A possible method for the determination of the magnitude and inclination of a sunspot magnetic-field

A method is presented in this paper for the determination of both the H and the γ of a sunspot magnetic field by means of two polarizers with transmission axes inclined at ± 45° to the fast axis of a quarter-wave plate. Previously, this arrangement was used to determine H only.It is shown that the profiles of the Stokes parameters are sensitive to the sunspot atmosphere model used whereas the results given by the present method are not. It is shown, more ever, that the formula for determining H from the wave length shift, Δλ = 4.67 × 10^?5gHλ², cannot be used in many cases.     

Dynamic analysis of three-dimensional marine cables

Marine cables are widely used in a variety of offshore activities. In this paper, a numerical approach is presented which is capable of predicting the dynamic behaviour of three-dimensional marine cables. The solution of this problem is of practical importance in the estimation of dybamic loading and motion, and thus has direct application to the enhancement of safety and the effectiveness of the offshore activities. The approach is based upon the lump-mass-and-spring model and the finite difference method. Mathematical analysis is provided on the basic characteristics of the model and the numerical stability. A numerical example is given to demonstrate the validity of the approach.     

Timing of UHP metamorphism in the Hong’an area,western Dabie Mountains,China: evidence from zircon U–Pb age,trace element and Hf isotope composition

The Hong’an area (western Dabie Mountains) is the westernmost terrane in the Qinling-Dabie-Sulu orogen that preserves UHP eclogites. The ages of the UHP metamorphism have not been well constrained, and thus hinder our understanding of the tectonic evolution of this area. LA-ICPMS U–Pb age, trace element and Hf isotope compositions of zircons of a granitic gneiss and an eclogite from the Xinxian UHP unit in the Hong’an area were analyzed to constrain the age of the UHP metamorphism. Most zircons are unzoned or show sector zoning. They have low trace element concentrations, without significant negative Eu anomalies. These metamorphic zircons can be further subdivided into two groups according to their U–Pb ages, and trace element and Lu–Hf isotope compositions. One group with an average age of 239 ± 2 Ma show relatively high and variable HREE contents (527 ≥ Lu_N ≥ 14) and ¹⁷⁶Lu/¹⁷⁷Hf ratios (0.00008–0.000931), indicating their growth prior to a great deal of garnet growth in the late stage of continental subduction. The other group yields an average age of 227 ± 2 Ma, and shows consistent low HREE contents and ¹⁷⁶Lu/¹⁷⁷Hf ratios, suggesting their growth with concurrent garnet crystallization and/or recrystallization. These two groups of age are taken as recording the time of prograde HP to UHP and retrograde UHP–HP stages, respectively. A few cores have high Th/U ratios, high trace element contents, and a clear negative Eu anomaly. These features support a magmatic origin of these zircon cores. The upper intercept ages of 771 ± 86 and 752 ± 70 Ma for the granitic gneiss and eclogite, respectively, indicate that their protoliths probably formed as a bimodal suite in rifting zones in the northern margin of the Yangtze Block. Young Hf model ages (T _DM1) of magmatic cores indicate juvenile (mantle-derived) materials were involved in their protolith formation. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

东营城区高精度三维地震采集方法研究

根据东营城区内建筑物较多，环境干扰较大，地下构造复杂，断裂非常发育，目的层埋藏深，资料信噪比较低的特点，以地震老资料和钻井资料为基础，建立地震地质模型，利用射线追踪技术选取合适的观测系统参数。充分利用卫星数字地图，没计了灵活多变的观测系统，采用可控震源与炸药震源配合使用方法，及时对城区内地下面元的覆盖次数、方位角和炮检距的分布进行质量监控，利用现场处理系统对资料进行及时分析，提高了地震资料品质。所获得的东营城区高精度三维地震采集资料显示，其浅中层分辨率和中深层信噪比都有了明显改善，取得了良好的地质效果。     

Strength Analysis of Turret Mooring Productive/Storage Tanker

The longitudinal strength of turret mooring productive/storage tanker is studied.A numeri-cal example has been implemented according to the method presented in this paper to give practical il-lustration.From the results of the numerical example,it is concluded that the turret hole located near theforward of the amidships has small effect on the longitudinal strength of the ship hull.As for design ex-treme value of wave bending moment of storage tanker,statistic method is a more reasonablemethodology,especially with the consideration of the servere environmental conditions.The primary esti-mation of design section modulus of turret storage tanker can be determined by this design bending mo-ment.     

