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991.
建立我国海滩质量标准分级体系的探讨 总被引:1,自引:0,他引:1
在参考国内外主要海滩质量标准评价体系的基础上,论文根据我国海滩的具体状况,提出适合我国国情的海滩质量标准体系。标准体系包括自然和社会经济两类共54个因子,对不同开发程度的海滩实行不同的评分标准,最终将海滩分为钻石、金、银、铜及不及格5个等级。论文对山东和福建共6个不同开发程度(开发成熟,低度开发/未开发)的海滩进行了试点应用,结果表明,厦门黄厝得分最高,霞浦大京得分最低。同时解释所提出标准的适用性,并对海滩资源可持续开发利用提出管理对策。 相似文献
992.
We equipped individual tiger (Galeocerdo cuvier Péron and Lesueur, 1822) and Galapagos (Carcharhinus galapagensis Snodgrass and Heller, 1905) sharks with both acoustic and satellite transmitters to quantify their long-term movements in
the Papahanaumokuakea Marine National Monument (Northwestern Hawaiian Islands). Tiger sharks exhibited two broad patterns
of behavior. Some individuals were detected at French Frigate Shoals (FFS) year round, whereas others visited FFS atoll in
summer to forage on fledging albatross, then swam thousands of kilometers along the Hawaiian chain, or out into open ocean
to the North Pacific transition zone chlorophyll front, before returning to FFS in subsequent years. These patterns suggest
tiger sharks may use cognitive maps to navigate between distant foraging areas. Different patterns of spatial behavior may
arise because cognitive maps are built up through individual exploration, and each tiger shark learns a unique combination
of foraging sites. Galapagos shark detections were all associated with FFS, suggesting these sharks may be more resident around
oceanic islands. Both Galapagos and tiger sharks primarily used the mixed layer (<100 m depth) and made occasional deeper
dives through the thermocline down to 680 m. Results show reef-associated sharks utilize a wide variety of habitats ranging
from shallow atoll lagoons to deep reefs and open ocean and may provide important trophic links between these habitats. 相似文献
993.
Parrotfishes can be significant bioeroders and sediment producers on coral reefs. We quantified the bioerosion rates of two
similarly sized Hawaiian parrotfishes with two different feeding modes (Scarus rubroviolaceus—a scraper and Chlorurus perspicillatus—an excavator). The results showed that feeding modes did not affect bioerosion rates but that bioerosion rates were size
dependent, with largest individuals (S. rubroviolaceus 45–54 cm FL) bioeroding up to 380 ± 67 kg ind−1 year−1. The size for onset of bioerosion capabilities for both species was 15 cm. Grazing by the two species consumed 60% of the
carbonate production of the fore reef area, suggesting that large parrotfishes in Hawaii are ecologically important bioeroders.
As individual large S. rubroviolaceus contributed disproportionately more to bioerosion and sediment production than the equivalent biomass of smaller conspecifics,
management strategies designed to retain normal reef bioerosion rates should seek to preserve the historical size structure
of S. rubroviolaceus populations and to especially protect the larger size classes. 相似文献
994.
Arsenic (As) contamination has become a serious environmental problem in many countries. We have performed batch-type leaching
experiments on mine tailing soils collected from three abandoned mine areas in South Korea with the objective of evaluating
the effect of indigenous bacterial activity on As mobilization. The analysis of physicochemical properties and mineralogical
compositions of the samples indicated that the secondary minerals or phases formed as a result of the oxidation or alteration
of primary minerals were associated with the labile and bioleachable fractions of As. Compared to simulated abiotic processes
using sterilization, the indigenous bacteria activated using a carbon source were able to enhance the dissolution of As under
both aerobic and anaerobic conditions. The bacterial dissolution of iron (Fe) and manganese (Mn) was found to occur simultaneously
with the dissolution of As, suggesting that the main bacterial mechanism was via the dissimilatory reduction of Fe(III),
Mn(IV), and As(V). An anaerobic environment was more favorable for the prominent dissolution of As in the tailing soils. These
results indicate that the mobilization of As can be enhanced in the oxygen-depleted part of the tailing dump, particularly
with the infiltration of organic substrates. The difference in the degree of As lixiviation between the three tailing soils
was found to be related to the bioavailability of As as well as the original biomass in the tailing soils. 相似文献
995.
Anthropogenic influence on surface water quality of the Nhue and Day sub-river systems in Vietnam 总被引:2,自引:0,他引:2
Pham Thi Minh Hanh Suthipong Sthiannopkao Kyoung-Woong Kim Dang The Ba Nguyen Quang Hung 《Environmental geochemistry and health》2010,32(3):227-236
In order to investigate the temporal and spatial variations of 14 physical and chemical surface water parameters in the Nhue
and Day sub-river systems of Vietnam, surface water samples were taken from 43 sampling sites during the dry and rainy seasons
in 2007. The results were statistically examined by Mann–Whitney U-test and hierarchical cluster analysis. The results show that water quality of the Day River was significantly improved during
the rainy season while this was not the case of the Nhue River. However, the river water did not meet the Vietnamese surface
water quality standards for dissolved oxygen (DO), biological oxygen demand (BOD5), chemical oxygen demand (COD), nutrients, total coliform, and fecal coliform. This implies that the health of local communities
using untreated river water for drinking purposes as well as irrigation of vegetables may be at risk. Forty-three sampling
sites were grouped into four main clusters on the basis of water quality characteristics with particular reference to geographic
location and land use and revealed the contamination levels from anthropogenic sources. 相似文献
996.
