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Experimental Investigation of Discharge Capacity of Labyrinth Weirs with and without Nappe Breakers

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World j.urnal of mechanics 2016年第7期6卷 207-221页

作者： Omer Bilhan m. Emin Emiroglu carol j. m.ller Department of Civil Engineering Nevsehir HBV University Nevsehir Turkey Department of Civil Engineering Firat University Elazig Turkey Department of Civil and Environmental Engineering Wayne State University Detroit MI USA

Labyrinth weirs provide higher discharge capacity than conventional weirs, with the ability to pass large flows at comparatively low heads. Labyrinth weirs are primarily used as spillways for dams where the spillway width is restricted. In recent years, many research investigations have considered the hydraulic performance of labyrinth weirs, particularly as dependent on the geometric features. The previous work has improved the design basis for such weirs. However, their design still requires experimentally derived and generalized performance curves. It is especially important to observe the behavior of the weir nappe to ensure the design provides hydraulic optimization and to account for pressure fluctuations, possible vibrations, resonance effect, noise and flow surging. In the present study, discharge coefficients were experimentally determined for both circular labyrinth weirs and sharp crested trapezoidal labyrinth weirs of varying side wall angle (α). Additional studies were completed with nappe breakers included to reduce the impact of vibration on the labyrinth weirs. In general, the test data indicated that nappe breakers placed on the trapezoidal labyrinth weirs and circular labyrinth weirs reduced the discharge coefficient by up to 4% of the un-amended weir.

关键词： Weir Discharge Coefficient Trapezoidal Circular Labyrinth Weir Nappe Breaker

Ecological factors influencing the beneficial endosymbionts of the hemlock woolly adelgid (Hemiptera:Adelgidae)

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Insect Science 2019年第1期26卷 97-107页

作者： Angela m.mech Sherilyn j.Harper Nathan P.Havill carol D.von Dohlen Gaelen R.Burke Department of Entomology University of GeorgiaAthensGeorgiaUSA School of Environmental and Forest Sciences University of WashingtonSeattleWashingtonUSA USDA Forest Service Northern Research StationHamdenConnecticutUSA Department of Biology Utah State UniversityLoganUtahUSA

Bacterial endosymbionts of sap-sucking insects provide their host with a num- ber of beneficial qualities,including the supply of nutrition,defense against parasitoids, and protection from heat *** to these bacterial associates can therefore have a negative impact on the fitness of their insect *** evaluated observational and experi- mental factors regarding the normative hemlock woolly adelgid (Adelges tsugae Annand) (Hemiptera:Adelgidae)to help understand the roles of its three recently identified symbionts,including under heat stress *** prevalence of ***'s facultafive symbiont (Serratia symbiotica)was examined at different spatial scales to determine how variable infection rates are for this *** was no significant difference found in infection rates between adelgids on a tree,within a plot,or within a ***, significantly more adelgids in Georgia (95%)had *** compared to those in New York (68%).microsatellite genotyping of the adelgids found that this difference was most likely not the result of a second introduction *** into eastern North *** *** proportions between first and fourth instars showed that symbiont absence did not affect the ability *** to survive *** of sym- biont densities within each adelgid found that when *** was absent,the density of obligate symbionts was significantly *** to heat stress (32.5℃)was not consistently correlated with changes in symbiont densities over a 4-d ***,we have shown that symbiont prevalence and densities vary within the broad population of *** in eastern North America,with potentially significant effects upon the ecology of this important pest.

关键词： Adelges tsugae Anncindia adelgestsuga bacterial endosymbionts Serratia symbiotica Pseudomonas adelgestsugas

Trans-Gulf of mexico loop migration of tree swallows revealed by solar geolocation

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Current Zoology 2014年第5期60卷 653-659页

作者： David W. BRADLEY Robert G. CLARK Peter O. DUNN Andrew j. LAUGHLIN Caz m. TAYLOR carol VLECK Linda A. WHITTINGHAm David W. WINKLER D. Ryan NORRIS Department of Integrative Biology University of Guelph Guelph Ontario N1G 2W 1 Canada Bird Studies Canada Port Rowan Ontario N0E 1M0 Canada Environment Canada. Saskatoon. Saskatchewan S7N 0X4. Canada Behavioral and molecular Ecology Group Department of Biological Sciences University of Wisconsin Milwaukee Wisconsin 53201 USA Department of Ecology and Evolutionary Biology Tulane University New Orleans Louisiana 70118 USA Department of Ecology Evolution and Organismal Biology Iowa State University Ames IA 50011-1020 USA Department of Ecology and Evolutionary Biology Museum of Vertebrates and Lab of Ornithology Comell University Ithaca New York 14853 USA

