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11.
杭州市医院固体废物现状调查与处置对策 总被引:1,自引:0,他引:1
通过对抗州城区69家医院1999—2001年固体废物的来源、种类、产生量及处置现状的调查研究,分析了医院固体废物在收集、处置过程中存在的问题,提出了相应的对策。 相似文献
12.
沈阳市环保产业现状及发展对策探讨 总被引:1,自引:0,他引:1
主要通过对沈阳市环保产业的现状和存在的问题进行了阐述,对沈阳市环保产业如何走向快速、稳定、健康的发展轨道,提出了沈阳市环保产业发展对策。 相似文献
13.
Food access, brood size and filial cannibalism in the fantail darter, Etheostoma flabellare 总被引:4,自引:0,他引:4
We compared the occurrence of filial cannibalism in fed and starved male fantail darters (Etheostoma flabellare). All males in the experiment consumed eggs, and 56% ate all of their eggs. A male's initial body condition did not explain
the number of eggs that he ate. Neither did non-fed males eat more eggs than fed males. Fed males were able to maintain better
body condition during the experiment, but the change in body condition also depended on the number of eggs eaten. Thus, males
who ate more eggs were able to maintain better body condition.The most important determinant of whether or not a male ate
all of his eggs was his initial egg number. Males with small egg masses ate all of their eggs whereas males with large egg
masses were only partial cannibals. There was, however, no difference in the total number of eggs eaten by total and partial
cannibals. We conclude that eggs are only partially eaten for energetic reasons. We also suggest that small egg masses are
completely consumed because the costs of caring for a small egg mass may exceed the expected reproductive benefits of a small
egg mass.
Received: 26 January 1996 / Accepted after revision: 2 November 1996 相似文献
14.
Pillar building in the fiddler crab Uca beebei: evidence for a condition-dependent ornament 总被引:2,自引:0,他引:2
Patricia R.Y. Backwell Michael D. Jennions John H. Christy Ursula Schober 《Behavioral ecology and sociobiology》1995,36(3):185-192
In the fiddler crab (Uca beebei) males build a small mud pillar next to their burrow which increases their attractiveness to females. Three hypotheses were tested to explain inter-male variation in pillar-building. (1) The benefits of pillar-building are density dependent. The experimental addition of vertical structures did not support this hypothesis as there was no change in the level of pillar-building. (2) There are two classes of males (pillar-builders and non-pillar-builders). This could either be due to an alternative mating strategy, or because pillar building is age or size-dependent. There was also no support for this hypothesis. (3) Pillar-building is an honest signal of male quality dependent on body condition. A food supplementation experiment was performed. Addition of food affected several aspects of male behaviour and resulted in a two fold increase in the number of pillars built between control and food treatments (P < 0.001). However, the percentage of males building pillars did not increase significantly. Pillar building in this species has been attributed to sensory exploitation. Our results indicate that a trait which may well have evolved through sensory exploitation also appears to be condition-dependent. We emphasise that showing that an ornament or behaviour is condition-dependent does not necessarily mean that it evolved through good gene processes. However, in terms of its current selective value, pillar building may be maintained through female choice because it acts as a signal of male condition. 相似文献
15.
Polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) are organic contaminants that tend to accumulate in fish. Estuaries are exposed to high anthropogenic activities, therefore tending to accumulate more contaminants than the adjacent coastal waters. Platichthys flesus, a fish with high economic value, was analysed for PCBs and HCB along its different age groups, in liver, gills, gonads and muscle. Younger fishes were caught in the estuary, whereas older fishes were caught in the adjacent coastal waters and acquired at Figueira da Foz Regional Office of Docapesca-Portos e Lotas, SA. Both contaminants concentrations follow the pattern: liver > gills > muscle. Hepatosomatic index had the lowest values in younger fishes and the highest values in older fishes. Condition factor values remain stable with age. Younger fishes had higher PCBs concentrations than the older fishes. In opposition HCB was only detected in fish from 3+ to 5+ and its concentration tended to increase with age. Overall P. flesus is considered safe for human intake. 相似文献
16.
