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1.
第  1 期论克拉梭粉外壁的超微结构 :西伯利亚侏罗纪的一个孢体NataliaE .Zavialova (1 )……………………………………………西伯利亚西部侏罗纪植物微体化石的热变质作用LidiyaV .Rovnina TatianaN .Savikina (8)………………………………印度Mahanadi盆地井下二叠纪下冈瓦纳岩层的微体植物化石组合ShampaChakraborty (1 3)…………………………………根据孢粉资料确定伏尔加地区弗拉阶和法门阶界线ValentinaN .Mantsourova (2 2 )……………………………………………中国北方上新世降温事件及其对温度纬度梯度变化的影响刘耕武…  相似文献   

2.
陕西镇安西口地区构造上属于南秦岭微板块,二叠纪时该地区与华南板块被勉略洋(东古特提斯洋的一个分支)分隔,而成为南秦岭微板块上的一个孤立台地。由于其二叠纪时处于华北和华南板块的汇聚带,同时又位于沟通古特提斯和泛大洋的重要通道上,其特殊的古地理位置使其具备与华南乃至全球其它地区二叠系对比的重要古地理和古环境意义,具有成为二叠系经典剖面的潜力。本次研究共分析60件样品,从中发现具有地层划分对比意义的平台型牙形刺分子4属18种。这些化石分布于上石炭统至上二叠统的地层中,且主要产于中二叠统水峡口组和上二叠统的西口组、熨斗滩组及龙洞川组。根据牙形刺的产出情况将研究区二叠系划分出13个带,自上而下为:长兴阶(Changhsingian)的Clarkina subcarinata带和C.changxingensis带;吴家坪阶(Wuchaipingian)的C.postbitteri带,C.dukouensis带,C.liangshanensis带和C.orientalis带;卡匹敦阶(Capitanian)的Mesogondolella posterserrata带,M.shannoni带,M.altudaensis带和M.granti带;罗德阶(Roadian)的M.nanjingensis带;亚丁斯克阶(Artinskian)的Sweetognathus whitei带;阿瑟尔阶(Asselian)-萨克马尔阶(Sakmarian)的S.inornatus带。最后,主要依据牙形刺带对陕西镇安西口二叠系剖面的生物地层进行重新划分,确立了3统9阶,从而能够更好地进行洲际对比。  相似文献   

3.
安徽巢湖地区早三叠世菊石序列   总被引:13,自引:0,他引:13  
由于地处低纬度下扬子碳酸盐缓坡台地较深水区 ,安徽巢湖地区的下三叠统由一系列泥、灰岩旋回层组成 ,并含有丰富的菊石化石。通过对巢北平顶山和马家山一带上二叠统顶部和下三叠统多条剖面的系统研究 ,建立了在华南乃至低纬度特提斯地区具有代表性的、以属级分类单位为基础的下三叠统菊石生物地层序列 (从下而上 ) :Ophiceras Lytophiceras带、Gyronites Prionolobus带、Flemingites Euflemingites带、Anasibirites带、Columbites Tirolites带和Subcolumbites带。在提议的全球印度阶 奥伦尼克阶界线层型候选剖面———巢湖平顶山西坡剖面上 ,Flemingites Euflemingites带之底与牙形石Neospathoduswaageni首现点比较接近 ,可以作为本界线主要辅助标志之一。记述采自该区上二叠统顶部及下三叠统 ,尤其是印度阶 奥伦尼克阶界线附近的一些具有年代地层意义的菊石化石资料 。  相似文献   

4.
虽然在华南中泥盆世艾菲尔期(Eifelian)较深水或斜坡相地层中产有许多国际标准的牙形类带化石,但在广阔的浅海相地层中却很难寻觅到其踪影。华南浅海相沉积地区是否缺失艾菲尔阶?在野外众多剖面的实地考察中表明,从下泥盆统埃姆斯阶到中泥盆统吉维特阶都是连续沉积,中间并没有发现地层的缺失或间断现象。浅海相的艾菲尔阶与其上覆的吉维特阶和下伏的埃姆斯阶都是连续沉积,说明可能是由于海水太浅,不太适合那些国际标准分子的生存而已。艾菲尔期中期末发生一次生物灭绝事件(Mid-Eifelian event),favositids,heliolitids和许多古老类型的珊瑚在地球上灭绝。华南艾菲尔期四射珊瑚可以划分成下、上两个完全不同的组合:1)Utara-tuiasinen sis-Sociop hyllum minor组合(牙形类partitus带—costatus带);2)Columnaria spinosa-Dendrostella praerhenana组合(牙形类australis带—kocklianus带)。  相似文献   

