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Analysis of sensitivity to hydrate blockage risk in natural gas gathering pipeline

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Petroleum Science 2024年第4期21卷 2723-2733页

作者： Ao-Yang Zhang Meng Cai Na wei Hai-Tao Li chao Zhang Jun Pei Xin-wei Wang State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Research Institute of Production Engineering Daqing Oilfield Co.Ltd.

During the operational process of natural gas gathering and transmission pipelines, the formation of hydrates is highly probable, leading to uncontrolled movement and aggregation of hydrates. The continuous migration and accumulation of hydrates further contribute to the obstruction of natural gas pipelines, resulting in production reduction, shutdowns, and pressure build-ups. Consequently, a cascade of risks is prone to occur. To address this issue, this study focuses on the operational process of natural gas gathering and transmission pipelines, where a comprehensive framework is established. This framework includes theoretical models for pipeline temperature distribution, pipeline pressure distribution, multiphase flow within the pipeline, hydrate blockage, and numerical solution methods. By analyzing the influence of inlet temperature, inlet pressure, and terminal pressure on hydrate formation within the pipeline, the sensitivity patterns of hydrate blockage risks are derived. The research indicates that reducing inlet pressure and terminal pressure could lead to a decreased maximum hydrate formation rate, potentially mitigating pipeline blockage during natural gas transportation. Furthermore, an increase in inlet temperature and terminal pressure, and a decrease in inlet pressure, results in a displacement of the most probable location for hydrate blockage towards the terminal station. However,it is crucial to note that operating under low-pressure conditions significantly elevates energy consumption within the gathering system, contradicting the operational goal of energy efficiency and reduction of energy consumption. Consequently, for high-pressure gathering pipelines, measures such as raising the inlet temperature or employing inhibitors, electrical heat tracing, and thermal insulation should be adopted to prevent hydrate formation during natural gas transportation. Moreover, considering abnormal conditions such as gas well production and pipeline network s

关键词： Natural gas hydrates Gathering pipeline Temperature variation Hydrate formation rate Sensitivity analysis

Effects of Helicobacter pylori and Moluodan on the Wnt/β-catenin signaling pathway in mice with precancerous gastric cancer lesions

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 979-990页

作者： Yi-Mei Wang Zheng-wei Luo Yu-Lin Shu Xiu zhou Lin-Qing Wang Chun-Hong Liang chao-Qun Wu Chang-Ping Li Department of Gastroenterology The Affiliated Hospital of Southwest Medical UniversityLuzhou 646000Sichuan ProvinceChina

BACKGROUND Helicobacter pylori(***)is the primary risk factor for gastric cancer(GC),the Wnt/β-Catenin signaling pathway is closely linked to *** has a high mortality rate and treatment cost,and there are no drugs to prevent the progression of gastric precancerous lesions to ***,it is necessary to find a novel drug that is inexpensive and preventive to against *** To explore the effects of *** and Moluodan on the Wnt/β-Catenin signaling pathway and precancerous lesions of GC(PLGC).METHODS Mice were divided into the control,N-methyl-N-nitrosourea(MNU),***+MNU,and Moluodan *** first created an *** infection model in the ***+MNU and Moluodan groups.A PLGC model was created in the remaining three groups except for the control *** was fed to mice in the Moloudan group ad *** general condition of mice were observed during the whole experiment *** tissues of mice were grossly and microscopically *** quantitative real-time PCR(qRT-PCR)and Western blotting analysis,the expression of relevant genes were *** Mice in the ***+MNU group showed the worst performance in general condition,gastric tissue visual and microscopic observation,followed by the MNU group,Moluodan group and the control ***-PCR and Western blotting analysis were used to detect the expression of relevant genes,the results showed that the ***+MNU group had the highest expression,followed by the MNU group,Moluodan group and the control *** *** can activate the Wnt/β-catenin signaling pathway,thereby facilitating the development and progression of *** suppressed the activation of the Wnt/β-catenin signaling pathway,thereby decreasing the progression of PLGC.

