煤变质程度的新指标——变质系数

通过对不同变质程度煤的Ｘ射线衍射分析，探讨了各种煤的结构特点，提出了考察煤变质程度的新指标——变质系数，不仅合理，而且能较精确地反映出煤的变质程度。

用XRD表征煤变质程度的改进方法

目前煤变质程度的X射线衡量方法存在γ带不好分峰、δ峰信息没有被使用、扣除背底不合理等问题,通过对比分析不同变质程度煤的X射线衍射图谱,提出在不扣除背底信息前提下,使用002峰斜率、延展半高宽和δ峰信息来修正变质系数公式。经过多组不同变质程度煤样X射线衍射(XRD)图谱的计算验证,表明该方法能够较好地表征煤的变质程度,避免了γ带不好分峰、δ峰有效信息没有使用和扣除背底不合理等问题,是一种简单可行而又较为准确的衡量煤变质程度的方法,建议在行业内推广使用。

四川盆地新场构造带上三叠统须家河组二段地层水化学动态特征及其成因

四川盆地新场构造带须家河组二段(须二段)地层水化学特征复杂,矿化度分布范围广,部分井在生产过程中地层水化学特征发生动态变化。因此,利用矿化度、氯镁系数、变质系数和诺瓦克相图等分析了须家河组各层段地层水化学特征,探讨了地层水的动态运移。结果显示:须二段地层水矿化度主要集中在70~110 g/L,氯镁系数大于50,变质系数大于10;须四段地层水矿化度主要集中在50~90 g/L,氯镁系数小于50,变质系数小于10;两者诺瓦克相图也具有明显差异。上述特征可作为地层水分布层系判别指标。须二段大部分井在生产过程中水化学特征较为稳定,表明地层水来源较为一致,以同层水为主;部分井如新856井、新2井、新10-1H井和新5井在生产过程中地层水化学特征发生了显著变化,根据判别指标,其地层水来源发生了变化。新2井和新856井在汶川地震后均有高矿化度、高溴离子浓度雷口坡组海相地层水混入;新10-1H井和新5井在生产过程中有须四段地层水进入,断层可能为地层水的跨层运移提供了通道。

柴达木盆地一里坪盐湖卤水水化学及夏季蒸发中钾、锂、硼行为

本文综合利用Na^+,K^+,Mg^(2+)//Cl^-,SO_4^(2-)-H_2O五元体系干基图、水图、钠图,研究柴达木盆地一里坪盐湖硫酸盐型卤水水化学特征受外来淡水补给掺杂、选择性溶解、年温差等多因素影响产生的季节性变化,其中温度为主要因素.当卤水温度降低至0℃,开始析出芒硝,水化学变质系数MgSO_4/MgCl_2比值急剧下降,水化学特征由硫酸镁亚型向氯化物型转化过渡.通过20～25℃晶间卤水L10和L20蒸发实验研究,确定了一里坪卤水蒸发路线、液固相组成、物相鉴定、水化学特征系数、离子行为等变化及成盐特征,并与25℃Na^+,K^+,Mg^(2+)//Cl^-,SO_4^(2-)-H_2O五元体系介稳相图理论预测计算综合对比,二者吻合性比较好,整体相对误差能控制在5%范围内,利用相图理论计算能够很好地指导实际硫酸盐型卤水蒸发析盐.利用水化学特征系数KCl/MgCl_2、MgSO_4/MgCl_2,研究了25℃硫酸盐型盐湖卤水钾盐成盐特征,当变质系数MgSO_4/MgCl_2高于0.13时,卤水钾盐矿物析出的同时,伴随有泻利盐共同析出.利用含Li^+、borate、Mg^(2+)水盐体系相图,研究一里坪老卤水深度蒸发中Li、B的行为,理论预测计算结果,剩余老卤水Mg^(2+)/Li^+比值降至27时,卤水中的Li、B始终以离子形式赋存于卤水中继续富集,此时卤水的累积成卤率仅为2.50%～3.20%,须引入新的工艺技术进行Li、B提取.研究结果为极高镁锂比、高镁硼比的硫酸盐型卤水的综合开发利用提供了理论支持.

