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Primordial black holes and curvature perturbations from false vacuum islands

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Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 58-72页

作者： Rong-Gen cai Yu-Shi Hao Shao-Jiang Wang School of Physical Science and Technology Ningbo UniversityNingbo 315211China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Asia Pacific Center for Theoretical Physics Pohang 37673Republic of Korea

Recently,much attention has been focused on the false vacuum islands that are flooded by an expanding ocean of true-vacuum bubbles slightly later than most of the other parts of the *** delayed decay regions will accumulate locally larger vacuum energy density by staying in the false vacuum longer than those already transited into the true vacuum.A false vacuum island with thus acquired density contrast of a super-horizon size will evolve locally from radiation dominance to vacuum dominance,creating a local baby Universe that can be regarded effectively as a local closed *** such density contrasts of super-horizon sizes can ever grow large enough to exceed the threshold of gravitational collapse,primordial black holes will form similar to those collapsing curvature perturbations on super-horizon scales induced by small-scale enhancements during *** not,such density contrasts can still induce curvature perturbations potentially observable *** this paper,we revisit and elaborate on the generations of primordial black holes and curvature perturbations from delayed-decayed false vacuum islands during asynchronous first-order phase transitions with fitting formulas convenient for future model-independent studies.

关键词： first-order phase transitions primordial black holes curvature perturbations

A Quasi-Linear Relationship between Planetary Outgoing Longwave Radiation and Surface Temperature in a Radiative-Convective-Transportive Climate Model of a Gray Atmosphere

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Advances in Atmospheric Sciences 2024年第1期41卷 8-18页

作者： Jie SUN Michael SECOR Ming cai Xiaoming HU Department of Earth Oceanand Atmospheric ScienceFlorida State UniversityTallahasseeFlorida 32304USA School of Atmospheric Sciences Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Guangdong Province Key Laboratory for Climate Change and Natural disaster Studies Zhuhai 519082China

In this study,we put forward a radiative-convective-transportive energy balance model of a gray atmosphere to examine individual roles of the greenhouse effect of water vapor,vertical convection,and atmospheric poleward energy transport as well as their combined effects for a quasi-linear relationship between the outgoing longwave radiation(OLR)and surface temperature(T_(S)).The greenhouse effect of water vapor enhances the meridional gradient of surface temperature,thereby directly contributing to a quasi-linear OLR-T_(S) *** atmospheric poleward energy transport decreases the meridional gradient of surface *** a result of the poleward energy transport,tropical(high-latitude)atmosphere-surface columns emit less(more)OLR than the solar energy input at their respective locations,causing a substantial reduction of the meridional gradient of the *** combined effect of reducing the meridional gradients of both OLR and surface temperature by the poleward energy transport also contributes to the quasi-linear OLR-T_(S) *** convective energy transport reduces the meridional gradient of surface temperature without affecting the meridional gradient of OLR,thereby suppressing part of the reduction to the increasing rate of OLR with surface temperature by the greenhouse effect of water vapor and poleward energy *** of the nature of the energy balance in the climate system,such a quasi-linear relationship is also a good approximation for the relationship between the annual-mean net downward solar energy flux at the top of the atmosphere and surface temperature.

关键词： outgoing longwave radiation greenhouse effect poleward energy transport

Lactate:a prospective target for therapeutic intervention in psychiatric disease

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Neural Regeneration Research 2024年第7期19卷 1473-1479页

作者： Yanhui cai Haiyun Guo Tianle Han Huaning Wang Department of Psychiatry Xijing HospitalFourth Military Medical UniversityXi’anShaanxi ProvinceChina Department of Anesthesiology and Perioperative Medicine Xijing HospitalFourth Military Medical UniversityXi’anShaanxi ProvinceChina

Although antipsychotics that act via monoaminergic neurotransmitter modulation have considera ble therapeutic effect,they cannot completely relieve clinical symptoms in patients suffering from psychiatric disorde *** may be attributed to the limited range of neurotransmitters that are regulated by psychotropic *** findings indicate the need for investigation of psychotropic medications that target less-studied neurotransmitte *** these candidate neurotransmitters,lactate is developing from being a waste metabolite to a glial-neuronal signaling molecule in recent *** studies have suggested that cerebral lactate levels change considerably in numerous psychiatric illnesses;animal experiments have also shown that the supply of exogenous la ctate exerts an antidepressant *** this review,we have described how medications targeting newer neurotransmitte rs offer promise in psychiatric diseases;we have also summarized the advances in the use of lactate(and its corresponding signaling pathways)as a signaling *** addition,we have described the alterations in brain lactate levels in depression,anxiety,bipolar disorder,and schizophrenia and have indicated the challenges that need to be overcome before brain lactate can be used as a therapeutic target in psychopharmacology.

