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   Science & Technology Review
2007, Vol.25, No. 0704
25 February 2007

Articles

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Science & Technology Review. 2007, 25 (0704): 1-1. ;  doi:
Full text: HTML (1 KB)  PDF  (79 KB)  ( 132 )
Abstract ( 370 )

Science & Technology Review. 2007, 25 (0704): 76-76. ;  doi:
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Abstract ( 276 )
Articles

Accelerating Independent Innovation of the Products with VM Technique

Science & Technology Review. 2007, 25 (0704): 5-14. ;  doi:
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Abstract ( 514 )
In this paper, the technical road map to accelerate independent innovation of the products with Virtual Manufacturing (VM) technique is proposed in executing the strategy “to promote the building of innovation-oriented country”. This paper discusses the features of VM technique. Three typical instances of product innovation, that is, the product innovation based on the reverse engineering, the independent product innovation, and the multi-disciplines product innovation, are introduced,in which the products of owing independent intellectual assets have been developed in short time. Some opinions how VM is applied in our industry are presented.

Collaboration Integrated Platform of Design, Simulation and Optimization for Complex Products

Science & Technology Review. 2007, 25 (0704): 15-24. ;  doi:
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Abstract ( 585 )
The industry for complex products is important for national economy and national safety. Although tools like Computer Aided Design, Computer Aided Engineering and Computer Aided Optimization have been used successfully, and with prominent results, the design, engineering, optimization are mostly dealt with separately, and in this way, the data of complex product virtual prototype is difficult to be managed. Now PDM system can manage document, product structure, engineering change and workflow jointly, but it can not integrate CAX process(CAD modeling process, CAE simulation process, CAO optimization process)and CAX data(CAD digital model, CAE analysis result, CAO optimization project). According to the features of complex product design, an integrated platform for collaborative design, simulation , optimization is proposed, which is useful in improving quality of complex products and reducing the cost.

Research on Virtual Machining and Its Key Techniques

Science & Technology Review. 2007, 25 (0704): 25-30. ;  doi:
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Abstract ( 1366 )
The virtual machining represents a trend in the machining of product parts. In this paper, based on the analysis of the concept and connotation of virtual machining, some of its key techniques are discussed, including geometry modeling, numeric control code translation, interference detection and material removal simulation. A typical architecture of virtual machining system is presented, based on which, a virtual machining system named as General Machining Procedure Simulator (GMPS) is implemented at the national CIMS Engineering Research Center (CIMS-ERC) in Tsinghua University. Now the system has been applied to practical engineering projects and some benefits are gained.

Research on Regional Evaportranspiration of Three Basins in Shanxi Based on Remote Sensing Method

Science & Technology Review. 2007, 25 (0704): 31-34. ;  doi:
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Abstract ( 495 )
Using visible and infrared satellite remote sensing data, SEBS (Surface Energy Balance System) is based on land surface energy balance theory combined with the in-situ meteorological data or the product of atmospheric numerical model to estimate land surface turbulent flux and the relative evaporation at different scales. On the basis of hydro-geological data, NOAA satellite data and the meteorological data, SEBS was used in this paper for the estimation of actual evaportranspiration of three basins. The distribution of regional evaportranspiration was evaluated and the influence factors were also analyzed in this paper.

Directional Solidification and Oriented Growth of TbDyFe Alloy

Science & Technology Review. 2007, 25 (0704): 35-38. ;  doi:
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Abstract ( 528 )
The solidification characteristics of Tb0.27Dy0.73Fex(x=1.8,1.95at%) alloy, as a giant magnetostrictive material, are studied with a super high temperature gradient directional solidification equipment developed by the authors. The microstructure of Tb0.27Dy0.73Fe1.8 with ordered plate-like structure, unordered cylindrical structure and mixed structure can be formed under different solidification conditions. For Tb0.27Dy0.73Fe1.95 alloy, however, the microstructure is always of ordered plate-like structure, independent of the temperature gradient GL and the crystal growth velocity V. The relationship between the solidification condition, the crystal morphology and the preferred growth direction of Tb0.27Dy0.73Fe1.95 alloy is analyzed. When the crystal morphology is cellular or non-branch dendritic, <110> orientation is preferred. A <112> orientation will be preferred when the crystal morphology is advanced dendritic, and when the crystal morphology is in the transition zone of cellular to dendrite, mixed orientations with <110>, <112> and <113> can occur. The cellular to dendrite transition zone is reduced with the increase of the temperature gradient. The solidification point GL/V is in the range of (9.60~10.45)×102 K·s/mm2 when the crystal morphology transits from cellular to dendrite.

An Approximate Method of Calculating the Fundamental Frequency of Multi-Cracked Beams

Science & Technology Review. 2007, 25 (0704): 38-40. ;  doi:
Full text: HTML (1 KB)  PDF  (390 KB)  ( 261 )
Abstract ( 537 )
An approximate method of calculating the fundamental frequency of bending vibrations of multi-cracked beams is proposed on the basis of a modification of the method for single-cracked structures. The deflection of multi-cracked beams is assumed by adding polynomial functions to that of the uncracked beams. This new deflection function satisfies the boundary and the kinematic conditions. The closed-form expressions for the fundamental frequency are obtained by using the Rayleigh method. Its validity is confirmed by comparison with Ansys simulation results.

