石油亚砜PSO—Ⅱ与P_(204),P_(507)萃取稀土的研究

分别用P_(204),P_(507),PSO—Ⅱ单独萃取混合氯化稀土,得到了萃取稀土的最佳条件,并对P_(204)与PSO—Ⅱ、P_(507)与PSO—Ⅱ,协同萃取稀土元素进行了初步探讨,发现P_(204)与PSO—Ⅱ,P_(507)与PSO—Ⅱ两者在萃取混合氯化稀土的试验条件下,均无协同效应。     

金刚石锯片使用性能与结合剂之间的关系

加工石材金刚石锯片的性能 ,既取决于金刚石 ,更取决于由金刚石与结合剂适当配合而构成的复合材料的整体性能。不同结合剂的类型、成份配比、相对密度、力学性能 ,均有着自身的特点和各自的适用范围     

Simulation techniques for generalized Gaussian densities

This contribution deals with the Monte Carlo simulation of generalized Gaussian random variables. Such a parametric family of distributions has been proposed in many applications in science to describe physical phenomena and in engineering, and it seems to be also useful in modelling economic and financial data. For values of the shape parameter α within a certain range, the distribution presents heavy tails. In particular, the cases α=1/3 and α=1/2 are considered. For such values of the shape parameter, different simulation methods are assessed.     

试论环境约束下的江苏省重工业发展之路

本文对江苏省主要重工业污染排放情况进行了因素分解,考察了江苏省的地方政策在重工业行业污染控制方面的有效性,并分析了污染控制目标下的经济效益,以期为产业政策的调整提供依据。     

近代天津的瘟疫流行与慈善机构的医疗救济

近代天津是一个瘟疫多发的城市,尤其是在水旱灾害频发的年份。瘟疫流行期间,天津市各慈善团体均致力于疫病的防治、控制和治疗。他们的善举有效地控制了疫情,拯救了许多人的生命,尤其是士绅倡导的"防疫"理念为近代公共卫生体制的确立提供了市民基础。     

Robust Bayesian nonlinear mixed‐effects modeling of time to positivity in tuberculosis trials

Early phase 2 tuberculosis (TB) trials are conducted to characterize the early bactericidal activity (EBA) of anti‐TB drugs. The EBA of anti‐TB drugs has conventionally been calculated as the rate of decline in colony forming unit (CFU) count during the first 14 days of treatment. The measurement of CFU count, however, is expensive and prone to contamination. Alternatively to CFU count, time to positivity (TTP), which is a potential biomarker for long‐term efficacy of anti‐TB drugs, can be used to characterize EBA. The current Bayesian nonlinear mixed‐effects (NLME) regression model for TTP data, however, lacks robustness to gross outliers that often are present in the data. The conventional way of handling such outliers involves their identification by visual inspection and subsequent exclusion from the analysis. However, this process can be questioned because of its subjective nature. For this reason, we fitted robust versions of the Bayesian nonlinear mixed‐effects regression model to a wide range of TTP datasets. The performance of the explored models was assessed through model comparison statistics and a simulation study. We conclude that fitting a robust model to TTP data obviates the need for explicit identification and subsequent “deletion” of outliers but ensures that gross outliers exert no undue influence on model fits. We recommend that the current practice of fitting conventional normal theory models be abandoned in favor of fitting robust models to TTP data.     

Campylobacter QMRA: A Bayesian Estimation of Prevalence and Concentration in Retail Foods Under Clustering and Heavy Censoring

A Bayesian statistical temporal‐prevalence‐concentration model (TPCM) was built to assess the prevalence and concentration of pathogenic campylobacter species in batches of fresh chicken and turkey meat at retail. The data set was collected from Finnish grocery stores in all the seasons of the year. Observations at low concentration levels are often censored due to the limit of determination of the microbiological methods. This model utilized the potential of Bayesian methods to borrow strength from related samples in order to perform under heavy censoring. In this extreme case the majority of the observed batch‐specific concentrations was below the limit of determination. The hierarchical structure was included in the model in order to take into account the within‐batch and between‐batch variability, which may have a significant impact on the sample outcome depending on the sampling plan. Temporal changes in the prevalence of campylobacter were modeled using a Markovian time series. The proposed model is adaptable for other pathogens if the same type of data set is available. The computation of the model was performed using OpenBUGS software.     

A new heavy-tailed distribution defined on the bounded interval: the logit slash distribution and its application

This paper proposes a new heavy-tailed and alternative slash type distribution on a bounded interval via a relation of a slash random variable with respect to the standard logistic function to model the real data set with skewed and high kurtosis which includes the outlier observation. Some basic statistical properties of the newly defined distribution are studied. We derive the maximum likelihood, least-square, and weighted least-square estimations of its parameters. We assess the performance of the estimators of these estimation methods by the simulation study. Moreover, an application to real data demonstrates that the proposed distribution can provide a better fit than well-known bounded distributions in the literature when the skewed data set with high kurtosis contains the outlier observations.     

雄奇悲凉的意象世界——论张承志小说的诗化及其美学风格

张承志的小说打破了小说和诗歌两种文体的严格界限 ,使二者之间能够进行对话和交流。他的小说充满了诗情画意 ,同时 ,象征手法的运用 ,又使之蕴涵着深刻的哲理意味。他的小说呈现崇高、深沉的美学风格     

Cloud manufacturing system for sheet metal processing

Abstract

Cloud computing is changing the way industries and enterprises run their businesses. Cloud manufacturing is emerging as an approach to transform the traditional manufacturing business model, while helping the manufacturer to align production efficiency with its business strategy, and creating intelligent factory networks that enable collaboration across the whole enterprise. Many production planning and control (PPC) problems are essentially optimisation problems, where the objective is to develop a plan that meets the demand at minimum cost or maximum profit. Because the underlying optimisation problem will vary in the different business and operation phases, it is important to think about optimisation in a dynamic mechanism and in a number of interlinked sub-problems at the same time. Cloud manufacturing has the potential to offer decision support as a service and medium of communication in PPC. To solve these problems and produce collaboration across the supply chain, this paper provides an overview of the state of the art in cloud manufacturing and presents a model of cloud-based production planning and production system for sheet metal processing.