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BackgroundThe etiology and pathogenesis of somatic symptom disorder are complicated， for which no effective treatment currently exists， posing a critical impact on their quality of life.ObjectiveTo analyze the current situation and development trend in domestic and foreign research on somatic symptom disorder from 2011 to 2021， and to better understand the research frontiers and hot spots in this field.MethodsOn 31 August 2022， literature on somatic symptom disorder published from January 1， 2011 to January 1， 2023 were searched in China National knowledge Infrastructure （CNKI）， Wanfang Data Knowledge Service Platform， Web of Science and PubMed， and a total of 15 035 articles were included， then the visualization analysis of the number of publications and keywords was conducted based on Microsoft Excel and CiteSpace software.ResultsIn the field of somatic symptoms disorder research from 2011 to 2021， the number of annual publications demonstrated an overall upward trend in foreign studies， and displayed a slow downward trend in domestic studies. The keyword co-occurrence network analysis revealed that the top five high-frequency keywords were "mental health" "depressive disorder" "depression" "anxiety" and "somatic symptom" in domestic studies， and were "symptom" "prevalence" "depression" "disorder" and "quality of life" in foreign studies. The burst analysis suggested that the burst terms in past five years were "somatic symptom" "syndrome" and "quality of life" in domestic studies， and were "major depressive disorder" and "outcome" in foreign studies. The clustering analysis yielded 8 clusters in domestic studies and 4 clusters in foreign studies， reflecting in the related disease， prevention and treatment protocols and epidemiological characteristics of somatic symptom disorder.ConclusionIn recent years， the publications and academic concerns regarding the research on somatic symptom disorder show an upward trend in foreign studies and are relatively inadequate in domestic studies， and both the domestic and foreign studies have been focused on the influencing factors of somatic symptom disorder. ［Funded by the Medical Health Science and Technology Project of Zhejiang Provincial （number， 2020PY064）； Medical Health Science and Technology Project of Hangzhou （number， 0020190783）］

The energy consumption of oil collection increases rapidly after oilfield enters the stage of high water cut. Carrying out gathering and transportation at normal or low temperature can save cost and bring certain enterprise benefit. In order to judge whether the gathering and transportation can be carried out at normal or low temperature, the thermodynamic hydraulic calculation model is constructed and modified according to the field measured data. Then the thermally hydraulic coupling calculation is carried out to determine the gathering and transportation radius. The single factor sensitivity analysis method was used to rank the sensitivity of the factors influencing the gathering and transportation radius, and the radius chart is made. The results show that the modified thermo-hydraulic model can better predict the temperature and pressure drop, and the average error of the calculated and the measured value is 2.5% and 7.67%. The four most influential factors from strong to weak are starting point temperature, liquid yield, moisture content of mass and ambient temperature. The chart drawn by the factors provides the basis for the normal temperature gathering and transportation of the pipeline, so the required temperature at the start of the pipe can be determined by querying the chart.

The current study is a simplification of related components of large floating roof tank and modeling for three dimensional temperature field of large floating roof tank. The heat transfer involves its transfer between the hot fluid in the oil tank, between the hot fluid and the tank wall and between the tank wall and the external environment. The mathematical model of heat transfer and flow of oil in the tank simulates the temperature field of oil in tank. Oil temperature field of large floating roof tank is obtained by numerical simulation, map the curve of central temperature dynamics with time and analyze axial and radial temperature of storage tank. It determines the distribution of low temperature storage tank location based on the thickness of the reservoir temperature. Finally, it compared the calculated results and the field test data; eventually validated the calculated results based on the experimental results.

AB line and C line of Trans-Asia natural gas pipeline has attained a gas transmission capacity as 55 billion cubic meters per year. In recent years, pipeline transportation throughput accounts for about 20% of Chinese apparent consumption of natural gas. In order to ensure an economic and efficient operation of this transnational pipeline system, this paper conducts a comprehensive study on the joint operation of AB line and C line of Uzbekistan section of Trans-Asia natural gas pipeline. This paper innovatively puts forward “Methods of correction on multi-pressure head and multi-performance curve of centrifugal compressor”, aka. Data difference adjustment method”, to correct the factory performance curve of compressor, to ensure that the simulation accuracy is higher than 95%, and to provide support for operation decision-making. Based on the principle of minimum energy consumption of AB line and C line system of Trans-Asian natural gas pipeline, a set of optimal air intake allocation scheme between AB and C lines is studied and integration method of process operation scheme of AB line and C line are studied to support the optimum operation. Pipeline joint operation method for different hydraulic systems is studied. The pressure control principle by pressure balance method which realizes the joint operation of pipelines from different hydraulic systems is suggested for the first time, by which the pipeline operates stably. This paper studies the best location of 8 bridges reservations in AB line and C line in Uzbekistan, in order to enhance the comprehensively allocation capability of the whole system of transnational pipeline network in an all-round way, and to realize the function of energy conservation under normal conditions and of throughput guarantee under abnormal conditions. With additional bridges, pipeline transportation capacity can be increased up to 26 million m3/day and save energy consumption by up to 660 thousand m3/day under accident conditions. Keywords: Natural gas pipeline, Joint operation, Transmission allocation principle, Energy consumption

