The alpine meadow, as one of the typical vegetation types on the Tibetan Plateau, is one of the most sensitive terrestrial ecosystems to climate warming. However, how climate warming affects the carbon cycling of the ...The alpine meadow, as one of the typical vegetation types on the Tibetan Plateau, is one of the most sensitive terrestrial ecosystems to climate warming. However, how climate warming affects the carbon cycling of the alpine meadow on the Tibetan Plateau is not very dear. A field experiment under controlled experimental warming and clipping conditions was conducted in an alpine meadow on the Northern Tibetan Plateau since July 2008. Open top chambers （0TCs） were used to simulate climate warming. The main objective of this study was to examine the responses of ecosystem respiration （Reco） and its temperature sensitivity to experimental warming and clipping at daily time scale. Therefore, we measured Reco once or twice a month from July to September in 2010, from June to September in 2011 and from August to September in 2012. Air temperature dominated daily variation of Reco whether or not experimental warming and clipping were present. Air temperature was exponentially correlated with Reco and it could significantly explain 58-96% variation of Redo at daily time scale. Experimental warming and clipping decreased daily mean Reco by 5.8-37.7% and -11.9-23.0%, respectively, although not all these changes were significant. Experimental warming tended to decrease the temperature sensitivity of Reco, whereas clipping tended to increase the temperature sensitivity of Reco at daily time scale. Our findings suggest that Reco wasmainly controlled by air temperature and may acclimate to climate warming due to its lower temperature sensitivity under experimental warming at daily time scale.展开更多
In this paper, a formulation for shakedown analysis of elastic-plastic offshore structures under cyclic wave loading is presented. In this formulation, a fast numerical solution method is used, suitable for the Finite...In this paper, a formulation for shakedown analysis of elastic-plastic offshore structures under cyclic wave loading is presented. In this formulation, a fast numerical solution method is used, suitable for the Finite Element Method (FEM) analysis of large offshore structures on which shear effects in addition to bending and axial effects are taken into account. The Morison equation is adopted for converting the velocity and acceleration terms into resultant forces and it is extended to consider arbitrary orientations of the structural members. The theoretical methods of the shakedown analysis are discussed in detail and the formulation is applied to an offshore structure to verify the concept employed and its analytical capabilities.展开更多
In order to maintain the health and vigour and to sustain the productivity, a pruning experiment was conducted on four year old ＂Balwant＂ cultivar of aonla grown in laterite soil, planted at a spacing of 5m×5m....In order to maintain the health and vigour and to sustain the productivity, a pruning experiment was conducted on four year old ＂Balwant＂ cultivar of aonla grown in laterite soil, planted at a spacing of 5m×5m. To find out the best pruning method, six levels of pruning was performed i.e., （1） Light judicious pruning, （2） Detopping of primary branches at 8 feet from ground level ＋ removal of all secondary branches, （3） Detopping of primary branches at 8 feet from the ground level ＋ removal of all secondary branches at 2 feet from the base of primary branches, （4） Detopping of primary branches at 8 feet from the ground level ＋ removal of all secondary branches at 1 feet from the base of primary branches, （5） Light judicious pruning ＋ Detopping of plant canopy of at 8 feet from the ground level, （6） No pruning （control）. Results of three consecutive years of investigation revealed that light judicious pruning of thin, overlapping, criss-crossed, dead, unproductive and looping branches gave highest fruit yield in all the three years and resulted 64.4 percent yield increment over control when average of three years was considered. Severe pruning of primary and secondary branches caused drastic reduction of yield for two consecutive years after pruning. Judicious pruning helped to produce better sizeable and quality fruits.展开更多
In the article,with the instruments of the Research Institute of Wood Industry,Chinese Academy of Forestry,the experiment method of Forintek Canada Corp.was used to test the laminating of lodgepole pine containing bee...In the article,with the instruments of the Research Institute of Wood Industry,Chinese Academy of Forestry,the experiment method of Forintek Canada Corp.was used to test the laminating of lodgepole pine containing beetle-transmitted bluestain;finally the result was compared with Canada report.The results show that the presence of glue joints of bluestained wood made with either PVA or PRF adhesive makes no difference to the shear strength of the joints,and no difference to durability of the joints using PRF.Also the presence of beetle-transmitted bluestain in wood does not affect the adherence of the interior finishes tested.展开更多
