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61.
Optimizing Transportation Problems with Multiple Objectives   总被引:3,自引:0,他引:3  
Virtually all models developed for transportation problems have focused upon the optimization of a single objective criterion, namely the minimization of total transportation costs. They have generally neglected or often ignored the multiple conflicting objectives involved in the problem, the priority structure of these objectives, various environmental constraints, unique organizational values of the firm, and bureaucratic decision structures. However, in reality these are important factors which greatly influence the decision process of transportation problems. In this study the goal programming approach is utilized in order to allow for the optimization of multiple conflicting goals while permitting an explicit consideration of the existing decision environment.  相似文献   
62.
It is contended that rehabilitation psychologists have remained content to continue using the same techniques for the same types of problems that they used more than a decade ago. Because of a temerity of thought, rehabilitation psychologists have not extended their particular research and technological expertise into the more major areas of health care. Examples are presented in which such psychological techniques as conditioning and biofeedback were employed to treat successfully a variety of serious health problems. Rather than leave the major areas of investigation and treatment to others, as has traditionally been the case, rehabilitation psychologists are urged to utilize their skills in studying and treating the major physical problems of their patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
63.
A combination of controlled annealing and characterization by scanning probe microscopy (SPM) is used to demonstrate that the refractive-index proffle of a commercially available silica-based optical fiber can be accurately reconfigured for use as an evanescent field sensor. The process relies on the controlled relocation of the silica glass dopants across the fiber cross section through heat treatment and the accurate measurement of the resulting dopant redistribution with SPM and differential etching techniques. The effect of variable annealing along a length of fiber is to produce a mode transformer to couple light from a laser source into the sensing region of the fiber.  相似文献   
64.
A method has been developed that enables resonance Raman spectra of photolabile species in solution to be recorded under conditions where the level of photoalteration is controlled: a low level enables reactant spectra to be recorded, whereas a high level enables the spectra of short-lived transient species to be recorded in real time using continuous-wave (CW) lasers and standard Raman detection equipment. The design includes a sealed flow system, enabling air-sensitive species to be studied under an inert atmosphere. A simple theoretical model has been developed to aid the interpretation of experimental results, and its applicability is demonstrated. Controlled photoalteration and its theory are demonstrated with 413.1-nm excitation of carbonmonoxymyoglobin (MbCO), which generates deoxymyoglobin (deoxy-Mb) on photolysis, and for which the spectra of both species are well established. The methods have also been applied to two air-sensitive, photolabile transition metal carbonyls using 514.5-nm wavelength excitation: for Cp2Mo2(CO)6 (Cp = eta5-C5H5), increasing levels of photoalteration result only in a decrease in the parent band intensities, relative to the solvent bands; for Cp2Fe2(CO)4, increasing levels of photoalteration result in the appearance of additional bands that are assigned to the transient species CpFe(mu-CO)3FeCp, formed following the loss of a CO ligand.  相似文献   
65.
LiCoO2 is the most common lithium storage material for lithium rechargeable batteries, used widely to power portable electronic devices such as laptop computers. Operation of lithium rechargeable batteries is dependent on reversible lithium insertion and extraction processes into and from the host materials of lithium storage. Ordering of lithium and vacancies has a profound effect on the physical properties of the host materials and the electrochemical performance of lithium batteries. However, probing lithium ions has been difficult when using traditional X-ray and neutron powder diffraction techniques due to lithium's relatively low scattering power when compared with those of oxygen and transition metals. In the work presented here, we have succeeded in simultaneously resolving columns of cobalt, oxygen and lithium atoms in layered LiCoO2 battery material, using experimental focal series of LiCoO2 images obtained at sub-?ngstrom resolution in a mid-voltage transmission electron microscope. Lithium atoms are the smallest and lightest metal atoms, and scatter electrons only very weakly. We believe our observations of lithium to be the first by electron microscopy, and that they show promise for direct visualization of the ordering of lithium and vacancies in transition metal oxides.  相似文献   
66.
Thymidine monophosphate kinase (TMPK) from Mycobacterium tuberculosis (TMPKmt) is an attractive target for the design of specific inhibitors. This fact is the result of its key role in the thymidine pathway and of unique structural features in the active site observed by X-ray crystallography, especially in comparison to its human counterpart (TMPKh). Different 5-modified thymidine derivatives, as well as purine and pyrimidine analogues or C-nucleosides were tested on TMPKmt and TMPKh, and the results were rationalized by docking studies. 5-Halogenated 2'-deoxyuridines are the best inhibitors of TMPKmt found and present the highest selectivity indexes in favor of TMPKmt.  相似文献   
67.
The antenna temperature measured by a microwave radiometer is converted in brightness temperature (TB) by removing the different contributions that do not come from the main lobe of the antenna. Among them, the Earth contribution in the sidelobes may be significant as for the Environmental Satellite mission due to the antenna position on the platform. In such a case, simple corrections commonly applied on previous altimetry missions are inadequate, and a more accurate correction should be determined. We propose in this paper a new method based on global seasonal tables of contamination. This allows application of an accurate sidelobe correction in space and time in the retrieved TB computation  相似文献   
68.
一种基于非线性超声谐波幅值比的微裂缝探测方法   总被引:2,自引:0,他引:2  
超声波穿过受损材料后,都会产生一定程度的非线性效应,如谐波.利用非线性波动理论中二阶谐波幅值与基波幅值的关系,探讨了通过测试谐波比关系的变化,获得材料非线性特征改变,进而判断材料损伤的方法,并进行了试验研究.试验中制作了两组水泥砂浆试棒,采用了相同活性碱骨料砂、相同水灰比,其中一组中通过碱骨料反应引入不同程度的微裂缝;另一组保持无损状态.两组水泥砂浆试验的对比试验结果表明,材料经碱骨料损伤后,其超声非线性特征变化十分明显.证明本方法对混凝土材料微裂缝的探测非常敏感,对于水泥基材料而言,是一种极具潜力的材料退化评估方法.  相似文献   
69.
任何新事物都会遇到抵抗.事情总是这样.每个组织都有一种免疫系统,具备自动袭击任何变化的抗体.  相似文献   
70.
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