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Vibration properties of Paulownia wood for Ruan sound quality using machine learning methods

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Journal of Forestry Research 2024年第5期35卷 216-222页

作者： yang yang College of Art and Design Harbin UniversityHarbin 150076People’s Republic of China College of Mechanical and Electrical Engineering Northeast Forestry UniversityHarbin 150040People’s Republic of China

As an important material for manufacturing resonant components of musical instruments,Paulownia has an important influence on the sound quality of *** this paper,a model for evaluating the sound quality of Ruan based on the vibration characteristics of wood is developed using machine learning ***,the selection of materials for Ruan manufacturing relies primarily on manually weighing,observing,striking,and listening by the instrument *** in scientific theory have hindered the quality of the finished *** this study,nine Ruans were manufactured,and a prediction model of Ruan sound quality was proposed based on the raw material information of *** of a total of 180 data sets,145 and 45 sets were chosen for training and validation,*** this paper,typical correlation analysis was used to determine the correlation between two single indicators in two adjacent pairwise combinations of the measured objects in each stage of the production process in *** vibra-tion characteristics of the wood were tested,and a model for predicting the evaluation of Ruan’s acoustic qualities was developed by measuring the vibration characteristics of the resonating plate *** acoustic quality of the Ruan sound board wood was evaluated and predicted using machine learning model generalized regression neural *** results show that the prediction of Ruan sound quality can be achieved using Matlab simulation based on the vibration characteristics of the soundboard *** the model-predicted values were compared with the tradi-tional predicted results,it was found that the generalized regression neural network had good performance,achieving an accuracy of 93.8%which was highly consistent with the experimental *** was concluded that the model can accurately predict the acoustic quality of the Ruan based on the vibration performance of the soundboards.

关键词： Sound quality Wood vibration performance Paulownia wood Machine learning methods

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基于手机上网记录数据的个体相遇预测

电信科学 2017年第10期33卷 115-123页

作者：李倩江昊杨锦涛武汉大学电子信息学院湖北武汉430072

随着反映个体位置信息的数据大量涌现,人类移动行为的研究引起了业界学者的广泛关注。针对个体相遇预测问题,使用用户手机终端上网产生的会话数据进行分析。首先基于用户相遇关系进行复杂网络建模,然后分析了网络拓扑结构特征,同时引入... 详细信息

随着反映个体位置信息的数据大量涌现,人类移动行为的研究引起了业界学者的广泛关注。针对个体相遇预测问题,使用用户手机终端上网产生的会话数据进行分析。首先基于用户相遇关系进行复杂网络建模,然后分析了网络拓扑结构特征,同时引入了用户移动性特征和上网行为特征,构造基于随机森林的预测模型,进行个体相遇预测。实验结果表明,相比于传统的网络拓扑结构特征,通过引入用户移动性特征和上网行为特征,能够显著地提升预测性能。

关键词：相遇预测移动互联网复杂网络随机森林

发酵鱼酱酸产GABA乳酸菌的分离筛选及发酵特性

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食品科学 2021年第18期42卷 73-79页

作者：刘璐吴江丽杨金桃唐忠月曾雪峰贵州大学酿酒与食品工程学院贵州贵阳550025

从传统发酵鱼酱酸中筛选出产γ-氨基丁酸(γ-aminobutyric acid,GABA)的乳酸菌并分析其菌株发酵特性。通过薄层色谱法定性、Berthelot比色法定量获得产GABA菌株,并进行耐酸、耐胆盐、氨基酸脱羧酶活性、抑菌性、生长曲线及pH值、产酸速... 详细信息

