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Multifractal estimation of NMR T_(2) cut-off value in low-permeability rocks considering spectrum kurtosis: SMOTE-based oversampling integrated with machine learning

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Petroleum Science 2023年第6期20卷 3411-3427页

作者： Xiao-Jun Chen rui-xue zhang Xiao-Bo Zhao Jun-Wei Yang zhang-Jian Lan Cheng-Fei Luo Jian-Chao Cai MOE Key Laboratory of Tectonics and Petroleum Resources Wuhan430074HubeiChina Department of Chemical Engineering and Analytical Science The University of ManchesterManchesterM139PLUK Jianghan Oilfied SINOPECQianjiang430063HubeiChina Hainan Branch of CNOOC Ltd Haikou570311HainanChina CNOOC EnerTech-Drilling&Production Co.CNOOC Central Laboratory(Zhanjiang) Zhanjiang524057GuangdongChina National Key Laboratory of Petroleum Resources and Engineering China University of PetroleumBeijing102249China

The transverse relaxation time (T_(2)) cut-off value plays a crucial role in nuclear magnetic resonance for identifying movable and immovable boundaries, evaluating permeability, and determining fluid saturation in petrophysical characterization of petroleum reservoirs. This study focuses on the systematic analysis of T_(2) spectra and T_(2) cut-off values in low-permeability reservoir rocks. Analysis of 36 low-permeability cores revealed a wide distribution of T_(2) cut-off values, ranging from 7 to 50 ms. Additionally, the T_(2) spectra exhibited multimodal characteristics, predominantly displaying unimodal and bimodal morphologies, with a few trimodal morphologies, which are inherently influenced by different pore types. Fractal characteristics of pore structure in fully water-saturated cores were captured through the T_(2) spectra, which were calculated using generalized fractal and multifractal theories. To augment the limited dataset of 36 cores, the synthetic minority oversampling technique was employed. Models for evaluating the T_(2) cut-off value were separately developed based on the classified T_(2) spectra, considering the number of peaks, and utilizing generalized fractal dimensions at the weight 0. The primary objective of this work is to gain insights into the relationship between the kurtosis of the T_(2) spectrum and pore types, as well as to predict the T_(2) cut-off value of low-permeability rocks using machine learning and data augmentation techniques.

关键词： Nuclear magnetic resonance Low-permeability porous media T_(2)cut-off value Fractal and multifractal Data augmentation Machine learning

Oxidative stress,epigenetic regulation and pathological processes of lens epithelial cells underlying diabetic cataract

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Advances in Ophthalmology Practice and Research 2023年第4期3卷 180-186页

作者： Zaoxia Guo Xiaopan Ma rui xue zhang Hong Yan Shaanxi Eye Hospital Xi'an People's Hospital(Xi'an Fourth Hospital)Affiliated People's Hospital of Northwest UniversityXi'anShaanxiChina Xi'an Key Laboratory of Stem Cell and Regenerative Medicine Institute of Medical ResearchNorthwestern Polytechnical UniversityXi'anShaanxiChina

Background:Cataract is a blinding disease *** is an age-related disease that mainly occurs in people over 65 years *** is also prevalent in patients with diabetes mellites(DM).The pathological mechanisms underlying diabetic cataract(DC)are more complex than that of age-related *** have identified that polyol pathway,advanced glycation end products(AGEs)and oxidative stress are the primary pathogenesis of *** recent years,molecular-level regulations and pathological processes of lens epithelial cells(LECs)have been confirmed to play roles in the initiation and progression of DC.A comprehensive understanding and elucidation of how chronic hyperglycemia drives molecular-level regulations and cytopathological processes in the lens will shed lights on the prevention,delay and treatment of *** text:Excessive glucose in the lens enhances polyol pathway and AGEs *** pathway causes imbalance in the ratio of NADPH/NADPt and NADH/*** in NADPH/NADPt ratio compromises antioxidant enzymes,while increase in NADH/NADt ratio promotes reactive oxygen species(ROS)overproduction in mitochondria,resulting in oxidative *** stress in the lens causes oxidation of DNA,proteins and lipids,leading to abnormalities in their structure and *** of proteins by AGEs decreases solubility of *** glucose triggered epigenetic regulations directly or indirectly affect expressions of genes and proteins in *** in autophagic activity,increases in fibrosis and apoptosis of LECs destroy the morphological structure and physiological functions of the lens epithelium,disrupting lens ***:In both diabetic animal models and diabetics,oxidative stress plays crucial roles in the formation of *** regulations,include lncRNA,circRNA,microRNA,methylation of RNA and DNA,histone acetylation and pathological processes,include autophagy,fibrosis and apoptosis of LECs also involved i

