凌庄子水厂保水堰流量系数试验

凌庄子水厂蓄水池进水口处有一保水堰,为非标准薄壁堰,不能使用已有堰流公式对其过流量进行准确计算。为了得出较为精确的过流流量,按照重力相似准则制作几何比尺为1∶5的模型进行试验研究。在已有自由出流公式的基础上,对自由出流流量系数进行修正并对淹没情况下流量变化过程进行研究。对该非标准堰自由出流流量系数的实测值与经验值进行分析比较,发现堰板槽降低了实际自由出流过流能力。淹没出流的流量系数主要与下游尾水位有关,试验中形成的淹没式堰流受实际堰型尺寸影响,下游尾水位和堰上水位近似相等,不完全适用已有淹没出流流量公式,通过试验给出了修正淹没系数随h/p的变化关系。结果表明利用堰前、堰后水位初步计算过流流量是可行的,可为该工程提供参考,也可为实际工程中非标准矩形堰的流量计算提供思路。     

切顶卸压技术在双鸭山矿区沿空留巷中的应用

为了使双鸭山矿区煤炭资源最大程度地被采掘,减少资源浪费,提高矿井效益,延长矿井服务年限及促进矿井安全生产,以双鸭山矿区3个缓倾斜中厚煤层综采工作面为工程背景,对切顶卸压无煤柱开采技术进行深入探索,经过实际的检验证明,在双鸭山矿区缓倾斜中厚煤层中,采用切顶卸压技术进行沿空留巷,技术可行,经济合理,工艺简单,成巷率高。     

Utilization of pyrolytic oil and hydrogen enriched syngas from single feedstock (delonix regia) through pyrolysis process and its influence on performance and emission characteristics in CI engine

The main objective of the present investigation is to conduct the performance, combustion and emission analysis of CI engine operated using hydrogen enriched syngas (pyrolytic gas) and biodiesel (pyrolytic oil) as dual fuel mode condition. Both the pyrolytic oil and syngas is obtained from single feedstock delonix regia fruit pod through pyrolysis process and then pyrolytic oil is converted into biodiesel through esterification. Initially biomass is subjected to thermal degradation at various pyrolysis temperature ranges like 350–600 °C. During the pyrolysis process syngas, pyrolytic oil and char are produced. The syngas is directly used in the CI engine and pyrolytic oil is converted into biodiesel and then used in the CI engine. The pyrolytic oil and syngas is subjected to FTIR and GC/TCD analysis respectively. The syngas analysis confirms the presence of various gases like H₂, CH₄, CO₂, CO and C₂H₄ in different proportions. The various proportions of the syngas is mainly depending upon the reactor temperature and moisture content in the biomass. The syngas composition varies with increase in the temperature and at 400 °C, higher amount of hydrogen is present and its composition are H₂ 28.2%, CO is 21.9%, CH₄ is 39.1% and other gases in smaller amounts. The biodiesel of B20 and syngas of 8lpm produced from the same feedstock are considered as test sample fuels in the CI engine under dual fuel mode operation to study the performance and emission characteristics. The study reveals that BTE has slight increase than diesel of 1.5% at maximum load. On the another hand emission like CO, HC and smoke are reduced by 15%,25% and 32% respectively at full load condition, whereas NO_x emission is increased at all loads in the range of 10–15%. Therefore B20+syngas of 8lpm can be used as an alternative fuel in CI engine without any modification and major products from pyrolysis process with waste biomass is fully used as fuel in the CI engine.     

“Peel cutting” – A new cutting method for difficult-to-cut workpieces with hard oxide surfaces

A new cutting method named “peel cutting” is proposed in this research to suppress notch wear in machining of metals with hard oxide surfaces. In general, metals are produced by hot deformation processes like rolling, forging, and extrusion, which cause hard oxide surfaces called scales on their surfaces. These hard scales need to be removed first in machining of precision parts. However, the machining causes the severe notch wear at the depth-of-cut position, where the tool contacts the hard scale. To solve this problem, the proposed peel cutting avoids this direct contact between the tool and the scale by inclining the end cutting edge at an extremely large inclination (oblique) angle. This extremely oblique cutting changes the material flow and generates a “burr-like chip”. In the proposed cutting method, the tool contacts only soft non-oxide metal under the scale during cutting. Cutting of titanium alloy Ti–6Al–4V is conducted by modifying commercial tools to provide extremely large inclination angles, and it is clarified that an inclination angle of 70 deg or greater is required to realize the proposed cutting. Tool wear in the proposed cutting of the alloy with a hard scale is also observed in comparison with the ordinary cutting, and the result verifies that the notch wear can be suppressed successfully by the proposed peel cutting.     

