配比试验在灰铸铁铸渗硼中的应用

本文用配比试验法研究了灰铸铁在铸型中进行碳化硼涂料渗硼工艺，证明了渗硼层有高的耐锌液腐蚀性能，因此，带有渗硼层的灰铸铁锌锅使用寿命长，可取得显著的经济效益。     

变温度荷载作用下半无限成层饱和介质的热固结分析

对半无限成层饱和多孔介质作用随时间变化的温度荷载的热固结问题进行解析求解．其中,热-水-力耦合线性弹性控制方程考虑了热渗效应和等温热流效应的影响．先采用Laplace变换求其在变换域上的解,然后用数值方法求逆变换．对半无限体表面作用呈指数衰减热荷载的双层体系进行研究,分析了两层介质热固结系数、弹性模量等的差异性对热固结特征的影响．研究表明:位移场和应力场对温度场的耦合作用可以忽略,而热渗效应对温度和孔压有显著影响．     

剥层法测硼磷离子注硅剖面的计算机模拟

本文用计算机模拟10~(12)至10~(14)/cm~2剂量的磷离子和10~(12)至10~(13)/cm~2剂量的硼离子注入硅后,用氧化剥层技术测试杂质分布的情况,特别是表面态和衬底PN结对剥层测试的影响。分析表明磷剂量低于10~(13)/cm~2和硼剂量低于10~(12)/cm~2时,剥层法测出的分布会严重偏离实际注入分布。还分析了用表面态耗尽层宽度来估计这种偏差不可靠的原因。     

储层岩石周期性电渗流特性的微观机制

以双电层电位理论和电渗流动的动量方程为基础,结合储层岩石平行毛管束模型,推导出岩石孔隙内周期性电渗流的解析式,揭示了储层中电渗效应的微观机制,分析了非密闭储层岩石中宏观电渗Darcy速度及密闭储层中电渗压力系数频散特性的影响因素．数学模拟结果表明:储层岩石孔隙中,周期性电渗流速度剖面在频率较高时呈“波浪”状;孔隙度越大,电渗Darcy速度模值越大,其相位也越大,而电渗压力系数数值越小．储层岩石的溶液浓度越小或阳离子交换量越大,电渗Darcy速度模值和电渗压力系数数值越大,但对电渗Darcy速度的相位没有影响．     

一个新的有自由面渗流问题的变分不等式提法

建立了一个新的有自由面渗流问题的变分不等式提法,提法通过将潜在出渗面上的边界条件提为Signorini型条件,从而从理论上消除了出渗点的奇性并解决了出渗点的定位问题．与其它变分不等式提法相比,该提法有更好的数值稳定性．     

三维MANDELBROT渗流下临界形状

本文研究了三雏andelbrot渗流下临界形态，证明了渗流函数θ（p）在pc点是不连续的，同时得到当p＜pc时，三维Mandelbrot渗流A的最大连通分支是点，即A是“尘状”的．     

土壤非光滑表面电渗粘附的试验优化技术研究

阎备战等．土壤非光滑表面电渗粘附的试验优化技术研究．数理统计与管理，１９９８，１７（２），１７～２１．本文应用正交多项式试验优化技术，对非光滑表面电渗原理进行了试验设计，探讨了非光滑表面电渗技术的两个重要影响因素对土壤粘附产生的影响作用，揭示了一定条件下直流电渗电压与电渗时间对粘附力的影响规律。     

超声速气流中含灰气体点源流动特性

采用Lagrange方法，研究了超声速气流中含灰气体点源的流动特性，求得了对称轴附近激波层内的流动参数．计算数值模拟结果揭示了大惯性颗粒在激波层内沿着相互交叉的振荡轨迹运动，颗粒分布形成了高、低密度层交错出现的“多层结构”，而且粒子在轨迹包络线附近急剧聚集．     

求解二层规划问题的遗传算法

本文求解二层规划问题的遗传算法，给出了算法基本框架并对算法实现进行了研究．算法适用于各类线性和非线性二层规划问题．数值计算结果显示，该方法是可行和有效的．     

指数分布无失效数据的多层Bayes分析

韩明等．指数分布无失效数据的多层Ｂａｙｅｓ分析．数理统计与管理，１９９８，１７（４），２４～２７．本文对指数分布无失效数据的失效率，在先验分布为Ｇａｍｍａ分布时，给出了多层Ｂａｙｅｓ估计。最后，结合实际问题进行了计算     

Nonlinear dynamics in orthogonal turning process

In this paper, the nonlinear dynamics methods were applied to analyze the experimental data captured during the orthogonal turning process. The analyzed data were the acquired time series represented by the cutting and thrust forces acting on the cutting tool. Workpieces of aluminum alloy, ductile cast iron, and gray cast iron were machined. The false nearest neighbors and the largest Lyapunov methods were considered to study the nonlinear phenomena occurring in turning process. An index of stability was also defined and used to compare the turning processes of all tested workpieces.     

