Low-temperature synthesis and magnetic properties of the mixed-valence lanthanide intercalation compounds EuxTiS2 and YbxTiS2

The lanthanide (L) intercalation compounds Eu_xTiS₂ (x=0.007,0.014, and 0.066) and Yb_xTiS₂ (x=0.060) have been synthesized by thermal deintercalation of NH₄⁺ and NH₃ from the corresponding L-NH₃ precursors at 270°C and characterized by thermogravimetric analysis, powder X-ray diffraction, and SQUID magnetometry. Both L²⁺ and L³⁺ are present in the van der Waals gap, and the deintercalation process is accompanied by the conversion of some of the L³⁺ to L²⁺. The resulting compounds contain comparable concentrations of L²⁺ and L³⁺. Magnetic exchange interactions are negligible due to the low concentrations of lanthanide cations.     

Preparation,characteristics and photovoltaic properties of cuprous oxide—a review

The photovoltaic properties of cuprous oxide (Cu₂O) are reviewed and discussed. The emphasis, however, is on reviewing the characteristics of Cu₂O prepared by different techniques such as high-temperature thermal oxidation, low-temperature thermal oxidation, electro-deposition, anodic oxidation, chemical oxidation and reactive sputtering. It is shown that despite the economic prospects of efficient cells based on Cu₂O, little is known about the photovoltaic properties of this material when it is fabricated by low-temperature techniques. The areas in which further research is needed because of the lack of information in the literature are pointed out.     

Marine chemistry and its role in pollution studies

This paper examines the need for information on marine chemistry, especially, but not exclusively, in relation to marine pollution studies, and attempts to assess the direction in which marine chemists can most usefully direct their work.     

Influence of propyl alcohol addition during processing of molybdenum trioxide powders: Observation of novel dual-wavelength excitation photochromism

The novel dual-wavelength excitation photochromic molybdenum trioxide (MoO₃) powders are fabricated successfully via the hydrothermal method by the addition of propyl alcohol. The samples were fully characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible diffuse reflectance spectroscopy (UV–vis), and colorimetry. The characteristic spectrum of XRD demonstrates that the as-obtained products are highly pure. The results show that the flowerlike MoO₃ sample with the inducer of propyl alcohol has better photochromic properties, which was analyzed by colorimetry. It is shown that both of the samples exhibit a strong adsorption band between 250 and 400 nm in the UV range. Moreover, the UV–vis spectra shows that MoO₃ synthesized with added propyl alcohol absorbs light not only between 250 and 400 nm but also displays an additional band between 500 and 800 nm, demonstrating novel dual-wavelength excitation photochromic properties.     

Multi-path connected network for medical image segmentation

In recent years, deep learning has been successfully applied to medical image segmentation. However, as the network extends deeper, the consecutive downsampling operations will lead to more loss of spatial information. In addition, the limited data and diverse targets increase the difficulty for medical image segmentation. To address these issues, we propose a multi-path connected network (MCNet) for medical segmentation problems. It integrates multiple paths generated by pyramid pooling into the encoding phase to preserve semantic information and spatial details. We utilize multi-scale feature extractor block (MFE block) in the encoder to obtain large and multi-scale receptive fields. We evaluated MCNet on three medical datasets with different image modalities. The experimental results show that our method achieves better performance than the state-of-the-art approaches. Our model has strong feature learning ability and is robust to capture different scale targets. It can achieve satisfactory results while using only 0.98 million (M) parameters.     

数据挖掘与OLAP在毕业生就业领域的应用

为了帮助高校毕业生就业管理部门更好的引导毕业生就业,在此研究、分析Microsoft Analysis Services体系作为OLAP应用和数据挖掘应用的平台。分析挖掘毕业生数据信息,通过关联规则的约束性Apriori算法分析、挖掘大量数据背后的潜在规律,为高校、用人单位指导毕业生就业部门提供决策支持服务;为高校在学生的培养模式、学科建设、课程设置等方面提供依据和参考。     

基于VC＋＋的超声波混凝土厚度检测软件的设计与实现

为检测混凝土厚度,研发了基于Windows平台的超声数据分析软件,并根据用户需求设计系统架构和模块功能,以提高软件的可靠性和易用性。该软件采用自定义数据格式,利用多种数字信号处理方法对原始数据进行分析处理,当发射器有效地监测到反射波时,软件根据收集到的数据计算出混凝土厚度。     

Impact of defects on exciton diffusion in organic light-emitting diodes

The impact of defect concentration and current density on the effective singlet exciton diffusion length in 4’-bis(carbazol-9-yl)biphenyl (CBP) is quantified by analyzing the electroluminescent characteristics of several sets of OLEDs. The defect concentration and effective diffusion length are determined through fitting of the defect and CBP emission bands in the electroluminescence spectra under constant current operation using an analytical model derived based on the competition between exciton diffusion and energy transfer to defects. Defect concentrations of 3 ± 1 × 10¹⁸ cm⁻³, 2 ± 1 × 10¹⁸ cm⁻³ and 0.3 ± 0.7 × 10¹⁸ cm⁻³ are calculated in three sets of OLEDs, in which the effective diffusion length decreases as the defect concentration increases. Modelling the dependence of the effective diffusion length on defect concentration a “defect free” diffusion length of 4.5 ± 0.3 nm is obtained for CBP singlet excitons in these devices operated under low current density. We also show that the driving voltage scales linearly with the defect concentration.     

判奇电路实现方法探讨

以三输入判奇电路设计为例,通过对其输出函数表达式的形式变换,分别采用多种门电路及译码器、数据选择器等74系列器件进行电路设计,给出了7种电路实现形式,并分析了各种电路实现的优缺点。此例说明了组合逻辑电路设计的灵活性及电路实现的多样性。所采用的设计方法对其他组合逻辑电路设计具有一定的启发与指导意义。     

Fabrication of organic flexible electrodes using transfer stamping process

A transfer stamping process is proposed to fabricate micro-scale organic flexible electrodes. With different adhesion forces of the transferring interfaces, ink/mold and ink/substrate, patterns are formed from the relief features of the elastomeric mold to the substrate without residual layer, and no complex pre-process and steps are needed. To estimate the deformation during pressing, the sagging height of the mold is analyzed with finite element method (FEM). Two conductive polymers, PEDOT:PSS and silver paste, are transferred from the flat relief features of the mold to the PET substrate. The coating characteristics and problems are discussed. The transfer stamping process is also employed to fabricate electrodes on the dielectric/ITO film and to form an organic flexible capacitance. This paper demonstrates the potential of transfer stamping in fabricating organic electronic components, such as organic integrated circuit, OLED and OTFT.