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A new method for a numerical investigation of windproof performance of porous windbreaks for high-speed railways based on a physical model
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作者 LIU Dong-run WAN Yuan +4 位作者 LI Yan-cheng ZHOU Nan-qing WANG Tian-tian ZHANG Lei LIN Tong-tong 《Journal of Central South University》 2025年第4期1535-1547,共13页
Following the fundamental characteristics of the porosity windbreak,this study suggests a new numerical investigation method for the wind field of the windbreak based on the porous medium physical model.This method ca... Following the fundamental characteristics of the porosity windbreak,this study suggests a new numerical investigation method for the wind field of the windbreak based on the porous medium physical model.This method can transform the reasonable matching problem of the porosity and windproof performance of the windbreak into a study of the relationship between the resistance coefficient of the porous medium and the aerodynamic load of the train.This study examines the influence of the hole type on the wind field behind the porosity windbreak.Then,the relationship between the resistance coefficient of the porous medium,the porosity of the windbreak,and the aerodynamic loads of the train is investigated.The results show that the porous media physical model can be used instead of the windbreak geometry to study the windbreak-train aerodynamic performance,and the process of using this method is suggested. 展开更多
关键词 porous windbreak windproof performance porous media physical model high-speed train
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A hierarchical simulation framework incorporating full-link physical response for short-range infrared detection
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作者 Mingze Gao Lixin Xu +4 位作者 Shiyuan Hu Xiaolong Shi Jiaming Gao Yanjiang Wu Huimin Chen 《Defence Technology(防务技术)》 2025年第8期351-363,共13页
Missile-borne short-range infrared detection(SIRD)technology is commonly used in military ground target detection.In complex battlefield environments,achieving precise strike on ground target is a challenging task.How... Missile-borne short-range infrared detection(SIRD)technology is commonly used in military ground target detection.In complex battlefield environments,achieving precise strike on ground target is a challenging task.However,real battlefield data is limited,and equivalent experiments are costly.Currently,there is a lack of comprehensive physical modeling and numerical simulation methods for SIRD.To this end,this study proposes a SIRD simulation framework incorporating full-link physical response,which is integrated through the radiative transfer layer,the sensor response layer,and the model-driven layer.In the radiative transfer layer,a coupled dynamic detection model is established to describe the external optical channel response of the SIRD system by combining the infrared radiation model and the geometric measurement model.In the sensor response layer,considering photoelectric conversion and signal processing,the internal signal response model of the SIRD system is established by a hybrid