字符串动态匹配算法在地层对比中的应用

提出改进的最大类间方差法通过计算有序序列最大类间方差、最小类内方差以实现测井曲线分层,弥补最大类间方差法只能将序列分成2类的缺陷。数值形式表示的曲线不便于对比的描述,提出将数值曲线序列提取特征并转换成离散的、相对抽象的字符串序列的方法,并以具有可以得到全局最优解特点的动态规划法为理论基础进行曲线对比。使用胜利油田地质科学院提供的真实地质数据,验证利用字符串进行动态匹配进行曲线对比在地层对比中的应用,实验结果表明,算法对地层缺失、地层尖灭和地层逆序的情况均适用,且具备简化特征提取、对比效率高的特点。     

Azeotrope formation in gasoline–ethanol blends. Part 1 – Impact of nonionic on E10 distillation curve

Blending 10?vol% of ethanol into hydrocarbon base gasoline (HBG) increases significantly the vapour pressure of the blend (E10), and exhibits near-azeotrope behaviour that severely affects the shape of E10 distillation curve. The distillation curves of HBG and E10 fuel blend, were constructed using ASTM D86 distillation data, and the areas under each distillation curve, were calculated through the numerical trapezoid rule (NTR) and calculus definite integration (CDI) methods. Consequently, the area due to azeotrope formation (ADAF), was estimated. In this paper, we present the impact of small concentration of nonionic surfactant on the area under distillation curve (AUDC) of E10 fuel blend and the area due to azeotrope formation (ADAF). Also, the influences of the added surfactant on the volatility criteria of the investigated E10 fuel blend were discussed.     

一种改进的椭圆曲线算法及在电子商务中的应用

椭圆曲线公钥密码体制(ECC)具有最高的位安全强度。文章分析了ECC的优势，讨论了椭圆曲线的数学基础和离散对数问题的复杂性，并对现有的ECC数字签名算法(ECDSA)进行了改进，进一步加快了运算速度，缩短了数据传输的时间。将改进的椭圆曲线密码体制应用在电子商务中实现数字签名，取得了较好的效果。     

教室体形对声学特性影响分析

应用声学仿真软件对不同体形的教室的声学特性进行模拟,探讨不同体形的教室对教室声学特性的影响。结果表明,当教室平面为矩形平面(讲台位于矩形的短边)切角时,其声学特性较好。     

基于matlab的环境数据曲线拟合在某子母弹引信机构仿真中的应用

以某子母弹为对象 ,分别论述不同的离散曲线的解析式近似表达方法 ,最后以不同方法的拟合结果作为仿真模型的输入 ,得到仿真结果进行分析     

Some problems with the development of combined generation of electricity and heat in Russia

The current state of cogeneration in Russia is analyzed. It is characterized by a sharp decrease in industrial heat consumption and a reduction in the demand for electricity. As a result many cogeneration plants presently operate under off-design conditions, which change their economic indexes to the worse. The ways of introducing small-scale cogeneration installations are considered, which show promise under the existing conditions of limited investments. The problems that accompany the introduction of modern highly efficient large-capacity power units at cogeneration plants are analyzed.     

Technological learning in bioenergy systems

The main goal of this article is to determine whether cost reductions in different bioenergy systems can be quantified using the experience curve approach, and how specific issues (arising from the complexity of biomass energy systems) can be addressed. This is pursued by case studies on biofuelled combined heat and power (CHP) plants in Sweden, global development of fluidized bed boilers and Danish biogas plants. As secondary goal, the aim is to identify learning mechanisms behind technology development and cost reduction for the biomass energy systems investigated. The case studies reveal large difficulties to devise empirical experience curves for investment costs of biomass-fuelled power plants. To some extent, this is due to lack of (detailed) data. The main reason, however, are varying plant costs due to differences in scale, fuel type, plant layout, region etc. For fluidized bed boiler plants built on a global level, progress ratios (PRs) for the price of entire plants lies approximately between 90–93% (which is typical for large plant-like technologies). The costs for the boiler section alone was found to decline much faster. The experience curve approach delivers better results, when the production costs of the final energy carrier are analyzed. Electricity from biofuelled CHP-plants yields PRs of 91–92%, i.e. an 8–9% reduction of electricity production costs with each cumulative doubling of electricity production. The experience curve for biogas production displays a PR of 85% from 1984 to the beginning of 1990, and then levels to approximately 100% until 2002. For technologies developed on a local level (e.g. biogas plants), learning-by-using and learning-by-interacting are important learning mechanism, while for CHP plants utilizing fluidized bed boilers, upscaling is probably one of the main mechanisms behind cost reductions.     

用于排架结构的铅剪切阻尼器试验及数值分析

为进一步促进铅阻尼器在工程中的应用,针对常见的排架结构,研制了一种铅剪切阻尼器,通过低周往复加载试验,逐个分析阻尼材料铅的有效剪切面积、受剪区厚度、剪切截面形式、加载位移幅值、加载频率、加载次数等因素对阻尼器耗能性能的影响。试验结果表明,设计的阻尼器的阻尼力—位移滞回曲线饱满,耗能性能良好,符合双线性力学模型,并对试验中两个典型型号的阻尼器进行了数值模拟分析,通过对比数模值和试验值,证明了数值计算模型的实用性,为阻尼器在结构体系中的减震应用奠定了基础。