5.
刘俊 《化石》2016,(3):43-52
正1841年罗德里克·默奇森(Roderick Murchison)命名了Permian(二叠系)。他依据的是俄罗斯乌拉尔山脉西坡附近的地层,Permian一词就源于彼尔姆(Perm)地区。因为这套地层分为上下两统,中文名称被译为二叠系。俄罗斯的二叠系非常经典,它的各个阶名作为世界标准长达150多年,到2000年二叠系三分,卡赞阶和  相似文献   

6.
文章通过贵州盘新塘原下二叠统下部紫松阶珊瑚化石的分析,将该地层划归上石炭统上部。描述上炭统威宁阶,过岩阶和紫松阶的四射珊瑚6属7种,其中5新种,通过对这些珊瑚的形态构造进行了剖析,略述了该地区在晚石炭世的环境特征。  相似文献   

7.
牟林 《古生物学报》2011,(4):439-449
基于一些业已报道的Kungurian阶与Roadian阶界线附近的菊石材料进行重新研究,认为中国中、下二叠统界线附近的菊石生物群主要分布在华南和中国西部两个地区.通过与俄罗斯地区同时代的菊石动物群比较后认为中国在这一界线附近的菊石群以地方性的分子为主,主要包括:假海罗菊石亚科(Pseudohaloritinae)和寿昌...  相似文献   

8.
近30年来,巴基斯坦盐岭地区的Wargal组和Chhidru组以及在喜马拉雅地区相当地层的地质时代被许多学者视为中二叠世(瓜达鲁普世)。根据华南与盐岭地区瓜达鲁普统和乐平统的牙形类化石带对比,可以确定Amb组和Wargal组底部的时代为瓜达鲁普世晚期,瓜达鲁普统与乐平统的界线位于Wargal组下部,吴家坪阶与长兴阶的界线位于Chhidru组的下部,而二叠与三叠系的界线位于Mianwali组下部的Kathwai段之内。我国西藏南部色龙群及相当地层含有与巴基斯坦盐岭地区Kalabagh段和Chhidru组可对比的乐平世腕足动物群以及二叠系—三叠系界线附近连续的牙形类化石带,由此可以推定色龙群的时代应为乐平世。  相似文献   

9.
贵州罗甸纳水上石炭统(宾夕法尼亚亚系)地层的再研究   总被引:5,自引:0,他引:5  
本文详细描述了贵州罗甸纳水上石炭统(宾夕法尼亚亚系)剖面的生物地层和年代地层,其牙形刺序列自上而下可详细划分为:Streptognathodus isolatus, S. wabaunsensis, S. tenuialveus, S. firmus, Idiognathodus nashuiensis , Streptognathodus simulator, S. guizhouensis , S. gracilis-S, excelsus , S. cancellosus , S. clavatulus , S. nodocarinatus , Idiognathodus podolskensis , Mesogondolella clarki -Idiognathodus robustus , Diplognathodus ophanus-D, ellesmerensis, Idiognathoides ouachitensis, Streptognathodus expansus, Idiognathoides sulcatus parva, Idiognathodus primulus-Neognathodus bassleri, Idiognathodus primulus-Neognathodus symmetricus, Neognathodus symmetricus, Idiognathoides corrugatus-I, pacificus, I. sinuatus, I. sulcatus sulcatus, Declinognathodus noduli ferus 和 Gnathodus bilineatus bollandensis 等带。 Declinognathodus noduliferus 和 Streptognathodus isolatus 的首次出现分别代表上石炭统(宾夕法尼亚亚系)和二叠系的开始。根据牙形刺和有孔虫的序列,罗甸纳水剖面的上石炭统(宾夕法尼亚亚系)地层自下而上可划分为罗苏阶(Luosuan)、滑石板阶(Huashibanian)、达拉阶(Dalaan)和马平阶(Mapingian),并可与俄罗斯的巴什基尔阶(Bashkirian)、莫斯科阶(Moscovian)、卡西莫夫阶(Kasimovian)和格舍尔阶(Gzhelian),北美的莫罗阶(Morrowan)、阿托克阶(Atokan)、得梅因阶(Desmoinesian)、密苏里阶(Missourian)和弗吉尔阶(Virgilian)进行对比。另外,本文也详细讨论了剖面中的石炭系中间界线及石炭-二叠系界线。  相似文献   

