具有HollingⅢ功能性反应和扩散的三种群模型的持久性和全局吸引性

研究一类含有连续时滞的HollingⅢ功能性反应和扩散的三种群捕食-食饵模型,讨论了该模型的一致持久性,从而得到了保证该系统持久性的充分条件;通过构造适当的Lyapunov函数得到了保证此系统全局吸引的充分条件.     

Impact of Background Fruit Odors on Attraction of Drosophila suzukii (Diptera: Drosophilidae) to Its Symbiotic Yeast

Background odors produced by plants in the environment can interfere with the response of insects to a point-releasing attractant, especially when their compositions overlap. In this study, a series of binary choice tests was conducted in a wind tunnel to investigate whether background odors emitted from cherry, blueberry, blackberry, or raspberry fruits would affect the level of Drosophila suzukii (Matsumura) attraction to its symbiotic yeast, Hanseniaspora uvarum (Niehaus) (Saccharomycetales: Saccharomycetaceae). Whether an increase in the intensity of background odors would affect the attractiveness of H. uvarum to D. suzukii was also investigated, either by increasing the number of cherry or raspberry fruit per cup or by increasing the number of fruit cups surrounding the cup baited with the yeast. In wind tunnel assays, background fruit odors interfering with D. suzukii attraction to the yeast varied among fruit types. Raspberry odor inhibited the attractiveness of H. uvarum to the fly the most, followed by blackberry odor, whereas cherry and blueberry odors had no significant impact on the attraction. An increase in the intensity of odors by adding more cherry or raspberry fruit per cup did not increase the impact of fruit odor on the attraction; however, adding more raspberry cups around H. uvarum linearly decreased its attractiveness, suggesting that background host fruit abundance and likely increase in host odor may influence D. suzukii attraction to yeast odor depending on host species.     

自然风景质量评价法在绵阳市旅游资源分等定级中的应用

采取自然风景质量评价法,以绵阳市8个旅游风景区作为基本单位,选取地形、植物、水体、色彩、近景观的影响、稀有性与人为改变7个风景质量因子作为风景资源质量评价项目,对这8个旅游风景区进行评价,依据美国土地管理局的风景资源管理系统,用特尔菲法评分,算出8个旅游风景区的风景质量等级,绘出绵阳市旅游资源等级图,得出绵阳市旅游资源优劣状况,提出景区的发展方向和相关问题的解决措施,为绵阳市旅游资源的开发提供有用的依据。     

三峡黄金旅游带旅游资源评价及开发研究

通过层次分析法、模糊赋分法对三峡工程蓄水后三峡黄金旅游带（重庆段）主要自然、人文景点（区）资源进行评价,并分析了旅游资源结构、开发价值及空间组合特点。在旅游带的旅游资源结构中,自然资源起着基础作用,人文景观为重要组成部分;在空间组合上可分为都市成片旅游区和沿江点状旅游区。基于上述评价结果,文章提出关于了三峡黄金旅游带旅游资源开发的一些思路。     

林区旅游资源产品化研究

林区是旅游资源的富集区,具有发展旅游业的潜力。但是,由于市场观念的缺乏,其资源优势并未转化为产品优势与经济优势,旅游资源产品化成为林区旅游发展的首要任务。本文剖析了旅游资源与旅游产品关系,在分析林区旅游资源产品化的背景及其旅游资源开发的优势与障碍的基础上,提出了林区旅游资源产品化的战略构想与策略。     

旅游活动对黄山土壤和植被的影响

为进一步掌握旅游对黄山景区的生态影响,本试验采用样方和室内分析方法,对黄山主要景点的植被和土壤进行了研究。结果表明:旅游对灌木层的高度没有明显影响,但对盖度影响很大,尤其是游径附近的盖度变化较大。游径0 m处的草本层的高度降低明显,10 m以外距离没有变化,同时旅游干扰增加了草本层的物种数量。此外,旅游活动显著降低了游径附近0~5 m的含水量及有机质含量,提高了土壤PH值,但对10 m以外的距离影响则不显著。     

基于旅游者价值的乡村旅游目的地产品提升策略研究

乡村旅游目的地是我国旅游业的重要组成部分,而旅游产品是旅游目的地实现盈利和发展的主要途径。随着我国乡村旅游目的地数量的不断增多,行业之间的竞争也日益加剧,这就需要目的地旅游企业采取更为有效的产品提升策略。目的地旅游企业管理者需从旅游者价值的角度出发,建立一个以旅游者为核心的良性循环管理系统,实现乡村旅游目的地产品的整体提升。     

Attractiveness of various protein sources to juvenile rockfish (Sebastes schlegeli,Hilgendorf 1880)

ABSTRACT

The attractiveness of various protein sources of 16 feed ingredients was determined in juvenile rockfish (Sebastes schlegeli) by using reinforced acrylic tank composed of three equally divided rectangular attracting chambers and an acclimatization chamber. Thirty fish were held in the acclimatization chamber at a time and tournament comparison of feed ingredients was applied to evaluate attractiveness. Jack mackerel (JM) (40.0%), sardine (SM) (33.3%), Pollack (PM) (40.0%), shrimp (SHM) (36.7%), mussel meal (40.0%) and oyster (43.3%) meals achieved the highest feeding attractiveness to rockfish in the 1^st through 6^th preliminary test, respectively. JM (40.0%), SHM (36.7%), squid meal (SQM) (33.3%), SM (40.3%), PM (40.0%) and PM (36.7%) achieved the highest feeding attractiveness to fish in the 7^th through 12^th preliminary test, respectively. Among the top five feed ingredients showing high attractiveness to rockfish, JM achieved higher attractiveness than PM and SHM in the 1^st trial. In the 2^nd trial, attractiveness of JM to rockfish was higher than SM and SQM. SM achieved higher attractiveness to rockfish than SQM, but not different from PM throughout the 30-min observation in the 3^rd trial. The strongest feeding attractant response of rockfish was observed in JM, followed by SM, SQM, PM, and SHM, in order among various feed ingredients.     

旅游购物市场利益关系协调发展研究

介绍了旅游购物市场、旅游商品的概念及旅游购物市场的利益关系,通过分析旅游购物市场利益不均衡现象,探究了利益关系失衡的深层次原因,并提出了协调利益关系的措施。     

旅游业的发展与相应法律法规的完善

本文从旅游资源环境、旅游企业经营、旅游者合法权益保护方面对旅游业存在的问题及现有法律、法规的不足进行了分析,并指出针对旅游现状应制定相应的法律规范,以保证旅游业的健康顺利发展。