检索结果-南通市图书馆

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

弹簧钢淬火残余应力模拟(英文)

金属热处理 2003年第11期28卷 47-52页

作者： G.Sánchez Sarmiento m.castro G.E.Totten L.Harvis G.Webster m.F.Cabré Universidad de Buenos Aires Facultad de IngenieríaUniversidad de Buenos AiresFacultad de IngenieríaDow Chemical Co.Tenaxol Inc.Dow Chemical Co.Universidad del Salvador Buenos AiresArgentinaBuenos AiresArgentinaTarrytownN YUSAMilwakeeWisconsinUSATarrytownN YUSABuenos AiresArgentina

对AISI 5 16 0H弹簧钢圆柱试样在不同温度的 2 5 %水溶性聚 (亚烷基 )二醇UCONHT淬火液和Arco5 2 1淬火油中淬火产生的残余应力及畸变进行了对比性研究。试棒的直径分2 0 5 6mm (0 81inches)和13 4 5mm (0 5 3inches)两种。先用I... 详细信息

对AISI 5 16 0H弹簧钢圆柱试样在不同温度的 2 5 %水溶性聚 (亚烷基 )二醇UCONHT淬火液和Arco5 2 1淬火油中淬火产生的残余应力及畸变进行了对比性研究。试棒的直径分2 0 5 6mm (0 81inches)和13 4 5mm (0 5 3inches)两种。先用INC PHATRAN代码计算出试样随时间变化的传热系数 ,并用ABAQUS/标准有限元软件估算热处理过程中的残余应力和畸变。在试样中心放置热电偶 ,测出冷却曲线 ,根据所测的冷却曲线 ,用INC PHATRAN解决了伴随相变时的逆向热传导问题。试验了这两种淬火介质 ,力图将热处理畸变和开裂减少到最少 ,并得出了颇有价值的结论。

关键词：弹簧钢淬火残余应力数值模拟

morphometric and Biochemical Changes in Agave americana *** Induced By Ethyl methanesulfonate

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Phyton-International Journal of Experimental Botany 2019年第3期88卷 277-284页

作者： S.J.Reyes-Zambrano m.L.Ramírez-merchant C.Arias-castro m.A.Rodríguez-mendiola C.A.Lecona-Guzmán V.m.Ruíz-Valdiviezo D.gonzález-mendoza F.A.Gutiérrez-miceli Laboratorio de Biotecnología Vegetal Instituto Tecnológico de Tuxtla GutiérrezTecnológico Nacional de México.Carretera Panamericana Km.1080TeránTuxtla GutiérrezChiapasC.P.29050México Laboratorios de Análisis Instrumental Bioquímico DEPI del Instituto Tecnológico de TlajomulcoTecnológico Nacional de México.Tlajomulco de ZuñigaC.P.45640México Instituto de Ciencias Agrícolas Universidad Autónoma de Baja California(ICA-UABC)Carretera a Delta s/n Ejido Nuevo LeónCP.21705Baja CaliforniaMéxico

*** *** a crop with very little genetic *** order to evaluate the effect of ethyl methanesulfonate(EmS)to induce variability in in vitro plantlets of ***,different explants(meristems,leaves and roots)were evaluated for the production of *** medium supplemented with ANA(2.68μm)and BAP(2.68μm)was *** obtained from apical meristem were treated with 15 mm EmS for two hours after which shoot formation was induced using 2,4-D(0.11μm)and BAP(44μm).The EmS induced variations in the morphometric and morphological parameters of the plantlets obtained,with 60%of the plantlets presenting differences such as dwarfism and different leaf forms,without the presence of spines,as well as an increase in fructan content of 30%with respect to the control *** was increased and this activity is related with higher anthocyanins concentration in *** ***.