关键词： antidepressant anxiety bipolar disorder depression lactate psychiatric disease psychopharmacology schizophrenia signal molecular therapeutics

Study on crustal thickness and the prediction of prolific depressions:the Bohai Basin as an example

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Acta Oceanologica Sinica 2024年第4期43卷 92-104页

作者： Mengke cai Gongcheng Zhang Wanyin Wang dingding Wang College of Geological Engineering and Geomatics Chang’an UniversityXi’an 710054China China National Offshore Oil Corporation(CNOOC)Research Institute Co. Ltd.Beijing 100028China Key Laboratory of Marine Geology and Environment Chinese Academy of SciencesQingdao 266071China National Engineering Research Center of Offshore Oil and Gas Exploration Beijing 100028China Department of Earth Environment and Resources SciencesUniversity of Naples FedericoⅡNaples 80138Italy

The deep crustal structure is closely related to oil and gas *** the oil and gas enrichment of depressions based on the Moho depth and crustal thickness is a promising research topic with significant implications for guiding exploration in petroliferous *** this study,seismic data were used as a constraint on the use of satellite gravity anomaly inversion to obtain the distribution of Moho depth and crustal thickness in the Bohai *** factors were calculated to analyze the differential distribution of deep crustal structural *** indicators,including the minimum Moho depth,minimum crustal thickness,sum of Moho stretching factors,and sum of crustal stretching factors,were *** component analysis was applied to reduce the dimensionality of the multi-indicator system and obtain an oil and gas enrichment score for quantitative prediction of favorable prolific *** deviation between the inverted Moho depth and seismic constraints was small;thus,the data effectively reflect the variations in the characteristics of each *** analysis revealed significant statistical features related to the minimum Moho depth/crustal thickness and the sum of Moho/crustal stretching factors associated with prolific *** on the oil and gas enrichment score,the depressions were classified into four categories related to their different deep crustal structural *** active ClassⅠ,ClassⅡ,and ClassⅢdepressions are predicted to be favorable prolific *** study expands the research on quantitatively predicting favorable prolific depressions in the Bohai Basin using the deep crustal structure and can contribute to reducing production costs and improving exploration efficiency in future explorations.

关键词： Bohai Basin satellite gravity anomaly deep crustal structure Moho depth crustal thickness favorable prolific depression

Cu-Based Materials for Enhanced C_(2+) Product Selectivity in Photo-/Electro-Catalytic CO_(2) Reduction: Challenges and Prospects

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Nano-Micro Letters 2024年第4期16卷 25-66页

作者： Baker Rhimi Min Zhou Zaoxue Yan Xiaoyan cai Zhifeng Jiang Institute for Energy Research School of Chemistry and Chemical EngineeringJiangsu UniversityZhenjiang 212013People’s Republic of China School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221116People’s Republic of China

Carbon dioxide conversion into valuable products using photocatalysis and electrocatalysis is an effective approach to mitigate global environmental issues and the energy shortages. Among the materials utilized for catalytic reduction of CO_(2), Cu-based materials are highly advantageous owing to their widespread availability, cost-effectiveness, and environmental sustainability. Furthermore, Cu-based materials demonstrate interesting abilities in the adsorption and activation of carbon dioxide, allowing the formation of C_(2+) compounds through C–C coupling process. Herein, the basic principles of photocatalytic CO_(2) reduction reactions(PCO_(2)RR) and electrocatalytic CO_(2) reduction reaction(ECO_(2)RR) and the pathways for the generation C_(2+) products are introduced. This review categorizes Cu-based materials into different groups including Cu metal, Cu oxides, Cu alloys, and Cu SACs, Cu heterojunctions based on their catalytic applications. The relationship between the Cu surfaces and their efficiency in both PCO_(2)RR and ECO_(2)RR is emphasized. Through a review of recent studies on PCO_(2)RR and ECO_(2)RR using Cu-based catalysts, the focus is on understanding the underlying reasons for the enhanced selectivity toward C_(2+) products. Finally, the opportunities and challenges associated with Cu-based materials in the CO_(2) catalytic reduction applications are presented, along with research directions that can guide for the design of highly active and selective Cu-based materials for CO_(2) reduction processes in the future.

关键词： Photocatalytic CO_(2)reduction Cu-based materials Electrocatalytic CO_(2)reduction

Limits of Uneven Battery Power in Modular Multilevel Converter-based Battery Energy Storage Systems

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 686-695页

作者： Yao Pan Xiaofeng Sun Wei Zhao Xin Li Yao cai Institute of Electrical Engineering Yanshan UniversityQinhuangdao 066004China

For modular multilevel converter-based battery energy storage systems (MMC-BESS), uneven power among batteries of SMs will be deduced by battery aging, battery fault, etc., which will degrade performance and even lead to system failure. For maintaining the balance of capacitor voltage, this paper analyzes the limits of the uneven power of batteries, which are presented as the current limits in this paper. According to analysis, an analytical method is proposed that only the dc and fundamental frequency components of the arm current are used to calculate current limits. With the current limits it is able to evaluate the reasonability of power distribution among batteries. Meanwhile, increase of fundamental frequency component will enhance the current limits, and the dc component determines the size relationship between the absolute values of the upper and lower current limits. Finally, simulation model and experiment prototype are built for verifying the theoretical analysis and current limits calculation method, and satisfactory results are provided.

