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Simultaneously achieving high sensitivity, low dark current and low detection limits in anti-perovskites towards X-ray detection

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Science China Materials 2024年第11期67卷 3757-3758页

作者： Haixing.meng Ying Li School of Integrated Circuits and Electronics Beijing Institute of Technology

X-ray detection technology plays an important role in various fields such as medical diagnosis, security inspection, nondestructive testing, space exploration, and scientific research. In recent years, X-ray direct detection has become a research hotspot due to its inherent advantages, such as high spatial resolution and simple configuration [1,2].

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Recent breakthrough in AI-driven materials science:tech giants introduce groundbreaking models

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Materials Futures 2024年第2期3卷 170-174页

作者： Miao Liu Sheng.meng Institute of Physics Chinese Academy of SciencesBeijing 100190People’s Republic of China Songshan Lake Materials Laboratory DongguanGuangdong 523808People’s Republic of China

A close look at google’s gNoME inorganic materials dataset(Merchant et al 2023 Nature 62480–85),and 11 things you would like to know.

关键词： AI gNoME dataset AI+materials science

Effect of stress-dependent microannulus aperture on well leakage

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Journal of Rock Mechanics and geotechnical Engineering 2024年第6期16卷 1967-1976页

作者： Meng.meng Luke P.Frash J.William Carey Mohamed Mehana Wenfeng Li Bailian Chen Earth and Environmental Sciences Los Alamos National LaboratoryLos AlamosNMUSA

Debonding at the cement-casing interface is recognized as a principal failure mechanism leading to CO_(2) leakage in *** detachment gives rise to a microannulus,which notably possesses greater permeability than undamaged cement,undermining its sealing ***,the permeability of the microannulus is regarded as a uniform value throughout the ***,fundamentally,a microannulus is one type of fracture,and its gap or aperture size is affected by the effective *** this work,we developed a unique experimental *** equipment facilitates the curing of cement inside a steel casing,the formation of a microannulus between the casing and the cement,and the investigation of the fluid flow dynamics along the microannulus under laboratory-replicated in situ *** microannulus was formed by injecting fluid from one end of the setup,and receiving similar amount of fluid on the other end signified the development of the leakage ***,strain gauges affixed to the casing’s external surface yielded key information on the microannulus’s opening and *** observed a noticeable decline in microannulus hydraulic aperture(or permeability)in relation to effective stress and an exponential equation fits their *** findings also indicate a distinct behavior when comparing liquid CO_(2) with ***,it is easier for liquid CO_(2) to create the ***,the hydraulic aperture range for this microannulus(0.7-6 mm)is considerably smaller than that created by water flow(2-17 mm).Finally,we integrated the stressdependent microannulus aperture size into the combined analysis of well mechanical integrity and well *** outcomes consistently demonstrated that when factoring in the stress-dependent aperture sizes,the leakage rates are 3e5 times compared to a fixed aperture *** traditional assumption of a constant aperture significantly underestimates fluid leakage risks.

关键词： Microannulus Leakage assessment Aperture size Triaxial experiment Carbon sequestration

Development of a deviation package method for low-cost robust optimization in compressor blade design

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Chinese Journal of Aeronautics 2024年第4期37卷 166-180页

作者： Mingzhi LI Xianjun YU Dejun meng guangfeng AN Baojie LIU Research Institute of Aero-Engine Beihang UniversityBeijing 100191China National Key Laboratory of Science&Technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing 100191China AECC Shenyang Engine Research Institute Shenyang 110015China

Manufacture variations can greatly increase the performance variability of compressor blades. Current robust design optimization methods have a critical role in reducing the adverse impact of the variations, but can be affected by errors if the assumptions of the deviation models and distribution parameters are inaccurate. A new approach for robust design optimization without the employment of the deviation models is proposed. The deviation package method and the interval estimation method are exploited in this new approach. Simultaneously, a stratified strategy is used to reduce the computational cost and assure the optimization accuracy. The test case employed for this study is a typical transonic compressor blade profile, which resembles most of the manufacture features of modern compressor blades. A set of 96 newly manufactured blades was measured using a coordinate measurement machine to obtain the manufacture variations and produce a deviation package. The optimization results show that the scatter of the aerodynamic performance for the optimal robust design is 20% less than the baseline value. By comparing the optimization results obtained from the deviation package method with those obtained from widely-used methods employing the deviation model, the efficiency and accuracy of the deviation package method are demonstrated. Finally, the physical mechanisms that control the robustness of different designs were further investigated, and some statistical laws of robust design were extracted.

