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Strong and tough chitin hydrogel constructed by dehydration and rehydration strategy

Nano Research 2024年第9期17卷 8192-8199页

作者： Rui-Rui liu li-bo Mao Shu-Hong Yu Division of Nanomaterials and Chemistry Hefei National Research Center for Physical Sciences at the MicroscaleDepartment of ChemistryInstitute of Biomimetic Materials and ChemistryAnhui Engineering Laboratory of Biomimetic MaterialsUniversity of Science and Technology of ChinaHefei 230026China Institute of Innovative Materials Department of Materials Science and EngineeringDepartment of ChemistrySouthern University of Science and TechnologyShenzhen 518055China

As a renewable,biocompatible,biodegradable soft material,chitin hydrogels have better advantages in stability,antibacterial activity,antifouling,cost,immunogenicity,and so on than most polymer ***,compared with other widely used polymer hydrogels with high strength and toughness,the practical applications of chitin-based hydrogels have been limited by their weak mechanical properties,such as cartilage repair and meniscus ***,we present the design and fabrication of chitin hydrogels with excellent mechanical strength and toughness by a dehydration and rehydration *** sequential dehydration and rehydration processes,the crystalline domains in the chitin hydrogels can be properly *** optimized crystallinity,the elastic modulus of the chitin hydrogels exceeds all previously reported values,and the fracture toughness is even comparable to some synthetic polymer hydrogels,while maintaining a high-water-content of about 80 wt.%.At the same water content,the mechanical properties of the chitin hydrogels are positively correlated with the hydrogel crystallinity,which proves that the change of mechanical properties of hydrogels is not simply dependent on weight *** hydrogels can be further strengthened by incorporating other biopolymers that are intrinsically weak,which makes the hydrogels promising for applications in fields such as cartilage repair and meniscus ***,the hydrogels enable loading and release of water-soluble and poorly water-soluble *** highly extendable strengthening and toughening strategy of chitin and chitin-based biopolymer hydrogels paves the way for their widely applications.

关键词： chitin hydrogel crystallinity rehydration chemical transformation strong and tough

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A Unified Model Fusing Region of Interest Detection and Super Resolution for Video Compression

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Computers, Materials & Continua 2024年第6期79卷 3955-3975页

作者： Xinkun Tang Feng Ouyang Ying xu ligu Zhu bo Peng School of Computer and Cyber Sciences Communication University of ChinaBeijing100024China Cable Television Technology Research Institute Academy of Broadcasting ScienceBeijing100866China

High-resolution video transmission requires a substantial amount of *** this paper,we present a novel video processing methodology that innovatively integrates region of interest(ROI)identification and super-resolution *** method commences with the accurate detection of ROIs within video sequences,followed by the application of advanced super-resolution techniques to these areas,thereby preserving visual quality while economizing on data *** validate and benchmark our approach,we have curated a new gaming dataset tailored to evaluate the effectiveness of ROI-based super-resolution in practical *** proposed model architecture leverages the transformer network framework,guided by a carefully designed multi-task loss function,which facilitates concurrent learning and execution of both ROI identification and resolution enhancement *** unified deep learning model exhibits remarkable performance in achieving super-resolution on our custom *** implications of this research extend to optimizing low-bitrate video streaming *** selectively enhancing the resolution of critical regions in videos,our solution enables high-quality video delivery under constrained bandwidth *** results demonstrate a 15%reduction in transmission bandwidth compared to traditional super-resolution based compression methods,without any perceivable decline in visual *** work thus contributes to the advancement of video compression and enhancement technologies,offering an effective strategy for improving digital media delivery efficiency and user experience,especially in bandwidth-limited *** innovative integration of ROI identification and super-resolution presents promising avenues for future research and development in adaptive and intelligent video communication systems.

