检索结果-南通市图书馆

Assessment of food supplementation and surveillance as techniques to reduce damage caused by black capuchin monkeys Sapajus nigritus to forest plantations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2014年第5期60卷 581-590页

作者： Sandra bos MIKICH Laboratory of Ecology (Laborat6rio de Ecologia) Embrapa Florestas Caixa Postal 319 CEP 83411-000 Colombo PR Brazil Black Capuchin Monkey Program (Programa Macaco-prego) National Fund for the Control of Forest Pests (Fundo Nacional de Controle de Pragas Florestais) Dieter Liebsch Environmental Consulting (Dieter Liebsch Consultoria Ambiental) Curitiba PR Brazil dieterliebsch@yahoo.com.br

Black capuchin monkeys Sapajus nigritus are among several mammalian species that damage forest plantations, pri- marily plantations of pine trees （Pinus spp.） in South Brazil. Management practices to reduce these damages include supplemen- tary food offerings and plantation surveillance. To assess the efficiency of these techniques, four treatments were evaluated： feeding （F, with supplementary bananas and maize）, surveillance （S, in situ, wherein men patrolled the plantations, deterring the monkeys）, feeding ＋ surveillance （FS） and control （no procedures）（C）. The efficiency assessment of each treatment involved the number of recorded primate sightings in the treatments with the presence of guards （S and FS） and a damage inventory of the outskirts of the experimental points immediately before and after the experiment. These data were complemented by a simulta- neous study of the availability of fruit, the primary item in the diet of this primate species, in the remnant native forest in the study area. Most sightings of S. nigritus occurred early in the morning, and in general, sightings were inversely proportional to the availability of native fruits. This trend was most evident in treatment FS, most likely due to the presence of food. Treatments F and FS exhibited higher percentages of damage, indicating that these are inefficient management techniques. Treatment S exhi- bited the lowest damage rate, but at a high cost, making this technique difficult to apply over large expanses. The development of other management techniques, such as environmental enrichment and the use of deterrents, is recommended to minimize the damage caused by capuchins in forest plantations [Current Zoology 60 （5）： 581-590, 2014].

关键词： Cebus Damage control Wildlife management Pinus Food provisioning

A study on joining magnesium alloy high pressure die casting components with thread forming fasteners

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 Magnesium and Alloys 2018年第2期6卷 114-120页

作者： Gerry Gang Wang Jeremy bos Meridian Lightweight Technologies StrathroyOntario N7G 4H6Canada N7G 4H6

With tremendous weight saving potential,magnesium alloy high pressure die casting components have been widely used for automotive *** fastening technology is thus becoming increasingly important to design *** as-cast holes of magnesium high pressure die casting components with thread forming fasteners provides significant advantages for the assembly process,overall cost benefit and joint *** type of joint is thus preferred for structural *** the thread forming fasteners with as-cast holes follows the general rules for designing for the machined holes,including carefully designing the variables such as the assembly torque range,the length of thread engagement,the hole diameter and required failure *** addition,special attention needs to be paid to the draft angles of the magnesium cast components that are required for the die casting *** this paper,the effects of above key factors,individually and combined,on the joint performance of thread forming fasteners with as-cast blind holes of AM60B magnesium components are studied.A joint design philosophy was proposed to optimize both joint performance(the prevailing torque,the failure torque and the failure mode)and manufacturing easiness(the hole diameter and corresponding draft angle).The detailed design considerations for as-cast holes of magnesium HPDC are discussed and explained through a hypothetical example.

关键词： Magnesium Die casting Fastening Joining Thread forming.

Cyclicity of the Lower Buntsandstein in the eastern part of the Central European Basin:implications for Early Triassic palaeogeography and for geochronological calibration

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 Palaeogeography 2024年第2期13卷 252-292页

作者： anna Becker Polish Geological Institute-National Research Institute 4 Rakowiecka str.00-975 WarsawPoland

