780 resultados para 956.94054


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工程开挖卸荷后岩体参数研究一直是工程界关注的焦点,是稳定性评价的基础性工作.本文以锦屏地下厂房开挖工程为背景,通过对上下游边墙不同桩号段开挖揭露的岩体进行工程地质岩组划分,进行了开挖后岩体质量评价并对其进行分类,通过在GSI(Geological Strength Index)评价体系中引入Jv(节理数/m3),使评价体系相对合理化,经回归分析,对不同风化程度的岩体进行了力学参数求解,发现内聚力及内摩擦角的计算值与建议值吻合较好

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应用全量子的分子轨道强耦合方法,研究了基态的O3+(2s22p2P)与氢分子碰撞的非解离电荷转移过程,计算了不同方位角(25°,45°,89°),能量分别为100,500,1000和5000eV/u时的单电子俘获的振动分辨的态选择截面及相应的微分截面.分子轨道强耦合计算中采用了自旋耦合价带理论计算的三原子分子势能面和径向耦合矩阵元.对氢分子的自身转动,采用无限阶的冲量近似方法;对体系的电子运动同H2或H2+的振动之间的耦合,采用了振动冲量近似.结果发现,对不同的入射能量,振动态选择截面随振动量子数的分布发生了一定的改变;不同入射能量和不同方位角的振动态分辨的微分截面具有类似的结构,在极小的散射角附近出现一个最大值平台,然后散射截面随着散射角的增大而减小,并出现大量的震荡结构,其中第一个震荡结构对应的散射角位置随入射能量Ep以Ep-1/2的标度规律变化;微分截面的结构和大小对H2方位角α的变化敏感,这种性质为H2取向的诊断提供了一种可能的途径.

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在Brueckner-Hartree-Fock理论框架内,研究了新生中子星的状态方程和性质,计算了新生中子星的最大质量和新生中子星中质子占总核子数的丰度,特别是讨论了三体核力和中微子束缚效应的影响以及三体核力和中微子束缚效应的相互影响.结果表明,无论是否考虑三体核力,中微子束缚对新生中子星的状态方程和质子丰度均有明显影响.中微子束缚导致新生中子星物质中的质子丰度显著增大.三体核力的贡献是使新生中子星的状态方程变硬并导致新生中子星中质子丰度明显增大.束缚在中子星物质中的中微子显著减弱了三体核力对于中子星物质中质子丰度的影响.

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IEECAS SKLLQG

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Charge transfer due to collisions of ground state O3+ (2s(2)2p P-2) ions with molecular hydrogen is investigated using the quantum-mechanical molecular-orbital close-coupling (MOCC) method, and electronic and vibrational state-selective cross sections along with the corresponding differential cross sections are calculated for projectile energies of 100, 500, 1000 and 5000 eV/u at the orientation angles of 25 degrees,45 degrees and 89 degrees. The adiabatic potentials and radial coupling matrix elements utilized in the QMOCC calculations were obtained with the spin-coupled valence-bond approach. The infinite order sudden approximation (IOSA) and the vibrational sudden approximation (VSA) are utilized to deal with the rotation of H-2 and the coupling between the electron and the vibration of H-2. It is found that the distribution of vibrationally resolved cross sections with the vibrational quantum number upsilon' of H-2(+) (upsilon') varies with the increment of the projectile energy; and the electronic and vibrational stateselective differential cross sections show similar behaviors: there is a highest platform within a very small scattering angle, beyond which the differential cross sections decrease as the scattering angle increases and lots of oscillating structures appear, where the scattering angle of the first structure decreases as E-P(-1/2) with the increment of the projectile energy E-P; and the structure and amplitude of the differential cross sections are sensitive to the orientation of molecule H-2, which provides a possibility to identify the orientations of molecule H-2 by the vibrational state-selective differential scattering processes.

