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Effects of Atmospheric Pressure on Developmental Characteristics and the Stability of Air Entraining Agent for Concrete

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 979-989页

作者：李立辉牛开民 TIAN Bo CHEN Xin FU Ziqian ZHU Xuwei School of Civil Engineering Chongqing Jiaotong UniversityChongqing 400074China Transportation Science and Engineering Harbin Institute of TechnologyHarbin 150090China Research Institute of highway Ministry of TransportBeijing 100088China

In order to ascertain the effects of atmospheric pressure on developmental characteristics and the stability of AEA(air-entraining agent)solution bubbles,AEA solution experiments and AEA solution bubble experiments were,respectively,conducted in Peking(50 m,101.2 kPa)and Lhasa(3,650 m,63.1 kPa).Surface tensions and inflection-point concentrations were tested based on AEA solutions,whilst developmental characteristics,thicknesses and elastic coefficients of liquid films were tested based on air bubbles of AEA *** study involved three types of AEAs,which were TM-O,226A,and *** experimental results show that initial sizes of TM-O,226A,and 226S are,respectively,increased by 43.5%,17.5%,and 3.8%.With the decrease of ambient pressure,the drainage rate and the drainage index of AEA solution bubbles *** experiments show that the liquid film thicknesses of all tested AEA solution bubbles are in micron *** the atmospheric pressure decreases from 101.2 to 63.1 kPa,the liquid film thicknesses of three types of AEA solutions decrease in various degrees;and film elasticities at critical thicknesses *** film of 226S solution bubbles is the most stable,presenting as a minimum thickness *** should be noted that elastic coefficient of liquid film only represents the level at critical thickness,thus it can not be applied as the only evaluating indicator of bubble *** a type of AEA,factors affecting the stability of its bubbles under low atmospheric pressure include initial bubbles size,liquid film thickness,liquid film elasticity,ambient temperature,etc.

关键词： air-entraining agent surface tension bubble size liquid film thickness liquid film elasticity atmospheric pressure

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Dynamic Stability and Fuzzy Reliability Analysis of Toppling Perilous Rock Under Seismic Excitation

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Journal of Earth Science 2024年第1期35卷 248-262页

作者： Linfeng Wang Jixu Zhang Wanchun Xia Xiaoming Huang Guojin Tan Key Laboratory of Geological Hazards Mitigation for Mountainous highway and Waterway Chongqing Jiaotong UniversityChongqing 400074China School of Transportation Southeast UniversityNanjing 211189China College of Transportation Jilin UniversityChangchun 130012China

To predict the occurrence of the collapse disaster in toppling perilous rock under the action of bidirectional earthquakes,the dynamic stability and fuzzy reliability calculation method of toppling perilous rock under the action of bidirectional earthquakes is ***,the mass viscoelasticity model is used to simulate two main control surfaces of toppling perilous rock,the seismic dynamic response model and motion equation of toppling perilous rock are established based on the D'Alembert principle,and the Newmark-β method is used to solve the dynamic motion ***,the instability event of toppling perilous rock is considered a fuzzy event,the membership function expression of the stability coefficient of toppling perilous rock is determined based on the fuzzy failure criterion,the calculation equations of the toppling perilous rock dynamic stability coefficient and fuzzy reliability are established,and the fuzzy reliability evaluation method based on the probability distribution of reliability is ***,the influence of different superposition modes of seismic excitation on the fuzzy reliability of toppling perilous rock is *** calculation results of toppling perilous rock in the engineering case show that the fuzzy reliability calculated after considering the fuzzy failure criterion is reduced by 10.73% to 25.66% compared with the classical *** the bidirectional seismic excitation,the fuzzy reliability of toppling perilous rock is reduced by 5.46% to 14.89%.Compared with using the acceleration peak time encounter mode to superpose the seismic excitation,the fuzzy reliability of toppling perilous rock is reduced by 3.4% when the maximum action effect time encounter mode is adopted.

