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1.
根据大量小哺乳动物化石在地层中的分布,将文王沟剖面23层划分出5个生物地层带: I带相当于榆社马会组;II带与Ⅲ带相当于高庄组; IV带相当于麻则沟组; V带为午城黄土底部。根据牛物属种转达换判定出 4个主要生物事件发生时期,分别在 5.8、36、3.0、2.4Ma左右。每一个生物事件集中发生的时期指示生态环境的一次显著向干冷方向变化。 相似文献
2.
甘肃灵台小石沟晚中新世—上新世小哺乳动物生物地层 总被引:7,自引:6,他引:1
根据发现的大量小哺乳动物化石,将甘肃灵台小石沟72074(4)地点剖面划分出4个生物地层带,Ⅰ带与榆社马会组化石组合相当,为中新世晚期;Ⅱ带、Ⅲ带及Ⅳ带代表中国上新世较为完整的小哺乳动物生物地层层序。 相似文献
3.
根据发现的大量小哺乳动物化石,将甘肃灵台小石沟72074(4)地点剖面划分出4个生物地层带。I带与榆社马会组化石组合相当,为中新世晚期;Ⅱ带、Ⅲ带及Ⅳ带代表中国上新世较为完整的小哺乳动物生物地层层序。 相似文献
4.
开展陕西宁强范家沟、赵家坝和四川广元谭家沟3条剖面奥陶系牙形刺生物地层研究。在宁强地区"涧草沟组"发现了凯迪阶中部的Protopanderodus insculptus生物带,它相当于湖北宜昌地区上奥陶统临湘组之同名带;宝塔组由上而下可划分为Hamarodus brevirameus,Baltoniodus variabilis,Yangtzeplacognathus jianyeensis和Y.foliaceus等牙形刺带,属达瑞威尔阶上部至凯迪阶下部,可与湖北宜昌地区中-上奥陶统牯牛潭组顶部至宝塔组的同名带对比;广元地区宝塔组则见Baltoniodus variabilis和Yangtzeplacognathus jianyeensis生物带,属达瑞威尔阶顶部至桑比阶,可与湖北宜昌地区庙坡组或南京地区大田坝组的同名带对比。上述发现改变了先前的认识:陕西宁强地区宝塔组划分为Hamarodus europaeus和Eoplacognathus jianyeensis两牙形刺带,与湖北宜昌地区庙坡组和宝塔组地层相当;四川广元地区宝塔组归入Pygodus serra-Eoplacognat... 相似文献
5.
白垩纪是大洋缺氧及生物灭绝等重大地质事件频发的一个时期,也是全球气候变暖的重要时期。因此,白垩纪研究对于探讨地质历史时期地球的系统演化,尤其是生物与环境之间的协同演化关系,具有十分重要的意义。西藏定日贡扎剖面保存着上白垩统较为完整的地层序列,文中对上白垩统岗巴村口组和宗山组剖面岩石样品中获得的有孔虫化石进行研究,鉴定出有孔虫化石8属22种,识别出Dicarinella asymetrica、Globotruncanita elevata、Globotruncana ventricosa、Radotruncana calcarata等4个有孔虫化石带。根据有孔虫化石确定贡扎剖面的地层时代为晚白垩世桑顿期(Santonian)至坎潘期(Campanian),桑顿阶/坎潘阶界线位于Dicarinella asymetrica带与Globotruncanita elevata带之间。 相似文献
6.
古地磁测年表明,甘肃董湾晚新近纪剖面代表了7.3~3.5 Ma间的连续风成古土壤堆积。在74.8 m厚的剖面上,发现了小哺乳动物化石层位40个,共产出小哺乳动物39种。根据小哺乳动物组合特点,董湾剖面可以划分出4个生物地层带,Ⅰ+Ⅱ带为晚中新世晚期,相当于保德期;Ⅲ+Ⅳ带为上新世早期,相当于榆社期早期。中新统/上新统界线(5.33 Ma)位于剖面距顶部35.5 m处,比以鼢鼠Mesosiphneus最早出现为标志的生物地层Ⅲ带的底界低2 m。由于榆社阶底界直接对应于中新统/上新统界线,该剖面因其良好的地层和生物条件可被推荐为榆社阶界线层型的候选剖面。 相似文献
7.
