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Unsupervised change detection of man-made objects using coherent and incoherent features of multi-temporal SAR images

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Journal of Systems Engineering and Electronics 2022年第4期33卷 896-906页

作者： FENG Hao WU jianzhong ZHANG lu LIAO Mingsheng State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan 430079China Key Laboratory of Land Subsidence Monitoring and Prevention Ministry of Land and ResourcesShanghai 200072China Shanghai Engineering Research Center of Land Subsidence Shanghai 200072China Shanghai Institute of Geological Survey Shanghai 200072China

Constrained by complex imaging mechanism and extraordinary visual appearance,change detection with synthetic aperture radar(SAR)images has been a difficult research topic,especially in urban areas.Although existing studies have extended from bi-temporal data pair to multi-temporal datasets to derive more plentiful information,there are still two problems to be solved in practical applications.First,change indicators constructed from incoherent feature only cannot characterize the change objects accurately.Second,the results of pixel-level methods are usually presented in the form of the noisy binary map,making the spatial change not intuitive and the temporal change of a single pixel meaningless.In this study,we propose an unsupervised man-made objects change detection framework using both coherent and incoherent features derived from multi-temporal SAR images.The coefficients of variation in timeseries incoherent features and the man-made object index(MOI)defined with coherent features are first combined to identify the initial change pixels.Afterwards,an improved spatiotemporal clustering algorithm is developed based on density-based spatial clustering of applications with noise(DBSCAN)and dynamic time warping(DTW),which can transform the initial results into noiseless object-level patches,and take the cluster center as a representative of the man-made object to determine the change pattern of each patch.An experiment with a stack of 10 TerraSAR-X images in Stripmap mode demonstrated that this method is effective in urban scenes and has the potential applicability to wide area change detection.

关键词： change detection multi-temporal synthetic aperture radar(SAR)data coherent and incoherent features clustering

A novel adaptive coordinated tracking control scheme for a morphing aircraft with telescopic wings

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Chinese Journal of Aeronautics 2024年第2期37卷 148-162页

作者： Enmei WANG Hao lu Jianchun ZHANG Chenliang WANG jianzhong QIAO Hangzhou Innovation Institute Beihang UniversityHangzhou 310051China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

Inspired by flight biology,morphing flight technology has great potential to improve the adaptability and maneuverability of aircraft.This paper is devoted to the flight control problem of morphing aircraft,and aimed at safe and fuel-saving flight through morphing actively.Specifically,the longitudinal dynamics of a morphing aircraft with telescopic wings is modelled as a strict-feedback nonlinear system.Through fitting the expression of aerodynamic parameters by the mor-phing ratio,the model uncertainties induced by morphing errors are embedded in the dynamics.To meet the safety and fuel-saving requirements,an Adaptive Coordinated Tracking Control Scheme(ACTCS)is then proposed,which consists of a morphing control module and a tracking control module.For the morphing control module,an on-line morphing decision model is given in an optimization process with respect to the morphing ratio,and a second-order tracking filter is introduced to smooth the decision output and ensure the physical realizability.For the tracking control module,the novel adaptive controllers for the velocity and altitude subsystems are proposed based on the dynamic surface control method,in which adaptive mechanisms are designed to com-pensate for the model uncertainties.Finally,the proposed ACTCS is simulated in nine different cases of the test flight mission,to verify its effectiveness,robustness and fuel-saving effect.

关键词： Morphing aircraft Adaptive tracking control Morphing decision Dynamic surface control Morphing error

Controlled wrinkling analysis of thin films on gradient substrates

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Applied Mathematics and Mechanics(English Edition) 2017年第5期38卷 617-624页

作者： jianzhong ZHAO Xingming GUO lu lu Shanghai Institute of Applied Mathematics and Mechanics Shanghai Key Laboratory of Mechanics in Energy EngineeringShanghai UniversityShanghai 200072China

The paper investigates continuously changing wrinkle patterns of thin films bonded to a gradient substrate. Three types of gradient substrates including exponential, power-law, and symmetry models are considered. The Galerkin method is used to dis- cretize the governing equation of film bonded to gradient substrates. The wavelength and the normalized amplitude of the wrinkles for substrates of various material gradients are obtained. The numerical simulation based on the finite element method （FEM） is used to evolve the wrinkle patterns. The result agrees well with that of the analytical model. It is concluded that localization of wrinkle patterns strongly depends on the material gradient. The critical membrane force depends on both the minimum value of wrinkle stiffness and the gradient of wrinkle stiffness when the wrinkle stiffness is at its minimum. This work provides a better understanding for local wrinkle formation caused by gradient substrates.

