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Evolution of Cenozoic sedimentary architecture in Central and Southern South China Sea basins

Journal of Palaeogeography 2024年第1期13卷 35-53页

作者： Wu Tang Xiao-Jun Xie Yi-Bo Wang Lian-Qiao Xiong Jia Guo Xin Li China National Offshore Oil Corporation research institute Beijing 100028China

The Central and Southern South China Sea(CSSCS) has a complex tectonic dynamic background and abundant oil and gas resources, which has always been a hot topic of academic and industrial ***, systematic analyses are still lacking regarding its sediment filling structure and evolution, mostly due to limited borehole penetration and poor quality of seismic reflection data for deeply buried sequences. No consensus has been reached yet on the sedimentary infilling processes, which impeded the reconstruction of the palaeogeography of Southeast Asia and the oil-and-gas exploration undertakings. Here, we illustrate the Cenozoic sedimentary evolution of the CSSCS region by synthesizing relevant data from previous literature and our own observations and displaying the evolution of depositional systems in sequential reconstructions. Besides, the controlling factors of preferred sedimentary scenarios in the CSSCS incorporate the latest interpretations of the spreading of South China Sea(SCS) as well as the demise of the hypothetical Proto-South China Sea(PSCS). The results show that there are three types of sedimentary basins in the CSSCS(foreland,strike-slip, and rift basins) with different sedimentary filling structures. The foreland basins formed a depositional pattern of ‘transition from deep water to shallow water environments', dominated by deep-water depositional systems which were formed before the Early Oligocene with submarine fans developed. Later,the foreland basins were gradually dominated by shallow-water depositional systems with deltas and shallow marine facies. The strike-slip basins showed the depositional architecture of ‘transition from lake to marine environments', i.e. the basins were dominated by lacustrine deposits during the Eocene and evolved into the marine depositional environment since Oligocene with delta developed in the western part of the basin. The depositional evolution of rift basins illustrated the characteristics of 'transiti

关键词： Central and Southern South China Sea Sedimentary filling Main controlling factors Proto-South China Sea South China Sea

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The behaviors of gas-liquid two-phase flow under gas kick during horizontal drilling with oil-based muds

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Petroleum 2024年第1期10卷 49-67页

作者： Yu Su Huiyun Ma Jianhua Guo Xinyu Shen Zhaoliang Yang Jie Wu Engineering Technology research institute PetroChina Southwest Oil & Gas Field Company

Natural gas is easily soluble in oil-based muds(OBM), leading to complex flow behavior in wellbores,especially in horizontal wells. In this study, a new transient flow model considering wellbore-formation coupling and gas solubility on flow behavior is developed to simulate gas kicks during horizontal drilling with OBM. Furthermore, the effect of gas solubility on parameters such as bottom-hole pressure(BHP),gas void fraction and mixture velocity in the flow behavior is analyzed. Finally, several critical factors affecting flow behavior are investigated and compared to gas kicks in water-based muds(WBM) where the effect of solubility is neglected. The results show that the invading gas exists as dissolved gas in the OBM and as free gas in the WBM. Before the gas escapes from the OBM, the pit gain is zero and there is barely any change in the BHP, annulus return flow rate and mixture velocity, which means that detecting gas kicks through these warning signs can be challenging until they get very close to the surface and develop rapidly. However, in WBM drilling, these parameters change quickly with the increasing gas kick time. Additionally, for both cases, the longer the horizontal length and the greater reservoir permeability,the greater the decrease in BHP, and the shorter the time for gas to migrate from the bottom-hole to the wellhead. A larger flow rate contributes to a greater initial BHP and a lesser BHP reduction. This research is of value in characterizing gas kick behavior and identifying novel ways for early gas kick detection during horizontal drilling with OBM.

