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1.
临海浙江翼龙及长尾雁荡鸟化石赋存于浙东小雄盆地晚白垩世形成的地层中。通过对比化石骨骼结构及生态习性,结合对地质背景、古地理、古生态环境及化石产地剖面岩性岩相、沉积构造、化石赋存状态、古植物及孢粉组合等研究认为:小雄盆地继承了早白垩世晚期永康期陆相盆地的构造格局,晚白垩世小雄早期,盆地间分布众多残存的湖泊沼泽,它们是翼龙类和鸟类最后的栖息地。受间歇性火山喷发影响,空落相火山碎屑物导致的湖泊萎缩及沼泽化、水体酸化、气候干热等是造成生活在湖泊沼泽周边和翱翔于天空中的翼龙及鸟类集群死亡的主要因素。小雄中晚期,浙东地区经历了较大规模的酸性岩浆喷溢及火山喷发堆积,为临海国家地质公园流纹岩地貌演化奠定了物质基础。  相似文献   

2.
浙东沿海上白垩统小雄组的建立   总被引:1,自引:0,他引:1  
浙东临海、三门东部的小雄盆地,发育一套中酸偏碱性的火山岩。长期以来,将其称为塘上组。详细的地质调查研究表明;这套火山岩与以天台盆地为代表的塘上组,在火山岩岩石组合、层序、古生物化石组合和同位素年龄等均不相同。火山岩是超覆于永康群馆头组、朝川组和小平田组之上,成岩时代在85—98Ma,产晚白垩世翼龙和鸟类化石,是晚白世的喷发一沉积产物。为一独立的具有自身特色的岩石地层单位,故建立新的岩石地层单位一小雄组。  相似文献   

3.
马尔柯夫预测模型在环境预测中的应用   总被引:2,自引:0,他引:2  
马尔柯夫预测模型利用系统的现在状态和发展方向去预测系统将来可能状态的概率。它在选择污染治理策略,环境状态变化的可能方向及发展趋势预测等方面地产可应用,其预测结果为某事件实现的概率即可能程度。  相似文献   

4.
正东依雄浑巍峨的白狼山,西衔蜿蜒流淌的大凌河,建昌县境山峦起伏,沟壑纵横,北魏时因县地曾受建德、昌黎二郡所辖,乾隆年间取两古郡首字而得名。在建昌这片古老而神奇的土地上,孕育出灿烂辉煌的历史文明。文明靠历史衔接,建昌历史源远流长,山嘴子洞穴遗址将中华文明史提前了1 000多年,可与牛河梁红山文化遗址媲美。赫氏近鸟龙、隐居森林翼龙、孔子天宇龙等世界级珍贵化石的发现,让建昌举世闻名。  相似文献   

5.
由于集成电路芯片生产过程中使用的危险化学品较多,这些化学品在使用、管理和运输过程中均存在一定的风险,针对该项目的环境特点和工程特点,论述了在集成电路芯片生产过程中可能产生的环境风险,分析其存在突发事故的可能性及隐患,分析其可能造成的危害及应采取的预防措施。  相似文献   

6.
锰矿砂对取代酚的光氧化作用研究   总被引:16,自引:1,他引:16  
研究了不同条件下锰矿砂对4种取代酚的光氧化作用。结果表明,pH=3.10±0.04时,苯酚、对氯苯酚、对氨基酚及对苯二酚均能被锰矿砂光催化氧化。低pH值,适当的苯酚初始浓度及适当的锰矿砂浓度有利于锰矿砂对取代酚的氧化;离子强度和溶解氧浓度不影响反应速度。对其可能的机理及取代基效应进行了讨论。  相似文献   

7.
《世界环境》2011,(5):95-95
一个由六名英国人组成的探险团队,8月26日划船抵达了15年前的地磁北极点,成为全球第一批划船到达这一区域的探险者。科学家之所以能划船到北极,皆是因为受到气候变化的影响,北冰洋冰盖在过去30年的不断退缩,使得这一过去认为不可能的探险成为了可能。这些探险家们是今年  相似文献   

8.
明火反烧技术及其应用   总被引:1,自引:0,他引:1  
魏惠荣 《陕西环境》1995,2(1):28-30
在我国的冶金,机械等行业,工业炉窑数量多,种类杂,多以煤为燃料,以人工层燃为燃烧方式,由于其装备水平低,技术落后,故耗煤多,污染大,已不能适应生产发展和保护环境的需要,而科学地改变燃烧工艺却能创造良好的燃烧条件,使可能造成的可燃物充分燃烧,从而提高燃烧效率,降低煤耗,从根本上解决消烟除尘问题,其环境效益和经济效益均佳,明火反烧技术正是这样一种科学的燃烧工艺。  相似文献   

