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Gas hydrate in-situ formation and dissociation in clayey-silt sediments: An investigation by low-field NMR

ENERGY EXPLORATION & EXPLOITATION 2021年第1期39卷 256-272页

作者： sun, Xiaoxiao Qin, xuwen Lu, Hongfeng Wang, Jingli Xu, Jianchun Ning, Zijie China Geol Survey Guangzhou Marine Geol Survey Guangzhou Peoples R China China Geol Survey Gas Hydrate Engn Technol Ctr Guangzhou Peoples R China China Univ Geosci Beijing Sch Energy Resources Beijing Peoples R China China Univ Petr East China Sch Petr Engn Qingdao Peoples R China

The hydrate reservoir in the Shenhu Area of the South China Sea is a typical clayey-silt porous media with high clay mineral content and poor cementation, in which gas hydrate formation and dissociation characteristics are unclear. In this study, the CO2 hydrate saturation, growth rate, and permeability were studied in sandstone, artificial samples, and clayey-silt sediments using a custom-built measurement apparatus based on the low-field NMR technique. Results show that the T-2 spectra amplitudes decrease with the hydrate formation and increase with the dissociation process. For the artificial samples and Shenhu sediments, the CO2 hydrate occupies larger pores first and the homogeneity of the sandstone pores becomes poor. Meanwhile, compared with the clayey-silt sediments, CO2 hydrate is easier to form and with higher hydrate saturation for the sandstone and artificial samples. In hydrate dissociation process, there exists a protection mechanism, i.e. the dissociation near the center of hydrates grain is suppressed when gas pressure drops suddenly and quickly. For permeability of those samples, it decreased with hydrate forms, and increases with hydrate dissociation. Meanwhile, with the same hydrate saturation, permeability is higher in hydrate formation than in dissociation.

关键词： Gas hydrate clayey-silt sediments NMR formation and dissociation permeability

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A Methionine Allocation Nanoregulator for the Suppression of Cancer Stem Cells and Support to the Immune Cells by Epigenetic Regulation

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ADVANCED SCIENCE 2025年第15期12卷 e2415207页

作者： Su, Boyu Chen, Qinjun Li, xuwen Fang, Mingzhu Wang, Yu Song, Haolin You, Haoyu Zhou, Zheng Wu, Yuxing Zhao, Zhenhao Chen, Yun Fan, Hongrui Li, Chufeng Jiang, Chen sun, Tao Fudan Univ State Key Lab Med Neurobiol Sch Pharm Dept PharmaceutKey Lab Smart Drug DeliveryMinist Shanghai 201203 Peoples R China MOE Frontiers Ctr Brain Sci Shanghai 201203 Peoples R China Fujian Med Univ Affiliated Hosp 1 Natl Reg Med Ctr Dept Digest Dis Binhai Campus Fuzhou 350212 Peoples R China Quzhou Fudan Inst Quzhou 324003 Peoples R China

Epigenetic dysregulation is prevalent in human cancers, affecting gene expression and metabolic patterns to meet the demands of malignant evolution and abnormal epigenetic processes, and resulting in a protumor immune microenvironment. Tumors require a steady supply of methionine for maintaining epigenetic flexibility, which is the only exogenous precursor of methyl donor S-adenosylmethionine for methylation, crucial for their resistance to therapies and survival in a nutrient-deficient microenvironment. Thus, tumor cells upregulate the Lat4 transporter to compete and deprive methionine in the microenvironment, sustaining their malignant phenotypes and also impairing immune cell functions. Addressing this methionine addiction is the key to overcoming drug resistance and improving immune response. Despite the challenge of lacking specific Lat4 inhibitors, an oxaliplatin prodrug crosslinked fluorinated polycation/anti-Lat4 small interfering RNA complex nanoregulator (AS-F-NP) has been designed and developed here. This nanoregulator restricted the greedy methionine uptake of tumor cells by knocking down Lat4, which in turn inhibited the malignant evolution of the tumor while restoring the viability and function of tumor-infiltrating immune cells.

