Iodine-catalyzed aerobic oxidation of o-alkylazoarenes to 2H-indazoles

An iodine-catalyzed aerobic-oxidative C-H functionalization of o-alkylazoarenes to afford 2H-indazoles has been developed. CuI was found to be an effective additive to accelerate the regeneration of iodine in the catalytic cycle. This catalytic system is suitable for both electron-rich and electron-deficient azoarenes and tolerates a variety of functional groups with high yields. A gram-scale reaction was successfully conducted, proving the scalability of this reaction.     

A sensitive, rapid ferricyanide-mediated toxicity bioassay developed using Escherichia coli

A need for rapid toxicity techniques has seen recent research into developing new microbiological assays and characterising their toxicity responses using a range of substances. A microbiological bioassay that determines changes in ferricyanide-mediated respiration for toxicity measurement (FM-TOX) shows particular promise. The development and optimisation of an improved FM-TOX method, incorporating novel features, is described using Escherichia coli as the biocatalyst. Omission of an exogenous carbon source, used in previously described FM-TOX assays, substantially improves the assay sensitivity. In addition, the development of a two-step procedure (toxicant exposure followed by determination of microbial respiratory activity) was found to enhance the inhibition of E. coli by 3,5-dichlorophenol and four other toxicants, compared to single-step procedures. Other assay parameters, such as the ferricyanide concentration, exposure times and optical density of the biocatalyst were also optimised, sometimes based on practical aspects. Toxicity tests were carried out using the adopted technique on both organic and inorganic toxicants, with classic sigmoid-shaped dose-response curves observed, as well as some non-standard responses. IC₅₀ data is presented for a number of common toxicants. The optimised assay provides a good foundation for further toxicity testing using E. coli, as well as the potential for expanding the technique to utilise other bacteria with complementary toxicity responses, thereby allowing use of the assay in a range of applications.     

以实验室文化为魂,创新高校实验室管理服务

实验室文化是高校校园文化的重要组成部分,对于营造积极向上、文明和谐的教学和科研环境,树立高校品牌,保持学校可持续发展,具有十分重要的意义.本文给出了营造实验室文化,创新实验室管理服务的几点做法.     

Fritz Reiche and the Emergency Committee in Aid of Displaced Foreign Scholars

I discuss the family background and early life of the German theoretical physicist Fritz Reiche (1883–1969) in Berlin; his higher education at the University of Berlin under Max Planck (1858–1947); his subsequent work at the University of Breslau with Otto Lummer (1860–1925); his return to Berlin in 1911, where he completed his Habilitation thesis in 1913, married Bertha Ochs the following year, became a friend of Albert Einstein (1879–1955), and worked during and immediately after the Great War. In 1921 he was appointed as ordentlicher Professor of Theoretical Physics at the University of Breslau and worked there until he was dismissed in 1933. He spent the academic year 1934–1935 as a visiting professor at the German University in Prague and then returned to Berlin, where he remained until, with the crucial help of his friend Rudolf Ladenburg (1882–1952) and vital assistance of the Emergency Committee in Aid of Displaced Foreign Scholars, he, his wife Bertha, and their daughter Eve were able to emigrate to the United States in 1941 (their son Hans had already emigrated to England in 1939).From 1941–1946 he held appointments at the New School for Social Research in New York, the City College of New York, and Union College in Schenectady, New York, and then was appointed as an Adjunct Professor of Physics at New York University, where his contract was renewed year-by-year until his retirement in 1958.     

如何撰写高水平的《大学化学》教学研究论文

论述了教学研究的重要性和复杂性。提出撰写教学研究论文应符合先进性、创新性、实证性、示范性和发展性等原则。介绍了教学研究涉及的主要领域,研究的主要内容和方法,对如何开展各领域教学研究并撰写高水平的教学研究论文进行了讨论并给出了示例。     

Assortment planning for vertically differentiated products under a consider-then-choose model

Consider-then-choose models, borne out by empirical literature in marketing and psychology, note that customers follow a two-stage procedure to choose among alternatives. In this paper, we consider the assortment optimization problem of a retailer who manages a category of vertically differentiated products under customers’ consider-then-choose behavior. We characterize some structural results of the optimal assortment and find that the problem can be solved as the shortest path problem. Also, we develop an efficient algorithm to identify an optimal assortment.     

Influence of surface relaxation on the IR spectrum of microcrystalline MgO

Relaxation effects on the infrared spectra of microcrystalline MgO prepared under controlled conditions have been studied both by varying the average particle size and by chemisorption of pyndine. The results are compared with the phonon density of states distribution calculated by other authors.     

Reactions of water with carbon and ethylene over illuminated pt/tio2

The room temperature reaction between gas phase water and active carbon to form carbon dioxide and hydrogen on a platinized titanium dioxide catalyst, illuminated with band gap radiation, is reported. Using the same catalyst system, ethylene is converted to ethane, carbon dioxide, hydrogen and a small amount of methane.