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抗高温低密度水泥浆体系研究与应用

当代化工研究 2024年第7期 108-110页

作者：肖振华丁志伟周琛洋张华张顺平中国石油西南油气田分公司勘探事业部四川610000 中国石油集团工程技术研究院有限公司北京102206 油气钻完井技术国家工程研究中心北京102206

为解决低密度水泥浆高温强度低、减轻材料承压能力不高、低密度水泥浆配浆困难等难题,研制了低密度增强材料DRA-2S、优选了耐压105 MPa的高性能空心玻璃微珠、聚羧酸分散剂DRS-2S及其他配套抗高温水泥外加剂,开发了抗高温低密度固井水... 详细信息

为解决低密度水泥浆高温强度低、减轻材料承压能力不高、低密度水泥浆配浆困难等难题,研制了低密度增强材料DRA-2S、优选了耐压105 MPa的高性能空心玻璃微珠、聚羧酸分散剂DRS-2S及其他配套抗高温水泥外加剂,开发了抗高温低密度固井水泥浆体系。研究结果表明,该水泥浆能够满足循环温度150℃、井底静止温度180℃、耐压105 MPa的固井要求,顶部127℃静胶凝13.3 h起强度,24 h抗压强度12.4 MPa。开发的抗高温低密度水泥浆在西南油气田高温探井ZJ2井Ф127 mm尾管固井成功应用,固井质量合格率96.7%,为西南油气田高温易漏失复杂深井勘探开发提供了固井技术支撑。

关键词：低密度高温深井精细控压尾管固井油基钻井液

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Perception Enhanced Deep Deterministic Policy Gradient for Autonomous Driving in Complex Scenarios

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 557-576页

作者： Lyuchao Liao Hankun xiao Pengqi Xing zhenhua Gan Youpeng He Jiajun Wang Fujian Provincial Key Laboratory of Automotive Electronics and Electric Drive Fujian University of TechnologyFuzhou350118China Fujian Provincial Universities Engineering Research Center for Intelligent Driving Technology Fuzhou350118China

Autonomous driving has witnessed rapid advancement;however,ensuring safe and efficient driving in intricate scenarios remains a critical *** particular,traffic roundabouts bring a set of challenges to autonomous driving due to the unpredictable entry and exit of vehicles,susceptibility to traffic flow bottlenecks,and imperfect data in perceiving environmental information,rendering them a vital issue in the practical application of autonomous *** address the traffic challenges,this work focused on complex roundabouts with multi-lane and proposed a Perception EnhancedDeepDeterministic Policy Gradient(PE-DDPG)for AutonomousDriving in the ***,themodel incorporates an enhanced variational autoencoder featuring an integrated spatial attention mechanism alongside the Deep Deterministic Policy Gradient framework,enhancing the vehicle’s capability to comprehend complex roundabout environments and make ***,the PE-DDPG model combines a dynamic path optimization strategy for roundabout scenarios,effectively mitigating traffic bottlenecks and augmenting throughput *** experiments were conducted with the collaborative simulation platform of CARLA and SUMO,and the experimental results show that the proposed PE-DDPG outperforms the baseline methods in terms of the convergence capacity of the training process,the smoothness of driving and the traffic efficiency with diverse traffic flow patterns and penetration rates of autonomous vehicles(AVs).Generally,the proposed PE-DDPGmodel could be employed for autonomous driving in complex scenarios with imperfect data.

关键词： Autonomous driving traffic roundabouts deep deterministic policy gradient spatial attention mechanisms

Research advances in enhanced coal seam gas extraction by controllable shock wave fracturing

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International Journal of Coal Science & Technology 2024年第3期11卷 1-31页

作者： Chaojun Fan Hao Sun Sheng Li Lei Yang Bin xiao zhenhua Yang Mingkun Luo xiaofeng Jiang Lijun Zhou College of Mining Liaoning Technical UniversityFuxin123000China College of Safety Science and Engineering Liaoning Technical UniversityFuxin123000China Energy Business Department Shanxi Lu’an Chemical GroupChangzhi046200China

