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Fieldwork Test Research of the Impact on Building Physical Environment on Six Types of Atrium Space in Cold Climates 被引量:3
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作者 Ye-Hao Song Jun-Jie Li +2 位作者 Ning Zhu Jia-Liang Wang Zheng-Hao Lin 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第4期84-90,共7页
Since the research on verification to passive design strategies in sustainable building is at the initial stage,and its test method and verification conclusion are not scientific enough to validate,this paper proposes... Since the research on verification to passive design strategies in sustainable building is at the initial stage,and its test method and verification conclusion are not scientific enough to validate,this paper proposes the necessity of building physical environmental monitoring to quantitative optimization of passive strategies efficiency from the perspective of architecture design and building environment. Adopting comparative research method,this research chooses six types of atrium space in cold climate in China as a prototype,focusing on building physical environmental performance difference in and between atrium and building main space. Spatial parameters of the atrium space will be divided into four factors: spatial geometry,interfacial properties,internal and external related categories. With subdividing these four factors into sub-factors,this paper makes crosscomparison among the sub-factors to clarify passive strategies effectiveness in atrium. Data comparison analysis shows that Winter atrium passive strategy in cold regions from traditional view is not obvious in practical application,and test data need to be stratified refined in atrium design in case of optimizing passive strategy from building prototype perspective. 展开更多
关键词 atrium space building physical environment fieldwork test space effect
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Technology and test results of space adaptability of passive hydrogen maser
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作者 Hefei Zheng Lianshan Gao +4 位作者 Keming Feng Jing Li Wenming Wang Chunyan Cao Jihong Zhang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第2期251-256,共6页
Based on the operating principle and the electric property design of the passive hydrogen maser, the technology and test results of its space adaptability are carried out under the special launch conditions and space ... Based on the operating principle and the electric property design of the passive hydrogen maser, the technology and test results of its space adaptability are carried out under the special launch conditions and space environment. The various perturbations affecting the output frequency of such a standard used for the navigation satellite system are specified, such as magnetic field change, vibration, thermal vacuum and radiation. Through the adaptability technology in the aspects above, the security and reliability of the space passive hydrogen maser sufficiently fulfill the requirements of space operation. At present, the space passive hydrogen maser is working normally on board, indicating that the space adaptability satisfies the design requirement. 展开更多
关键词 passive hydrogen maser space ADAPTABILITY performance test
