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排序方式: 共有407条查询结果,搜索用时 25 毫秒
1.
In this paper, a hybrid algorithm consisting of particle swarm optimization and pattern search algorithm is proposed to evaluate and optimize the design and operation of microgrids (MGs) in combined gas and power networks. Key performance indicators (KPIs) are modeled and proposed to evaluate and assess MGs. The paper begins by proposing a comprehensive study to define KPIs, which are used to evaluate the following MG parameters: economical efficiency, reliability, environmental conservation, and power quality. Multi‐objective evaluation functions are then developed by building a relationship matrix of MG and KPI components. The results are then displayed as optimized power generation percentages for each technology with values for four KPI categories: cost, quality, reliability and environmental friendliness. Two case studies are examined in this paper; both the province of Ontario and Toronto regional zone under all system parameters with varying percentage of generation via gas technology. Results indicated that the optimal scenario for both Ontario and Toronto was achieved at hybrid PSO–patern search percentage generation via gas technology with improved cost KPI and other KPIs remaining approximately constant. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
2.
The Mediterranean diet is considered one of the healthiest diets in the world. This is often attributed to low saturated fat consumption, moderate wine consumption, and high vegetable consumption. However, herbs and spices associated with these diets may also play an important role in the quality of this diet. This review summarizes the most recent research regarding the anti-diabetic, anti-inflammatory, anti-hyperlipidemic and anti-hypertensive properties of this collection of culinary species. Additionally, this review briefly summarizes studies performed on lesser known herbs from around the world, with the goal of identifying new culinary species that may be useful in the treatment or prevention of diseases.  相似文献   
3.

Wintertime measurements of atmospheric aerosol over the size range 3-500 nm made approximately 30 m above street level in central Manchester are reported. These are compared with measurements of trace gases. It is found that secondary accumulation mode particles follow closely the values of NOx in the atmosphere and are closely related to vehicle activity, reaching a maximum at about 9 am. New particle formation close to the observation point is closely related to SO2 concentrations, predominately during daylight hours, and is a maximum around mid-day but persists after dark. The concentrations of fine and Aitken mode particles were much higher than in nearby rural areas, but the concentration of particles in the size range 200-500 nm were similar at the urban and rural sites. In addition, measurements of ammonia, a gas often important in nucleation kinetics, revealed concentrations up to 17 ppb in Manchester.  相似文献   
4.
The sources of ultra low frequency (ULF) waves in the magnetosphere are generally believed to be either the external solar wind perturbations or the internal plasma instabilities. When a sudden impulse of the solar wind dynamic pressure impinges on the magnetopause, ULF waves might be excited and thus the solar wind energy is transported into the earth’s magnetosphere. In this paper, we study the ULF waves excited by different kinds of sudden solar wind pressure impulses through an MHD simulation. We primar...  相似文献   
5.
The authors argue that persons derive in-group expectancies from self-knowledge. This implies that perceivers process information about novel in-groups on the basis of the self-congruency of this information and not simply its valence. In Experiment 1, participants recalled more negative self-discrepant behaviors about an in-group than about an out-group. Experiment 2 replicated this effect under low cognitive load but not under high load. Experiment 3 replicated the effect using an idiographic procedure. These findings suggest that perceivers engage in elaborative inconsistency processing when they encounter negative self-discrepant information about an in-group but not when they encounter negative self-congruent information. Participants were also more likely to attribute self-congruent information to the in-group than to the out-group, regardless of information valence. Implications for models of social memory and self-categorization theory are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
6.
The authors discuss empirical research about the cognitive structures and strategies used by programmers during fault location. Empirical evidence indicates the cognitive processes involved in fault detection consist of a comprehension process and a fault location process. The two processes are distinct and separate. The comprehension process is extremely important and was found to be superior in experts due to the semantic encoding they utilize. The semantic representations used by experts consist of abstract hierarchies based on functional meaning. Fault location is less important and usually takes the form of hand simulation or causal reasoning. The fault locating strategies used by experts and novices were similar. The better debugging performance by experts is due to their superior abilities at comprehension. Research indicates that the semantic organizations used by experts can be successfully taught to novices and used by them to improve performance.

The authors also examine two methods, slicing and team reviews, which seek to improve the debugging process. Each was found to affect comprehension and fault location differently. A review of slicing research revealed that it is performed during the fault location process, and does not apply to the comprehension process as some believe. Automating slicing was found to be a technique with potential benefits for debugging. The survey of the team dynamics during inspections and other reviews found them to be effective by enhancing the comprehension process, by improving fault location, and by providing more than one chance to catch each error.  相似文献   
7.
The Dst index,designed as a proxy of ring current intensity,is known to be also affected by other magnetospheric current systems,e.g.magnetopause current.The pressure-corrected Dst index is obtained by removing the effects of the solar wind dynamic pressure and the quiet time ring current.However,all previous studies treated the correction coefficient as an averaged parameter for storms of different intensity.In this paper,based on the Burton's equations and employing two independent methods,we will show a ...  相似文献   
8.
The C-Cl stretching regions of the Raman spectra of a number of samples of PVC prepared by various methods which lead to differences in tacticity, conformational content and crystallinity have been studied. It is shown that the spectra of all samples can be fitted well with a set of nine Lorentzian peaks whose positions and widths are the same for each spectrum. Two of these peaks are attributable to the Ag and B3g species vibrations of crystalline material and the remaining seven may be assigned with reasonable confidence to specific structures in the amorphous regions, three of which are associated with isotactic placements. The area under the Ag and B3g peaks may be used to estimate the crystallinity of the samples and the area under the peaks assigned to isotactic material may be used to estimate the tacticity of the polymer.  相似文献   
9.
A flextensional actuator was designed using commercial multilayer stacked actuator so as to produce large displacements at intermediate force levels. The simple design chosen eliminated the need for bonding the actuators into the frame and permitted easy series connection of multiple units. To satisfy the need for a fiber grating tuning device to interrogate an array of Bragg grating fiber optic stress sensors, a tuning device using four series connected units was constructed. The unit performs well, but the actual measured amplification is less than theoretical expectation. The problem was traced to unwanted flexing of the simple original frame and a hinged more robust flexing beam construction was shown to eliminate the problem.  相似文献   
10.
Wild-type chloroperoxidase catalyzes the efficient chiral epoxidation of secondary olefins but is rapidly inactivated in a mechanism-based suicide reaction when incubated with hydrogen peroxide and primary olefins. Directed evolution mutants of chloroperoxidase have now been isolated that are resistant to suicidal inactivation. Plasmid vectors containing error-prone copies of the chloroperoxidase gene and a hygromycin B resistance marker gene have been used to transform Caldariomyces fumago spheroplasts and produce mutant libraries. The mutant library clones were screened for their ability to resist mechanism-based inactivation by allylbenzene. Four generations of PCR-based random mutagenesis and screening yielded mutants that were completely resistant to the suicide-inactivation reaction. Rather surprisingly, the fourth generation mutant developed enhanced epoxidation activity in addition to resistance to allylbenzene inactivation. These initial results suggest that the directed evolution technique can be used to produce chloroperoxidase variants that can further exploit the potential of chloroperoxidase for the synthesis of chiral intermediates.  相似文献   
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