With the continuous increase of mining in depth,the gas extraction faces the challenges of low permeability,great ground stress,high temperature and large gas pressure in coal *** controllable shock wave(CSW),as a new method for enhancing permeability of coal seam to improve gas extraction,features in the advantages of high efficiency,eco-friendly,and low *** order to better utilize the CSW into gas extraction in coal mine,the mechanism and feasibility of CSW enhanced extraction need to be *** this paper,the basic principles,the experimental tests,the mathematical models,and the on-site tests of CSW fracturing coal seams are reviewed,thereby its future research directions are *** on the different media between electrodes,the CSW can be divided into three categories:hydraulic effect,wire explosion and excitation of energetic materials by detonating *** the process of propagation and attenuation of the high-energy shock wave in coal,the shock wave and bubble pulsation work together to produce an enhanced permeability effect on the coal *** stronger the strength of the CSW is,the more cracks created in the coal is,and the greater the length,width and area of the cracks *** repeated shock on the coal seam is conducive to the formation of complex network fracture system as well as the reduction of coal seam strength,but excessive shock frequency will also damage the coal structure,resulting in the limited effect of the enhanced gas *** the influence of ground stress,the crack propagation in coal seam will be *** difference of horizontal principal stress has a significant impact on the shape,propagation direction and connectivity of the CSW induced *** permeability enhancement effect of CSW is affected by the breakage degree of coal *** shock wave is absorbed by the broken coal,which may hinder the propagation of CSW,resulting in a poor effect of permeability *** arranging two a

关键词： Controllable shock wave Permeability enhancement Gas extraction Basic principle Experimental test Mathematical models On-site test

Application of wastewater-based epidemiological monitoring of COVID-19 for disease surveillance in the city

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Frontiers of Environmental Science & Engineering 2024年第8期18卷 81-87页

作者： Heng Chen zhenhua Chen Liwen Hu Fengzhu Tang Dan Kuang Jiayi Han Yao Wang xiao Zhang Yue Cheng Jiantong Meng Rong Lu Lan Zhang Chengdu Workstation for Emerging Infectious Disease Control and Prevention Chinese Academy of Medical SciencesChengdu 610047China Chengdu Center for Disease Control and Prevention Chengdu 610047China National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases Beijing 100050China National Institute of Environmental Health Chinese Center for Disease Control and PreventionBeijing 100050China

Wastewater-based surveillance serves as a supplementary approach to clinical surveillance of COVID-19 during the *** study aimed to track the prevalence of the disease and the viral genetic variability through wastewater-based surveillance in the post-epidemic *** January to December 2023,samples were collected from the influent lines of two wastewater treatment plants(WWTPs),concentrated using PEG8000,and subjected to detection of the target genes ORF 1ab and N of SARS-CoV-2 via reverse transcriptional quantitative PCR(RT-qPCR).For next-generation sequencing(NGS),high-quality samples from both wastewater and clinical patients were *** analysis were performed using R software to evaluate the correlation between the SARSCoV-2 RNA concentrations in wastewater and positive rate of reported cases,indicating a positive *** diversity patterns of SARS-CoV-2 in wastewater resembled those in the patient source based on Principal Coordinates Analysis(PCoA)with three clusters for different *** rise of RNA concentration in wastewater indicates the growth of cases and the emergence of new variants,serving as an early warning of potential viral mutations,disease outbreaks even possible ***,the genomic surveillance of wastewater could help identify new variants that may not be captured through population monitoring,especially when sample sizes are ***,surveillance of SARS-CoV-2 in municipal wastewater has emerged as a reliable,earlywarning monitoring system for COVID-19 in the post-epidemic era.

关键词： Wastewater-based epidemiology Monitoring COVID-19 Post-epidemic era

MXene Sediment-Based Poly(vinyl alcohol)/Sodium Alginate Aerogel Evaporator with Vertically Aligned Channels for Highly Efficient Solar Steam Generation

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Nano-Micro Letters 2024年第10期16卷 638-654页

作者： Tian Wang Meng Li Hongxing Xu xiao Wang Mingshu Jia Xianguang Hou Shuai Gao Qingman Liu Qihang Yang Mingwei Tian Lijun Qu zhenhua Song xiaohu Wu Lili Wang Xiansheng Zhang Shandong Key Laboratory of Medical and Health Textile Materials College of Textiles and ClothingState Key Laboratory of Bio-Fibers and Eco-TextilesResearch Center for Intelligent and Wearable TechnologyQingdao UniversityQingdao 266071People's Republic of China Department of Pharmacology Qingdao University School of PharmacyQingdao UniversityQingdao 266071People's Republic of China Shandong Institute of Advanced Technology Jinan 250100People's Republic of China College of Electromechanical Engineering Qingdao University of Science and TechnologyQingdao 266061People's Republic of China

