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Exploring the potential of olivine-containing copper-nickel slag for carbon dioxide mineralization in cementitious materials

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International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 562-573页

作者： Qianqian Wang Zequn Yao Lijie Guo Xiaodong Shen College of Materials Science and Engineering Nanjing Tech UniversityNanjing 211816China State Key Laboratory of Materials-Oriented Chemical Engineering Nanjing 211816China BGRIMM Technology group Beijing 100160China

Water-quenched copper-nickel metallurgical slag enriched with olivine minerals exhibits promising potential for the production of CO_(2)-mineralized cementitious *** this work,copper-nickel slag-based cementitious material(CNCM)was synthesized by using different chemical activation methods to enhance its hydration reactivity and CO_(2) mineralization *** water curing ages and carbonation conditions were explored related to their carbonation and mechanical properties ***,thermogravimetry differential scanning calorimetry and X-ray diffraction methods were applied to evaluate the CO_(2) adsorption amount and carbonation products of *** development of carbonated CNCM blocks was examined by backscattered electron imaging(BSE)with energy-dispersive X-ray *** showed that among the studied samples,the CNCM sample that was subjected to water curing for 3 d exhibited the highest CO_(2) sequestration amount of 8.51wt%at 80℃and 72 h while presenting the compressive strength of 39.07 *** result indicated that 1 t of this CNCM can sequester 85.1 kg of CO_(2) and exhibit high compressive *** the addition of citric acid did not improve strength development,it was beneficial to increase the CO_(2) diffusion and adsorption amount under the same carbonation conditions from BSE *** work provides guidance for synthesizing CO_(2)-mineralized cementitious materials using large amounts of metallurgical slags containing olivine minerals.

关键词： copper-nickel slag fayalite CO_(2)sequestration cementitious material admixtures carbonation conditions

Three-dimensional parametric contact analysis of planetary roller screw mechanism and its application in grouping for selective assembly

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Frontiers of Mechanical Engineering 2024年第1期19卷 53-72页

作者： Huilin HE Peitang WEI Huaiju LIU Xuesong DU Rui HU Genshen LIU Yajun WU State Key Laboratory of Mechanical Transmission for Advanced Equipment Chongqing UniversityChongqing 400044China Taiyuan Heavy Machinery group Co. Ltd.Taiyuan 030024China

The planetary roller screw mechanism(PRSM)is a novel precision transmission mechanism that realizes the conversion between linear and rotary *** contact characteristics of helical surfaces directly determine PRSM’s performance in load-carrying capacity and transmission ***,studying the contact characteristics of PRSM forms the fundamental basis for enhancing its transmission *** this study,a three-dimensional parametric analysis method of contact characteristics is proposed based on the PRSM meshing principle and PyVista(a high-level API to the Visualization Toolkit).The proposed method considers the influence of machining errors among various thread *** effects of key machining errors on contact positions and axial clearance,as well as their sensitivities,are *** excellent solution accuracy,this method exhibits higher calculation efficiency and stronger robustness than the analytical and numerical meshing *** influence of nominal diameter and pitch errors of the screw,roller,and nut on the axial clearance follows a linear relationship,whereas flank angle errors have negligible effects on the axial *** corresponding influence coefficients for these three machining errors on the axial clearance are 0.623,0.341,and *** variations in contact positions caused by individual errors are *** angle errors and roller diameter errors result in linear displacements of the contact points,whereas pitch errors cause the contact points to move along the arc of the roller *** on the proposed threedimensional parametric contact characteristics analysis method,the Fuzzy C-Means clustering algorithm considering error sensitivity is utilized to establish a component grouping technique in the selective assembly of critical PRSM components,ensuring the rational and consistent clearances based on the given component’s machining *** study provides effective guidance for analyzing conta

关键词： planetary roller screw mechanism(PRSM) contact position axial clearance machining error grouping for selective assembly

Pavement Pothole Detection System Based on Deep Learning and Binocular Vision

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Journal of Traffic and Transportation Engineering(English Edition) 2024年

作者： Tian Guan Jianyuan Cai Yu Wang Wei Yang Xiaobo Chang Yi Han School of Automobile， Chang'an University China National Heavy Duty Truck group Company Limited

