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樊世兰 《贵州工业大学学报(自然科学版)》2007,36(5):80-84
在民族地区开发、建设新小区,除了要考虑小区的现代生活环境、建筑功能、保温节能外,还应综合考虑小区的民族特色、绿色环保因素。以贵州凯里绿都小区建设为例,对民族地区小区规划、设计进行了探讨。 相似文献
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帽儿山森林生态系统蚯蚓区系组成研究 总被引:5,自引:0,他引:5
帽儿山林区蚯蚓种类较丰富,有2科6属8种,正蚓科的赤子爱胜蚓、粉正蚓及微小双胸蚓为优势种,从年龄结构上看,该地区蚯蚓种群属增长型,成蚓少于幼蚓,对林型系列研究表明白桦林的蚯蚓数量最少,对生态系列蚯蚓研究表明,蚯蚓生物量和个体密度随着地形坡位的升高而增大,热量因子对森林生态系统蚯蚓种群分布起着重要作用。 相似文献
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A new species of Gobiconodon (Triconodonta, Mammalia) and its implication for the age of Jehol Biota
LIChuankui WANGYuanqing HUYaoming MENGJin 《科学通报(英文版)》2003,48(11):1129-1134
A new species of Gobiconodon is found from the Yixian Formation of western Liaonlng, China. The new taxa,G zofiae sp. nov., has a confluent opening for branches Ⅱand Ⅲ of the trigeminal nerve on the anterior lamina of the petrosal. G zofiae sp. nov. is similar to Repenomamus in having an ossified Meckel‘s cartilage connecting the lower jaws and ear region. The new species, with enlarged I^1/I1, posteriorly located infraorbital foramen and four mental foramina,distinctly differs from the other species of Gobiconodon. The new material indicates that Gobiconodon has four, not five,upper molariforms. The presence of Gobiconodon in Jchol Biota makes it possible to correlate Jehol Biota with faunas in eastern Asia and North America, and suggests the age of the Yixian Formation to be Early Cretaceous. 相似文献
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辽西地区义县组湖泊沉积层中产出著名的“热河生物群”化石,对于此时期古环境的研究一直是诸多学者关注的焦点.本文对大康堡层湖相纹泥展开研究,重建此时期古环境.通过野外及室内对纹泥组成、类型、厚度等方面的观测,对此时期古气候有了新的认识.纹泥厚度特征变化表明沉积期降水量和沉积速率逐渐减小,统计洪水沉积间纹层数量可指示沉积期洪水事件的频率和规模.结合近现代纹泥形成和保存条件,可知该地区沉积期湖泊水体较深,湖水分层,存在一个缺氧环境,具有较小的表面积/深度比,湖盆形态适合,未受到风的侵扰. 相似文献
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Previous studies have evaluated acritarchs from the Balang and Pingzhai sections of the Early-Middle Cambrian Kaili Formation in east Guizhou, China. The results of these studies suggest that the acritarchs in these sections have potential biostratigraphic significance. More recently, 34 samples collected from 83m lower part of the Lower-Middle cambrian Kaili Formation in the Jianshan section of Chuandong, Guizhou Province were prepared for palynological analysis. Analysis of these samples revealed a distinct change in the acritarch assemblages at the bed, which was approximately 46m above the bottom of the Kaili Formation. These findings suggest a boundary represented by an important alteration of the ecological environment. In addition, the position of the acritarch biostratigraphic change is somewhat higher than the boundary between Cambrian Series 2 and Series 3 based on trilobites found in the same section. This indicates that the distinct change in acritarch assemblages is similar to the change in trilobite assemblages that occurs around the boundary between Cambrian Series 2 and Series 3. Therefore, acritarch biostratigraphy can provide data that can be used to define the base of Cambrian Series 3 in this region, and possibly worldwide. 相似文献
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热河生物群--探索中生代生命演化的世界级化石宝库 总被引:5,自引:0,他引:5
最近十多年来,我国在热河生物群各门类生物研究方面取得了一系列重要的发现和成果。我国辽西地区已经成为世界上研究鸟类起源,恐龙的进化,鸟类、哺乳动物以及被子植物的早期演化和辐射等最重要的地区之一。同位素测年技术的广泛应用,表明热河生物群属于早白垩世,在地球上延续了大约2千万年。热河生物群的繁盛和东亚地区当时特有的温暖的淡水和陆地环境具有密切的联系。而频繁的火山活动又是化石得以大量完美保存的重要因素之一。热河生物群的研究还具有很大的潜力,而对化石的科学发掘和保护的任务还十分艰巨。 相似文献
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Despite of the recent influx of reports describing important fossil specimens from the Mesozoic Jehol Biota, detailed information on the mechanism of fossilization and paleoenvironment in which these fossils were deposited is scanty. We present an analysis of microenvironment based upon scanning electron microscope observations of in situ pyrite framboids and microcrystallines of plant and vertebrate feather fossils in the Jehol Biota. Pyrite microcrystallines and framboids occur extensively inside and on surface of plant fossils.Framboids found on feathers and in sedimentary matrix were in a lower abundance. These framboids have diameters ranging from 6 μm to 31 μm with an average of 20 μm, indicating a dysoxic aqueous condition with free oxygen level less than 30 μmol/L for the microenvironment where these framboids were formed. The outgrowth of framboids inside plant tissues suggests the presence of water molecules and free oxygen at the cellular level during pyritization; the relative timing between tissue decay and framboid formation implies a rapid tissue degradation occurred during the very early stage of fossilization. This line of reasoning is consistent with the observation that cell level structure of plant fossils from these deposits is rarely preserved. We propose a "fossil envelop" model to accommodate the different geochemical conditions between the microenvironment surrounding the fossil material and the macroenvironment of background lake bottom water. 相似文献
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OryctocephalinaLermontova,1940是凯里地区凯里组中世界最丰富的掘头虫类组合中个最大的一个属。本文 描述了1个新种及1个新亚种。 相似文献