关键词： Fructans callus mutagenesis flavonoids anthocyanins phenylalanine ammonia lyase activity

Variation in SARS-CoV-2 seroprevalence in children in the region of Asturias,Northern Spain

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2022年第12期18卷 835-844页

作者： Elisa García-García mercedes Rodríguez-Pérez David Pérez-Solís Carlos Pérez-méndez Cristina molinos-Norniella Ángeles Cobo-Ruisánchez Eva maría Fernández Fernández Noelia García gonzález laura Calle-miguel Pediatrics Department Centro de Salud LaviadaCalle Juanín de Mieres833207GijónSpain microbiology Department Hospital Universitario Central de AsturiasOviedoSpain Pediatrics Department Hospital Universitario San AgustínAvilésSpain Pediatrics Department Hospital Universitario de CabueñesGijónSpain Pediatrics Department Hospital Carmen y Severo Ochoa.Cangas del NarceaSpain Pediatrics Department Centro de Salud TeatinosOviedoSpain Pediatrics Department Hospital Universitario Central de AsturiasOviedoSpain

Background Updated seroprevalence estimates are important to describe the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)landscape and to guide public health *** aims are to describe longitudinal changes in seroprevalence in children in a region in Northern Spain and to analyze factors associated with SARS-CoV-2 *** Prospective multicenter longitudinal study with subjects recruited from July to September ***(up to 14 years old)were included and followed up until September *** blood samples were collected every six months during three testing rounds and were analyzed for SARS-CoV-2 *** data regarding epidemiological features,contact tracing,symptoms,and virological tests were *** evolution of SARS-CoV-2 seroprevalence during the study and the differences between children with positive and negative SARS-CoV-2 antibody tests were *** Two hundred children were recruited(50.5%girls,median age 9.7 years).The overall seroprevalence increased from round 1[1.5%,95%confidence interval(CI)0.3%–4.3%]to round 2(9.1%,95%CI 4.6%–12.7%)and round 3(16.6%,95%CI 9.5%–19.6%)(Pmain changes occurred in children aged zero to four years(P=0.001)who lived in urban areas(Pme *** multivariable analysis,three variables independently associated with SARS-CoV-2 seropositivity were identified:close contact with coronavirus disease 2019(COVID-19)confirmed or suspected cases[odds ratio(OR)=3.9,95%CI 1.2–12.5],previous positive virological test(OR=17.1,95%CI 3.7–78.3)and fatigue(OR=18.1,95%CI 1.7–193.4).Conclusions SARS-CoV-2 seroprevalence in children has remarkably increased during the time of our *** was the only COVID-19-compatible symptom that was more frequent in seropositive than in seronegative children.

关键词： Antibodies Child COVID-19 Seroepidemiologic studies

Addition of phenolic compounds to bread: antioxidant benefits and impact on food structure and sensory characteristics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Food Production, Processing and Nutrition 2021年第1期3卷 314-325页

作者： Yesica A.Czajkowska–gonzález Emilio Alvarez–Parrilla Nina del Rocío martínez–Ruiz Alma A.Vázquez–Flores marcela Gaytán–martínez laura Ade la Rosa Departament of Chemical Biological Sciences Institute of Biomedical SciencesUniversidad Autónoma de Ciudad JuárezAnillo Envolvente del PRONAF y Estocolmos/nC.P.32310 Cd.JuárezMéxico Programa de Posgrado en Alimentos del Centro de la República(PROPAC) Research and Graduate Studies in Food ScienceSchool of ChemistryUniversidad Autónoma de QuerétaroCentro UniversitarioCerro de las Campanas S/NC.P.76010 Santiago de QuerétaroMexico

The use of flours or phenolic extracts obtained from non-traditional sources or agri-food industry by-products has been a strategy used to formulate new bakery products with characteristics of a functional ***,phenolic compounds present great structural diversity,as well as the ability to interact in a complex way with the macromolecules that constitute the bread ***,the addition of these flours,extracts or pure compounds produces various effects on the microstructure of bread,and several of its sensory *** is mainly due to interactions between phenolic compounds and gluten *** objective of this review is to analyze some of the most recent published works on the addition of phenolic compounds in wheat bread to identify the type of positive and negative effects that have been observed and how they can be related to the physicochemical interactions between phenolic compounds and the macromolecules that constitute the food matrix,mainly *** effect of monomeric and polymeric phenolic compounds on the strength of these interactions and on the properties of dough and bread are discussed.

