A MORE GENEEAL PRODUCTIVE FORCES DISTRIBUTION MODEL WITH ENTROPY CONSTRAINT     

He Zonglu Duan Yurong 《保鲜与加工》1990,(5):98-105

The productive forces distribution model with entropy constraint is established. it satisfies both the demand with minimization of total cosls and the other demands with optimum distribution at a certain level. The model's regular optimal solution is a gravity molel..  相似文献   

森林景观的旅游吸引力及其评价   总被引：1，自引：0，他引：1  

陈端吕  董明辉  彭保发 《中南林业调查规划》2006,25(4):25-28

旅游资源，是在现实条件下能够刺激人们的旅游动机以进行旅游活动，并能为旅游业所利用而产生良好效益的各种客体和因素的总和。森林景观是陆地上一种重要的旅游资源，通过剖析影响森林景观旅游吸引力的因子关联．并引入心理物理学方法与模糊评价方法，建立森林景观旅游吸引力评价指标体系。结果表明：①森林景观具有旅游吸引物撞击旅游者的吸引力场域，主观上体现着旅游者对森林旅游资源的消费偏好；②森林景观的旅游吸引力在客观上反映了森林景观本身的奇特度、完整度、组合度等特性；③森林景观的旅游吸引力因旅游者文化层次、民族风俗、个人偏好产生差异性。只有在考虑客源特征一致的前提下，旅游吸引力才具有可比性。  相似文献   

人工巢箱招引杂色山雀研究   总被引：2，自引：0，他引：2  

王爽  金春日  万冬梅  曲再春  姜玉乙 《辽宁林业科技》2007,(2):8-11

2005年3-7月于辽宁省白石砬子国家级自然保护区悬挂人工巢箱招引杂色山雀,共设置80个巢箱,其中11个巢箱被4种鸟利用。鸟类的进驻率为13.75%,其中杂色山雀利用了8个巢箱,利用率占招引总数的72.73%。对招引到杂色山雀的巢箱因素进行分析,结果表明:杂色山雀多选择2m以上、南坡中下部、巢口朝西南的巢箱,而巢箱悬挂的树种对其选择没有影响,人为或天敌干扰会导致杂色山雀放弃巢箱。该项试验为进一步保护稀有物种和研究其繁殖生态提供了初步的依据。  相似文献   

Artificial Reefs, the Attraction-production Issue, and Density Dependence in Marine Ornamental Fishes     

Jacqueline Wilson  Craig W. Osenberg  Colette M. St. Mary  Craig A. Watson  William J. Lindberg 《Aquarium Sciences and Conservation》2001,3(1-3):95-105

Artificial reefs may provide a useful tool to enhance production of marine ornamentals and to divert detrimental harvesting activities from sensitive natural habitat. The efficacy of this strategy depends, in part, on the extent to which artificial reefs contribute to new production (vs. attract fishes from natural habitat) and therefore benefit harvested populations on a local and regional basis. Here the attraction and production hypotheses and their application to marine ornamentals are presented. Specifically, it is discussed how the strength and timing of density dependence can affect the response of fish population dynamics to artificial reefs. In addition to this discussion, examples of density dependence in marine ornamentals and related reef fishes are provided. Based on this information, a simple conceptual model is presented to clarify the role of density dependence, and this is followed by a discussion on the use of artificial reefs in the management and production of marine ornamentals. Finally, unresolved scientific issues that remain to be addressed are provided.  相似文献   

景区周边环境范围定量界定—山岳型景区山西绵山实例研究   总被引：2，自引：1，他引：1  

胡炜霞 《干旱区资源与环境》2010,(5)

随着旅游业的快速发展和城镇现代化的推近,景区周边涌现出了大量与景区不协调的问题,同时,由于人们对景区所处背景环境标准的提高,忽视周边环境与景区完整性的做法已不能适应新时代旅游者的需求。未来景区的竞争已延伸到景区周边环境范围。为此建议今后在景区规划工作中,亦应将制定科学详尽的周边环境保护整治规划放在重要位置,因此周边环境应有一个较为清晰的地域范围,以便于环境质量评价和规划运作,以及行之有效地落实周边环境调控。提出对景区周边环境地域范围定量界定的影响拐点法,并以绵山景区为例进行实证研究。结果显示景区能规划管理至定量方法所做的周边环境范围,无论对游客还是周边居民来说,满意度均较高。周边环境调控对于提高景区综合环境质量具有重要意义。  相似文献   