10.
贵州珊瑚是一种个体大,隔壁多而长,鳞板带宽,构造较特征的双带型珊瑚。俞建章(1931)创立该属时仅描述了Kueichouphyllum sinense Y(?)一种,产于下石炭统大塘阶上司组,视为Yuanophyllum带下亚带的带化石。俞建章(1933)研究我国南方下石炭统珊瑚化石,又描述了该属另一新种和一新亚种Kueichouphyllum heishihkuanense Y(?), K.sinense gracile Y(?),其层位仍为大塘阶上司组。杨敬之、盛金章、吴望始等(1962)总结中国的石炭系时指出,我国南方地区大塘早期地层里产有许多Kueichouphyllum sinense Y(?),与Thysanophyllum共生,主张以Thysanophyllum-Kueichouphyllum sinense共同作  相似文献   

11.
A new polynitro cage compound 2, 4, 6, 8, 10, 12, 13, 14, 15-nonanitro-2, 4, 6, 8, 10, 12, 13, 14, 15-nonaazaheptcyclo [5.5.1.1(3,11).1(5,9)] pentadecane (NNNAHP) was designed in the present work. Its molecular structure was optimized at the B3LYP/6-31 G(d,p) level of density functional theory (DFT) and crystal structure was predicted using the Compass and Dreiding force fields and refined by DFT GGA-RPBE method. The obtained crystal structure of NNNAHP belongs to the P-1 space group and the lattice parameters are a = 9.99 ?, b = 10.78 ?, c = 9.99 ?, α = 90.01°, β = 120.01°, γ = 90.00°, and Z = 2, respectively. Based on the optimized crystal structure, the band gap, density of state, thermodynamic properties, infrared spectrum, strain energy, detonation characteristics, and thermal stability were predicted. Calculation results show that NNNAHP has detonation properties close to those of CL-20 and is a high energy density compound with moderate stability.  相似文献   

12.
Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.  相似文献   

13.
14.
The goal of this article was to establish reference ranges of the concentration of trace elements in human serum and to compare these results with those reported by other authors. We describe the sample preparation and measurement conditions that allow the rapid, precise, and accurate determination of Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum samples (n=110) by inductively coupled plasma-mass spectrometry (ICP-MS). Accuracy and precision were determined by analyzing three reconstituted reference serum samples by comparison with other methods and by the standard addition procedure. The advantages of the ICP-MS method include short time of analysis of the elements mentioned, low detection limit, high precision, and high accuracy. Disadventages include a high risk of contamination due to the presence of some of the elements of interest in the environment, the relatively delicate sample handling, and the high cost of the equipment.  相似文献   

15.
This report attempts to formulate reference ranges of elemental concentrations for 15 trace elements in selected human tissues and body fluids. A set of samples consisting of whole blood, blood serum, urine, milk, liver, and hair were chosen and considered for 15 elements of biological significance: As, Cd, Co, Cr, Cu, F, Fe, I, Hg, Mn, Mo, Ni, Pb, Se, and Zn. The results represent wholly or partially data received from 40 countries of the global regions of Africa, Asia, Europe, North, South, and Central America, Australia, and New Zealand. This survey, even if qualitative, has been useful in demonstrating certain trends of trace-element scenarios around the world. It is of course recognized that both diet and environment exert a strong influence on the distribution pattern of several elements, such as As, Cd, Mn, Pb, Se, and Zn. A limited comparison of the available information on soil status of different countries reflected some interesting associations for elements, such as Mn and Zn. Importantly, this study revealed that only a few countries were in a position to identify a reasonable amount of data on samples requested for this project. Regretably, for a number of countries, any dependable data for even such essential elements as Cu, Fe, and Zn were not available. In view of the nutritional importance of many elements, the time is ripe for concerted efforts by intergovernmental agencies to initiate investigations or commission task forces/projects to generate reliable reference data for selected global regions, which sadly lack data of any kind at present.  相似文献   