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Dead Space Breathing in Patients with Malignancies: Determination by Cardiopulmonary Exercise Testing
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作者 Harrison Ngue Maranda Ngue +2 位作者 Ian Lee Ching-Fei Chang Ahmet Baydur 《Open Journal of Respiratory Diseases》 2022年第1期15-36,共22页
Rationale: Patients with cancer commonly experience dyspnea originating from ventilatory, circulatory and musculoskeletal sources, and dyspnea is best determined by cardiopulmonary exercise testing (CPET). Objectives:... Rationale: Patients with cancer commonly experience dyspnea originating from ventilatory, circulatory and musculoskeletal sources, and dyspnea is best determined by cardiopulmonary exercise testing (CPET). Objectives: In this retrospective pilot study, we evaluated patients with hematologic and solid malignancies by CPET to determine the primary source of their dyspnea. Methods: Subjects were exercised on a cycle ergometer with increasing workloads. Minute ventilation, heart rate, breathing reserve, oxygen uptake (V’O<sub>2</sub>), O<sub>2</sub>-pulse, ventilatory equivalents for carbon dioxide and oxygen (V’<sub>E</sub>/V’CO<sub>2</sub> and V’<sub>E</sub>/V’O<sub>2</sub>, respectively) were measured at baseline and peak exercise. The slope and intercept for V’<sub>E</sub>/V’CO<sub>2</sub> was computed for all subjects. Peak V’O<sub>2</sub> 4% predicted indicated a circulatory or ventilatory limitation. Results: Complete clinical and physiological data were available for 36 patients (M/F 20/16);32 (89%) exhibited ventilatory or circulatory limitation as shown by a reduced peak V’O<sub>2</sub> and 10 subjects with normal physiologic data. The largest cohort comprised the pulmonary vascular group (n = 18) whose mean ± SD peak V’O<sub>2</sub> was 61% ± 17% predicted. There were close associations between V’O<sub>2</sub> and spirometric values. Peak V’<sub>E</sub>/V’O<sub>2</sub> and V’<sub>E</sub>/V’CO<sub>2</sub> were highest in the circulatory and ventilatory cohorts, consistent with increase in dead space breathing. The intercept of the V’<sub>E</sub>-V’CO<sub>2</sub> relationship was lowest in patients with cardiovascular impairment. Conclusion: Dyspneic patients with malignancies exhibit dead space breathing, many exhibiting a circulatory source for exercise limitation with a prominent pulmonary vascular component. Potential factors include effects of chemo- and radiation therapy on cardiac function and pulmonary vascular endothelium. 展开更多
关键词 Cardiopulmonary Exercise testing Cardiovascular Limitation Dead space Breathing DYSPNEA MALIGNANCIES Oxygen Uptake Pulmonary Vascular Limitation Ventilatory Equivalents
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大模型在航天嵌入式软件测试中的应用研究
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作者 李东玲 黄晨 +1 位作者 杨建磊 杨书坤 《微电子学与计算机》 2026年第1期44-53,共10页
大语言模型(Large Language Model, LLM),尤其是一些预训练的深度神经网络,拥有强大的表征学习能力,不仅能学习典型的软件缺陷,还能够深度分析软件隐含的缺陷,给出风险提示和改进建议。大模型的应用,使得测试方法和流程更加智能化,且能... 大语言模型(Large Language Model, LLM),尤其是一些预训练的深度神经网络,拥有强大的表征学习能力,不仅能学习典型的软件缺陷,还能够深度分析软件隐含的缺陷,给出风险提示和改进建议。大模型的应用,使得测试方法和流程更加智能化,且能够发现之前难以捕捉的复杂缺陷。航天器软件以其独特性、专业性、复杂性、高可靠性、高安全性的特点,需要通过专业的方法训练专业的大模型来满足航天嵌入式软件测试的需要。研究表明,大模型结合有效的测试方法形成的完备思维链(Chain of Thought, Cot)可以有效提高软件缺陷检出率。将测试专家的思维和大模型相结合,用专家思维链引导大模型查找软件缺陷,在提示词中增加测试专家的思维链可以有效提升软件缺陷检出效率,保证软件质量,显著提升测试团队的整体专业水平。 展开更多
关键词 软件测试 航天嵌入式软件 测试缺陷集 思维链 专用大模型
