伊春地区晚印支期I型花岗岩带特征及其构造背景   总被引：8，自引：0，他引：8  

刘宝山任凤和  李仰春赵焕力 《地质与勘探》2007,43(1):74-78

晚印支期花岗岩岩石类型主要为一套含角闪石黑云母二长花岗岩及含黑云母正长花岗岩，岩石中暗色闪长质岩包体发育较普遍，富含角闪石及镁质黑云母，副矿物以榍石、磁铁矿、磷灰石常见，Al2O3／（Na2O十K2O＋CaO）〈1．1，显示出I型花岗岩特征。利用岩石矿物组合、岩石化学特征判别其产于碰撞后构造环境，认为造山后伸展体制是这期花岗岩形成的重要原因。岩石（^87 Sr／^86 Sr）；及δEu值反映其源区为壳幔过渡区，氧同位素（δ^18 O）测定值在5．5‰-10‰之间，具壳幔混源的特点，表明岩石来源于下地壳或壳幔过渡部分，与下地壳的部分熔融或壳幔过渡区部分熔融作用有关。  相似文献   

刚毛柽柳种子萌发对盐分与干旱胁迫的响应     

孙红叶  李利  刘国军  张希明  李应罡 《干旱区地理》2007,30(3):14-419

通过对不同温度、盐分和干旱胁迫对刚毛柽柳种子萌发实验研究影响,结果表明:刚毛柽柳种子的适宜萌发温度范围为10~35℃,萌发率高达80%以上,且萌发迅速。不同浓度NaCl溶液对刚毛柽柳种子萌发有明显抑制作用,种子萌发率随NaCl溶液浓度的增大而下降,到0.7 mol/L时,萌发率仅为1.67%,种子发芽受到抑制。相同渗透势PEG-6 000溶液中的萌发率低于NaCl溶液,渗透势为-0.5 MPa是二者影响作用的分界点。渗透势为-1.8 MPa时,萌发率已急剧下降到0,其对种子萌发的抑制作用大于NaCl溶液。将在两溶液中处理10天的种子转移至蒸馏水后,随着NaCl溶液浓度的增大,萌发恢复率逐渐升高,0.7 mol/L时,萌发恢复率为60%;随着PEG-6 000溶液浓度增大,萌发恢复率先升高后降低,渗透势为-1.4 MPa时,种子萌发恢复率达到最大为67.5%,但两种处理下种子的最终萌发率(总萌发率)都低于在蒸馏水中的。  相似文献   

0605号台风"格美"在江西致灾的气象成因分析     

许彬  许爱华  魏丽  陈建萍 《气象与减灾研究》2007,30(1):60-63

运用常规观测资料、T213资料等,对0605号台风“格美”的移动路径和暴雨成因进行了分析。分析结果表明,“格美”登陆后虽然强度迅速减弱,但由于其减弱后的低气压环流在江西逗留时间长,所携带的水汽和造成的辐合上升条件足以造成江西出现暴雨天气。通过分析探空、地面加密自动站和闪电定位等资料进一步指出,地面中尺度辐合线、对流不稳定和地形抬升的共同作用,加剧了赣西南局地降雨的强度。由于前期台风“碧利斯”已造成赣州市出现较强降水,赣南土壤含水量、地下水位和江河湖库水位均较高,使得“格美”造成的短时强降雨迅速产生有效径流和汇流,导致局地山洪暴发而致灾。  相似文献   

地下管线元数据建设探讨     

李黎  李剑 《现代测绘》2006,29(1):29-30,32

本文介绍了武汉市地下管线信息系统时,为了解决海量数据的管理和查询等问题,进行了有针对性的元数据建设,并详细介绍了元数据的具体内容。  相似文献   

洛阳分县温度周滚动预报系统   总被引：1，自引：0，他引：1  

姬鸿丽禹东晖  盛建萍陈红霞  聂玉梅马俊 马淑玲 《河南气象》2006,(3):40-42

利用洛阳9县(市)2002年11月~2004年9月逐日最高、最低气温资料,应用欧洲中心数值预报产品,建立了洛阳9个县(市)的温度周滚动预报方程。2004~2005年试报结果表明:24~48 h预报准确率在70%左右,绝对误差在2℃以内;24~144 h预报准确率在62%~70%之间,绝对误差在2℃左右;最低气温预报效果要好于最高气温,最低气温的绝对误差与准确率分别为1.98℃和67%,最高气温的绝对误差与准确率分别为2.28℃和61%。  相似文献   

