华北—东北地区震磁异常与日本强震对应关系

选取2009—2014年华北—东北地区发生的12次中等地震,对该区8个地磁台站记录的地磁Z分量日变幅进行小波分析及合成计算,与日本海沟同期发生的12次M≥6.5强震进行关联性分析,发现日本强震对中国华北—东北地区中等地震活动具有连带作用,表现在:①日本强震发生前后,华北或东北地区均有M4—5地震出现,频次一般为1—3,间隔几天至5个月左右;②2011年3月10日日本M9.1地震后,华北、东北地区中等地震震级有所升高,其中东北地区由M4升至M5,距日本最近的中俄交界甚至出现M6.1地震,华北地区唐山老震区出现1次M4.8地震,震级接近5;③每次日本强震出现后几天至2个月内,8个地磁台地磁Z分量小波细节6阶合成曲线值均出现2—6个月高值异常,但幅度大小与强震震级无明显规律可循,而华北或东北地区中等地震一般在异常高值出现前后低值附近发生。     

Atmospheric eddy anomalies associated with the wintertime North Pacific subtropical front strength and their influences on the seasonal-mean atmosphere

This study investigates transient eddy activity anomalies in the mid-latitude upper troposphere associated with intensity variability of the wintertime North Pacific subtropical front. Our results show that the meridional gradient of air temperature and baroclinic instability in the mid-latitude atmosphere become stronger as the subtropical front intensifies, and the mid-latitude westerly jet accelerates with barotropic structure. We further divide the mid-latitude atmospheric eddy activities into high-(2–7 days) and low-frequency(10–90 days) eddy activities according to their life periods. We find that, when the oceanic subtropical front intensifies, the high-frequency atmospheric eddy activity in the mid-latitudes strengthens while the low-frequency eddy activity weakens. The stronger high-frequency eddy activity tends to moderate the air temperature gradient and baroclinicity in the mid-latitudes. High-frequency eddy anomalies accelerate the westerly jet on the northern side and downstream of the westerly jet, and enhance the jet with equivalent barotropic structure. In contrast, the weaker low-frequency eddy activity has a negative contribution to zonal wind speed tendency and attenuates the zonal homogenization of the jet. The anomalous thermodynamic forcing of the low-frequency eddy activity helps maintain the meridional gradient of air temperature in the mid-troposphere.     

Soil quality changes in land degradation as indicated by soil chemical, biochemical and microbiological properties in a karst area of southwest Guizhou, China

Not only the nutritional status and biological activity but also the soil ecological functioning or soil health has been impacted profoundly by land degradation in the karst area of southwest China where the karst ecosystems are generally considered as extremely vulnerable to land degradation under intensified land-use changes. The objectives of this study are to elucidate the changes in overall soil quality by a holistic approach of soil nutritional, biological activity, and soil health indicators in the karst area as impacted by intense cultivation and vegetation degradation. Topsoil samples were collected on selected eco-tesserae in a sequence of land degradation in a karst area of southwest Guizhou in 2004. The soil nutrient pools of organic carbon (C_org), extractable extracellular carbon (C_ext), total soil nitrogen (N_t), alkali-hydrolyzable nitrogen (N_ah), total phosphorus (P_t), available phosphorus (P_a) were analyzed by wet soil chemistry. The soil biological properties were studied by means of measurements of microbial biomass carbon (both by fumigation–extraction, FE-C_mic, and by calculation from substrate-incubation respiration, SIR-C_mic) of respiration [respiration without addition of substrates, basal respiration (BR), and potential respiration (PR) with substrate-incubation] and of soil enzyme activities (invertase, urease, and alkaline phosphatase). Soil health status was assessed by simple indices of C_mic/C_org and BR/C_mic in conjunction with bacterial community structures determined by polymerase chain reaction and denaturing gradient gel electrophoresis. While the nutritional pool parameters, such as C_org and C_ext, described basically the changes in soil life-supporting capacity with cultivation interference and vegetation declined, those parameters of biological activity such as FE-C_mic, SIR, and SIR-C_mic as well as bacterial community structures measured by molecular method evidenced well the changes in soil functioning for ecosystem health with the land degradation.     

