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The time model for event processing in internet of things

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Frontiers of Computer Science 2019年第3期13卷 471-488页

作者： Chunjie ZHOU Xiaoling WANG Zhiwang zhang zhenxing zhang Haiping QU Department of Information and Electrical Engineering Ludong University Shandong 264025 China Department of Software East China Normal University Shanghai 200062 China

The time management model for event processing in internet of things has a special and important requirement. Many events in real world applications are long-lasting events which have different time granularity with order or out-of-order. The temporal relationships among those events are often complex. An important issue of complex event processing is to extract patterns from event streams to support decision making in real-time. However, current time management model does not consider the unified solution about time granularity, time interval, time disorder, and the difference between workday calendar systems in different organizations. In this work, we analyze the preliminaries of temporal semantics of events. A tree-plan model of out-of-order durable events is proposed. A hybrid solution is correspondingly introduced. A case study is illustrated to explain the time constraints and the time optimization. Extensive experi? mental studies demonstrate the efficiency of our approach.

关键词： time model event processing internet of things time interval time disorder

Synthesis of mesoporous nano-TiO_(2)doped with Sn by auto-assembly method and photo-catalytic property

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Science China Chemistry 2005年第5期48卷 436-441页

作者： zhang Meihong DING Shiwen WANG zhenxing zhang Yuzhuo College of Chemistry and Environmental Science Hebei University Baoding 071002 China College of Chemistry and Environmental Science Hebei University Baoding 071002 China College of Chemistry and Environmental Science Hebei University Baoding 071002 China College of Chemistry and Environmental Science Hebei University Baoding 071002 China

A series of mesoporous nano-TiO2 material doped with Sn are synthesized by a homogenous precipitation method aided by microwave heating, using TiCl4 and SnCl4 as raw materials, urea as precipitator, active carbon as templet, and soluble starch as anti- agglomer-ating reagent. XRD results show that the precursor exists in the amorphous phase, and trans-forms to anatase structure above 400℃. TEM results show that the particle is in spherical shape and the average diameter is 20 nm. EDS results show that the measuring value of compound is in accord with the actual value of the raw materials, and the doping uniformity is good. The photo-catalytic experimental results show that the highest photo-catalytic efficiency can be ob-tained when the content of Sn is 10% (mol pecent), and the decolorization rate of navy blue dye can be as high as 100% after being illuminated by sunlight for 70 min. The photo-catalytic reac-tion is a first-order kinetic reaction.

关键词： nano-TiO2 doped with Sn, microwave synthesis, template control, homogenous precipitation, mesoporous material, photo-catalysis.

Graphene-based ambipolar electronics for radio frequency applications

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Chinese Science Bulletin 2012年第23期57卷 2956-2970页

作者： WANG zhenxing zhang ZhiYong PENG LianMao Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics Peking University Beijing 100871 China

Graphene is considered as a promising material to construct field-effect transistors (FETs) for high frequency electronic applications due to its unique structure and properties,mainly including extremely high carrier mobility and saturation velocity,the ultimate thinnest body and *** continuously scaling down the gate length and optimizing the structure,the cut-off frequency of graphene FET (GFET) was rapidly increased and up to about 300 GHz,and further improvements are also *** of the lack of an intrinsic band gap,the GFETs present typical ambipolar transfer characteristic without off state,which means GFETs are suitable for analog electronics rather than digital *** advantage of the ambipolar characteristic,GFET is demonstrated as an excellent building block for ambipolar electronic circuits,and has been used in applications such as highperformance frequency doublers,radio frequency mixers,digital modulators,and phase detectors.

关键词： graphene radio frequency field-effect transistor ambipolar electronics high-κ dielectrics

Experimental realization of nonadiabatic geometric gates with a superconducting Xmon qubit

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Science China(Physics,Mechanics & Astronomy) 2021年第5期64卷 2-9页

作者： PeiZi Zhao zhangJingZi Dong zhenxing zhang GuoPing Guo DianMin Tong Yi Yin Deparment of Physies Shandong Universiry Jinan 250100 China Department of Physics Zhejiang UniversityHangzhou 310027China Key Labortlory of Quanwum Information University of Science and Technology of ChinaHefei 230026China Origin Quantum Computing Hefei 230026China

