Science Letters:Remediation of Cr(Ⅵ) in solution using vitamin C

The effectiveness of vitamin C in treating Cr(Ⅵ)-contaminated water is being evaluated. Cr(Ⅵ) is an identified pollutant of some soils and groundwater. Vitamin C, an important biological reductant in humans and animals, can be used to transform Cr(Ⅵ) to essentially nontoxic Cr(Ⅲ). The removal efficiency was 89% when the mass concentration of vitamin C was 80 mg/L in 60 min, and nearly 100% Cr(Ⅵ) was removed when the mass concentration was 100 mg/L. Our data demonstrated that the removal efficiency was affected by vitamin C concentration, the reaction temperature and the dissolved oxygen concentration.The reaction mechanism of Cr(Ⅵ) by vitamin C was presented. Our study opens the way to use vitamin C to remediate Cr(Ⅵ)-contaminated soils and groundwater.     

数值分析方法与不等式的证明

利用连续函数图象的一些局部性质，结合数值分析方法给出二个不等式的证明：(1)当s∈(0，1]时，成立不等式：(1/4 4^1/s-1/4)^ss≤1．(2)当s∈(0，log54]时，成立不等式：(4^1/s-2)^1-ss≥1．     

“陌生人”视角下社会化媒体与网络社会“不确定性”研究

本研究通过社会心理学的"陌生人"视角,分析了网络陌生人的人际不确定性和情感正向性特征,讨论了陌生人复杂互动如何导致社会化媒体内舆论领袖和议题涌现,并实现情感和信息的极化与放大;再通过"不确定性"的理论视角,讨论这种陌生人复杂互动如何通过社会化媒体间共振、潮涌,导致社会化媒体传播和动员能力的突生性和意外效果,进而生成网络社会的不确定性。     

An Experimental Test of Medical Disclosure and Consent Documentation: Assessing Patient Comprehension,Self-Efficacy,and Uncertainty

Effectively conveying risks and hazards in medical disclosure and informed consent documentation is a crucial type of communication. However, existing protocols typically do not meet the needs of patients or practitioners. In the present study, we advance a reconceptualization of obtaining written informed consent by analyzing it as a process of uncertainty management rather than a matter of document readability and recall. Results of this randomized trial indicated that patients who reviewed a simplified consent document reported greater comprehension of medico-legal terminology and lower uncertainty about the document, although they did not evince greater self-efficacy. Health literacy was a significant moderator of the relationship between consent form version and comprehension.     

A novel reduction of diketones with i-RMgBr catalyzed by Cp<Subscript>2</Subscript>TiCl<Subscript>2</Subscript> and deoxygenation of sulfoxides by Cp<Subscript>2</Subscript>TiCl<Subscript>2</Subscript>/Al system

α-diketones and β-diketones react with Grignard reagents in the presence of a catalytic amount of Cp₂TiCl₂ to yield α-ketols and corresponding ketones respectively. Sulfoxides can be deoxygenated by Cp₂TiCl₂/Al system. The possible mechanisms are also discussed. Project (No. 20072033) supported by the National Natural Science Foundation of China and the Specialized Research Fund for the Doctoral Program of Higher Education Ministry, China     

祁连、焉支山在新疆辩疑(下)

本文在《祁连、焉支山在新疆辩疑(上)》篇的基础上,从分析祁连、焉支山所在河西走廊生态经济特征、战略地位的角度及反证法论证了巴里坤山、哈尔里克山/东天山与汉代史籍中祁连、焉支山无关。     

Contribution of uncertainty in estimation of active drag using assisted towing method in front crawl swimming

Active drag force in swimming can be calculated from a function of five different variables: swim velocity, tow velocity, belt force, power output and exponent of velocity. The accuracy of the drag force value is dependent on the accuracy of each variable, and on the contribution of each variable to drag estimation. To calculate uncertainty in drag value, first the derivatives of the active drag equation with respect to each variable were obtained. Second, these were multiplied by the uncertainty of that variable. Twelve national age and open level swimmers were recruited to complete four free swimming and five active drag trials. The uncertainties for the free and the tow swim velocities, and for the belt force, contributed approximately 5–6% and 2–3% error, respectively, in calculation of drag. The result of the uncertainty of the velocity exponent (1.8–2.6) indicated a contribution of about 6% error in active drag. The contribution of unequal power output showed that if a power changed 7.5% between conditions, it would lead to about 30% error in calculated drag. Consequently, if a swimmer did not maintain constant power output between conditions, there would be substantial errors in the calculation of active drag.     

亚里士多德模态三段论的化归

在现代逻辑看来，亚里士多德实然三段论都可以化归为第一格AAA式。那么，现代逻辑如何看待亚式模态三段论的化归呢?亚式模态三段论可以化归为哪些格式呢?本认为，从联合演算出发，能更精确、更贴近地反映亚式模态三段论的原貌。本的分析表明，亚式模态三段论虽有疏漏，但仍然可以化归为基本的格式，因而自成系统。     

论模糊美及其中介

模糊数学、耗散结构论等自然科学的理论引入到美学中来 ,建立了一门崭新学科———模糊美学。模糊美学研究的对象是模糊美。模糊美的本质在于中介的不确定性 ,即事物与事物 ,事物的两极之间的流动的跨区和中间地带的相互渗透、相互交融、相互转化 ,形成亦此亦彼 ,非此非彼的不确定状态。这种不确定状态中的美 ,就是模糊美。     

对"交换物质影响平衡移动教材稿"的几点补充

着重介绍了"两步法"阐明外物干扰下平衡移动的必要性,讨论了论题关系式推演过程中化归原理的使用步骤等数学技巧问题。