关键词： thin film gradient substrate wrinkle material gradient Galerkin method

All-inorganic TiO_(2)/Cs_(2)AgBiBr_(6) composite as highly efficient photocatalyst under visible light irradiation

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Frontiers of Chemical Science and Engineering 2023年第12期17卷 1925-1936页

作者： jianzhong Ma lu Wen Qianqian Fan Siying Wei Xueyun Hu Fan Yang College of Bioresources Chemical and Materials Engineering Shaanxi University of Science and TechnologyXi’an 710021China College of Chemistry and Chemical Engineering Shaanxi University of Science and TechnologyXi’an 710021China Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry(Ministry of Education) Shaanxi University of Science and TechnologyXi’an 710021China Xi’an Key Laboratory of Green Chemicals and Functional Materials Shaanxi University of Science and TechnologyXi’an 710021China College of Environmental Science and Engineering Shaanxi University of Science and TechnologyXi’an 710021China

In recent years, limited photocatalysis efficiency and wide band gap have hindered the application of TiO_(2) in the field of photocatalysis. A leading star in photocatalysis has been revealed as lead-free Cs_(2)AgBiBr_(6) double halide perovskite nanocrystals, owing to its strong visible light absorption and tunable band gap. In this work, this photocatalytic process was facilitated by a unique TiO_(2)/Cs_(2)AgBiBr_(6) composite, which was identified as an S-cheme heterojunction. TiO_(2)/Cs_(2)AgBiBr_(6) composite was investigated for its structure and photocatalytic behavior. The results showed that when the perovskite dosage is 40%, the photocatalytic rate of TiO_(2) could be boosted to 0.1369 min^(-1). This paper discusses and proposes the band gap matching, carrier separation, and photocatalytic mechanism of TiO_(2)/Cs_(2)AgBiBr_(6) composites, which will facilitate the generation of new ideas for improving TiO_(2)’s photocatalytic performance.

关键词： Cs_(2)AgBiBr_(6)nanocrystals visible-light photocatalyst Cs_(2)AgBiBr_(6) TiO_(2)heterojunction

An improved U-Net for cell confluence estimation

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Optoelectronics Letters 2022年第6期18卷 378-384页

作者： BAI Hua lu Changhao MA Ming YAN Shulin ZHANG jianzhong HAN Zhibo Tianjin Key Laboratory of Optoelectronic Detection Technology and Systems School of Electronic and Information EngineeringTiangong UniversityTianjin300387China Tianjin Key Laboratory of Engineering Technologies for Cell Phamaceutical Tianjin 300457China National Engineering Research Center of Cell Products/Am Cell Gene Co. Ltd.Tianjin 300457China State Key Lab of Experimental Hematology Chinese Academy of Medical Sciences&Peking Union Medical CollegeTianjin 300020China

Cell confluence is an important metric to determine the growth and the best harvest time of adherent cells. At present, the evaluation of cell confluence mainly relies on experienced labor, and thus it is not conducive to the automated cell culture. In this paper, we proposed an improved U-Net algorithm(called DU-Net) for the segmentation of adherent cells. First, the general convolution was replaced by the dilated convolution to expand the receptive fields for feature extraction. Then, the convolutional layers were combined with the batch normalization layers to reduce the dependence of the network on initialization. As a result, the segmentation accuracy and F1-score of the proposed DU-Net for adherent cells with low confluence(luence(≥50%), they reached 98.63% and 98.98%, respectively. Further, the paired t-test results showed that the proposed DU-Net was statistically superior to the traditional U-Net algorithm.

