浅析英法哥特建筑的发展

哥特式建筑于11世纪开始登上历史舞台,它在这个舞台上闪耀了8个世纪,也影响了整个欧洲乃至全世界的建筑风格。文章就英法两国哥特式建筑风格在不同历史背景下的发展和形成原因进行对比分析,并挖掘其历史成因和文化内涵。     

MEMS 姿态传感器在边坡表面位移监测的应用研究

水电站库区两岸边坡地质状况复杂多变,边坡的稳定工作状态与水电站的安全运行息息相关,本文在雅砻江官地水电站库区左岸边坡覆盖层处,将MEMS姿态传感器(陀螺仪和加速度计)按照阵列方式布置在边坡上,建立边坡稳定状态数据实时采集系统,利用初始对准确定导航目标参数姿态、方位、速度和位置的初始值,计算出目标姿态矩阵,再通过姿态矩阵实时将MEMS姿态传感器获取的载体系下的加速度和角速度转换到导航系下,用于实时计算边坡变化姿态矩阵和位移开展试验研究。试验结果表明,将MEMS姿态传感器应用到边坡位移监测中能够实现边坡表面位移数据的实时获取,位移数据获取精度能够达到毫米级,满足工程实际使用需求,该项研究成果对边坡表面位移稳定状态进行实时监测分析具有十分重要的意义。     

Lower down both ohmic and cathode polarization resistances of solid oxide fuel cell via hydrothermal modified gadolinia doped ceria barrier layer

Hydrothermal reaction in Cerium and Gadolinium solution as an optimization method is developed and first reported for the densification of gadolinia doped ceria, the barrier layer between Zirconia electrolyte and (La,Sr)(Co,Fe)O_3-δ cathode. This method is based on the hydrothermal reaction for nano particles in-situly grown on porous surface, to improve barrier layer density, alongside the sintering of cathode at 1075 °C. As a result, the ohmic resistance is prominently decreased by ～16.4 % at 750 °C for electrolyte supported symmetrical cell. Whereas, the cathode polarization resistance is decreased by as much as a factor of ～3 from 0.3702 Ω·cm² to 0.1325 Ω·cm² at 750 °C and $p_{O_2}=0.21atm$. Furthermore, the anode supported cell exhibits higher open circuit voltage, smaller area specific resistance, elevated performance output and less degradation. And this modified barrier layer shows reduced Sr migration in 300 h operation at 750 °C. The hydrothermal reaction is demonstrated to prepare denser and sintering-active barrier layer with faster oxygen ion transfer and better interface connection, with large-scale application prospects and cost-competitiveness.     

Fabrication of three-dimensional mPEG-PCL-mPEG scaffolds combined with cell-laden gelatin methacrylate (GelMA) hydrogels using thermal extrusion coupled with photo curable technique

Microsystem Technologies - It has remained a great challenge to design a tissue engineering scaffold for tissue regeneration, which should be suitable for cell adhesion, proliferation and...     

Immunomodulation-Enhanced Nanozyme-Based Tumor Catalytic Therapy

Nanozyme-based tumor catalytic therapy has attracted widespread attention in recent years. However, its therapeutic outcomes are diminished by many factors in the tumor microenvironment (TME), such as insufficient endogenous hydrogen peroxide (H₂O₂) concentration, hypoxia, and immunosuppressive microenvironment. Herein, an immunomodulation-enhanced nanozyme-based tumor catalytic therapy strategy is first proposed to achieve the synergism between nanozymes and TME regulation. TGF-β inhibitor (TI)-loaded PEGylated iron manganese silicate nanoparticles (IMSN) (named as IMSN-PEG-TI) are constructed to trigger the therapeutic modality. The results show that IMSN nanozyme exhibits both intrinsic peroxidase-like and catalase-like activities under acidic TME, which can decompose H₂O₂ into hydroxyl radicals (•OH) and oxygen (O₂), respectively. Besides, it is demonstrated that both IMSN and TI can regulate the tumor immune microenvironment, resulting in macrophage polarization from M2 to M1, and thus inducing the regeneration of H₂O₂, which can promote catalytic activities of IMSN nanozyme. The potent antitumor effect of IMSN-PEG-TI is proved by in vitro multicellular tumor spheroids (MCTS) and in vivo CT26-tumor-bearing mice models. It is believed that the immunomodulation-enhanced nanozyme-based tumor treatment strategy is a promising tool to kill cancer cells.     