渤海、黄海强温跃层数值预报模式

文中对前人关于水温垂直结构计算、模拟和预报研究成果进行了评价，并在此基础上建立了考虑海面吸收辐射和透射辐射、地形、风、海流、界面摩擦及其引起的混合作用的强温跃层三维数值预报模式。该模式运行的驱动量仅为风和气温场资料，因而具有较好的实用性；此外，从试报的结果看，效果是令人满意的。     

油页岩综合利用对周围环境的影响——以抚顺矿区为例

世界能源日益减少的局面为油页岩的开发应用带来广阔的前景，但油页岩工业所带来的环境影响亦不容忽视。以抚顺油页岩为例，从油页岩综合利用和油页岩工业对环境的影响等方面系统讨论了在我国发展油页岩工业时，如何本着节约能源、保护环境、实现可持续发展的观念，利用现有先进技术，科学发展油页岩工业，降低生产过程中的固、液、气污染物对环境的危害。     

激光剥蚀等离子体质谱分析中激光剥蚀参数对信号响应的影响

探讨了激光剥蚀等离子体质谱固体微区分析中激光剥蚀参数对元素分析信号灵敏度及稳定性的影响。这些参数包括激光功率、脉冲频率、剥蚀孔经、散焦距离、剥蚀方式等。讨论了优化的激光剥蚀等离子体质谱信号采集及数据处理方式。在全质量范围内选用具有代表性的元素作为研究对象,建立了激光剥蚀的一般性特征规律和266nm紫外激光系统的最佳操作条件。在选定的激光剥蚀参数下,大多数被测元素的检出限为22.8~457ng/g,能够满足固体微区分析的要求。     

Physical properties of ultrahigh-pressure metamorphic rocks from the Sulu terrain, eastern central China: implications for the seismic structure at the Donghai (CCSD) drilling site

About 30 samples representing major lithologies of Sulu ultrahigh-pressure (UHP) metamorphic rocks were collected from surface exposures and exploration wells, and compressional (Vp) and shear wave (Vs) velocities and their directional dependence (anisotropy) were determined over a range of constant confining pressures up to 600 MPa and temperatures ranging from 20 to 600 °C. Samples range in composition from acidic to ultramafic. P- and S-wave velocities measured at 600 MPa vary from 5.08 to 8.64 km/s and 2.34 to 4.93 km/s, respectively. Densities are in the range from 2.60 to 3.68 g/cm³. To make a direct tie between seismic measurements (refraction and reflection) and subsurface lithologies, the experimental velocity data (corresponding to shallow depths) were used to calculate velocity profiles for the different lithologies and profiles of reflection coefficients at possible lithologic interfaces across the projected 5000-m Chinese Continental Scientific Drilling Program (CCSD) crustal segment. Comparison of calculated in situ velocities with respective intrinsic velocities suggests that the in situ velocities at shallow depths are lowered by an increased abundance of open microcracks. The strongly reflective zone beneath the Donghai drill site can be explained by the impedance contrasts between the different lithologies. Contacts between eclogite/peridotite and felsic rocks (gt-gneiss, granitic gneiss), in particular, may give rise to strong seismic reflections. In addition, shear-induced (lattice preferred orientation (LPO)-related) seismic anisotropy can increase reflectivity. For the explanation of the high velocity bodies (>6.4 km/s) around 1000 m and below 3200-m depth, large proportions of eclogite/peridotite (about 40 and 30 vol.%, respectively) are needed.