瓦斯含量计量单位的基准调整初探

根据山西省左权县高家庄勘探报告与山西省平定县孟家村勘探报告中的CH4实际测试资料,分别用ml/gdaf和ml/g(ad)不同基准计量单位计算了CH4含量,进而阐述了不同瓦斯含量基准计量单位对勘探成果的影响,并认为用ml/gdaf基准计量单位,不能真正反应正常煤层的储气特征,因而建议将基准作相应调整。

煤体含水量对瓦斯解吸特性影响规律实验研究

为了验证含水量对煤体中瓦斯解吸特性的影响,以新景矿3号煤层为实验对象对煤体的饱和吸附量、解吸量和解吸速度进行了测试。结果表明:随着煤体含水量的增加,煤体的瓦斯吸附量逐渐减少,且减少幅度越来越小;随着煤体含水量的增加,煤体的瓦斯解析量减少且解吸速度越慢;含水量达到11.5%后,含水量对煤体的瓦斯解吸特性影响非常小。研究结果对确定瓦斯压力和突出风险具有重要的作用。

煤层瓦斯实验影响因素分析与研究

煤层瓦斯是煤炭开采中的主要安全隐患之一,煤层瓦斯事故频发,严重影响了矿工的安全生产和生活。本研究通过对煤层瓦斯实验数据进行收集和分析,探讨现场解析量、损失量、实验室脱气量、瓦斯含量(气体组分摩尔分率)等不同因素对煤层瓦斯涌出量的影响。结果表明,现场解吸量和损失量中的瓦斯含量的成分分析有显著影响,以Gbt23249-2009《地勘时期煤层瓦斯含量测定方法》和Gbt23250-2007《煤层瓦斯含量直接测定方法》为例存在很大的不同,根据Clapeyron方程,现场解析量和损失量、实验室脱气量随着温度压力的变化存在着很大不同;实验室瓦斯解残余气体含量对瓦斯涌出量的变化也有着很大的影响;煤工业分析中的灰分、水分以及煤的可燃质对相对瓦斯涌出量有着显著的影响。通过对这些数据的深入分析,可以为煤矿安全生产提供科学依据和技术支持,从而减少煤层瓦斯事故的发生,保障矿工的安全和健康。

有机无机肥配合对土壤磷素吸附、解吸和迁移特性的影响

通过32P示踪、薄层层析和土柱淋洗研究了经过四季不施磷肥、施用纯无机磷肥以及有机无机磷肥3种处理对土壤磷素迁移的影响。结果表明:有机无机肥配合处理的土壤磷吸附亲和力常数和最大吸附量显著低于化肥处理,磷累积解析量高于化肥处理,而32P在薄层板的迁移距离显著高于化肥及对照处理;淋洗试验中有机无机肥配合处理土壤中的32P最先在淋洗液达到13.1mL时出现,而化肥及对照的32P则分别在淋洗液达19.0和19.8mL时出现;在淋洗液体积达到50mL时,对照、化肥及有机无机肥配合处理淋出的32P总量分别为总加入量的1.6%、8.4%和9.8%。有机无机肥配合可以减少土壤磷素的固定,增强磷在土壤中的移动,提高磷的有效性。

Singularity-free expression of magnetic field of cuboid under undulating terrain

Most of the current computing methods used to determine the magnetic field of a uniformly magnetized cuboid assume that the observation point is located in the upper half space without a source. However, such methods may generate analytical singularities for conditions of undulating terrain. Based on basic geomagnetic field theories, in this study an improved magnetic field expression is derived using an integration method of variable substitution, and all singularity problems for the entire space without a source are discussed and solved. This integration process is simpler than that of previous methods, and final integral results with a more uniform form. AT at all points in the source-flee space can be calculated without requiring coordinate transformation; thus forward modeling is also simplified. Corresponding model tests indicate that the new magnetic field expression is more correct because there is no analytical singularity and can be used with undulating terrain.

