检索结果-南通市图书馆

Atmospheric-pressure dielectric barrier discharge generation by a full-bridge flying capacitor multilevel inverter

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2017年第7期19卷 40-49页

作者： rosendo PE?A-EGUIlUZ José A lópez-FErNáNDEZ Antonio MErCADO-CABrErA Bethsabet JArAMIllO-SIErrA régulo lópez-CAllEJAS Benjamín rODríGUEZ-MéNDEZ raúl vAlENCIA-AlvArADO Allan A FlOrES-FUENTES Arturo E MU?OZ-CASTrO Plasma Physics laboratory Instituto Nacional de Investigaciones Nucleares Tecnológico de Estudios Superiores de Tianguistenco Universidad Autónoma del Estado de México

A new configuration of a resonant full-bridge flying capacitor multicell inverter has been designed and constructed with the aim of achieving an extended output voltage frequency range with low harmonic distortion and reduced semiconductor commutation losses. This configuration was tested as a power supply for two different coaxial dielectric barrier discharge reactors, one of them employed for electric characterization and the other one for inorganic compound elimination in an aqueous solution. Two different gas mixtures, 90% Ar-10% 02 and 80% Ar-20% 02, were individually supplied during the experiments; the results showed a high- efficiency removal of meta-cresol （m-cresol） to the order of 98%, which was obtained by adding more oxygen to the plasma gas mixture.

关键词： plasma applications water pollution plasma sources power supply circuits electricdischarges

Preparation of neodymium-doped yttrium aluminum garnet powders and fibers

在线全文

学校读者我要写书评

暂无评论

Journal of rare Earths 2008年第5期26卷 670-673页

作者： r. lópez J. Zárate E. A. Aguilar J. Muoz-Saldaa Instituto de Investigaciones Metalurgicas UMSNH Morelia Centro de Investigación y de Estudios Avanzados del IPN Unidad Queretaro

Using nitrate precursors, a novel spray-drying assisted citrate gel process for the preparation of neodymium-doped yttrium alumi- num garnet （YAG） phase was developed. Synthesis of single-phase polycrystalline YAG was achieved at temperatures as low as 800 ℃ using the spray-drying methodology whilst conventional approaches currently available require 1000 ℃. Initially, a solution was prepared by mixing aluminum and yttrium nitrates, citric acid, etilenglycol and neodymium oxide. This solution was dried by pulverization （spray dryer） to obtain aggregated precursor powders of the compound. These aggregates were calcined at 800, 850 and 900 ℃ to determine the phase evolution from amorphous to crystalline by X-ray diffraction （XrD）. The morphology of aggregates was characterized by scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. Moreover, through XrD it was determined that the crystallization of YAG phase started at about 800 ℃ without any intermediate phases. The powders were composed of spherical aggregates with an average diameter of 1 um. From these powders, ceramic fibers with additions of 2at.% and 5at.% Nd, were extracted from the melt with diameters ranging from 30 um to 50 um.

关键词： spray-drying melt extraction fibers yttrium aluminum garnet rare earths

Bulk lateral shearing interferometry for spatiotemporal study of time-varying ultrashort optical vortices

在线全文

学校读者我要写书评

暂无评论

Photonics research 2022年第4期10卷 922-931页

作者： Miguel lopez-ripa Inigo J.Sola Benjamin Alonso Grupo de Aplicaciones del laser y Fotonica(AlF) Departamento de Fisica AplicadaUniversidad de Salamanca37008 SalamancaSpain

The spatiotemporal measurement of ultrashort laser beams usually involves techniques with complex set-ups or limited by instabilities that are unable to accurately retrieve the frequency-resolved wavefront. Here, we solve these drawbacks by implementing a simple, compact, and ultra-stable spatiotemporal characterization technique based on bulk lateral shearing spectral interferometry using a birefringent uniaxial crystal. We apply it to retrieve complex spatiotemporal structures by characterizing ultrafast optical vortices with constant and time-varying orbital angular momentum. This technique can operate in all the transparency range of the anisotropic elements,enabling the characterization in different spectral ranges like infrared, visible, or ultraviolet.

关键词： ultrashort shearing interferometry

Novel kinetic model for the simulation analysis of the butanol productivity of Clostridium acetobutylicum ATCC 824 under different reactor configurations

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2018年第4期26卷 812-821页

作者： Hugo I.velázquez-Sánchez ricardo Aguilar-lópez Center of research and Advances Studies of the National Polytechnic Institute (CINvESTAv) Biotechnology and Bioengineering DepartmentAv. National Polytechnic Institute 2508 Col. San Pedro Zacatenco

Acetone–butanol–ethanol(ABE)fermentation process can be exploited for the generation of butanol as biofuel,however it does need to overcome its low volumetric solvent productivity before it can commercially compete with fossil fuel *** this regard,mathematical modelling and simulation analysis are tools that can serve as the base for process engineering development of biological *** this work,a novel phenomenological kinetic model of Clostridium acetobutylicum ATCC 824 was considered as a benchmark system to evaluate the behaviour of an ABE fermentation under different process configurations using both free and immobilized cells:single stage batch operation,fed-batch,single stage Continuous Stirred Tank reactor(CSTr)and multistage CSTrs with and without biomass *** proposed model achieved a linear correlation index r^2=0.9952 and r^2=0.9710 over experimental data for free and immobilized cells *** predicted maximum butanol concentration and productivity obtained were 13.08 g·l^(-1)and 1.9620 g·l^(-1)·h^(-1)respectively,which represents an increase of 1.01%and 990%versus the currently developed industrial scale process reported currently into the *** results provide a reliable platform for the design and optimization of the ABE fermentation system and showcase the adequate predictive nature of the proposed model.

