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Influences of shale microstructure on mechanical properties and bedding fractures distribution

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Petroleum Science 2024年第3期21卷 1944-1954页

作者： Ming-Zhe Gu Mao sheng Shi-Zhong Cheng Fan-Hao Gong Gen-sheng li State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum-BeijingBeijing2249China College of Petroleum Engineering China University of Petroleum-BeijingBeijing102249China Shenyang Center of China Geological Survey ShenyangLiaoning110034China

The difference in microstructure leads to the diversity of shale mechanical properties and bedding fractures distribution *** this paper,the microstructure and mechanical properties of Longmaxi marine shale and Qingshankou continental shale were studied by X-ray diffractometer(XRD),field emission scanning electron microscope(FE-SEM)with mineral analysis system,and ***,the typical bedding layers area was properly stratified using Focused Ion Beam(FIB),and the effects of microstructure and mechanical properties on the distribution patterns of bedding fractures were *** results show that the Longmaxi marine shale sample contains more clay mineral grains,while the Qingshankou continental shale sample contains more hard brittle mineral grains such as *** Longmaxi marine shale sample,hard brittle minerals with grain sizes larger than 20μm is18.24%and those with grain sizes smaller than 20μm is 16.22%.For Qingshankou continental shale sample,hard brittle minerals with grain sizes larger than 20μm is 40.7%and those with grain sizes smaller than 20μm is 11.82%.In comparison to the Qingshankou continental shale sample,the Longmaxi marine shale sample has a lower modulus,hardness,and *** shales are formed by alternating coarse-grained and fine-grained layers during *** average single-layer thickness of Longmaxi marine shale sample is greater than Qingshankou continental shale *** two types of shale have similar bedding fractures distribution patterns and fractures tend to occur in the transition zone from coarse-grained to fine-grained *** orientation of the fracture is usually parallel to the bedding plane and detour occurs in the presence of hard brittle *** fracture distribution density of the Longmaxi marine shale sample is lower than that of the Qingshankou continental shale sample due to the strong heterogeneity of the Qingshankou continental *** current resea

关键词： Shale Nanoindentation Microstructure Mechanical property Fracture

Gut microbiota intervention attenuates thermogenesis in broilers exposed to high temperature through modulation of the hypothalamic 5‑HT pathway

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Journal of Animal Science and Biotechnology 2024年第2期15卷 679-698页

作者： sheng li Xiaoqing li Kai Wang Yansen li Kentaro Nagaoka Chunmei li Research Centre for livestock Environmental Control and Smart Production College of Animal Science and TechnologyNanjing Agricultural UniversityNanjing 210095China Laboratory of Veterinary Physiology Department of Veterinary MedicineFaculty of AgricultureTokyo University of Agriculture and TechnologyTokyo 183‑8509Japan

Background Broilers have a robust metabolism and high body temperature,which make them less tolerant to hightemperature(HT)environments and more susceptible to challenges from elevated *** microbes,functioning as symbionts within the host,possess the capacity to significantly regulate the physiological functions and environmental adaptability of the *** study aims to investigate the effects of gut microbial intervention on the body temperature and thermogenesis of broilers at different ambient temperatures,as well as the underlying mechanism involving the"gut-brain"*** Broilers were subjected to gut microbiota interference with or without antibiotics(control or ABX)starting at 1 day of *** 21 day of age,they were divided into 4 groups and exposed to different environments for 7 d:The control and ABX groups at room temperature(RT,24±1℃,60%relative humidity(RH),24 h/d)and the control-HT and ABX-HT groups at high temperature(HT,32±1℃,60%RH,24 h/d).Results The results demonstrated that the antibiotic-induced gut microbiota intervention increased body weight and improved feed conversion in broiler chickens(Pliver(Plistipes was enriched in control *** contrast,antibioticinduced gut microbiota intervention resulted in a decrease in the relative abundance of Alistipes(P<0.05).Moreover,this difference was accompanied by increased hypothalamic 5-hydroxytryptamine(5-HT)content and TPH2 expression(P<0.05).Conclus

关键词： 5-HT Broiler chickens Gut microbiota Thermogenesis Thermoregulation

A novel metal-free porous covalent organic polymer for efficient room-temperature photocatalytic CO2 reduction via dry-reforming of methane

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Green Energy & Environment 2024年第9期9卷 1407-1418页

