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含预紧弹簧碰撞系统的两参数动力学

振动与冲击 2024年第4期43卷 12-19页

作者：吕小红王继培张锦涛兰州交通大学机电工程学院兰州730070

考虑含预紧弹簧机械碰撞系统,构建由光滑流映射和不连续映射复合的Poincaré映射,给出Floquet乘子计算的数值方法。数值仿真系统在两参数平面的周期吸引子模式及其参数域,应用延拓打靶法和胞映射法研究周期1吸引子的分岔特征以及不连续... 详细信息

考虑含预紧弹簧机械碰撞系统,构建由光滑流映射和不连续映射复合的Poincaré映射,给出Floquet乘子计算的数值方法。数值仿真系统在两参数平面的周期吸引子模式及其参数域,应用延拓打靶法和胞映射法研究周期1吸引子的分岔特征以及不连续擦边分岔、擦边和周期倍化诱导的分岔、亚临界周期倍化分岔和激变等不连续分岔行为,揭示迟滞域和亚谐包含域的形成机理。不连续擦边分岔在相邻1-m与1-(m+1)吸引子的转迁过程中产生迟滞域和亚谐包含域。然而,当预压量等于0时,擦边诱导的鞍结和周期倍化分岔分别产生迟滞域和亚谐包含域。研究结果能够为工程实际含预紧弹簧机械碰撞系统的参数设计与优化提供参考。

关键词：非光滑系统数值延拓两参数动力学周期吸引子分岔

Does climate change alter the nutrient trends of Cedrela fissilis *** in the southern Brazilian Amazon?

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Ecological Processes 2023年第1期12卷 806-827页

作者： Daigard R.Ortega Rodriguez raúl Sánchez-Salguero Andrea Hevia Renata C.Bovi Marciel J.Ferreira James H.Speer Fidel A.Roig Mario Tomazello-Filho Escola Superior de Agricultura luiz de Queiroz Departamento de Ciências FlorestaisUniversidade de São PauloAv.Pádua Dias 11PiracicabaSão Paulo 13418-900Brazil DendrOlavide-Department Sistemas Físicos Químicos y NaturalesUniversidad Pablo de OlavideCrta.Utrera Km.141013 SevilleSpain Department of Ecology Universidad de JaénCampus Las Lagunillas s/n.23009 JaénSpain Departamento de Ciência Florestal Solos e AmbienteUniversidade Estadual PaulistaAv.Universitária 3780BotucatuSão Paulo 18610-034Brazil laboratory of Silviculture Universidade Federal do Ama-zonasAv.Gen.Rodrigo Octávio 6200ManausAmazonas 69080-900Brazil Department of Earth and Environmental Systems Indiana State UniversityTerre MauteIN 47809USA Argentine Institute of Nivology Glaciology and Environmental Sciences(IANIGLA CONICETUniversidad Nacional de Cuyo)5500 MendozaArgentina Hémera Centro de Observación de la Tierra Escuela de Ingeniería ForestalFacultad de CienciasUniversidad MayorSantiagoChile

Background The increase in the frequency and intensity of droughts is pointed out as one of the main factors altering biogeochemical cycles in the Amazon *** eco-nutritional approach using X-ray fluorescence micro-analysis(μXRF)is proposed to verify the long-and short-term effects of droughts on the growth and xylem nutrient concentrations of Cedrela fissilis *** Fourteen radii were selected from a tree-ring width chronology and X-rayed by Itrax *** of ring width,wood density,and concentrations of aluminum(Al),phosphorus(P),sulfur(S),calcium(Ca),potassium(K),manganese(Mn),iron(Fe)and strontium(Sr)together with Al/Ca,Ca/Mn,K/Ca,Sr/Ca and Mn/S ratios were constructed and correlated with precipitation,temperature,the difference between precipitation and potential evapotranspiration(P-PET)and standardized precipitation-evapotranspiration index(SPEI).Results During dry years,*** showed narrower,less dense rings,lower Al,P,S and Ca,and higher K and Fe concentrations(the opposite was found in wet years).Ring width decreased(together with Al,P,S,K,Ca,Mn,Fe,Sr,Al/Ca,K/Ca and Sr/Ca)and wood density increased(together with Ca/Mn and Mn/S),which was associated with an increase in evapotranspiration and temperature over time,mainly since *** fissilis showed a tendency to increase its capacity for resistance,and a recovery and resilience in growth over time associated with responses in Al,Ca,P and ***,it showed a risk in the capacity for recovery of the pre-drought density values,associated with unsatisfactory responses in Al,Ca,K,Fe and *** This study is the first attempt to analyze tree-ring nutritional evidences of *** trees to climate sensitivity and resilience to drought,based on long-term data from seasonal moist tropical forests of the *** data suggested that *** is undergoing alterations in the concentration,use and redistribution of nutrients associated with increasing wood density and d