“RSA-ANP-SSD”组合赋权模式下的铅锌企业低碳发展水平二级模糊层综合评价模型

首先提出了一种新的既能兼顾决策者属性偏好,又能减小决策者主观随意性的"RSA-ANP-SSD"组合赋权模式,然后,建立了铅锌企业低碳发展水平评价指标体系,构建了我国铅锌企业低碳发展水平的二级模糊层综合评价模型,从而较好地解决了低碳经济背景下我国铅锌企业急需解决的低碳发展水平评价问题,为铅锌企业低碳战略的制定及实施提供了一种有用的数学分析工具和决策支持.     

An empirical re-examination of natural resource scarcity and economic growth

This paper is concerned with the effect of natural resource scarcity on economic growth in the United States. After defining the notion of scarcity and introducing two measures of scarcity—unit costs and relative resource price—changes in resource scarcity trends for lead, zinc, nickel, aluminium, silver, iron and copper over the most recent three decades are investigated. Only for silver and iron is there any indication that such a change has occurred. For silver, the change is transitory. To the extent that change takes place, it has implications for future economic growth, i.e. natural resource scarcity and economic growth are interrelated. To see whether this is a relevant concern, subsequent to the examination of changing resource scarcity trends an objective effort is made to identify a long-run equilibrium relationship between natural resource scarcity and economic growth. Relying on cointegration techniques, only for the unit cost measure for lead and copper for one of the measures of cointegration is there a suggestion that natural resource scarcity has affected economic growth in the United States over the period 1889–1992.     

Absorption of light and development of a laser crack

Conclusions 1. The effective threshold for the absorption of laser radiation by a crack on repeated irradiation is 15–30 J/cm².2. After reaching the threshold, the surface of the crack in the irradiation zone becomes clarified and passes light almost to the same extent as the undamaged material.3. The absorption observed in the present experiments is due to the opaque products of polymer decomposition. The gray absorbing deposit is probably soot, very finely dispersed. Adhesion takes place at the instant at which the crack jumps, when there is an effective injection of gas into the almost evacuated space of the new break; it occupies a time t 10 µ sec. It is by no means impossible that the decomposition process which started in the highly absorbing gray layer initiates and attracts into reaction a thin layer of the pure material as well.4. The repeated irradiation of the crack through the clarified zone so created may lead to the decomposition of the material, the formation of gas, and the completion of crack development. For this purpose the energy density has to be roughly doubled by comparison with the threshold value corresponding to the nonclarified crack.Institute of Problems in Mechanics, Academy of Sciences of the USSR, Moscow. Translated from Mekhanika Polimerov, No. 5, pp. 777–781, September–October, 1976.     

Electrochemical behaviour of zinc in alkaline solutions

As the whole passivation phenomenon in the case of zinc is very quick and sudden and as it cannot be fully studied and followed by galvanostatic techniques alone, the constant over-potential technique has, for the first time, been applied to zinc and results reported. A special apparatus consisting of suitable oscillator, modulator, demodulator and a stable D.C. amplifier with a gain of 100,000 was used for the purposes and is described. Potential curves for equilibrium current rates, achieved on 0·1 V. and 25 mV. steps after 1 minute each, have been obtained in 6N, N, 0·1 N KOH and zincate solutions for the complete range of ?1·3 to about ?2·0 volts with reference to Hg/HgO/KOH reference electrode. It has been found that in the first truly active region, the main electrode reaction is the formation of zinc ions while after the passivation it changes to gas evolution. Potentiostatic techniques reveal intermediary stages, undisclosed by constant current methods, of pseudo-passivation and current-plateau regions in which the anodic layer thickens, controlled by the high field cation transport. These observations and explanations are further supported by plotting rate-time transients obtained by suddenly dropping the potentials from higher to lower values, when the rates were found to cut off. Some anomalies and sudden reversal of currents with increasing over-voltages, have also been fully discussed. The influence of other factors,e.g., concentration, stirring, sudden changes in over-voltages, presence of zincate, sulphate, etc., has also been considered. Studies such as these are found to throw considerable light on the electrochemical behaviour of zinc.     

