In order to take advantage of the climate resources more effectively ac- cording to the local circumstances and to plan and develop the citrus industry in Southern Shaanxi more reasonably. On the basis of the investig...In order to take advantage of the climate resources more effectively ac- cording to the local circumstances and to plan and develop the citrus industry in Southern Shaanxi more reasonably. On the basis of the investigation of freeze dam- age to citrus occurring in Southern Shaanxi in the winter of 2010, the climatic back- ground for the formation of this freeze damage was analyzed. In combination with the freeze damage indicators during the overwintering period and the harmful accu- mulated cold during the cold wave, indexes for grading the freeze damage in southern Shaanxi were analyzed and verified, and the perspective of grading the freeze damage using the harmful accumulated cold during the cold wave was also presented. Through analyzing the extremely lowest temperature and the harmful ac- cumulated cold in the winter of 2010 and in history at 12 citrus growing counties （districts） in Ankang area and Hanzhong area, the reasons why the freeze damage to citrus during the overwintering period was severer in the west than in the east of Southern Shaanxi were discussed, and the results obtained were basically consistent with the actual situation observed from investigation. Finally, defensive countermea- sures against the freeze damage to citrus during the overwintering period were put forward from several aspects.展开更多
In Rels. [2-4] there is an Adaptive. Open Boundary Condition (AOBC) designed for transient waves which overcomes the limitation of the existing Open BoundaryCondition (OBC) and can be used for the cases of waves with...In Rels. [2-4] there is an Adaptive. Open Boundary Condition (AOBC) designed for transient waves which overcomes the limitation of the existing Open BoundaryCondition (OBC) and can be used for the cases of waves with arbitrary incidentangles. In this article a new family of high order AOBC has been designed on the basisof the above mentioned AOBC with the first order.In comparison with all other OBC with the same order, this new family of AOBC has the highest precision.展开更多
On the basis of the principle of Ground Penetrating Radar (GPR) method and geophysical characteristics, this paper discusses in detail detection method of civil air defense distinguished by GPR under the complex geolo...On the basis of the principle of Ground Penetrating Radar (GPR) method and geophysical characteristics, this paper discusses in detail detection method of civil air defense distinguished by GPR under the complex geological condition through using the analysis and application in the survey of underground civil air defense as an example. Three dimensional image of the defense clearly reflects its underground structure. Test result has the greatly high detection precision. This example illustrates the effectiveness and practicability of GPR in the respect of detection of the civil air defense and also accumulates experiences for the application of GPR in urban geological survey.展开更多
[ Objective]The research aimed to study influences of the climate conditions on organic agriculture and defense countermeasures of the meteorological disasters in Boshan District of Shandong. [ Method ] From climate r...[ Objective]The research aimed to study influences of the climate conditions on organic agriculture and defense countermeasures of the meteorological disasters in Boshan District of Shandong. [ Method ] From climate resources, relationships between meteorological conditions （tem- perature, water and sunshine, etc. ） and growth of the organic crops in Boshan District of Shandong were analyzed. 5-year development plan was put forward. Influences of the main meteorological disasters in growth process of the organic crops were analyzed. Moreover, corresponding de- fense countermeasures were put forward. [ Result] Due to monsoon influence in Boshan, rain and heat were in same season. Sunshine, heat and water coordinated well, and effectivity of the agricultural climate resources was higher. Qualities of the soil and water were good. Vegetation was complete. These conditions were all favorable for developing organic agricultural region. But the precipitation variability was big, which limited effec- tive utilizations of the sunshine and heat resources at different degrees. Meanwhile, in organic crops growth season when sunshine, heat and water were sufficient, meteorological disasters happened frequently. [ Conclusion] We should accelerate construction of the small water conservancy facil- ities, making rainstorm and flood as resources, and realizing timely watering. In addition, we ought to accelerate construction of the industrialized organic a clriculture to improve agricultural benefit.展开更多
