检索结果-南通市图书馆

Addressing soil protection concerns in forest ecosystem management under climate change

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Forest Ecosystems 2020年第3期7卷 432-442页

作者： Ana Raquel Rodrigues Brigite Botequim catarina tavares Patrícia Pécurto JoséGBorges Forest Research centre School of AgricultureLisbon UniversityTapada da Ajuda1349-017LisbonPortugal

Background: climate change may strongly influence soil erosion risk, namely through variations in the precipitation pattern. Forests may contribute to mitigate the impacts of climate change on soil erosion and forest managers are thus challenged by the need to define strategies that may protect the soil while addressing the demand for other ecosystem services. Our emphasis is on the development of an approach to assess the impact of silvicultural practices and forest management models on soil erosion risks under climate change. Specifically, we consider the annual variation of the cover-management factor(c) in the Revised Universal Soil Loss Equation over a range of alternative forest management models to estimate the corresponding annual soil losses, under both current and changing climate conditions. We report and discuss results of an application of this approach to a forest area in Northwestern Portugal where erosion control is the most relevant water-related ecosystem ***: Local climate change scenarios will contribute to water erosion processes, mostly by rainfall erosivity *** forest management models provide varying levels of soil protection by trees, resulting in distinct soil loss ***: Results confirm the suitability of the proposed approach to address soil erosion concerns in forest management planning. This approach may help foresters assess management models and the corresponding silvicultural practices according to the water-related services they provide.

关键词： c-factor Erosivity Ecosystem services Forest management Revised universal soil loss equation(RUSLE)

Simultaneous binding of folic acid and lutein to β-lactoglobulin and α-lactalbumin: A spectroscopic and molecular docking study

在线全文

学校读者我要写书评

暂无评论

Food Bioscience 2022年第6期50卷 973-981页

作者： Danilo c.Vidotto Guilherme M.tavares Department of Food Science and Nutrition School of Food EngineeringUniversity of Campinas (UNICAMP)CampinasBrazil

Whey proteins are versatile molecules with great nutritional value and multiple functionalities. One of these functionalities is the ability to bind and protect bioactive compounds. Lutein and folic acid (FA) are bioactive molecules with a remarkable relevance for developing functional foods. FA contributes in preventing the occurrence of neural tube defects during the early stages of life, while lutein is a macular pigment that contributes to the development of the retina. In this context, the aim of this work was to evaluate the ability of the main whey proteins, β-lactoglobulin and α-lactalbumin, to simultaneously bind FA and lutein. The binding was evaluated through intrinsic fluorescence quenching and molecular docking, and the impact of the binding on the secondary structure and denaturation temperature of the proteins were also evaluated through circular dichroism and differential scanning calorimetry, respectively. Both proteins had similar behavior on the performed analyses. The multi-binding ability of β-lactoglobulin and α-lactalbumin to FA and lutein was observed. The presence of the first ligand slightly reduced the association constant between the second one and the proteins;in particular for the binding of lutein in the presence of FA (reduction of around 36%–38% on the KSV values). Molecular docking indicated that both ligands interact, preferentially, on the same region of the studied protein structures. The secondary structure of the proteins, as well as their denaturation temperatures were minimally impacted by the presence of these ligands, themselves. Our results may contribute to the development of multi-functional protein-rich food products.

关键词： Whey proteins Multi-binding Folic acid Lutein Fluorescence quenching Molecular modeling

Lithic soils in the semi-arid region of Brazil:edaphic characterization and susceptibility to erosion

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 Arid Land 2022年第1期14卷 56-69页

作者： carlos R PINHEIRO JUNIOR conan A SALVADOR Tiago R tavares Marcel c ABREU Hugo S FAGUNDES Wilk S ALMEIDA Eduardo c SILVA NETO Lúcia H c ANJOS Marcos G PEREIRA Federal Rural University of Rio de Janeiro(UFRRJ) Department of SoilsSeropédicaRio de Janeiro 23890Brazil center for Nuclear Energy in Agriculture(cENA) University of São Paulo(USP)PiracicabaSão Paulo 13416Brazil Federal Institute of Education Science and Technology of Rondônia(IFRO)Rural ZoneAriquemesRondônia 78930Brazil

