共查询到20条相似文献，搜索用时 62 毫秒
1.
湖南桃源县花香坪铅锌矿为低温热液型铅锌矿,以闪锌矿为主,兼有方铅矿.铅锌矿体受层位和构造双重控制,主要控矿层位为震旦系下统陡山沱组硅质白云岩;矿体形态受构造的影响,变化较大,主要为脉状、透镜状和似层状.本文从成矿温度、成矿物质条件、成矿物质的聚集与矿体形成三个方面分析了花香坪铅锌矿成矿条件,与MVT型铅锌矿相似,提出该矿床为MVT型铅锌矿. 相似文献
2.
舒国文 《国土资源导刊(湖南)》2002,21(4):275-278
湘西地区磷矿资源较丰富,主要为赋存于震旦系上统陡山沱组中的磷块岩矿床.该类矿床在湘西部分县市含矿层位稳定,分布广,矿床(点)多,埋藏浅,但品位低,选矿难,利用成本高.针对这些特征,提出如下勘查和开发的建议即在整个湘西含磷层位出露范围内进行地质调查,对湘西震旦系磷块岩矿床资源进行总体综合评价,加强开采、选矿和加工等方面的技术攻关;同时充分利用地方政策、水电能源、交通条件等优势对较低品位、中小规模磷块岩矿进行开发利用. 相似文献
3.
宜昌斜坡区钻获南方复杂构造区下寒武统水井沱组、下震旦统陡山沱组高含气页岩，首次实现了古老层系页岩气重大发现，南华系-震旦系构造-沉积格局是认识盆地构造属性及古老页岩气富集的关键。基于前人的研究成果，开展了宜昌地区南华系-震旦系沉积岩石特征、地震资料分析。结果表明:宜昌及周缘存在克拉通内Ⅰ型(宜昌型)、克拉通边缘过渡区Ⅱ型(长阳型)断坳结构控制的沉积区类型。在经历了早期断陷、中期成冰、断坳转换及晚期坳陷4个演化阶段，断坳结构控制了陡山沱组及灯影组-水井沱组ⅠⅠ型台地边缘-斜坡和ⅠⅡ型台内洼地及Ⅱ型陆棚相沉积区，富有机质页岩相对发育。结论认为:Ⅰ型、Ⅱ型断坳结构发育区是陡山沱组-水井沱组自生自储页岩气的规模聚集区；Ⅰ型控制下灯影组旁生侧储边缘滩也是天然气聚集的有利场所。 相似文献
4.
上扬子地台震旦系铅锌矿床类型及找矿方向 总被引：13，自引：0，他引：13
上扬子地台含铅锌矿地层主要为震旦系。震旦系在上扬子地台主要发育上统灯影组,次有下统陡山沱组。将上扬子地台震旦系铅锌矿床成因划分为一级为叠生矿床,二级为层控矿床,三级为热水沉积改造矿床和热水沉积再造矿床四级类型,该类型按铅锌比例进一步划分为富铅型、富锌型、铅锌共生型。研究区内最重要的铅锌矿床成因类型为南郑马元、会东大梁子铅锌矿为代表的富锌型。陕西南郑、紫阳—镇坪地区,湖北武当、神农架、黄陵地区,以及地台西缘的安宁河、甘洛—小江、峨边—寻甸等地区的震旦系是寻找铅锌矿的最有利地段。 相似文献
5.
西宝山耐火黏土矿为沉积型矿床,目前揭露1个耐火黏土矿矿层,赋存于石盒子群万山组底部“B”层黏土岩的下部,厚度较稳定,勘查开发潜力较大。通过对其地质特征、矿层特征、矿石结构构造及矿床成因分析,提出了找矿方向。认为该耐火黏土矿受沉积地层控制,呈层状分布,分布较稳定。依据该区地层产出情况,在青龙山断裂与禹王山断裂之间及两侧均具有良好的找矿前景,这为下一步找矿工作奠定了基础。 相似文献
6.
7.
“扬子型”铅锌矿床的地质特征
一、矿化集中的时空分布
“扬子型”铅锌矿床在准地台周边及其隆起的碳酸盐中分布很广，成矿时期从南华纪至早古生代，最重要的有南华系莲沱组（彭山式），震旦系陡山沱组上部（董家河式），震旦一寒武系麦地坪组（大渡河式），下寒武系清虚洞组（花垣式）。除此，在奥陶系、石炭系和三叠系也有发现。这类矿床形成于晋宁造山后扬子地台伸展裂陷构造环境，是罗迪尼亚超大陆裂解事件的产物。空间上主要分布以下地区： 相似文献
8.