Analytical Modeling of Threshold Voltage for Double-Gate MOSFET Fully Comprising Quantum Mechanical Effects

The analytical solutions to 1D Schrdinger equation (in depth direction) in double gate (DG) MOSFETs are derived to calculate electron density and threshold voltage.The non uniform potential in the channel is concerned with an arbitrary depth so that the analytical solutions agree well with numerical ones.Then,an implicit expression for electron density and a closed form of threshold voltage are presented fully comprising quantum mechanical (QM) effects.This model predicts an increased electron density with an increasing channel depth in subthreshold region or mild inversion region.However,it becomes independent on channel depth in strong inversion region,which is in accordance with numerical analysis.It is also concluded that the QM model,which barely considers a box like potential in the channel,slightly over predicts threshold voltage and underestimates electron density,and the error increases with an increasing channel depth or a decreasing gate oxide thickness.

基于非结构化单元的磁场及梯度模拟计算

在地球物理磁法勘探中,磁场及其梯度张量数据是磁法正反演及解释的重要基础。本文结合磁梯度张量解析解表达式,实现了一种基于非结构化四面体单元的磁场及梯度模拟计算方法,该方法弥补了传统方法难以处理任意复杂模型的缺陷,同时大幅提高了模拟计算精度。首先,采用非结构化单元剖分异常体可以显著地减小几何误差,更好地模拟带地形复杂模型。其次,采用新的磁梯度张量解析解表达式,其精度比传统的有限元、有限差分方法更高。本文设计了单个球体模型和组合体模型,模拟计算结果体现了该方法的适用性和准确性。

Three direction analytical signal analysis method of magnetic gradient tensor and application in the interpretation

Compared to conventional magnetic data,magnetic gradient tensor data contain more high-frequency signal components,which can better describe the features of geological bodies.The directional analytic signal of the magnetic gradient tensor is not easily interfered from the tilting magnetization,but it can infer the range of the fi eld source more accurately.However,the analytic signal strength decays faster with depth,making it diffi cult to identify deep fi eld sources.Balanced-boundary recognition can eff ectively overcome this disadvantage.We present here a balanced-boundary identifi cation technique based on the normalization of three-directional analytic signals from aeromagnetic gradient tensor data.This method can eff ectively prevent the fast attenuation of analytic signals.We also derive an Euler inversion algorithm of three-directional analytic signal derivative.By combining magnetic-anomaly model testing with the traditional magnetic anomaly interpretation method,we show that the boundary-recognition technology based on a magnetic gradient tensor analytic signal has a greater advantage in identifying the boundaries of the geological body and can better refl ect shallow anomalies.The characteristics of the Euler equation based on the magnetic anomaly direction to resolve the signal derivative have better convergence,and the obtained solution is more concentrated,which can obtain the depth and horizontal range information of the geological body more accurately.Applying the above method to the measured magneticanomaly gradient data from Baoding area,more accurate fi eld source information is obtained,which shows the feasibility of applying this method to geological interpretations.

Solutions of Dirac Equation for Makarov Potential with Pseudospin Symmetry

The pseudospin symmetry in the Makarov potential is investigated systematically by solving the Diracequation.The analytical solution for the Makarov potential with pseudospin symmetry is obtained by Nikiforov-Uvarov(N-U)method.The eigenfunctions and eigenenergies are presented with equal mixture of vector and scalar potentials inopposite signs,for which is exact.

Thermogravimetric Study and Modeling of Direct Sulfation of Limestone by Sulfur Dioxide

The direct sulfation of limestone from different sources in Iran was studiedin a thermogravimetric analyzer under atmospheric pressure. All limestone samples tested have higherthan 97% CaCO_3. Experimental conditions were as follows: particle size levels ranging from 1.6 μmto 7.8 μm, four level reaction temperatures (700℃, 750℃, 800℃ and 850℃), and two SO_2concentrations (2.4 x 10^(-3) and 3.2 x 10^(-3) mol · mol^(-1)). The particle size and temperatureshowed dominant influences on the rate and level of conversion while the effect of SO_2concentration was weak. The shrinking core model can be used to describe the behavior of thesulfation process. The reaction kinetics and diffusion mechanism are both important in controllingthe rate of the process. The two key parameters of the model, chemical rate constant K_s andeffective diffusion coefficient D_(eff) were obtained. Model predictions are in good agreement withthe experimental data.

