Misleading the Colorado potato beetle with an odor blend

Walking tracks of Colorado potato beetles,Leptinotarsa decemlineata Say, were recorded on a locomotion-compensator in response to wind, odors of host plantsSolanum tuberosum L. and nonhost plantsLycopersicon hirsutum f.glabratum C.H. Mull, and to mixtures of these plant species. Host-plant odor induced positive anemotactic responses in starved females, whereas odor of the nonhostL. hirsutum was neither repellent nor attractive. The attractiveness of host-plant odor, however, was neutralized in the odor blend of plant species. Masking the attractive host-plant odor will hinder the beetle's searching for host-plant patches, and this principle may be exploited in pest control by mixed cropping.The locomotion-compensator was constructed with financial support from the Foundation for Fundamental Biological Research (BION), which is subsidized by the Netherlands Organization for the Advancement of Pure Research (ZWO), grant 14-02-02. The first author was supported by a grant from the French Ministry of Industry and Research.     

英语情态句的情感倾向性分析

该文研究了英语情态句的情感倾向性分析问题。情态句是英语中的常用句型,在用户评论文本中占有很大的比例。由于其独有的语言学特点,情态句中的情感倾向很难被已有的方法有效地分析。在该文中,我们借助词性标签进行了情态句的识别,并提出了一种情态特征用于帮助情态句情感倾向性的分析。为了进一步提高分析效果,我们还给出了通过合并同义情态特征来缓解情态特征稀疏性问题的方法。实验结果表明,在二元及三元情感倾向性分类问题上,该文提出的方法在F值上较经典分类方法分别有4%及7%的提高。     

Formation of Nanocrystalline Calcia by the Decomposition of Calcite

Formation of nanocrystalline calcia from calcite has been studied in situ via transmission electron microscopy. The crystallographic transformation occurred via two mechanisms: the first is by distortion of the cleaved rhombohedron of calcite, formed by {104} planes in hexagonal coordinates, into a cube. This produced a microstructure of oriented, elongated nanocrystals of calcia with planar boundaries. In the second mechanism, the micrometer-sized parent calcite particles broke up into nano-sized grains as the decomposition began, leading to irregularly shaped, randomly oriented nanocrystals of calcia.     

基于数据挖掘的高职学生专业倾向性分析

高职教育为社会培养高素质的技能型人才发挥了重要作用,但是有部分高职学生在就业中并没有从事跟本专业相关的职业.造成这种结果的一个原因就是学生的专业选择.利用数据挖掘技术对专业倾向性进行分析,找出影响专业学习的因素,帮助学生进行专业的选择,同时也使得高职院校在专业的课程设置中更有针对性.     

塑料注塑加工中结晶与取向的探讨

介绍结晶性塑料在注塑过程中的塑化特点、取向与结晶的关系及其对制品性能的影响，注塑参数对结晶性塑料塑化、取向、结晶的影响。讨论了在实际工作中如何利用这些特性进行注塑机塑化系统、模具的设计并确定注塑工艺，从而得到品质优良的制品。     

浅议我国成品油销售企业竞争力的提升

为了应对加入WTO后我国成品油销售面临的竞争，提出以低成本战略、企业再造战略、品牌营销战略、服务营销战略作为提升成品油销售企业竞争力的重要策略。     

Photoalignment dynamics of azo dyes series with different coordination metals

There are many photoaligned azo dyes that can be used for orientation of liquid crystals in various display devices. However, the structure of these compounds needs to be optimized to increase the rate of the process of molecule photoalignment, as well as to spread the application of these compounds. The main coordination metal that presents in the molecules of azo dyes is sodium derivatives. The use of other alkali metals remains an open question. We used quantum‐chemical computation methods and reversible intermolecular bonding model to determine the effect of metal coordination on the velocity of photoalignment. The theoretical predictions were experimentally verified using sodium, potassium, lithium, and cesium salts of the model azo dye synthesized by us. We conclude that potassium azo derivatives are the fastest, ceteris paribus.     

Aggregation arrestant pheromone of the German cockroach,Blattella germanica (L.) (Dictyoptera: Blattellidae): Isolation and structure elucidation of blattellastanoside-A and -B

The aggregation pheromone of the German cockroach,Blattella germanica, consists of attractant and arrestant, which can be detected by olfactometer and choice-chamber assay, respectively. Both were extracted from the frass-contaminated filter paper being used as a shelter. They were separated by solvent partition withn-butanol and water. The arrestant from then-butanol phase was purified by open column chromatography and then successive HPLC isolated two major arrestant components. Spectral evidence from SI-MS, HR-EI-MS, and NMR experiments with pulse techniques provided possible structures as 1-(6-chloro-4,5-epoxy-5-stigmast-3-yl)--d-glucopyranoside and 1-(6-chloro-5-hydroxy-5-stigmast-3-yl)--d-glu-copyranoside, denoted as blattellastanoside-A and blattellastanoside-B, respectively. They represented arrestant activity as median effective doses (ED₅₀) at 0.044 (A) and 3.2 (B) nmol on 1.0 cm² of Whatman No. 1 filter paper.     

Piezo- and pyroelectricity in polymer blends of poly(vinylidene fluoride)/poly(methyl methacrylate)

Compatible polymer blends of poly(vinylidene fluoride) (PVDF) and poly(methyl methacrylate) (PMMA) can be used as suitable model systems for investigating the relationship between the physico-chemical structure of polymers and their piezo- and pyroelectric activity. The structure of PVDF/PMMA blends can be varied over a very wide range which can lead to a strong influence on the piezo- and pyroelectric activity and the corresponding coefficients d₃₁ and g₃. The values of d₃₁ and g₃ were found to vary over nearly five decades whereas the normalized coefficients $\text{d}{}_{31}\text{P}$ and $\text{g}{}_3\text{P}$ remain largely unaffected. This emphasizes the importance of the molecular processes causing the macroscopic polarization P during the poling procedure. For a given polarization P and a given temperature T the properties of the polymer matrix, however, are far less important for the values obtained for d₃₁ and g₃. The experimental results were compared with theoretical predictions based on models which were recently developed by Tashiro et al., Broadhurst et al. and by Mopsik et al.. Considering the appropriate scope of each model a good agreement between theory and experiment is observed and general contradictions have not been found.     

网络口碑传播对顾客品牌认知的影响

互联网改变了人们的生活习惯,也创造了新的商业模式。在竞争激烈的现代市场环境下,传统的营销模式已不能满足企业生存与发展的需要。网络口碑传播作为一种廉价的信息传播工具与可信度高的宣传媒介,已经引起了营销者的关注。而品牌作为企业的核心资产,企业要想塑造成功的品牌就应了解顾客的品牌认知。基于此,分析网络口碑传播对品牌认知的影响,构建基于品牌认知的网络口碑传播模型,提出企业在网络口碑传播中提高顾客的品牌认知的策略具有较好的现实意义。