东濮凹陷砂岩储集层物性参数关系研究及随钻应用方法

储集层的物性参数是评价储集层的重要基础数据,对储集层评价的准确程度有较大影响,文章统计分析结果表明砂岩储集层岩石密度与储集层主要物性参数之间有良好的相关性。以区域统计规律为基础,建立了东濮凹陷砂岩储集层体积密度与孔隙度和渗透率的关系方程。介绍了录井施工现场应用岩屑样品体积置换法、泥岩密度计法两种常规检测方法,能较准确的获取砂岩储集层的体积密度,反演计算孔隙度和渗透率数据,合理评价储集层物性参数,为准确评价储集层提供了可信度高的重要基础数据,从而弥补了录井现场物性参数获取不足的缺陷,在随钻评价油气储集层过程中有一定的实用价值。     

基于溶解度参数离子液体溶胀煤分散剂的选择

选择3种分散剂甲醇(M)、丙酮(A)和四氢呋喃(T),以及3种分散剂分别与离子液体1-丁基-3-甲基咪唑四氟硼酸盐([BMIM]BF₄)组成的混合溶剂甲醇/[BMIM]BF₄(M-ILs)、丙酮/[BMIM]BF₄(A-ILs)和四氢呋喃/[BMIM]BF₄(T-ILs)对新疆烟煤(C_R)进行溶胀处理,研究了不同溶剂溶胀对煤样溶解度参数及液化效能的影响。扫描电镜分析结果表明,C_R经6种溶剂溶胀后微观形貌均呈现不同程度的疏松。溶解度参数测试结果表明:溶剂与C_R之间的溶解度参数的差值越小,溶剂对煤样的溶胀效果越好;所得溶胀煤样的溶解度参数越低,溶胀煤样的液化性能越好。同时,分散剂与离子液体[BMIM]BF₄共同作用更有利于煤的溶胀,3种混合溶剂M-ILs、A-ILs和T-ILs对C_R的溶胀效果比对应的单一分散剂M、A和T对C_R的溶胀效果分别高出9.65%、14.28%和11...     

服装笔式绘图仪的技术改进

介绍了国内服装笔式绘图仪的发展现状,分析了常见服装笔式绘图仪的主要结构及工作原理,提出了几种技术改进途径,并对服装笔式绘图仪的市场前景作了展望。     

STUDIES ON RETRIEVAL OF THE TURBULIVITY OF ATMOSPHERIC BOUNDARY LAYER

1. INTRODUCTION Human activities mainly occur in the atmospheric boundary layer and turbulent transfer is a key factor for the exchange of substance and energy of the earth-atmosphere system, so atmospheric turbulence must be described accurately for all …     

自适应调整峰半径的适应值共享遗传算法

适应值共享遗传算法需要事先给出解空间中峰的数目或峰的半径,这对于某些问题来说是有困难的.针对这类问题,提出将峰的半径作为决策变量,对其进行编码并放入染色体中参与演化过程,利用遗传算法的优化能力在对问题进行优化的同时对个体的峰半径进行自适应调整.用所提出的方法对多个标准测试问题的优化结果表明,采用自适应峰半径调整方法的适应值共享遗传算法有很强的多峰搜索能力.     

面向数据发布的隐私保护模型及参数优选方法

为更好地对待发布数据进行隐私保护,构建综合k-匿名、l-多样性和t-闭合方法的匿名化隐私保护模型.利用该模型能够选择最适合的隐私保护方法,并优选对应的隐私保护参数,达到数据提供者所期望的隐私保护效果,满足数据使用者对可用性的要求.实验结果表明,该方法不仅可以找到相对较优的参数值,而且能够有效满足具有不同身份和应用需求的...     