关键词： condensed tannins hydrolysable tannins phenolic acids gluten food rheology food texture protein-phenolic interactions disulfide bonds non-covalent interactions

Using Support Vector machines and neural networks to classify merlot wines from South America

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Information Processing in Agriculture 2019年第2期6卷 265-278页

作者： Nattane Luı´za Costa laura Andrea Garcı´a Llobodanin Inar Alves castro Rommel Barbosa Instituto de Informa´tica Universidade Federal de Goia´sGoiaˆnia-GoBrazil LADAF-Laboratory of Functional Foods Department of Food and Experimental NutritionFaculty of Pharmaceutical SciencesUniversity of Sa˜o PauloAv.Lineu Prestes580B1405508-900 Sa˜o PauloBrazil

Wines with a clear geographical origin are an issue of interest for consumers and food *** paper presents a data mining study of merlot wines from South America to identify the fingerprint of their geographical origin.A group of samples from Argentina(n=17),Brazil(n=12),Chile(n=48),and Uruguay(n=6)was *** chemical compounds were determined by high-performance liquid chromatography(HPLC).These compounds include antioxidant activity,total polyphenols,total anthocyanins,individual anthocyanins and *** binary classification problems were performed(Brazil versus non-Brazil,Argentina versus non-Argentina,Chile versus non-Chile,and Uruguay versus non-Uruguay)to investigate the geographic characteristics of each *** the evaluation of binary classifications in our dataset it was possible to identify the main variables(chemical compounds)that discriminate between the *** used the following algorithms:Synthetic minority over-sample Technique and under-sampling to balance the dataset of each classification approach,the Relief algorithm to obtain a variable importance ranking and the classifiers Support Vector machines,multilayer Perceptron and Radial Basis Function Network with dynamic decay *** model obtained the highest performance measures among the classifiers for each dataset(93.73%of accuracy for the Brazil versus non-Brazil,91.18%for the Argentina versus non-Argentina,79.16%for the Chile versus non-Chile,and 91.67%for the Uruguay versus non-Uruguay classification).These accuracies were achieved by the search of the possible variable subsets according to Relief for each classification *** found that some variables,such as DPPH,wine color and individual anthocyanins,are among the most important variables in the characterization of merlot wines.

关键词： Support Vector machine multilayer Perceptron Anthocyanins Feature selection merlot wines South America wines

Soil seed bank assembly following secondary succession on abandoned agricultural fields in Nicaragua

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Forestry Research 2009年第4期20卷 349-354,I0006页

作者： Benigno gonzález-Rivas mulualem Tigabu Guillermo castro-marín Per Christer Odén Facultad de Recursos Naturales y del Ambiente. Universidad Nacional Agraria. managua Swedish University of Agricultural Sciences Faculty of Forest Sciences Southern Swedish Forest Research Centre Sweden.

The composition and density of seeds in soils of secondary forests derived on abandoned fields after 4, 9 and 14 years of aban- donment were quantified to examine whether the soil seed bank assembles during secondary succession as the plant communities assemble. A total of 18, 37 and 48 soil samples from 4-, 9- and 14-year old sites, respectively were collected in 15 cm × 15 cm plots up to 9 cm depth. A total of 3, 5 and 9 species were found on sites abandoned 4, 9 and 14 years ago, respectively, Among different life forms, trees were highly represented in the soil seed bank of 9-year （60%） and 14-year （33%） old sites compared to 4-year old site entirely dominated by non- woody flora. The total number of seeds ranged from 327 in the 4-year old site to 146 in the 14-year old site, and the corresponding density of viable seeds ranged from 141 seeds m^-2 in the 4- year old site to 26 seeds m^-2 in the 14-year old site with a consistent decreasing pattern in the chronosequence. The similarity between the soil seed flora and the standing woody vegetation was low for both 9- and 14-year old sites while complete dissimilarity was found for 4-year old site. We concluded that the species composition of soil seed banks assemble gradually during secondary succession, but the overall seed density is still low for natural regeneration of trees to rely on. To expedite the recovery of secondary forests on such abandoned fields, the seed bank needs to be supplemented by direct seeding, enrichment planting of desired species and installing artificial perches for facilitating seed dispersal.

