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Dynamic Properties of Steel Catenary Riser near Touchdown Point Under Coplanar Vessel Heave and Vortex Induced Vibration

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China Ocean Engineering 2023年第2期37卷 288-298页

作者： zhang xiang-rui WANG Kun-peng JIANG Da-peng TANG Kai LI Yu-long Marine Design and Research Institute of China Shanghai 200011China School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 510275China

The present study establishes a simple numerical model for the coupled response of a steel catenary riser(SCR) subjected to coplanar vessel motion and vortex-induced vibration(VIV). Owing to the large deflection of the SCR, the geometric nonlinearity is considered in this model. The hydrodynamic force comprises the excitation force and hydrodynamic damping, where the excitation force that only exists when the non-dimensional frequency is located in the lock-in range, is associated with the VIV. The hydrodynamic force model is validated based on the published VIV test data.As for the seabed resistance at the touchdown zone(TDZ), integrated with an initial seabed trench, the hysteretic feature is modeled. Based on the model, the study emphasizes on the coupled response characteristics near the touchdown point(TDP) induced by coplanar vessel heave and VIV, and analyzes the sensitivity of the coupled response to the heaving amplitude and frequency. It is found that with the increase of the heave amplitude and frequency, the VIV can be obviously mitigated, but the heave-related response in the coupled analysis seems to be close to that in the heave-only simulation. Finally, the fatigue damage near TDP is parametrically investigated based on the separate analysis and the coupled analysis. The results demonstrate that the coupled effect plays a significant role in the fatigue assessment near TDP. Besides, the proportion of the coupled effect accounting for the total fatigue damage decreases with the increasing seabed stiffness, while increases with the increasing seabed trench depth.

关键词： vessel heave vortex induced vibration coupled effect steel catenary riser(SCR)-seabed interaction seabed trench

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静电成形薄膜反射面天线的裁剪设计

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工程力学 2024年第6期41卷 224-234页

作者：杜雪林张瑞翔张康夏杰湖南工学院智能制造与机械工程学院湖南衡阳421002 西安电子科技大学电子装备结构设计教育部重点实验室陕西西安710071

该文通过裁剪和拼接平面薄膜片来对静电成形薄膜反射面天线的表面进行设计制作。由于抛物面型薄膜反射面是一个不可展开表面,通常由许多平面薄膜片制作而成,将不可避免地降低反射面表面的精度。因此,需要详细地分析裁剪和拼接过程对反... 详细信息

该文通过裁剪和拼接平面薄膜片来对静电成形薄膜反射面天线的表面进行设计制作。由于抛物面型薄膜反射面是一个不可展开表面,通常由许多平面薄膜片制作而成,将不可避免地降低反射面表面的精度。因此,需要详细地分析裁剪和拼接过程对反射面表面精度的影响,从而获得设计需要的表面精度。该文基于旋转抛物面的无矩理论建立了工作状态的反射面模型,采用常应变三角形单元离散反射面,建立了反射面的展平和拼接有限元模型。将同口径反射面沿经线划分若干组不同数量子曲面,通过子曲面进行展平和拼接数值仿真分析,对薄膜反射面进行裁剪设计。最后,制作了0.55 m口径的薄膜反射器,并进行了摄影测量实验。验证了该方法的有效性,并讨论了制造误差的影响。

关键词：机械工程结构设计数值仿真静电成形薄膜反射面三角形单元无矩理论裁剪设计摄影测量实验

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亚临床嗜铬细胞瘤的临床认识与研究

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中国实用内科杂志 2024年第5期44卷 419-423页

作者：张瑞祥孙洪平沈赟黄文彬韦晓刘超南京中医药大学附属中西医结合医院内分泌科江苏南京210028 江苏省中医药研究院江苏南京210028

儿茶酚胺是一种含有儿茶酚和胺基的神经类物质,由肾上腺髓质、肾上腺神经元及肾上腺外嗜铬体分泌,其在人体生命活动中扮演着重要角色[1]。分泌儿茶酚胺的肿瘤多种多样,如神经母细胞瘤、神经节细胞瘤等,但临床上最多见的为铬细胞瘤/副神... 详细信息

