检索结果-南通市图书馆

Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 793-807页

作者： jinpeng hu Tao Sun Fujun Cao Yifu Shen Zhiyuan Yang Chan Guo College of Materials Science and Technology Nanjing University of Aeronautics and Astronautics(NUAA)Nanjing 210016China

Submerged friction stir processing(SFSP)with flowing water was employed to alleviate the porosities and coarse-grained structure introduced by wire-arc *** a result,uniform and ultrafine grained(UFG)structure with average grain size of 0.83μm was achieved with the help of sharply reduced heat input and holding time at elevated *** optimized UFG structure enabled a superior combination of strength and ductility with high ultimate tensile strength and elongation of 273.17 MPa and 15.39%.Specifically,grain refinement strengthening and decentralized θ(Al_(2)Cu)phase in the sample subjected to SFSP made great contributions to the enhanced *** addition,the decrease in residual stresses and removal of pores substantially enhance the *** rates of cooling and low temperature cycling,which are facilitated by the water-cooling environment throughout the machining process,are vital in obtaining superior *** work provides a new method for developing a uniform and UFG structure with excellent mechanical properties.

关键词： Submerged friction stir processing Wire-arc additive manufacturing Al-Cu alloy Residual stress Strengthening and toughening mechanism Ultrafine grained microstructure

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

基于氧含量的自然地带区划新认识

地理教学 2024年第6期 4-7页

作者：胡金鹏胡小康王静爱北京师范大学地理科学学部北京100875

自然地带区划是培养学生的人地协调观、综合思维、区域认知等地理学科核心素养的重要途径。本文以“三维自然地带”分布规律为基础,对比分析了青藏高原地表氧含量新区划与原有自然区划,得到了新的认识:基于地表氧含量的自然地带区划能... 详细信息

自然地带区划是培养学生的人地协调观、综合思维、区域认知等地理学科核心素养的重要途径。本文以“三维自然地带”分布规律为基础,对比分析了青藏高原地表氧含量新区划与原有自然区划,得到了新的认识:基于地表氧含量的自然地带区划能够反映更加综合定量的地域分异特点;氧含量的地域差异能够反映人地关系的地域差异。本文可为相关课程的教学提供新的视角,帮助学生综合认知区域自然环境特点和人地缺氧健康风险。

关键词：自然地带区划地表氧含量青藏高原地理学科核心素养

城内迁居导致的街区尺度人口动态变化测度及其空间分异特征——基于手机信令数据的武汉市实证

在线全文

学校读者我要写书评

暂无评论

地理科学进展 2024年第8期43卷 1481-1495页

作者：牛强胡金鹏梁晓倩刘晓阳伍磊武汉大学城市设计学院武汉430072 湖北省人居环境工程技术研究中心武汉430072

准确把握城市内部人口动态变化规律,有助于推动区域协调发展、优化社会空间结构。既有研究多集中于宏观尺度的人口总量及分布变化,对于城内迁居导致的人口动态变化过程缺乏关注,其测度方法、特征规律等尚待探讨。论文基于手机信令大数据... 详细信息

准确把握城市内部人口动态变化规律,有助于推动区域协调发展、优化社会空间结构。既有研究多集中于宏观尺度的人口总量及分布变化,对于城内迁居导致的人口动态变化过程缺乏关注,其测度方法、特征规律等尚待探讨。论文基于手机信令大数据,以武汉市为例展开实证分析,构建人口动态变化的“规模—方向—动静”三维测度指标体系,运用聚类分析方法,解析城内迁居带来的街区尺度人口动态变化特征,探究人口动态变化综合类型及分异规律。结果表明:①中心城区到近郊区的人口动态变化具有“高活跃→中活跃→非活跃”的规模特征、“出入大致平衡→严重失衡”的方向特征以及“静态为主→动态为主”的动静特征;②武汉都市发展区人口动态变化综合类型共有5类,其中高活跃增长动态型和高活跃流失弱动态型主要穿插分布于中心城区和近郊区组团的核心区,中活跃微流失弱动态型主要分布在上述两类的外围,低活跃微增长强动态型与低活跃平衡动态型分布于中心城区边缘和近郊区组团外围;③武汉都市发展区内部人口动态变化综合类型具有“中心—外围”嵌套结构,中心城区与近郊区之间人口动态变化的空间分异主要与区位、居住环境品质有关,中心城区内部、近郊区组团内部的空间分异则主要与产业发育及类型有关。研究拓展了人口迁移和人口变化研究领域的理论方法,为优化城市社会空间结构、精细化制定居住空间供给政策等提供了参考依据。

