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981.
Variation in reproductive potential usually occurs among individuals of both sexes; for example, some individuals may carry
more gametes or be able to continue to generate more gametes in their reproductive life than others. Therefore, to maximize
their reproductive success, both sexes are expected to show adaptations for mate choice. However, most authors concentrated
on how females choose their mates with the belief that females invest more in reproduction than males, and males are generally
eager to pair with any female. In this paper, we report our work on a polygamous moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), with special emphasis on male pre- and in-copulation mate choice in relation to the reproductive
quality and re-copulation potential of females. We show that in E. kuehniella, younger and heavier females have significantly higher reproductive value than older and lighter ones, and male sperm supply
significantly decreases over successive copulations. Males exercise pre-copulation mate choice by selecting females with higher
reproductive potential for copulation and in-copulation mate choice by allocating more sperm to females with higher reproductive
potential. However, high-quality females are more likely to re-copulate than low-quality ones, and allocation of more sperm
to females by males does not increase female reproductive outputs. It is suggested that the allocation of more sperm to high-quality
females functions to increase sperm competitiveness against rivals. 相似文献
982.
Zhou Yongchao Zhang Ping Zhang Yiping Li Jin Zhang Tuqiao Yu Tingchao 《Environmental science and pollution research international》2017,24(29):23133-23143
Environmental Science and Pollution Research - Sewer sediments and their associated contaminant released along with wet-weather discharges pose potential pollution risks to environment. This paper... 相似文献
983.
Shishir Kumar Behera Jun Mo Park Kyeong Ho Kim Hung-Suck Park 《Waste management (New York, N.Y.)》2010,30(8-9):1502-1508
Due to the prohibition of food waste landfilling in Korea from 2005 and the subsequent ban on the marine disposal of organic sludge, including leachate generated from food waste recycling facilities from 2012, it is urgent to develop an innovative and sustainable disposal strategy that is eco-friendly, yet economically beneficial. In this study, methane production from food waste leachate (FWL) in landfill sites with landfill gas recovery facilities was evaluated in simulated landfill reactors (lysimeters) for a period of 90 d with four different inoculum–substrate ratios (ISRs) on volatile solid (VS) basis. Simultaneous biochemical methane potential batch experiments were also conducted at the same ISRs for 30 d to compare CH4 yield obtained from lysimeter studies. Under the experimental conditions, a maximum CH4 yield of 0.272 and 0.294 L/g VS was obtained in the batch and lysimeter studies, respectively, at ISR of 1:1. The biodegradability of FWL in batch and lysimeter experiments at ISR of 1:1 was 64% and 69%, respectively. The calculated data using the modified Gompertz equation for the cumulative CH4 production showed good agreement with the experimental result obtained from lysimeter study. Based on the results obtained from this study, field-scale pilot test is required to re-evaluate the existing sanitary landfills with efficient leachate collection and gas recovery facilities as engineered bioreactors to treat non-hazardous liquid organic wastes for energy recovery with optimum utilization of facilities. 相似文献
984.
Chul H. Song Mi E. Park En J. Lee Jae H. Lee Bo K. Lee Dong S. Lee Jhoon Kim Jin S. Han Kwang J. Moon Yutaka Kondo 《Atmospheric environment (Oxford, England : 1994)》2009,43(13):2168-2173
Simultaneous measurements of gaseous species and fine-mode, particulate inorganic components were performed at the University of Seoul, Seoul in Korea. In the simultaneous measurements, a certain level of nitrous acid (HONO) was observed in the gas-phase, indicating possible heterogeneous HONO production on the surface of the ambient aerosols. On the other hand, high particulate nitrite (NO2?) concentrations of 1.41(±2.26) μg/m3 were also measured, which sometimes reached 18.54 μg/m3. In contrast, low HONO-to-NO2 ratios of 0.007(±0.006) were observed in Seoul. This indicates that a significant fraction of HONO is dissolved in atmospheric aerosols. Around the Seoul site, sufficient alkalinity may have been provided to the atmospheric aerosols from the excessive presence of NH3 in the gas-phase. Due to the alkaline particulate conditions (defined in this study as a particle pH >~3.29), the HONO molecules produced at the surface of the atmospheric aerosols appeared to have been converted into particulate nitrite, thereby preventing their further participation in the atmospheric O3/NOy/HOx photochemical cycles. It was estimated that a minimum average of 65% of HONO was captured by alkaline, anthropogenic, urban particles in the Seoul measurements. 相似文献
985.