mode of parametric modeling and analog circuit analysis.In the model-driven layer,a cosimulation application based on a three-dimensional virtual environment is proposed to drive the full-link physical model,and a parallel ray tracing method is employed for real-time synchronous simulation.The proposed simulation framework can provide pixel-level signal output and is verified by the measured data.The evaluation results of the root mean square error(RMSE)and the Pearson correlation coefficient(PCC)show that the simulated data and the measured data achieve good consistency,and the evaluation results of the waveform eigenvalues indicate that the simulated signals exhibit low errors compared to the measured signals.The proposed simulation framework has the potential to acquire large sample datasets of SIRD under various complex battlefield environments and can provide an effective data source for SIRD application research. 展开更多
关键词 Short-range infrared detection Full-link physical response Signal level simulation
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Experimental and mechanistic study on iron extraction from high-iron red mud under multiple physical field coupling conditions
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作者 DONG Hai-pei YANG Jin-lin +3 位作者 ZHOU Wen-tao YU Xu-yang MA Shao-jian WANG Ding-zheng 《Journal of Central South University》 2025年第7期2476-2486,共11页
Red mud is a solid waste discharged in the process of alumina production,and how to realize the efficient recovery of its iron is an urgent problem to be solved.In this study,the iron extraction test and mechanism stu... Red mud is a solid waste discharged in the process of alumina production,and how to realize the efficient recovery of its iron is an urgent problem to be solved.In this study,the iron extraction test and mechanism study of high iron red mud were carried out under the coupling conditions of multiple physical field(microwave field,gas-solid flow field and temperature field)with biomass as the reducing agent.The test results showed that under the optimal conditions,an iron concentrate with a yield of 78.4%,an iron grade of 59.23%,and a recovery rate of 86.65%was obtained.The analyses of XRD,XPS,TEM,and SEM-EDS showed that during the roasting process,the hematite in the high-iron red mud was completely converted to magnetite,and the biomass produced the reductant that provided the magnetization reaction;A large number of cracks and pores appeared in the surface of the hematite reduction product particles,which helped to induce iron minerals to undergo effective mineral phase transformation.The above study provides ideas for the phase transformation and efficient recovery of iron minerals in red mud. 展开更多
关键词 multiple physical field high-iron red mud BIOMASS mineral phase transformation iron extraction
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The noise analysis and multi-physical field coupling study of high-precision SERF atomic gyroscopes
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作者 Jiaxin Liu Xusheng Lei +3 位作者 Yu Yuan Yizhe Zhou Haoying Pang Zhihong Wu 《Defence Technology(防务技术)》 2025年第8期213-224,共12页
