2011年建湖震群初步分析

从2010年12月30日起,江苏建湖相继发生100多次地震事件（含单台地震事件）,其中ML≥3.0地震6次,初步分析发现,与1987年射阳地震前地震活动性具有较好相似性.     

天津蓟县中新元古代串岭沟组次火山岩系及其赋存金矿

天津蓟县中新元古界地层剖面闻名于世。最近在该剖面上,发现了东山金矿,该金矿赋存于变质核杂岩上的一条大的滑脱面上,金矿形成与大陆伸展构造有关。该金矿主要形成于长城系串岭沟组黑色页岩内的次火山岩中,这种次火山岩包括超浅成侵入岩相、次火山相和隐爆喷出相。笔者认为,该金矿应属构造蚀变岩型。矿体常呈囊状、透镜体或脉状,Au含量为3×10-6～8×10-6,矿体长度、宽度变化较大。     

Effects of structural characterizations on fragility functions of bridges subject to seismic shaking and lateral spreading

This paper evaluates the seismic vulnerability of different classes of typical bridges in California when subjected to seismic shaking or liquefaction-induced lateral spreading. The detailed structural configurations in terms of superstructure type, connection, continuity at support and foundation type, etc. render different damage resistant capability. Six classes of bridges are established based on their anticipated failure mechanisms under earthquake shaking. The numerical models that are capable of simulating the complex soil-structure interaction effects, nonlinear behavior of columns and connections are developed for each bridge class. The dynamic responses are obtained using nonlinear time history analyses for a suite of 250 earthquake motions with increasing intensity. An equivalent static analysis procedure is also implemented to evaluate the vulnerability of the bridges when subjected to liquefaction-induced lateral spreading. Fragility functions for each bridge class are derived and compared for both seismic shaking （based on nonlinear dynamic analyses） and lateral spreading （based on equivalent static analyses） for different performance states. The study finds that the fragility functions due to either ground shaking or lateral spreading show significant correlation with the structural characterizations, but differences emerge for ground shaking and lateral spreading conditions. Structural properties that will mostly affect the bridges＇ damage resistant capacity are also identified.     

Characteristics of nutrients in the Jiulong River and its impact on Xiamen Water, China

Water samples were collected at 20 sites on 4 occasions in 2009(twice in May,and once in both August and November) along the Jiulong River,South China to examine how nutrient inputs from the Jiulong River could affect the nutrient status of the Xiamen Water.Samples were analyzed for nitrite(NO2-N),nitrate(NO3-N),ammonium(NH4-N),phosphate(PO4-P),silicate(SiO3-Si),salinity,and temperature,to determine the nutrient and trophic status of the river.The results indicate that nutrients are derived mainly from river runoff.NO3-N was the main form of DIN in most parts of the river.In addition,NO3-N,DIN,and SiO3-Si behave conservatively.There is a surplus of DIN and SiO3-Si in the river,and PO4-P is a limitation on phytoplankton growth.The concentration of DIN is typically above 0.60 mg/dm3,and higher than 1.00 mg/dm3in most parts of the river.The concentration of PO4-P is typically above 0.02 mg/dm3,while the concentration of SiO3-Si is higher than 1.00 mg/dm3.Between 2003 and 2008,samples were collected 3 times per year(May,August and November) at 27 sites in the Xiamen Water and analyzed for NO2-N,NO3-N,NH4-N,PO4-P,salinity,and temperature.We discovered that the Jiulong River was the key source of DIN into the Xiamen Water,but not PO4-P,indicating the reason of the N/P molar ratio imbalance in the Xiamen Water.In the future,the effects of high DIN concentrations on the phytoplankton communities and marine ecosystems of the Xiamen Water shall be studied.     

GRAPES-SDM沙尘模式预报与卫星遥感监测结果对比

GRAPES-SDM沙尘模式和卫星遥感监测是目前沙尘暴监测预报业务中重要的工具.本文使用天气学检验方法,对中国气象局兰州干旱气象研究所目前使用的GRAPES-SDM沙尘模式2012年春季沙尘天气预报情况以及FY-2D卫星遥感产品沙尘指数IDDI的监测效果进行检验评估.结果表明:沙尘模式在西北沙尘暴预报业务中具有很好的预报参考价值,卫星遥感沙尘指数也具有较好的监测效果,但两者均存在一定的问题.沙尘模式对大范围沙尘暴过程有较好的预报能力,但对沙尘强度预报偏强;卫星遥感沙尘指数虽然不能定性地表示沙尘强度,但是在一定程度上能够反映沙尘强度的变化,不过反映沙尘强度的数值及其分布区间还有待于进一步完善.卫星遥感在南疆盆地常会将大片深厚的沙尘气溶胶区域误判为云区,造成对沙尘天气特别是沙尘暴天气未能识别的现象,另外IDDI指数不能用于夜间沙尘监测.     

桥面铺装低掺聚丙烯纤维混凝土耐久性试验与分析

试验研究以本地化的材料,针对寒区桥面铺装这一特殊应用领域要求进行低掺聚丙烯纤维混凝土配合比设计及优选。然后对不同掺入量组成的低掺聚丙烯纤维混凝土的冻融循环、冻融-氯盐共同作用下的耐久性试验研究,并对试验结果进行分析评价。     

2009年初冬沪宁高速公路大雾过程成因分析

利用沪宁高速公路自动气象监测站(AMW)数据,结合NCEP/NCAR的1°×1°格点再分析资料,对2009年12月1—2日发生在沪宁高速公路上的大雾天气过程的能见度演变特征及其与相关气象要素的关系进行了分析,并对大雾形成机理进行了研究。结果表明:能见度与各气象要素之间均呈非线性关系,与相对湿度呈稳定的指数衰减关系,与温度及风速呈复杂的多项式关系;高空暖性高压脊和地面变性冷高压的高低空环流配置为雾的形成提供了逆温层结和近地面的弱风场条件;偏东气流和逆温层保证了水汽供应及在低层汇聚;雾区上空的热力因子和动力因子的分析证明了雾区大气层结状态的稳定性。     

用测井曲线识别地质标志层位

利用动态规划算法进行有序序列匹配来识别地质标志层位,在选取特征模式参数时,不仅考虑了曲线形态的特征,而且考虑了地层岩性的特征。对特征模式向量进行了量纲一致性处理。识别时既可以对全孔所有层识别,也可以只做部分层位识别,还可以分段识别。对山东唐口地区的几口井做了识别处理,均取得较满意的结果。      

天津团泊洼水库水体生物生产力与渔业开发利用

天津市团泊洼水库属华北平原滨海盐碱性水库。1989年多学科综合调查的结果表明:该水体中营养盐类含量氮高磷低,挺水植物藨草、芦苇为主要初级生产者,浮游生物种类贫乏,现存量不高,周丛生物丰富。结果还表明,该水体仍有较大渔产潜力。应从调整鱼类种群结构着手,充分而合理地利用水体中的可更新资源,使渔业、环境协调发展。