608 research outputs found

    The Value Orientation of the Governance of Teaching Quality for Vocational Education

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    The governance of modern vocational education’s teaching quality is regarded as a unity of value orientation for the value goal of variants-mixed teaching quality , the value judgment of multi-direction-accreting teaching quality governance, and the value choice of multi-dimension-integrated teaching quality governance. Respectively, they are demonstrated as a variants-mixed target system of quality governance featuring results, efficiency, benefits, efficacy and effects; an advantage integration conforming to needs, purposes, standards, and development nature re

    Study on barrel vibration characteristics of typical sniper rifle

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    The firing accuracy of sniper rifle is significantly affected by the barrel vibration induced by shooting load. The barrel vibration is an important parameter needing to be precisely controlled, whose measurement is less studied before. The vertical vibration characteristics of sniper rifle barrel is obtained for the duration of 500 ms with high speed photography system. Both the averaged vibration frequency and maximum amplitude of the measured muzzle are gained. It is found from the test that after the appearance of the maximum value, the vibration amplitude of the muzzle reduces with nearly fixed vibration frequency. In addition, the finite element model is conducted for the barrel vibration regarding sniper rifle. And then the natural frequency as well as the vibration reflection of the barrel under the effort of shooting load is calculated with the model. The model accuracy is well validated for the numerical results are substantially in line with the measurements

    Modeling and simulation study of electromechanically system of the human extremity exoskeleton

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    In order to design a suitable control scheme for human extremity exoskeleton, the interaction force control scheme which regards human body as the work environment of human extremity exoskeleton was proposed. And then, the electromechanical system of human extremity exoskeleton was simplified, and the modeling and simulation study of the electromechanical system by using Matlab/Simulink module was carried out. The angular deviations between human extremity exoskeleton joints and human body joints were obtained by the simulation. Besides, the torques provided by human body and motors for human extremity exoskeleton joints to bear heavy payload were calculated. The analysis of the simulation calculation results proves that the interaction force control scheme can achieve good man-machine coordinated walking as well as help human body bear heavy payload. Besides, the upper extremity exoskeleton experiment was conducted, and the same conclusion with the simulation study was obtained

    Exogenous High-Mobility Group Box 1 Protein Injection Improves Cardiac Function after Myocardial Infarction: Involvement of Wnt Signaling Activation

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    Exogenous high-mobility group box 1 protein (HMGB1) injection could prevent left ventricular remodeling and enhance left ventricular function during myocardial infarction (MI). However, the mechanism remains unclear. This paper was to investigate in the mechanism of cardioprotection of HMGB1 during MI in rats. Anesthetized male rats were treated once with HMGB1 (200 ng) 4 h after MI and then executed after 7 and 28 days, respectively. Cardiac function, collagen deposition, and dishevelled-1 and β-catenin protein expression were measured. After MI 7 days or 28 days, the left ventricular ejection fraction (LVEF) was significantly decreased compared to that of sham-operated control group (P < 0.05). However, the LVEF HMGB1-treated groups were significantly higher compared to those of the MI group in both 7 days and 28 days (P < 0.05). The collagen volume fraction was significantly reduced in the HMGB1-treated group in infarcted border zone. HMGB1 could activate the expression of dishevelled-1 and β-catenin proteins (P < 0.05). Our study suggested that exogenous high-mobility group box 1 protein injection improves cardiac function after MI, which may be involved in Wnt/β-catenin signaling activation

    Incentives, Positive Emotions and SWOM Intention: Moderating Roles of Allocation Type and Emotion Regulation

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    With the increasing popularity of social networking sites (SNS), companies are adopting monetary incentives to generate eWOM on SNS (SWOM). Drawing on emotion and equity theories, this study explores effects of perceived magnitude of monetary incentives and emotions on consumer SWOM intention. In addition, this study investigates the moderating effects of allocation types of rewards (positive inequity and negative inequity) and emotion regulation (reappraisal and suppression emotion regulation) on these relationships. An online situational experiment was conducted and yielded valid responses from 193 WeChat users in China. With the preliminary data, we tested the direct, mediation, and moderation effects using SmartPLS 3.0. The empirical results show that (1) perceived monetary incentives have a positive effect on SWOM intention; (2) positive emotions of senders mediates the relationship between incentives and SWOM intention; (3) negative-inequity incentives negatively moderates the relationship between incentives and positive emotion, while the moderating effect of positive-inequity incentives is insignificant on the relationship between incentives and positive emotion; (4) reappraisal emotion regulation strengthens the effect of positive emotion on SWOM intention, whereas the moderating effect of suppression emotion regulation between positive emotion and SWOM intention is not statistically significant

    Optimizing plant transporter expression in Xenopus oocytes

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    BACKGROUND: Rapid improvements in DNA synthesis technology are revolutionizing gene cloning and the characterization of their encoded proteins. Xenopus laevis oocytes are a commonly used heterologous system for the expression and functional characterization of membrane proteins. For many plant proteins, particularly transporters, low levels of expression can limit functional activity in these cells making it difficult to characterize the protein. Improvements in synthetic DNA technology now make it quick, easy and relatively cheap to optimize the codon usage of plant cDNAs for Xenopus. We have tested if this optimization process can improve the functional activity of a two-component plant nitrate transporter assayed in oocytes. RESULTS: We used the generally available software (http://www.kazusa.or.jp/codon/; http://genomes.urv.es/OPTIMIZER/) to predict a DNA sequence for the plant gene that is better suited for Xenopus laevis. Rice OsNAR2.1 and OsNRT2.3a DNA optimized sequences were commercially synthesized for Xenopus expression. The template DNA was used to synthesize cRNA using a commercially available kit. Oocytes were injected with cRNA mixture of optimized and original OsNAR2.1 and OsNRT2.3a. Oocytes injected with cRNA obtained from using the optimized DNA template could accumulate significantly more NO(3)(-) than the original genes after 16 h incubation in 0.5 mM Na(15)NO(3). Two-electrode voltage clamp analysis of the oocytes confirmed that the codon optimized template resulted in significantly larger currents when compared with the original rice cDNA. CONCLUSION: The functional activity of a rice high affinity nitrate transporter in oocytes was improved by DNA codon optimization of the genes. This methodology offers the prospect for improved expression and better subsequent functional characterization of plant proteins in the Xenopus oocyte system

    An Improved Scale-Adaptive Simulation Model for Massively Separated Flows

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    Modeling and simulation study of electromechanically system of the human extremity exoskeleton

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    In order to design a suitable control scheme for human extremity exoskeleton, the interaction force control scheme which regards human body as the work environment of human extremity exoskeleton was proposed. And then, the electromechanical system of human extremity exoskeleton was simplified, and the modeling and simulation study of the electromechanical system by using Matlab/Simulink module was carried out. The angular deviations between human extremity exoskeleton joints and human body joints were obtained by the simulation. Besides, the torques provided by human body and motors for human extremity exoskeleton joints to bear heavy payload were calculated. The analysis of the simulation calculation results proves that the interaction force control scheme can achieve good man-machine coordinated walking as well as help human body bear heavy payload. Besides, the upper extremity exoskeleton experiment was conducted, and the same conclusion with the simulation study was obtained
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