关键词： ATCC 运动模型模拟分析生产率反应堆配置发酵过程数学建模

CrISPr/Cas9 editing of the polygalacturonase FaPG1 gene improves strawberry fruit firmness

在线全文

学校读者我要写书评

暂无评论

Horticulture research 2023年第3期10卷 201-210页

作者： Gloria lópez-Casado Cristina Sánchez-raya Pablo D.ric-varas Candelas Paniagua rosario Blanco-Portales Juan Muñoz-Blanco Sara Pose Antonio J.Matas Jose A.Mercado Departamento de Botánica y Fisiología vegetal Instituto de Hortofruticultura Subtropical y Mediterránea‘La Mayora’(IHSM-UMA-CSIC)Universidad de Málaga29071 MálagaSpain Departamento de Bioquímica y Biología Molecular Universidad de Córdoba14071CórdobaSpain

Firmness is one of the most important fruit quality traits in *** postharvest shelf life of this soft fruit is highly limited by the loss of firmness,where cell wall disassembly plays an important *** studies demonstrated that the polygalacturonase FaPG1 has a key role in remodelling pectins during strawberry *** this study,FaPG1 knockout strawberry plants have been generated using the CrISPr/Cas9 system delivered via Agrobacterium *** independent lines,cv.“Chandler”,were obtained,and all of them were successfully edited as determined by PCr amplification and T7 endonuclease *** targeted mutagenesis insertion and deletion rates were analyzed using targeted deep *** percentage of edited sequences varied from 47%up to almost 100%,being higher than 95%for seven of the selected *** analyses showed that 7 out of the eight lines analyzed produced fruits significantly firmer than the control,ranging from 33 to 70%increase in *** was a positive relationship between the degree of FaPG1 editing and the rise in fruit *** changes were observed in other fruit quality traits,such as colour,soluble solids,titratable acidity or anthocyanin *** fruits showed a reduced softening rate during postharvest,displayed a reduced transpirational water loss,and were less damaged by Botrytis cinerea *** analysis of four potential off-target sites revealed no mutation *** conclusion,editing the FaPG1 gene using the CrISPr/Cas9 system is an efficient method for improving strawberry fruit firmness and shelf life.

关键词： fir straw PG1

role of seed size, phenology, oogenesis and host distribution in the specificity and genetic structure of seed weevils (Curculio spp.) in mixed forests

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2018年第3期13卷 267-279页

作者： Harold ArIAS-lEClAIrE raúl BONAl Daniel GArCÍA-lÓpez Josep Maria ESPElTA CrEAF Centre for Ecological Research and Forestry ApplicationsCerdanyola del Vallès08193Spain Exact and Natural Sciences School State Distance University of Costa RicaUNEDMercedes de Montes de OcaSan JoséCosta Rica Forest research Group INDEHESAUniversity of ExtremaduraPlasenciaSpain DITEG research Group University of Castilla-La ManchaToledoSpain Zoology Department Autonomous University of BarcelonaCerdanyola del VallèsSpain

Synchrony between seed growth and oogenesis is suggested to largely shape trophic breadth of seed-feeding insects and ultimately to contribute to their co-existence by means of resource partitioning or in the time when infestation *** we investigated:(i)the role of seed phenology and sexual maturation of females in the host specificity of seed-feeding weevils(Curculio spp.)predating in hazel and oak mixed forests;and(ii)the consequences that trophic breadth and host distribution have in the genetic structure of the weevil *** analyses were used to establish unequivocally host specificity and to determine the population genetic *** identified 4 species with different specificity,namely Curculio nucum females matured earlier and infested a unique host(hazelnuts,Corylus avellana)while 3 species(Curculio venosus,Curculio glandium and Curculio elephas)predated upon the acorns of the 2 oaks(Quercus ilex and Quercus pubescens).The high specificity of *** coupled with a more discontinuous distribution of hazel trees resulted in a significant genetic structure among *** addition,the presence of an excess of local rare haplotypes indicated that *** populations went through genetic expansion after recent ***,these effects were not observed in the more generalist Curculio glandium predating upon ***,co-existence of weevil species in this multi-host-parasite system is influenced by both resource and time *** what extent the restriction in gene flow among *** populations may have negative consequences for their persistence in a time of increasing disturbances(*** in Mediterranean areas)deserves further research.

