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41.
This paper investigates the relationships between the accepting powers of three-dimensional six-way finite automata (3-FA's) and three-dimensional five-way Turing machines (5WTM's), where the input tapes of these automata are restricted to cubic ones. A 3-FA (5WTM) can be considered as a natural extension of the two-dimensional four-way finite automaton (two-dimensional three-way Turing machine) to three dimensions. The main results are: (1) n2logn (n3) space is necessary and sufficient for deterministic 5WTM's to simulate deterministic (nondeterministic) 3-FA's; (2) n2 (n2) space is necessary and sufficient for nondeterministic 5WTM's to simulate deterministic (nondeterministic) 3-FA's.  相似文献   
42.
This paper investigates closure properties (under row and column catenations, row and column closures, row and column cyclic closures, and projection) of the classes of sets accepted by four-way and three-way tape-bounded two-dimensional Turing machines whose input tapes are not restricted to square ones.  相似文献   
43.
ZL101合金半固态二次加热   总被引:4,自引:1,他引:4  
采用半固态合金二次加热,对半固态坯料施加合理的二次加热路径,重新获得适于后续加工的具有近球状固相颗粒均匀分布的半固态组织。采用功率为20kW,频率为30kHz的高频感应加热装置,研究了采用再熔融加热法制备的ZL101半固态合金坯料的二次加热过程。结果表明:为了获得适于最终成形的半固态组织,有必要把半固态坯料二次加热过程分为几个加热速率不同的加热阶段,然后在半固态温度区间某一需要加工温度下进行适度保温。通过实验给出了ZL101合金半固态坯料二次加热条件,并讨论了二次加热条件对半固态组织演化的影响。  相似文献   
44.
1 Introduction Unidirectional solidification technology is used to get special properties of casting, for example, to get the turbine blades with columnar or single crystal structures. Several modelling approaches have been carried out for the structure d…  相似文献   
45.
Cytological changes of feather pulp lesions (FPL) sampled chronologically from the same specific-pathogen free chickens inoculated with Marek's disease virus serotype 1 (MDV) were examined, comparing with their histological changes. The birds having Marek's disease (MD) lymphomas or nerve lesions exhibited the characteristic lesion changes on the cytological smears of FPL; the initial non-suppurative inflammatory to the late lymphomatous FPL. The birds having neither the MD visceral lymphomas nor the nerve lesions manifested only non-suppurative inflammatory FPL on the cytological smears throughout the experimental periods. Histological evaluation of FPL sampled from the same birds confirmed as above mentioned cytological results. From these results, the cytological evaluation of FPL proved to be an effective diagnostic and prognostic tool in foreseeing MD incidence.  相似文献   
46.
Superconducting generators have many advantages such as increasing generator efficiency and improving power system stability. In Japan, a national project has been conducted since 2000 which is aimed at the development of fundamental technologies required for high‐output‐density and large‐capacity superconducting generators. This paper describes the results of this project, focusing on 6000‐A‐class field winding development. Copyright © 2004 Wiley Periodicals, Inc. A superconducting generator with a high output density and a large capacity has inherent factors that decrease superconducting stability. These are: (1) increase in the magnetic field in the winding which is caused by the increase in winding current density and (2) difficulty in fabricating windings which increases as a conductor diameter becomes larger. To secure the stability, we adopted a higher‐copper‐content conductor and a design that increases winding fixing pressure, along with devising a winding method that accommodates larger conductor diameter. These improvements were applied to a partial model of a 600‐MW field winding. Test results of the model showed good stability, indicating that design and fabrication technique for a 6000‐A‐class superconducting field winding has been successfully evaluated. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(2): 7– 18, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20332  相似文献   
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48.
This paper investigates a space hierarchy of the classes of sets accepted by alternating space-bounded two-dimensional Turing machines which have only universal states and whose input tapes are restricted to square ones and shows that there exists a dense hierarchy for the classes of sets accepted by these Turing machines with spaces of size less than or equal to logm.  相似文献   
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“Cutting strength” is proposed as a new indicator of the resistance of materials to cutting. This indicator is the ratio of the cutting force in the orthogonal cutting and the cross section of the part of the specimen to be cut. It essentially depends only on the property of the material and is independent of the cutting width or depth. It can also give an indication of the resistance of surfaces to scratching.  相似文献   
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