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排序方式: 共有626条查询结果,搜索用时 703 毫秒
81.
Kostantine Katcko Etienne Urbain Franck Ngassam Lalit Kandpal Bhavishya Chowrira Filip Schleicher Ufuk Halisdemir Di Wang Torsten Scherer Damien Mertz Benoit Leconte Nicolas Beyer Daniel Spor Pierre Panissod Arnaud Boulard Jacek Arabski Christophe Kieber Emmanuel Sternitzky Victor Da Costa Michel Hehn François Montaigne Armel Bahouka Wolfgang Weber Eric Beaurepaire Christian Kübel Daniel Lacour Mébarek Alouani Samy Boukari Martin Bowen 《Advanced functional materials》2021,31(15):2009467
The quantum states of nano-objects can drive electrical transport properties across lateral and local-probe junctions. This raises the prospect, in a solid-state device, of electrically encoding information at the quantum level using spin-flip excitations between electron spins. However, this electronic state has no defined magnetic orientation and is short-lived. Using a novel vertical nanojunction process, these limitations are overcome and this steady-state capability is experimentally demonstrated in solid-state spintronic devices. The excited quantum state of a spin chain formed by Co phthalocyanine molecules coupled to a ferromagnetic electrode constitutes a distinct magnetic unit endowed with a coercive field. This generates a specific steady-state magnetoresistance trace that is tied to the spin-flip conductance channel, and is opposite in sign to the ground state magnetoresistance term, as expected from spin excitation transition rules. The experimental 5.9 meV thermal energy barrier between the ground and excited spin states is confirmed by density functional theory, in line with macrospin phenomenological modeling of magnetotransport results. This low-voltage control over a spin chain's quantum state and spintronic contribution lay a path for transmitting spin wave-encoded information across molecular layers in devices. It should also stimulate quantum prospects for the antiferromagnetic spintronics and oxides electronics communities. 相似文献
82.
Navarro Jordan Jomard Etienne Saleur Émilie Abrard William Cegarra Julien 《Cognition, Technology & Work》2022,24(4):609-624
Cognition, Technology & Work - The main objective of the current contribution was to investigate human–machine cooperation over time. Participants were asked to choose repeatedly between... 相似文献
83.
84.
In their article ( https://doi.org/10.1002/adfm.201703511 ), Bojnicic‐Kninski et al. expose the known methods used for creating, on a same substrate, patterns composed of different types of particles. This approach is called “combinatorial particle patterning.” They describe various techniques and group them depending on the used methods or driving forces that enable the directed assemblies of particles. A substantial part of the article (Part 2: Electrical Particle Patterning) referred to particle assemblies guided by electrostatic forces, i.e., electrophoretic or dielectrophoretic forces. However, this part, especially the paragraph on “Nanoxerography” (cf. 2.2 of the article) suffers from some inaccuracies that lead to partially wrong conclusions regarding combinatorial particle patterning. The goal of this comment is double: i) giving a complete and up to date definition of nanoxerography ii) reporting the results on combinatorial particle patterning using nanoxerography to correct the article inaccuracies. 相似文献
85.
Back Cover: On the Influence of the Protonation States of Active Site Residues on AChE Reactivation: A QM/MM Approach (ChemBioChem 7/2017) 下载免费PDF全文
86.
Mony M Bisaillon E Shoukry E Ostafew C Grondin E Aimez V Plant DV 《Applied optics》2007,46(18):3724-3729
A novel reprogrammable optical phase array (ROPA) device is presented as a reconfigurable electro-optic element. One specific application of the ROPA, a 1 x 6 electro-optic space switch, is fully described. Switching angles are within 2 degrees , and switching is achieved through a complementary metal-oxide semiconductor (CMOS) controlled, diffraction based, optical phase array in a bulk BaTiO3 crystal. The crystal is flip-chipped to the CMOS chip, creating a compact fully integrated device. The design, optical simulation, and fabrication of the device are described, and preliminary experimental results are presented. 相似文献
87.
88.
Sillam-Dussès D Sémon E Lacey MJ Robert A Lenz M Bordereau C 《Journal of chemical ecology》2007,33(10):1960-1977
In the framework of an evolutionary study, trail pheromones have been studied in the most basal extant termite, Mastotermes darwiniensis (Mastotermitidae), and two other basal termites, the Termopsidae Porotermes adamsoni (Porotermitinae) and Stolotermes victoriensis (Stolotermitinae). Although workers of M. darwiniensis do not walk in single file while exploring a new environment under experimental conditions and are unable to follow artificial
trails in ‘open field’ experiments, they do secrete a trail-following pheromone from their sternal glands. This unique behavior
might reflect a primitive function of communication of the sternal gland. The major component of the pheromone appears to
be the same in the three basal species: the norsesquiterpene alcohol (E)-2,6,10-trimethyl-5,9-undecadien-1-ol. This represents a new chemical category of trail-following pheromones for termites.