关键词： Dendrochemistry μXRF Drought Tropical tree Eco-chemical indicator Resilience Resistance Recovery

Surgical or medical treatment of obesity-associated type 2 diabetesan increasing clinical conundrum

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World Journal of Diabetes 2024年第10期15卷 2036-2040页

作者： Ryan J Jalleh Karen l Jones Md Shahidul Islam lu Cai Michael Horowitz Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health University of Adelaide Endocrine and Metabolic Unit Royal Adelaide HospitalAdelaide 5000South AustraliaAustralia Department of Biochemistry School of Life SciencesUniversity of KwaZulu-NatalDurban 4000KwaZulu-NatalSouth Africa Pediatric Research Institute Departments of PediatricsRadiation OncologyPharmacology and ToxicologyUniversity of LouisvilleWendy Novak Diabetes InstituteNorton Children’s HospitalLouisvilleKY 40202United States

In this editorial,we comment on the article by He et al,specifically in relation to the efficacy of bariatric surgery vs glucagon-like peptide-1 receptor agonist(GlP-1ra)therapy in the management of type 2 diabetes(T2D)associated with *** surgery has now also been shown to be safe and effective in pre-teens and teenagers with obesity and T2D,but information on newer GlP-1ras in these groups is predictably *** older individuals(age>65 years),both bariatric surgery and GlP-1ra therapy improve cardiovascular ***-tric surgery is not infrequently associated with post-operative postprandial hypoglycemia,which is not the case with GlP-1ras and,paradoxically,there is evidence that GlP-1ras may reduce both the frequency and severity of postprandial *** trials of the long-term efficacy of bariatric surgery and GlP-1ras are indicated.

关键词： Glucagon-like peptide-1 Glucagon-like peptide-1 receptor agonist Obesity Diabetes Weight loss Bariatric surgery Metabolic surgery Hypoglycemia

Human endogenous retroviruses: Their possible role in the molecular etiology of the schizophrenia

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Open Journal of Genetics 2012年第1期2卷 70-76页

作者： raúl Alelú-Paz Ignacio Iturrieta-Zuazo Department of Anatomy and Embriology. School of Medicine. San Pablo CEU University Department of Biochemistry and Molecular Biology. School of Medicine. University of Alcalá

Human endogenous retroviruses (HERVs) represent footprints of previous retroviral infections. They are integrated within the human germ line and constitute approximately 8% of our genome. They have the potential to harm, given their capacity to alter the cellular metabolism, and could be involved in various pathological processes. This revision intends to highlight the importance of HERVs in health and disease, and the increasing interest of the scientific community in their biology. In this overview, we will present a brief summary of the structure and physiological function of HERVs and an analysis of their role in schizophrenia, a paradigm of mental illness, particularly stressing the importance of HERV research to explore the more basic mechanisms disrupted in this psychiatric condition.

关键词： HERVs Schizophrenia Molecular Biology

Evaluating Sensitivity to Different Options and Parameterizations of a Coupled Air Quality Modelling System over Bogotá, Colombia. Part I: WRF Model Configuration

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Open Journal of Air Pollution 2015年第2期4卷 47-64页

作者： Beatriz Reboredo raúl Arasa Bernat Codina Air Quality Department Meteosim S.L. Barcelona Spain Department of Astronomy and Meteorology Barcelona Spain

Meteorological inputs are of great importance when implementing an air quality prediction system. In this contribution, the Weather Research and Forecast (WRF-ARW) model was used to compare the performance of the different cumulus, microphysics and Planet Boundary layer parameterizations over Bogotá, Colombia. Surface observations were used for comparison and the evaluated meteorological variables include temperature, wind speed and direction and relative humidity. Differences between parameterizations were observed in meteorological variables and Betts-Miller-Janjic, Morrison 2-moment and Boulac schemes proved to be the best parameterizations for cumulus, microphysics and PBl, respectively. As a complement to this study, a WRF-large Eddy simulation was conducted in order to evaluate model results with finer horizontal resolution for air quality purposes.

