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Subharmonic and ultraharmonic emissions based on the nonlinear oscillation of encapsulated microbubbles in ultrasound contrast agents

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Chinese Science Bulletin 2005年第18期50卷 1975-1978页

作者： GONG yanjun ZHANG dong GONG Xiufen State Key Lab of Modern Acoustics Institute of Acoustics Nanjing University Nanjing 210093 China

Subharmonics or ultraharmonics provides better contrast-to-tissue ratio (CTR) than the fundamental or the second harmonics, having prospective application in medical diagnosis. In this paper, subharmonic and ultra-harmonic emissions are theoretically studied through nonlinear oscillation of encapsulated bubbles. The optimized frequencies for emissions of the subharmonics and ultra-harmonics are discussed. In addition, sound pressure de-pendences of the subharmonics and ultraharmonics are studied in theory as well as in measurement. Results reveal that the developments of both subharmonics and ultrahar-monics have the same trend, i.e. occurrence, growth and saturation, but the generation of ultraharmonic is a little earlier than that of subharmonic.

关键词：分频谐波非线性振动超频率音响超谐波 UCA

Three Dimensional Metal-Surface Processing Parameter Generation Through Machine Learning-Based Nonlinear Mapping

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Tsinghua Science and Technology 2023年第4期28卷 754-768页

作者： Min Zhu yanjun dong Bingqing Shen Haiyan Yu Lihong Jiang Hongming Cai School of Software Shanghai Jiao Tong UniversityShanghai 200240China School of Mechanical Engineering Donghua UniversityShanghai 200240China

The accuracy and efficiency of three-dimensional(3D)surface forming,which directly affects the cycle and quality of production,is important in *** practice,given the uncertainty of metal plate springback,an error exists between the actual plate and the target surface,which creates a nonlinear mapping from computer aided design models to bending *** need to reconfigure parameters and process a surface multiple times to delicately control springback,which greatly wastes human and material *** study aims to address the springback control problem to improve the efficiency and accuracy of sheet metal forming.A basic computation approach is proposed based on the DeepFit model to calculate the springback value in 3D surface *** address the sample data shortage problem,we put forward an advanced approach by combining a deep learning model with case-based reasoning(CBR).Next,a multi-model fused bending parameter generation framework is devised to implement the advanced springback computation approach through surface data preprocessing,CBR-based model matching,convolution neural network-based machining surface generation,and bending parameter generation with a series of model ***,the proposed approaches and the framework are verified by considering saddle surface processing as an ***,this study provides a new idea to improve the accuracy and efficiency of surface processing.

关键词： 3D surface point-cloud machine learning case-based reasoning industrial software

Early Paleozoic Granulite-Facies Metamorphism and Magmatism in the Northern Wulan Terrane of the Quanji Massif:Implications for the Evolution of the Proto-Tethys Ocean in Northwestern China

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Journal of Earth Science 2018年第5期29卷 1081-1101页

作者： Qinyan wang yanjun dong Yuanming Pan Fanxi Liao Xiaowei Guo School of Earth Sciences Zhejiang UniversityHangzhou 310027China School of Earth Sciences State Key Laboratory of Geological Processes and Mineral ResourcesChina University of GeosciencesWuhan 430074China Hubei Earthquake Administration Wuhan 430071China Department of Geological Sciences University of SaskatchewanSaskatoon S7N 5E2Canada

