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贝壳形屋盖风压系数密度峰值聚类分区研究

建筑科学与工程学报 2024年第1期41卷 158-170页

作者：林拥军周畅张曾鹏余国菲谢远昂西南交通大学土木工程学院四川成都610031

鉴于贝壳形屋盖表面风压分布的特殊性,提出基于快速搜索技术的密度峰值聚类风压系数分区方法。以某贝壳形屋盖表面风压分布试验结果为基础,进行密度峰值聚类风压系数分区,采用SD有效性指标验证分区数的合理性,并与改进k-means聚类分区... 详细信息

鉴于贝壳形屋盖表面风压分布的特殊性,提出基于快速搜索技术的密度峰值聚类风压系数分区方法。以某贝壳形屋盖表面风压分布试验结果为基础,进行密度峰值聚类风压系数分区,采用SD有效性指标验证分区数的合理性,并与改进k-means聚类分区结果进行对比。结果表明:密度峰值聚类风压系数分区以风压系数相对距离、局部密度和综合指数为特征参数,能较好反映屋面风压分布特性,有效保证类聚合性和类类分离性;相较于改进k-means分区法,不同风向角下密度峰值聚类得到的分区数与SD最优聚类数接近;密度峰值聚类分区结果能更准确反映贝壳形屋盖表面风压分布特性,充分体现测点风压系数局部密度和相对距离特征值较大的基本原则,对于贝壳形屋盖的风压系数分区具有更好的适用性;贝壳形屋盖密度峰值聚类分区最大负风压系数在-0.59~-1.74之间。

关键词：密度峰值快速搜索聚类风压系数分区贝壳形屋盖

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自然资源三维分析系统框架研究与应用探索

地理空间信息 2024年第6期22卷 74-76页

作者：林勇军梁瑞松深圳市规划国土发展研究中心广东深圳518034

在数字政府和实景三维中国建设的背景下,三维地理空间信息系统将迎来巨大的发展机遇和应用前景,如何建设和应用三维地理空间信息系统是当前自然资源领域的重要研究课题。通过对自然资源三维分析系统的建设思路与解决方案进行研究,提出... 详细信息

在数字政府和实景三维中国建设的背景下,三维地理空间信息系统将迎来巨大的发展机遇和应用前景,如何建设和应用三维地理空间信息系统是当前自然资源领域的重要研究课题。通过对自然资源三维分析系统的建设思路与解决方案进行研究,提出相应的设计方法和技术路线。基于这些研究初步搭建了自然资源三维分析原型系统,并在系统中探索了几个常用的自然资源应用场景,为后续类似的自然资源三维分析系统设计、建设和应用提供经验参考。

关键词：自然资源三维分析系统框架应用场景

有氧运动治疗应用在单纯性肥胖儿童中对其糖脂代谢、胰岛素抵抗及血管内皮功能的影响分析

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中外医疗 2024年第9期43卷 39-42页

作者：林拥军杨美真黄丹丹福建省泉州市洛江区妇幼保健院儿童保健科福建泉州362000 泉州医学高等专科学校附属人民医院手术室福建泉州362000

目的研究分析有氧运动治疗对单纯性肥胖儿童糖脂代谢、胰岛素抵抗以及血管内皮功能的影响。方法简单随机选取2020年5月—2023年5月福建省泉州市洛江区妇幼保健院收治的60例单纯性肥胖的儿童作为研究对象,依据随机数表法分组,对照组(n=30... 详细信息

目的研究分析有氧运动治疗对单纯性肥胖儿童糖脂代谢、胰岛素抵抗以及血管内皮功能的影响。方法简单随机选取2020年5月—2023年5月福建省泉州市洛江区妇幼保健院收治的60例单纯性肥胖的儿童作为研究对象,依据随机数表法分组,对照组(n=30)予以常规饮食及行为干预,观察组(n=30)基于对照组干预条件予以有氧运动治疗,比较两组儿童不同干预时间的糖脂代谢指标、机体胰岛素抵抗状况以及血管内皮功能。结果干预后,观察组空腹血糖(Fasting Plasma Glucose,FPG)、胆固醇(Cholesterol,TC)以及三酰甘油(Triglyceride,TG)水平依次为(4.83±0.53)、(4.03±0.42)、(1.56±0.21)mmol/L,均低于对照组,分别为(5.19±0.61)、(4.65±0.53)、(1.79±0.24)mmol/L,差异有统计学意义(t=2.440、5.021、3.950,P均lin,FINS)、胰岛素抵抗指数(Insulin Resistance Index,HOMA-IR)]均低于对照组,差异有统计学意义(t=3.472、2.544,P均lin-1,ET-1)较对照组更低,差异有统计学意义(t=2.719、3.298,P均<0.05)。结论对单纯性肥胖儿童实施有氧运动疗法干预,能够有效改善其糖脂代谢状况以及胰岛素抵抗问题,并且对血管内皮功能的恢复有良好助益。

