420nm thick CH_3NH_3PbI_(3-x)Br_x capping layers for efficient TiO_2 nanorod array perovskite solar cells

The rutile TiO_2 nanorod arrays with 240 nm in length, 30 nm in diameter, and 420 μm~(-2) in areal density were prepared by the hydrothermal method to replace the typical 200-300 nm thick mesoporous TiO_2 thin films in perovskite solar cells. The CH_3NH_3PbI_3-xBrx capping layers with different thicknesses were obtained on the TiO_2 nanorod arrays using different concentration PbI_2·DMSO complex precursor solutions in DMF and the photovoltaic performances of the corresponding solar cells were compared. The perovskite solar cells based on 240 nm long TiO_2 nanorod arrays and 420 nm thick CH_3NH_3PbI_(3-x)Br_x capping layers showed the best photoelectric conversion efficiency(PCE) of 15.56%and the average PCE of 14.93 ± 0.63% at the relative humidity of 50%-54% under the illumination of simulated AM 1.5 sunlight(100 mW·cm~(-2)).     

含丹磺酰基树枝状化合物研究进展

含丹磺酰基树枝状化合物具有独特的发光性能和潜在的应用价值,在化学传感器、药物传输、光捕获天线材料、有机电致发光器件、纳米材料等领域有着广阔的应用前景,已经引起化学家们的广泛关注.综述了近年来含丹磺酰基树枝状化合物的研究进展,讨论了树枝结构对丹磺酰基荧光性质的影响,并展望了此类化合物良好的应用前景.     

Ce1+εFe4B4一维成分无公度结构的研究

本文用X射线粉末衍射和电子衍射的方法,研究了Ce-Fe-B合金中的富B相Ce_1+εFe₄B₄的晶体结构,发现该化合物具有一种罕见的晶体结构——烟囱-梯子型的一维成分无公度结构,是由两套亚结构即Fe-B亚结构和Ce亚结构所组成,两套亚结构都具有四方对称性,其点阵常数α值相同。Ce_1+εFe₄B₄在室温的点阵常数α=0.7068 nm,c_Fe-B=0.3902 nm,c_Ce=0.3440 nm。在950℃粉末淬炼后的点阵常数α=0.7065nm,c_Fe-B=0.3887 nm,c_Ce=0.3563 nm。Fe-B亚结构的空间群为P4₂/ncm,Ce亚结构的空间群为I4/mmm。     

The theoretical studies on the two-photon absorption properties of symmetric l,4-bis{2-[4-(2-aryl)phenyl]vinyl}-2,5-bisdialkoxybenzenes

<正>On the level of the time-dependent hybrid density functional theory,the one- and two-photon absorption properties of a series of symmetric 4-bis{2-[4-(2-aryl) phenyl]vinyl}-2,5-bisdialkoxybenzenes are studied respectively utilizing the analytic response theory and the few-state model methods.The calculated results show that the planarity of the geometrical structure plays a great role in enhancing the linear and nonlinear optical abilities of the molecule.However the effect of the length of the chain linked to theπ-centre on the optical property is very little.For the investigated compounds,the A-π-A type charge-transfer molecules display more superior one- and two-photon absorption characteristics than the D-π-D type ones.Furthermore,the two-photon absorption results by use of few-state model are generally consistent with those by analytic response theory,demonstrating the reliability of the few-state model for evaluating the two-photon absorption cross section.The numerical simulations are in good agreement in tendency with the available experimental measurements.     

