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The rotor machine was invented in 1915 by two Dutch navy officers, R. P. C. Spengler and Th. van Hengel, who were working at the Navy Department in the Dutch East Indies. A prototype was built by W. K. Maurits, a mechanical engineer, and tested during the summer of that year on board the flagship of the Dutch Navy in the East Indies on order of the fleet commander Rear Admiral F. Bauduin. Though the Dutch Navy decided not to adopt the device for it prevented the invention from being patented by the original inventors. The Navy could not prevent the rotor machine from being patented, however, by Hugo Alexander Koch—an engineer and businessman working in close collaboration with Arthur Scherbius in Germany—who probably became familiar with the idea through his brother-in-law, Huybrecht Verhagen, a patent attorney working at the firm that had supported the abortive patent application by the original inventors.  相似文献   

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This paper presents an overview of the development of aeronautical satellite communi-cations over the past 30 years. The initial development of aeronautical satellite communications is de-scribed in the paper. The civil aviation growth and current unaccommodated communication systemsare discussed as well. The inherent shortcomings of present air-ground HF communications have hin-dered the development of civil aviation. but according to the Future Air Navigation Systems(FANS) concept aeronautical satellite communication-including Automatic Dependent Surveillance(ADS)-will be the key to eliminating the shortcomings of HF communication systems. Satellite-basedcommunication and surveillance will significantly improve air traffic control (ATC) over the oceanicand remote terrestrial airspace, and it will benefit civil aviation authorities, airlines as wel as passen-gers. This paper discusses the availability of system elements, and world wide trials, demonstrtionsand preoperational use of aeronautical satelli  相似文献   

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Abstract

In this paper, the authors continue developing a Linguistic Theory of the Complex Structural Models, but in terms of the Semantics. Each symbol (transformed function) is syntactically a lexeme, carrying associate a sememe or atomic semantic unit. Each sememe can be decomposed in semes or quantic semantic unities. They are studied the semantic systems, associated with the syntactic, and that serve them as suprastruc-ture, in terms of two levels: the quantic and the atomic. Also, it is demonstrated that for all model of the complex reality, will exist always a most complex model from the syntactic and semantic point of view.  相似文献   

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Totally 8 diffusion couples were prepared and the composition-dependent interdiffusion coefficients in bcc V–Mn, V–Sn and V–Ni alloys were measured between 1323 and 1503 K by means of Sauer-Freise method coupled with electronic probe microanalysis (EPMA) technique. The errors of the interdiffusion coefficients were computed by error propagation method. Based on the measured interdiffusivities and thermodynamic parameters from the literature, the atomic mobilities of bcc V–X (X = Mn, Sn and Ni) alloys were obtained by using the CALTPP (CALculation of ThermoPhysical Properties) program with the features of high efficiency and accuracy in the framework of CALPHAD (CALculation of PHAse Diagram) approach. For each system, the presently obtained atomic mobilities were validated by good agreement between the calculated interdiffusivities and the measured ones. The model-predicted concentration profiles in this work are consistent with the experimental ones. This work contributes to the establishment of the atomic mobility database containing V element and the key input for microstructure simulations in V-based alloys.  相似文献   

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The sodium pyrovanadate (Na4V2O7) powder was synthesized by solid-state reaction using sodium carbonate (Na2CO3) and vanadium pentoxide (V2O5) as raw materials. X-ray powder diffraction (XRD), scanning electron microscope (SEM), and differential scanning calorimeter (DSC) were used to accurately characterize the synthesized sample. The solid-state phase transformation from α-Na4V2O7 to β-Na4V2O7 occurs at the temperature 696 K and the enthalpy is equals to 1.03 ± 0.01 kJ/mol, the endothermic effect at 931 K and the enthalpy is equals to 31.35 ± 0.31 kJ/mol, which is related to the melting of Na4V2O7. The high-temperature heat capacity of Na4V2O7 was measured using a Multi-high temperature calorimeter 96 line and DSC. The obtained high-temperature heat capacity of Na4V2O7, as a function of temperature, was modeled as: Cp=314.62+0.05T-5494390T-2 J·mol-1·K-1 (298.15-873 K). The temperature dependence on heat capacity was then used for computing changes in the enthalpy, entropy, and Gibbs free energy at the specific temperature internal.  相似文献   

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泛系兵法研究(V):经济·人才·诡道·社会·风险   总被引:4,自引:0,他引:4  
本文论述与兵法、权谋、对策、决策、运筹有关的经济学、风险学、诡道学、人才学与社会学的泛系研究以及权谋运筹的白道黑道理法。具体内容包括前言;泛系新理法;泛系经济学与泛系社会学的一些理法;大经济的泛系网络;泛系相对论;乏定客观·风险观控;泛系决策;军工与高技术投资释例分析。本研究系列也是或的泛系对策论、泛系经济学的论纲。  相似文献   

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There is strong research evidence showing that people naturally align to each other’s vocabulary, sentence structure, and acoustic features in dialog, yet little is known about how the alignment mechanism operates in the interaction between users and computer systems let alone how it may be exploited to improve the efficiency of the interaction. This article provides an account of lexical alignment in human–computer dialogs, based on empirical data collected in a simulated human–computer interaction scenario. The results indicate that alignment is present, resulting in the gradual reduction and stabilization of the vocabulary-in-use, and that it is also reciprocal. Further, the results suggest that when system and user errors occur, the development of alignment is temporarily disrupted and users tend to introduce novel words to the dialog. The results also indicate that alignment in human–computer interaction may have a strong strategic component and is used as a resource to compensate for less optimal (visually impoverished) interaction conditions. Moreover, lower alignment is associated with less successful interaction, as measured by user perceptions. The article distills the results of the study into design recommendations for human–computer dialog systems and uses them to outline a model of dialog management that supports and exploits alignment through mechanisms for in-use adaptation of the system’s grammar and lexicon.  相似文献   

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