Conspecific attraction in loggerhead shrikes: implications for habitat conservation and reintroduction     

Matthew A Etterson 《Biological conservation》2003,114(2):199-205

The loggerhead shrike, Lanius ludovicianus, is a declining songbird that forms breeding aggregations. Despite such reports from several populations, only one statistical analysis of loggerhead shrike territory distribution has been published to date. I use a spatio-temporal simulation technique to test for deviations from randomness in the spatial distribution of point data that takes into account date of nest establishment. I apply this model to data on the distribution of shrike nests in Comanche County, Oklahoma, USA, collected over the 1998 and 1999 breeding seasons. When the data are considered without regard to date of nest-establishment, the results are equivocal; nests are significantly aggregated in 1999, but not 1998. However, when order of nest establishment is taken into account, later nests are significantly more likely to be closer than expected to conspecifics in both years. This is true even when the distribution of simple resources, such as suitable nest-trees, is included in the model. These results are consistent with the hypothesis that loggerhead shrikes ‘prospect’ for suitable habitat using the distribution of breeding conspecifics. This aspect of loggerhead shrike breeding ecology should be considered for both habitat conservation and captive breeding and reintroduction programs for this species.  相似文献   

灭蚁灵药袋材料对白蚂蚁的诱食效果研究     

张必成 《现代农业科技》2011,(11):160-161

应用不同材料制作药袋,做成"灭蚁灵"药包,在桉树林下诱杀白蚂蚁,诱食效果试验表明:纸质材料做成的药包诱食效果比尼龙质的药包好;不同处理的药包诱食消耗结果具有极显著差异。其中,9号药包在所有试验材料中表现最为突出。  相似文献   

利用人际吸引因素解决新生的交往心理障碍     

王勇 《安徽农业大学学报》2001,(2):50-51

大一新生普遍感到人际关系紧张，互想之问疑心较重，有些同学还存在交往的心理障碍。本文论述了新生交往心理障碍的主要表现，通过团体心理辅导和心理教育使同学们学习人际吸引的因素及规律，达到解决心理障碍的目的。  相似文献   

Use of time-activity budgets to measure early progress of a social attraction restoration project     

Peter J. Kappes  Gerard J. McChesney  Michael W. Parker  Harry R. Carter  Stephen W. Kress  Richard T. Golightly 《Biological conservation》2011,(1):620-626

Social attraction is a useful technique for re-establishing or relocating waterbird colonies and other species groups. However, little information exists regarding how newly attending individuals behave when the social environment is influenced predominantly by artificial stimuli. To help assess early progress of colony re-establishment, we compared time-activity budgets of common murres (Uria aalge) at a social attraction site (Devil’s Slide Rock; DSR) in central California with two nearby reference colonies during the first 3 years (1996–1998) of efforts. Murres at all colonies spent over 95% of their time engaged in resting, comfort, courtship, and alert activities during the pre-breeding period and over 88% of their time in similar activities during the breeding period. Although patterns were similar overall, comparisons of pooled and year-specific time budget data revealed significant differences between all three colonies, especially during pre-breeding. Murres at DSR typically engaged in comfort behaviors less frequently and in alert and courtship behaviors more frequently than reference colonies. Differences likely were due to recent re-establishment, including lower bird densities and higher proportions of non-breeders and first-time breeders at DSR, along with other factors such as disturbance. Results indicate that newly attracted birds at DSR behaved “normally” even though the social environment was influenced predominantly by artificial stimuli. Furthermore, re-established breeding in the first year of efforts, subsequent colony growth, and high productivity reflected successful restoration efforts. Thus, time-activity budgets can provide important measures of early progress of social attraction efforts and as such can be used to inform adaptive management decisions.  相似文献   

旅游吸引物形态与旅游形象策划     

林振华 《林业调查规划》2006,31(1):120-124

旅游业靠两源(资源、客源)、两划(策划、规划,先策划后然后开发);旅游形象是联系资源与客源的媒介,在市场经济条件下,旅游竞争是比价格、比服务、比文化,文化内涵是旅游竞争力的核心,形象是旅游区的生命。文章探讨了旅游地“文脉”、旅游吸引物升华态与旅游形象策划的有机结合,塑造良好的旅游形象,以提高旅游地竞争力。  相似文献