麦棉套作主要虫害发生与气象条件的关系   总被引：1，自引：0，他引：1  

王登琪刘学义  范小九高伟力白春社  康自红郭志强 《河南气象》2006,(4):56-57

根据危害棉花最重的棉蚜、棉红蜘蛛、棉铃虫和棉盲蝽象4大害虫的生物学特性、发生时段的气候条件和麦棉套种棉田生态因素,分析了4大害虫大发生的原因及预测预报,并提出了防治措施。  相似文献   

Phosphorus limitation of bacterial growth in high Arctic lakes and ponds   总被引：4，自引：0，他引：4  

Wilhelm?Granéli  Stefan?BertilssonEmail author  Aline?Philibert 《Aquatic Sciences - Research Across Boundaries》2004,66(4):430-439

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An infrared and <Superscript>1</Superscript>H MAS NMR investigation of strong hydrogen bonding in ussingite,Na<Subscript>2</Subscript>AlSi<Subscript>3</Subscript>O<Subscript>8</Subscript>(OH)     

E.A.?JohnsonEmail author  G.R.?Rossman 《Physics and Chemistry of Minerals》2004,31(2):115-121

The mineral ussingite, Na₂AlSi₃O₈(OH), an interrupted tectosilicate, has strong hydrogen bonding between OH and the other nonbridging oxygen atom in the structure. Infrared spectra contain a strongly polarized, very broad OH-stretching band with an ill-defined maximum between 1500 and 1800 cm^–1, and a possible OH librational bending mode at 1295 cm^–1. The IR spectra confirm the orientation of the OH vector within the triclinic unit cell as determined from X-ray refinement (Rossi et al. 1974). There are three distinct bands in the ¹H NMR spectrum of ussingite: a predominant band at 13.5 ppm (TMS) representing 90% of the structural hydrogen, a second band at 15.9 ppm corresponding to 8% of the protons, and a third band at 11.0 ppm accounting for the remaining 2% of structural hydrogen. From the correlation between hydrogen bond length and ¹H NMR chemical shift (Sternberg and Brunner 1994), the predominant hydrogen bond length (H...O) was calculated to be 1.49 Å, in comparison to the hydrogen bond length determined from X-ray refinement (1.54 Å). The population of protons at 15.9 ppm is consistent with 5–8% Al–Si disorder. Although the ussingite crystal structure and composition are similar to those of low albite, the bonding environment of OH in low albite and other feldspars, as characterized through IR and ¹H NMR, is fundamentally different from the strong hydrogen bonding found in ussingite.  相似文献   

Summary of recent volcanic activity     

Edward?VenzkeEmail author  Jessica?Ball 《Bulletin of Volcanology》2004,67(1):92-93

Information included in this summary is based on more detailed reports published in the Bulletin of the Global Volcanism Network, v. 29, no. 4, April 2004 (on the Internet at ). Edited by scientists at the Smithsonian, this Bulletin includes reports provided by a worldwide network of correspondents. The reports contain the names and contact information for all sources. Please note that these reports are preliminary and subject to change as events are studied in more detail. The Global Volcanism Program welcomes further reports of current volcanism, seismic unrest, monitoring data, and field observations.  相似文献   

Smithsonian Institution’s Global Volcanism Network     

Devra?WexlerEmail author 《Bulletin of Volcanology》2004,66(6):562-564

Information included in this summary is based on more detailed reports published in the Bulletin of the Global Volcanism Network, vol. 28, No. 9, September 2003 (on the Internet at ). Edited by scientists at the Smithsonian, this bulletin includes reports provided by a worldwide network of correspondents. The reports contain the names and contact information for all sources. Please note that these reports are preliminary and subject to change as events are studied in more detail. The Global Volcanism Program welcomes further reports of current volcanism, seismic unrest, monitoring data, and field observations.  相似文献