检索结果-南通市图书馆

高等数学教学中课程思政的教学实施——以《定积分的概念》为例

在线全文

学校读者我要写书评

暂无评论

高等数学研究 2022年第6期25卷 87-90页

作者：田进凤宁夏大学民族预科教育学院宁夏银川750001

以定积分的概念为例,剖析了定积分概念中蕴含的思政元素,并给出了在定积分的概念教学中如何实施课程思政的具体过程.

关键词：课程思政高等数学定积分的概念

Recent progress in side chain engineering of Y-series non-fullerene molecule and polymer acceptors

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第3期67卷 788-805页

作者： Li tian Chunchen Liu Fei Huang School of Materials Science and Engineering Henan University of TechnologyZhengzhou 450001China Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and DevicesSouth China University of TechnologyGuangzhou 510640China

Organic solar cells(OSCs) have drawn considerable attention in the last decade due to the great potential of light weight,flexibility, and low-cost solution processing. Particularly, Y-series non-fullerene acceptors(NFAs) including small molecular acceptors(SMAs) and polymerized small molecular acceptors(PSMAs) have become research hot spots due to their excellent power conversion efficiency. Side chain engineering is crucial to adjust the solubility and crystallinity of NFAs, which will significantly affect the morphology of active layers and the efficiency of OSCs. However, the understanding of side chain engineering on NFAs is still limited and lacks a systematic review. This review aims to provide a brief summary of the recent developments in side chain engineering of NFAs, with a special focus on the design and application of Y-series SMAs and PSMAs for high-efficiency non-fullerene organic solar cells(NF-OSCs). In addition, the review also points out challenges and provides useful guidance regarding side chain regulation for Y-series NFAs.

关键词： organic solar cell Y-series non-fullerene acceptors side chain engineering

Martensitic transformation pathways and crystallographic orientation relationships in steel

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第7期174卷 74-84页

作者： tian-Wei Liu Xiao-Lei Wu State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Martensite is one of the most important structures determining the ability to tailor the performance of steel and several other engineering *** previous studies,the face-centered cubic(FCC)to hexag-onal close-packed(HCP)(or body-centered cubic(BCC))martensitic transformation and the FCC to body-centered tetragonal(BCT)(or BCC)martensitic transformation during deformation and quenching were widely investigated;these transformations usually improve the plasticity and strength of steel,*** this work,detailed transmission electron microscopy(TEM)observations and electron diffraction pattern analyses of the BCT and BCC twins are performed along the[110],[131],and[¯153]zone *** transformation of BCT twins into BCC twins along the[131]zone axis is also analyzed through in situ heating during the TEM *** high-resolution TEM observations of mutually perpendicular BCT variants are consistent with the atomic arrangement obtained for the quenching pathway during the martensitic *** addition,different orientation relationships between austenite and marten-site are explained in terms of the atomic migration occurring during the deformation pathway and the quenching pathway of the martensitic transformation.

关键词： Body-centered tetragonal twin Martensitic transformation Steel Transmission electron microscopy Orientation relationship

New method for multibody dynamics based on unknown constraint force

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

Science China(Technological Sciences) 2024年第3期67卷 791-808页

作者： tian Ying JIA YingHong ZHANG Jun School of Astronautics Beihang UniversityBeijing 100191China Beijing Institute of Control Engineering Beijing 100190China National Laboratory of Space Intelligent Control Beijing 100190China

This paper presents a new method for the dynamics of multibody systems based on unknown constraint force. The method can uniformly solve multibody systems with typical configurations, including the system with rigid-flexible coupling, the system in tree topology, and the system with loop constraints. Unlike common methods, the proposed method can model the loop system without “cutting off” loop constraints, leading to the exact same modelling process as the tree-like system performs. Based on graph theory, a topological record matrix M_(rec) is proposed to capture the arbitrary system configuration. Moreover, constraint forces are selected as the key variables in semi-recursive framework. With the recursive kinematics relationship between adjacent bodies, the constraint force equation is further assembled to achieve the full-state system solution. The numerical simulations demonstrate the accuracy of the proposed method.