Solar-driven interfacial evaporation from seawater is considered an effective way to alleviate the emerging freshwater crisis because of its green and environmentally friendly ***,developing an evaporator with high efficiency,stability,and salt resistance remains a key ***,with an internal photothermal conversion efficiency of 100%,has received tremendous research interest as a photothermal ***,the process to prepare the MXene with monolayer is inefficient and generates a large amount of“waste”MXene sediments(MS).Here,MXene sediments is selected as the photothermal material,and a three-dimensional MXene sediments/poly(vinyl alcohol)/sodium alginate aerogel evaporator with vertically aligned pores by directional freezing method is innovatively *** vertical porous structure enables the evaporator to improve water transport,light capture,and high evaporation *** swabs and polypropylene are used as the water channel and support,respectively,thus fabricating a self-floating *** evaporator exhibits an evaporation rate of 3.6 kg m^(-2)h^(-1)under one-sun illumination,and 18.37 kg m^(-2)of freshwater is collected in the condensation collection device after 7 h of outdoor sun *** evaporator also displays excellent oil and salt *** research fully utilizes“waste”MS,enabling a self-floating evaporation device for freshwater collection.

关键词： MXene sediments Porous structure Desalination Self-floating

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CYCLIC SOFTENING IN HOT-WORKING DIE STEELS DURING LOW-CYCLE FATIGUE

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Acta Metallurgica Sinica(English Letters) 1990年第3期3卷 199-203页

作者： HU zhenhua xiao Jiexuan Huazhong University of Science and Technology,Wuhan,China HU zhenhua,Associate Professor,Huazhong University of Science and Technology,Wuhan 430074,China

The characteristics and microstructural changes of cyclic softening in hot-working die steels 5CrNiMo and 5Cr2NiMoVSi were studied under strain controlled low-cycle *** re- sults show that the cyclic softening is featured in both steels hardened in different conditions under the strain controlled amplitude range of Δε_t/2=0.6-1.8×10^(-2).The softening effect mainly occurs in some initial cycles and the stress amplitude varies slightly in the sequential cycles,*** softening effect is *** obvious stress saturation phenomenon was ob- served during the whole cyclic *** TEM analysis shows that the cyclic softening is related to heterogenity of plastic *** softening of the tested steels is caused by the formation of the dislocation cell structure with low density and low internal stress,and by the fragmentation and redissolution of fine carbides into matrix.

关键词： low-cycle fatigue hot work die steel cyclic softening

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Four development stages of collective intelligence

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Frontiers of Information Technology & Electronic Engineering 2024年第7期25卷 903-916页

作者： Renbin xiao School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhan 430074China Key Laboratory of Image Information Processing and Intelligent Control Ministry of EducationWuhan 430074China

The new generation of artificial intelligence(AI)research initiated by Chinese scholars conforms to the needs of a new information environment changes,and strives to advance traditional artificial intelligence(AI 1.0)to a new stage of AI *** one of the important components of AI,collective intelligence(CI 1.0),i.e.,swarm intelligence,is developing to the stage of CI 2.0(crowd intelligence).Through in-depth analysis and informative argumentation,it is found that an incompatibility exists between CI 1.0 and CI ***,CI 1.5 is introduced to build a bridge between the above two stages,which is based on biocollaborative behavioral *** 1.5 is the transition from CI 1.0 to CI 2.0,which contributes to the compatibility of the two ***,a new interpretation of the meta-synthesis of wisdom proposed by Qian Xuesen is *** meta-synthesis of wisdom,as an improvement of crowd intelligence,is an advanced stage of bionic intelligence,i.e.,CI *** is pointed out that the dual-wheel drive of large language models and big data with deep uncertainty is an evolutionary path from CI 2.0 to CI 3.0,and some elaboration is *** a result,we propose four development stages(CI 1.0,CI 1.5,CI 2.0,and CI 3.0),which form a complete framework for the development of *** different stages are progressively improved and have good *** to the dominant role of cooperation in the development stages of CI,three types of cooperation in CI are discussed:indirect regulatory cooperation in lower organisms,direct communicative cooperation in higher organisms,and shared intention based collaboration in *** division is the main form of achieving cooperation and,for this reason,this paper investigates the relationship between the complexity of behavior and types of labor ***,based on the overall understanding of the four development stages of CI,the future development direction and research issues of CI are explored.

