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Chinese Science Bulletin 1999年第S2期44卷 24-25页

作者： LIU Xianfan~(1.2), GAO Zhenmin~1. LIU Jiajun~1. ZHAN Xinzhi~1. LI Chaoyang~1.and SU wenchao 1. Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China 2. Chengdu Institute of Technology, Chengdu 61.059, China Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Chengdu Institute of Technology Chengdu 610059 China

SANJING region (the region of three rivers, i.e. Jinsha-Lanchang-Nujiang rivers) is a very active Cenozoicinterplate deformation area on the east margin of Qinghai-Xizang Plateau, where the alkali-rich porphyrybodies occur extensively and the porphyry-related polymetallic mineral resources are produced. Manystudies on the petrology and geochemistry of the alkali-rich porphyry have been carried out and thegenerally accepted conclusion is that the petrogenesis material source has something to do with the enriched source in the mantle. The integrated interactive factors of the mineralization related to the alkalirich porphyry consist in the favourable combination of the mantle fluid metasomatism, which is derivedfrom the deep processes, and the conducting and controlling roles of the large-scale deep faults. Alongwith the changes in physical and chemical conditions caused by the diffusion of the ore-forming

关键词： low-temperature mineralization mantle fluid processes alkali-rich porphyry deposit Cenozoic Yunnan.

Recursive Projected Filter Algorithm with Binary-Valued Observations

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Journal of Systems Science & Complexity 2024年第5期37卷 1832-1860页

作者： ZHANG Xiaoyan WANG Ying XUE wenchao ZHAO Yanlong Key Laboratory of Systems and Control Institute of Systems ScienceAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China

This paper focuses on the state estimate for a class of systems with both process noise and measurement noise under binary-valued observations,in which the Gaussian assumption on the predicted density of the state is not required.A recursive projected filter algorithm with time-varying thresholds is constructed to estimate the state under binary-valued *** time-varying thresholds are designed as the prediction value of the measurement,which can provide more information about the system *** convergence property is established with some suitable stability,boundedness and observability *** particular,the estimation error between state and estimate is proved to be asymptotically bounded in the mean-square sense,whose upper bound is related to the variance of process ***,the theoretical results are demonstrated via numerical examples of first-order and high-order systems.

关键词： Binary-valued observations convergence recursive filter time-varying thresholds

Silica photonic crystals with quasi-full band gap in the visible region prepared in ethanol

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Progress in Natural Science:Materials International 2003年第9期 79-82页

作者： ZHANG Hui, WANG Xidong, ZHAO Xiaofeng, LI wenchao and TANG Qing (1. University of Science and Technology Beijing, Beijing 1.0083, China 2. Institute of Process Engineering, Chinese Academy of Sciences, Beijing 1.0080, China) University of Science and Technology Beijing，Beijing 1.0083，China Institute of Process Engineering，Chinese Academy of Sciences，Beijing 1.0080，China University of Science and Technology Beijing，Beijing 1.0083，China Institute of Process Engineering，Chinese Academy of Sciences，Beijing 1.0080，China

Monodisperse silica spheres of 252 nm with a standard deviation of 5.7% are prepared by Stber method. By compari-son of both of media, ethanol instead of water is used to assemble opal, and the artiflcial opal has been prepared by the sedimentation inethanol of silica spheres. The structure of the opal prepared has been examined and discussed. The results show that the artificial opal hasa structure similar to the face-centered cubic (fcc) type packed system with silica spheres. Transmission measurements of the artificial opalhave been conducted, which shows that the artificial opal is quasi-full band gap silica photonic crystals in the visible region.

关键词： photonic crystals artificial opal quasi-full band gap.

On extended state Kalman filter-based identification algorithm for aerodynamic parameters

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Control Theory and Technology 2024年第2期22卷 235-243页

作者： Wenyan Bai Ruizhe Jia Peng Yu wenchao Xue Beijing Aerospace Automatic Control Institute Beijing100854China School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing100083China Key Laboratory of Knowledge Automation for Industrial Processes Ministry of EducationBeijing100083China Key Laboratory of Systems and Control Institute of Systems ScienceAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing100190China

In this paper, the problem of time-varying aerodynamic parameters identification under measurement noises is studied. By analyzing the key aerodynamic parameters that affect the aircraft control system, a system model with extended states for identifying equivalent aerodynamic parameters is established, and error parameters are extended to the system state, avoiding the difficulty caused by the unknown dynamic in the system. Furthermore, an identification algorithm based on extended state Kalman filter is designed, and it is proved that the algorithm has quasi-consistency, thus, the estimation error can be evaluated in real time. Finally, the simulation results under typical flight scenarios show that the designed algorithm can accurately identify aerodynamic parameters, and has desired convergence speed and convergence precision.

