摘要：This study presents a simple and robust three-dimensional human hepatic tissue model to emulate steatotic and fibrotic conditions and provide an in vitro model for drug testing and mechanistic *** a photolithographic biofabrication method with a photomask featuring hexagonal units,liver cells,including a human hepatic cell line(HepG2-C3A)and a human hepatic stellate cell line(LX-2)were embedded in gelatin methacryloyl *** steatosis was induced by supraphysiological concentration of free fatty acids;hepatic fibrosis was induced by transforming growth factor-β*** of steatosis was confirmed by Oil Red O and BODIPY staining and was inhibited with toyocamycin and obeticholic *** of fibrosis was confirmed by immunostaining for collagen type I and alpha smooth muscle actin and inhibited by rapamycin and curcumin *** model was further preliminarily validated using primary human hepatocytes in a similar *** constructs provide a viable,biologically relevant,and higher throughput model of hepatic steatosis and fibrosis and may facilitate the study of the mechanisms of disease and testing of liver-directed drugs.

摘要：建立较为精确的磁流变减振器阻尼力模型是设计控制策略并获得良好控制效果的关键。基于流体动力学理论和磁流变液流变特性,对阻尼通道内磁流变液进行流体动力学分析,详细推导磁流变减振器阻尼力模型。结合阻尼通道处磁场有限元分析,完善阻尼力模型。最后试验测试自制磁流变减振器在不同励磁电流和不同活塞速度下的示功特性和速度特性,利用试验数据对模型进行系数辨识,建立磁流变减振器简化力学模型。研究结果表明,励磁电流小于0.8 A时,输出阻尼力试验值与计算值较吻合,当励磁电流增大,阻尼力试验值与计算值最大相差约100 N,计算值相对于试验值的误差在19%以内,该简化力学模型能描述磁流变减振器的基本力学特性,能为半主动悬架控制研究提供理论指导。

摘要：A magnetic bar carbon paste electrode （MBCPE） modified with Fe3O4 magnetic nanoparticles （Fe3O4NPs） and 2‐（3,4‐dihydroxyphenyl） benzothiazole （DPB） for the electrochemical determina‐tion of hydrazine was developed. The DPB was firstly self‐assembled on the Fe3O4NPs, and the re‐sulting Fe3O4NPs/DPB composite was then absorbed on the designed MBCPE. The MBCPE was used to attract the magnetic nanoparticles to the electrode surface. Owing to its high conductivity and large effective surface area, the novel electrode had a very large current response for the electrocat‐alytic oxidation of hydrazine. The modified electrode was characterized by voltammetry, scanning electron microscopy, electrochemical impedance spectroscopy, infrared spectroscopy, and UV‐visible spectroscopy. Voltammetric methods were used to study the electrochemical behaviour of hydrazine on MBCPE/Fe3O4NPs/DPB in phosphate buffer solution （pH = 7.0）. The MBCPE/Fe3O4NPs/DPB, acting as an electrochemical sensor, exhibited very high electrocatalytic activity for the oxidation of hydrazine. The presence of DPB was found to reduce the oxidation potential of hydrazine and increase the catalytic current. The dependence of the electrocatalytic current on the hydrazine concentration exhibited two linear ranges, 0.1–0.4 μmol/L and 0.7–12.0 μmol/L, with a detection limit of 18.0 nmol/L. Additionally, the simultaneous determination of hydrazine and phe‐nol was investigated using the MBCPE/Fe3O4NPs/DPB electrode. Voltammetric experiments showed a linear range of 100–470 μmol/L and a detection limit of 24.3 μmol/L for phenol, and the proposed electrode was applied to the determination of hydrazine and phenol in water samples.

摘要：The International Telecommunications Union （ITU-T） and the International Standardization Organization/International Electrotechnical Commission （ISO/IEC） are the only two formal organizations that developed video coding standards. The ITU-T video coding standards called recommendations and are usually optimized for real-time video communication such as videoconference and video telephony while the ISO/IEC standards are mainly designed for storage （DVD） and broadcast （satellite and digital TV）. ITU-T and the ISO/IEC JTC1 have agreed to join their efforts in the development of H.264 standard, which was initiated by ITU-T committee. The ITU-T H.264 video coding standard has been developed to achieve significant improvements over the existing standards in compression performance, although the basic coding framework of the standard is similar to that of the existing standards. H.264 standard is compared with H.263 and test results showed the coding gains obtained by the H.264 encoder is over the H.263 encoder for Common Intermediate Format （CIF） and Quarter Common Intermediate Format （QCIF）sequences, respectively. H.264 achieves an average of 4 dB PSNR（peak signal-to-noise rate） gain for the selected ten CIF sequences at 30 frames per second, and 4.57 dB Peak Signal-to-Noise Rate （PSNR） gain for the selected ten QCIF sequences at 30 frames per second.

