1989年3月特强磁暴期间的电离层暴

用欧亚大陆地面电离层垂测站资料考察1989年3月12～16日磁暴期间的电离层暴形态及其发展变化. 特强磁暴引发的电离层暴是全球性的,但自磁层沉降的高能粒子对热层低部的加热程度及区域分布不同,因而各经度链区域内电离层暴的特征也有所差异. 本文研究表明,与理论推断对照,欧洲地区内F2层最大电子密度NmaxF2(或f0F2)并不出现正暴现象,而负暴自高纬向低纬的发展则与典型的热层环流结果相符. 此外,此磁暴过程期间在中低纬区存在明显的波动过程. 在亚洲高纬地区,磁暴初期13日有约10 h的正暴,而负暴过程则与欧洲地区类似,但不太清晰;且无波动现象. 磁暴期间,同一经度链的中低纬地区,夜间常发生多站同时的h′F突增. 本文再次证实这是一般磁暴期间常出现的普遍现象.     

俄、蒙、中交界7.9级地震

2003年9月27日19时33分,在俄、蒙、中边界地区发生了Ms7．9地震,新疆阿尔泰地区强烈有感,地震造成经济损失7600万元人民币。文章对此次地震的基本参数、震源机制作了概述,并用遥感资料对地震的构造环境和破裂过程进行了初步分析。     

Observation and Research of the Transits of Extrasolar Planets

In order to make more accurate estimates of the physical parameters of extrasolar planets, the observation and research on the phenomena of transits of the 7 known stars with the planetary systems TrES-1, TrES-3, XO-2, WASP-1, WASP-2, WASP-3 and HAT-P-7 are carried out with the 1-m reflecting telescope at Shandong University Weihai Astronomical Observatory/Weihai Municipal Astronomical Observatory. The fundamental conditions of the observation and data processing are introduced, and the transit light curves as well as the parameters of some planets derived from them are given. At the same time, when the results are summarized and analyzed, the prospects for the more in-depth and detailed researches which will be further carried out are also described.     

Enhancing the mechanical properties of marine clay using cement solidification

Abstract

The use of soft clay and dredged marine clays as the construction material is challenging. This is because the high water content, high compressibility and low permeability of the clay causing the instability of ground and structure. This detrimental effect of soft clay can be improved by the cement solidification process, which is relatively cheap and efficient. This paper mainly focuses on the study of improvement on the mechanical behavior of cement mixed marine clay. The soil is reconstituted by using ordinary Portland cement of 5%, 10%, 15% and 20% by its mass. The study reveals that cementation of clay significantly improves the peak and residual strength of soil. Similarly, the primary yield stress of the soil is also improved from 16 to 275?kPa as cement content increases from 5% to 20%, respectively. By using statistical tools, the relationships between various parameters are established, which are very important to define the mechanical behavior of the clay. This study reveals that the yield surface of the solidified marine clay is not a smooth elliptical surface. Rather it is composed of two linear surfaces followed by a log-linear surface which can be modeled by using simple parameters obtained from triaxial tests.     

凡纳滨对虾(Litopenaeus vannamei)体重、存活性状的遗传参数和基因型与环境互作效应

利用7个凡纳滨对虾(Litopenaeus vannamei)引进群体,通过双列杂交和巢式交配设计构建家系,建立育种基础群体,估计体重、存活性状的遗传参数和基因型与环境互作效应(genotype by environment interactions,G×E)。结果表明,凡纳滨对虾基础群体体重和存活性状的遗传力估计值范围分别在(0.19±0.09)—(0.43±0.09),(0.27±0.04)—(0.45±0.06),均属于中高遗传力水平,并且统计检验显著(P<0.05)。Z-score检验表明,体重和存活性状遗传力估计值在河北黄骅(HBHH)和青岛鳌山(QBAS)两个测试场间差异均不显著。体重和存活性状的表型和遗传相关系数分别为0.007和0.008,表现为低度线性负相关。对于体重和存活性状,HBHH和QBAS场间的遗传相关分别为0.83±0.04和0.40±0.11。体重性状的G×E效应不显著(K<0.5),但存活性状存在显著的G×E效应(K>0.5)。上述结果显示,凡纳滨对虾基础群体体重和存活性状的遗传变异丰富,多代选择可获得较大的遗传进展。     

