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71.
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Ruijia Zhang Zengqi Huang Weipeng Chen Benzheng Lyu Hong Zhang Xinjun He Xiaotian Hu Yanlin Song Wallace C. H. Choy 《Advanced functional materials》2023,33(5):2210063
Advancing hole transport layers (HTL) to realize large-area, flexible, and high-performance perovskite solar cells (PSCs) is one of the most challenging issues for its commercialization. Here, a self-assembled gradient Ti3C2Tx MXene incorporated PEDOT:PSS HTL is demonstrated to achieve high-performance large-area PSCs by establishing half-caramelization-based glucose-induced MXene redistribution. Through this process, the Ti3C2Tx MXene nanosheets are spontaneously dispersed and redistributed at the top region of HTL to form the unique gradient distribution structure composed of MXene:Glucose:PEDOT:PSS (MG-PEDOT). These results show that the MG-PEDOT HTL not only offers favorable energy level alignment and efficient charge extraction, but also improves the film quality of perovskite layer featuring enlarged grain size, lower trap density, and longer carrier lifetime. Consequently, the power conversion efficiency (PCE) of the flexible device based on MG-PEDOT HTL is increased by 36% compared to that of pristine PEDOT:PSS HTL. Meanwhile, the flexible perovskite solar minimodule (15 cm2 area) using MG-PEDOT HTL achieve a PCE of 17.06%. The encapsulated modules show remarkable long-term storage stability at 85 °C in ambient air (≈90% efficiency retention after 1200 h) and enhanced operational lifetime (≈90% efficiency retention after 200 h). This new approach shows a promising future of the self-assembled HTLs for developing optoelectronic devices. 相似文献
74.
针对干旱区平原水库水深浅、风速大、气温高、空气相对湿度低而导致蒸发损失严重的问题,在吐鲁番市胜金乡胜金沟三期水土保持水库进行了一整年不同覆盖面积的带磁性浮板与非磁性浮板覆盖水面来减少水面蒸发的试验,以此来分析相同覆盖面积下带磁性浮板成片整体分布与非磁性浮板分散分布对水库水面蒸发的节水效率。试验结果表明:在气象因素相同的情况下,带磁性浮板分别覆盖水面25%,50%和75%时,蒸发抑制率分别为27.4%,41.5%和59.1%;非磁性浮板分别覆盖水面25%,50%和75%时,蒸发抑制率分别为22.1%,38.1%和57.3%;带磁性浮板比非磁性浮板蒸发抑制率分别提高了5.3%,3.4%和1.8%。可见,带磁性浮板节水效果更加显著,对提高干旱区平原水库水资源的利用效率具有显著意义。 相似文献
75.
高锰奥氏体低温钢作为一种经济型低温钢材料,具有非常巨大的发展空间.为进一步研究晶粒尺寸对高锰奥氏体低温钢的影响,本文对其进行了不同工艺的固溶处理,测试了不同晶粒尺寸实验钢的室温拉伸及低温冲击性能, 通过扫描电镜(SEM)、背散射电子衍射(EBSD)等方法进行表征并计算其Hall-Petch关系式.-196 ℃冲击实验结果表明,高锰奥氏体低温钢拥有良好而稳定的超低温冲击性能,且其超低温冲击性能不随晶粒尺寸的增加而发生变化.经计算实验钢屈服强度所对应的Hall-Petch常数Ky为7.27 MPa·mm0.5,明显小于其他被研究的奥氏体高锰钢.进一步计算拉伸过程中不同真应变ε对应的Hall-Petch常数K(ε),发现在拉伸过程中,受TWIP效应产生的变形孪晶影响,K(ε)值随应变量的增加而增加;当真应变达到0.3时,组织内变形孪晶不再继续生成,加工硬化过程不再进行,K(ε)也达到极大值. 相似文献
76.
