An efficient method for gravity field determination from CHAMP orbits and accelerometer data is referred to as the energy balance approach. A new CHAMP gravity field recovery strategy based on the improved energy bala...An efficient method for gravity field determination from CHAMP orbits and accelerometer data is referred to as the energy balance approach. A new CHAMP gravity field recovery strategy based on the improved energy balance approach IS developed in this paper. The method simultaneously solves the spherical harmonic coefficients, daily Integration constant, scale and bias parameters. Two 60 degree and order gravitational potential models, XISM-CHAMPO1S from the classical energy balance approach, and XISM-CHAMPO2S from the improved energy balance, are determined using about one year＇s worth of CHAMP kinematic orbits from TUM and accelerometer data from GFZ. Comparisons among XISM-CHAMPO1S, XISM-CHAMPO2S, EIGEN-CGO3C, EIGEN-CHAMPO3S, EIGEN2, ENIGNIS and EGM96 are made. The results show that the XISM-CHAMPO2S model is more accurate than EGM96, EIGENIS, EIGEN2 and XISM-CHAMPO1S at the same degree and order, and has almost the same accuracy as EIGEN-CHAMPO3S.展开更多
Based on the reality of college English teaching, this paper puts forward the concept of three-dimensional teaching in college English. Combined with the application of modern technology, this paper discusses the syst...Based on the reality of college English teaching, this paper puts forward the concept of three-dimensional teaching in college English. Combined with the application of modern technology, this paper discusses the system of college English teaching curriculum, the modernization of teaching content, and the modernization of teaching methods under the network environment. The teaching methods are diversified, and the content of college English teaching reform is discussed in detail. The combination of the leading role of teachers and the main role of students is proposed.展开更多
The light weight heat treated B-grade bulletproof steel was developed through composition design and optimization based on multiplex alloying,multiplex micro-alloying design ideas and complex phase structure strengthe...The light weight heat treated B-grade bulletproof steel was developed through composition design and optimization based on multiplex alloying,multiplex micro-alloying design ideas and complex phase structure strengthening theory.The puzzle how to avoid the quenching deformation problem of super high strength thin sheet was solved through heat treatment in a die with a set of cooling system.Such B-grade bulletproof steel plate has fine tempered lath martensite structure.The shooting and certification test results showed that the shoot resistance of B-grade bulletproof steel plate can meet the protection demand of Protection specification for cash carrying vehicles(GA 164—2005).In comparison with B-grade bulletproof steel plate made by one of the companies in Sweden,the weight of the developed B-grade bulletproof steel plate can be decreased by 8 %under the same shoot resistance condition.It will be meaningful for cash truck and anti-hijacking vehicle to realize light weight,energy conservation and emission reduction.展开更多
This paper presents the data from two-year experiments concerning with doses of sewage sludge （0, 7, 14 and 21 ton.ha^-1） and inorganic nitrogen doses （0, 50, 100 and 150 kg.ha^-1） from the Municipality of Van, wh...This paper presents the data from two-year experiments concerning with doses of sewage sludge （0, 7, 14 and 21 ton.ha^-1） and inorganic nitrogen doses （0, 50, 100 and 150 kg.ha^-1） from the Municipality of Van, which is located at an altitude of 1,725 m of eastern Anatolia in Turkey. A study was conducted to assess two different N sources on sandy-silty-clay soils grown to crested wheatgrass Agropyron cristatum （L.） Gaertn, grass pasture which had been amended with sewage sludge for two years. Plant tissue and DTPA （diethylenetriamine pentaacetic acid） extractable soil nutrient were evaluated; twelve elements were analyzed in the plant tissue and six elements in the soil extract in different soil depths. The research demonstrated that the applications produced increase contents of N, P, Mg, Mn, Zn and Pb in the plant. There was a significant （P 〈 0.01） accumulation of DTPA extractable concentrations of Fe, Mn, Cu, Zn and Pb in the top soil horizon. Also, sewage sludge resulted in 51 folded increase in extractable P in 0-20 cm soil horizon. However, DTPA concentrations of in soil showed that Fe exhibited a significant positive correlation with the concentrations of exchangeable fractions of Mn, Cu, Zn and Pb with the correlation. Positive correlations were also observed between Cu-Mn, Mn-Zn, Mn-Pb, Cu-Zn, Cu-Pb and Zn-Pb concentrations. In the same way, plant uptake of the Mn, Zn and Pb was highly correlated with concentrations of Cu, Zn and Pb in the soil. It was concluded that sewage sludge is a valuable source of nutrient and also provides an opportunity to increase soil organic matter.展开更多