作者： sheng-Yan Yin Ziyi li Yingcai Hu Xiao Luo Jishan li College of Chemistry and Chemical Engineering Hunan University Institute of Basic Medicine and Cancer (IBMC) Chinese Academy of Sciences

At room temperature,the conversion of greenhouse gases into valuable chemicals using metal-free catalysts for dry reforming of methane（DRM） is quite promising and ***,we developed a novel covalent organic porous polymer （TPE-COP） with rapid charge separation of the electron–hole pairs for DRM driven by visible light at room temperature,which can efficiently generate syngas （CO and H2）.Both electron donor (tris（4-aminophenyl）amine,TAPA) and acceptor (4,4',4'',4'''-(（1 E,1'E,1''E,1'''E）-(ethene-1,1,2,2-tetrayltetrakis （benzene-4,1-diyl）)tetrakis （ethene-2,1-diyl）)tetrakis (1-（4-formylbenzyl）quinolin-1-ium),TPE-CHO) were existed in TPE-COP,in which the push–pull effect between them promoted the separation of photogenerated electron–hole,thus greatly improving the photocatalytic *** functional theory （DFT） simulation results show that TPE-COP can form charge-separating species under light irradiation,leading to electrons accumulation in TPE-CHO unit and holes in TAPA,and thus efficiently initiating *** 20 h illumination,the photocatalytic results show that the yields reach 1123.6 and 30.8μmol g-1for CO and H2,respectively,which are significantly higher than those of TPE-CHO small *** excellent result is mainly due to the increase of specific surface area,the enhancement of light absorption capacity,and the improvement of photoelectron-generating efficiency after the formation of ***,this work contributes to understanding the advantages of COP materials for photocatalysis and fundamentally pushes metal-free catalysts into the door of DRM field.

关键词： Metal-free Photocatalytic CO 2 reduction Covalent organic polymer Dry-reforming of methane Electron donor and acceptor

Unconventional Fluorescent and Multi-responsive Polysiloxane:Synthesis,Characterization and Biological Applications

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Chinese Journal of Polymer Science 2024年第5期42卷 579-590,I0006页

作者： Xiao-Di li Shu-sheng li Xu-Bao Jiang Xiao-li Zhu Xiang Zheng Kong College of Chemistry and Chemical Engineering University of JinanJinan250022China College of Chemical Engineering Tianjin UniversityTianjin300072China Foshan(Southern China)Institute for New Materials Foshan528200China

Owing to their high significance in fundamental study and diverse applications,stimuli-responsive and fluorescent polymers,particularly those with cluster-triggered emission(CTE)featured by non-conjugated chromophores,have drawn tremendous attention in recent *** this work,fluorescent and multi-responsive polysiloxane(FRPS)was synthesized by hydrolytic condensation polymerization of 3-aminopropyl methyl diethoxysilane(APMS)with 3-(N-isopropyl propionamide)iminopropyl methyl diethoxysilane(APMS-NIP),which was formed in situ through aza-Michael addition between APMS and N-isopropyl *** was not only highly sensitive to temperature,pH and CO_(2) in water,but also showed an enhanced and stimuli-adjustable fluorescence *** effects of monomer feeding,pH and CO_(2) on its lower critical solution temperature and fluorescent property were *** fluorescence emission was ascribed to CTE *** addition,FRPS was shown to be highly potential as physiological indicator for cell imaging,and for controlled release and trace detection of *** study provides therefore a type of stimuli-responsive and fluorescent material for potential applications in biomedical fields,and it is also of great significance for understanding of the fluorescence mechanism of polysiloxane-based stimuli-responsive polymers.

关键词： Polysiloxane Multi-responsiveness Cluster-triggered emission Cell imaging Controlled drug release

Snowpack variations and their hazardous effects under climate warming in the central Tianshan Mountains

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Advances in Climate Change Research 2024年第3期15卷 442-451页

作者： Jian-sheng HAO Yan WANG Lan-Hai li Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences(CAS)Beijing 100101China Xinjiang Key Laboratory of Water Cycle and Utilization in Arid Zone Urumqi 830011China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Tianshan Snowcover and Avalanche Observation and Research Station of Xinjiang Xinyuan 835800China CAS Research Center for Ecology and Environment of Central Asia Urumqi 830011China

