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Distribution of oxide inclusions in H13 castings under super-gravity field with multi-stage rotation speeds

Journal of Iron and Steel Research International 2024年第1期31卷 121-133页

作者： Shao-ying Li xiao-jun Xi xing-ming Zhao Han-jie Guo Jing Guo School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing100083China Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials Beijing100083China Beijing Beiye Functional Materials Corporation Beijing100192China Shandong Tianwu Forming Technology Co. Ltd.Liaocheng252024ShandongChina

The 42 kg industrial H13 castings were prepared by different super-gravity fields with multi-rotation speeds,and the distribution of oxide inclusions in the castings was *** addition,the inward movement Reynolds number and inward movement time of oxide inclusions as well as the solidification time of molten steel at different positions in the castings were calculated to clarify the removal mechanism of oxide inclusions in super-gravity *** results show that the large size(i.e.,greater than 10μm)oxide inclusions are mainly concentrated in the inner and outer parts of the super-gravity castings with constant rotation speed(500 r min^(-1))and five-stage rotation speeds(500,600,750,850,and 950 r min^(-1)),respectively,while there are no large oxide inclusions in the super-gravity castings with three-stage rotation speeds(500,600,and 750 r min^(-1)).Although an increase in the particle size of inclusion and the rotation speed in super-gravity field is conducive to the increase in the inward movement Reynolds number of oxide inclusions and reduction in the inward movement time of oxide inclusions,it will reduce the local solidification time of molten *** the range of the rotation speed studied,the super-gravity field with three-stage rotation speeds has the best effect on the removal of inclusions in H13 molten steel.

关键词： Distribution Oxide inclusion H13 casting Super-gravity field Rotation speed

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Paleoenvironmental reconstruction and organic matter accumulation of the paleogene shahejie oil shale in the Zhanhua Sag, Bohai Bay Basin, Eastern China

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Petroleum Science 2024年第3期21卷 1552-1568页

作者： xiao-Lin Wang xiao-Min Zhu Jin Lai xing-Yue Lin Xiang Wang Yu-Shan Du Chao Huang Yu-Rui Zhu State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China College of Geosciences China University of Petroleum(Beijing)Beijing102249China Shengli Oilfield SINOPECDongying257000ShandongChina

The controlling factors of organic-rich shale accumulation is essential for the exploration and development of shale oil and gas *** sedimentary environment plays a vital role in the formation of organic-rich sediments in lacustrine *** article unravels the mineralogy,geochemistry,and paleoenvironmental evolution during the deposition of the Paleogene Shahejie Formation(Es_(3)^(L)).It discusses the effects of paleoclimate,paleosalinity,paleoredox conditions,paleowater depth,and paleoproductivity on organic matter(OM)***,the OM enrichment model was *** results show that the mineralogical compositions are mainly composed of calcite(avg.40.13%),quartz(avg.21.64%)and clay minerals(avg.24.07%),accompanied by dolomite(avg.7.07%),feldspar(avg.6.36%)and pyrite(avg.2.95%).The Es_(3)^(L) shale has a high abundance of OM,with total organic carbon(TOC)ranging from 1.07%to 5.12%.The organic matter type is mainly composed of type I-II_(1) kerogen,which is generally considered a good-quality source *** source of OM is a mixture of lower bacteria,algae,and *** the early sedimentary period,the paleoclimate was dry and cold,with high salinity,intense reducibility,and relatively low *** the late sedimentary period,the climate became warmer and more *** a result,the salinity decreased to a level that was suitable for biological reproduction,and productivity increased gradually due to the input of terrigenous *** and paleoclimate determined the environment of the sedimentary period,in addition,paleoproductivity and paleoredox condition indicated the formation and preservation conditions of *** warm and humid climate,brackish water,suitable reduction conditions and high productivity are the favorable conditions for the generation and preservation of organic *** research results may have implications for the genetic mechanisms of organic matter *** will provide theoret

关键词： Elemental geochemical Paleoenvironment Organic matter accumulation Paleogene shahejie formation Zhanhua Sag Bohai Bay Basin