儿茶酚胺是一种含有儿茶酚和胺基的神经类物质,由肾上腺髓质、肾上腺神经元及肾上腺外嗜铬体分泌,其在人体生命活动中扮演着重要角色[1]。分泌儿茶酚胺的肿瘤多种多样,如神经母细胞瘤、神经节细胞瘤等,但临床上最多见的为铬细胞瘤/副神经节瘤。以往认为,嗜铬细胞瘤(pheochromocytoma,PCC)是一种由肾上腺嗜铬细胞引起的神经内分泌儿茶酚胺释放肿瘤;当肿瘤生长在肾上腺外时,称为分泌性副神经节瘤(paraganglioma,PCL),二者合称为嗜铬细胞瘤/副神经节瘤(pheochromocytoma and paraganglioma,PPGL)[2]。

关键词：嗜铬细胞瘤亚临床肾上腺素儿茶酚胺基因突变

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MdbHLH162 connects the gibberellin and jasmonic acid signals to regulate anthocyanin biosynthesis in apple

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Journal of Integrative Plant Biology 2024年第2期66卷 265-284页

作者： Jian-Ping An rui-rui Xu Xiao-Na Wang Xiao-Wei zhang Chun-xiang You Yuepeng Han Apple technology innovation center of Shandong Province College of Horticulture Science and EngineeringShandong Agricultural UniversityTai-An 271018China CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture Wuhan Botanical GardenHubei Hongshan LaboratoryThe Innovative Academy of Seed Design of Chinese Academy of SciencesWuhan 430074China College of Biology and Oceanography Weifang UniversityWeifang 261061China

Anthocyanins are secondary metabolites induced by environmental stimuli and developmental signals.The positive regulators of anthocyanin biosynthesis have been reported,whereas the anthocyanin repressors have been neglected.Although the signal transduction pathways of gibberellin(GA)and jasmonic acid(JA)and their regulation of anthocyanin biosynthesis have been investigated,the cross-talk between GA and JA and the antagonistic mechanism of regulating anthocyanin biosynthesis remain to be investigated.In this study,we identified the anthocyanin repressor MdbHLH162 in apple and revealed its molecular mechanism of regulating anthocyanin biosynthesis by integrating the GA and JA signals.MdbHLH162 exerted passive repression by interacting with MdbHLH3 and MdbHLH33,which are two recognized positive regulators of anthocyanin biosynthesis.MdbHLH162 negatively regulated anthocyanin biosynthesis by disrupting the formation of the anthocyanin-activated MdMYB1-MdbHLH3/33complexes and weakening transcriptional activation of the anthocyanin biosynthetic genes MdDFR and MdUF3GT by MdbHLH3 and MdbHLH33.The GA repressor MdRGL2a antagonized MdbHLH162-mediated inhibition of anthocyanins by sequestering MdbHLH162 from the MdbHLH162-MdbHLH3/33 complex.The JA repressors MdJAZ1 and MdJAZ2 interfered with the antagonistic regulation of MdbHLH162 by MdRGL2a by titrating the formation of the MdRGL2a-MdbHLH162 complex.Our findings reveal that MdbHLH162 integrates the GA and JA signals to negatively regulate anthocyanin biosynthesis.This study provides new information for discovering more anthocyanin biosynthesis repressors and explores the cross-talk between hormone signals.