关键词： Oxidative stress Epigenetic regulation Autophagy Fibrosis Apoptosis Diabetic cataract

Short-term effects of intravitreal Conbercept injection combined with laser photocoagulation on macular edema secondary to ischemic retinal vein occlusion

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International Journal of Ophthalmology(English edition) 2021年第5期14卷 732-736页

作者： Zheng-Feng Liu Xing-Rong Wang Xiao-Yan zhang xue-Mei Pan rui-xue zhang Hong-Sheng Bi Ying Wen Medical School of Ophthalmology&Optometry Shandong University of Traditional Chinese MedicineJinan 250355Shandong ProvinceChina Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine Jinan 250002Shandong ProvinceChina Shandong Provincial Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular Diseases Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular Diseases in Universities of ShandongEye Institute of Shandong University of Traditional Chinese MedicineJinan 250002Shandong ProvinceChina

AIM:To observe changes in the best-corrected visual acuity(BCVA),central macular thickness(CMT),and central choroidal thickness(CCT)of patients with macular edema(ME)secondary to ischemic retinal vein occlusion(i RVO)following intravitreal Conbercept ***:This retrospective study included 33 eyes from 33 patients who received intravitreal injections of Conbercept for ME secondary to i *** were performed on a 3+pro re nata(3+PRN)*** of the patients were examined by fundus fluorescein angiography and spectral domain optical coherence tomography at the first *** photocoagulation was performed in the nonperfusion area of the retina of all eyes after the first ***,CMT,and CCT were observed before and after 6 mo of *** number of injections necessary to achieve improved vision was also ***:Following Conbercept treatment,the mean BCVA significantly improved from 0.81±0.39 at baseline to 0.41±0.25 and 0.43±0.29 log MAR in the third and sixth months,respectively(both P=0.000).The CMT of the patients at baseline was 556.75±98.57μm;304.78±68.53 and 306.85±76.77μm 3 and 6 mo after treatment,respectively(both P=0.000 vs baseline).The CCTs of the patients at baseline,3 and 6 mo after treatment were 304.63±57.83,271.31±45.53,and 272.29±39.93μm,respectively(P=0.026 and 0.035 vs baseline).No severe adverse event relevant to the therapy was noted,and the average number of injections delivered was ***:Intravitreal Conbercept injection combined with laser photocoagulation appears to be a safe and effective treatment for ME secondary to i RVO in the short-term.

关键词： Conbercept laser photocoagulation macular edema ischemic retinal vein occlusion

Quantitative understanding of phase segregation behaviors by precisely building discrete oligo-ester-b-oligo-olefin block copolymers

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Science China Chemistry 2024年第3期67卷 1008-1016页

作者： Yuxin Liu rui Tan Haibing Wu xue-Hui Dong Zhengbiao zhang College of Chemistry Chemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123China State Key Laboratory of Radiation Medicine and Protection Soochow UniversitySuzhou 215123China South China Advanced Institute for Soft Matter Science and Technology School of Molecular Science and EngineeringSouth China University of TechnologyGuangzhou 510640China

Block copolymers(BCPs) with high Flory-Huggins parameter(χ) and balanced surface energy have aroused tremendous interest for ultra-small nanopatterns ***,high χ and balanced surface energy are generally *** fine tune of chain structure might be a useful way to achieve high χ and balanced surface *** realize this,the block copolymer with exactly uniform chain structure,i.e.,defined molecular structure,is highly desirable for accurately evaluating the phase ***,two kinds of discrete oligo ester-b-oligo olefin block copolymers with different chemical structures(oligo lactic acid-boligo olefin BCP,oLA_(n)-b-C_(m);oligo phenyl lactic acid-b-oligo olefin BCP,oPL_(n)-b-C_(m)) were modularly synthesized through iterative growth *** effect of chain structure on segregation strength and surface properties was quantitatively investigated using the discrete BCPs as precise *** the one hand,introducing rigid and nonpolar phenyl groups into oligo ester block has a negligible effect on the chemical incompatibility,as confirmed by the identical high χ values of oLA_(n)-b-C_(m) and oPL_(n)-b-C_(m)(χ_(oLA/C)=0.21 and χ_(oPL/C)=0.19).On the other hand,the incorporation of nonpolar phenyl groups creates balanced surface energy,that is,the high χ and balanced surface energy were simultaneously achieved by oPL_(n)-b-C_(m).Therefore,sub-10 nm perpendicular nanopatterns can be easily produced upon brief thermal treatment,demonstrating its potential application in semiconductor manufacturing with ultra-small feature *** discrete BCP can serve as a quantitative and exquisite model to study the critical contribution of chain structures on phase separation behavior,providing insightful understanding to facilitate the potential application in the chip process.