The quantity of pheromone was estimated as 20 pg/individual in M. darwiniensis, 700 pg/individual in P. adamsoni, and 4 pg/individual in S. victoriensis. The activity threshold was 1 ng/cm in M. darwiniensis and 10 pg/cm in P. adamsoni. In M. darwiniensis, the trail pheromone was secreted by sternal gland 4 and to a lesser degree by sternal gland 3, sternal gland 5 being almost
inactive. This study highlighted phylogenetic relationships between the Mastotermitidae and two subfamilies of the Termopsidae,
the Porotermitinae and the Stolotermitinae. Furthermore, it indicated a heterogeneity within the Termopsidae, with Porotermitinae
and Stolotermitinae on one hand, and Termopsinae on the other. Finally, Mastotermitidae and Termopsidae, with C14 trail pheromones,
are clearly separated from the Kalotermitidae, Rhinotermitidae, and Termitidae that secrete C12 or C20 trail pheromones. 相似文献
89.
Eliel González‐García Yann Alexandrine Tatiana Silou‐Etienne Harry Archimède 《Journal of the science of food and agriculture》2009,89(11):1918-1926
BACKGROUND: The in situ technique (IS) is used for characterising, screening and evaluating feedstuffs in ruminants. However, it is often not adapted to the particular characteristics of feeds (i.e. kinetics of starchy feeds with a standard framework used in forage). This may lead to potential biases in the final conclusions. In two successive experiments, we evaluated the degradative characteristics of conventional (CON) and unconventional (UNC) starchy feedstuffs (ING) and factors affecting their washable fractions (WF). The suitability of IS was then assessed. RESULTS: Two well‐defined ruminal fermentation patterns (CON and UNC) were observed. The WF and insoluble washable (ISWF) fractions were affected by ING, state of presentation [WAY, fresh (F) or pre‐dried (D)], particle size (PSI) and their interactions. The UNC and F feeds had greater WF and ISWF than CON and D, respectively. Increasing PSI linearly reduced WF and its proportion of ISWF. CONCLUSION: The PSI and WAY are critical factors to consider when designing experiments for the evaluation of starchy feedstuffs for ruminants using IS. It is still very risky to propose ‘standard’ parameters as this will always depend on the particular ING evaluated. Conducting pre‐evaluation tests before implementing each research protocol could help to refine the procedure. Copyright © 2009 Society of Chemical Industry 相似文献
90.
Sam L. J. Page Md Elahi Baksh Etienne Duveiller Stephen R. Waddington 《Food Security》2009,1(1):99-109
This paper reports on a ‘bottom-up’ system of wheat seed technology transfer that was piloted in north–west Bangladesh with
45 mainly marginal (food insecure) farming families during the 2004–2005 wheat season, then scaled out to a further 545 mainly
marginal, farming families during the 2006–2007 season. The system was devised following a survey which indicated that such
farmers can obtain a 52% increase in wheat grain yield and extra income by switching from the old Kanchan variety to the newer, heat and disease-tolerant Shatabdi variety. The bottom-up wheat seed dissemination system involved the creation of an enabling environment which allowed poor
and ultra-poor farmers to store and sell selected seed of recently-released wheat varieties that they produced in 20 decimal
(0.08 ha) plots. During the pilot phase of the project in 2005, farmers produced 7, 976 kg of grain and more than 50% of this
was selected as high quality seed, stored during the monsoon season and marketed to other farmers just prior to the following
wheat season. This seed was sold at Tk25–30/kg and realised profits averaging Tk3,002 (€38.49; exchange rate was 78:1 in October
2005) per household. In 2007, the seed price had risen to Tk33–50/kg and a larger group of farmers produced, stored and marketed
168,800 kg of high quality wheat seed, which realised profits averaging Tk5,080, equivalent to €51 (exchange rate was 99.6:1
in October 2007), per household. This bottom up seed production and dissemination system met the wheat seed requirements of
more than 1,400 neighbouring farmers in areas with a deficit of wheat seed for planting, and enabled poor and ultra-poor farmers
to earn more than 50% of the income they needed to cross the local poverty line.