关键词： toppling perilous rock bidirectional earthquake fuzzy failure criterion dynamic stability fuzzy reliability Newmark-βmethod probability distribution function

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Stratigraphic framework and sedimentary evolution during the Cryogenian-Ediacaran transition in northeastern Sichuan Basin,South China

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Petroleum Science 2024年第2期21卷 823-835页

作者： Yi Zhang Hong-Wei Kuang Yong-Qing Liu Qiang Shi Dong-Ge Wang Ke-Ning Qi Yu-Chong Wang Da-Wei Qiao Xiao-Shuai Chen Li-Zhi Wu Meng Tian Long Chen Yi Wei Liao-Yuan Song Jian Li Zi-Gang Wu Yun-Qian Liu Xuan-Chun Liu An-Qing Chen Zhi-Wei Liao Institute of Geology Chinese Academy of Geological SciencesBeijing100037China State Key Laboratory of Coal Mine Disaster Dynamics and Control School of Resources and Safety EngineeringChongqing UniversityChongqing400044China No.205 Geological Team Chongqing Bureau of Geology and Minerals ExplorationChongqing401121China chongqing Institute of Geological Survey Chongqing401122China Key Laboratory of Deep-time Geography and Environment Reconstruction and Applications of Ministry of Natural Resources Chengdu University of TechnologyChengdu610059SichuanChina

The northeastern Sichuan area in the northern Yangtze margin has unique Ediacaran geological records,especially the Doushantuo Formation(DST),and become a hot research area in recent ***,the Cryogenian-Ediacaran(C-E)boundary has not been precisely identified,which restricts the in-depth study of geological information during this crucial transitional period and is unfavorable for a systematic and complete understanding of the Yangtze Block and even the global paleogeographic *** study conducted stratigraphy,sedimentology,and chronostratigraphy to establish the stratigraphic framework and sedimentary evolution of the C-E transition strata in northeastern *** results showed that the Ediacaran sediments,without the cap dolomite,unconformably overlaid the Cryogenian sediments in the studied *** Member II of the DST,characterized by 50-160 m of red-green sandstone(approximately equivalent to the original Chengkou“Guanyinya Formation”),directly overlaid the Cryogenian sediments and displayed a 623±2.3 Ma maximum depositional age from the detrital zircon U-Pb *** stratigraphic correlations indicate that the C-E transition strata in northeastern Sichuan had a consistent lithological association and sedimentary sequence characteristics but differed from the Three ***,the upper Nantuo massive glacial diamictites transition to the icebergs rafted lonestone-bearing mudstones at the top,then change upward to DST barrier coast *** proposed DST of the northeastern Sichuan Basin was divided into three lithostratigraphic members without the regional Member I cap dolomite:(i)Member II purple-red,gray-green sandstone strata,(ii)MemberⅢblack mudstone strata,and(iii)Member IV P-Mn bearing *** the C-E transition,the study area experienced(i)the global deglaciation stage in the terminal Marinoan glaciation and(ii)the filling-leveling up stage with clastic rocks in the early ***,the early Ediacaran

关键词： Marinoan glaciation Doushantuo formation Cap dolomite Deglacial and coastal deposits Detrital zircon U-Pb dating

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Octopus-like DNA nanostructure coupled with graphene oxide enhanced fluorescence anisotropy for hepatitis B virus DNA detection

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Chinese Chemical Letters 2024年第6期35卷 531-535页

作者： Jia-Li Xie Tian-Jin Xie Yu-Jie Luo Kai Mao Cheng-Zhi Huang Yuan-Fang Li Shu-Jun Zhen Key Laboratory of Luminescence Analysis and Molecular Sensing(Southwest University) Ministry of EducationCollege of Chemistry and Chemical EngineeringSouthwest UniversityChongqing 400715China Key Laboratory of Luminescent and Real-Time Analytical Chemistry(Southwest University) Chongqing Science and Technology BureauCollege of Pharmaceutical SciencesSouthwest UniversityChongqing 400715China

