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11.
Yip Hing Lum Azizah Shaaban Nona Merry M. Mitan Mohd Fairuz Dimin Noraiham Mohamad Nadiah Hamid Sian Meng Se 《Journal of Polymers and the Environment》2013,21(4):1083-1087
The influence of the blending ratio of biodegradable starch/polyvinyl alcohol (PVA)/glycerol in encapsulating urea has been investigated. It is found that water absorption capacity increased approximately 135 % as the amounts of starch, PVA and glycerol in the composite film increase. Therefore, the swell ability of the composite film is increased and the urea is released from the composite film in the wet environment. The FTIR shows that the urea had been encapsulated successfully in the composite films. Moreover, the soil burial biodegradation results indicated that the biodegradability of the starch/PVA/glycerol/urea composite film strongly depended on the PVA proportion in the composite film matrix. The DSC results show that the higher the amount of PVA in the composite film, the less change of the melting enthalpy value. The crystalline region of PVA remains after biodegradation. 相似文献
12.
Arsenic and copper stabilisation in a contaminated soil by coal fly ash and green waste compost 总被引:1,自引:0,他引:1
Daniel C. W. Tsang Alex C. K. Yip William E. Olds Paul A. Weber 《Environmental science and pollution research international》2014,21(17):10194-10204
In situ metal stabilisation by amendments has been demonstrated as an appealing low-cost remediation strategy for contaminated soil. This study investigated the short-term leaching behaviour and long-term stability of As and Cu in soil amended with coal fly ash and/or green waste compost. Locally abundant inorganic (limestone and bentonite) and carbonaceous (lignite) resources were also studied for comparison. Column leaching experiments revealed that coal fly ash outperformed limestone and bentonite amendments for As stabilisation. It also maintained the As stability under continuous leaching of acidic solution, which was potentially attributed to high-affinity adsorption, co-precipitation, and pozzolanic reaction of coal fly ash. However, Cu leaching in the column experiments could not be mitigated by any of these inorganic amendments, suggesting the need for co-addition of carbonaceous materials that provides strong chelation with oxygen-containing functional groups for Cu stabilisation. Green waste compost suppressed the Cu leaching more effectively than lignite due to the difference in chemical composition and dissolved organic matter. After 9-month soil incubation, coal fly ash was able to minimise the concentrations of As and Cu in the soil solution without the addition of carbonaceous materials. Nevertheless, leachability tests suggested that the provision of green waste compost and lignite augmented the simultaneous reduction of As and Cu leachability in a fairly aggressive leaching environment. These results highlight the importance of assessing stability and remobilisation of sequestered metals under varying environmental conditions for ensuring a plausible and enduring soil stabilisation. 相似文献
13.
A laboratory scale two-stage sequencing batch reactor (TSSBR) was used to study the effectiveness of pH as a real-time control parameter in swine wastewater treatment. A Ringlace media was inserted into the A/O (Anoxic/Oxic) reactor for bacteria immobilization. The TSSBR was subjected to three levels of organic loading. The pH and ORP (Oxidation Reduction Potential) patterns obtained were consistent with distinct features, enabling the real-time control strategy to effectively set a flexible aeration time pending on influent concentration, hence resulting in flexible cycle time and HRT (Hydraulic Retention Time) for the system. The real-time process ensured a removal efficiency of over 99% and 95%, respectively, for ammonia and TOC (Total Organic Carbon). For NO3(-)-N and PO4(-3), the run with influent TOC = 4,000 mg/L yielded the most efficient removal of 61% and 95%, respectively. Test results suggest that pH can be a viable tool for on-line real-time control of a biological treatment process. 相似文献
14.
Removal process estimation of population size for a population with a known sex ratio 总被引:2,自引:0,他引:2
A removal model for estimating population size which uses the known population sex ratio is studied. A maximum likelihood estimate and an optimal martingale estimate of the population size are proposed. Their standard errors and large sample properties are obtained. Simulation studies are reported, and the performance of the proposed estimators are compared with the standard maximum likelihood estimator which ignores the sex ratio information. An example on a capture study of deer mice is given. 相似文献
15.
Wang Jian Meng Qingyue Winnie Yip Sun Qiang Qu Jiangbin Jia Liying 《中国人口.资源与环境(英文版)》2013,11(1):81-87
Abstract The objective of social development is to construct a harmonious society. In China, the key to a harmonious society is the happiness of more than 900 million farmers living in the rural areas. This study aimed to measure rural residents’ subjective well-being (SWB) through the day reconstruction method, as well as to analyze SWB’s influencing factors through a variety of statistical methods. The results showed that the average U index was 12.79%, indicating that respondents were unhappy 12.79% of the time. Twenty-seven percent of the population had a U index greater than 0, with the average value being 47%, indicating that these people were unhappy 47% of the time. The study also found that SWB varied according to the characteristics of the respondents. Logistic regression analysis showed that social and demographic factors, including age, education, county, household size, generation number, per capita income, migration status and social networking, which significantly affected rural residents’ SWB. The size of the impact varied with the different factors. 相似文献
16.
