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Gas exchange of Populus euphratica leaves in a riparian zone

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Journal of Arid Land 2013年第4期5卷 531-541页

作者： Dieter OVERDIECK daniel ZICHE RuiDe YU Institute of Ecology/Ecology of Woody Plants TU-BerlinD-14195 BerlinGermany von Thuenen-Institut Institute of Forest Ecology and Forest InventoryD-16225 EberswaldeGermany Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences

Riparian vegetation belts in arid regions of Central Asia are endangered to lose their ecosystem services due to intensified land *** the development of sustained land use,management knowledge of plant performance in relation to resource supply is *** estimated productivity related functional traits at the edges of the habitat of Populus euphratica *** leaf area （SLA） and carbon/nitrogen （C/N） ratio of *** leaves growing near a former river bank and close to moving sand dunes in the Ebinur Lake National Nature Reserve in Xinjiang,Northwest China （near Kazakhstan） were determined and daily courses of CO2 net assimilation （PN）,transpiration （E）,and stomatal conductance （gs） of two consecutive seasons were measured during July-August 2007 and June-July *** level was high （1.5-2.5 m below ground） throughout the years and no flooding occurred at the two tree *** was slightly lower near the desert than at the former river bank and leaves contained less N in relation to *** E and gs of *** were reached in the morning before noon on both stands and a second low maximum occurred in the afternoon despite of the unchanged high levels of air to leaf water vapor pressure deficit （ALVPD）.Decline of gs in *** was followed by decrease of *** use efficiency （WUE） of leaves near the desert were higher in the morning and the evening,in contrast to leaves from the former river bank that maintained an almost stable level throughout the *** light compensation points and high light saturation levels of PN indicated the characteristics of leaves well-adapted to intensive irradiation at both *** general,leaves of *** decreased their gs beyond 20 Pa/kPa ALVPD in order to limit water *** of E did not occur in both stands until 40 Pa/kPa ALVPD was *** stomatal closure of *** was achieved at 60 Pa/kPa ALVPD in both stands.E through the leaf surface amounted up to 30％ of

关键词： Populus euphratica water vapor pressure deficit transpiration stomatal conductance water use efficiency leaf functional traits

Development of a nanostructured filter for pyrolysis wax purification:Effects of particulate filter aids

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Particuology 2021年第1期19卷 164-172页

作者： Juliano Missau daniel Assumpcao Bertuol Eduardo Hiromitsu Tanabe Environmental Processes Laboratory(LAPAM) Chemical Engineering DepartmentFederal University of Santa Maria–UFSMAvenida Roraima 100097105-900Santa MariaRSBrazil

Wax obtained from the pyrolysis of polyethylene waste can contain inorganic contaminants and must be purified before *** evaluated different filter aids(perlite,sand,and rice husk ash)for the filtration of a crude wax and a pyrolysis wax through a filter medium that was coated with nylon 6 nanofibers to improve filtration *** first examined the performance of the filter aids in improving crude wax filtration,with the filtration time,temperature,and pressure held constant at 1 h,170℃,and 2.5 bar,*** wax was then produced by pyrolysis of high-density polyethylene(HDPE)waste in the temperature range 425-475℃.The best filter aid was perlite,which had a filtrate production rate of 5.47×10^(-5)m^(3)/*** highest oily wax yield(87.8%)was achieved at a pyrolysis temperature of 425℃.The assembly comprising the filter medium coated with nylon 6 nanofibers plus perlite as a filter aid was most suitable for removing impurities from the oily wax generated by the HDPE pyrolysis as it achieved a purification efficiency of 99.9%.

关键词： HDPE pyrolysis wax Plastic solid waste Nanofiber-coated filter Filter aids Filtration

The relationship between intraspecific assortative mating and reproductive isolation between divergent populations

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Current Zoology 2012年第3期58卷 484-492页

作者： daniel I. BOLNICK Mark KIRKPATRICK Howard Hughes Medical Institute and Section of Integrative Biology One University Station C0930 University of Texas at Austin Austin TX 78712 USA Section of Integrative Biology One University Station C0930 University of Texas at Austin Austin TX 78712 USA

The term ＇assortative mating＇ has been applied to describe two very different phenomena：（1） the tendency for indi- viduals to choose phenotypically similar mates from among conspecifics; or （2） the tendency to prefer conspecific over hete- rospecific mates （behavioral reproductive isolation）. Both forms of assortative mating are widespread in nature, but the relation- ship between these behaviors remains unclear. Namely, it is plausible that a preference for phenotypically similar conspecifics in cidentally reduces the probability of mating with phenotypically divergent heterospecifics. We present a model to calculate how the level of reproductive isolation depends on intraspecific assortative mating and the phenotypic divergence between species. For empirically reasonable levels of intraspecific assortment on a single trait axis, we show that strong reproductive isolation requires very substantial phenotypic divergence. We illustrate this point by applying our model to empirical data from threespine stickleback Gasterosteus aculeatus and Darwin＇s Finches （Geospiza spp）. We conclude that typical levels of intraspecific assortment cannot generally be extrapolated to explain levels of interspecific reproductive isolation. Instead, reproductive isolation between species likely arises from different mate choice behaviors, or multivariate assortative mating [Current Zoology 58 （3）： 484-492, 2012].