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基于dSPACE的AMT电控操纵系统试验台设计 被引量:1
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作者 曹淼龙 李强 杨礼康 《汽车技术》 北大核心 2015年第4期41-45,共5页
以AMT为研究对象,以实现电控操纵选换挡为目标,设计电控操纵系统试验台。由d SPACE控制变速器试验台操纵机构自动完成选换挡动作,通过运动模拟软件计算和试验验证两种方法获得换挡操纵杆运动过程中操纵杆特定点位的空间位置、速度和定... 以AMT为研究对象,以实现电控操纵选换挡为目标,设计电控操纵系统试验台。由d SPACE控制变速器试验台操纵机构自动完成选换挡动作,通过运动模拟软件计算和试验验证两种方法获得换挡操纵杆运动过程中操纵杆特定点位的空间位置、速度和定向载荷及其变化率等系列参数。对比验证表明该设计方案合理可行,对开发AMT操纵系统测试装置具有借鉴意义。 展开更多
关键词 AMT 电控操纵系统 试验台 Dspace
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小净距隧道-滑坡正交体系衬砌受力特征试验研究
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作者 侯彦东 董世文 +2 位作者 乔雄 雷广军 唐东昌 《公路交通科技》 北大核心 2026年第2期141-150,共10页
【目标】随着中国西部山区高速公路和铁路的快速发展,山区运营隧道在滑坡作用下的病害问题日益突出。当前的研究主要针对单洞隧道-滑坡体系,对小净距隧道-滑坡体系研究相对不足。为此,本文以小净距隧道-滑坡正交体系为研究对象,研究小... 【目标】随着中国西部山区高速公路和铁路的快速发展,山区运营隧道在滑坡作用下的病害问题日益突出。当前的研究主要针对单洞隧道-滑坡体系,对小净距隧道-滑坡体系研究相对不足。为此,本文以小净距隧道-滑坡正交体系为研究对象,研究小净距隧道穿越滑坡段,深埋侧为下穿滑带,浅埋侧与滑带正交工况下衬砌结构的受力特征。【方法】以某小净距高速公路隧道为原型,通过室内物理模型试验,采用后部加载方式模拟了新建隧道施工或其他因素引起滑坡滑动速率增大的情况。【结果】受浅埋侧隧道衬砌结构影响,对滑坡前期滑动有一定抑制作用,导致变坡段坡体滑动具有滞后性。浅埋侧隧道内侧拱脚处土压力变小,衬砌结构倾向于倾覆破坏,尤其在内侧拱肩及外侧拱脚处容易发生受压破坏。隧道呈明显偏压状态,滑坡体滑动速率增大时,深埋侧隧道偏压状态更明显。随着后缘荷载增大,衬砌结构弯矩迅速增大,浅埋侧隧道主要在内侧拱底及拱脚处轴向受压,且更容易在滑带相交处发生剪切破坏,而深埋侧隧道衬砌结构内侧倾向于受拉破坏,外侧倾向于受压破坏。【结论】在小净距隧道穿越变坡滑坡地段时,滑动首先于滑带周围发生;随着滑坡推力的增大,隧道两侧衬砌结构产生相互作用,致使浅埋侧衬砌显著承受滑坡推力,深埋侧衬砌轴力发生明显变化。 展开更多
关键词 隧道工程 衬砌结构 模型试验 小净距隧道 变坡滑坡 偏压应力比
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文献“GLAST large area telescope calorimeter subsystem:vibration test”点评
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作者 冯振兴 《航天器环境工程》 2010年第4期528-530,408,共3页
文章点评的对象是一个执行宇宙粒子物质观测任务的高分辨率、长寿命、高可靠光学部组件.点评的中心内容是关于"大面积望远镜"地面振动试验,包括对试验任务的提出、试验的具体实施以及试验后的设计评审、合格标准、技术规范等... 文章点评的对象是一个执行宇宙粒子物质观测任务的高分辨率、长寿命、高可靠光学部组件.点评的中心内容是关于"大面积望远镜"地面振动试验,包括对试验任务的提出、试验的具体实施以及试验后的设计评审、合格标准、技术规范等等地面力学环境试验要素进行一一介绍与评述,以供业内人士参考或商榷. 展开更多
关键词 太空望远镜 振动试验 环境试验 规范 可靠性 设计评审
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文献《Validation of commercial fiber optic components for aerospace environments》点评
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作者 冯振兴 《航天器环境工程》 2011年第4期390-393,共4页
文章是对一篇SPIE会议文献《用于太空环境的商业光纤器件地面验证方法》的点评。介绍了商业光纤部件从市场采购到准备作为太空飞行部件使用前,在空间环境作用(包括真空、热、振动、辐射)下的地面工艺性合格鉴定试验技术。这项技术由NAS... 文章是对一篇SPIE会议文献《用于太空环境的商业光纤器件地面验证方法》的点评。介绍了商业光纤部件从市场采购到准备作为太空飞行部件使用前,在空间环境作用(包括真空、热、振动、辐射)下的地面工艺性合格鉴定试验技术。这项技术由NASA哥达德空间飞行中心(GSFC)创立并命名为"工艺技术有效性保证法",该项技术还包括如何建立商用光纤产品制造工艺性合格鉴定试验验收标准或准则方面的内容。"点评"还针对文献中3个实例之一"水星激光高度仪"试验件的热与振动环境试验规范、试验夹具等重要试验技术信息进行详细介绍。 展开更多
关键词 光电子器件 COTS产品 光纤 环境试验 太空飞行 规范
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医药中试基地多元创新主体分布特征及选址策略研究——基于北京、上海、武汉的比较
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作者 关梦冉 程芳欣 《城市建筑》 2026年第1期155-159,共5页
医药中试是衔接研发与制造的关键环节,其科学选址对提升医药领域科技成果的转化效率具有重要影响。现有研究多聚焦于单一中试基地的物理空间构成,缺乏从创新生态系统视角对其区位选择共性规律的解析。本研究整合地理兴趣点(POI)数据和... 医药中试是衔接研发与制造的关键环节,其科学选址对提升医药领域科技成果的转化效率具有重要影响。现有研究多聚焦于单一中试基地的物理空间构成,缺乏从创新生态系统视角对其区位选择共性规律的解析。本研究整合地理兴趣点(POI)数据和多尺度空间分析方法,以北京、上海、武汉为例,系统解析医药中试基地中多元创新主体的分布特征。结果表明:宏观层面,三市分别呈现研发与制造端分离、单核高密度连绵与轴线延伸结构;微观层面,核心园区周边分别形成梯度扩散型、集群嵌入型与规划引导型三类要素集聚模式。研究提炼出研发型、制造型、集群嵌入型与政策引导型等四类中试基地类型,明确了其选址逻辑与功能导向,为医药创新空间组织的优化提供了差异化策略与理论依据。 展开更多
关键词 医药中试基地 多元创新主体 分布特征 选址策略 多案例比较
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山西省夏季各月不同等级降水时空特征分析
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作者 张博 李姝雯 +1 位作者 肖晓 王超 《中国民航飞行学院学报》 2026年第2期5-10,共6页