The burrowing and movement ability of the New Zealand cockle Austrovenus stutchburyi is reduced when infected by echinostome trematodes. Previous experimental evidence from a single site suggests that this
parasite-induced behavioural change of a key bivalve can affect the structure of the surrounding benthic community. By using
multiple regression analyses on data collected from 17 intertidal flats, we here show that cockle parasitism is associated
with macrozoobenthic community structure on a larger spatial scale. Regressions were performed for animal abundance, biomass,
species diversity and species richness separately, entering cockle parasitism (infection intensity), presence/absence of ghost
shrimps (Callianassa filholi), cockle density, primary producer abundance and organic content, particle size, sorting coefficient and gravel content of
the substrate as predictors. Next to ghost shrimps, cockle parasitism was the best predictor of animal abundance by affecting
(mainly positively) 8 of the 49 most widespread species significantly. Cockle parasitism was also associated with the biomass
of anthozoans (positively), nemerteans (negatively) and bivalves (positively), whereas overall animal biomass was positively
related to the sorting coefficient of the substrate. Species diversity was positively associated with cockle parasitism and
gravel content of the substrate. Species richness was significantly associated with cockle parasitism (positively), ghost
shrimps (negatively) and abundance of primary producers (positively) in combination. The impact of cockle parasitism on benthic
community structure is believed governed directly or indirectly by (1) reduced sediment disturbance, (2) increased surface
structural complexity and (3) availability of larval trematodes as an additional food source. 相似文献
997.
Organic contaminated soils have become a widespread environmental problem, which may lead to a great threat to the quality of agricultural production and to human health. Physical, chemical, and biological technologies have been employed for the mitigation and remediation of organic contaminated soils. This paper reviews the progress of mitigation and remediation technologies for organic contaminated soils and suggests two different strategies for the mitigation of ’slightly-contaminated’ agricultural soils and the remediation of ‘heavily-contaminated’ soils/sites, respectively. On this basis, directions for future research in this field are suggested. 相似文献
998.
Kyung Soo Park Yu Chang Kim 《International journal of occupational safety and ergonomics》2013,19(3-4):119-128
Presses are very widely used in industrial and commercial companies and are often the source of serious accidents occurring during operation. Most of the accidents are due to inadequate training of novice operators. Continuous recordings of eye and hand movements of five novice operators and five experienced operators in press operation were made. Significant difference between novice and experienced operators was observed in eye fixation time, eye movement patterns, hand dwell time, and eye-hand coordination. Also, differences were observed in spatial distribution of eye fixations during the die-closing portion of a stroke. There were no significant differences between novice and experienced operators in the eye and the hand movement time. The results could be used as basic data to establish a guide determining the method and training period to train novice operators. 相似文献
999.
Kwang Seok Choi Tomofumi Mogami Teruo Suzuki Sung Chul Kim Mizuki Yamaguma 《Journal of Loss Prevention in the Process Industries》2013,26(1):255-260
As a method to prevent or mitigate electrostatic charge and/or discharges, we have developed a novel AC electrostatic ionizer. In this study, we evaluated experimentally the practical version of the novel AC electrostatic ionizer with a modeling test system and a pneumatic powder transport facility. In addition, electrostatic discharges generated inside a silo while loading polypropylene (PP, 3 mm) granules were observed visually with/without the novel AC ionizer. The specific charge was clearly decreased with the novel AC electrostatic ionizer. The specific charge obtained with the four arranged AC electrostatic ionizers used was approximately one eighth of that without the AC ionizer. The incendiary bulk surface discharges completely died out inside the silo by using the four arranged ionizers. 相似文献
1000.
Byung Kyu Kim Dedy Ng Ray A. Mentzer M. Sam Mannan 《Journal of Loss Prevention in the Process Industries》2013,26(6):1670-1678
Concerns over public safety and security of a potential liquefied natural gas (LNG) spill have promoted the need for continued improvement of safety measures for LNG facilities. The mitigation techniques have been recognized as one of the areas that require further investigation to determine the public safety impact of an LNG spill. Forced mitigation of LNG vapors using a water curtain system has been proven to be effective in reducing the vapor concentration by enhancing the dispersion. Currently, no engineering criteria for designing an effective water curtain system are available, mainly due to a lack of understanding of the complex droplet–vapor interaction. This work applies computational fluid dynamics (CFD) modeling to evaluate various key design parameters involved in the LNG forced mitigation using an upwards-oriented full-cone water spray. An LNG forced dispersion model based on a Eulerian–Lagrangian approach was applied to solve the physical interactions of the droplet–vapor system by taking into account the various effects of the droplets (discrete phase) on the air–vapor mixture (continuous phase). The effects of different droplet sizes, droplet temperatures, air entrainment rates, and installation configurations of water spray applications on LNG vapor behavior are investigated. Finally, the potential of applying CFD modeling in providing guidance for setting up the design criteria for an effective forced mitigation system as an integrated safety element for LNG facilities is discussed. 相似文献