Lower Buntsandstein small—scale cycles recognized in the Central European Basin(CEB) are readily used for astrochronological calibration of the Early Triassic time scales,although they are not well studied *** borehole sections from the eastern part of the CEB,forming a south-north transect perpendicular to the basin axis,were studied in terms to better understand the depositional history of the Lower Buntsandstein developed as the Baltic Formation in the studied Polish part of the *** sedimentary facies were recognized,based on lithological and sedimentological investigations of 655.7 m of drill cores from the Otyń IG 1,Gorzów Wielkopolski IG 1 and Kamień Pomorski IG 1 *** facies can be grouped according to a lithological criterion into facies of predominantly siliciclastic lithology(including 9facies types) and facies of predominantly carbonate lithology(including 2 facies types).Facies analysis allowed to distinguish 8 facies associations of:1) alluvial fan,2) playa,3) sandy-muddy coastal plain,4)embayment and distal delta,5) lagoon,6) sand bars or shoals,7) ooidal shoals or bars,and 8) ***-upward(DC) and shallowing-upward(SC) sedimentary cycles were recognized in parts of the Baltic Formation,with DCs dominating in the southernmost located Otyń IG 1,and SCs dominating in Gorz ow Wielkopolski IG 1,located in the axial part of the *** cycles are very *** statistical significance of the sedimentary cycles is relatively low according to Markov-chain analysis conducted with the phpSedistat software of Stanova et al.(2009).Analysis of small—scale cycles performed on well logs of investigated boreholes and additional boreholes in the vicinity of Otyń IG 1,implementing the earlier study of Becker(2005),showed that the correlation of well-log cycles(GR cycles) and sedimentary cycles is not *** cycles can be roughly correlated with lithological carbonate—siliciclastic cycles(c-s cycles),refle

关键词： Triassic Lower Buntsandstein Cyclicity Central European Basin

Weakly Admissible Meshes and Discrete Extremal Sets

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

Numerical Mathematics(Theory,Methods and Applications) 2011年第1期4卷 1-12页

作者： Len bos Stefano De Marchi Alvise Sommariva Marco Vianello Department of Computer Science University of VeronaStrada Le Grazie 15-37134 VeronaItaly Department of Pure and Applied Mathematics University of PaduaVia Trieste 63-35121 PaduaItaly

We present a brief survey on (Weakly) Admissible Meshes and corresponding Discrete Extremal Sets, namely Approximate Fekete Points and Discrete Leja *** provide new computational tools for polynomial least squares and interpolationon multidimensional compact sets, with different applications such as numerical cubature, digital filtering, spectral and high-order methods for PDEs.

关键词： Weakly admissible meshes Approximate Fekete points Discrete Leja points

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cornea modelling

Eye and Vision 2020年第1期7卷 11-25页

作者： anna Pandolfi Department of Civil and Environmental Engineering Politecnico di MilanoPiazza Leonardo da Vinci 3220133 MilanoItaly

Background:Biomechanics introduces numerous technologies to support clinical practice in ophthalmology,with the goal of improving surgical outcomes and to develop new advanced technologies with minimum impact on clinical ***,a few misconceptions on the way that computational methods should be applied to living tissues contributes to a lack of confidence towards computer-based ***:Corneal biomechanics relies on sound theories of mechanics,including concepts of equilibrium,geometrical measurements,and complex material *** peculiarities of biological tissues require the consideration of multi-physics,typical of the eye environment,and to adopt customized geometrical models constructed on the basis of advanced optical imaging and in-vivo ***:Patient-specific models are able to predict the outcomes of refractive surgery and to exploit the results of in-vivo test to characterize the material properties of the corneal ***:Corneal biomechanics can become an important support to clinical practice,provided that methods are based on the actual multi-physics and use customized geometrical and mechanical models.

关键词： Corneal biomechanics Physiologic configuration Tonometry modelling Refractive surgery modelling

Joint power and spectrum allocation algorithm in cognitive radio networks

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 Systems Engineering and Electronics 2011年第4期22卷 691-701页

作者： anna Auguste Anghuwo Communication Research Center Harbin Institute of Technology

The spectrum sharing problem between primary and cognitive users is mainly investigated. Since the interference for primary users and the total power for cognitive users are constrained, based on the well-known water-filling theorem, a novel one-user water-filling algorithm is proposed, and then the corresponding simulation results are given to analyze the feasibility and validity. After that this algorithm is used to solve the communication utility optimization problem subject to the power constraints in cognitive radio network. First, through the gain to noise ratio for cognitive users, a subcarrier and power allocation algorithm based on the optimal frequency partition is proposed for two cognitive users. Then the spectrum sharing algorithm is extended to multiuser conditions such that the greedy and parallel algorithms are proposed for spectrum sharing. Theory and simulation analysis show that the subcarrier and power allocation algorithms can not only protect the primary users but also effectively solve the spectrum and power allocation problem for cognitive users.

