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Securing offshore resources development: A mathematical investigation into gas leakage in long-distance flexible pipes

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Petroleum Science 2024年第4期21卷 2734-2744页

作者： Xiang-An Lu liang-liang Jiang Jian-Sheng Zhang min-Gui Wang Guangling College of Yangzhou University Department of Chemical and Petroleum Engineering University of Calgary Department of Energy and Power Engineering Tsinghua University

Gas flexible pipes are critical multi-layered equipment for offshore oil and gas development. Under high pressure conditions, small molecular components of natural gas dissolve into the polymer inner liner of the flexible pipes and further diffuse into the annular space, incurring annular pressure build-up and/or production of acidic environment, which poses serious challenges to the structure and integrity of the flexible pipes. Gas permeation in pipes is a complex phenomenon governed by various factors such as internal pressure and temperature, annular structure, external temperature. In a long-distance gas flexible pipe, moreover, gas permeation exhibits non-uniform features, and the gas permeated into the annular space flows along the metal gap. To assess the complex gas transport behavior in long-distance gas flexible pipes, a mathematical model is established in this paper considering the multiphase flow phenomena inside the flexible pipes, the diffusion of gas in the inner liner, and the gas seepage in the annular space under varying permeable properties of the annulus. In addition, the effect of a variable temperature is accounted. A numerical calculation method is accordingly constructed to solve the coupling mathematical equations. The annular permeability was shown to significantly influence the distribution of annular pressure. As permeability increases, the annular pressure tends to become more uniform, and the annular pressure at the wellhead rises more rapidly. After annular pressure relief followed by shut-in, the pressure increase follows a convex function. By simulating the pressure recovery pattern after pressure relief and comparing it with test results, we deduce that the annular permeability lies between 123 and 512 m D. The results help shed light upon assessing the annular pressure in long distance gas flexible pipes and thus ensure the security of gas transport in the emerging development of offshore resources.

关键词： Offshore resources development Transport security Long-distance flexible pipes Gas leakage Heat and mass transfer model Finite difference calculation

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Impact of propofol and sevoflurane anesthesia on cognition and emotion in gastric cancer patients undergoing radical resection

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World Journal of Gastrointestinal Oncology 2024年第1期16卷 79-89页

作者： Ao-Han Li Su Bu Ling Wang Ai-min liang Hui-yu Luo Department of Anesthesiology Xiangyang No.1 People's HospitalHubei University of MedicineXiangyang 441000Hubei ProvinceChina Department of Cardiothoracic Surgery Xiangyang No.1 People's HospitalHubei University of MedicineXiangyang 441000Hubei ProvinceChina Department of Rehabilitation Xiangyang No.1 People's HospitalHubei University of MedicineXiangyang 441000Hubei ProvinceChina Department of Internal Medicine-Cardiovascular Xiangyang No.1 People's HospitalHubei University of MedicineXiangyang 441000Hubei ProvinceChina

BACKGROUND Propofol and sevoflurane are commonly used anesthetic agents for maintenance anesthesia during radical resection of gastric ***,there is a debate concerning their differential effects on cognitive function,anxiety,and depression in patients undergoing this *** To compare the effects of propofol and sevoflurane anesthesia on postoperative cognitive function,anxiety,depression,and organ function in patients undergoing radical resection of gastric *** A total of 80 patients were involved in this *** subjects were divided into two groups:Propofol group and sevoflurane *** evaluation scale for cognitive function was the Loewenstein occupational therapy cognitive assessment(LOTCA),and anxiety and depression were assessed with the aid of the self-rating anxiety scale(SAS)and self-rating depression scale(SDS).Hemodynamic indicators,oxidative stress levels,and pulmonary function were also *** The LOTCA score at 1 d after surgery was significantly lower in the propofol group than in the sevoflurane ***,the SAS and SDS scores of the sevoflurane group were significantly lower than those of the propofol *** sevoflurane group showed greater stability in heart rate as well as the mean arterial pressure compared to the propofol ***,the sevoflurane group displayed better pulmonary function and less lung injury than the propofol *** Both propofol and sevoflurane could be utilized as maintenance anesthesia during radical resection of gastric *** anesthesia has a minimal effect on patients'pulmonary function,consequently enhancing their postoperative *** anesthesia causes less impairment on patients'cognitive function and mitigates negative emotions,leading to an improved postoperative mental ***,the selection of anesthetic agents should be based on the individual patient's specific circumstances.