Drowsiness has been recognized as a pervasive problem for drivers, with effects comparable to alcohol. Alcohol, however, has a clear legal limit for impairment; there are no comparable criteria to suggest sleepiness. Drowsiness has been associated with light and circadian rhythm. To investigate the joint effects of these factors on crash occurrence, along with other factors, single vehicle crashes reported in Ontario (1999–2004) were analyzed. Crashes occurring at four times of day, when light varies and circadian rhythm is low (2–5 a.m. and 2–4 p.m.) and with similar light conditions and higher circadian rhythm (9–11 p.m. and 10 a.m.–12 noon). Logistic regression was used to see how light and other factors are associated with single vehicle crashes occurring at times of low circadian rhythm, when drowsiness is more likely.Initial results indicated many circumstances associated with occurrence at these times: the age and sex of the driver and reported driver condition as well as weather. There is, however, an interaction between light and presumed alertness. In separate analyses for daytime and night time crashes most variables were significant for nighttime crashes but not for daytime events. The effects of alcohol and youth remained. A lack of light may exacerbate the effects of other factors at times of low alertness; this should be further investigated in controlled environments such as sleep laboratories and/or driving simulators. 相似文献
986.
Seungmoon Lee Seung-Kwun Yoo Jaehoon Lee Jin-Won Park 《Journal of Material Cycles and Waste Management》2009,11(3):191-196
In this study, experimental conditions were optimized to maximize the production of hydrogen gas from refuse plastic fuel
(RPF) by pyrolysis and steam gasification processes conducted in a laboratory-scale reactor. We carried out gasification using
10-g RPF samples at different temperatures (700°-1000°C) with and without steam. The effect of the amount of steam (0–0.25
g/min) for RPF steam gasification was also studied. The effect of K2CO3 as a catalyst on these processes was also investigated. Experimental results showed that the hydrogen gas yield increased
with temperature; with respect to the gas composition, the hydrogen content increased mainly at the expense of other gaseous
compounds, which highlights the major extension of secondary cracking reactions in the gaseous fraction at higher temperatures. 相似文献
987.
Young M. Noh Detlef Müller Dong H. Shin Hanlim Lee Jin S. Jung Kwon H. Lee Maureen Cribb Zhanqing Li Young J. Kim 《Atmospheric environment (Oxford, England : 1994)》2009,43(4):879-888
Aerosol optical and microphysical parameters from severe haze events observed in October 2005 at Gwangju, Korea (35.10°N, 126.53°E) were determined from the ground using a multi-wavelength Raman lidar, a sunphotometer, and a real-time carbon particle analyzer and from space using satellite retrievals. Two different aerosol types were identified based on the variability of optical characteristics for different air mass conditions. Retrievals of microphysical properties of the haze from the Raman lidar indicated distinct light-absorbing characteristics for different haze aerosols originating from eastern and northern China (haze) and eastern Siberia (forest-fire smoke). The haze transported from the west showed moderately higher absorbing characteristics (SSA = 0.90 ± 0.03, 532 nm) than from the northern direction (SSA = 0.96 ± 0.02). The organic/elemental carbon (OC/EC) ratio varied between 2.5 ± 0.4 and 4.1 ± 0.7. 相似文献
988.
Jin Ma Li-bo Pan Qin Wang Chun-ye Lin Xiao-li Duan Hong Hou 《Environmental geochemistry and health》2018,40(1):295-301
A total of 60 children (31 males and 29 females) between the ages of 3 and 12 years were randomly selected from Lanzhou City in Gansu Province, northwest China. Hand (soil/dust) SD samples from these children were collected using hand wipes. We determined the approximate amounts of hand SD and the concentrations of three tracer soil elements (Ce, Y, and V) in these samples. The approximate amounts of hand SD ranged from 42.28 to 173.76 mg, with a median value of 85.42 mg. In addition, the mean amounts of hand SD estimated using the concentrations of Ce, Y, and V in the samples were 4.63, 3.43, and 3.42 mg, respectively. The amount of hand SD varied greatly among the age groups: primary school children had more hand SD than kindergarten children, males had more hand SD than females, and children from rural areas had more hand SD than those from urban areas. The rates of daily ingestion of hand SD for kindergarten and primary school children were estimated to be 7.73 and 6.61 mg/day, respectively. 相似文献
989.
990.
起重机械作业人员职业适性检测指标研究 总被引:5,自引:1,他引:4
采用Delphi法对起重机械作业人员职业适性指标进行了研究。咨询专家就各备择指标对工作重要性及发生事故的关系进行了评估。结果表明:专家积极程度与意见集中程度良好;事故重要性与工作重要性排序一致性良好,两者呈高度正相关。依据专家对“重要性”的排序,再通过专家会议与现场考证等方法,最终确定了起重机械作业人员职业适性检测指标体系。 相似文献