according to the characteristics of waxy crystal phase change during waxing process of crude oil, a novel model that was a wide phase transition interface partition model was established, and the equivalent specific heat capacity method was used to deal with latent heat problem. The governing equations for each partition were proposed. Compared with the experimental data, the maximum relative error was 3.41%, and then the model was used to analyze the heat transfer process of oil phase change. The research results can provide important theoretical support for the practical application of overhead pipeline shutdown and maintenance. Keywords: Waxy crystal, Wide phase transition interface, Overhead pipeline, Heat transfer

In order to investigate the interphase mass transfer and component distribution characteristics of the CO2–water system under micro-scale and nano-scale transport conditions, a micro-scale kinetic model representing interphase mass transfer in the CO2–water/saline system is developed in this paper. The molecular dynamics method is employed to delineate the diffusion and mass transfer processes of the system's components, revealing the extent of the effects of variations in temperature, pressure, and salt ion concentration on interphase mass transfer and component distribution characteristics. The interphase mass transfer process in the CO2–water system under transport conditions can be categorized into three stages: approach, adsorption, and entrance. As the system temperature rises and pressure decreases, the peak density of CO2 molecules at the gas–liquid interface markedly drops, with their aggregation reducing and their diffusion capability enhancing. The specific hydration structures between salt ions and water molecules hinder the entry of CO2 into the aqueous phase. Additionally, as the salt concentration in water increases, the density peak of CO2 molecules at the gas–liquid interface slightly increases, while the density value in the water phase region significantly decreases. [ABSTRACT FROM AUTHOR]

The non-equilibrium melting of Na crystals at high heating rates and the evolutions of the atomic clusters are studied by the MD method and PTM analysis. Results show that as the heating rate rises from 1 × 1011 K/s to 2 × 1013 K/s, the non-equilibrium melting temperature of Na increases non-linearly from 417 K to 480 K, the melting temperature difference experienced increases from 7 K to 27 K, while the melting time decreases from 70 ps to 1 ps. Through the PTM analysis, it is found that some BCC clusters transform into the disordered Other clusters through intermediate HCP and FCC clusters with increasing temperature, and the BCC cluster's reduction rate and the Other cluster's growth rate are getting slower with increasing heating rate. There is a good correspondence between the evolutions of the atomic clusters, the changes of macroscopic physical parameters, and the peaks and valleys of RDF with temperature. [ABSTRACT FROM AUTHOR]

Carbon dioxide flooding is one of the main methods used to improve crude oil recovery. It can not only improve oil recovery but also reduce greenhouse gas emissions. However, the addition of carbon dioxide makes crude oil become a more complex multiphase fluid; that is, carbon dioxide flooding-produced fluid, in which CO2 and various components in crude oil mass transfer each other. This results in significant changes in the structure and properties of crude oil that increase the hazards associated with its gathering and transportation. Therefore, it is very important to explore the microscopic mechanism for the diffusion mass transfer of CO2 and crude oil in this fluid, especially during its gathering and transportation. In this study, the diffusion mass transfer process of CO2 and crude oil in fluids produced via CO2 flooding is studied using molecular dynamics, and the influences of temperature, gas–oil ratio and water content are explored. Observations of the configuration and dynamic behaviour of the system show that after the system reaches equilibrium, the majority of the CO2 molecules are distributed at the oil–water interface, and CO2 is more prone to diffusing into the oil phase than the water phase. Increases in temperature and water content inhibit, while increases in the gas–oil ratio promote, the diffusion mass transfer of CO2 in the crude oil system. The results of this study reveal the mechanism for the diffusion mass transfer of CO2 and crude oil in fluids produced via CO2 flooding and account for the influence of the water phase, which is consistent with actual production conditions and has certain guiding significance for the safe operation of oil and gas gathering and transportation. [ABSTRACT FROM AUTHOR]

The current situation of the energy conservation standard system in the oil and gas industry and the actual needs of the energy consumption quota standard system are analyzed, which include the hierarchical division of the energy consumption quota index system and the energy consumption quota index. The energy consumption quota index system for oil and gas field production is established. The formulation methods mainly include the actual measurement method, the technical calculation method and the statistical analysis method, which are compared and analyzed. The energy consumption quota indicator system and quota formulation method for oil and gas field production can provide scientific support for the formulation of energy consumption quota for oil and gas fields, so as to promoting the improvement of quality and efficiency of oil and gas field enterprises. [ABSTRACT FROM AUTHOR]