松辽盆地敖古拉断裂的封烃泄水作用

敖古拉断裂位于齐家一古龙坳陷生油气区向西运移的指向上。且其走向与油气运移方向垂直。该断裂自基底一直断到第四系。具同生正断特征。通过封堵率计算研究表明,该断裂的侧向封烃能力在姚家组和泉头组地层中为中等,在嫩江组和青山口组地层中较好。通过断面压力计算发现,该断裂垂向封闭性在浅部差,深部好;在断裂走向上断裂中部差。向两端逐渐变好。通过地层水矿化度和变质系数等参数的分布规律及一系列折算水位剖面图的分析发现。该断裂对水是不封闭的,并且是盆地西缘大气渗入水向东流动(向心流)及齐家—古龙坳陷沉积压实水向西流动(离心流)的共同泄水带。所以,该断裂是一条封烃泄水断裂。敖古拉断裂封烃泄水的主要机理是毛细管压力作用。由于敖古拉断裂的封烃泄水作用,使其对齐家—古龙坳陷向西运移的油气起到了一定的屏障作用。

耐火材料隧道窑火用分析

通过对某耐火材料隧道窑系统能量分析,求得其火用效率及火用变质系数,找出了隧道窑系统能量利用的薄弱环节,提出了节能挖潜措施,以利于尽可能利用资源,降低成本。

苏里格气田苏20区块气水关系研究

苏20区块是苏里格气田近几年投入开发的重要区块,伴随开发的不断深入,局部生产井出现了不同程度的产水现象。为进一步提高油气开发效率,通过引入水文地质学理论和方法,对地层水的化学性质进行了分析,利用矿化度和水化学特征系数(变质系数、脱硫系数、成因系数)等判别标志参数对产出水的类型进行了划分,系统研究了苏20区块岩性气藏的气水分布规律。认为产出水是天然气运聚成藏的产物,其分布受生气强度、砂顶微幅度构造、藏内温度、压力条件、天然气充注程度和储集层质量控制。

基于Weibull分布的易腐品补货策略研究

易腐品在生产与生活中比较常见,随着时间的变化会具有损耗、过期、贬值的特性,人们对易腐品的需求量逐年增加,易腐品的生产加工企业、零售企业等会常常面临易腐品的订购补充问题,研究易腐品库存的相关理论与方法对企业的生产与经营具有重要意义。文章以一家大型消费品仓储配送中心易腐品的补货为研究对象,引入具有很强适用性的三参数Weibull分布来研究易腐品的非线性变质率问题,用函数参数来模拟相关性的变质率系数,考虑市场需求率随着价格的变化波动,建立了具有周期性的易腐品补货策略模型。通过引入仓储配送中心的算例分析,应用Matlab得出补货策略最优解。最后给出了模型参数的灵敏度分析,研究参数的变化对企业易腐品补货水平的影响,为仓储配送中心易腐品补货提供一种决策方法。

Novel Ka-band low-noise down-converter assembly

An efficient way to design a down-converter assembly for the Ka-band millimeter system is presented, in which dielectric resonators （DR＇s） are adopted in the Schottky barrier diode image recovery mixer and the local oscillator （LO）. DR structures guarantee high frequency stability with an acceptable volume. The configurations of low noise amplifier, mixer and oscillator in the assembly are described and fabricated to estimate the chain performance. According to the verification results, the assembly exhibits the noise figure of less than 5 dB over 1 GHz frequency range, and the single-sideband phase noise （200 kHz offset from carrier frequency） of - 70 dBc/Hz. Utilizing the DR structure, the frequency stability of the local oscillator is less than 60 × 10^-6/℃.

Comparative analysis of coal and coal-shale intrinsic factors affecting spontaneous combustion

Coal and coal-shales tend to undergo spontaneous combustion under favourable atmospheric conditions. Spontaneous combustion liability index and intrinsic properties of coals and coal-shales varies between （above and below） coal seams. The spontaneous combustion liability index （obtained from the Wits-Ehac Index） and intrinsic properties （obtained from proximate, ultimate, and petrographic analysis） of fourteen samples representative of in situ coal （bituminous） and fourteen coal-shales obtained in Witbank coalfield, South Africa were experimentally studied. Comparative analysis of the relationships between the spontaneous combustion liability index and intrinsic properties of coals and coalshales were established to evaluate their effects on self-heating potential. The intrinsic properties show linear relationship with spontaneous combustion liability and therefore, identifies the factors affecting spontaneous combustion of these materials. The influence of coal-shales intrinsic properties towards spontaneous combustion liability shows higher correlation coefficients than the coals. Both coals and coal-shales show inertinite maceral as major constituents than the vitrinite and liptinite macerals, hence the reactivity of inertinite macerals may show greater influence on spontaneous combustion liability. A definite positive or negative trends exists between the intrinsic properties and spontaneous combustion liability index. This research is part of a larger project which is considering the influence of intrinsic properties of coals and coal-shales on spontaneous combustion liability.