In this article, we introduce the system of high throughput screening (HTS). Its role in new drug study and current development is described. The relationship between research achievements of genome study and new type...In this article, we introduce the system of high throughput screening (HTS). Its role in new drug study and current development is described. The relationship between research achievements of genome study and new type screening model of new drugs is emphasized. The personal opinions of current problems about HTS study in China are raised.展开更多
Focusing inversion is accomplished by the iterative of abnormal source to make the image gradually focused. It can better reflect the underground geological geometry and physical parameters. The model experiments in t...Focusing inversion is accomplished by the iterative of abnormal source to make the image gradually focused. It can better reflect the underground geological geometry and physical parameters. The model experiments in the study show that gravity focusing inversion allows inversion image stabilization and polymerization,which solves the multiple solutions and instability of inversion and so on. The method is applied to measured gravity data processing of certain region of Changbai Mountain,compared to Euler deconvolution,the results show that the method for determining the horizontal position and depth of underground anomalies has good efforts.展开更多
The determination of initial equilibrium shapes is a common problem in research work and engineering applications related to membrane structures. Using a general structural analysis framework of the finite particle me...The determination of initial equilibrium shapes is a common problem in research work and engineering applications related to membrane structures. Using a general structural analysis framework of the finite particle method （FPM）, this paper presents the first application of the FPM and a recently-developed membrane model to the shape analysis of light weight mem- branes. The FPM is rooted in vector mechanics and physical viewpoints. It discretizes the analyzed domain into a group of parti- cles linked by elements, and the motion of the free particles is directly described by Newton＇s second law while the constrained ones follow the prescribed paths. An efficient physical modeling procedure of handling geometric nonlinearity has been developed to evaluate the particle interaction forces. To achieve the equilibrium shape as fast as possible, an integral-form, explicit time integration scheme has been proposed for solving the equation of motion. The equilibrium shape can be obtained naturally without nonlinear iterative correction and global stiffness matrix integration. Two classical curved surfaces of tension membranes pro- duced under the uniform-stress condition are presented to verify the accuracy and efficiency of the proposed method.展开更多
基金Supported by the National Natural Science Foundation of China （No.40604003, 40474001）. Acknowledgements： We are grateful to the ISDC of the GFZ Potsdam for providing the data and to Gerlach C. and Svehla D. at the TUM for the kinematic orbits.
文摘An efficient method for gravity field determination from CHAMP orbits and accelerometer data is referred to as the energy balance approach. A new CHAMP gravity field recovery strategy based on the improved energy balance approach IS developed in this paper. The method simultaneously solves the spherical harmonic coefficients, daily Integration constant, scale and bias parameters. Two 60 degree and order gravitational potential models, XISM-CHAMPO1S from the classical energy balance approach, and XISM-CHAMPO2S from the improved energy balance, are determined using about one year＇s worth of CHAMP kinematic orbits from TUM and accelerometer data from GFZ. Comparisons among XISM-CHAMPO1S, XISM-CHAMPO2S, EIGEN-CGO3C, EIGEN-CHAMPO3S, EIGEN2, ENIGNIS and EGM96 are made. The results show that the XISM-CHAMPO2S model is more accurate than EGM96, EIGENIS, EIGEN2 and XISM-CHAMPO1S at the same degree and order, and has almost the same accuracy as EIGEN-CHAMPO3S.
文摘Based on the reality of college English teaching, this paper puts forward the concept of three-dimensional teaching in college English. Combined with the application of modern technology, this paper discusses the system of college English teaching curriculum, the modernization of teaching content, and the modernization of teaching methods under the network environment. The teaching methods are diversified, and the content of college English teaching reform is discussed in detail. The combination of the leading role of teachers and the main role of students is proposed.
