伏尔加—卡马梯级水库调度方式的变动对航运条件的影响

在国民经济蓬勃发展条件下,自然资源(包括水资源)多部门的综合利用是极其重要的。在伏尔加河流域水资源有限的情况下,正是通过这一途径满足国民经济部门和居民用水量日益增长的需求。     

六枝大用煤矿预抽煤层瓦斯防止煤与瓦斯突出

<正>六枝矿务局煤与瓦斯突出严重.全局七对矿井均为突出矿井,其突出次数占贵州突出总次数的3/4以上,而大用矿又是这些矿井中突出次数最多、强度最大的一个矿井.预抽煤层瓦斯作为防突措施,曾在中梁山、北票等局、矿作了局部试验.在透气性较好的条件下,有明显效果,在透气性很低时效果则差.而且预抽防突的机理、工艺、参数等方面存在许多急待解决的问题.     

用溶胶—凝胶法制备纳米级TiO2粒子的结晶

用溶胶－凝胶法制备了ＴｉＯ２溶胶，并用通过动态光散射了它们的表观尺寸，在反应初期阶段观察到一种不稳定的行为，在此不稳定阶段之间后粒子大小到一种稳定状态，在此，溶胶的微料大小恒定只是数目增加，只在溶胶浓度达到空们的重叠值（ｏｖｅｒｌａｐ）凝胶阶段便发生，用该法制备的样品通过喇曼光散谱和Ｘ－射线衍射法研究了材料的结晶动力学的特征。     

RESIDUAL GAS IONIZATION BEAM PROFILE MONITOR ON 40MeV H^— BEAM TRANSPORT LINE

The monitor is composed of a pair of electrodes,a single stage of microchannel plate,a phosphor screen,a CCD camera and a PC computer,To obtain a good uniform collecting field,forming electrodes system is used instead of that with a resistive divider,The readout system is performed by the phosphor screen and the CCD camera because the spatial resolution is not limited by the mechanical structure like the anode strip type and such video display system is very useful for beam studies and operation of the 40MeV linac,Besides,the design and test results are described in detail.     

湘钢二烧系统取消热振筛之利弊探析

当前国内外大中型烧结机都倾向于取消热振筛,但取消后生产工艺之利弊如何,又怎样根据不同厂情、地情、国情、市场情况以扬其利、克其弊,还有待于进一步探讨。本文根据湘钢的生产实际,对这一问题进行了探析。     

Technology enters the hospital's executive suite

Two major forces are driving the emergence of more powerful and comprehensive executive information systems: compression of the time horizon--CEO's cannot wait weeks or months for historical trends data--and EIS technological development that allows executives to tap into daily operations on all levels.     

砷化镓材料中EPR“As_(Ga)”的退火行为

本文比较了中子辐照。压缩变形和原生LEC砷化镓等三种不同来源样品的EPR“As_(Ga)”的Hamiltonian参数。并系统地研究了EPR“As_(Ga)”的浓度和低温光猝灭行为随退火温度的变化,从而进一步验证了EPR“As_(Ga)”的本性,即除孤立As_(Ga)反位原子外,还可能包括As_(Ga)的一些空位络合物。这些不同本性的EPR“As_(Ga)”缺陷及其它有关的缺陷在样品热处理过程中可能相互转化。按照物理化学中Le Chatlier原理,缺陷的原始浓度和晶体内部应变能似应是引起这些转化反应的重要因素。     

Morse set classification and hierarchical refinement using Conley index

Morse decomposition provides a numerically stable topological representation of vector fields that is crucial for their rigorous interpretation. However, Morse decomposition is not unique, and its granularity directly impacts its computational cost. In this paper, we propose an automatic refinement scheme to construct the Morse Connection Graph (MCG) of a given vector field in a hierarchical fashion. Our framework allows a Morse set to be refined through a local update of the flow combinatorialization graph, as well as the connection regions between Morse sets. The computation is fast because the most expensive computation is concentrated on a small portion of the domain. Furthermore, the present work allows the generation of a topologically consistent hierarchy of MCGs, which cannot be obtained using a global method. The classification of the extracted Morse sets is a crucial step for the construction of the MCG, for which the Poincare′ index is inadequate. We make use of an upper bound for the Conley index, provided by the Betti numbers of an index pair for a translation along the flow, to classify the Morse sets. This upper bound is sufficiently accurate for Morse set classification and provides supportive information for the automatic refinement process. An improved visualization technique for MCG is developed to incorporate the Conley indices. Finally, we apply the proposed techniques to a number of synthetic and realworld simulation data to demonstrate their utility.