为分析山西省夏季各月不同等级降水的时空演变特征,揭示其变化规律。针对山西省27个气象观测站1970-2019年夏季逐日降水资料,根据24h降水量将夏季降水划分为小雨、中雨以及大雨3个不同等级,采用Morlet小波分析法、Mann-Kendall趋势检验... 为分析山西省夏季各月不同等级降水的时空演变特征,揭示其变化规律。针对山西省27个气象观测站1970-2019年夏季逐日降水资料,根据24h降水量将夏季降水划分为小雨、中雨以及大雨3个不同等级,采用Morlet小波分析法、Mann-Kendall趋势检验等方法研究其变化特征。时间分布方面,山西夏季降水整体呈减少趋势,各等级降水均有下降,在1982年和1996年前后降水有明显的突变趋势,6月平均降水的第一主周期为2a,7、8月平均降水第一主周期为4-5a。空间分布方面,6、7月降水量呈现东北多西南少的特征,8月降水量呈现南多北少的特征。各等级雨量的贡献率方面,大雨对夏季降水量的总体贡献达50%以上。小雨贡献率总体由西北向东南递减,中雨由中部向东、西两侧递减,大雨总体由东南向西北递减。各等级雨量的发生率方面,小雨频率最高,中雨次之,大雨最少。 展开更多
关键词 M-K检验 小波分析 时空特征 不同等级降水
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基于Authentication Test方法的高效安全IKE形式化设计研究 被引量:3
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作者 蒋睿 胡爱群 李建华 《计算机学报》 EI CSCD 北大核心 2006年第9期1694-1701,共8页
基于Authentication Test方法,围绕高效安全Internet密钥交换(ESIKE)协议的安全目标,提出一种具体地构建唯一满足两个通信实体变换边的形式化协议设计方法,设计出了高效安全的IKE协议;并且基于StrandSpace模型和Authentication Test方法... 基于Authentication Test方法,围绕高效安全Internet密钥交换(ESIKE)协议的安全目标,提出一种具体地构建唯一满足两个通信实体变换边的形式化协议设计方法,设计出了高效安全的IKE协议;并且基于StrandSpace模型和Authentication Test方法,形式化分析ESIKE协议,证明了其所具有的安全特性.该ESIKE协议克服了原有Internet密钥交换(IKE)协议存在的安全缺陷,提供了安全的会话密钥及安全关联(SA)协商,保护了通信端点的身份,并且保证了协议发起者和响应者间的双向认证.同时,ESIKE仅需3条消息及更少的计算量,更加简单、高效. 展开更多
关键词 协议设计 形式化方法 AUTHENTICATION testS 密钥交换Strand space模型
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地下空间建筑防火封堵技术的可靠性与耐久性研究
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作者 刘杨 《工程建设与设计》 2026年第3期77-80,共4页
以某地下空间工程为研究对象,对建筑防火封堵技术的可靠性与耐久性进行研究。分析其结构特征与火灾荷载条件,明确防火封堵性能需求,构建可靠性评价指标体系。采用耐火试验、密封完整性检测和结构稳定性测试开展验证,同时设计加速老化试... 以某地下空间工程为研究对象,对建筑防火封堵技术的可靠性与耐久性进行研究。分析其结构特征与火灾荷载条件,明确防火封堵性能需求,构建可靠性评价指标体系。采用耐火试验、密封完整性检测和结构稳定性测试开展验证,同时设计加速老化试验,模拟热循环、湿度与化学侵蚀等环境作用。并提出新型复合材料研发、施工工艺优化及智能监测系统的应用等提升防火封堵技术可靠性和耐久性的策略。 展开更多
关键词 地下空间建筑 防火封堵 可靠性 耐久性 耐火试验
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Research on Two Types of Buffer Zone Impact on Surrounding Office Space Environment in Winter in Cold Climate Zone—a Fieldwork in Architectural Design Institute Building of Tsinghua University,Beijing 被引量:1
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作者 Ye-Hao Song Jun-Jie Li +2 位作者 Ning Zhu Jia-Liang Wang Shi-Meng Hao 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第5期33-39,共7页
Building buffer zone space is not only one of essential approaches for better mental quality of interior building space, but also an important factor that may influence interior thermal comfort and energy consumption.... Building buffer zone space is not only one of essential approaches for better mental quality of interior building space, but also an important factor that may influence interior thermal comfort and energy consumption. This study aims to analyze regulative advantages of buffer zone to the surrounding functional spaces. Based on a fieldwork test in a typical office building in cold climate zone in Beijing,China,the monitor data show interior physical performance in the Winter. The research selects two types of different buffer zones in the same building. One is a south-faced greenhouse which has large dimension with plenty of vegetation,and the other is a simple atrium in the middle of five floor building with mount of skylights. The factors and their influence to surrounding functional spaces and the whole building are found out from the comparisons of collected data by floor to floor monitor test on both buffer zones at the same time. The comparisons of two types of buffer zones conclude that the greenhouse is more effective to air quality regulation but not so clearly wellperformed to thermal buffering as expected due to the dominate active central heating in the Winter. This fieldwork test results for building performance can be helpful for both architects and engineers in the early phase of sustainable design. 展开更多
