城市创新生态系统评价指标探索

开展城市创新生态系统的评价可以更好地把握城市创新生态系统的发展方向和水平, 从而进行科学、合理 的决策。对评价的指标体系进行框架研究,我们是建立在生态学的理论基础之上的,通过NDMEFE模型分析,从活力 动力系统、自组织系统、平衡系统的几个维度,探讨适合生态化的城市创新驱动发展特点的评价指标体系框架,并对 上海创新生态系统评价进行展望,提出建议。     

从《京华烟云》中译本看张振玉的翻译思想

张振玉是一位杰出的台湾翻译家。他翻译的林语堂长篇小说《京华烟云》受到广泛的欢迎。在语言风格上,张振玉巧妙地运用白话文和文言文,文而不古,白而不俗;文化策略上张振玉不仅翻译出原文写明的事物,还补充了没有写明的事物,曲尽原意,并且删略了原文的纯解释性文字。试借《京华烟云》,来初步探析张振玉的翻译思想。     

独立学院艺术专业大学英语教学改革新思路

拟从独立学院艺术专业大学英语教学现状入手,说明了在独立学院艺术专业实行大学英语分级教学改革的必要性,并以大连理工大学城市学院艺术专业大学英语分级教学改革为蓝本,剖析了实行分级教学改革过程中出现的问题,提出任务型教学法和以内容为依托的教材编写方案。希望社会各界更多地关注高校艺术专业大学英语教学,在教学改革、教材编写上予以支持。     

RFID技术在起重机检验中的应用探讨

首先对RFID技术进行了介绍,包括其定义、组成及工作原理,然后对其应用现状进行了阐述。最后结合特种设备中的起重机检验,对RFID技术在特种设备检验中的应用进行了探讨。     

Ds-echinoside A, a new triterpene glycoside derived from sea cucumber, exhibits antimetastatic activity via the inhibition of NF-κB-dependent MMP-9 and VEGF expressions

Ds-echinoside A (DSEA), a non-sulfated triterpene glycoside, was isolated from the sea cucumber Pearsonothuria graeffei. In vitro and in vivo investigations were conducted on the effects of DSEA on tumor cell adhesion, migration, invasion, and angiogenesis. In this study, we found that DSEA inhibited the proliferation of human hepatocellular liver carcinoma cells Hep G2, with a half-maximal inhibitory concentration (IC₅₀) of 2.65 μmol/L, and suppressed Hep G2 cell adhesion, migration, and invasion in a dose-dependent manner. DSEA also reduced tube formation of human endothelial cells ECV-304 on matrigel in vitro and attenuated neovascularization in the chick embryo chorioallantoic membrane (CAM) assay in vivo. Immunocytochemical analysis revealed that DSEA significantly decreased the expression of matrix metalloproteinase-9 (MMP-9), which plays an important role in the degradation of basement membrane in tumor metastasis and angiogenesis. DSEA also increased the protein expression level of tissue inhibitor of metalloproteinase-1 (TIMP-1), an important regulator of MMP-9 activation. From the results of Western blotting, the expressions of nuclear factor-kappa B (NF-κB) and vascular endothelial growth factor (VEGF) were found to be remarkably reduced by DSEA. These findings suggest that DSEA exhibits a significant antimetastatic activity through the specific inhibition of NF-κB-dependent MMP-9 and VEGF expressions.     

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.     

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.     

Smart elasto-magneto-electric （EME） sensors for stress monitoring of steel structures in railway infrastructure

Steel structures are widely used in railway infrastructures. Their stress state is the most important determinant of the safety of these structures. The elasto-magnetic (EM) sensor is the most promising for stress monitoring of in-service steel structures. Nevertheless, the necessity of magnetic excitation to saturation due to the use of a secondary coil for signal detection, keeps from its engineering application. In this paper, a smart elasto-magneto-electric (EME) sensor using magneto-electric (ME) sensing units to take the place of the secondary coil has been exploited for the first time. The ME sensing unit is made of ME laminated composites, which has an ultrahigh ME voltage coefficient and can measure the magnetic induction simply and precisely. Theoretical analysis and characterization experiments firstly conducted on the ME laminated composites showed that the ME sensing units can be applied in the EM sensor for improved performance in stress monitoring. A tension test of a steel bar was carried out to characterize our smart EME sensor and the results showed high accuracy and sensitivity. The present smart EME sensor is a promising tool for stress monitoring of steel structures in railway and other civil infrastructures.     

环境工程专业模型嵌入式实验教学改革与实践

为保障新建本科院校高级应用型人才的培养质量,针对环境工程实验教学中普遍存在的问题,构建了模型嵌入式实验教学体系。以重庆文理学院环境工程专业为例,介绍了模型嵌入式实验教学体系的特点和运行过程,提出并实施了该教学体系的几点保障措施,取得了一定的实践教学成效。     

校园精神文化弘扬社会主义核心价值观的现实路径——以阿克苏市高级中学为例

社会主义核心价值观乃育人之本,推动着校园精神文化的内涵式生长。文章以阿克苏市高级中学为例,阐述了社会主义核心价值观与校园精神文化深度融合的现实路径,如以校训为精神代表的治学理念、"教师领导力"理念实践、彰显学校价值取向的校园行为文化活动等。