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The key techniques in the design of the stratospheric platform involved material science, energy, construction project, manufacturing, atmospheric environment, control, navigation and communication, etc.
Airship key techniques include aerodynamic design, structural design, energy, envelope materials, power plant, environmental data collection, simulation environment test and outfield test.
Envelope Materials.
Qu: Materials Engineering Vol.8 (1993), p. 44 [10] J.H.
Wu: Journal of System Simulation Vol.20 (2008), p. 165

Fatigue Properties of Spherical Graphite Iron Crankshafts Mingtu MA1, a, Zhigang LI1, Hongliang YI1 and Hao ZHANG2 1 Department of Materials Science and Technology, Chian Chongqing Automobile Research Institute, Chongqing 400039, P.
To save the cost of producing of parts, casting may be used to replace forging via enhancing the properties of traditional materials by high technology.
As a consequence, the QT800-3 is chose as the substitute materials for crankshafts due to its similar properties to the heat treatment 40Cr forging steel.
The equation indicates that the existence of crack C brings about the decline of fracture strength of materials, and then if the C is bigger, the fracture stress will be smaller.
Dong: Strength of Metallic Material, Science Publishing, Beijing (1989).

These include approaches like acoustic insulation of the gearbox housing or using vibration damping materials, which are less direct and aim to reduce noise transmission rather than addressing the source.
- Gearbox Housing Design and Material Use: Innovative Gearbox Housing Materials [20]: Exploring materials with better acoustic damping properties to reduce noise transmission from the gearbox.
Ding et al., "A Comprehensive Approach to Gear Vibration and Noise Control," International Journal of Mechanical Sciences, vol. 64, no. 1, pp. 1-12, 2022
Shaikh, "Noise Reduction in Gear Systems by Phase Tuning," Journal of Sound and Vibration, 2014
Singh, "Materials and Acoustic Insulation Techniques in Automotive Gearboxes," Journal of Sound and Vibration, 2012

The V-notch Charpy impact test, which has been widely used as a pre-qualification test of material toughness, is also used for estimating "fracture mechanics-based toughness of materials".
This method is based on the Weibull stress criterion, in which the Weibull stress at brittle fracture could provide materials constants independent of differences in loading rate and specimen geometry.
This method is based on the Weibull stress criterion, in which the Weibull stress that is influenced by the mechanical and toughness properties of materials is assumed to provide materials constants.
The materials were selected in terms of the yield-to-tensile ratio YR, which exerts a strong influence on crack-tip stress fields.
Trolldenier: International Journal of Fracture Vol. 54(1992), pp. 197-210

Table 6: Effective density results for the mineral materials of rubber-modified asphalt mixture Test items Weight of pot spoon in the air (g) Weight of pot spoon in the water (g) Weight of pot spoon mineral materials in the air (g) Weight of pot spoon asphalt mineral materials in the air (g) Weight of pot spoon asphalt mineral materials in the water (g) Effective relative density Aveage of effective relative density Compound mineral materials 116.6 86.2 606.8 1023.3 412.1 2.7356 2.735 104.4 83.3 594.7 1011.5 409.2 2.7345 Rubber-modified asphalt 91.1 68.2 --- 522.5 83.3 1.0363 1.037 86.5 65.5 --- 516.6 81.2 1.0379 GTM and Marshall method are respectively used to study specimens at the hot-mix temperature and the test temperature prepared in Table 5, and then the bulk density is measured to calculate the porosity; test and calculation data are shown in Table 7, and the trend of bulk density and void ratio of the molded specimens changing with the molding temperature
Fujian Building Materials, 2010(2):20～22.
Journal of Hunan University (Natural Sciences), 2010, 37(8):1～5.
Journal of East China Jiaotong University.2010, 27(4):22～25.
Journal of Building Materials, 2009, 12(4):438～441.