关键词： Sensitivity Analysis Air Quality Modelling Meteorological Modelling WRF Physical Options

Understorey plant community assemblage of Australian Eucalyptus woodlands under elevated CO_(2)is modulated by water and phosphorus availability

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Journal of Plant Ecology 2021年第3期14卷 478-490页

作者： raúl Ochoa-Hueso rani Carroll Juan Piñeiro Sally A.Power Ecosystem Function and Integration Theme Hawkesbury Institute for the EnvironmentWestern Sydney UniversityLocked Bag 1797PenrithNew South Wales 2751Australia Department of Biology IVAGROUniversity of CadizCampus de Excelencia Internacional Agroalimcntario(CciA3)Campus del Rio San Pedro11510 Puerto RealCadizSpain Davis College of Agriculture Natural Resourcesand DesignDivision of Plant and Soil SciencesWest Virginia UniversityMorgantownWVUSA

Aims Given the key functional role of understorey plant communities and the substantial extent of forest cover at the global scale,investigating understorey community responses to elevated CO_(2)(eCO_(2))concentrations,and the role of soil resources in these responses,is important for understanding the ecosystem-level consequences of rising CO_(2)concentrations for forest ***,we evaluated how experimentally manipulating the availabilities of the two most limiting resources in an extremely phosphorus-limited eucalypt woodland in eastern Australia(*** and phosphorus)can modulate the response of the understorey community to eCO_(2)in terms of germination,phenology,cover,community composition and leaf *** We collected soil containing native soil seed bank to grow experimental understorey plant communities under glasshouse *** Findings Phosphorus addition increased total plant cover,particularly during the first 4 weeks of growth and under high water conditions,a response driven by the graminoid component of the plant ***,the treatment differences diminished as the experiment progressed,with all treatments converging at〜80%lant cover after〜11 *** contrast,plant cover was not affected by eCO_(2).Multivariate analyses reflected temporal changes in the composition of plant communities,from pots where bare soil was dominant to high-cover pots dominated by a diverse ***,both phosphorus addition and the interaction between water availability and CO_(2)affected the temporal trajectory of the plant community during the ***_(2)also increased community-level specific leaf area,suggesting that functional adaptation of plant communities to CO_(2)may precede the onset of compositional *** that the response of our seed bank-derived understorey community to CO_(2)developed over time and was mediated by interactions with phosphorus and water availability,our results suggest a limited ro

关键词： elevated CO_(2) Eucalyptus woodland modulating drivers plant community dynamics soil resources

Using a Coupled Air Quality Modeling System for the Development of an Air Quality Plan in Madrid (Spain): Source Apportionment and Analysis Evaluation of Mitigation Measures

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Journal of Geoscience and Environment Protection 2016年第3期4卷 46-61页

作者： raúl Arasa Anna Domingo-Dalmau Ricardo Vargas Technical Department Barcelona Spain Environmental and Territorial Planning Agency Regional Government of Madrid Madrid Spain

In this contribution, we use a coupled air quality modelling system (AQM) as a tool to design and develop an air quality plan in Madrid. AQM has allowed us to obtain a preliminary evaluation of the effect of mitigation measures over regional and local air quality levels. To achieve these goals, we have prepared a sophisticated AQM, coupling the meteorological model WRF, the emission model AEMM, and the photochemical model CMAQ. AQM was evaluated using the whole modelling year 2010 working with high horizontal resolution, 3 km for the region of Madrid and 1km for urban metropolitan area of Madrid. Two different analyses have been realized: a source apportionment exercise following a zero-out methodology to obtain the contribution to the air quality levels of the different emission sector;and an evaluation of the main mitigation measures considered in the air quality plan using sensitivity analysis. The air quality plan was focused on the improvement of NO2 levels and AQM analyzed the effect of the mitigation measures during ten episodes of 2011 where NO2 or O3 levels were the highest of the year;so we analyzed the effect of the mitigation plan in worst conditions. Results provided by the AQM system show that it accomplishes the European Directive modelling uncertainty requirements and the mean absolute gross error for 1-h maximum daily NO2 is 31% over locations with higher levels of this atmospheric pollutant;the road traffic is the main contributor to the air quality levels providing a 81% for NO2, 67% for CO and 46% for PM10;measures defined in the plan achieve to reduce up to 11 μgm-3 NO2 levels offering highest reductions over urban areas with traffic influence.

