： Distributed optimization Multi-agent systems Model-free adaptive control Event-triggered mechanism

An efficient molten-salt electro-deoxidation strategy enabling fast-kinetics and long-life aluminum-selenium batteries

在线全文

学校读者我要写书评

暂无评论

SusMat 2024年第1期4卷 126-139页

作者： Jiguo Tu zheng Huang Cheng Chang Haiping Lei shuai Wang Shuqiang Jiao State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijingChina School of Chemistry Chemical Engineering and BiotechnologyNanyang Technological UniversitySingaporeSingapore School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijingChina School of Electrical and Electronic Engineering Nanyang Technological UniversitySingaporeSingapore

Aluminum-selenium(Al-Se)batteries have been considered as one of the most promising energy storage systems owing to their high capacity,energy density,and cost effectiveness,but Se falls challenges in addressing the shuttle effect of soluble intermediate product and sluggish reaction kinetics in the solid-solid conversion process during ***,we propose an unprecedented design concept for fabricating uniform Se/C hollow microspheres with controllable morphologies through low-temperature electro-deoxidation in neutral NaCl-AlCl_(3) molten salt *** Se/C hollow microspheres are demonstrated to hold a favorable hollow structure for hosting Se,which can not only suppress the dissolution of soluble intermediate products into the electrolyte,thereby maintaining the structural integrity and maximizing Se utilization of the active material,but also promote the electrical/ionic conductivity,thus facilitating the rapid reaction kinetics during ***,the as-prepared Se/C hollow microspheres exhibit a high reversible capacity of 720.1 mAh g^(−1)at 500 mA g^(−1).Even at the high current density of 1000 mA g^(−1),Se/C delivers a high discharge capacity of 564.0 mAh g^(−1),long-term stability over 1100 cycles and high Coulombic efficiency of 98.6%.This present work provides valuable insights into short-process recovery of advanced Se-containingmaterials and value-added utilization for energy storage.

关键词： aluminum-ion batteries hollow Se/C microspheres long-term cycling stability lowtemperature electro-deoxidation NaCl-AlCl_(3)molten salt

Hydration Behavior and Cementitious Properties of Calcium Carbonate-aluminate Minerals Composite

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 126-133页

作者：王冲周帅 ZOU Luyao LIU Jiawen zheng Yalin College of Materials Science and Engineering Chongqing UniversityChongqing 400045China China West Construction Group Co. Ltd.Chengdu 610015China

The purpose of this research is to investigate the hydration behavior and cementitious properties of the mixture of calcium carbonate and aluminate, and to explore whether it can be adopted as a new low-carbon cementitious material. The composite system of calcium carbonate and aluminate minerals is studied by measuring the component of hydration products, the hydration heat, setting time and compressive *** results prove that the composite system has certain cementitious properties and is feasible to prepare new low-carbon cement.

关键词： limestone hydrated calcium carboaluminate cementitious properties mechanical properties

Unresolved Excess Accumulation of Myelin-Derived Cholesterol Contributes to Scar Formation after Spinal Cord Injury

在线全文

学校读者我要写书评

暂无评论

Research 2024年第1期2023卷 17-32页

作者： Bolin zheng Yijing He shuai Yin Xu Zhu Qing Zhao Huiyi Yang Zhaojie wang Rongrong Zhu Liming Cheng Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration Ministry of EducationDepartment of OrthopedicsTongji HospitalSchool of MedicineTongji UniversityShanghai 200092China Frontier Science Center for Stem Cell Research School of Life Science and TechnologyTongji UniversityShanghai 200092China Clinical Center for Brain and Spinal Cord Research Tongji UniversityShanghai 200092China