秦岭商丹断裂带的构造样式与变形分析

商丹断裂带作为扬子板块与华北板块的缝合带,在秦岭造山带中占据重要的地位。对其进行精细的构造研究,是了解扬子板块与华北板块相互作用过程的关键。研究工作在商丹断裂带东段展开,对该带进行了详细的野外观察、显微构造观察、糜棱岩化过程中温度的估算、有限应变测量、差异应力的计算以及糜棱岩化过程中运动学涡度的计算。变形温压条件指示糜棱岩形成于中-高绿片岩相到低角闪岩相变质条件。差异应力计算结果指示商丹带具备大型构造动力特征。涡度分析表明该断裂带的变形以纯剪切作用占据主导作用,但包含有简单剪切的分量,从而证明了扬子板块与华北板块之间具有以碰撞挤压为主的斜向汇聚方式。     

湘黔桂交界区富禄组与富禄间冰期的再划分

在中国南华系层型剖面优选区之一——湘黔桂交界区,富禄间冰期可再分为3个相对较暖热的气候阶段(间冰段)和2个相对寒冷的气候阶段(冰段),即(自老而新)：三江间冰段、龙家冰段、烂阳间冰段、两界河冰段、大塘坡间冰段。相应地,富禄间冰期沉积地层——富禄组可分5个段,即：三江段、龙家段、烂阳段、两界河段、大塘坡段。另外,对古城组和铁丝坳组层型的湖北长阳古城剖面、贵州松桃大塘坡剖面和相关资料的再研究揭示,“古城组”和“铁丝坳组”都是富禄间冰期晚冰段(即两界河冰段)的沉积,均不宜替代长安组作为南华纪早冰期沉积的代表。     

山东沂南金场矽卡岩型金铜矿床地质地球化学特征及矿床成因

金场金铜矿床是沂沐断裂带西侧与中生代次火山作用有关金铜矿床的典型代表。该矿地质地球化学特征的综合研究表明“其成矿岩体具有富碱、富钾、富轻稀土和大离子亲石元素的特点，是由成熟度较高的中－下部地壳物质经重熔再生的 产物。     

长江口基础生物资源现状及年际变化趋势分析

探讨长江口生物资源可持续利用和对生物栖息环境的保护措施,2004年对长江口海域的基础生物资源进行4次监测。结果表明:浮游植物5月份有5门39属86种,8月份有6门48属139种,河口锋附近水域的浮游植物种类、数量较多,中肋骨条藻(Skeletonema costatum)在数量上处于绝对优势;浮游动物5月份为77种,8月份为91种,中小型浮游动物的数量在河口锋附近水域较高,主要优势种有针刺拟哲水蚤(Paracalanus aculeatus)等,大型浮游动物种类数量较高的区域位于长江冲淡水以外的海域,主要优势种为中华哲水蚤(Calanus sinicus)、五角水母(Muggiaea atlantica)、真刺唇角水蚤(Labidocera euchaeta);2004年共鉴定底栖生物146种,5月份63种,8月份108种,其中多毛类41种、甲壳类41种、软体动物32种、棘皮动物6种、鱼类21种、其他4种;长江口沿岸的崇明东滩、南汇边滩和嵊山岛共鉴定潮间带生物126种,其中5月份86种,8月份71种;鱼卵仔鱼计8目20科30属34种,鱼卵中绝大部分为凤鲚,其数量占95.7%,仔鱼以中华小公鱼出现频次最多。通过年际变化分析表明,长江口门以内区域浮游生物种类明显下降,长江冲淡水区域的生物资源基础饵料生物种类数基本保持稳定,浮游生物群落结构发生变化,硅藻比重减少,甲藻增加,长江口区域的潮下带和潮间带底栖生物种类数也存在不同程度的下降,以口门以内区域下降明显。     

渤海、黄海、东海海面热量平衡的平均状况——Ⅰ.资料处理和计算方法

渤、黄、东海海面热量平衡状况对该海域海洋水文和中国气候有着重要的影响。我们对该海域热量平衡各分量的年平均和年变化进行了计算,并分别就资料处理和计算方法、年平均状况、年变化特征等几个方面进行了分析。本文作为该项研究的第一部分,讨论了所用的资料和计算公式,提出了在稳定温度层结条件下的交换系数的校正方法。     

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。