Soils(Leptosols or Epileptic Regosols)with lithic contact at a depth of 50 cm occupy almost 20%of the Brazilian semi-arid *** lithic soils are susceptible to erosion due to faster saturation of water-holding capacity during rainfall,which accelerates the beginning of ***,erosion traits of lithic soils in the semi-arid region of Brazil are less *** aim of this study was to characterize the soil and landscape attributes in areas with Neossolos Litólicos(Entisols)in the caatinga biome to identify region of high susceptibility to *** showed that the soils were characterized by a sandy texture,soil structure with poor development and low content of organic *** attributes increase susceptibility to erosion and reduce water storage capacity,especially in the states of cearáand *** these states,the content of rock fragments in the soil reaches 790 g/*** contents of silt and fine sand,high silt/clay ratio,predominance of Leptosols and strong rainfall erosivity were observed in Piauíand northwestern ceará.A very high degree of water erosion was observed in the states of Pernambuco and Paraí*** the low degree of erosion observed in the state of Bahia,it is highly susceptible to erosion due to the predominance of very shallow soils,rugged relief and high values of rainfall *** vulnerability was observed in the state of Alagoas because of its more smoothed relief,greater effective soil depth,thicker A horizon of soil and lower rainfall *** general,the characteristics that intensify the susceptibility to erosion in the caatinga biome are those soil structures with poor development or without aggregation,low contents of organic carbon,high contents of silt and fine sand,high values of silt/clay ratio and rugged relief in some *** study collected information contributing to a better characterization of soils with lithic contact in the semi-arid region of *** addition,regions with

关键词： caatinga biome drylands erosive processes leptosols soil degradation

A Survey on Performance Optimization of High-Level Synthesis Tools

在线全文

学校读者我要写书评

暂无评论

Journal of computer Science & Technology 2020年第3期35卷 697-720页

作者： Lan Huang Da-Lin Li Kang-Ping Wang Teng Gao Adriano tavares college of computer Science and Technology Jilin UniversityChangchun 130012China Key Laboratory of Symbol computation and Knowledge Engineering of Ministry of Education Jilin University Changchun 130012China Zhuhai Laboratory of Key Laboratory of Symbol computation and Knowledge Engineering of Ministry of Education Zhuhai college of Jilin University Zhuhai 519041China Algorithm center University of MinhoGuimaraes 4800058Portugal

Field-programmable gate arrays(FPGAs)have recently evolved as a valuable component of the heterogeneous *** register transfer level(RTL)design flows demand the designers to be experienced in hardware,resulting in a possible failure of ***-level synthesis(HLS)permits designers to work at a higher level of abstraction through synthesizing high-level language programs to RTL *** provides a promising approach to solve these ***,the performance of HLS tools still has *** example,designers remain exposed to various aspects of hardware design,development cycles are still time consuming,and the quality of results(QoR)of HLS tools is far behind that of RTL *** this paper,we survey the literature published since 2014 focusing on the performance optimization of HLS *** with previous work,we extend the scope of the performance of HLS tools,and present a set of three-level evaluation criteria,covering from ease of use of the HLS tools to promotion on specific metrics of *** also propose performance evaluation equations for describing the relation between the performance optimization and the *** find that it needs more efforts on the ease of use for efficient HLS *** suggest that it is better to draw an analogy between the HLS development process and the embedded system design process,and to provide more elastic HLS methodology which integrates FPGAs virtual machines.

关键词： evaluation criterion field-programmable gate array(FPGA) high-level synthesis(HLS) performance optimization quality of results(QoR)

Gold Supported on Metal Oxides for carbon Monoxide Oxidation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2011年第2期4卷 180-193页

作者： Sonia A. c. carabineiro Nina Bogdanchikova Miguel Avalos-Borja Alexey Pestryakov Pedro B. tavares Jose L. Figueiredo Laboratário de catálise e Materiais Associate Laboratory LSRE/LCM Departamento de Engenharia Química Faculdade de Engenharia Universidade do Porto 4200-465 Porto Portugal Universidad Nacional Autónoma de México Centro de Nanociencias y Nanotecnologia Carretera Tijuana-Ensenada 22800 Ensenada Baja California México Tomsk Polytechnic University 30 Lenin Avenue Tomsk 634050 Russia Universidade de Trás-os-Montes e Alto Douro Centro de Quimica-Vila Real Departamento de Química 5001-911 Vila Real Portugal