关键词： Super resolution region of interest detection video compression

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Fractal Characteristics and Main Controlling Factors of High-Quality Tight Sandstone Reservoirs in the Southeastern Ordos Basin

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Journal of Earth Science 2024年第2期35卷 631-641页

作者： Ruilin Hao Wenhui Huang Jiu bo li Yuan Key Laboratory for Marine Reservoir Evolution and Hydrocarbon Abundance Mechanism School of Energy ResourcesChina University of GeosciencesMinistry of EducationBeijing100083China

Due to the complex conditions and strong heterogeneity of tight sandstone reservoirs,the reservoirs should be classified and the controlling factors of physical properties should be *** thin section observations,cathodoluminescence,scanning electron microscopy(SEM),X-ray diffraction(XRD),and high-pressure mercury injection(HPMI)were used to classify and optimize the *** Brooks-Corey model and stepwise regression were used to study the fractal dimension and main controlling factors of the physical properties of the high-quality *** results show that the reservoirs in the study area can be divided into four types,and the high-quality reservoir has the best physical properties and pore-throat *** the high-quality reservoir,the homogeneity of transitional pores was the best,followed by that of micropores,and the worst was *** porosity was controlled by depth and *** model with standardized coefficients is y=12.454−0.778×(Depth)+0.395×(Kaolinite).The permeability was controlled by depth,illite/montmorillonite,and siliceous cement,and the model with standardized coefficients is y=1.689−0.683×(Depth)−0.395×(Illite/Montmorillonite)−0.337×(Siliceous Cement).The pore-throat evolutionary model shows that the early-middle diagenetic period was when the reservoir physical properties were at their best,and the kaolinite intercrystalline pores and residual intergranular pores were the most important.

关键词： fractal dimension main controlling factors stepwise regression high-quality tight sandstone reservoir Ordos Basin petroleum geolgoy

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Fluorescent Probes for Cysteine and Cysteine Oxidation Imaging

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Chemical Research in Chinese Universities 2024年第2期40卷 225-236页

作者： ZHANG Xia li Guocheng PAN Wei li Na li Yanhua TANG bo College of Chemistry Chemical Engineering and Materials ScienceKey Laboratory of Molecular and Nano ProbesMinistry of EducationCollaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of ShandongInstitute of Molecular and Nano ScienceShandong Normal UniversityJinan250014P.R.China Laoshan Laboratory Qingdao266237P.R.China

Cysteine is an important regulator of redox *** to the nucleophilic and oxidative sensitivity,cysteine residues in proteins can be oxidized by intracellular reactive oxygen species(ROS),which can lead to protein structural and functional ***,the development of fluorescent probes to image cysteine and cysteine oxidation is of great significance for the study of redox homeostasis in living *** this review,the development of fluorescent probes for imaging cysteine and cysteine oxidation was ***,we further analyzed defects of the reported fluorescent probes and made suggestions for the future development of fluorescent *** expect that this review can not only provide a deeper understanding of the role of cysteine and cysteine oxidation in oxidative stress,but also broaden the application of fluorescent probes in imaging cysteine and cysteine oxidation.

关键词： Cysteine Cysteine oxidation Fluorescent probe Oxidative stress

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Detecting the distribution of and public attitudes to charismatic alien species based on media coverage

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Avian Research 2024年第3期15卷 379-384页

作者： Yuexuan liu Ruichang Sun bo li Zhijun Ma Shanghai Institute of Infectious Disease and Biosecurity Ministry of Education Key Laboratory for Biodiversity Science and Ecological EngineeringNational Observations and Research Station for Wetland Ecosystems of the Yangtze Estuaryand Institute of Eco-Chongming(SIEC)School of Life SciencesFudan UniversityShanghai200433China Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology and Centre for Invasion Biology Institute of BiodiversitySchool of Ecology and Environmental ScienceYunnan UniversityKunming650504YunnanChina

Charismatic species are often reported by the media,providing information for detecting population status and public *** identify the number and distribution of free-living Black Swan(Cygnus atratus),a charismatic alien species in Chinese mainland and to detect the public and the media attitudes to the species,we analyzed the reports and emotional tendency from media coverage in 2000-2022 using manual reading,crawler extraction and latent Dirichlet allocation.A total of 6654 Black Swans were reported at 711 sites,including 147 individuals at 30 nature *** breeding was reported at one-fourth of the total sites,including five nature *** proportion of positive emotional tendency to Black Swans was overwhelming in the reports and was higher than that to alien species in general,suggesting that the public and the media are unaware of the risk of biological *** management of invasive species requires the media clarifies the invasion risk of charismatic alien *** the unity between the harmfulness of abstract concept of alien species and the charisma of a specific alien species among the public help effective management.