关键词： Propofol Sevoflurane Radical resection of gastric cancer Anesthetic effect Cognitive function Negative emotion

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In Situ Atomic Reconstruction Engineering Modulating Graphene-Like MXene-Based Multifunctional Electromagnetic Devices Covering Multi-Spectrum

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Nano-Micro Letters 2024年第9期16卷 247-261页

作者： Ting‑Ting Liu Qi Zheng Wen‑Qiang Cao yu‑Ze Wang min Zhang Quan‑liang Zhao Mao‑Sheng Cao School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081People’s Republic of China Department of Physics Beijing Technology and Business UniversityBeijing 100048People’s Republic of China School of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144People’s Republic of China

With the diversified development of big data,detection and precision guidance technologies,electromagnetic(EM)functional materials and devices serving multiple spectrums have become a hot *** the multispectral response of materials is a challenging and meaningful scientific *** this study,MXene/TiO_(2)hybrids with tunable conduction loss and polarization relaxation are fabricated by in situ atomic reconstruction *** importantly,MXene/TiO_(2)hybrids exhibit adjustable spectral responses in the GHz,infrared and visible spectrums,and several EM devices are constructed based on *** antenna array provides excellent EM energy harvesting in multiple microwave bands,with|S11|up to−63.2 dB,and can be tuned by the degree of *** ultra-wideband bandpass filter realizes a passband of about 5.4 GHz and effectively suppresses the transmission of EM signals in the *** infrared stealth device has an emissivity of less than 0.2 in the infrared spectrum at wavelengths of 6-14μ*** work can provide new inspiration for the design and development of multifunctional,multi-spectrum EM devices.

关键词： Graphene-like MXene hybrids Multi-spectral response Multi-function antenna Ultra-wideband bandpass filter Electromagnetic device

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Chord length sampling correction analysis for dispersion fuel in Monte Carlo simulation

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Nuclear Science and Techniques 2024年第4期35卷 57-64页

作者： Zhao-yu liang Ding She yu-Tong Wen Lei Shi Institute of Nuclear and New Energy Technology(INET) Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of EducationTsinghua UniversityBeijing 100084China

Dispersion fuels,knowned for their excellent safety performance,are widely used in advanced reactors,such as hightemperature gas-cooled *** with deterministic methods,the Monte Carlo method has more advantages in the geometric modeling of stochastic *** explicit modeling method has high computational accuracy and high computational *** chord length sampling(CLS)method can improve computational efficiency by sampling the chord length during neutron transport using the matrix chord length?s probability density *** study shows that the excluded-volume effect in realistic stochastic media can introduce certain deviations into the CLS.A chord length correction approach is proposed to obtain the chord length correction factor by developing the Particle code based on equivalent transmission *** numerical analysis against reference solutions from explicit modeling in the RMC code,it was demonstrated that CLS with the proposed correction method provides good accuracy for addressing the excludedvolume effect in realistic infinite stochastic media.

关键词： Stochastic media Monte Carlo Chord length sampling Excluded-volume effect Chord length correction

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Heat Transfer Characteristics of a Microchannel Heat Sink with Highly-Dense Micro-Jet Arrays

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Journal of Thermal Science 2024年第3期33卷 1148-1160页

作者： ZHANG yu CHEN Xiaoyan MIAO Lin CHEN liang HOU yu State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an710049China Beijing Aerospace Technology Institute Beijing100083China

This paper proposed a new structure of highly-dense micro-jet arrays for hybrid jet-impingement/microchannel heat sinks(~120 jet per cm^(2) with jet width of 0.35 mm).Parametric study is performed to investigate the influence of structure and flow parameters on the convective heat transfer of water jet cooling in confined *** simulation results show that the optimal jet width,jet spacing and impingement distance are around 0.2 mm,0.2 mm and 0.3 mm,respectively,which can achieve a low thermal resistance as well as a relatively low pressure *** analysis of the heat transfer pathways shows that the micro-fin jet structures can extend the impinging heat transfer area and conduct a considerable proportion of heat,which can reach up to 38.9%with the Reynolds number ranging from 797.1 to *** heat transfer characteristics in the heat sink will shift from impingement dominated heat transfer to the channel-convection dominated heat transfer as the jet impingement distance increases.A correlation is proposed to predict the average Nusselt number on the stagnation area for the heat sink with different structure parameters,and the deviations of predictions from the numerical results are less than 10%.

