Entity

Time filter

Source Type

Hangzhou, China

Zhejiang Sci-Tech University is a university in Zhejiang province provides programs in the fields of engineering, science, humanities , economics, management and law with engineering being its main focus. It is run jointly by Ministry of Education and the Zhejiang provincial government, the latter being the main administrative body. Wikipedia.


Li Q.,Zhejiang Sci-Tech University
IEEE Transactions on Robotics | Year: 2010

Parasitic motion is a major drawback of the general 1T2R parallel mechanism (PM), where T denotes a translation degree of freedom (DOF) and R a rotational DOF. This paper investigates the type synthesis of the 1T2R PM without parasitic motion. First, a brief review on the planar spherical bond and its mechanical generators is presented. Then, the difference between the general and special aT bR motion is discussed. Relations between the parasitic motion and the general and special aTb R motion are revealed. An infinitesimal 1T2R PM with rotation bifurcation is presented as a special case. Further, the definition of the 1T2R PM without parasitic motion is presented, and the limb bond {G(u)}{S(N)} is identified. Geometrical conditions to construct an 1T2R PM without parasitic motion are presented, and nonoverconstrained 1T2R PMs without parasitic motion are synthesized. Idle pairs in the nonoverconstrained 1T2R PMs without parasitic motion are detected. Finally, overconstrained 1T2R PMs without parasitic motion are obtained by removing the idle pairs in the nonoverconstrained 1T2R PMs. © 2010 IEEE. Source


Salvia miltiorrhiza is one of the most important traditional Chinese medicinal plants because of its excellent performance in treating coronary heart disease. Phenolic acids mainly including caffeic acid, rosmarinic acid and salvianolic acid B are a group of active ingredients in S. miltiorrhiza. Abscisic acid (ABA), gibberellin (GA) and ethylene are three important phytohormones. In this study, effects of the three phytohormones and their interactions on phenolic production in S. miltiorrhiza hairy roots were investigated. The results showed that ABA, GA and ethylene were all effective to induce production of phenolic acids and increase activities of PAL and TAT in S. miltiorrhiza hairy roots. Effects of phytohormones were reversed by their biosynthetic inhibitors. Antagonistic actions between the three phytohormones played important roles in the biosynthesis of phenolic acids. GA signaling is necessary for ABA and ethylene-induced phenolic production. Yet, ABA and ethylene signaling is probably not necessary for GA3-induced phenolic production. The complex interactions of phytohormones help us reveal regulation mechanism of secondary metabolism and scale-up production of active ingredients in plants. Source


Xue M.,Zhejiang University | Yang Y.,Zhejiang Sci-Tech University | Chi X.,Zhejiang University | Zhang Z.,Zhejiang University | Huang F.,Zhejiang University
Accounts of Chemical Research | Year: 2012

Because of the importance of novel macrocycles in supramolecular science, interest in the preparation of these substances has grown considerably. However, the discovery of a new class of macrocycles presents challenges because of the need for routes to further functionalization of these molecules and good host-guest complexation. Furthermore, useful macrocylic hosts must be easily synthesized in large quantities. With these issues in mind, the recently discovered pillararenes attracted our attention. These macrocycles contain hydroquinone units linked by methylene bridges at para positions. Although the composition of pillararenes is similar to that of calixarenes, they have different structural characteristics. One conformationally stable member of this family is pillar[5]arene, which consists of five hydroquinone units. The symmetrical pillar architecture and electron-donating cavities of these macrocycles are particularly intriguing and afford them with some special and interesting physical, chemical, and host-guest properties. Due to these features and their easy accessibility, pillararenes, especially pillar[5]arenes, have been actively studied and rapidly developed within the last 4 years.In this Account, we provide a comprehensive overview of pillararene chemistry, summarizing our results along with related studies from other researchers. We describe strategies for the synthesis, isomerization, and functionalization of pillararenes. We also discuss their macrocyclic cavity sizes, their host-guest properties, and their self-assembly into supramolecular polymers. The hydroxyl groups of the pillararenes can be modified at all positions or selectively on one or two positions. Through a variety of functionalizations, researchers have developed many pillararene derivatives that exhibit very interesting host-guest properties both in organic solvents and in aqueous media. Guest molecules include electron acceptors such as viologen derivatives and (bis)imidazolium cations and alkyl chain derivatives such as n-hexane, alkanediamines, n-octyltrimethyl ammonium, and neutral bis(imidazole) derivatives. These host-guest studies have led to the fabrication of (pseudo)rotaxanes or poly(pseudo)rotaxanes, supramolecular dimers or polymers, artificial transmembrane proton channels, fluorescent sensors, and other functional materials. © 2012 American Chemical Society. Source


Wang Y.,Zhejiang Sci-Tech University
Physica Status Solidi - Rapid Research Letters | Year: 2010

Using first-principles calculations, we investigate the electronic properties of two-dimensional hydrogenated and semihydrogenated hexagonal boron nitride (BN) sheets. We find that the hydrogenation effects in BN sheets are quite different from those in the graphene sheets. The hydrogenization changes the band character of BN sheets, which causes the hydrogenated BN sheet having a smaller band gap than the pristine one. While for the semihydrogenated one, the stable B-semihydro BN sheet is a ferromagnetic metal due to the unpaired 2pz electrons of N atoms. Our studies demonstrate that the electronic properties of BN sheets can be well tuned by the hydrogenation. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Liao Z.,Zhejiang Sci-Tech University
Renewable and Sustainable Energy Reviews | Year: 2016

The rapid growth of China's installed wind power capacity in recent years is closely related to the wind energy policies issued by the Chinese government. Using content analysis and quantitative analysis methods, this paper studies the historical evolution of Chinese wind energy policies. Based on 72 wind energy policies issued in the past two decades (1995-2014), this paper analyzes the issuing organization, form, number and stringency of wind energy policies and compares different policy instruments in two periods. The results show that the number and stringency of wind energy policies fluctuated greatly from 1995 to 2014 and that more than twenty organizations had independently or jointly issued the policies. The main organization issuing wind energy policies, however, is the department that controls key economic and administrative resources and not the one that is in charge of wind energy. Of the 72 policies issued, twenty-three took the form of notices, and eleven were measures. As to the policy instrument, environmental policies are most widely applied by the Chinese government, and "regulation control" and "goal-planning" instruments are the ones most frequently adopted. Furthermore, the application of supply- and demand-type policies is inadequate, and few effective instruments have been adopted. © 2015 Elsevier Ltd. All rights reserved. Source

Discover hidden collaborations