关键词：人口动态变化三维测度指标体系地理空间分异手机信令数据城内迁居武汉

SiO_(2)@CeO_(2)/Ag核壳结构复合催化剂的制备及催化性能分析

在线全文

学校读者我要写书评

暂无评论

高技术通讯 2024年第9期34卷 988-994页

作者：邓璐莹胡金朋郭彦炳陈松华龙岩市漳平环境监测站龙岩364499 福建龙新三维阵列科技有限公司龙岩364012 华中师范大学化学学院武汉430079 龙岩学院化学与材料学院龙岩364000

为解决目前商用催化型柴油颗粒捕集器存在的催化剂与碳烟颗粒物接触面积低、催化性能受限制的问题,设计并制备了一种SiO_(2)@CeO_(2)/Ag核壳结构复合微/纳米结构催化剂。X射线衍射仪(XRD)、扫描电子显微镜(SEM)及透射电子显微镜(TEM)证... 详细信息

为解决目前商用催化型柴油颗粒捕集器存在的催化剂与碳烟颗粒物接触面积低、催化性能受限制的问题,设计并制备了一种SiO_(2)@CeO_(2)/Ag核壳结构复合微/纳米结构催化剂。X射线衍射仪(XRD)、扫描电子显微镜(SEM)及透射电子显微镜(TEM)证明了该种微米级的核壳结构复合材料的成功合成。性能测试结果表明,以此为活性组分的催化型柴油颗粒捕集器能够显著降低碳烟颗粒物的起燃温度,并表现出了良好的机械稳定性。本研究结果表明,由Ag、SiO_(2)和CeO_(2)3种材料构筑的核壳结构复合微/纳米结构催化剂在碳烟颗粒物催化氧化方面具有优势。该创新性的催化剂设计为改进商用柴油颗粒捕集器的性能提供了新的可能途径。

关键词： Ag SiO_(2) CeO_(2) 核壳结构催化燃烧

Numerical simulation and mechanism analysis of freak waves

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2007年第5期26卷 116-124页

作者： ZHANG Yunqiu ZHANG Ningchuan hu jinpeng State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China College of Traffic and Communications South China University of Technology Guangzhou 510640 China

A numerical wave model based on the modified fourth-order nonlinear Schroe dinger equation （mNLSE） in deep water was developed to simulate the formation of freak waves and a standard split - step, pseudo-spectral method was used to solve the equation. The validation of the model is firstly verified, then the simulation of freak waves was performed by changing sideband conditions, and the variation of wave energy was also analyzed in the evolution. The results indicate that Benjamin - Feir instability （ sideband instability） is an important mechanism for freak wave formation.

关键词： freak waves nonlinear Schroe dinger equation pseudo-spectral method sideband instability numerical model

荒漠草原盐沼湿地苦豆子土壤细菌群落构建机制及其影响因素

在线全文

学校读者我要写书评

暂无评论

微生物学通报 2024年第1期51卷 111-126页

作者：文婧荣潘雅清康鹏张亚琪胡金鹏雷茜北方民族大学生物科学与工程学院宁夏银川750021 中国科学院西北生态环境资源研究院沙坡头沙漠研究试验站甘肃兰州730000

【背景】荒漠草原盐沼湿地是陆地生态系统的重要组成部分,土壤水分和盐分变化是影响该生态系统土壤细菌群落构建的重要因素。【目的】土壤细菌群落构建是由确定性和随机性主导的连续生态过程,阐明荒漠草原盐沼湿地土壤细菌群落的构建机... 详细信息