关键词： anthocyanin biosynthesis bHLH transcription factor gibberellin jasmonic acid regulatory network transcriptional regulation

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S1-supported Pd@CeO_(2) quasi-core@shell materials as advanced catalysts for selective hydrogenation of furfural

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Chinese Chemical Letters 2024年第3期35卷 493-496页

作者： xiang Chu Lingling zhang Ke Wang rui zhang Xiao Wang Shuyan Song Hongjie zhang State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Bare Pd metal nanoparticles invariably suffer from poor selectivity in furfural hydrogenation by forming flat configurations,with the aromatic ring of the substrate molecules parallel to the metal surface.Herein,we put forward a promising solution by using CeO_(2)as promoters to modify Pd nanoparticles for modulating the adsorption behaviors of furfural molecules.To achieve the highly-desired ultra-small Pd@CeO_(2)core@shell nanostructure,a“constrained auto-redox”synthesis is developed,in which silicalite-1 supports play the key role of providing their surface as the landing place of PdO_(x)precursors for inhibiting the overgrowth and the deformation.To the best of our knowledge,this is one of the smallest core@shell materials obtained from aqueous synthesis.When evaluated as catalysts,Pd@CeO_(2)/S-1 gives 98.9%conversion of furfural with 94.3%selectivity for furfural alcohol in 15 h,which is much better than that of Pd/S-1(88.6%conversion with 44.3%selectively).The DFT simulation reveals a strong interaction between the defects of CeO_(2)and the oxygen atom of the–CHO group in furfural molecules,which benefits the selective hydrogenation occurred in the–CHO group rather than the furan ring.

关键词： Core@shell Palladium Ceria Auto-redox synthesis Hydrogenation

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The anti-inflammatory effects of exercise on autoimmune diseases:A 20-year systematic review

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Journal of Sport and Health Science 2024年第3期13卷 353-367,I0001页

作者： Beibei Luo Dao xiang Xiaorong Ji Xuan Chen rui Li Shuxin zhang Yujun Meng David C.Nieman Peijie Chen School of Exercise and Health Shanghai University of SportShanghai 200438China Shanghai Key Laboratory of Human Performance Shanghai University of SportShanghai 200438China Department of Diving and Hyperbaric Medicine Naval Medical CenterShanghai 200433China National Key Laboratory of Immunity and Inflammation Naval Medical UniversityShanghai 200433China Human Performance Laboratory Appalachian State UniversityNorth Carolina Research CampusKannapolisNC 28081USA Research Institute for Doping Control Shanghai University of SportShanghai 200438China

Background:The anti-inflammatory effect of exercise may be an underlying factor in improving several autoimmune diseases.The aim of this systematic review was to examine the evidence on the role of exercise training in mitigating inflammation in adolescents and adults with autoimmune disease.Methods:PubMed,Web of Science,and Embase databases were systematically reviewed for related studies published between January 1,2003,and August 31,2023.All randomized and non-randomized controlled trials of exercise interventions with autoimmune disease study participants that evaluated inflammation-related biomarkers were included.The quality of evidence was assessed using the Tool for the assEssment of Study qualiTy and reporting in EXercise scale and Cochrane bias risk tool.Results:A total of 14,565 records were identified.After screening the titles,abstracts,and full texts,87 were eligible for the systematic review.These studies were conducted in 25 different countries and included a total of 2779 participants(patients with autoimmune disease,in exercise or control groups).Overall,the evidence suggests that inflammation-related markers such as C-reactive protein,interleukin 6,and tumor necrosis factor a were reduced by regular exercise interventions.Regular exercise interventions combined with multiple exercise modes were associated with greater benefits.Conclusion:Regular exercise training by patients with autoimmune disease exerts an anti-inflammatory influence.This systematic review provides support for the promotion and development of clinical exercise intervention programs for patients with autoimmune disease.Most patients with autoimmune disease can safely adopt moderate exercise training protocols,but changes in inflammation biomarkers will be modest at best.Acute exercise interventions are ineffective or even modestly but transiently pro-inflammatory.

