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Hydrodynamic Characteristics of Undular Tidal Bores in the Qiantang River Based on Field Observations

China Ocean Engineering 2024年第3期38卷 505-518页

作者： ZHANG Shu-yu PAN Cun-hong ZHANG Shen-yang LI Ruo-hua cheng wenlong XIE Dong-feng Zhejiang Tongji Vocational College of Science and Technology Hangzhou 311231China Zhejiang Institute of Hydraulics and Estuary Hangzhou 310020China

Understanding the undular tidal bores in the Qiantang River is essential for effective river management and *** breaking tidal bores have been studied extensively, reports on undular tidal bores in the Qiantang Riverremain limited. Furthermore, observed data on undular tidal bores fulfilling the requirements of short measurementtime intervals, and spring, medium, and neap tide coverage, and providing detailed data for the global vertical stratificationof flow velocity are quite limited. Based on field observations at Qige in the Qiantang estuary, we analyzedthe characteristics of undular tidal bores. The results showed that the flooding amplitude (a) of the first wave isalways larger than its ebbing amplitude (b). Moreover, the vertical distribution of the maximum flood velocity exhibitesthree shapes, influenced by the tidal range, while that of the maximum ebb velocity exhibites a single shape. Duringthe initial phase of the flood tide in the spring and medium tides, the upper water body experiences multiple oscillatingchanges along the flow direction, corresponding to the alternating process of the crest and trough of the tide levelupon the arrival of the tidal bore. The tidal range is a crucial parameter in tidal bore hydrodynamics. By establishingthe relationship between hydrodynamic parameters and tidal range, other hydrodynamic parameters, such as the tidalbore height, maximum flood depth–averaged velocity, maximum flood stratified velocity at the measurement points,and duration of the flood tide current, can be effectively predicted, thereby providing an important reference for rivermanagement and maintenance.

关键词： tidal bores Qiantang Estuary tidal bore height tidal bore velocity propagation speed

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小倾角对Ω形弯曲热管传热特性的影响

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北京航空航天大学学报 2024年第7期50卷 2314-2321页

作者：王卓潘宇晖赵锐年永乐程文龙中国科学技术大学工程科学学院合肥230027

为研究小倾角对Ω形槽道弯曲热管传热特性的影响,搭建了热管传热性能实验台,基于实验对不同小倾角下热管的温度分布、总热阻、当量导热系数和最大输入功率进行分析。结果表明:在相同输入功率下,倾角为0°和倾角为负的热管壁温均匀性优... 详细信息

为研究小倾角对Ω形槽道弯曲热管传热特性的影响,搭建了热管传热性能实验台,基于实验对不同小倾角下热管的温度分布、总热阻、当量导热系数和最大输入功率进行分析。结果表明:在相同输入功率下,倾角为0°和倾角为负的热管壁温均匀性优于倾角为正的热管;倾角为正的热管总热阻最大,倾角为0°和倾角为负的热管总热阻相近;热管倾角为0°时的最大输入功率最高。热管安装和应用中易出现重力倾角偏差,研究结果表明,较小倾角会对Ω形槽道弯曲热管的传热性能造成影响。

关键词：热管传热小倾角热阻当量导热系数最大输入功率

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两步法高效含氚净化水空气载带系统研究

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原子能科学技术 2024年第5期58卷 1160-1168页

作者：程文龙许张敏年永乐赵锐陈华中国科学技术大学工程科学学院安徽合肥230027 合肥工业大学汽车与交通工程学院安徽合肥230009

针对现有含氚净化水空气载带技术排放效率低、环境适应性差的问题,提出一种基于溴化锂制冷驱动溶液除湿和高效雾化加湿的两步法含氚净化水空气载带系统,搭建了载带量大于2 t/d的试验样机,并在不同工况下开展了载带实验研究。结果显示:... 详细信息

