检索结果-南通市图书馆

基于子区间修正摄动法的汽车高频噪声优化设计

在线全文

学校读者我要写书评

暂无评论

汽车技术 2024年第5期 45-50页

作者：郝耀东陈达亮邓江华李林吴保江中汽研(天津)汽车工程研究院有限公司天津300399

为抑制声学包零件参数较强的不确定性引起的车内高频噪声大范围波动,提出了一种基于子区间修正摄动法的汽车高频噪声不确定性分析与优化方法,首先建立汽车高频噪声分析的统计能量基本方程,将不确定性参数划分为若干子区间,采用修正区间... 详细信息

为抑制声学包零件参数较强的不确定性引起的车内高频噪声大范围波动,提出了一种基于子区间修正摄动法的汽车高频噪声不确定性分析与优化方法,首先建立汽车高频噪声分析的统计能量基本方程,将不确定性参数划分为若干子区间,采用修正区间摄动法计算每个子区间的摄动半径,得到高频噪声性能的中心值和摄动半径,并利用区间不确定性优化方法对车辆的高频噪声性能和零件质量进行了优化设计。应用该方法对某车型的内前围、地毯进行分析和优化设计,结果表明,优化后,声学包零件质量减轻了3%,噪声波动区间下降幅度超过35%,系统的稳健性显著提升。

关键词：声学包装子区间模型修正区间摄动法不确定性优化

维普期刊数据库博看期刊

同方期刊数据库

在线全文

学校读者我要写书评

暂无评论

内置式起发一体机的设计与优化

微特电机 2024年第6期52卷 17-22页

作者：左佳顾西平武宝江赵丽颖商荣翔北京七星飞行电子有限公司北京100005

随着飞行器技术的不断进步,飞行器内部的电路结构向着小型化和高功率化发展。起发一体机将飞行器的起动、发电结合为一体,不仅可以减小飞行器的体积,还可以为飞行器提供起动转矩和电源支持。对起发一体机的研究现状进行了综述,以内置式... 详细信息

随着飞行器技术的不断进步,飞行器内部的电路结构向着小型化和高功率化发展。起发一体机将飞行器的起动、发电结合为一体,不仅可以减小飞行器的体积,还可以为飞行器提供起动转矩和电源支持。对起发一体机的研究现状进行了综述,以内置式永磁同步电机作为起发一体机,对转子结构进行了对比选型。选取了“一+V”型转子,经过优化的电机性能最终符合了设计要求。

关键词：起发一体机内置式永磁同步电机 “一+V”型转子

在线全文

学校读者我要写书评

暂无评论

荷斯坦奶牛胚胎基因组遗传评估研究

畜牧兽医学报 2024年第7期55卷 2940-2950页

作者：郭子骄郑伟杰孙伟吴宝江包向男张琪贺巾锋包斯琴赵高平王子馨韩博李喜和孙东晓中国农业大学动物科学技术学院农业农村部动物遗传育种与繁殖重点实验室动物育种国家工程实验室畜禽生物育种全国重点实验室北京100193 内蒙古赛科星家畜种业与繁育生物技术研究院有限公司呼和浩特011517 国家乳业技术创新中心呼和浩特010020 内蒙古大学生命科学学院呼和浩特010021

旨在建立一种荷斯坦奶牛胚胎细胞早期基因组检测和遗传评估的方法并筛选优秀种用胚胎,通过胚胎移植技术选育优秀种牛,进一步缩短世代间隔,加快遗传进展。本研究基于4头荷斯坦种公牛克隆细胞,比较分析2细胞、5细胞的微量基因组DNA提取效... 详细信息

旨在建立一种荷斯坦奶牛胚胎细胞早期基因组检测和遗传评估的方法并筛选优秀种用胚胎,通过胚胎移植技术选育优秀种牛,进一步缩短世代间隔,加快遗传进展。本研究基于4头荷斯坦种公牛克隆细胞,比较分析2细胞、5细胞的微量基因组DNA提取效果、全基因组芯片检出率及错配率;随后提取24枚荷斯坦奶牛早期胚胎5细胞样本的基因组DNA,利用150K芯片进行基因组检测;基于大规模基因组选择参考群体,采用GBLUP方法计算每枚胚胎9个性状的基因组育种值。结果表明,2和5克隆细胞的基因组DNA浓度、纯度和相对完整性均较好;5克隆细胞样品的150K芯片检出率较高(89.54%~95.07%)、错配率较低(1.02%~4.67%)。24枚胚胎的5细胞样品基因组DNA质量、总量和相对完整性均较好,150K芯片数据检出率为92.28%~98.51%,9个性状(产奶、体型和体细胞评分)基因组评估准确性为55%~79%,平均基因组评估准确性不低于65%。综上,本研究优化并建立了奶牛胚胎少量细胞DNA提取及基因组评估技术,胚胎样本基因组检出率不低于90%,平均基因组评估准确性不低于0.65。