A Ranking Method for DEA Based on Common Weights Vector Set

Science & Technology Review. 2007, 25 (0704): 41-43. ;  doi:
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Abstract ( 503 )
In this paper, a ranking method for DMU based on a set of common weights to obtain the DMU's relative efficiency index is analyzed, and the shortcoming of this method is pointed out. Then a definition of common weights vector set is given and a new ranking method for DEA based on it is proposed.

Viral Hepatitis: A Dangerous Zoonosis

Science & Technology Review. 2007, 25 (0704): 44-52. ;  doi:
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Abstract ( 425 )
In this paper, the characteristics and the epidemic of viral hepatitis are reviewed, including also the animal model and the natural infection in various animals. The research progress on viral hepatitis of animals in our lab is briefly described. The cause of viral hepatitis is quite complex and its incidence is still rising, which seriously threatens human health. Lots of animals have been infected, which suggests that viral hepatitis has already become a dangerious zoonosis, especially, viral hepatitis of livestock and poultry, which are so close to human beings. This might explain the wide viral hepatitis epidemic in human beings. Viral hepatitis of animal has already become an important issue with respect to public health, so we must attach great importance to research on the relationship between viral hepatitis of animals and that of human beings, their interspecies transmission mechanism, especially. for viral hepatitis of domestic animals and poultry.

State of Art of Investigation on Stealth Aircraft

Science & Technology Review. 2007, 25 (0704): 53-56. ;  doi:
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Abstract ( 1295 )
Stealth technology of aircraft plays a more and more important role in improving weapons on power of breach and attack in depth, and it was reported that military powerful nations like the USA and Russia had applied plasma stealth technology to military equipments. The designer of F-16 fighter of the USA and the chief editor of Topgun pointed out in Jane's Defence Weekly that "F-22 stealth aircraft is not ideal like what we want" and the fact that F-16 fighter produced by the USA was detected by Yugoslavia radars, not very advanced in technology and was shot down by outdated missiles indicates that the stealthy is not effective using coating radar absorbing materials, configuration design and plasma. In order to solve above problems and develop military weapons by plasma stealth technology in China, one has to follow the guideline of innovation and self-reliance and to use non-equilibrium plasma sources with low energy consumption and high ionization degree.

A Study on Theory and Methodology of Science Citation

Science & Technology Review. 2007, 25 (0704): 57-62. ;  doi:
Full text: HTML (1 KB)  PDF  (396 KB)  ( 278 )
Abstract ( 434 )
A systematic research on science citation is proposed in this paper. The research objective, tasks and its relation with other studies are demonstrated. The main research subjects and methodologies are discussed.

Determination of Science and Technology Progress Contribution Rate in Shaanxi Province

Science & Technology Review. 2007, 25 (0704): 63-66. ;  doi:
Full text: HTML (1 KB)  PDF  (505 KB)  ( 197 )
Abstract ( 433 )
The ratio of the average capital contribution, the science and technology contribution, and the labor contribution in Shaanxi province is determined to be 5:4:1 from 1979 to 2005. The results of recent 10 years are compared with those of previous 17 years, and it is shown that Shaanxi Province's yearly average technology development rate has been dropped by 1.7 percentage points. It can also be shown that the stability and usability of data can be increased by averaging the original data, and by moving forward or backward. The model can be made more rational by adding limits to parameters. The accuracy can be improved by normalizing calculation steps. We can eliminate those contribution rates that can not be explained reasonably, and improve the results by adjusting.

Analysis on Industrial Structural Reorientation of Resource Exhausted Cities in China

Science & Technology Review. 2007, 25 (0704): 67-71. ;  doi:
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Abstract ( 480 )
Industrial structural reorientation is an inevitable choice for all resource-exhausted cities to achieve a sustainable economical and social development. The government should provide three mechanisms for the reorientation, namely, compensation for resource exploitation, assistance for declined industries and support for substitutive industries, to help the resource-exhausted cities. The material connotation of each mechanism is analyzed in this paper, and it is shown that a reform of the resource taxation and charge system is most important for the compensation for resource exploitation; the essence of helping declined industries is to help resource-exhausted state-owned enterprises to back out, and the choice and development of dominant substitutive industry is essential to the substitutive industry support mechanism.

An Analysis on the Issue of “Seeing the Great Wall from Space”

Science & Technology Review. 2007, 25 (0704): 72-76. ;  doi:
Full text: HTML (1 KB)  PDF  (812 KB)  ( 218 )
Abstract ( 1366 )
From the mechanism of optical sensing, color sensing and shape sensing of human eyes, this paper shows that the plane shape sensing and solid shape sensing depend on the size and the distance of the observed objects. With this point of view in mind and with the main research results of the Great Wall remote sensing image processing, various statements on this issue are analyzed and it is shown that human eyes can not see the Great Wall from space orbit, which can only be seen from the Great Wall image of high spatial resolution satellite sensing.

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