9.
高效液相色谱法测定饮用水酚类分合物   总被引:1,自引:0,他引:1  
酚类化合物是芳香族羟基化合物,其羟基与苯环上的碳相连,根据苯环上羟基和氯根的数目和位置,一般常见的酚类有:苯酚、4-硝基酚、3-甲基酚、2,4-二氯酚、2,4,6-三氯酚、五氯酚等。在天然水中,一般检出不出酚类化合物,但受到如焦化、煤气制造、石油精炼、木材防腐、造纸及石油化工所排放的工业废水污染的水源可能含有该类物质。这些酚类化合物一般毒性不大,但多有恶臭,尤其苯酚,在饮用水加氯消毒时能形成嗅味更强烈的氯酚。因此,研究酚类化合物检测方法已迫眉睫。  相似文献   

10.
丙溴磷影响海洋微藻生长机理的初步研究   总被引:13,自引:1,他引:13  
研究了丙溴磷对三角褐指藻和青岛大扁藻生长的影响及其可能的机理。结果显示,低浓度的丙溴磷可以刺激它们的生长,高浓度的丙溴磷则对其生长产生抑制作用;低浓度丙溴磷还使藻细胞的脂质过氧化程度在低水平增高,SOD活性有所降低;高浓度时则使其指质过氧化程度过量升高,SOD活性显著下降,加入抗氧化剂不仅可抑制低浓度丙溴磷对微藻生长的刺激效应,而且能缓解高浓度丙溴磷对微藻的毒害作用,因此,丙溴磷作用于微灌的抗氧化  相似文献   

11.
Die Pterosaurier     
During the Mesozoic the pterosaurs, or flying reptiles, were widely spread over the world. The distribution of the pterosaur fossils shows a restriction to a zone within 40 ° latitude in relation to the paleoequators. Probably all pterosaurs had hairs, thus indicating homoiothermic conditions. The brain structure is similar to the bird's brain but relatively smaller. With regard to certain osteologic features the pterosaurs have to be classified as archosaurs. Their origin is not known and they probably became extinct due to the change of climate during the late Cretaceous.  相似文献   

12.
Toothless pterosaurs played a key role in broadening the taxonomic, morphological and ecological diversity of Cretaceous pterosaurs. Here we report a complete, articulated skeleton of a 1.4-m-wingspan pterosaur from the Lower Cretaceous Jiufotang Formation of Liaoning Province, China which is identified as a new genus and species, Shenzhoupterus chaoyangensis gen. et sp. nov. The new taxon is edentulous, with a relatively large skull and a remarkably large, tall nasoantorbital fenestra that extends well above the main part of the braincase. Phylogenetic analysis shows that Shenzhoupterus gen. nov. belongs in a distinct clade of azhdarchoid pterosaurs, formally recognised here as a new family, Chaoyangopteridae, that also includes Chaoyangopterus, Jidapterus and Eoazhdarcho from the Jiufotang Formation and Eopteranodon from the Yixian Formation. These new data clarify recent confusion surrounding the systematics of these Lower Cretaceous taxa and provide new insights into the evolutionary history of pterosaurs.  相似文献   

13.
关于浙东塘上组的时代问题   总被引:5,自引:0,他引:5  
浙东塘上组中、下部火山岩的沉积夹层中首次发现?Halysestheria叶肢介及孢粉化石,并找到Pseudofrcneloysis parceramosa与P.cf.rapillosa为主的植物化石。本文综合各门类化石所反映的地质时代,认为浙东塘上组应归属早白垩世晚期。这与剖面上获得的同位素年龄值(110 Ma)相吻合。塘上组层位与邻区石帽山群上组、禾口组(闽),周家店组(赣东),徽州组上部(皖南)及葛村组上部(江苏)相当。  相似文献   

14.
Birds and crocodilians (extant archosaurs) have differing, distinctive morphologies. Birds have respiratory airsacs with diverticula that pneumatize the postcranial skeleton, a feature absent in crocodilians. Bony correlates of pneumatic sinuses are known in the vertebrae of some non-avian dinosaurs and in pterosaurs - taxa more closely related to birds than crocodilians. This and the apparent absence of pneumatic postcranial bones in fossil archosaurs more closely related to crocodilians than to birds, has been interpreted as evidence that postcranial pneumaticity is a derived character of birds and their nearest fossil relatives. The presence of apparent osteological correlates of postcranial pneumaticity is here reported in some non-crown-group archosaurs, and some of the fossil taxa more closely related to crocodilians than to birds. This suggests that the last common ancestor of birds and crocodilians might have had a pneumatized postcranium, and that the absence of this feature in crocodilians might be derived.  相似文献   