关键词：荷斯坦奶牛胚胎基因组选择

同方期刊数据库博看期刊

Ballistic performances of the hourglass lattice sandwich structures under high-velocity fragments

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第1期31卷 312-325页

作者： He-xiang wu Jia Qu Lin-zhi wu Key Laboratory of Advanced Ship Materials and Mechanics College of Aerospace and Civil EngineeringHarbin Engineering UniversityHarbin150001China School of Civil Engineering Northeast Forestry UniversityHarbin150040China

In this paper,the numerical simulation method is used to study the ballistic performances of hourglass lattice sandwich structures with the same mass under the vertical incidence of *** is paid to elucidating the influences of rod cross-section dimensions,structure height,structure layer,and rod inclination angle on the deformation mode,ballistic performances,and ability to change the ballistic direction of *** results show that the ballistic performances of hourglass lattice sandwich structures are mainly affected by their structural *** this respect,structural parameters optimization of the hourglass lattice sandwich structures enable one to effectively improve their ballistic limit velocity and,consequently,ballistic performances.

关键词： Hourglass lattice sandwich structures Ballistic performances high-velocity Finite element analysis

Resilience-incorporated seismic risk assessment of precast concrete frames with“dry”connections

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2024年第2期23卷 403-425页

作者： wu Chenhao Tang Yuchuan Cao Xuyang wu Gang Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education Nanjing 211102China Department of Civil and Environmental Engineering University of CaliforniaLos AngelesCA 90095USA School of Civil Engineering Southeast UniversityNanjing 211102China College of Civil and Transportation Engineering Hohai UniversityNanjing 210024China

A resilience-incorporated risk assessment framework is proposed and demonstrated in this study to manifest the advantageous seismic resilience of precast concrete frame(PCF)structures with“dry”connections in terms of their low damage and rapid *** framework integrates various uncertainties in the seismic hazard,fragility,capacity,demand,loss functions,and post-earthquake *** this study,the PCF structures are distinguished from ordinary reinforced concrete frame(RCF)structures by characterizing multiple limit states for the PCF based on its unique damage ***,probabilistic story-wise pushover analyses are performed to yield story-wise capacities for the predefined limit *** the seismic resilience analysis,a step-wise recovery model is proposed to idealize the functionality recovery process,with separate considerations of the repair and non-repair *** recovery model leverages the economic loss and downtime to delineate the stochastic post-earthquake recovery curves for the resilience loss *** such,contingencies in the probabilistic post-earthquake repairs are incorporated and the empirical judgments on the recovery parameters are largely *** proposed framework is demonstrated through a comparative study between two“dry”connected PCFs and one RCF designed as alternative structural systems for a prototype *** results from the risk quantification indicate that the PCFs show reduced loss hazards and lower expected losses relative to the ***,the PCF equipped with energy dissipation devices at the“dry”connections largely reduces the expected economic loss,downtime,and resilience loss by 29%,56%,and 60%,respectively,compared to the RCF.

关键词： precast concrete frame non-emulative precast system seismic resilience seismic risk functional recovery

New findings on the influence of El Ni?o events on tropical cyclone formation

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第3期67卷 892-893页

作者： Liguang wu Fudan University Department of Atmospheric and Oceanic Sciences Institute of Atmospheric Sciences

Tropical cyclones typically form over warm tropical and subtropical ocean surfaces, as their formation and intensification rely primarily on the energy provided by the ocean. Pioneering research by Gray (1968) revealed that the formation of tropical cyclones requires the sea surface temperature (SST) to be no less than 26.5°C. Consequently, SST is commonly recognized as a crucial parameter among the environmental factors influencing tropical cyclone formation(Gray, 1979; Emanuel and Nolan, 2004).

关键词： INDEX

同方期刊数据库

Two-dimensional semiconductor heterostructures for photocatalytic CO_(2)conversion

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第8期67卷 2434-2447页

作者： Yang wu Mingyu wu Yongfu Sun Yi Xie Hefei National Research Center for Physical Sciences at Microscale University of Science and Technology of ChinaHefei 230026China

The CO_(2)reduction into carbon-contained fuel via solar energy offers the powerful tools to realize the zero-emission carbon *** to the intriguing features of the two-dimensional(2D)heterostructures,it is susceptible to modulate the electronic structure as well as the surface geometry for optimizing the photocatalytic CO_(2)*** this perspective,we surveyed the fundamental insights of 2D semiconductor heterostructures,involving the fabrication strategies and classification of the 2D semiconductor ***,we have detailly discussed the overview of 2D semiconductor heterostructure for optimizing CO_(2)photocatalytic influenced factors,including the solar energy utilization,photogenerated carriers separation,and redox reaction ***,we showed the significant advantages of 2D heterostructures in elevating CO_(2)photoreduction performance,focusing on activity,selectivity and *** analyzing the limitations and developments,we ended by putting forward insights into the further researches about the CO_(2)photocatalysts and reactor design,even industrial applications.