关键词： Flow behavior Gas solubility Gas kick Horizontal drilling Oil-based muds Water-based muds

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Developing a multi-method approach to identifying e-scooter hazard hotspots

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第4期11卷 667-680页

作者： Michael Hardinghaus Simon Nieland Rebekka Oostendorp Jan Weschke German Aerospace Center(DLR)institute of Transport research Berlin 12489Germany

In recent years,e-scooters have been introduced in many European *** several places we have witnessed a rapid uptake of this new mode of transport mainly as a result of public sharing schemes.A number of incidents,injuries and even fatalities have given rise to questions regarding the safety of these *** questions are being researched mainly using official crash data and data specifying injuries and hospital *** now,the research has focused on investigating typical injury patterns and estimating risk *** little is known about exactly where conflicts and crashes *** of hazard hotspots is crucial when investigating risk levels and improving safety for all road ***,this paper develops an approach to investigating locations with potentially dangerous interactions within the active mobility system in the city of *** approach consists of explorative expert interviews,an online poll,and quantitative *** the latter we combine three ***,we research crash hotspots using official ***,we use data based on acceleration sensors from cyclists'smartphones to find locations of sudden ***,we use trip data from the operators of escooter sharing *** information gathered is used in a conclusive expert workshop to identify hazard *** show that many of the conflicts with pedestrians are caused by parked ***,e-scooter trips are concentrated in the inner city and along specific *** moving traffic,various data sources are used to identify hotspots at intersections and in areas between *** present research lays the foundation for important further studies to investigate interactions at hotspots in detail by determining nine specific locations in the city of Berlin.

关键词： E-scooter Accidents Crashes Active mobility Micromobility Road safety

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Towards cultivar-oriented gene discovery for better crops

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The Crop Journal 2024年第3期12卷 670-675页

作者： Dengcai Liu Triticeae research institute Sichuan Agricultural UniversityChengdu 611130SichuanChina

The continued expansion of the world population,increasingly inconsistent climate and shrinking agricultural resources present major challenges to crop ***,the increasing ability to discover and manipulate genes creates new opportunities to develop more productive and resilient *** genes have been described in papers as being beneficial for yield ***,few of them have been translated into increased yield on *** contrast,commercial breeders are facing gene decidophobia,i.e.,puzzled about which gene to choose for breeding among the many identified,a huge chasm between gene discovery and cultivar *** purpose of this paper is to draw attention to the shortfalls in current gene discovery research and to emphasise the need to align with cultivar *** methodology dictates that genetic studies not only focus on gene discovery but also pay good attention to the genetic backgrounds,experimental validation in relevant environments,appropriate crop management,and data *** close of the gaps should accelerate the application of molecular study in breeding and contribute to future global food security.

关键词： Cultivar innovation Data reusability Gene discovery Gene decidophobia Omnigenic model

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Application of sparse S transform network with knowledge distillation in seismic attenuation delineation

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Petroleum Science 2024年第4期21卷 2345-2355页

作者： Nai-Hao Liu Yu-Xin Zhang Yang Yang Rong-Chang Liu Jing-Huai Gao Nan Zhang School of Information and Communications Engineering Xi'an Jiaotong University School of Software Engineering Xi'an Jiaotong University PetroChina research institute of Petroleum Exploration and Development (RIPED) CNPC research institute of Exploration and Development Yumen Oilfield Company CNPC

Time-frequency analysis is a successfully used tool for analyzing the local features of seismic ***, it suffers from several inevitable limitations, such as the restricted time-frequency resolution,the difficulty in selecting parameters, and the low computational efficiency. Inspired by deep learning,we suggest a deep learning-based workflow for seismic time-frequency analysis. The sparse S transform network(SSTNet) is first built to map the relationship between synthetic traces and sparse S transform spectra, which can be easily pre-trained by using synthetic traces and training labels. Next, we introduce knowledge distillation(KD) based transfer learning to re-train SSTNet by using a field data set without training labels, which is named the sparse S transform network with knowledge distillation(KD-SSTNet).In this way, we can effectively calculate the sparse time-frequency spectra of field data and avoid the use of field training labels. To test the availability of the suggested KD-SSTNet, we apply it to field data to estimate seismic attenuation for reservoir characterization and make detailed comparisons with the traditional time-frequency analysis methods.

