检索结果-南通市图书馆

Journal of Hydrodynamics 2023年第5期35卷 942-953页

作者： Xiang-qing zhang Xiao-fei zhang Xu qiu Dan Gao yu-ning zhang Key Laboratory of Power Station Energy Transfer Conversion and System(Ministry of Education) School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing102206China China Atomic Energy Publishing and Media Co.LTD Beijing100048China China Institute of Nuclear Industry Strategy Beijing100048China National Institute of Energy Development Strategy North China Electric Power UniversityBeijing102206China

Based on high-speed photographic experiments,this study presents a detailed qualitative and quantitative analysis of the dynamics of a single cavitation bubble near the boundary of a rigid wall in asymmetric *** main findings are reported as follows:(1)The non-sphericity of the bubble interface decreases with increasing spacing between the bubble and the boundary,and the asymmetry of the bubble becomes more significant with increasing asymmetry angle.(2)The motion mode of the bubble cluster in the second oscillation cycle can be divided into two typical modes depending on the direction of movement.(3)The angle between the oblique jet pointing towards the upper wall surface and the horizontal direction in the second oscillation cycle decreases as the dimensionless spacing decreases.

关键词： Asymmetry boundary cavitation bubble high-speed photography jet non-sphericity

Approximately orthogonal nonnegative Tucker decomposition for flexible multiway clustering

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

Science China(Technological Sciences) 2021年第9期64卷 1872-1880页

作者： qiu YiChun SUN WeiJun zhang yu GU XiaoBo ZHOU GuoXu School of Automation Guangdong University of TechnologyGuangzhou 510006China Key Laboratory of Intelligent Detection and The Internet of Things in Manufacturing Ministry of EducationGuangzhou 510006China Department of Bioengineering Lehigh UniversityBethlehemPA 18015USA Guangdong-Hong Kong-Macao Joint Laboratory for Smart Manufacturing Guangzhou 510006China Guangdong Key Laboratory of IoT Information Technology Guangzhou 510006China

High-order tensor data are prevalent in real-world applications, and multiway clustering is one of the most important techniques for exploratory data mining and compression of multiway data. However, existing multiway clustering is based on the K-means procedure and is incapable of addressing the issue of crossed membership degrees. To overcome this limitation, we propose a flexible multiway clustering model called approximately orthogonal nonnegative Tucker decomposition(AONTD). The new model provides extra flexibility to handle crossed memberships while fully exploiting the multilinear property of tensor *** accelerated proximal gradient method and the low-rank compression tricks are adopted to optimize the cost function. The experimental results on both synthetic data and real-world cases illustrate that the proposed AONTD model outperforms the benchmark clustering methods by significantly improving the interpretability and robustness.

关键词： multiway data analysis nonnegative Tucker decomposition flexible clustering accelerated proximal gradient

Plasmonic metafibers electro-optic modulators

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2023年第9期12卷 1893-1901页

作者： Lei zhang Xinyu Sun Hongyan yu Niping Deng Feng qiu Jiyong Wang Min qiu College of Information Science and Electronic Engineering Zhejiang UniversityHangzhou 310027China Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang Province School of EngineeringWestlake University18 Shilongshan RoadHangzhou 310024 ZhejiangChina Institute of Advanced Technology Westlake Institute for Advanced Study18 Shilongshan RoadHangzhou 310024 ZhejiangChina College of Optical Science and Engineering Zhejiang UniversityHangzhou 310027China Hangzhou Institute for Advanced Study University of Chinese Academy of SciencesHangzhou 310024China Ministry of Education Engineering Research Center of Smart Microsensors and Microsystems School of Electronics and InformationHangzhou Dianzi UniversityHangzhou 310018China