关键词： Arm current balance of capacitor voltage current limits MMC-BESS uneven power

Hydrodynamics and OCM reaction performance in a bubbling fluidized bed reactor and a riser reactor

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Particuology 2024年第3期86卷 188-204页

作者： Min cai Shuangzhu Kong Sheng Chen Mengxi Liu Chunxi Lu State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China China Special Equipment Inspection and Research Institute Beijing102249China

The reasonable reactor design is of great importance for increasing the C_(2) yield(C2H4 and C2H6)of the oxidative coupling of methane(OCM),and the OCM reactor should remove the heat released in reactions quickly and efficiently and minimize the consecutive reaction of ethylene to carbon *** fluidized bed reactor is characterized by excellent heat transfer,superior mass transport,and large handling capacity,while fewer studies focused on large-scale fluidized bed reactors for the OCM ***,large cold-model experiments and computational fluid dynamics simulations were conducted to investigate hydrodynamics and the OCM reaction performance in a large-scale bubbling fluidized bed(BFB)and a large-scale *** the BFB reactor,consecutive reactions of ethylene are acute because of the strong gas back-mixing,high solids holdup,and non-uniform solids *** the consecutive reactions of ethylene are negligible due to the plug flow structure and low solids holdup in the riser ***,both reactors can achieve isothermal operation for the OCM *** C_(2) selectivity of 45.4% and C_(2) yield of 21.1% are obtained in the riser reactor,increasing by 20.3% and 5.8% individually than that in the BFB *** study provides useful information and reference to the OCM reactor designandcommercialization.

关键词： Oxidative coupling of methane Bubbling fluidized bed reactor Riser reactor Hydrodynamics Isothermal operation

Self-reinforced Calcium Phosphate Cement Inspired by Sea Cucumber Dermis

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 682-688页

作者：吴治文 WANG Zihao cai Zepeng QU Liting 于涛 College of Chemistry and Materials Science Jinan UniversityGuangzhou 510632China Guangdong Provincial Key Laboratory of Spine and Spinal Cord Reconstruction The Fifth Affiliated Hospital(Heyuan Shenhe People’s Hospital)Jinan UniversityHeyuan 517000China

A composite bone cement based onα-TCP with self-reinforcing characteristics is prepared by compounding cellulose whiskers and polyvinyl alcohol in different *** this system,we are inspired by the sea cucumber,which can alter the stiffness of their inner dermis *** the formation of hydrogen bonds between the hydroxyl groups on the cellulose whiskers and PVA,the bone cement matrix can be strengthened during the curing process of *** the process of bone cement blending,there is more water,the hydrogen bond connection is destroyed,so the slurry has better fluidity at this *** the hydration of the bone cement progresses,the reduction of the water phase leads to the formation of a permeable network structure of hydrogen bond connections between the *** dual-phase action of PVA and whiskers greatly increases the mechanical strength of the bone cement system(5.5 to 23.8 MPa),while the presence of polyvinyl alcohol improves the toughness of the bone cement *** work was supposed to explore whether the chemoresponsive materials can be adapted to biomedical materials,for example,bone repair.

关键词： bone repair self-reinforce chemoresponsive hydrogen bond

Multi-faceted spatio-temporal network for weather-aware air traffic flow prediction in multi-airport system

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Chinese Journal of Aeronautics 2024年第7期37卷 301-316页

作者： Kaiquan cai Shuo TANG Shengsheng QIAN Zhiqi SHEN Yang YANG School of Electronic and Information Engineering Beihang UniversityBeijing 100191China State Key Laboratory of CNS/ATM Beijing100191China Institute of Automation Chinese Academy of SciencesBeijing 100190China Research Institute for Frontier Science Beihang UniversityBeijing 100191China

As one of the core modules for air traffic flow management,Air Traffic Flow Prediction(ATFP)in the Multi-Airport System(MAS)is a prerequisite for demand and capacity balance in the complex meteorological *** to the challenge of implicit interaction mechanism among traffic flow,airspace capacity and weather impact,the Weather-aware ATFP(Wa-ATFP)is still a nontrivial *** this paper,a novel Multi-faceted Spatio-Temporal Graph Convolutional Network(MSTGCN)is proposed to address the Wa-ATFP within the complex operations of ***,a spatio-temporal graph is constructed with three different nodes,including airport,route,and fix to describe the topology structure of ***,a weather-aware multi-faceted fusion module is proposed to integrate the feature of air traffic flow and the auxiliary features of capacity and weather,which can effectively address the complex impact of severe weather,e.g.,***,to capture the latent connections of nodes,an adaptive graph connection constructor is *** experimental results with the real-world operational dataset in Guangdong-Hong Kong-Macao Greater Bay Area,China,validate that the proposed approach outperforms the state-of-the-art machine-learning and deep-learning based baseline approaches in performance.

关键词： Air traffic control Graph neural network Multi-faceted information Air traffic flow prediction Multi-airport system