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Remote estimates of suspended particulate matter in global lakes using machine learning models

International Soil and Water Conservation Research 2024年第1期12卷 200-216页

作者： Zhidan Wen Qiang Wang Yue Ma Pierre Andre Jacinthe Ge Liu Sijia Li Yingxin Shang Hui Tao Chong Fang Lili Lyu Baohua Zhang Kaishan Song Northeast Institute of Geography and Agroecology CASChangchunJilin130102China Department of Geology Indiana University∼Purdue UniversityIndianapolisIN44602USA University of Chinese Academy of Sciences Beijing100100China College of Geography and Urban Planning Liaocheng UniversityLiaochengChina

Suspended particulate matter(spm)in lakes exerts strong impact on light propagation,aquatic ecosystem productivity,which co-varies with nutrients,heavy metal and micro-pollutant in waters.In lakes,spm exerts strong absorption and backscattering,ultimately affects water leaving signals that can be detected by satellite sensors.Simple regression models based on specific band or hand ratios have been widely used for spm estimate in the past with moderate accuracy.There are still rooms for model accuracy improvements,and machine learning models may solve the non-linear relationships between spectral variable and spm in waters.We assembled more than 16,400 in situ measured spm in lakes from six continents(excluding the Antarctica continent),of which 9640 samples were matched with Landsat overpasses within±7 days.Seven machine learning algorithms and two simple regression methods(linear and partial least squares models)were used to estimate spm in lakes and the performance were compared.To overcome the problem of imbalance datasets in regression,a Synthetic Minority Over-Sampling technique for regression with Gaussian Noise(SMOGN)was adopted in this study.Through comparison,we found that gradient boosting decision tree(GBDT),random forest(RF),and extreme gradient boosting(XGBoost)models demonstrated good spatiotemporal transferability with SMOGN processed dataset,and has potential to map spm at different year with good quality of Landsat land surface reflectance images.In all the tested modeling approaches,the GBDT model has accurate calibration(n=6428,R^(2)=0.95,MAPE=29.8%)from spm collected in 2235 lakes across the world,and the validation(n=3214,R^(2)=0.84,MAPE=38.8%)also exhibited stable performance.Further,the good performances were also exhibited by RF model with calibration(R^(2)=0.93)and validation(R^(2)=0.86,MAPE=24.2%)datasets.We applied GBDT and RF models to map spm of typical lakes,and satisfactory result was obtained.In addition,the GBDT model was evaluated by historical spm measurements coincident with di

关键词： Landsat imagery Remote estimation spm Transferability

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Interactions of Aurein with Model Membranes and Antimalarials

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American Journal of Analytical Chemistry 2024年第2期15卷 72-98页

作者： Anaif M. Alhewaitey Nsoki Phambu Naif M. Alhawiti Department of Chemistry Tennessee State University Nashville USA Department of Chemistry University of Tabuk Tabuk Saudi Arabia CAHFS University of California Davis Davis USA

Aurein is a cationic antimicrobial peptide, rich in phenylalanine residues. Although the peptide has been extensively studied, its mechanism of action is not fully understood and has not been established. This project is focused on studying the interactions of aurein with model biological membranes and antimalarials using Fourier Transform Infrared (FTIR), fluorescence, dynamic light scattering (DLS), atomic force microscopy (AFM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) techniques. FTIR data revealed conformational changes to the secondary structure of the peptide in the presence of the model membranes. The strongest interactions of aurein were found with DOPC and lipid raft systems. Fluorescence data revealed some differences in the mechanism of interaction between aurein and lipid rafts. Topographical analysis was performed using atomic force microscopy (AFM). AFM images of the peptide with its lipid rafts showed a change in surface roughness suggesting a different mechanism of interaction. DLS data in agreement with FTIR confirmed that aurein interacts differently with the lipid rafts. The results gathered from this study provided new insights on the interaction of aurein. On the other hand, drug-drug interaction issues continue to present a major dilemma for the clinician caring for complex patients such as those infected with infectious disease. This study has examined the interaction of aurein with quinine, primaquine, and chloroquine. Significant interactions between aurein and antimalarials occured at a higher concentration of antimalarials. Interactions between aurein and anti-malarials reveal a strong interaction between aurein and primaquine. Interactions between aurein and quinine or chloroquine were found to be weak and negligible. FTIR, TGA, and DSC may be used in a complementary way to gain insights into the possible drug-drug interactions involving aurein. These studies are needed to initiate in vivo controlled interaction studies between antibiotics and anti