关键词： S transform Deep learning Knowledge distillation Transfer learning Seismic attenuation delineation

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Effects of 1-methylcyclopropene on skin greasiness and quality of'Yuluxiang'pear during storage at 20℃

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Journal of Integrative Agriculture 2024年第7期23卷 2476-2490页

作者： Wanting Yu Xinnan Zhang Weiwei Yan Xiaonan Sun Yang Wang Xiaohui Jia research institute of Pomology Chinese Academy of Agricultural SciencesXingcheng 125100China

During storage at 20℃,specific pear cultivars may exhibit a greasy texture and decline in quality due to fruit *** these varieties,‘Yuluxiang’is particularly susceptible to peel greasiness,resulting in significant economic ***,there is an urgent need for a preservative that can effectively inhibit the development of *** studies have demonstrated the efficacy of 1-methylcyclopropene(1-MCP)in extending the storage period of *** hypothesize that it may also influence the occurrence of postharvest peel greasiness in the‘Yuluxiang’*** this study,we treated‘Yuluxiang’pears with *** stored them at 20℃while analyzing the composition and morphology of the surface waxes,recording enzyme activities related to wax synthesis,and measuring indicators associated with fruit storage quality and physiological *** results demonstrate that prolonged storage at 20℃leads to a rapid increase in skin greasiness,consistent with the observed elevations in L^(*),greasiness score,and the content of total wax and greasy wax ***,there were indications that cuticular waxes underwent melting,resulting in the formation of an amorphous *** comparison to controls,the application of 1-MCP significantly inhibited increments in L^(*) values as well as grease scores while also reducing accumulation rates for oily waxes throughout most stages over its shelf period,additionally delaying transitions from flaky-wax structures towards their amorphous *** the initial 7 d of storage,several enzymes involved in the biosynthesis and metabolism of greasy wax components,including lipoxygenase(LOX),phospholipase D(PLD),andβ-ketoacyl-CoA synthase(KCS),exhibited an increase followed by a subsequent *** activity of LOX during early shelf life(0–7 d)and the KCS activity during middle to late shelf life(14–21 d)were significantly suppressed by ***,1-MCP effectively maintained firmness,

关键词： ‘Yuluxiang’pear skin greasiness 1-methylcyclopropene storage quality

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Next-generation regenerative therapy for ischemic stroke using peripheral blood mononuclear cells

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Neural Regeneration research 2024年第11期19卷 2341-2342页

作者： Masato Kanazawa Itaru Ninomiya Yutaka Otsu Masahiro Hatakeyama Department of Neurology Brain Research InstituteNiigata UniversityNiigataJapan

Stroke is the second leading cause of death and the third leading cause of disability worldwide after heart *** predict that stroke deaths and permanent disabilities will increase worldwide by the year ***-target therapies may be insufficient,because ischemic cerebral injury involves several ***-mediated therapies are ideal,because they target multiple cell types to enhance protection and recovery.

关键词： ischemic death cerebral

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Design and Experimental Verification of a Roll Control Strategy for Large Wingspan Flapping-Wing Aerial Vehicle

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Journal of Bionic Engineering 2024年第4期21卷 1644-1661页

作者： Rui Meng Bifeng Song Jianlin Xuan Xiaojun Yang Dong Xue School of Aeronautics Northwestern Polytechnical UniversityXi’an710072China research and Development institute of Northwestern Polytechnical University in Shenzhen Shenzhen518057China Yangtze River Delta research institute of Northwestern Polytechnical University Taicang215400China

