1980—2015年风蚀影响下中国北方土壤有机质与养分流失时空特征

中国北方干旱/半干旱区是全球主要的沙尘源区之一,风蚀造成的沙尘排放可导致大量的土壤有机质（SOM）与养分流失,并通过传输与沉降过程对其进行空间再分配,对空气质量、气候变化、植被生长及生物地球化学过程等具有重要影响。本文利用WRF/Chem（Weather Research Forecasting with Chemistry）v3.7.1大气化学传输模型,对1980—2015年间中国北方沙尘排放及其引起的SOM、全氮（TN）与全磷（TP）的时空变化过程进行了精细化模拟,探究了中国北方风蚀引起的SOM、TN与TP养分流失的时空变化特征。结果表明：① 1980—2015年来平均每年约有66.59 Tg的沙尘颗粒排放至大气;② 沙尘排放具有较大的时空差异,沙尘排放源区主要集中在新疆东部、内蒙古西部的巴丹吉林沙漠和腾格里沙漠等地区;③ 每年因沙尘排放引起的SOM、TN和TP流失量分别约为0.07 Tg、0.004 Tg和0.005 Tg;④ 1980—2015年间中国北方沙尘排放及其引起的SOM、TN与TP的流失量具有较强的年际波动,未呈现显著的趋势性变化特征。本研究对于认知风蚀在碳循环与养分循环过程中的作用,以及对深入了解中国北方的土地退化机理具有重要意义。     

Cu2+、Zn2+、SDS、DBS对脊尾白虾的毒性试验

选用铜、锌2种常见重金属和十二烷基硫酸钠(SDS)、十二烷基苯磺酸钠(DBS)2种阴离子表面活性剂对脊尾白虾Palaemon carincauda仔虾进行96h急性毒性试验。结果表明,Cu2 、Zn2 、SDS、DBS对脊尾白虾仔虾的96h LC50分别为0.34、0.82、14.3和14.4 mg.L-1。将脊尾白虾仔虾对这4种毒物的敏感性与文献报道的其它动物进行了比较,结果认为可以将其作为毒性测试的标准试验生物。     

杭州湾工业带经济发展对湿地的影响

Based on Landsat TM images in 2005 and urban planning data of 2005-2020 in Hangzhou Bay Industrial Belt,this paper studied the potential risk of the planned urban construction land extension to the wetlands by employing a GIS spatial analysis method.The results show that:(1) The wetland resources are widely distributed and diverse,with a proximal distribution to present urban construction lands spatially.(2) From 2005 to 2020,the urban construction lands will expand vastly and rapidly,and will take over lar...     

Sedimentary cycle pattern and stacked style of sand-body of the Lower Jurassic Sangonghe Formation in belly of Junggar Basin

The coarse grain braided river delta in Jurassic Sangonghe Formation of Junggar Basin formed the main Mesozoic reservoir system. At present,there are obvious different opinions on the sedimentary cycle characteristics of Jurassic Sangonghe Formation,and there is a lack of research on the driving mechanisms of sedimentary cyclicity,which leads to a great dispute on the stacked style of sand-bodies. Using 38 wells coring and logging data in the belly of Junggar Basin,based on principles and methods of sedimentology and sedimentary basin analysis,the characteristics of sedimentary cycle in Sangonghe Formation are systematically analyzed. The stacked style and combination rule of sand-bodies are studied in detail within sedimentary cyclic framework. The characteristics of basement subsidence and multi-stage uplifting during the Early Jurassic of Junggar Basin are discussed,so as to clear the driving mechanisms of positive sedimentary cycle. The Sangonghe Formation in the study area is divided into four system tract level positive cycles with no reverse cycle deposition,which reflects the sedimentary characteristics of slow lacustrine transgress and fast lacustrine retrogress. The sand-bodies in the braided river delta front of the Sangonghe Formation show five stacking patterns: Strong erosion of superimposed sand-body by subaqueous distributary channel,weak erosion of superimposed sand-body by subaqueous distributary channel,superimposed river-mouth bar on subaqueous distributary channel,distal bar-blanket sand assemblage,beach bar sand-body. The first cycle is the intermittent distribution of beach bar sand-bodies. The second cycle includes continuous distribution of strong erosion of superimposed sand-body by subaqueous distributary channel,weak erosion of superimposed sand-body by subaqueous distributary channel,and superimposed river-mouth bar on subaqueous distributary channel. The third cycle is composed of relatively continuous distribution of weak erosion of superimposed sand-body by subaqueous distributary channel and distal bar-blanket sand assemblage. The fourth cycle is scattered distribution of beach bar sand-body. It is possible because of the slow subsidence and intermittent rapid uplift of the basement of Junggar Basin that regressive superposition and the scour interface between each sedimentary cycle are formed.     

现今板块运动模型的发展及其比较

从地质数据的不断完善到空间大地测量数据的广泛应用,现今板块运动模型的发展有了质的飞跃.评述了其现状与发展趋势;利用ITRF2005的速度场建立了一个完全基于现代空间大地测量实测结果的现今全球板块运动模型ITRF2005VEL,并与地质模型NNR-NUVEL1A进行了比较.结果表明,从整体上看ITRF2005VEL与NNR-NUVEL1A模型有较好的一致性,且较以往的ITRF序列的模型精度更高,但同时也存在着一定的差异性,这与观测台站、板块本身等相关因素都有关.     