关键词： Alien species Biological invasion Cygnus atratus Emotional tendency Invasive species Media coverage Public perception

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Design of distributed dynamic absorbers for vibration suppression of panel structures

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Acta Mechanica Sinica 2024年第7期40卷 164-180页

作者： liyuan li Bin li Zehua xu School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China China Aero-Polytechnology Establishment Beijing 100028China

Distributed dynamic absorbers have many advantages such as wide frequency bandwidth for vibration suppression,strong detuning adaptability,and high system stability,making them very suitable for the vibration and noise control of continuous ***,they have broad application prospects in various fields such as transportation,aviation,and ***,there are still many challenges in the engineering applications of distributed dynamic absorbers for vibration suppression,including the engineering realization of the optimal damping of traditional optimal coherence dynamic absorbers,and the engineering applicability of the finite periodic array dynamic *** on the damping material properties obtained by the dynamic mechanical analyzer tests,this paper establishes the finite element model of the cantilever-beam-type dynamic absorber with constrained damping layers,aiming to realize the accurate determination of the optimal *** are conducted by attaching the traditional dynamic absorbers with the optimal damping to a thin-walled panel with four clamped *** show that the vibration of the panel is well suppressed,with the reduction of the frequency response peak larger than 14 dB and the reduction ratio of RMS larger than 58%within 500 ***,the periodically arrayed dynamic absorbers are designed according to the bandgap regulation *** tuning behavior of the arrayed dynamic absorbers by changing designing parameters is *** vibration reduction effect of arrayed dynamic absorbers is compared with that of the traditional dynamic absorbers under the same mass ratio through *** indicate that the arrayed dynamic absorbers are easier to design,and have a similar reduction effect on the modal vibration of the thin panel as the traditional dynamic absorbers within a narrow frequency range near the natural frequency,while they perform unsatisfactory in a broad ***,if t

关键词： Distributed dynamic absorbers Engineering realization of the optimal damping Vibration suppression Low-frequency and broadband

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Major risk-stratification models fail to predict outcomes in patients with multivessel coronary artery disease undergoing simultaneous hybrid procedure

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Chinese Medical Journal 2013年第3期126卷 450-456页

作者： WANG Hao-ran ZHENG Zhe XIONG Hui xu bo li li-huan GAO Run-lin HU Sheng-shou Research Center for Cardiac Regenerative Medicine of the Ministry of Health Cardiovascular Institute & Fuwai Hospital Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100037 China

Background The hybrid procedure for coronary heart disease combines minimally invasive coronary artery bypass grafting （CABG） and percutaneous coronary intervention （PCI） and is an alternative to revascularization treatment. We sought to assess the predictive value of four risk-stratification models for risk assessment of major adverse cardiac and cerebrovascular events （MACCE） in patients with multivessel disease undergoing hybrid coronary revascularization. Methods The data of 120 patients were retrospectively collected and the SYNTAX score, EuroSCORE, SinoSCORE and the Global Risk Classification （GRC） calculated for each patient. The outcomes of interest were 2.7-year incidences of MACCE, including death, myocardial infarction, stroke, and any-vessel revascularization. Results During a mean of 2.7-year follow-up, actuarial survival was 99.17%, and no myocardial infarctions occurred. The discriminatory power （area under curve （AUC）） of the SYNTAX score, EuroSCORE, SinoSCORE and GRC for 2.7-year MACCE was 0.60 （95% confidence interval 0.42-0.77）, 0.65 （0.47-0.82）, 0.57 （0.39-0.75） and 0.65 （0.46-0.83）, respectively. The calibration characteristics of the SYNTAX score, EuroSCORE, SinoSCORE and GRC were 3.92 （P=0.86）, 5.39 （P=0.37）, 13.81 （P=0.32） and 0.02 （P=0.89）, respectively. Conclusions In patients with multivessel disease undergoing a hybrid procedure, the SYNTAX score, EuroSCORE, SinoSCORE and GRC were inaccurate in predicting MACCE. Modifying risk-stratification models to improve the predictive value for a hybrid procedure is needed.

