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Research 2024年第1期2023卷 339-349页

作者： donghai zhang Shanshan Jiang Xiaodong Tao Fulin Lin Lingyi Meng Xu-Lin Chen Can-Zhong Lu State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian 350002China Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China FuzhouFujian 350108China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamenFujian 361021China University of Chinese Academy of Sciences Beijing 100049China

Thermally activated delayed fluorescence(TADF)materials with both high photoluminescence quantum yield(PLQY)and fast reverse intersystem crossing(RISC)are strongly desired to realize efficient and stable organic light-emitting diodes(OLEDs).Control of excited-state dynamics via molecular design plays a central role in optimizing the PLQY and RISC rate of TADF materials but remains challenging.Here,3 TADF emitters possessing similar molecular structures,similar high PLQYs(89.5%to 96.3%),and approximate energy levels of the lowest excited singlet states(S_(1)),but significantly different spin-flipping RISC rates(0.03×10^(6) s^(−1) vs.2.26×10^(6) s^(−1))and exciton lifetime(297.1 to 332.8μs vs.6.0μs)were systematically synthesized to deeply investigate the feasibility of spin-flip between charge-transfer excited states(^(3)CT–^(1)CT)transition.

关键词： transition lifetime desired

Spatiotemporal changes in vegetation coverage and its driving factors in the Three-River Headwaters Region during 2000-2011

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Journal of Geographical Sciences 2014年第2期24卷 288-302页

作者： LIU Xianfeng zhang Jinshui ZHU Xiufang PAN Yaozhong LIU Yanxu zhang donghai LIN Zhihui State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University Beijing 100875 China College of Resources Science & Technology Beijing Normal University Beijing 100875 China College of Urban and Environmental Sciences Peking University Beijing 100871 China College of Tourism and Environment Shaanxi Normal University Xi'an 710062 China

The Three-River Headwaters Region （TRHR）, which is the source area of the Yangtze River, Yellow River, and Lancang River, is of key importance to the ecological secu- rity of China. Because of climate changes and human activities, ecological degradation oc- curred in this region. Therefore, ＂The nature reserve of Three-River Sou,＇ce Regions＂ was established, and ＂The project of ecological protection and construction for the Three-River Headwaters Nature Reserve＂ was implemented by the Chinese government. This study, based on MODIS-NDVI and climate data, aims to analyze the spatiotemporal changes in vegetation coverage and its driving factors in the TRHR between 2000 and 2011, from three dimensions. Linear regression, Hurst index analysis, and partial correlation analysis were employed. The results showed the following：（1） In the past 12 years （2000-2011）, the NDVI of the study area increased, with a linear tendency being 1.2%/10a, of which the Yangtze and Yellow River source regions presented an increasing trend, while the Lancang River source region showed a decreasing trend. （2） Vegetation coverage presented an obvious spatial difference in the TRHR, and the NDVI frequency was featured by a bimodal structure. （3） The area with improved vegetation coverage was larger than the degraded area, being 64.06% and 35.94%, respectively during the study period, and presented an increasing trend in the north and a decreasing trend in the south. （4） The reverse characteristics of vegetation cov- erage change are significant. In the future, degradation trends will be mainly found in the Yangtze River Basin and to the north of the Yellow River, while areas with improving trends are mainly distributed in the Lancang River Basin. （5） The response of vegetation coverage to precipitation and potential evapotranspiration has a time lag, while there is no such lag in the case of temperature. （6） The increased vegetation coverage is mainly attributed to the warm-wet climate change and the implementation of the ecological protectio

关键词： vegetation coverage spatiotemporal change future trend influence factors Three-River HeadwatersRegion

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膨胀型钢结构防火涂料的研究进展

涂料工业 2024年第3期54卷 59-65页

作者：吴沛沛张依晴田爱琴曹鑫张玲王锦张冬海中车青岛四方机车车辆股份有限公司国家工程研究中心山东青岛266111 北京科技大学化学与生物工程学院化学与化学工程系北京100083 中国科学院过程工程研究所多相复杂系统国家重点实验室北京100190 上海鹏图抗菌新材料有限公司上海201800