Spinal cord injury triggers complex pathological cascades,resulting in destructive tissue damage and incomplete tissue *** formation is generally considered a barrier for regeneration in the central nervous ***,the intrinsic mechanism of scar formation after spinal cord injury has not been fully ***,we report that excess cholesterol accumulates in phagocytes and is inefficiently removed from spinal cord lesions in young adult ***,we observed that excessive cholesterol also accumulates in injured peripheral nerves but is subsequently removed by reverse ***,preventing reverse cholesterol transport leads to macrophage accumulation and fibrosis in injured peripheral ***,the neonatal mouse spinal cord lesions are devoid of myelin-derived lipids and can heal without excess cholesterol *** found that transplantation of myelin into neonatal lesions disrupts healing with excessive cholesterol accumulation,persistent macrophage activation,and *** internalization suppresses macrophage apoptosis mediated by CD5L expression,indicating that myelin-derived cholesterol plays a critical role in impaired wound *** together,our data suggest that the central nervous system lacks an efficient approach for cholesterol clearance,resulting in excessive accumulation of myelin-derived cholesterol,thereby inducing scar formation after injury.

关键词： healing Spinal impaired

Technologies and studies of gas exchange in two-stroke aircraft piston engine:A review

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第1期37卷 24-50页

作者： Yu ZHOU Xueyu LI Shuiting DING shuai ZHAO Kun ZHU Longtao SHAO Farong DU Gerui WANG zheng XU Research Institute of Aero-Engine Beihang UniversityBeijing 100191China Aircraft/Engine Integrated System Safety Beijing Key Laboratory Beijing 100191China School of Transportation Science and Engineering Beihang UniversityBeijing 100191China Civil Aviation University of China Tianjin 300300China Aero Engine Academy of China Beijing 101304China School of Energy and Power Engineering Beihang UniversityBeijing 100191China Beihang Hangzhou Innovation Institute Yuhang Hangzhou 310052China

The in-cylinder gas exchange process is crucial to the power performance of two-stroke aircraft piston engines,which is easily influenced by complex factors such as high-altitude performance variation and in-cylinder flow *** paper reviews the development history and characteristics of gas exchange types,as well as the current state of theory and the validation methods of gas exchange technology,while also discusses the trends of cutting-edge technologies in the *** paper provides a theoretical foundation for the optimization and engineering design of gas exchange systems and,more importantly,points out that the innovation of gas exchange types,the modification of theoretical models,and the technology of variable airflow organization are the key future research directions in this field.

关键词： Aircraft piston engine Aircraft power systems Gas exchange High-altitude performance In-cylinder flow Two-stroke Unmanned Aerial Vehicles(UAVs)

A semantic vector map-based approach for aircraft positioning in GNSS/GPS denied large-scale environment

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第4期34卷 1-10页

作者： Chenguang Ouyang Suxing Hu Fengqi Long shuai Shi Zhichao Yu Kaichun Zhao zheng You Junyin Pi Bowen Xing State Key Laboratory of Precision Measurement Technology and Instruments Tsinghua UniversityBeijing 100084China School of Mechanical and Information Engineering China University of Mining and Technology(Beijing)Beijing 100083China

Accurate positioning is one of the essential requirements for numerous applications of remote sensing data,especially in the event of a noisy or unreliable satellite *** this end,we present a novel framework for aircraft geo-localization in a large range that only requires a downward-facing monocular camera,an altimeter,a compass,and an open-source Vector Map(VMAP).The algorithm combines the matching and particle filter *** vector and correlation between two building contour vectors are defined,and a coarse-to-fine building vector matching(CFBVM)method is proposed in the matching stage,for which the original matching results are described by the Gaussian mixture model(GMM).Subsequently,an improved resampling strategy is designed to reduce computing expenses with a huge number of initial particles,and a credibility indicator is designed to avoid location mistakes in the particle filter *** experimental evaluation of the approach based on flight data is *** a flight at a height of 0.2 km over a flight distance of 2 km,the aircraft is geo-localized in a reference map of 11,025 km~2using 0.09 km~2aerial images without any prior *** absolute localization error is less than 10 m.

关键词： Large-scale positioning Building vector matching Improved particle filter GPS-Denied Vector map