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Within the Brueckner-Hartree-Fock framework, the equation of state and the properties of newborn neutron stars are investigated by adopting a realistic nucleon-nucleon interaction AV(18) supplemented with a microscopic three-body force or a phenomenological three-body force. The maximum mass of newborn neutron star and the proton fraction in the newborn beta-stable neutron-star matter are calculated. The neutrino-trapping and the three-body force effects are discussed, and the interplay between the effects of the trapped neutrino and the three-body force are especially explored. It is shown that neutrino trapping considerably affects the proton abundance and the equation of state of the newborn neutron star in both cases with and without the three-body forces. The effect of neutrino trapping remarkably enhances the proton abundance, and the contribution of the three-body force makes the equation of state of the newborn neutron star much stiffer at high densities and consequently increases the proton abundance strongly. The trapped neutrinos significantly reduce the influence of the three-body force on the proton abundance in newborn neutron stars.

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采用空间直观景观模型(LANDIS)模拟了3种不同经营措施(假设1987年未发生特大火灾,完全依靠天然更新(M1);1987年特大火灾发生后依靠天然更新(M2)和火灾后采取目前森林经营措施(M3))下图强林业局落叶松及其成过熟林300年的动态变化.结果表明:林业局整体水平上,M1和M3方案下落叶松林面积占森林总面积的比例明显高于M2方案.M3方案下落叶松面积比例开始时低于M1方案,但由于大规模的人工更新,随后迅速增加,约100年后赶上M1方案.不同经营措施对落叶松面积百分比影响较大,并对其年龄结构有显著影响.M1方案下落叶松成过熟林面积比例明显高于M2方案;而在M3方案下,由于火后10年大规模的森林采伐,落叶松成过熟林的面积比例锐减,随后逐渐增加,但需要近100年才能达到并超过其他2种方案.此外,在火烧区和未火烧区,落叶松及其成过熟林在不同经营措施下的变化趋势存在明显差异.

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近年来大气中CO2体积分数急剧上升,对植物的光合作用、呼吸作用、水分利用等产生重要的影响。文章利用开顶式气室(OTC)研究了大气CO2体积分数升高条件下玉米(ZeamaysL.)叶片抗氧化能力的变化。结果表明,整个生长季内,与对照相比,在高体积分数CO2(550×10-6)条件下,玉米叶片的相对电导率和MDA含量下降,说明膜脂过氧化程度有所降低;O2?.产生速率和H2O2含量与对照相比呈下降趋势并在灌浆期呈显著性差异(P<0.05),但是随着熏蒸时间的延长,高体积分数CO2处理的植株O2?.产生速率和H2O2含量都逐渐降低,这说明高体积分数CO2下活性氧产生减少;SOD、POD、CAT的活性与对照相比明显升高并达到显著(P<0.05)或极显著水平(P<0.01);百粒质量、穗粒数和穗粒质量均高于对照,说明CO2体积分数升高有利于提高玉米的抗氧化能力,促进植物生长。

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妇宁生物液是以发酵性金色链霉菌代谢产物为主要成分 ,配以蛇床子、龙涎香、薄荷等制成的消毒液。在悬液定量杀菌试验中 ,以其 1∶1稀释液对白色念珠菌作用 2min ,或以其 1∶2稀释液作用 10min ,杀灭率均达 99 9%。向菌悬液中加 50 %小牛血清 ,其杀菌效果明显下降。该剂放置于 54℃下 14d ,其 1∶1稀释液将白色念珠菌杀灭 99 9%的作用时间需延长至 10min。

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根据我国北方地区历年油松飞播调查资料和对典型播区的调查 ,阐明了油松飞播的地理分布和效果 ;同时运用统计分析和模糊数学分析等方法 ,对影响油松飞播成效的主要因子作了系统的宏观分析 ,得出年均降水量和年均气温是影响飞播效果的主要因子。在此基础上 ,对北方地区油松飞播造林进行了适宜性分区 ,分区结果将油松飞播划分为 3个区 ,即造林适宜区 ,造林次适宜区和造林非适宜区 ,对指导今后油松飞播生产具有重要意义