导游特色化初探

基于旅游市场对特色导游迫切需求的主要原因,阐述了导游特色化培养对于满足市场需求、提高服务质量、拓宽就业渠道、细化旅游学科专业建设具有的重要意义,并提出实现导游特色化可以从政策导向、教育、广纳人才等几个途径来实现。     

现阶段中国农地利用专业化的主要限制因素

中国农地利用专业化发展缓慢,落后于西方发达国家,成为其农产品国际竞争力不足的一个重要影响因素。对其原因,目前学术界仍存争议,尚无令人信服的结论。论文利用1991—2013年全国、省域,以及2001—2013年县域（杭嘉湖地区）3个尺度的种植面积数据,采用赫芬达尔专业化指数（SHHI）,并结合关联政策的资料分析,重点检验主粮生产对农地利用专业化的主控性和限制性,探讨现阶段中国农地利用专业化的主要限制因素。结果显示：1）现阶段中国农地利用专业化水平受主粮播种面积占比的控制,全国和省域尺度上,无论时间维度还是空间维度,两变量均在5%以下显著性水平上呈正相关关系;县域尺度上,两变量在空间维度上呈显著高度正相关,时间维度上76%的区县呈显著正相关。2）粮食生产保护政策约束了粮食作物的退出,压缩了非粮作物的增长空间,限制了农地利用专业化的发展。结果表明,国家对粮食（尤其是主粮）生产的保护是现阶段中国农地利用专业化的主要限制因素。因此,论文提出转变“粮食安全”观、优化农业生产布局等促进农地利用专业化的政策建议。     

四川省二○○一年生态足迹分析

论文以四川省2002年统计年鉴的数据力依据，对四川省2001年的生态足迹进行了计算和分析，结果表明四川省2001年人均生态赤字为1．115hm^2。这反映出人类的生产、生活强度超过了生态系统的承载能力，此区域生态系统处于人类的过度开发利用和压力之下。     

测定生产力中"叶绿泰a"的方法探讨

对测定生产力中"叶绿素a"的方法进行了探讨与改进,并进行了方法的验证.本方法的精密度范围为6.1%～8,4%,实验证明,本方法具有简单、快速、准确等特点.     

东江流域低产耕地的低产原因及改良利用对策

根据调查数据，指出森林破坏严重、水利不过关、土壤质量低、有机肥施用量减少、以及农产品价格偏低而导致经济投入减少和管理不善，是东江流域低产耕地的主要低产原因，并提出了如下的改良利用对策：继续进行林业建设和改造，加强水利建设、完善排灌系统和采用节水措施，改良土壤提高地力，因地制宜合理利用，增加投入和制订粮食收购保护价。     

Functional Homogenization Effect of Urbanization on Bird Communities

Abstract:  We studied the community richness and dynamics of birds in landscapes recently affected by urbanization to test the prediction that biotic communities living in degraded landscapes are increasingly composed of generalist species. We analyzed bird communities in 657 plots monitored by the French Breeding Bird Survey from 2001 to 2005, accounting for the probability of species detection and spatial autocorrelation. We used an independent land-cover program to assess urbanization intensity in each FBBS plot, from 1992 to 2002. We found that urbanization induced community homogenization and that populations of specialist species became increasingly unstable with increasing urbanization of the landscape. Our results emphasize that urbanization has a substantial impact on the spatial component of communities and highlight the destabilizing effect of urbanization on communities over time. These results illustrate that urbanization may be a strong driving force in functional community composition and that measuring community homogenization is a powerful tool in the assessment of the effects of landscape changes and thus aides sustainable urban planning.     

Task specialization in a wild bee,Apis florea (Hymenoptera: Apidae), revealed by RFLP banding

Workers in a wild in situ colony of the dwarf honey bee, Apis florea, were observed undertaking the following behavior: liquid foraging, pollen foraging, guarding, stinging, fanning and wagging abdomen. Bees of each behavioral class were separately collected and frozen. Collections were made over a period of 10 days. Random samples of brood and workers were also collected. DNA was extracted from each bee and fingerprinted using a probe of unknown sequence obtained from an A. mellifera genomic library. Patterns of fingerprints (Fig. 1) were dissimilar among behavioral classes (Tables 1 and 2), strongly suggesting a genetic component to division of labor in this species. This result supports similar findings in A. mellifera in a species that is not troubled by many of the experimental difficulties inherent in A. mellifera. Correspondence to: B.P. Oldroyd     

加快优势矿产开发,建设原材料生产基地

攀西-六盘水地区矿产资源种类繁多,储量丰富,优势明显,在国内占有重要地位。本文从区内赋存的矿产资源条件和现有工业基础出发,分析了发展高耗能原材料工业的有利条件和制约因素,阐述了建设以钢铁、有色金属和磷化工为主的原材料生产基地的布局构想,并提出了加快开发利用优势矿产资源的对策建议。     

Differential use of conspecific-derived information by sexual and asexual parasitic wasps exploiting partially depleted host patches

When foraging partially depleted patches (i.e., a fraction of hosts are already parasitized), female parasitoids must decide: 1—whether to superparasitize, and 2—whether to stay in their current patch (thus missing the opportunity of finding a better patch elsewhere). To make these decisions, parasitoids may rely on different cues, produced both by the environment and by conspecifics. Animals thriving in different environments may differ in cues they use. In the solitary parasitoid Venturia canescens, thelytokous (asexual) and arrhenotokous (sexual) individuals are found in two contrasting environments. Thelytokous females, from anthropogenic conditions, are known to cope with superparasitism in an adaptive way. On the other hand, little is known about superparasitism by arrhenotokous females. We compared the host exploitation strategies of thelytokous and arrhenotokous females in partially depleted patches. Hosts parasitized by thelytokous females were more frequently avoided than those parasitized by arrhenotokous females, suggesting a stronger chemical marking of the former. Only thelytokous females used information from conspecifics for patch-leaving decisions. The conformity of the differences in the behavior of thelytokous and arrhenotokous females with the environmental conditions they experience in their habitat is discussed.     

中国畜牧业地理集聚特征及其演化机制

农业地理集聚是有效实现农业分工的空间组织形态。以畜牧业为例,采用基尼系数、专业化指数、产业集中度和产业平均集聚率等指标与模型,分析了畜牧业地理集聚的发展特征、演变态势及其形成机制。结果表明:1980-2011 年中国畜牧业地理集聚程度不断增强,呈现出先增强后减弱再到稳定上升的阶段性演化特征,但不同畜产品生产的地理集聚过程差异显著;省域尺度上,畜牧业平均集聚率重心不断北移,逐步形成了北方地区高度集聚、南方地区中低度集聚的空间分异格局;畜牧业地理集聚格局经历了由自然集聚到空间重构再到空间优化的过程,自然资源禀赋、农业生产力以及市场与政策,在不同时期主导着中国畜牧业空间格局的演变,构成了我国畜牧业地理集聚格局的演化机制。