检索结果-南通市图书馆

维普期刊数据库博看期刊

Spatial and temporal evolution of landfast ice near Zhongshan Station, East Antarctica, over an annual cycle in 2011/2012

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2019年第5期38卷 51-61页

作者： Jiechen Zhao Qinghua Yang Bin Cheng Matti Lepp?ranta Fengming Hui Surui Xie Meng Chen yining yu Zhongxiang Tian Ming Li Lin Zhang College of Oceanic and Atmospheric Sciences Ocean University of China National Marine Environmental Forecasting Center First Institute of Oceanography Ministry of Natural Resources Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies School of Atmospheric Sciences Sun Yat-sen University Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Finnish Meteorological Institute Institute of Atmospheric and Earth Sciences University of Helsinki College of Global Change and Earth System Sciences (GCESS) Beijing Normal University School of Geosciences University of South Florida Meteorological Service of Youyang Tujia and Miao Autonomous County College of Global Change and Earth System Sciences Beijing Normal University

Annual observations of first-year ice(FYI) and second-year ice(SYI) near Zhongshan Station, East Antarctica,were conducted for the first time from December 2011 to December 2012. Melt ponds appeared from early December 2011. Landfast ice partly broke in late January, 2012 after a strong cyclone. Open water was refrozen to form new ice cover in mid-February, and then FYI and SYI co-existed in March with a growth rate of 0.8 cm/d for FYI and a melting rate of 2.7 cm/d for SYI. This difference was due to the oceanic heat flux and the thickness of ice,with weaker heat flux through thicker ice. From May onward, FYI and SYI showed a similar growth by 0.5 cm/*** maximum thickness reached 160.5 cm and 167.0 cm, respectively, in late October. Drillings showed variations of FYI thickness to be generally less than 1.0 cm, but variations were up to 33.0 cm for SYI in March,suggesting that the SYI bottom was particularly uneven. Snow distribution was strongly affected by wind and surface roughness, leading to large thickness differences in the different sites. Snow and ice thickness in Nella Fjord had a similar "east thicker, west thinner" spatial distribution. Easterly prevailing wind and local topography led to this snow pattern. Superimposed ice induced by snow cover melting in summer thickened multi-year ice,causing it to be thicker than the snow-free SYI. The estimated monthly oceanic heat flux was ～30.0 W/m2 in March–May, reducing to ～10.0 W/m2 during July–October, and increasing to ～15.0 W/m2 in November. The seasonal change and mean value of 15.6 W/m2 was similar to the findings of previous research. The results can be used to further our understanding of landfast ice for climate change study and Chinese Antarctic Expedition services.

关键词： landfast ice thickness oceanic heat flux Prydz Bay East Antarctica

Anomalous extensive landfast sea ice in the vicinity of Inexpressible Island, Antarctica

在线全文

学校读者我要写书评

暂无评论

Advances in Polar Science 2019年第4期30卷 406-411页

作者： ZHAI Mengxi ZHAO Tiancheng HUI Fengming CHENG Xiao LIUAobo yuAN Jiawei yu yining DING Yifan MNR Key Laboratory for Polar Science Polar Research Institute of ChinaShanghai 200136China School of Environmental Science Nanjing Xiaozhuang UniversityNanjing 211171China School of Geospatial Engineering and Science Sun Yat-Sen UniversityGuangzhou 510275China College of Global Change and Earth System Science Beijing Normal UniversityBeijing 100875China

On 10 December 2017,a Chinese research vessel R/V Xuelong encountered an extensive area of landfast ice offshore Inexpressible Island(Antarctica)near the location where the fifth Chinese Antarctic research station is to be *** multi-source satellite images and weather data,we analyzed the ice conditions during the event season and reconstructed the development of landfast *** stages in late September and early October were identified as contributing to the final ice *** two events are highly related to local-and large-scale weather *** images from 2003 to 2017 showed that four in fifteen years experienced severe landfast ice conditions,suggesting that it is not a rare phenomenon.

