影响蒸汽驱效果的主要因素分析

本文研究了影响蒸汽驱效果的主要因素,分析了油藏地质条件和蒸汽驱过程中的操作参数两方面因素对蒸汽驱效果的影响,总结出适合蒸汽驱的油藏地质条件和合理的蒸汽驱操作条件。     

射线型原油含气、含水率自动监测仪及在安塞油田的应用

射线型原油舍气、含水率自动计量系统是基于油、气、水三种不同介质对一定能量的γ射线的吸收不同。通过检测γ射线穿过油、气、水的混合物后的透射计数。经过理论计算。实现对原油舍气、含水率在线分析。工作方式为全自动在线连续测量。该计量系统设计新颖、测量准确、安全可靠、运行稳定、使用寿命长、便于操作。特则是修正了由于原油中舍气(乳化或游离)对含水率测量的影响。使该仪表在安塞油田原油计量中具有明显的优势。     

重夸克碎裂运动学参数的味修正

以组分夸克模型导出的重子内轻夸克的动量分布参数为基础,通过味修正可以获得重强子内重夸克的动量分布参数及重夸克碎裂函数,其结果与实验数据较好相符。     

倒分系数计量方式在处理站的应用

倒分系数法是静态计量和动态计量相结合的一种计量方式,主要应用于负责处理不同采油作业区含水原油的集输站库。近年来由于油田快速发展,采油区块的增多,某处理站负责处理3个采油作业区原油,使用倒分系数计量方式实现了对原油产量的准确计量。     

The burden of preserved ejection fraction heart failure in a real-world Swedish patient population

Objectives:

To evaluate resource use and associated costs in patients with a diagnosis of heart failure with preserved ejection fraction (HF-PEF) in Sweden.

Methods:

This retrospective study identified real-world patients with an ICD-10 diagnosis code for heart failure (I50) for the period between July 1, 2005 and December 31, 2006 from electronic medical records of primary care centers in Uppsala County Council, and in the Swedish patient registry data. Patients were categorized as having HF-PEF (left ventricle ejection fraction [LVEF] > 50%) during the index period. The study assessed medication utilization, outpatient visits, hospitalizations, and associated healthcare costs, as well as the incidence rates and time to all-cause and heart failure mortality following the index period.

Results:

The study included 137 HF-PEF patients with a mean age of 77.1 (SD?=?9.1) years. Over 50% of HF-PEF patients were female and hypertensive. Nearly all patients received ≥1 medication post-index. Patients had an average of 1.5 heart failure related hospitalizations per follow-up year. The average annual per patient cost for the management of a HF-PEF patient was found in Sweden to be Swedish Krona (SEK) 108,246 (EURO [EUR] 11,344). Hospitalizations contributed to more than 80% of the total cost. All-cause mortality over the 18-month study period was 25.5%, and more than 50% of these deaths occurred within 1 year of index.

Limitations:

Due to the limitations of registry data, it is not possible to confirm the HF diagnosis, and therefore the accuracy of registry records must be assumed. Other factors such as short follow-up time, the study-mandated LVEF assessment, and a lack of drug duration data may also have an impact on the study results.

Conclusions:

All-cause mortality was high in the HF-PEF population, with more than half of patients dying within 1 year of study follow-up. Study results also indicate that 60% of HF-PEF patients have ≥1 hospitalization during follow-up. Hospitalizations, especially heart failure related admissions, represent a substantial proportion of the total healthcare burden of patients with HF-PEF in Sweden.     

Using the Fraction of Missing Information to Identify Auxiliary Variables for Imputation Procedures via Proxy Pattern‐mixture Models

In many surveys, imputation procedures are used to account for non‐response bias induced by either unit non‐response or item non‐response. Such procedures are optimised (in terms of reducing non‐response bias) when the models include covariates that are highly predictive of both response and outcome variables. To achieve this, we propose a method for selecting sets of covariates used in regression imputation models or to determine imputation cells for one or more outcome variables, using the fraction of missing information (FMI) as obtained via a proxy pattern‐mixture (PMM) model as the key metric. In our variable selection approach, we use the PPM model to obtain a maximum likelihood estimate of the FMI for separate sets of candidate imputation models and look for the point at which changes in the FMI level off and further auxiliary variables do not improve the imputation model. We illustrate our proposed approach using empirical data from the Ohio Medicaid Assessment Survey and from the Service Annual Survey.     

Heterogeneity,convergence, and autocorrelations

This paper is a contribution to the literature on the explanatory power and calibration of heterogeneous asset pricing models. We set out a new stochastic market-fraction asset pricing model of fundamentalists and trend followers under a market maker. Our model explains key features of financial market behaviour such as market dominance, convergence to the fundamental price and under- and over-reaction. We use the dynamics of the underlying deterministic system to characterize these features and statistical properties, including convergence of the limiting distribution and autocorrelation structure. We confirm these properties using Monte Carlo simulations.     

原油价格与原油性质关系的初步探讨

以欧佩克15种原油与迪拜原油的价差，对美制密度（API）、硫的质量分数的相关性进行了统计分析。     

色谱技术在重质油品馏程分析中的应用

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。