以P-C-N(聚磷酸铵APP、季戊四醇PER、三聚氰胺MEL组成)为膨胀体系的钢结构防火涂料应用广泛,但普遍存在耐水性差、防火抑烟效果达不到预期等问题。以P-C-N膨胀体系的优化及发展为主线,梳理和总结了膨胀型钢结构防火涂料相关研究。发现... 详细信息

以P-C-N(聚磷酸铵APP、季戊四醇PER、三聚氰胺MEL组成)为膨胀体系的钢结构防火涂料应用广泛,但普遍存在耐水性差、防火抑烟效果达不到预期等问题。以P-C-N膨胀体系的优化及发展为主线,梳理和总结了膨胀型钢结构防火涂料相关研究。发现通过对膨胀体系中亲水性组分的改性来优化P-C-N膨胀体系、在防火涂料中添加碳材料、过渡金属化合物等填料,可协同提高防火涂料性能并取得了较好的效果。然而,这些研究仍未能很好地解决防火涂料环境耐久性及高效防火的发展要求,因此开发新的膨胀体系已成为当前研究的需求与热点。

关键词：钢结构防火涂料膨胀体系研究进展

安全鞋品质检测与监管抽查联动机制构建与实践研究

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鞋类工艺与设计 2024年第4期4卷 3-5页

作者：常征张东海潍坊市产品质量检验所山东潍坊261031

近年来,随着我国乃至全球对安全生产法规的日益完善以及劳动者权益保护意识的提升,市场对于高品质、高防护性能的安全鞋需求正逐年增长,不仅要求产品具备严格的质量保证,同时还强调其舒适度和耐用性。但从现实情况来看,安全鞋品质检测... 详细信息

近年来,随着我国乃至全球对安全生产法规的日益完善以及劳动者权益保护意识的提升,市场对于高品质、高防护性能的安全鞋需求正逐年增长,不仅要求产品具备严格的质量保证,同时还强调其舒适度和耐用性。但从现实情况来看,安全鞋品质检测与监管还存在一定程度的问题,导致安全鞋的质量参差不齐。针对上述问题,本研究从安全鞋品质检测与监管工作现状入手,提出安全鞋品质检测与监管抽查联动机制的构建措施与建议,仅供参考与借鉴。

关键词：安全鞋品质检测监管抽查联动机制

基于p阶线性模型的地埋管换热器流体温度分布研究

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太阳能学报 2024年第6期45卷 51-59页

作者：赵鹏张东海李晓昭张古彬寇亚飞高蓬辉中国矿业大学深部岩土力学与地下工程国家重点实验室徐州221116 深地科学与工程云龙湖实验室徐州221006 中国矿业大学土木与力学学院徐州221116 河南省地质调查院郑州450001

利用自主研发的分层热响应测试系统,获取沿深度方向上(竖向)管内流体温度实测数据,对比p阶线性分布模型计算结果和实测数据,研究两种典型工况条件下分层岩土介质中管内流体竖向分布规律和最佳p值。结果表明:恒热流工况时,p=-5阶线性分... 详细信息

利用自主研发的分层热响应测试系统,获取沿深度方向上(竖向)管内流体温度实测数据,对比p阶线性分布模型计算结果和实测数据,研究两种典型工况条件下分层岩土介质中管内流体竖向分布规律和最佳p值。结果表明:恒热流工况时,p=-5阶线性分布模型能够准确预测管内流体温度分布;恒温工况时,最佳p值随流量的变化而变化,其关系为:|p|=7.361ln V+6.684。

关键词：地热能地埋管换热器岩土传热地质结构分层参数估值

Numerical investigation and modeling of sweep effects on inlet flow field of axial compressor cascades

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Chinese Journal of Aeronautics 2024年第2期37卷 296-308页

作者： Jiancheng zhang donghai JIN Xingmin GUI School of Energy and Power Engineering Beihang UniversityBeijing 100191China Jiangxi Research Institue of Beihang University Nanchang 330096China

Swept blades are widely utilized in transonic compressors/fans and provide high load,high through-flow,high efficiency,and adequate stall margin.However,there is limited quantitative research on the mechanism of the effect of swept blades on the flow field,resulting in a lack of direct quantitative guidance for the design and analysis of swept blades in fans/compressors.To better understand this mechanism,this study employs a reduced-dimensional force equilibrium method to analyze more than 1500 swept cascades data.Results verify that circumferential fluctuation terms are responsible for inducing radial migration in the inlet airflow field of the swept blade,resulting in variations in the incidence angle and consequently leading to changes in the characteristics of the swept blade.Thus,a combination of simple functions and machine learning is utilized to model the circumferential fluctuation terms and quantify the sweep mechanism.The prediction accuracy of the model is high,with coefficient of determination greater than 0.95 on the test set.When the model is applied in a meridional flow analysis program,the calculation accuracy of the program for the incidence angle is improved by 0.4°and 0.6°at the design and off-design conditions respectively,compensating for the program’s original deficiencies.Meanwhile,the model can also provide quantitative guidance for the design of swept blades,thereby reducing the number of design iterations and improving design efficiency.