关键词： Helicobacter pylori Gastric cancer Wnt/β-catenin signaling pathway Moluodan

A Cloud-Fog Enabled and Privacy-Preserving IoT Data Market Platform Based on Blockchain

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 2237-2260页

作者： Yurong Luo wei You chao Shang Xiongpeng Ren Jin Cao Hui Li School of Cyber Engineering State Key Laboratory of Integrated Service NetworkXidian UniversityXi’an710126China

The dynamic landscape of the Internet of Things(IoT)is set to revolutionize the pace of interaction among entities,ushering in a proliferation of applications characterized by heightened quality and *** the pivotal applications within the realm of IoT,as a significant example,the Smart Grid(SG)evolves into intricate networks of energy deployment marked by data *** evolution concurrently entails data interchange with other IoT ***,there are also several challenges including data-sharing overheads and the intricate establishment of trusted centers in the IoT *** this paper,we introduce a hierarchical secure data-sharing platform empowered by cloud-fog ***,we propose a novel non-interactive zero-knowledge proof-based group authentication and key agreement protocol that supports one-to-many sharing sets of IoT data,especially SG *** security formal verification tool shows that the proposed scheme can achieve mutual authentication and secure data sharing while protecting the privacy of data *** with previous IoT data sharing schemes,the proposed scheme has advantages in both computational and transmission efficiency,and has more superiority with the increasing volume of shared data or increasing number of participants.

关键词： IoT data sharing zero-knowledge proof authentication privacy preserving blockchain

Weak interaction-steered evolution of polyoxovanadate-based metal-organic polyhedra from transformation via interlock to packing

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Chinese Chemical Letters 2024年第2期35卷 527-533页

作者： Yan-Hu Wang Ke-wei Tong chao-Qin Chen Jing Du Peng Yang College of Chemistry and Chemical Engineering Advanced Catalytic Engineering Research Center of the Ministry of EducationHunan UniversityChangsha 410082China College of Chemistry and Materials Science Testing and Analysis CenterHebei Normal UniversityShijiazhuang 050024China

A bottleneck in biomimetic synthesis consists in the full copy of,for example,the hierarchical structure of proteins directed by weak *** contrast with covalent bonds bearing definite orientation and high stability,weak intermolecular forces within a continuous dynamic equilibrium can be hardly tamed for molecular *** this endeavor,a ligand-dominated strategy that embodies tunable electrostatic repulsion andπ···πstacking was first employed to shape polyoxovanadate-based metal-organic polyhedra(VMOPs).Structural evolution involving transformation,interlock,and discovery of an unprecedented prototype of the Star of David was hence *** only as a handy tool for the primary structural control over VMOPs,these weak forces allow for an advanced management on the spatial distribution of such manmade macromolecules as well as the associated physicochemical behaviors,representing an ideal model for simulating and interpreting the conformation-function relationship of proteins.

关键词： Polyoxometalates Polyoxovanadates Metal-organic polyhedron Interlock Weak intermolecular forces

In situ embedded bismuth nanoparticles among highly porous carbon fibers for efficient carbon dioxide reduction

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Rare Metals 2024年第9期43卷 4312-4320页

作者： wei-Jian Guo Ao zhou Wen-Wen Cai Jin-Tao Zhang Key Laboratory for Colloid and Interface Chemistry (Ministry of Education) School of Chemistry and Chemical EngineeringShandong University

Electrocatalysis provides an optimal approach for the conversion of carbon dioxide(CO2) into high-value chemicals, thereby presenting a promising avenue toward achieve carbon neutrality. However, addressing the selectivity and stability challenges of metal catalysts in electrolytic reduction remains a daunting task. In this study, the electrospinning method is employed to fabricate porous carbon nanofibers loaded with bismuth nanoparticles with the help of in situ pyrolysis. The porous carbon nanofibers as conductive support would facilitate the dispersion of bismuth active sites while inhibiting their aggregation and promoting the mass transfer, thus enhancing their electrocatalytic activity and stability. Additionally, nitrogen doping induces electron delocalization in bismuth atoms through metal-support interactions, thus enabling efficient adsorption of intermediates for improving selectivity based on the theoretical calculation. Consequently, Bi@PCNF-500 exhibits the exceptional selectivity and stability across a wide range of potential windows. Notably, its faradaic efficiency(FE) of formate reaches 92.7% in H-cell and94.9% in flow cell, respectively, with good electrocatalytic stability. The in situ characterization and theoretical calculations elucidate the plausible reaction mechanism to obtain basic rules for designing efficient electrocatalyst.

关键词： Carbon dioxide reduction Electron delocalization N-doping Porous carbon nanofiber

Deformation of Rigid Conjugate Self-dual Galois Representations

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Acta Mathematica Sinica,English Series 2024年第7期40卷 1599-1644页

作者： Yi Feng LIU Yi chao TIAN Liang XIAO wei ZHANG Xin Wen ZHU Institute for Advanced Study in Mathematics Zhejiang UniversityHangzhou 310058P.R.China Morningside Center of Mathematics AMSSChinese Academy of SciencesBeijing 100190P.R.China New Cornerstone Lab Beijing International Center for Mathematical ResearchPeking Ui Beijing 100871P.R.China Department of Mathematics Massachusetts Institute of TechnologyCambridge MA 02139United States Department of Mathematics Stanford UniversityStanfordCA 94305United States

In this article,we study deformations of conjugate self-dual Galois *** study is ***,we prove an R=T type theorem for a conjugate self-dual Galois representation with coefficients in a finite field,satisfying a certain property called ***,we study the rigidity property for the family of residue Galois representations attached to a symmetric power of an elliptic curve,as well as to a regular algebraic conjugate self-dual cuspidal representation.