关键词： seed dispersal dry forest seed bank secondary succession restoration Nicaragua

Contribution of major Hydrophilic and Lipophilic Antioxidants from Papaya Fruit to Total Antioxidant Capacity

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Food and Nutrition Sciences 2013年第8期4卷 93-100页

作者： laura E. Gayosso-García Sancho Elhadi m. Yahia Gustavo A. gonzález-Aguilar Coordinación de Tecnología de Alimentos de Origen Vegetal Centro de Investigación en Alimentación y Desarrollo Hermosillo México Facultad de Ciencias Naturales Universidad Autónoma de Querétaro Querétaro México Jefatura de Nutrición Humana Universidad Estatal de Sonora Hermosillo México

Several studies have shown that phenolic and carotenoid compounds protect against oxidative stress, reducing the risk of cardiovascular diseases and some types of cancers. The objective of this research was to determine the individual contribution of the main phenolic compounds from the papaya fruit skin and the individual contribution of main carotenoids from the pulp for total antioxidant capacity at four ripening stages;and the individual and combined radical scavenging ability used the essays DPPH (radical 2, 2-diphenyl-1-picryhydrazyl) and ABTS (radical 2, 20-azino-bis (3-ethylbenzothiazoline)-6 sulphonic acid). Phenolic acids standards for this study were ferulic (FA), caffeic (CA) and p-coumaric (pCA) acids and carotenoids studied were Lycopene, β-carotene and β-cryptoxanthin. The phenol that showed the best DPPH· and ABTS·+ radical scavenging ability was CA, with 89.47% and 92.98%, respectively. Lycopene contributed the greatest to the TAC (11.9-43.2). Lycopene also showed the best DPPH· and ABTS ·+ radical scavenging ability with 62.12% and 94.26%, respectively. Antiradical ability of phenolics and carotenoids depended on the structure of the compound and its concentration.

关键词： Carica Papaya Carotenoids Phenolics Radical Scavenging Activity TEAC DPPH

Global wild rice germplasm resources conservation alliance:World Wild-Rice Wiring

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

molecular Plant 2024年第4期17卷 516-518页

作者： Xiaoming Zheng Disna Ratnasekera Jiayu Fan Robert J.Henry Beng-Kah Song Kenneth m.Olsen Bal Krishna Joshi maria Celeste N.Banaticla-Hilario Tonapha Pusadee Adane Getachew melaku Yeyinou laura Estelle Loko Koukham Vilayheuang Gavers K.Oppong Samuel Aduse Poku Peterson W.Wambugu Song Ge Aldo merotto Junior Ohn mar Aung Ramaiah Venuprasad Ajay Kohli Wenbin Zhou Qian Qian National Key Facility for Crop Gene Resources and Genetic Improvement Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijing 100081China Sanya National Research Institute of Breeding in Hainan Chinese Academy of Agricultural SciencesBeijing 100081China International Rice Research Institute DAPO Box 7777Metro Manila 4031Philippines Department of Agricultural Biology Faculty of AgricultureUniversity of RuhunaMatara 81000Sri Lanka Yazhouwan National Laboratory No.8 Huanjin RoadYazhou DistrictSanya CityHainan Province 572024China Hainan University Haikou 570228China ARC Centre of Excellence for Plant Success in Nature and Agriculture University of QueenslandBrisbaneQLD4072Australia School of Science Monash University Malaysia47500 Bandar SunwaySelangor 47500Malaysia Department of Biology Washington University in St.LouisSt.LouisMO 63130-4899USA National Agriculture Genetic Resources Center(Genebank) KhumaltarPO Box 3055KathmanduNepal Plant Biology Division Insttute of Biological SciencesUniversity of the Pilippines Los BanosLos BanosLaguna 4031Philippines Division of Agronomy Department of Plant and Soil SciencesFaculty of AgricultureChiang Mai UniversityChiang Mai 50200Thailand Bio and Emerging Technology Institute Addis Ababa 1165Ethiopia National University of Sciences TechnologiesEngineering and Mathematics(UNSTIM)Dassa-ZouméBP 14Benin National Genebank Rice and Cash Crops Research CenterNAFRIVientiane 0605Lao PDR Plant Sciences and the Bioeconomy Rothamsted ResearchHarpenden AL52JQUK UK Future Food Beacon of Excellence and School of Biosciences and University of Nottingham Nottingham LE125RDUK Department of Plant and Environmental Biology University of GhanaAccraGhana Kenya Agricultural and Livestock Research Organization Genetic Resources Research InstituteNairobi 00200Kenya Institute of Botany Chinese Academy of SciencesBeijing 100093China Federal University of Rio Grande do Sul UFRGSPorto Alegre 91501-970RSBrazil Department of Agricultur

