Advanced Materials Research Vol. 937

Abstract: Grazing, one of the most important disturbance in Northern China, influenced vegetation restoration on the aspects of population survival, community structure and landscape patterns. However, effects of grazing on elm trees (Ulmus pumila), the key species in climax community in Horqin Sandy Land, were not fully understood, especially on the aspects of reproductive allocation. Reproductive allocation was vital to affect seed production, which determined the number of seed source used for recruitment. Furthermore, recruitment regulated the population dynamic even to the community structure. To estimate effects of grazing on elm trees reproductive allocation, a field experiment was conducted in Wulanaodu, southern of Horqin Sandy Land. Elm trees suffering grazing with intensities were classified with diameter in breast (DBH). Current-year shoots, leaves and seeds in each tree mentioned above, were selected and measured in the laboratory respectively. The dry weight of them considered as biomass allocated to reproductive and vegetative growth. Our results showed that the reproductive allocation of early-matured and over-matured trees were 25.17% and 35.91% separately in closed land and were 42.48% and 60.03% in light grazed land correspondingly, indicating the reproductive allocation of early-matured and over-matured trees in closed land was significant lower than in grazed land (P<0.05). Meanwhile, matured trees devoted 71.15% of required resource to reproduction in closed land, and this ratio was 67.34% and 71.75% in light and heavy-grazed land, indicating the difference of reproductive allocation was not significant between the grazed and closed lands (P>0.05). Furthermore, matured trees devoted 71.75% of resource to seeds and the corresponding ratio was 60.03% and 42.48% in over-matured trees and early-matured trees, indicating matured trees significantly devoted more resource to reproduction than over-matured trees and early-matured trees (P<0.05). It is suggested that grazing improved the ratio of biomass allocation to reproduction.

Abstract: Water resource is irreplaceable as one kind of important natural resources and strategic economic resources. Water resources optimal allocation is an important means to solve the problem of water resources to keep the relative balance of the supply and demand. For ensuring the sustainable development, according to the South-to-North Water Transfer Project, and aiming at the maximum synthesized benefits, the model for water resources optimal allocation was established. A lot of factors were considered. The cause function, restriction and parameters were discussed. At last, optimal allocation of water resources in the middle line of Project in Hebei Province was studied under the guarantee of 95 % in 2010 and 2014. The results showed that the Project can solve the serious water shortage in Hebei province, North China.

Abstract: Using FieldSpec ® 4 Hi-Res portable coverings spectrometer, we have measured the main vegetation and siol reflectance based on different habitats:Surface water swamping meadow, a seasonal water swamping beach, wet beach without of water and sandy in the little Park Lake, East of the Qinghai Lake and analyzed the spectral differences. The results show that: Soil moisture is one of the important factors that affect reflectivity. Under the premise of similar other soil properties, soil moisture and reflectivity shows a negative correlation with each other. 350-1000nm wavelength range is ideal to distinguish vegetation and soil. Due to the presence of water absorption bands, within 1000-1300nm the spectrum derivative of soil and vegetation has a strong similarity, but still can be used to identify the spectrum of vegetation and soil. In addition to sandy habitats, vegetation and soil spectrum has a strong similarity in the 1300-2500nm wavelength range, it is more tolerance translation will confuse the two bands, the spectrum has a strong similarity in the range of 1300-2500nm, so it is relatively easy to confuse the two spectrum.

Abstract: In order to provide information for biological monitoring of environmental pollution and help people to develop pharmaceutical wastewater pollutant monitoring and emission standard, in this paper, acute toxicity experiments of three heavy metal pollutants, Zn²⁺,Cd²⁺ and Hg²⁺ existed usually in pharmaceutical wastewater, were done and their 24hr LC₅₀ on the Paramecium were got individually, safety thresholds were calculated. At the same time, impact of different concentration heavy metal ions on population growth curve of Paramecium caudatum were researched. Results indicated that the acute toxicity of Hg²⁺ are the strongest, and the population growth curve changed significantly by three different types under three heavy metal ions pressure.

