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81.
In this article, an improved differential evolution algorithm (IDE) based on two different colonies is proposed and applied to time‐modulated conformal arrays syntheses. The whole population of IDE is divided into two parts. The one part searches the solution globally while the other searches the neighborhood of the solution provided by the previous one. Benchmark functions are provided to testify IDE. Furthermore, IDE is applied to synthetize sum‐difference patterns with a 1 × 16 elements time‐modulated circular array and low sidelobe level (SLL) patterns with an 8 × 12 elements time‐modulated cone array. After optimization, the sideband level (SBL) of the circular array at the first sideband frequency is ?1.00 dB. The SLL and SBL at the first sideband frequency of the cone array are lower than ?30.00 and ?20.00 dB, respectively. Experiment results verify the superior performance of IDE. Moreover, to accelerate the computation speed, graphics processing unit parallel computing technique is introduced into pattern synthesis and the acceleration ratios of more than 23 times can be achieved. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:697–705, 2014.  相似文献   
82.
Nickel-cobalt and nickel-iron electrodeposits were characterized as hydrogen electrodes in alkaline water electrolysis (6 mol/L KOH, 25°C). The nickel-based codeposits were fabricated with different bath compositions and at different current densities. The hydrogen evolution in water electrolysis on the nickel-based codeposits was apparently enhanced as compared with that on nickel. The improvement of the electrocatalytic behaviour of the hydrogen electrodes is attributed to their composition and an increase of their active surface, which are dependent on the electrodeposition conditions.  相似文献   
83.
《Graphical Models》2014,76(5):507-521
The 2.1D sketch is a layered image representation, which assigns a partial depth ordering of over-segmented regions in a monocular image. This paper presents a global optimization framework for inferring the 2.1D sketch from a monocular image. Our method only uses over-segmented image regions (i.e., superpixels) as input, without any information of objects in the image, since (1) segmenting objects in images is a difficult problem on its own and (2) the objective of our proposed method is to be generic as an initial module useful for downstream high-level vision tasks. This paper formulates the inference of the 2.1D sketch using a global energy optimization framework. The proposed energy function consists of two components: (1) one is defined based on the local partial ordering relations (i.e., figure-ground) between two adjacent over-segmented regions, which captures the marginal information of the global partial depth ordering and (2) the other is defined based on the same depth layer relations among all the over-segmented regions, which groups regions of the same object to account for the over-segmentation issues. A hybrid evolution algorithm is utilized to minimize the global energy function efficiently. In experiments, we evaluated our method on a test data set containing 100 diverse real images from Berkeley segmentation data set (BSDS500) with the annotated ground truth. Experimental results show that our method can infer the 2.1D sketch with high accuracy.  相似文献   
84.
对无氧条件下Pt/TiO_2光催化重整甲醇制氢的基本步骤进行简化,在同一体系中进行了光催化剂的合成和光催化制氢的两步反应。基于正交设计法对该复杂体系进行了分析,得到Pt载量、甲醇/水体积、灯距、前反应时间这4种影响因素的3个不同水平对放氢速率的影响。确定了最佳实验条件为Pt载量0.5%(mol)、甲醇/水体积比5:1、灯距12 cm、前反应时间3h。分析结果表明,Pt载量对放氢速率的影响最大。实验获得的最高放氢速率为5.84 ml·h~(-1)·g~(-1)。  相似文献   
85.
The inhibition of ATP synthesis, proton uptake, and electron transport (basal, phosphorylating, and uncoupled) from water to methylviologen by zaluzanin C indicates that it acts as an electron transport inhibitor. Uncoupled photosystem I electron transport rate was not affected by zaluzanin C; however, uncoupled photosystem II electron flow from water to 2,3,5,6-tetramethyl phenylenediamine and from water to silicomolybdate was inhibited, but electron transport from diphenylcarbazide to silicomolybdate was not affected. We conclude that the site of inhibition by zaluzanin C is located at the oxygen evolution level.  相似文献   
86.
