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Numerical simulation of low-flow channel evolution due to sediment augmentation

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International Journal of Sediment Research 2012年第3期27卷 351-361页

作者： Hiroshi MIWA gary PARKER Department of Civil Engineering Maizuru National College of Technology Department of Civil and Environmental Engineering University of Illinois at Urbana-Champaign

For the conservation and restoration of river environment,a sediment replenishment technique, which conveys a part of the sediments excavated and/or dredged from reservoirs to the river below dams is developed and has been implemented tentatively in several *** placed as replenishment can be flushed out and transported downstream by floodwater or dam *** flushed sediments are expected to contribute to the control of degradation and the variation of the low-flow ***,this technique is in the development stage because there are many unknown ***,systematic investigations are necessary for practical management of the *** this study,the effects of the location of replenishment sediment on sediment flushing and on control of degradation were investigated by means of flume experiments.A two-dimensional numerical model was also developed to further investigate the effects of sediment augmentation on river *** numerical model treats bank erosion and sediment transport over fixed beds. The simulation results were verified against the experimental *** flushing process of replenishment sediment was investigated first,and then its effect as a countermeasure for river bed degradation was *** are summarized as follows:(1) Augmentation at upper riffles is effective for flushing of replenishment sediment and variation of low-flow channel.(2) Amelioration of degradation can be found in the cases of two types of *** amelioration effect of upper riffle placement was larger than that of lower riffle placement(3) Aggradation rate of the bed near the replenishment site in the fixed bed is large in the lower riffle placement compared with the upper riffle placement.(4) The numerical model was found to be generally successful as a predictive tool.

关键词： River restoration Low-flow channel Degradation Sediment replenishment Numerical simulation

Low power 3.1–10.6 GHz IR-UWB transmitter for Gbps wireless communications

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Science China(Information Sciences) 2011年第5期54卷 1094-1102页

作者： WANG Albert ZHANG gary Department of Electrical Engineering University of California Riverside 92521 USA Skyworks Solutions Inc. Irvine CA USA

This paper reviews and discusses the design of a low-power single-full-band (3.1-10.6 GHz) non- carrier impulse-radio ultra wideband (UWB) transmitter featuring 5th-order Gaussian derivative pulse shaping, integrated BPSK modulation, and 2.5 kV whole-chip ESD (electrostatic discharge) protection. The UWB transmitter design has been implemented in a commercial 0.18 μm CMOS technology with a very small die size of 0.25 mm2. The fabricated chips have demonstrated full functionality, extremely low power consumption of 0.14 pJ/p-mV, and an ultra short pulse width of 394 ps. This ESD-protected UWB transmitter has the potential to support wireless streaming to gigabit per second (Gbps).

关键词： UWB impulse radio BPSK transmitter ESD protection

Spermatids do it differently! Paip2a--the essential regulator of spermiogenesis？

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Asian Journal of Andrology 2011年第1期13卷 122-124页

作者： Eileen A McLaughlin gary R Hime ARC Centre of Excellence in Biotechnology and Development Callaghan NSW 2308 Australia School of Environmental and Life Sciences University of Newcastle Callaghan NSW 2308 Australia Anatomy and Cell Biology University of Melbourne Parkville VIC 3010 Australia

The mechanisms underpinning the latter stages of spermiogenesis are poorly understood and male germ cells have been presumed to extensively employ post-tran- scriptional regulatory machinery,

关键词： .Spermatids Paip translational activation RNA-binding

Interfacial Strategies for Smart Slippery Surfaces

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Journal of Bionic Engineering 2020年第4期17卷 633-643页

作者： Glen McHale Rodrigo Ledesma-Aguilar gary George Wells Smart Materials&Surfaces Laboratory Faculty of Engineering and EnvironmentNorthumbria UniversityNewcastle upon TyneNE18STUK

The problem of contact line pinning on surfaces is pervasive and contributes to problems from ring stains to ice *** we provide a single conceptual framework for interfacial strategies encompassing five strategies for modifying the solid-liquid interface to remove pinning and increase droplet *** biomimetic strategies are included,(i)reducing the liquid-solid interfacial area inspired by the Lotus effect,(ii)converting the liquid-solid contact to a solid-solid contact by the formation of a liquid marble inspired by how galling aphids remove honeydew,and(iii)converting the liquid-solid interface to a liquid-lubricant contact by the use of a lubricant impregnated surface inspired by the Nepenthes Pitcher *** further strategies are,(iv)converting the liquid-solid contact to a liquid-vapor contact by using the Leidenfrost effect,and(v)converting the contact to a liquid-liquid-like contact using slippery omniphobic covalent attachment of a liquid-like coating(SOCAL).Using these approaches,we explain how surfaces can be designed to have smart functionality whilst retaining the mobility of contact lines and ***,we show how droplets can evaporate at constant contact angle,be positioned using a Cheerios effect,transported by boundary reconfiguration in an energy invariant manner,and drive the rotation of solid components in a Leidenfrost heat *** conceptual framework enables the rationale design of surfaces which are slippery to liquids and is relevant to a diverse range of applications.

