Optimal search direction for an animal flying or swimming in a wind or current

The problem of the optimal direction in which a flying or swimming animal should search for a chemical plume was addressed. Active spaces were approximated by sphere, prolate ellipsoids, or rectangular parallelepipeds of various length-to-width ratios. The optimum course direction for the sphere was in the direction of flow (downwind). For active spaces that were highly elongated along the direction of the wind or current, the optimal course heading (with respect to the moving medium) was nearly across the flow. For intermediate shapes, the optimal course was intermediate. Because of the effect of the moving medium, these course headings resulted in actual ground tracks that were more in the direction of the flow, depending on the relative speeds of flying (swimming) and the wind (current). When the two speeds were equal, the magnitude of the advantage of choosing the optimum direction over a random direction was close to 50% with a small dependence on the shape of the active space. If the active space was spherical or highly elongated or locomotor speed was much greater than the speed of the current, the advantage approached a factor of /2 ( 1.57).     

A reappraisal of insect flight towards a distant point source of wind-borne odor

This communication reappraises the behavioral evidence concerning insect flight toward a point source of wind-borne odor in the light of meteorological information not yet considered in this context. The horizontal tracks of puffs of smoke from a generator in the open air were videorecorded and found to continue along nearly straight lines from the source for at least 25 m, while the shifting wind direction caused the plume formed by the succession of puffs to snake to and fro. It is inferred from this and much previous work that within such a distance the wind will be aligned on the source of any wind-borne odor wherever the odor can be detected. This being so, a strategy of finding the odor source by flying roughly upwind on meeting the odor, but holding station against the wind with or without casting across it on losing the odor (odor-modulated anemotaxis), seems likely to be highly adaptive, whereas a strategy of flying along the plume (odor-trail following) seems unlikely since it would often take the flier in wrong directions and would be more disrupted by turbulence.     

Chemical orientation of lobsters,homarus americanus,in turbulent odor plumes

The lobster,Homarus americanus, relies upon its lateral antennules to make initial directional choices in a turbulent odor plume. To determine whether chemical signals provide cues for source direction and distance during orientation, we studied the search patterns of the lobster orienting within a turbulent odor plume. In an odor plume, animals walked significantly more slowly and most often up the middle of the tank; control animals (no odor present) walked rapidly in straight lines, frequently along a wall. Search patterns were not stereotyped either for the population of experimental animals or for individuals. Three different phases of orientation were evident: an initial stage during which the animals increased their walking speeds and decreased their heading angles; an intermediate stage where both the walking speed and headings were constant; and the final stage close to the source, where heading angles increased while walking speed decreased. During this last stage the animals appear to be switching from a distance orientation (mediated by the antennules) to a local food search (mediated by the walking legs) as evidenced by a great increase in leg-raking behavior.     

Habitat-specific Signal Structure for Olfaction: An Example from Artificial Streams

Many animals use chemical signals to acquire information about their habitats. The structure of this information is dependent upon specific features within a habitat, and the information in signals can be habitat-specific. We quantified the spatial and temporal information in an aquatic odor plume in three different artificial stream habitats with different substrate types by measuring turbulent odor plumes with an electrochemical detection system. Streams had one of three substrate types that correlated with typical aquatic habitats: sand (4.2 × 10^–2 cm diameter), gravel (2.5 cm), and cobble (4.5 cm). As predicted from the hydrodynamics, the spatial and temporal structures of the signals were different on different substrates. Spectral analysis showed that the sand and cobble substrates had signals that were dominated by lower frequency fluctuations, whereas gravel had the highest and broadest range of signal fluctuations. Cross- and autocorrelations showed that signals on the gravel substrate had the largest spatial and shortest temporal components. Our results imply that the information obtained from chemical signals may be limited in some habitats. These constraints on information may affect how organisms perform chemically mediated behaviors.     

车用聚丙烯制件气味来源分析和控制

车用聚丙烯制件气味是影响整车气味的主要因素之一.从聚丙烯原料、工艺以及过程污染等各环节分析引起车用聚丙烯制件气味的原因,并提出相应的控制方法,为改善聚丙烯制件气味提供了正向控制方案.     

风力发电发展现状及复合材料在风力发电上的应用

介绍了风电装机技术、单机容量、主要风电设备供应商、海上风电场等世界风电发展现状,详细描述了三北地区、东南沿海及岛屿地区、内陆局部风能丰富区、海上风能丰富区等中国风能资源及其分布,并分析了中国风电产业现状,介绍国内风电产业发展规划和复合材料在风力发电上的应用。     

凌仕契合香精的香气分析及模拟研究

通过顶空固相微萃取-气相色谱/质谱技术,结合感官分析,对凌仕契合香精的香气组成和香韵结构进行了分析,得出了果香韵、醛香韵、青香韵、木香韵、花香韵和海洋香韵等6种不同香韵,以及34种调配原料。考察了不同香韵组成对香精主体特征香气的影响,最终模拟得到了香气相似度较好的凌仕契合香精。     

污水处理厂除臭设计体会

简要介绍污水处理厂恶臭污染的主要危害及来源、臭气的基本成分;概述并比较了近几年来污水行业常用的加盖技术、臭气处理技术;简介了臭气处理的新技术等。     

高强度低VOC玻璃纤维增强聚丙烯材料的开发

以含30％短玻璃纤维的聚丙烯(PP)为基础,从源头开始控制材料的气味和VOC含量,即将所有可能用到的配料参照大众汽车PV3900气味测试标准进行筛选,优先选择气味等级不超过3级的原料和助剂.主要对当前市场上的几种不同的低气味马来酸酐接枝聚丙烯相容剂(PP-g-MAH)、不同抗氧剂体系和不同气味吸收剂进行了研究.结果表明...     

