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Experimental measurement of bipartite entanglement using parameterized quantum circuits

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Science China(Physics,Mechanics & Astronomy) 2022年第8期65卷 73-84页

作者： Shunzhong Xue Yulei Huang Dafa Zhao Chao Wei Jun Li Ying Dong Jiancun Gao Dawei lu Tao Xin Gui-lu long State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics Tsinghua UniversityBeijing100084China Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and TechnologyShenzhen518055China Guangdong Provincial Key Laboratory of Quantum Science and Engineering Southern University of Science and TechnologyShenzhen518055China Research Center for Quantum Sensing Zhejiang LabHangzhou311121China Frontier Science Center for Quantum Information Beijing100084China Beijing National Research Center for Information Science and Technology Beijing100084China Beijing Academy of Quantum Information Sciences Beijing100193China

Entanglement in quantum systems plays a crucial role in various quantum information tasks. Measuring entanglement has been an important issue in both experiments and theories. In this work, we use parameterized quantum circuits(PQCs) to diagonalize density matrices of quantum states and obtain entanglement by only measuring the diagonal elements. With this method, full quantum state tomography can be bypassed, greatly reducing the number of measurements. A comprehensive characterization of entanglement was performed by using Rényi entropy and partially transposed moments. Mutual information, calculated from entropy is also used to characterize dynamical quantum phase transitions. We experimentally demonstrated the method on a four-qubit nuclear magnetic resonance quantum simulator. Our results agree with the theoretical descriptions. The measurement complexity of our PQC-based method grows linearly with the number of diagonal elements in the density matrix, a square root reduction over the full quantum tomography. The proposed method can have great potential in quantum systems with a large number of particles.

关键词： quantum information entanglement characterization quantum tomography

Compact high-order quint-band superconducting band-pass filter

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Chinese Physics B 2018年第6期27卷 518-523页

作者： Di Wu Bin Wei Xi-long lu Xin-Xiang lu Xu-Bo Guo Bi-Song Cao State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics Tsinghua University Beijing 100084 China The No. 14 Research Institute China Electronic Technology Corporation （CETC） Nanjing 210013 China Department of Physics and Electronic Engineering Shaoxing University Shaoxing 312000 China

In this paper, we present a compact quint-band superconducting filter operating at 2.4, 3.5, 4.7, 5.3, and 5.9 *** junctions with different impedance branch lines are used to connect a dual-band sub-filter with a tri-band sub-filter and to reduce the channel interactions. The quint-band filter design is divided into two sections to determine the controllable frequencies and bandwidths, while ensuring compact size and reducing design complexity. The filter is fabricated on double-sided YBCO film deposited on an Mg O substrate with a size of 26 mm×19 mm. The measured results match well with the simulations.

关键词： high-temperature superconducting bandpass filter multi-band quint-band filter

A viscoelastic metamaterial beam for integrated vibration isolation and energy harvesting

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1243-1260页

作者： long ZHAO Zeqi lu Hu DING Liqun CHEN Shanghai Institute of Applied Mathematics and Mechanics Shanghai Key Laboratory of Mechanics in Energy EngineeringShanghai Frontier Science Center of MechanoinformaticsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai200072China School of Microelectronics Shanghai UniversityShanghai201800China

Locally resonant metamaterials have low-frequency band gaps and the capability of converging vibratory energy in the band gaps at resonant *** has been demonstrated by several researchers that the dissipatioin of vibratory energy within the band gap can be improved by using viscoelastic *** paper designs an integrated viscoelastic metamaterial for energy harvesting and vibration *** viscoelastic metamaterial is achieved by a viscoelastic beam periodically arrayed with spatial ball-pendulum nonlinear energy *** nonlinear resonator with an energy harvesting function is achieved by placing a free-rolling magnetic ball in a spherical cavity with an additional induction *** dynamic equations of viscoelastic metamaterials under transverse excitation are established,and the energy harvesting and vibration isolation characteristics within the dispersion relation of viscoelastic metamaterials are *** results show that the vibrations of the main body of the viscoelastic metamaterial beam are significantly suppressed in the frequency range of the local resonance band *** the same time,the elastic waves are limited in the nonlinear resonator with an energy harvesting function,which improves the energy ***,an experimental platform of viscoelastic metamaterial vibration is established for validation purposes.

