红阳煤田石炭-二叠纪含煤地层的沉积特征

红阳煤田含煤地层太原组与山西组,是一套典型的“海陆交互相”沉积。依据剖面上沉积相序列变化特点,可划分为14个沉积旋回,每个沉积旋回均含有一层煤。有二种聚煤环境:一是海水退出潮坪后形成的泥炭沼泽聚积的煤层;二是扇三角洲平原形成的泥炭沼泽聚积的煤层。     

Heat-shock protein 70 expression in shrimp Fenneropenaeus chinensis during thermal and immune-challenged stress

Using western immunoblotting, we obtained heat-shock protein 70 (HSP70) induction data and distribution in different tissues from shrimp Fenneropenaeus chinensis during thermal and immune-challenged stresses. This is probably the first report of the effects of various stressors on the expression of HSP70 in shrimp.HSP70 was prominently induced in hepatopancreas and gills, but not in muscle, eyestalk and hemolymph, when the shrimp were exposed to heat shock and Vibrio anguillavium-challenged stresses. Cold shock and WSSV treatment had no significant effects on the levels of HSP70 expression in all tissues examined. HSP70 induction was greatest after 2 h exposure to heat shock stress, which was elevated after acute heat shock exposure of 10℃ above ambient temperature.     

Approach to Mountain Hazards in Tibet, China

Tibet is located at the southwest boundary of China. It is the main body of the Qinghai-Tibet Plateau, the highest and the youngest plateau in the world. Owing to complicated geology, Neo-tectonic movements, geomorphology, climate and plateau environment, various mountain hazards, such as debris flow, flash flood, landslide, collapse, snow avalanche and snow drifts, are widely distributed along the Jinsha River (the upper reaches of the Yangtze River), the Nu River and the Lancang River in the east, and the Yarlungzangbo River, the Pumqu River and the Poiqu River in the south and southeast of Tibet. The distribution area of mountain hazards in Tibet is about 589,000 km^2, 49.3% of its total territory. In comparison to other mountain regions in China, mountain hazards in Tibet break out unexpectedly with tremendously large scale and endanger the traffic lines, cities and towns, farmland, grassland, mountain environment, and make more dangers to the neighboring countries, such as Nepal, India, Myanmar and Bhutan. To mitigate mountain hazards, some suggestions are proposed in this paper, such as strengthening scientific research, enhancing joint studies, hazards mitigation planning, hazards warning and forecasting, controlling the most disastrous hazards and forbidding unreasonable human exploring activities in mountain areas.     

Matlab遗传算法工具GUI率定马斯京根模型参数

本文针对传统及改进马斯京根洪水演算模型,利用简单易行的Matlab遗传算法工具(gatool)GUI进行模型参数最优估计,获得不同优化准则下的模型参数,并进行检验.结果表明用Matlab遗传算法工具GUI优选改进后的马斯京根模型参数,收敛能力强、计算时间短、所得演算流量更接近实际.     

An Approach to Stability Analysis of Embedded Large-Diameter Cylinder Quay

The large-diameter cylinder structure, which is made of large successive bottomless cylinders placed on foundation bed or partly driven into soil, is a recently developed retaining structure in China. It can be used in port, coastal and off-shore works. The method for stability analysis of the large-diameter cylinder structure, especially for stability analysis of the embedded large-diameter cylinder structure, is an important issue. In this paper, an idea is presented that is, em-bedded large-diameter cylinder quays can be divided into two types, i.e. the gravity wall type and the cylinder pile wall type. A method for stability analysis of the large-diameter cylinder quay of the cylinder pile wall type is developed and a method for stability analysis of the large-diameter cylinder quay of the gravity wall type is also proposed. The effect of sig-nificant parameters on the stability of the large-diameter cylinder quay of the cylinder pile wall type is investigated through numerical calculation.     

东太平洋柱状沉积物的古气候和古环境记录

太平洋深海盆地的远洋沉积物在物质组成和来源上远较大陆边缘简单.由于远离大陆,又有海沟与周边大陆分隔,太平洋深海沉积物中通常不包含由河流水系搬运而来的悬浮物,因此从深海沉积物中提取古气候、古环境信息可以避免诸多地质因素相互叠加和干扰[1].深海远洋沉积物中的主要组分是风成陆源碎屑(包括火山碎屑)和来自上层海水的生源组分(降落到洋底的生物壳体)以及由海解作用形成的自生矿物[2],其中陆源碎屑的相对含量、粒度及矿物成分可以反映大气环流的强度及物源区的气候环境[1],生源组分的组成、相对含量和丰度以及种属含量变化则与表层海水的生产力和溶解作用有关.     

