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101.
Christophe Duhamel Andréa Cynthia Santos Daniel Brasil Eric Châtelet Babiga Birregah 《Annals of Operations Research》2016,247(2):693-713
In this study, we propose a mathematical model and heuristics for solving a multi-period location-allocation problem in post-disaster operations, which takes into account the impact of distribution over the population. Logistics restrictions such as human and financial resources are considered. In addition, a brief review on resilience system models is provided, as well as their connection with quantitative models for post-disaster relief operations. In particular, we highlight how one can improve resilience by means of OR/MS strategies. Then, a simpler resilience schema is proposed, which better reflects an active system for providing humanitarian aid in post-disaster operations, similar to the model focused in this work. The proposed model is non-linear and solved by a decomposition approach: the master level problem is addressed by a non-linear solver, while the slave subproblem is treated as a black-box coupling heuristics and a Variable Neighborhood Descent local search. Computational experiments have been done using several scenarios, and real data from Belo Horizonte city in Brazil. 相似文献
102.
Chemical Synthesis of Phosphorylated Histone H2A at Tyr57 Reveals Insight into the Inhibition Mode of the SAGA Deubiquitinating Module 下载免费PDF全文
103.
The classical Square Root Law formula for emergency travel times consists of one observable component, the density of patrol coverage, and one unknown component that must be estimated empirically, the effective travel speed. The effective travel speed is typically assumed to be an empirical constant. We test whether this simplifying assumption is justified empirically. We propose a modern machine-learning approach and a Least Absolute Shrinkage and Selection Operator regression to incorporate into a travel speed model various exogenous factors such as call type, incident location, weather conditions and traffic congestion. The value of the proposed analytical approach and some practical implications are demonstrated using operational data from a large urban police jurisdiction based in British Columbia, Canada. Although the analysis is framed within the context of urban emergency police operations, the proposed approach has the potential to be useful for other emergency services or roving business units that deal with unscheduled service calls. 相似文献
104.
A two-step convenient sequence for the synthesis of previously inaccessible mono-Boc-protected bis-N-heterocyclic alkyl substituted ether derivatives 4 is described. Mitsunobu protocol was applied to the preparation of pyridinyl ether precursor 5. The reduction of the electron rich pyridinyl system 5 has been achieved catalytically using the combination of PtO2-H2SO4 or PtO2-pTsOH under a hydrogen atmosphere maintained by a gas balloon at ambient temperature. 相似文献
105.
The mononuclear cations of the general formula [(η6-arene)RuCl(dpqMe2)]+ (dpqMe2 = 6,7-dimethyl-2,3-di(pyridine-2-yl)quinoxaline; arene = C6H6, 1; C6H5Me, 2; p-PriC6H4Me, 3; C6Me6, 4) as well as the dinuclear dications [(η6-arene)2Ru2Cl2(μ-dpqMe2)]2+ (arene = C6H6, 5; C6H5Me, 6; p-PriC6H4Me, 7; C6Me6, 8) have been synthesised from 6,7-dimethyl-2,3-di(pyridine-2-yl)quinoxaline (dpqMe2) and the corresponding chloro complexes [(η6-C6H6)Ru(μ-Cl)Cl]2, [(η6-C6H5Me)Ru(μ-Cl)Cl]2, [(η6-p-PriC6H4Me)Ru(μ-Cl)Cl]2 and [(η6-C6Me6)Ru(μ-Cl)Cl]2, respectively. The X-ray crystal structure analyses of [1][PF6], [3][PF6] and [6][PF6]2 reveal a typical piano-stool geometry around the metal centre; in the dinuclear complexes the two chloro ligands, with respect to each other, are found to be trans oriented. 相似文献
106.
107.
Ab initio density functional and molecular orbital calculations provide singlet and triplet electronic potential energy surfaces for the reactions of CF3CH2I+O(3P) leading to OI and HF eliminations, reactions which have been the subject of recent experimental studies. A barrier to OI formation occurs on the triplet potential energy surface; there is no reverse barrier to OI formation on the singlet pathway. Findings suggest that two competing pathways may form HF. One is an addition-insertion-elimination process involving insertion of O into the C-I bond. The alternate path involves OI elimination, addition of an O atom to CF3CH2, and subsequent HF elimination. The computed reactant pathways and energetics are discussed in relation to recent experiments. 相似文献
108.
Quek SY Biener MM Biener J Bhattacharjee J Friend CM Waghmare UV Kaxiras E 《The Journal of chemical physics》2007,127(10):104704
We develop an atomic-scale model for an ordered incommensurate gold sulfide (AuS) adlayer which has previously been demonstrated to exist on the Au(111) surface, following sulfur deposition and annealing to 450 K. Our model reproduces experimental scanning tunneling microscopy images. Using state-of-the-art Wannier-function-based techniques, we analyze the nature of bonding in this structure and provide an interpretation of the unusual stoichiometry of the gold sulfide layer. The proposed structure and its chemistry have implications for related S-Au interfaces, as in those involved in self-assembled monolayers of thiols on Au substrates. 相似文献
109.
Creation of mammalian single- and double-stranded DNA surfaces: a real-time QCM-D study 总被引:1,自引:0,他引:1
Rawle RJ Selassie CR Johal MS 《Langmuir : the ACS journal of surfaces and colloids》2007,23(19):9563-9566
The quartz crystal microbalance with dissipation monitoring (QCM-D) is an excellent method for studying the creation of DNA-based surfaces and films. Previous studies have used QCM-D to focus on the construction of DNA surfaces composed of short synthetic DNA oligomers or plasmid DNA. Here, we have used QCM-D to monitor the creation of genomic single- and double-stranded calf thymus DNA surfaces on a polycation adsorbed to a SiO2 support. We have successfully monitored the hybridization between the ssDNA surfaces and their complementary strands in solution and have also shown that DNA multilayer formation can be observed using denatured calf thymus DNA. We have furthermore established that the ssDNA and dsDNA surfaces show different binding characteristics to ethidium bromide, a common dsDNA intercalator, demonstrating the potential use of such surfaces to identify possible DNA ligands. 相似文献
110.
Saver C 《OR manager》2007,23(9):1, 7, 9-1, 7,11