关键词： Environmental Assessment Air Quality Modelling CMAQ Emissions Madrid Air Quality Plan Mitigation Measures

Total phenolic content,in vitro antioxidant activity and chemical composition of plant extracts from semiarid Mexican region

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Asian Pacific Journal of Tropical Medicine 2015年第2期8卷 104-111页

作者： Jorge E.Wong-Paz Juan C.Contreras-Esquivel raúl Rodríguez-Herrera María l.Carrillo-Inungaray lluvia I.lópez Guadalupe V.Nevárez-Moorillón Cristóbal N.Aguilar laboratory of Bioprocesses and Natural Products Food Research DepartmentSchool of ChemistryUniversidad Autónoma de CoahuilaSaltillo25280México laboratory of Biochemistry Multidisciplinary Academic Unit-HuastecaUniversidad Autónoma de San Luis Potosí79060Cd.VallesS.L.P.Mexico Department of Microbiology School of ChemistryUniversidad Autónoma de Chihuahua31125 ChihuahuaMexico

Objective:To determine the extraction suitable conditions of total phenolic content(TPC) by heat-reflux system,antioxidant activities and HPlC characterization of the aqueous-ethanolic extracts of Jatropha dioica(***)(Dragon's blood).Flourensia cernua(***)(Tar bush).Eucalyptus camaldulensis(***)(Eucalyptus) and Turnera diffusa(***)(Damiana).Methods:TPC was evaluated by the well-known colorimetric assay using FolinCiocalteu *** antioxidant activities were assayed by three methods based on scavenging of DPPH,ABTS and by lipid oxidation *** chemical composition of the extracts obtained was subject to HPlC ***:TPC in the plant extracts ranged from 2.3 to14.12 mg gallic acid equivalents/g for *** and ***,*** plant extracts of ***,*** and *** showed similar strong antioxidant activities on scavenging of DPPH and lipid oxidation *** contrast,*** extracts had lowest potential antioxidant in three assays *** assay showed the presence of several phenolic compounds in the extracts ***:The results obtained suggest that ***,*** and *** are potential sources to obtain bioactive phenolic compounds with high antioxidant properties which can be used in the factories as antioxidant agents or for treatments in diseases.

关键词： Plant-extracts Polyphenols Natural antioxidants Mexican plants Heat-reflux system

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氟化钙样物质的合成和检测的体外研究

中华口腔医学杂志 1995年第4期30卷 222-224页

作者：郑睿 ra.,Z.l. 北京医科大学口腔医学院材料研究室

牙釉质经氟化物处理后，表面生成“氟化钙样”的物质（“ＣａＦ＿２－ｌｉｋｅ”ｍａｔｅｒｉａｌｓ）。这种物质为量极少，且采集技术也有困难，故很难利用其作为防龋机理研究的样本。为获取代替牙面的氟化钙样物质，本研究采用化学合... 详细信息

牙釉质经氟化物处理后，表面生成“氟化钙样”的物质（“ＣａＦ＿２－ｌｉｋｅ”ｍａｔｅｒｉａｌｓ）。这种物质为量极少，且采集技术也有困难，故很难利用其作为防龋机理研究的样本。为获取代替牙面的氟化钙样物质，本研究采用化学合成的方法，制备了不同磷含量的氟化钙样物质，并分析、测定了这种物质在醋酸钾缓冲液中的溶解性能。对氟化钙样物质中磷与溶解性能的关系，作了定量的分析，并在其成分、溶解性、晶形结构等方面与纯氟化钙进行了比较。结果表明，用化学方法合成的氟化钙样物质，可以反应对牙面上氟化钙样物质的研究。本研究还验证了磷能使氟化钙样物质的结晶形态从立方晶形转变为微小的球滴状，溶解性随着磷含量的增加而加大。该实验是对氟防龋机理研究的一种方法。

关键词：氟化钙类龋齿磷牙釉质