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A novel Omega-driven dynamic PANS model

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Journal of Hydrodynamics 2020年第4期32卷 710-716页

作者： Chao-yue wang Fu-jun wang Ben-hong wang yuan Tang Hao-ru Zhao college of Water Resources and Civil Engineering China Agricultural UniversityBeijing 100083China beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System Beijing 100083China

A novel Omega(Ω)-driven dynamic partially-averaged Navier-Stokes(PANS)model is proposed in this *** ratio of the modeled-to-total turbulent kinetic energies fk is dynamically adjusted by the rigid vorticity ratio(the ratio of the rigid vorticity to the total vorticity),the key parameter of the Ω vortex identification *** classical flow cases with rotation and curvature are used to test the *** results show that the turbulent viscosity is effectively adjusted by the new dynamic fk and the LES-like mode is activated,which can help the revelation of more turbulence information and improve the prediction *** new PANS model does not contain any explicit dependency on the grid size and enjoys good adaptability to the flow fields,and can be used for efficient engineering computations of the turbulent flows in the hydraulic machinery.

关键词： Dynamic partially-averaged Navier-Stokes(PANS) turbulence model Omega engineering computations

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刚性桩复合地基在不同荷载下的桩土分担特性

天津大学学报（自然科学与工程技术版） 2003年第3期36卷 359-363页

作者：池跃君宋二祥陈肇元清华大学土木工程系北京100084

利用解析解答对刚性桩复合地基在竖向荷载下的工作特性进行了较深入的分析,着重讨论了桩土应力比及荷载分担比等随复合地基荷载、垫层厚度、垫层模量、桩长、桩间距、桩间土模量和桩端土抗力系数等因素变化的规律.计算结果表明,竖向荷... 详细信息

利用解析解答对刚性桩复合地基在竖向荷载下的工作特性进行了较深入的分析,着重讨论了桩土应力比及荷载分担比等随复合地基荷载、垫层厚度、垫层模量、桩长、桩间距、桩间土模量和桩端土抗力系数等因素变化的规律.计算结果表明,竖向荷载作用下,桩土应力比随复合地基荷载、垫层模量、桩长和桩间距的增加而增大,随垫层厚度和土体模量的增加而减小,同时也表明复合地基的设计参数有合理的取值范围.

关键词：刚性桩复合地基竖向荷载桩土应力比荷载分担比垫层厚度垫层模量桩长桩间距土体模量

Effect of heat treatment on microstructure and mechanical properties of selective laser-melted PH13-8Mo stainless steel

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Journal of Iron and Steel Research International 2024年第4期31卷 945-955页

作者： yuan Zhang Xiang Liu Chang-jun wang Chang Liu School of Material science and Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina Central Iron&Steel Research Institute Co. Ltd.Beijing 100081China

PH13-8Mo stainless steel powder with high sphericity and well fluidity was prepared by the plasma rotating electrode *** formed parts with ultra-high purity were manufactured by selective laser *** tensile and impact mechanical properties of the printed parts under three heat treatment regimes were compared to those without heat *** microstructure,grain orientation and phase composition were characterized by electron-backscatter diffraction,X-ray diffraction and transmission electron *** characterization results reveal that the addition of heat treatment makes the grains enlarge,and after different heat treatments,the average grain size from 1.51μm in the printed state increases to 2.78,3.09 and 2.06μm,*** formed parts are mainly composed of martensite and retained ***,the NiAl and M23C precipitates form,which are the major strengthening phases of PH13-8Mo stainless *** optimal heat treatment process is 925℃×1 h water cooling(WC)+0℃×2 h air cooling(AC)+540℃×4 h *** this heat treatment process,PH13-8Mo formed parts have the optimal comprehensive mechanical properties:the tensile strength,yield strength and impact energy KU2 are 1492 MPa,1432 MPa and 63 J,*** strengthening and toughening via heat treatment are mainly attributed to dislocation strengthening,the formation of NiAl and M23Co precipitates and the change of volume fraction of the retained austenite.

关键词： High-strength stainless steel-Selective laser melting-Heat treatment Microstructure Mechanical property

Antidepressant-like effects of albiflorin involved the NO signaling pathway in rats model of chronic restraint stress

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Chinese Journal of Natural Medicines 2020年第11期18卷 872-880页

作者： ZHU Ying-Li wang Lin-yuan ZHAO Dan-Ping wang Cheng-Long ZHANG rui FEI Wen-Ting wang Jing-Xia ZHANG Jian-jun School of Chinese Materia Medica Bejing University of Chinese MedicineBejing100029China School of Traditional Chinese Medicine Bejing University of Chinese MedicineBeijing100029China