关键词： hybrid heat sink impingement microchannel thermal management high heat flux

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Optimization on crystallization process of the magnetic core lysozyme

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Particuology 2024年第4期87卷 106-113页

作者： Lixia Hou Chunxiao Qu min Su Zhihan liang Qi Hao School of Chemical Engineering Hebei University of TechnologyTianjin300130China

The continuous growth of the biomedical market highlights the significance of improvement in the ef-ficiency of batch production for protein drug ***,we investigated the effect of polymer-modified Fe_(3)O_(4) nanoparticles on lysozyme(Lys)crystallization at different conditions,using function-alized Fe_(3)O_(4) magnetic nanoparticles(Polymer C@Fe_(3)O_(4))as nucleation *** study revealed that the surface charge density of Polymer C@Fe_(3)O_(4) was highest at a modification mass ratio of Fe_(3)O_(4) to Polymer C is 8∶*** ratio facilitates the augmentation of electrostatic interaction and the promotion of *** adding 15%of the PolymerC@Fe_(3)O_(4) prepared from Fe_(3)O_(4) with an average particle size of 150 nm,the magnetic core lysozyme(M-Lys)crystals with an average particle size of 11.08μm,narrow size distribution,and regular morphology were obtained in a yield of 82.42%within 60 min.

关键词： Protein Crystallization Magnetic particle Lysozyme

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Surfactant-assisted crystallization of lysozyme and its mechanism

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Particuology 2024年第7期90卷 199-208页

作者： yujie Song Rongfei Ren min Su Zhihan liang Qi Hao School of Chemical Engineering Hebei University of TechnologyTianjin 300130China

Surfactants were used to assist in the crystallization of *** types of surfactants with different structures(sodium dodecyl sulfate,cetyltrimethylammonium bromide,or betaine hydrochloride[BH])were *** study indicated that three surfactants were all capable of shortening the crystallization induction time of lysozyme,with BH inducing the shortest crystallization induction time(t=1 min)and the largest crystal size(37μm).The molecular interactions among each of the three surfactants aforementioned and lysozyme were also investigated by *** was found that hydrogen bonding dominantly acted between the carboxyl structure of the surfactant BH and the lysozyme,which produced the most favorable conformation for the self-assembly of lysozyme(promote lysozyme orderly aggregation and shorten the crystallization induction time).On this basis,the mechanism of surfactant-promoted lysozyme crystallization was proposed.

关键词： Protein Crystallization Surfactant Lysozyme Molecular interaction Mechanism

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Probing the Kinematic Signatures of Planet Formation in the Gas Disk of MWC 480

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Research in Astronomy and Astrophysics 2024年第6期24卷 110-118页

作者： min Zhao Haochuan yu Zhengxiang Li Department of Astronomy Beijing Normal UniversityBeijing 100875China Sub-department of Astrophysics Department of PhysicsUniversity of OxfordOxfordOX13RHUK

The disk around MWC 480 has shown multiple substructures in both dust and gas observations,possibly suggesting ongoing planet formation in *** this paper,we explore the gas kinematics of the MWC 480 disk by analyzing the archival Atacama Large Millimeter/submillimeter Array observations of^(12)CO(J=2-1),^(13)CO(J=2-1),and C^(18)O(J=2-1).By modeling the line-of-sight velocities,inferred from the Doppler shifts of the emission lines,we are able to decompose the three-dimensional(3D)velocity field of the disk into rotational,radial,and vertical *** analysis reveals the presence of large-scale gas flows in the(r,z)***,we identify potential meridional flows across various heights as traced by all three CO isotopologues in the 80–120 au region,possibly associated with ongoing planet formation activities in this ***,we find upward flows near 200 au for all three CO isotopologues,which may point to the presence of disk winds.