辽宁凌源及内蒙古宁城地区下白垩统义县组脊椎动物生物地层 总被引:42,自引:5,他引:42
辽宁凌源及相邻内蒙古南部宁城地区义县组发现多个重要脊椎动物化石地点,通过岩 石地层、脊椎动物生物地层和同位素年代地层对比,建立了该地区义县组地层层序。凌源一宁 城地区义县组有 2个脊椎动物化石层位:下部道虎沟层含 Lycopteraer Ichthyofauna, Psittacosaurus Fauna和Confuciusornis Avifauna等3个动物群,可以与北票尖山沟层的四合 屯脊椎动物化石群对比,层位相当于义县组一、三段;上部大王杖子(大新房子)层含 Lycoptera Ichthyofauna和Liaoxiornis Avifauna等2个动物群,为义县组中部沉积,在四合屯地 区缺失。冀北丰宁四岔口-森吉图地区义县组脊椎动物化石层对应于凌源大王杖子层;滦平 大北沟组为义县组最下部沉积,其上覆的大店子组相当于宁城道虎沟层和北票四合屯义县组 一、三段。热河群义县组和九佛堂组发现3个连续的鸟类群;义县组下部Confuciusornis Avifauna、义县组中部Liaoxiornis Avifauna和九佛堂组Cathayornis-Chaoyangia Avifauna。义 县组和九佛堂组Lycoptera I 相似文献
8.
准噶尔盆地北缘谢家阶底界—推荐界线层型及其生物—年代地层和环境演变意义 总被引:1,自引:1,他引:0
新疆准噶尔盆地北缘铁尔斯哈巴合地层剖面构造简单并含有丰富的晚渐新世及早中新世哺乳动物化石。其中铁尔斯哈巴合组及索索泉组沉积基本连续,两组界线位于剖面米距33m处。依据该剖面中8个层位和相邻的XJ99005剖面中18个层位上采集的化石以及它们的上下关系和生物组合性质,划分出5个哺乳动物组合带,其中两个位于铁尔斯哈巴合组中(铁-Ⅱ带),3个在索索泉组下部(索-Ⅰ,Ⅱ,Ⅲ带)。从剖面的铁尔斯哈巴合组、索索泉组和哈拉玛盖组中以0.5m的间距采集了348组古地磁样品,获得的磁性剖面包含了16个正向带和16个反向带(事件),其中包含了相当于地磁极时间表中C7n~C5E段的完整磁极带。铁-Ⅰ~Ⅱ带与塔本布鲁克哺乳动物群相近,为中国已知位置最西、构成门类和数量最多的一个晚渐新世哺乳动物组合。索-Ⅰ带应为中国目前所知的最晚渐新世的哺乳动物带。早中新世索-Ⅱ带与谢家动物群和蒙古中部渐新世—中新世过渡带D带可以对比。早中新世索-Ⅲ带相当于过去使用的“索索泉动物群”,时代大致与乌尔图动物群相当。根据地磁极时间校正,铁尔斯哈巴合剖面中铁尔斯哈巴合组和索索泉组跨越了从24.5Ma(地磁极时带C7n.2n)到18Ma(地磁极时带C5Dr.2r)大约6.5Ma的时间,岩体平均沉积速率大约为2.5cm/千年。剖面中5个生物组合带的时间跨度大致分别为:铁-Ⅰ带:24.4~24.15Ma;铁-Ⅱ带:23.2~23.1Ma;索-Ⅰ带接近但还未到达渐新世/中新世界线的23.03Ma;索-Ⅱ带:21.9~21.7 Ma;索-Ⅲ带:21.68~21.15Ma。我们推荐将铁尔斯哈巴合剖面作为中国区域年代地层单位谢家阶(期)底界界线层型的一个候选剖面。与谢家阶底界相对应的界线暂定在剖面由底向上40.25m处,对应于地磁极时带C6Cn.2n底界。该界线位于索索泉组内部,索-Ⅰ和索-Ⅱ带之间。根据定义,该界线也分别对应于阿基坦阶、中新统以及新近系的底界,年龄为23.03Ma。文章还讨论了下列问题:1)索索泉组的绝大部分应当和谢家阶以及山旺阶地层对比,仅其底部含有索-Ⅰ带化石组合的部分可与塔本布鲁克阶地层对比。2)在进行生物地层对比时尽量使用不同的索索泉组哺乳动物组合带,传统的“索索泉动物群”仅大体相当于索-Ⅲ带。3)许多过去认为的渐新世哺乳动物分子的生存时代实际上延伸到了早中新世,仅以这些分子的存在,不能说明一个动物群及其地层的确切年代。