Fluorescence Anisotropy(FA)is an effective biochemical detection method based on molecular *** oxide(GO)has been extensively used as an FA ***,the enhancement of FA by GO alone is limited and the strong scattering of GO will easily make the measurement of FA *** order to address these problems,an octopus-like DNA nanostructure(ODN)was designed and coupled with GO to enhance the FA together in this *** mimicking the multi-clawed structure of the octopus,the ODN can be adsorbed on GO tightly,which not only could improve the sensitivity because of the double FA enhancement abilities of GO and ODN,but also could improve the specificity due to the decrease of the nonspecific interaction in complex ***,ODN could maintain a certain distance between the fluorophore and GO to reduce the fluorescence quenching efficiency of GO,which could improve the *** method has been applied for the detection of hepatitis B virus DNA(HBV-DNA)in a range of 1-50 nmol/L and the limit of detection(LOD)was 330 pmol/*** addition,the proposed method has been successfully utilized to detect HBV-DNA in human serum,indicating that this method has a great practical application prospect.

关键词： Fluorescence anisotropy Graphene oxide(GO) Octopus-like DNA nanostructure HBV-DNA

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Recent advances in electrochemical performance of Mg-based electrochemical energy storage materials in supercapacitors:Enhancement and mechanism

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Journal of Magnesium and Alloys 2024年第1期12卷 35-58页

作者： Yuntao Xiao Xinfang Zhang Can Wang Jinsong Rao Yuxin Zhang College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

The application of Mg-based electrochemical energy storage materials in high performance supercapacitors is an essential step to promote the exploitation and utilization of magnesium resources in the field of energy ***,the inherent chemical properties of magnesium lead to poor cycling stability and electrochemical reactivity,which seriously limit the application of Mg-based materials in ***,in this review,more than 70 research papers published in recent 10 years were collected and *** representative research works were selected,and the results of various regulative strategies to improve the electrochemical performance of Mg-based materials were *** effects of various regulative strategies(such as constructing nanostructures,synthesizing composites,defect engineering,and binder-free synthesis,etc.)on the electrochemical performance and their mechanism are demonstrated using spinelstructured MgX_(2)O_(4) and layered structured Mg-X-LDHs as *** addition,the application of magnesium oxide and magnesium hydroxide in electrode materials,MXene's solid spacers and hard templates are ***,the challenges and outlooks of Mg-based electrochemical energy storage materials in high performance supercapacitors are also discussed.

关键词： Supercapacitor Electrochemical energy storage Mg-based materials

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Vibration attenuation performance of wind turbine tower using a prestressed tuned mass damper under seismic excitation

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 511-524页

作者： Lei Zhenbo Liu Gang Wang Hui Hui Yi School of Civil Engineering Chongqing UniversityChongqing 400045China Key Laboratory of New Technology for Construction of Cities in Mountain Area Chongqing UniversityMinistry of EducationChongqing 400045China

With the rapid development of large megawatt wind turbines,the operation environment of wind turbine towers(WTTs)has become increasingly *** particular,seismic excitation can create a resonance response and cause excessive vibration of the *** investigate the vibration attenuation performance of the WTT under seismic excitations,a novel passive vibration control device,called a prestressed tuned mass damper(PS-TMD),is presented in this ***,a mathematical model is established based on structural dynamics under seismic ***,the mathematical analytical expression of the dynamic coefficient is deduced,and the parameter design method is obtained by system tuning ***,based on a theoretical analysis and parameter design,the numerical results showed that the PS-TMD was able to effectively mitigate the resonance under the harmonic basal ***,the time-history analysis method is used to verify the effectiveness of the traditional pendulum tuned mass damper(PTMD)and the novel PS-TMD device,and the results indicate that the vibration attenuation performance of the PS-TMD is better than the *** addition,the PS-TMD avoids the nonlinear effect due to the large oscillation angle,and has the potential to dissipate hysteretic energy under seismic excitation.