Au has been loaded （1% wt.） on different commercial oxide supports （cuO, La2O3, Y2O3, NiO） by three different methods： double impregnation （DIM）, liquid-phase reductive deposition （LPRD）, and ultrasonication （US）. Samples were characterised by N2 adsorption at -196℃, high-resolution transmission electron microscopy, selected area electron diffraction, energy dispersive X-ray spectrometry, high-angle annular dark-field imaging （Z-contrast）, X-ray diffraction, and temperature programmed reduction. cO oxidation was used as a test reaction to compare the catalytic activities. The best results were obtained with Au loaded by DIM on the NiO support, with an activity of 7.2 × 10^（-4） molco·gAu^（-1）·s^（-1） at room temperature. This is most likely related to the Au nanoparticle size being the smallest in this catalyst （average 4.8 nm）, since it is well known that gold particle size determines the catalytic activity. Other samples, having larger Au particle sizes （in the 2-12 nm range, with average sizes ranging from 4.8 to 6.8 nm）, showed lower activities. Nevertheless, all samples prepared by DIM had activities （from 1.1 × 10^（-4） to 7.2 × 10^（-4） molco·gAu^（-1）·S^（-1）, at room temperature） above those reported in the literature for gold on similar oxide supports. Therefore, this method gives better results than the most usual methods of deposition-precipitation or co-precipitation.

关键词： Gold heterogeneous catalysis oxidation electron diffraction X-ray diffraction

chromomagnetic and chromoelectric dipole moments of quarks in the reduced 331 model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

chinese Physics c 2021年第11期45卷 11-24页

作者： A.I.Hemandez-Juarez G.tavares-Velasco A.Moyotl Facultad de ciencias Fisico Matematicas Benemerita Universidad Autonoma de PueblaApartado Postal 1152PueblaPueblaMexico Ingenieria en Mecatronica Universidad Politecnica de PueblaTercer Carril del Ejido Serrano s/nSan Mateo CuanalaJuan C.BonillaPueblaPueblaMexico

The one-loop contributions to the chromomagnetic dipole momentˆμt(q2)and electric dipole momentˆd t(q2)of the top quark are calculated within the reduced 331 model(RM331)for non-zero *** is argued that the results are gauge independent and thus represent valid observable *** the RM331,ˆμt(q2)receives new contributions from two heavy gauge bosons,namely Z′and V±,and one neutral scalar boson h2,along with a new contribution from the standard model's Higgs boson via flavor changing neutral *** latter,which is also mediated by the Z′gauge boson and the scalar boson h2,can provide a non-vanishingˆd t(q2)if there is a cP-violating *** analytical results are presented in terms of both Feynman parameter integrals and Passarino-Veltman scalar functions,which are useful to cross-check the numerical ***ˆμt(q2)andˆd t(q2)are numerically evaluated for parameter values still allowed by the constraints from experimental *** is found that the new one-loop contributions of the RM331 to the real(imaginary)part ofˆμt(q2)are of the order of 10−5(10−6),which means at least three orders of magnitude smaller than the standard model prediction but larger than the predictions of other models of new *** the RM331,the dominant contribution arises from the V±gauge boson for‖q‖in the 30-1000 GeV interval and a mass mV of the order of a few hundreds of *** forˆd t(q2),it receives its largest contribution from h2 exchange and can reach values of the order of 10−19,i.e.,smaller than the contributions predicted by other standard model extensions.

关键词： chromomagnetic chromoelectric 331 models

Polarized and unpolarized off-shell H^(*)→ZZ→4■ decay above the 2m_(z) threshold

在线全文

学校读者我要写书评

暂无评论

chinese Physics c 2024年第11期48卷 22-42页

作者： A.I.Hernandez-Juarez R.Gaitan G.tavares-Velasco Departamento de Fisica FES-CuautitlanUniversidad Nacional Autonoma de MexicoC.P.54770Estado de MexicoMexico Facultad de ciencias Fisico Matematicas Benemerita Universidad Autonoma de PueblaApartado Postal 1152PueblaPueblaMexico