The spin-exchange relaxation-free atomic gyroscope,with its exceptionally high theoretical precision,demonstrates immense potential to become the next-generation strategic-grade gyroscope.However,due to technological ... The spin-exchange relaxation-free atomic gyroscope,with its exceptionally high theoretical precision,demonstrates immense potential to become the next-generation strategic-grade gyroscope.However,due to technological noise,there is still a significant gap between its actual precision and theoretical precision.This study identifies the key factor limiting the precision of the SERF gyroscope as coupling noise.By optimizing the detection loop structure,a distinction between the dual-axis signals'response to optical and magnetic fields was achieved-where the optical errors responded similarly,while the response to magnetic noise was opposite.Based on the differences in the optical-magnetic response of the dual-axis signals,empirical mode decomposition was used to decompose the dual-axis gyroscope signals into multiple intrinsic mode functions,and Allan deviation analysis was applied to analyze the noise characteristics of the intrinsic mode functions over various periods.This study successfully reveals that optical errors caused by thermal-optical coupling and long-period magnetic noise induced by thermal-magnetic coupling are the dominant factors limiting the long-term stability of the SERF gyroscope.Based on these analyses,the study concludes that to achieve strategic-grade precision for the SERF gyroscope,it is essential to effectively address the noise issues caused by multi-physical field couplings. 展开更多
关键词 SERF gyroscope Empirical mode decomposition Allan deviation Noise feature recognition Multi physics field coupling
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Optimal two-channel switching false data injection attacks against remote state estimation of the unmanned aerial vehicle cyber-physical system
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作者 Juhong Zheng Dawei Liu +1 位作者 Jinxing Hua Xin Ning 《Defence Technology(防务技术)》 2025年第5期319-332,共14页
A security issue with multi-sensor unmanned aerial vehicle(UAV)cyber physical systems(CPS)from the viewpoint of a false data injection(FDI)attacker is investigated in this paper.The FDI attacker can employ attacks on ... A security issue with multi-sensor unmanned aerial vehicle(UAV)cyber physical systems(CPS)from the viewpoint of a false data injection(FDI)attacker is investigated in this paper.The FDI attacker can employ attacks on feedback and feed-forward channels simultaneously with limited resource.The attacker aims at degrading the UAV CPS's estimation performance to the max while keeping stealthiness characterized by the Kullback-Leibler(K-L)divergence.The attacker is resource limited which can only attack part of sensors,and the attacked sensor as well as specific forms of attack signals at each instant should be considered by the attacker.Also,the sensor selection principle is investigated with respect to time invariant attack covariances.Additionally,the optimal switching attack strategies in regard to time variant attack covariances are modeled as a multi-agent Markov decision process(MDP)with hybrid discrete-continuous action space.Then,the multi-agent MDP is solved by utilizing the deep Multi-agent parameterized Q-networks(MAPQN)method.Ultimately,a quadrotor near hover system is used to validate the effectiveness of the results in the simulation section. 展开更多