沈家垭金矿位于上扬子地块与华南裂陷槽的接壤地带—江南地块北西部,即冷家溪隆起西部与沅麻盆地、沅辰坳陷接合部区内,构造形迹相当复杂,化探异常发育,成矿条件极为有利。加里东运动继承雪峰运动,使前期断裂构造复活,并在层间破碎带中形成新的断裂构造,从深部上升并萃取围岩的含矿热液再次进入破碎蚀变带,使金进一步富集并在有利构造部位形成富矿体。 相似文献
9.
王家辇-南王孔地区水泥用灰岩矿位于青州市西北10km处。区内第四系广布,以大站组为主,含矿地层为奥陶纪马家沟群北庵庄组微晶灰岩、泥质条带灰岩,呈单斜形式产出,矿层延伸稳定。区内构造以断裂构造为主,断裂只对矿体有局部的位移,以及岩石的破碎,对矿体、矿石质量基本没有影响。矿石自然类型为微晶灰岩型和条带状灰岩型。工业类型为水泥用灰岩,成矿类型为浅海相沉积矿床。 相似文献
10.
本文着重研究了扬子地台北缘上震旦统陡山沱组、灯影组及下寒武统下部岩家河段的微古植物组合特征。初步建立了Ⅰ、Ⅱ两个微古植物组合，分别与陡山沱村阶和灯影峡阶相对应，分析了微古植物组合在地层划分与对比及在震旦系－寒武系界线的划分上所起的作用。 相似文献
11.
Cloning, expressing, and hemolysis of tdh, trh and tlh genes of Vibrio parahaemolyticus 总被引：1，自引：0，他引：1
Vibrio parahaemolyticus (VP) is one of the pathogenic vibrios endangering net-cage cultured Pseudosciaena crocea,Fennerpenaeus chinensis, and shellfish in coastal areas of China. Several types of hemolysins produced by Vp have been characterized as major virulence factors.They are thermostable direct hemolysin (TDH),TDH-related hemolysin (TRH) and thermolabile hemolysin (TLH). In this study, we cloned tdh, trh, and tlh genes from the genome DNA of VP by polymerase chain reaction (PCR).We ligated the three genes into prokaryotic expression vector pET-28a (+),and transformed the recombinant plasmids into Es-cherichia coli BL21 (DE3). The expression of recombinant proteins was induced by isopropyl-β-D-thiogalacto-pyranoside (IPTG). The recombinant proteins were expressed in a form of inclusion bodies and thus purified with Ni-NTA affinity chromatography. Western blotting results showed that recombinant proteins,TDH, TRH and TLH, could be recognized by rabbit anti-VP serum. The three purified proteins were renatured by gradient dialysis.The renatured proteins exhibited hemolytic activity except for TLH in the presence of phosphatidylcholine. These results not only are helpful for better understanding these genes’ functions under a single factor level, but also provide evidence for VP vaccine engineering. 相似文献
12.
13.
RELATIONSHIPS BETWEEN FRACTIONATIONS OF Pb, Cd, Cu, Zn AND Ni AND SOIL PROPERTIES IN URBAN SOILS OF CHANGCHUN, CHINA 总被引：4，自引：1，他引：3
GUOPing XIEZhong-lei LIJun KANGChun-li LIUJian-hua 《中国地理科学(英文版)》2005,15(2):179-185
1IN T R O D U C T IO N With therapiddevelopment of urbanizatio,nurban land was exploitedand utilizetdoform differendtomains be- ing subjectto many potentialpollutionsourcessuch as vehicleemission, industrialactivitieasnd household garbage.Particularl, yur… 相似文献
14.
15.
The contents of nearly forty-elements in surface sediments in Jiaozhou Bay were determined using a Neutron Activation Analysis Technique(Grancini,et al.,1976;Li Peiquan et al.,1985,1986;Li Xiuxia etal.,1986).This paper's detailed discussion on only nine elements(Fe,Mn,Co,Cr,Sc,As,Sb,Zn andV)includes their distributions,concentrations,correlationships,material sources,background,etc.Based on Zavaristski's classification method,Fe,Mn,Co Cr and V belong to the second group;As and Sb to theeighth groups:Sc and Zn to the third and sixth groups.It was found that their notably good correla-tionship is mainly due to the similarity of their ionic structures and that their variation is controlled by theFe content(except Mn).The source of sediments is mainly terristrial material,and the composition ofsediment is similar to that of shale and shale+clay.The contents for a large number of ele-ments are within the scope of the background level,but there still is pollution of Zn and Cr,at least in a few stations. 相似文献
16.