关键词： multibody system dynamic modelling rigid-flexible coupling unknown constraint force graph theory semi-recursive algorithm

在线全文

学校读者我要写书评

暂无评论

液质联用法测定野拔子蜂蜜中林可霉素

食品工业 2019年第10期40卷 293-295页

作者：田金凤尚远宏郑毅攀枝花学院

采用同位素内标-超高效液相色谱串联三重四极杆质谱法测定野拔子蜂蜜中林可霉素残留量。样品经Tris缓冲液(pH 9)提取,Oasis HLB固相萃取柱净化,采用ZORBAX SB-C18色谱柱分离,以0.1%的甲酸水溶液和乙腈为流动相进行梯度洗脱;采用电喷雾-... 详细信息

采用同位素内标-超高效液相色谱串联三重四极杆质谱法测定野拔子蜂蜜中林可霉素残留量。样品经Tris缓冲液(pH 9)提取,Oasis HLB固相萃取柱净化,采用ZORBAX SB-C18色谱柱分离,以0.1%的甲酸水溶液和乙腈为流动相进行梯度洗脱;采用电喷雾-正离子多反应监测模式检测,同位素内标法定量。当林可霉素的浓度为1.0~100.0 ng/mL时,线性关系良好,相关系数(r)>0.999,空白样品的3个添加水平(0.5,2.0和5.0μg/kg)的回收率为91.2%~96.7%,RSD为8.6%~11.8%(n=6),定量限为0.6μg/kg,检出限为0.2μg/kg。说明该方法灵敏度及准确度良好,能满足野拔子蜂蜜中林可霉素残留分析的要求。

关键词：超高效液相色谱串联三重四极杆质谱法林可霉素野拔子蜂蜜

Preparation of Self-limiting Heating Cables with Excellent Processability, Mechanical Properties and PTC Effect via Thermal and Electrical Treatments

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第4期42卷 511-520页

作者： tian-Hao Yang Tong Wu Qiang Fu State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China State Key Laboratory of Polymer Materials Engineering Polymer Research Institute of Sichuan UniversityChengdu610065China

Polymer/conductive filler composites have been widely used for the preparation of self-limiting heating cables with the positive temperature coefficient (PTC) effect. The control of conductive filler distribution and network in polymer matrix is the most critical for performance of PTC materials. In order to compensate for the destruction of the filler network structure caused by strong shearing during processing, an excessive conductive filler content is usually added into the polymer matrix, which in turn sacrifices its processability and mechanical properties. In this work, a facile post-treatment of the as-extruded cable, including thermal and electrical treatment to produce high-density polyethylene (HDPE)/carbon black (CB) cable with excellent PTC effect, is developed. It is found for the as-extruded sample, the strong shearing makes the CB particles disperse uniformly in HDPE matrix, and 25 wt% CB is needed for the formation of conductive paths. For the thermal-treated sample, a gradually aggregated CB filler structure is observed, which leads to the improvement of PTC effect and the notable reduction of CB content to 20 wt%. It is very interesting to see that for the sample with combined thermal and electrical treatment, CB particles are agglomerated and oriented along the electric field direction to create substantial conductive paths, which leads to a further decrease of CB content down to 15 wt%. In this way, self-limiting heating cables with excellent processability, mechanical properties and PTC effect have simultaneously been achieved.