关键词： Autoimmune diseases Cytokines Inflammation Physical activity Training

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Pre-combustion mercury removal with co-production of hydrogen via coal electrolysis

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Journal of Environmental Sciences 2024年第2期136卷 382-389页

作者： xiang Lyu Runming Tao Tianyu zhang Chemical and Biomolecular Engineering Department Ohio University165 Stocker CenterAthensOH45701USA Electrification and Energy Infrastructures Division Oak Ridge National LaboratoryOak RidgeTN37831USA Beijing Key Lab for Source Control Technology of Water Pollution College of Environmental Science and EngineeringBeijing Forestry UniversityBeijing 100083China Engineering Research Center for Water Pollution Source Control&Eco-remediation College of Environmental Science and EngineeringBeijing Forestry UniversityBeijing 100083China

Pre-combustion mercury removal via coal electrolysis was performed and investigated on a bench-scale coal electrolytic cell(CEC)systemically,and factorial design was used to determine the effect of different operating conditions(coal particle size,operating temperature,operating cell voltage,and flow rate of slurry)on the percentage of mercury removal,percentage of ash removal,and dry heating value change.The results showed that the operating cell voltage,as well as the interaction between operating cell voltage and coal particle size,are significant factors in the percentage of mercury removal.There is no significant factor in the percentage of ash removal and the dry heating value change,but the coal could be purified while keeping the dry heating value almost constant after electrolysis.A co-product of hydrogen could be produced during coal electrolysis with 50%lower energy consumption compared with water electrolysis.Meanwhile,a mechanism for mercury removal in coal was proposed.The facts indicate that coal electrolysis is a promising method for precombustion mercury removal.

关键词： Pre-combustion mercury removal Coal electrolysis Ash removal Dry heating value Hydrogen production

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In situ modification of heavy oil catalyzed by nanosized metal-organic framework at mild temperature and its mechanism

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Chinese Journal of Chemical Engineering 2024年第3期67卷 166-173页

作者： Li Wang Ji-xiang Guo rui-Ying Xiong Chen-Hao Gao Xiao-Jun zhang Dan Luo The Unconventional Oil and Gas Institute China University of Petroleum-BeijingBeijing 102200China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China

Two catalysts, nano-sized cobalt-metal-organic framework(Co-MOF) and nickel(Ni)-MOF, were successfully prepared by the modification method. Tetralin(C10H12) was used as the hydrogen donor for the catalytic cracking and hydrogenation modification study of the dehydrated crude oil from the Shengli Oilfield. The optimal reaction conditions were determined through orthogonal experiments, and the components of the crude oil and modified oil samples were analyzed. The results revealed that the nanoMOF catalysts were successfully prepared and exhibited high catalytic activity. They could catalyze the cracking of large molecules in heavy oil at mild temperatures(<300°C), leading to the decomposition of the hydrogen donor. When the mass fraction of the catalyst was 0.2%, the mass fraction of the hydrogen donor was 1%, and the reaction temperature was 280°C, the Ni-MOF showed the best catalytic viscosity reduction effect. It could reduce the viscosity of heavy oil at 50°C from 15761.9 m Pa.s to 1266.2 m Pa.s,with a viscosity reduction rate of 91.97%. The modification effect of Co-MOF was the next best, which could reduce the viscosity of heavy oil to 2500.1 m Pa.s with a viscosity reduction rate of 84.14%. Molecular dynamics simulations revealed a strong interaction force between the MOF surface and asphaltene molecules. In the process of heavy-oil catalytic hydrogenation, the nano-MOF catalyst exhibited high catalytic activity. On the one hand, the empty d orbitals outside the metal atoms in the catalyst could polarize the carbon atoms in the organic matter, accelerating the breaking of long chains. On the other hand, the metal atoms in the catalyst could bond with the carbon σ bonds, breaking the carbon-carbon bonds. This disrupted the structure of the recombined components in the crude oil, irreversibly reducing the viscosity of the heavy oil and improving its fluidity.

