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1.
作者对舟山港区43个表层沉积物样品进行定量分析,共鉴定出底栖有孔虫33属60种。研究海域各站位均发现浮游有孔虫壳体,个体细小、属种单一,未发现活体个体。研究海域底栖有孔虫组合以玻璃质壳为主,平均含量86.71%,有孔虫丰度均值为1 676枚/50克,总体有孔虫组合为Ammonia beccarii vars.-A.maruhasii-Epistominella naraensis。研究发现,表层沉积物中大个体有孔虫(Ammonia beccarii vars.等)与小个体有孔虫(Epistominella naraensis)分布与潮流搬运呈密切相关关系,提示可能存在不同的搬运机制。与前人研究相比,研究海域有孔虫组合呈现以下变化:(1)胶结质壳有孔虫含量增加,个别站位出现15.89%的高值;(2)出现耐污染属种;(3)环境敏感属种畸形比例增加。研究表明,沉积搬运作用和环境参数变化是影响研究区有孔虫组合的重要因素,为有孔虫作为环境指标的进一步研究提供了基础数据。  相似文献   

2.
苏北海岸带有孔虫Ammonia beccarii微环境分布的初步研究   总被引:1,自引:0,他引:1  
本文通过对苏北海岸从北到南采样,统计有孔虫的个数,着重分析Ammonia beccarii(毕克卷转虫),并结合样品粒度分析、化学分析,试图寻找这单一属种的分布规律,发现.Ammonia beccarii的丰度、活体百分含量、优势度沿海岸线变化与有孔虫群的变化有较好的对应关系,但优势度在有孔虫群落中并不明显,基本在20%以下;Ammonia beccarii在分布上有如下特征:滩面上丰度与活体百分含量较大,在海滩、河口环境较小,在人工泻湖中极大;在南北方向上的分布变化没有显著规律;在沉积物中,一般在中值粒径较小(Mdφ≤0.8)或较大(Mdφ≥5.44)的沉积物中,Ammonia beccarii是不适宜生长的;另外,有机质含量可能是限制.Ammonia beccarii生长的一个条件。  相似文献   

3.
文中对上海奉贤DY03孔222m长的沉积物柱状样样品进行有孔虫定量统计分析,结合颗石藻、孢粉等其它古生物学资料,重建了晚新生代长江三角洲南部沉积环境变化。钻孔孔深60m以上发现有孔虫产出,包括60—40m与24.6—2m两层位,尤以24.6—2m有孔虫丰度较高。孔深60m附近有孔虫丰富,底栖有孔虫主要属种为Ammonia beccarii vars.,Nonionella stella,Protelphidium tuberculatum,Elphidium advenum和Astrononion tasmanensis等,而58.8—49.2m则不含有孔虫;孔深48.8—40m,有孔虫丰度、分异度均从下而上降低,从以Ammonia beccarii vars.-Elphidium advenum组合为主,Ammonia compressiuscula,Florilus decorus,Pseudononionella variabilis及Nonionella stella等繁盛的面貌,变为仅含少量的Ammonia beccarii vars.和Elphidium limpidum等。有孔虫群落在60—40m层位呈现了其沉积环境由滨岸演变为浅海、又转变为滨岸的演化序列。另一有孔虫丰富层位(埋深为24.6—2m)中,有孔虫分布连续、丰度高、属种分异度高,其中下部21.4—8.8m含有大量的低盐种Pseudononionella variabilis,Stomoloculinasp.以及少量Heterolepaspp.和Lagena hispida;中部8.4—5.0m产出大量深水型分子Ammonia compressiuscula及代表高温、高盐环境的瓷质类型Quinqueloculina seminula,Triloculina rotunda和Spiroloculina laevigata;上部4.8—2m中深水类型缺失,从下至上显示了一个海水由浅到深再变浅、海水盐度由低到高再变低、海水温度由低到高再变低的海侵-海退过程,且本次海侵较上次海侵水深更深、范围更广。对比显示,DY03孔24.6—2m地层相当于中国东部广泛存在的第一海侵层(全新世),而60—40m地层则相当于第二海侵层(晚更新世),有孔虫等生物群落演化反映了该地区晚更新世以来的两次较大海水进退过程。  相似文献   

4.
本文分析了自江苏海门、浙江舟山和象山沿岸三个潮间带采集的上层10 cm沉积物中活体底栖有孔虫的分布情况,结果显示有孔虫群落的简单、复合分异度自表层向深层减小,在垂直分布上对环境适应性强的优势属Am-monia更容易向深分布.在表层充氧的舟山潮间带,Ammonia属的绝对丰度自表层向深处减小,但在生长水草的海门潮间带和布...  相似文献   

5.
对江苏省盐城市大丰区野鹿荡DF20钻孔21 m长沉积物岩芯开展了详细微体古生物学定量分析研究,结果显示,沉积物中浮游有孔虫仅在下部部分层位少见,含丰富的底栖有孔虫化石。研究共识别出47属66种底栖有孔虫,尤其以Ammonia beccarii var.,Cribrononion vitreum,Cribrononion subincertum,Elphidium advenum,Pseudononionella variabilis,Stomoloculina multangula,Elphidium magellanicum,Pararotalia nipponica,Elphidium hispidulum和Ammonia compressiuscula等近岸和内陆架浅水分子高含量为主。其中Ammonia beccarii var.最高达87.5%,平均含量超过50%。结合钻孔底部沉积物中贝壳的初步测年资料,该钻孔底栖有孔虫组成和变化揭示了野鹿荡地区近七千年来沉积环境存在一个由相对较深的近岸浅水海洋环境向海陆过渡相半咸水环境的演化过程。  相似文献   