The depressant-like effects of albiflorin(AF) were studied on stressed chronic restraint stress(CRS) rats. Experimental rats were subjected to immobilization stress for a daily 6 h-restraining in a plastic restrainer for continuous 21 d and were treated with 30 or 15 mg·kg-1 of AF for 21 d. Control rats were maintained in completely non stressed conditions. Behavioral tests and biochemical analysis were applied to investigating a regulatory mechanism of anti-stress of AF. Treatment with AF significantly restored the depressant-like behaviors. Besides, AF increased the levels of 5-hydroxytryptophan(5-HT), 5-hydroxyindoleacetic acid(5-HIAA),noradrenaline(NE) and dopamine(DA) in the hippocampus and increased the level of brain-derived neurotrophic factor(BDNF) in serum and protein expression in hippocampus. In addition, AF decreased the levels of hypothalamo-pituitary-adrenal(HPA) cascade,reduced the level of NO and c GMP in serum and inhibited the overexpression of 5-HT2AR m RNA and protein expression. Taken together, AF can modulate the NO-mediated network pathway in the hippocampus against stress-induced depressive-like *** physiological and behavioral changes allow rats to avoid potential deleterious effects of stress that may result from chronically elevated levels of glucocorticosteroids over days.

关键词： Paeonia lactiflora Albiflorin Chronic restraint stress Anti-stress NO-mediated pathway

Visible light cross-linking and bioactive peptides loaded integrated hydrogel with sequential release to accelerate wound healing complicated by bacterial infection

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Nano Research 2024年第3期17卷 1737-1747页

作者： Guiyan wang Ning yuan jun Zhang Man Qin Suwei Dong Yuguang wang Department of Pediatric Dentistry Peking University School and Hospital of StomatologyBeijing 100081China State Key Laboratory of Natural and Biomimetic Drugs Chemical Biology Centerand School of Pharmaceutical SciencesPeking UniversityBeijing 100191China Department of Prosthodontics Peking University School and Hospital of StomatologyBeijing 100081China

The effective management of bacterial infections that are resistant to multiple drugs remains a substantial clinical *** eradication of drug-resistant bacteria and subsequent promotion of angiogenesis are imperative for the regeneration of the infected ***,a novel and facile peptide containing injectable hydrogel with sustained antibacterial and angiogenic capabilities is *** antibacterial peptide that consists of 11 residues(CM11,WKLFKKILKVL)is loaded onto acrylate-modified gelatin through charge interactions.A vascular endothelial growth factor mimetic peptide KLT(KLTWQELYQLKYKGI)with a GCG(Gly-Cys-Gly)modification at the N-terminal is covalently coupled through a visible light-induced thiol-ene *** this reaction,the acrylate gelatin undergoes cross-linkage within *** on the physical/chemical double crosslinking strategy,the bioactive peptides achieve sustained and sequential *** results show that the hydrogel significantly inhibits methicillin-resistant Staphylococcus aureus(MRSA)growth through the rapid release of CM11 peptides at early stage;it forms obvious growth inhibition zones against pathogenic bacterial ***,cell counting kit-8 assay and scratch test confirm that the CM11/KLT-functionalized hydrogels promote cell proliferation and migration through the later release of KLT *** a mouse skin wound infected with self-luminous MRSA,the CM11/KLT-functionalized hydrogels enhance wound healing,with rapidly bacterial infection reduction,lower expression of inflammatory factors,and neovascularization *** results suggest that the rationally designed,sustained and sequential release CM11/KLT-functionalized hydrogels have huge potential in promoting the healing of multi-drug resistant bacterial infected wounds.

关键词： antimicrobial peptide vascular endothelial growth factor(VEGF)mimetic peptide sequential release visible-light crosslinking hydrogel wound therapy

Differential diagnosis of vasovagal syncope and postural tachycardia syndrome in children

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World Journal of Pediatrics 2020年第6期16卷 549-552页

作者： yuan-yuan wang jun-Bao Du Hong-Fang Jin Department of Pediatrics Peking University First HospitalNo.1Xi'an-men Street.West DistrictBeijing 100034China Key Lab of Molecular Cardiovascular sciences The Ministry of EducationBeijing 100191China

Orthostatic intolerance(OI)is defined as a syndrome consisting of a group of clinical symptoms including headache,dizziness,palpitation,chest tightness,nausea,vomiting,pale complexion,and even syncope due to the inability to tolerate the upright *** condition is relieved by recumbence[1,2].OI is common and affects the quality of life and the psychosocial well-being[3-5]Previous studies have shown that the pathogenesis of OI is mainly related to the enhanced endothelium-dependent diastolic function[6],abnormal Bezold-Jarisch reflex[7],central hypovolemia[8],and autonomic dysfunction[9].