关键词： cancer therapy epigenetic immune methionine oxaliplatin siRNA

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基于动态规划的舰用软件研制成本控制

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舰船电子工程 2019年第3期39卷 126-128页

作者：李伟龙飞孙续文海军大连舰艇学院大连116018

针对在舰用软件研制过程中不能对成本实施有效控制的实际问题,研究了已有评估方式的特点及不足,分析了运筹学原理应用于成本评估的可行性,提出了基于动态规划的成本测算解决方案。根据问题的具体特点对动态规划的阶段和状态进行了定义,... 详细信息

针对在舰用软件研制过程中不能对成本实施有效控制的实际问题,研究了已有评估方式的特点及不足,分析了运筹学原理应用于成本评估的可行性,提出了基于动态规划的成本测算解决方案。根据问题的具体特点对动态规划的阶段和状态进行了定义,按照运筹学模型的参数要求进行了全面构建,说明了成本计算的基本依据,并以具体实例进行了演示,对于软件研制方案的优选和提高军事资源使用效率具有一定借鉴意义。

关键词：动态规划舰用软件研制成本解决方案

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Combined Separated Oscillatory Fields Technique

Combined Separated Oscillatory Fields Technique

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European Frequency and Time Forum (EFTF)

作者： Fuyu sun Chao Li xuwen Hu Shougang Zhang National Time Service Center Chinese Academy of Sciences Xi'an China Key Laboratory of Time Reference and Applications Chinese Academy of Sciences Xi'an China

ISBN: (数字)9798350354270

ISBN: (纸本)9798350354287

Ramsey's method of separated oscillatory fields (SOFs) has been originally used in beam magnetic resonance apparatuses, which leads to the establishment of atomic definition of time interval and frequency. Since then, various versions of the SOFs technique have been widely used for precise measurement of different physical quantities. Here, we present an alternative method to generate atomic beam magnetic resonance signals by combining two Ramsey cavities with phase differences of 0 and 1t. It is found that the strength of the resonance signals generated using this combined SOFs technique is approximately twice that of the resonance signals produced by the conventional SOFs techniques. In addition to generating stronger resonance, the combined Ramsey method eliminates the Rabi background superimposed on the Ramsey interference pattern without increasing the Ramsey signal linewidth. Thus, this technique serves a promising tool for high-precision measurements.

关键词： Atomic measurements Time-frequency analysis Magnetic field measurement Atomic beams Magnetic resonance Europe Interference

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基于系统理论的舰艇指控系统软件质量量化评估

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舰船电子工程 2019年第4期39卷 114-116页

作者：李伟龙飞孙续文海军大连舰艇学院大连116018

为了科学评估舰艇指控系统软件的质量,提高军舰作战指挥的整体水平,在对舰艇指控系统进行深入分析的基础上,提取了与系统紧密相关的质量要素,探讨了评估的准则和指标量化的主要困难,利用系统质量要素之间的相互关系提出了基于判断矩阵... 详细信息

为了科学评估舰艇指控系统软件的质量,提高军舰作战指挥的整体水平,在对舰艇指控系统进行深入分析的基础上,提取了与系统紧密相关的质量要素,探讨了评估的准则和指标量化的主要困难,利用系统质量要素之间的相互关系提出了基于判断矩阵和系统理论的量化评估解决方案。

关键词：指控系统软件系统质量要素界定量化评估

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Ultrathin and Wavy PdB Alloy Nanowires with Controlled Surface Defects for Enhanced Ethanol Oxidation Electrocatalysis

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ACS APPLIED MATERIALS & INTERFACES 2021年第15期13卷 17599-17607页

作者： Wang, Yaru Lv, Hao sun, Lizhi Guo, xuwen Xu, Dongdong Liu, Ben Nanjing Normal Univ Jiangsu Collaborat Innovat Ctr Biomed Funct Mat Sch Chem & Mat Sci Jiangsu Key Lab New Power Batteries Nanjing 210023 Peoples R China Sichuan Univ Coll Chem Chengdu 610064 Peoples R China