6.
本文通过对广东江门市蓬江区沉积物钻孔产出有孔虫的鉴定与定量统计分析,结合沉积物中双壳类壳体AMS~(14)C测年结果,揭示了该区晚更新世末期以来经历了陆相-海陆过渡相-陆相的沉积古环境演变过程。海陆过渡相地层中的有孔虫分异度极低、但丰度较高,以近岸浅水种Ammonia beccarii vars.和Elphidium magellanicum为优势种,反映三角洲平原环境受径流影响强烈。位于同一剖面的多个钻孔横向对比显示海水最远达到江门市蓬江区弓田村附近。最大海侵发生应晚于7540aBP(日历年)。  相似文献   

7.
Ammonia aomoriensis(Asano,1951)和Ammonia beccarii(Linnaeus,1758)是两个形态学易混淆,但被广泛使用并具有重要环境指示意义的有孔虫。通过对渤海、黄海和东海陆架区60个站位表层沉积物的水平分布调查,并连续17个月对潮间带分低潮区和高潮区进行了季节调查,对二者的形态分类、生态分布和环境关系进行比较研究。结果表明A.aomoriensis和A.beccarii在潮间带的丰度都有季节性变化,体现冬高夏低的特点,前者一般在高潮区较多,后者在低潮区较多。二者的丰度从潮间带到陆架区随着水深的增加呈阶梯式锐减:平均含量分别达22%和39%;在水深<20m的陆架区平均含量分别降至15%和6%;在水深>20m的陆架区平均含量分别再次降至0.6%和1.4%。统计分析表明二者对盐度和水深的响应相似,但对温度的反应存在差异:在潮间带环境,二者的丰度都与盐度显著正相关;在浅海陆架环境,二者的丰度都与水深呈显著负相关;无论在潮间带还是陆架海区,A.beccarii的丰度都与海水温度呈显著负相关,但A.aomoriensis与温度相关性不显著。本研究结果显示A.aomoriensis和A.beccarii对滨岸浅海都具有优越的指示作用,在古环境分析中,首先可根据二者的含量进行环境推测(潮间带或者陆架浅海),再利用不同环境下本文所建立的线性方程对海水温、盐、深进行大体的估算。  相似文献   

8.
有孔虫是海洋环境中一种重要的原生动物,对环境变化响应敏感。潟湖作为海陆交互连接带,生境梯度明显,但目前学术界对此类水体中有孔虫种群的研究报道有限。本文以中国典型潟湖广东省汕尾市品清湖为例,于2021年至2022年间系统调查了该湖不同区域20个采样点的水环境参数(水深、盐度和pH值等)、沉积物的环境特征(粒度和污染物含量等)及有孔虫的群落组成。结果显示品清湖现今水质大部分均为四类或劣四类,活性磷酸盐和无机氮超标严重;重金属Cu、Zn和Hg浓度相对较高,部分区域浓度达到二类标准。该湖表层沉积物中共鉴定出底栖有孔虫15属35种,以玻璃质壳(Hyaline)为主,瓷质壳(Porcelaneous)次之,胶结质(Agglutinated)含量最低,优势属种为Ammonia aomoriensis, Elphidium advenum, Elphidium hispidulum和Spiroloculina laevigata,丰度及分异度呈现西部入海口高,东部低。统计分析结果显示,影响品清湖有孔虫分布的主要环境因子为水深和水体Cu浓度,分别解释了34.2%和14.9%的有孔虫群落信息。研究结果表明...  相似文献   

9.
对渤海莱州湾海域240个站位表层沉积物中底栖有孔虫群落进行了分析,共鉴定常见的底栖有孔虫42种。结果表明,莱州湾表层沉积物中底栖有孔虫主要以玻璃质壳为主(平均丰度达70.9%),瓷质壳含量次之,胶结壳含量最低;玻璃质壳占有孔虫全群的百分含量,随水深的增加而增加;从黄河口向外海方向,有孔虫分异度和丰度都逐渐增大。该海域底栖有孔虫平面分布的主要控制因素为盐度和底质沉积物类型,大体可分为两个组合分区,I区为Ammonia beccarii-Quinqueloculina spp.组合,代表盐度较低的近岸海陆过渡浅水环境;II区为Cribrononionsub-incertum-Protelphidium tuberculatum组合,代表盐度较高的远岸内陆架环境。  相似文献   

10.
海南岛近岸沉积物中的有孔虫特征与分布   总被引:1,自引:0,他引:1  
对位于海南岛近岸7-170 m水深、180个站位沉积物表层样的有孔虫分析表明,研究区浮游有孔虫类型较少、共发现浮游有孔虫19种,单个站位最多含有浮游有孔虫16种,而且浮游有孔虫含量(丰度)亦较低.底栖有孔虫则较为丰富,仅在较粗砂中底栖有孔虫丰度相对较低.常见近40多个底栖有孔虫属种,多数样品中以含有螺旋式与平旋式玻璃质底栖有孔虫为主,少数样品以胶结壳、列式玻璃质壳或大型底栖有孔虫为优势特征.本研究在详细阐述了底栖有孔虫主要特征属种的基础上进行了有孔虫分区,从而揭示其所包含的环境意义.  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 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   

15.
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   

16.
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   

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.
《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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