Heidi Van den Broeck Hans De Wolf Ronny Blust 《Environmental pollution (Barking, Essex : 1987)》2010,158(5):1791-1799
Metal (i.e. Ag, As, Ca, Cd, Co, Cu, Mn, Pb and Zn) and metallothionein (MT) concentrations in the soft tissue of Littorina littorea were measured along the heavily polluted Western Scheldt (WS) and relatively clean Eastern Scheldt (ES) estuary. Along the WS metal and MT levels in periwinkles reflected the known downstream decreasing pollution gradient. Surprisingly in ES animals As, Mn and Zn concentrations decreased from east to west reflecting past pollution. Compared to the WS metal concentrations of ES periwinkles were significantly lower and both estuaries were maximally discriminated from each other based on their Cd soft tissue concentration using a canonical discriminant analysis. Furthermore, no overall difference was found in MT levels among animals from both estuaries. Using previously obtained condition data (i.e. dry/wet weight ratio and lipid content) the relation between soft tissue metal concentration (i.e. Cd, Cu and Zn) and fitness indicators (i.e. MT and condition data) was examined using a canonical correlation analysis. Periwinkles with a high metal load (i.e. Cd and Zn) also had high MT levels but were in a relatively poor condition. 相似文献
17.
通过文献调研和数据搜集构建高碑店污水处理厂的基本信息库,利用GF-1/GF-2等高分辨率卫星遥感数据对2015年高碑店污水处理厂的运行状况进行动态监测。结果表明:GF-1号影像显示2015年2月16日和3月25日污水处理厂均有1个二沉池有藻类分布,疑似未正常投入使用;GF-2号影像显示9月2日污水处理厂有5个二沉池和部分曝气池的廊道有藻类分布,疑似未正常投入使用;3月和9月数据对比发现,西侧的8个污泥消化罐和3个污泥浓缩池均消失。该结果与临近时期的Google Earth影像显示情况相一致。 相似文献
18.
S. B. Kendie 《Environmental management》1996,20(1):1-10
In the examination of the implementation of rural drinking water facilities, not enough attention has been paid to analyzing
the socioeconomic and political relationships that affect the effective utilization of the facilities, particularly as these
relate to women in rural society. This paper suggests that much of the difficulty in instituting the utilization of safe water
supply sources has to do with the rather low economic status of women—the main water collectors. Poverty consigns women to
long periods of work in activities or jobs that bring little reward. This makes it difficult to effectively digest the messages
delivered by program staff and limits the extent of usage of the safe water facilities. 相似文献
19.
本文扼要记述了陕西1950~1992年重大地质(崩塌、滑坡、泥石流)灾害及发生年代、地点、灾情,为本区国土整治、区域开发提供了基础资料。 相似文献
20.
Tae Won Kim Kotaro Sakamoto Yasuhisa Henmi Jae C. Choe 《Behavioral ecology and sociobiology》2008,62(7):1139-1147
For males, courting and foraging are often behavioral alternatives, which take time and consume energy. When males have a
possibility of mating with receptive females, there may be a behavioral trade-off between courtship and feeding; the outcome
of which may be affected by male physiological condition and food availability. Although many mathematical models and empirical
studies suggest that the expression of male courtship signals are condition-dependent, decisions about courtship and mating
strategies in relation to food availability have not attracted much attention. In this study, we tested whether daily changes
in food availability affect males’ decisions about whether to court. We conducted experiments with the fiddler crab Uca lactea by providing males with additional food every other day. In food-supplemented enclosures, males did not increase courtship
activity on the days when food was supplemented. However, they built more courtship structures (semidomes) and waved more
on the days when they were not given additional food. Male size had a strong influence on the number of days the males courted.
We also tested whether the frequency of surface mating, as an alternative reproductive tactic, decreased when food was supplemented.
Contrary to our expectation, the number of males that exhibited the surface-mating tactic increased when food was supplemented
whereas the number of mate-searching females did not change. Our findings in this field study suggest that reproductive decisions
by male fiddler crabs are affected by fluctuating food availability and present body condition, and the alternative mating
tactic of this species may be more frequently used by males under good condition. 相似文献