关键词： Galois deformation rigid conjugate self-dual Galois representations

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The Consistency of LSE Estimators in Partial Linear Regression Models under Mixing Random Errors

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Acta Mathematica Sinica,English Series 2024年第5期40卷 1244-1272页

作者： Yun Bao YAO Yu Tan LÜ chao LU wei WANG Xue Jun WANG School of Mathematical Sciences Anhui UniversityHefei 230601P.R.China School of Big Data and Artificial Intelligence Chizhou UniversityChizhou 247000P.R.China School of Big Data and Statistics Anhui UniversityHefei 230601P.R.China

In this paper,we consider the partial linear regression model y_(i)=x_(i)β^(*)+g(ti)+ε_(i),i=1,2,...,n,where(x_(i),ti)are known fixed design points,g(·)is an unknown function,andβ^(*)is an unknown parameter to be estimated,random errorsε_(i)are(α,β)-mix_(i)ng random *** p-th(p>1)mean consistency,strong consistency and complete consistency for least squares estimators ofβ^(*)and g(·)are investigated under some mild *** addition,a numerical simulation is carried out to study the finite sample performance of the theoretical ***,a real data analysis is provided to further verify the effect of the model.

关键词： (α,β)-mixing random variables partial linear regression model least squares estimator consistency

A supramolecular self-assembly material based on cucurbituril and cationic TPE as ultra-sensitive probe of energetic pentazolate salts

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Defence Technology（防务技术） 2024年第5期35卷 69-76页

作者： Boan Tang Jingxiang Zhong Shutao Wang Shiyu zhou Yongxing Tang wei Huang School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094China

The successful synthesis of the pentazolate anion(cyclo-N-5)has been a great breakthrough in the field of energetic ***,the detection methods for these energetic materials based on the pentazolate anion are quite ***,two fluorescent probes for cyclo-N-5anion were *** 1(TPE2N)was synthesized with a tetraphenylethylene functionalized by two cationic groups which can generate strong electrostatic interactions with pentazolate anion and result in specific fluorescent *** 2 was designed based on sensor 1 and supramolecular cucurbit[7]uril(CB[7]).The unique structural features of CB[7]provide sites for the interaction between the cations and N-5anion in its cavity,which would generate a platform for the detection and enhance the recognition *** titration calorimetry(ITC)experiment and fluorescence titration experiment indicate the binding molar ratio between sensor 1 with CB[7]is 1:*** sensors display typical aggregation-induced emission(AIE)features and good *** sensors demonstrate excellent sensitivity to pentazole hydrazine salt with high enhancement constant(sensor 1:1.34×10^(6);sensor 2:3.78×10^(6))and low limit of detection(LOD:sensor 1=4.33μM;sensor 2=1.54μM).The formation of an AIE-based supramolecular sensor effectively improves the sensitivity to *** addition,the probes also have good selectivity of N-5anion *** research would shed some light on the design of novel fluorescent sensors to detect pentazolate-based molecules and provides an example of supramolecular chemistry combined with fluorescent probes.

关键词： Pentazolate anion Explosives detection Aggregation-induced emission(AIE) Host-guest interaction

Optimal search path planning of UUV in battlefeld ambush scene

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Defence Technology（防务技术） 2024年第2期32卷 541-552页

作者： wei Feng Yan Ma Heng Li Haixiao Liu Xiangyao Meng Mo zhou Naval Research Institute Beijing100161China

Aiming at the practical application of Unmanned Underwater Vehicle(UUV)in underwater combat,this paper proposes a battlefield ambush scene with UUV considering ocean ***,by establishing these mathematical models of ocean current environment,target movement,and sonar detection,the probability calculation methods of single UUV searching target and multiple UUV cooperatively searching target are given ***,based on the Hybrid Quantum-behaved Particle Swarm Optimization(HQPSO)algorithm,the path with the highest target search probability is ***,through simulation calculations,the influence of different UUV parameters and target parameters on the target search probability is analyzed,and the minimum number of UUVs that need to be deployed to complete the ambush task is demonstrated,and the optimal search path scheme is *** method proposed in this paper provides a theoretical basis for the practical application of UUV in the future combat.

关键词： Battlefield ambush Optimal search path planning UUV path Planning Probability of cooperative search