关键词： Corylus avellana Curculio spp. genetic structure Quercus spp. trophic breadth

Newtonian Gravitational radiation and Waves

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 Applied Mathematics and Physics 2020年第8期8卷 1449-1455页

作者： Gustavo v. lópez Departamento de Física Universidad de Guadalajara Guadalajara Mexico

In this paper, we review historical Maxwell's equation for gravity and recent studies on the lack of curvature of linear dipole gravitational waves. The extended Newton's gravity necessarily has the continuity equation for the conservation of mass, and with the Gauss' equation associated to gravitational time depending field rong>rrong>, bring about a new field rong>Wrong> which resembles the magnetic field in Electrodynamics. Although this field has not been found yet, its existence comes from a strong mathematical statement, and it is shown that linear dipole gravitational waves have their origin in extended Newton theory of gravity. This is a direct mathematical consequence of Gauss' law and the continuity equation for the density of mass and current, and as a direct result of this, any accelerated mass will emit mainly dipole gravitational radiation. Then, one concludes that dipole gravitational waves can have its origin on the extended Newton's gravity equations.

关键词： Gravitational Field Maxwell's Equations Gravitational Waves Gravitational radiation reaction

Novel electrode structure in a DBD reactor applied to the degradation of phenol in aqueous solution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasma Science and Technology 2017年第7期19卷 71-84页

作者： Antonio MErCADO-CABrErA rosendo PE?A-EGUIlUZ régulo lópez-CAllEJAS Bethsabet JArAMIllO-SIErrA raúl vAlENCIA-AlvArADO Benjamín rODríGUEZ-MéNDEZ Arturo E MU?OZ-CASTrO Instituto Nacional de Investigaciones Nucleares Plasma Physics Laboratory Tecnológico de Estudios Superiores de Tianguistenco

Phenol degradation experimental results are presented in a similar wastewater aqueous solution using a non-thermal plasma reactor in a coaxial dielectric barrier discharge. The novelty of the work is that one of the electrodes of the reactor has the shape of a hollow screw which shows an enhanced efficiency compared with a traditional smooth structure. The experimentation was carried out with gas mixtures of 90% Ar-10% O2, 80% At-20% 02 and 0% Ar-100% 02. After one hour of treatment the removal efficiency was 76%, 92%, and 97%, respectively, assessed with a gas chromatographic mass spectrometry technique. For both reactors used, the ozone concentration was measured. The screw electrode required less energy, for all gas mixtures, than the smooth electrode, to maintain the same ozone concentration. On the other hand, it was also observed that in both electrodes the electrical conductivity of the solution changed slightly from ,-0.0115 S m^-1 up to -0.0430 S m^-1 after one hour of treatment. The advantages of using the hollow screw electrode structure compared with the smooth electrode were：（1） lower typical power consumption, （2） the generation of a uniform plasma throughout the reactor benefiting the phenol degradation, （3） a relatively lower temperature of the aqueous solution during the process, and （4） the plasma generation length is larger.

关键词： DBD gas discharges removal organic compounds discharge in liquids

relationship between Tomato (Solanum lycopersicum) Nutrition and the Severity of the vascular Fusariosis

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences 2023年第4期14卷 570-583页

作者： Mendoza-Medrano Daniel lópez-Orona Carlos Alfonso Martínez-Gallardo José Ángel lópez-Urquidez Guadalupe Alfonso Angulo-Castro Azareel león-Félix Josefina Agronomy Faculty Universidad Autónoma de Sinaloa Culiacán México Centro de Investigación en Alimentación y Desarrollo Culiacán México

The vascular fusariosis is one of the main obstacles in the tomato crop production. Currently, the management of the nutrient solution is presented as a control option for fusariosis, for such reason different nutrient solutions with nitrogen (N), phosphorus (P), potassium (K) and calcium (Ca) modifications;in four saladette tomato varieties Bony Best (BB), Manapal (M), Walter (W) and FlA were evaluated in this research, in order to analyze the damage caused by Fusarium oxysporum ***. lycopersici (FOl) severity. Tomato plants were inoculated with 3 FOl breeds, establishing a completely random design with a factorial arrangement with six repetitions. Disease’s severity was evaluated 30 days after the inoculation using levels of (0 - 4) of the methodology established by Marlatt and Correll (1988). Afterwards, a statistical analysis was done through the Kruskal Wallis test, in which it was observed that treatments 93 (Ca 207 mg∙l-1, r3, variety BB), 95 (207 mg∙l-1 Ca, r3, variety W), 81 (0Ca, r3, BB) showed less disease severity. In the foliar analysis, the best treatments were 22 (193 mg∙l-1 N, r3, M) for N, the greatest P content was treatment 94 (207 mg∙l-1 Ca, r3, M) for K treatment three and 93 (207 mg∙l-1 Ca, r3, variety BB) greatest Ca content.

关键词： Fusarium oxysporum f.sp. lycopersici Nutrient Solution Cultural Control