New exact solutions of the Tzitzéica-type equations in non-linear optics using the expa function method

One specific class of non-linear evolution equations, known as the Tzitzéica-type equations, has received great attention from a group of researchers involved in non-linear science. In this article, new exact solutions of the Tzitzéica-type equations arising in non-linear optics, including the Tzitzéica, Dodd–Bullough–Mikhailov and Tzitzéica–Dodd–Bullough equations, are obtained using the exp_a function method. The integration technique actually suggests a useful and reliable method to extract new exact solutions of a wide range of non-linear evolution equations.     

珲春地区高瓦斯矿井煤自然发火标志气体研究

为了探究珲春地区高瓦斯矿井煤自然发火情况，选取该地区板石煤矿22、23a和八连城煤矿18#、26#共4个煤层进行程序升温特性实验，分析了CO及烃类气体产生量随温度的变化规律，优选自然发火标志气体，测算煤自燃临界温度。结果表明，板石22、23a和八连城18#、26#四个煤层的自燃临界温度分别为101.0℃、97.6℃、121.0℃、169.1℃。CO和C2H4的初现温度大约在30℃与80～120℃，且产生量随温度单调递增，可作为煤自燃预测预报的主要参考指标|而同时，为了保证检测的全面与准确，还可以将规律性良好的其他烃类气体、烯烷比和链烷比进行辅助参考。     

埋地管道腐蚀防护--防腐层与阴极保护存在的问题分析

在埋地管道研究工作中,关于其腐蚀的防护一直是研究的焦点问题,但现阶段常用的防护手段多为防腐层与阴极防护。为此,在文中主要对二者的保护措施展开了相应地阐述,并重点分析了2种保护手段存在的问题,旨在为后续的管道防腐研究提供相应的参考。     

Delay compensated control of the Stefan problem and robustness to delay mismatch

This paper presents a control design for the one‐phase Stefan problem under actuator delay via a backstepping method. The Stefan problem represents a liquid‐solid phase change phenomenon which describes the time evolution of a material's temperature profile and the interface position. The actuator delay is modeled by a first‐order hyperbolic partial differential equation (PDE), resulting in a cascaded transport‐diffusion PDE system defined on a time‐varying spatial domain described by an ordinary differential equation (ODE). Two nonlinear backstepping transformations are utilized for the control design. The setpoint restriction is given to guarantee a physical constraint on the proposed controller for the melting process. This constraint ensures the exponential convergence of the moving interface to a setpoint and the exponential stability of the temperature equilibrium profile and the delayed controller in the norm. Furthermore, robustness analysis with respect to the delay mismatch between the plant and the controller is studied, which provides analogous results to the exact compensation by restricting the control gain.     

分时电价下多目标绿色可重入混合流水车间调度

针对多目标绿色可重入混合流水车间调度问题（RHFSP）的特点，在机器分配和工序排序的基础上引入分时电价机制，构建了以最小化最大完工时间、总能耗成本和碳排放为目标的绿色调度优化模型，提出了一种改进的多目标文化基因算法（MOMA）来求解该问题，通过数值实验验证了所设计的MOMA算法的可行性。实验结果表明MOMA算法在非劣解的收敛性、多样性和支配性指标方面都显著优于多目标蚁狮优化算法(MOALO)、多目标粒子群优化算法（MOPSO）和带精英策略的非支配排序遗传算法（NSGA-Ⅱ），四种算法的分布性指标无显著差异。所提出的模型能够使企业有效避开高电价时段作业，合理转移用电负荷，达到降低总用电成本和碳排放的目的。     

楼宇型分布式能源系统设备容量和运行策略优化研究

设备容量优化和运行策略优化是分布式能源系统设计，运行的关键问题。为实现分布式能源系统的经济效益，能效水平和环境效益最大化，针对楼宇型分布式能源系统建立了相对普适化的物理模型和数学模型，以粒子群优化算法和线性规划相结合，采用两阶段优化方法计算系统的最优容量配置，并给出运行策略。以某写字楼的分布式能源系统为例，得到最优的系统设备容量和全年逐时运行策略，并采用遍历法验证计算结果的准确性。优化的分布式能源系统与传统供能系统相比，费用年值降低7.79%，年总能耗降低24.18%，污染物排放量减少了62.77 %。     

Probabilistic tree-based representation for solving minimum cost integer flow problems with nonlinear non-convex cost functions

The minimum cost flow problem (MCFP) is the most generic variation of the network flow problem which aims to transfer a commodity throughout the network to satisfy demands. The problem size (in terms of the number of nodes and arcs) and the shape of the cost function are the most critical factors when considering MCFPs. Existing mathematical programming techniques often assume the cost functions to be linear or convex. Unfortunately, the linearity and convexity assumptions are too restrictive for modelling many real-world scenarios. In addition, many real-world MCFPs are large-scale, with networks having a large number of nodes and arcs. In this paper, we propose a probabilistic tree-based genetic algorithm (PTbGA) for solving large-scale minimum cost integer flow problems with nonlinear non-convex cost functions. We first compare this probabilistic tree-based representation scheme with the priority-based representation scheme, which is the most commonly-used representation for solving MCFPs. We then compare the performance of PTbGA with that of the priority-based genetic algorithm (PrGA), and two state-of-the-art mathematical solvers on a set of MCFP instances. Our experimental results demonstrate the superiority and efficiency of PTbGA in dealing with large-sized MCFPs, as compared to the PrGA method and the mathematical solvers.     

某尾矿库调洪计算

调洪计算在尾矿库设计和运行管理中都是非常重要的，水量平衡是常用计算方法，涉及较多的插值计算与试算。为了提高计算效率和计算质量，在利用Excel强大数据处理功能的同时，采用VBA编程方法实现计算过程自动化。降低了人工插值和试算对计算结果的影响，提高了工作效率。计算过程清晰，通用性强。     

BIM技术在地下工程中的应用分析及展望

BIM技术以三维设计为基础,以数字信息为载体,将建筑信息贯穿于建筑的全生命周期中。然而由于地下工程的内部结构较为复杂,受地质条件影响较大,BIM技术在地下工程中的应用并不多见。叙述了BIM技术在隧道、地铁和矿井建设几种地下工程中应用的现状,并对几个典型案例进行分析,指出了BIM技术在地上工程和地下工程中应用的异同。最后,提出了目前BIM技术在地下工程中应用的问题以及对未来发展的建议。为推动BIM在我国地下工程中更广泛深入的应用提供重要参考价值。     

Complexity and performance of an Augmented Lagrangian algorithm

Algencan is a well established safeguarded Augmented Lagrangian algorithm introduced in [R. Andreani, E. G. Birgin, J. M. Martínez, and M. L. Schuverdt, On Augmented Lagrangian methods with general lower-level constraints, SIAM J. Optim. 18 (2008), pp. 1286–1309]. Complexity results that report its worst-case behaviour in terms of iterations and evaluations of functions and derivatives that are necessary to obtain suitable stopping criteria are presented in this work. In addition, its computational performance considering all problems from the CUTEst collection is presented, which shows that it is a useful tool for solving large-scale constrained optimization problems.