关键词 Unmanned aerial vehicle(UAV) Cyber physical systems(CPS) K-L divergence Multi-sensor fusion kalman filter Stealthy switching false data injection(FDI) ATTACKS
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2009--2013年广州市普通高考招生体格检查检出结核病情况分析 被引量:4
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作者 伍小英 谭守勇 +12 位作者 罗少霞 张晋昕 陈其琛 刘国标 梁志强 宋涛 黄冬生 杜雨华 邝浩斌 周惠贤 龚芳 温兴煊 何贤英 《中国防痨杂志》 CAS 2014年第5期337-340,共4页
目的了解广州市普通高考招生体格检查结核病检出特征并进行分析。方法采用回顾性调查研究方法,收集2009--2013年广州市普通高考招生体格检查病案资料和全国结核病信息管理系统的疫情资料,共有316386名考生参加体格检查,采用描述性统... 目的了解广州市普通高考招生体格检查结核病检出特征并进行分析。方法采用回顾性调查研究方法,收集2009--2013年广州市普通高考招生体格检查病案资料和全国结核病信息管理系统的疫情资料,共有316386名考生参加体格检查,采用描述性统计分析方法对检出的238例活动性肺结核患者进行分析,组间比较用7。检验,P〈0.05为差异有统计学意义。结果2009--2013年广州市普通高考招生体格检查活动性肺结核患者检出率为75.2/10万,2010年和2011年检出率较高,分别为115.0/10万、102.0/10万,2012年检出率最低,为46.5/10万。其中男性为55.9%(133/238),女性为44.1%(105/238)。根据学校生源地区检出例数从高至低排列前5位为番禺区54例、越秀区37例、荔湾区29例、增城区25例、天河区22例、白云区22例。5年间检出患者均为初治类型,涂阳肺结核患者占18.I%(43/238),涂阴肺结核患者占81.9%(195/238),肺部病灶以1~2个肺野为主,占90.7%(216/238)。结论广州市普通高考招生体格检查活动性肺结核检出率较高,应加强广州市在校高中学生,尤其是老城区和流动人口密集区域高中学生的结核病控制工作。 展开更多
关键词 结核 肺预防和控制 体格检查 学生 广州市
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招收飞行学员体格检查标准适宜性评估 被引量:5
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作者 焦志刚 王致洁 +5 位作者 曹伟民 郑颖鹃 姜媛媛 张雁歌 陈勇胜 周锡江 《解放军医学杂志》 CAS CSCD 北大核心 2012年第3期253-256,共4页
目的评估招收飞行学员体格检查标准能否满足飞行学员医学选拔的需要。方法分3个步骤实施招收飞行学员体格检查标准的评估。第一步,编制调查手册。根据标准条款适宜性评估涉及的主要因素,编制由适宜性评估及使用情况调查两部分内容组成... 目的评估招收飞行学员体格检查标准能否满足飞行学员医学选拔的需要。方法分3个步骤实施招收飞行学员体格检查标准的评估。第一步,编制调查手册。根据标准条款适宜性评估涉及的主要因素,编制由适宜性评估及使用情况调查两部分内容组成的调查手册。第二步,筛选专家。采用社会调查学的方法,选择119名专家(其中招飞体检专家98人,航空临床医学专家21人)对359个标准条款进行适宜性评估,并分析评估结果的可靠性。第三步,制定判断标准。根据专家的选择来判断条款的价值。若某一标准条款被超过80%以上的专家评估为适宜,则适宜性高;若低于60%,则适宜性低。结果发放调查手册134份,回收128份,专家参加评估的积极指数为0.95,而权威系数=0.86。在359个条款中,有271条(占75.5%)的适宜性获得专家认可,而有27条(占7.5%)未得到专家的普遍认可,多为不易把握的功能评价条款。结论尽管"招飞标准"大多数条款的适宜性获得专家认可,但仍有少数条款的适宜性不被专家普遍接受,应结合实际使用情况予以重点关注。 展开更多
关键词 飞行人员 体格标准 评估
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Physical Literacy的本土化:概念厘定、实践反思及应对 被引量:3
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作者 刘艳妮 王辉 +1 位作者 赵犇 熊文 《山东体育学院学报》 北大核心 2024年第2期96-103,共8页
Physical Literacy(简称PL)是身体活动与健康促进领域的重要理念,也是新时代学校体育的开拓点之一。长期以来,学界对PL的认知存在争议或模糊不清,导致其在实践中出现了一定的迟滞和偏差,故对相关认知加以厘定与反思具有重要意义。研究认... Physical Literacy(简称PL)是身体活动与健康促进领域的重要理念,也是新时代学校体育的开拓点之一。长期以来,学界对PL的认知存在争议或模糊不清,导致其在实践中出现了一定的迟滞和偏差,故对相关认知加以厘定与反思具有重要意义。研究认为:(1)从形式逻辑来看,我国学者构建的PL概念在内涵与外延上存在争议或误用。内涵方面,“素养”作为属概念规定了PL的内在特性;“体育素养”的转译窄化了PL的内涵,而译为“身体素养”更能体现PL的身体本源性;作为面向全民的基础生活素养,PL并非核心素养在体育学科的具体化,不宜将其与体育学科核心素养相等同。外延方面,部分PL的外延体系存在偷换“Physical”概念、子素养客体化、子素养相容等问题。(2)在本土实践中,对PL的评价被横向割裂,且纵向衔接不畅;PL的发展情境囿于学校,家庭、社区等校外情境应用不足。针对以上问题,该研究建议未来既要构建横纵贯通的评价体系,也要注意营造多样化的发展情境。 展开更多
关键词 身体素养 体育素养 核心素养 本土化
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混合性评价模式在诊断学体格检查实践教学中的实施效果分析 被引量:12
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作者 刘理静 钱红 +3 位作者 胡柯 贺兼斌 李汉文 李玉娴 《中国卫生事业管理》 北大核心 2019年第9期686-689,共4页