关键词：单纯性肥胖有氧运动治疗糖脂代谢胰岛素抵抗血管内皮功能

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基于时钟循环神经网络的光伏故障诊断

山东电力技术 2024年第1期51卷 52-58,76页

作者：林永君张世成杨凯李静华北电力大学河北保定071003

光伏电站大多地处恶劣环境,遭受风沙雨雪腐蚀,电池板容易出现多类型故障,如何对故障进行有效识别与定位尤为重要。为此,提出了一种基于时钟循环神经网络(clockwork-recurrent neural network,CW-RNN)的光伏故障诊断策略。首先,建立了光... 详细信息

光伏电站大多地处恶劣环境,遭受风沙雨雪腐蚀,电池板容易出现多类型故障,如何对故障进行有效识别与定位尤为重要。为此,提出了一种基于时钟循环神经网络(clockwork-recurrent neural network,CW-RNN)的光伏故障诊断策略。首先,建立了光伏阵列系统仿真模型,分析了光伏发电故障的成因,模拟了不同故障下的光伏阵列输出特征;其次,采用CW-RNN方法建立了故障诊断模型,对光伏阵列故障进行识别与定位;最后,基于实时数据库系统搭建了光伏发电故障分析平台,对所提出的故障诊断模型性能进行验证,结果表明其有效性和准确性,对光伏电站高效地进行故障准确识别与定位具有一定参考意义。

关键词：光伏阵列故障诊断时钟循环神经网络算法数据库仿真平台

大型抽水蓄能电站水轮机组机械振动故障判别模型

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机械与电子 2024年第7期42卷 64-68页

作者：蔡喜昌冯文嵛林杰胜林泳骏李东璐南方电网调峰调频发电有限公司运行分公司广东清远513207

为了提高大型抽水蓄能电站水轮机组机械振动故障判别精度,以及时对其进行维修,保证抽水蓄能电站水轮机组设备安全运行,延长机械使用时长,提出了一种水轮机组机械振动故障判别方法。利用无量纲处理水轮机组机械信号,去除冗余信号,确定振... 详细信息

为了提高大型抽水蓄能电站水轮机组机械振动故障判别精度,以及时对其进行维修,保证抽水蓄能电站水轮机组设备安全运行,延长机械使用时长,提出了一种水轮机组机械振动故障判别方法。利用无量纲处理水轮机组机械信号,去除冗余信号,确定振动参数加权分布,设置故障特征量权值,构建抽水蓄能电站水轮机组分布式健康函数,完成水轮机组机械振动故障判别方法设计,检测水轮机组是否为正常状态,实现机械振动故障判别。实验表明,所提模型可以准确判别故障振动,确保后续及时维修,提高工作效率。

关键词：大型抽水蓄能电站水轮机组机械振动故障判别信号处理

Review and prospect of transgenic rice research

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Chinese Science Bulletin 2009年第18期54卷 4049-4068页

作者： CHEN Hao lin yongjun ZHANG QiFa National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural University Wuhan 430070 China

Rice is one of the most important crops as the staple food for more than half of the world's population. Rice improvement has achieved remarkable success in the past half-century, with the yield doubled in most parts of the world and even tripled in certain regions, which has contributed greatly to food security globally. Rapid population growth and economic development pose a constantly increased food requirement. However, rice yield has been hovering in the past decade, which is mainly caused by the absence of novel breeding technologies, reduction of genetic diversity of rice cultivars, and serious yield loss due to increasingly severe occurrences of insects, diseases, and abiotic stresses. To address these challenges, Chinese scientists proposed a novel rice breeding goal of developing Green Super Rice to improve rice varieties and realize the sustainable development of agriculture, by focusing on the following 5 classes of traits: insect and disease resistance, drought-tolerance, nutrient-use efficiency, quality and yield potential. As a modern breeding approach, transgenic strategy will play an important role in realizing the goal of Green Super Rice. Presently, many transgenic studies of rice have been conducted, and most of target traits are consistent with the goal of Green Super Rice. In this paper, we firstly review technical advances of rice transformation, and then outline the main progress in transgenic rice research with respect to the most important traits: insect and disease-resistance, drought-tolerance, nutrient-use efficiency, quality, yield potential and herbicide-tolerance. The prospects of developing transgenic rice are also discussed.