敦煌雅丹国家地质公园地质资源调查及地学意义

敦煌雅丹国家地质公园集雅丹和沙漠湖泊地貌类型于一体,是极端干旱区大型地貌景观类地质公园的典型代表。公园内地质遗迹资源典型,保存系统、完整,类型多样,可分为地质剖面、地质构造、地貌景观、水体景观和环境地质遗迹景观5大类。以雅丹和鸣沙山月牙泉等为代表的地貌景观与享誉国内外的古丝绸之路遗迹、敦煌文化等人文历史资源相结合,是敦煌雅丹国家地质公园的优势。敦煌雅丹与其他区域的雅丹地貌相比,除具有一定的相似性外,还具有类型多、密度大、走向变化明显形态丰富、反映了多个形成演化阶段等独特性。实施地质资源调查对保护地质遗迹、开展地质科学研究和普及地学等科学知识都有重要意义。同时,对提升景区品位,进而带动敦煌旅游业的发展都将起到积极的推动作用。     

陕北地区奥陶纪马家沟组五段沉积时期岩相古地理演化*

陕北地区马家沟组五段沉积时期(简称马五期)沉积的碳酸盐岩地层是重要的天然气储集层。为明确各沉积期岩相古地理演化特征,在对周缘野外地质剖面考察、研究区内98口井的岩心观察、测井曲线形态分析的基础上,对陕北地区马家沟组马五₁₀—马五₁各亚段的岩相古地理演化特征进行了恢复。结果表明,马五₁₀—马五₁各亚段以海相碳酸盐岩台地沉积为主,包括局限台地、开阔台地和蒸发台地3种亚相,并进一步细分为: 云坪、膏云坪、含膏云坪、泥云坪、灰云坪、灰坪、颗粒滩、云灰坪、泥灰坪、膏盐湖等10种沉积微相;从马五₁₀到马五₁岩相古地理单元整体表现为自东向西的环带状分布特征,环带中心主要位于延长、延川和清涧一带,值得注意的是,马五₂沉积时期由于受南部较强构造抬升作用影响,古地理单元环带中心呈现出向西北挪移的特征,环带中心位于靖边、子长一带;马家沟组各沉积时期的旋回性环带沉积为储集层叠合发育奠定了物质基础,云坪、膏云坪、含膏云坪、颗粒滩微相易于形成有利储集空间,纵向上的马五₁₊₂、马五₄、马五₅、马五₇、马五₉亚段为该类相带较发育的层位,是区域勘探开发的重点领域。     

北黄海海底麻坑群形态的定量研究及控制因素

本文基于高分辨率多波束水深数据和反向散射强度数据,对北黄海海底麻坑群的形态参数进行定量研究,结合水深、地形坡度和后向散射强度的变化准确界定了麻坑的轮廓,识别出圆形、椭圆形、拉长型麻坑共282个,并在ArcGIS软件中对其形态参数进行了分析计算,麻坑的平均长轴1.36 km,短轴0.78 km,直径0.94 km,面积0.88 km2,平均周长3.82 km,长宽比1.83,深度0.3~2.5 m,平均面积密集度13%,麻坑的剖面形态有麻坑边缘凹陷、中部有明显凸起（W1型）,麻坑边缘凹陷、中部略凸起（W2型）,麻坑中部单纯凹陷（V型）,分别集中分布在麻坑群的北部、南部、西部。麻坑的平面规模大、深度小的原因与地层中形成麻坑的游离气体浓度较小有关,也可能受到了地震、海啸等外力的诱发。麻坑的长轴优势走向为ENE-WSW、NNE-SSW,底流对其形状的塑造起了较大作用,部分麻坑成串排列,形成串珠状的麻坑链,其排列方式受到海底古河道、古潟湖等沉积地层结构的控制。海底麻坑群发育区反向散射强度为-60~-71 dB,麻坑内部较麻坑外部平均高5 dB,可能为麻坑内部气体泄漏引起海底沉积物被剥蚀后残留下的粗颗粒物质或海底生物活动留下的遗迹导致的。     

斜压罗斯贝变形半径优化的误差相关尺度及其对最优插值效果的改进

利用最优插值方法进行三维温盐场重构时,如何正确估算背景场误差协方差至关重要。针对背景场误差协方差主要取决于误差相关尺度的问题,本文提出了用中国东部海域及其附近海域的最新的高分辨率气候态数据进行斜压罗斯贝变形半径优化其误差相关尺度计算的研究方案和技术途径;对比分析了均一化相关尺度方案和法国ISAS系统尺度方案,讨论了变形半径对最优插值的影响。结果表明:均一化相关尺度方案的均方根误差小于ISAS方案,但温度场过于平滑,难以刻画一些重要的物理现象;相比而言,本文提出的基于变形半径的相关尺度方案在取2倍变形半径时,不仅均方根误差在各水平层较小,且温度场能够更好地刻画四国海盆海域涡旋及黑潮影响的温度场三维结构。由于实际海洋中各层物理过程的尺度存在差异,实际应用时各层的最优尺度设置也应有所不同。     

The impact of the herbicide atrazine on growth and photosynthesis of seagrass, Zostera marina (L.), seedlings

The impact of the widely used herbicide atrazine on seedling growth and photosynthesis of eelgrass was determined. The long-term impact of the herbicide atrazine (1, 10 and 100 μg/L) on growth of eelgrass Zostera marina (L.) seedlings, maintained in outdoor aquaria, was monitored over 4 weeks. Exposure to 10 μg/L atrazine resulted in significantly lower plant fresh weight and total chlorophyll concentration and up to 86.67% mortality at the 100 μg/L concentration. Short-term photosynthetic stress on eelgrass seedlings was determined and compared with adult eelgrass using chlorophyll fluorescence. The effective quantum yield in eelgrass seedlings was significantly depressed at all atrazine concentrations (2, 4, 8, 16, 32 and 64 μg/L) even within 2 h and remained at a lower level than for adult plants for each concentration. These results indicate that atrazine presents a potential threat to seagrass seedling functioning and that the impact is much higher than for adult plants.