Geometric phases are only dependent on evolution paths but independent of evolution details so that they possess some intrinsic noise-resilience features. Based on different geometric phases, various quantum gates have been proposed, such as nonadiabatic geometric gates based on nonadiabatic Abelian geometric phases and nonadiabatic holonomic gates based on nonadiabatic nonAbelian geometric phases. Up to now, nonadiabatic holonomic one-qubit gates have been experimentally demonstrated with superconducting transmons, where the three lowest levels are all utilized in operation. However, the second excited state of transmons has a relatively short coherence time, which results in a decreased fidelity of quantum gates. Here, we experimentally realize Abelian-geometric-phase-based nonadiabatic geometric one-qubit gates with a superconducting Xmon qubit. The realization is performed on the two lowest levels of an Xmon qubit and thus avoids the influence from the short coherence time of the second excited state. The experimental result indicates that the average fidelities of single-qubit gates can be up to 99.6% and 99.7% characterized by quantum process tomography and randomized benchmarking.

关键词： geometric phases geometric quantum computation superconducting qubit

Simulating a topological transition in a superconducting phase qubit by fast adiabatic trajectories

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Science China(Physics,Mechanics & Astronomy) 2018年第4期61卷 75-81页

作者： Tenghui Wang zhenxing zhang Liang Xiang Zhihao Gong Jianlan Wu Yi Yin physics Department Zhejiang UniversityHangzhou 310027China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China

The significance of topological phases has been widely recognized in the community of condensed matter physics. The well controllable quantum systems provide an artificial platform to probe and engineer various topological phases. The adiabatic trajectory of a quantum state describes the change of the bulk Bloch eigenstates with the momentum, and this adiabatic simulation method is however practically limited due to quantum dissipation. Here we apply the "shortcut to adiabaticity"(STA) protocol to realize fast adiabatic evolutions in the system of a superconducting phase qubit. The resulting fast adiabatic trajectories illustrate the change of the bulk Bloch eigenstates in the Su-Schrieffer-Heeger(SSH) model. A sharp transition is experimentally determined for the topological invariant of a winding number. Our experiment helps identify the topological Chern number of a two-dimensional toy model, suggesting the applicability of the fast adiabatic simulation method for topological systems.

关键词： quantum state transfer shortcut to adiabaticity topological transition

High-performance magnesium ion asymmetric Ppy@FeOOH//Mn3O4 micro-supercapacitor

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Journal of Energy Chemistry 2022年第9期31卷 352-360,I0010页

作者： Xueliang Lv Yaxiong zhang Xijuan Li Zhiye Fan Guo Liu Wenjian zhang Jinyuan Zhou Erqing Xie zhenxing zhang Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education School of Physical Science and TechnologyLanzhou UniversityLanzhou 730000GansuChina

Micro-supercapacitors(MSCs)are attractive electrochemical energy storage devices owing to their high power density and extended cycling ***,relatively low areal energy density still hinders their practical ***,an asymmetric Mg ion MSC with promising high energy density is ***,indium tin oxide(ITO)NWs were synthesized by chemical vapor deposition as the excellent current ***,nanostructured Mn_(3)O_(4)and Ppy@FeOOH were deposited on the laser-engraved interdigital structure ITO NWs electrodes as the positive and negative electrodes,*** from the hierarchical micro-nano structures of active materials,high conductive electron transport pathways,and charge-balanced asymmetric electrodes,the obtained MSC possesses a high potential window of 2.2 V and a high areal capacitance of 107.3 mF cm^(-2)at 0.2 mA cm^(-2).The insitu XRD,VSM,and ex-situ XPS results reveal that the primary energy storage mechanism of Mg ions in negative FeOOH electrode is Mg ions de-/intercalation and phase transition reaction of ***,the MSC exhibits a high specific energy density of 71.18μWh cm^(-2)at a power density of 0.22 mWh cm^(-2)and capacitance retention of 85%after 5000 cycles with unvaried Coulombic *** results suggest promising applications of our MSC in miniaturized energy storage devices.

