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591.
Matthew?A.?CooperEmail author Filippo?Aureli Mewa?Singh 《Behavioral ecology and sociobiology》2004,56(3):217-227
Socioecological theory suggests that between-group competition is an important factor affecting the nature of primate social relationships. Between-group encounters in macaques may involve female resource defense, male mate defense, and male resource defense. We observed between-group encounters in two groups (a forest group and a temple group) of bonnet macaques (Macaca radiata). We observed 102 encounters in 875 h of observation of the forest group (1.40 per 12-h day) and 58 encounters in 907 h of observation of the temple group (0.77 per 12-h day). Aggressive interactions between groups occurred in 32.4% and 29.3% of encounters in the forest and temple groups, respectively. Overall, we found little support for the female resource defense hypothesis. Females in both groups rarely participated aggressively in between-group encounters. We found support for the male mate defense hypothesis. For example, males of the forest group were more aggressive during encounters in the mating season than in the non-mating season. Males were also aggressive to females from their own group immediately following encounters. We also found partial support for the male resource defense hypothesis. Encounters in the forest group occurred in a feeding context more often than expected based on time budgets. Also, males in the temple group were more often aggressive in food-related encounters than in other encounters. The findings of this study suggest that socioecological models of primate social relationships need to distinguish male and female strategies during between-group encounters and integrate the resulting functional outcomes.Communicated by T. Czeschlik 相似文献
592.
4种中草药的超临界CO2萃取物对霉菌的抑制效果 总被引:1,自引:1,他引:1
利用气相扩散法、固相扩散法、平板法研究了荷叶、艾叶、佩兰、细辛4种中草药的超临界CO2萃取物对霉菌的抑制作用和最低抑制浓度(MIC).结果表明,4种中草药的超临界CO2萃取物对单一或混合霉菌均有较强的抑制作用,荷叶和细辛的MIC<1.56g/L,佩兰的MIC<0.63g/L,艾叶的MIC<0.2g/L.表3参11 相似文献
593.
袁助人 《城市环境与城市生态》1996,9(3):42-47
辽宁中部城市群是由以沈阳为中心,包括沈阳,鞍山、抚顺、本溪、辽阳、铁岭六个市。本文分三部分,辽宁中部城市不境质量现状基本概况,辽宁中部城市九环境保护治理,辽宁中部城市群环境保护政策措施。 相似文献
594.
595.
贺志民 《湖南环境生物职业技术学院学报》2003,9(2):125-128
要实现培养创造力人才的目标,教育信息化是最有效途径之一,教育信息化要从资源(包括多媒体辅助教学资源)库整合、资源管理信息化(ERM)等多方面着手,并使它们协调运行才能有效推进教育信息化进程.整合MCAI资源库,建立资源管理信息化系统的实现流程,共建共享资源,快速推进教育信息化进程. 相似文献
596.
The least-cost-first extraction rule for deposits with different extraction costs previously has been shown to be invalid in general equilibrium. This paper demonstrates that this rule also does not hold in partial equilibrium when extraction capacity is limited. Necessary and sufficient conditions for several surprising extraction orders are presented. If extraction from a high-cost resource is constrained, it may be optimal to begin extraction from a high-cost deposit (or backstop) strictly before extracting from a lower-cost deposit. If extraction from a low-cost resource is limited, it may be optimal to exhaust a high-cost deposit strictly before the low-cost deposit is exhausted or to abandon extraction temporarily from a high-cost deposit and then to exhaust it later. The analysis demonstrates how extraction constraints affect the order of extraction and shows that certain cost reversals are caused by limited extraction capacity rather than by the general equilibrium definition of extraction costs. 相似文献
597.
Although set-up costs are prevalent and substantial in natural resource extraction, it is known that a Walrasian competitive equilibrium cannot exist in simple extraction models with set-up costs. This paper demonstrates that this result is sensitive to the assumption of unlimited extraction capacity and derives sufficient conditions for existence. An equilibrium exists if extraction is limited such that each firm earns sufficient surplus to cover its set-up costs or if firms choose extraction capacity subject to non-increasing returns. The resulting competitive equilibrium price either grows at the rate of interest when total extraction is below industry capacity or is constant when industry capacity is fully utilized. In the equilibrium, identical deposits are opened simultaneously, and set-up costs for new deposits are incurred when the industry has excess capacity rather than when capacity is fully utilized. 相似文献
598.
几种化感物质对杉木幼苗生长的影响 总被引:25,自引:1,他引:25
采用培养皿滤纸法 ,研究了不同浓度的肉桂酸、苯甲酸、对羟基苯甲酸对杉木 (Cunninghamialanceolata)幼苗生长的影响 .结果表明肉桂酸、苯甲酸、对羟基苯甲酸分别在 1× 10 -5molL-1、1× 10 -3molL-1、1× 10 -4 molL-1浓度时降低了叶绿素含量 (P =0 .0 5 ) ,而在 1× 10 -6molL-1、1× 10 -4 molL-1、1× 10 -5molL-1浓度时抑制了杉木幼苗胚根和胚芽的生长 (P =0 .0 1) .3种酚类物质对胚根生长的抑制作用明显高于对胚芽生长的抑制作用 .在 3种酚类物质中 ,肉桂酸对杉木幼苗生长的抑制作用最强 ,对羟基苯甲酸次之 ,苯甲酸最弱 .这表明酚类物质能在不同程度上抑制杉木幼苗的生长 ,降低其生产力 ,可能是连栽杉木人工林生产力降低的因素之一 .图 2表 1参 14 相似文献
599.
中国的太阳能资源及应用潜力 总被引:9,自引:0,他引:9
太阳能资源被认为是21世纪最引人注目的可再生能源和洁净能源,为了经济的可持续发展,应该把环境保护和长期利益作为研究目标,文章估算了中国14个城市的太阳能资源,分析了太阳能热水系统和PIVP系统的经济性,研究结果表明,中国的太阳能利用潜力很大,政府应该对其发展发挥重要作用。 相似文献
600.
DANIEL C. NEPSTAD†‡ CLAUDIA M. STICKLER†§ ORIANA T. ALMEIDA† 《Conservation biology》2006,20(6):1595-1603
Abstract: Amazon beef and soybean industries, the primary drivers of Amazon deforestation, are increasingly responsive to economic signals emanating from around the world, such as those associated with bovine spongiform encephalopathy (BSE, "mad cow disease") outbreaks and China's economic growth. The expanding role of these economic "teleconnections" (coupled phenomena that take place in distant places on the planet) led to a 3-year period (2002–2004) of historically high deforestation rates. But it also increases the potential for large-scale conservation in the region as markets and finance institutions demand better environmental and social performance of beef and soy producers. Cattle ranchers and soy farmers who have generally opposed ambitious government regulations that require forest reserves on private property are realizing that good land stewardship—including compliance with legislation—may increase their access to expanding domestic and international markets and to credit and lower the risk of "losing" their land to agrarian reform. The realization of this potential depends on the successful negotiation of social and environmental performance criteria and an associated system of certification that are acceptable to both the industries and civil society. The foot-and-mouth eradication system, in which geographic zones win permission to export beef, may provide an important model for the design of a low-cost, peer-enforced, socioenvironmental certification system that becomes the mechanism by which beef and soy industries gain access to markets outside the Amazon. 相似文献