关键词： Collective intelligence Meta-synthesis of wisdom Incompatibility Labor division Cooperative behavior Collective intelligence emergence Large language model

Two-dimensional atomically thin Pt layers on MXenes: The role of electronic effects during catalytic dehydrogenation of ethane and propane

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Nano Research 2024年第3期17卷 1251-1258页

作者： Zhe Li Tobias K.Misicko Fan Yang xiaopeng Liu Zhenwei Wu xiaoyang Gao Tao Ma Jeffrey T.Miller Daniela S.Mainardi Collin D.Wick zhenhua Zeng Yang xiao Yue Wu Department of Chemical and Biological Engineering Iowa State University618 Bissell RoadAmesIA 50011USA Institute for Micromanufacturing Louisiana Tech University505 Tech DriveRustonLA 71272USA Davidson School of Chemical Engineering Purdue University480 Stadium Mall DriveWest LafayetteIN 47907USA Michigan Center for Materials Characterization University of Michigan2800 Plymouth RdAnn Arbor MI 48109USA College of Engineering and Science Louisiana Tech UniversityRustonLA 71272USA

Atomically thin Pt nanolayers were synthesized on the surface of Mo2TiC2 MXenes and used for the catalytic dehydrogenation of ethane and propane into ethylene and propylene,two important chemicals for the petrochemical *** compared with Pt nanoparticles,the atomically thin Pt nanolayer catalyst showed superior coke-resistance(no deactivation for 24 h),high activity(turnover frequencies(TOFs)of 0.4–1.2 s^(-1)),and selectivity(>95%)toward ethylene and *** unique Pt nanolayer has a similar geometric surface to Pt nanoparticles,enabling the investigations of the electronic effect on the catalytic performance,where the geometric effect is *** is found that the electronic effect plays a critical role in dehydrogenative product selectivity and catalyst *** metal–support interaction is found dependent on the substrate and metal components,providing wide opportunities to explore high-performance MXene-supported metallic catalysts.

关键词： MXene catalysis alkane dehydrogenation nanolayers

Mulberry Biomass-Derived Nanomedicines Mitigate Colitis through Improved Inflamed Mucosa Accumulation and Intestinal Microenvironment Modulation

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Research 2024年第1期2023卷 791-807页

作者： Wenjing Yang Ya Ma Haiting Xu zhenhua Zhu Jiaxue Wu Cheng Xu Wei Sun Erhu Zhao Min Wang Rui L.Reis Subhas C.Kundu xiaoxiao Shi Bo xiao State Key Laboratory of Silkworm Genome Biology College of SericultureTextileand Biomass SciencesSouthwest UniversityChongqing 400715China Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing Faculty of Materials and EnergySouthwest UniversityChongqing 400715China Department of Gastroenterology The First Affiliated Hospital of Nanchang UniversityNanchang 330006China Bs Research Group I3Bs—Research Institute on BiomaterialsBiodegradables and BiomimeticsUniversity of MinhoHeadquarters of the European Institute of Excellence on Tissue Engineering and Regenerative MedicineAveParkBarco 4805-017GuimaraesPortugal ICVS/3B’s-PT Government Associate Laboratory BragaGuimarãesPortugal

The therapeutic outcomes of conventional oral medications against ulcerative colitis(UC)are restricted by inefficient drug delivery to the colitis mucosa and weak capacity to modulate the inflammatory ***,a fluorinated pluronic(FP127)was synthesized and employed to functionalize the surface of mulberry leaf-derived nanoparticles(MLNs)loading with resveratrol nanocrystals(RNs).The obtained FP127@RN-MLNs possessed exosome-like morphologies,desirable particle sizes(around 171.4 nm),and negatively charged surfaces(−14.8 mV).The introduction of FP127 to RN-MLNs greatly improved their stability in the colon and promoted their mucus infiltration and mucosal penetration capacities due to the unique fluorine effect.

关键词： fluorine sizes Biomass