排序方式： 共有28条查询结果，搜索用时 15 毫秒
11.
阐述了块煤螺旋溜槽防破碎技术(以下简称螺旋溜槽)的理论及发展史,螺旋溜槽的设计原理。针对某煤矿原煤的性质与特点,经过研究分析,设计了井上煤场输送机螺旋溜槽,确定了其结构参数,经过安装实测,成功提高了该矿的块煤率,显著地降低了限下率,使该企业的生产盈利情况有了明显的提高。 相似文献
12.
13.
14.
色谱模拟蒸馏技术应用于炼厂重质油品馏程测定,具有测试结果精密度高、人员劳动强度低、自动化程度高的特点。色谱模拟蒸馏方法与实验室常用的减压蒸馏方法相比较,从理论上更接近多塔板蒸馏,分析结果能更好地反映工艺状况,可替代传统的人工减压蒸馏,在炼油厂的分析检验中具有很好的应用前景。 相似文献
15.
控制权协议转让通常导致上市公司控股股东的更换,然而控股股东的更换是否能提高上市公司的绩效呢?本文对这一问题进行了实证研究.本文认为,控股股东的更换效率受投资者保护环境的影响,由于我国投资者保护环境尚不完善,控制权协议转让中存在较多的无效率交易,因此我国上市公司控股股东的更换并不能有效的提高公司绩效,这在股权转让比例较低... 相似文献
16.
In spite of Taguchi's robust parameter design (Introduction to quality engineering: designing quality into products and processes, 1986, Asian Productivity Organization, Tokiyo), tolerance design is still important at the design stage of products and processes. Taguchi's proposal and related methods for tolerance design, however, do not efficiently use the information that can be obtained from the parameter design experiment. In this paper, we introduce a new method for tolerance design based on the response surface approach to parameter design. It is a flexible method because non-normal distributions of the noise factors and the quality characteristic are allowed. Moreover, it is unnecessary to perform a new physical experiment. Essentially, tolerances of noise factors are maximized, subject to constraints to ensure that the mean value of the quality characteristic remains on target and the fraction nonconforming is below a pre-specified maximum. Some aspects of model uncertainty are discussed and the method is illustrated by means of an example. 相似文献
17.
Nur Shahidah Ab Aziz Rafiziana Md. Kasmani Mohd Dinie Muhaimin Samsudin Arshad Ahmad 《Process Safety Progress》2020,39(Z1):e12124
High momentum release of jet fire can be very intense, and the released heat can be very high, depending on the source capacity. One of the key parameters in characterizing the jet fire is the radiative fraction. The previous study has correlated the radiative fraction to the source using a Froude number basis. Nevertheless, the flame mechanism and associated geometrical features gave significant effects on the global radiative heat flux to some extent. Therefore, the characterization of the main geometrical features, particularly on jet flame structures at higher momentum release conditions and its correlation with the radiative fraction, are valuable to be investigated. In this work, propane was used as fuel and released through a 9.8 mm circular nozzle with the exit velocities were set ranging between 27 and 65 m/s. It was found that the liftoff length estimation from this work is in a good agreement with the jet fire release under sub-atmospheric pressure in a vertical orientation. Furthermore, the flame projected length and height were characterized by momentum-driven length (L m) and buoyancy-driven height (L b) by the dimensionless characteristics length (Ʌ). The experimental observations indicate that as the Ʌ ≥ 0.0001, the radiative fraction shows a decreasing trend. 相似文献
18.
Metrika - What are optimal observation times of a random process to obtain good prediction or good estimation of the (parametric) trend? In the presented paper we discuss especially the following... 相似文献
19.
高树祥 《沈阳工程学院学报(社会科学版)》2003,(3):140-141
水泊梁山英雄都有宗派观念。这可以从宋江成为起义军的领袖 ,他对待卢俊义的态度 ,复杂的关系网和英雄排座次的场面中看出来。 相似文献
20.
本文将混沌与分形运用到汇率研究中,运用R/S方法研究了外汇收益率的长记忆性,并将传统的协整理论推广到广义的分数维协整,研究了时间序列之间的长期均衡关系,并以外汇市场中的欧元和新加坡元兑美元的汇率为例进行了实证分析,指出这两种货币收益率服从分形分布,具有相同的分整阶数且二者存在分数维协整关系。 相似文献