关键词： convolution estimation batch

Suppression of inner energy dissipation in Yb-doped NaErF_(4)upconversion nanocrystals through an energy cycling strategy

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Journal of Rare Earths 2023年第7期41卷 975-980,I0001页

作者： Yunfeng Bai Xiaoxi Liu Shaojian Zhang Haili Jiang lu Liu Isam Ud Din jianzhong Zhang Key Laboratory of Micro Nano Optoelectronic Devices and Intelligent Perception Systems School of Electronic Information and EngineeringYangtze Normal UniversityChongqing 408100China College of Physics and Optoelectronic Engineering Harbin Engineering UniversityHarbin 150001China

Suppression of the inner energy dissipation,related to the lattice phonons and inner defects,in lanthanide doped upco nversion luminescent materials remains a formidable challenge.Herein,we reveal an energy cycling strategy capable of suppressing the inner energy dissipation in lanthanide doped upconversion nanocrystals.Yb^(3+)ions were introduced in Er^(3+)heavily doped nanocrystals as an energy reservoir to compete with the inner energy dissipation.The detailed energy cycling processes between Er^(3+)activator and Yb^(3+)reservoir,responsible for the enhancement of Er^(3+)upconversion intensity,are proposed and further verified on the basis of spectral observations.The energy cycling strategy,with unique merits like facile and cost-effective preparation as well as broad scope of application,is highly valuable in lanthanide luminescent nano materials.

关键词： Upconversion Er^(3+) 1530 nm excitation Inner energy dissipation Energy cycling Rare earths

Computational screening and design of nanoporous membranes for efficient carbon isotope separation

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Green Energy & Environment 2020年第3期5卷 364-373页

作者： Jingqi Wang Musen Zhou Diannan lu Weiyang Fei jianzhong Wu Department of Chemical Engineering Tsinghua UniversityBeijing100084China Department of Chemical and Environmental Engineering University of CaliforniaRiversideCA92521United States

Stable isotopes have been routinely used in chemical sciences,medical treatment and agricultural research.Conventional technologies to produce high-purity isotopes entail lengthy separation processes that often suffer from low selectivity and poor energy efficiency.Recent advances in nanoporous materials open up new opportunities for more efficient isotope enrichment and separation as the pore size and local chemical environment of such materials can be engineered with atomic precision.In this work,we demonstrate the unique capability of nanoporous membranes for the separation of stable carbon isotopes by computational screening a materials database consisting of 12,478 computation-ready,experimental metal-organic frameworks(MOFs).Nanoporous materials with the highest selectivity and membrane performance scores have been identified for separation of^(12)CH_4/^(13)CH_4 at the ambient condition(300 K).Analyzing the structural features and metal sites of the promising MOF candidates offers useful insights into membrane design to further improve the performance.An upper limit of the efficiency has been identified for the separation of^(12)CH_4/^(13)CH_4 with the existing MOFs and those variations by replacement of the metal sites.

关键词： Metal-organic frameworks Isotope separation Computational materials design Thermodynamics

Total Nitrogen and Total Phosphorus Pollution Reshaped the Relationship Between Water Supply and Demand in the Huaihe River Watershed, China

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Chinese Geographical Science 2023年第3期33卷 512-530页

作者： lu Yan LIU Lyuyi QIN Fen WANG Jiayao LIU jianzhong LI Yingjie WAN luwen School of Geoscience and Technology Zhengzhou UniversityZhengzhou 450001China Henan Provincial Academy of Eco-Environmental Sciences Zhengzhou 450003China Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions Ministry of EducationHenan UniversityKaifeng 475000China Henan Industrial Technology Academy of Spatio-Temporal Big Data Henan UniversityKaifeng 475000China College of Geography and Environmental Science Henan UniversityKaifeng 475000China Environmental Science and Policy Program Michigan State UniversityEast LansingMI 48824USA