Due to strong vibrations and the impact on high-speed vehicles， road potholes may cause discomfort to passengers， damaging the durability of the suspension and the integrity of the cargo. Therefore， a road pothole detection system is proposed， which uses deep learning and binocular vision for precise detection in the front. Based on the impact of road surface potholes on human driving behavior decisions of manually driven vehicles， which can cause drivers to slow down or stop， change driving routes， or even increase accident risks， road surface potholes can be divided into three categories: severe potholes (deep and large potholes)， non damaged road surfaces (flat surfaces without obvious potholes or damage)， and completely damaged road surfaces (there may be large areas of potholes， cracks， or other structural damage). 6848 road surface pit condition recognition datasets were constructed using a vehicle mounted binocular camera. group attention shuffling block (CASB) is designed to enhance the expression of channel and spatial feature information in road images， while improving the existing shuffling network (ShuffleNetv2). This establishes a ShuffleNetv2 (CASB ShuffleNetv2) model based on mixed attention for identifying the state of road potholes. The experimental results show that the model has better accuracy than the basic model and can effectively detect road potholes. Due to the varying sizes of potholes on the road surface， small potholes may only require slight avoidance， while large potholes may cause serious vehicle damage. And there are different visual effects on the vertical distance of the pit. To address the aforementioned issues， the LabelImg image annotation tool was used to manually annotate the pothole areas， in order to construct a dataset for detecting 2029 road pothole areas. We replaced the ordinary convolution in the CenterNet feature extraction network with pyramid convolution with multiple receptive fields， and designed a feature fusion mo

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Thermodynamic property of sandwich cylindrical shell structure with metallic wire mesh:Numerical modeling and experimental analysis

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Chinese Journal of Aeronautics 2024年第1期37卷 138-152页

作者： Xin XUE Guojian SHEN Juan LIAO Institute of Metal Rubber&Vibration Noise School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou 350116China Fujian Shuikou Power Generation group Co. LTDFuzhou 350000China

As a new addition to lightweight composite structures,the sandwich cylindrical shell with a metallic wire mesh core has emerged as a promising solution for thermodynamic performance analysis at elevated *** intricate interwoven cellular formations within the metallic wire mesh pose difficulties for thermo-mechanical modeling and property ***,the constitutive models employed to characterize hysteresis phenomena were presented,comprising isotropic elasticity,Bergstrom-Boyce model,Ogden hyper-elasticity,and parameter identification through mechanical examinations at varying ***,the finite element modeling of cylindrical shell structures was determined for modal and steady-state dynamic ***,the experimental procedures were carried out,including the preparation of the sandwich cylindrical shell and the dynamic testing *** first-order natural frequency of the cylindrical shell structure is close to the resonance frequency of the dynamic test results,with a maximum error of 6.5%,demonstrating the accuracy of the simulation *** compared to the solid-core cylindrical shell,the average insertion loss of the sandwich cylindrical shell structure within the frequency range of 10–1000 Hz at room temperature is up to 11.09 ***,at elevated temperatures,the average insertion loss of the sandwich cylindrical shell decreases but fluctuates as the temperature changes.

关键词： Energy dissipation Metallic matrix composites Numerical analysis Sandwich structure Thermodynamic properties

Pollen analysis reveals the effects of uncovered interactions,pollen-carrying structures,and pollinator sex on the structure of wild bee-plant networks

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Insect Science 2024年第3期31卷 971-988页

作者： Clément Tourbez Carmelo Gómez-Martínez MiguelÁngel Gonzalez-Estévez Amparo Lazaro Mediterranean Institute for Advanced Studies(UIB-CSIC) Global Change Research GroupEsporlesBalearic IslandsSpain Department of Biology Ecology AreaUniversity of the Balearic/slandsPalmaSpain