Sam L. J. Page Ph.D. I have been working in rural development for more than 30 years in both government and non-government sectors. My early research was concerned with pest management in food cropping systems and later I began investigating underlying causes of household food insecurity in southern Africa, as well as the use of indigenous food cropping systems to mitigate the impacts of HIV/AIDS. I am currently based at CABI Europe-UK, where I am implementing the Good Seed Initiative which aims to alleviate poverty by enabling food insecure farming families to profit from producing and marketing seed of indigenous and improved varieties. Dr. Baksh is an experienced agricultural economist and Principal Scientific Officer in the Wheat Research Centre of the Bangladesh Agricultural Research Institute (BARI). He specialises in economic aspects of the rice–wheat cropping system that characterises much of south Asia and has published 20 scientific papers. For the past 8 years he has been the Principal Investigator for several DFID, IFAD, IRRI and CIMMYT funded projects that aim to design and disseminate resource-conserving technologies to improve the livelihoods of the poorest farming families in the region. Dr. Etienne Duveiller is a plant pathologist specializing in cereal disease resistance and integrated crop management with more than 25 years experience in international agriculture and development projects. He received his M.Sc. (1980) and Ph.D. (1992) from University of Louvain (UCL) in Belgium and a special degree in social sciences from the Developing Countries Institute at the same university (1981). After working in capacity building in Bolivia for an NGO, and in Burundi on rice diseases, he joined CIMMYT Wheat Program in 1987. After10 years at CIMMYT headquarters in Mexico and frequent visits to South Asia, he spent 8 years on the Indian Subcontinent as CIMMYT regional pathologist based in Nepal and participated in several wheat disease surveys in central Asia and Iran. He returned to Mexico in 2006 as Head of Wheat Pathology at the CIMMYT Global Wheat program. Stephen Waddington is an agronomist. He has 26 years of experience working with the International Maize and Wheat Improvement Centre (CIMMYT) and its partners in Mexico, southern and eastern Africa and in Bangladesh. His main research interests involve smallholder farming systems and participatory research, maize and wheat crop production agronomy, soil fertility and water management, and cereal yield physiology. He has considerable experience in capacity building and networking in many of these areas. Waddington was South Asia regional agronomist and head of the CIMMYT Office in Bangladesh from 2005 to 2007 and is currently located in Mexico. 相似文献
Stephen R. WaddingtonEmail: |
Sam L. J. Page Ph.D. I have been working in rural development for more than 30 years in both government and non-government sectors. My early research was concerned with pest management in food cropping systems and later I began investigating underlying causes of household food insecurity in southern Africa, as well as the use of indigenous food cropping systems to mitigate the impacts of HIV/AIDS. I am currently based at CABI Europe-UK, where I am implementing the Good Seed Initiative which aims to alleviate poverty by enabling food insecure farming families to profit from producing and marketing seed of indigenous and improved varieties. Dr. Baksh is an experienced agricultural economist and Principal Scientific Officer in the Wheat Research Centre of the Bangladesh Agricultural Research Institute (BARI). He specialises in economic aspects of the rice–wheat cropping system that characterises much of south Asia and has published 20 scientific papers. For the past 8 years he has been the Principal Investigator for several DFID, IFAD, IRRI and CIMMYT funded projects that aim to design and disseminate resource-conserving technologies to improve the livelihoods of the poorest farming families in the region. Dr. Etienne Duveiller is a plant pathologist specializing in cereal disease resistance and integrated crop management with more than 25 years experience in international agriculture and development projects. He received his M.Sc. (1980) and Ph.D. (1992) from University of Louvain (UCL) in Belgium and a special degree in social sciences from the Developing Countries Institute at the same university (1981). After working in capacity building in Bolivia for an NGO, and in Burundi on rice diseases, he joined CIMMYT Wheat Program in 1987. After10 years at CIMMYT headquarters in Mexico and frequent visits to South Asia, he spent 8 years on the Indian Subcontinent as CIMMYT regional pathologist based in Nepal and participated in several wheat disease surveys in central Asia and Iran. He returned to Mexico in 2006 as Head of Wheat Pathology at the CIMMYT Global Wheat program. Stephen Waddington is an agronomist. He has 26 years of experience working with the International Maize and Wheat Improvement Centre (CIMMYT) and its partners in Mexico, southern and eastern Africa and in Bangladesh. His main research interests involve smallholder farming systems and participatory research, maize and wheat crop production agronomy, soil fertility and water management, and cereal yield physiology. He has considerable experience in capacity building and networking in many of these areas. Waddington was South Asia regional agronomist and head of the CIMMYT Office in Bangladesh from 2005 to 2007 and is currently located in Mexico. 相似文献