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196,329 Research products, page 1 of 19,633

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  • Open Access
    Authors: 
    Graeme C. Hays; Luciana C. Ferreira; Ana M. M. Sequeira; Mark G. Meekan; Carlos M. Duarte; Helen Bailey; Fred Bailleul; W. Don Bowen; M. Julian Caley; Daniel P. Costa; +30 more
    Publisher: Elsevier BV
    Countries: Germany, United States, France, United Kingdom, Spain

    It is a golden age for animal movement studies and so an opportune time to assess priorities for future work. We assembled 40 experts to identify key questions in this field, focussing on marine megafauna, which include a broad range of birds, mammals, reptiles, and fish. Research on these taxa has both underpinned many of the recent technical developments and led to fundamental discoveries in the field. We show that the questions have broad applicability to other taxa, including terrestrial animals, flying insects, and swimming invertebrates, and, as such, this exercise provides a useful roadmap for targeted deployments and data syntheses that should advance the field of movement ecology. Workshop funding was granted to M.T., A.M.M.S., and C.M.D. by the UWA Oceans Institute, the Australian Institute of Marine Science, and the Office of Sponsored Research at King Abdullah University of Science and Technology (KAUST). Hays, Graeme C. et al. Peer reviewed

  • Open Access
    Authors: 
    Zhan Zhou; Xingfu Zou;
    Publisher: Elsevier BV
    Project: NSERC

    Abstract In this paper, we consider a discrete logistic equation x ( n +1)= x ( n ) exp r ( n ) 1 − x ( n ) K ( n ) where {r(n)} and {K(n)} are positive ω-periodic sequences. Sufficient conditions are obtained for the existence of a positive and globally asymptotically stable ω-periodic solution. Counterexamples are given to illustrate that the conclusions in [1] are incorrect.

  • Open Access
    Authors: 
    Anne MacKay; Alexander Melnikov; Yuliya Mishura;
    Publisher: Informa UK Limited

    In this paper, we investigate two-sided bounds for the small ball probability of a mixed fractional Brownian motion with a general deterministic trend function, in terms of respective small ball probability of a mixed fractional Brownian motion without trend. To maximize the lower bound, we consider various ways to split the trend function between the components of the mixed fractional Brownian motion for the application of Girsanov theorem, and we show that the optimal split is the solution of a Fredholm integral equation. We find that the upper bound for the probability is also a function of this optimal split. The asymptotic behaviour of the probability as the ball becomes small is analyzed for zero trend function and for the particular choice of the upper limiting function.

  • Open Access
    Authors: 
    Polly L. Arnold; Michał S. Dutkiewicz; Markus Zegke; Olaf Walter; Christos Apostolidis; Emmalina Hollis; Anne-Frédérique Pécharman; Nicola Magnani; Jean-Christophe Griveau; Eric Colineau; +4 more
    Publisher: Wiley
    Country: United Kingdom
    Project: UKRI | Actinide Polyoxo Chemistr... (EP/M010554/1), NSERC

    A dramatic difference in the ability of the reducing An(III) center in AnCp3 (An=U, Np, Pu; Cp=C5 H5 ) to oxo-bind and reduce the uranyl(VI) dication in the complex [(UO2 )(THF)(H2 L)] (L="Pacman" Schiff-base polypyrrolic macrocycle), is found and explained. These are the first selective functionalizations of the uranyl oxo by another actinide cation. At-first contradictory electronic structural data are explained by combining theory and experiment. Complete one-electron transfer from Cp3 U forms the U(IV) -uranyl(V) compound that behaves as a U(V) -localized single molecule magnet below 4 K. The extent of reduction by the Cp3 Np group upon oxo-coordination is much less, with a Np(III) -uranyl(VI) dative bond assigned. Solution NMR and NIR spectroscopy suggest Np(IV) U(V) but single-crystal X-ray diffraction and SQUID magnetometry suggest a Np(III) -U(VI) assignment. DFT-calculated Hirshfeld charge and spin density analyses suggest half an electron has transferred, and these explain the strongly shifted NMR spectra by spin density contributions at the hydrogen nuclei. The Pu(III) -U(VI) interaction is too weak to be observed in THF solvent, in agreement with calculated predictions.

