Applied Mechanics and Materials Vols. 295-298

Abstract: Knowledge remains limited about whether the optimum culture condition of getting the most virulent M.oryzae toxins can be found and applied for resistant seed selection. The inhibition of seed germination and the growth of embryo and radicle in rice treated by the Magnaporthe grisea toxin that got from different culture conditions were studied. The result suggested that the M.oryzae toxin had great inhibitory effect on seed germination and growth of embryo and radicle in rice. The M.oryzae toxin cultivated on 23 °C, pH 8.0 for 20d has strongest inhibition on seed germination of the hybrid rice variety of GangYou725, the inhibition rate approach 70%; Being cultivated at the same pH and 23°C～28°C for approximate 10d, it is easy to get the M.oryzae toxin for high growth inhibition of embryo and radicle. It can reduce the workload and increase accuracy to use M.oryzae toxin to identify blast resistances of rice and select resistant materials.

Abstract: Considering the valuation of forest stands based on revenue from wood sales, concession policy (such as carbon subsidies) and associated costs, the paper focuses on the stochastic control model to study the forest asset dynamic management. The key contribution is to find the optimal dynamic strategy about harvesting quantity in the continual and multiple periods in conditions of stochastic commodity price and timber growth by using portfolio approach. Finally, an analytical optimal strategy is obtained to analyze the quantification relations through which some important conclusions about the optimal forest management can be drawn.

Abstract: Since the establishment of the first forest park in 1982, the development of forest parks has been gone through 30 years in China. They are not evenly distributed, and form three levels of ladder pattern with forest park numbers increasing from west to east. They are centralized in the provinces which the forest landscape resources are abundant. The prominent problems in the development of the forest parks are: the imbalance of the development speed; the insufficiency of the approval system; the improper matching between the employees and the forest park resources; the lag of the legal construction; the shortage of the government investment, and which is not matched with the forest park resources; the insecurity of the funds investment, and which decreases the investment of environmental protection. The solutions to the problems in the development of the forest parks are: perfecting the approval system and controlling the scale of the national forest parks; balancing the government investments and the number of employees; perfecting the laws and regulations related to the forest parks; increasing the public welfare and the investment of environmental protection.

Abstract: A novel grey assessment model with variable weights was proposed to assess the ecological adaptation of major strains of trees commercially used in China. The contribution of each criterion was measured by the classified information entropy and the degrees of whitenization functions. The results show that the new model can integrate experts’ experience and sample information for confirming each criterion’s weight.

Abstract: By using Ecological Observatory Station survey data and Landsat-5 TM remote sensing image data in 2008 as the basic data to construct the conventional multivariate statistical model. The determination coefficient of regression model was 0.788 and the average test accuracy was 81.1%. By using the parameters of this model as the input data to Geographic Information System (GIS) to reveal the spatial distribution of quantity and value, then estimated the total forest water conservation quantity of Laoshan in 2008, I = 263.78 tons, established the currency structure model of the study area to estimate the total value quantity of water conservation effective, E = 1.3189 million yuan. And then analyzed the variation feature of quantity change with topographical, also, the variation fits the truth.

Abstract: This study selected 16 families and 20 genera 20 species of garden plant as the research object, and through pot experiment, study the influence of cadmium, zinc, lead on plant growth, determine the content of heavy metal in the plant organs, determine the ability of heavy metal enrichment to different plants, in order to provide scientific basis through repairing the soil use these plants and configurating the garden plant reasonable.

Abstract: Heavy metal accumulation is effect normal plant growth, and brings potential human health risk in edible and medicinal plants. Erigeron breviscapus is a famous and important traditional China medicine plant, but research of absorption and accumulation for heavy metal is very limited, however that will help the guarantee of quality and food safety as medicine, and offer cultivation guidance and selection of main medicinal parts. The results showed that in pollution-free soil four heavy metals (lead, chromium, cadmium and cuprum) are low concentration in Erigeron breviscapus, but with an increase of heavy metal concentration in soil its amount showed a rising trend in different organs. Lead and chromium enriched mainly by plant root, but cadmium and cuprum easily transfer into above-ground parts because of strongly translocation ability themselves. Therefore cultivate of medicine materials must select pollution-free soil to avoid direct and indirect danger from heavy metal pollution.

Abstract: The Etropy problem has been widely applied in the assessment and analysis of landscape ecology. Research results are just at the indicators, not able to describe the spatial distribution of the landscape. In this paper, we will simulate the results of the application Etropy problem in landscape assessment based on a GIS. A GIS is used to store the information of layers on landscape structure, indicator analysis and map-layer assessment. This is a new research direction, research results of Etropy problem will be simulated by the evaluation map. Research have been applied in Sa Pa area - one of Vietnam's most mountainous district. Research results shown the landscape diversity in the research area and landscape area identification to be conserved.

Abstract: This paper used GIS spatial analysis and data processing technologies and multi-source data fusion technology to spatialize the population data of Meijiang river basin. Land use was selected as the index factor and the settlements as the indicative factor. Selected terrain, roads and rivers were the main influencing factors and were further classified into several sub-factors. During the simulation, we first calculated the weight indexes of sub-factors on the settlements distribution and then fused the indexes to calculate the weight indexes of the main factors. Second we calculated the weight indexes of settlements on the population distribution. Last we fused the weight indexes of the main factors and the weight indexes of settlements to obtain the population density indexes of whole region and then generated the 100m×100m resolution raster population density map.

Abstract: A precise and reliable basic data is an important for flood control and management for each reservoir, especially DEM. The topographic map above water surface can easily be digitized based on GIS technology. The underwater digital elevation model (DEM) was measured integrated with GPSRTK technology and precision shallow water echo sounder. Therefore, DEM overall reservoir area can be built by integrating these two results. Using the methods of this paper, the reservoir capacity can be automatically generated, reservoir storage capacity table can be automatically prepared, and reservoir capacity curve can also be automatically drawn. The applications in the Guxian and Baisha Reservoir show that this method is simple and feasible.