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A deep Koopman operator-based modelling approach for long-term prediction of dynamics with pixel-level measurements

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CAAI Transactions on Intelligence Technology 2024年第1期9卷 178-196页

作者： Yongqian xiao Zixin tang Xin Xu xinglong Zhang Yifei Shi College of Intelligence Science and Technology National University of Defense TechnologyChangshaChina

Although previous studies have made some clear leap in learning latent dynamics from high-dimensional representations,the performances in terms of accuracy and inference time of long-term model prediction still need to be *** this study,a deep convolutional network based on the Koopman operator(CKNet)is proposed to model non-linear systems with pixel-level measurements for long-term *** adopts an autoencoder network architecture,consisting of an encoder to generate latent states and a linear dynamical model(i.e.,the Koopman operator)which evolves in the latent state space spanned by the *** decoder is used to recover images from latent *** to a multi-step ahead prediction loss function,the system matrices for approximating the Koopman operator are trained synchronously with the autoencoder in a mini-batch *** this manner,gradients can be synchronously transmitted to both the system matrices and the autoencoder to help the encoder self-adaptively tune the latent state space in the training process,and the resulting model is time-invariant in the latent ***,the proposed CKNet has the advantages of less inference time and high accuracy for long-term *** are per-formed on OpenAI Gym and Mujoco environments,including two and four non-linear forced dynamical systems with continuous action *** experimental results show that CKNet has strong long-term prediction capabilities with sufficient precision.

关键词： deep neural networks image motion analysis image sequences sequential estimation

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Acoustic characterization of hydrate formation and decomposition in clay-bearing sediments

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Petroleum Science 2024年第4期21卷 2830-2838页

作者： Yi-Jian Zhu xiao-Mei Yang xing Huang Hao Li xiao-Hui Wang Yi-Fei Sun Peng xiao Chang-Yu Sun Guang-Jin Chen State Key Laboratory of Heavy Oil Processing College of Chemical Engineering and Environment China University of Petroleum

Understanding the acoustic characteristics of hydrates in various sediments is crucial for hydrate resource detection and safe and efficient exploitation, as hydrate occurrence patterns vary greatly in different sediments. In this work, sediments with different bentonite contents, water saturations, and types were prepared to investigate the characteristics of P-wave velocity(reflecting the magnitude of hydrate saturation in the sediment) and amplitude(reflecting the degree of hydrate-sediment cementation) during hydrate formation and depressurization. During hydrate formation, the P-wave velocity and amplitude have similar trends. As clay content increases, the P-wave velocity increase rates quickened. On the other hand, the increased rate of P-wave velocity slows down with the increase of water saturation in the clay-bearing sediments. Comparing various types of sediment shows that the water absorption and swelling of bentonite reduce the pore space, speeding up the cementation of the hydrate with the sediment and increasing P-wave velocity at a faster rate. Correspondence between P-wave velocity and hydrate saturation is strongly related to sediment type, clay content, and water *** rapidly decreasing amplitude in the early stage of hydrate depressurization indicates that hydrate in clay-bearing sediments is weakly cemented to the sediments, which is prone to stratigraphic *** findings of this study offer guidance for hydrate resource assessments in clay-bearing sediments as well as geologic risk estimations during hydrate mining.

关键词： gas hydrate bentonite illite P-wave velocity amplitude

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Identification and functional analysis of CG3526 in spermatogenesis of Drosophila melanogaster

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Insect Science 2024年第1期31卷 79-90页

作者： Qihao Hu Yanhong xiao Runnan Wei Ting tang Liang Wen Yuzhen Lu xiao-Qiang Yu Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology Guangzhou Key Laboratory of Insect Development Regulation and Application ResearchInstitute of Insect Science and TechnologySchool of Life SciencesSouth China Normal UniversityGuangzhou510631 China