关键词： Aurein Fluorescence DPPC spm cholesterol DPPC-spm-CHOL Quinine Antimalarials

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断续+连续模式机器人冲压生产线的节拍提升

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锻造与冲压 2024年第2期 39-45页

作者：邝志铭刘聪钟剑广汽埃安新能源汽车股份有限公司

冲压生产线spm(Stroke Per Minute),即每分钟压力机的冲压次数,是生产节拍最直接的反映,也是影响整线生产效率的重要指标之一。提升生产线spm后,在相同的时间内可以冲压出更多的零件,产能得到进一步提高,从而降低企业的劳务费、能源费... 详细信息

冲压生产线spm(Stroke Per Minute),即每分钟压力机的冲压次数,是生产节拍最直接的反映,也是影响整线生产效率的重要指标之一。提升生产线spm后,在相同的时间内可以冲压出更多的零件,产能得到进一步提高,从而降低企业的劳务费、能源费等生产成本,对于公司的发展具有积极的作用。本文基于我公司Y车型现场三个月的调试经验,从压力机和机器人动作配合原理、节拍影响因素以及节拍提升优化方法等方面进行全面分析探讨,对机器人冲压生产线整线效率提升具有十分重要的指导意义。

关键词：冲压生产线压力机机器人生产节拍调试经验连续模式劳务费 spm

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Robust Watermarking Algorithm for Medical Volume Data Based on Polar Cosine Transform and 3D-DCT

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Computers, Materials & Continua 2023年第6期75卷 5853-5870页

作者： Pengju Zhang Jingbing Li Uzair Aslam Bhatti Jing Liu Yen-wei Chen Dekai Li Lei Cao School of Information and Communication Engineering Hainan UniversityHaikou570100China State Key Laboratory of Marine Resource Utilization in the South China Sea Hainan UniversityHaikou570100China Research Center for Healthcare Data Science Zhejiang LabHangzhou311121China Graduate School of Information Science and Engineering Ritsumeikan UniversityKyoto5258577Japan

The amount of 3D data stored and transmitted in the Internet of Medical Things(IoMT)is increasing,making protecting these medical data increasingly prominent.However,there are relatively few researches on 3D data watermarking.Moreover,due to the particularity of medical data,strict data quality should be considered while protecting data security.To solve the problem,in the field of medical volume data,we proposed a robust watermarking algorithm based on Polar Cosine Transform and 3D-Discrete Cosine Transform(PCT and 3D-DCT).Each slice of the volume data was transformed by PCT to obtain feature row vector,and then the reshaped three-dimensional feature matrix was transformed by 3D-DCT.Based on the contour information of the volume data and the detail information of the inner slice,the visual feature vector was obtained by applying the per-ceptual hash.In addition,the watermark was encrypted by a multi-sensitive initial value Sine and Piecewise linear chaotic Mapping(spm)system,and embedded as a zero watermark.The key was stored in a third party.Under the same experimental conditions,when the volume data is rotated by 80 degrees,cut 25%along the Z axis,and the JPEG compression quality is 1%,the Normalized Correlation Coefficient(NC)of the extracted watermark is 0.80,0.89,and 1.00 respectively,which are significantly higher than the comparison algorithm.

关键词： Volume data watermark zero watermark spm PCT and 3D-DCT

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Bubble domain evolution in well-ordered BiFeO_(3) nanocapacitors

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Journal of Advanced Dielectrics 2023年第6期13卷 13-19页

作者： Fengyuan Zhang Guo Tian Lina Zhao Xingsen Gao Jiangyu Li Department of Materials Science and Engineering Southern University of Science and Technology Shenzhen 518055P.R.China Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices Southern University of Science and Technology Shenzhen 518055P.R.China Institute for Advanced Materials South China Academy of Advanced Optoelectronics South China Normal UniversityGuangzhou 510006P.R.China Guangdong Provincial Key Laboratory of Optical Information Materials and Technology South China Normal University Guangzhou 510006P.R.China Institute of Data and Information Tsinghua Shenzhen International Graduate School Shenzhen 518055P.R.China

