基于AHP-熵-TOPSIS对极轨气象卫星应用系统健康程度评价指标体系

以实现对极轨气象卫星应用系统健康程度进行综合评价为目的,提出结合主观分析的层次分析法(Analytic Hierarchy Process,AHP)和客观分析的熵权法(Entropy Weight,EW)确定待评价系统指标值的综合权重,再采用逼近理想解排序法(Technique for Order Preference by Similarity to an Ideal Solution,TOPSIS)对系统的指标进行多角度评价排序来作为最终评价结果。本文根据连续5个月3颗极轨气象卫星在实际业务系统运行中异常指标样本进行实证分析。结果表明该方法较为全面考虑了影响应用系统的多种因素,避免了单一判据的局限性,并对各指标的重要性进行综合对比分析,使得评价结果更科学准确,可以作为构建极轨气象卫星应用系统健康程度评价指标体系的一种方法。     

Effects of boundary conditions and viscous energy dissipation on carbon burning in thermonuclear supernova models

Based on a one-dimensional hydrodynamic model, we investigate carbon burning in a thermonuclear type-Ia supernova in the approximation of unsteady convection. The relatively broad range of convective parameters, 1×10^?3≤α_c≤2×10^?3, in which delayed detonation from the edge takes place was found to be preserved only for cases with a low boundary temperature at the presupernova stage, T _b ^(PS) = 6.4 × 10⁶ K, and with a high envelope mass, m_ex ? 2 × 10^?3M_⊙. In cases with a more realistic temperature, T _b ^(PS) = 2 × 10⁸ K, which corresponds to helium burning in the shell source, and with a lower mass m_ex, delayed detonation from the edge takes place only at α_c = 2 × 10^?3, while at α_c = 1 × 10^?3, numerous model pulsations occur during t?500 s. Artificial viscosity is shown to give a determining contribution to the increase in entropy in outer model shells, which is caused by the generation of weak shock waves during pulsations. We also show that the entropies calculated by two independent methods are equal.     

The application of commutative algebra to geodesy: two examples

Algebra, in particular commutative algebra, is applied here to provide a general unified solution to nonlinear systems of equations encountered in geodesy. Starting with the “Abelian group”, the “polynomial ring” is defined and used to form generators of ideals. By applying Buchberger or polynomial resultant algorithms, these generators are reduced to simple structures often comprising a univariate polynomial in one of the unknowns. The advantage of the proposed unified approach is that it provides exact solutions to geodetic nonlinear systems of equations without the traditional requirements of linearization, iterations or approximate starting values. The commutative algebraic approach therefore alleviates the need for isolated exact solutions to various geodetic nonlinear systems of equations. The procedure is applied to GPS meteorology to compute refraction angles, and Helmert’s one-to-one mapping of topographical points onto the reference ellipsoid.     

西太平洋副热带高压中期变化的数值试验 Ⅱ.热带西太平洋热源的作用

用一个全球谱模式作数值试验,研究了１９７９年６月中蟾一次西太平洋副热带高压西伸北进的中期天气过程中热带西太平洋地区理想热源的作用。结果表明：理想热源的作用大约在４天以后可以影响我国东部的副热带高压和中高纬度的环流;理想热源在热带洋面上产生的扰动首先沿副高南边的东风气流向西北方向传播,到中纬西风带后分为两支,一支继续向西北方向传播,另一支转向东北偏东方向传播,两支扰动的共同作用导致副热带高压和西风带     

导爆管起爆系统的现状与展望

本文在实验研究和文献分析的基础上,论述了导爆管的结构、性质、爆轰机理以及使用技术。对起爆系统的进一步发展,笔者提出了包括系统元件系列化与配套生产、无雷管起爆系统的研究以及扩大应用领域等方面的建议。     

基于岩石爆破损伤理论的预裂爆破参数研究及应用

工程中预裂爆破参数确定方法通常为经验类比法。该方法以经验公式为基础,存在理论依据较为缺乏等缺点。为此,引入岩石爆破损伤、应力波和爆生气体共同作用等理论,在考虑岩石初始损伤等影响因素的基础上,提出预裂爆破参数计算式。基于提出的理论方法,在现场开展了预裂爆破试验。针对爆破试验,比较了采用经验类公式和提出的理论计算式得到的线装药密度,并对爆破效果进行了分析。试验结果表明,预裂爆破效果良好。考虑爆破损伤效应的爆破参数确定方法比经验类比法合理。最后,在提出的理论计算方法基础上,给出了实际工程中确定预裂爆破参数的建议。     

补偿向下延拓方法研究及应用

位场向下延拓是重、磁处理和解释的常用方法,但其不稳定性限制了其在资料处理及反演中的应用.本文基于补偿圆滑滤波思想以及空间域向下延拓迭代法,通过逐次补偿的办法实现位场的稳定向下延拓.同时,在频率域空间给出了该下延方法的频率域响应因子,并讨论了其低通滤波特性,理论模型和实际位场资料试验表明该方法向下延拓稳定性具有较高的延拓精度.将其应用于重力密度界面反演中,改进反演的稳定性,实际莫霍界面反演表明下延因子具备实用性.     

Granitic rocks of Yosemite Valley and an ideal granite model

Stochastic models of an ideal, a degenerate ideal granite, and two models for metasomatically transformed granites have been compared with sequences of grains observed in granitic rocks of Yosemite Valley, California. Properties of the granitic rocks appear to show a relationship to the topography and stream directions, and may reflect the behavior of the granitic rocks with respect to fracturing and weathering.     

山东大磨曲家金矿深部盲矿定位预测的构造叠加晕理想模型

研究了矿床的构造叠加晕特征,建立了金矿深部盲矿定位预测的构造叠加晕理想模型,并取得了很好的找矿效果.     

石笕岭隧道掘进爆破方案设计

分析了石笕岭隧道短台阶掘进爆破施工中存在的问题，在使用自制简易凿岩平台可实现全断面掘进钻眼条件下，提出了全断面掘进爆破方案。采用工程类比法设计，并通过场试验确定了合理适用的光面爆破参数。探讨了在隧道掘进中，利用非电毫秒差雷管孔外微差接力传爆，扩大起爆雷管使用段数的方法。