Climate change alters snowpack evolution,which in turn influences the likelihood of snow avalanches and flood *** lack of systemic observational data on key snow characteristics in high mountains remains a scientific challenge in terms of systematically elucidating the dynamic chain of variations in climate-snowpack-snow *** restricts our understanding and poses challenges in the prediction of snow-related disaster *** such,this study analysed the variations of temperature and snowfall and the physical characteristics of snowpacks based on ground-based observations from the Kunse River Valley situated in the Tianshan Mountains from 1967 to *** results reveal that the temperature increased significantly by 0.32°C per decade(plier ***,average and maximum snow depths increased along with an increase in peak snow water equivalent,thus indicating a higher frequency of extremely scarce or abundant snow *** low snowpack temperature gradient and earlier snowmelt dates in spring lead to earlier occurrences of snowmelt floods and wet *** the risks of these events increase,they pose greater threats to farmlands,road transportation,water-electricity infrastructure and several other human ***,these insights are critical for providing vital information that can deepen our understanding of the impact of climate change on snowpack characteristics and improve management strategies for snow-related disaster prevention and mitigation.

关键词： Climate change Snowpack variations Snow-related disaster Tianshan Mountains

Solvent-free carbon sphere nanofluids towards intelligent lubrication regulation

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Friction 2024年第1期12卷 95-109页

作者： sheng ZHANG Wen li Xiaoliang MA Xiaoqiang FAN Minhao ZHU Tribology Research Institute School of Mechanical EngineeringSouthwest Jiaotong UniversityChengdu 610031China Key Laboratory of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China

By simply switching the electrical circuit installed on steel/steel contact,the tribological behaviors of nanofluids(NFs)can be regulated in real time,thereby achieving the desired performance of friction reduction and wear ***,solvent-free carbon spherical nanofluids(C-NFs)were successfully prepared for intelligent lubrication regulation.C-NFs with excellent lubrication performance can immediately reduce the coefficient of friction(COF)despite applying a weak electric potential(1.5 V).Moreover,polyethylene glycol 400(PEG400)containing 5.0 wt%C-NFs remained responsive to electrical stimulation under the intermittent voltage application with an average coefficient of friction(ACOF)reduction of 20.8%over *** intelligent lubrication regulation of C-NFs under an external electric field(EEF)mainly depends on the orderly arranged double-electric adsorption film of ion canopy-adsorbed carbon spheres(CSs).The intermittent electrical application can continuously reinforce the adsorption film and its durability for real-time controlling the sliding ***-stimulation-responsive intelligent lubricants provide a new technical support for realizing intelligent stepless control of devices.

关键词： solvent-free carbon spherical nanofluids(C-NFs) intelligent lubrication regulation lubrication performance adsorption film

A CSMA/CA based MAC protocol for hybrid Power-line/Visible-light communication networks:Design and analysis

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Digital Communications and Networks 2024年第2期10卷 481-497页

作者： sheng Hao Huyin Zhang Fei Yang Chenghao li Jing Wang School of Computer Science Central China Normal UniversityWuhan430079PR China Hubei Key Laboratory of intelligent Robot(Wuhan Institute of Technology) Wuhan430079PR China School of Computer Science Wuhan UniversityWuhan430079China School of Information Science and Engineering Shandong Normal UniversityJinan250000China School of Computer Science Hubei University of TechnologyWuhan430079China

Hybrid Power-line/Visible-light Communication(HPVC)network has been one of the most promising Cooperative Communication(CC)technologies for constructing Smart Home due to its superior communication reliability and hardware *** research on HPVC networks focuses on the performance analysis and optimization of the Physical(PHY)layer,where the Power line Communication(PLC)component only serves as the backbone to provide power to light Emitting Diode(LED)*** designing a Media Access Control(MAC)protocol remains a great challenge because it allows both PLC and Visible light Communication(VLC)components to operate data transmission,i.e.,to achieve a true HPVC network *** solve this problem,we propose a new HPC network MAC protocol(HPVC MAC)based on Carrier Sense Multiple Access/Collision Avoidance(CSMA/CA)by combining IEEE 802.15.7 and IEEE 1901 ***,we add an Additional Assistance(AA)layer to provide the channel selection strategies for sensor stations,so that they can complete data transmission on the selected channel via the specified CSMA/CA mechanism,*** on this,we give a detailed working principle of the HPVC MAC,followed by the construction of a joint analytical model for mathematicalmathematical validation of the HPVC *** the modeling process,the impacts of PHY layer settings(including channel fading types and additive noise feature),CSMA/CA mechanisms of 802.15.7 and 1901,and practical configurations(such as traffic rate,transit buffer size)are comprehensively taken into ***,we prove the proposed analytical model has the ***,through extensive simulations,we characterize the HPVC MAC performance under different system parameters and verify the correctness of the corresponding analytical model with an average error rate of 4.62%between the simulation and analytical results.