目的:探讨混合性评价模式在诊断学体格检查实践教学中的实施效果。方法按数字表法随机抽取我校2015级本科临床医学专业两个教学班共242名学生为研究对象;将其分为研究组(119人)和对照组(123人),研究组实施混合性评价模式;对照组采用传... 目的:探讨混合性评价模式在诊断学体格检查实践教学中的实施效果。方法按数字表法随机抽取我校2015级本科临床医学专业两个教学班共242名学生为研究对象;将其分为研究组(119人)和对照组(123人),研究组实施混合性评价模式;对照组采用传统评价模式,结束教学后,根据诊断学体格检查实践考核成绩、出勤率、问卷调查、评价模式满意度调查及学生访谈进行教学效果的评价。结果研究组诊断学体格检查实践考核成绩明显高于对照组(P<0.01),同时,研究组在出勤率、问卷调查、评价模式满意度调查和学生访谈上对诊断学体格检查实践教学效果的评价优于对照组(P<0.01).结论混合性评价模式能明显提高诊断学体格检查实践教学效果,值得在以后的教学中推广使用。 展开更多
关键词 混合性评价模式 诊断学 体格检查 实践教学 教学效果
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头晕/眩晕的临床诊断基本功:病史采集与体格检查 被引量:3
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作者 漆微韡 徐雪 黄海威 《重庆医科大学学报》 CAS CSCD 北大核心 2021年第7期769-772,共4页
头晕和眩晕是临床最为常见的主诉症状之一。由于症状的非特异性,临床诊治往往较为困难。详尽的病史采集及系统完整的体格检查有助于初步判定病变部位,从而更加有针对性地选择相应的辅助检查,更快捷有效地明确病因,选择正确的治疗策略。... 头晕和眩晕是临床最为常见的主诉症状之一。由于症状的非特异性,临床诊治往往较为困难。详尽的病史采集及系统完整的体格检查有助于初步判定病变部位,从而更加有针对性地选择相应的辅助检查,更快捷有效地明确病因,选择正确的治疗策略。本文基于笔者临床处理众多头晕/眩晕患者的诊治经验,从问诊及体格检查方面简要阐释头晕和眩晕的诊治思路。 展开更多
关键词 头晕 眩晕 病史采集 体格检查
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体格检查、脉搏血氧饱和度筛查和灌注指数在新生儿先天性心脏病筛查中的作用 被引量:21
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作者 潘诚 邹小明 +3 位作者 陈刚 王涛 江先宇 陈建勇 《临床儿科杂志》 CAS CSCD 北大核心 2018年第3期166-169,共4页
目的寻找可靠、简便、易推广的先天性心脏病(CHD)筛查方法。方法选择2017年1月-7月出生的新生儿7 105例,以彩色超声心动图为CHD诊断金标准,评估体格检查、脉搏血氧饱和度筛查(POS)及灌注指数(PI)在CHD筛查中的真实性、可靠性。结果将体... 目的寻找可靠、简便、易推广的先天性心脏病(CHD)筛查方法。方法选择2017年1月-7月出生的新生儿7 105例,以彩色超声心动图为CHD诊断金标准,评估体格检查、脉搏血氧饱和度筛查(POS)及灌注指数(PI)在CHD筛查中的真实性、可靠性。结果将体格检查、POS、PI单独作为筛查指标时,其灵敏度13.11%~73.77%,特异度50.20%~99.34%,约登指数0.12~0.70,总符合率50.40%~98.86%,阳性预测值1.27%~40.70%,阴性预测值99.29%~99.70%;以体格检查、POS及PI三个筛查指标组成混合组(三项指标中两项阳性或三项同时阳性)进行筛查时,其灵敏度、约登指数分别为85.25%、0.82,均较其他三个指标单独筛查CHD时的灵敏度、约登指数高,说明混合组真实性最高;混合组总符合率为97.07%,虽然比POS组(98.86%)和PI筛查组(98.58%)低,但仍具有较好的可靠性。结论联合体格检查、POS和PI筛查在新生儿CHD筛查中具有一定的临床推广价值。 展开更多
关键词 体格检查 脉搏血氧饱和度筛查 灌注指数 先天性心脏病 筛查
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Influences of oscillation on the physical stability and explosion characteristics of solid-liquid mixed fuel
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作者 Chi Zhang Ge Song +2 位作者 Hui Guo Jiafan Ren Chunhua Bai 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第10期191-198,共8页
The stratification phenomenon resulting from differences in the physical properties of solid-liquid components seriously affect the final combustion and explosion characteristics of mixed fuel under the action of osci... The stratification phenomenon resulting from differences in the physical properties of solid-liquid components seriously affect the final combustion and explosion characteristics of mixed fuel under the action of oscillation.The effects of oscillation on the physical stability of mixed fuel with two solid-liquid ratios and three liquid component distribution ratios have been investigated using a self-designed experimental system at oscillation frequencies of 60-300 r/min.The explosion characteristics of mixed fuel before and after oscillation are gained from a 20 L spherical explosion container system.When the mass ratio of liquid components is controlled at 66.9%,64.7%,62.6%the final explosion characteristics are stable,with a maximum difference of only 0.71%.The volume of liquid fuel precipitation increases with increasing oscillation frequency when the mass ratio of liquid components reaches 71.7%,69.6%,67.7%.The fuel explosion overpressure after oscillation decreases with increasing liquid precipitation volume,and the repeatability is poor,with a maximum standard deviation of 82.736,which is much higher than the ratio without stratification.Properly controlling the mass ratio of liquid components of the mixed fuel can effectively combat the impact of oscillation on the physical state and maintain the stability of the final explosion characteristics. 展开更多
