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AN EFFICIENT BIT RATE ALLOCATION ALGORITHM FOR MOTION JPEG2000 TRANSPORT IN TILE ENCODING

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Journal of Electronics(China) 2008年第2期25卷 200-203页

作者： liu Jieyu Zhang Deyun Wang Yue li zhe School of Electronics and Information Engineering Xi＇an Jiaotong University Xi＇an 710049 China

An efficient bit rate allocation algorithm for video sequence transmission in motion JPEG2000 is presented. In many cases,the moving portions of video are often the interested regions. Based on tile encoding of JPEG2000,the important regions are discerned by two parameters. One is the complexity of a tile;the other is the motion activity of a tile. Thus an adaptive rate-allocation is re-alized in a lower complexity and the perceptive quality of a frame is improved. Experimental results show the effectiveness of this algorithm.

关键词： Motion JPEG2000 Tile Regions-Of-Interest (ROI) Bit rate allocation

核电厂丧失厂外电源事件下柴油发电机系统动态响应分析

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核动力工程 2012年第1期33卷 60-65页

作者：李哲中国再保险(集团)股份有限公司中国核共体执行机构北京100033

将系统可靠性分析方法 GO法与Markov法相结合,对核电厂概率安全分析(PSA)中厂外电源丧失(LOOP)后柴油发电机应急响应系统在24h内缓解全厂断电(SBO)事件中的动态过程进行分析,解决了维修相关存在下可修系统可靠性精确计算问题,并通过创... 详细信息

将系统可靠性分析方法 GO法与Markov法相结合,对核电厂概率安全分析(PSA)中厂外电源丧失(LOOP)后柴油发电机应急响应系统在24h内缓解全厂断电(SBO)事件中的动态过程进行分析,解决了维修相关存在下可修系统可靠性精确计算问题,并通过创建GO法"备用门"操作符真实地模拟应急响应系统工作的逻辑关系。通过将2种可靠性分析方法相结合使用的尝试,使之与柴油发电机应急响应系统存在维修相关的实际情况相适应,拓展了2种方法的分析领域,同时能够更为精确地得出SBO对系统安全运行的影响。

关键词：厂外电丧失全厂断电事件 GO法 Markov法可靠性分析

Direct Climatic Effect of Aerosols and Interdecadal Variations over East Asia Investigated by a Regional Coupled Climate-Chemistry/Aerosol Model

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Atmospheric and Oceanic Science Letters 2011年第6期4卷 299-303页

作者： HAN Zhi-Wei XIONG zhe li Jia-Wei Key Laboratory of Regional Climate-Environment Research for Temperate East Asia （RCE-TEA） Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The direct climatic effect of aerosols for the 1980-2000 period over East Asia was numerically investigated by a regional scale coupled climate-chemistry/ aerosol model, which includes major anthropogenic aerosols （sulfate, black carbon, and organic carbon） and natural aerosols （soil dust and sea salt）. Anthropogenic emissions used in model simulation are from a global emission inventory prepared for the Intergovernmental Panel on Climate Change Fifth Assessment Report （IPCC AR5）, whereas natural aerosols are calculated online in the model. The simulated 20-year average direct solar radiative effect due to aerosols at the surface was estimated to be in a range of-9- -33 W m-2 over most areas of China, with maxima over the Gobi desert of West China, and-12 W m-2 to -24 W m-2 over the Sichuan Basin, the middle and lower reaches of the Yellow River and the Yangtze River. Aerosols caused surface cooling in most areas of East Asia, with maxima of-0.8℃ to -1.6℃ over the deserts of West China, the Sichuan Basin, portions of central China, and the middle reaches of the Yangtze River. Aerosols induced a precipitation decrease over almost the entire East China, with maxima of-90 mm/year to -150 mm/year over the Sichuan Basin, the middle reaches of the Yangtze River and the lower reaches of the Yellow River. Interdecadal variation of the climate response to the aerosol direct radiative effect is evident, indicating larger decrease in surface air temperature and stronger per- turbation to precipitation in the 1990s than that in the 1980s, which could be due to the interdecadal variation of anthropogenic emissions.