Ce1+εFe4B4合金一维无公度调制结构的透射电子显微镜研究

用电子衍射和高分辨电子显微术研究了永磁合金Ce₁₅Fe(77)B₀中富硼相Ce_1+εFe₄B₄(ε≈0.1)的晶体结构,确定了Ce_1+εFe₄B₄合金具有烟囱-梯子型一维无公度调制结构,它由Ce原子和Fe-B原子团分别组成的两套亚结构相互嵌套形成。Ce亚结构晶胞参数为a=7.08?,c_Ce=3.51—3.60? 关键词：     

嵌段共聚物PDTC-PEG-PDTC的降解和释药性能

研究了5，5-二甲基-三亚甲基碳酸酯的均聚物(PDTC)及其与聚乙二醇(PEG)组成的嵌段共聚物(PDTC-PEG-PDTC)的亲水性、水解和酶解性能以及药物释放性能，结果表明：随着聚合物中PEG含量的增加，聚合物的亲水性显著增强；当PEG含量较高时，PEG从聚合物链上断裂溶解使得聚合物的降解速率相对较快；在猪胰脂肪酶(PPL)或假丝酵母皱褶酶(CL)的催化下水解108h，PEG含量对聚合物的水解速率影响不大；药物释放速率随着PEG含量的增大明显提高，n(EO)／n(DTC)为4：1的嵌段共聚物在30min时释药率高达95％。     

Adaptive window iteration algorithm for enhancing 3D shape recovery from image focus

Depth from focus(DFF) is a technique for estimating the depth and three-dimensional(3D) shape of an object from a multi-focus image sequence. At present, focus evaluation algorithms based on DFF technology will always cause inaccuracies in deep map recovery from image focus. There are two main reasons behind this issue. The first is that the window size of the focus evaluation operator has been fixed. Therefore, for some pixels, enough neighbor information cannot be covered in a fixed window and is easily disturbed by noise, which results in distortion of the model. For other pixels, the fixed window is too large, which increases the computational burden. The second is the level of difficulty to get the full focus pixels, even though the focus evaluation calculation in the actual calculation process has been completed. In order to overcome these problems, an adaptive window iteration algorithm is proposed to enhance image focus for accurate depth estimation. This algorithm will automatically adjust the window size based on gray differences in a window that aims to solve the fixed window problem.Besides that, it will also iterate evaluation values to enhance the focus evaluation of each pixel. Comparative analysis of the evaluation indicators and model quality has shown the effectiveness of the proposed adaptive window iteration algorithm.     

单边核磁共振传感器研究及其应用

单边核磁共振(single-sided NMR)传感器具有体积小、造价低和结构开放等特点,特别适用于大型样品的现场无损检测,具有广阔的应用前景.该文介绍了一种均匀度较高的单边核磁共振传感器,在10 mm×10 mm的水平目标区域内,静态磁场均匀度为338×10–6,在垂直方向上静态磁场具有4.6 T/m的恒定梯度.结合该磁场分布的梯度特性,提出了一种基于快速傅里叶变换和带通滤波处理的回波信号处理方法,可提取薄层样品的核磁共振信号,从而实现对样品纵深方向的高分辨率一维测量(分辨率达到50?m).最后使用该传感器对复合绝缘子高分子聚合物、液体的扩散行为,以及植物叶片的枯萎过程进行了测量.展现了该方法在高分子材料分析、液体测量以及农业应用方面的潜力.     

膦酸根型水溶性膦配体的质子离解和紫外光谱特性

随着两相催化研究的深入 ,各种水溶性配体 ,特别是水溶性膦配体的种类和合成方法日益多样化[1 ] ,含磷酸根的膦配体是其中一类重要的水溶性膦配体[2 ,3] ,微溶于水 ,其膦酸钠、钾盐具有良好的水溶性 ,因此膦酸根中质子离解对配体和金属配合物的存在形式[4,5] 、水溶性和金属配合物的回收使用都会有较大的影响。我们曾报道以乙烯利为起始原料合成氨乙基膦酸及其衍生物的简便方法[6] ,并利用Ｍａｎｎｉｃｈ型反应引入二苯基膦甲基配位络合基团 ,制备其相应的水溶性钠盐[7] 。本文报道二苯基膦甲基、醚键和羟基的引入对上述水溶性配体中膦酸根…     

磺化含芴聚醚醚酮酮的合成及与八苯胺基POSS的杂化

设计并合成了一种新型的含有芴结构的磺化聚醚醚酮酮, 并将八苯胺-POSS引入聚合物中, 制备出一类具有酸-碱相互作用的复合型质子交换膜, 并对其性能进行了研究.