Spermatogenesis is a critical part of reproduction in insects;however,its molecular mechanism is still largely *** this study,we identified a testis-specific gene CG3526 in Drosophila *** analysis showed that CG3526 contains a zinc binding domain and 2 C2H2 type zinc fingers,and it is clustered to the vertebrate really interesting new gene(RING)family E3 ubiquitin-protein *** CG3526 was knocked down by RNA interference(RNAi),the testis became much smaller in size,and the apical tip exhibited a sharp and thin end instead of the blunt and round shape in the control *** importantly,compared to the control flies,only a few mature sperm were present in the seminal vesicle of C587-Gal4>CG3526 RNAi *** staining of the testis from CG3526 RNAi flies showed that the homeostasis of testis stem cell niche was disrupted,cell distribution in the apical tip was scattered,and the process of spermatogenesis was not ***,we found that the phenotype of CG3526 RNAi flies’testis was similar to that of testis of Stat92E RNAi flies,the expression level of CG3526 was significantly downregulated in the Stat92EF06346 mutant flies,and the promoter activity of CG3526 was upregulated by *** together,our results indicated that CG3526 is a downstream effector gene in the JAK-STAT signaling pathway that plays a key role in the spermatogenesis of Drosophila.

关键词： CG3526 JAK-STAT spermatogenesis STAT92E testis

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Piperine regulates the circadian rhythms of hepatic clock gene expressions and gut microbiota in high-fat diet-induced obese rats

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Food Science and Human Wellness 2024年第3期13卷 1617-1627页

作者： Weiyun Zhang Chi-tang Ho Wenlian Wei Jie xiao Muwen Lu Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods College of Food ScienceSouth China Agricultural UniversityGuangzhou 510642China Department of Food Science Rutgers UniversityNew Brunswick 08901USA

The interplay between the host circadian clock and microbiota has significant influences on host metabolism processes,and circadian desynchrony triggered by high-fat diet(HFD)is closely related to metabolic *** this study,the modulatory effects of piperine(PIP)on lipid metabolism homeostasis,gut microbiota community and circadian rhythm of hepatic clock gene expressions in obese rats were *** Sprague-Dawley(SD)rats were fed with normal diet(ND),HFD and HFD supplemented with PIP,*** 9 weeks,rats were sacrificed with tissue and fecal samples collected for circadian *** showed that chronic PIP administration ameliorated the obesity-induced alterations in lipid metabolism and dysregulation of hepatic clock gene expressions in obese *** gut microbial communities studied through 16S rRNA sequencing showed that PIP ameliorated the imbalanced nicrobiota and recovered the circadian rhythm of Lactobacillaceae,Desulfovibrionaceae,Paraprevotellaceae,and *** fecal metabolic profiles indicated that 3-dehydroshikimate,cytidine and lithocholyltaurine were altered,which were involved in the amino acid and fatty acid metabolism *** findings could provide theoretical basis for PIP to work as functional food to alleviate the lipid metabolism disorder,circadian rhythm misalignment,and gut microbiota dysbiosis with wide applications in the food and pharmaceutic industries.

关键词： Piperine Circadian clock Obesity Gut microbiota

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CAOSA-extracted lignin improves enzymatic hydrolysis of cellulose

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Green Energy & Environment 2024年第7期9卷 1101-1111页

作者： Sen Ma Zheng Li Jonathan Sperry xing tang Yong Sun Lu Lin Jian Liu Xianhai Zeng College of Energy State Key Laboratory of Physical Chemistry of Solid Surfaces Xiamen University Fujian Engineering and Research Centre of Clean and High-valued Technologies for Biomass Xiamen Key Laboratory of Clean and High-valued Utilization of Biomass Centre for Green Chemical Science University of Auckland