关键词： viscoelastic metamaterial nonlinear vibration vibration isolation energy harvesting

Establish a special conservation zone for the captive giant panda

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Ecosystem Health and Sustainability 2018年第2期4卷 16-21页

作者： Yi-ping Chen Aaron M.Ellison Yong-long lu SKLLQG Institute of Earth EnvironmentChinese Academy of SciencesXi'anChina College of Geography and Environment science Northwest Normal UniversityLanzhouChina Harvard University Harvard ForestPetershamMAUSA Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijingChina

The giant panda(Ailuropoda melanoleuca)is recognized worldwide as an icon for wildlife *** the introduction in 1992 of reliable methods for artificial insemination,the population of captive pandas has grown to approximately 350 individuals in ***,ca ptive panda populations are harmed by environmental pollution,diseases trans-mitted from domestic animals,and other anthropologenic *** the Chinese government has proposed the creation of a Giant Panda National Park,there are at least three reasons that suggest that it is premature to reintroduce captive pandas into this proposed national ***,habitat fragmentation remains the greatest threat to survival of giant pandas;second,most captive pandas are hybrids of the Sichuan and Qinling subspecies and release of hybrids may lead to further introgression between the two subspecies;and third,captive pandas may be competitively inferior to wild pandas in the region,and may not survive fights for food or *** an alternative,we suggest establishing a special con-servation zone in the Shennongjia National Nature Reserve for wild training of captive pandas prior to their reintroduction into the National Park.

关键词： Giant panda habitat protection captive breeding centers wildlife conservation panda special zone Giant Panda National Park

Sediment permeability change on natural gas hydrate dissociation induced by depressurization

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China Geology 2020年第2期3卷 221-229页

作者： Lei Wang Li-juan Gu Hai-long lu Beijing International Center for Gas Hydrate Peking UniversityBeijing 100871China Department of Energy and Resources Engineering College of EngineeringPeking UniversityBeijing 100871China

The permeability of a natural gas hydrate reservoir is a critical parameter associated with gas hydrate *** producing gas from a hydrate reservoir via depressurization,the permeability of sediments changes in two ways with hydrate dissociation,increasing with more pore space released from hydrate and decreasing due to pore compression by stronger effective stress related to *** order to study the evolution of sediment permeability during the production process with the depressurization method,an improved pore network model(PNM)method is developed to establish the permeability change *** this model,permeability change induced by hydrate dissociation is investigated under hydrate occurrence morphology of pore filling and grain *** results obtained show that hydrate occurrence in sediment pore is with significant influence on permeability *** a reasonable degree of pore compression in field trial,the effect of pore space release on the reservoir permeability is greater than that of pore *** permeability of hydrate containing sediments keeps increasing in the course of gas production,no matter with what hydrate occurrence in sediment pore.

关键词： Natural gas hydrate Reservoir sediment Permeability Pore network model Depressurization Oil gas exploration engineering South China Sea China

Current Soil Nutrient Status of Intensively Managed Greenhouses

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Pedosphere 2012年第6期22卷 825-833页

作者： HU Yun-Cai SONG Zhi-Wen lu Wen-long C. POSCHENRIEDER U. SCHMIDHALTER Chair of Plant Nutrition Technische Universitat Miinchen D-85350 Freising (Germany) Institute of Information Tianjin Academy of Agricultural Sciences Tianjin (China)

