Comparison of Penman-Monteith and non-linear energy balance approaches for estimating leaf wetness duration and apple scab infection     

Alexandre Leca  Luciana ParisiAndré Lacointe  Marc Saudreau 《Agricultural and Forest Meteorology》2011,151(8):1158-1162

Leaf Wetness Duration (LWD) is the main parameter involved in the apple scab development in apple orchards. LWD values can be inferred from weather conditions by solving a non-linear energy balance equation. Such energy balance equation is usually linearized leading to the Penman-Monteith equations. However this approximation leads to significant errors in the evaporative term and by consequence in the LWD computation. In this work, consequences of the use of the Penman-Monteith equations instead of the exact solution were firstly investigated on single droplets and compared to experimental values obtained in controlled and constant conditions. For these studies, the LWD is overestimated by 12% when Penman-Monteith equations were used. The ability of LWD estimate from the linearized energy balance equation to forecast risk infection of a leaf by V. inaequalis conidia was investigated. For some conditions, the error in LWD estimate by Penman-Monteith approached 6 h, leading to an incorrect risk assessment of apple scab development.  相似文献   

Near-perfect elastoplasticity in pure nanocrystalline copper     

Champion Y  Langlois C  Guérin-Mailly S  Langlois P  Bonnentien JL  Hytch MJ 《Science (New York, N.Y.)》2003,300(5617):310-311

Ductile metals and alloys undergo plastic yielding at room temperature, during which they exhibit work-hardening and the generation of surface instabilities that lead to necking and failure. We show that pure nanocrystalline copper behaves differently, displaying near-perfect elastoplastic behavior characterized by Newtonian flow and the absence of both work-hardening and neck formation. We observed this behavior in tensile tests on fully dense large-scale bulk nanocrystalline samples. The experimental results further our understanding of the unique mechanical properties of nanocrystalline materials and also provide a basis for commercial technologies for the plastic (and superplastic) formation of such materials.  相似文献   

Characteristics and potential pedogenetic processes of a Technosol developing on iron industry deposits     

Hermine Huot  Marie-Odile Simonnot  Philippe Marion  Jacques Yvon  Philippe De Donato  Jean-Louis Morel 《Journal of Soils and Sediments》2013,13(3):555-568

Purpose

Technosols include soils dominated or strongly influenced by human-made materials. Similarly to natural soils, technogenic parent materials submitted to environmental factors undergo weathering and transformation processes. But the pedogenesis of Technosols remains little known. With this aim in view, a Technosol developing on purely technogenic materials resulting from an iron industry was thoroughly characterized in order to discuss the pedogenetic evolution of this Technosol using knowledge about the pedogenesis of natural soils.

Materials and methods

The studied site was a former settling pond where mainly sludge generated by wet cleaning of blast furnace fumes was dumped probably until the mid-twentieth century. Thereafter, the pond has been colonized by vegetation and is covered by a diversified forest. The soil was composed of contrasted layers. A 20-cm organic layer has developed at the surface. Samples were collected in the first 2 m which are under root influence. Elemental composition, agronomic parameters, mineralogy, as well as the physical and hydraulic properties of the soil materials were characterized.

Results and discussion

Some characteristics of the Technosol, e.g. elemental composition, mineralogy or profile stratification, resulted mainly from industrial processes. However, some properties of the Technosol can be compared with natural soils. Particularly, the presence of low periodic order minerals and physical and hydraulic properties were analogous to the properties of Andosols. However, alkaline pH and the carbonate contents made the Technosol closer to carbonated soils. Moreover, the presence of Mn oxides, high porosity and water retention were also encountered in Mn-bearing soils. Early pedogenic processes, e.g. development of organic surface layer and signs of mineral weathering, were observed. But transfers seemed to be rather limited and/or slow in the profile. However, the physical and chemical properties, e.g. high water retention and high pH, were rather favourable to element retention.

Conclusions

The evolution of the Technosol seems to be still limited in the profile, which could be explained by the high retention capacity of the soil. The presence of highly reactive mineral phases, such as low periodic order Mn oxides or allophane-like minerals, with high contents of carbonates is rarely encountered in the natural environment and may suggest an important potential for pedogenic evolution, which could be directed by the balance between the weathering processes of these phases.  相似文献   

IUSS SUITMA 6 International Symposium 2011   总被引：1，自引：1，他引：0  

Nicholas Dickinson  Jean-Louis Morel  Richard K. Shaw  Gerd Wessolek 《Journal of Soils and Sediments》2013,13(3):489-490

  相似文献   

Effect of some repetitive factors on turbot stress response   总被引：2，自引：0，他引：2  

Chantal Mugnier  Alexis Fostier  Sylvie Guezou  Jean-Louis Gaignon  Loic Quemener 《Aquaculture International》1998,6(1):33-45