A constrained portfolio selection model at considering risk-adjusted measure by using hybrid meta-heuristic algorithms

Portfolio selection is a key issue in the business world and financial fields. This article presents a new decision making method of portfolio optimization (PO) issues in different risk measures by using new evolutionary computing method and cardinality constrains which is mentioned as hybrid meta-heuristic algorithms. Based on mean–variance (MV) Method by Markowitz we collected three risk levels; mean absolute deviation (MAD), semi variance (SV) and variance with skewness (VWS). The developed algorithms are Electromagnetism-like algorithm (EM), particle swarm optimization (PSO), genetic algorithm (GA), genetic network programming (GNP) and simulated annealing (SA). Also a diversification mechanism strategy is implemented and hybridized with the developed algorithms to increase the diversity and overcome local optimality. The sustainability of this proposed model is verified by 50 factories on the Iranian stock exchange. Finally, experimental results of proposed algorithms with cardinality constraint are compared with each other by four effective metrics in which the algorithms performance for achieving the optimal solution discussed. In addition, we have done the analysis of variance technique to confirm the validity and accurately analyze of the results which the success of this method was proved.     

基于DAE-BP神经网络的股票预测研究

股票指标数据种类多、维度高，且指标之间存在多重共线性。为了降低数据的维度、消除指标间的多重共线性和预测股票价格，首先构建了基于受限布尔兹曼机的深度自编码器，实现了高维数据向低维空间的压缩编码。然后基于BP神经网络建立了低维编码序列与股票价格之间的回归模型。实验结果表明，深度自编码器提取特征的能力优于主成分分析法和因子分析法；相比较使用降维前的数据，使用编码后的数据用预测股票价格，模型可以减少计算开销，并且获得更高的预测精度。     

时态神经网络模型及其在股票分类预测上应用

对具有时间属性的数据进行数据挖掘称为时态数据挖掘，用以发现数据在时间上的知识，当数据变化不规律时，如股票交易数据,就很难发现有价值的规律与规则。而神经网络具有并行、容错、可以硬件实现以及自我学习的优点,可作为股票分类预测应用的一种方法。通过将股票数据与时态型相结合，将股票数据转换成时态型股票数据，提出时态神经网络模型的分类方法，对收集的若干上市公司十年内的股票数据进行分析，构建了时态股票数据神经网络分类器对股票进行分类预测。经过实验验证，相比改进前的神经网络和支持向量机方法，该分类器具有更高的分类准确率。结果证明，这种时态数据神经网络模型对于多只股票的分类预测是非常有效的，可以很好地运用到股票市场的分类预测中。     

基于平面不封闭图形切割的路径规划

在平面切割环节中，如何确定更短切割路径以减少加工成本、降低设备损耗和提升切割质量是工业应用和学术研究的重点。目前国内外对平面切割路径的研究主要集中于封闭图形，为此，针对在激光刀模行业中不封闭图形的问题，提出一种基于禁忌搜索的贪婪算法和贪婪准则的局部优化。首先使用构建型的贪婪算法和改进型的禁忌搜索算法相结合的方式对加工过程中的图元路径进行优化排序，随后提出贪婪准则的局部优化系数，削弱贪婪算法的“贪心”思想，解决加工路径的规划和优化问题。实验数据表明，禁忌搜索的贪婪算法和局部优化在对切割路径的规划和空行程优化上有显著效果，空行程减少50%以上，并且其优化性能和图元数量成正比，能有效地解决刀模行业以及其他激光雕刻行业中图形不封闭的切割难题。     

Experimental investigation of different morphology textured ceramic tools by in-situ formed for the dry cutting

Surface texture is considered an important measure to improve the cutting performance of a tool. In this study, we have prepared three types of textured and conventional tools on the rake face by an in-situ formed method. During the experiment, the best parameters of three types of textured tools were selected for dry cutting AISI 1045 steel at different cutting speeds. Cutting forces, cutting temperatures, workpiece surface roughness, and tool wear were measured during the cutting process. The results showed that textured tools have significantly reduced cutting force, cutting temperature, and tool wear, and the roughness of the workpiece was improved compared with the conventional tool. The micro-pit texture tool has less stress contact region than the micro-groove width texture tool, but the micro-groove width texture tool exhibiting the best cutting performance. This investigation clearly showed that the textured tool prepared by the in-situ formed method has improved cutting performance.     

东河煤矿2206工作面无煤柱自成巷关键技术研究及应用

针对传统沿空留巷采煤技术因增设巷道掘进作业造成煤炭资源浪费的问题,以东河煤矿2260工作面为工程背景,在分析该工作面地质、水文以及煤层情况的基础上,研究了无煤柱自成巷关键技术,并应用到2260工作面中,最终取得了较为理想的留巷效果,为类似综采工作面避免煤炭资源浪费和提升作业人员安全系数提供了有益借鉴.