The nature and evolution of the Proto-Tethys Ocean originated from the breakup of the supercontinent Rodinia remain controversial. Early Paleozoic magmatism and metamorphism can pro- vide important constraints on the closure of the Proto-Tethys Ocean. This paper reports on a set of geological, petrographical, geochronological, mineralogical and geochemical data for Early Paleozoic granite, gabbro, granulite and granitic leucosome in the northern Wulan terrane of the Quanji Massif. Zircon LA-ICP-MS U-Pb dating reveals two episodes of magmatism, with the emplacement of a gran- itic pluton at 476.7±2.8 Ma and a gabbroic dike at 423±2 Ma. Whole-rock geochemistry suggests an arc affinity for the magma of the granitic pluton but a post-collisional extension setting for the gabbroic dike. Zircon LA-ICP-MS U-Pb dating also shows that the peak granulite-facies metamorphism and anatexis occurred at --475 Ma, coeval with the formation of the granitic pluton in the Quanji Massif as well as the early lawsonite-bearing eclogites in the North Qaidam high-pressure and ultrahigh-pressure （HP-UHP） metamorphic belt to the south. The granulite-facies metamorphism with peak P-T condi- tions at 718-729 ℃ and 0.46-0.53 GPa is characterized by an anticlockwise P-T path. Our data provide compelling evidence for Early Paleozoic paired metamorphic belts with HP-UHP metamorphism in the North Qaidam to the south and low PIT metamorphism in the Quanji Massif as a continental arc to the north, hence suggesting a northward subduction polarity for the Proto-Tethys oceanic plate. The intrusion of the post-collisional gabbroic dike supports for the closure of the Proto-Tethys Ocean in north- western China before 423 Ma.

关键词： arc magmatism low P/T granulite-facies metamorphism paired metamorphic belts Proto-Tethys Ocean northern Wulan terrane NW China.

Comparison in phytoplankton diversity-productivity-community stability between river-type reservoir and lake-type reservoir

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Journal of Oceanology and Limnology 2022年第4期40卷 1485-1507页

作者： Qiong WU Qiuhua LI Huan LUO Qian CHEN Huaxiang CHEN yanjun dong Shenghua LI College of Environment Hohai UniversityNanjing 210098China Pearl River Water Resources Research Institute Guangzhou 510611China Key Laboratory of the Pearl River Estuary Regulation and Protection of Ministry of Water Resources Guangzhou 510611China Guangdong Provincial Engineering Technology Research Center for Life and Health of River&Lake Guangzhou 510611China Key Laboratory for Information System of Mountainous Area and Protection of Ecological Environment of Guizhou Province Guizhou Normal UniversityGuiyang 550001China Bureau of Ecological Environment of Xunwu County of Jiangxi Province Xunwu 342200China

Relationship between biodiversity and ecosystem function is one of the core issues in ecological ***,as the main producer of aquatic ecosystem,its diversity,productivity,and community stability are of great signifi cance to reveal ecosystem *** are signifi cant diff erences in hydrodynamics,water retention time,and phytoplankton community structure between river-type reservoir and newly built lake-type *** comparative analysis of phytoplankton community stability between the two types of reservoir has not been *** Reservoir(river-type)and Taihu Reservoir(lake-type),the two reservoirs in the dongjiang River source area of Zhujiang(Pearl)River Basin,were selected for comparison in terms of multi-year operation *** impoundment,river-type ***-type,and shallow water ***-deep water *** were collected in dry season(December 2019),normal season(March 2020),and wet season(August 2020),on which the phytoplankton diversity and productivity of the two reservoirs,and the relationship and diff erence of community stability were *** show that(1)the number of phytoplankton species in Jiuquwan Reservoir decreased comparing that before algal bloom and the restoration treatment,while that in Taihu Reservoir increased compared with that before the impoundment of the *** was no signifi cant diff erence in functional groups and species number between the two reservoirs(P>0.05);(2)the biological stability,diversity,productivity,and resource utilization effi ciency of newly built lake-type reservoir were higher than those of multi-year river-type *** addition,the utilization effi ciency of phytoplankton resources was the highest in wet season in both *** increases in biodiversity,richness,and evenness promoted the stability of the community,while increases in productivity and resource utilization effi ciency weakened the stability of the community;(3)community stabili

关键词： community stability functional group stability phytoplankton diversity resource utilization effi ciency reservoir

TCD5 Enhances the Photosynthesis Capacity,Increases the Panicle Number and the Yield in Rice

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Phyton-International Journal of Experimental Botany 2023年第9期92卷 2649-2663页

