Research on method of pressure grouting piling of driven tube

The pressure grouting pile of driven tube can improve the load bearing capacity of the single pile from the mechanism of pressure grouting pile of driven tube.On the basis of analyzing the mechanism,the authors designed the machines and tools of pressure grouting,determined the operating manufacture and technology parameter on the pressure grouting secondly.The result shows that the pressure grouting pile of driven tube not only changes the pile type but also reduce the length of the pile and its engineering cost,it enhances the load bearing capacity of single pile an the same time.     

Isolation and biological characteristics of aerobic marine magnetotactic bacterium YSC-1

1 INTRODUCTION Magnetotactic bacteria are able to respond and orient along the direction of terrestrial or artificial magnetic field, a behavior referred to as magneto- taxis. In the majority of magnetotactic bacteria, the magnetosomes are 25–120 nm in d…     

空间数据自动化建库工具研究

空间数据库的建设速度和成本是影响GIS应用的重要因素。目前空间数据建库存在软件通用性差、建库过程操作复杂、人工干预多、建库效率低等问题。本文针对建库中存在的问题，研究并提出了基于可视化建模思想的空间数据库自动化建库技术，有助于大幅度降低建库复杂性及建库成本，提高效率。     

基于CC的防火墙安全功能分析

防火墙是网络安全的核心手段。依据基于CC（Common Criteria）制订的国家标准——包过滤防火墙安全技术要求和应用级防火墙安全技术要求，提出每项安全功能要求对应的实际安全措施，并分析当前防火墙未实现的安全功能要求。     

中国古代太阳中天观测及二至点测算精度

研究了元代《授时历议))所保存的天象观测和推步资料，得出：(1)在AD1277—1280年问所作的98次太阳中天观测的时刻及地平高度的绝对值平均误差分别为2．64min和6．78′．(2)6部古历——《大衍历》、《宣明历》、《纪元历》、《统天历》、《重修大明历》和《授时历》推步BC522年前的3个冬至时刻的误差范围为0．97—3．51d；而AD435—1280年间的45个冬至时刻的绝对值平均误差则分别为9．35、10．42、5．54、2．97、5．68、3．36h．(3)古代确定的AD442—1280年间的16个二至时刻的绝对值平均误差为199．59min，其中元代的误差为27．89min．     

Magnetic reconnection induced by Kelvin Helmholtz instability

MHD simulation study is performed to investigate magnetic reconnection induced by the Kelvin Helmholtz instability in the initially sheared magnetic field geometry as well as in the uniform magnetic field geometry. Slow mode rarefaction structures seen in the uniform field case are not observed in the sheared field case. Dynamo action is less prominent and the conversion of plasma flow energy into the other forms of energy is also smaller in the sheared field case than in the uniform field case. Momentum transport is mostly due to the hydrodynamic stress in the sheared field case, while the electromagnetic stress is dominant in the uniform field case. The long term evolutions are also markedly different in the two cases. In the uniform field geometry, the magnetic field lines twisted due to the Kelvin Helmholtz instability become reconnected and flattened so that they resume the straight field line structure which resembles the initial field geometry. The magnetic field, however, is not uniform with smaller intensity in the central region where the pressure balance is partially maintained by the enhanced thermal pressure. In the initially sheared magnetic field geometry, magnetic reconnection continues to operate until the end of the simulation and the conversion of the flow energy into the thermal energy is still seen.     

关于大陆动力学几个问题的思考

本文对大陆动力学研究中密切关注的问题，如大陆裂解和碰撞的经典、非经典、非威尔逊旋回；盆─山转换的多类型多阶段；大陆垂向增生与侧向增生──是拆沉还是抽拉？造山带结构的复杂性和多样性以及大陆岩石圈发展与演化的“力源”等问题进行了归纳分析和讨论，同时提出了笔者对上述问题的看法。     

Filament activation and magnetic reconnection

Solar Physics - A curved filament in a decaying active region (AR&;nbsp;8329) was observed on 9 September 1998 with a combination of several instruments. The main data base is a 4-hour long time...