关键词： Inexpressible Island Antarctic landfast ice Chinese Antarctic research station

Impact of Pd single-site coordination structure on catalytic performance for semihydrogenation of acetylene

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第9期17卷 8243-8249页

作者： yu Zeng Minqi Xia Fujie Gao Changkai Zhou Xueyi Cheng Liwei Liu Liu Jiao Qiang Wu Xizhang Wang Lijun Yang yining Fan Zheng Hu Key Laboratory of Mesoscopic Chemistry of MOE and Jiangsu Provincial Laboratory for Nanotechnology School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

Semihydrogenation of trace acetylene in an ethylene gas stream is a vital step for the industrial production of polyethylene,in which Pd single-site catalysts(SSCs)have great ***,two Pd SSCs with different coordination structures are prepared on hierarchical nitrogen-doped carbon nanocages(hNCNC)by regulating the nitrogen species with or without using *** using dicyandiamide,the obtained Pd1-Ndicy/hNCNC SSC features the coordinated Pd by two pyridinic N and two pyrrolic N(PdN^(py)_(2)N^(pr)_(2)).Without using dicyandiamide,the obtained Pd1/hNCNC SSC features the coordinated Pd by pyridinic N and C(PdN^(py_(x)C_(4-x)),x=1-4).The former exhibits an 18-fold increase in catalytic activity compared to the *** results reveal the abundant unoccupied orbital states above the Fermi level of moiety,which can facilitate the activation of substrate molecules and dynamics of acetylene hydrogenation as supported by the combined theoretical and experimental *** addition,PdN^(py)_(2)N^(pr)_(2)the moiety presents a favorable desorption of ***,the Pd1-Ndicy/hNCNC SSC exhibits high C2H2 conversion(99%)and C2H4 selectivity(87%)at 160℃.This study demonstrates the impact of Pd single-site coordination structure on catalytic performance,which is significant for the rational design of advanced Pd SSCs on carbon-based supports.

关键词： coordination structure hierarchical nitrogen-doped carbon nanocages palladium semihydrogenation of acetylene singlesite catalysts

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

考虑多技能人力资源的分布式多项目调度问题

系统工程理论与实践 2020年第11期40卷 2921-2933页

作者：于懿宁徐哲刘东宁北京航空航天大学经济管理学院北京100191

在分布式多项目管理中,当考虑共享资源为多技能人力资源时,共享资源的指派涉及到"活动-技能-资源"的匹配关系,进一步考虑人力资源多技能异质的特性,还会导致活动实际执行工期会随着指派方案的不同而变化,因此,考虑共享资源为多技能人力... 详细信息

在分布式多项目管理中,当考虑共享资源为多技能人力资源时,共享资源的指派涉及到"活动-技能-资源"的匹配关系,进一步考虑人力资源多技能异质的特性,还会导致活动实际执行工期会随着指派方案的不同而变化,因此,考虑共享资源为多技能人力资源的分布式多项目调度问题是一类具有很强现实背景和理论研究价值的NP-hard问题.基于多Agent系统,建立以单项目完工时间为优化目标的局部调度模型,以及多项目总延期成本为优化目标的全局协调决策模型;考虑人力资源多技能异质的特点,设计基于贪婪指派策略的序贯博弈谈判机制指派共享的人力资源;基于Ran Gen随机生成的多项目算例开展实验研究.研究表明:基于贪婪指派策略的序贯博弈谈判机制对于程度不同的资源冲突和不同规模问题的求解均具有较好的适应性,可有效降低多项目总延期成本,且求解效果优于随机分配策略;设计的优先指派技能水平高、掌握技能数少、工作时间短的全局资源指派策略,可获得较优的人力资源指派方案和多项目调度计划.