基金funded by the National Natural Science Foundation of China (Grant Nos. 41171084and 40771121)Innovation Project of the Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences (Grant No.2012ZD005)+2 种基金the Natural Science Foundation of the Tibet Autonomous Region (Name. the Response Experiment of the Alpine Meadow Vegetation to Climate Warming)the National Basic Research Program of China (Grant No.2010CB951704)the National Science and Technology Plan Project of China (Grant No.2011BAC09B03)
文摘The alpine meadow, as one of the typical vegetation types on the Tibetan Plateau, is one of the most sensitive terrestrial ecosystems to climate warming. However, how climate warming affects the carbon cycling of the alpine meadow on the Tibetan Plateau is not very dear. A field experiment under controlled experimental warming and clipping conditions was conducted in an alpine meadow on the Northern Tibetan Plateau since July 2008. Open top chambers （0TCs） were used to simulate climate warming. The main objective of this study was to examine the responses of ecosystem respiration （Reco） and its temperature sensitivity to experimental warming and clipping at daily time scale. Therefore, we measured Reco once or twice a month from July to September in 2010, from June to September in 2011 and from August to September in 2012. Air temperature dominated daily variation of Reco whether or not experimental warming and clipping were present. Air temperature was exponentially correlated with Reco and it could significantly explain 58-96% variation of Redo at daily time scale. Experimental warming and clipping decreased daily mean Reco by 5.8-37.7% and -11.9-23.0%, respectively, although not all these changes were significant. Experimental warming tended to decrease the temperature sensitivity of Reco, whereas clipping tended to increase the temperature sensitivity of Reco at daily time scale. Our findings suggest that Reco wasmainly controlled by air temperature and may acclimate to climate warming due to its lower temperature sensitivity under experimental warming at daily time scale.
文摘In this paper, a formulation for shakedown analysis of elastic-plastic offshore structures under cyclic wave loading is presented. In this formulation, a fast numerical solution method is used, suitable for the Finite Element Method (FEM) analysis of large offshore structures on which shear effects in addition to bending and axial effects are taken into account. The Morison equation is adopted for converting the velocity and acceleration terms into resultant forces and it is extended to consider arbitrary orientations of the structural members. The theoretical methods of the shakedown analysis are discussed in detail and the formulation is applied to an offshore structure to verify the concept employed and its analytical capabilities.
文摘In order to maintain the health and vigour and to sustain the productivity, a pruning experiment was conducted on four year old ＂Balwant＂ cultivar of aonla grown in laterite soil, planted at a spacing of 5m×5m. To find out the best pruning method, six levels of pruning was performed i.e., （1） Light judicious pruning, （2） Detopping of primary branches at 8 feet from ground level ＋ removal of all secondary branches, （3） Detopping of primary branches at 8 feet from the ground level ＋ removal of all secondary branches at 2 feet from the base of primary branches, （4） Detopping of primary branches at 8 feet from the ground level ＋ removal of all secondary branches at 1 feet from the base of primary branches, （5） Light judicious pruning ＋ Detopping of plant canopy of at 8 feet from the ground level, （6） No pruning （control）. Results of three consecutive years of investigation revealed that light judicious pruning of thin, overlapping, criss-crossed, dead, unproductive and looping branches gave highest fruit yield in all the three years and resulted 64.4 percent yield increment over control when average of three years was considered. Severe pruning of primary and secondary branches caused drastic reduction of yield for two consecutive years after pruning. Judicious pruning helped to produce better sizeable and quality fruits.
文摘In the article,with the instruments of the Research Institute of Wood Industry,Chinese Academy of Forestry,the experiment method of Forintek Canada Corp.was used to test the laminating of lodgepole pine containing beetle-transmitted bluestain;finally the result was compared with Canada report.The results show that the presence of glue joints of bluestained wood made with either PVA or PRF adhesive makes no difference to the shear strength of the joints,and no difference to durability of the joints using PRF.Also the presence of beetle-transmitted bluestain in wood does not affect the adherence of the interior finishes tested.
