The influence of Gd/Ce substitution on the magnetic properties,electronic structure and the valence of cerium in the solid solution CexGd1−xNi3

The polycrystalline compounds Ce_xGd_1−xNi₃ with a rhombohedral PuNi₃ (x ≤ 0.2) and hexagonal CeNi₃ (x ≥ 0.8) – type of crystal structures have been obtained. The change of the lattice parameters may suggest an unstable valence of cerium in the studied system. The effect of partial substitution of Gd by Ce is reflected in a change of the cell volume V(x), the Curie temperature T_C(x) and in the temperature dependence of the magnetic susceptibility and electrical resistivity. Thus, T_C(x) decreases from 115 K (x = 0) to ∼6.8 K (x = 0.8). The XPS spectra have been measured at room temperature. The valence band spectra (VB) as well as the core level lines have been analysed as influence of the Gd/Ce substitution on the electronic structure. The VB near the Fermi level (E_F) is dominated by Ni3d states. In the VB region some slight effects of hybridization and changes of intensity of states on E_F have been noticed. The analysis of Ce core level lines reveals the occurrence of possible intermediate valence. The values of the Ce4f - state occupation parameter (n_f) and the hybridization energy (Δ) have been estimated. The gradual filling of the Ni3d band is revealed by a reduction of the 6 eV satellite intensities in the Ni2p core level spectrum. All these effects can modify the magnetic properties of the investigated compounds.     

Isolation of exopolysaccharide‐producing bacteria and yeasts from Tibetan kefir and characterisation of the exopolysaccharides

Fifteen organisms were isolated from Tibetan kefir. Six of them were exopolysaccharide (EPS)‐producing strains cultured in skim milk medium, which included two yeasts (Kazachstania unispora), one acetic acid bacterium (Acetobacter okinawensis) and three lactic acid bacteria (Leuconostoc pseudomesenteroides). The protein oxidative damage protection assay revealed that preincubation of exopolysaccharides (EPSs) could restore the levels of protein oxidation in a dose‐dependent manner. The SEM images indicated that there were great differences in the microstructures and surface morphologies among the EPSs. The GC analysis of the EPSs showed that all of the EPSs were composed of more than one kind of monosaccharide.     

夏玉米田蒸发蒸腾量与棵间蒸发的试验研究

本文利用2年的大型称重式蒸渗仪和小型棵间蒸发器的测定资料，研究了不同灌水(2001年灌140mm、2002年灌65mm)条件下夏玉米生长期间的逐日蒸发蒸腾和棵间蒸发过程。结果表明，2年夏玉米生长期间棵间蒸发占总蒸发蒸腾量的比例分别为43.69%和48.12%。分析得出夏玉米出苗前利用小型棵间蒸发器实测蒸发的修正系数为0.96。同时，分析了棵间蒸发占蒸发蒸腾的比例随叶面积指数(LAI)和表层土壤含水量的变化关系。     

一种面向服务的事件驱动架构信息集成平台构造方法

信息集成方法研究对企业异构复杂应用集成具有重要的学术和应用价值.提出一种面向服务的事件驱动架构SOEDA,可构建灵活的分布式信息集成平台.采用以服务单元形式封装的适配器连接各种异构系统,通过分布式标准消息路由器作为底层平台实现服务单元的注册、发现和通信.层次化体系和模块化设计有助于提高应用系统的敏捷性、互操作和集成能力.服务单元中采用事件驱动和动态线程池技术保障了系统的高效性.引入系统外部负载、线程开销和资源冲突,采用排队论模型对其性能进行评价.实例表明采用该方法构建的SynchroESB平台能够灵活集成企业遗留系统,提供高效可靠服务.     