关键词： CVD Iron hydroxide Electrochemical deposition Asymmetric micro-supercapacitor Laser engraving

Antlion optimizer algorithm based on chaos search and its application

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Journal of Systems Engineering and Electronics 2019年第2期30卷 352-365页

作者： zhang zhenxing YANG Rennong LI Huanyu FANG Yuhuan HUANG Zhenyu zhang Ying Air Traffic Control and Navigation College Air Force Engineering University Unit 95939 of PLA

Aiming at the problems of premature convergence and easily falling into local optimums of the antlion optimization algorithm, a chaos antlion optimization algorithm based on the chaos search is proposed. Firstly, in the algorithm, the population is initialized by using the tent chaotic mapping, and the self-adaptive dynamic adjustment of chaotic search scopes is proposed in order to improve the overall fitness and the optimization efficiency of the population. Then, the tournament strategy is used to select antlions. Finally, the logistic chaos operator is used to optimize the random walk of ants, which forms a global and local parallel search mode with the antlion’s foraging behavior. The performance algorithm is tested through 13 complex high-dimensional benchmark functions and three dimensional path planning problems. The experimental results of six complex high-dimensional benchmark functions show that the presented algorithm has a better convergence speed and precision than the standard antlion algorithm and other optimization algorithms, and is suitable for the optimization of complex high dimensional functions. The trajectory planning experimental results show that compared with the antlion optimizer(ALO) algorithm, grey wolf optimizer(GWO), particle swarm optimization(PSO) and artificial bee colony(ABC) algorithm, it has advantages in speed and accuracy to obtain a specific path, and it is of great value in actual problems.

关键词： antlion optimizer(ALO) algorithm chaos theory tent mapping tournament selection strategy logistic mapping path planning

Subsurface aeration alters the fungal composition of rhizosphere soil and tomato plant performance in Northwest China

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International Journal of Agricultural and Biological Engineering 2023年第1期16卷 172-183页

作者： Yuan Li Mingzhi zhang Xiaoshu Cao Jingwei Wang zhenxing zhang Quanwen Niu Northwest Land and Resources Research Center Shaanxi Normal UniversityXi’an 710062China Institute of Soil and Water Conservation Northwest A&F UniversityYangling 712100ShaanxiChina Key Laboratory of Vegetation Ecology Ministry of EducationInstitute of Grassland ScienceNortheast Normal UniversityChangchun 130024China

Rhizosphere hypoxia constrains plant growth,and numerous studies have shown that root zone aeration accelerates plant photosynthesis and growth and increases crop ***,the mechanism by which soil microorganisms are involved in this process is not *** purpose of the present study was to examine the effects of aeration and irrigation depth on the composition and structure of rhizosphere soil fungal communities and tomato plant *** amount of aeration assayed was equal to 0(CK),0.5(V1),1(V2),and 1.5(V3)times the porosity of the *** two depths of subsurface drip irrigation used were 15(D15)and 40 cm(D40).The results demonstrated that soil aeration not only increased tomato plant performance but also influenced fungal diversity and *** to the no-aeration treatment,the V3 soil aeration treatment increased the total dry weight and fruit yield by 39.9%and 65.6%,*** results also showed that the abundance of the phylum Ascomycota and the family Lasiosphaeriaceae increased with increasing soil aeration,whereas those of members of the phylum Zygomycota and the order Capnodiales decreased with increasing soil ***,the variation in subsurface irrigation depth altered the rhizosphere soil fungal *** general,the results of this study demonstrate that root zone aeration can ameliorate hypoxic conditions in Lou soils and is beneficial to soil fungal communities and tomato plant performance.

关键词： tomato soil aeration rhizosphere soil fungal community plant performance

Shell-thickness dependent optical properties of CdSe/ CdS core/shell nanocrystals coated with thiol ligands

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Nano Research 2016年第1期9卷 260-271页

作者： Wanzhen Lin Yuan Niu Renyang Meng Lin Huang Hujia Cao zhenxing zhang Haiyan Qin Xiaogang Peng Center for Chemistry of Novel & High-Performance Materials Department of Chemistry Zhejiang University Hangzhou 310027 China

Using CdSe/CdS core/shell nanocrystals with 1-10 monolayers of CdS shell as the model system, we studied effects of thiol ligands on optical properties of the nanocrystals. The core/shell nanocrystals with original ligands possessed near unity photoluminescence （PL） quantum yield and single-exponential PL decay dynamics. The effects of thiol ligands on optical properties were found to depend on the shell thickness, environment （with/without oxygen）, and excitation power （single- or multi-exciton）. Systematic and quantitative results reported in this work should provide necessary information for fundamental understanding and technical applications of quantum dots （QDs） coated with thiol ligands.

关键词： colloidal semiconductor nanocrystals thiol ligands photoluminescencequantum yield single-dot spectroscopy