An analysis of the off-shell H^(*)→Zz-■_(1)■_(1)■_(2)■_(2) decay width is presented for both unpolarized and polarized Z gauge bosons in the scenario with the most general H^(*)ZZ vertex function,which is expressed in terms of two cP-even(bz and cz)and one cP-odd(bz)anomalous *** SM contributions to the H^(*)ZZ coupling up to the one-loop level are also *** analytic results for the unpolarized and polarized H^(*)-Zz-■_(1)■_(1)■_(2)■_(2) square amplitudes and the four-body phase space are presented,out of which several obseryable quantities can be obtained *** numerical analysis,a cross-check was performed via MadGraph5_aMc@NLO,where our model was implemented with the aid of *** then considered the most stringent bounds on anomalous complex H^(*)ZZ couplings and analyzed the effects of the polarizations of the Z gauge bosons through the polarized H^(*)-ZZ→■_(1)■_(1)■_(2)■_(2) decay width as well as left-right and forward-backward asymmetries,which were found to be sensitive to new-physics *** focus was put on the effects of the absorptive parts of the anomalous H^(*)ZZ couplings,which have been largely overlooked up to now in LHc *** was found that the studied observable quantities,particularly the left-right asymmetries,can be helpful to search for effects of cP-violation in the H^(*)ZZ coupling and set bounds on the absorptive *** completeness,we also analyzed the case of unpolarized Z gauge bosons.

关键词： polarization off-shell Higgs anomalous couplings cP violation

Influence of Management on the Water Quality and Sediment in Tropical Fish Farm

在线全文

学校读者我要写书评

暂无评论

Journal of Water Resource and Protection 2013年第5期5卷 495-501页

作者： Lúcia H.Sipaúba-tavares Rodrigo N.Millan Atanásio A.do Amaral Aquaculture center University of Sao Paulo StateJaboticabalBrazil Federal Institute of Espirito Santo—Ifes AlegreBrazil

A seven-month research evaluated the management effect on the water quality and sediment of seven fish ponds. Water and sediment were collected at nine sample sites: seven in the fish ponds;one in inlet water and another in the fish farm’s effluent. The soil samples were analyzed for macro- and micro-nutrients and the water samples were analyzed for physical and chemical parameters. Management and local climate conditions affected nutrient seasonality in the sediment and featured high concentrations of Al, ca, cu, K, Mg, c, Na, Zn and OM at the effluent with low pH, ranging between 4.4 and 6.5. Sudden decrease of DO (less than 3 mg/L) during the rainy season, with a 180 mmrainfall, and a TSS increase (approximately 10 mg/L) were reported. Use of organic manure in fish pond V6 caused higher rates of ammonia (over 1 mg/L). Due to the sediment’s acid pH (less than 4.8) and Al at 0.92 mg/L at the effluent, great care was required in the fish farm. Maintenance and procedures management in the fish farm under analysis should be given more attention since high levels of Al, Fe and acid pH and low levels of potassium and phosphorus in the sediment may produce unfavorable conditions in the water column, and may ultimately have an impact on fish.

关键词： Water Quality Fish Ponds Management Sediment

锆和钽基氧气还原反应催化剂的简易合成(英文)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

催化学报 2015年第4期36卷 484-489页

作者： David Sebastián Vincenzo Baglio Shuhui Sun Ana c.tavares Antonino S.Aricò Istituto di Tecnologie Avanzate per l’Energia "Nicola Giordano" CNR Via Salita Santa Lucia sopra Contesse 5 98126 Messina Italy Institut National de la Recherche Scientifique-énergie Matériaux et Télécommunications 1650 Boulevard Lionel-Boulet Varennes QC J3X 1S2 Canada

cathode catalysts for direct alcohol fuel cells(DAFcs) must have high catalytic activity for the oxy-gen reduction reaction(ORR), low cost, and high tolerance to the presence of methanol or ethanol. Pt is the benchmark catalyst for this application owing to its excellent electrocatalytic activity, but its high cost and low tolerance to the organic fuel permeating through the membrane have hindered the commercialization of DAFcs. Herein we present a facile synthesis route to obtain organic fuel-tolerant Zr- and Ta-based catalysts supported on carbon. This method consists of a simple precipitation of metal precursors followed by a heat treatment. X-ray diffraction analyses confirmed that the obtained samples were crystalline ZrO 2-x and Na2Ta8O21-x having crystallite sizes of 26 and 32 nm, respectively. The thermal treatment effectively increased the activity of the catalysts to-wards the ORR, although further optimization is necessary. Both catalysts exhibited a high tolerance to the presence of methanol with only a moderate reduction in ORR activity even at high methanol concentration(0.5 mol/L).

关键词：阴极催化剂还原反应简便合成低氧直接醇类燃料电池电催化活性 X射线衍射分析钽基