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Natural Convection of a Power-Law Nanofluid in a Square Cavity with a Vertical Fin

Fluid Dynamics & materials Processing 2024年第9期20卷 2091-2108页

作者： Amira m’hadbi mohammed El Ganaoui Haïkel Ben Hamed Amenallah Guizani Khalid Chtaibi LERmaB Department of Transition and Energy Efficiency ProfessionsIUT H Poincaréde LongwyUniversity of LorraineLongwy54400France LPT Center for Energy Research and Technologies(Borj Cedria2084)University of Tunis El ManarTunis1068Tunisia LTI Department of Mechanical Engineering and ProductionIUTUniversity of Picardie Jules-VerneAmiens80025France

The behavior of non-Newtonian power-law nanofluids under free convection heat transfer conditions in a cooled square enclosure equipped with a heated fin is investigated *** particular,the impact of nanofluids,composed of water and Al_(2)O_(3),TiO_(2),and Cu nanoparticles,on heat transfer enhancement is *** aim of this research is also to analyze the influence of different parameters,including the rayleigh number(ra=10^(4)-10^(6)),nanoparticle volume fraction(φ=0%-20%),non-Newtonian power-law indexes(n=0.6-1.4),and fin dimensions(Ar=0.3,0.5,and 0.7).Streamlines and isotherms are used to depict flow and related heat transfer *** indicate that thermal performance improves with increasing rayleigh number,regardless of the nanoparticle type or nanofluid rheological *** suggests that the buoyancy force has a significant impact on heat transfer,particularly near the heat *** Nusselt number is more sensitive to variations in Cu nanoparticle volume fractions compared to Al₂O₃and TiO₂.moreover,the average Nusselt numbers for power-law nanofluids with n1)are greater(smaller)than for Newtonian fluids due to the decrease(increase)in viscosity with increasing(decreasing)shear rate,at the same values of rayleigh number ra owing to the amplification(attenuation)of the convective ***,the most substantial enhancement is observed with Cu-water shear-thinning nanofluid,where the Nusselt number increases by 136%when changing from Newtonian to shear thinning behavior and by 154.9%when adding 16%nanoparticle volume ***,an even larger increase of 57%in the average Nusselt number is obtained on increasing the fin length from 0.3 to 0.7.

关键词： Heat transfer nanofluid non-Newtonian fluid natural convection

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Evaluating the influence of a structured nursing protocol on targeted outcomes in rheumatoid arthritis patients

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Journal of Integrative Nursing 2024年第1期6卷 22-28页

作者： mohammed Elsayed ZAKY Shimaa magdi FARGHALY Osama mohamed Elsayed ramaDAN Rehab m.ABDELKADER mostafa SHABAN Department of medical Surgical Nursing Faculty of Nursing Cairo UniversityCairoEgypt Department of medical Surgical Nursing College of NursingJouf UniversitySakakaAljawfSaudi Arabia Faculty of Nursing Cairo University CairoEgypt Department of Geriatric Nursing Faculty of Nursing Cairo UniversityCairoEgypt

Objective:Rheumatoid arthritis(ra)requires comprehensive *** nursing protocols may enhance outcomes,but evidence is *** study evaluated the effect of a structured nursing protocol on ra *** and methods:In this one-group pre-post study,30 Egyptian ra patients completed assessments before and after a 12-week nursing protocol comprising education,psychosocial support,and self-management *** included clinical evaluation of joint counts,erythrocyte sedimentation rate(ESR),and C-reactive protein(CRP)and patient-reported Arthritis Self-Efficacy Scale(ASES),Health Assessment Questionnaire(HAQ),Visual Analog Scale(VAS)for pain,and Hospital Anxiety and Depression Scale(HADS).Results:The study demonstrated significant improvements in both clinical-and patient-reported *** count decreased from 18.4±4.2 to 14.2±3.8(Pm 30.1±6.8 mm/h to 25.5±6.8 mm/h(Pm 15.2±3.6 mg/L to 11.8±2.9 mg/L(Pmes showed a marked increase in ASES score from 140±25 to 170±30(Pm 1.6±0.4 to 1.3±0.3(Pm 7.8±1.7 to 6.2±1.2(Pm 11±3 to 8±2(Pmproved clinical disease activity,physical functioning,pain,self-efficacy,and emotional well-being in ra patients.A multifaceted nursing intervention appears beneficial for optimizing ra outcomes.

