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71.
利用质量平衡方程建立了一次回风定风量系统室内PM2.5浓度模型,并对新风PM2.5浓度、新风量、室内污染源、过滤器效率、过滤器安装位置等因素对室内PM2.5浓度的影响进行了模拟分析。模拟结果表明:新风PM2.5浓度和室内污染源强度的变化对室内PM2.5浓度均有较大影响;新风量越大,室内PM2.5浓度受新风PM2.5浓度变化的影响越大;将过滤器分别安装在送风段、新风段和回风段,新风比为0.1时,过滤器安装在送风段效果最好,安装在新风段最差,新风比为0.8时,过滤器安装在送风段效果最好,安装在回风段最差;过滤器安装在送风段时,过滤器效率越高,室内PM2.5浓度越低,波动越小。 相似文献
72.
中国内河船舶大气防污染对策及运力结构改善对沿岸港口大气环境质量的影响 总被引:5,自引:0,他引:5
针对IMO防止船舶大气污染的国际公约及中国内河船舶大气污染防治历史与现状,结合西部大开发及中国内河航运的发展规划,对内河船舶大气污染的防治对策、主任任务及措施实施后对沿线主要港口城市大气环境质量的影响进行了研究和探讨,在此基础上提出了中国内河船舶未来一段时期大气污染防治的根本思路与战略。 相似文献
73.
中国南方喀斯特地区面积大,自然资源丰富,生态环境脆弱,在世界喀斯特地区中极具代表性。文章依据中国南方喀斯特地区独特的自然特征和社会、经济功能,借助申报自然遗产机遇,为实现该区人口、资源、环境与社会的可持续发展,提出了一系列针对中国南方喀斯特地区的保护策略及措施。 相似文献
74.
本文详细的论述了地震灾害效应,并给出了地震灾害防御对策的准确概念。在总结中国近二十年地震灾害防御对策的基础上,给出了今后我国地震灾害防御对策的发展趋势,对于我国今后开展震害防御工作具有一定意义。 相似文献
75.
Dhazn Gillig Bruce A. McCarl Ronald D. Sands 《Mitigation and Adaptation Strategies for Global Change》2004,9(3):241-259
An econometrically estimated family ofresponse functions is developed forcharacterizing potential responses togreenhouse gas mitigation policies by theagriculture and forestry sectors in theU.S. The response functions are estimatedbased on results of anagricultural/forestry sector model. Theyprovide estimates of sequestration andemission reductions in forestry andagriculture along with levels of sectoralproduction, prices, welfare, andenvironmental attributes given a carbonprice, levels of demand for agriculturalgoods, and the energy price. Sixalternative mitigation policiesrepresenting types of greenhouse gasoffsets allowed are considered. Resultsindicate that the largest quantity ofgreenhouse gas offset consistently appearswith the mitigation policy that pays forall opportunities. Restricting carbonpayments (emission tax or sequestrationsubsidy) only to aff/deforestation or onlyto agricultural sequestration substantiallyreduces potential mitigation. Highercarbon prices lead to more sequestration,less emissions, reduced consumer and totalwelfare, improved environmental indicatorsand increased producer welfare. 相似文献
76.
J. Martín L. de Neve V. Polo J. A. Fargallo M. Soler 《Behavioral ecology and sociobiology》2006,60(6):778-784
Predators may select more often to attack the more vulnerable prey or those with an inferior health status. Thus, prey should be able to assess their own vulnerability to predation and modify their antipredatory behavior accordingly. When approached by predator skuas, unguarded penguin chicks flee short distances, and usually aggregate in dense packs, but there is a clear interindividual variability in their responses under similar conditions. We hypothesized that this variability in escape responses might be related to the perceived vulnerability to predation of each individual chick. We simulated predator attacks to chinstrap penguin chicks and analyzed the sources of variation in their escape response, such as the presence of adults or the density of other chicks, and the sex, age, body condition, and health status of responding chicks. Chicks allowed shorter approach distances when they had a better health condition (i.e., a greater T-cell-mediated immunity, CMI), when they were younger, and when the density of adults around was higher. Sex and density of other chicks were not important. Similarly, chicks fled from the experimenter to longer distances when they had a lower CMI and when the density of adults was lower. Therefore, escape characteristics of chicks depended on the presence of adults that can deter predators and on the health-dependent vulnerability of chicks. 相似文献
77.
Tamara Fraizer 《Behavioral ecology and sociobiology》1997,41(6):423-434
I develop a state-based dynamic model of behavior to demonstrate that size-dependent differences in temperature tolerances
are not necessary to account for the activity of small male digger wasps late in the day. In the model, males defend or patrol
the nesting area, wait near nests, or feed away from the nesting area depending on time of day, energy reserves and size rank.