关键词：转基因水稻展望农作物发展

Responses of arbuscular mycorrhizal fungi to straw return and nitrogen fertilizer reduction in a rainfed maize field

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Pedosphere 2024年第2期34卷 351-360页

作者： Zhenling PENG Hao XI lin MAO Huyuan FENG Jianjun ZHANG yongjun LIU State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems College of EcologyLanzhou UniversityLanzhou 730000China College of Life Sciences Northwest Normal UniversityLanzhou 730070China School of Life Sciences Lanzhou UniversityLanzhou 730000China Dryland Agriculture Institute Gansu Academy of Agricultural SciencesLanzhou 730070China

Straw return can be used to reduce fertilizer input and improve agricultural sustainability and soil ***,how straw return and reduced fertilizer application affect beneficial soil microbes,particularly arbuscular mycorrhizal fungi(AMF),remains poorly ***,we conducted a five-year field experiment in a rainfed maize field on the Loess Plateau of northwestern *** tested four treatments with straw return combined with four nitrogen(N)application rates,i.e.,100%,80%,60%,and 0%of the common N application rate(225 kg N ha^(-1)year^(-1))in this region,and two reference treatments(full or no N application),with three replicates for each *** colonization was quantified and AMF communities colonizing maize roots were characterized using Illumina *** virtual taxa(VTs)of AMF were identified in root samples,among which VT113(related to Rhizophagus fasciculatus)and VT156(related to Dominikia gansuensis)were the predominant *** root length colonization and AMF VT richness were sensitive to N fertilization,but not to straw return;furthermore,both gradually increased with decreasing N application *** VT composition of the AMF community was also affected by N fertilization,but not by straw return,and the community variation could be well explained by soil available N and phosphorus ***,60%,80%,and full N fertilization produced similar maize ***,our study revealed the response patterns of AMF to straw return and N fertilizer reduction and showed that straw return combined with N fertilizer reduction may be a promising practice to maintain mycorrhizal symbiosis concomitantly with crop productivity.

关键词： agricultural sustainability crop productivity mycorrhizal colonization mycorrhizal symbiosis root length colonization virtual taxon

Constructing high-toughness polyimide binder with robust polarity and ion-conductive mechanisms ensuring long-term operational stability of silicon-based anodes

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Journal of Energy Chemistry 2024年第6期93卷 580-591,I0014页

作者： yongjun Kang Nanxi Dong Fangzhou Liu Daolei lin Bingxue Liu Guofeng Tian Shengli Qi Dezhen Wu State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China ENFI R&D Institute China ENFI Engineering CorporationBeijing 100038China China Automotive Battery Research Institute Co. Ltd.Beijing 101407China Changzhou Institute of Advanced Materials Beijing University of Chemical TechnologyChangzhou 213164JiangsuChina

Silicon-based materials have demonstrated remarkable potential in high-energy-density batteries owing to their high theoretical ***,the significant volume expansion of silicon seriously hinders its utilization as a lithium-ion ***,a functionalized high-toughness polyimide(PDMI) is synthesized by copolymerizing the 4,4'-Oxydiphthalic anhydride(ODPA) with 4,4'-oxydianiline(ODA),2,3-diaminobenzoic acid(DABA),and 1,3-bis(3-aminopropyl)-tetramethyl disiloxane(DMS).The combination of rigid benzene rings and flexible oxygen groups(-O-) in the PDMI molecular chain via a rigidness/softness coupling mechanism contributes to high *** plentiful polar carboxyl(-COOH) groups establish robust bonding *** ionic transport is achieved by incorporating the flexible siloxane segment(Si-O-Si),which imparts high molecular chain motility and augments free volume holes to facilitate lithium-ion transport(9.8 × 10^(-10) cm^(2) s^(-1) vs.16 × 10^(-10) cm^(2) s~(-1)).As expected,the SiO_x@PDMI-1.5 electrode delivers brilliant long-term cycle performance with a remarkable capacity retention of 85% over 500 cycles at 1.3 A g^(-1).The well-designed functionalized polyimide also significantly enhances the electrochemical properties of Si nanoparticles ***,the assembled SiO_x@PDMI-1.5/NCM811 full cell delivers a high retention of 80% after 100 *** perspective of the binder design strategy based on polyimide modification delivers a novel path toward high-capacity electrodes for high-energy-density batteries.

关键词： Polyimide binder High toughness Robust ionic transport Silicon-based anodes Lithium-ion batteries

A Flexible Voltage Control Strategy Based on Stage-division for Microgrids

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Protection and Control of Modern Power Systems 2024年第3期9卷 60-69页

作者： yongjun Zhang Kaidong lin Wenyang Deng Di Zhang Dongliang Xiao IEEE the South China University of Technology GuangzhouChina the Department of Electric Power South China University of TechnologyGuangzhouChina the School of Electric Power South China University of TechnologyGuangzhou 510640China

The occurrence of power flow reversal and off-limit of the voltage on common bus becomes more frequent because of the increasing penetration of renewable energy sources(RES)in *** guarantee the safe and stable operation,adjusting the power output of RES-based inverters to avoid the off-limit voltage is *** the apparent power characteristics of inverters,as well as the minimum participation of active power,a voltage control strategy based on stage division to be within the voltage limit is investigated in this *** the case of unknown demand and distribution of loads,the proposed control strategy is able to make full use of the apparent power to regulate voltage using simple calculations,while the performance in economical operation is *** results prove the effectiveness of the proposed method on the common bus off-limit voltage adjustment.

关键词： Off-limit voltage microgrids voltage control inverter stage division