Pollination networks are increasingly used to model the complexity of interactions between pollinators and flowering plants in *** methods exist to sample these interactions,with direct observations of plant-pollinator contacts in the field being by far the most *** the identification of pollen carried by pollinators allows uncovering interactions and increasing sample sizes,the methods used to build pollen-transport networks are variable and their effect on network structure remains *** understand how interaction sampling influences the structure of networks,we analyzed the pollen found on wild bees from eight communities across Mallorca Island and investigated the differences in pollen loads between bee body parts(scopa ***)and *** then assessed how these differences,as well as the uncovered interactions not detected in the field,influenced the structure of wild bee-plant *** identified a higher quantity and diversity of pollen in the scopa than in the rest of the female body,but these differences did not lead to differences in structure between plant-pollination(excluding scopa pollen)and bee-feeding interaction(including scopa pollen)***,networks built with pollen data were richer in plant species and interactions and showed lower modularity and specialization(H2'),and higher nestedness than visitation networks based on field *** interactions with plants were stronger compared to those of males,although not ***,females were more generalist(low d')and tended to be more central in interaction networks,indicating their more key role structuring pollination networks in comparison to *** study highlights the importance of palynological data to increase the resolution of networks,as well as to understand important ecological questions such as the differences between plant-pollination and bee-feeding interaction networks,and the role of sexes in pollination.

关键词： palynology pollen-transport networks pollination role of bee sexes sampling methodology visitation networks

Universal Hyperthermal Model for Mass Extinctions

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Journal of Earth Science 2024年第2期35卷 704-707页

作者： Michael J.Benton Paleobiology Research group School of Earth SciencesUniversity of BristolLife Sciences BuildingTyndall AvenueBristolBS81TQUK

INTRODUCTION Earth scientists have long sought universal features of past extinction *** can be argued that each past extinction event was a singularity,caused by combinations of circumstances that are unique in each case,and therefore that the search for common causes is ***,a key feature of the uniformitarian approach to geology is that past processes are the same as modern-day processes and,with that in mind,earth scientists are keen to use their knowledge to contribute some understanding to the study of the present and future climate crisis.

关键词： extinction singularity Extinction

Individual consistency in spatiotemporal characteristics of migratory Whimbrels in the East Asian-Australasian Flyway

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Avian Research 2024年第3期15卷 308-315页

作者： Siwei An Fenliang Kuang Wei Wu Chris J.Hassell Jonathan T.Coleman Zijing Gao Xuena Sun Yue Yuan Grace Maglio Kar-Sin K.Leung Xuesong Feng Zhijun Ma Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering Coastal Ecosystems Research Station of the Yangtze River EstuaryInstitute of Biodiversity ScienceSchool of Life SciencesFudan UniversityShanghai200433China School of Chemistry and Environment Yunnan Minzu UniversityKunming650504China Shanghai Chongming Dongtan Nature Reserve Administration Center ChongmingShanghai202183China Global Flyway Network PO Box 3089BroomeWA 6725Australia Australasian Wader Studies group BroomeWA6725Australia Queensland Wader Study group Shailer ParkQLD4128Australia Hong Kong Waterbirds Ringing group Hong Kong999077China

Many migratory birds exhibit interannual consistency in migration schedules,routes and stopover *** the interannual consistency in spatiotemporal characteristics helps understand the maintenance of migration and enables the implementation of targeted conservation *** tracked the migration of Whimbrel(Numenius phaeopus)in the East Asian-Australasian Flyway and collected spatiotemporal data from individuals that were tracked for at least two *** non-parametric tests were used to compare the interannual variations in the dates of departure from and arrival at breeding/nonbreeding sites,and the inter-annual variation in the longitudes when the same individual across the same *** exhibited a high degree of consistency in the use of breeding,nonbreeding,and stopover sites between *** variation of arrival dates at nonbreeding sites was significantly larger than that of the departure dates from nonbreeding and breeding *** used stopover sites by the same individuals in multiple years were concentrated in the Yellow Sea coast during northward migration,but were more widespread during southward *** stopover duration at repeatedly used sites was significantly longer than that at sites used only *** flying across the Yellow Sea,Whimbrels breeding in Sakha(Yakutia)exhibited the highest consistency in migration routes in both autumn and ***,the consistency in migration routes of Yakutia breeding birds was generally higher than that of birds breeding in *** results suggest that the northward migration schedule of the Whimbrels is mainly controlled by endogenous factors,while the southward migration schedule is less affected by endogenous *** repeated use of stopover sites in the Yellow Sea coast suggests this region is important for the migration of Whimbrel,and thus has high conservation value.

