AN EFFICIENT SOLUTION OF THE ELASTIC MECHANISM NON-LINEAR DIFFERENTIAL EQUATION OF MOTION

ABSTRACT A general form of non-linear differential motion equations for the elastic mechanism is presented. Based on the analysis of the structure property of the equations, a numerical solution method which combines the State Space Method with Iterative Method is put forward. The solution efficiency and precision are improved greatly through analyzing the solution method of the matrix exponent function and the equations with belt shape and side block coefficient matrices. Finally, as an example, the dynamic properties of a mold oscillation mechanism with 4-eccentric axes for continuous casting machine are analyzed. The results illustrate the correctness and feasibility of the method

WTC2005-63258 RESEARCH ON THE IDENTIFICATION METHODS OF FRICTION IN KINEMATICAL JOINTS OF MECHANICAL SYSTEMS

ABSTRACT This paper describes two approaches for the simultaneous identification of the coulomb and viscous parameters in kinematical joints. One is a time-domain method (TDM) and the other is a frequency-domain method (FDM). Simulation shows that both of the two methods have good performances in identifying friction at high SNR (90dB). But at low SNR (20dB), the estimation accuracy of the frequency-domain method is higher than that of the time-domain method. A field experiment employing a linkage mechanism driven by motor is also carried out. The experimental results obtained by the two approaches are almost identical under different experiment conditions. It has been concluded that the presented identification methods of friction in kinematical joints are correct and applicable. INTRODUCTION Kinematical joint is an absolutely necessary structural connection in mechanical systems. The kinematical joint is responsible for transferring energy to a remote site, and may change the type of motion, as needed. The characteristics of kinematical joints have been studied in many paper

A Novel Kunitzin-Like Trypsin Inhibitor Isolated from Defensive Skin Secretion of Odorrana versabilis

Protease inhibitors that were identified from amphibian skin secretions with low molecular weights and potent inhibitory activity were thought to be potential candidates for novel peptide drugs. Here, a novel peptide with trypsin inhibitory activity was found in the skin secretion of the Chinese bamboo leaf odorous frog, Odorrana versabilis. Based on the sequence alignments of sequencing results, the novel peptide (ALKYPFRCKAAFC) was named as Kunitzin-OV. The synthetic replicate of Kunitzin-OV was subjected to a series of functional assays, and it exhibited a trypsin inhibitory activity with a Ki value of 3.042 µM, whereas, when Lys-9 at P1 position was substituted by Phe, trypsin inhibitory activity was undetected and the chymotrypsin inhibitory activity was optimized with a Ki value of 2.874 µM. However, its protease-binding loop was catabolized by trypsin during the trypsin cleavage test. In conclusion, Kunizin-OV is a novel peptide with trypsin inhibitory activity as a member of kunitzins, which is a non-typical Kunitz-like trypsin inhibitor with a highly conserved reactive site (K-A) and quite a short sequence

A Novel Bradykinin-Related Peptide, RVA-Thr6-BK, from the Skin Secretion of the Hejiang Frog; Ordorrana hejiangensis: Effects of Mammalian Isolated Smooth Muscle

A novel naturally-occurring bradykinin-related peptide (BRP) with an N-terminal extension, named RVA-Thr6-Bradykinin (RVA-Thr6-BK), was here isolated and identified from the cutaneous secretion of Odorrana hejiangensis (O. hejiangensis). Thereafter, in order to evaluate the difference in myotropic actions, a leucine site-substitution variant from Amolops wuyiensis skin secretion, RVA-Leu1, Thr6-BK, was chemically synthesized. Myotropic studies indicated that single-site arginine (R) replacement by leucine (L) at position-4 from the N-terminus, altered the action of RVA-Thr6-BK from an agonist to an antagonist of BK actions on rat ileum smooth muscle. Additionally, both BK N-terminal extended derivatives (RVA-Thr6-BK and RVA-Leu1, Thr6-BK) exerted identical myotropic actions to BK, such as increasing the frequency of contraction, contracting and relaxing the rat uterus, bladder and artery preparations, respectively

WTC2005-63258 RESEARCH ON THE IDENTIFICATION METHODS OF FRICTION IN KINEMATICAL JOINTS OF MECHANICAL SYSTEMS

ABSTRACT This paper describes two approaches for the simultaneous identification of the coulomb and viscous parameters in kinematical joints. One is a time-domain method (TDM) and the other is a frequency-domain method (FDM). Simulation shows that both of the two methods have good performances in identifying friction at high SNR (90dB). But at low SNR (20dB), the estimation accuracy of the frequency-domain method is higher than that of the time-domain method. A field experiment employing a linkage mechanism driven by motor is also carried out. The experimental results obtained by the two approaches are almost identical under different experiment conditions. It has been concluded that the presented identification methods of friction in kinematical joints are correct and applicable. INTRODUCTION Kinematical joint is an absolutely necessary structural connection in mechanical systems. The kinematical joint is responsible for transferring energy to a remote site, and may change the type of motion, as needed. The characteristics of kinematical joints have been studied in many paper

A portable, auxiliary photovoltaic power system for electric vehicles based on a foldable scissors mechanism

In recent years, countries worldwide have actively advocated electric vehicles for environmental protection. However, restrictions on the driving range and charging have hampered the promotion of electric vehicles. This study proposes a portable, auxiliary photovoltaic power system based on a foldable scissors mechanism for electric vehicles. The system includes a photovoltaic power generation module and an electricity transfer module. The photovoltaic power generation module built based on a foldable scissors mechanism is five times smaller than in its unfolded state, improving its portability in its folded state. The electricity transfer module transfers electricity into the cabin via wireless power transfer units and stores electricity in supercapacitors. Solar simulation experiments were conducted to evaluate the system's performance: maximum output power of 1.736 W is measured when the load is 5 Ω, while maximum wireless power transfer efficiency is up to 57.7% with 10 Ω load. An electric vehicle in Chengdu city was simulated for a case study. The results show that the annual output of a single photovoltaic power system can drive the MINIEV for 423.625 km, indicating that the proposed system would be able to supply power for electric vehicles as an auxiliary power supply system

A Quantitative Framework to Evaluate Modeling of Cortical Development by Neural Stem Cells

Neural stem cells have been adopted to model a wide range of neuropsychiatric conditions in vitro. However, how well such models correspond to in vivo brain has not been evaluated in an unbiased, comprehensive manner. We used transcriptomic analyses to compare in vitro systems to developing human fetal brain and observed strong conservation of in vivo gene expression and network architecture in differentiating primary human neural progenitor cells (phNPCs). Conserved modules are enriched in genes associated with ASD, supporting the utility of phNPCs for studying neuropsychiatric disease. We also developed and validated a machine learning approach called CoNTExT that identifies the developmental maturity and regional identity of in vitro models. We observed strong differences between in vitro models, including hiPSC-derived neural progenitors from multiple laboratories. This work provides a systems biology framework for evaluating in vitro systems and supports their value in studying the molecular mechanisms of human neurodevelopmental disease