长直链烷基苯的异常分布及其成因探讨

来自楚雄盆地三叠系地层的三个沥青样品长直链烷基苯在C16～C20范围内具强烈的偶碳优势。正构烷烃和烷基环己烷与烷基苯分布的差异表明:偶碳数烷基苯不可能来自直链脂肪酸,也不可能来自一些细菌和某些藻类生物体中的环己基脂肪酸,它可能是成岩作用阶段,在矿物催化作用下偶数碳醇与生物体中简单的芳烃化合物进行烷基化反应抑或是在深成作用早期,长链偶碳数伯醇通过自由基反应与存在于干酪根中苯进行烷基化作用而形成。烷基苯这一分布特征与热演化没有相关关系。     

基于前景理论和BWM的深基坑支护方案综合评价

针对深基坑施工工程的复杂性及决策者风险态度对多指标决策的影响,构建了融合前景理论的深基坑施工支护最优方案选择模型。首先建立深基坑支护方案优选决策问题的多目标评价指标体系,借鉴TOPSIS思想将正、负理想方案作为决策者参照值,在此基础上,进一步将灰色关联分析法引入前景理论定义了正、负价值函数;通过BWM方法得出各指标的客观权重,根据权重函数得到决策者对客观权重的主观评价,在此基础上计算每个备选方案的综合前景值并排序,获得最优支护方案。最终通过两个工程实例验证了模型的有效性,并通过与其他方法比较说明了该模型在准确性方面的优势。     

Larval host plant origin modifies the adult oviposition preference of the female European grapevine moth <Emphasis Type="Italic">Lobesia botrana</Emphasis>

According to the 'natal habitat preference induction' (NHPI) hypothesis, phytophagous insect females should prefer to lay their eggs on the host species on which they developed as larvae. We tested whether this hypothesis applies to the breeding behaviour of polyphagous European grapevine moth, Lobesia botrana, an important pest in European vineyards. We previously found that different grape cultivars affect several life history traits of the moth. Because the different cultivars of grapes are suspected to provide different plant quality, we tested the NHPI hypothesis by examining oviposition choice of L. botrana among three Vitis vinifera cultivars (Pinot, Chasselas and Chardonnay). In a choice situation, females of L. botrana that had never experienced grapes were able to discriminate between different grape cultivars and preferentially selected Pinot as an oviposition substrate. This 'naive' preference of oviposition could be modified by larval environment: Females raised on grapes as larvae preferred to lay eggs on the cultivar that they had experienced. Furthermore, experience of the host plant during adult emergence could be excluded because when pupae originating from our synthetic diet were exposed to grapes, the emerging adults did not show preference for the cultivar from which they emerged. The NHPI hypothesis that includes the two sub-hypothesis "Hopkins host selection principle" and "chemical legacy" may thus be relevant in this system.     

Complexity in an obligate mutualism: do fungus-gardening ants know what makes their garden grow?

Fungus gardening ants make clear choices among fungal substrates (food for their fungus). It has been proposed, but never demonstrated, that these ants are collecting the best for their symbiotic fungus and the production of ant biomass (fitness). The goal of this study was to determine whether preferred substrates lead to higher fitness in the attine, Trachymyrmex septentrionalis. Preferences exhibited by foragers were established. Colonies were fed a single substrate or a mixture of substrates during the entire course of the experiment, which ended when sexual offspring appeared in the nest. The response variables were numbers and weights of ant offspring and the chitin content of fungus gardens. Preference was not strongly related to fitness. The preferred oak catkins produced the highest amounts of ant and fungal biomass, but the ants collected much more material than needed, which indicates that forager activity is decoupled from fitness. The preferred caterpillar feces were rejected shortly after the feedings began. The unpreferred oak leaves were just as effective at producing ant and fungal biomass as catkins. Leaves are possibly unpreferred because they are expensive to cut. The unpreferred huckleberry flowers were inferior but did not cause rejection behavior. The mixed diet was just as productive as catkins or leaves. This study indicates that foragers possess a default mechanism to prefer catkins and frass, which can be quickly changed if substrates are bad. In contrast, there does not appear to be a similar mechanism causing substrates to become preferred quickly.     