摘要：飞行控制设计的最新进展提高了复杂自主飞行器完成各类任务的能力.在各类垂直起降飞行器中,涵道风扇飞行器(DFAVs)是一种非常重要的尾座式飞行器,其运动和驱动部件由称为涵道的环形机身所屏蔽.这一结构使得其能够很好地保护飞行器自身和操作人员的安全,让飞行器能够在狭窄、杂乱和危险的环境中飞行.此外,DFAVs具有固定翼飞机和直升机的特点,能够同时展现它们的优良特性,如长时居高监视能力和大有效载荷能力.本文是关于DFAVs的第1篇综述论文,旨在概述与其相关的几个方面的最新进展.首先,综述了世界范围内开发的此类飞行平台的历史与分类,并总结了它们的优缺点.然后,介绍了用于控制这些飞行器的多种控制方法.最后,给出总结,并讨论了现存的挑战,以及新的研究趋势.

摘要：通行能力预测是公路设施规划、设计与运营中的基础环节.本文基于埃及曼努菲亚省12条农村双车道路段数据,研究了公路线形等几何特征对通行能力的影响以及线形由切线变为平曲线时通行能力的损失.所选取的路段线形包括直线和随后的平曲线.同时,采集了各路段上车流量及速度数据,利用基于基本图的外推法研究流量和密度关系.路段上不同车型的车辆均转换为小客车当量.此外,针对不同情形(切线、平曲线及对应流量损失),分别建立了最佳回归模型.结果表明,切线型道路的关键自变量是路宽、肩宽以及切线长;平曲线道路的关键变量是曲线半径和路宽.通行能力和几何特征关系最佳模型的自变量为曲线半径.本文的模型可用于分析评价农村双车道道路的通行能力,尤其是评价文中所研究路段的通行能力.

摘要：We propose a polarization-insensitive design of a hybrid plasmonic waveguide(HPWG)optimized at the 3.392µm wavelength which corresponds to the absorption line of methane *** waveguide design is capable of providing high mode sensitivity(Smode)and evanescent field ratio(EFR)for both transverse electric(TE)and transverse magnetic(TM)hybrid *** modal analysis of the waveguide is performed via 2-dimension(2D)and 3-dimension(3D)finite element methods(FEMs).At optimized waveguide parameters,Smode and EFR of 0.94 and 0.704,can be obtained for the TE hybrid mode,respectively,whereas the TM hybrid mode can offer Smode and EFR of 0.86 and 0.67,*** TE and TM hybrid modes power dissipation of~3 dB can be obtained for a 20-µm-long hybrid plasmonic waveguide at the 60%gas *** believe that the highly sensitive waveguide scheme proposed in this work overcomes the limitation of the polarization controlled light and can be utilized in gas sensing applications.

摘要：高质量材料的使用以及土层的处理是保持建筑结构稳定并保证其设计寿命的重要因素,尤其是在垫层较差的地区。对未加筋、土工格栅加筋和折叠土工格栅加筋细砂上方的条形基础进行试验研究,以评估平面土工格栅层数、折叠土工格栅在土中的位置、土工格栅折叠层的厚度、折叠土工格栅的搭接长度、土工格栅折叠层的间距以及土工格栅的层数等因素的影响。与平面土工格栅加筋砂相比,折叠土工格栅加筋砂在静载作用下的性能更好。此外,在基础下方一定深度处存在一个临界区域。在该区域内,折叠土工格栅会导致基础沉降量增加。这一临界区域会影响较小基础宽度处的砂土特性。试验结果表明,折叠土工格栅的最优埋置深度为基础宽度的0.41,厚度为基础宽度的0.20。增加折叠土工格栅的层数可以明显减少沉降比。该试验表明,包裹式加筋可以显著提高结构框架的承载能力,减少沉降,并使得它们可以在狭小的空间中使用。

摘要：对含矩形边缘分层缺陷层合板的压缩性能进行试验研究和理论分析,考察了层合板厚度(含铺层形式)、分层位置、形状、面积以及环境等因素对压缩强度的影响,并采用分层扩展以及软化夹杂两种模型对含分层层合板的压缩强度进行了计算和破坏机理分析。结果表明:厚板对边缘分层缺陷不敏感,中等厚度和薄层合板比较敏感;缺陷的位置和形状对层合板压缩强度有一定的影响;湿热环境改变了含缺陷板的压缩破坏机理,并对中等厚度板和薄板的压缩强度有明显的影响。两种模型中软化夹杂模型效果较好,可用于工程设计计算。

摘要：家具体现人类在物质、精神层面的追求,同时也是历史文化的载体。中国是四大文明古国之一,叙利亚大马士革是世界最古老的首都,两国都有悠久的历史,两国传统家具受各自文化影响,在不同时期呈现不同的面貌与民族特点。本文从设计的角度进行中叙家具民族性文化比较研究,考察民族性对两国传统家具设计的影响,研究两国传统家具的异同,总结两国在传统家具设计方面的优势,取长补短,探讨中叙两国在现代家具发展道路上的方向。