关键词 Solid-liquid mixed fuel physical stability Explosion characteristics
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A data and physical model dual-driven based trajectory estimator for long-term navigation
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作者 Tao Feng Yu Liu +2 位作者 Yue Yu Liang Chen Ruizhi Chen 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第10期78-90,共13页
Long-term navigation ability based on consumer-level wearable inertial sensors plays an essential role towards various emerging fields, for instance, smart healthcare, emergency rescue, soldier positioning et al. The ... Long-term navigation ability based on consumer-level wearable inertial sensors plays an essential role towards various emerging fields, for instance, smart healthcare, emergency rescue, soldier positioning et al. The performance of existing long-term navigation algorithm is limited by the cumulative error of inertial sensors, disturbed local magnetic field, and complex motion modes of the pedestrian. This paper develops a robust data and physical model dual-driven based trajectory estimation(DPDD-TE) framework, which can be applied for long-term navigation tasks. A Bi-directional Long Short-Term Memory(Bi-LSTM) based quasi-static magnetic field(QSMF) detection algorithm is developed for extracting useful magnetic observation for heading calibration, and another Bi-LSTM is adopted for walking speed estimation by considering hybrid human motion information under a specific time period. In addition, a data and physical model dual-driven based multi-source fusion model is proposed to integrate basic INS mechanization and multi-level constraint and observations for maintaining accuracy under long-term navigation tasks, and enhanced by the magnetic and trajectory features assisted loop detection algorithm. Real-world experiments indicate that the proposed DPDD-TE outperforms than existing algorithms, and final estimated heading and positioning accuracy indexes reaches 5° and less than 2 m under the time period of 30 min, respectively. 展开更多
关键词 Long-term navigation Wearable inertial sensors Bi-LSTM QSMF Data and physical model dual-driven
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对人犯体格检查预防和打击牢头狱霸 被引量:1
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作者 易志成 《湖南大学学报(社会科学版)》 1999年第S1期72-74,共3页
提出抓住重点时期、重点对象,对人犯进行体格检查,同时与有关方面配合,有力地打击牢头狱霸。
关键词 人犯 体格检查 牢头狱霸
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Key Physical Factors Affecting Spatial-temporal Variation of Labile Organic Carbon Fractions by Biochar Driven in Mollisols Region of Northeast China
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作者 Zhao Wei Liang Fangyuan +4 位作者 Liang Ying Zhao Hongrui Hao Shuai Wang Hongyan Wang Daqing 《Journal of Northeast Agricultural University(English Edition)》 CAS 2024年第1期28-41,共14页