15.
The bird fossil record is globally scarce in Africa. The early Tertiary evolution of terrestrial birds is virtually unknown in that continent. Here, we report on a femur of a large terrestrial new genus discovered from the early or early middle Eocene (between ~52 and 46?Ma) of south-western Algeria. This femur shows all the morphological features of the Phororhacoidea, the so-called Terror Birds. Most of the phororhacoids were indeed large, or even gigantic, flightless predators or scavengers with no close modern analogs. It is likely that this extinct group originated in South America, where they are known from the late Paleocene to the late Pleistocene (~59 to 0.01?Ma). The presence of a phororhacoid bird in Africa cannot be explained by a vicariant mechanism because these birds first appeared in South America well after the onset of the mid-Cretaceous Gondwana break up (~100?million years old). Here, we propose two hypotheses to account for this occurrence, either an early dispersal of small members of this group, which were still able of a limited flight, or a transoceanic migration of flightless birds from South America to Africa during the Paleocene or earliest Eocene. Paleogeographic reconstructions of the South Atlantic Ocean suggest the existence of several islands of considerable size between South America and Africa during the early Tertiary, which could have helped a transatlantic dispersal of phororhacoids.  相似文献   

16.
A new giant pterosaur, Hatzegopteryx thambema, nov.gen., nov.sp., from the Maastrichtian Densu?-Ciula Formation of Romania is remarkable for its very large size (estimated wing span > or = 12 m) and for the robustness of its large skull, which may have been nearly 3 m long. The stout skull bones contrast with the usually thin and slender skull elements of other pterosaurs, and raise the question of how the weight of the skull was reduced in order to make flight possible. The answer probably lies in the very peculiar internal structure of the bones, which consists of a dense network of very thin trabeculae enclosing small alveoli. This structure is reminiscent of expanded polystyrene and, like it, probably combined strength with lightness.  相似文献   

17.
机动车排放污染的主要监测方法和手段   总被引:2,自引:2,他引:0       下载免费PDF全文
笔者重点介绍了中国的机动车污染监测方法 (包括怠速法、工况法、汽油机排放污染物测量方法、柴油机自由加速及全负荷烟度测量方法等 ) ,同时简要介绍了欧美及日本机动车排放污染的主要监测方法。另外 ,简述了公路隧道法等机动车排放污染的间接监测方法。   相似文献   

18.
Arctostylopids are common in Late Palaeocene and Early Eocene mammal faunas of Asia, but they are rare in North America. From the time of their first discovery, arctostylopids were grouped with the strictly endemic South American Notoungulata based on their strikingly similar dental morphology. This relationship was challenged based on dental morphology of more recently discovered arctostylopids and on supposed tarsal morphology (based on unassociated material) of the Asian arctostylopid Palaeostylops. Therefore, Arctostylopidae were placed in a separate order, Arctostylopida, of enigmatic affinities. Many authors, however, continue to unite Arctostylopidae and Notoungulata based on dental similarities. In the Late Palaeocene Subeng site in Inner Mongolia, we identified the Palaeostylops tarsals based on their size and abundance. This identification is supported by comparison to unpublished Arctostylops tarsals from the North American Clarkforkian, derived from a semi-articulated skeleton also including dental material. Tarsal morphology shows moderate similarity to the gliriform Pseudictops, and strong resemblance to the tarsally conservative gliroid Rhombomylus. Hence, Arctostylopidae may best be grouped with Asian non-gliroid Gliriformes, which we interpret as having dispersed into North America in the Late Palaeocene.Pieter Missiaen is an aspirant of the Research Foundation-Flanders (RF-Flanders)  相似文献   

19.
Although disinfection byproducts(DBPs) in drinking water have been suggested as a cancer causing factor, the causative compounds have not yet been clarified. In this study, we used liquid chromatography quadrupole-time-of-flight spectrometry(LC-QTOF MS) to identify the unknown disinfection byproducts(DBPs) in drinking water produced from Taihu Lake source water, which is known as a convergence point for the anthropogenic pollutants discharged from intensive industrial activities in the surroundi...  相似文献   

20.
基于2000—2019年全球猪肉贸易数据,采用复杂网络分析方法,研究了全球猪肉贸易网络格局演变及中国猪肉贸易网络特征,并进一步探讨了中国扩大猪肉进口的潜在贸易伙伴选择问题。研究结果表明:过去近20年来,全球猪肉贸易网络核心国相对固定,猪肉贸易网络呈“碎片化”特征。目前中国已经成为全球第一大猪肉进口国,且进口呈现北美、西欧、南美“三足鼎立”的来源格局。未来中国扩大猪肉进口,潜在的贸易伙伴可选范围比较广泛。一方面可以继续巩固和深化同德国、西班牙、美国、巴西等传统贸易伙伴之间的合作关系,另一方面也可以积极拓展朋友圈,增加从意大利、比利时等其他出口国及泰国、越南等周边国家的进口,以打造更加多元高效的猪肉进口网络。  相似文献   

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