关键词： discrete polymer iterative growth self-assembly highχ balanced surface

Merging non-covalent and covalent crosslinking:En route to single chain nanoparticles

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Chinese Chemical Letters 2024年第6期35卷 307-311页

作者： Yifei zhang Yuncong xue Laiwei Gao rui Liao Feng Wang Fei Wang CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China Department of Neurosurgical The First Affiliated Hospital of University of Science and Technology of ChinaDivision of Life Sciences and MedicineHefei 230026China

Single-chain nanoparticles represent an emerging class of nanomaterials designed to mimic protein's folding *** covalent crosslinking toward the formation of single-chain nanoparticles encounters complex energy landscapes,leading to the potential occurrence of misfolding *** noncovalent crosslinking can circumvent this issue,the resulting single-chain nanoparticles exhibit lower structural stability compared to their covalently crosslinked *** this study,we present a novel approach for the synthesis of single-chain nanoparticles,achieved through the combination of non-covalent and covalent intramolecular *** grafted onto the linear polymer form intrachain non-covalent stacks aided by hydrogen bonds,leading to the formation of non-covalently crosslinked single-chain *** nanoparticles undergo conversion to covalently crosslinked nanostructures through subsequent photo-irradiation using[2+2]photocycloaddition,a process facilitated by the supramolecular confinement ***,the resulting single-chain nanoparticles demonstrate both intrachain folding efficiency and substantial stability,offering significant potential for advancing applications across diverse fields.

关键词： Single chain nanoparticles Intrachain folding Supramolecular confinement Cyanostilbenes [2+2]photocycloaddition

Magnetic NiFe_(2)O_(4)@FeNi_(3)core-shell nanospheres derived from FeNi-LDH precursor anchoring on rGO nanosheets for enhanced electromagnetic wave absorption

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Journal of Materials Science & Technology 2024年第4期171卷 101-114页

作者： Kunyao Cao Yuan Fang Shuai Wang Yue zhang Jiayue Wen Jun Chen rui Zhao Weidong xue School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 610054China

Graphene has been extensively utilized in the domain of electromagnetic wave(EMW)absorption ma-terials because of its excellent electrical ***,the inferior impedance matching per-formance and the single loss mechanism vastly restrict the ***,it’s an effective strat-egy to solve these issues by introducing magnetic ***,layer double hydroxide(LDH)is an appropriate template to obtain magnetic component *** that ferromagnetic met-als such as Fe,Co,Ni,and their corresponding metal oxides are usually treated as magnetic compo-nents which are promising candidates for EMW absorption ***,in this work,a FeNi-layered double hydroxide-reduced graphene oxide(FeNi-LDH-rGO)aerogel was synthesized through a series of processes such as electrostatic self-assembly,hydrothermal,freeze-drying,and *** magnetic NiFe_(2)O_(4)@FeNi_(3)core-shell nanospheres were obtained from FeNi-LDH precursor,anchoring on rGO nanosheets after the annealing ***,the effects of different mass ratios of LDH to GO as well as different annealing temperatures of LDH-rGO aerogel on the EMW absorption prop-erty and impedance matching performance were *** a consequence,the fabricated ultralight 600LDH-rGO 2:1 aerogel shows a broad effective absorption bandwidth(EAB)of 7.04 GHz at a thickness of 2.3 mm with a low filling content of only 6 wt%and a low density of 4.4 mg/cm^(3).In conclusion,the synthetic LDH-rGO aerogels offer an effective strategy for preparing EMW absorption materials that own three-dimensional porous network structure and unique magnetic NiFe_(2)O_(4)@FeNi_(3)core-shell struc-ture nanospheres.