关键词： hybrid coronary revascularization risk stratification model multivessel coronary artery disease

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New strategies for asymmetric photocatalysis: asymmetric organocatalytic/photoredox relay catalysis for efficient synthesis of polycyclic compounds containing vicinal amino alcohols

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Science China Chemistry 2024年第3期67卷 945-952页

作者： Jia-Lu Zhang Wen-bo He Xiu-Qin Hu Peng-Fei xu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000China State Key Laboratory of Veterinary Etiological Biology College of Veterinary MedicineLanzhou UniversityLanzhou Veterinary Research InstituteChinese Academy of Agricultural SciencesLanzhou 730000China MOE Frontiers Science Center for Rare Isotopes Lanzhou UniversityLanzhou 730000China

An asymmetric catalytic strategy in photocatalysis utilizing a chirality-induced approach through an organocatalytic/photoredox relay catalysis strategy is successfully achieved for the rapid construction of polycyclic compounds containing vicinal amino alcohols in a one-pot protocol. This methodology facilitates the efficient synthesis of diverse substituted polycyclic tetrahydroquinoline and benzofuran-derived vicinal amino alcohols, each containing five consecutive chiral centers, with high yields,excellent diastereoselectivities and enantioselectivities(up to 95% yield, >20:1 dr and 98% ee), under mild reaction conditions driven by sequential bifunctional squaramide organocatalyst-catalyzed [4+2] annulation and photocatalyst-catalyzed ketyl radical addition cyclization reaction process. Furthermore, investigations into the stereoselectivity mechanism and high-resolution mass spectrometry(HRMS) experiments on free radical trapping have provided evidence for elucidating the detailed mechanism of chirality-induced processes and chiral intermediate conversions in this procedure.

关键词： enantioselective photocatalysis asymmetric organocatalytic/photocatalysis relay catalysis five consecutive chiral centers chirality-induced strategy chirality vicinal amino alcohols

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High corrosion and wear resistant electroless Ni–P gradient coatings on aviation aluminum alloy parts

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 155-164页

作者： bo Wang Jiawei li Zhihui Xie Gengjie Wang Gang Yu College of Chemistry and Chemical Engineering Hunan UniversityChangsha 410012China Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province/College of Chemistry and Chemical Engineering China West Normal UniversityNanchong 637002China Zhongchuan Machinery Ltd.Co. Aero Engine Corporation of ChinaChangsha 410200China

A Ni–P alloy gradient coating consisting of multiple electroless Ni–P layers with various phosphorus contents was prepared on the aviation aluminum alloy. Several characterization and electrochemical techniques were used to characterize the different Ni–P coatings’ morphologies, phase structures, elemental compositions, and corrosion protection. The gradient coating showed good adhesion and high corrosion and wear resistance, enabling the application of aluminum alloy in harsh environments. The results showed that the double zinc immersion was vital in obtaining excellent adhesion (81.2 N). The optimal coating was not peeled and shredded even after bending tests with angles higher than 90°and was not corroded visually after 500 h of neutral salt spray test at 35℃. The high corrosion resistance was attributed to the misaligning of these micro defects in the three different nickel alloy layers and the amorphous structure of the high P content in the outer layer. These findings guide the exploration of functional gradient coatings that meet the high application requirement of aluminum alloy parts in complicated and harsh aviation environments.

关键词： aluminum alloy electroless nickel coating corrosion adhesion

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Corporate Credit Ratings Based on Hierarchical Heterogeneous Graph Neural Networks

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Machine Intelligence Research 2024年第2期21卷 257-271页

作者： bo-Jing Feng Xi Cheng Hao-Nan xu Wen-Fang xue Center for Research on Intelligent Perception and Computing National Laboratory of Pattern RecognitionInstitute of AutomationChinese Academy of SciencesBeijing 100190China

order to help investors understand the credit status of target corporations and reduce investment risks,the corporate credit rating model has become an important evaluation tool in the financial *** models are based on statistical learning,machine learning and deep learning especially graph neural networks(GNNs).However,we found that only few models take the hierarchy,heterogeneity or unlabeled data into account in the actual corporate credit rating ***,we propose a novel framework named hierarchical heterogeneous graph neural networks(HHGNN),which can fully model the hierarchy of corporate features and the heterogeneity of relationships between *** addition,we design an adversarial learning block to make full use of the rich unlabeled samples in the financial *** experiments conducted on the public-listed corporate rating dataset prove that HHGNN achieves SOTA compared to the baseline methods.

关键词： Corporate credit rating hierarchical relation heterogeneous graph neural networks adversarial learning

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