Oblique Wave Motion over Multiple Submerged Porous Bars near a Vertical Wall

This study examines oblique wave motion over multiple submerged porous bars in front of a vertical wall. Based on linear potential theory, an analytical solution for the present problem is developed using matched eigenfunction expansions. A complex dispersion relation is adopted to describe the wave elevation and energy dissipation over submerged porous bars. In the analytical solution, no limitations on the bar number, bar size, and spacing between adjacent bars are set. The convergence of the analytical solution is satisfactory, and the correctness of the analytical solution is confirmed by an independently developed multi-domain BEM （boundary element method） solution. Numerical examples are presented to examine the reflection and transmission coefficients of porous bars, CR and Cv, respectively, for engineering applications. The calculation results show that when the sum of widths for all the porous bars is fixed, increasing the bar number can significantly improve the sheltering function of the bars. Increasing the bar height can cause more wave energy dissipation and lower CR and Cr. The spacing between adjacent bars and the spacing between the last bar and the vertical wall are the key parameters affecting CR and Ct. The proposed analytical method may be used to analyze the hydrodynamic performance of submerged porous bars in preliminary engineering designs.

Key Exchange Protocol Based on Tensor Decomposition Problem

The hardness of tensor decomposition problem has many achievements, but limited applications in cryptography, and the tensor decomposition problem has been considered to have the potential to resist quantum computing. In this paper, we firstly proposed a new variant of tensor decomposition problem, then two one-way functions are proposed based on the hard problem. Secondly we propose a key exchange protocol based on the one-way functions, then the security analysis, efficiency, recommended parameters and etc. are also given. The analyses show that our scheme has the following characteristics: easy to implement in software and hardware, security can be reduced to hard problems, and it has the potential to resist quantum computing.Besides the new key exchange can be as an alternative comparing with other classical key protocols.

体细胞重编程的转化医学研究

脑血管疾病、痴呆、糖尿病、恶性肿瘤、骨退行性病等重大临床疾患的发病率、患病率、病死率和致残率居高不下,细胞保护与细胞损伤修复药物、策略和方法的转化研发、应用与推广一直停滞不前或进展过缓应是其重要原因之一。本研究通过医学、生物学、数据库构建、程序编写、软件研制、统计分析及管理工程等多个领域专业人员的通力合作,对2012年诺贝尔生理学或医学奖两位获奖者关于"成熟细胞可以被重编程而多能化"的原始研究及其被引用的大规模复杂信息数据做整体定量对比和局部关联解析,探讨体细胞重编程研究的临床应用前景和实现策略,发现两位获奖者原创性研究及其影响在时间、学科、科学和技术等多个层面与角度上差异具有统计学意义,揭示和证明了加强与加快转化医学和转化神经科学研究的时代意义、紧迫需求、重要方向、目标与路径及我国医学科研管理体系因此所面临的重要挑战。

An Analytical Solution to the Model for Single Three-Level Trapped Ion Driven by External Fields

The interaction of a single three-level trapped ion with two laser beams has been studied theoretically. With application of two successive unitary transformations, an analytical solution to this quantum system has been obtained.