Potential Impacts of Global Warming on the Diversity and Distribution of Stream Insects in South Korea

Globally, the East Asian monsoon region is one of the richest environments in terms of biodiversity. The region is undergoing rapid human development, yet its river ecosystems have not been well studied. Global warming represents a major challenge to the survival of species in this region and makes it necessary to assess and reduce the potential consequences of warming on species of conservation concern. We projected the effects of global warming on stream insect (Ephemeroptera, Odonata, Plecoptera, and Trichoptera [EOPT]) diversity and predicted the changes of geographical ranges for 121 species throughout South Korea. Plecoptera was the most sensitive (decrease of 71.4% in number of species from the 2000s through the 2080s) order, whereas Odonata benefited (increase of 66.7% in number of species from the 2000s through the 2080s) from the effects of global warming. The impact of global warming on stream insects was predicted to be minimal prior to the 2060s; however, by the 2080s, species extirpation of up to 20% in the highland areas and 2% in the lowland areas were predicted. The projected responses of stream insects under global warming indicated that species occupying specific habitats could undergo major reductions in habitat. Nevertheless, habitat of 33% of EOPT (including two‐thirds of Odonata and one‐third of Ephemeroptera, Plecoptera, and Trichoptera) was predicted to increase due to global warming. The community compositions predicted by generalized additive models varied over this century, and a large difference in community structure in the highland areas was predicted between the 2000s and the 2080s. However, stream insect communities, especially Odonata, Plecoptera, and Trichoptera, were predicted to become more homogenous under global warming. Impacto Potencial del Calentamiento Global sobre la Diversidad y la Distribución de Insectos de Arroyo en Corea del Sur     

Could we remain simply applying discount rate to evaluate the life quality of our future generations?

When we try to estimate future environmental costs resulting from our current economic activities,we usually calculate the present value of the consequences for our future generations by utilizing a discount rate as a standard economic procedure.The popularity of this procedure is solely supported by its simplicity which assumes:(1)a perfect financial market over even 100 years,and(2)existence of a stable time preference between two consecutive periods for an individual consumer.An apparent deficiency of this approach is that the present value of life quality of future generations varies to a large extent along an arbitrarily chosen discount rate.As a matter of fact,the discount rate,which could reflect the time preference as2%or 5%,matters when we predict current strategies of environmental protection for future generations.Simply applying a discount rate to evaluate the quality of our future generation,without clarifying the actual production mechanism behind this,is almost to the same as ignoring the fact that all of the goods are produced through an actual production process and that environmental degradation reduces the efficiency of that process.The greatest concern for our future generations should not be given by an assumed discount rate,since the discount rate itself is determined by financial market conditions at certain points in time.     

基于犹豫直觉模糊集-TOPSIS的危险品多式联运风险评估

为了对危险品的多式联运系统风险进行评估,首先在"人、机、管、环"4M理论的基础上,将多式联运中"转运"这一特殊流程考虑进去,以"人、机、管、环、转运"这5个因素作为决策问题中的属性;其次,采用犹豫直觉模糊语言集为决策者的初始决策矩阵赋值,并利用均值-标准差的汉明距离来衡量两个犹豫直觉模糊语言数之间的距离;然后,以危险品多式联运系统中的风险为标准,采用基于犹豫直觉模糊语言集的TOPSIS方法进行不同方案的决策。最后,以磷酸在宜昌-衢州之间的运输为案例,对4种常用运输方案进行风险评估,以综合评价指数进行对比。结果表明,在先水路后铁路、先水路后公路、先公路后铁路、先铁路后公路4种方案中,从宜昌到衢州之间先公路后铁路的运输方式所得综合评价值最高,应选择方案3。     

河南省入境旅游市场时空演变规律研究

在分析河南省入境旅游市场发展现状的基础上,应用地理集中指数、亲景度和竞争态三种市场指标体系和EXCEL统计软件对河南入境旅游客源市场进行分析,揭示了河南入境旅游市场时空演替规律.据此划分河南入境旅游的重点市场、主要市场、潜在市场和机会市场,并提出了进一步拓展河南入境旅游客源市场的几点建议.