针对现有含氚净化水空气载带技术排放效率低、环境适应性差的问题,提出一种基于溴化锂制冷驱动溶液除湿和高效雾化加湿的两步法含氚净化水空气载带系统,搭建了载带量大于2 t/d的试验样机,并在不同工况下开展了载带实验研究。结果显示:试验样机在空气温度3~50℃、空气相对湿度0~90%的环境工况下可安全、高效地排放含氚净化水,试验样机在典型工况、高湿工况、高温工况下,载带量分别为100.8、119.9、96.0 kg/h,与一步法相比,载带量分别提升了298.4%、508.6%、60.0%。这表明,基于两步法的含氚净化水空气载带系统可大幅拓宽含氚净化水安全排放的环境适应范围,且排放效率较高,可为含氚净化水的排放应用提供参考。

关键词：含氚净化水空气载带溶液除湿溴化锂制冷雾化加湿

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术前导尿对输尿管镜置镜成功率的影响研究

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中国现代医生 2024年第17期62卷 59-61页

作者：李钦涛程文龙北京市大兴区瀛海医院外科北京100163 北京市朝阳区双桥医院泌尿外科北京102600

目的评估术前导尿对输尿管镜置镜成功率的影响。方法选取2020年10月至2023年9月期间收治的400例输尿管结石患者为研究对象,均行输尿管镜钬激光碎石术,根据术前是否导尿,将患者分为两组:观察组(导尿组)200例,对照组(非导尿组)200例。记... 详细信息

目的评估术前导尿对输尿管镜置镜成功率的影响。方法选取2020年10月至2023年9月期间收治的400例输尿管结石患者为研究对象,均行输尿管镜钬激光碎石术,根据术前是否导尿,将患者分为两组:观察组(导尿组)200例,对照组(非导尿组)200例。记录并分析两组患者一次性置镜成功例数、置镜手术时间、并发症发生率等。结果观察组的置镜时间为(126.35±1.55)s,明显低于对照组的(241.33±1.50)s(P0.05)。结论术前导尿可以缩短输尿管镜置镜时间,并且置镜成功率和安全性更高,值得临床推广。

关键词：输尿管镜钬激光碎石术输尿管镜置镜

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基于热电制冷的微流体线性降温特性研究

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制冷学报 2024年第1期45卷 55-62页

作者：王好卿孙东方高才程文龙周培唐景春朱俊叶韩雪张梦飞合肥工业大学汽车与交通工程学院合肥230009 中国科学技术大学工程科学学院合肥230026

目前,微流体的精确线性降温是微流控技术在医学和生命科学等领域发展应用过程中面临的难题。为实现微流控芯片目标区域的线性降温,本文设计了基于热电制冷的微流体芯片温度调控系统,通过数值模拟和实验测试,实现了电流、制冷量及微流体... 详细信息

目前,微流体的精确线性降温是微流控技术在医学和生命科学等领域发展应用过程中面临的难题。为实现微流控芯片目标区域的线性降温,本文设计了基于热电制冷的微流体芯片温度调控系统,通过数值模拟和实验测试,实现了电流、制冷量及微流体温度之间的线性耦合响应。结果表明:常规恒定电流驱动热电制冷器时,微流体样品池降温过程线性度仅为0.598,采用单一函数非稳态电流可显著提升微流体降温的线性度,但在不同时间段仍存在冷量盈余与缺口,无法满足线性降温的精度要求。因此,将多种电流波形耦合获得了实现热电冷却微流体线性降温的非稳态过渡电流机制,最终实现了微流体在-19~26℃与24~42℃/min之间的线性降温,线性度在0.9981以上,并通过实验验证了热电冷却微流体线性降温机制的准确性。

关键词：热电制冷微流控线性降温降温速率非稳态电流

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Experimental investigation on weak shock wave mitigation characteristics of flexible polyurethane foam and polyurea

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Defence Technology（防务技术） 2024年第1期31卷 179-191页

作者： Shiyu Jia cheng Wang wenlong Xu Dong Ma Fangfang Qi State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China Institute for Advanced Technology Shandong UniversityJinan250061China