关键词： Nursing care patient education quality of life rheumatoid arthritis self‑management

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Environmental determinants of social wasp diversity and assemblage structure in an Amazonian archipelagic landscape

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Zoological Research(Diversity and Conservation) 2024年第2期1卷 121-129页

作者： Jose Victor Alves Ferreira Alexandre Somavilla maíra Benchimol Ana Filipa Palmeirim Carlos APeres Danielle Storck-Tonon Laboratório de Ecologia Aplicada àConservação Universidade Estadual de Santa CruzIlhéus 45662-900Brazil Instituto Nacional de Pesquisas da Amazônia Coordenação de BiodiversidadeManaus 69067-001Brazil CIBIO Centro de Investigação em Biodiversidade e Recursos GenéticosInBIO Laboratório AssociadoCampus de VairãoUniversidade do PortoVairão 4485-661Portugal BIOPOLIS Program in Genomics Biodiversity and Land PlanningCIBIOCampus de VairãoVairão 4485-661Portugal School of Environmental Sciences University of East AngliaNorwich NR47TJUK Instituto Juruá Manaus69057-060Brazil Programa de Pós-Graduação em Ambiente e Sistemas de Produção Agrícola(PPGASP) Universidade do Estado de Mato GrossoTangaráda Serra 78300-970Brazil

Hydropower development has become an important driver of habitat loss and fragmentation across lowland tropical *** ample evidence on the detrimental effects of insular habitat fragmentation on biodiversity,invertebrate taxa,that may be critical to ecosystem functioning,have been *** assessed the assemblage-level responses of social wasps to forest insularization induced by the Balbina Hydroelectric Dam in Central Brazilian *** malaise trapping,we captured wasps on 27 forest islands and three continuous *** constructed Generalized Linear models and employed a model selection approach to examine the impact of local variables(fire severity(FIRE)and basal area of pioneer tree species(PIONEER))and landscape-scale variables(amount of habitat(COVER))on patterns of species richness,composition,and body size of wasps.A total of 374 individuals(29 species)were collected across all sampling *** was the main predictor of species richness,while PIONEER was the only variable that explained variation in community composition,with a negative effect on body *** results add evidence to the pervasive impacts of large hydroelectric dams on tropical forest biodiversity,and suggest that social wasps,among other invertebrates,can be used as bioindicators in infrastructure development projects.

关键词： Habitat amount hypothesis Habitat fragmentation Habitat loss Hydroelectric dams Invertebrates

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Biodiversity responses to insular fragmentation in Amazonia: Two decades of research in the Balbina Hydroelectric Reservoir

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Zoological Research(Diversity and Conservation) 2024年第2期1卷 106-116页

作者： Ana Filipa Palmeirim maíra Benchimol Danielle Storck-Tonon Anderson SBueno Isabel LJones Gilmar Klein Carlos APeres CIBIO Research Centre of Biodiversity and Genetic ResourcesInBIO Associated LabVairão CampusUniversity of PortoVairão 4485-661Portugal BIOPOLIS Program in Genomics Biodiversity and Land PlanningCIBIOVairão CampusUniversity of PortoVairão 4485-661Portugal Laboratório de Ecologia AplicadaàConservação Universidade Estadual de Santa CruzIlhéusBahia 45662-900Brazil Programa de Pós-Graduação em Ambiente e Sistemas de Produção Agrícola(PPGASP) Universidade do Estado de Mato GrossoTangaráda SerraMato Grosso 78301-532Brazil Instituto Federal de Educação Ciência e Tecnologia FarroupilhaJúlio de CastilhosRio Grande do Sul 98130-000Brazil Biological and Environmental Sciences University of StirlingStirling FK94LAUK REBIO Uatumã/ICmBio Presidente FigueiredoAmazonas 69736-000Brazil Centre for Ecology Evolution and ConservationSchool of Environmental SciencesUniversity of East AngliaNorwich NR47TJUK JuruáInstitute ManausAmazonas 69057-060Brazil