关键词： Assortative mating Hybridization Mating preference Reproductive isolation Speciation

Utilizing a novel fiber optic technology to capture the axial responses of fully grouted rock bolts

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第2期10卷 222-235页

作者： Nicholas Vlachopoulos daniel Cruz Bradley Forbes Department of Civil Engineering Royal Military College of Canada Department of Geological Sciences and Geological Engineering Queen's UniversityKingston

Rock bolts are one of the primary support systems utilized in underground excavations within the civil and mining engineering industries. Rock bolts support the weakened rock mass adjacent to the opening of an excavation by fastening to the more stable, undisturbed formations further from the excavation. The overall response of such a support element has been determined under varying loading conditions in the laboratory and in situ experiments in the past four decades; however, due to the limitations with conventional monitoring methods of capturing strain, there still exists a gap in knowledge associated with an understanding of the geomechanical responses of rock bolts at the microscale. In this paper, we try to address this current gap in scientific knowledge by utilizing a newly developed distributed optical strain sensing(DOS) technology that provides an exceptional spatial resolution of 0.65 mm to capture the strain along the rock bolt. This DOS technology utilizes Rayleigh optical frequency domain reflectometry(ROFDR) which provides unprecedented insight into various mechanisms associated with axially loaded rebar specimens of different embedment lengths, grouting materials, borehole annulus conditions, and borehole diameters. The embedment length of the specimens was found to be the factor that significantly affected the loading of the rebar. The critical embedment length for the fully grouted rock bolts(FGRBs) was systematically determined to be430 mm. The results herein highlight the effects of the variation of these individual parameters on the geomechanical responses FGRBs.

关键词： Fiber optic technology Fully grouted rock bolts Load transfer Stress distribution

Reinforcement＇s incidental effects on reproductive isolation between conspecifics

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Current Zoology 2016年第2期62卷 135-143页

作者： Biology Department daniel R. MATUTE Biology Department University of North Carolina 250 Bell Tower Road Chapel Hill NC 27599 USA

Reinforcement--the process whereby maladaptive hybridization leads to the strengthening of prezygotic isolation between species--has a long history in the study of speciation. Because reinforcement affects traits involved in mate choice and fertility, it can have indirect effects on reproductive isolation between populations within species. Here we review examples of these ＂cascading effects of reinforcement＂（CER） and discuss different mechanisms through which they can arise. We discuss three factors that are predicted to influence the potential occurrence of CER： rates of gene flow among populations, the strength of selection acting on the traits involved in reinforcement, and the genetic basis of those traits. We suggest that CER is likely if （1） the rate of gene flow between conspecific populations is low; （2） divergent selection acts on phenotypes involved in reinforcement between sympatric and allopatric populations; and （3） the genetic response to reinforcement differs among conspecific populations subject to parallel reinforcing selection. Future work continuing to address gene flow, selection, and the genetic basis of the traits involved in the reinforcement will help develop a better understanding of reinforcement as a process driving the production of species diversity, both directly and incidentally.

关键词： reinforcement speciation reproductive character displacement

Adaptation Decision Support: An Application of System Dynamics Modeling in Coastal Communities

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International Journal of Disaster Risk Science 2017年第4期8卷 374-389页

作者： daniel Lane Shima Beigzadeh Richard Moll C-Change International Community-University Research Alliance (ICURA) Telfer School of Management University of Ottawa

This research develops and applies a system dynamics(SD) model for the strategic evaluation of environmental adaptation options for coastal communities. The article defines and estimates asset-based measures for community vulnerability, resilience, and adaptive capacity with respect to the environmental, economic, social, and cultural pillars of the coastal community under threat. The SD model simulates the annual multidimensional dynamic impacts of severe coastal storms and storm surges on the community pillars under alternative adaptation *** calculation of the quantitative measures provides valuable information for decision makers for evaluating the alternative strategies. The adaptation strategies are designed model results illustrated for the specific context of the coastal community of Charlottetown, Prince Edward Island, Canada. The dynamic trend of the measures and model sensitivity analyses for Charlottetown—facing increased frequency of severe storms, storm surges, and sea-level rise—provide impetus for enhanced community strategic planning for the changing coastal *** research is presented as part of the International Community-University Research Alliance C-Change project ‘‘Managing Adaptation to Environmental Change in Coastal Communities: Canada and the Caribbean'' sponsored by the Social Science and Humanities Research Council of Canada and the International Development Resource Centre.