关键词： Aerodynamic parameters Parameter identification Extended state Kalman filter

Compensated acceleration feedback based active disturbance rejection control for launch vehicles

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Chinese Journal of Aeronautics 2024年第4期37卷 464-478页

作者： Xiaoyan ZHANG wenchao XUE Zibo LIU Ran ZHANG Huifeng LI Key Laboratory of Systems and Control Institute of Systems ScienceAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Astronautics Beihang UniversityBeijing 100191China

In this paper, the attitude tracking and load relief control problems against wind disturbances and uncertain aerodynamics as well as the engine thrust of launch vehicles are ***, a framework of Compensated Acceleration Feedback based Active Disturbance Rejection Control(CAF-ADRC) is established to achieve both desired attitude tracking and load relief performances. In particular, the total disturbance that includes the effects caused by both aerocoefficient perturbations and disturbances is estimated by constructing an Extended State Observer(ESO) to achieve attitude tracking. Furthermore, combined with the normal acceleration due to the engine thrust, the accelerometer measurement is also compensated to enhance the load relief ***, the quantitative analysis of ESO and the entire closed-loop system are studied. It can be concluded that the desired attitude tracking and load relief performances can be achieved simultaneously under the proposed approach. Besides, tuning laws of the proposed approach are systematically given, which are divided into ESO, Proportional Derivative(PD) and Compensated Acceleration Feedback(CAF) modules. Moreover, the performances under CAF-ADRC approach can be better than those under CAF based PD(CAF-PD) approach by tuning load relief ***, the approach presented is applied to a typical control problem of launch vehicles with wind disturbances and parameter uncertainties.

关键词： Launch vehicles Uncertainty analysis Active disturbance rejection control(ADRC) Load relief control Extended state observer(ESO)

Visualization of oxygen vacancies in nanomaterials

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Science China Materials 2024年第11期67卷 3753-3754页

作者： wenchao Bi Kaixuan Wang Guozhong Cao Department of Physics College of ScienceUniversity of Shanghai for Science and Technology Departments of Materials Science and Engineering and Chemical Engineering University of Washington

Oxygen vacancies are one of the most common *** are imperfections in the regular geometrical arrangement of the atoms in crystalline solid. There are point defects,linear defects, plane defects and volume defects in crystals. In an elemental crystal, point defects are formed when atoms are removed from the position that should be filled in the crystal,creating vacancies, or when atoms occupy interstitial sites where no atom would ordinarily appear, causing interstitialcy [1..

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An Environment‑Tolerant Ion‑Conducting Double‑Network Composite Hydrogel for High‑Performance Flexible Electronic Devices

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Nano-Micro Letters 2024年第5期16卷 352-369页

作者： wenchao Zhao Haifeng Zhou Wenkang Li Manlin Chen Min Zhou Long Zhao State Key Laboratory of Advanced Electromagnetic Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China School of Chemistry and Chemical Engineering Huazhong University of Science and TechnologyWuhan 430074People’s Republic of China

High-performance ion-conducting hydrogels(ICHs)are vital for developing flexible electronic ***,the robustness and ion-conducting behavior of ICHs deteriorate at extreme tempera-tures,hampering their use in soft *** resolve these issues,a method involving freeze–thawing and ionizing radiation technology is reported herein for synthesizing a novel double-network(DN)ICH based on a poly(ionic liquid)/MXene/poly(vinyl alcohol)(PMP DN ICH)*** well-designed ICH exhibits outstanding ionic conductivity(63.89 mS cm^(-1. at 25℃),excellent temperature resistance(-60–80℃),prolonged stability(30 d at ambient temperature),high oxidation resist-ance,remarkable antibacterial activity,decent mechanical performance,and ***,the ICH performs effectively in a flexible wireless strain sensor,thermal sensor,all-solid-state supercapacitor,and single-electrode triboelectric nanogenerator,thereby highlighting its viability in constructing soft electronic *** highly integrated gel structure endows these flexible electronic devices with stable,reliable signal output *** particular,the all-solid-state supercapacitor containing the PMP DN ICH electrolyte exhibits a high areal specific capacitance of 253.38 mF cm^(-2)(current density,1.mA cm^(-2))and excellent environmental *** study paves the way for the design and fabrication of high-performance mul-tifunctional/flexible ICHs for wearable sensing,energy-storage,and energy-harvesting applications.

关键词： Ionic liquids Double-network hydrogels Temperature tolerance Multifunctionality Flexible electronic devices

Crack mechanism of ground fissures in loess layer of Fenwei Basin, China

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Journal of Mountain Science 2024年第5期21卷 1683-1696页

作者： LI Cong LU Quanzhong WANG Feiyong LUO wenchao XU Qiang School of Geological Engineering and Geomatics Chang’an UniversityXi’an 710054China Key Laboratory of Western Mineral Resources and Geological Engineering Ministry of EducationXi’an 710054China Observation and Research Station of Ground Fissure and Land Subsidence Ministry of Natural ResourcesXi’an 710054China School of Engineering and Technology China University of GeosciencesBeijing 100083China