  • Publication . Conference object . 2020
    Closed Access
    Authors: 
    Navid Heydarishahreza; Saeed Ebadollahi; Reza Vahidnia; F. John Dian;
    Publisher: IEEE

    Wireless Sensor Networks, basically applied to gather information about the environments, consist of various elements interconnection. They are mainly deployed in the areas hard to reach, so they are routinely powered by the batteries. Due to the complexity of WSNs and the impact they have on the 21st century proceeding technology, they have received lots of attention during past decades, hence it is mandatory to study their fundamentals before any forthcoming research. This paper reviews the alphabets of WSNs in a straight scenario, categorizing them in terms of application, routing and connectivity schemes, besides, practical design challenges and energy supply ways have been classified.

  • Open Access
    Authors: 
    Ziwei Li; Zhiming Qi; Qianjing Jiang; Nathan Sima;
    Publisher: Elsevier BV

    Abstract Many recent studies on soil and crop management practices have demonstrated their possibility in mitigating greenhouse gas emissions (GHG) from cropland. The response of GHG emissions to management practices can be quantitatively simulated using biophysics-based agricultural system models. However, the economic feasibilities of such management adoption are yet to be evaluated, especially when the producers have to adopt only one profitable management plan. This paper presents a field-scale economic analysis software that is capable of estimating the net benefits under various greenhouse gas mitigating management practices. The calculated net benefits are based on the benefit-cost analysis (BCA), where GHG emissions are converted to the CO2 equivalent and priced using the information from the current carbon trade market. GHG emissions and crop yield are simulated using the Root Zone Water Quality Model (RZWQM2), an agricultural system model coupled with the BCA software. A case study for a cornfield at the Saint Emmanuel site near Montreal, Canada, from 2012 to 2015 under two water table management practices, i.e., free-drainage (FD) and controlled drainage (CD), results showed that FD was more profitable than CD. Although fewer greenhouse gases were emitted under CD than under FD, the potential benefit under current carbon credit payment from GHG reduction under CD was far less than the additional cost from installing new instruments and excessive maintenance fees. This study suggests that the government subsidy is needed to provide further incentives for producers to adopt new greenhouse gas emission mitigating management practices.

  • Open Access
    Authors: 
    Hélène Seller; Samuel Palato; Patanjali Kambhampati;
    Publisher: EDP Sciences

    Coherent Multi-dimensional Spectroscopy is ideally suited to investigate many-body effects in semiconductor nanostructures. Here we employ 2D optical spectroscopy on the model system of CdSe quantum dots to reveal the structure of the bandedge biexciton.

  • Closed Access
    Authors: 
    Yulei Sui; Qingxia Liu; Tao Jiang; Yufeng Guo;
    Publisher: Elsevier BV

    Abstract For the first time, a one-step synthetic strategy has been developed towards the preparation of Ti3+ self-doped TiO2 with internal-pores and highly exposed {001} facets using ethylene glycol (EG) and HF as control agents. The obtained samples were characterized by XRD, XPS, SEM, TEM, HAADF-STEM, photoluminescence spectroscopy (PL), and UV–vis reflectance spectroscopy. The synergistic effect of EG and HF plays a vital role in the formation of synthesized TiO2 with Ti3+ self-doping, internal-pores and highly exposed {001} facets. As-synthesized TiO2 exhibit much higher activity than commercial P25 on photocatalytic degradation of phenol and the outstanding performance is attributed to the synergistic effect of Ti3+ doping, internal-pores, and facets heterojunction.

  • Authors: 
    Jinyan Dong; Lei Zhang; Jiaqi Zhou; Weiwei Pan; Xijia Gu; Yan Feng;
    Publisher: The Optical Society

    An over 200 W high-power first-order random Raman fiber laser (RRFL) at 1238 nm is demonstrated. The laser is based on a half-open cavity with a piece of 30 m phosphosilicate fiber. This RRFL is pumped by a conventional 1064 nm Yb-doped fiber laser. After suppressing the silica Raman component, a maximum output power of 206.7 W is obtained with a full width half-maximum linewidth of 7.1 nm at a pump power of 346.3 W, corresponding to an optical-to-optical efficiency of 59.7%. To the best of our knowledge, this is the highest reported output power of RRFL on the basis of phosphosilicate fiber with the shortest cavity length.