Xinjun Zhang 《Journal of Wind Engineering & Industrial Aerodynamics》2007,95(3):149-164
As the span length of suspension bridges increases, the diameter of cables and thus the wind load acting on them, the nonlinear wind-structure interaction and the spatial non-uniformity of wind speed (including the vertical and horizontal variations) all increase consequently, which may have unnegligible influence on the aerostatic and aerodynamic behavior of long-span suspension bridges. In this paper, the models of aerostatic and aerodynamic forces are established, in which the nonlinear wind-structure interaction and the spatial non-uniformity of wind speed are both considered. By taking the Runyang Bridge over the Yangtze River as example, effects of the nonlinear wind-structure interaction, wind speed spatial non-uniformity, and the cable's wind load on the aerostatic and aerodynamic behavior of the bridge are investigated analytically. The results show that the aerostatic behavior is significantly influenced by these factors, but for the aerodynamic stability, it is greatly influenced by the nonlinear wind-structure interaction and the horizontal variation of wind speed, and the other factors have no influence on it. 相似文献
77.
针对电力系统分析综合程序(power system analysis software package , PSASP)中现有的用户自定义(user-defined,UD)建模功能存在诸如方便性、灵活性、计算精度、仿真效率等方面的不足,笔者对其进行了优化升级,以进一步满足用户进行大规模电力系统仿真分析的需要.为此,提供了2种优化措施,一是采用一种拓扑结构排序算法,即Kosaraju 算法;二是引入用户自约定临时变量.最后,通过PSASP 中36节点机电暂态算例和小干扰稳定算例对2种优化方法进行验证,算例结果证明了该方法的有效性 相似文献
78.
SAPO-34分子筛的结构特征,使其在MTO工艺中可以高选择性地将甲醇转化为乙烯、丙烯。纯的SAPO-34用作MTO催化剂时,催化效率相对较低,通常需要对SAPO-34进行酸性调整、酸中心调整以及孔口径尺寸调整等改性。通过将金属元素引入SAPO-34分子筛骨架上,改变分子筛酸性和孔口径大小,得到小孔口径和中等强度的酸中心,而孔口径变小限制了大分子的扩散,有利于小分子烯烃选择性的提高。认为采取复合改性的方法,是分子筛改性的最直接、最经济、最简便和最容易取得效果的方法。有时,将具有不同孔口径、不同结构的分子筛按一定比例进行物理复合,制成的复合分子筛的性能完全满足工艺要求,而其成本却是最低的。从SAPO-34分子筛、流化床SAPO分子筛、金属改性SAPO分子筛,SAPO分子筛的预处理,复合分子筛,核壳结构催化剂及催化剂的再生等方面,综述了MTO工艺用SAPO系列分子筛的中国专利技术进展。 相似文献
79.
80.
Type synthesis of 4-DOF parallel kinematic mechanisms based on Grassmann line geometry and atlas method 总被引:1,自引:1,他引:0
Many methods are proposed to deal with the type synthesis of parallel kinematic mechanisms(PKMs), but most of them are less intuitive to some extent. Thus, to propose a concise and intuitive type synthesis method for engineering application is a very challenging issue, which should be further studied in the field. Grassmann line geometry, which can investigate the dimensions of spatial line-clusters in a concise way, is taken as the mathematic foundation. Atlas method is introduced to visually describe the degrees of freedom(DOFs) and constraints of a mechanism, and the dual rule is brought in to realize the mutual conversion of the freedom-space and constraint-space. Consequently, a systematic method based on Grassmann line geometry and Atlas method is generated and the entire type synthesis process is presented. Three type 4-DOF PKMs, i.e., 1T3R, 2T2R and 3T1R(T: translational DOF; R: rotational DOF), are classified according to the different combinations of the translational DOFs and rotational DOFs. The type synthesis of 4-DOF PKMs is carried out and the possible configurations are thoroughly investigated. Some new PKMs with useful functions are generated during this procedure. The type synthesis method based on Grassmann line geometry and Atlas method is intuitive and concise, and can reduce the complexity of the PKMs' type synthesis. Moreover, this method can provide theoretical guidance for other PKMs' type synthesis and engineering application. A novel type synthesis method is proposed, which solves the existing methods' problems in terms of complicated, not intuitive and unsuitable for practical application. 相似文献