For animals living in natural or semi-natural settings, empirical data on how sociality changes in response to increasing population density are few, especially with respect to true conspecific density and not group size. However, insight into this line of research may be far-reaching--from understanding density dependence in sexual selection to improving models of disease transmission. Using elk (Cervus elaphus Linnaeus) held in enclosures, we conducted sex-stratified experiments to test how the frequency of dyadic pairings (interaction rate) and their quality (duration) responded to manipulations in exposure to density. Using proximity-logging radio collars we recorded when and for how long individuals shared a space within 1.4 m of each other. As predicted, males increased their interaction rate as density increased. Female interaction rates, however, increased initially as density increased but soon declined to become indistinguishable from rates at low density. Females interacted for longer periods at medium densities, whereas male interaction length clearly decreased as density increased. We highlight a sexually dichotomous, density-dependent response in sociality that has yet to be reported. In addition to furthering our understanding of sociobiology (e.g., implications of time constraints presented by density on dyadic interactions), our results have implications for managing communicable disease in gregarious species of livestock and wildlife. 相似文献
17.
-PbO2 electrodes were prepared by electro-deposition and characterized by scanning electron microscopy, X-ray diffraction, X-ray
photoelectron spectroscopy, and linear sweep voltammetry. We confirmed pure -PbO2 crystals were on the electrode and it had a high
oxygen evolution potential. The photoactivity and photoelectrochemical (PEC) properties of the -PbO2 electrode were investigated
under visible light irradiation ( > 420 nm) for the decolorization of Methylene Blue. Pseudo first-order kinetics parameter (Kapp) for
dye decolorization using the -PbO2 electrode achieved 6.71×10?4 min?1 under visible light irradiation, which indicated its excellent
visible light-induced photoactivity. The Kapp of the PEC process was as much as 1.41×10?3 min?1 and was 1.71 times that of visible light
irradiation or electrolysis even in the presence of the -PbO2 electrode. A significant synergetic effect was observed in the PEC system.
We also employed TiO2 modified -PbO2 electrodes in this test, which revealed that the TiO2 immobilized on the -PbO2 electrode
inhibited the visible light-induced PEC efficiency despite the amount of TiO2 used for electrode preparation. The -PbO2 electrode was
also superior to the dimensionally stable anode (Ti/Ru0:3Ti0:7O2) in visible light-induced photoactivity and PEC efficiency. 相似文献
18.
Hanqing Fan Yuxuan Huang Ngai Yin Yip 《Frontiers of Environmental Science & Engineering》2023,17(2):25
19.
Winnie Yip 《中国人口.资源与环境(英文版)》2010,8(1):81-87
The objective of social development is to construct a harmonious society.In China,the key to a harmonious society is the happiness of more than 900 million farmers living in the rural areas.This study aimed to measure rural residents' subjective well-being(SWB) through the day reconstruction method,as well as to analyze SWB's influencing factors through a variety of statistical methods.The results showed that the average U index was 12.79%,indicating that respondents were unhappy 12.79% of the time.Twenty-seven percent of the population had a U index greater than 0,with the average value being 47%,indicating that these people were unhappy 47% of the time.The study also found that SWB varied according to the characteristics of the respondents.Logistic regression analysis showed that social and demographic factors,including age,education,county,household size,generation number,per capita income,migration status and social networking,which significantly affected rural residents' SWB.The size of the impact varied with the different factors. 相似文献
20.
Mick E. Hanley P. Y. S. Yip S. Hoggart D. T. Bilton S. D. Rundle R. C. Thompson 《Journal of Coastal Conservation》2013,17(4):799-803
Supra-tidal plant communities fulfil a vital role in coastal protection and conservation but despite an increased likelihood of salt-water inundation from storm surges, we understand remarkably little on how salinity affects habitats like coastal grasslands or their component species. We quantified the survival and growth of a common coastal grassland plant, Plantago lanceolata when exposed to short-duration (1-, 2-, 4-, or 8-h) immersion in sea water. We also calculated root:shoot ratios (R:SR) and specific leaf area (SLA) to examine how salinity stress affects above- and below-ground resource allocation patterns and likely interactions with other trophic levels. Immersion in sea water reduced Plantago survival particularly at longer durations of 4- and 8 h, and for surviving plants, growth was also much reduced. Contrary to studies with crop plants however, we found reduced allocation to root biomass (R:SR) and increased SLA. The fact that Plantago displayed opposite ecophysiological responses to those consistently reported in the literature highlights that the response of coastal grassland plants to storm surge events cannot be assumed from conventional wisdom. In order to better protect and conserve these internationally important ecosystems from the effects of anthropogenically induced sea-level rise, a systematic exploration of the effects of sea water flooding on coastal grasslands is required. 相似文献