关键词： Self-limiting heating cables Positive temperature coefficient Thermal treatment Electrical treatment

砂型3D打印材料在岩体物理模型试验中的应用研究及展望

在线全文

学校读者我要写书评

暂无评论

材料导报 2024年第12期38卷 73-81页

作者：余宸田威王杰高晋峰长安大学建筑工程学院西安710061

无法获得内部结构高度一致的岩体试样以及预制缺陷制作困难一直是岩石室内物理试验中面临的关键问题。3D打印技术作为近年来快速发展的先进制造技术,可以作为有效方法实现对复杂结构的制备,目前已经有众多研究学者将其应用于岩石室内物... 详细信息

无法获得内部结构高度一致的岩体试样以及预制缺陷制作困难一直是岩石室内物理试验中面临的关键问题。3D打印技术作为近年来快速发展的先进制造技术,可以作为有效方法实现对复杂结构的制备,目前已经有众多研究学者将其应用于岩石室内物理试验中。为了寻求最接近于天然岩石细微观结构特征以及脆性特征的3D打印类岩石模型,相关学者采用了砂型材料对类岩石模型进行打印以达到代替天然岩石进行试验的目的,相关研究成果证实砂型3D打印材料具有与天然岩石材料相似的脆性特征、表面粗糙度特征、细微观结构特征、裂纹扩展规律等,为砂型3D打印类岩石模型开展岩石室内物理试验奠定了基础。基于此,根据近年来国内外相关研究以及本课题组近六年的研究成果,对基于砂型3D打印材料的岩体模型在岩石室内试验中的研究成果进行了总结分析,指出了现有研究存在的问题和局限性,并对未来砂型3D打印材料应用于岩石室内物理试验中的前景进行了展望。

关键词：岩石力学岩体物理模型 3D打印砂型材料力学性能裂纹扩展

Electrochemical anodic oxidation assisted fabrication of memristors

在线全文

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2024年第3期6卷 250-272页

作者： Shuai-Bin Hua tian Jin Xin Guo School of Materials Science and Engineering State Key Laboratory of Material Processing and Die&Mould TechnologyHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China

Owing to the advantages of simple structure,low power consumption and high-density integration,memristors or memristive devices are attracting increasing attention in the fields such as next generation non-volatile memories,neuromorphic computation and data ***,the deposition of memristive films often requires expensive equipment,strict vacuum conditions,high energy consumption,and extended processing *** contrast,electrochemical anodizing can produce metal oxide films quickly(e.g.10 s) under ambient *** means of the anodizing technique,oxide films,oxide nanotubes,nanowires and nanodots can be fabricated to prepare *** film thickness,nanostructures,defect concentrations,etc,can be varied to regulate device performances by adjusting oxidation parameters such as voltage,current and *** memristors fabricated by the anodic oxidation technique can achieve high device consistency,low variation,and ultrahigh yield *** article provides a comprehensive review of the research progress in the field of anodic oxidation assisted fabrication of ***,the principle of anodic oxidation is introduced;then,different types of memristors produced by anodic oxidation and their applications are presented;finally,features and challenges of anodic oxidation for memristor production are elaborated.

关键词： anodic oxidation anodized aluminium oxide memristor resistive switching electrical properties

Friendship Inference Based on Interest Trajectory Similarity and Co-occurrence

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2024年第3期33卷 708-720页

作者： Junfeng tian Zhengqi HOU School of Cyber Security and Computer Hebei University Hebei Key Laboratory of High Confidence Information Systems Hebei University

Most of the current research on user friendship speculation in location-based social networks is based on the co-occurrence characteristics of users,however,statistics find that co-occurrence is not common among all users;meanwhile,most of the existing work focuses on mining more features to improve the accuracy but ignoring the time complexity in practical *** this basis,a friendship inference model named ITSIC is proposed based on the similarity of user interest tracks and joint user location *** utilizing MeanShift clustering algorithm,ITSIC clustered and filtered user check-ins and divided the dataset into interesting,abnormal,and noise *** interest trajectories were constructed from user interest check-in data,which allows ITSIC to work efficiently even for users without *** the same time,by application of clustering,the single-moment multi-interest trajectory was further proposed,which increased the richness of the meaning of the trajectory *** extensive experiments on two real online social network datasets show that ITSIC outperforms existing methods in terms of AUC score and time efficiency compared to existing methods.

关键词： Data privacy Social networking (online) Noise Clustering algorithms Prediction algorithms Inference algorithms Data models