Engineering crystalline structures/defects and elemental compositions is synthetically critical to optimize surface features of noble metal nanocrystals and thus improve their catalytic performances in various reactions. In this manuscript, we report a facile one-step aqueous synthesis of one-dimensional (1D) noble metal-metalloid alloy nanowires (NWs) with an ultrathin and wavy morphology, controlled crystalline defects, and binary PdB compositions as a highly efficient catalyst toward the electrochemical ethanol oxidation reaction (EOR). We show that the utilization of hexadecylpyridinium chloride as functional surfactant is of great importance to confine in-the-columnar epitaxial nucleation of anisotropic ultrathin PdB NWs, while the attachment growth precisely controls their surface crystalline defects with a wavy morphology. Meanwhile, this strategy is synthetically universal and can be readily extended to engineer an ultrathin wavy morphology and crystalline defect of ternary PdMB (M = Cu and Pt) alloy NWs. Owing to multiple structural and compositional merits, resultant PdB alloy NWs synergistically expose more electrocatalytically active sites and also kinetically accelerate the removal of CO-related poisons, remarkably improving electrocatalytic EOR activity and stability compared to their counterpart catalysts. Besides, wavy PdB alloy NWs are also electrochemically more active for electrocatalytic oxidation of other alcohols (methanol, glycerol, and glucose). The findings reported here thus shed a bright light on rational design of the high-performance metal alloy catalysts for their potential applications in fine chemical synthesis, fuel cells, and beyond.

关键词： nanowires crystalline defects metal-metalloid catalysis ethanol oxidation reaction

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A machine learning ensemble model for predicting pavement conditions using automatic laser crack measurement data

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INTERNATIONAL JOURNAL OF PAVEMENT ENGINEERING 2023年第1期24卷

作者： Bai, Lihui Zhang, Jie Zhu, xuwen Alam, Md Morshedul sun, Zhihui Univ Louisville Dept Ind Engn Louisville KY 40292 USA FedEx Corp Memphis TN USA Univ Alabama Dept Informat Syst Stat & Management Sci Tuscaloosa AL USA Univ Louisville Dept Civil & Environm Engn Louisville KY USA

Automated pavement survey (APS) systems (e.g. Laser Crack Measurement System) are increasingly adopted by transportation planners as a data-enriching and economical alternative to the traditional windshield pavement survey (WPS) systems. Application arises where transportation planners wish to use APS measurements to predict WPS distress scores, as such prediction will enable them to continue using the WPS-based pavement asset management system while using the newly collected APS data. In this paper, we develop a machine learning model to predict the WPS pavement distress scores using APS variables, by employing decision tree classifier based ensemble learning model. The novelty is threefold. First, instead of using the mean we use the distributions of APS variables in the prediction, by examining multiple statistics for every APS variable. Second, these statistics are then used to develop decision tree classifiers as base learners in predicting WPS distress scores. Third, base learners are ensembled using various weight assignment strategies. Our computational test uses the WPS and APS data for two wheel path crack distress from the Kentucky roadway systems, and suggests that conditional probability-based weight assignment provides the best prediction with approximately 79% accuracy.

关键词： Automated pavement survey windshield pavement survey pavement condition pavement management system decision tree classifier ensemble model

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Nanomaterials with dual immunomodulatory functions for synergistic therapy of breast cancer brain metastases

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Bioactive Materials 2023年第9期27卷 474-487页

作者： Zhenhao Zhao Chufeng Li Yiwen Zhang Chao Li Yongchao Chu xuwen Li Peixin Liu Hongyi Chen Yu Wang Boyu Su Qinjun Chen Tao sun Chen Jiang Department of Pharmaceutics School of PharmacyFudan UniversityKey Laboratory of Smart Drug DeliveryMinistry of EducationState Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceShanghai201203China

A long-standing paucity of effective therapies results in the poor outcomes of triple-negative breast cancer brain *** has made progress in the treatment of tumors,but limited by the non-immunogenicity of tumors and strong immunosuppressive environment,patients with TNBC brain metastases have not yet benefited from *** immunoregulatory strategies with enhanced immune activation and reversal of the immunosuppressive microenvironment provide new therapeutic options for ***,we propose a cocktail-like therapeutic strategy of microenvironment regulation-chemotherapy-immune synergistic sensitization and construct reduction-sensitive immune microenvironment regulation nanomaterials(SIL@T).SIL@T modified with targeting peptide penetrates the BBB and is subsequently internalized into metastatic breast cancer cells,releasing silybin and oxaliplatin responsively in the ***@T preferentially accumulates at the metastatic site and can significantly prolong the survival period of model *** studies have shown that SIL@T can effectively induce immunogenic cell death of metastatic cells,activate immune responses and increase infiltration of CD8+T ***,the activation of STAT3 in the metastatic foci is attenuated and the immunosuppressive microenvironment is *** study demonstrates that SIL@T with dual immunomodulatory functions provides a promising immune synergistic therapy strategy for breast cancer brain metastases.