A cross-cultural study on the attitude towards personal odors

Human axillary odor was used in testing the ability of male and female subjects to distinguish between gender and individuals. The subjects also gave a qualitative evaluation of the odors. The tests were carried out in Japan, Italy, and Germany. Of all three cultures, 80% of the participants could significantly distinguish among the odor of individuals; 50% could identify the person correctly to whom the recognized odor belonged. Discrimination between male and female odor was significantly shown by 20% of Italian, 30% of German, and 60% of Japanese subjects. The qualitative evaluation of male and female odor was the same in the three cultures: male odor was classified more unpleasant and less pleasant than female odor. Men classified their own odor more unpleasant than women did with their own. A cultural difference was found concerning partner's odor: though men classified it alike (predominantly pleasant), women differed. Japanese and Italian women classified their partner's odor predominantly unpleasant, German women predominantly pleasant. In general the Japanese subjects classified the odors less often pleasant than the Italian and German subjects did.     

燃煤电厂湿烟羽治理技术研究进展

湿法脱硫方式在我国燃煤电厂的脱硫系统中占主要地位,其中以石灰石–石膏湿法脱硫方式应用最多。湿法脱硫后的烟气通常为湿饱和烟气,若烟气在排放时环境的温度及湿度较低,则会在烟囱口产生“湿烟羽”现象。湿烟羽一般呈白色或灰色,含大量水汽及污染物,湿烟羽的出现对环境及人体健康产生危害。因此企业在采用脱白技术进行排放改造将会减少烟气中污染物的排放,使烟气更好地扩散。为了更好地了解湿烟羽现象,帮助待改造企业选用适合自身的技术路线,本工作对湿法脱硫工艺及湿烟羽形成原因进行了简单介绍,对国内部分地区出台的有关政策进行了汇总,并综述了湿烟羽特性的研究现状(包括湿烟羽的长度、抬升高度及消除特性)。湿烟羽的控制技术较多,主流技术可分为烟气冷凝技术、烟气加热技术及烟气冷凝再热技术,应用温湿图对各控制技术的原理进行解释,根据控制技术的分类对各类别下的应用进行了综述,提出控制技术复合使用的可能,在节能及经济性允许的前提下,各企业应尝试更多技术路线,为湿烟羽的治理拓宽道路。     

Specific anosmia to trimethylamine: The fishy primary odor

About 7% of human subjects are specifically anosmic to the odor of trimethylamine. Odor threshold measurements on 16 aliphatic amines were made with panels of specific anosmics and normal observers. The anosmia is most pronounced with low-molecular-weight tertiary amines, but is also observed in lesser degree with primary and secondary amines. It is suggested that this specific anosmia corresponds with the absence of a new olfactory primary, the fishy odor. Trimethylamine has been reported to occur in human menstrual blood and in the anal gland of the red fox, implying some pheromonal function.     

Estimating maximum horizontal area of pheromone plumes

Graphs and simple Gaussian plume equations are presented for estimating the maximum horizontal area within a pheromone plume. In its simplest form the area,A _R , for a given scaling factor,R = Q/(Ku), isA _R = A_I R , whereQ is the release rate,K is a specified concentration threshold,u is the wind velocity, and is an atmospheric stability index. Estimates ofA _I and are given for several atmospheric stability typing schemes applicable to field and forest habitats.     

Sensitivity of women to musk odor: No menstrual variation

It has been reported that the sensitivity of women to the musky odor of pentadecalactone exhibits cyclic variation,with a marked peak at about the time of ovulation. This claim was carefully reinvestigated, but was found to be untrue-in the conditions of our experiments. Possible reasons for the discrepancy are discussed.     

复合材料风电叶片的发展现状及若干问题的对策

综叙复合材料在风力发电机转子叶片上的应用及生产现状,介绍现有复合材料风电叶片的结构、材料体系、生产工艺及发展方向等,针对目前大型风电叶片生产过程中遇到的一些问题提出解决方案或构想。可以预见,随着叶片的日益大型化,内置热源的大型复合材料组合模具、改进的真空导入树脂模塑法及可回收利用的热塑性叶片可能是今后风电叶片的主要发展方向。     

海洋清花香型香精的研究

通过顶空固相微萃取-气相色谱质谱技术．结合感官分析,对海洋花香型香精的香气组成和香韵结构进行了分析,得出了5种不同果香、清香、海洋香、花香、龙涎麝香香韵的28种原料,并考察了不同香韵组成对香精主体特征香气的影响,最终模拟得到了香气相似度较好的海洋花香型香精。     

生物法治理恶臭研究进展

生物处理恶臭物质已成为当今恶臭处理研究的主流，对当前国内外各种生物处理方法进行了综述，同时介绍了一些微生物脱臭的最新研究成果，阐述了生物脱臭的前景与展望。     

臭味层次分析法（FPA）评价饮用水臭味的人为影响因素

通过嗅觉测试簿辨识、阈值及强度等级评价等几项培训来验证臭味层次分析法（FPA）测定嗅觉能力与性别、年龄、生活习惯等之间的关系及影响程度。结果表明20～30岁人群100％符合筛选标准,且一半以上嗅觉测试达到优秀。女性嗅觉比男性灵敏,女性MIB（土霉味）平均嗅阈值低至2．77ng／L,但男性对生活中常见臭味更为敏感。此外符合嗅觉测试簿标准的20~30岁及40～50岁人群的嗅觉辨识度和强度等级评价精确度较高,但总体嗅觉辨识度及灵敏度随年龄增长而下降。