【背景】荒漠草原盐沼湿地是陆地生态系统的重要组成部分,土壤水分和盐分变化是影响该生态系统土壤细菌群落构建的重要因素。【目的】土壤细菌群落构建是由确定性和随机性主导的连续生态过程,阐明荒漠草原盐沼湿地土壤细菌群落的构建机制对于加深微生物作为关键生态系统因子重要性的理解具有积极意义。【方法】以宁夏中部典型荒漠草原盐沼苦水湖湿地为研究对象,对近湖边(near the lake,NL)和远离湖边(far from the lake,FL)苦豆子群落土壤理化特性进行测定并结合土壤细菌高通量测序分析。【结果】NL和FL样地具有明显的水盐梯度变化,NL样地土壤pH、含水量和电导率均显著高于FL样地;变形菌门、放线菌门、厚壁菌门、拟杆菌门和黏菌门是研究区域土壤细菌群落的优势菌门,变形菌门相对丰度随水盐梯度上升而升高,放线菌门和厚壁菌门相对丰度则随之下降,门下成员大多与水盐变化具有明显的相关性;此外,FL样地土壤细菌网络则具有稳定的网络关系;随着NL样地向FL样地的延伸,土壤细菌群落由随机过程主导,并且受pH、电导率和环境变量的影响。【结论】荒漠草原盐沼湿地水分和盐分的变化改变了土壤细菌群落结构;土壤细菌群落通过生态位占据等策略提高逆境下的生存能力;细菌群落构建是随机过程和确定性过程组成的连续统一体,同样受环境变化的影响。本结果揭示了荒漠草原盐沼湿地细菌群落结构和相互关系对环境变化的响应特征,同时阐明了该区土壤细菌群落的构建机制及影响因素,也为相关科学研究提供了一定理论参考。

关键词：盐沼湿地苦豆子群落土壤细菌网络关系群落构建

CROWN:A service grid middleware with trust management mechanism

在线全文

学校读者我要写书评

暂无评论

Science in China(Series F) 2006年第6期49卷 731-758页

作者： huAI jinpeng hu Chunming LI Jianxin SUN Hailong WO Tianyu School of Computer Science & Engineering Beihang University Beijing 100083 China

Based on a proposed Web service-based grid architecture, a service grid middleware system called CROWN is designed in this paper. As the two kernel points of the middleware, the overlay-based distributed grid resource management mechanism is proposed, and the policy-based distributed access control mechanism with the capability of automatic negotiation of the access control policy and trust management and negotiation is also discussed in this paper. Experience of CROWN testbed deployment and application development shows that the middleware can support the typical scenarios such as computing-intensive applications, data-intensive applications and mass information processing applications.

关键词： Grid computing service grid middleware resource management distributed access control trust management CROWN.

Accurate and efficient remaining useful life prediction of batteries enabled by physics-informed machine learning

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第4期91卷 512-521页

作者： Liang Ma jinpeng Tian Tieling Zhang Qinghua Guo Chunsheng hu School of Mechanical MaterialsMechatronic and Biomedical EngineeringUniversity of WollongongWollongongNSW 2522Australia Department of Electrical and Electronic Engineering and Research Centre for Grid Modernization The Hong Kong Polytechnic UniversityKowloonHong Kong 999077China School of Electrical Computer and Telecommunications EngineeringUniversity of WollongongWollongongNSW 2522Australia School of Advanced Interdisciplinary Studies Ningxia UniversityYinchuan 750000NingxiaChina

The safe and reliable operation of lithium-ion batteries necessitates the accurate prediction of remaining useful life(RUL).However,this task is challenging due to the diverse ageing mechanisms,various operating conditions,and limited measured *** data-driven methods are perceived as a promising solution,they ignore intrinsic battery physics,leading to compromised accuracy,low efficiency,and low *** response,this study integrates domain knowledge into deep learning to enhance the RUL prediction *** demonstrate accurate RUL prediction using only a single charging ***,a generalisable physics-based model is developed to extract ageing-correlated parameters that can describe and explain battery degradation from battery charging *** parameters inform a deep neural network(DNN)to predict RUL with high accuracy and *** trained model is validated under 3 types of batteries working under 7 conditions,considering fully charged and partially charged *** data from one cycle only,the proposed method achieves a root mean squared error(RMSE)of 11.42 cycles and a mean absolute relative error(MARE)of 3.19%on average,which are over45%and 44%lower compared to the two state-of-the-art data-driven methods,*** its accuracy,the proposed method also outperforms existing methods in terms of efficiency,input burden,and *** inherent relationship between the model parameters and the battery degradation mechanism is further revealed,substantiating the intrinsic superiority of the proposed method.