Most flapping-wing aircraft wings use a single degree of freedom to generate lift and thrust by flapping up and down,while relying on the tail control surfaces to manage ***,these aircraft have certain limitations,such as poor accuracy in attitude control and inadequate roll control *** paper presents a design for an active torsional mechanism at the wing's trailing edge,which enables differential variations in the pitch angle of the left and right wings during *** simple mechanical form significantly enhances the aircraft's roll control *** experimental verification of this mechanism was conducted in a wind tunnel using the RoboEagle flapping-wing aerial vehicle that we *** study investigated the effects of the control strategy on lift,thrust,and roll moment during flapping ***,the impact of roll control on roll moment was examined under various wind speeds,flapping frequencies,angles of attack,and wing ***,several rolling maneuver flight tests were performed to evaluate the agility of RoboEagle,utilizing both the elevon control strategy and the new roll control *** results demonstrated that the new roll control strategy effectively enhances the roll control capability,thereby improving the attitude control capabilities of the flapping-wing aircraft in complex wind field *** conclusion is supported by a comparison of the control time,maximum roll angle,average roll angular velocity,and other relevant parameters between the two control strategies under identical roll control input.

关键词： Roll control Bio-inspired Roll moment Flapping wing aerial vehicle

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Fine description of unconventional clastic oil reservoirs

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Petroleum research 2024年第2期9卷 289-303页

作者： Huanqing Chen research institute of Petroleum Exploration&Development PetroChinaChina

The latest researches reveal that studies on unconventional clastic oil reservoirs in China generally lag far behind those in other countries in respect of content and *** study presents the definition and classification of unconventional oil reservoirs and analyzes the problems in the fine description of unconventional oil *** key content of the fine description of unconventional oil reservoirs is summarized from four aspects:fine fracture characterization based on fine structure interpretation,reservoir architecture characterization based on sedimentary facies,characteristics of nanoscale microscopic pore structure of reservoir,and evaluation of source rock and“sweet spot zone”.Finally,this study suggests that development of fine description of unconventional clastic oil reservoirs in the future should focus on rock brittleness analysis and fracture modeling,geophysical characterization of unconventional clastic oil reservoirs,fluid description of tight reservoirs,and physical/numerical simulation experiments of unconventional oil reservoirs.

关键词： Unconventional clastic reservoir Fine reservoir description Oil sand Tight oilShale oil Fracture characterization Nanoscale microscopic pore structure Sweet spot

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Anticipating the lifespan: Predicting the durability of an anode-supported solid oxide fuel cell short stack over 50,000 h

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Progress in Natural Science:Materials International 2024年第3期34卷 606-613页

作者： Muhammad Zubair Khan Amjad Hussain Seung-Bok Lee Tak-Hyoung Lim Rak-Hyun Song Department of Materials Science & Engineering Pak-Austria Fachhochschule: Institute of Applied Sciences and Technology Hydrogen Energy research Division Korea Institute of Energy Research Department of Advanced Energy and System Engineering Korea University of Science and Technology (UST)

In the present study, the operational lifetime of a solid oxide fuel(SOFC) short stack is predicted by investigating the performance degradation of both the short stack and its cells throughout 1000 h at 800°C. The short stack and integral cell voltages are continuously measured during the long-term test, with electrochemical impedance spectroscopy(EIS) conducted every 200 h. The short stack voltage decreased rapidly for the initial 200–300 h and afterwards, it decreased at a slow rate due to the increase in the Ohmic and polarization resistances in the same manner. Scanning electron microscopy results show that there is no delamination or cracking among constituent layers of the short-stack cells. The single degradation effects of the Ni coarsening in the anode, cation migration and surface segregation in cathode and oxide scale growth in metallic interconnect mesh are successfully integrated into a comprehensive lifetime prediction model. The experimentally measured voltage degradation data of the short stack fits well with the developed mathematical model and allows the successful prediction of the lifetime up to 50,000 h.

关键词： Degradation Impedance Lifetime SOFC Stack

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