差分法判别地倾斜异常的实用性研究

本文以新疆十多年来定点形变连续观测资料为基础,对观测数据差分值变化预报地震进行了实用性研究。给出了差分异常震例和计算统计分析结果,认为一阶差分法是一种比较实用而有前途的地震预报方法。     

On sexual dimorphism in Paleoparadoxia tabatai

Abstract Upon studying the well preserved skulls referred to Paleoparadoxia tabatai from Japan, the short and low skull of the Yanagawa specimen requires an explanation. Six cranial and dental characters lead us to suggest that the Yanagawa individual is a female while the Izumi, Ohnohara, and Itsukaichi skulls are male. The important characters in the Yanagawa skull are its shortness and shallow depth, less pronounced sagittal and nuchal crests, smaller zygoma, and the small dentition with especially poorly erupted canines, most of which are indicative of weak masticatory musculature.     

Estimating fish length and age at 50% maturity using a logistic type model

We propose a two-parameter logistic type model for estimating fish length and age at 50% maturity using the nonlinear least-squares method. The independent and dependent variables in the model are length (or age) and the corresponding arcsin-square-root transformed proportion of mature fish (P_i). The two parameters in the model are length (or age) at 50% maturity (L50 or A50) and instantaneous rate of maturation (K). A simulation study was conducted to examine the statistical behaviour of the proposed model in estimating L50 and K. The L50 was well estimated with a small bias (<1%) using the proposed model in all simulation cases. The K was well estimated (bias < 1%) when its true value and the variance in P_i were small. The proposed model was found to have relatively smaller bias than the probit and Lysack's methods in estimating L50 (or A50). To examine whether there are significant differences in maturation patterns between different groups of fish, we propose fitting the maturation data to the proposed model, and then conducting an analysis of residuals sum of squares to test whether there are significant differences in the fitted models.     

Early diagenesis in anaerobic lake sediments—II. Thermodynamic and kinetic factors controlling the formation of iron phosphate

The ion activity product of Fe and phosphate in interstitial waters from four sediment cores taken from Greifensee, Switzerland indicate the presence of vivianite [Fe₃(PO₄)₂ · 8 H₂O] in the solid phase. Analysis of the sediment using an electron microprobe and by electron microscopy revealed P-rich grains to be also enriched in Fe. The combined methods provide strong evidence that vivianite is forming authigenically in the sediments. Thermodynamic stability calculations demonstrate that the most stable Fe and phosphate minerals (pyrite, siderite and apatite) are not the ones controlling the pore water chemistry. The results emphasize the importance of rate processes of mineral formation in early diagenesis.Calculations based on the sediment phosphate concentration, and the degree of supersaturation of Fe and phosphate in the upper portion (0–15 cm) of the pore waters, indicate that the rate of vivianite mineral growth is controlled by a surface reaction rather than a diffusion mechanism. The response time of dissolved phosphate in the sediment pore waters with respect to mineral precipitation is on the order of 1–20 days. Less than 15% of the phosphate released by organic matter degradation at the sediment-water interface and below is retained in the sediments.     

三丁基氧化锡(TBTO)对太平洋牡蛎性成熟的影响

利用流水饲养法研究了不同浓度的三丁基氧化锡 (0 .5 μg/ L和 1.0 μg/ L TBTO)对太平洋牡蛎卵巢中卵母细胞直径、RNA/ DNA比、蛋白质和卵黄蛋白含量的影响。卵母细胞径的增长在0 .5 μg/ L实验组受到阻碍 ,并随着 TBTO浓度的增大而更加明显。TBTO暴露组的 RNA/ DNA比在精巢中无明显变化 ,但在卵巢中显著低于对照组。 TBTO暴露组的卵巢中蛋白质和卵黄蛋白含量显示了与 RNA/ DNA比相同的变化趋势 ,表明 TBTO的积累阻碍卵黄蛋白的合成。TBTO暴露4 2 d采集的牡蛎样品中出现 3个雌雄同体 ,暗示 TBTO可能引起牡蛎发生性转变进而产生雌雄同体     

Parameter identification method for determination of elastic modulus of rock based on adjoint equation and blasting wave measurements

The purpose of this paper is to present a parameter identification method to determine the force of a blast and the elastic modulus of the ground using the measurements of a dynamic elastic wave, the adjoint equation method of optimal control theory, and the finite element method. Before the excavation of rocky ground, it is important to estimate the ground properties. In this paper, the elastic modulus is determined as the performance function is minimized using a technique based on the first‐order adjoint method. The performance function is a square sum of the discrepancies between the computed and the observed values of the velocities. After the determination of the magnitude of the blasting force, we can determine the elastic modulus of the rock. As the basic equation to calculate the velocities of dynamic elastic body, elastic equilibrium equations with linear viscosity are employed. The adjoint equation method has been utilized in order to calculate the gradient of the performance function with respect to the parameters. The gradient of the performance function is calculated using the first‐order adjoint equation. The weighted gradient method is applied for minimization. In order to solve the state equations in space and time, the finite element method and the Newmark $\frac{1}{4}$ method are used. In this paper, we tested the practical application of our proposed method for determination of the elastic modulus of rock at the Ikawa tunnel located in the Tokushima prefecture, Japan. Copyright © 2009 John Wiley & Sons, Ltd.     

近40 a来新疆极地类对流层顶温度变化的若干事实和突变分析

采用1963—2002年新疆12个探空站逐日探测资料．按气候特点和地理分布把新疆划分为阿尔泰山．天山和昆仑山3个研究区域。分析了40a来新疆全年各区极地类对流层顶平均温度变化的若干事实、变化的趋势和变化的空间分布差异,用Mann-Kendall法对其进行了气候突变检验。研究表明：新疆极地类对流层顶平均温度总体呈下降趋势;从年代际变化来看40a共下降了0．5℃,下降速率为0．125℃／（10a）。同时,该层温度于1976年发生了气候突变,皿著水平达5％以上．由此说明新疆近年来高空的一些特性层也同样发生了气候变化。     

济阳坳陷中、新生代成熟度曲线及其在剥蚀量计算中的运用

在地温场的作用下,样品的镜质体反射率与埋深呈指数关系。依据大量的分析测试数据,拟合了济阳坳陷新生代成熟度曲线关系式,并根据济阳坳陷中、新生代古地温梯度、古地表温度的差异性,推算出中生代成熟度曲线关系式,为该地区分析、判断烃源岩的成熟度提供了参考依据。在此基础上,利用热史演化与构造升降的对应关系,介绍了利用镜质体反射率资料推算地层剥蚀量的两种具体方法,并就济阳坳陷中生界与古生界不整合面的地层剥蚀量进行了实例分析。结果表明,发生于晚三叠世的印支运动造成了济阳坳陷区3000余米的地层剥蚀,剥蚀掉的地层包括早、中三叠世沉积的全部地层及石炭系顶部的部分地层,从而得出济阳坳陷区三叠纪地层的缺失不是沉积缺失,而是剥蚀缺失的认识。