  • Open Access
    Authors: 
    K. Kiiveri; Daniel Gruen; Alexis Finoguenov; Thomas Erben; L. van Waerbeke; Eli S. Rykoff; Lance Miller; Steffen Hagstotz; R. A. Dupke; J. Patrick Henry; +12 more
    Publisher: Oxford University Press (OUP)
    Countries: Finland, France, Italy

    The COnstrain Dark Energy with X-ray clusters (CODEX) sample contains the largest flux limited sample of X-ray clusters at $0.35 < z < 0.65$. It was selected from ROSAT data in the 10,000 square degrees of overlap with BOSS, mapping a total number of 2770 high-z galaxy clusters. We present here the full results of the CFHT CODEX program on cluster mass measurement, including a reanalysis of CFHTLS Wide data, with 25 individual lensing-constrained cluster masses. We employ $lensfit$ shape measurement and perform a conservative colour-space selection and weighting of background galaxies. Using the combination of shape noise and an analytic covariance for intrinsic variations of cluster profiles at fixed mass due to large scale structure, miscentring, and variations in concentration and ellipticity, we determine the likelihood of the observed shear signal as a function of true mass for each cluster. We combine 25 individual cluster mass likelihoods in a Bayesian hierarchical scheme with the inclusion of optical and X-ray selection functions to derive constraints on the slope $��$, normalization $��$, and scatter $��_{\ln ��| ��}$ of our richness-mass scaling relation model in log-space: $\left = ����+ ��$, with $��= \ln (M_{200c}/M_{\mathrm{piv}})$, and $M_{\mathrm{piv}} = 10^{14.81} M_{\odot}$. We find a slope $��= 0.49^{+0.20}_{-0.15}$, normalization $ \exp(��) = 84.0^{+9.2}_{-14.8}$ and $��_{\ln ��| ��} = 0.17^{+0.13}_{-0.09}$ using CFHT richness estimates. In comparison to other weak lensing richness-mass relations, we find the normalization of the richness statistically agreeing with the normalization of other scaling relations from a broad redshift range ($0.0 37 pages, 12 figures

Advanced search in
Research products
arrow_drop_down
Searching FieldsTerms
Any field
arrow_drop_down
includes
arrow_drop_down
Include:
The following results are related to Canada. Are you interested to view more results? Visit OpenAIRE - Explore.
196,329 Research products, page 1 of 19,633
  • Open Access
    Authors: 
    Graeme C. Hays; Luciana C. Ferreira; Ana M. M. Sequeira; Mark G. Meekan; Carlos M. Duarte; Helen Bailey; Fred Bailleul; W. Don Bowen; M. Julian Caley; Daniel P. Costa; +30 more
    Publisher: Elsevier BV
    Countries: Germany, United States, France, United Kingdom, Spain

    It is a golden age for animal movement studies and so an opportune time to assess priorities for future work. We assembled 40 experts to identify key questions in this field, focussing on marine megafauna, which include a broad range of birds, mammals, reptiles, and fish. Research on these taxa has both underpinned many of the recent technical developments and led to fundamental discoveries in the field. We show that the questions have broad applicability to other taxa, including terrestrial animals, flying insects, and swimming invertebrates, and, as such, this exercise provides a useful roadmap for targeted deployments and data syntheses that should advance the field of movement ecology. Workshop funding was granted to M.T., A.M.M.S., and C.M.D. by the UWA Oceans Institute, the Australian Institute of Marine Science, and the Office of Sponsored Research at King Abdullah University of Science and Technology (KAUST). Hays, Graeme C. et al. Peer reviewed

  • Open Access
    Authors: 
    Zhan Zhou; Xingfu Zou;
    Publisher: Elsevier BV
    Project: NSERC

    Abstract In this paper, we consider a discrete logistic equation x ( n +1)= x ( n ) exp r ( n ) 1 − x ( n ) K ( n ) where {r(n)} and {K(n)} are positive ω-periodic sequences. Sufficient conditions are obtained for the existence of a positive and globally asymptotically stable ω-periodic solution. Counterexamples are given to illustrate that the conclusions in [1] are incorrect.