关键词： Hybrid power-line/Visible light communication (HPVC)networks MAC protocol CSMA/CA IEEE 802.15.7 IEEE 1901 Performance analysis

Phosphine/Benzocyclone-based Neutral Nickel Catalysts for Ethylene Polymerization and Copolymerization with Polar Monomers

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Chinese Journal of Polymer Science 2024年第2期42卷 202-212,I0007页

作者： Fei Wang li Pan Vladislav A.Tuskaev Svetlana Ch.Gagieva Yue-sheng li Tianjin Key Lab of Composite&Functional Materials School of Material Science and EngineeringTianjin UniversityTianjin300072China Department of Chemistry Lomonosov Moscow State UniversityRussian Federation InstitutionLeninskie Gory 1Moscow119991Russian Federation A N Nesmeyanov Institute of Organoelement Compounds Russian Academy of SciencesVavilova st.28Moscow119991Russian Federation

The efficient copolymerization of olefin with polar monomers using nickel-based catalysts presents a longstanding challenge. In this contribution, three phosphine-benzocyclone ligands and corresponding neutral nickel catalysts(Ni1: Ar = Ph;Ni2: Ar = 2-(C_(6)H_(5))C_(6)H_(4);Ni3: Ar = 2-[2',6'-(Me O)_(2)-C_(6)H3]C_(6)H_(4)) were prepared and applied for the ethylene polymerization and copolymerization with polar monomers without any cocatalyst. The bulky substituent groups in complexes Ni2 and Ni3 contributed to high catalytic activities(up to 7.24×10^(6) and 9.04×10^(6)g·mol Ni^(-1)·h^(-1), respectively), and produced high-molecular-weight polyethylene(Mw up to 545.7 k Da). Complex Ni3 exhibited high activities for ethylene polymerization at the level of 10^(6) g·mol Ni^(-1)·h^(-1) across a wide range from 30 ℃ to 120 ℃, exhibiting excellent high temperature tolerance. These nickel complexes were also effectively employed in the copolymerization of ethylene with methyl acrylate, ethyl acrylate, butyl acrylate and lauryl acrylate, producing copolymers with high molecular weights(Mw up to 80.5 k Da) and high polar monomer incorporation(up to 8.2 mol%). Microstructure analyses revealed that the introduction of large sterically hindered substituents facilitated the incorporation of polar functional units into the polymer backbone. This study demonstrates the potential of these nickel-based catalysts for efficient copolymerization of olefin with polar monomers.

关键词： Neutral nickel catalyst Ethylene polymerization Copolymerization Polar acrylate monomers

The Multiple Roles of Autophagy in Neural Function and Diseases

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Neuroscience Bulletin 2024年第3期40卷 363-382页

作者： Yan-Yan li Zheng-Hong Qin Rui sheng Department of Pharmacology and Laboratory of Aging and Nervous Diseases Jiangsu Key laboratory of Neuropsychiatric DiseasesCollege of Pharmaceutical Sciences of Soochow UniversitySuzhou 215123China

Autophagy involves the sequestration and delivery of cytoplasmic materials to lysosomes,where proteins,lipids,and organelles are degraded and *** to the way the cytoplasmic components are engulfed,autophagy can be divided into macroautophagy,microautophagy,and chaperone-mediated ***,many studies have found that autophagy plays an important role in neurological diseases,including Alzheimer's disease,Parkinson's disease,Huntington's disease,neuronal excitotoxicity,and cerebral *** maintains cell homeostasis in the nervous system via degradation of misfolded proteins,elimination of damaged organelles,and regulation of apoptosis and ***-mTOR,Beclin 1,TP53,endoplasmic reticulum stress,and other signal pathways are involved in the regulation of autophagy and can be used as potential therapeutic targets for neurological ***,we discuss the role,functions,and signal pathways of autophagy in neurological diseases,which will shed light on the pathogenic mechanisms of neurological diseases and suggest novel targets for therapies.

关键词： Autophagy Neurodegenerative diseases Cerebral ischemia AMPK mTOR Beclin 1 TP53 Endoplasmic reticulum stress