SOLUTIONS OF THE GENERALn－TH ORDER VARIABLE COEFFICIENTS LINEAR DIFFERENCE EQUATION

ＳＯＬＵＴＩＯＮＳＯＦＴＨＥＧＥＮＥＲＡＬｎ－ＴＨＯＲＤＥＲＶＡＲＩＡＢＬＥＣＯＥＦＦＩＣＩＥＮＴＳＬＩＮＥＡＲＤＩＦＦＥＲＥＮＣＥＥＱＵＡＴＩＯＮＺｈｏｕＺｈｉ－ｈｕ（周之虎）（ＡｎｈｕｉＡｒｃｈｉｔｅｃｔｕｒｅＩｎｄｕｓｔｒｙＣｏｌｌｅｇｅ）．Ｈ...     

THE THEORETICAL COST OF SEQUENTIAL AND PARALLEL ALGORITHMS FOR SOLVING LINEAR SYSTEMS OF EQUATIONS

ＴＨＥ　ＴＨＥＯＲＥＴＩＣＡＬ　ＣＯＳＴ　ＯＦ　ＳＥＱＵＥＮＴＩＡＬ　ＡＮＤ　ＰＡＲＡＬＬＥＬ　ＡＬＧＯＲＩＴＨＭＳ　ＦＯＲ　ＳＯＬＶＩＮＧ　ＬＩＮＥＡＲ　ＳＹＳＴＥＭＳ　ＯＦ　ＥＱＵＡＴＩＯＮＳＳａｌｍａｎＨ．Ａｂｂａｓ（ＲｅｃｅｉｖｅｄＭａｙ２４...     

RESEARCH OF THE PERIODIC SOLUTION FOR A CLASS OF NONLINEAR DIFFERENTIAL EQUATIONS

ＲＥＳＥＡＲＣＨＯＦＴＨＥＰＥＲＩＯＤＩＣＳＯＬＵＴＩＯＮＦＯＲＡＣＬＡＳＳＯＦ　ＮＯＮＬＩＮＥＡＲＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＳＲＥＳＥＡＲＣＨＯＦＴＨＥＰＥＲＩＯＤＩＣＳＯＬＵＴＩＯＮＦＯＲＡＣＬＡＳＳＯＦＮＯＮＬＩＮＥＡＲＤＩＦＦＥ...     

THE APPLICATION OF MULTI－SCALE PERTURBATION METHOD TO THE STABILITY ANALYSIS OF PLANE COUETTE FLOW

ＴＨＥＡＰＰＬＩＣＡＴＩＯＮＯＦＭＵＬＴＩ－ＳＣＡＬＥＰＥＲＴＵＲＢＡＴＩＯＮＭＥＴＨＯＤＴＯＴＨＥＳＴＡＢＩＬＩＴＹＡＮＡＬＹＳＩＳＯＦＰＬＡＮＥＣＯＵＥＴＴＥＦＬＯＷＺｈｏｕＺｈｅ－ｗｅｉ（周哲玮）（ＳｈａｎｇｈａｉＵｎｉｖｅｒｓｉｌｙ;Ｓｈａｇ...     

THE EXISTENCE OF PERIODIC SOLUTIONS FOR A CLASS OF FUNCTIONAL DIFFERENTIAL EQUATIONS AND THEIR APPLICATION

ＴＨＥＥＸＩＳＴＥＮＣＥＯＦＰＥＲＩＯＤＩＣＳＯＬＵＴＩＯＮＳＦＯＲＡＣＬＡＳＳＯＦＦＵＮＣＴＩＯＮＡＬＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＳＡＮＤＴＨＥＩＲＡＰＰＬＩＣＡＴＩＯＮＺｈａｏＪｉｅ－ｍｉｎ（赵杰民）;ＨｕａｎｇＫｅ－ｌｅｉ（黄克累）...     

AN ITERATIVE METHOD FOR THE DISCRETE PROBLEMS OF A CLASS OF ELLIPTICAL VARIATIONAL INEQUALITIES

ＡＮＩＴＥＲＡＴＩＶＥＭＥＴＨＯＤＦＯＲＴＨＥＤＩＳＣＲＥＴＥＰＲＯＢＬＥＭＳＯＦＡＣＬＡＳＳＯＦＥＬＬＩＰＴＩＣＡＬＶＡＲＩＡＴＩＯＮＡＬＩＮＥＱＵＡＬＩＴＩＥＳＺｈｅｎｇＴｉｅ－ｓｈｅｎｓ（郑铁生）ＬｉＬｉ（李立）ＸｕＱｉｎｇ－ｙｕ（许庆余）（Ｄ...     