Biochar is widely used to improve soil physical properties and carbon sequestration. However, few studies focuse on the impact of maize stalk biochar on labile organic carbon(LOC) pool and the relationship between phy... Biochar is widely used to improve soil physical properties and carbon sequestration. However, few studies focuse on the impact of maize stalk biochar on labile organic carbon(LOC) pool and the relationship between physical properties and LOC fractions. A field positioning experiment was performed in Mollisols region of Northeast China to evaluate the influence of maize stalk biochar on the spatial distribution and temporal changes of physical properties and LOC fractions. Maize stalk biochar treatments included C1(1.5 kg·hm^(-2)), C2(3 kg·hm^(-2)), C3(15 kg·hm^(-2)), C4(30 kg·hm^(-2)), and CK(0). The results showed that maize stalk biochar increased soil water contents(SWC) and soil porosity(SP), but reduced bulk density(BD). Maize stalk biochar reduced dissolved organic carbon(DOC) contents in the 0-20 cm soil layer, ranging from 0.25 g·kg^(-1) to 0.31 g·kg^(-1) in harvest period, while increased in the 20-40 cm soil layer. In addition, the application of biochar had a significant impact on the spatial distribution and temporal change of SWC, BD, SP, DOC, hot-water extractable carbon(HWC), acid hydrolyzed organic carbon(AHC Ⅰ, Ⅱ), and readily oxidized organic carbon(ROC). High amounts of maize stalk biochar up-regulated the contents of soil organic carbon SOC, HWC, AHC Ⅰ, AHC Ⅱ, and ROC. In addition, SWC and SP were the key physical factors to affect LOC fractions. In conclusions, maize stalk biochar could improve physical properties, and then influence LOC fractions, and maize stalk biochar could be used as an organic amendment for restoring degraded soils governed by their rates of addition. 展开更多
关键词 maize stalk biochar labile organic carbon fraction Mollisols region soil physical property dissolved organic carbon
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四川大学网络空间安全学院最新研究成果发表于《Physics Reports》
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《信息网络安全》 北大核心 2025年第3期466-466,共1页
近日,四川大学网络空间安全学院助理研究员唐瑞与西南医科大学、重庆医科大学合作,在国际期刊《Physics Reports》上发表题为“Network Alignment”的长篇综述论文。唐瑞为论文第一作者,四川大学网络空间安全学院为第一单位。真实和虚... 近日,四川大学网络空间安全学院助理研究员唐瑞与西南医科大学、重庆医科大学合作,在国际期刊《Physics Reports》上发表题为“Network Alignment”的长篇综述论文。唐瑞为论文第一作者,四川大学网络空间安全学院为第一单位。真实和虚拟世界复杂系统中,组成元素之间的复杂交互可以建模为复杂网络,从而借助图论、概率统计和人工智能等理论与技术进行挖掘和研究。 展开更多
关键词 physics Reports Network Alignment
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中老年男性体格测量、体成分与定量CT腰椎骨密度相关性
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作者 刘澳 周菁 +9 位作者 孙永兵 戚昕 杜亚玮 周阳 李中林 武肖玲 邹智 吕雪 李永丽 李昊 《中国骨质疏松杂志》 北大核心 2025年第2期204-209,共6页