Nine districts covering the main greenhouse vegetable areas in Tianjin Municipality of the North China Plain were selected for the soil investigation in 2010 to survey the current soil nutrient status (soil available N, P and K), acidification and salinization due to excessive input of fertilizers in greenhouses in Tianjin. The study showed that, in particular, soil available P content increased with the age of greenhouses. In contrast, our results did not reveal higher K accumulation and lowered pH in the greenhouse soils compared with cultivation in open fields. Over-fertilization, causing high NO 3 accumulation, most likely resulted in salinity problems in the greenhouses. Ninety percent of the investigated greenhouse soils had electrical conductivity values of saturated paste extracts of 2-10 d S m-1 , which might affect the yields of vegetable crops like green bean, pepper, cabbage, carrot, eggplant, lettuce, spinach, celery, cucumber and tomato. The findings of our survey of the current fertility and salinity problems in greenhouse soils suggest that there is an urgent need to improve the farmers' practices and strategies in fertilization management in greenhouses of China. Because education and the agricultural technical extension services may play a more important role in avoiding overuse of fertilizers, we suggest that current nutrient management practices should be improved in the near future through training of local farmers in farmers' schools and through strengthening the agricultural extension services with practical techniques.

关键词： electrical conductivity greenhouse vegetables over-fertilization soil pH soil survey

Integrated intrusion detection model based on artificial immune

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The Journal of China Universities of Posts and Telecommunications 2014年第2期21卷 83-90页

作者： ZHANG Ling BAI Zhong-ying lu Yun-long ZHA Ya-xing LI Zhen-wen School of Computer Science Beijing University of Posts and Telecommunications Zhengzhou University of Light Industry

The author puts forward an integrated intrusion detection （ID） model based on artificial immune （IIDAI）, a vaccination strategy based on the significance degree of genes and a method to generate initial memory antibodies with rough set （RS）. IIDAI integrates two kinds of intrusion detection mode： misuse detection and anonymous detection. Misuse detection and anonymous detection are applied to detect the known and the unknown attacks, respectively. On the basis of IIDAI model, an ID algorithm is presented. Simulation shows that the IIDAI has better performance than traditional ID methods in feasibility and effectiveness. It is very prone to achieve a higher convergence rate by using the vaccination strategy. Moreover, RS can remove the redundancy attributes and increase the detection speed. It can also increase detection rate by applying the integrated method.

关键词： ID RS artificial immune vaccination

Generalized Kibble-Zurek mechanism for inhomogeneous systems

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Science China(Physics,Mechanics & Astronomy) 2023年第8期66卷 162-162页

作者： Gui-lu long Department of Physics Tsinghua UniversityBejing 100084China Beijing Academy of Quantum Information Sciences Beijing 100193China

The Kibble-Zurek(KZ)mechanism was first proposed in 1976,which broadly describes the topological defect generation in cosmology in spontaneous symmetry breaking[1].Later,Zurek[2]conducted extensive studies and demonst... 详细信息

关键词： mechanism defect inhomogeneous

Fabrication of corrosion inhibiting microcapsules functional coating and their high-efficiency corrosion resistance

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Rare Metals 2024年第2期43卷 842-848页

作者： Hao-Ran Yun lu lu Xue-long Hao Xing-Xiang Zhang School of Material Science and Engineering Tiangong UniversityTianjin300387China National Center of Analysis and Testing for Nonferrous Metals and Electronic Materials General Research Institute for Nonferrous MetalsBeijing100088China Guobiao(Beijing)Testing&Certification Co. Ltd.Beijing101407China

Benzotriazole(BTA)was loaded into calcium carbonate microsphere shell by self-assembly method and a new type of high-efficiency corrosion inhibiting microcapsules(CIMs)were fabricated,which were added and dispersed into epoxy resin coating to obtain a new corrosion resistance functional *** corrosion inhibition effect of benzotriazole on aluminum alloy matrix was verified by polarization curve *** effectiveness of the CIMs and their loading capacity on inhibitor were evaluated by scanning electron microscope,laser confocal Raman spectroscopy together with thermogravimetric analysis.

关键词： corrosion coating resistance