Microbiological and chemical changes during the manufacture of Kefir made from cows’ milk,using a commercial starter culture

The counts of total aerobic mesophilic bacteria, lactic acid bacteria (in three different culture media, M17 agar, MSE agar, and Rogosa agar) and yeasts, and some biochemical parameters (levels of lactose, glucose, galactose, L(+)- and D(−)-lactic acids, ethanol, titratable acidity and pH) were determined during 196 h of fermentation in five batches of Kefir made from cows’ milk using a commercial starter culture. Lactococcus spp. predominated during the first 48 h of fermentation (∼8 log₁₀ cfu g⁻¹); Lactobacillus spp. became the predominant species after 48 h (∼8.5 log₁₀ cfu g⁻¹). During the first 24 h of fermentation, the lactose content decreased from a mean value of 4.92% (w/w) to 4.02% (w/w); the concentration of L(+)-lactic acid increased from 0.01% to 0.76% (w/w) and the pH decreased to 4.24 over the same period. After 24 h of fermentation, the changes in the levels of lactose and L(+)-lactic acid, and in pH, occurred more slowly. Neither glucose nor galactose were detected during fermentation. The production of ethanol was limited, reaching a mean final value of 0.018% (w/w).     

Micromechanical model of time-dependent damage and deformation behavior for an orthogonal 3D-woven SiC/SiC composite at elevated temperature in vacuum

This paper presents a micromechanical model to predict the time-dependent damage and deformation behavior of an orthogonal 3-D woven SiC fiber/BN interface/SiC matrix composite under constant tensile loading at elevated temperature in vacuum. In-situ observation under monotonic tensile loading at room temperature, load–unload tensile testing at 1200 °C in argon, and constant load tensile testing at 1200 °C in vacuum were conducted to investigate the effects of microscopic damage on deformation behavior. The experimentally obtained results led to production of a time-dependent nonlinear stress–strain response model for the orthogonal 3-D woven SiC/SiC. It was established using the linear viscoelastic model, micro-damage propagation model, and a shear-lag model. The predicted creep deformation was found to agree well with the experimentally obtained results.     

红外图像的一种Type-II模糊增强算法

提出了一种基于Type-II模糊集的红外图像增强算法,该算法首先根据像素的邻域相关性对图像进行预处理,然后以Ostu分割阈值为基础,构造了红外图像的Type-II模糊特征平面;然后,采用不同的变换规则对图像进行模糊增强,并将结果进行融合;最后,通过Type reduction和去模糊化操作得到增强后的输出图像。对几幅典型的红外图像的增强实验表明,提出的方法能够有效地提高红外图像的对比度。     

楔形变截面梁单元力学模型的研究

根据对变截面杆件的研究，建立了一种宽度自适应的变截面梁单元模型，并用能量法导出了楔形变截面梁单元的刚度矩阵。     

Preparation of copper oxide/oak-based biomass nanocomposite for electrochemical hydrogen storage

In this study, oak fruit as a biomass was used to prepare CuO/OBM nanocomposite and the electrochemical hydrogen storage (EHS) capacity of this nanocomposite was investigated. The product was characterized via energy dispersive X-ray analysis (EDX), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and X-ray diffraction (XRD). Then, the effect of CuO/OBM ratio on the electrochemical hydrogen storage was investigated via chronopotentiometry method. After 20 cycles, the discharge capacities of OBM and CuO/OBM nanocomposite under 1 mA current were achieved from 3490 to 5950 mAh/g, respectively. Results show that coating of CuO on the OBM leads to improve the discharge capacity, but by increasing the CuO/OBM ratio, the discharge capacity has been decreased. Results of this study show that produced nanocomposite can be hopeful in replacing of fossil fuel.     

基于轻量级卷积神经网络的植物叶片病害识别方法

针对目前农业信息领域植物病害识别精度较低、实时性较差的问题,提出了一种基于轻量级卷积神经网络(CNN)的植物叶片病害识别方法.在原有网络中引入深度可分离卷积(DSC)和全局平均池化(GAP)方法,分别用来代替标准卷积运算操作并对网络末端的全连接层部分进行替换.同时,批归一化的技巧也被运用到训练网络的过程中,以改善中间层...