关键词： Nano-sized MOF Petroleum Viscosity reduction Catalyst Nanomaterials

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Evolution of HIV/AIDS Prevention and Control Policies in China:A Grounded Theory Approach

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China CDC weekly 2024年第1期6卷 12-22页

作者： Huang Li rui Gao Chichen zhang School of Public Health Southern Medical UniversityGuangzhou CityGuangdong ProvinceChina School of Health Management Southern Medical UniversityGuangzhou CityGuangdong ProvinceChina Key Laboratory of Philosophy and Social Sciences of Colleges and Universities in Guangdong Province for Collaborative Innovation of Health Management Policy and Precision Health Service Southern Medical UniversityGuangzhou CityGuangdong ProvinceChina Graduate School Xi’an Jiaotong-Liverpool UniversitySuzhou CityJiangsu ProvinceChina School of Political Science and Public Administration Soochow UniversitySuzhou CityJiangsu ProvinceChina

Objective:This study aims to provide a theoretical foundation for the development and practical application of human immunodeficiency virus(HIV)/acquired immunodeficiency syndrome(AIDS)prevention and control policy systems in China by scrutinizing,analyzing,and synthesizing the evolution of Chinese policies in this domain.Methods:Utilizing grounded theory,we employed NVivo12 software to perform text content analysis,mining,and coding classification,along with visualization techniques,on policy texts sourced from Chinese government platforms,including the official website of China’s State Council.We considered four analytical dimensions—time,subject,type,and object.Results:The National Health Commission and the State Council emerged as the primary entities engaged in policymaking for HIV/AIDS in China.We identified four distinct stages in the evolution of these policies,culminating in a novel‘sun-shaped’HIV/AIDS prevention and control policy network model with an emphasis on‘knowledge,attitude,and practice’at its nucleus,which aligns with national conditions and societal progress.Furthermore,the focal groups of these policies have been dynamically refined and updated over time.Conclusions:Our findings introduce a‘sunshaped’HIV/AIDS prevention and control policy network model specific to China.We observed a conceptual policy shift towards prioritizing overall human health rather than confining the focus to disease treatment.Additionally,in light of China’s growing elderly population,the imperative to address HIV/AIDS prevention and control among older adults is an issue that warrants increased attention.

关键词： prevention HIV/AIDS policy

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Insights into in-situ imbibition behavior of fracturing fluid in propped shale fractures based on nuclear magnetic resonance:A case study from Longmaxi Formation shale,Sichuan Basin,China

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Petroleum Science 2024年第1期21卷 410-429页

作者： Jing-Jing Guo Kai-xiang Di Lie-Hui zhang Yu-Long Zhao Hui-Ying Tang rui-Han zhang Ye Tian National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500SichuanChina

Shale gas is an important component of unconventional oil and gas resources.Studying the imbibition behavior is helpful to optimize flowback parameters and enhance gas recovery.Recent imbibition studies have focused on shale matrix,and the pressure conditions discussed were mostly atmospheric.The initial imbibition behavior begins from propped fractures to matrix,but there are few studies working on explaining the imbibition behavior in propped fractures or the phenomenon of many shale wells exhibit higher productivity after a“soaking”period.Therefore,propped fracture samples were designed for imbibition and migration experiments.In order to accurately study the mechanism and main influencing factors of fracturing fluid imbibition and migration in propped and unpropped shale fractures under high temperature and high pressure,a series of experiments based on nuclear magnetic resonance(NMR)were carried out.Results showed that NMR T_(2) spectra of all samples exhibited a bimodal distribution.The final imbibition volume of fracturing fluid was positively related to pressure and fracture width.The imbibition effect of fracturing fluid was more evident in matrix pores under high pressure.In the migration during soaking stage,the fracturing fluid gradually migrated from large pores to small pores and gradually displaced the shale gas from the matrix,thus allowing the water blocking in propped fractures to self-unlock to some extent.Gas permeability decreased in the imbibition stage,while it recovered in the migration stage to some extent.

关键词： Forced imbibition Migration Soaking NMR T_(2)spectra Propped fracture Permeability recovery

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