Abstract: Severe ice-snows caused break of many trees and a lot of crown debris in south China in 2008. Stem damage and crown debris. In order to determine the water holding characteristics of the crown debris, the water holding rate and water absorption rates of crown debris and litter were studied in a Cunninghamia lanceolata stand suffering from ice-snow damage occurring from January to February, 2008. The order of water-holding capacity of the components was leaves > litter > branches> stemwood > stembark in each stage of immersing water. The maximum water holding capacities of stemwood, branch, leaves, stembark and litter were 6.75, 8.13, 10.9, 2.72 and 8.22 t•ha 1, respectively. Maximum water holding rates of stemwood, branch, leaves, stembark and litter were 2271, 2144, 3199, 2800 and 3018 g•kg 1, respectively. Water absorption rate of each component sharply decreased with increasing immersed time from 0.5 to 4 hours, and then slowly decreased. The logarithm equation predicted water-holding capacity and water holding rates of crown debris and litter quite well and the negative exponential equation predicted water absorption rate within an 8.5% error.

Abstract: Using large-scale shearing device, isotropiclly consolidated-drained triaxial test under different confining pressures are performed for overburden material of ShuangJiangKou earth dam which relative density is 0.8. The relationship between particle breakage of coarse-grained soil and input plastic work under loading and between particle breakage and confining pressure and between particle breakage and strength of coarse-grained soil. The results show that the particle breakage of coarse-grained soil and the input plastic work under loading is closely related. The particle breakage of coarse-grained soil increase with the input plastic work and there is a relationship of power function between B_g and W_p. the increase of confining pressure will lead to the increase of particle breakage of coarse-grained soil, and there is a relationship of power function between B_g and . the increase of particle breakage of coarse-grained soil will lead to the decrease of strength of coarse-grained soil, and a relationship of linear between B_g and φ.

Abstract: With the deep landslide induced by rainfall or more in practice, the existing evaluation methods are not suitable for to explain this kind of landslide during rainfall, which is the phenomenon of strong activity. This paper tries to improve existing methods for analyzing the stability of the landslide, the article set up to consider soil stability analysis method of the matrix suction side article discusses rainfall infiltration process middle side matrix suction changes impacting on the stability of the landslide, the preliminary discussion on the effect of rainfall on deep landslide are studied. Considering soil of the side of the evaluation methods of matrix suction jettisoned traditional saturated unsaturated soil mechanics analysis method, it can well reflect the process of rainfall infiltration, the matrix suction decreases, and the inter-atomic forces, stability factor to reduce the process, providing a train of thought for landslides evaluation.

Abstract: Dongtiaoxi and Xitiaoxi river are the two main discharge rivers of Taihu Lake. It is important to research the provenances of suspended sediments (SS) and the difference of the provenances. This paper establishes the geochemical model to quantify the proportions of SS sources with geochemical parameters, and then analyzes the contribution differences of the sources to SS in the basins and its reasons. The results show that the contribution of woodland is highest in the upper reaches of both Dongtiaoxi and Xitiaoxi basin, but the contribution of arable land has more differences. Arable land becomes a major contributor to the midstream of Dongtiaoxi and Xitiaoxi basin, while the contributions of woodland and urban land are larger in Dongtiaoxi basin. The SS contribution of urban land is highest in the downstream of Dongtiaoxi and Xitiaoxi basin, while the contribution of arable land is larger in Dongtiaoxi basin. During wet season and dry season, the differences of the sources contribution variations in Dongtiaoxi basin are not obvious, while that in Xitiaoxi basin are significantly obvious, that is the SS contributions of woodland and urban land in wet season are significantly higher than in dry season, while the contributions of arable land and bank sediment are on the contrary.

Abstract: Abstract: in this paper, combining with engineering examples, this paper introduces the Midas GTS software application in the design of foundation pit excavation, and compared with the actual monitoring results, verify the feasibility of the software used in the actual engineering design and reliability.

Abstract: Water scarcity and pollution pose critical situation in all walks of life.Among the available purification methods,desalination process proves to be a safer and more stable solution for solving this problem. This paper provides an overview of the purification effect of distillation process, along with theprinciples and research progress ofdifferent distillation techniques for small scale drinking water preparation.This paper also analyzes the advantages and disadvantages of each method, as well as proposes an outlook forthe distillation technology on drinking water preparation. This paper also indicates that the removallaw of organic pollutants, especially the volatile organic pollutants during distillation process should attract researchers' attention, whilereducing energy consumption of distillation technology through various means is still the development tendency.