关键词 public building buffer zone building performance fieldwork test space effect
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Space-time evolution rules of acoustic emission location of unloaded coal sample at different loading rates 被引量:12
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作者 Ai Ting Zhang Ru +1 位作者 Liu Jianfeng Ren Li 《International Journal of Mining Science and Technology》 SCIE EI 2012年第6期847-854,共8页
By using MTS815 rock mechanics test system,a series of acoustic emission(AE) location experiments were performed under unloading confining pressure,increasing the axial stress.The AE space-time evolution regularities ... By using MTS815 rock mechanics test system,a series of acoustic emission(AE) location experiments were performed under unloading confining pressure,increasing the axial stress.The AE space-time evolution regularities and energy releasing characteristics during deformation and failure process of coal of different loading rates are compared,the influence mechanism of loading rates on the microscopic crack evolution were studied,combining the AE characteristics and the macroscopic failure modes of the specimens,and the precursory characteristics of coal failure were also analyzed quantitatively.The results indicate that as the loading rate is higher,the AE activity and the main fracture will begin earlier.The destruction of coal body is mainly the function of shear strain at lower loading rate and tension strain at higher rate,and will transform from brittleness to ductility at critical velocities.When the deformation of the coal is mainly plasticity,the amplitude of the AE ringing counting rate increases largely and the AE energy curves appear an obvious ''step'',which can be defined as the first failure precursor point.Statics of AE information shows that the strongest AE activity begins when the axial stress level was 92-98%,which can be defined as the other failure precursor point.As the loading rate is smaller,the coal more easily reaches the latter precursor point after the first one,so attention should be aroused to prevent dynamic disaster in coal mining when the AE activity reaches the first precursor point. 展开更多
关键词 Acoustic emission testing Acoustic emissions COAL Coal mines DEFORMATION Disaster prevention Fracture mechanics Rock mechanics Shear strain Strain rate UNLOADING
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A Specification-Based Case Study from Test Class Framework
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作者 LIU Ling, MIAO Huai kou School of Computer Engineering and Science, Shanghai University, Shanghai, 200072, China 《Journal of Shanghai University(English Edition)》 CAS 2001年第3期205-210,共6页