关键词：分布式多项目调度多技能人力资源全局资源贪婪指派策略序贯博弈谈判机制

MOSS:An Open Conversational Large Language Model

在线全文

学校读者我要写书评

暂无评论

Machine Intelligence Research 2024年第5期21卷 888-905页

作者： Tianxiang Sun Xiaotian Zhang Zhengfu He Peng Li Qinyuan Cheng Xiangyang Liu Hang Yan yunfan Shao Qiong Tang Shiduo Zhang Xingjian Zhao Ke Chen yining Zheng Zhejian Zhou Ruixiao Li Jun Zhan yunhua Zhou Linyang Li Xiaogui Yang Lingling Wu Zhangyue Yin Xuanjing Huang yu-Gang Jiang Xipeng Qiu Fudan University Shanghai200438China

Conversational large language models(LLMs)such as ChatGPT and GPT-4 have recently exhibited remarkable capabilities across various domains,capturing widespread attention from the *** facilitate this line of research,in this paper,we report the development of MOSS,an open-sourced conversational LLM that contains 16 B parameters and can perform a variety of instructions in multi-turn interactions with *** base model of MOSS is pre-trained on large-scale unlabeled English,Chinese,and code *** optimize the model for dialogue,we generate 1.1 M synthetic conversations based on user prompts collected through our earlier versions of the model *** then perform preference-aware training on preference data annotated from AI *** results on real-world use cases and academic benchmarks demonstrate the effectiveness of the proposed *** addition,we present an effective practice to augment MOSS with several external *** the development of MOSS,we have established a complete technical roadmap for large language models from pre-training,supervised fine-tuning to alignment,verifying the feasibility of chatGPT under resource-limited conditions and providing a reference for both the academic and industrial *** weights and code are publicly available at https://***/OpenMOSS/MOSS.

关键词： Large language models natural language processing pre-training alignment chatGPT MOSS

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

旧将焉在:晋末宋初北府的权力重组

史学月刊 2024年第8期 5-19页

作者：李祎凝武汉大学历史学院湖北武汉430072

东晋末期,以刘牢之自缢为标志,旧有北府最终走向解体。直到刘裕京口举义,击败桓玄,北府方得以重建。从刘牢之到刘裕,北府内部不仅权力主体发生变动,其权力结构也与昔日迥然有别。在刘牢之统领时,北府尚未形成严格的统属关系。刘牢之虽... 详细信息

东晋末期,以刘牢之自缢为标志,旧有北府最终走向解体。直到刘裕京口举义,击败桓玄,北府方得以重建。从刘牢之到刘裕,北府内部不仅权力主体发生变动,其权力结构也与昔日迥然有别。在刘牢之统领时,北府尚未形成严格的统属关系。刘牢之虽名为北府领袖,实则并无权力节制所有兵力,最终亦因此为桓玄所败。刘牢之死后,北府旧将或被桓玄收编,或流亡至十六国北族政权,依违于南北之间。刘裕逐灭桓玄后,以刘敬宣、司马休之为代表的流亡北府将领得以重返故土,凭借其在北府兵中的号召力,被刘裕授予显职,但终究实权有限。而旧有北府松散的权力架构,也被刘毅、孟昶等京口新贵继承。北府存在的权力分化倾向,始终与刘裕重树皇权的集权需要相冲突。义熙年间,通过讨伐刘毅、诸葛长民、司马休之等人,刘裕将北府军权集中于一身,同时在地缘层面将北府统治扩大到长江上游。北府中的旧将与新贵,最终被整合进以刘裕为主导的集权体制内,而北府的集权化转型,也为刘宋皇权专制与中央集权提供了军事基础。

关键词：晋宋嬗代桓玄北府旧将刘裕京口新贵

在线全文

学校读者我要写书评

暂无评论

分布式资源受限多项目调度问题研究综述

工业工程与管理 2023年第5期28卷 199-210页

作者：李飞飞徐哲刘东宁赵松于懿宁北京联合大学管理学院北京100101 北京航空航天大学经济管理学院北京100191 中国科学院大学经济与管理学院北京100190

传统的资源受限多项目调度集中式决策方法已无法满足信息不对称环境下的多项目管理需求,分布式资源受限多项目调度问题研究的是多个自主决策者分别进行全局资源的协调分配决策与局部项目的调度优化决策。鉴于较强的实际应用背景,这类问... 详细信息

传统的资源受限多项目调度集中式决策方法已无法满足信息不对称环境下的多项目管理需求,分布式资源受限多项目调度问题研究的是多个自主决策者分别进行全局资源的协调分配决策与局部项目的调度优化决策。鉴于较强的实际应用背景,这类问题逐渐成为项目调度领域新的研究热点。首先,在系统介绍分布式资源受限多项目调度问题特点与模型构建的基础上,分类梳理并评述了问题求解的代表性方法;其次,总结了分布式多项目调度的相关扩展问题以及在不同领域的典型应用;最后,讨论了目前研究中存在的主要问题与未来可能的拓展研究方向。