关键词： diagnosis syncope tachycardia

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安徽省社区体育发展战略研究

体育科学 2004年第10期24卷 21-25,30页

作者：高维岭邵苏华李燕汪伟信袁守龙金广江安徽省体育局安徽合肥230001 安徽省体育科学研究所安徽合肥230001 中国科学技术大学体育部安徽合肥230052 北京体育大学研究生院北京100084

采用文献研究、问卷调查、现场观察、数理统计和逻辑分析法 ,对安徽省不同地域和不同经济发展水平的 7个省级市和 4个县 (市 )社区体育发展规模、活动内容、组织结构、经费来源、健身动机等进行了研究分析 ,总结了安徽省社区体育发展的... 详细信息

采用文献研究、问卷调查、现场观察、数理统计和逻辑分析法 ,对安徽省不同地域和不同经济发展水平的 7个省级市和 4个县 (市 )社区体育发展规模、活动内容、组织结构、经费来源、健身动机等进行了研究分析 ,总结了安徽省社区体育发展的一般规律与特征 ,并对安徽省社区体育在新世纪中的发展战略。

关键词：社区体育发展战略研究安徽

Strategies to approach high performance in Cr^(3+)-doped phosphors for high-power NIR-LED light sources

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Light(science & Applications) 2020年第1期9卷 1190-1198页

作者： Zhenwei Jia Chenxu yuan Yongfu Liu Xiao-jun wang Peng Sun Lei wang Haochuan Jiang jun Jiang Ningbo Institute of Materials Technology&Engineering Chinese Academy of SciencesNingbo 315201China college of Physics and Optoelectronics Taiyuan University of TechnologyTaiyuan 030024China university of Chinese Academy of sciences Beijing 100049China Department of Physics Georgia Southern UniversityStateboreGA 30460USA

Broadband near-infrared(NIR)-emitting phosphors are key for next-generation smart NIR light sources based on blue *** achieve excellent NIR phosphors,we propose a strategy of enhancing the crystallinity,modifying the micromorphology,and maintaining the valence state of Cr^(3+) in Ca_(3)Sc_(2)Si_(3)O_(12) garnet(CSSG).By adding fluxes and sintering in a reducing atmosphere,the internal quantum efficiency(IQE)is greatly enhanced to 92.3%.The optimized CSSG:6% Cr^(3+) exhibits excellent thermal *** 150℃,97.4% of the NIR emission at room temperature can be *** fabricated NIR-LED device emits a high optical power of 109.9mW at 520 *** performances of both the achieved phosphor and the NIR-LED are almost the best results until *** mechanism for the optimization is *** application of the NIR-LED light source is demonstrated.

关键词： phosphors power light

Effect of nano TiO_(2) and SiO_(2) on gelation performance of HPAM/PEI gels for high-temperature reservoir conformance improvement

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Petroleum science 2023年第6期20卷 3819-3829页

作者： Yang Liu Hong-jun Zhang Dao-Yi Zhu Zi-yuan wang jun-Hui Qin Qi Zhao Yu-Heng Zhao Ji-rui Hou china university of Petroleum Beijing102249China

Nanoparticles have been widely used in polymer gel systems in recent years to improve gelation performance under high-temperature reservoir conditions. However, different types of nanoparticles have different effects on their gelation performance, which has been little researched. In this study, the high-temperature gelation performance, chemical structure, and microstructure of polymer gels prepared from two nanomaterials (i.e., nano-SiO_(2) and nano-TiO_(2)) were measured. The conventional HPAM/PEI polymer gel system was employed as the control sample. Results showed that the addition of nano-TiO_(2) could significantly enhance the gel strength of HPAM/PEI gel at 80 ℃. The gel strength of the enhanced HPAM/PEI gel with 0.1 wt% nano-TiO_(2) could reach grade I. The system also had excellent high-temperature stability at 150 ℃. The enhanced HPAM/PEI gel with 0.02 wt% nano-TiO_(2) reached the maximum gel strength at 150 ℃ with a storage modulus (G′) of 15 Pa, which can meet the need for efficient plugging. However, the nano-SiO_(2) enhanced HPAM/PEI polymer gel system showed weaker gel strength than that with nano-TiO_(2) at both 80 and 150 ℃ with G′ lower than 5 Pa. Microstructures showed that the nano-TiO_(2) enhanced HPAM/PEI gel had denser three-dimensional (3D) mesh structures, which makes the nano-TiO_(2) enhanced HPAM/PEI gel more firmly bound to water. The FT-IR results also confirmed that the chemical structure of the nano-TiO_(2) enhanced HPAM/PEI gel was more thermally stable than nano-SiO_(2) since there was a large amount of –OH groups on the structure surface. Therefore, nano-TiO_(2) was more suitable as the reinforcing material for HPAM/PEI gels for high-temperature petroleum reservoir conformance improvement.

关键词： Nano-TiO_(2) Nano-SiO_(2) Gel strength Polymer gel High-temperature reservoirs.