Testing is a standard method for verification of software performance. Producing efficient and appropriate test case is an important aspect in testing. Specification based testing presents a method to derive test dat... Testing is a standard method for verification of software performance. Producing efficient and appropriate test case is an important aspect in testing. Specification based testing presents a method to derive test data from software specification. Because of the precision and concision of specification, the test data derived from specification can test the software efficiently and entirely. This paper demonstrates a test class framework(TCF) on a file reading case study, specified using Z notation. This test class framework defines test case sets, providing structure to the testing process. Flexibility is preserved so that many testing strategies can be used. 展开更多
关键词 test class framework (TCF) test case testing strategy test class (TC) test hierarchy test state space (TSS) Z SCHEMA
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Modeling of a space flexible probe–cone docking system based on the Kane method 被引量:2
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作者 Zhang Xiang Huang Yiyong +1 位作者 Chen Xiaoqian Han Wei 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2014年第2期248-258,共11页
Recent developments in micro- and nano-satellites have attracted the interest of the research community worldwide. Many colleges and corporations have launched their satellites in space. Meanwhile, the space flexible ... Recent developments in micro- and nano-satellites have attracted the interest of the research community worldwide. Many colleges and corporations have launched their satellites in space. Meanwhile, the space flexible probe-cone docking system for micro- and nano-satellites has become an attractive topic. In this paper, a dynamic model of a space flexible probe-cone dock- ing system, in which the flexible beam technology is applied, is built based on the Kane method. The curves of impact force versus time are obtained by the Lagrange model, the Kane model, and the experimental method. The Lagrange model was presented in the reference and verified by both finite element simulation and experiment. The results of the three methods show good agreements on the condition that the beam flexibility and the initial relative velocity change. It is worth mentioning that the introduction of vectorial mechanics and analytical mechanics in the Kane method leads to a large reduction of differential operations and makes the modeling process much easier than that of the Lagrange method. Moreover, the influences of the beam flexibility and the initial relative velocity are discussed. It is concluded that the initial relative velocity of space docking operation should be controlled to a certain value in order to protect the docking system. 展开更多
关键词 Dynamic models Flexible structures Impact testing Kane method space probe-cone docking
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数字经济发展对长三角地区城市低碳转型的影响研究——基于“三生空间”视角 被引量:2
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作者 安慧 张佳豪 安敏 《生态经济》 北大核心 2025年第12期105-115,共11页
在粗放型经济发展模式向集约型发展转型的关键阶段,数字经济发展是城市低碳转型的重要选择。论文从“三生空间”(生产、生活、生态)视角出发,以长三角地区的41个城市为研究对象,构建城市低碳转型评价指标体系,运用熵权法与耦合协调模型... 在粗放型经济发展模式向集约型发展转型的关键阶段,数字经济发展是城市低碳转型的重要选择。论文从“三生空间”(生产、生活、生态)视角出发,以长三角地区的41个城市为研究对象,构建城市低碳转型评价指标体系,运用熵权法与耦合协调模型测算各评价指标值,并建立双向固定效应模型检验数字经济发展对城市低碳转型影响。研究结论如下:首先,长三角地区城市数字经济发展水平、城市低碳转型水平均有所提高,其中安徽省数字经济发展水平增长了34.62%,浙江省低碳转型水平增长了58.5%。其次,数字经济能够驱动城市低碳转型,其影响系数为0.216。最后,从区域分布异质性来看,浙江省在发展数字经济和城市低碳转型上比江苏省和安徽省更具有优势。按资源禀赋划分研究区域来看,数字经济发展对非资源型城市低碳转型水平的正向提升更加明显。 展开更多