One of the greatest feats of avian migration is the non-stop crossing of extensive areas of inhospitable habitat such as deserts and seas. Differences in spring and autumn migration routes have been reported in species that cross such barriers, and are thought to have evolved in response to seasonal variation in prevailing wind direction. We tested the hypothesis that migration routes vary seasonally with respect to the Gulf of mexico in the tree swallow Tachycineta bicolor using solar geolocators attached and retrieved at 4 breeding sites in central North America. We found that 100 % of birds （n = 10） made a trans-Gulf flight of 〉850 km from Louisiana south to their wintering grounds in the Yucatan Peninsula in 12-36 hours, achieving minimum ground speeds as high as 32 m/s. Although most days during autumn migration were characterized by unfavorable headwinds blowing to the northwest, migration over the Gulf mostly occurred on days with strong winds blowing to the south. In contrast, in 8 of 9 （88 %） birds on spring migration returned from the wintering grounds towards Louisiana following a clockwise loop pat- tern flying over land to the west around the Gulf. During this spring period there were few days with prevailing winds from the south to assist northward migration. Results suggest that, despite being up to three times further （ca. 2,700 kin）, a coastal circum-Gulf spring migration represents the less risky route when wind conditions are not favorable. These findings also help to resolve a long-standing dispute in the literature concerning migration patterns between the US Gulf coast and mexico, and provide insight into the factors shaping migration strategies of small songbirds migrating across large bodies of water [Current Zoology 60（5）： 653-559, 2014].

关键词： Ecological Barrier Geolocation Gulf of mexico Tachycineta bicolor Tree swallow migration

Essentials of Pathophysiology: Concepts of Altered Health States (Point (Lippincott Williams & Wilkins)) 2nd ed.

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Cellular modelling using P systems and process algebra

2007年

作者： carol Porth

来源：畅想之星图书光盘版（南... 评论

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Progress in Natural Science:materials International 2007年第4期17卷 375-383页

作者： Francisco j. Romero-Campero marian Gheorghe Gabriel Ciobanu j.hn m. Auld mario j. Pérez-j.ménez Research Group on Natural Computing Department of Computer Science and Artificial IntelligenceUniversity of SevilleAvda.Reina Mercedes41012 SevillaSpain Department of Computer Science The University of Sheffield Regent CourtPortobello StreetSheffield S1 4DPUK Romanian Academy Institute of Computer ScienceBlvd. Carol I nr. 11700505IasiRomania

In this paper various molecular chemical interactions are modelled under different computational paradigms. P systems andπ-calculus are used to describe intra-cellular reactions like protein-protein interactions and ... 详细信息

关键词： cellular modelling P systems process algebra.

Feeding the world: impacts of elevated [CO_(2)] on nutrient content of greenhouse grown fruit crops and options for future yield gains

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Horticulture Research 2023年第4期10卷 83-100页

作者： Nicholas H.Doddrell Tracy Lawson Christine A.Raines carol Wagstaff Andrew j.Simkin NIAB New RoadEast MallingKentME196BJ UK Department of Food and Nutritional Sciences University of ReadingWhiteknightsReadingBerkshire RG66DZUK School of Life Sciences University of EssexColchester CO44SQUK School of Biosciences University of KentCanterburyUnited Kingdom CT27NJUK

Several long-term studies have provided strong support demonstrating that growing crops under elevated[CO_(2)]can increase photosynthesis and result in an increase in yield,flavour and nutritional content(including but not limited to Vitamins C,E and pro-vitamin A).In the case of tomato,increases in yield by as much as 80%are observed when plants are cultivated at 1000 ppm[CO_(2)],which is consistent with current commercial greenhouse productionmethods in the tomato fruit *** results provide a clear demonstration of the potential for elevating[CO_(2)]for improving yield and quality in greenhouse *** maj.r focus of this review is to bring together 50 years of observations evaluating the impact of elevated[CO_(2)]on fruit yield and fruit nutritional *** the final section,we consider the need to engineer improvements to photosynthesis and nitrogen assimilation to allow plants to take greater advantage of elevated CO_(2) growth conditions.

关键词： crops greenhouse content

Foliar-Applied Cytokinins and Nitrogen Reduce Alternate Bearing and Increase Cumulative Yield of Pistachio

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Foliar-Applied Cytokinins and Nitrogen Reduce Alternate Bear...