Ferroelectric nanocapacitors have attracted intensive research interest due to their novel functionalities and potential application in nanodevices.However,due to the lack of knowledge of domain evolution in isolated nanocapacitors,precise manipulation of topological domain switching in the nanocapacitor is still a challenge.Here,we report unique bubble and cylindrical domains in the well-ordered BiFeO_(3) nanocapacitor array.The transformation of bubble,cylindrical and mono domains in isolated ferroelectric nanocapacitor has been demonstrated via scanning probe microscopy(spm).The bubble domain can be erased to mono domain or written to cylindrical domain and mono domain by positive and negative voltage,respectively.Additionally,the domain evolution rules,which are mainly affected by the depolarization field,have been observed in the nanocapacitors with different domain structures.This work will be helpful in understanding the domain evolution in ferroelectric nanocapacitors and providing guidance on the manipulation of nanoscale topological domains.

关键词： Ferroelectrics spm domain evolution bubble domain nanocapacitor array

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Development of spm Quantitative Micromorphology Analysis Software

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International Journal of Minerals,Metallurgy and Materials 1999年第2期13卷 136-138页

作者： Suozai Li Libing Liao(School of Materials Science and Engineering, China University of Geosciences, Beijing 100083, China) School of Materials Science and Engineering China University of Geosciences Beijing 100083 China

Scanning Probe Microscope (spm) has great advantages in quantitative micromorphology analysis because of its conveniencein obtaining micromorphology information of materials on nanometer or atomic scale under control of a computer. Based on an established spm quantitative micromorphology analysis model, an spm image analysis software Which can calculate both two- and three-dimensional micromorphology parameters is developed.

关键词： spm quantitative micromorphology analysis software

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Frequency-dependent alterations in regional homogeneity in young carriers of the apolipoprotein E genotype

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Science Bulletin 2017年第9期62卷 654-655页

作者： Xi-Ze Jia Yi-Wen Zhang Yu-Feng Zang Hui-Jie Li CAS Key Laboratory of Behavioral Science Institute of Psychology Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments Center for Cognition and Brain Disorders Hangzhou Normal University Hangzhou 311121 China Institutes of Psychological Sciences Hangzhou Normal University Hangzhou 311121 China

Using resting-state functional magnetic resonance imaging(rf MRI),previous studies showed that the APOE e4 allele might affect the functional connectivity between remote brain regions[1,2].However,the local functional... 详细信息

关键词： test MRI data spm Re Frequency-dependent alterations in regional homogeneity in young carriers of the apolipoprotein E genotype MTL FWHM FOV

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Zinc Isotope Characteristics in the Biogeochemical Cycle as Revealed by Analysis of Suspended Particulate Matter(spm) in Aha Lake and Hongfeng Lake, Guizhou, China

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Journal of Earth Science 2020年第1期31卷 126-140页

作者： Lili Liang Cong-Qiang Liu Xiangkun Zhu Bryne TNgwenya Zhongliang Wang Liuting Song Jin Li School of Environmental Studies China University of GeosciencesWuhan 430074China State Key Laboratory of Environmental Geochemistry Chinese Academy of SciencesGuiyang 550002China Key Laboratory of Isotopic Geology of the Ministry of Land and Resources Institute of GeologyChinese Academy of Geological SciencesBeijing 100037China School of Geosciences University of EdinburghEdinburgh EH93FEUK School of Geographic and Environmental Sciences Tianjin Normal UniversityTianjin 300387China College of Water Sciences Beijing Normal UniversityBeijing 100875China