Effect of Sr modification on microstructure and thermal conductivity of hypoeutectic Al−Si alloys

Trace amount of Sr(0.05 wt.%)was added into the hypoeutectic Al−Si(3−12 wt.%Si)alloys to modify their microstructure and improve thermal conductivity.The results showed that the thermal conductivity of hypoeutectic Al−Si alloys was improved by Sr modification,and the increment and increasing rate of the thermal conductivity gradually increased with Si content increasing.The improvement of thermal conductivity was primarily related to the morphology variation of eutectic Si phases.In Sr-modified Al−Si alloys,the morphology of eutectic Si phases was a mixed morphology of fiber structure and fine flaky structure,and the proportion of the fine flaky eutectic Si phases gradually decreased with Si content increasing.Under the Si content reaching 9 wt.%,the proportion of fine flaky eutectic Si phases was nearly negligible in Sr-modified alloys.Correspondingly,the increment and increasing rate of thermal conductivity of Sr-modified alloys reached the maximum and tended to be stable.

Fluid-solid coupling numerical simulation of charge process in variable-mass thermodynamic system

Abstract： A joint solution model of variabk：-mass flow in two-phase region and fluid-solid coupling heat transfer, concerned about the charge process of variable-mass thermodynamic system, is built up and calculated by the finite element method （FEM）. The results are basically consistent with relative experimental data. The calculated average heat transfer coefficient reaches 1.7~105 W/（m2. K）. When the equal percentage valve is used, the system needs the minimum requirements of valve control, but brings the highest construction cost. With the： decrease of initial steam pressure, the heat transfer intensity also weakens but the steam flow increases. With the initial water filling coefficient increasing or the temperature of steam supply decreasing, the amount of accumulative steam flow increases with the growth of steam pressure. When the pressure of steam supply drops, the steam flow gradient increases during the maximum opening period of control valve, and causes the maximum steam flow to increase.

EFFECTS OF ROCK BEHAVIOR AND STRESS CONDITION ON FIELD STRESS DETERMINATION

Non-consistency of stress results is of ten observed during field measurements. In some cases, even the rneasurernents are made at the same location in a massive rockrnass, the results can vary widely. In order to solve the problem, extensive research has been carried out to study the major factors wh1ch rnay affect stress deterrnlnation. They include the rock behaviour and the stress state. For rocks showing non-isotropic behaviour, the values of Young’s modulus and Poisson ratio vary with the orientation of loading and measurement. Stress condition in the rock affects the rock behaviour. Furtherrnore, the loading condition on rock samples durlng laboratory tests is different from in the field and therefore the determined e1astic constants may not represent the field condi tion. In general , the Young’s modulus may depend on the orientation, the loading path, the stress magnitude and the stress ratio. This paper examines in detail the effects of those factors, especially for rocks showing transversely isotropic behaviour. It is found that the discrepancy of stress results from field measurernents in this type of rock is mainly due to over simplification of the rock behavior and inadequate use of elastic constants of the rock during stress calculation. A case study is given,which indicates the significance of these factors and demonstrates the proper procedure for stress calculation from measurements.

Precise Measurement of Subsurface Seismic Velocity Variation by Coda Wave Interferometry

A filed experiment was conducted continuously for three days,and the velocity variation was measured using coda wave interferometry.The measurement error is estimated to be around 10-4,which coincides well with the theoretical error.The velocity variation during this period is up to 10-3.The relationship between velocity variation and changes in air temperature,barometric pressure and solid earth tide was analyzed with linear least square fitting.The velocity has no dependence on air temperature,but displayed change of the order of 10-6～10-7 when the barometer or earth tide changed one Pa.

On Integrable Properties for Two Variable-Coefficient Evolution Equations

With the help of the extended binary Bell polynomials, the new bilinear representations, Backlund trans- formations, Lax pair and infinite conservation laws for two types of variable-coefficient nonlinear integrable equations are obtained, respectively, which are more straightforward than previous corresponding results obtained. Finally, we obtain new multi-soliton wave solutions of a reduced soliton equations with variable coefficients.

Geometrical characterization of reduced density matrices reveals quantum phase transitions in many-body systems

Quantum phase transitions (QPTs) play a central role for understanding many-body physics [1]. Different from classical phase transitions which are driven by thermal fluctuations, QPTs are driven by quantum fluctuations at zero temperature and can be accessed by varying some physical parameters of the many-body system. Characterizing QPTs, which normally needs complicated theoretical calculations, becomes a fundamental problem to further study quantum matters. Here a group of physicists proposed to connect the geometrical properties of reduced density matrices (RDMs) of the physical system with its quantum phase transitions [2,3]