I assume a large male competitive advantage, so mating opportunities decrease with size rank for territorial or patrolling
males and are rare for all waiting males; the costs of patrolling or defense are higher than the costs of waiting. If energy
reserves of all males are initially small, all males alternate feeding and territorial or patrolling behavior. If energy reserves
are initially large, large males patrol or maintain territories until they risk starvation and leave the area to feed. At
this time, smaller males that have conserved their resources by waiting and feeding may defend territories or patrol. I simulate
the behavior of three populations representing two species of Microbembex by assuming large initial energy reserves for populations in which males were territorial and small initial reserves for
populations in which males patrolled, and then convert the predicted time of activity to temperature using local regressions
from field studies. Temporal patterns in the activity of large and small males were similar to those actually observed, and
relationships between size and temperature predicted by the model corresponded to most observations and were sometimes positive.
Thus, the delayed activity of smaller males does not correspond to activity at higher temperatures and is probably not attributable
to size-dependent thermal tolerances, but may represent a temporal displacement of mating activity due to intra-sexual competition
and mediated by energetics. The model makes testable predictions on the timing of feeding and depletion of energy reserves
in relation to size and initial energy state, and suggests how differences among species may influence the temporal and spatial
organization of male mating behavior.
Received: 27 February 1997 / Accepted after revision: 26 July 1997 相似文献
78.
Aneil F. Agrawal Nicole Combs Edmund D. Brodie III 《Behavioral ecology and sociobiology》2005,57(6):566-574
The evolution of life history characters, including parental care behaviors, depends on costs and benefits. When offspring can influence parental behaviors, parent-offspring conflict over parental care can occur, but only if these parental behaviors are costly. Mother burrower bugs (Sehirus cinctus) exhibit extended and complex care of offspring. Mothers guard eggs until hatching and then attend and provision offspring for approximately 2 weeks after hatching. Using four experimental treatments, we attempted to identify the costs associated with specific components of these behaviors. Under laboratory conditions, egg guarding increases inter-clutch interval, but provisioning does not appear to be very costly. We discuss additional ecological factors that may be important in mediating provisioning costs under natural conditions. Through analysis of individual maternal performance, we find no evidence for trade-offs between successive clutches. These data suggest that variation in overall condition may obscure variation in allocation strategies.Communicated by F. Trillmich 相似文献
79.
J.?MartínEmail author P.?López W.?E.?CooperJr. 《Behavioral ecology and sociobiology》2003,54(5):505-510
Because time spent in refuge may be costly if prey lose opportunities to forage, fight, or mate, prey allow predators to approach closer before beginning to flee when opportunity costs are high. Because the same opportunity costs may apply to refuge use as to escape, prey should make similar trade-offs between risk of emerging and cost of remaining in refuge. In the Iberian rock lizard, Lacerta monticola, we studied the effects of sex, reproductive season, speed of predator approach, and potential loss of mating opportunities on time spent in refuge following simulated predatory attacks. Lizards of both sexes adjusted refuge use to the level of risk by spending more time in refuge when approached rapidly than slowly. Females remained in refuge for equal times in the mating and postreproductive seasons, but males emerged sooner during the mating season, suggesting adjustment to a cost of lost opportunity to search for mates during the mating season. When a tethered female was nearby, males emerged from refuge earlier than if no female was present, indicating a trade-off between risk and mating opportunity. Approach speed affected emergence time when females were absent, but not when a female was present. Approach speed did not affect the probability that, after emerging, a male would return to court the female. For males that courted females intensely (bit them) before entering refuge, approach speed did not affect latency to emerge, but males that courted less intensely emerged sooner if approached slowly than rapidly. These findings show that males adjust the length of time spent in refuge to both risk of predation and reproductive cost of refuge use.Communicated by A. Mathis 相似文献
80.
The establishment of fighting rules and the ability to recognise individual conspecifics and to assess their fighting ability
and/or roles may help to reduce costs of fighting. We staged encounters between males of the lizard Podarcis hispanica to examine whether lizards used fighting strategies and whether a previous agonistic experience affects the outcome and characteristics
of a subsequent encounter. The results showed that simple rules such as body size differences and residence condition were
used to determine the outcome of agonistic interactions as quickly as possible. Thus, larger males were dominant in most encounters.
However, when size differences between opponents are smaller, they may be more difficult to estimate and, then, residence
condition was more important. In addition, the intensity of interactions between males could be explained according to the
”sequential assessment game”, supporting the idea that P. hispanica males acquire information about fighting ability gradually during the progress of a fight. Our results also showed that the
second fight of the same pair of males was less aggressive, even when its outcome was the opposite of the first. This result
suggests that male P. hispanica can recognise individual opponents and that they use this information to reach a contest outcome more quickly, thus reducing
unnecessary aggression levels in subsequent interactions. These fighting strategies and assessment mechanisms may help to
stabilise the social system of this lizard.
Received: 2 November 1999 / Revised: 26 August 2000 / Accepted: 4 September 2000 相似文献