关键词： protoplanetary disks planet-disk interactions planet-star interactions

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Supramolecular Biomaterials for Cancer Immunotherapy

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Research 2024年第2期2023卷 491-509页

作者： Huan liang Qingqing Lu Jie Yang Guocan yu College of Science Nanjing Forestry UniversityNanjing 210037P.R.China Key Laboratory of Bioorganic Phosphorus Chemistry&Chemical Biology Department of ChemistryTsinghua UniversityBeijing 100084P.R.China

Cancer immunotherapy has achieved tremendous successful clinical results and obtained historic victories in tumor ***,great limitations associated with feeble immune responses and serious adverse effects still cannot be neglected due to the complicated multifactorial etiology and pathologic microenvironment in *** rapid development of nanomedical science and material science has facilitated the advanced progress of engineering biomaterials to tackle critical *** supramolecular biomaterials with flexible and modular structures have exhibited unparalleled advantages of high cargo-loading efficiency,excellent biocompatibility,and diversiform immunomodulatory activity,thereby providing a powerful weapon for cancer *** past decades,supramolecular biomaterials were extensively explored as versatile delivery platforms for immunotherapeutic agents or designed to interact with the key moleculars in immune system in a precise and controllable *** this review,we focused on the crucial role of supramolecular biomaterials in the modulation of pivotal steps during tumor immunotherapy,including antigen delivery and presentation,T lymphocyte activation,tumor-associated macrophage elimination and repolarization,and myeloid-derived suppressor cell *** on extensive research,we explored the current limitations and development prospects of supramolecular biomaterials in cancer immunotherapy.

关键词： biomaterials limitations thereby

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Perinatal prevalence of birth defects in the Mainland of China,2000–2021:a systematic review and meta-analysis

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World Journal of Pediatrics 2024年第7期20卷 669-681页

作者： liang-yu Kang Zi-Rui Guo Wei-Jing Shang Gui-Ying Cao Yi-Ping Zhang Qiao-Mei Wang Hai-Ping Shen Wan-Nian liang min Liu Department of Epidemiology and Biostatistics School of Public HealthPeking UniversityNo.38Xueyuan RoadHaidian DistrictBeijing100191China Vanke School of Public Health Tsinghua UniversityNo.1Tsinghua GardenHaidian DistrictBeijing100084China Department of Maternal and Child Health National Health Commission of the People’s Republic of ChinaNo.1Xizhimenwai South RoadXicheng DistrictBeijingChina Institute of Healthy China Tsinghua UniversityNo.1Tsinghua GardenHaidian DistrictBeijing100084China Key Laboratory of Epidemiology of Major Diseases(Peking University) Ministry of Education BeijingNo.38Xueyuan RoadHaidian DistrictBeijing100191China

Background Although birth defects are of great concern globally,the latest national prevalence has not yet been quantified in *** conducted a systematic review and meta-analysis to estimate the perinatal prevalence of birth defects in the Mainland of China between 2000 and *** We performed a systematic literature search of six databases for relevant articles published between January 1,2000,and March 1,*** included published studies that reported data on the perinatal prevalence of birth defects in the Mainland of *** DerSimonian and Laird random-effects models were used to estimate the pooled prevalence and its 95%confidence interval(CI).We also conducted subgroup analyses and univariable meta-regressions to explore differences in prevalence by time period,geographic region,and other *** We included 254 studies reporting the perinatal prevalence of birth defects and 86 studies reporting only the prevalence of specific types of birth *** on 254 studies covering 74,307,037 perinatal births and 985,115 cases with birth defects,the pooled perinatal prevalence of birth defects was 122.54(95%CI 116.20–128.89)per 10,000 perinatal births in the Mainland of China during 2000–***,the perinatal prevalence of birth defects increased from 95.60(86.51–104.69)per 10,000 in 2000–2004 to 208.94(175.67–242.22)per 10,000 in 2020–*** were also significant disparities among different geographical *** heart defects(33.35 per 10,000),clefts of the lip and/or palate(13.52 per 10,000),polydactyly(12.82 per 10,000),neural tube defects(12.82 per 10,000),and inborn errors of metabolism(11.41 per 10,000)were the five most common types of birth *** perinatal prevalence among males was significantly higher than that among females(β=2.44×10^(−3),P=0.003);a higher perinatal prevalence of birth defects was observed among perinatal births whose mothers were≥35 years(β=4.34×10^(−3),P<0.001).Conclusion Compreh

关键词： Birth defects China Perinatal Prevalence

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