关键词： superhydrophobicity SLIPS liquid marbles leidenfrost SOCAL

Endogenous testosterone and mortality risk

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Asian Journal of Andrology 2018年第2期20卷 115-119页

作者： Emily J Meye gary Wittert Endocrine Diabetes and Metabolic Unit Royal Adelaide Hospital Port Road SA 5000 Australia Discipline of Medicine University of Adelaide Adelaide SA 5000 Australia Discipline of Medicine and Freemasons Foundation Centre for Men's Health University of Adelaide SA 5000 Australia

In men, obesity and metabolic complications are associated with lower serum testosterone （T） and dihydrotestosterone （DHT） and an increased risk of, and mortality from, multiple chronic diseases in addition to cardiovascular disease （CVD）. The causal interrelationships between these factors remain a matter of debate. In men with untreated congenital and lifelong forms of hypogonadotropic hypogonadism, there appears to be no increased risk. Men with Klinefelter＇s syndrome have an increased risk of various types of cancers, as well as CVD, which persist despite T therapy. In the absence of pathology of the hypothalamic-pituitary- gonadal axis, the effect of modest reductions in serum T in aging men is unclear. The prevalence of low serum T concentrations is high in men with cancer, renal disease, and respiratory disease and is likely to be an indicator of severity of systemic disease, not hypogonadism. Some population-based studies have found low serum T to be associated with a higher risk of deaths attributed to cancer, renal disease, and respiratory disease, while others have not. Although a meta-analysis of longitudinal studies has shown an association between low serum T and all-cause mortality, marked heterogeneity between studies limited a firm conclusion. Therefore, while a decrease in T particularly occurring later in life may be associated with an increase in all-cause and specific types of mortality in men, the differential effects, if any, of T and other sex steroids as compared to health and lifestyle factors are unknown at the current time.

关键词： hypogonadism mortality testosterone

Topographic Influence on Wetland Distribution and Change in Maduo County, Qinghai-Tibet Plateau, China

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Journal of Mountain Science 2012年第3期9卷 362-371页

作者： Jay GAO LI Xilai gary BRIERLEY School of Environment University of Auckland lo Symonds Street Auckland New Zealand College of Agriculture andAnimal Husbandry Qinghai University Xining 810016 China

Accurate information on the spatial distribution and temporal change of wetlands is vital to devise effective measures for their protection. This study uses satellite images in 1994 and 2001 to assess the effects of topography and proximity to channels on wetland change in Maduo County on the Qinghai-Tibet Plateau, western China. In 1994 wetlands in the study area extended over 6,780.0 km2. They were distributed widely throughout the county, with a higher concentration in the south, and were especially prominent close to streams. The pattern of wetlands demonstrated a bell-shaped distribution curve with elevation, ranging over hill slopes with gradients from 0-19°, the commonest gradient being around 3°. Although the aspects of these hill slopes range over all directions, there is a lower concentration of wetlands facing east and southeast. The extent of wetlands in 2001 decreased to 6,181.1 km2. Marked spatial differentiation in the pattern of wetlands is evident, as their area increased by 1,193.3 km2 at lower elevations but decreased by 1,792.2 km2 at higher ground, resulting in a net decrease of 598.8 km2. In areas with a gradient 9° the area of wetlands remained approximately consistent from 1994-2001. Newly retained wetlands are situated in relatively flat lowland areas, with no evident preference in terms of aspect. Wetlands on north-, east- and northeast-facing hillslopes with a bearing of 1-86° were more prone to loss of area than other orientations. The altered pattern of wetland distribution from higher to lower elevation on north-facing slopes coincided with the doubling of annual temperature during the same period, suggesting that climate warming could be an important cause.