关键词： aerosols direct radiative effect climatic response interdecadal variation model simulation

Optimizing side chains on different nitrogen aromatic rings achieving 17% efficiency for organic photovoltaics

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Journal of Energy Chemistry 2022年第2期31卷 173-178页

作者： zhe li Can Zhu Jun Yuan liuyang Zhou Wei liu Xinxin Xia c Juan Hong Honggang Chen Qingya Wei Xinhui Lu Yongfang li Yingping Zou College of Chemistry and Chemical Engineering Central South UniversityChangsha 410000HunanChina CAS Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of SciencesBeijing 100000China Department of Physics The Chinese University of Hong KongHong Kong 999077China

Balancing charge generation and low energy loss(E_(loss)), especially in the wide spectral absorption region is critical to obtain high-performance organic photovoltaics(OPVs). Therefore, Y11-M and Y11-EB are designed and synthesized through modifying alkyl chains on different nitrogen aromatic rings of the reported non-fullerene acceptor Y11. Although all the molecules have almost similar low band-gap(around 1.30 e V), Y11-M and Y11-EB exhibit wider absorption in 410–870 nm region. Eventually, the conventional devices based on Y11-M and Y11-EB possess more efficient charge generation with low Eloss(around 0.44 e V). In addition, outstanding efficiencies of 16.64% and 17.15% with the fill factor of 76.15% and 74.73% are obtained in PM6:Y11-M and PM6:Y11-EB-based devices, both higher than Y11:PM6. The results highlight the importance of rational alkyl chains optimization, and a good structureproperty relationship is established as well.

关键词： Fused-ring benzotriazole Side chains modification Low band-gap acceptors High-efficiency organic photovoltaics

Decision making module based on stochastic magnetic tunnel junctions

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 202-209页

作者： Yifan Miao li Zhao Yajun Zhang zhe Yuan Center for Advanced Quantum Studies and Department of Physics Beijing Normal University Institute for Nanoelectric Devices and Quantum Computing Fudan University Interdisciplinary Center for Theoretical Physics and Information Sciences Fudan University

In biological neural systems, noise is ubiquitous but does not affect the correct decisions made in the complex cognitive ***-making in biological neural system is typically achieved by accumulating input information over a period of *** by recent developments in neurosciences, we design a decision-making module based on spintronic devices, utilizing superparamagnetic tunnel junctions as artificial neurons. The feasibility of this decision-making module is verified through circuit simulations. Taking a multi-layer perceptron as an example, the module significantly improves the accuracy of the perceptron in the handwritten digit recognition task. Furthermore, the spintronic decision-making module offers advantages over the conventional pooling methods, such as adaptive decision time, high performance and the absence of analog-to-digital conversion. The decision-making module is flexible to be integrated into artificial neural networks and provides a general yet effective solution to enhance performance against device noise.

关键词： neuromorphic computing spintronics magnetic tunnel junction neural networks

Simultaneous acquisition of Fe3O4 monocrystals:Tunable magnetic properties with various morphologies

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Progress in Natural Science:Materials International 2020年第1期30卷 41-46页

作者： Zemin zheng Yiming Cao zhe li Huiyong li Dafeng Hu Hao Jiang Xuemin Geng Jiangwei Lu Xudong Zhang Peng Yang Yanfen Wan School of Materials Science and Engineering Yunnan Key Laboratory for Micro/nano Materials & TechnologyYunnan University Center for Magnetic Materials and Devices & Key Laboratory for Advanced Functional and Low Dimensional Materials of Yunnan Higher Education Institute Qujing Normal University

Fe3O4nanoparticles（NPs） with a face-centered cubic（fcc） structure and two different morphologies（nanospheres and nanoprisms） were synthesized by a facile one-step *** synthesized Fe3O4nanospheres and nanoprisms were monocrystalline and separable in a magnetic *** different volume ratios of oleylamine（OAm） to dibenzyl ether,the sizes of the prepared Fe3O4NPs ranged from 5 to 21 *** OAm amount in the synthesis can significantly control the morphology of *** the OAm content increased from 10 ml to 30 ml,the faceted nanoprisms shrank while the nanospheres *** an OAm content of 25 ml,the nanoprisms diminished while more hexagonal and sphere-like particles appeared,implying a critical point of morphology transition from triangle to *** magnetic properties also depended on the NP morphology and *** prepared Fe3O4NPs are promising candidates in medical applications such as magnetic resonance imaging,targeted drug delivery,blood purification,and tumor hyperthermia.

关键词： Fe 3 O 4 Nanoparticles Nanoprism Nanosphere Superparamagnetic

Structural and magnetocaloric properties in hexagonal MnNiGa alloys with Co doping

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Rare Metals 2017年第7期36卷 601-606页

作者： Kun Xu zhe li Hai-Chun Zhou Yuan-Lei Zhang Dan Yan Wei Sun Dong zheng Chao Jing Research Center for Magnetic Materials and Devices Key Laboratory for Advanced Functional and Low Dimensional Materials of Yunnan Higher Education InstituteQujing Normal University Department of Physics Yunnan Normal University Department of Physics Shanghai University