作者： Jing Yang Yufeng Wang Zhanghua Hu Xiaoping Chen yanjun dong Sheng Teng Zhejiang Provincial Key Laboratory of Biometrology and Inspection&Quarantine College of Life SciencesChina Jiliang UniversityHangzhou310018China CAS Center for Excellence in Molecular Plant Sciences Chinese Academy of SciencesShanghai200032China Institute of Virology and Biotechnology Zhejiang Academy of Agricultural SciencesHangzhou310021China Agrotechnical Extension Station in Tiantai County Taizhou317200China College of Life Sciences Shanghai Normal UniversityShanghai200234China

Improvement of photosynthetic efficiency is a major approach to increase crop yield ***,we cloned a gene encoding the chloroplast-located putative monooxygenase TCD5,which is essential in plastid development under low temperature in rice(Oryza sativa L.).In this study,the effects of TCD5 on the photosynthesis and the yields were investigated in *** sets of genetic materials with three levels of TCD5 expression,including tcd5 mutant or TCD5 RNAi transgenic lines and TCD5 over-expression transgenic lines in Jiahua1 and Nipponbare backgrounds,were used in the field trails of multi-locations and ***5 positively affected the panicle number and the yield at *** with the wild-types,the panicle numbers were 12.4%-14.6%less in tcd5 mutant and 8.3%-38.6%less in TCD5 RNAi lines,but 26.2%-61.8%more in TCD5 over-expression *** grain yields per plant were 9.1%-18.4%less in tcd5 mutant and 14.3%-56.7%less in TCD5 RNAi lines,but 6.9%-56.5%more in TCD5 over-expression *** measurements of net photosynthetic rate indicated that mutation or knock down of TCD5 decreased the net photosynthetic rate by 10.4%and 15.6%,respectively,while increasing it by 8.9%and 8.7%in the TCD5 over-expression lines in Jiahua1 and Nipponbare backgrounds,***,the measurements of chlorophyll fluorescence parameters showed that the electron transport rate and quantum yield decreased in tcd5 mutant or TCD5 RNAi lines but increased in TCD5 overexpression lines,both in Jiahua1 and Nipponbare ***-MS screening revealed that TCD5 interacts with 29 chloroplast proteins involved in chlorophyll synthesis,photo-reactions of the photosynthesis,carbon assimilation and metabolism,energy metabolism,redox balance,protein synthesis and *** TCD5 interacted proteins,D1 and FBA were effective targets for improving *** results suggest a potentially new strategy for increasing rice yield by enhancing photosynthe

关键词： TCD5 photosynthesis panicle number yield

The rice OsV4 encoding a novel pentatricopeptide repeat protein is required for chloroplast development during the early leaf stage under cold stress

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Journal of Integrative Plant Biology 2014年第4期56卷 400-410页

作者： Xiaodi Gong Qianqian Su dongzhi Lin Quan Jiang Jianlong Xu Jianhui Zhang Sheng Teng yanjun dong Development Center of Plant Germplasm Resources College of Life and Environmental Sciences Shanghai Normal University Institute of Crop Sciences the Chinese Academy of Agricultural Sciences Institute of Plant Physiology and Ecology Shanghai Institute for Biological Sciences the Chinese Academy of Sciences

Pentatricopeptide repeat （PPR） proteins, charac- terized by tandem arrays of a 35 amino acid motif, have been suggested to play central and broad roles in modulating the expression of organelle genes in plants. However, the molecular mechanisms of most rice PPR genes remains unclear. In this paper, we isolated and characterized a temperature-conditional virescent mutant, OsV4, in rice （Oryza sativa cultivar Jiahual （WT, japonica rice variety））. The mutant displays albino phenotype and abnormal chloroplasts at the three leaf stage, which gradually turns green after the four leaf stage at a low temperature （20℃）. But the mutant always develops green leaves and well-developed chloroplasts at a high temperature （32℃）. Genetic and molecular analyses uncovered that OsV4 encodes a novel chloroplast-targeted PPR protein including four PPR motifs. Further investigations show that the mutant phenotype is associated with changes in chlorophyll content and chloroplast development. The OsV4 transcripts only accumulate to high levels in young leaves, indicating that its expression is tissue-specific. In addition, transcript levels of some ribosomal components and plastid- encoded polymerase-dependent genes are dramatically re- duced in the albino mutants grown at 20℃. These findings suggest that OsV4 plays an important role during early chloroplast development under cold stress in rice.