南海晚第四纪浮游有孔虫类群变化所表征的古海洋学特征

通过对南海4个岩心的74个样品进行Q型因子分析,求得4个浮游有孔虫组合:亚热带-热带组合,温凉组合,热带易溶组合和亚热带组合。亚热带-热带组合为优势组合,它的发育状况反映了晚第四纪西太平洋热带海水对南海的影响程度,其因子载荷作为古海流特征的参数。温凉组合的发育与南海存在冷涡有关。利用转换函数FP-12E计算了南海南部表层古水温,冰期与间冰期的表层水温平均变化冬季为4.7℃和2.9℃,夏季为3.0℃和2.1℃,季节性温差冰期最大可达8.6℃,间冰期最大可达5.0℃,均比太平洋同一纬度海区的大。冬季表层古水温波动比夏季的大。全新世的表层水温呈上升趋势,但在NS86-43柱中有一变冷现象,这可能和the younger Younger Dryas有关。     

四川攀枝花云鹿矿区特殊类型铂族元素成矿作用的发现

四川攀枝花云鹿铜铂金矿区是一个新发现的比较罕见的新类型含铂族元素矿床,其特殊性至少表现为矿化体赋存在炭质岩系中、炭质岩系中富含镁电气石(MgO含量7.68%～8.64%,平均8.15%)、表生过程中低温条件下铂族元素发生了活化转移(含铜钟乳石中含PGE 0.14×10-6).铂族元素的最初富集可能与元古宙的海底喷气活动有关.此类铂族元素的矿化在国内外罕见,有可能是第一次发现,但类似的成矿地质条件在中国西南地区普遍存在,应该在今后的地质研究与找矿过程中加以注意.     

New Early Cretaceous paleomagnetic results from Qilian orogenic belt and its tectonic implications

Lower Cretaceous red sedimentary rocks from the depositional basin of East Qilian fold belt have been collected for a paleomagnetic study. Stepwise thermal demagnetization reveals two or three components of magnetization from dark red sandstones. Low-temperature magnetic component is consistent with the present Earth Field direction in geographic coordinates. High-temperature magnetic components are mainly carried by hematite. The mean pole of 19 sites for high-temperature magnetic components after tilt-correction is λ=62.2°N, φ=193.4°E, A95=3.2°, and it passes fold tests at 99% confidence level and reversal tests at 95% confidence level. The paleopole is insignificantly different from that of Halim et al. (1998) from the same sampling area at the 95% confidence level. Compared with paleomagnetic results for North China, South China, and Eurasia, our results suggest that no significant relative latitudinal displacement has taken place between Lanzhou region and these blocks since Cretaceous time. Remarkably, the pole of Lanzhou shows a 20° clockwise rotation with respect to those of North China, South China, and Eurasia. Geological information indicates that the crustal shortening in the western part of Qilian is greater than that in eastern part. In this case, the clockwise rotation of sampling area was related to India/Eurasia collision, and this collision resulted in a left-lateral strike-slip motion of the Altun fault in north Tibetan Plateau after the Cretaceous.     

末次冰期东亚季风气候的变迁：贵州都匀七星洞石笋的δ18O记录

通过对贵州都匀七星洞4根石笋系统的31件TIMS U系及543件稳定同位素分析，揭示出其气候变化记录时限范围为1．1～8．5万a，相当于海洋同位素阶段的MIS2，MIS3，MIS4及MIS5a。根据δ^18O的变化可以准确确定它们之间的界线，其年龄值为：MISl／MIS2 11．3kaB．P．，MIS2／MIS3 28．7kaB．P．，MIS3／MIS4 59．6kaB．P．，MIS4／MIS5a 78．5kaB．P．。研究表明，末次冰期相当于格陵兰冰芯记录、北大西洋沉积记录的YD、Heinrich事件等的气候跃变事件，几根石笋取得了非常一致的准确定位及定年。其中YD事件发生于12．76～11．52kaB．P．，Heinrich事件的H1～H6分别为15～17kaB．P．，24．6kaB．P．，30．5kaB．P．，39．3kaB．P．，46．8～47．8kaB．P．以及60．4kaB．P．。在MIS4阶段，石笋记录于66．4kaB．P．及73．8kaB．P．揭示了两次冷事件，也可于格陵兰冰芯记录中找到相对应的冷谷。通过与GISP2的对比研究，表明东亚季风气候的百年至千年尺度的气候演变，与北大西洋及格陵兰高纬度地区的气候变化具有非常协调的对应关系。它对研究季风气候的动力机制及其与全球变化的响应关系具有特别重要的意义。