关键词： Turbomachinery Sweep aerodynamics Quasi-3D method Incidence angle Circumferential fluctuation Machine learning

智能网联技术下机载电子电气设备检测系统设计

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电子设计工程 2024年第4期32卷 153-157页

作者：孙小伟张启浩李琦刘畅张东海南方电网有限责任公司超高压输电昆明局云南昆明650214 云南兆富科技有限公司云南昆明650217

机载电子电气设备检测容易受到外界干扰,出现参数辨识不精准,导致检测结果不精准的情况。针对该问题,在智能网联技术下设计机载电子电气设备检测系统。使用嵌入式检测适配器,对输出信号进行放大、隔离、变换处理。结合防错插设计方式,... 详细信息

机载电子电气设备检测容易受到外界干扰,出现参数辨识不精准,导致检测结果不精准的情况。针对该问题,在智能网联技术下设计机载电子电气设备检测系统。使用嵌入式检测适配器,对输出信号进行放大、隔离、变换处理。结合防错插设计方式,确保检测装置安全连接。利用光耦合器实现信号的驱动与变换,使用智能网联技术聚集特征向量构建密度函数,获取聚类同期运行的峰值参数。归一化处理智能网联聚类参数,计算实际与理论辨识参数之间的差值,以此为依据判断设备运行状态。以报文ID数据标识为特征,计算时间窗口为1的信息熵值,实现固定时间窗口下的设备检测。由实验结果可知,该系统在三种场景下与实际熵值的最大误差为1.2,说明使用该系统检测结果较精准。

关键词：智能网联技术机载电子电气设备参数辨识

EAF+VAR生产15-5PH不锈钢点状缺陷成因及改进

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特殊钢 2024年第4期45卷 94-98页

作者：章东海潘明旭李旭许勇熊皓大冶特殊钢有限公司锻造事业部黄石435001 大冶特殊钢有限公司黄石435001

采用冶炼成本较低的EAF→VOD→LF+VD→浇注6 t电极棒→真空自耗重熔(VAR)的新工艺流程代替传统双真空冶炼工艺生产15-5PH不锈钢,使用扫描电镜、ASPEX等对其探伤点状缺陷进行检测,并分析其产生原因。结果表明,自耗电极中已存在铝酸钙及... 详细信息

采用冶炼成本较低的EAF→VOD→LF+VD→浇注6 t电极棒→真空自耗重熔(VAR)的新工艺流程代替传统双真空冶炼工艺生产15-5PH不锈钢,使用扫描电镜、ASPEX等对其探伤点状缺陷进行检测,并分析其产生原因。结果表明,自耗电极中已存在铝酸钙及镁铝尖晶石非金属夹杂物,真空自耗重熔过程的不稳定,将锭冠和非金属漂浮物卷入熔池残留在自耗锭中,导致锻造成材后产生点状缺陷。通过工艺优化改进,VOD还原渣料由铝粒9 kg/t调整为硅铁8 kg/t、铝粒5 kg/t复合脱氧,精炼渣系成分由(质量分数)CaO为50%~55%、SiO_(2)为10%~15%、Al_(2)O_(3)为20%~25%调整为CaO为45%~50%、SiO_(2)为5%~10%、Al_(2)O_(3)为33%~38%,真空自耗重熔熔速由4.2 kg/min提高至6 kg/min、熔滴时间由0.23 s提高至0.27 s,自耗电极洁净度得到较大的提升,自耗重熔过程熔速控制稳定,熔池液面非金属漂浮物得以去除,成品材高低倍检验均满足标准要求,探伤合格率提高至98%以上。