钻孔机器人钻进工况智能感知与自适应控制机理研究

为提高瓦斯抽采孔钻进过程中控制参数调节的智能化程度,揭示了钻孔机器人钻进工况智能感知与自适应控制机理,开发了钻进参数自适应控制技术。以最高钻进效率为控制目标,选择卡钻概率、排渣顺畅性和锚固稳定性为边界条件,并据此划分了钻进状态种类。通过分析边界条件对钻进过程的影响,建立了各边界条件的数学模型,构建了钻孔机器人钻进工况智能感知与自适应控制机理数学模型体系。根据钻进工况智能感知与自适应控制机理,开发了基于差分进化算法的自适应控制技术,实现了钻孔机器人控制向量的自动优化。地面钻进试验表明,钻进工况智能感知与自适应控制技术能控制钻孔机器人在钻进岩层突变时较快地实现对控制参数的自动调节,使钻孔机器人保持高效、稳定的钻进状态。     

Invited review: Genetics and modeling of milk coagulation properties

Milk coagulation properties (MCP) are conventionally measured using computerized renneting meters, mechanical or optical devices that record curd firmness over time (CF_t). The traditional MCP are rennet coagulation time (RCT, min), curd firmness (a₃₀, mm), and curd-firming time (k₂₀, min). The milk of different ruminant species varies in terms of CF_t pattern. Milk from Holstein-Friesian and some Scandinavian cattle breeds yields higher proportions of noncoagulating samples, samples with longer RCT and lower a₃₀, and samples for which k₂₀ is not estimable, than does milk from Brown Swiss, Simmental, and other local Alpine breeds. The amount, proportion, and genetic variants (especially κ-casein) of milk protein fractions strongly influence MCP and explain variable proportions of the observed differences among breeds and among individuals of the same breed. In addition, other major genes have been shown to affect MCP. Individual repeatability of MCP is high, whereas any herd effect is low; thus, the improvement of MCP should be based principally on selection. Exploitable additive genetic variation in MCP exists and has been assessed using different breeds in various countries. Several models have been formulated that either handle noncoagulating samples or not. The heritability of MCP is similar to that of other milk quality traits and is higher than the heritability of milk yield. Rennet coagulation time and a₃₀ are highly correlated, both phenotypically and genetically. This means that the use of a₃₀ data does not add valuable information to that obtainable from RCT; both traits are genetically correlated mainly with milk acidity. Moreover, a₃₀ is correlated with casein content. The major limitations of traditional MCP can be overcome by prolonging the observation period and by using a novel CF_t modeling, which uses all available information provided by computerized renneting meters and allows the estimation of RCT, the potential asymptotic curd firmness, the curd-firming rate, and the syneresis rate. Direct measurements of RCT obtained from both mechanical and optical devices show similar heritabilities and exhibit high phenotypic and genetic correlations. Moreover, mid-infrared reflectance spectroscopy can predict MCP. The heritabilities of predicted MCP are higher than those of measured MCP, and the 2 sets of values are strongly correlated. Therefore, mid-infrared reflectance spectroscopy is a reliable and cheap method whereby MCP can be improved at the population level; this is because such spectra are already routinely acquired from the milk of cows enrolled in milk recording schemes.     

不饱和氟化烯烃及其混合制冷剂应用研究的最近进展与成果

制冷剂的替代是当今国内外制冷空调界关注的热点问题.一年多来,国外在不饱和氟化烯烃(HFO)及其混合制冷剂的应用开发上获得了可喜成果.为使我国更多业内人士及时了解相关进展与成果,以笔记摘录的形式介绍了国外在HFO及其混合制冷剂的状态方程、特性参数、传输特性、系统性能等方面的研究成果以及一些产品研发成果.     

An Estimation Method to Determine Equivalent Circuit Parameters for Harmonic Analysis

This paper proposes a new estimation method to determine arbitrary circuit parameters for the harmonic analysis of a distribution network. Harmonic analysis is important in maintaining electric power quality. An interesting phenomenon, a temporary cut‐down of the harmonic voltage level at dawn, even if demand is slightly increasing at this time, is often observed in actual power systems. This paper proposes to utilize observations of this phenomenon to estimate circuit parameters. In addition, it is claimed that a detailed equivalent circuit is preferable to a conventional simplified equivalent circuit for explaining the phenomenon. This paper also discusses the usefulness of the Harmonic Characteristics Curve, which is proposed in this paper as a new concept, at the secondary winding of the distribution transformer, and the correlation of PQ, the monitored values of the active and reactive power at the secondary winding of distribution transformer. This correlation should determine the equivalent fundamental frequency admittance of the shunt capacitors installed for distribution lines. © 2014 Wiley Periodicals, Inc. Electr Eng Jpn, 187(1): 16–23, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22451