中华哲水蚤(Calanus sinicus)个体核酸含量及其对生长状况的指示作用

采用荧光染色法对黄、东海春、秋季中华哲水蚤(Calanus sinicus)个体核酸含量进行了研究,初步探讨了RNA∶DNA比对中华哲水蚤生长状况的指示作用。结果表明,中华哲水蚤在饥饿培养24h后RNA∶DNA比值显著降低;雄性个体RNA含量和RNA∶DNA比值显著低于雌体和C5期幼体;春、秋季(2009年5月和2010年11月)个体RNA含量和RNA∶DNA比值存在显著的空间变化,两者最高值均出现在近岸;两个月份DNA含量相对稳定,在2.5—3.5μg/ind之间;个体RNA含量和RNA:DNA比值与叶绿素之间显著正相关,说明饵料是中华哲水蚤的生长过程中重要的影响因素。     

海水中溶解态铵盐氮同位素分析的预处理方法

以蒸馏法为基础, 研究了适合海水中铵盐稳定氮同位素分析的预处理方法。对蒸馏法预处理过程中的最佳蒸馏时间、沸石的选取、铵盐最适浓度范围等分别进行改进和优化, 获得稳定、高效的海水中铵盐氮稳定同位素分析预处理方法。结果表明: 最佳蒸馏时间为50 min, 铵盐的回收率为(97±5.8)%。测定了不同沸石对不同浓度氨氮的吸附率, 筛选出酸性条件下铵氮吸附效率较高且稳定的康华科技沸石; 确定铵盐的最佳适用浓度范围为2～10 μmol/L, 在该浓度范围内氮回收率94%～99%,氮分馏系数为0.1‰～0.8‰。将此方法应用于长江口海域水样分析, 结果表明, 这一方法可以应用于河口中铵盐的氮同位素分析, 能够为河口中溶解态氮的来源及循环机理等研究提供有效信息。     

Stable Isotope Composition of Rainfall,Surface Water and Groundwater along the Yellow River

The intention of this work is to consider the stable isotopic compositions of oxygen and deuterium in rainfall, surface water and groundwater along the Yellow River in the North China Plain (NCP). This demonstrated that the δ18O values in groundwater varied from –10.17 to –6.85‰, with mean value of –8.76‰, and that the δD ranged from –68.7 to –58.0‰, with mean value of –63.4‰, respectively. The δ18O values in surface water varied from –8.36 to 1.32‰, with mean value of –6.8‰, and δD ranged from –64.4 to –35.1‰, with mean value of –57.6‰, respectively. Further, The range of Cl- values of groundwater varied from 5.9 to 340.5 mg/L and that values ranged from 30.1 to 81.9 mg/L in surface water samples and Na+ value changed from 27.4 to 321 mg/L in groundwater, while that in surface water varied from 24.8 to 50.5 mg/L. Most of the points fall below the GMWL?, but are close to the LMWL.? Therefore the results indicated that the groundwaters along the Yellow River were influenced by rainfall in heavy events and surface water.     

辽西黄土陡坡的冲刷破坏机制

以70°辽西黄土陡坡为例,在降雨强度为2.7 mm/min条件下对边坡坡面冲刷破坏特征进行了室内物理试验模拟。试验发现：随着降雨的持续坡面水流能量不断增加,致使侵蚀强度增强;边坡的侵蚀方式从试验初期的片蚀,到中期的细沟侵蚀,最后演化为坡顶部的切沟侵蚀和坍塌。基于试验成果,采用SEEP/W程序对降雨条件下边坡降雨入渗规律进行数值模拟,发现在降雨过程中坡顶部所产生的水头压力最大,随高度降低呈减小趋势;运用PFC2D颗粒流软件从微观角度对坡体土颗粒运动情况进行模拟,结果发现位于坡顶的颗粒最先被径流冲刷带走,且下落速度很快。经对比表明：数值模拟结果和物理模拟试验现象基本一致,可为进一步研究黄土边坡冲刷破坏规律提供参考。     

线阵影像GC3多视匹配模型的匹配方向线研究

针对线阵影像的几何成像特点,介绍了GC3及其改进匹配模型的匹配原理;根据模拟参数,推导了GC3多视匹配模型的同轨立体匹配方向线、异轨立体匹配方向线严密函数表达式,给出了匹配方向线分析结论;分别采用模拟数据与ADS40影像数据进行了实验分析,实验结果证明：在实际匹配过程中,匹配方向线在局部范围内可近似为直线使用。