Relation between relative permeability and hydrate saturation in Shenhu area, South China Sea

Nuclear magnetic resonance measurements in hydrate-bearing sandstone samples from the Shenhu area, South China Sea were used to study the effect of gas hydrates on the sandstone permeability. The hydrate-bearing samples contain pore-filling hydrates. The data show that the pore-filling hydrates greatly affect the formation permeability while depending on many factors that also bear on permeability; furthermore, with increasing hydrate saturation, the formation permeability decreases. We used the Masuda model and an exponent N = 7.9718 to formulate the empirical equation that describes the relation between relative permeability and hydrate saturation for the Shenhu area samples.

Borehole deviation limits and injection permeability

Monitoring drilling deviation is important for drilling of boreholes and measuring injection rock permeability by Lugeon value for safe and efficient drilling and grouting. This paper is aiming at the study drilling deviation and relationship between drilling and injection permeability at the depth of 100 m in dam of Pushi River. The results show that at different depths the deviation of grouting borehole is within the allowable range according to specifications. LU value decreases with the depth increased in general, but at the depths between 40-41 m the permeability is 1.5 LU, and at 24 m the LU value is the largest (2 LU) in this site by this study. The study thus concludes that even though the rocks are hard and their injection permeability decreases with depth increased, good drilling practices including carefully considering technical and geological specifications can get good drilling boreholes.

Co_(90)Zr_(7)Ta_(3)三元合金微观组织及磁性能的研究

通过金相组织观察、XRD分析和透磁率检测,研究了Co_(90)Zr_(7)Ta_(3)三元合金微观组织,并通过分析材料组织与透磁率(pass through flux,PTF)变化,得到热机械处理对透磁率的影响。结果表明:真空熔炼制备的Co_(90)Zr_(7)Ta_(3)三元合金有大量枝晶组织,主要包含Co基体和枝晶结构的(Co,Ta)_(11)Zr_(2)。采用轧制及热处理后,合金内部枝晶结构破碎,发生球化。合金中Co基体中的fcc相转变为hcp相,hcp相中(0001)含量的增加提高了靶材透磁率。

集成电路用高纯镍铂靶材的制备及发展趋势

本文围绕半导体集成电路产业的需求,综合说明了高纯镍铂靶材制备过程中纯度、组织及透磁率、表面质量的控制要求、技术难点及发展趋势。针对65 nm以下制程使用的高纯镍铂靶材,纯度方面由4N5(99.995%)逐步提升至5N(99.999%)及以上;组织及透磁率方面向精确调控晶粒取向追求高透磁同时保证组织均匀的方向不断优化;表面质量方面向低粗糙度方向不断发展。

Control of Wave Propagation and Effect of Kerr Nonlinearity on Group Index

We use four-level atomic system and control the wave propagation via forbidden decay rate. The Raman gain process becomes dominant on electromagnetically induced transparency (EIT) medium by increasing the forbidden decay rate via increasing the number of atoms [G.S. Agarwal and T.N. Dey, Phys. Rev. A 74 (2005) 043805 and K. Harada, T. Kanbashi, and M. Mitsunaga, Phys. Rev. A 73 (2006) 013803]. The behavior of wave propagation is dramatically changed from normal (subluminal) to anomalous (superluminal) dispersion by increasing the forbidden decay rate. The system can also give a control over the group velocity of the light propagating through the medium via Kerr field.

Negative refraction with absorption suppressed by electromagnetically induced transparency in a left-handed atomic system

This paper intends to realize negative refraction with absorption suppressed by the electromagnetically induced transparency (EIT) in a dense four-level atomic system.Without the two equal transition frequencies responding to the probe field,the atomic system displays a negative refraction with the simultaneously negative permittivity and negative permeability (left-handedness).The response of the probe field is amplified and propagates transparency in some frequency extents.Therefore,our aim for searching the low-loss negative refraction can be achieved in the scheme,given the main applied limitation of the negative refractive materials is the large amount of dissipation and absorption.However,an excessive signal field intensity would increase the absorption near the resonance in our scheme.

High Efficiency Four-Wave Mixing with Relaxation Coupling of Longitude-Optical Phonons in Semiconductor Quantum Wells

The time-dependent analysis of four-wave mixing(FWM) has been performed in four-level double semiconductor quantum wells(SQWs) considering the cross-coupling of the longitude-optical phonons(LOP) relaxation. It is shown that both the amplitude and the conversion efficiency of the FWM field enhance greatly with the increasing strength of cross-coupling of LOP relaxation. Interestingly, a double peak value of the conversion efficiency is obtained under a relatively weak single-photon detuning considering the LOP coupling. When the detuning becomes stronger,the double peaks turn into one peak appearing at the line respect to the about equality two control fields. The results can be interpreted by the effect of electromagnetically induced transparency and the indirect transition. Such controlled high efficiency FWM based on the cross-coupling LOP may have potential applications in quantum control and communications.

Modelling and mathematical results arising from ferromagnetic problems

Abstract In this article, we investigate the equations of magnetostaties for a configuration where a ferromagnetic material occupies a bounded domain and is surrounded by vacuum. Furthermore, the ferromagnetic law takes the form B=μ0μr（｜H｜）Hi i.e., the magnetizing field H and the magnetic induction B are collinear, but the relative permeability μr is allowed to depend on the modulus of H. We prove the well-posedness of the magnetostatic problem under suitable convexity assumptions, and the convergence of several iterative methods, both for the original problem set in the Beppo-Levi space W1（R3）, and for a finite-dimensional approximation. The theoretical results are illustrated by numerical examples, which capture the known physical phenomena.