Digitalizing optical signals through electric driving signals,electro-optic modulators(EOMs)are one of the cardinal elements in modern optical *** of current EOM devices are targeting on-chip integrations,which routinely suffer from high coupling losses,complex optical alignments and single-band *** this study,we for the first time integrate a lumped EOM device on the endfaces of a single-mode optical fiber jumper for fast amplitude *** from ultrathin and high quality-factor plasmonic metasurfaces,nanofabrication-friendly and highly efficient EO polymers and coupling-free connections with fiber networks,our EOM is demonstrated to allow dual-band operations(telecom O band and S band)and high-speed modulations(~1 GHz at a bias voltage of±9 V).This work offers an avenue to‘plug-and-play’implementations of EO devices and ultracompact“all-in-fibers”optical systems for communications,imaging,sensing and many others.

关键词： fiber fibers operations

日粮中添加枯草芽孢杆菌对高氧气调包装猪肉蛋白质和脂质氧化的影响

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

食品科学 2025年第1期46卷 142-148页

作者：张悦于江刘飞张玉玉张一敏毛衍伟山东农业大学食品科学与工程学院山东泰安271018 山东省农业科学院畜牧兽医研究所农业农村部畜禽生物组学重点实验室山东济南250100

为探究日粮添加枯草芽孢杆菌对猪肉抗氧化能力以及高氧气调包装贮藏期间猪肉肉色、蛋白质氧化、脂质氧化和感官品质的影响,选取对照组(只饲喂基础日粮)和处理组(基础日粮添加枯草芽孢杆菌)的三元杂交(杜洛克×长白×大约克)猪各6只,屠... 详细信息

为探究日粮添加枯草芽孢杆菌对猪肉抗氧化能力以及高氧气调包装贮藏期间猪肉肉色、蛋白质氧化、脂质氧化和感官品质的影响,选取对照组(只饲喂基础日粮)和处理组(基础日粮添加枯草芽孢杆菌)的三元杂交(杜洛克×长白×大约克)猪各6只,屠宰后取背最长肌测定抗氧化酶活性,其余背最长肌样品进行高氧气调包装,4℃冷库贮藏,分别在0、5、10、15、20?d测定肉色、丙二醛(malondialdehyde,MDA)、羰基和巯基含量,并进行感官评价。结果表明:与对照组相比,处理组能够显著提高超氧化物歧化酶、谷胱甘肽过氧化物酶和过氧化氢酶活性(P<0.05),增强猪肉的抗氧化能力;日粮中添加枯草芽孢杆菌可以显著改善高氧气调包装猪肉的肉色(P<0.05);在低温贮藏期间,处理组能够显著降低MDA含量(P<0.05),抑制高氧气调包装猪肉的脂肪氧化;日粮中添加枯草芽孢杆菌能够显著抑制高氧气调包装猪肉的蛋白质氧化、羰基的生成和巯基损失(P<0.05),同时显著提高猪肉打开包装前的颜色和打开包装后的总体喜爱度评分(P<0.05)。综上,在日粮中添加枯草芽孢杆菌可提高猪肉的抗氧化能力、改善猪肉在高氧气调包装中的肉色、抑制蛋白质和脂质氧化,提高猪肉的食用品质。

关键词：枯草芽孢杆菌猪肉抗氧化能力脂质氧化蛋白质氧化

An efficient focusing model for generation of freak waves

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2011年第6期30卷 19-26页

作者： LIU Zanqiang zhang Ningchuan yu yuxiu State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China

Based on the Longuet-Higgins wave model theory, the previews studies have shown that freak waves can be generated in finite space and time successfully. However, as to generating high nonlinear freak waves, the simulation results will be unrealistic. Therefore, a modified phase modulation method for simulating high nonlinear freak waves was developed. The surface elevations of some wave components at certain time and place are positive by modulating the corresponding random initial phases, then the total surface elevation at the focused point is enhanced and furthermore a freak wave event is generated. The new method can not only make the freak wave occur at certain time and place, but also make the simulated wave surface time series satisfy statistical properties of the realistic sea state and keep identical with the target wave spectrum. This numerical approach is of good precision and high efficiency by the comparisons of the simulated freak waves and the recorded freak waves.