关键词： Wetland change detection Topographicinfluence Remote Sensing GIS Qinghai-TibetPlateau

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Biochar derived from papermill factories improves soil physical and hydraulic properties in no-till cotton fields

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Biochar 2023年第1期5卷 603-620页

作者： Yuanyuan Li gary Feng Haile Tewolde School of Agricultural Sciences Zhengzhou UniversityZhengzhou 450001China USDA-ARS Genetics and Sustainable Agriculture Research UnitMississippi StateMS 39762USA State Key Lab.of Soil Erosion and Dryland Farming On the Loess Plateau Institute of Soil and Water Conservation Northwest A&F Univ.Yangling 712100ShaanxiChina

Whether biochar produced as a by-product of energy generation from the papermill industry,and often disposed in landfills,can be gainfully applied to commercial croplands has not been *** objective of this study was to investigate the physical and hydraulic properties of soils in commercial cotton fields managed as no-till systems following repeated applications of biochar generated as a waste of a papermill *** cores and disturbed soil samples were collected from 0-5 and 5-10 cm layers from five commercial no-till fields in Mississippi,USA that received 6.7 Mg ha^(−1) year^(−1) biochar for 0,2,3,5 or 10 years.A number of physical,hydraulic,and chemical properties of these samples were measured in the *** results showed that biochar reduced the degree of soil compactness and increased soil aggregation and structural stability *** findings were particularly apparent for the 10 years of consecutive application,which increased soil aggregate stability by up to 67%,reduced bulk density from 1.40 to 1.26 g cm^(−3),and reduced degree of compactness from 73.2%to 62.8%.Biochar increased soil porosity but much of this increase(55%)occurred for small pores(50μm).Consequently,biochar increased soil field capacity by up to 26%,but PAW increased by only 17%.Biochar significantly increased soil physical quality index score in the 0-5 cm layer from 0.16 to 0.26 and the increase was positively correlated with the number of years of *** results suggest biochar generated as a byproduct of papermill could be land-applied in real-world crop production systems to improve soil health as an alternative to disposal in landfills.

关键词： Biochar Papermill Disposal Commercial no-till cotton field Plant available water Soil physical quality index(SPQI)

Priming of antiherbivore defensive responses in plants

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Insect Science 2013年第3期20卷 273-285页

作者： Jinwon Kim gary W. Felton Department of Entomology Pennsylvania State University University Park PA 16802 United States

Abstract Defense priming is defined as increased readiness of defense induction. A growing body of literature indicates that plants （or intact parts of a plant） are primed in anticipation of impending environmental stresses, both biotic and abiotic, and upon the following stimulus, induce defenses more quickly and strongly. For instance, some plants previously exposed to herbivore-inducible plant volatiles （HIPVs） from neighboring plants under herbivore attack show faster or stronger defense activation and enhanced insect resistance when challenged with secondary insect feeding. Research on priming of antiherbivore defense has been limited to the HIPV-mediated mechanism until recently, but significant advances were made in the past three years, including non-HIPV-mediated defense priming, epigenetic modifications as the molecular mechanism of priming, and others. It is timely to consider the advances in research on defense priming in the plant- insect interactions.

关键词： defense priming epigenetic modifications plant-insect interactions

Flood Resilience Building in Thailand: Assessing Progress and the Effect of Leadership

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International Journal of Disaster Risk Science 2018年第1期9卷 44-54页

作者： Somporn Khunwishit Chanisada Choosuk gary Webb Faculty of Management Sciences Prince of Songkla University Faculty of Environmental Management Prince of Songkla University Emergency Management and Disaster Science (EMDS)Department College of Health and Public Service University of North Texas

Disaster risk reduction has become a global strategy for making cities more resilient since the establishment of the Hyogo Framework for Action in 2005. The question that still challenges emergency management scholars and professionals, however, is what contributes to the progress of resilience building. Previous literature suggests that disaster resilience can be attributable to multiple factors, including leadership. But the specific abilities that help leaders promote resilience have not yet been examined empirically. To address this problem, using the United Nations International Strategy for Disaster Reduction 10 Essentials for Making Cities Resilient as guidelines, we assessed the progress of flood resilience building in Thailand and its relationship to local government leaders' abilities. Our research showed that, since the flood disaster in 2011, municipalities in Thailand have made moderate progress in flood resilience building. The results of a multiple regression analysis revealed that disaster resilience leadership abilities have had a statistically significant, positive effect on the progress of flood resilience building. Our findings underscore the role of leadership in making cities more resilient and shed light on how local government leaders can contribute to the progress ofdisaster risk reduction. We also outline the academic implications and practical contributions of our research.

关键词： Disaster management Disaster resilience leadership Disaster risk reduction Flood resilience building Thailand

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