从传统发酵鱼酱酸中筛选出产γ-氨基丁酸(γ-aminobutyric acid,GABA)的乳酸菌并分析其菌株发酵特性。通过薄层色谱法定性、Berthelot比色法定量获得产GABA菌株,并进行耐酸、耐胆盐、氨基酸脱羧酶活性、抑菌性、生长曲线及pH值、产酸速率等菌株发酵特性分析。结果表明:从分离自鱼酱酸不同发酵阶段的387株乳酸菌中,获得15株典型产GABA菌株,包括2株食窦魏斯氏菌(Weissella cibaria)、1株熊蜂魏斯氏菌(Weissella bombi)、11株植物乳杆菌(Lactobacillus plantarum)和1株戊糖乳杆菌(Lactobacillus pentosus)。15株乳酸菌产GABA能力及发酵特性在主成分分析图上差异显著,其中食窦魏斯氏菌Y113产GABA量为0.239 mg/mL,高于其他菌株;植物乳杆菌Y279和Y64展现出较好的耐酸性、耐胆盐性、抑菌性、无氨基酸脱羧酶活性、生长速率及产酸速率快的特点。鉴于其优良的发酵特性、益生特性及产GABA能力,菌株Y279可作为鱼酱酸工业化、标准化生产的潜在优良菌株。

关键词：鱼酱酸 γ-氨基丁酸乳酸菌分离鉴定

Sensitivity Improvements for Picosecond Ultrasonic Thickness Measurements in Gold and Tungsten Nanoscale Films

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Nanomanufacturing and Metrology 2024年第2期7卷 1-12页

作者： Jiaqi Dong Chengyuan Yao Yuanhao Zhu Shaojie Li Bowen Liu jintao Fan Chunguang Hu Youjian Song Minglie Hu Key Laboratory of Opto-Electronic Information Science and Technology of Ministry of Education School of Precision Instruments and Opto-Electronics EngineeringTianjin UniversityTianjin 300072China State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

Picosecond ultrasonics,as a nondestructive and noncontact method,can be employed for nanoscale metallic film thickness *** sensitivity of the system,which determines the measurement precision and practicability of this technique,is often limited by the weak intensity of the ultrasonic *** solve this problem,we investigate the distinct mechanisms involved in picosecond ultrasonic thickness measurement for two types of metals,namely tungsten(W)and gold(Au).For thickness measurement in W films,theory and simulation show that optimizing the pump and probe laser wavelengths,which determine the intensity and shape of the ultrasonic signal,is critical to improving measurement sensitivity,while for Au film measurements,where acoustic-induced beam distortion is dominant,the signal intensity can be optimized by selecting an appropriate aperture size and sample *** above approaches are validated in experiments.A dual-wavelength pump-probe system is constructed based on a passively mode-locked ytterbium-doped fiber *** smoothing method and multipeak Gaussian fitting are employed for the extraction of ultrasonic *** measurement precision is achieved in a series of W and Au films with thicknesses of 43-750 *** work can be applied to various high-precision,noncontact measurements of metal film thickness in the semiconductor industry.

关键词： Picosecond ultrasonics Thickness measurement Optical pump-probe Beam distortion technique

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复合滤层深床滤池用于污水深度处理

净水技术 2021年第5期40卷 87-91页

作者：杨瑾涛中铁第一勘察设计院集团有限公司陕西西安710043

以南京J污水处理厂二级出水为原水,总结主要水质特征,构建复合滤层深床滤池工艺,分析该工艺对水质的改善效能。结果表明:在水温为19~24℃,滤速为2 m/h条件下,反应装置对总氮、COD_(Cr)、总磷、浑浊度、色度的平均去除率分别为33.3%、55... 详细信息

以南京J污水处理厂二级出水为原水,总结主要水质特征,构建复合滤层深床滤池工艺,分析该工艺对水质的改善效能。结果表明:在水温为19~24℃,滤速为2 m/h条件下,反应装置对总氮、COD_(Cr)、总磷、浑浊度、色度的平均去除率分别为33.3%、55.4%、65.2%、91.2%、88.8%;经过铁碳材料层之后,二级出水B/C由0.094增至0.288,可生化性大幅提升。复合滤层深床滤池工艺能够全面改善水质,处理效能较好且稳定,同时,每吨水处理成本增加的费用约为0.061元。因此,在污水深度处理方面具有良好应用前景。

关键词：复合滤层深床滤池二级出水可生化性

Overview of radar detection methods for low altitude targets in marine environments

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Journal of Systems Engineering and Electronics 2024年第1期35卷 1-13页

作者： yang Yong yang Boyu School of Electronic Science National University of Defense TechnologyChangsha 410073China

In this paper,a comprehensive overview of radar detection methods for low-altitude targets in maritime environments is presented,focusing on the challenges posed by sea clutter and multipath *** performance of the radar detection methods under sea clutter,multipath,and combined conditions is categorized and summarized,and future research directions are outlined to enhance radar detection performance for low-altitude targets in maritime environments.