关键词：分布式多项目资源局部调度全局协调

High-performance,stable CoNi LDH@Ni foam composite membrane with innovative peroxymonosulfate activation for 2,4-dichlorophenol destruction

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第7期141卷 235-248页

作者： yu Liu Weibao Liu Xinrui Gan Jiangwei Shang Xiuwen Cheng College of Chemistry and Environmental Science Xinjiang Laboratory of Phase Transitions and Microstructures of Condensed Matter PhysicsYili Normal UniversityYining 835000China Key Laboratory for Environmental Pollution Prediction and Control Gansu ProvinceCollege of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China

In this study,the cobalt-nickel layered double hydroxides(CoNi LDH)were synthesized with a variety of Co/Ni mass ratio,as *** comparison,Co1Ni3LDH presented the best peroxymonosulfate(PMS)activation efficiency for 2,4-dichlorophenol ***,CoNi LDH@Nickel foam(CoNi LDH@NF)composite membrane was constructed for enhancing the stability of catalytic ***,CoNi LDH@NF-PMS system exerted high degradation efficiency of 99.22%within 90 min for 2,4-DCP when[PMS]_(0)=0.4 g/L,Co^(1)Ni^(3)LDH@NF=2 cm×2 cm(0.2 g/L),reaction temperature=298 *** the surface morphology and structure of the catalyst,it was demonstrated that the CoNi LDH@NF composite membrane possessed abundant cavity structure,good specific surface area and sufficient active ***,·OH,SO_(4)·^(-)and^(1)O_(2)played the primary role in the CoNi LDH@NF-PMS system for 2,4-DCP decomposition,which revealed the PMS activation mechanism in CoNi LDH@NF-PMS ***,this study eliminated the stability and adaptability of CoNi LDH@NF composite membrane,proposing a new theoretical basis of PMS heterogeneous catalysts selection.

关键词： CoNi LDH@NF composite membrane Peroxymonosulfate 2,4-dichlorophenol Reactive radicals

基于优化VMD-CNN-BiLSTM的电机轴承智能故障诊断研究

在线全文

学校读者我要写书评

暂无评论

现代电子技术 2024年第12期47卷 115-121页

作者：曹景胜于洋王琦董翼宁沈阳工业大学信息科学与工程学院辽宁沈阳110870 辽宁工业大学汽车与交通工程学院辽宁锦州121001

针对滚动轴承早期故障信号较弱及特征数据提取效果差,导致故障诊断准确率低以及故障诊断效率低的问题,提出一种信号处理结合深度神经网络的故障诊断方法。首先,采用变分模态分解(VMD)法提取主轴承振动数据中的特征数据;然后为了确定VMD... 详细信息

针对滚动轴承早期故障信号较弱及特征数据提取效果差,导致故障诊断准确率低以及故障诊断效率低的问题,提出一种信号处理结合深度神经网络的故障诊断方法。首先,采用变分模态分解(VMD)法提取主轴承振动数据中的特征数据;然后为了确定VMD算法中最佳的模态分量个数K及惩罚参数α,增强特征提取的效果,将最小排列熵作为适应度函数,采用全局优化能力强的正弦混沌自适应鲸鱼优化算法(CAWOA)进行参数的确定,得到最优模态分量;接着,根据最优模态分量构造特征向量,将特征向量作为CNN-BiLSTM网络的输入,实现故障的分类。最后,根据实验平台采集的数据进行实验分析。结果表明,优化VMD-CNN-BiLSTM轴承故障诊断模型相较于其他故障诊断模型,在准确率以及实时性上均有明显提升。

关键词：变分模态分解(VMD) 卷积神经网络(CNN) 双向长短期记忆(BiLSTM) 滚动轴承智能故障诊断特征数据提取正弦混沌自适应鲸鱼优化算法

维普期刊数据库博看期刊