4)塔本布鲁克动物群及相关的期、阶名为有效名称,具有合法性;该阶底界有待确立。5)如果山旺阶底界(谢家阶顶界)位于地磁极时带C6An.1r底,年代为20.43Ma,相应的界线应位于铁尔斯哈巴合剖面89.25m处,因此,铁尔斯哈巴合剖面中有可能产生谢家阶的单位层型,该阶的地质时间跨度为2.6Ma。6)5个生物带都是以兔形类、啮齿类以及食虫类等小哺乳动物为主要分子,而且同门类的属种问具有相当近的演化关系,说明这个地区从晚渐新世到早中新世的一段时期中,动物群性质没有明显变化,总体上反映了一个从早渐新世以来就比较干旱的环境;渐新世和中新世动物群成分在种一级上仍有明显差异;而相当于谢家动物群的索-Ⅱ带则带有明显的过渡性质。7)从索索泉组的岩性、分布的地理部位以及与甘肃秦安剖面相近的时代和动物群等来看,不排除含有风成沉积物的可能。 相似文献
9.
黑龙江宁安盆地穆棱组及其孢粉型组合新发现 总被引:8,自引:2,他引:6
黑龙江宁安盆地是一个具有油气勘探远景的中小型盆地,主要目的层为下白垩统。新发现了一套相当于邻区穆棱组的地层,孢粉化石十分丰富,建立了5个孢粉组合带,通过对两口石油探井生物地层的研究,建立了该舅地新的地层层序,并对穆棱组的时代和沉积环境进行了讨论。 相似文献
10.
《微体古生物学报》2017,(3)
通过对前人在南海北部地区的中新世浮游有孔虫生物地层研究结果的对比,发现其中分带方案有一定的差异,而且分带依据和生物事件年龄也存在争议,特别是利用岩屑样品进行地层划分与对比的钻井尤为突出,对于后续研究和南海地区的地层对比都有较大的不利影响。基于此,我们对比了前人在南海北部中新世浮游有孔虫生物地层的研究成果,结合"2012国际地质年代表"和ODP184航次提供的经天文调谐的浮游有孔虫生物事件年龄,总结了研究区中新世以浮游有孔虫生物事件末现面为基础的13个地层分带,为南海北部地区浮游有孔虫生物地层的划分与对比,特别是生产单位利用岩屑样品进行研究的钻井地层划分,提供了可供对比的基础与依据。并依据上述分带方案,将南海北部陆丰凹陷LF14-4-1D井中新世地层详细划分出早中新世至上新世期间共9个有孔虫化石带或联合带,即早中新世M3带,早-中中新世M4-6联合带,中中新世M7带,M8带,M9带,M10带,M11带,晚中新世M12带和晚中新世-早上新世M13-PL1联合带。 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
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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
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.
G. V. Iyengar 《Biological trace element research》1987,12(1):263-295
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.
Vladimir Zaichick Sofia Zaichick Vasilii Karandashev Sergey Nosenko 《Biological trace element research》2009,129(1-3):107-115
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
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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