文摘The light weight heat treated B-grade bulletproof steel was developed through composition design and optimization based on multiplex alloying,multiplex micro-alloying design ideas and complex phase structure strengthening theory.The puzzle how to avoid the quenching deformation problem of super high strength thin sheet was solved through heat treatment in a die with a set of cooling system.Such B-grade bulletproof steel plate has fine tempered lath martensite structure.The shooting and certification test results showed that the shoot resistance of B-grade bulletproof steel plate can meet the protection demand of Protection specification for cash carrying vehicles(GA 164—2005).In comparison with B-grade bulletproof steel plate made by one of the companies in Sweden,the weight of the developed B-grade bulletproof steel plate can be decreased by 8 %under the same shoot resistance condition.It will be meaningful for cash truck and anti-hijacking vehicle to realize light weight,energy conservation and emission reduction.
文摘This paper presents the data from two-year experiments concerning with doses of sewage sludge （0, 7, 14 and 21 ton.ha^-1） and inorganic nitrogen doses （0, 50, 100 and 150 kg.ha^-1） from the Municipality of Van, which is located at an altitude of 1,725 m of eastern Anatolia in Turkey. A study was conducted to assess two different N sources on sandy-silty-clay soils grown to crested wheatgrass Agropyron cristatum （L.） Gaertn, grass pasture which had been amended with sewage sludge for two years. Plant tissue and DTPA （diethylenetriamine pentaacetic acid） extractable soil nutrient were evaluated; twelve elements were analyzed in the plant tissue and six elements in the soil extract in different soil depths. The research demonstrated that the applications produced increase contents of N, P, Mg, Mn, Zn and Pb in the plant. There was a significant （P 〈 0.01） accumulation of DTPA extractable concentrations of Fe, Mn, Cu, Zn and Pb in the top soil horizon. Also, sewage sludge resulted in 51 folded increase in extractable P in 0-20 cm soil horizon. However, DTPA concentrations of in soil showed that Fe exhibited a significant positive correlation with the concentrations of exchangeable fractions of Mn, Cu, Zn and Pb with the correlation. Positive correlations were also observed between Cu-Mn, Mn-Zn, Mn-Pb, Cu-Zn, Cu-Pb and Zn-Pb concentrations. In the same way, plant uptake of the Mn, Zn and Pb was highly correlated with concentrations of Cu, Zn and Pb in the soil. It was concluded that sewage sludge is a valuable source of nutrient and also provides an opportunity to increase soil organic matter.
文摘In this article, we introduce the system of high throughput screening (HTS). Its role in new drug study and current development is described. The relationship between research achievements of genome study and new type screening model of new drugs is emphasized. The personal opinions of current problems about HTS study in China are raised.
文摘Focusing inversion is accomplished by the iterative of abnormal source to make the image gradually focused. It can better reflect the underground geological geometry and physical parameters. The model experiments in the study show that gravity focusing inversion allows inversion image stabilization and polymerization,which solves the multiple solutions and instability of inversion and so on. The method is applied to measured gravity data processing of certain region of Changbai Mountain,compared to Euler deconvolution,the results show that the method for determining the horizontal position and depth of underground anomalies has good efforts.
基金Project supported by the National Natural Science Foundation of China （Nos. 51025858 and 51178415）
文摘The determination of initial equilibrium shapes is a common problem in research work and engineering applications related to membrane structures. Using a general structural analysis framework of the finite particle method （FPM）, this paper presents the first application of the FPM and a recently-developed membrane model to the shape analysis of light weight mem- branes. The FPM is rooted in vector mechanics and physical viewpoints. It discretizes the analyzed domain into a group of parti- cles linked by elements, and the motion of the free particles is directly described by Newton＇s second law while the constrained ones follow the prescribed paths. An efficient physical modeling procedure of handling geometric nonlinearity has been developed to evaluate the particle interaction forces. To achieve the equilibrium shape as fast as possible, an integral-form, explicit time integration scheme has been proposed for solving the equation of motion. The equilibrium shape can be obtained naturally without nonlinear iterative correction and global stiffness matrix integration. Two classical curved surfaces of tension membranes pro- duced under the uniform-stress condition are presented to verify the accuracy and efficiency of the proposed method.