关键词： wind turbine tower prestressed tuned mass damper vibration control seismic excitation numerical simulation

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Highly efficient recognition of similar objects based on ionic robotic tactile sensors

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Science Bulletin 2024年第13期69卷 2089-2098页

作者： Yongkang Kong Guanyin Cheng Mengqin Zhang Yongting Zhao Wujun Meng Xin Tian Bihao Sun Fuping Yang Dapeng Wei chongqing Key Laboratory of Generic Technology and System of Service Robots Chongqing Institute of Green and Intelligent TechnologyChinese Academy of SciencesChongqing 400714China School of Computer Science and Technology Chongqing University of Posts and TelecommunicationsChongqing 400065China

Tactile sensing provides robots the ability of object recognition,fine operation,natural interaction,***,in the actual scenario,robotic tactile recognition of similar objects still faces difficulties such as low efficiency and accuracy,resulting from a lack of high-performance sensors and intelligent recognition *** this paper,a flexible sensor combining a pyramidal microstructure with a gradient conformal ionic gel coating was demonstrated,exhibiting excellent signal-to-noise ratio(48 dB),low detection limit(1 Pa),high sensitivity(92.96 kPa^(-1)),fast response time(55 ms),and outstanding stability over 15,000 compression-release ***,a Pressure-Slip Dual-Branch Convolutional Neural Network(PSNet)architecture was proposed to separately extract hardness and texture features and perform feature *** tactile experiments on different kinds of leaves,a recognition rate of 97.16%was achieved,and surpassed that of human hands recognition(72.5%).These researches showed the great potential in a broad application in bionic robots,intelligent prostheses,and precise human–computer interaction.

关键词： Tactile recognition Conformal ionic gel coating Flexible sensors Dual-branch convolutional neural network

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Precise construction of RuPt dual single-atomic sites to optimize oxygen electrocatalytic behaviors for high-performance Zn-air batteries

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Journal of Energy Chemistry 2024年第10期97卷 520-528页

作者： Xiaolin Hu Zhenkun Wu Chaohe Xu School of Science Chongqing Key Laboratory of New Energy Storage Materials and Devices Chongqing University of Technology School of Chemistry and Engineering Chongqing University College of Materials Science and Engineering Chongqing University

The development of redox bifunctional electrocatalysts with high performance,low cost,and long lifetimes is essential for achieving clean energy *** study proposed an atom capture strategy for anchoring dual single atoms（DSAs） in a zinc-zeolitic imidazolate framework（Zn-ZIF）,followed by calcination under an N2atmosphere to synthesize ruthenium-platinum DSAs supported on a nitrogendoped carbon substrate（RuPt DSAs-NC）.Theoretical calculations showed that the degree of Ru 5dxz-*O 2pxorbital hybridization was high when*O was adsorbed at the Ru site,indicating enhanced covalent hybridization of metal sites and oxygen ligands,which benefited the adsorption of intermediate *** presence of the RuPtN6active center optimized the absorption-desorption behavior of intermediates,improving the electrocatalytic performance of the oxygen reduction reaction（ORR） and the oxygen evolution reaction（DER）,RuPt DSAs-NC exhibited a 0.87 V high half-wave potential and a 268 mV low overpotential at 10 mA cm-2in an alkaline ***,rechargeable zinc-air batteries（ZABs）achieved a peak power density of 171 MW *** RuPt DSAs-NC demonstrated long-term cycling for up to 500 h with superior round-trip *** study provided an effective structural design strategy to construct DSAs active sites for enhanced electrocata lytic performance.

关键词： Atom capture Dual single atoms catalysts Oxygen evolution reaction Oxygen reduction reaction Rechargeable Zn-air batteries

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New therapeutic target NCF1-directed multi-bioactive conjugate therapies prevent preterm birth and adverse pregnancy outcomes

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Science Bulletin 2024年第16期69卷 2604-2621页

作者： Juan Cheng Xiaoyan Jia Limei Yang Siqi Zhang Zhiyu Chen Qian Gui Ting Li Zedan Pu Hongbo Qi Jianxiang Zhang chongqing Key Laboratory of Maternal and Fetal Medicine The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China Women and Children’s Hospital of chongqing Medical University Chongqing 401147China Department of Obstetrics The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China Department of Pharmaceutics College of PharmacyThird Military Medical University(Army Medical University)Chongqing 400038China Department of Orthopedics The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China Yu-Yue Pathology Scientific Research Center Chongqing 400039China State Key Laboratory of Trauma and Chemical Poisoning Third Military Medical University(Army Medical University)Chongqing 400038China

