Remarkably enhanced energy storage properties of lead-free Ba0.53Sr0.47TiO3 thin films capacitors by optimizing bottom electrode thickness

The lead-free Ba_0.53Sr_0.47TiO₃ (BST) thin films buffered with La_0.67Sr_0.33MnO₃ (LSMO) bottom electrode of different thicknesses were fabricated by pulsed laser deposition method on a (001) SrTiO₃ substrate. It was found that the roughness of electrode decreases and substrate stress relaxes gradually with the increase of LSMO thickness, which is beneficial for weakening local high electric field and achieving higher E_b. Therefore, the recoverable energy density (W_rec) of BST films can be greatly improved up to 67.3 %, that is, from 30.6 J/cm³ for the LSMO thickness of 30 nm up to 51.2 J/cm³ for the LSMO thickness of 140 nm after optimizing the LSMO thickness. Furthermore, the thin film capacitor with a 140 nm LSMO bottom electrode shows an outstanding thermal stability from 20 °C to 160 °C and superior fatigue resistance after 10⁸ electrical cycles with only a slightly decrease of W_rec below 1.6 % and 3.7 %, respectively. Our work demonstrates that optimizing bottom electrodes thickness is a promising way for enhancing energy storage properties of thin-film capacitors.     

Excited-state absorption of meso-tetrasulfonatophenyl porphyrin: Effects of pH and micelles

The influence of the environment on the excited state transitions of meso-tetrakis(p-sulfonatophenyl) porphyrin (TPPS) is reported. TPPS was investigated in protonated and non-protonated forms, and in the presence of the cationic cetyltrimethylammonium bromide (CTAB) micelles. The singlet excited-state absorption spectra were measured by using the white-light continuum Z-scan technique and the triplet–triplet absorption spectra were acquired employing an association of laser flash photolysis and Z-scan techniques. Our results show that the perseveration of the molecular symmetry, upon excitation, depends on the state of multiplicity of the molecules, as well as on the environment and structural characteristics of the porphyrin. Additionally, it was observed that for excited molecules, the ring distortion caused by the protonation of porphyrin ring has great influence on the changes observed for the symmetry and vibronic structure. The results clearly show that the porphyrin investigated is a promising candidate for optical limiting applications for all investigated environments.     

Flame Front Deformation Instabilities of Filtration Combustion for Initial Thermal Perturbation

The flame front deformation instability of low-velocity filtration combustion within an inert packed bed is studied based on the initial preheating non-uniformity. Based on the experimental phenomena, an initial thermal perturbation model is numerically proposed so as to predict the deformation behaviors of the flame front instabilities. The numerical prediction indicates that the assumption of an initial thermal perturbation is a feasible explanation as the cause of the flame front inclination instability. As the initial thermal perturbation increases, the phenomena of the flame front break and shrinking instabilities could easily occur at high filtration velocity or low equivalence ratio. Moreover, the evolutions of the flame front break rate and the shrinking rate are quantitatively analyzed.     

基于桥墩防护的铁塔基础成品防护技术及其装置设计

为了降低铁塔基础的破损率,提高工程创优质量,根据对基础破损现状的调查、五种基础成品防护方法的对比分析、借鉴桥墩防护技术,提出了基础成品防护技术建议。从保护装置组装方式、接口设置、基础保护范围、保护装置材质四个方面论证分析,提出了保护装置的最佳设计方案。研究结果表明:不采取基础成品防护措施时,基础破损率平均达到7.3%;保护装置的最佳设计方案为楔形组装方式,四边设置接口,对基础四角及棱边、四角纵向延长均采取保护,采用NBR+PVC合成材料,在结构上由固定部件和可调整部件构成。经现场使用验证保护效果明显,还具有防盗、安装拆卸简便、便于运输、循环利用率高等特点。     

基于空间句法的传统村落保护规划编制应用的思考——以国家级历史文化名村唐模为例

传统村落保护规划的编制是解决传统村落保护发展基础性和全局性的工作。运用空间句法的相关理论与技术对唐模古村进行空间解析,利用量化后的空间分析结果对传统村落保护规划中的保护区划划定、街巷路网调整、功能结构布局等重要规划内容提供了依据。廓清了空间句法在传统村落保护规划中应用的若干问题,为传统村落保护规划编制提供了可借鉴的技术路线和修正的思考。     

基于场所复兴的新徽派建筑浅析——以绩溪博物馆为例

在"文化趋同"愈发明显的当今社会,城市本土文化正在逐渐消失。新徽派建筑作为传统文化的现代化继承,绽放于各个地区。本文以场所复兴为出发点,从"建筑与环境的对话"、"建筑本我的表达"以及"情感体验"三个方面举例论述了场所精神的营造。     

太阳能双功能集热器被动采暖模式的理论模拟和实验验证

针对一种太阳能空气-水双集热功能的平板式集热器开展研究。将集热器与具有蓄热特性的建筑南墙结合,建立实验平台,并构建了集热器被动采暖空气集热模式的瞬态理论模型。利用数值迭代方法对模型进行求解,并将计算结果与实验数据进行对比,对理论模型进行实验验证。结果表明,计算结果和实测数据结果吻合良好,模型可以准确模拟被动采暖模式下集热器、房间围护结构和空气的温度场以及温度随变化的变化情况。     

浅析安徽地方文庙的布局特征——以寿州孔庙为例

儒学被认为是古代封建文化的正统,地方文庙也随着封建统治者对尊孔祭祀活动的升级而逐渐普及。寿州孔庙建筑群是安徽省境内始建年代较早,现存较为完整的地方文庙代表。本文以寿州孔庙建筑群为例,从特点鲜明的建筑组成,庙学合一的功能组织,礼制规范的形制格局,层层递进的序列空间等方面解析作为地方文庙建筑的典型布局特征,以期为安徽地方文庙建筑的保护研究提供参考。     

一株铜绿微囊藻溶藻菌的溶藻机理研究

以铜绿微囊藻为溶解对象,从巢湖中分离到1株溶藻菌H2。探讨了菌株H2对铜绿微囊藻的溶藻方式,菌株H2胞外活性物质的溶藻特性。结果表明,菌株H2是间接溶藻。溶藻菌起溶藻作用的胞外分泌液中活性物质主要为分子量小于3.5k D的物质,并且活性物质是混合物质;菌株胞外分泌液经乙醇沉淀后,上清液部分的溶藻率大于沉淀部分,为52.50%;胞外分泌液经不同温度和酸碱度处理后,在25℃、p H=12.0时,活性较强,溶藻率分别为98.0%和97.1%;胞外分泌液中活性物质具有一定的抗氧化性。     

建筑施工过程碳排放量预测模型及应用研究

在明确碳排放量计算公式和碳排放因子的基础上,文章建立建筑施工过程中碳排放量预测模型,并对建筑施工过程中材料及机械设备使用情况进行实证分析,得出建筑面积与施工过程碳排放量存在显著的线性关系。最后通过实例对该碳排放量预测模型进行应用研究。