Renmin University of China

About: Renmin University of China is a education organization based out in Beijing, Beijing, China. It is known for research contribution in the topics: China & Population. The organization has 11325 authors who have published 15498 publications receiving 238419 citations. The organization is also known as: Renmin University & People's University of China.

Iron-catalyzed tandem oxidative coupling and annulation: an efficient approach to construct polysubstituted benzofurans.

Abstract: The combination of FeCl(3) x 6 H(2)O and di-tert-butyl peroxide offers a novel and efficient method for the construction of polysubstituted benzofurans 3 from the reaction of simple phenols 1 and beta-keto esters 2, which are expected to give coumarins in the well-known Pechmann condensation. A variety of phenols reacted with beta-keto esters to provide a range of benzofuran products in moderate to excellent yields. The regio-specific annulation was proven by the X-ray molecular structure of the product 3k. Hydrate of FeCl(3) is essential for an achievement of the present transformation. The kinetic isotopic effect (KIE) experiments were carried out by competition experiments and displayed a k(H)/k(D) = 1.0 +/- 0.1. The kinetic isotopic effect indicated that aromatic C-H bond cleavage is not involved in the rate-determining steps of the present transformation. Moreover, the results clearly demonstrate that the dichotomous catalytic behavior of the iron catalyst, which is transition-metal catalyst in the oxidative coupling step and Lewis acid in the condensation step. The possible intermediate 5 was synthesized and converted into the desired benzofuran 3a under the reaction conditions. A tentative mechanism of the formation of benzofurans 3 was proposed.

Distributed Aggregate Privacy-Preserving Authentication in VANETs

Abstract: Existing secure and privacy-preserving vehicular communication protocols in vehicular ad hoc networks face the challenges of being fast and not depending on ideal tamper-proof devices (TPDs) embedded in vehicles. To address these challenges, we propose a vehicular authentication protocol referred to as distributedaggregate privacy-preserving authentication. The proposed protocol is based on our new multiple trusted authority one-time identity-based aggregate signature technique. With this technique a vehicle can verify many messages simultaneously and their signatures can be compressed into a single one that greatly reduces the storage space needed by a vehicle or a data collector (e.g., the traffic management authority). Instead of ideal TPDs, our protocol only requires realistic TPDs and hence is more practical.

Corporate Governance in China: A Survey

Abstract: This article surveys corporate governance in China, as described in a growing literature published in top journals. Unlike the classical vertical agency problems in Western countries, the dominant agency problem in China is the horizontal agency conflict between controlling and minority shareholders arising from concentrated ownership structure; thus one cannot automatically apply what is known about the USA to China. As these features are also prevalent in many other countries, insights from this survey can also be applied to countries far beyond China. We start by describing controlling shareholder and agency problems in China, and then discuss how law and institutions are particularly important for China, where controlling shareholders have great power. As state-owned enterprises have their own features, we separately discuss their corporate governance. We also briefly discuss corporate social responsibility in China. Finally, we provide an agenda for future research.

Cloning of mpd gene from a chlorpyrifos-degrading bacterium and use of this strain in bioremediation of contaminated soil

Abstract: An effective chlorpyrifos-degrading bacterium (named strain YC-1) was isolated from the sludge of the wastewater treating system of an organophosphorus pesticides manufacturer. Based on the results of phenotypic features, phylogenetic similarity of 16S rRNA gene sequences and BIOLOG test, strain YC-1 was identified as the genus Stenotrophomonas. The isolate utilized chlorpyrifos as the sole source of carbon and phosphorus for its growth and hydrolyzed chlorpyrifos to 3,5,6-trichloro-2-pyridinol. Parathion, methyl parathion, and fenitrothion also could be degraded by strain YC-1 when provided as the sole source of carbon and phosphorus. The gene encoding the organophosphorus hydrolase was cloned using a PCR cloning strategy based on the known methyl parathion degrading (mpd) gene of Plesiomonas sp. M6. Sequence blast result indicated this gene has 99% similar to mpd. The inoculation of strain YC-1 (10(6) cells g(-1)) to soil treated with 100 mg kg(-1) chlorpyrifos resulted in a higher degradation rate than in noninoculated soils. Theses results highlight the potential of this bacterium to be used in the cleanup of contaminated pesticide waste in the environment.