  • Open Access
    Authors: 
    Anne MacKay; Alexander Melnikov; Yuliya Mishura;
    Publisher: Informa UK Limited

    In this paper, we investigate two-sided bounds for the small ball probability of a mixed fractional Brownian motion with a general deterministic trend function, in terms of respective small ball probability of a mixed fractional Brownian motion without trend. To maximize the lower bound, we consider various ways to split the trend function between the components of the mixed fractional Brownian motion for the application of Girsanov theorem, and we show that the optimal split is the solution of a Fredholm integral equation. We find that the upper bound for the probability is also a function of this optimal split. The asymptotic behaviour of the probability as the ball becomes small is analyzed for zero trend function and for the particular choice of the upper limiting function.

  • Open Access
    Authors: 
    Polly L. Arnold; Michał S. Dutkiewicz; Markus Zegke; Olaf Walter; Christos Apostolidis; Emmalina Hollis; Anne-Frédérique Pécharman; Nicola Magnani; Jean-Christophe Griveau; Eric Colineau; +4 more
    Publisher: Wiley
    Country: United Kingdom
    Project: UKRI | Actinide Polyoxo Chemistr... (EP/M010554/1), NSERC

    A dramatic difference in the ability of the reducing An(III) center in AnCp3 (An=U, Np, Pu; Cp=C5 H5 ) to oxo-bind and reduce the uranyl(VI) dication in the complex [(UO2 )(THF)(H2 L)] (L="Pacman" Schiff-base polypyrrolic macrocycle), is found and explained. These are the first selective functionalizations of the uranyl oxo by another actinide cation. At-first contradictory electronic structural data are explained by combining theory and experiment. Complete one-electron transfer from Cp3 U forms the U(IV) -uranyl(V) compound that behaves as a U(V) -localized single molecule magnet below 4 K. The extent of reduction by the Cp3 Np group upon oxo-coordination is much less, with a Np(III) -uranyl(VI) dative bond assigned. Solution NMR and NIR spectroscopy suggest Np(IV) U(V) but single-crystal X-ray diffraction and SQUID magnetometry suggest a Np(III) -U(VI) assignment. DFT-calculated Hirshfeld charge and spin density analyses suggest half an electron has transferred, and these explain the strongly shifted NMR spectra by spin density contributions at the hydrogen nuclei. The Pu(III) -U(VI) interaction is too weak to be observed in THF solvent, in agreement with calculated predictions.

  • Publication . Conference object . 2020
    Closed Access
    Authors: 
    Navid Heydarishahreza; Saeed Ebadollahi; Reza Vahidnia; F. John Dian;
    Publisher: IEEE

    Wireless Sensor Networks, basically applied to gather information about the environments, consist of various elements interconnection. They are mainly deployed in the areas hard to reach, so they are routinely powered by the batteries. Due to the complexity of WSNs and the impact they have on the 21st century proceeding technology, they have received lots of attention during past decades, hence it is mandatory to study their fundamentals before any forthcoming research. This paper reviews the alphabets of WSNs in a straight scenario, categorizing them in terms of application, routing and connectivity schemes, besides, practical design challenges and energy supply ways have been classified.

  • Open Access
    Authors: 
    Ziwei Li; Zhiming Qi; Qianjing Jiang; Nathan Sima;
    Publisher: Elsevier BV

    Abstract Many recent studies on soil and crop management practices have demonstrated their possibility in mitigating greenhouse gas emissions (GHG) from cropland. The response of GHG emissions to management practices can be quantitatively simulated using biophysics-based agricultural system models. However, the economic feasibilities of such management adoption are yet to be evaluated, especially when the producers have to adopt only one profitable management plan. This paper presents a field-scale economic analysis software that is capable of estimating the net benefits under various greenhouse gas mitigating management practices. The calculated net benefits are based on the benefit-cost analysis (BCA), where GHG emissions are converted to the CO2 equivalent and priced using the information from the current carbon trade market. GHG emissions and crop yield are simulated using the Root Zone Water Quality Model (RZWQM2), an agricultural system model coupled with the BCA software. A case study for a cornfield at the Saint Emmanuel site near Montreal, Canada, from 2012 to 2015 under two water table management practices, i.e., free-drainage (FD) and controlled drainage (CD), results showed that FD was more profitable than CD. Although fewer greenhouse gases were emitted under CD than under FD, the potential benefit under current carbon credit payment from GHG reduction under CD was far less than the additional cost from installing new instruments and excessive maintenance fees. This study suggests that the government subsidy is needed to provide further incentives for producers to adopt new greenhouse gas emission mitigating management practices.

