or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. lower soil temperatures than the bare soil. Beijing is located in the northern part of China, with an annual mean temperature of 11.0 to 12.0°C, and growing degree days are limited during the year. Increasing the soil temperature of the seedbed is benefi cial for the winter plants the region of Beijing, where a wheat-maize annual double-cropping system is practiced. Raised beds have the eff ect of restoring the soil temperature. To make use of the advantages of no-till and raised beds, adoption of permanent raised beds is essential (Hari Ram et al., 2011).Combining no-till, permanent bed planting, and furrow irrigation with controlled traffi c, the PRB system has proven itself to be an eff ective method to improve soil properties. Th e developments of PRB technology in diff erent areas are summarized below.In arid and semiarid areas, Verhulst et al. (2011) evaluated the eff ects of tillage and residue management in an arid, irrigated bed planting system with a wheat-maize rotation in an annual double-cropping system and stated that PRB seemed to be the most sustainable option. Devkota et al. (2013) compared permanent beds and residue retention with conventional tillage combined with diff erent levels of residue cover and N fertilization in irrigated arid lands under a cotton (Gossypium hirsutum L.)-wheatmaize rotation system and found that the former can increase water productivity in wheat by 27% and in maize by 84% while increasing yields of wheat by 12% and maize by 42%. A PRB system also signifi cantly increased soil water content, soil temperature, water use effi ciency, soil structure, and spring wheat yield in arid northwestern China under a spring wheat-maize rotation system compared with TT and no-till . In another study, the PRB planting system reduced operational costs up to 40% and enhanced physical and biological soil quality parameters (compared with traditional ridge beds) in the coarse, sandy clay soils ABSTRACT As a typical semi-humid area with a wheat (Triticum aestivum L.)-maize (Zea mays L.) annual double-cropping system, Beijing has the lowest food production per capita and is su ering from severe soil degradation and low seedbed temperature in winter. is study evaluated the permanent raised bed (PRB) system in Beijing from 2005 to 2011 to investigate the e ects of combining no tillage, residue cover, and controlled tra c with raised beds for improving soil properties. We found that the overall soil bulk density (0-30 cm) in PRB plots was signi cantly (P < 0.05) lower (by 12.4%) than that in traditional tillage (TT) plots, while the penetration resistance in the 10-to 20-and 20-to 30-cm soil layers of PRB plots was 18.2 and 26.1% lower (P < 0.05), respectively, than that of TT. e percentage of water-stable soil macroaggregates (>0.25 mm) in the PRB plots was 89.8% (P < 0.05) higher than in the TT plots, while the soil temperature was approximatel...

The shell model (SM) can simulate dipole and other properties concerning electrons. In this paper, an new scheme of SM potential is developed. Unlike the traditional SM, there are no harmonic spring between core and shell, and the potential functions are Coulomb potential multiplied by trigonometric function. The parameters of SM for hydrogen system were fitted by electronic structure data, which is from quantum chemistry ab initio calculation of H, + 2 H and 2 H . And the potential was examined by calculating the most stable structure of H2 and + 2 H by geometry optimization globally, which is agree with the ab initio calculation results. Furthermore, even the energy level of H atom can be calculated by this scheme SM potential, but the reasonable results can not obtained.

This article introduces the recent research of SuperLU algorithms and the optimal storage method for [1] the sparse linear equations of coefficient matrix. How to solve large-scale non-symmetric sparse linear equations by SuperLU algorithm is the key part of this article. The advantage of SuperLU algorithm compared to other algorithms is summarized at last. SuperLU algorithm not only saves memory space, but also reduces the computation time. Because of less storage needed by this algorithm, it could solve equation with larger scale, which is much more useful.