The stress response of the turbot, Scopthalmus maximus (L.), to repetitive factors including netting, air exposure, blood sampling and hand-stripping, were tested using two different tank sizes as well as two blood sampling techniques. Exposure of juvenile fish to air for 1-4 min had no immediate effect on plasma cortisol concentrations or haematocrit values. Similarly, the serial netting of immature fish from tanks did not significantly modify plasma cortisol concentrations, haematocrit or osmolarity values. Hand-stripping of mature males was more disturbing than air exposure. The cumulative effect on plasma cortisol levels and osmolarity of stress factors such as netting, air exposure, blood sampling and stripping applied simultaneously to mature males in a 16 m3 tank and repeated twice daily for several days was recorded. The level of cortisol increased from 5 ng ml-1 to 300 ng ml-1 after 10 days of treatment, while an osmoregulatory imbalance and fish death were observed. Moreover, adaptation of fish to smaller tanks seemed to improve the increased plasma cortisol levels and death rate. Reduction in the number of stress factors applied greatly decreased both the range of physiological responses and the death rate. In order to avoid a cumulative stress response, handling of fish should therefore be reduced to a minimum.  相似文献   

Extra-large-pore zeolites with two-dimensional channels formed by 14 and 12 rings     

Paillaud JL  Harbuzaru B  Patarin J  Bats N 《Science (New York, N.Y.)》2004,304(5673):990-992

Stable zeolites that have larger pore apertures and a three-dimensional pore topology are of interest because they could be used to adsorb larger molecules, particularly for application in oil refining. Several large-pore zeolitic materials with channels formed by openings of more than 12 rings are known, but all of them have a one-dimensional channel system that limits their use in catalysis. We report the synthesis and some characterizations of IM-12, a thermally stable germanium-containing zeolite that contains the first two-dimensional channel system with extra-large pores formed by 14- and 12-ring channels.  相似文献   

Preface     

Christina Siebe  Maxine J. Levin  Jean-Louis Morel 《Journal of Soils and Sediments》2018,18(2):333-335

  相似文献   

Erratum to: Do bird spatial distribution patterns reflect population trends in changing landscapes?     

Clélia Sirami  Lluis Brotons  Jean-Louis Martin 《Landscape Ecology》2010,25(1):159-160

  相似文献   

Changes in the diversity and geographic distribution of cultivated millet (Pennisetum glaucum (L.) R. Br.) and sorghum (Sorghum bicolor (L.) Moench) varieties in Niger between 1976 and 2003     

Gilles Bezançon  Jean-Louis Pham  Monique Deu  Yves Vigouroux  Fabrice Sagnard  Cédric Mariac  Issoufou Kapran  Aïssata Mamadou  Bruno Gérard  Jupiter Ndjeunga  Jacques Chantereau 《Genetic Resources and Crop Evolution》2009,56(2):223-236

Changes in the diversity of landraces in centres of diversity of cultivated plants need to be assessed in order to monitor and conserve agrobioversity—a key-element of sustainable agriculture. This notably applies in tropical areas where factors such as increased populations, climate change and shifts in cropping systems are hypothesized to cause varietal erosion. To assess varietal erosion of staple crops in a country subjected to various anthropogenic and natural environmental changes, we carried out a study based on a comparison of the diversity of pearl millet and sorghum varieties collected in 79 villages spanning the entire cereal-growing zone of Niger over a 26 year period (1976–2003). For these two crops, the number, name and type of varieties according to important traits for farmers were considered at different spatial scales (country, region, village) at the two collection dates. The results confirmed the high diversity of millet and sorghum varieties in Niger. No erosion of varietal diversity was noted on a national scale during the period covered. Some changes were observed but were limited to the geographical distribution of certain varieties. This highlights that farmers’ management can preserve the diversity of millet and sorghum varieties in Niger despite recurrent and severe drought periods and major social changes. It also indicates that rainfed cereal cropping systems in Niger should remain to be based on millet and sorghum, while reinforcing farmers’ seed systems.  相似文献   

A long-term tree-ring chronology over 796 years for silver fir (<Emphasis Type="Italic">Abies alba</Emphasis> Mill.) in Southern France     

Lisa Shindo  Christelle Belingard  Jean-Louis Edouard  Mélanie Saulnier 《Annals of Forest Science》2017,74(4):67

? Key message This paper presents ring width data of silver fir trees (Abies alba Mill.) from buildings and living trees from 1214 to 2009 in southeastern France. A 796-year chronology spanning the period 1214–2009 has been built. Data can be used for dating projects, paleoecology studies, and climate reconstructions. Dataset access is at https://hal.archives-ouvertes.fr/hal-01528324 . Associated metadata is available at https://metadata-afs.nancy.inra.fr/geonetwork/srv/fre/catalog.search#/metadata/a74b4869-318c-458c-a5fe-f9ff44a5082c   相似文献