  • Open Access
    Authors: 
    Hélène Seller; Samuel Palato; Patanjali Kambhampati;
    Publisher: EDP Sciences

    Coherent Multi-dimensional Spectroscopy is ideally suited to investigate many-body effects in semiconductor nanostructures. Here we employ 2D optical spectroscopy on the model system of CdSe quantum dots to reveal the structure of the bandedge biexciton.

  • Closed Access
    Authors: 
    Yulei Sui; Qingxia Liu; Tao Jiang; Yufeng Guo;
    Publisher: Elsevier BV

    Abstract For the first time, a one-step synthetic strategy has been developed towards the preparation of Ti3+ self-doped TiO2 with internal-pores and highly exposed {001} facets using ethylene glycol (EG) and HF as control agents. The obtained samples were characterized by XRD, XPS, SEM, TEM, HAADF-STEM, photoluminescence spectroscopy (PL), and UV–vis reflectance spectroscopy. The synergistic effect of EG and HF plays a vital role in the formation of synthesized TiO2 with Ti3+ self-doping, internal-pores and highly exposed {001} facets. As-synthesized TiO2 exhibit much higher activity than commercial P25 on photocatalytic degradation of phenol and the outstanding performance is attributed to the synergistic effect of Ti3+ doping, internal-pores, and facets heterojunction.

  • Authors: 
    Jinyan Dong; Lei Zhang; Jiaqi Zhou; Weiwei Pan; Xijia Gu; Yan Feng;
    Publisher: The Optical Society

    An over 200 W high-power first-order random Raman fiber laser (RRFL) at 1238 nm is demonstrated. The laser is based on a half-open cavity with a piece of 30 m phosphosilicate fiber. This RRFL is pumped by a conventional 1064 nm Yb-doped fiber laser. After suppressing the silica Raman component, a maximum output power of 206.7 W is obtained with a full width half-maximum linewidth of 7.1 nm at a pump power of 346.3 W, corresponding to an optical-to-optical efficiency of 59.7%. To the best of our knowledge, this is the highest reported output power of RRFL on the basis of phosphosilicate fiber with the shortest cavity length.

  • Open Access
    Authors: 
    K. Kiiveri; Daniel Gruen; Alexis Finoguenov; Thomas Erben; L. van Waerbeke; Eli S. Rykoff; Lance Miller; Steffen Hagstotz; R. A. Dupke; J. Patrick Henry; +12 more
    Publisher: Oxford University Press (OUP)
    Countries: Finland, France, Italy

    The COnstrain Dark Energy with X-ray clusters (CODEX) sample contains the largest flux limited sample of X-ray clusters at $0.35 < z < 0.65$. It was selected from ROSAT data in the 10,000 square degrees of overlap with BOSS, mapping a total number of 2770 high-z galaxy clusters. We present here the full results of the CFHT CODEX program on cluster mass measurement, including a reanalysis of CFHTLS Wide data, with 25 individual lensing-constrained cluster masses. We employ $lensfit$ shape measurement and perform a conservative colour-space selection and weighting of background galaxies. Using the combination of shape noise and an analytic covariance for intrinsic variations of cluster profiles at fixed mass due to large scale structure, miscentring, and variations in concentration and ellipticity, we determine the likelihood of the observed shear signal as a function of true mass for each cluster. We combine 25 individual cluster mass likelihoods in a Bayesian hierarchical scheme with the inclusion of optical and X-ray selection functions to derive constraints on the slope $��$, normalization $��$, and scatter $��_{\ln ��| ��}$ of our richness-mass scaling relation model in log-space: $\left = ����+ ��$, with $��= \ln (M_{200c}/M_{\mathrm{piv}})$, and $M_{\mathrm{piv}} = 10^{14.81} M_{\odot}$. We find a slope $��= 0.49^{+0.20}_{-0.15}$, normalization $ \exp(��) = 84.0^{+9.2}_{-14.8}$ and $��_{\ln ��| ��} = 0.17^{+0.13}_{-0.09}$ using CFHT richness estimates. In comparison to other weak lensing richness-mass relations, we find the normalization of the richness statistically agreeing with the normalization of other scaling relations from a broad redshift range ($0.0 37 pages, 12 figures