In recent years,explosion shock wave has been considered as a signature injury of the current military *** strong shock wave is lethal to the human body,weak shock wave can cause many more lasting *** investigate the protection ability and characteristics of flexible materials and structures under weak shock wave loading,the blast wave produced by TNT explosive is loaded on the polyurethane foam with the density of 200.0 kg/m3(F-200)and 400.0 kg/m3(F-400),polyurea with the density of 1100.0 kg/m^(3)(P-1100)and structures composed of the two materials,which are intended for individual *** results indicate that the shock wave is attenuated to weak pressure disturbance after interacting with the flexible materials which are not *** shock wave protective capability of single-layer materials is dependent on their thickness,density and microscopic *** overpressure,maximum pressure rise rate and impulse of transmitted wave decrease exponentially with increase in sample *** the same thickness,F-400 provides better protective capability than F-200 while P-1100 shows the best protective capability among the three *** this study,as the materials are not destroyed,F-200 with a thickness more than10.0 mm,F-400 with a thickness more than 4.0 mm,and P-1100 with a thickness more than 1.0 mm can attenuate the overpressure amplitude more than 90.0%.Further,multi-layer flexible composites are *** layer layouts of designed structures and layer thickness of the single-layer materials can affect the protective *** the research range,the structure in which polyurea is placed on the impact side shows the optimal shock wave protective performance,and the thicknesses of polyurea and polyurethane foam are 1.0 mm and 4.0 mm *** overpressure attenuation rate reached maximum value of 93.3%and impulse attenuation capacity of this structure are better than those of s

关键词： Free-field explosion Weak shock wave mitigation Polyurea Polyurethane foam Multi-layered composites

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Single-cell transcriptome atlas reveals spatiotemporal developmental trajectories in the basal roots of moso bamboo (Phyllostachys edulis)

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Horticulture Research 2023年第8期10卷 59-71页

作者： Zhanchao cheng Changhong Mu Xiangyu Li wenlong cheng Miaomiao Cai Chongyang Wu Jutang Jiang Hui Fang Yucong Bai Huifang Zheng Ruiman Geng Junlei Xu Yali Xie Yuping Dou Juan Li Shaohua Mu Jian Gao Key Laboratory of National Forestry and Grassland Administration/Beijing for Bamboo&Rattan Science and Technology International Center for Bamboo and RattanBeijing 100102China

Roots are essential for plant growth and *** is a large Poaceae perennial with 1642 species ***,little is known about the transcriptional atlas that underpins root cell-type ***,we set up a modified protocol for protoplast preparation and report single-cell transcriptomes of 14279 filtered single cells derived from the basal root tips of moso *** identified four cell types and defined new cell-type-specific marker genes for the basal *** reconstructed the developmental trajectories of the root cap,epidermis,and ground tissues and elucidated critical factors regulating cell fate *** to in situ hybridization and pseudotime trajectory analysis,the root cap and epidermis originated from a common initial cell lineage,revealing the particularity of bamboo basal root *** further identified key regulatory factors for the differentiation of these cells and indicated divergent root developmental pathways between moso bamboo and ***,PheWOX13a and PheWOX13b ectopically expressed in Arabidopsis inhibited primary root and lateral root growth and regulated the growth and development of the root cap,which was different from WOX13 orthologs in *** together,our results offer an important resource for investigating the mechanism of root cell differentiation and root system architecture in perennial woody species of Bambusoideae.

关键词： inhibited roots bamboo

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Spectral purification improves monitoring accuracy of the comprehensive growth evaluation index for film-mulched winter wheat

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Journal of Integrative Agriculture 2024年第5期23卷 1523-1540页

作者： Zhikai cheng Xiaobo Gu Yadan Du Zhihui Zhou wenlong Li Xiaobo Zheng Wenjing Cai Tian Chang Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid AreasMinistry of Education/Northwest A&F University Yangling712100China