As hydropower development expands across lowland tropical forests,flooding and concomitant insular fragmentation have become important threats to *** created insular landscapes serve as natural laboratories to investigate biodiversity responses to *** of these most iconic landscapes is the Balbina Hydroelectric Reservoir in Brazilian Amazonia,occupying>400000 ha and comprising>3500 forest ***,we synthesise the current knowledge on responses of a wide range of biological groups to insular fragmentation at *** has largely concentrated on a set of 22 islands and three mainland *** total,39 studies were conducted over nearly two decades,covering 17 vertebrate,invertebrate,and plant *** species responses varied according to taxonomic group,island area was consistently included and played a pivotal role in 66.7%of all studies examining patterns of species *** persistence was further affected by species traits,mostly related to species capacity to use/traverse the aquatic matrix or tolerate habitat degradation,as noted for species of vertebrates and orchid *** research is needed to improve our understanding of such effects on wider ecosystem *** Impact Assessments must account for changes in both the remaining habitat amount and configuration,and subsequent long-term species losses.

关键词： Habitat loss Hydropower dams Landbridge Local extinctions Species-area relationships Species diversity Tropical forests

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Design of pH-responsive antimicrobial peptide melittin analog-camptothecin conjugates for tumor therapy

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Asian Journal of Pharmaceutical Sciences 2024年第1期19卷 135-146页

作者： Sujie Huang Yuxuan Gao Ling ma Bo Jia Wenhao Zhao Yufan Yao Wenyuan Li Tongyi Lin Rui Wang Jingjing Song Wei Zhang Institute of Pharmacology School of Basic Medical SciencesLanzhou UniversityLanzhou 730000China Key Laboratory of Preclinical Study for New Drugs of Gansu Province School of Basic Medical Sciences&Research Unit of Peptide ScienceChinese Academy of Medical SciencesLanzhou UniversityLanzhou 730000China State Key Laboratory of Veterinary Etiological Biology College of Veterinary MedicineLanzhou UniversityLanzhou 730000China Lanzhou University Second Hospital Lanzhou UniversityLanzhou 730000China

melittin,a classical antimicrobial peptide,is a highly potent antitumor ***,its significant toxicity seriously hampers its application in tumor *** this study,we developed novel melittin analogs with pH-responsive,cell-penetrating and membranelytic activities by replacing arginine and lysine with *** conjugation with camptothecin(CPT),CPT-AAm-1 and CPT-AAm-2 were capable of killing tumor cells by releasing CPT at low concentrations and disrupting cell membranes at high concentrations under acidic ***,we found that the C-terminus of the melittin analogs was more suitable for drug conjugation than the ***-AAm-1 significantly suppressed melanoma growth in vivo with relatively low ***,the present study demonstrates that the development of antitumor drugs based on pH-responsive antimicrobial peptide-drug conjugates is a promising strategy.