Zn isotope is a useful tool for tracing biogeochemical processes as zinc plays important roles in the biogeochemistry of natural systems. However, the Zn isotope composition in the lake ecosystems has not been well characterized. In order to resolve this problem, we investigate the Zn isotope compositions of suspended particulate matter(spm) and biological samples collected from the Aha Lake and Hongfeng Lake, and their tributaries in summer and winter, aiming to explore the potential of this novel isotope system as a proxy for biogeochemical processes in aqueous environments. Concentration of dissolved Zn ranges from 0.65 to 5.06 μg/L and 0.74 to 12.04 μg/L for Aha Lake and Hongfeng Lake, respectively, while Zn(spm) ranges from 0.18 to 0.70 mg/g and 0.24 to 0.75 mg/g for Aha Lake and Hongfeng Lake, respectively. The Zn isotope composition in spm from Aha Lake and its main tributaries ranges from -0.18‰ to 0.27‰ and -0.17‰ to 0.46‰, respectively, and it varies from -0.29‰ to 0.26‰ and -0.04‰ to 0.48‰, respectively in Hongfeng Lake and its main tributaries, displaying a wider range in tributaries than lakes. These results imply that Zn isotope compositions are mainly affected by tributaries inputting into Aha Lake, while adsorption process by algae is the major factor for the Zn isotope composition in Hongfeng Lake, and ZnS precipitation leads to the light Zn isotope composition of spm in summer. These data and results provide the basic information of the Zn isotope for the lake ecosystem, and promote the application of Zn isotope in biogeochemistry.

关键词： Zn isotope spm Aha Lake Hongfeng Lake tributary

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Comparison of high-energy multi-pass Ti:sapphire amplifiers with a different Ti-dopant concentration

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Chinese Optics Letters 2017年第9期15卷 66-70页

作者：甘泽彪梁晓燕於亮红洪佳琪徐明杭寅李儒新 State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing100049China Key Laboratory of Materials for High Power Laser Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China

We experimentally compare the output abilities of lightly and heavily doped Ti：Sapphire（Ti：S） amplifiers with diameters as large as 150 mm. Although a lightly doped Ti：S is more favorable to overcome parasitic lasing（PL）and transverse amplified spontaneous emission（TASE）, the self-phase-modulation（spm） effect becomes more pronounced when a longer crystal is used. Recompression of the amplified, stretched pulses can be seriously affected by the spm effect. We then propose a temporal multi-pulse pump scheme to suppress PL and TASE in a thin, heavily doped Ti：S crystal. This novel temporal multi-pulse pump technique can find potential applications in 10 PW chirped-pulse amplification laser systems.

关键词： Ti Comparison of high-energy multi-pass Ti:sapphire amplifiers with a different Ti-dopant concentration spm

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Validation of MODIS ocean-colour products in the coastal waters of the Yellow Sea and East China Sea

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Acta Oceanologica Sinica 2020年第1期39卷 91-101页

作者： Lingling Jiang Xiangyu Guo Lin Wang Shubha Sathyendranath Hayley Evers-King Yanlong Chen Bingnan Li College of Environmental Science and Engineering Dalian Maritime UniversityDalian 116026China Ministry of Ecology Environment National Marine Environmental Monitoring CenterDalian 116023China Plymouth Marine Laboratory(PML) PlymouthDevonPL13DHUK

An extensive study collected in situ data along the Yellow Sea(YS) and East China Sea(ECS) to assess the radiometric properties and the concentration of the water constituents derived from Moderate Resolution Imaging Spectroradiometer(MODIS). Thirteen high quality match-ups were obtained for evaluating the MODIS estimates of Rrs(λ), chlorophyll a(Chl a) and concentrations of suspended particulate sediment matter(spm). For MODIS Rrs(λ), the mean absolute percentage difference(APD) was in the range of 20%–36%, and the highest uncertainty appeared at 412 nm, whereas the band ratio of Rrs(λ) at 488 nm compared with that at 547 nm was highly consistent, with an APD of 7%. A combination of near-infrared bands and shortwave infrared wavelengths atmosphere correction algorithm(NIR-SWIR algorithm) was applied to the MODIS data, and the estimation accuracy of Rrs were improved at most of the visible spectral bands except 645 nm, 667 nm and 678 nm. Two ocean-colour empirical algorithms for Chl a estimation were applied to the processed data, the results indicated that the accuracy of the derived Chl a values was obviously improved, the four-band algorithms outperformed the other algorithm for measured and simulated datasets, and the minimum APD was 35%. The spm was also quantified. Two regional and two coastal spm algorithms were modified according to the in situ data. By comparison, the modified Tassan model had a higher accuracy for the application along the YS and ECS with an APD of 21%. However, given the limited match-up dataset and the potential influence of the aerosol properties on atmosphere correction, further research is required to develop additional algorithms especially for the low Chl a coastal water.

关键词： MODIS turbid waters chlorophyll a spm retrieval algorithms Yellow and East China Sea

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