Applied Mechanics and Materials Vols. 668-669

Abstract: According to the characteristics of rural household garbage and the realistic conditions of rural areas in Hainan Province, and based on the experience of the rural household garbage processing, this paper discusses the rural garbage recovery processing pattern, funds and management of Hainan province and other relevant problems, in order to provide suggestions and comments about the processing of rural household garbage for Hainan as a tourist province.

Abstract: In this document we analysis the lead contamination in tree ring of Platycladus orientalis and Poplar, and found that lead concentrations in contaminated tree rings has a good relationship with industrial dust emissions and automobiles, the lead contamination in tree ring can reconstruction the lead contamination history of Jinan. The case study in Jinan, showed that trees can provide continuous monitoring data for assessment of trace metal pollution in the future.

Abstract: Sand samplers were layed out in the grassland located in the northern foot of Yinshan Mountain for collecting soil flux samples from 0 to 1.5m height above the surface from Mar., 1, 2008 to Feb., 29, 2009.Exponential and Power functions were both used for describing vertical distribution of sand flux in the grassland, the results indicated that determination coefficient of Power function varied from 0.898 to 0.992 while 0.432 to 0.661 for exponential function. Power function is better than exponential function in describing the vertical distribution of both annual and seasonal soil flux, summer excluded. Annual cumulative percentage of each height was determined indirectly according to the power function mentioned above, the result indicated that up to 2m height,15-25% of soil flux concentrated with in 10cm above the surface,25-35% of soil flux concentrated within 20cm above the surface,30-40% of soil flux concentrated within 30 cm above the surface, 43-54% of soil flux concentrated within 50 cm above the surface,85-90% of soil flux concentrated within 150 cm above the surface, respectively. No significant differences of soil flux structures in spring, autumn, winter and in the whole year were found. The research on wind erosion of grassland in the vertical direction more dispersed, in the height range of sediment accumulated percentage was lower than that of the previous research.

Abstract: The energy saving and environmental protection design of agricultural machinery is a new design concept. Based on the analysis of meaning and significance of agricultural machinery energy saving and environmental protection design, Elaborated the trends of energy saving and environmental protection of agriculture machinery. The paper also pointed out that the green design is the inevitable trend of the development of agricultural machinery.

Abstract: On the basis of properties analysis of disaster chain, the assumption of connotation and extension of systematic natural disaster chain is clarified. Therefore the natural disaster chain structural model in the form of mathematical language is defined, and the relation and property of the structural model is studied. According to the analysis of the mathematical model of disaster chain, it shows that the disaster chain is caused and dominated by both the outside environments and structural relation of inner state. The outside environment influence is the gestation of disaster and the interaction of inner state is the necessary condition of disaster chain. The disaster mitigation mode is studied from the point of both sides, and the emphasis is on the inner structural relations chain-cycle. An example in view of snowstorm in 2008 is presented to apply and verify the above theory.

Abstract: Through the study of Beier depression accumulation critical moment, divided into three sets of petroleum system in beier depression: passive faulted depression primary petroleum system, active faulted depression primary petroleum system and fault depression transform secondary petroleum system. Through the typical reservoir oil-water distribution rule and reservoir dissect result can get to know oil and gas of Beier depression concentration distribute in passive faulted depression sequence petroleum system, mainly develop reverse fault block reservoir as well as buried hill reservoir blocked by fault and uncomformable surface, active faulted depression sequence petroleum system mainly develop structure and fault-lithologic composite reservoir; Secondary petroleum system mainly develops fault lithologic reservoir; Secondary petroleum system and primary petroleum system ‘complementary’ distribution of oil and gas. Through the petroleum system classification, to find the distribution regularity of oil and gas, and guide field work.

Abstract: Single factor and Plackett-Burman design were used to determine the key environmental factors for Aspergillus flavus growth and aflatoxin production. The results showed that the key factors were culture time, moisture content. So Controling of moisture was crucial for Aflatoxin contamination prevention and control.

Abstract: The hip implant is a very successful treatment for serious osteoarthritis, especially in older patients, but less desirbale for earlier interventions. There is a growing consensus that most hip arthritis is due to shape abnormalities that cause impingement at the ball and socket, collectively called femoroacetabular impingement (FAI). The ball does not fit accurately into the socket, leading to premature wear, and then destructive arthritis. It is not then necessary to replace the whole hip joint; newly developed surgical techniques that accurately reshape the bones to relieve impingement and reduce wear have been shown to be effective. This surgery can be performed with a conventional open approach, or be arthroscopic (keyhole) surgery. It would be better to reshape bones to suit each individual patient. Finite element methods (FEM) have been widely used for biomechanical studies of hip implants and periacetabular osteotomy, but hardly at all in hip reshaping. Non-linear FEM is employed in the current study to perform biomechanical evaluations of differences in contact pressure between normal and arthritic hip joints to help basic understanding and lead to more accurate surgery. The hip joint bone structure is obtained through a medical CT scan and then the CT images have been converted into a format readable by FEM solvers. A sophisticated non-linear contact model of the hip joint bringing together the interactions of true geometry, natural movement and contact forces has been established using this advanced FEM.

Abstract: Restenosis is a re-narrowing or blockage of an artery at the same site where treatment like stent procedure has already taken place. The aim of this study is to more conclusively identify the mechanical stimulus for in-stent restenosis by means of numerical model based on the finite element method. The finite element model simulating the stent, balloon, crimping tool and artery interaction in the coronary artery is developed. The present model is used to determine the stress distribution in the artery wall followed by stent implantation. It is indicated that the compliance mismatch of stent with vascular induces the stress concentration in the stented artery, which impact the level of vascular injury caused to the artery by the stent. This study supports the hypothesis that the artery develops restenosis in response to injury, where high vessel stresses are a good measure of the injury.

Abstract: In optometry, simplified models are usually used to analyze refractive property of optometry system on the assumption that lenses are thin and close enough to each other. However, in fact those lenses do have stated center thickness and lens space between them. The simplified models are not suitable for accurate analysis and system design. In this paper, first, accurate mathematic model for refractive property of single spherical and cylindrical lens is established. Next, accurate model is established for complex optometry system with different kinds of lenses combination. Then, influence factors such as lens structural parameter, lens space and lens position are analyzed for refractive property. Results show that correct lens position is very important for complex optometry system. Parallel light should pass lower power lens first and then higher power lens. When lens power and lens space gets bigger the influence of lens space will be more significant on refractive property. For uncertainty component, uncertainty from front and back surface radii are the biggest, secondary is the refractive index and lens space, and uncertainty from lens thickness is the least.