The effect of the deformation condition on the axial compressive precision forming process of tube with curling die was investigated by using a rigid-plastic FEM. The results show that the forming accuracy depends mai...The effect of the deformation condition on the axial compressive precision forming process of tube with curling die was investigated by using a rigid-plastic FEM. The results show that the forming accuracy depends mainly on geometric condition rp/d0, little on tube material properties and friction condition; the relative gap △/2rp of double-walled tubes obtained decreases with Increasing rp/d0, and there is a parameter k for a given to/do or rp/t0, when rp/d0 >k, △/2rp< 1, otherwise △/2rp>1.展开更多
Continuously differentiable radial basis functions (C<sup>∞</sup>-RBFs), while being theoretically exponentially convergent are considered impractical computationally because the coefficient matrices are ...Continuously differentiable radial basis functions (C<sup>∞</sup>-RBFs), while being theoretically exponentially convergent are considered impractical computationally because the coefficient matrices are full and can become very ill- conditioned. Similarly, the Hilbert and Vandermonde have full matrices and become ill-conditioned. The difference between a coefficient matrix generated by C<sup>∞</sup>-RBFs for partial differential or integral equations and Hilbert and Vandermonde systems is that C<sup>∞</sup>-RBFs are very sensitive to small changes in the adjustable parameters. These parameters affect the condition number and solution accuracy. The error terrain has many local and global maxima and minima. To find stable and accurate numerical solutions for full linear equation systems, this study proposes a hybrid combination of block Gaussian elimination (BGE) combined with arbitrary precision arithmetic (APA) to minimize the accumulation of rounding errors. In the future, this algorithm can execute faster using preconditioners and implemented on massively parallel computers.展开更多
To improve the reliability of the light emitting diode(LED)signal lamp filament current monitoring alarm instrument for metro systems,a new type of hot standby online monitoring apparatus was developed which is based ...To improve the reliability of the light emitting diode(LED)signal lamp filament current monitoring alarm instrument for metro systems,a new type of hot standby online monitoring apparatus was developed which is based on synchronous transmission data(STD)bus technology.In this system,a double hot standby mode can be achieved by adopting bus arbitration.In addition,to detect the effective value of alternating current which is from 0 to 200 mA in the signal lamp lighting circuit,a precision rectifier signal conditioning circuit and an isolated acquisition circuit were designed.This new type of alarm instrument has high detection accuracy and could meet the functional requirements for metro signal systems after comparing it with some industry products that were applied on the spot.展开更多
基金Supported by Shaanxi"13115"Public Service Platform Construction Program for Science&Technology Innovation Projects(2010FWPT-17)~~
文摘In order to take advantage of the climate resources more effectively ac- cording to the local circumstances and to plan and develop the citrus industry in Southern Shaanxi more reasonably. On the basis of the investigation of freeze dam- age to citrus occurring in Southern Shaanxi in the winter of 2010, the climatic back- ground for the formation of this freeze damage was analyzed. In combination with the freeze damage indicators during the overwintering period and the harmful accu- mulated cold during the cold wave, indexes for grading the freeze damage in southern Shaanxi were analyzed and verified, and the perspective of grading the freeze damage using the harmful accumulated cold during the cold wave was also presented. Through analyzing the extremely lowest temperature and the harmful ac- cumulated cold in the winter of 2010 and in history at 12 citrus growing counties （districts） in Ankang area and Hanzhong area, the reasons why the freeze damage to citrus during the overwintering period was severer in the west than in the east of Southern Shaanxi were discussed, and the results obtained were basically consistent with the actual situation observed from investigation. Finally, defensive countermea- sures against the freeze damage to citrus during the overwintering period were put forward from several aspects.
文摘In Rels. [2-4] there is an Adaptive. Open Boundary Condition (AOBC) designed for transient waves which overcomes the limitation of the existing Open BoundaryCondition (OBC) and can be used for the cases of waves with arbitrary incidentangles. In this article a new family of high order AOBC has been designed on the basisof the above mentioned AOBC with the first order.In comparison with all other OBC with the same order, this new family of AOBC has the highest precision.