关键词： radar sea clutter multipath scattering detection low altitude target

Fresh-Keeping Decision and Coordination of Fresh Agricultural Product Supply Chain Considering Carbon Cap-and-Trade under Different Dominance

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Journal of Systems Science and Systems Engineering 2024年第1期33卷 30-51页

作者： yang yang Guanxin Yao China Institute for Agricultural Equipment Industrial Development Jiangsu UniversityZhenjiang212013China Jiangsu Modern Logistics Research Base Yangzhou UniversityYangzhou225009China

In the context of low carbon,this paper discussed the impact of the carbon cap-and-trade policy on the fresh-keeping decision-making of two-echelon fresh agricultural product supply chains under different dominance,and designed cost-sharing contracts to coordinate the supply chain of fresh agricultural products dominated by suppliers and retailers *** results showed that:dominance has no effect on the fresh-keeping decision and total revenue of fresh agricultural product supply chain,but it affects the internal income distribution,and dominance does not always bring more benefits;the implementation of carbon cap-and-trade reduces the fresh-keeping decision-making of fresh agricultural products supply chain and reduces the free-rider income of followers;the role of higher carbon trading price is twofold,which not only brings about the speculation of leading enterprises,but also promotes the application of low-carbon technologies;consumers’high preference for freshness,low-cost and high-efficiency low-carbon technology are all conducive to improving the fresh-keeping efforts and benefits of the supply chain;cost-sharing contracts can coordinate the supply chain of fresh agricultural products.

关键词： Dominant power carbon cap-and-trade policy fresh agricultural product supply chain fresh-keeping decision-making

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一种具有双级LC滤波电路的动态电压调节器

电力自动化设备 2016年第8期36卷 70-75页

作者：杨金涛乐健刘开培韩英铎武汉大学电气工程学院湖北武汉430072 清华大学电机工程与应用电子技术系北京100084

提出具有双级LC滤波电路的动态电压恢复器(DVR),以解决采用单级滤波器时输出电压易受负荷谐波电流影响的问题,同时更好地滤除高频开关谐波,减小电感与电容容量。首先建立了采用双级LC滤波电路的DVR的数学模型,根据Routh稳定判据分析了... 详细信息

提出具有双级LC滤波电路的动态电压恢复器(DVR),以解决采用单级滤波器时输出电压易受负荷谐波电流影响的问题,同时更好地滤除高频开关谐波,减小电感与电容容量。首先建立了采用双级LC滤波电路的DVR的数学模型,根据Routh稳定判据分析了系统的稳定性,并给出了控制系统参数的设计方法,进行了采用双级和单级LC滤波器DVR响应特性的比较。通过仿真和实验验证了所提出的具有双级LC滤波电路的DVR能更加有效地提高输出电压的质量,抑制负载谐波电流对DVR系统的影响。

关键词：动态电压调节器双级LC滤波器电压暂降 Routh稳定判据

10kV区域补偿型动态电压补偿器的补偿选线研究

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电测与仪表 2015年第6期52卷 107-112页

作者：刘阳乐健杨金涛张广怡武汉大学电气工程学院武汉430072

提出了区域型动态电压补偿器(Dynamic Voltage Restorer,DVR)的设计思想,介绍了该DVR的主电路拓扑、电压跌落检测算法、参考电压计算方法和脉冲调制方法。基于目标变电站及馈线下不同负荷类型,根据不同负荷类型对电压暂降的敏感性,提出... 详细信息

提出了区域型动态电压补偿器(Dynamic Voltage Restorer,DVR)的设计思想,介绍了该DVR的主电路拓扑、电压跌落检测算法、参考电压计算方法和脉冲调制方法。基于目标变电站及馈线下不同负荷类型,根据不同负荷类型对电压暂降的敏感性,提出了确定区域补偿型DVR接入位置的馈线选择原则,以某变电站为例说明了具体的选线方法。仿真分析了不同故障类型下DVR的补偿效果,验证了其设计的有效性和合理性。

关键词：区域补偿动态电压补偿器馈线选择脉冲调制电压跌落