Preterm birth(PTB)is a leading cause of neonatal morbidity and mortality worldwide,yet the cellular and molecular mechanisms driving this condition remain undeciphered,thus limiting discovery of new ***-depth analyses of human and mouse tissues associated with PTB,in combination with cellular studies,indicated that aberrantly high-expressed neutrophil cytoplasmic factor(NCF)1 leads to oxidative distress,recruitment,and pro-inflammatory activation of neutrophils and macrophages,while sequentially overexpressed pro-inflammatory mediators induce contractions of uterine smooth muscle cells(USMCs)as well as apoptosis of USMCs and amniotic epithelial cells,thereby causing *** to these new findings,we rationally engineered an amphiphilic macromolecular conjugate LPA by covalently integrating low-molecular-weight heparin,a reactive oxygen species-responsive/scavenging component,and an anti-inflammatory *** bioengineered macromolecular conjugate can selfassemble into multi-bioactive nanoparticles(LPA NP).In a mouse model of PTB,LPA NP effectively delayed PTB and inhibited adverse pregnancy outcomes,by regulating NCF1-mediated oxidativeinflammatory cascades,i.e.,attenuating oxidative stress,inhibiting inflammatory cell activation,reducing local inflammation,and decreasing contraction/apoptosis of myometrial *** LPA NP into temperature-responsive,self-healing,and bioadhesive hydrogel further potentiated its in vivo efficacies after intravaginal delivery,by prolonging retention time,sustaining nanotherapy release,and increasing bioavailability in the placenta/***,both the conjugate/nanotherapy and hydrogel formulations exhibited excellent safety profiles in pregnant mice,with negligible side effects on the mother and offspring.

关键词： Preterm birth Neutrophil cytoplasmic factor Bioactive conjugate Nanotherapy Hydrogel therapy

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Health risk assessment of trace metal(loid)s in agricultural soils based on Monte Carlo simulation coupled with positive matrix factorization model in chongqing, southwest China

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Journal of Mountain Science 2024年第1期21卷 100-112页

作者： MA Jie CHU Lijuan SUN Jing WANG Shenglan GE Miao DENG Li chongqing Ecological and Environmental Monitoring Center Chongqing 401147China Key Laboratory of Organic Pollutants in Environmental Chemical Behavior and Ecological Toxicology of chongqing Chongqing 401147China Department of Pediatrics Chongqing Health Center for Women and ChildrenChongqing 401147China Department of Pediatrics Women and Children’s Hospital of Chongqing Medical UniversityChongqing 401147China

This study aimed to investigate the pollution characteristics, source apportionment, and health risks associated with trace metal(loid)s(TMs) in the major agricultural producing areas in chongqing, China. We analyzed the source apportionment and assessed the health risk of TMs in agricultural soils by using positive matrix factorization(PMF) model and health risk assessment(HRA) model based on Monte Carlo simulation. Meanwhile, we combined PMF and HRA models to explore the health risks of TMs in agricultural soils by different pollution sources to determine the priority control factors. Results showed that the average contents of cadmium(Cd), arsenic (As), lead(Pb), chromium(Cr), copper(Cu), nickel(Ni), and zinc(Zn) in the soil were found to be 0.26, 5.93, 27.14, 61.32, 23.81, 32.45, and 78.65 mg/kg, respectively. Spatial analysis and source apportionment analysis revealed that urban and industrial sources, agricultural sources, and natural sources accounted for 33.0%, 27.7%, and 39.3% of TM accumulation in the soil, respectively. In the HRA model based on Monte Carlo simulation, noncarcinogenic risks were deemed negligible(hazard index <1), the carcinogenic risks were at acceptable level(10^(-6)

关键词： Monte Carlo simulation Health risk assessment Trace metal(loid)s Positive matrix factorization Agricultural soils

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