16.
The variation with age of the 18 trace element mass fractions and some histological characteristics of intact prostate glands of 50 subjects aged 0–30 years was investigated by instrumental neutron activation analysis, inductively coupled plasma atomic emission spectrometry, and a quantitative morphometric analysis. Mean values ± standard error of the mean (M ± SΕΜ) for the mass fractions (in milligrams per kilogram wet tissue) of these trace elements in pre-puberty were: Al 28.5 ± 9.0, B 0.40 ± 0.11, Ba 1.48 ± 0.44, Br 10.5 ± 1.5, Ca 241 ± 30, Cl 3,203 ± 278, Cu 3.51 ± 0.89, Fe 33.7 ± 4.1, K 2,364 ± 145, Li 0.020 ± 0.004, Mg 153 ± 23, Mn 0.46 ± 0.06, Na 2,286 ± 130, P 1,391 ± 100, S 1,698 ± 132, Si 62 ± 11, Sr 0.38 ± 0.08, and Zn 27.6 ± 2.3. During puberty and postpuberty, when there is a significant increase in circulating androgens, the mean values were: Al 7.2 ± 1.4, B 0.21 ± 0.05, Ba 0.25 ± 0.06, Br 5.8 ± 1.0, Ca 433 ± 81, Cl 2,314 ± 201, Cu 1.77 ± 0.13, Fe 20.9 ± 1.6, K 2,585 ± 118, Li 0.0088 ± 0.0014, Mg 232 ± 27, Mn 0.34 ± 0.04, Na 1,875 ± 107, P 1,403 ± 98, S 1,673 ± 73, Si 22.2 ± 3.1, Sr 0.22 ± 0.03, and Zn 93.3 ± 8.9. Mean values (M ± SΕΜ) of percent volumes (%) of the stroma, epithelium and lumen in the prostate before puberty were 73.4 ± 2.6, 20.4 ± 1.7, and 4.45 ± 0.94, respectively, versus 46.5 ± 2.5, 38.5 ± 1.9, and 14.9 ± 1.2 during puberty and postpuberty. This work’s results confirm that the Zn mass fraction in prostate tissue is an androgen-dependent parameter. For the first time it has been demonstrated that the glandular lumen is a main pool of Ca, Mg, and Zn accumulation and that the stroma is a main pool of Al, B, Ba, Br, Cl, Cu, Fe, Mn, Na, and Si accumulation in the normal human prostate, for the age range 0–30 years. It was concluded that the Ca, Mg, and Zn binds tightly within the prostatic fluid, because the volume of glandular lumen reflects the volume of prostatic fluid.  相似文献   

17.
The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.  相似文献   

18.
19.
《Ibis》1894,36(3):447-460
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20.
Oral cancer is one of the main causes of cancer-related deaths in South-Asian countries. There are very limited treatment options available for oral cancer. Research endeavors focused on discovery and development of novel therapies for oral cancer, is necessary to control the ever rising oral cancer related mortalities. We mined the large pool of compounds from the publicly available compound databases, to identify potential therapeutic compounds for oral cancer. Over 84 million compounds were screened for the possible anti-cancer activity by custom build SVM classifier. The molecular targets of the predicted anti-cancer compounds were mined from reliable sources like experimental bioassays studies associated with the compound, and from protein-compound interaction databases. Therapeutic compounds from DrugBank, and a list of natural anti-cancer compounds derived from literature mining of published studies, were used for building partial least squares regression model. The regression model thus built, was used for the estimation of oral cancer specific weights based on the molecular targets. These weights were used to compute scores for screening the predicted anti-cancer compounds for their potential to treat oral cancer. The list of potential compounds was annotated with corresponding physicochemical properties, cancer specific bioactivity evidences, and literature evidences. In all, 288 compounds with the potential to treat oral cancer were identified in the current study. The majority of the compounds in this list are natural products, which are well-tolerated and have minimal side-effects compared to the synthetic counterparts. Some of the potential therapeutic compounds identified in the current study are resveratrol, nimbolide, lovastatin, bortezomib, vorinostat, berberine, pterostilbene, deguelin, andrographolide, and colchicine.  相似文献   

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