关键词： two-dimensional semiconductor heterostructures photocatalysis CO_(2)conversion

The Functional Redundancy of Neddylation E2s and E3s in Modulating the Fitness of Regulatory T Cells

在线全文

学校读者我要写书评

暂无评论

Research 2024年第2期2023卷 373-387页

作者： Di wu Yi Sun Cancer Institute(Key Laboratory of Cancer Prevention and Intervention China National Ministry of Education)of the Second Affiliated Hospital and Institute of Translational MedicineZhejiang University School of MedicineHangzhou 310029China Cancer Center of Zhejiang University Hangzhou 310029China Zhejang Provincial Clinical Research Center for Cancer Zhejang ProvinceChina Key Laboratory of Molecular Biology in Medical Sciences Zhejang ProvinceChina Research Center for Life Science and Human Health Binjiang Institute of Zhejiang UniversityHangzhou 310053China

Neddylation is necessary for activation of Cullin-RING ligases(CRLs),which degrade various immune regulatory *** recent study showed that while depletion of neddylation E2-E3 pair Ube2f-Sag in regulatory T(T_(reg))cells had no obvious phenotype,the same depletion of either Ube2m or Rbx1 caused inflammation disorders with different *** these E2s or E3s compensate each other in functional regulations of T_(reg)cells is,however,previously *** this report,we generated Foxp3^(Cre);Ube2m^(fl/fl);Ube2f^(fl/fl)or Foxp3^(Cre);Rbx1^(fl/fl);Sag^(fl/fl)double-null mice by simultaneous deletion of both neddylation E2s or E3s in T_(reg)cells,***,Ube2m&Ube2f double-null mice developed much severe autoimmune phenotypes than did Ube2m-null mice,indicating that Ube2m markedly compensates Ube2f in T_(reg)*** minor worsened autoimmune phenotypes seen at the very early stage in Rbx1&Sag double-null than Rbx1-null mice is likely due to already severe phenotypes of the later,indicating a minor compensation of Rbx1 for *** RNA profiling-based analyses revealed that up-and down-regulations of few signaling pathways in T_(reg)cells are associated with the severity of autoimmune ***,severer inflammation phenotypes seen in mice with double E3-null than with double E2-null T_(reg)cells indicate a neddylation-independent mechanism of 2 E3s,also known to serve as the RING component of CRLs in regulation of T_(reg)cell fitness.

关键词： Foxp3 inflammation markedly

Rational surface charge engineering of haloalkane dehalogenase for boosting the enzymatic performance in organic solvent solutions

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第1期65卷 276-285页

作者： Yin wu Yan Sun Department of Biochemical Engineering School of Chemical Engineering and Technology and Key Laboratory of Systems Bioengineering and Frontiers Science Center for Synthetic Biology(Ministry of Education)Tianjin UniversityTianjin 300350China

Biocatalysis in organic solvents(OSs)has numerous important applications,but native enzymes in OSs often exhibit limited catalytic ***,we proposed a computation-aided surface charge engineering strategy to improve the catalytic performance of haloalkane dehalogenase DhaA in OSs based on the energetic analysis of substrate binding to the DhaA *** variants with enhanced OS resistance were obtained by replacing negative charged residues on the surface with positive charged residue(Arg).Particularly,a four-substitution variant E16R/E93R/E121R/E257R exhibited the best catalytic performance(five-fold improvement in OS resistance and seven-fold half-life increase in 40%(vol)dimethylsulfoxide).As a result,the overall catalytic performance of the variant could be at least 26 times higher than the wild-type *** spectroscopy and molecular dynamics simulation studies revealed that the residue substitution mainly enhanced OS resistance from four aspects:(a)improved the overall structural stability,(b)increased the hydrophobicity of the local microenvironment around the catalytic triad,(c)enriched the hydrophobic substrate around the enzyme molecule,and(d)lowered the contact frequency between OS molecules and the catalytic *** findings validate that computationaided surface charge engineering is an effective and ingenious rational strategy for tailoring enzyme performance in OSs.

关键词： Surface charge engineering Organic solvent resistance Molecular dynamics simulation Haloalkane dehalogenase