As total nitrogen(TN)and total phosphorus(TP)pollution is the main source of water pollution in the Huaihe River watershed in China,it is important to understand how TN and TP pollution affect the relationship between water supply and demand.Quantifying their impacts and describing the spatiotemporal distribution of these relationships are necessary for furtherly deepening the theory of TN and TP pollution on water bodies,and this information is also particularly essential for managing water resources regionally.In this study,based on the potential water supply,the water demand and the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)water purification models,we estimated the TN and TP pollution from agricultural fertilizer,livestock and poultry breeding,and rural residents in the Huaihe River watershed and simulated TN and TP impacts on the relationship between water supply and demand.We found that if the impact of TN and TP pollution on water supply was not taken into account,on average,there was excess water supply in 79.20%of the watershed and excess demand in 20.80%of the rest during 1980–2018.Under the TN concentration limit,Grade-Ⅱ(The water quality meets the secondary level of water body qualified in GB3838–2002,classified as Grade-II)water was the main watersupply type in 1980–2018,followed by Grade-Ⅰ and Grade-Ⅲ water.The total water shortage showed an inverted V-shaped trend:first increasing and then decreasing at the same period.The proportion of the water shortage of Grade-I water in the total water shortage was the largest,followed by Grade-Ⅱ and Grade-III water.Areas with excess demand were located on the north bank of Wang-Beng,Yishuhe,and Huxi regions,although the water in these sub-watersheds met the water quality standards of Grade-Ⅰ water.Under the TP concentration limit,Grade-Ⅱ and Grade-Ⅰ water were the main water-supply types.The overall water shortage trend first increased and then decreased,exhibiting an inverted V-shape from 1980 to 2018.The water shortages of Grade-Ⅰ and

关键词： watershed breeding poultry

DOK3 promotes proliferation and inhibits apoptosis of prostate cancer via the NF-κB signaling pathway

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Chinese Medical Journal 2023年第4期136卷 423-432页

作者： Kun Jin Shi Qiu Bo Chen Zilong Zhang Chichen Zhang Xianghong Zhou lu Yang jianzhong Ai Qiang Wei Department of Urology and National Clinical Research Center for Geriatrics West China HospitalSichuan UniversityChengduSichuan 610041China Center of Biomedical Big Data West China HospitalSichuan UniversityChengduSichuan 610041China Department of Urology and Institute of Urology West China HospitalSichuan UniversityChengduSichuan 610041China

Background: DOK3 (Downstream of kinase 3) is involved primarily with immune cell infiltration. Recent research reported the role of DOK3 in tumor progression, with opposite effects in lung cancer and gliomas;however, its role in prostate cancer (PCa) remains elusive. This study aimed to explore the role of DOK3 in PCa and to determine the mechanisms involved. Methods: To investigate the functions and mechanisms of DOK3 in PCa, we performed bioinformatic and biofunctional analyses. Samples from patients with PCa were collected from West China Hospital, and 46 were selected for the final correlation analysis. A lentivirus-based short hairpin ribonucleic acid (shRNA) carrier was established for silencing DOK3. A series of experiments involving the cell counting kit-8, bromodeoxyuridine, and flow cytometry assays were performed to identify cell proliferation and apoptosis. Changes in biomarkers from the nuclear factor kappa B (NF-κB) signaling pathway were detected to verify the relationship between DOK3 and the NF-κB pathway. A subcutaneous xenograft mouse model was performed to examine phenotypes after knocking down DOK3 in vivo . Rescue experiments with DOK3 knockdown and NF-κB pathway activation were designed to verify regulating effects. Results: DOK3 was up-regulated in PCa cell lines and tissues. In addition, a high level of DOK3 was predictive of higher pathological stages and worse prognoses. Similar results were observed with PCa patient samples. After silencing DOK3 in PCa cell lines 22RV1 and PC3, cell proliferation was significantly inhibited while apoptosis was promoted. Gene set enrichment analysis revealed that DOK3 function was enriched in the NF-κB pathway. Mechanism experiments determined that knockdown of DOK3 suppressed activation of the NF-κB pathway, increased the expressions of B-cell lymphoma-2 like 11 (BIM) and B-cell lymphoma-2 associated X (BAX), and decreased the expression of phosphorylated-P65 and X-linked inhibitor of apoptosis (XIAP). In the rescue experiments, pharmacological activat

关键词： Prostate cancer Downstream of kinase 3 Prognosis Nuclear factor kappa B