In order to further improve the utility of unmanned aerial vehicle(UAV)remote-sensing for quickly and accurately monitoring the growth of winter wheat under film mulching, this study examined the treatments of ridge mulching,ridge–furrow full mulching, and flat cropping full mulching in winter *** on the fuzzy comprehensive evaluation (FCE) method, four agronomic parameters (leaf area index, above-ground biomass, plant height, and leaf chlorophyll content) were used to calculate the comprehensive growth evaluation index (CGEI) of the winter wheat, and 14 visible and near-infrared spectral indices were calculated using spectral purification technology to process the remote-sensing image data of winter wheat obtained by multispectral *** machine learning algorithms, partial least squares, support vector machines, random forests, and artificial neural network networks(ANN), were used to build the winter wheat growth monitoring model under film mulching, and accuracy evaluation and mapping of the spatial and temporal distribution of winter wheat growth status were carried *** results showed that the CGEI of winter wheat under film mulching constructed using the FCE method could objectively and comprehensively evaluate the crop growth *** accuracy of remote-sensing inversion of the CGEI based on the ANN model was higher than for the individual agronomic parameters, with a coefficient of determination of 0.75,a root mean square error of 8.40, and a mean absolute value error of *** purification could eliminate the interference of background effects caused by mulching and soil, effectively improving the accuracy of the remotesensing inversion of winter wheat under film mulching, with the best inversion effect achieved on the ridge–furrow full mulching area after spectral *** results of this study provide a theoretical reference for the use of UAV remote-sensing to monitor the growth status of winter wheat with film mulching.

关键词： mulched winter wheat machine learning fuzzy comprehensive evaluation comprehensive growth evaluation index unmanned aerial vehicle

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Soft piezoresistive pressure sensing matrix from copper nanowires composite aerogel

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Science Bulletin 2016年第20期61卷 1624-1630页

作者： Lim Wei Yap Shu Gong Yue Tang Yonggang Zhu wenlong cheng Department of Chemical Engineering Monash UniversityClayton VIC 3800 Australia Melbourne Centre for Nanofabrication Clayton VIC 3168Australia CSIRO Manufacturing Flagship Clayton VIC 3168 Australia

We report on a simple yet efficient approach to fabricate soft piezoresistive pressure sensors using copper nanowires-based *** sensors exhibit excellent sensitivity and durability and can be easily scalable to form l... 详细信息

关键词： Copper nanowires Aerogel Piezoresistive Pressure sensing matrix

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Stable alkali halide vapor assisted chemical vapor deposition of 2D HfSe2 templates and controllable oxidation of its heterostructures

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Frontiers of physics 2024年第3期19卷 29-38页

作者： wenlong Chu Xilong Zhou Ze Wang Xiulian Fan Xuehao Guo cheng Li Jianling Yue Fangping Ouyang Jiong Zhao Yu Zhou School of Physics Hunan Key Laboratory of Nanophotonics and DevicesCentral South UniversityChangsha 410083 China 2.State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083 China 3.School of Physical Science and Technology Xinjiang UniversityUrumqi 830046 China 4.Department of Applied Physics The Hong Kong Polytechnic UniversityKowloonHong KongChina

Two-dimensional hafnium-based semiconductors and their heterostructures with native oxides have been shown unique physical properties and potential electronic and optoelectronic ***,the scalable synthesis methods for ultrathin layered hafnium-based semiconductor laterally epitaxy growth and its heterostructure are still restricted,also for the understanding of its formation ***,we report the stable sublimation of alkali halide vapor assisted synthesis strategy for high-quality 2D HfSe_(2) nanosheets via chemical vapor ***-crystalline ultrathin 2D HfSe_(2) nanosheets were systematically grown by tuning the growth parameters,reaching the lateral size of 6‒40μm and the thickness down to 4.5 *** scalable amorphous HfO_(2)and HfSe_(2)heterostructures were achieved by the controllable oxidation,which benefited from the approximate zero Gibbs free energy of unstable 2D HfSe_(2) *** crystal structure,elemental,and time dependent Raman characterization were carried out to understand surface precipitated Se atoms and the formation of amorphous Hf−O bonds,confirming the slow surface oxidation and lattice incorporation of oxygen *** relatively smooth surface roughness and electrical potential change of HfO_(2)−HfSe_(2) heterostructures indicate the excellent interface quality,which helps obtain the high performance memristor with high on/off ratio of 105 and long retention period over 9000 *** work introduces a new vapor catalysts strategy for the synthesis of lateral 2D HfSe_(2) nanosheets,also providing the scalable oxidation of the Hf-based heterostructures for 2D electronic devices.

关键词： chemical vapor deposition HfSe_(2)−HfO_(2) nanoelectronics

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