铝合金抽油杆柱深抽的初步研究

机抽井深抽是恢复油井产量行之有效的措施，为解决钢质杆深抽时驴头负荷、曲柄扭矩和杆柱应力过大的问题，我国西部某油田提出了使用铝合金抽油杆的设想。本主根据抽油杆柱设计理论导出了深抽杆柱各级下入深度的公式；对不同工艺参数配合下的计算结果进行了对比分析，对铝合金抽油杆柱用于深抽的可行性进行了初步研究。     

Multi-neighborhood based iterated tabu search for routing and wavelength assignment problem

The routing and wavelength assignment problem (RWA) has shown to be NP-hard if the wavelength continuity constraint and the objective of minimizing the number of wavelengths are considered. This paper introduces a multi-neighborhood based iterated tabu search algorithm (MN-ITS), which consists of three neighborhoods with a unified incremental evaluation method, to solve the min-RWA problem. The proposed MN-ITS algorithm is tested on a set of widely studied real world instances as well as a set of challenging random ones in the literature. Comparison with other reference algorithms shows that the MN-ITS algorithm is able to improve five best upper bounds obtained by other competitive reference algorithms in the literature. This paper also presents an analysis to show the significance of the unified incremental evaluation technique and the combination of multiple neighborhoods.     

浙商“穿越现实”经验与中国式现代性自由

针对中国现代知识分子依附既定中西方观念造成的"平面化自由"问题,以及东亚现代化不能向世界贡献东方式的现代重大理论的"弱创造性自由"问题,浙商"穿越现实"的个体自由经验值得重视。这种经验以"亲和群体但不依附群体的隐性个体自立"、"亲和经验但不限于经验的潜在个体理解"为其基本内容,不仅可以诊治中国学界百年来依附西方"超越现实"的自由观批判中国传统思想的文化错位之症,也可为东亚的世俗性现代化提供一种"穿越世俗"的东方自由文化理想图景。     

高职院校校园文化建设要融入行业文化——以陕西铁路工程职业技术学院为例

高职院校校园文化建设是高职院校精神文明建设的重要内容,高职院校校园文化应以特色专业文化为核心,走与行业文化相互融合的建设之路,只有这样,才能突出高职院校校园文化的特色.     

Quasi-minimax estimation in the partial linear model

This article discusses the minimax estimator in partial linear model y = Zβ + f + ε under ellipsoidal restrictions on the parameter space and quadratic loss function. The superiority of the minimax estimator over the two-step estimator is studied in the mean squared error matrix criterion.     

中国文章学成立与古文之学的兴起

关于中国文章学成立时代的讨论,不仅是对成立时间的不同判断,更涉及对中国文章学的基本内涵、理论体系、总体特色与历史演变的理解与认同。魏晋南北朝中国文章学的基本内涵已经明确,理论系统初步建构,并且产生代表性成果,可以视为中国文章学成立的时代。魏晋南北朝文章学以诗赋骈文为中心。宋代以后,散体古文占据文坛中心地位,古文之学的兴盛引发中国文章学中心发生转移,并导致文学批评的一系列变化。不能以古文文章学的成立等同于中国文章学的成立,文话也难以称为中国文章学成立的标志。"文章"与"文章学"应视为动态的、有弹性的历史概念,中国文章学系统兼具开放与稳定的特点。     

丝绸之路经济带农牧业合作的空间、潜力与中国农业“走出去”策略

通过丝绸之路经济带的建设,强化我国与中亚五国在政治、经济、文化和民族间的联系,开展农业领域的合作,发展地区经济,是一件互利双赢的事业.与中亚国家进行深度的农牧业合作,既可以加快这些国家农牧业的发展,提高人民食物保障能力或提高其农产品出口的水平,又可以为我国的涉农企业走向深度参与一带一路建设、消化产能、布局农产品全球供应链提供良好的机遇.     

Multiple comparisons of exponential location parameters with a control based on doubly censored sample under heteroscedasticity

In this article, a one-sample procedure for multiple comparisons of exponential location parameters with a control under heteroscedasticity is proposed. The observations are obtained by doubly censored samples. A one-sided and two-sided confidence intervals are used to perform such multiple comparisons. Statistical tables of critical values and an example of comparing four drugs in treating leukemia are provided.     

Contents of heavy metals in arable soils and birth defect risks in Shanxi, China: a small area level geographic study

The burgeoning demands of China’s urbanization and industrial development put pressure on the resources of the entire country and have direct and indirect effects on the health of individuals, at times in areas far removed from cities themselves. Current evidence suggests that heavy metal pollution in soil, a common by-product of coal mining and other industrial activities, may be linked to risk of birth defects. We examine this hypothesis using small area level data including soil samples and detailed birth records from 2002 to 2004 from 97 villages in Shanxi province, a heavy coal-mining region. We find that soils containing arsenic, lead, and nickel are significantly correlated with the incidence of birth defects. In particular, we find a strong positive dose-dependent association of birth defects with lead, a moderate positive effect with arsenic, and a dose-dependent negative association with nickel. These results are consistent with the postulated link between arsenic and lead and human birth defects, but raise questions about the effects of nickel in this context. China’s rapid urbanization underscores the need for closer attention to the relationship between the health and the environment.