关键词： Longuet-Higgins wave model modified phase modulation method freak waves wave focusing

The least squares problem of the matrix equation A_1X_1B_1~T+A_2X_2B_2~T=T

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2009年第4期24卷 451-461页

作者： qiu yu-yang zhang Zhen-yue WANG An-ding Department of Mathematics Zhejiang University Yuquan Campus Hangzhou 310027 China College of Statistics and Mathematics Zhejiang Gongshang University Hangzhou 310018 China College of Information and Electronics Zhejiang Gongshang University Hangzhou 310018 China

The matrix least squares （LS） problem minx ｜｜AXB^T--T｜｜F is trivial and its solution can be simply formulated in terms of the generalized inverse of A and B. Its generalized problem minx1,x2 ｜｜A1X1B1^T ＋ A2X2B2^T - T｜｜F can also be regarded as the constrained LS problem minx=diag（x1,x2）｜｜AXB^T -T｜｜F with A = [A1, A2] and B = [B1, B2]. The authors transform T to T such that min x1,x2 ｜｜A1X1B1^T＋A2X2B2^T -T｜｜F is equivalent to min x=diag（x1 ,x2）｜｜AXB^T - T｜｜F whose solutions are included in the solution set of unconstrained problem minx ｜｜AXB^T - T｜｜F. So the general solutions of min x1,x2 ｜｜A1X1B^T ＋ A2X2B2^T -T｜｜F are reconstructed by selecting the parameter matrix in that of minx ｜｜AXB^T - T｜｜F.

关键词： least squares problem generalized inverse solution set general solutions parameter matrix

Water quality, agriculture and food safety in China:Current situation, trends, interdependencies, and management

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2015年第11期14卷 2365-2379页

作者： zhang Xiao-nan GUO qiu-ping SHEN Xiao-xue yu Sheng-wen qiu Guo-yu Shenzhen Engineering Laboratory for Water Desalinization with Renewable Energy School of Environment and EnergyPeking University Chinese Academy for Environmental Planning

Water quality in China is becoming a severe challenge for agriculture and food safety, and it might also impact health of population via agriculture and food. Thus, it is causing widespread concern. Based on extensive literatures review and data mining, current situation of water pollution in China and its effects on food safety were analyzed. The 2nd National Water Resource Survey in China show that the surface water all over the country was under slight pollution and about 60% of groundwater is polluted. Drinking water quality is basically guaranteed in urban area but it is worrisome in rural areas. In addition, China is the largest consumer of fertilizer and pesticide in the world and the amounts of application still show increasing trends. Fertilizers and pesticides are the most important sources of pollution, which affect human health as persistent organic pollutants and environmental endocrine disruptors. Eutrophication of surface water and nitrate pollution of groundwater are serious threats to drinking water safety. Sewage irrigation is becoming a pollution source to China＇s water and land because of lacking of effective regulations. Although, with the advance in technology and management level, control of nitrogen and phosphorus emissions and reducing water pollution is still a major challenge for China.

关键词： agriculture drinking water eutrophication fertilizer food safety groundwater heavy metals microcystin nitrate pesticide pollution water quality

Improved Active Islanding Detection Technique for Multi-Inverter Power System

在线全文

学校读者我要写书评

暂无评论

Journal of Electronic Science and Technology 2021年第2期19卷 186-195页

作者： Jie zhang yu-Hua Cheng Kai Chen Gen qiu School of Automation Engineering University of Electronic Science and Technology of ChinaChengdu 610054

Due to the increased penetration of multi-inverter distributed generation(DG)systems,different DG technologies,inverter control methods,and other inverter functions are challenging the capabilities of islanding *** addition,multi-inverter networks connecting the distribution system point of common coupling(PCC)create islanding at paralleling inverters,which adds the vulnerability of islanding ***,available islanding detection must overcome more challenges from non-detection zones(NDZs)under reduced power ***,in this study,a new method called parameter self-adapting active islanding detection was utilized to minimize the dilution effect and reduce NDZs in multi-inverter power *** method utilizes an active frequency drift(AFD)method and applies a positive feedback gain of adoption parameters,which significantly minimizes NDZs at parallel *** simulation and experimental outcomes indicate that the proposed method can effectively weaken the dilution effect in multi-inverter networks connecting the distribution system PCC.