关键词： Manufacture variations Robust design optimization Compressor leading edge Aerodynamics Physical mechanism

Proppant transport in rough fracture networks using supercritical CO_(2)

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Petroleum Science 2024年第3期21卷 1852-1864页

作者： Yong Zheng.meng-meng Zhou Ergun Kuru Bin Wang Jun Ni Bing Yang Ke Hu Hai Huang Hai-Zhu Wang School of Petroleum Engineering Xi'an Shiyou UniversityXian710065ShaanxiChina Shaanxi Key Laboratory of Carbon Dioxide Sequestration and Enhanced Oil Recovery Xi'an710075ShaanxiChina State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing2249China School of Mining and Petroleum Engineering University of AlbertaEdmontonTG2W2AlbertaCanad Shaanxi Yanchang Petroleum(group)Co. Ltd.Xi'an710075ShaanxiChina

Proppant transport within fractures is one of the most critical tasks in oil,gas and geothermal reservoir stimulation,as it largely determines the ultimate performance of the operating *** transport in rough fracture networks is still a relatively new area of research and the associated transport mechanisms are still *** this study,representative parameters of rough fracture surfaces formed by supercritical CO_(2) fracturing were used to generate a rough fracture network model based on a spectral synthesis *** fluid dynamics(CFD)coupled with the discrete element method(DEM)was used to study proppant transport in this rough fracture *** reveal the turning transport mechanism of proppants into branching fractures at the intersections of rough fracture networks,a comparison was made with the behavior within smooth fracture networks,and the effect of key pumping parameters on the proppant placement in a secondary fracture was *** results show that the transport behavior of proppant in rough fracture networks is very different from that of the one in the smooth fracture *** turning transport mechanisms of proppant into secondary fractures in rough fracture networks are gravity-driven sliding,high velocity fluid suspension,and fracture structure *** the same injection conditions,supercritical CO_(2)with high flow Reynolds number still has a weaker ability to transport proppant into secondary fractures than *** of the supercritical CO_(2)needs to be increased beyond a certain value to have a significant effect on proppant carrying,and under the temperature and pressure conditions of this paper,it needs to be increased more than 20 times(about 0.94 m Pa s).Increasing the injection velocity and decreasing the proppant concentration facilitates the entry of proppant into the branching fractures,which in turn results in a larger stimulated reservoir *** results help to understand the pro

关键词： Reservoir stimulation CCUS Rough fracture network Supercritical CO_(2) Proppanttransport

A review on ultra-small undoped MoS_(2) as advanced catalysts for renewable fuel production

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Carbon Energy 2024年第2期6卷 92-112页

作者： guoping Liu Lingling Ding Yuxuan meng Ahmad Ali guifu Zuo Xianguang.meng Kun Chang Oi Lun Li Jinhua Ye Hebei Provincial Laboratory of Inorganic Nonmetallic Materials College of Materials Science and EngineeringNorth China University of Science and TechnologyTangshanChina College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjingChina School of Materials Science and Engineering Pusan National UniversityBusanKorea International Center for Materials Nanoarchitectonics(WPIMANA) National Institute for Materials Science(NIMS)1-1 NamikiTsukubaIbarakiJapan

Molybdenum disulfide(MoS_(2))has garnered significant attention in the field of catalysis due to the high density of active sites in its unique two-dimensional(2D)structure,which could be developed into numerous high-performance *** synthesis of ultra-small MoS2 particles(ghly desired in various experimental *** ultra-small structure could often lead to a distinct S-Mo coordination state and nonstoichiometric composition in MoSx,minimizing in-plane active sites of the 2D structure and making it probable to regulate the atomic and electronic structure of its intrinsic active sites on a large extent,especially in MoSx *** article summarizes the recent progress of catalysis over ultra-small undoped MoS_(2) particles for renewable fuel *** a systematic review of their synthesis,structural,and spectral characteristics,as well as the relationship between their catalytic performance and inherent defects,we aim to provide insights into catalysis over this matrix that may potentially enable advancement in the development of high-performance MoS_(2)-based catalysts for sustainable energy generation in the future.

关键词： applications catalytic MoS_(2) structure synthesis

SFC placement and dynamic resource allocation based on VNF performance-resource function and service requirement in cloud-edge environment

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Journal of Systems Engineering and Electronics 2024年第4期35卷 906-921页

作者： HAN Yingchao meng Weixiao FAN Wentao School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China China Mobile(Suzhou)Software Technology Company Limited Suzhou 215000China

With the continuous development of network func-tions virtualization(NFV)and software-defined networking(SDN)technologies and the explosive growth of network traffic,the requirement for computing resources in the network has risen *** to the high cost of edge computing resources,coordinating the cloud and edge computing resources to improve the utilization efficiency of edge computing resources is still a considerable *** this paper,we focus on optimiz-ing the placement of network services in cloud-edge environ-ments to maximize the *** is first proved that,in cloud-edge environments,placing one service function chain(SFC)integrally in the cloud or at the edge can improve the utilization efficiency of edge *** a virtual network function(VNF)performance-resource(P-R)function is proposed to repre-sent the relationship between the VNF instance computing per-formance and the allocated computing *** select the SFCs that are most suitable to deploy at the edge,a VNF place-ment and resource allocation model is built to configure each VNF with its particular P-R ***,a heuristic recur-sive algorithm is designed called the recursive algorithm for max edge throughput(RMET)to solve the *** simula-tions on two scenarios,it is verified that RMET can improve the utilization efficiency of edge computing resources.

