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关键词： 高超音速飞行  

ISBN: (纸本)9787030755728

摘要： 本书主要介绍高超声速航空发动机的定义与内涵、科学意义和战略价值，从涡轮冲压组合高超声速航空发动机、涡轮/火箭基组合循环高超声速航空发动机、空气涡轮火箭高超声速航空发动机、强预冷高超声速航空发动机等方面介绍高超声速航空发动机的发展现状与趋势，凝练出高超声速航空发动机的关键科学问题、关键技术问题与发展方向，并提出高超声速航空发动机领域发展的相关政策建议。

关键词： 汉语   对外汉语教学   资格考试   习题集  

ISBN: (纸本)9787301340035

摘要： 《国际中文教师证书》考试是由教育部中外语言交流合作中心主办的一项标准化考试。本书在第一版的基础上，依据2021年7月发布的《国际中文教育中文水平等级标准》修改、更换相关试题（涉及词汇语法等级、教学对象级别等相关题目）。本书充分考虑读者要素，紧扣大纲，案例导入，并配有答案和详细解析。本试题集共有5套试卷，可供参加《国际中文教师证书》考试的考生使用，也可作为国家公派出国中文教师、中文教师志愿者和国际中文教育教研人员的参考用书。

摘要： Total knee arthroplasty (TKA), also known as total knee replacement, is a surgical procedure to replace damaged parts of the knee joint with artificial components. It aims to relieve pain and improve knee function. TKA can improve knee kinematics and reduce pain, but it may also cause altered joint mechanics and complications. Proper patient selection, implant design, and surgical technique are important for successful outcomes. Kinematics analysis plays a vital role in TKA by evaluating knee joint movement and mechanics. It helps assess surgery success, guides implant and technique selection, informs implant design improvements, detects problems early, and improves patient outcomes. However, evaluating the kinematics of patients using conventional approaches presents significant challenges. The reliance on 3D CAD models limits applicability, as not all patients have access to such models. Moreover, the manual and time-consuming nature of the process makes it impractical for timely evaluations. Furthermore, the evaluation is confined to laboratory settings, limiting its feasibility in various locations. This study aims to address these limitations by introducing a new methodology for analyzing in vivo 3D kinematics using an automated deep learning approach. The proposed methodology involves several steps, starting with image segmentation of the femur and tibia using a robust deep learning approach. Subsequently, 3D reconstruction of the implants is performed, followed by automated registration. Finally, efficient knee kinematics modeling is conducted. The final kinematics results showed potential for reducing workload and increasing efficiency. The algorithms demonstrated high speed and accuracy, which could enable real-time TKA kinematics analysis in the operating room or clinical settings. Unlike previous studies that relied on sponsorships and limited patient samples, this algorithm allows the analysis of any patient, anywhere, and at any time, accommodating larg

摘要： There has been a lot of research on sports demand since the 1950s. However, unfortunately, there are few studies on the demand for the Chinese Super League (CSL). With this problem in mind, this dissertation explores broadcasters' selection and audience demand for CSL games in the media. Specifically, two studies are presented to understand the viewing demand of CSL television viewers and streaming platform viewers, as well as the factors influencing the choice of broadcasters. A series of study was performed in Study 1 to examine the factors affecting broadcasters choice of matches and audience viewership of live CSL matches. Data were collected from 2017 to 2021, amounting to a total of 1056 matches. Among these matches, 208 were televised on CCTV5 and received national coverage. Broadcasters match selections and TV ratings were regressed on a series of antecedent factors of the demand for broadcasted CSL matches. The findings showed that both broadcasters and TV audiences display a preference for matches between teams with larger fan bases, higher rankings, and higher salaries. Furthermore, Study 1 also analyzing the demand for live CSL matches among TV viewers in different city tiers. The results indicate that viewers in all three city tiers have a preference for games that feature more star players and are broadcasted on weekends and during nighttime. Additionally, it was found that matches involving older teams have a negative impact on television ratings. Study 2 analyzes the demand for CSL matches on streaming platforms, specifically focusing on highlight videos and full game replays. The study covers both the Tencent Sports CSL channel and the CCTV streaming media CSL channel, with data collected from the 2022 CSL season, comprising 18 teams and 306 games. On Tencent Sports, certain variables such as goals scored, total current points, red cards, team age, star players, and upload time significantly influence highlight video view counts, suggesting viewers'

关键词： 自组装   肽   微观作用力   分子动力学模拟   π-π堆积作用   水桥  

摘要： 本文通过全原子分子动力学研究了典型的自组装芳香二肽分子(z-FF)自组装过程的微观结构演化,探索了肽分子间以及肽分子与溶剂水分子的微观作用力在自组装各个阶段的作用.模拟结果显示,尽管π-π堆积作用占分子间作用能的比重不高,但其在自组装初期对分子聚集起到的驱动力的贡献大于非π-π堆积作用力.肽分子与溶剂水分子形成的氢键数量随着组装进程而减少,总体呈现去溶剂化效应,但同时伴随着多次再溶剂化过程.水化层中的水分子存在两种特殊的"水桥"形式,即"单分子水桥"和"水团簇水桥",其在水化层水分子中占比在30％～70％之间涨落.水桥的涨落伴随着肽分子结构重排,在自组装各个阶段(相分离、成核、生长和纤维交联)起着重要作用.

关键词： PSCAD/EMTDC   电磁暂态   恒导纳矩阵   DFIG   等效模型  

摘要： 随着风电装机容量在电力系统中所占的比重不断增大，风电与电网的相互影响越来越复杂。异步电机作为双馈风电机组重要的发电设备，其暂态模型是否准确直接决定了系统的仿真精度。然而，PSCAD/EMTDC等电磁暂态仿真软件将异步电机数字封装，虽然模型精度高，但速度过于缓慢、用户无法获取电机内部结构，这限制了风电机组的仿真设计与优化加速。针对这一问题，提出了双馈异步风力发电机（Doubly-Fed Induction Generator，DFIG）的电磁暂态等效仿真模型，首先，基于abc/dq0变换重构了发电机的数学方程，利用后退欧拉法对基本方程进行了离散化；其次，通过近似参数，将电机模型的导纳矩阵转为恒导纳矩阵，通过定转子系统的坐标反变换得到了发电机与外部电网络的直接机网接口；最后，在PSCAD/EMTDC环境中搭建了DFIG测试系统，多工况验证所提发电机模型的可行性，并利用最大相对误差和2范数误差分析方法进行了准确度分析。所提出的DFIG等效建模方法，可为大规模风电机组的电磁暂态模型设计和仿真加速提供模型基础。

关键词： 伯努利方程   课程思政   教学设计  

摘要： 伯努利方程是流体力学课程中的基本方程之一,也是重要的学习内容.文章以工科背景下流体力学课程中的"伯努利方程"为对象阐述课程思政教学设计和具体实施过程,确立知识、能力、思政三位一体的教学思想,希冀借此建立的课程思政设计思路为其他专业课程的教学设计提供参考.

关键词： 大单元   PBL模式   物理中考复习  

摘要： 在物理中考复习中,大单元统整下的PBL模式能够帮助学生将零散的知识点串联起来,形成一个完整的知识体系.文章尝试运用知识系统化、情景项目化、解题模型化的策略,引导学生在发现、分析、解决物理问题的过程中对新旧知识进行关联、迁移、转化和运用,落实初中物理学科核心素养.