关键词： 15-5PH不锈钢点状缺陷精炼渣系真空自耗重熔熔滴时间

Summer Atmospheric Water Cycle under the Transition Influence of the Westerly and Summer Monsoon over the Yarlung Zangbo River Basin in the Southern Tibetan Plateau

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Advances in Atmospheric Sciences 2024年第5期41卷 830-846页

作者： Qianhui MA Chunyan zhang donghai WANG Zihao PANG School of Atmospheric Sciences Sun Yat-sen UniversityGuangdong Province Key Laboratory for Climate Change and Natural Disaster StudiesKey Laboratory of Tropical Atmosphere-Ocean SystemMinistry of EducationZhuhai 519082China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China Guangdong Meteorological Data Center Guangdong Meteorological ServiceGuangzhou 510080China National Observation and Research Station of Coastal Ecological Environments in Macao Macao Environmental Research InstituteMacao University of Science and TechnologyMacao SAR 999078China National Meteorological Information Center China Meteorological AdministrationBeijing 100081China

This study compares the summer atmospheric water cycle,including moisture sources and consumption,in the upstream,midstream,and downstream regions of the Yarlung Zangbo River Basin in the southern Tibetan Plateau.The evolutions of moisture properties under the influence of the westerly and summer southerly monsoon are examined using 5-yr multi-source measurements and ERA5 reanalysis data.Note that moisture consumption in this study is associated with clouds,precipitation,and diabatic heating.Compared to the midstream and downstream regions,the upstream region has less moisture,clouds,and precipitation,where the moisture is brought by the westerly.In early August,the vertical wet advection over this region becomes enhanced and generates more high clouds and precipitation.The midstream region has moisture carried by the westerly in June and by the southerly monsoon from July to August.The higher vertical wet advection maximum here forms more high clouds,with a precipitation peak in early July.The downstream region is mainly affected by the southerly-driven wet advection.The rich moisture and strong vertical wet advection here produce the most clouds and precipitation among the three regions,with a precipitation peak in late June.The height of the maximum moisture condensation is different between the midstream region(325 hPa)and the other two regions(375 hPa),due to the higher upward motion maximum in the midstream region.The diabatic heating structures show that stratiform clouds dominate the upstream region,stratiform clouds and deep convection co-exist in the midstream region,and deep convection systems characterize the downstream region.

关键词： Yarlung Zangbo River Basin atmospheric water cycle constrained variational analysis moisture source and consumption

贵州省不同强度区域性凝冻过程环流形势对比分析

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气象科技 2024年第2期52卷 228-242页

作者：李忠燕任曼琳谭娅姮严小冬张东海贵州省气候中心贵阳550002 贵州省山地气候与资源重点实验室贵阳550002

利用贵州省84个气象站逐日观测资料以及再分析资料,对4种不同强度区域性凝冻过程进行对比分析。结果表明:500 hPa位势高度场上中高纬度的亚洲东部区域距平场呈现“+-”的分布或有切断低压分布,贝加尔湖至中国华北地区以经向环流为主;850... 详细信息

利用贵州省84个气象站逐日观测资料以及再分析资料,对4种不同强度区域性凝冻过程进行对比分析。结果表明:500 hPa位势高度场上中高纬度的亚洲东部区域距平场呈现“+-”的分布或有切断低压分布,贝加尔湖至中国华北地区以经向环流为主;850 hPa风场上云南南部以南受偏南风和西南风控制,并且在江南至华南存在西南或西风急流,是4种不同强度凝冻过程中形势场共性特征。500 hPa高度场上中高纬度地区呈两槽一脊或一槽一脊分布;风场上850 hPa东北风回流和700 hPa西南急流形成上暖下冷的形势场,同时850 hPa形成稳定低层切变线;温度场上存在冷暖冷的夹心结构,近地面层0℃线维持在900 hPa以下,均是较强等级以上的区域性凝冻过程中形势场共性特征。而对于一般性区域性凝冻过程,500 hPa位势高度场上呈多槽脊分布,风场上是否存在东北风回流和低层切变线,温度场上是否存在冷暖冷的夹心结构以及近地面层0℃线位置等特征均不统一。温度剖面图上,当近地面层0℃线位置最低时或出现冷暖冷的夹心结构时段与凝冻过程影响范围最广、灾情最重的时间段对应。

关键词：区域性凝冻过程不同强度逆温层融化层东北风回流