The Design of Flash Network Courseware Weiyan Liang Jiaying University, School of Education Science, Meizhou, Guangdong, 514015 liangweiyan@jyu.edu.cn Keywords: Flash, Network Courseware, Design.
Production Material Collection.
The multi-media materials cover all audio and visional material adopted in multi-media courseware.
The material collection shall be subject to needs of script.
The excellent courseware shall integrate science, art and technique, so as to maximize the potential of course ware, strengthen presentation effect and improve the quality of multimedia courseware.

(refer with: fig 2), and assumptions as the following : In order to simulate loaded analysis and calculate value, consider tool, tool rest, and slip sheet material as a whole.
In general, according to the processing parameters, choose carbon steel as the workpiece material, cutting speed , feeding the f = 0.5 mm/r, turning back .
According to the cutting force empirical formula: [5-6] (1) In the formula, ─depend on the coefficient of processed materials and cutting condition; , , ─index of cutting parameter in formula; ─ among the component force calculation, when the actual machine tool processing situation and the empirical formula used situation are inconsistent, multiply-add of the correction coefficient of multiple conditions influence on cutting force ,each coefficient, index and the correction coefficient value can refer to the handbook of metal cutting. select ,,,, = 0.9807 ,then calculate the experience value of the radial cutting force: .
Therefore to reduce the machine tool geometric error under the cutting force influence, a reasonable choice of a strong strength materials, reasonable design which increase the strength of machine tools; In order to reduce the stress, the cutting parameters of machine tool should be adjusted; According to the cutting condition, software compensation on the machine tool geometric error are quite necessary.
Journal of mechanical engineering, Vol. 12 (2002) No.38, p. 151-154

Journal Citation (to be inserted by the publisher) Copyright by Trans Tech Publications Characterization of Nanoporous Low Dielectric Polysilsesquioxane Thin Films Jingyu Hyeon-Lee *1, Yi Yeol Lyu 1, Mong Sup Lee 2 , Jin-Heong Yim 1 and Sang Youl Kim 2 1 Electronic Materials Laboratory, Samsung Advanced Institute of Technology, Suwon, 440-600, Korea 2 Department of Chemistry, Korea Advanced Institute of Science and Technology, Taejon, 305-701, Korea.
Introduction As the minimum geometry of microelectronic devices continues to shrink, the conventional dielectric material, silicon dioxide (k~ 4.0), is no longer adequate for next generation integrated circuits.
Therefore, new materials with low dielectric constants are required to minimize the RC delay.
Current chip manufacturing processes require the insulating materials to have low moisture uptake, good mechanical strengths, and thermal stability, etc.
Jun-Hee Hahn of Korea Research Institute of Standards and Science is acknowledged for hardness and modulus measurements.

Acknowledgement This research was supported by the financial supports from Jiangsu Natural Science Fund, P.
China (BK2006723), Natural Science Fund by the Education department of Henan Province P.R.
XU and Y.C.FU: Key Engineering Materials, Vol. 359-360.(2008), pp 43-47
TSAI and S.T.LIN: Materials Chemistry and Physics, Vol. 84 (2004), pp. 251–258
Chinese Journal of lasers, Vol. 36 (2009), pp 3079-3083.

The principle of magnetic flux leakage testing The magnetic flux leakage testing is a kind of nondestructive testing technology that finds defects through detecting magnetic flux leakage forming on the surface of the material due to the defects after the ferromagnetic material has attained saturation magnetization[2].
Tubing magnetic flux leakage testing is for such high magnetic permeability materials as the tubing (steel pipe).
As shown in Fig.1(a), if a tubing with no surface cracks, no internal defects and no inclusions is in saturation magnetization, all its magnetic lines of force through the magnetic circuit made ​​of ferromagnetic materials in theory.
Acknowledgment This work was supported by National Science & Technology Pillar Program (2013BAF06B00), Doctoral Fund of Ministry of Education of China (20100032110006), Key Projects of Science and Technology Support of Tianjin(12ZCZDGX01600).
[3] Wang Taiyong, Jiang Qi, Study on quantitative recognition technology of pipeline defect, Journal of Tianjin University. 36 (2003) 55-58