排序方式: 共有18条查询结果,搜索用时 15 毫秒
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河南新乡铁西国家粮食储备库新建2栋粮仓 ,每栋粮仓平面结构尺寸为21m×60m ,建筑面积1296m2。采用先张法预应力拱板屋架 ,屋架实际长22.94m(两端各出轴线0.97m) ,宽1.98m。屋架下弦板为40mm厚平板(主筋48b5) ,上弦板为50mm厚抛物线型折线板(主筋21b5) ,上下弦板之间间隔2.1m ,用40mm厚混凝土隔板连接(图1)。上下弦板为C40 ,隔板为C20混凝土。根据工期要求及现场实际情况(建设单位无预制场地) ,经分析决定在高空一次定位现浇成型拱板屋架。为此将屋架在圈梁以外的8… 相似文献
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介绍了硅在砷化镓扩散的几种模型。对高剂量离子注入情况,提出了自己的模型,并对硅扩散行为进行了模拟。 相似文献
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A simple model is described to simulate Kinetic preocesses in dielectric barrier discharges for O2/NOx mixtures.A threshold of ozone production found experimentally is confirmed by the calculations of this modeling,and the underlying chemical reaction mechanisms are discussed.It is also found that the effects of diffusion processes in the period of the lifetime of O atoms are not important to microdischarge channels with a large radius.i.e.larger than 150μm. 相似文献
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提出了一种有效的双向边分布式造构Delaunay三角剖分拓扑图算法(MEDDEL),该算法仅利用一跳邻居节点的信息,高效构造MEDDEL拓扑图,避免了大量通信代价和能量消耗。然后给出了MEDDEL拓扑图下支撑值计算的证明。最后在传感器能量模型和MEDDEL拓扑图下,利用分布式最佳覆盖路下的最短穿越和最小能耗算法(SMBCP)解决无线传感器网络中栅栏覆盖最佳路径的问题。仿真实验结果分析表明,与RNG、GG、PLDEL、UDEL、DEL相比较,在MEDDEL拓扑结构下寻找到路径支撑值最小的情况下,运行SMBCP算法能找到最佳覆盖路径下的最短穿越路径和最小能耗路径。 相似文献
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一、概述本文介绍一台可靠性较高,速度较快,外围控制电路简单的动态MOS存储器模块及其检测系统。为了提高机器效率,主机采用两条流水线并行读写,每条流水线存储容量为24k字30位,(其中6位为海明校验位),分为三 相似文献
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采用X射线衍射(XRD)、差热分析(DTA)和电子显微镜研究Ni60Nb40和Ni40Nb60快淬非晶的晶化行为。结果表明,在10 K/min加热速率下采用差热分析测得Ni60Nb40和Ni40Nb60的非晶初始晶化温度分别为913和917K,且两种非晶样品在低于各自初始晶化温度退火时均发生了晶化。其中,Ni60Nb40样品经763 K退火48 h后仍保持非晶态,而经873 K退火1 h后,则析出面心立方纳米晶颗粒;对于Ni40Nb60非晶合金,在763 K温度下退火48 h就发生晶化,析出面心立方纳米相。晶化样品中均发生明显的成分偏聚现象。结合金属玻璃中的微结构与动力学不均匀性以及β弛豫过程,初步探讨Ni60Nb40和Ni40Nb60快淬非晶相关低温纳米晶化行为的内在机制。 相似文献
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汪庄井田采煤沉陷特征及沉陷治理方法 总被引:1,自引:0,他引:1
阐述了因煤层开采引起的地表沉陷类型及其基本特征,从煤层赋存条件、开采方法、塌陷现状和人为因素等方面分析了井田内地表沉陷形成的原因及危害。针对开采造成的地表沉陷特点,从开采方法和采空区处理两个方面给出了地表沉陷的治理方法及防治对策。 相似文献
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Haozhe KONG 《等离子体科学和技术》2022,24(9):95101
Adiabatic response effects on high-frequency fishbone instability driven by passing energetic ions are studied. With finite orbit width effects, the adiabatic contribution $\delta {W}_{{\rm{hf}}}$ is derived analytically for purely passing energetic ions. By approximating the adiabatic contribution to the first order of the reverse aspect ratio $\varepsilon ,$ we derive one of its analytic expressions, which is expected to be more accurate than that in a previous work (Graves J P 2004 Phys. Rev. Lett. 92 185003). For high-frequency fishbone instability, nonadiabatic response is usually dominant over adiabatic response, but under certain circumstances the latter plays an important role, comparable to the former. With a more generalized distribution function by introducing Gaussian-type factors representing their pitch and radial dependences and using a slowing-down equilibrium distribution for the energy of energetic ions, numerical analysis indicates that the adiabatic contribution is conducive to stabilization of the mode and causes a decrease in mode frequency. In addition, we find that the adiabatic contribution has a weak stabilizing effect on the fishbone instability when the finite orbit width effect is taken into account. We further analyze the dependence of the adiabatic contribution on the characteristic parameters of the distribution function. When the neutral beam has either a larger deviation from the plasma axis or a larger radial profile, the adiabatic contribution has a more evident effect on the fishbone instability. When the neutral beam has a relatively small critical energy, the adiabatic contribution has a greater effect on the mode instability. 相似文献