关键词： cognitive radio spectrum sharing water-filling algo-rithm interference constraint communication overhead.

Plasma-assisted oxidation of benzoic acid

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

Frontiers of Chemical Science and Engineering 2020年第4期14卷 513-521页

作者： anna Khlyustova Nikolay Sirotkin Laboratory of Chemistry of Hybrid Nanomaterials and Supermolecular Systems G.A.Krestov Institute of Solution Chemitry of Russian Academy of SciencesIvanovo 153045Russia

Plasma-assisted oxidation of organic com-pounds is one of the developing technologies for wastewater *** effectively accelerate degradation processes due to plasma generated reactive species and ultra-violet *** of BA in aqueous solutions by the atmospheric pressure glow discharge and underwater diaphragm discharge was studied and monitored by fluorescence and spectrophoto-metric *** type and solution pH affect the formation rates of mono-and dihydroxybenzoic *** derivatives were formed only by glow discharge *** yields of hydroxyl radical were estimated on the kinetics data for the hydroxylation of benzoic *** steps of the hydroxylation processes and further oxidation were described.

关键词： atmospheric pressure glow discharge under-water diaphragm discharge oxidation benzoic acid hydroxyl radical

Each coin has 2 sides: a positive role of alien Potamopyrgus antipodarum (Grey, 1843) snails in reducing the infection of native lymnaeids with trematodes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2024年第2期70卷 262-269页

作者： anna Cichy anna Stanicka Elzbieta Zbikowska Faculty of Biological and Veterinary Sciences Nicolaus Copernicus University in TorunLwowska 187-100 TorunPoland

The change in the distribution of organisms in freshwater ecosystems due to natural or manmade processes raises the question of the impact of alien species on local *** most studies indicate a negative effect,the positive one is more difficult to discern,espe-cially in multispecies systems,including hosts and *** purpose of the study was to check whether the presence of an alien host,Potamopyrgus antipodarum,reduces the intensity of Echinoparyphium aconiatum metacercariae in a native host,Radix *** additionally tested the impact of water temperature and the biomass of the alien host on the dilution *** experimentally studied(1)the lifespan of echinostome cercariae in different temperatures,(2)the infectivity of cercariae toward the alien host and native host,and(3)the impact of different biomass of the alien host on the intensity of metacercariae in the native *** found that cercarial survival and infectivity were tem-perature ***,cercarial survival decreased with increasing temperature,contrary to cercarial *** cercariae entered the renal cavity of both the native host and alien host,and successfully transformed into *** number of metacercariae in the native host decreased with the increasing biomass of the alien *** results indicate that lymnaeids may benefit from the co-occur-rence with P antipodarum,as the presence of additional hosts of different origins may reduce the prevalence of parasites in native ***,the scale of the dilution effect depends not only on the increased spectrum of susceptible hosts but also on the other variables of the environment,including water temperature and host density.

关键词： biological invasion density dilution effect echinostomes Radix spp. temperature.

Regulation of Meristem Size by Cytokinin Signaling

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 Integrative Plant Biology 2011年第6期53卷 446-454页

作者： anna Skylar Molecular and Computational Biology University of Southern CaliforniaLos AngelesCA

The plant meristems possess unique features that involve maintaining the stem cell populations while providing cells for continued development. Although both the primary shoot apical meristem （SAM） and the root apical meristem （RAM） are specified during embryogenesis, post-embryonic tissue proliferation is required for their full establishment and maintenance throughout a plants＇ life. The phytohormone cytokinin （CK） interacts with other systemic signals and is a key regulator of meristem size and functions. The SAM and the RAM respond to CK stimulations in different manners： CK promotes tissue proliferation in the SAM through pathways dominated by homeobox transcription factors, including the class I KNOX genes, ST^P, and WUS; and curiously, it favors proliferation at low levels and differentiation at a slightly higher concentration in the RAM instead. Here we review the current understanding of the molecular mechanisms underlying CK actions in regulating meristematic tissue proliferation.

关键词： cytokinin signaling meristem tissue proliferation.