Wild relatives of crop are key genetic resources serving as diversity reservoirs for crop improvement under changing ***(Oryza sativa)is one of the most important crops in the world,providing staple food for half of the world's *** rice is thus a critical germplasm resource for sustained global food security,ensuring high production yields,improved quality,and stress resistance in the face of climate *** rice is closely related to domesticated rice and has a rich genetic diversity and exceptional adaptability to extreme *** has played a pivotal role in the history of rice hybridization and has become a key resource for rice breeding *** identification of wild-type cytoplasmic male sterility resources paved the way for the achievement of the“three lines”goal in hybrid rice,leading to a significant increase in rice *** addition,the use of resistance alleles found in wild rice is making rice production more resilient to losses caused by environmental ***,wild rice germplasm resources are threatened due to habitat destruction and other anthropogenic *** the same time,the lack of centralized distribution of wild rice has hampered the sharing of basic information on wild rice resources and the utilization and conservation of wild rice in each country,as well as collaboration among scientists.

关键词： germplasm breeding crops

Environmental Deterioration of the Tecomate Coastal Lagoon, in the Guerrero State, mexico

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Geosciences 2016年第1期7卷 1-10页

作者： Salvador Villerías-Salinas Juan Violante-gonzález Neftalí García-castro Lorena Alonzo-Guzmán Centro de Estudios y Posgrado en Estudios Socioterritoriales Universidad Autónoma de Guerrero Chilpancingo México Unidad Académica de Ecología marina Universidad Autónoma de Guerrero Acapulco México Unidad Académica de Ingeniería Universidad Autónoma de Guerrero Chilpancingo México

An exhaustive field study was undertaken between November 2011 and August 2012, with the aim to know the causes of the environmental deterioration of the Tecomate Lagoon, in the Guerrero state, mexico. Data of temperature, dissolved oxygen, salinity parameters and depth of the lagoon were interpolated using the Kriging geostatistical method to generate a prediction surface. The lagoon registered a great variation in its saline concentration, which ranged from 8.0 to 65.0 ppt, with the lowest values in November 2011 and the highest at may 2012. The great variability in the salinity throughout the year contributed in significant form to the lagoon’s instability. An average water temperature of 32?C and dissolved oxygen levels of 4.49 to 7.44 mg/L were recorded. The low depth registered in the lagoon (mean = 1 m), is related to fluvial and marine processes, both of which modify depth through the transport of sediment to its interior. Currently, fishing is scarce, with the mangrove forest in some areas in a process of deterioration due to a lack of moisture. The lagoon system is undergoing a process of environmental deterioration, with an advanced ecological succession and non-aquatic vegetable species colonizing the area surrounding the lagoon.

关键词： Tecomate Lagoon Environmental Parameters Habitat Deterioration Aquatic Ecosystem