Reliability study on rheological and cracking behavior of mastics using different sized particles

The objective of this present work was to evaluate the rheological and cracking behavior of mastics fabricated with different sized particles and asphalt types. Two asphalts (base and modified) and three fillers with different sized particles (C, M and F) were investigated. The rheological functions including the creep and recovery property and the fatigue property were measured by multiple stress creep-recovery (MSCR) and time sweep (TS) tests, respectively, while the cracking behavior of asphalt materials was investigated using extensile (ES) tests. Moreover, the dispersion characteristics of various sized particles inside a bituminous matrix and the associated mastic morphology were assessed by a scanning electron microscope (SEM). The results revealed that the presence of coarse-sized particles in matrix increased the non-recoverable compliance and fracture energy but decreased fatigue life of the mastics. The presence of medium-sized particles in matrix enhanced the high-temperature elasticity recovery behavior and degraded the low-temperature fracture energy and the cohesive strength of asphalt mastics, regardless of asphalt types. When filler particle size dropped down to a minimum dimension, asphalt type had negligible effects on the fatigue response and exerted a positive effect on the low-temperature cohesive strength for the related mastics. In addition, the dispersion characteristics of various sized particles inside a bituminous matrix and the associated mastic morphology can account for the rheological response and cracking behavior of the corresponding mastics.     

Recycling of steel slag as an alkali activator for blast furnace slag: geopolymer preparation and its application in composite cement

Clean Technologies and Environmental Policy - The recycling–utilization rate of steel slag in China is less than 30%. Steel slag is rich in CaO and can produce the Ca(OH)2 after hydration,...     

Characteristic model based all-coefficient adaptive control of an AMB suspended energy storage flywheel test rig

Feedback control of active magnetic bearing (AMB) suspended energy storage flywheel systems is critical in the operation of the systems and has been well studied. Both the classical proportional-integral-derivative (PID) control design method and modern control theory, such as H_∞ control and μ-synthesis, have been explored. PID control is easy to implement but is not effective in handling complex rotordynamics. Modern control design methods usually require a plant model and an accurate characterization of the uncertainties. In each case, few experimental validation results on the closed-loop performance are available because of the costs and the technical challenges associated with the construction of experimental test rigs. In this paper, we apply the characteristic model based all-coefficient adaptive control (ACAC) design method for the stabilization of an AMB suspended flywheel test rig we recently constructed. Both simulation and experimental results demonstrate strong closed-loop performance in spite of the simplicity of the control design and implementation.     

Nanoscale origins of small hysteresis and remnant strain in Bi0.5Na0.5TiO3-based lead-free ceramics

BiAlO₃-doped Bi_0.5Na_0.5TiO₃-Bi_0.5K_0.5TiO₃ (BA-doped BNT-BKT) ceramics are greatly concerned due to their sufficient electric-field-induced strain with small hysteresis and remnant strain for high precision positioning devices and other actuators. In this paper, the structural analysis especially the high-resolution transmission electron microscope (HRTEM) is used to reveal the origin of excellent properties obtained in 0.96(0.75BNT-0.25BKT)-0.04BA, which exhibits a large strain of 0.21% at ～70 kV/cm, a small strain hysteresis of only 24% and a near-zero remnant strain. Using HRTEM, the antiferroelectric nano-domains composited by three variants of in-phase a⁰a⁰c⁺ octahedral tilting coexisted with the remnant ferroelectric nano-domains of anti-phase a^?a^?a^? octahedral tilting are directly identified. Then a continuous tilting model is proposed to interpret the gradually transitional tilting involving nano-domains leading to the small hysteresis and near-zero remnant strain. The findings may pave a way for further optimizing the properties through creating stable antiferroelectric nano-domains in BNT-based ceramics and the analogues.