关键词： Breast cancer brain metastases Drug delivery Immunogenic cell death Microenvironmental regulation STAT3

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Improved formation and evolution models for hydrate flow barriers in water-dominated systems based on flowloop experiments

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CHEMICAL ENGINEERING SCIENCE 2024年 297卷

作者： Kong, Qingwen Qin, xuwen Ji, Peng Wang, Zhiyuan Zhang, Jianbo Fu, Weiqi sun, Baojiang China Univ Petr East China Sch Petr Engn Qingdao Peoples R China China Geol Survey Aero Geophys Survey & Remote Sensing Ctr Nat Resou Beijing Peoples R China CNPC Offshore Engn Co Ltd Tianjin Branch Tianjin Peoples R China Natl Engn Res Ctr Oil & Gas Drilling & Complet Tec Qingdao Peoples R China China Univ Min & Technol State Key Lab Coal Resources & Safe Min Xuzhou Peoples R China

During gas hydrate and deep -water oil and gas exploitation, hydrate flow barriers in water -dominated systems represent a critical safety issue. In this study, hydrate formation and blockage were investigated using flowloop and focused beam reflectance measurement. An improved hydrate kinetic model suitable for cooling conditions was established considering various bubble behaviors. The special large aggregate size range was defined as 150 - 500 mu m. A new hydrate aggregation -blockage evolution model is proposed based on three significant events: large aggregate appearance, large aggregate blockage, and particle and small aggregate blockage. The results show that a critical initial flow velocity of 0.65 +/- 0.07 m/s determines whether large hydrate aggregates appear immediately at the onset of hydrate formation. Moreover, the prediction error for the flow velocity drop at significant events was less than +/- 9.1 %. Based on these results, two main hydrate blockage mechanisms in waterdominated systems are revealed.

关键词： Gas hydrate Hydrate formation Blockage Bubbly flow Significant events

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Fuzzy Multilevel Image Thresholding Based on Improved Coyote Optimization Algorithm

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IEEE ACCESS 2021年 9卷 33595-33607页

作者： Li, Linguo sun, Lijuan Xue, Yu Li, Shujing Huang, xuwen Mansour, Romany Fouad Nanjing Univ Posts & Telecommun Sch Comp Nanjing 210003 Peoples R China Fuyang Normal Univ Coll Informat Engn Fuyang 236041 Peoples R China Nanjing Univ Informat Sci & Technol Sch Comp & Software Nanjing 210044 Peoples R China Fuyang Normal Univ Coll Comp & Informat Engn Fuyang 236041 Peoples R China New Valley Univ Fac Sci Dept Math El Kharga 72511 Egypt

Due to the computational complexity of multilevel image thresholding, Swarm Intelligence Optimization Algorithm (SIOA) has been widely applied to improve the calculation efficiency. Therefore, more and more attention has been paid to exploring the application of the latest SIOA in multilevel segmentation. This article takes Otsu and fuzzy entropy as the objective functions, using Coyote Optimization Algorithm (COA) for multilevel thresholds optimization selection, through fuzzy median aggregation of local neighborhood information and then forms the Fuzzy Coyote Optimization Algorithm (FCOA), so that the thresholding image segmentation can be achieved in the end. To prevent the COA algorithm from falling into the local optimum, this article follows the differential evolution strategy adopted by the standard COA, using the number of iterations to construct the differential scaling factor to form the Improved Coyote Optimization Algorithm (ICOA). The experimental results show that fuzzy Kapur entropy and fuzzy median value aggregation-based ICOA(FICOA) achieves better image segmentation quality. Compared with Grey Wolf Optimizer (GWO), Fuzzy Modified Quick Artificial Bee Colony and Aggregation Algorithm (FMQABCA) and Fuzzy Modified Discrete Grey Wolf Optimizer and Aggregation Algorithm (FMDGWOA), FCOA and FICOA have certain advantages in visual effects of image segmentation and PSNR, FSIM evaluation indices. Particularly compared with GWO (also a wolf evolutionary algorithm), FICOA shows significant advantages.

关键词： Image segmentation Optimization Linear programming Entropy Particle swarm optimization Histograms Heuristic algorithms Coyote optimization algorithm information entropy image segmentation multilevel thresholding

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