关键词： Antimicrobial peptide Peptide-drug conjugate Cell-penetrating activity membrane disruption Antitumor activity

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Linear Active Disturbance Rejection Control with a Fractional-Order Integral Action

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Computers, materials & Continua 2022年第11期73卷 3057-3079页

作者： maâmar Bettayeb rachid mansouri Ubaid m.Al-Saggaf Abdulrahman U.Alsaggaf mohammed moinuddin Electrical Engineering Department University of SharjahUnited Arab Emirates L2CSP Laboratory University Mouloud Mammeri of Tizi-OuzouAlgeria Center of Excellence in Intelligent Engineering Systems(CEIES) King Abdulaziz UniversityJeddahSaudi Arabia Electricaland Computer Engineering Department King Abdulaziz UniversityJeddahSaudi Arabia

Linear active disturbance rejection control(LADRC)is a powerful control structure thanks to its performance in uncertainties,internal and external disturbances estimation and *** extended state observer(ESO)based controller is the key to the LADRC *** this article,the LADRC scheme combined with a fractional-order integral action(FOILADRC)is proposed to improve the robustness of the standard *** the robust closed-loop Bode’s ideal transfer function(BITF),an appropriate pole placement method is proposed to design the set-point tracking controller of the FOI-LADRC *** simulations and experimental results on a cart-pendulum system will illustrate the effectiveness of the proposed FOI-LADRC scheme for the disturbance rejection,the set-point tracking and the improved *** illustrate the LADRC control schemes and to verify the performance of the proposed FOI-LADRC,compared to the standard LADRC and IOI-LADRC structures,two tests will be carried ***,simulation tests on an academic example will be presented to show the effect of the different parameters of the control law on the performance of the closed-loop ***,these three control structures are implemented on an experimental test bench,the cart-pendulum system,to show their efficiency and to show the superiority of the proposed method compared to the two other structures.

关键词： Fractional calculus active disturbance rejection control pole placement cart-pendulum system robust control

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聚硅氮烷/moS_(2)高温自润滑涂层的制备及性能研究

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摩擦学学报（中英文） 2024年第6期44卷 752-762页

作者：李谋吉杨武芳汤洁马正峰王睿麻拴红于波周峰中国科学院兰州化学物理研究所固体润滑国家重点实验室甘肃兰州730000 中国科学院大学北京100049

高温固体自润滑涂层因具有优异的摩擦学性能和极好的附着力,已被广泛应用于航空、航天等领域.本文中采用陶瓷前驱体聚硅氮烷为粘接剂,moS_(2)为润滑填料制备了1种新型的宽温域减摩抗磨涂层.系统探究了各因素对涂层摩擦学性能的影响,并... 详细信息

高温固体自润滑涂层因具有优异的摩擦学性能和极好的附着力,已被广泛应用于航空、航天等领域.本文中采用陶瓷前驱体聚硅氮烷为粘接剂,moS_(2)为润滑填料制备了1种新型的宽温域减摩抗磨涂层.系统探究了各因素对涂层摩擦学性能的影响,并利用扫描电镜(SEm)、X射线衍射(XRD)和raman等表征分析涂层的微观组织、物相组成及磨损机理.结果表明:聚硅氮烷/moS_(2)涂层不仅和基底结合力强,且在25~300℃较宽温域范围内具有优异的减摩抗磨性能.其中300℃热处理的涂层在200℃、9 N及90 r/min的测试条件下具有最佳润滑性能:平均摩擦系数为0.05,磨损率为7.6×10^(-5)mm^(3)/(N·m).涂层在中高温下体现出优异的润滑和耐磨性能,这主要得益于moS_(2)特殊层状结构和弱的剪切应力以及高硬度无机非晶态陶瓷相SiOC的形成.该涂层的成功制备有望为高温工况下服役的零部件表面润滑防护提供理论依据及数据支持.

关键词：聚硅氮烷二硫化钼宽温域高温润滑耐磨涂层

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基于分形和S型效用的选股策略及m-CVaR最优资产配置

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系统科学与数学 2024年第3期44卷 792-808页

作者：孙景云马小雯兰州财经大学统计与数据科学学院兰州730020 甘肃经济发展数量分析研究中心兰州730020

以上证50指数的主要成分股为研究对象,首先基于分形与S型效用理论构建股票风险综合评估指标,作为构建投资组合的选股依据.然后在金融资产收益率服从非对称拉普拉斯分布的假设下,采用CVaR值度量投资组合的风险,进而构建m-CVaR最优资产配... 详细信息