关键词： Chloroplast development pentatricopeptide repeat plastid-encoded polymerase rice virescent

P-twisted affine Lie algebra and its realizations by twisted vertex operators

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Science China Mathematics 2005年第z1期48卷 295-305页

作者： LU Keping, CHU yanjun, ZHENG Zhujun & dong Wenfeng Institute of Mathematics, Henan University, Kaifeng 475001, China USTC Shanghai Institute for Advanced Studies, University of Science and Technology of China, Shanghai 201315, China Henan Univ Inst Math Kaifeng 475001 Peoples R China Univ Sci & Technol China Shanghai Inst Adv Studies Shanghai 201315 Peoples R China

In this paper, we define a P-twisted affine Lie algebra, and construct its realizations by twisted vertex operators.

关键词： P-twisted affine Lie algebra, twisted vertex operator, extended P-twisted afline algebra.

Study of Co-Simulation Methods Applied in Power Systems （Part I）： VPNET

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中国电机工程学报 2012年第13期32卷 I0013-I0013,196页

作者： LI Weilin ZHANG Xiaobin dong yanjun RWTH Aachen University Northwestern Polytechnic University

随着智能化电力电子装置在现代电力系统中的应用，信息交换成为电力系统完成复杂保护及控制功能的重要因素，因此通信系统的影响也应该在设计电力系统的过程中给予充分的考虑。但是，传统的电力系统仿真软件都没有系统仿真通信影响的能... 详细信息

随着智能化电力电子装置在现代电力系统中的应用，信息交换成为电力系统完成复杂保护及控制功能的重要因素，因此通信系统的影响也应该在设计电力系统的过程中给予充分的考虑。但是，传统的电力系统仿真软件都没有系统仿真通信影响的能力；同时，搭建一种新的仿真软件需较多的时间和投入。联合仿真因此成为解决此类问题的另外一种选择，它能够利用各单个仿真软件已经存在的仿真模型，同时支持跨学科仿真软件之间的联合仿真。提出了一种新的联合仿真的平台VPNET，它综合了电力系统虚拟测试平台（virtualtestbed，VTB）和通信仿真软件OPNET来研究通信在电力系统中的影响。首先回顾了电力系统联合仿真方法的国内外发展概况，然后介绍了仿真方案VPNET以及实现该方案所需的关键技术。接着列举了该方案的2个具体应用：一是仿真网络化控制中延迟的影响；二是仿真基于多智能体通信的船舶电力系统保护。仿真结果符合理论分析，验证了该平台的有效性。

关键词：电力系统应用程序仿真方法电子信息交换通信网络调制解调器系统模拟器电源系统

“东数西算”背景下多数据中心联合消纳可再生能源途径研究综述

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高电压技术 2024年第1期50卷 55-64页

作者：苏娟董彦君赵晶董敏杜松怀中国农业大学信息与电气工程学院北京100083

“碳达峰、碳中和”和“东数西算”战略目标背景下,新能源装机占比和数据中心机架数量持续增长,数据中心的负荷调节能力可有效促进新能源消纳。与传统的可中断、可转移负荷不同,数据中心作为一种用电量可观的新型负荷,在时间、空间尺度... 详细信息

“碳达峰、碳中和”和“东数西算”战略目标背景下,新能源装机占比和数据中心机架数量持续增长,数据中心的负荷调节能力可有效促进新能源消纳。与传统的可中断、可转移负荷不同,数据中心作为一种用电量可观的新型负荷,在时间、空间尺度上均有调节潜力。因此,立足于现有研究成果,该文首先对数据中心能耗模型进行分析,对比了几种常见的建模方法;其次,通过对数据中心时空转移特性的定性分析和对消纳可再生能源潜力定量评估方法的总结,揭示了数据中心的消纳潜力;再次,分别从技术和管理2个层面梳理了数据中心消纳可再生能源的途径;最后,展望了“东数西算”背景下多数据中心联合消纳可再生能源的途径,为可再生能源消纳提供新的思路,助力我国“双碳”目标的实现。

关键词：数据中心可再生能源能耗模型潜力评估消纳途径