关键词： cloud-edge environment virtual network function(VNF)performance-resource(P-R)function edge resource allo-cation

Evolutionary mechanisms and practical significance of reproductive success and clonal diversity in unisexual vertebrate polyploids

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Science China(Life Sciences) 2024年第3期67卷 449-459页

作者： meng Lu Li Zhou Jian-Fang gui State Key Laboratory of Freshwater Ecology and Biotechnology Hubei Hongshan Laboratorythe Innovation Academy of Seed DesignInstitute of HydrobiologyChinese Academy of SciencesWuhan 430072China University of Chinese Academy of Sciences Beijing 100049China

Unisexual reproduction is generally relevant to polyploidy, and unisexual vertebrates are often considered an evolutionary “dead end” due to the accumulation of deleterious mutations and absence of genetic diversity. However, some unisexual polyploids have developed strategies to avoid genomic decay, and thus provide ideal models to unveil unexplored evolutionary mechanisms, from the reproductive success to clonal diversity creation. This article reviews the evolutionary mechanisms for overcoming meiotic barrier and generating genetic diversity in unisexual vertebrates, and summarizes recent research advancements in the polyploid Carassius complex. gynogenetic gibel carp(Carassius gibelio) is a unique amphitriploid that has undergone a recurrent autotriploidy and has overcome the bottleneck of triploid sterility via gynogenesis. Recently, an efficient strategy in which ploidy changes, including from amphitriploid to amphitetraploid, then from amphitetraploid to novel amphitriploid, drive unisexual-sexual-unisexual reproduction transition and clonal diversity has been *** on this new discovery, multigenomic reconstruction biotechnology has been used to breed a novel strain with superior growth and stronger disease resistance. Moreover, a unique reproduction mode that combines both abilities of ameiotic oogenesis and sperm-egg fusion,termed as ameio-fusiongensis, has been discovered, and it provides an efficient approach to synthesize sterile allopolyploids. In order to avoid ecological risks upon escape and protect the sustainable property rights of the aquaculture seed industry, a controllable fertility biotechnology approach for precise breeding is being developed by integrating sterile allopolyploid synthesis and gene-editing *** review provides novel insights into the origin and evolution of unisexual vertebrates and into the attempts being made to exploit new breeding biotechnologies in aquaculture.

关键词： unisexual vertebrates polyploidy reproduction transition clonal diversity precise breeding genomic reconstruction controllable fertility

BAD-FM:Backdoor Attacks Against Factorization-Machine Based Neural Network for Tabular Data Prediction

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Chinese Journal of Electronics 2024年第4期33卷 1077-1092页

作者： Lingshuo meng Xueluan gONg Yanjiao CHEN College of Electrical Engineering Zhejiang University School of Computer Science Wuhan University

Backdoor attacks pose great threats to deep neural network models. All existing backdoor attacks are designed for unstructured data(image, voice, and text), but not structured tabular data, which has wide real-world applications, e.g., recommendation systems, fraud detection, and click-through rate prediction. To bridge this research gap, we make the first attempt to design a backdoor attack framework, named BAD-FM, for tabular data prediction models. Unlike images or voice samples composed of homogeneous pixels or signals with continuous values, tabular data samples contain well-defined heterogeneous fields that are usually sparse and discrete. Tabular data prediction models do not solely rely on deep networks but combine shallow components(e.g., factorization machine, FM) with deep components to capture sophisticated feature interactions among fields. To tailor the backdoor attack framework to tabular data models, we carefully design field selection and trigger formation algorithms to intensify the influence of the trigger on the backdoored model. We evaluate BAD-FM with extensive experiments on four datasets, i.e.,HUAWEI, Criteo, Avazu, and KDD. The results show that BAD-FM can achieve an attack success rate as high as 100%at a poisoning ratio of 0.001%, outperforming baselines adapted from existing backdoor attacks against unstructured data models. As tabular data prediction models are widely adopted in finance and commerce, our work may raise alarms on the potential risks of these models and spur future research on defenses.

关键词： Adaptation models Systematics Frequency modulation Finance Predictive models Prediction algorithms Data models