《电子技术实践》课程“教学做一体”的改革与实践

遵循“能力本位”课程现,以培养应用技能、职业素养、实践能力的高技能人才为目标,以高职学生的基本专业能力和可持续发展能力为核心,基于工作过程的项目教学为突破口,探讨了融“教学做”为一体的高职《电子技术实践》课程改革与实践的实施过程。     

农村中小学《体育与健康》校本课程开发研究

在对《体育与健康》校本课程开发概念进行界定的基础上,对《体育与健康》校本课程开发的影响因素进行了探讨,以期为各个学校进行《体育与健康》校本课程开发提供理论参考.     

基于蓝牙技术的RFID-SIM卡在SQLite中的数据存储过程分析

RFID-SIM卡既具有普通SIM卡一样的移动通讯功能,又能够通过附与其上的天线与读卡器进行近距离无线通信,从而能够扩展至非典型领域,尤其是手机现场支付和身份认证功能.蓝牙技术,实际上是一种低功率短距离无线连接技术,是通过由无线电收发器和链路控制器组成蓝牙芯片进行数据传输的.SQLite是一种轻量级的、嵌入式的关系型数据库.它是采用程序驱动,即由程序调用相应的API来实现数据的存取.其资源占用少,不具有外部依赖性,能直接嵌入到应用程序中,目前已经在Android手机等许多领域中采用.讨论RFID-SIM卡非接触面的无线射频功能通过蓝牙技术在SQLite中进行数据存储的应用,系统研究了整个数据流程.     

Cross-boundary e-government systems: Determinants of performance

This study examines the performance of a cross-boundary e-government system. It draws from studies in the fields of e-government, collaborative public management, and information system success with a focus on inter-organizational information systems to develop a conceptual framework. This framework includes efficiency, effectiveness, and accountability as key performance measures; identifies technical, managerial, and inter-organizational factors for success; and develops hypotheses accordingly. Empirical investigation utilizes user-level data from an inter-organizational e-government system that provides integrated commerce and industry service. The results underscore the importance of management support, shared goals, and inter-agency trust in improving all three measures of performance. In addition, citizen-centric and innovative organizational culture enhances efficiency and accountability while administrative interdependence impacts effectiveness and accountability. The managerial and theoretical implications of these findings and future research opportunities are also explored.     

现代思想政治教育发展动因探讨

在现代社会,思想政治教育不仅没有退出历史舞台,反而得到更为丰富的发展,为我国经济工作、政治工作等社会主义各项事业提供着强大的理论支撑和智力支持。究其原因,思想政治教育的科学性是其理论动因,思想政治教育的政治性是其外部动因,思想政治教育的价值性是其内部动因,思想政治教育的草根性是其社会动因。     

Effect of three cooking methods on nutrient components and antioxidant capacities of bamboo shoot (Phyllostachys praecox C.D. Chu et C.S. Chao)

Three cooking methods, namely boiling, steaming, and stir-frying for 5 to 10 min, were used to evaluate the effect on nutrient components, free amino acids, l-ascorbic acid, total phenolic contents, and antioxidant capacities of bamboo shoots (Phyllostachys praecox). Results showed that boiling and stir-frying had a great effect on the nutrient components and they decreased the contents of protein, soluble sugar, and ash, and caused a great loss in the total free amino acids (decreased by 38.35% and 34.86%, respectively). Significant differences (P<0.05) in free amino acids were observed in the samples cooked by different methods. Stir-fried bamboo shoots had a high fat content which increased by 528.57% because of the addition of edible oil. After boiling, the L-ascorbic acid and total phenolic contents were significantly reduced, while steaming increased total phenolic content by 3.98% and stir-frying well-preserved L-ascorbic acid (78.87% of its previous content). Results of the antioxidative property study showed that stir-frying could increase antioxidant capacities of bamboo shoots. It is concluded that stir-frying is more suitable for bamboo shoots because it could obtain the maximum retention of antioxidant capacities.     