以上证50指数的主要成分股为研究对象,首先基于分形与S型效用理论构建股票风险综合评估指标,作为构建投资组合的选股依据.然后在金融资产收益率服从非对称拉普拉斯分布的假设下,采用CVaR值度量投资组合的风险,进而构建m-CVaR最优资产配置模型,并将该模型转化为二次规划问题进行求解.在实证分析阶段,利用滑动窗口法分别以月、季度、半年和一年为周期对最佳股票投资集的最优配置比例进行动态调整.结果表明,利用分形与S型期望效用理论筛选出的部分股票投资集可以获得比全部股票投资集更优的投资收益,且发现调整周期为1年的资产配置方案能获得较其他调整周期更高的累计收益率和夏普比率.

关键词：分形理论 S型期望效用非对称拉普拉斯分布 CVaR

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GH625镍基高温合金化学抛光工艺

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电镀与涂饰 2024年第4期43卷 79-86页

作者：马宁张峻山沈阳航空航天大学机电工程学院辽宁沈阳110136

[目的]化学抛光是高温合金化学铣切的关键步骤之一,能够去除高温合金表面的微观不平整缺陷,令其满足航空航天、石油化工等领域对零件表面高品质的要求。[方法]通过正交试验和单因素实验研究了抛光液配方和工艺参数对GH625高温合金化学... 详细信息

[目的]化学抛光是高温合金化学铣切的关键步骤之一,能够去除高温合金表面的微观不平整缺陷,令其满足航空航天、石油化工等领域对零件表面高品质的要求。[方法]通过正交试验和单因素实验研究了抛光液配方和工艺参数对GH625高温合金化学抛光速率和表面粗糙度的影响。[结果]GH625高温合金化学抛光的较佳配方和工艺条件为:盐酸100 g/L,硝酸170 g/L,氢氟酸90 g/L,Fe^(3+)170 g/L,温度50℃,时间5 min,试片水平放置。在该条件下化学抛光后,GH625高温合金表面变得平整均匀而富有金属光泽,表面粗糙度ra从初始的10.3μm降至1.1μm。[结论]本文的研究结果可为GH625高温合金的化学抛光提供参考。

关键词：镍基高温合金化学抛光表面粗糙度材料去除速率

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C/SiC复合材料表面SiC过渡层的包埋法制备与性能

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电镀与涂饰 2024年第6期43卷 33-39页

作者：赵泽马壮高丽红北京理工大学材料学院北京100081 冲击环境材料技术国家级重点实验室北京100081 北京理工大学唐山研究院河北唐山063000

[目的]碳/碳化硅(C/SiC)复合材料是航空航天领域最有发展前景的高温热防护结构材料之一,但其表面由于制备过程中化学气相渗透而造成粗糙度低、与涂层间结合强度差的问题有待解决。[方法]以Si粉、C粉和少量Al_(2)O_(3)粉为原料,通过包埋... 详细信息

[目的]碳/碳化硅(C/SiC)复合材料是航空航天领域最有发展前景的高温热防护结构材料之一,但其表面由于制备过程中化学气相渗透而造成粗糙度低、与涂层间结合强度差的问题有待解决。[方法]以Si粉、C粉和少量Al_(2)O_(3)粉为原料,通过包埋法在C/SiC基体表面制备了SiC涂层。[结果]该涂层与基体之间具有较好的化学亲和性,热膨胀系数匹配度高,表面状态改善情况好。SiC涂层的表面粗糙度(ra)相较于C/SiC基体实现了从1.732μm到5.531μm超2倍的提升,且涂层与基体结合良好,平均抗拉结合强度达到了4.946 mPa。[结论]该方法处理后的C/SiC复合材料满足了后续制备功能化涂层的要求。

关键词：碳/碳化硅复合材料过渡层包埋法表面粗糙度抗拉结合强度

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