《中国海洋湖沼学报》2017,(1)
Aquaculture production efficiency may increase by using feed additives. This study investigated the effects of different dietary additives [w/w: 2% small peptides, 0.01% probiotics( Bacillus licheniformis) and 0.2% prebiotics(inulin)] on growth performance, digestive enzyme activities, and oxidative stress in juvenile Epinephelus coioides reared in artificial seawater of two salt concentrations(13.5 vs. 28.5). Weight gain rate was significantly higher in fish fed the diet supplemented with small peptides, B. licheniformis, inulin, or synbiotics than that in fish fed the basal diet; the greatest weight gain rate was found in fish fed the small peptide treatment [56.0% higher than basal diet]. Higher feed efficiency was detected in fish fed the diet supplemented with small peptides than that of fish in the other dietary treatments. Total protease activity in the stomach and intestines was highest in fish fed the small peptide-treated diet, whereas lipase activity was highest in those fed synbiotics(combination of Bacillus licheniformis and inulin) than that in fish fed the other treatments. Antioxidant enzyme(total superoxide dismutase and catalase) activities and hepatic malondialdehyde content were higher in fish receiving the dietary supplements and maintained in artificial seawater containing 13.5 salinity compared with those in the control(28.5). Hepatic catalase activity in grouper fed the diets with small peptides or synbiotics decreased significantly compared with that in control fish. Overall, the three types of additives improved growth rate of juvenile grouper and digestive enzymes activities to varying degrees but did not effectively improve antioxidant capacity under low-salinity stress conditions. 相似文献
17.
Potassium, sodium, magnesium and iodine requirements of shrimp,Penaeus chinensis were studied. Orthogonal design was employed in this experiment. The composition of the basal diet consisted of fish meal,
peanut cake, corn meal, soybean cake, wheat bran, vitamin mix and mineral mix, and supplementations of potassium, sodium,
magnesium and iodine in the basal diet were made according to the L9(34) orthogonal table. The results indicated that iodine supplementation improved growth of the shrimp significantly and raised
survival very significantly, iodine requirement of the shrimp was 0.003%; sodium requirement was 0.87% or less; and that 1.1–1.3%
potassium and 0.18–0.38% magnesium in the diet were proper nutrition supplements for the shrimp.
Contribution No. 2342 from the Institute of Oceanology, Chinese Academy of Sciences. 相似文献
18.
Oyster peptide–zinc nanoparticles(OPZNPs)(28–108 nm) were prepared in the presence of 0.5%–0.9% zinc sulfate at pH 6.0–11.0. The obtained nanoparticles exhibited uniform size distribution and spherical shapes. Nanoparticle characteristics, such as size, surface charge, and hydrophobicity, could be adjusted by controlling zinc sulfate concentration and environmental pH. Increasing pH value or decreasing zinc sulfate concentration tended to reduce nanoparticle size and increase nanoparticle surface charge and hydrophobicity. OPZNPs presented good stability at near-neutral pH and could be stored for at least 20 days at 4℃. The results of the peptide conformation study and nanoparticle dissociation test proved that zinc ions and carboxyl groups are the key factors that affect OPZNP formation. The intermolecular combinations of carboxyl groups via zinc bridging facilitated the aggregation of oyster peptides. Nanoparticle formation was accompanied by aggregate association and conformational changes. These changes included increments in β-sheets, especially intermolecular β-sheets, at the expense of α-helixes. Overall, this work provided a green alternative route for the synthesis of OPZNPs. 相似文献
19.
Landscape ecology: Coupling of pattern,process, and scale 总被引：5，自引：1，他引：4
Landscape ecology provides new theoretical frameworks and methodologies for understanding complex ecological phenomena at multiple scales.Studies of landscape ecology focus on understanding the dynamics of eco-logical patterns and processes,and highlight the integration of multiple disciplines.In this paper,we discussed the problems and challenges that landscape ecology is currently facing,emphasizing the limitations of current methods used to describe dynamic landscape patterns and processes.We suggested that the focus should be on the integration of ground-based observation,mobile monitoring,transect survey,and remote-sensing monitoring,as well as improved coupling of experimental and model simulations.In addition,we outlined the research frontiers in landscape ecology,including scaling,integrated pattern and process modeling,and regional synthesis.Lastly,a brief review of pat-tern-process-scale coupling studies in China was provided.We concluded by pointing out that pattern-process-scale interactions,correlations between natural,economic,and social processes,and the coupling of human and natural systems will be major research areas in landscape ecology in the future. 相似文献
20.
杨励轩 《广东海洋大学学报》2013,(2)
雷歌研究自清末民初的黄景星起至今近90年,在雷歌起源、流变、词曲形态、音韵及音调等方面积累了较多描述性研究成果,为后续研究提供了宝贵资料,但研究格局僵化,领域有限,主题高度重复,缺乏方法论意识,研究成果宏观上表现零散、随意及表层化,突破性成果匮乏,微观上则有概念模糊缺乏足够实证材料之弊端。 相似文献