Light absorption and laser-crack development. 2

Conclusions 1. The gray color of a laser crack in PMMA (black in polystyrene) is caused by carbon-black particles that adhere to its walls.2. Further experimentation under an electron microscope is necessary to determine the size of the carbon-black particles. Making use of these new data and the results described here, we can define their absorption index more precisely.3. The absorption index of the gaseous medium between the walls of the crack in a layer 30–100 µ thick is 20 cm^–1; this is 1000 times smaller than that of graphite, but approximately 1000 times greater than that of the ordinary block polymer.4. As a result of photochemical and photothermal reactions, the laser source creates a gray (PMMA) or black (polystyrene) absorbent layer located in the crack and on its walls. Thus, the energy of the laser beam is absorbed due to "self-inductive" opacity. This leads to an increase in the mass of the "gas wedge," to a pressure increase, and ultimately, to crack propagation.For communication 1, see [1].Institute of the Problems of Mechanics, Academy of Sciences of the USSR, Moscow. Translated from Mekhanika Polimerov, No. 3, pp. 409–412, May–June, 1977.     

Studies onO-Vanillinoxime as an analytical reagent

o-Vanillinoxime has now been used for the gravimetric determination of copper and nickel alone and in presence of many foreign ions. Copper can be estimated in presence of appreciable amounts of cadmium, zinc, cobalt and lead. The interference due to iron (III), antimony (III), bismuth (III) and tin (II) can be removed by suitable masking agents. Determination of copper and nickel in presence of each other has also been carried out.     

磁场和热辐射对可变表面热通量作用下的竖直圆锥体自然对流的影响

就圆锥体表面受到可变表面热通量作用,计及磁场和热辐射的综合影响,数值研究了流经竖直圆锥体的自然对流及其热交换特点.认为流体是灰色的、吸收-发射的辐射介质,而非散射介质,通过近似变换,将自由对流区中流动的边界层控制方程,简化为无量纲方程.利用Crank-Nicol-son形式的隐式有限差分法(具有收敛快、精度高、无条件稳定的特点),求解了无量纲的控制方程.得到了数值结果,以及空气和水中的速度、温度、局部和平均的壁面剪应力、局部和平均的Nusselt数.将所得到的结果与先前文献报道的结果进行比较,发现两者有着很好的一致性.     

基于深度学习的交通运输业能耗预测——以“一带一路”主要经济体为例

为合理规划一次能源使用,深入推进节能减排,需对交通运输能耗进行预测.使用灰色综合关联度模型筛选出客运、货运和经济发展水平三个方面共八个影响因素作为模型输入,提出了主要由LSTM层、Dropout层和Bi-LSTM层构成的深度学习模型,并使用天牛群优化算法精调模型超参数,在此基础上对2019至2025年中国、印度、东南亚和巴基斯坦四个"一带一路"沿线经济体交通运输能耗进行预测.研究结果表明:首先,BSO-LSTM模型较GA-BPNN、GA-SVR、GA-LSTM和PSO-LSTM模型具有最高的预测精度.其次,2019-2025年,中、印、东、巴交通运输业能耗总体上在波动中上升,年均增长率分别为2.92%、5.64%、3.05%和4.88%.再次,2024年中、印、东、巴交通运输业单位GDP能耗分别为29.41、37.41、46.67和83.12,除巴基斯坦外,较2018年均有所下降.最后,中国、东南亚2018-2024年交通运输业能源消费弹性系数较2012-2018年有所下降,而印度、巴基斯坦仍保持上升趋势.     

区间灰数直觉模糊集及其G-TOPSIS模糊多属性决策方法

提出以区间灰数为隶属度、非隶属度和犹豫度的区间灰数直觉模糊集概念,定义了两个区间灰数直觉模糊集之间的距离.对于以灰直觉模糊数为属性值的模糊多属性决策,依据经典TOPSIS准则,提出了基于区间灰数直觉模糊集的模糊多属性决策方法G-TOPSIS.其包含两种方法:一是将区间灰数白化后,按直觉模糊集的TOPSIS方法进行;一是基于区间灰数直觉模糊距离的TOPSIS方法.示例分析表明了两种方法的有效性与一致性.