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1.
软骨鱼类的微体化石具有区域甚至全示性的地层对比潜力,还可以用于有机成熟度的分析。贵州关岭中晚三叠世法郎组产数量丰富,类型繁多的软骨鱼类微体化石,本文按照形态分类系统,对其进行了分类和描述。  相似文献   

2.
记述了浙江长兴县煤山剖面、江西修水县四都乡东岭剖面和信丰县铁石口镇铁石口剖面二叠/三叠系界线以下的软骨鱼类10个类别的微体化石,包含5科6属5种,其中有3新属5新种,它们是:刘氏煤山鲨(Meishanselache liuigen.et sp.nov.)、王氏长兴鲨(Changxingsela-che wangigen.et sp.nov.)、东岭中华尖齿鲨(Sinacrodus donglingensis gen.et sp.nov.)、修水滑齿鲨(Lissodus xiushuiensis sp.nov.)和江西多尖齿鲨(Polyacrodus jiangxiensis sp.nov.)。浙、赣两省的这批软骨鱼类微体化石显示两个特点:组成以弓鲛超科化石为主;发现于特提斯区三叠纪的鲨类与发现于中国南方晚二叠世的鲨类具有密切的亲缘关系。这是包含全球二叠/三叠系界线层型剖面和点位(GSSP)在内的全球二叠/三叠系界线以下软骨鱼类微体化石序列的首次报道。软骨鱼类是我国鱼类化石研究中最为薄弱的一个环节,本文化石的记述大大地填补了这个薄弱环节。  相似文献   

3.
塔里木板块巴麦地区志留系钻井岩芯中的化石十分贫乏,很难作高精度地层划分和对比。本文综合分析柯坪-巴楚露头区及巴麦覆盖区典型钻井志留系,对巴麦地区多口主要钻井志留系岩电特征对比厘定。井下志留系自下而上可划分为早志留世柯坪塔格组、塔塔埃尔塔格组及依木干他乌组。柯坪塔格组仅发育上段,缺失中-下段,主要见于D5-B7-C2井以北地区,厚度一般在200m左右,具有北厚南薄、东厚西薄的变化;塔塔埃尔塔格组地层序列较全,均发育下部的红泥岩段与上部的上砂岩段,主要见于D5-B7-C2井以北地区,厚度一般在400m左右,最厚可大于1 000m,由南向北变厚;依木干他乌组序列较全,分布于C2-B8-C7井西部及C1-B4-B1井以北,厚度一般在200m左右,具有北厚南薄、西厚东薄的特点,最厚可达300m以上。  相似文献   

4.
对甘肃靖远一带和内蒙古自治区黑山地区早石炭世前黑山组、臭牛沟组和靖远组中三亚纲鱼类微体化石进行了形态学和古组织学研究。这些化石涉及 7个目或亚目 ,含 4属 4种 ,其中有 2新种。文中记述的属均为全球广布的属。建立了 3个早石炭世鱼类组合 ,这是我国早石炭世第一个鱼类组合序列。辐鳍鱼类和软骨鱼类中 2个目的化石均为我国早石炭世鱼类的首次记录  相似文献   

5.
本文报道产自贵州西南部中三叠世拉丁期晚期竹杆坡组的软骨鱼类鱼鳞化石,这些化石归属于4属6种,其中有3新种,即Rugosicoronaci rcacarina sp.nov.,Fragilicorona wanlantricuspis sp.nov.和Glabrisubcorona triridgecorona sp.nov.。并将中国西南部与加拿大东南部相当地层中软骨鱼类微体化石进行了初步对比。  相似文献   

6.
本文首次报道产自鄂西宜昌大天坑茅口组中的几种软骨鱼类的鱼鳞化石和硬骨鱼类(葆青鱼和古鳕鱼)鱼牙化石,这些鱼类微体化石与牙形刺Mesogondolella aserrata,Hindeodus minutus,Ellisonia teicherli,Xaniog-nathus elongatus等共生,表明其所在地层的时代为中二叠世。  相似文献   

7.
扬子区志留纪兰多维列统胞石序列   总被引:11,自引:3,他引:8  
扬子区志留系的兰多维列统(Llandovery),以笔石最丰,研究亦最详.正是已故的穆恩之教授,"奠定了我国笔石地层的分层和笔石分带的基础"(卢衍豪,1987,14页).然而,有些地层不仅不含笔石,而且其它大化石,或缺如,或偶有见及,亦难作洲际对比.因此,这些地层的时代问题纷争不已.又是穆师高瞻远瞩,生前多次疾呼,要研究微体化石并对其寄予厚望.作者对于兰多维列统胞石序列的研究,正是在他的大力支持与亲切关怀下开展起来的.如今,在这些地层中已相继觅得有助于确定时代的胞石类化石.胞石序列,草创初成,始可告慰穆师于九泉之下.  相似文献   

8.
西秦岭是开展华南板块志留/泥盆系界线层序研究的一个重要地区.该区普通沟剖面中的志留/泥盆系过渡带包括羊路沟组上部和下普通沟组下部,产丰富的鱼类微体化石,包括花鳞鱼类、棘鱼类、软骨鱼类及盾皮鱼类.这些化石构成两个完全不同的鱼类微体化石组合:羊路沟组合和下普通沟组合.通过与波罗的海等地区鱼类微体化石带的对比,羊路沟和下普通沟组合的地质时代分别为志留纪普里道利世晚期和早泥盆世洛霍考夫期早期.西秦岭地区志留/泥盆系过渡带中的鱼类微体化石及其组合序列的研究,为该区志留/泥盆系界线的精确确定提供了重要的古鱼类学证据.  相似文献   