关键词 “三生空间” 异质性检验 数字经济 低碳转型
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不同横肋间距的土工格栅界面特性宏细观研究 被引量:2
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作者 靳静 温馨 +3 位作者 梁小勇 王迪 杨广庆 周诗广 《铁道科学与工程学报》 北大核心 2025年第4期1602-1613,共12页
土工格栅与土之间界面特性是影响加筋土结构稳定的关键因素。为研究不同横肋间距土工格栅的界面摩擦特性,对3种横肋间距(28、35、50 cm)土工格栅进行室内宏观拉拔试验和离散元细观模拟,宏观层面分析不同横肋间距下拉拔力与拉拔位移的关... 土工格栅与土之间界面特性是影响加筋土结构稳定的关键因素。为研究不同横肋间距土工格栅的界面摩擦特性,对3种横肋间距(28、35、50 cm)土工格栅进行室内宏观拉拔试验和离散元细观模拟,宏观层面分析不同横肋间距下拉拔力与拉拔位移的关系、界面摩擦特性的变化规律,细观层面上研究颗粒配位数、孔隙率、位移场,以及拉拔过程中土体内部力链的变化规律。研究结果表明:拉拔力-拉拔位移关系曲线呈非线性,随着横肋间距的减小,峰值拉拔力不断增大。在法向应力为200 kPa作用下,横肋间距由50 cm减至28 cm时,峰值拉拔力提高70%,28 cm横肋间距的土工格栅抗剪强度较强。筋土界面的黏聚力和摩擦角也随横肋间距的减小而增大。在细观层面,较小横肋间距的土工格栅砂土密实性更好,土体内部颗粒分布更均匀。同时,随着拉拔位移的增加,筋土界面配位数随之减小,使得土体发生一定的剪胀现象。随着横肋间距的减小,土体整体孔隙率下降,密实性明显提高,土工格栅对土体嵌固作用增强。在拉拔过程中土工格栅横肋附近的颗粒旋转,横肋间距较大时,土体内部难以形成贯通的剪切带。较小横肋间距的土工格栅在横肋节点附近力链分布更强。研究结果可为土工格栅加筋土结构设计与应用提供一定的参考。 展开更多
关键词 土工格栅 横肋间距 拉拔试验 离散元法 筋土界面
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A test method for evaluating the thermal environment of underground coal mine refuge alternatives
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作者 D.S.Yantek L.Yan +2 位作者 N.W.Damiano M.A.Reyes J.R.Srednicki 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2019年第3期343-355,共13页
Since 2009,the Mine Safety and Health Administration(MSHA)has required mines to install refuge alternatives(RAs)in underground coal mines.One of the biggest concerns with occupied RAs is the possible severity of the r... Since 2009,the Mine Safety and Health Administration(MSHA)has required mines to install refuge alternatives(RAs)in underground coal mines.One of the biggest concerns with occupied RAs is the possible severity of the resulting thermal environment.In 30 CFR 7.504,the maximum allowable apparent temperature(AT)for an occupied RA is specified as 35℃(95°F).Manufacturers must conduct heat/humidity tests to demonstrate that their RAs meet the 35℃(95°F)AT limit.For these tests,heat input devices are used to input the metabolic heat of actual miners.A wide variety of test methods,sensors,and heat input devices could be used when conducting such tests.Since 2012,the National Institute for Occupational Safety and Health(NIOSH)has conducted over thirty 96-hour heat/humidity tests on four different RAs.This paper discusses the test equipment and procedures used during these investigations.This information is useful for RA manufacturers conducting RA heat/humidity tests,for other researchers investigating RA heat/humidity buildup,and for those who need to assess the thermal environment of any confined space where people may be trapped or are seeking refuge. 展开更多
关键词 REFUGE CHAMBER REFUGE ALTERNATIVE CONFINED space THERMAL environment test method Temperature
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长螺旋钻孔压灌桩施工对砂土液化的影响分析
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作者 祖保利 《工程建设》 2026年第3期72-78,共7页
长螺旋钻孔压灌桩在砂土地层施工中,可导致砂土从固态转变为液态,对工程质量造成潜在威胁。文章以河北省中国医学科学院项目为工程背景,介绍了长螺旋钻孔压灌桩施工技术的工艺流程,对砂土在饱和状态下液化的机理及影响因素进行阐述,设... 长螺旋钻孔压灌桩在砂土地层施工中,可导致砂土从固态转变为液态,对工程质量造成潜在威胁。文章以河北省中国医学科学院项目为工程背景,介绍了长螺旋钻孔压灌桩施工技术的工艺流程,对砂土在饱和状态下液化的机理及影响因素进行阐述,设计了一个长螺旋钻孔压灌桩施工的模型并进行试验。通过观察实验现象和处理数据,结果表明:不同的桩距和螺旋钻杆转速对饱和砂土液化程度不同,桩距减小导致土体的约束作用增强,加剧饱和细砂的液化程度,钻杆转速增大,饱和细砂所受到的扰动和剪切力会相应增强,导致其液化现象变得更为严重。本文结论可为今后类似工程施工提供参考。 展开更多
关键词 长螺旋钻孔压灌桩 砂土液化 模型试验 钻杆转速 桩间距
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