Produced water constitutes a large amount of waste fluids during the production operation of an oil field. Underground injection for disposing the wastewater from hydrocarbon production is an engineering problem due to the possibility of leakage of injected pollutant material from receiving medium to a drinking water source. This paper describes a method for optimization of polluted aquifer remediation design using one of the artificial intelligence optimization methods, namely Genetic Algorithms (GAs). As a case study, the contaminated area was created by using a groundwater transport simulator, which is based on Method of Characteristics (MOC). Then, the developed computer program was run to find the optimum solution for remediation, and the solution yielded from the program was verified by using a groundwater simulator. The plume was captured and the concentration level of chloride ion within the aquifer was diminished by using extraction wells. The analytical model approach provided different alternatives for appropriate isolation of plume. GAs were used as an optimization technique for making a decision among the alternatives, by considering operation time, number of wells, pumping rate and drawdown as decision variables and constraints. 相似文献
We consider inhomogeneous quantum groups that transform various types of fermions: standard fermions, commuting fermions and orthofermions. These quantum groups are notq-deformations. 相似文献
Light scattering is a useful diagnostic tool for characterization of particles. Direct scattering measurements for arbitrarily shaped micro-scale particles is difficult due to small-scale limitations. Microwave analogy is a convenient approach to realize such measurements as it enables realization of analogous experiments with larger model particles in a spectral domain where wavelengths are on centimeter scale. In the present study a test model analogous to light scattering by a micro-scale aggregate of dielectric spheres was constructed and experimentally characterized in the microwave regime. Measured amplitude and phase of the scattered field were compared with theoretical predictions obtained from quasi-exact multiple-scattering T-matrix method and discrete dipole approximation (DDA). Excellent agreement demonstrates the validities of both the experiment and the models. 相似文献
This paper reports results from a written assessment given to 290 third-, fourth-, and fifth-grade students prior to any instructional intervention. We share and discuss students’ responses to items addressing their understanding of equation structure and the meaning of the equal sign. We found that many students held an operational conception of the equal sign and had difficulty recognizing underlying structure in arithmetic equations. Some students, however, were able to recognize underlying structure on particular tasks. Our findings can inform early algebra efforts by highlighting the prevalence of the operational view and by identifying tasks that have the potential to help students begin to think about equations in a structural way at the very beginning of their early algebra experiences. 相似文献
The current contribution serves as a critical update to a previous feature article from us (Macromol. Rapid Commun. 2012 , 33, 958−971), and highlights the latest advances in the preparation of single chain polymeric nanoparticles and initial—yet promising—attempts towards mimicking the structure of natural biomacromolecules via single‐chain folding of well‐defined linear polymers via so‐called single chain selective point folding and repeat unit folding. The contribution covers selected examples from the literature published up to ca. September 2015. Our aim is not to provide an exhaustive review but rather highlight a selection of new and exciting examples for single‐chain folding based on advanced macromolecular precision chemistry. Initially, the discussion focuses on the synthesis and characterization of single‐chain folded structures via selective point folding. The second part of the feature article addresses the folding of well‐defined single‐chain polymers by means of repeat unit folding. The current state of the art in the field of single‐chain folding indicates that repeat unit folding‐driven nanoparticle preparation is well‐advanced, while initial encouraging steps towards building selective point folding systems have been taken. In addition, a summary of the—in our view—open key questions is provided that may guide future biomimetic design efforts.
Reaction of the oxo-molybdenum(V) compound, [MoTp*(O)Cl2], [Tp*=hydrotris(3,5-dimethylpyrazol-1-yl)borate] with p-methoxy and p-nitroaniline in the presence of Et3N under N2, afforded the oxo-bridged oxo(arylimido) molybdenum(V) complexes, [MoTp*(O)Cl](-O)[MoTp*(Cl)(NC6H4R)] (1, R=OMe; 2, R=NO2). The new compounds were characterized by elemental analysis, i.r., mass, and 1H-n.m.r. spectra. The single crystal X-ray crystallographic determination of [MoTp*(O)Cl](-O)[MoTp*(Cl)(NC6H4OMe)] was carried out to confirm that there is a Mo—O—Mo bridge and a near linear arylimido group in the structure. 相似文献
The controlled folding of a single polymer chain is for the first time realized by metal‐ complexation. α,ω‐Bromine functional linear polymers are prepared via activators regenerated by electron transfer (ARGET) ATRP (,SEC = 5900 g mol−1, Đ = 1.07 and 12 000 g mol−1, Đ = 1.06) and the end groups of the polymers are subsequently converted to azide functionalities. A copper‐catalyzed azide–alkyne cycloaddition (CuAAC) reaction is carried out in the presence of a novel triphenylphosphine ligand and the polymers to afford homotelechelic bis‐triphenylphosphine polymeric‐macroligands (MLs) (,SEC = 6600 g mol−1, Đ = 1.07, and 12 800 g mol−1, Đ = 1.06). Single‐chain metal complexes (SCMCs) are formed in the presence of Pd(II) ions in highly diluted solution at ambient temperature. The results derived via 1H and 31P{1H} NMR experiments, SEC, and DLS unambiguously evidence the efficient formation of SCMCs via metal ligand complexation.
Although graphite and hexagonal form of BN (h-BN) are isoelectronic and have very similar lattice structures, it has been
very difficult to
intercalate h-BN while there are hundreds of intercalation compounds
of graphite. We have done a comparative first principles investigation of lithium intercalation of graphite and hexagonal
boron nitride to provide clues for the difficulty of h-BN intercalation. In
particular lattice structure, cohesive energy, formation enthalpy,
charge transfer and electronic structure of both intercalation
compounds are calculated in the density functional theory framework
with local density approximation to the
exchange-correlation energy. The calculated formation enthalpy
of the considered forms of Li intercalated h-BN is found to be positive which rules out h-BN intercalation without externally
supplied energy. Also, the Li(BN)3 form of Li-intercalated
h-BN is found to have a large electronic density of states at the Fermi level and an interlayer state that crosses Fermi level
at the zone center; these properties make it an interesting material to investigate the role of interlayer states in the superconductivity
of alkali intercalated layered structures. The most pronounced change in the charge distribution of the intercalated compounds
is found to be charge transfer from the planar σ states to the π states. 相似文献