Hexagonal MnNiGe-based alloys are a series of novel functional materials with potential magnetostructural transitions （MSTs）. Accordingly, it was investigated the magnetic features of bulk hexagonal MnNiGa alloy and attempted to partially substitute Mn by Co atoms to tailor its structural and magnetic properties. Nonetheless, the introduction of magnetic Co atom fails to bring about the first-order phase transition and gives rise to the emergence of second phase with cubic structure instead. For ternary MnNiGa parent alloy, the second-order nature of transition is confirmed by both the absence of thermal hysteresis and the standard Arrott plot. To the end, the values of isothermal entropy change are determined by Maxwell relation, and the maximal values follow the trend predicted by the mean-field theory. Its broad transition region （-53 K） leads to only a very small value of entropy change （- 2.4 J·kg^-1·K^- 1 at a field change of 3 T）. In turn, the wide transition ensures a relative large refrigerant capacity （-89.4 J·kg^-1）, which is comparable to that of MnNiGe-based systems. Although the substitution of Co for Mn site is unsuccessful, the chemically modified MnNiGa is still a promising candidate for the application of magnetocaloric effect （MCE） with merits of higher magnetization and better mechanical performance than MnNiGe-based systems.

关键词： Magnetocaloric effect Second-order magnetictransition Arrott plot Isothermal entropy change

Structure-based discovery of orally efficient inhibitors via unique interactions with H-pocket of PDE8 for the treatment of vascular dementia

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Acta Pharmaceutica Sinica B 2022年第7期12卷 3103-3112页

作者： Xu-Nian Wu Qian Zhou Ya-Dan Huang Xi Xie zhe li Yinuo Wu Hai-Bin Luo School of Pharmaceutical Sciences Sun Yat-sen UniversityGuangzhou510006China Key Laboratory of Tropical Biological Resources of Ministry of Education and One Health Institute School of Pharmaceutical SciencesHainan UniversityHaikou 570228China

Our previous study demonstrated that phosphodiesterase 8(PDE8)could work as a potential target for vascular dementia(Va D)using a chemical probe ***,compound 3a is a chiral compound which was obtained by chiral resolution on HPLC,restricting its usage in ***,a series of non-chiral 9-benzyl-2-chloro-adenine derivatives were discovered as novel PDE8 *** 15 exhibited potent inhibitory activity against PDE8A(IC_(50)=11 nmol/L),high selectivity over other PDEs,and remarkable drug-like properties(worthy to mention is that its bioavailability was up to 100%).Oral administration of 15 significantly improved the c AMP level of the right brain and exhibited dosedependent effects on cognitive improvement in a Va D mouse ***,the X-ray crystal structure of the PDE8A—15 complex showed that the potent affinity and high selectivity of 15 might come from the distinctive interactions with H-pocket including T-shapedπ—πinteractions with Phe785 as well as a unique H-bond network,which have never been observed in other PDE-inhibitor complex before,providing new strategies for the further rational design of novel selective inhibitors against PDE8.

关键词： Phosphodiesterase 8(PDE8) Vascular dementia Structure-based drug design MM-GB/SA Free energy prediction Structure—activity relationship Binding potencies

Optimal edge-cloud collaboration based strategies for minimizing valid latency of railway environment monitoring system

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High-Speed Railway 2023年第3期1卷 185-194页

作者： Xiaoping Ma Jing Zhao limin Jia Xiyuan Chen zhe li Key Laboratory of Rail Trafic Control and Safety Beijing Jiaotong UniversityBeijing 100044China Beijing Research Center of Urban Traffic Information Inteligent Sensing and Service Technologies Beijing 100044China Research and Development Center of Transport Industry of Technologies and Equipments of Urban Rail Operation Safety Management MOTBeijing 100044China School of Trafic and Transportation Beijing Jiaotong UniversityBeijing 100044China National Innovation Center of Intelligent and Connected Vehicles Beijing 102607China

Response speed is vital for the railway environment monitoring system,especially for the sudden-onset *** edge-cloud collaboration scheme is proved efficient to reduce the ***,the data characteristics and communication demand of the tasks in the railway environment monitoring system are all different and changeable,and the latency contribution of each task to the system is ***,two valid latency minimization strategies based on the edge-cloud collaboration scheme is developed in this ***,the processing resources are allocated to the tasks based on the priorities,and the tasks are processed parallly with the allocated resources to minimize the system valid ***,considering the differences in the data volume of the tasks,which will induce the waste of the resources for the tasks finished in ***,the tasks with similar priorities are graded into the same group,and the serial and parallel processing strategies are performed intra-group and inter-group *** with the other four strategies in four railway monitoring scenarios,the proposed strategies proved latency efficiency to the high-priority tasks,and the system valid latency is reduced *** performance of the railway environment monitoring system in security and efficiency will be promoted greatly with the proposed scheme and strategies.

关键词： Railway environment monitoring Edge-cloud collaboration computing Valid latency optimization