The conversion of biomass into sugar platform compounds is very important for the biorefinery industry. Pretreatment is essential to the biomass of the sugar platform, however, the lignin obtained by pretreatment, as a key part of lignocellulose, generally has a passive effect on the enzymatic hydrolysis of cellulose into sugars. In this study, p-TsOH(p-toluenesulfonic acid), DES(Deep eutectic solvent) and CAOSA(cooking with active oxygen and solid alkali) pretreatment ways were used to fraction lignin from bamboo biomass. After CAOSA treatment, the hydrolysis efficiency of the pulp was 95.57%. Moreover, the effect of different treatment methods on lignin properties was studied and the promotion effect of lignin was investigated by adding it to the cellulose enzymatic hydrolysis system. In this work, the results showed that CAOSA-extracted lignin with lower ?(1.31–1.25) had a better adsorption effect on the enzyme protein. p-TsOH-extracted lignin with a larger S/G ratio enhanced the inhibition of enzymatic hydrolysis. In addition, the presence of-COOHs in lignin could reduce its inhibitory effect on cellulose saccharification.

关键词： Biomass pretreatment CAOSA Cellulose hydrolysis Lignin Enzyme

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Quantum squeezing induced nonreciprocal phonon laser

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 20-30页

作者： Tian-Xiang Lu Yan Wang Keyu Xia xing xiao Le-Man Kuang Hui Jing College of Physics and Electronic Information Gannan Normal UniversityGanzhou 341000China Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China Academy for Quantum Science and Technology Zhengzhou University of Light IndustryZhengzhou 450002China College of Engineering and Applied Sciences National Laboratory of Solid State Microstructuresand Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210023China

Phonon lasers or coherent amplifications of mechanical oscillations are powerful tools for fundamental studies on coherent acoustics and hold potential for diverse applications,ranging from ultrasensitive force sensing to phononic information ***,we propose the use of an optomechanical resonator coupled to a nonlinear optical resonator for directional phonon *** find that by pumping the nonlinear optical resonator,directional optical squeezing can occur along the pump *** a result,we can achieve the directional mechanical gain using directional optical squeezing,thereby leading to nonreciprocal phonon lasing with a well-tunable directional power *** work proposes a feasible way to build nonreciprocal phonon lasers with various nonlinear optical media,which are important for a wide range of applications,such as directional acoustic amplifiers,invisible sound sensing or imaging,and one-way phononic networks.

关键词： nonreciprocal phonon laser directional quantum squeezing optomechanics

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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

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Failure behavior and strength model of blocky rock mass with and without rockbolts

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International Journal of Mining Science and Technology 2024年第6期34卷 747-762页

作者： Chun Zhu Xiansen xing Manchao He Zhicheng tang Feng Xiong Zuyang Ye Chaoshui Xu School of Earth Sciences and Engineering Hohai UniversityNanjing 210024China Key Laboratory of Water Management and Water Security for Yellow River Basin Ministry of Water Resources(under construction)Zhengzhou 450003China State Key Laboratory for Geomechanics&Deep Underground Engineering China University of Mining and TechnologyBeijing 10083China Faculty of Engineering China University of GeosciencesWuhan 430074China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China School of Resource and Environmental Engineering Wuhan University of Science and TechnologyWuhan 430081China School of Chemical Engineering Faculty of SciencesEngineering and TechnologyThe University of AdelaideAdeliade 5005Australia

To better understand the failure behaviours and strength of bolt-reinforced blocky rocks,large scale extensive laboratory experiments are carried out on blocky rock-like specimens with and without rockbolt *** results show that both shear failure and tensile failure along joint surfaces are observed but the shear failure is a main controlling factor for the peak strength of the rock mass with and without *** rockbolts are necked and shear deformation simultaneously happens in bolt reinforced rock *** the joint dip angle increases,the joint shear failure becomes more *** number of rockbolts has a significant impact on the peak strain and uniaxial compressive strength(UCS),but little influence on the deformation modulus of the rock *** the Winkler beam model to represent the rockbolt behaviours,an analytical model for the prediction of the strength of boltreinforced blocky rocks is *** agreement between the UCS values predicted by proposed model and obtained from experiments suggest an encouraging performance of the proposed *** addition,the performance of the proposed model is further assessed using published results in the literature,indicating the proposed model can be used effectively in the prediction of UCS of bolt-reinforced blocky rocks.

关键词： Blocky rock mass Rockbolt ground support Uniaxial compression test Failure mechanism Uniaxial compressive strength model

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