关键词： Canada Charlottetown Climate change adaptation Coastal community resilience Coastal community vulnerability System dynamics model

Pathophysiology and treatment of Barrett's esophagus

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World Journal of Gastroenterology 2010年第30期16卷 3762-3772页

作者： daniel S Oh Steven R DeMeester Department of Surgery The University of Southern CaliforniaKeck School of MedicineLos AngelesCA 90033United States

Gastroesophageal reflux disease (GERD) affects an estimated 20% of the population in the United States. About 10%-15% of patients with GERD develop Barrett’s esophagus, which can progress to adenocarcinoma, currently the most prevalent type of esophageal cancer. The esophagus is normally lined by squamous mucosa, therefore, it is clear that for adenocarcinoma to develop, there must be a sequence of events that result in transformation of the normal squamous mucosa into columnar epithelium. This sequence begins with gastroesophageal reflux, and with continued injury metaplastic columnar epithelium develops. This article reviews the pathophysiology of Barrett’s esophagus and implications for its treatment. The effect of medical and surgical therapy of Barrett’s esophagus is compared.

关键词： Gastroesophageal reflux disease Barrett’s esophagus Lower esophageal sphincter Esophageal motility Proton pump inhibitors Antireflux surgery

Main linac lattice design and optimization for E_(cm)=1 TeV CLIC

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Chinese Physics C 2014年第6期38卷 117-124页

作者：王毅伟 SCHULTE daniel 高杰 Institute of High Energy Physics Chinese Academy of Sciences CERN Geneva Switzerland

The Compact Linear Collider （CLIC） is a future e＋e linear collider. The CLIC study concentrated on a design of center-of-mass energy of 3 TeV and demonstrated the feasibility of the technology. However, the physics also demands lower energy collision. To satisfy this, CLIC can be built in stages. The actual stages will depend on LHC results. Some specific scenarios of staged constructions have been shown in CLIC Concept Design Report （CDR）. In this paper, we concentrate on the main linac lattice design for Ecm=l TeV CLIC aiming to upgrade from E~.,=500 GeV CLIC and then to Ecru=3 TeV one. This main linac accelerates the electron or positron beam froth 9 GeV to 500 GeV. A primary lattice design based on the 3 TeV CLIC main linac design and its optimization based on the beam dynamics study will be presented. As we use the same design principles as 3TeV CLIC main linac, this optimization is basically identical to the 3 TeV one. All the simulations results are obtained using the tracking code PLACET.

关键词： CLIC main linac lattice design beam dynamics

Why are Nitrogen Concentrations in Plant Tissues Lower under Elevated CO_2? A Critical Examination of the Hypotheses

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Journal of Integrative Plant Biology 2008年第11期50卷 1365-1374页

作者： daniel R. Taub Xianzhong Wang Biology Department and Environmental Studies Program Southwestern University Georgetown Texas 78626 USA Department of Biology Indiana University-Purdue University Indianapolis Indianapolis Indiana 46202 USA

Plants grown under elevated atmospheric [CO2] typically have decreased tissue concentrations of N compared with plants grown under current ambient [CO2]. The physiological mechanisms responsible for this phenomenon have not been definitely established, although a considerable number of hypotheses have been advanced to account for it. In this review we discuss and critically evaluate these hypotheses. One contributing factor to the decreases in tissue N concentrations clearly is dilution of N by increased photosynthetic assimilation of C. In addition, studies on intact plants show strong evidence for a general decrease in the specific uptake rates （uptake per unit mass or length of root） of N by roots under elevated CO2. This decreased root uptake appears likely to be the result both of decreased N demand by shoots and of decreased ability of the soil-root system to supply N. The best-supported mechanism for decreased N supply is a decrease in transpiration-driven mass flow of N in soils due to decreased stomatal conductance at elevated CO2, although some evidence suggests that altered root system architecture may also play a role. There is also limited evidence suggesting that under elevated CO2, plants may exhibit increased rates of N loss through volatilization and/or root exudation, further contributing to lowering tissue N concentrations.

关键词： carbon dioxide dilution elevated CO2 graphical vector analysis nitrogen plants root uptake tissue concentrations.