关键词： Electrostatic self-assembly Electromagnetic wave absorption LDH-rGO aerogel Layered double hydroxide Reduced graphene oxide NiFe_(2)O_(4)@FeNi_(3)core-shell structure

Experimental and DFT Investigations of AlNbTiVZr High Entropy Alloys with Excellent Mechanical Properties

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Acta Metallurgica Sinica(English Letters) 2024年第9期37卷 1480-1490页

作者： Hongwei Yan Yong'an zhang Wei Xiao Boyu xue rui Liu Xiwu Li Zhihui Li Baiqing Xiong State Key Laboratory of Nonferrous Metals and Processes China GRINM Group Co.Ltd.Beijing100088China GRIMAT Engineering Institute Co. Ltd.Beijing101407China General Research Institute for Nonferrous Metals Beijing100088China

This study investigated the microstructure and mechanical properties of AlNbTiVZr series high-entropy alloys(HEAs)through both experimental studies and density functional theory *** improvements in the microstructures and mechanical properties were achieved for the AlNbTiVZr series HEAs by meticulously adjusting the alloy composition and employing homogenization heat ***,the specimen designated as Al_(0.5)NbTiVZr_(0.5) demonstrated excellent mechanical properties including a compressive yield strength of 1162 MPa and a compressive strength of 1783 *** homogenization heat treatment at 1000℃ for 24 h,the Al_(0.5)NbTiVZr_(0.5) alloy exhibits brittle-to-ductile *** atomic-scale theoretical simulations reveal that the decrease of Al content intrinsically enhances the ductility of the alloys,thereby indicating that the mechanical properties of the AlNbTiVZr series HEAs were significantly influenced by the chemical ***,specific atomic pair formations were observed to adversely affect the microstructure of the AlNbTiVZr series HEAs,particularly in terms of *** findings provide valuable insights for the design and optimization of light weight HEAs,emphasizing the synergistic adjustment of alloy composition and heat treatment processes to achieve a balance between the strength and ductility.

关键词： High-entropy alloy Microstructure Mechanical properties Density functional theory

Electrochemical converting ethanol to hydrogen and acetic acid for large scale green hydrogen production

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Nano Research 2024年第3期17卷 1542-1551页

作者： Yufeng zhang Wei Zhu Jinjie Fang Zhiyuan Xu Yanrong xue Jiajing Pei rui Sui Xingdong Wang xuejiang zhang Zhongbin Zhuang State Key Lab of Organic-Inorganic Composites and Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China Laboratory of Advanced Functional Materials of Nanjing Nanjing Xiaozhuang UniversityNanjing 211171China Beijing Key Laboratory of Energy Environmental Catalysis Beijing University of Chemical TechnologyBeijing 100029China

Electrochemical coupling hydrogen evolution with biomass reforming reaction(named electrochemical hydrogen and chemical cogeneration(EHCC)),which realizes green hydrogen production and chemical upgrading simultaneously,is a promising method to build a carbon-neutral ***,we analyze the EHCC process by considering the market *** ethanol to acetic acid and hydrogen approach is the most feasible for large-scale hydrogen *** develop AuCu nanocatalysts,which can selectively oxidize ethanol to acetic acid(>97%)with high long-term *** isotopic and in-situ infrared experiments reveal that the promoted water dissociation step by alloying contributes to the enhanced activity of the partial oxidation reaction path.A flow-cell electrolyzer equipped with the AuCu anodic catalyst achieves the steady production of hydrogen and acetic acid simultaneously in both high selectivity(>90%),demonstrating the potential scalable application for green hydrogen production with low energy consumption and high profitability.

关键词： selective ethanol electrooxidation gold alloy catalyst electrochemical-coupled hydrogen production market assessment interfacial water activation

Recent Advances in the Electrochemical Defluorinative Transformations of C-F Bonds

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Chinese Journal of Chemistry 2024年第16期42卷 1913-1928页

作者： Qinhui Wan rui-xue Liu Zhongyi zhang Xia-Die Wu Zhong-Wei Hou Lei Wang Advanced Research Institute and Schoolof Pharmaceutical Sciences Taizhou UniversityJiaojiangZhejiang 318000China Department of Chemistry Southern University of Science and TechnologyhenzhenGuangdong 518055China College of Material Chemistry and Chemical Engineering Key Laboratory of Organosilicon Chemistry and Material Technology Ministryof EducationHangzhou Normal UniversityHangzhouZhejiang 311121China

Organic fluorine compounds are ubiquitous and pivotally important organic molecules,yet their activation and transformation have long been a formidable challenge due to the high energy and low reactivity of C-F *** electrosynthesis,an environmentally benign synthetic method in organic chemistry,enables a myriad of chemical transformations without the need for external redox *** recent years,organic electrochemistry has emerged as a powerful tool for achieving the activation and transformation of C-F bonds in fluorine-containing *** review aims to succinctly recapitulate the latest advancements in the electrochemical defluorinative transformations of C-F bonds and to delve into the reaction design,mechanistic insights,and developmental prospects ofthese methods.

关键词： Organic electrochemistry Electroreduction Defluorination C-F bond activation Organic fluorine compounds