Preparation of anodes for oxygen evolution in seawater electrolysis was carried out. Manganese-molybdenum double oxides, Mn1−xMoxO2+x, prepared by anodic deposition from MnSO4-Na2MoO4 solutions showed the 100% oxygen evolution efficiency at a current density of 1000 A m−2 in 0.5 M NaCl at 30 °C and pH 12, but an increase in solution temperature resulted in dissolution of the oxides as molybdate and permanganate ions. In order to increase the stability of the electrodes at higher temperatures the addition of iron to the manganese-molybdenum oxides was performed by anodic deposition in MnSO4-Na2MoO4-FeNH4(SO4)2 solutions. The electrodes thus prepared showed the 100% oxygen evolution efficiency at 1000 A m−2 in 0.5 M NaCl at 30-90 °C, when proper amounts of molybdenum and iron were contained. The iron addition also enhanced the oxygen evolution efficiency. The electrodes were not composed of oxide mixtures but triple oxides, Mn1−xyMoxFeyO2+x−0.5y, consisting of Mn4+, Mo6+ and Fe3+. The formation of the triple oxides seemed responsible for enhancement of both oxygen evolution efficiency and stability.  相似文献   
87.
Conium maculatum, a Eurasian weed naturalized in North America, contains high concentrations of piperidine alkaloids that act as chemical defenses against herbivores. C. maculatum was largely free from herbivory in the United States, until approximately 30 yr ago, when it was reassociated via accidental introduction with a monophagous European herbivore, the oecophorid caterpillar Agonopterix alstroemeriana. At present, A. alstroemeriana is found in a continuum of reassociation time and intensities with C. maculatum across the continent; in the Pacific Northwest, A. alstroemeriana can cause severe damage, resulting in some cases in complete defoliation. Studies in biological control and invasion biology have yet to determine whether plants reassociated with a significant herbivore from the area of indigeneity increase their chemical defense investment in areas of introduction. In this study, we compared three locations in the United States (New York, Washington, and Illinois) where C. maculatum experiences different levels of herbivory by A. alstroemeriana to determine the association between the intensity of the interaction, as measured by damage, and chemical defense production. Total alkaloid production in C. maculatum was positively correlated with A. alstroemeriana herbivory levels: plants from New York and Washington, with higher herbivory levels, invested two and four times more N to alkaloid synthesis than did plants from Illinois. Individual plants with lower concentrations of alkaloids from a single location in Illinois experienced more damage by A. alstroemeriana, indicative of a preference on the part of the insect for plants with less chemical defense. These results suggest that A. alstroemeriana may act either as a selective agent or inducing agent for C. maculatum and increase its toxicity in its introduced range.  相似文献   
88.
微分进化算法(DE)是模仿生物进化“优胜劣汰、适者生存”的一种随机优化算法,具有简单、快速、鲁棒性好等特点,已经得到广泛应用.通过运用微分进化算法的整数编码方法,在整数空间中求解,并在实数空间中计算解的适应度.使用测试函数对程序进行测试,证明了整数编码解对空间个体中寻优的快速性、准确性.  相似文献   
89.
针对特征模型的演化导致特征间的冲突问题, 从特征模型的演化方面进行研究, 提出了一种基于本体的特征模型演化的一致性验证方法。首先采用本体理论方法对特征模型的演化进行分析和建模, 建立本体的特征模型元模型; 其次基于上述元模型, 为网上购物系统实例建立相应的网上购物的领域特征模型, 根据需求裁剪出产品特征模型; 然后在Eclipse集成开发环境下, 通过Jena推理机加载规则和产品特征模型进行一致性验证, 当检测到冲突时, 采用演化策略来消除冲突; 最后通过实例研究说明了该方法的有效性。  相似文献   
90.
Exothermic regimes in the Earth's interior at an early stage of evolution are considered. Conditions are found that lead to selfaccelerating development of gravitational differentiation—separation of the heavier material forming the Earth's core from silicates in extended and heated local areas.  相似文献   
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