关键词： Consistency Migration route Migration timing Shorebird

The organic geochemistry of crude oil in the Saltpond Basin(Ghana):Organic source input,depositional environment,and thermal maturity

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Acta Geochimica 2024年第3期43卷 424-440页

作者： Kojo Amoako Ningning Zhong Nancy Pearl Osei-Boakye Ebenezer Apesegah Research group for Marine Geochemistry(ICBM-MPI Bridging group) Institute for Chemistry and Biology of the Marine Environment(ICBM)School of Mathematics and ScienceCarl von Ossietzky UniversitäOldenburgAmmerläder HeerstraВ114-11826129 OldenburgGermany State Key Laboratory of Petroleum Resources and Prospecting College of GeosciencesChina University of PetroleumBeijing 102249China Petroleum Corporation GNPCPMBPetroleum HouseTemaGhana

The Saltpond Basin,situated within the South Atlantic margin of Ghana,is a significant area for petro-leum exploration but has received relatively limited research *** studies have examined source rock com-position,but data on crude oil organic chemistry are lack-ing,hindering understanding of the basin’s petroleum system and *** address this gap,we analyzed biomarkers and stable carbon-isotope ratios in Saltpond Basin crude oil using gas chromatography–mass spectrometry and gas chromatography–isotope ratio mass spectrometry to eluci-date organic matter source,depositional environment,and thermal *** were compared with oils from the West African segment of the South Atlantic margin,namely the Tano Basin and the Niger Delta Basin,to iden-tify potential correlations and gain insights into regional *** and isotopic results unveiled a sig-nificant prevalence of organic matter derived from lower marine *** of organic matter deposition and preservation in Saltpond oil samples suggested a suboxic marine transitional environment,contradicting conventional understanding of terrestrial dominance in such ***,the potential for degradation processes to obscure differentiation between terrestrial and marine organic mat-ter origins underscores the complex nature of organic mat-ter dynamics in transitional marine *** of molecular thermal maturity indices suggested Saltpond oils were expelled from source rocks exhibiting thermal maturity at the early maturity *** analysis unveiled genetic disparities among crude oils sourced from the Saltpond Basin and those from the Tano and Niger Delta Basin,primarily due to variations in source input and depo-sitional environment *** oil exhibits lower terrestrial organic input than Tano Basin’s crude oils,which also have less terrestrial input than Niger Delta Basin crude ***,its paleodepositional envi

关键词： Biomarkers Carbon isotopes Crude oil Saltpond Basin Ghana

Flower-like tin oxide membranes with robust three-dimensional channels for efficient removal of iron ions from hydrogen peroxide

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Chinese Journal of Chemical Engineering 2024年第1期65卷 1-7页

作者： Risheng Shen Shilong Li Yuqing Sun Yuan Bai Jian Lu Wenheng Jing State Key Laboratory of Materials-Oriented Chemical Engineering Nanjing Tech UniversityNanjing 210009China National Energy group Science and Technology Research Institute Co. Ltd.Nanjing 210023China

Membrane technology has become the mainstream process for the production of electronic grade hydrogen peroxide(H_(2)O_(2)).But due to the oxidation degradation of the organic membranes(***)by the strong oxidative radicals(e.g.OH)generated via the activation of H_(2)O_(2)by iron ions(Fe^(3+)),the short effective lifetime of membranes remains a *** nano tin oxide(SnO_(2))has great potential for the removal of Fe^(3+)in strongly oxidative H_(2)O_(2)because of its ability to stabilize H2O_(2)and preferentially adsorb Fe^(3+).Herein,we have designed for the first time a flower-like robust SnO_(2)membrane on the ceramic support by in situ template-free one-step hydrothermal *** three-dimensional loose pore structure in the membrane built by interlacing SnO_(2)nanosheets endows the SnO_(2)membrane with a high specific surface area and abundant adsorption sites(AOH).Based on the coordination complexation and electrostatic attraction between the SnO_(2)surface and Fe^(3+),the membrane shows a high Fe3+removal efficiency(83%)and permeability(24 L·m^(-2)·h^(-1)·MPa^(-1))in H_(2)O_(2).This study provides an innovative and simple approach to designing robust SnO_(2)membranes for highly efficient removal of Fe^(3+)in harsh environments,such as strong oxidation conditions.

关键词： Hydrogen peroxide SnO_(2)membrane Adsorption Hydrothermal