Polyethylenimine-cyclodextrin-tegafur conjugate shows anti-cancer activity and a potential for gene delivery

Polyethylenimine-cyclodextrin-tegafur (PEI-CyD-tegafur) conjugate was synthesized as a novel multifunctional prodrug of tegafur for co-delivery of chemotherapeutic agent tegafur and enhanced green fluorescent protein (EGFP) reporter plasmid DNA. Conjugation of tegafur to PEI-CyD via chemical linkage was characterized by ¹H NMR spectrometry and ultraviolet (UV) spectrometry. PEI-CyD-tegafur was able to condense plasmid DNA into complexes of around 150 nm with positive charge at the N/P ratio of 25, in accordance with electron microscopy observation of compact and monodisperse nanoparticles. The results of in vitro experiments showed enhanced cytotoxicity and considerable transfection efficiency in B16F10 cell line. Therefore, PEI-CyD-tegafur may have great potential as a co-delivery system with anti-cancer activity and potential for gene delivery.     

Effect of epidermal growth factor on follicle-stimulating hormone-induced proliferation of granulosa cells from chicken prehierarchical follicles

The development of ovarian follicular cells is controlled by multiple circulating and local hormones and factors, including follicle-stimulating hormone (FSH) and epidermal growth factor (EGF). In this study, the stage-specific effect of EGF on FSH-induced proliferation of granulosa cells was evaluated in the ovarian follicles of egg-laying chickens. Results showed that EGF and its receptor (EGFR) mRNAs displayed a high expression in granulosa cells from the prehierarchical follicles, including the large white follicle (LWF) and small yellow follicle (SYF), and thereafter the expression decreased markedly to the stage of the largest preovulatory follicle. SYF represents a turning point of EGF/EGFR mRNA expression during follicle selection. Subsequently the granulosa cells from SYF were cultured to reveal the mediation of EGF in FSH action. Cell proliferation was remarkably increased by treatment with either EGF or FSH (0.1–100 ng/ml). This result was confirmed by elevated proliferating cell nuclear antigen (PCNA) expression and decreased cell apoptosis. Furthermore, EGF-induced cell proliferation was accompanied by increased mRNA expressions of EGFR, FSH receptor, and the cell cycle-regulating genes (cyclins D1 and E1, cyclin-dependent kinases 2 and 6) as well as decreased expression of luteinizing hormone receptor mRNA. However, the EGF or FSH-elicited effect was reversed by simultaneous treatment with an EGFR inhibitor AG1478. In conclusion, EGF and EGFR expressions manifested stage-specific changes during follicular development and EGF mediated FSH-induced cell proliferation and retarded cell differentiation in the prehierarchical follicles. These expressions thus stimulated follicular growth before selection in the egg-laying chicken.     

探析当前计算机网络安全的现状与防范

随着计算机技术的飞速发展和全球信息化趋势的不可避免,计算机网络安全问题日渐成为世界各国所面临的主要问题之一。网络的开放性和自由性也产生了私有信息和数据被破坏或侵犯的可能性,网络信息的安全性变得日益重要起来,已被信息社会的各个领域所重视。针对目前计算机网络存在的安全隐患,防范策略分析研究有着重要意义。     

Lumped parameter model for resonant frequency estimation of a thermoacoustic engine with gas-liquid coupling oscillation

Gas-liquid coupling oscillation is a novel approach to reducing the resonant frequency and to elevating the pressure amplitude of a thermoacoustic engine. If a thermoacoustic engine is used to drive low-frequency pulse tube refrigerators, the frequency matching between the thermoacoustic engine and the refrigerator plays an important role. Based on an acoustic-electric analogy, a lumped parameter model is proposed to estimate the resonant frequency of a standing-wave thermoacoustic engine with gas-liquid coupling oscillation. Furthermore, a simplified lumped parameter model is also developed to reduce the computation complexity. The resonant frequency dependence on the mean pressure, the gas space volume, and the water column length is computed and analyzed. The impact of different working gases on the resonant frequency is also discussed. The effectiveness of the models is validated by comparing the computed results with the experimental data of the gas-liquid coupling oscillation system. An increase in the mean working pressure can lead to a rise in the resonant frequency, and a lower resonant frequency can be achieved by elongating the liquid column. In comparison with nitrogen and argon, carbon dioxide can realize a lower frequency due to a smaller specific heat ratio.