文摘On the basis of the principle of Ground Penetrating Radar (GPR) method and geophysical characteristics, this paper discusses in detail detection method of civil air defense distinguished by GPR under the complex geological condition through using the analysis and application in the survey of underground civil air defense as an example. Three dimensional image of the defense clearly reflects its underground structure. Test result has the greatly high detection precision. This example illustrates the effectiveness and practicability of GPR in the respect of detection of the civil air defense and also accumulates experiences for the application of GPR in urban geological survey.
基金Supported by Policy Guidance Item of Science and Technology Development Plan in Shandong Province(2010YD17006)
文摘[ Objective]The research aimed to study influences of the climate conditions on organic agriculture and defense countermeasures of the meteorological disasters in Boshan District of Shandong. [ Method ] From climate resources, relationships between meteorological conditions （tem- perature, water and sunshine, etc. ） and growth of the organic crops in Boshan District of Shandong were analyzed. 5-year development plan was put forward. Influences of the main meteorological disasters in growth process of the organic crops were analyzed. Moreover, corresponding de- fense countermeasures were put forward. [ Result] Due to monsoon influence in Boshan, rain and heat were in same season. Sunshine, heat and water coordinated well, and effectivity of the agricultural climate resources was higher. Qualities of the soil and water were good. Vegetation was complete. These conditions were all favorable for developing organic agricultural region. But the precipitation variability was big, which limited effec- tive utilizations of the sunshine and heat resources at different degrees. Meanwhile, in organic crops growth season when sunshine, heat and water were sufficient, meteorological disasters happened frequently. [ Conclusion] We should accelerate construction of the small water conservancy facil- ities, making rainstorm and flood as resources, and realizing timely watering. In addition, we ought to accelerate construction of the industrialized organic a clriculture to improve agricultural benefit.
基金The authors would like to thank NSFC for support toenable the performing of this research (No. 59775055).
文摘The effect of the deformation condition on the axial compressive precision forming process of tube with curling die was investigated by using a rigid-plastic FEM. The results show that the forming accuracy depends mainly on geometric condition rp/d0, little on tube material properties and friction condition; the relative gap △/2rp of double-walled tubes obtained decreases with Increasing rp/d0, and there is a parameter k for a given to/do or rp/t0, when rp/d0 >k, △/2rp< 1, otherwise △/2rp>1.
文摘Continuously differentiable radial basis functions (C<sup>∞</sup>-RBFs), while being theoretically exponentially convergent are considered impractical computationally because the coefficient matrices are full and can become very ill- conditioned. Similarly, the Hilbert and Vandermonde have full matrices and become ill-conditioned. The difference between a coefficient matrix generated by C<sup>∞</sup>-RBFs for partial differential or integral equations and Hilbert and Vandermonde systems is that C<sup>∞</sup>-RBFs are very sensitive to small changes in the adjustable parameters. These parameters affect the condition number and solution accuracy. The error terrain has many local and global maxima and minima. To find stable and accurate numerical solutions for full linear equation systems, this study proposes a hybrid combination of block Gaussian elimination (BGE) combined with arbitrary precision arithmetic (APA) to minimize the accumulation of rounding errors. In the future, this algorithm can execute faster using preconditioners and implemented on massively parallel computers.
文摘To improve the reliability of the light emitting diode(LED)signal lamp filament current monitoring alarm instrument for metro systems,a new type of hot standby online monitoring apparatus was developed which is based on synchronous transmission data(STD)bus technology.In this system,a double hot standby mode can be achieved by adopting bus arbitration.In addition,to detect the effective value of alternating current which is from 0 to 200 mA in the signal lamp lighting circuit,a precision rectifier signal conditioning circuit and an isolated acquisition circuit were designed.This new type of alarm instrument has high detection accuracy and could meet the functional requirements for metro signal systems after comparing it with some industry products that were applied on the spot.