9.
记述了浙江长兴县煤山剖面、江西修水县四都乡东岭剖面和信丰县铁石口镇铁石口剖面二叠/三叠系界线层上下的辐鳍鱼类6个类别的微体化石,包含2新属2新种,它们是:赵氏浙江鱼(Zhejiangichthys zhaoi gen.et sp.nov.)和小齿葆青鱼(Baoqingichthys microdontus gen.et sp.nov.)。这是包括全球二叠/三叠系界线层型剖面和点位(GSSP)在内的全球二叠/三叠系界线层上下辐鳍鱼类微体化石序列的首次报道。在总结煤山剖面已记述的鱼类大化石和微体化石资料的基础上,分析了长兴煤山剖面二叠纪末鱼类的集群绝灭。绝灭发生得很晚,持续的时间很短,规模也很大,绝灭率高达93%。讨论了华南二叠/三叠系之交大绝灭后鱼类的复苏和辐射,认为鱼类和牙形类一样都是大绝灭后在三叠纪最早复苏的类别,最早复苏的鱼类为裂齿鱼类;鱼类从绝灭期到辐射期仅用了1.3 Ma到4 Ma,从地质时间考虑,大绝灭后鱼类的复苏和辐射是相当快的。华南早三叠世以裂齿鱼类的张氏鱼(Zhangina)和软骨鱼类的弓鲛(Hybodus)为代表的组合替代了晚二叠世以古鳕类的中华扁体鱼(sinoplatysomys)和软骨鱼类的中华尖齿鲨(Sinacrodus)为代表的组合。华南晚二叠世海相地层产出的辐鳍鱼类和软骨鱼类的一些土著属与产于特提斯区三叠纪的一些属非常相近,表明华南下扬子区很可能是后来繁盛于特提斯区的三叠纪鱼类的发源地。  相似文献   

10.
峡东区上震旦统宏体化石藻类的发现   总被引:5,自引:0,他引:5  
我国峡东地区的震旦系剖面,是南方震旦系层型剖面,过去只报道过“Collenia”型藻叠层石。近年来,陆续发现大量微体植物化石、宏体植物化石及后生动物化石,其中带藻类极为丰富,遍及灯影组中段。1978年陈孟莪和马国干为追索震旦系—寒武系界线,在从野猫面(秭归县龙江公社前进四队)下到庙河的半山坡的大路旁,在陡山沱组上部的黑色页岩中发现了宏体化石藻类和可能是属于浮游生物的印痕化石。  相似文献   

11.
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   

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.
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   

14.
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   

15.
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   

16.
The unitary conductances and permeability sequences of the rat connexin40 (rCx40) gap junction channels to seven monovalent cations and anions were studied in rCx40-transfected neuroblastoma 2A (N2A) cell pairs using the dual whole cell recording technique. Chloride salt cation substitutions (115 mM principal salt) resulted in the following junctional maximal single channel current-voltage relationship slope conductances (γj in pS): CsCl (153), RbCl (148), KCl (142), NaCl (115), LiCl (86), TMACl (71), TEACl (63). Reversible block of the rCx40 channel was observed with TBA. Potassium anion salt γj are: Kglutamate (160), Kacetate (160), Kaspartate (158), KNO3 (157), KF (148), KCl (142), and KBr (132). Ion selectivity was verified by measuring reversal potentials for current in rCx40 gap junction channels with asymmetric salt solutions in the two electrodes and using the Goldman-Hodgkin-Katz equation to calculate relative permeabilities. The permeabilities relative to Li+ are: Cs+ (1.38), Rb+ (1.32), K+ (1.31), Na+ (1.16), TMA+ (0.53), TEA+ (0.45), TBA+ (0.03), Cl (0.19), glutamate (0.04), and NO3− (0.14), assuming that the monovalent anions permeate the channel by forming ion pairs with permeant monovalent cations within the pore thereby causing proportionate decreases in the channel conductance. This hypothesis can account for why the predicted increasing conductances with increasing ion mobilities in an essentially aqueous channel were not observed for anions in the rCx40 channel. The rCx40 effective channel radius is estimated to be 6.6 Å from a theoretical fit of the relationship of relative permeability and cation radius.  相似文献   

17.
18.
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   

19.
Nine blood group systems of goats were identified using 12 caprine reagents produced by absorption of alloimmune antisera. The caprine C blood group system, possibly homologous to the ovine C blood group system, was characterized by two reagents and shown to be controlled by three alleles,C 12,C 25, andC . A more complex blood group system of goats, designated G, was identified using three reagents and shown to be controlled by six codominant alleles (G 10.19.20,G 10.19,G 10.20,G 10,G 19,G 20) and a recessive allele (G ). A further seven one-factor two-allelic systems were identified by seven reagents. The nine genetic systems provided exclusion probabilities of 0.479, 0.492, 0.548, and 0.572 in Australian Angora, Dairy, Cashmere, and Texan Angora goat breeds, respectively. This work was supported by a grant from the Australian Stud Book, Alison Road, Randwick, New South Wales 2031, Australia.  相似文献   

20.
《Ibis》1894,36(3):447-460
  相似文献   

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