某汽油发动机三元催化器内流场分析

首先介绍了三元催化器的主要特点,然后通过大型CFD软件AVL-FIRE对某型汽油机的三元催化器内流场进行数值模拟,计算出内流场的速度分布,并得到了催化剂载体前端的速度均匀性系数。     

加强建筑企业财务内部控制的思考

文章分析了我国建筑企业财务内部制度的现状,提出了加强建筑企业财务内部控制的措施.     

香瓜子煮制过程中汤料水稳定性研究

分别采用分光光度法、液相色谱法和气相色谱法、滴定法测定了香瓜子煮制工艺汤料水的吸光度值、甜味剂含量及食盐的含量,根据测定的吸光度值、甜味剂及食盐含量变化特性并结合汤料水的pH值变化来确定香瓜子煮制工艺的稳定性及适宜连续煮制锅次.结果表明：采用文中所述的香瓜子煮制工艺,汤料水的pH值在4.7以上的连续煮制锅次可达到80锅,汤料水的吸光度值及甜味剂含量在一定范围内基本趋于平稳,从而验证了该煮制工艺的稳定性.     

Asymptotics for the linear kernel quantile estimator

TEST - The method of linear kernel quantile estimator was proposed by Parzen (J Am Stat Assoc 74:105–121, 1979), which is a reasonable estimator for Value-at-risk (VaR). In this paper, we...     

基于电磁散射特征参数提取与数据分布分析的非线性目标识别

非线性目标的探测与识别在国防、反恐、安保、救援、交通安全等领域均具有重要意义.为提高上述场景下对非线性目标的探测识别能力，文中以典型的非线性器件——肖特基二极管为例，构建了非线性目标的谐波散射模型，并在此基础上利用不同类型非线性目标散射的各次谐波强度与变化趋势不同的特性，提出了一种利用数理方法提取分析目标散射特征参数进而实现对非线性目标探测识别的方法.实验结果显示，本次提出的方法在小样本下对未知非线性目标的识别率在81%左右，证明了该方法对非线性器件有较好的探测与识别能力.     

Surface modification of composite ion exchange membranes by polyaniline

The aim of this work is to develop new selective cation exchange membranes (CEMs) from bivalent to monovalent selectivity by surface functional groups. So, a novel hybrid cation exchange membrane was prepared by polymerization of polyaniline on a composite membrane, made of polyvinylidene fluoride (PVDF) and sulfonated PVDF (S-PVDF). Polyaniline was doped with different doping agents and their effect on total salt extraction and selectivity of bivalent to monovalent cations was evaluated. The chemical and morphological properties of hybrid membranes were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Ion exchange capacity (IEC), transport number, ion conductivity and water uptake decreased after surface polymerization. Composite membrane has a good selectivity (∼2) for bivalent and excellent removal of both cations. The hybrid membrane, doped with pTSA has a very high selectivity for monovalent ions (∼7.1) and a high removal of monovalent ions.     

Where AD plants wildly grow: The spatio-temporal diffusion of agricultural biogas production in the Czech Republic

There is fundamental agreement about the environmental benefits of renewable energy technologies, but unintended consequences arising from their deployment are frequent sources of conflicts. The Czech Republic has committed itself to supply 13.5% of its electricity consumption from renewable sources by 2020. High state incentives for renewable energies have been provided to achieve this target, however critical questions can be asked about the appropriateness of the design of the supporting frameworks which caused a boom in photo-voltaic (PV) installations on agricultural land, as well as a boom in the installation of agricultural anaerobic digestion (AD) plants fuelled by dedicated energy crops. This paper analyses the diffusion of agricultural AD plants in the Czech Republic, focusing especially on locational characteristics in relation to the quality of agricultural land, agricultural and population census data. Statistical analysis of those spatial datasets show that agricultural AD plants are mostly located in less favourable agricultural areas, in regions having recently experienced a reduction in cattle breeding, and in regions with significant increases of sowing areas of green maize. These findings suggests shortcomings in the supporting policy for AD plants in the Czech Republic, resulting in unintended environmental consequences, and missed opportunities to enhance energy self-sufficiency and resilience in the countryside.     

Discounted cash flow analysis of greenhouse-type solar kilns

This paper describes the overall discounted cash flow (DCF) analysis of two greenhouse-type solar kilns (Oxford and Boral) for hardwood drying processes. The financial performance of both the kilns was found to be mainly dominated by the costs/benefits associated with the model-predicted future thermal energy flows. All the costs and benefits were calculated based on the current energy prices, while adjusting all future cash flows (either costs or benefits) to their respective present values by incorporating appropriate inflation and discount rates. The overall results indicated that the net present cash benefit and the present drying energy benefit were larger for the Oxford kiln than those for the Boral kiln, by approximately 38% and 16%, respectively, while the present energy-loss cost was smaller for the Oxford kiln by 23% than that for the Boral kiln. A sensitivity analysis was carried out in order to assess the robustness of the results against the uncertain parameters. In general, the Oxford kiln design was found to be more cost-effective and environmentally beneficial than the Boral kiln design for hardwood drying.     

PLDD: Point-lines distance distribution for detection of arbitrary triangles,regular polygons and circles

In this paper, a general framework is presented for detection of arbitrary triangles, regular polygons, and circles, which is inspired by the common geometric property that the incenter of the shape is equidistant to the tangential lines of the contour points. The idea of point-lines distance distribution (PLDD) is introduced to compute the shape energy of each pixel. Then, shape centers can be exacted from the produced PLDD map, and shape radii are obtained simultaneously based on the distance distribution of the shape center. The shape candidates are thus determined and represented with three independent characteristics: shape center, shape radius, and contour points. Finally, distinguish different types of the shape from shape candidates using shape contour points information. Compared with exiting methods, the PLDD based method detects the shapes mainly using the inherent information of edge points, such as distance, and it is simple and general. Comparative experiments both on synthetic and natural images with the state of the art also prove that the PLDD based method performs more robustly and accurately with the maximal time complexity O(n²) at the worst condition.