目的应用定量CT(quantitative computed tomography,QCT)技术测量腰椎骨密度(bone mineral density,BMD),探讨体格测量、体成分分析指标与中老年男性腰椎BMD的相关性。方法本研究为横断面研究,选取2018年1月至2023年2月在河南省人民医... 目的应用定量CT(quantitative computed tomography,QCT)技术测量腰椎骨密度(bone mineral density,BMD),探讨体格测量、体成分分析指标与中老年男性腰椎BMD的相关性。方法本研究为横断面研究,选取2018年1月至2023年2月在河南省人民医院健康管理中心接受体格检查的1152名中老年男性体检者为研究对象,采集受试者年龄、身高、体重、血压、腰围、臀围、体脂肪质量与体肌肉质量数据,并计算体质量指数(body mass index,BMI)、体脂率(body fat percentage,BFP)与骨骼肌质量指数(skeletal muscle mass index,SMI)。同时使用QCT技术测量受试者腰椎BMD值,按照BMI进行分组,分为BMI正常组(18.5≤BMI<24 kg/m^(2))、超重及肥胖组(BMI为>24 kg/m^(2)),并在两组中分别按照骨量诊断标准进行讨论。采用单因素方差分析,Pearson相关性分析和偏相关分析体格测量、体成分分析指标与腰椎BMD的相关性。结果在BMI正常组中,骨质疏松组的年龄、收缩压、腰臀比、BFP显著高于骨量正常组,SMI显著低于骨量正常组与骨量减少组(P均<0.05);超重及肥胖组中,骨质疏松组的年龄、收缩压、腰围、腰臀比与BFP显著高于骨量正常组,SMI显著低于骨量正常组与骨量减少组(P均<0.05)。Pearson相关性分析结果显示,BMI正常组中腰椎BMD值与年龄、腰围、腰臀比、BFP呈显著负相关关系(r=-0.385,r=-0.122,r=-0.199,r=-0.168,P均<0.05),与SMI呈正相关(r=0.226,P<0.05);超重及肥胖组中腰椎BMD值与年龄、收缩压、腰围、腰臀比、BFP呈显著负相关关系(r=-0.379,r=-0.087,r=-0.101,r=-0.187,r=-0.199,P均<0.05),与SMI呈正相关(r=0.251,P<0.05)。在校正年龄因素后,偏相关分析分析结果显示,BMI正常组中腰椎BMD值与腰围、腰臀比、BFP呈显著负相关关系(r=-0.157,r=-0.212,r=-0.134,P均<0.05),与SMI呈正相关(r=0.167,P<0.05);超重及肥胖组中腰椎BMD值与腰围、腰臀比、BFP呈显著负相关关系(r=-0.120,r=-0.163,r=-0.126,P均<0.05),与SMI呈正相关(r=0.159,P<0.05)。结论腰围、腰臀比、BFP、SMI与中老年男性体检人群腰椎BMD值密切相关,对肥胖和骨质疏松症的预防与管理具有一定临床价值。 展开更多
关键词 QCT技术 腰椎BMD 体格测量 体成分分析 相关性分析
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浅谈诊断学基础体格检查教学中的三个基本环节
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作者 杨慧 陈秀娥 《教育理论与实践》 CSSCI 北大核心 2002年第S1期143-,共1页
一是教室教学。体格检查是对身体各系统进行全面检查的基本方法,在教授过程中首先要复习有关系统脏器的解剖位置及各种生理功能。例如:心脏检查,心脏位于胸骨体和第2-6肋软骨后方,第5-8胸椎前方,上方与大血管相连,下方为膈,其2/3居前正... 一是教室教学。体格检查是对身体各系统进行全面检查的基本方法,在教授过程中首先要复习有关系统脏器的解剖位置及各种生理功能。例如:心脏检查,心脏位于胸骨体和第2-6肋软骨后方,第5-8胸椎前方,上方与大血管相连,下方为膈,其2/3居前正中线左侧,1/3在其右侧;心脏功能是按一定频率通过其收缩、舒张推动血液在血管中流动。这样就便于心脏检查手法的讲解。学生掌握了各脏器解剖、生理功能后。 展开更多
关键词 体格检查 实验室 阳性体征 示教
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基于COMSOL Multiphysics软件的某地铁配电柜温湿度控制策略 被引量:1
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作者 邓雷 崔光磊 《城市轨道交通研究》 北大核心 2025年第4期71-77,共7页
[目的]运行在长江流域高温高湿环境中的配电柜,易受自然环境的影响发生内部凝露现象,引发设备受潮及故障。为避免凝露引发的配电柜故障,有必要分析凝露现象产生的机理,研究配电柜的温湿度控制策略。[方法]基于凝露引发的配电柜故障,分... [目的]运行在长江流域高温高湿环境中的配电柜,易受自然环境的影响发生内部凝露现象,引发设备受潮及故障。为避免凝露引发的配电柜故障,有必要分析凝露现象产生的机理,研究配电柜的温湿度控制策略。[方法]基于凝露引发的配电柜故障,分析了凝露现象产生的机理及主要影响因素。以中部某城市地铁配电间内配电柜为例,利用COMSOL Multiphysics仿真软件构建配电柜全尺寸多物理场耦合仿真模型。基于环境测控的历史数据进行仿真,分析配电柜内温度及湿度变化对柜内凝露现象的影响。基于2022年数据,统计自然状态下各月的凝露概率,结合仿真计算结果提出配电柜温湿度控制策略,并通过仿真计算对控制效果进行分析。[结果及结论]凝露现象同相对湿度和露点温度密切相关。6月和7月的凝露概率最高,入夜后凌晨至清晨最易发生凝露。提高配电间空调设置温度并降低环境相对湿度,可显著降低配电柜发生凝露的概率。具体控制策略为:在夏季空调制冷时,配电间内空调温度设置不宜低于26℃:在配电间增设除湿机,将环境相对湿度降低至75%及以下。经仿真结果验证,温湿度控制策略具有良好的防凝露效果。 展开更多
关键词 地铁 配电柜 多物理场 温湿度 凝露
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对我国体育素养概念的理解——基于对Physical Literacy的解读 被引量:181
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作者 陈思同 刘阳 +1 位作者 唐炎 陈昂 《体育科学》 CSSCI 北大核心 2017年第6期41-51,共11页
Physical Literacy是当前国际体育教育学者关注的研究热点,与我国体育素养概念有着相似的背景、价值、特性和发展路径。在我国体育素养概念发展存在不足的情况下,可以借鉴Physical Literacy的概念进一步推动我国体育素养概念的发展。研... Physical Literacy是当前国际体育教育学者关注的研究热点,与我国体育素养概念有着相似的背景、价值、特性和发展路径。在我国体育素养概念发展存在不足的情况下,可以借鉴Physical Literacy的概念进一步推动我国体育素养概念的发展。研究旨在:1)回顾我国体育素养的概念;2)系统阐释Physical Literacy的概念,在汉语环境中解释这一概念;3)参考Physical Literacy的价值为我国学界进一步发展体育素养的概念提供经验,也为我国学校体育的发展提供启示。通过文献梳理和比较分析:1)我国体育素养的概念存在"概念失真"、价值窄化、定义不清晰和属性不明确等不足;2)Physical Literacy概念可以被翻译为"体育素养",是人类在整个生命过程中维持身体活动所需的综合能力;3)借鉴Physical Literacy的价值和理念,我国体育素养的概念可以被理解为"人类在生命过程中获得利于全人生存发展的运动要素的综合,包括体育意识、体育知识、体育行为、体育技能、体质水平"。建议进一步理解体育素养概念的价值,通过扎实的操作研究和社会行动,探索体育素养概念的深层次价值。此外,学校体育环境是发展体育素养的有效环境。 展开更多
关键词 学校体育 physical LITERACY 体育素养 体质健康
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