THE EXISTENCE OF PERIODIC SOLUTION OF THE FOURTH ORDINARY NONLINEAR DIFFERENTIAL EQUATION CAUSED BY FLOW－IN

ＴＨＥＥＸＩＳＴＥＮＣＥＯＦＰＥＲＩＯＤＩＣＳＯＬＵＴＩＯＮＯＦＴＨＥＦＯＵＲＴＨＯＲＤＩＮＡＲＹＮＯＮＬＩＮＥＡＲＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＣＡＵＳＥＤＢＹＦＬＯＷ－ＩＮＤＵＣＥＤＶＩＢＲＡＴＩＯＮＧｕＱｉｎｇ－ｆａｎｇ（顾清芳）Ｔａ...     

THE DIFFERENTIAL SOLUTION TO THE FLYING LOCUS EQUATION OF THE SHOT AND ITS APPLICATION

ＴＨＥＤＩＦＦＥＲＥＮＴＩＡＬＳＯＬＵＴＩＯＮＴＯＴＨＥＦＬＹＩＮＣＬＯＣＵＳＥＱＵＡＴＩＯＮＯＦＴＨＥＳＨＯＴＡＮＤＩＴＳＡＰＰＬＩＣＡＴＩＯＮＬｉｕＸｉａｏ－ｘｉａｎｇ（刘小湘）　　（ＸｉａｎｇｔａｎｉｎｓｔｉｔｕｉｅｏｆＭａｃｈｉｎｅｒｙａｎｄ...     

THE EXACT SOLUTIONS OF ELASTIC－PLASTIC CRACK LINE FIELD FOR MODE Ⅱ PLANE STRESS CRACK

ＴＨＥＥＸＡＣＴＳＯＬＵＴＩＯＮＳＯＦＥＬＡＳＴＩＣ－ＰＬＡＳＴＩＣＣＲＡＣＫＬＩＮＥＦＩＥＬＤＦＯＲＭＯＤＥⅡＰＬＡＮＥＳＴＲＥＳＳＣＲＡＣＫＹｉＺｈｉｊｉａｎ（易志坚）ＷａｎｇＳｈｉｊｉｅ（王士杰）ＷａｎｇＸｉａｎｇｊｉａｎ（王向坚）（Ｒｅｃｅｉ...     

ON THE BOUNDEDNESS AND THE STABILITY RESULTS FOR THE SOLUTION OF CERTAIN FOURTH ORDER DIFFERENTIAL EQUATIONS VIA THE INTRINSIC METHOD

ＯＮＴＨＥＢＯＵＮＤＥＤＮＥＳＳＡＮＤＴＨＥＳＴＡＢＩＬＩＴＹＲＥＳＵＬＴＳＦＯＲＴＨＥＳＯＬＵＴＩＯＮＯＦＣＥＲＴＡＩＮＦＯＵＲＴＨＯＲＤＥＲＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＳＶＩＡＴＨＥＩＮＴＲＩＮＳＩＣＭＥＴＨＯＤＣｅｍｉｌＴＵＮＣ;Ａ...     

王营子矿煤层中水—煤层气两相流体渗流规律的研究

本文通过在实验室中自行设计的装置,测定了阜新王营子矿煤层中水、煤层气共同流动时的两相流体的流量、渗透率及随水的饱合度变化关系,并根据这种数据模拟出了该煤层反映水、煤层气渗透基本规律的数学关系式,从而为它的煤层气开采提供了理论依据。     

煤层气在非饱和水流阶段的非定常渗流摄动解

煤层甲烷由煤层的割理裂隙系统流入生产井一般经历：单相水流、非饱和流和气、水两相饱和流三个阶段，在非饱和流阶段，储层压力降至临界解吸压力之后，储存在煤基质中的吸附气体少量被解吸出来形成互不连续的气泡并阻止水的流动，含气量尚未达到饱和程度。同时煤层甲烷运移包含渗流场、变形场和应力场的动态耦合过程。本文考虑渗流过程中水-气两相不溶混流体与固体耦合作用，建立了非饱和水流阶段非定常渗流问题的流固耦合数学模型，对该强非线性一维数学模型采用摄动法和积分变换法进行解析求解，并讨论了其压力动态特性，分析了压力随饱和度S及时间t变化的规律和气相及耦合作用的影响，这些研究对煤层气、石油和天然气的开采等地下工程领域具有一定的指导意义。     

Mathematical modeling of methane flow in a borehole coal mining system

Safety in coal mining is greatly increased by the drainage of the methane content of coal seams through boreholes, simultaneously producing significant energy. The design of suitable drainage technology is based on the mathematical modeling of methane flow in coal seams. In the calculation of the methane pressure, the new mathematical model presented in this paper considers both the sorption phenomenon of methane depending upon the methane pressure and the fact that the variation in methane pressure can create a change in the stress condition of the rock and, as a consequence of this, a change in the permeability of the coal. The new mathematical model can be used for the numerical simulation of the flow processes in coal seams and methane drainage technology can be designed more accurately.     