The Fenwei Basin, covered by loess, experiences severe ground fissure disasters. These disasters disrupt the continuity of the loess and pose significant threats to engineering construction safety along transportation routes. Nevertheless, the crack characteristics and the influence zone of ground fissures in the loess layer remain inadequately investigated. To effectively prevent and control ground fissure disasters, physical model tests and the PFC(particle flow code) numerical simulation method are used to investigate the crack mechanism of buried ground fissures in the loess layer. The results show that there are two main cracks in the layer profile, which have a Y-shape morphology. As the dip angle of the preset cracks increased from 60° to 90°, the main deformation zone at the surface gradually shifted towards the footwall. The process of crack propagation from depth to surface is divided into five stages. Additionally, the results confirm the accuracy of the width of the rupture zone d2in the footwall calculated by the cantilever beam theory. These findings can offer theoretical guidance for determining the avoidance distance of ground fissures in loess regions, as well as for implementing disaster prevention and corresponding control measures for various stages of buried ground fissure propagation.

关键词： Ground fissure Fenwei Basin Physical model test Particle flow code Crack propagation

Smart Colorimetric Corn Starch Films Combined with Anthocyanin-Loaded Glutenin-Carboxymethyl Chitosan Nanocomplexes for Freshness Monitoring of Chilled Pork

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Journal of Renewable Materials 2024年第1期12卷 71-87页

作者： Juan Yan wenchao Li Xianfang Zhang Shisheng Liu College of Food Science and Engineering Hainan UniversityHaikou570100China Engineering Research Center for Utilization of Tropical Polysaccharide Resources Ministry of EducationHaikou570100China

In this study,intelligent,pH-responsive colorimetric films were prepared by encapsulating anthocyanins in nanocomplexes prepared from glutenin and carboxymethyl *** nanocomplexes were added to a corn starch matrix and used in the freshness monitoring of chilled *** effects of anthocyanin-loaded nanocomplexes on the physical,structural,and functional characteristics of the films were *** addition of anthocyanin-loaded nanocomplexes increased the tensile strength,elongation at break,hydrophobicity,and light transmittance of the films while decreasing their water vapor *** is because new hydrogen bonds are formed between the film components,resulting in a more homogeneous and dense *** colorimetric film has a significant color response to pH *** films were used in experiments on the freshness of chilled pork,in which the pH changes with changing freshness *** results show that the colorimetric film can monitor changes in the freshness of chilled pork in real time,where orange,pink,and green represent the fresh,secondary fresh,and putrefied states of pork,***,the intelligent colorimetric film developed in this study has good application potential in the food industry.

关键词： Carboxymethyl chitosan glutenin nanocomplexes anthocyanins pH indicator film chilled pork

Druse Calcite Crystals Formed by Mesoproterozoic Paleo-Earthquake Activity in the Northern Margin of the North China Craton

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Journal of Earth Science 2024年第2期35卷 514-524页

作者： Yueshuang Du Zhiguang Zhou Guosheng Wang Chen Wu wenchao Xu School of Earth Sciences and Resources China University of GeosciencesBeijing100083China Key Laboratory of Continental Collision and Plateau Uplift Institute of Tibetan Plateau Researchand Center for Excellence in Tibetan Plateau Earth SciencesChinese Academy of SciencesBeijing100101China No.1.Institute of Geological and Mineral Resources Survey Henan Bureau of Geo-Exploration&Mineral DevelopmentLuoyang471000China

The Meso-neoproterozoic Bayan Obo rift is located along the northern margin of the North China Craton,and was associated with the break-up of the Columbia *** rift evolution,syn-sedimentary deformation occurred due to tectonic activity and *** events are recorded in the Jianshan Formation of the Bayan Obo Group,Inner Mongolia,as soft sediment deformation structures in the central Bayan Obo *** calcite crystals and collapse breccias in the Jianshan Formation may provide information on the rift *** druse calcite crystals are idiomorphic-columnar in shape and associated with graphite,pyrite,and quartz.δ^(1.)C values of the graphite are−20‰,indicative of biogenic deoxygenation and formation in *** druse calcite crystals are inorganic in origin and formed in water at a temperature of 55℃,based on calciteδ^(1.)C andδ^(1.)O *** calcite grew in paleo-caves containing fault breccias,with heat derived from *** such,the druse calcite crystals are important evidence for seismic *** collapse breccias(i.e.,fault breccias)and other indicators of slip show that displacement occurred from NE to SW,which is different from the paleocurrent direction in the Jianshan *** thickness of the collapse breccia is∼200 m,which represents the height of the fault *** strike of the fault scarp was NE-SW,based on the distribution of the collapse *** Bayan Obo and Yanliao rifts experienced rapid NW-SE extension,and developed similar deformation structures at ca.1.6 Ga related to break-up of the Columbia supercontinent.

关键词： North China Craton druse calcite crystals paleo-earthquake activity collapse breccia Bayan Obo rift Proterozoic