关键词： Lithium-ion batteries Remaining useful life Physics-informed machine learning

Buried interface management via bifunctional NH_(4)BF_(4)towards efficient CsPbI_(2)Br solar cells with a V_(oc)over 1.4 V

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第2期89卷 364-370,I0009页

作者： Fazheng Qiu Ming-hua Li jinpeng Wu Jin-Song hu School of Materials Science and Engineering NingboTech UniversityNingbo 315100ZhejiangChina Beijing National Laboratory for Molecular Sciences(BNLMS) Institute of ChemistryChinese Academy of SciencesBeijing 100190China College of Chemical Engineering Beijing Advanced Innovation Center for Soft Matter Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China School of Chemical Sciences University of Chinese Academy of SciencesBeijing 100049China

CsPbI_(2)Br perovskite solar cells(PSCs)have drawn tremendous attention due to their suitable bandgap,excellent photothermal stability,and great potential as an ideal candidate for top cells in tandem solar ***,the abundant defects at the buried interface and perovskite layer induce severe charge recombination,resulting in the open-circuit voltage(V_(oc))output and stability much lower than ***,a novel buried interface management strategy is developed to regulate interfacial carrier dynamics and CsPbI_(2)Br defects by introducing ammonium tetrafluoroborate(NH_(4)BF_(4)),thereby resulting in both high CsPbI_(2)Br crystallization and minimized interfacial energy ***,NH_(4)^(+)ions could preferentially heal hydroxyl groups on the SnO_(2)surface and balance energy level alignment between SnO_(2)and CsPbI_(2)Br,enhancing charge transport efficiency,while BF_(4)^(-)anions as a quasi-halogen regulate crystal growth of CsPbI_(2)Br,thus reducing perovskite ***,it is proved that eliminating hydroxyl groups at the buried interface enhances the iodide migration activation energy of CsPbI_(2)Br for strengthening the phase *** a result,the optimized CsPbI_(2)Br PSCs realize a remarkable efficiency of 17.09%and an ultrahigh V_(oc)output of 1.43 V,which is one of the highest values for CsPbI_(2)Br PSCs.

关键词： Inorganic perovskite Buried interface Defect Stability Open-circuit voltage loss

氧化苦参碱对牙周膜干细胞干性标志物表达和成骨分化的作用

在线全文

学校读者我要写书评

暂无评论

中国组织工程研究 2025年第19期29卷 3992-3999页

作者：罗晶雍敏陈琦杨长怡赵恬马静梅冬兰虎金鹏杨昭君王钰然刘博宁夏医科大学口腔医学院宁夏回族自治区银川市750004 宁夏回族自治区干细胞与再生医学重点实验室宁夏回族自治区银川市750004 宁夏医科大学总医院口腔正畸科宁夏回族自治区银川市750004 宁夏医科大学总医院牙周病科宁夏回族自治区银川市750004

背景:人牙周膜干细胞是牙周再生组织工程潜在的功能细胞,然而长期体外培养会导致牙周膜干细胞干性减低并发生复制性衰老,从而影响其治疗效果。目的:探讨氧化苦参碱在体外对牙周膜干细胞干性维持和骨向分化的影响,并寻找潜在的影响机制... 详细信息

背景:人牙周膜干细胞是牙周再生组织工程潜在的功能细胞,然而长期体外培养会导致牙周膜干细胞干性减低并发生复制性衰老,从而影响其治疗效果。目的:探讨氧化苦参碱在体外对牙周膜干细胞干性维持和骨向分化的影响,并寻找潜在的影响机制。方法:采用组织块酶消化法从人牙周膜组织中分离、培养得到牙周膜干细胞,并使用流式细胞仪进行间充质细胞表面标志物鉴定。用0,2.5,5,10μg/mL氧化苦参碱孵育牙周膜干细胞,通过CCK8实验检测氧化苦参碱对牙周膜干细胞增殖活性的影响,筛选后续实验合适的药物质量浓度,采用Western blot检测牙周膜干细胞中干细胞非特异性蛋白SOX2和OCT4的表达,采用qRT-PCR、Western blot检测牙周膜干细胞中成骨相关基因和蛋白表达水平。结果与结论:①CCK8实验结果显示2.5μg/mL氧化苦参碱对牙周膜干细胞增殖活性有显著增强作用,后续实验选用2.5μg/mL氧化苦参碱进行干预;②与空白对照组相比,氧化苦参碱组牙周膜干细胞的干性标志物SOX2蛋白表达水平变化不明显(P>0.05),OCT4蛋白表达明显上调(P<0.05);③与成骨诱导组相比,氧化苦参碱+成骨诱导组牙周膜干细胞成骨相关基因ALP、RUNX2 mRNA表达及成骨相关蛋白ALP蛋白表达明显下调(P<0.05);④氧化苦参碱上调牙周膜干细胞干性标志物表达,抑制牙周膜干细胞骨向分化,高通量测序结果表明可能与WNT2、WNT16、COMP、BMP6有关。

关键词：牙周膜干细胞苦参碱类生物碱成骨细胞增殖氧化苦参碱干性维持高通量测序