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Although the faunal elements of Far East Asian Mesozoic terrestrial biota have attracted much attention in recent years, their palaeoecology remains poorly known. In particular, features of the palaeoclimate are highly controversial. To address this point we used the Mesozoic fossil wood Xenoxylon , a genus recognized as an indicator of wet temperate biotopes and which is common in the area during the Carnian–Maastrichtian interval. We re-appraised bibliographic data and gathered new data for Xenoxylon in the Mesozoic of Far East Asia. This demonstrated that previous taxonomic approaches to the genus have been so far idiosyncratic. We examined the anatomical diversity of morphogenus Xenoxylon in Far East Asia and compared it to that of samples from Europe. This indicates that in an area centred on north-eastern China, Xenoxylon reached a level of anatomical diversity unmatched elsewhere in the world. We hypothesize that this diversity witnesses the persistence of palaeoecological conditions particularly suitable for Xenoxylon and that a wet temperate climate prevailed over most of the area throughout the Carnian–Maastrichtian interval. It is in this setting that the famous Jehol Biota probably evolved.  相似文献   
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The application of sensory methodology for measuring deodorizing effect of an air conditioner equipped with electric plasma was introduced. Deodorizing effect was measured using chemical and sensory methods at different time (0, 30 and 60 min) and mode (control, blowing and cooling) of an air conditioner. Smoke from a roll of cigarette in a closed room was used as a source of odor and the concentrations of acetic acid and ammonia were measured as odorous chemical components. As one of the sensory methods triangle test was used and as a first step to obtain deodorizing effects by triangle test, the threshold of each panelist was obtained as the log dilution ratio of odor concentration at which the difference from odorless air was detected. The odor concentration at each time and mode was calculated using the threshold of the panel and the deodorizing effect was obtained on the basis of the odor concentration. In addition to a triangle test, scaling methods such as category scaling or magnitude estimation were used to measure deodorizing effect of an air conditioner. Deodorizing effects by scaling methods were calculated based on odor intensity with time at each mode. The regression analysis was done between the efficacy of deodorizing effect by sensory test and those by acetic acid and ammonia, the R2 values of the regression equations for triangle test, category scale, and magnitude estimation were 0.84, 0.72 and 0.69, respectively. Deodorizing effect by triangle test explained the decrease of acetic acid and ammonia better than those by category scaling or magnitude estimation while high cost and time consuming labor involved in triangle tests reduced the merit. The results of this study demonstrated that various sensory methods could be used to measure deodorizing effect of air conditioners and further researches on fast and reliable methods are needed to establish the official procedures.  相似文献   
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To examine morphological differences among queens, workers and males, 14 external body characters were measured in two colonies of the Taiwanese stingless bee Trigona ventralis hoozana. Queens were largest in all of the body parts measured except eye width and mesoscutum length, and values for most variables in queens did not overlap with those of workers and males. In contrast, the worker : male size ratios for 11 variables were close to 1.0, showing that overall body size and shape of workers resembled that of males rather than of queens. Males had the largest eyes and their mesoscutum length was comparable to that of queens. ancova between 14 morphometric variables and mesoscutum width chosen as standard body size showed that allometric growth in most variables was not linear. Plotting of some variables on mesoscutum width showed that queens had a proportionally wider first metasomal tergum and longer antennal scape, but a proportionally narrower head and eye than workers and males. These tests suggest that the morphological caste differences in this species belong to a category of complete dimorphism.  相似文献   
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稻巢螟又名苞螟。它的幼虫为害水稻,取食叶片,吐丝缀叶,连同粪粒做成筒状虫苞并在其间匿居。稻叶受害破碎枯黄影响生长,以前认为稻巢螟只有一种,我们现在研究发现三种。本文目的是对稻巢螟种类进行全面分析研究,根据历年采集收藏的标本,从外形结合生殖器形态构造特征对我国种类作一订正并讨论它的分布。对台湾种类由于手边缺乏标本暂缓讨论。研究用标本都保存在动物研究所。  相似文献   
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巢草螟属(Ancylolomia H(?)bner,1825)分类位置是隶于草螟亚科。现根据幼虫卷叶造巢的习性属于草螟类群取名。全世界至今已知64种和5个亚种。我国种类据陆近仁等(1953)记载只知A.chrysog raphella Kollar一种。 1965年Bleszynski发表见于中国的有A.japonica Zeller及A.rotaxella Blesz.。其后,他于1970年又发表中国有A.indica Felder&Rogenhofer和A.likiangella Blesz.。我们近来研究国内历年采集的标本,经整理鉴定发现本属还有四个是科学上未曾报道过的新种,四个种是国内首次  相似文献   
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Cuticle micromorphology of 21 species of Pinus in east and south-east Asia was studied with scanning electron microscopy and leaf morphology was described. Cuticle characters that can be distinguished by their size, shape, and surface texture, as well as by the number of subsidiary cells, the rows of epidermal cells within a stomatal band, the number of cells between stomata in stomatal rows, and the patterns of cuticular flanges are described in detail. Most of these characters have not been considered in sufficient detail previously. Some of the inner cuticular features, such as the texture of periclinal walls, the shape of the top of the anticlinal walls, the comparative size of the lateral and polar subsidiary cells, and the development of the groove near bristles, are diagnostic characters for subgenera. The agreement between cuticle characters and taxa is discussed. Cuticular characters were used to try to resolve the position of taxa that currently appear in different places in different classifications.  相似文献   
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