Theoretical Study on Xe…N non-Covalent Interactions:Three Hybridization N with XeO_(3) and XeOF_(2)

The interactions of complexes of XeOF_(2) and XeO_(3) with a series of different hybridization N-containing donors are studied by means of DFT and MP_(2) calculations.The aerogen bonding interaction energies range from 6.5 kcal/mol to19.9 kcal/mol between XeO_(3) or XeOF_(2) and typical N-containing donors.The sequence of interaction for N-containing hy-bridization is sp^(3)>sp^(2)>sp,and XeO_(3)is higher than XeOF_(2).For some donors of sp^(2)and sp^(3) hybridization,the steric effect plays a minor role in the interaction with the evidence of reduced density gradient plots.The dominant stable part is the electrostatic interaction.In complex of XeO_(3),the weight of polarization is larger than dispersion,while the situation is opposite for XeOF_(2)complexes.Except for the sum of the maximum value of molecular electrostatic potential on Xe atom and minimum value of molecular electrostatic potential on N atom,the other five interaction parameters including the potential energy density at bond critical point,the equilibrium distances,interaction energies with the basis set superposition error correction,localized molecular orbital energy decomposition analysis interaction energies,and the electron charge density,show great linear correlation coefficients with each other.

The new surveying method of studying the internal layer's deformation law

This thesis illustrates the method and precision of employing analytical photogrammetry to carry out similar materials model experiment in surveying the displacement of surveying points and analyzing the deformation law of rock layersand earths surface according to the results in the studying the deformation law of the earths surface caused by extracting mine coal underground.

Exciting Forces for a Wave Energy Device Consisting of a Pair of Coaxial Cylinders in Water of Finite Depth

Two coaxial vertical cylinders-one is a riding hollow cylinder and the other a solid cylinder of greater radius at some distance above an impermeable horizontal bottom,were considered.This problem of diffraction by these two cylinders,which were considered as idealization of a buoy and a circular plate,can be considered as a wave energy device.The wave energy that is created and transferred by this device can be appropriately used in many applications in lieu of conventional energy.Method of separation of variables was used to obtain the analytical expressions for the diffracted potentials in four clearly identified regions.By applying the appropriate matching conditions along the three virtual boundaries between the regions,a system of linear equations was obtained,which was solved for the unknown coefficients.The potentials allowed us to obtain the exciting forces acting on both cylinders.Sets of exciting forces were obtained for different radii of the cylinders and for different gaps between the cylinders.It was observed that changes in radius and the gap had significant effect on the forces.It was found that mostly the exciting forces were significant only at lower frequencies.The exciting forces almost vanished at higher frequencies.The problem was also investigated for the base case of no plate arrangement,i.e.,the case having only the floating cylinder tethered to the sea-bed.Comparison of forces for both arrangements was carried out.In order to take care of the radiation of the cylinders due to surge motion,the corresponding added mass and the damping coefficients for both cylinders were also computed.All the results were depicted graphically and compared with available results.

Surface Fires： No Wind, No Slope, Marginal Burning

The first aim of this work is to provide an analytical expression to calculate the rate of spread of surface fires under no wind and no slope conditions. A previous simplified model was improved for this particular case of fire propagation. The test of this proposed model was performed by using two complete sets of experimental results with several fuel beds and variable parameters such as moisture content or bulk density. The second aim of this article is to highlight two conditions that allow stopping a fire： the low leaf area and the high value of the moisture content.

Approximate Solution of D-Dimensional Klein-Gordon Equation with Hulthn-Type Potential via SUSYQM

Approximate analytical solutions of the D-dimensional Klein-Gordon equation are obtained for the scalarand vector general Hulthen-type potential and position-dependent mass with any l by using the concept of supersymmetricquantum mechanics (SUSYQM).The problem is numerically discussed for some cases of parameters.

Competition between(18,18)and(18,16)Configurations in Ni2(CO)5:An Isomerization Energy Decomposition Analysis

The potential energy landscape of the neutral Ni_(2)(CO)_(5) complex was re-examined.A new C_(2v) structure with double bridging carbonyls is found to compete with the previously proposed triply carbonyl-bridged D_(3h) isomer for the global minimum of Ni_(2)(CO)_(5).Despite that the tri-bridged isomer possesses the more favored(18,18)configuration,where both metal centers satisfy the 18-electron rule,the neutral Ni_(2)(CO)_(5) complex prefers the di-bridged geometry with(18,16)configuration.The isomerization energy decomposition analysis reveals that the structural preference is a consequence of the maximization of electrostatic and orbital interactions.