煤与瓦斯突出的一维流动模型和启动判据

本文将煤与瓦斯突出这一现象和因素模化,建立了研究机理的一维流动模型,给出了基本方程和突出基本准则——破碎起动准则。在这理想模型中,开挖前的围压作为煤体受载因素影响破碎起动从而影响流场,流场与应力场则解耦,可独立地研究流场,研究瓦斯渗流,煤的破碎起动及随后的两相流与纯气相流。 掘进是外加扰动,使渗流相对加剧,是启动突出的基本因素。讨论恒速掘进下的渗流过程,从渐近解——恒稳渗出解给出启动判据,分别表示成:可能条件——地应力条件;孕育条件——掘进条件或瓦斯条件;触发条件——渗出速度条件。     

Mathematical Model of Coalbed Gas Flow with Klinkenberg Effects in Multi-Physical Fields and its Analytic Solution

The deep-mining coal seam impacted by high in situ stress, where Klinkenberg effects for gas flow were very obvious due to low gas permeability, could be regarded as a porous and tight gas-bearing media. Moreover, the Klinkenberg effects had a significant effect on gas flow behavior of deep-mining coal seam. Based on the gas flow properties of deep-mining coal seams affected by in situ stress field, geothermal temperature field and geo-electric field, a new mathematical model of coalbed gas flow, which reflected the impact of Klinkenberg effects on coalbed gas flow properties in multi-physical fields, was developed by establishing the flow equation, state equation, and continuity equation and content equation of coalbed gas. The analytic solution was derived for the model of one-dimensional steady coalbed gas flow with Klinkenberg effects affected by in situ stress field and geothermal temperature field, and a sensitivity analysis of its physical parameters was carried out by comparing available analytic solutions and the measured values. The results show that the analytic solutions of this model of coalbed gas flow with Klinkenberg effects are closer to the measured values compared to those without Klinkenberg effects, and this model can reflect more accurately gas flow of deep-mining coal seams. Moreover, the analytic solution of this model is more sensitive to the change of Klinkenberg factor b and temperature grad G than depth h.     

Finite Element Analysis of Two- and Three-dimensional Flows Around Box-type Bridge Sections

Multilayer seepage model is proposed instead of three dimensional model. Optimum theory based on multilayer finite element formulation is applied to planning the efficient flow rate and pumping well layout. The Sakawa-Shindo method is used for the optimum control calculation. As a numerical example, calculations are carried out to determine an optimum pumping flow for use where a cut-off wall and pumping wells are combined.     

Transient gas flow around boreholes

We present numerical solutions and analytical approximate solutions to problems of gas flow in porous media arising in the modelling of outbursts in coal mines and the efficient recovery of methane from coal seams.     

One-dimensional flow model for coal-gas outbursts and initiation criterion

This paper discribes a one-dimensional flow model to explain the basic mechanism of coal-gas outbursts. A break-start criterion of coal, as the elementary outburst criterion, is given approximately. In this ideal model, the tectonic pressure before excavation, as a load on coal body, affects the break-start and then the flow field. The flow field is decoupled with the stress field, so that the gas seepage through unbroken coal body, break-start and consequent two-phase flow, and pure gas flow can be analysed independently of the stress field. The tunnelling, an external disturbance that makes the seepage intensify relatively, is an essential factor for initiating outburst. Under steady tunnelling, seepage ought to tend to be steadily progressive. From its asymptotic solution initiation criterion is obtained. This is described by three conditions, possibility condition —tectonic pressure condition, incubation condition—tunnelling or gas condition and triggering condition —seepage velocity condition. The project supported by the National Natural Science Foundation of China     

作用在裂隙中的渗透力分析

裂隙岩体中流体对岩体的作用力, 是研究岩体稳定性的重要问题。本文认为流体作用于裂隙壁面上的力包括两部分, 即垂直于裂隙壁面的流体静水压力 (导致裂隙垂向变形)和平行于裂隙壁面的拖曳力 (导致裂隙切向变形), 此拖曳力为面力。文中以单裂隙水流的立方定律为基础, 运用流体力学的动量方程, 推导出了单一平直光滑无充填裂隙、有充填的裂隙及水流和充填物一起运动情况下, 裂隙壁面承受的切向拖曳力公式。该公式对于分析流体对裂隙岩体变形性能及强度的影响具有重要价值。     

Flow characteristics of mixed particles with a simulated cold state in moving bed reactor

The funnel flow of high-temperature circulating ash and coal in moving bed with height restrictions directly influences the efficiency of coal pyrolysis and scale-up design of reactor. It is one of the technical bottlenecks in the use of moving bed. In order to provide data support for the particle flow and pyrolysis model close to the actual working conditions in the future, this study describes the flow characteristics of solid–solid mixed particles in a cold two-dimensional moving bed. The results indicate that flow characteristics of mixed particles in the quartz sand–coal system are better than those in the cold circulating ash–coal system. The optimized conditions were obtained, the insert half angle is 20° and a heat carrier to coal ratio of 6:1. As the mixture progressed downstream, secondary separation of the heat carrier and coal become apparent. Furthermore, mixture residence time has been investigated to explore the relationship between regional residence time and to predict accurately the actual pyrolysis progress in pyrolyzer.