关键词： Active frequency drift(AFD) active islanding detection method multi-inverter power system non-detection zones(NDZs)

Self-powered forest ambient monitoring microsystem based on wind energy hybrid nanogenerators

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2022年第10期65卷 2348-2360页

作者： LI Boyuan qiu yu HUANG Peng TANG WenJie zhang XiaoSheng School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

In response to the call for zero-carbon energy supply for Internet of Things(IoTs)applications and to get rid of the dependence of traditional distributed IoTs devices on batteries,the invention of nanogenerators that can convert wind energy in the surrounding environment into electrical energy have received widespread ***,a wind energy hybrid harvester(WH-EH)combining a soft-friction and positive-directional triboelectric nanogenerator(SP-TENG)and a hierarchical rotating electromagnetic nanogenerator(HR-EMG)is reported to construct a self-powered forest environment monitoring *** the design of thin inner wall beams and comb-shaped electrodes,the SP-TENG is able to change the output into positivedirectional,which can be stored directly in the energy storage device,breaking the limitation of the alternating positive and negative output of conventional *** addition,the HR-EMG embeds coils in the cup lid to make the most of the available space in the external *** the WH-EH,a layered structure,including the HR-EMG and SP-TENG is adopted to jointly utilize wind energy for both higher output and higher *** order to effectively implement wireless monitoring of the forest environment,the WH-EH is further utilized to develop a self-powered forest environment monitoring microsystem by powering the IoTs sensor nodes,realizing ambient temperature and humidity sampling and wireless transmission,so as to achieve the purpose of preventing forest *** is believed that the development of the WH-EH and the self-powered forest environment monitoring microsystem provides diverse options for the practicalization of self-powered IoTs systems and the energy supply problem of IoTs sensor networks.

关键词： self-powered nanogenerator MEMS energy harvesting microsystem

同方期刊数据库

Intraspecific floral colour variation in three Pedicularis species

在线全文

学校读者我要写书评

暂无评论

Plant Diversity 2024年第2期46卷 274-279页

作者： qiu-yu zhang Zhe Chen Hang Sun Yang Niu State Key Laboratory of Plant Diversity and Specialty Crops Kunming Institute of BotanyChinese Academy of SciencesKunming 650201YunnanChina University of Chinese Academy of Sciences Beijing 100049China

Flower constancy describes the phenomenon that pollinators tend to successively visit flowers of a single species during foraging,reducing reproductive interference in natural *** extent of flower constancy is largely determined by the floral traits of co-flowering *** higher inter-specific and lower intraspecific differences of floral traits should contribute to a higher level of flower ***,previous studies mainly focused on interspecific difference,and the intraspecific variation(consistency)of floral traits received much less *** hypothesise that selection may favour lower intraspecific floral trait variation in communities composed of multiple co-flowering *** investigated the floral colour variation of three focal Pedicularis species that share pollinators in 19communities composed of either single or multiple Pedicularis *** was quantified using image-based colour analysis as perceived by *** found that most of the intrapopulation floral colour variation was below the colour discrimination threshold of bumblebees,implying strongly constrained by the visual selection by *** to the hypothesis,there is no significant difference in intraspecific floral colour variation between different community *** may be due to the relatively large interspecific floral colour differences of most co-flowering *** influence of community context on intraspecific variation may be reflected in floral traits other than colours.

关键词： Flower constancy Floral colour variation Plantepollinator interactions Pollinator vision