某工程静钻根植桩工法应用

本文介绍了新型预制桩施工方法--静钻根植桩工法。该施工工艺结合了钻孔桩和预制桩的优点，适用于粘性土、粉土、砂土等各种土层和各种抗震设防烈度地区，可承受较高的竖向抗压、抗拔和水平荷载。     

Physico-chemical concept of drag reduction nature in dilute polymer solutions (the Toms effect)

The physicochemical concept of turbulent drag reduction (the Toms effect) integrates physicochemical characteristics of polymer solutions with hydrodynamic and rheological flow parameters into a generalized equation, where the increment in volumetric flow rate Q_P is a function of the external shear stress τ_w, temperature, volume of macromolecular coils with immobilized solvent V_c and a function of their volume fraction Ψ = C · [η]/(1 + C · [η]). The Q_P depends on the coil intrinsic elasticity [G] = kT/V_c as well. This model allows one: (1) to describe the Toms effect in terms of useful elastic work spent by macromolecular coils with immobilized solvent to overcome the frictional forces (i.e. the forces of intermolecular interactions), (2) to forecast the initial conditions of the Toms effect (τ_* ≈ (RT)/(M · [η])) and (3) to explain the unusual temperature dependence of the polymer solutions flow.     

含2个S副间隙6-SPS机构奇异性分析

6-SPS机构位姿矩阵采用四元数法描述,并将该矩阵和矢量坐标扩展为4维形式,推导出无间隙机构的运动方程,得到了机构运动的新型雅克比矩阵J_A和J_B;在此基础上,利用连续接触模型得到了两个含间隙S副共连杆和异杆时机构的运动系数矩阵。分别把各个运动系数的行列式展开,得到含间隙机构第一类奇异和第二类奇异的轨迹方程,利用MATLAB得到了机构在给定位置时的第一类位姿奇异轨迹和第二类位姿奇异三维轨迹曲面;通过将两类含间隙机构奇异轨迹曲面的比较,发现机构间隙对第二类奇异的影响大于对第一类奇异的影响;在两类奇异轨迹中,当S副异杆时,机构间隙的影响均大于S副共连杆时的影响。以无间隙机构奇异轨迹曲面上奇异点作为参考点,通过含间隙机构奇异轨迹曲面上与参考点相对应奇异点的相互比较,发现存在一个关于参考点的奇异域。     

The relationship between cell phone use,academic performance,anxiety, and Satisfaction with Life in college students

While functional differences between today’s cell phones and traditional computers are becoming less clear, one difference remains plain – cell phones are almost always on-hand and allow users to connect with an array of services and networks at almost any time and any place. The Pew Center’s Internet and American Life Project suggests that college students are the most rapid adopters of cell phone technology and research is emerging which suggests high frequency cell phone use may be influencing their health and behavior. Thus, we investigated the relationships between total cell phone use (N = 496) and texting (N = 490) on Satisfaction with Life (SWL) in a large sample of college students. It was hypothesized that the relationship would be mediated by Academic Performance (GPA) and anxiety. Two separate path models indicated that the cell phone use and texting models had good overall fit. Cell phone use/texting was negatively related to GPA and positively related to anxiety; in turn, GPA was positively related to SWL while anxiety was negatively related to SWL. These findings add to the debate about student cell phone use, and how increased use may negatively impact academic performance, mental health, and subjective well-being or happiness.     

Design,development and testing twin pulse tube cryocooler

The design and development of Twin Pulse Tube Cryocooler (TPTC) is presented. Both the coolers are driven by a single Linear Moving Magnet Synchronous Motor (LMMSM) with piston heads at both ends of the mover shaft. Magnetostatic analysis for flux line distribution was carried-out during design and development of LMMSM based pressure wave generator. Based on the performance of PWG, design of TPTC was carried out using Sage and Computational Fluid Dynamics (CFD) analysis. Detailed design, fabrication and testing of LMMSM, TPTC and their integration tests are presented in this paper.     

重庆嘉悦大桥下塔柱无支架翻模施工技术

该文结合重庆嘉悦大桥下塔柱施工实际情况,详细介绍了大跨径斜拉桥柔性双薄壁变截面空心高墩大块定制钢模无支架翻模施工技术,为今后类似变截面高墩施工提供参考。     

衬套内外封闭8字形油槽加工装置

通过对衬套油槽的分析,提出了车衬套内外封闭8字形油槽的加工装置,并详细分析了该加工装置的结构。经生产实践证明:该加工装置调试简单,工作时稳定性强,加工出的零件达到了使用要求。     

不连沟选煤厂降低介耗的措施

结合不连沟选煤厂工艺流程,分析了不连沟选煤厂介耗不稳定的原因。通过加强介质质量管理、改变介质添加方式、调整磁选机磁偏角、减小磁选机滚筒与槽体间隙、提高磁选机精矿挡沿、控制分流量、增加加压泵、清理维护固定筛、调整脱泥筛筛板筛孔尺寸等措施,不连沟选煤厂降低了磁选机尾矿带介量和产品带介损失,有效减少了-3 mm碎煤进入重介系统,减轻了磁选机工作负荷,改善了悬浮液不稳定的情况,有效平稳了合介桶位,分流量得到合理有效的控制。2010年11月—2011年4月,选煤厂介耗由1.26 kg/t降至0.18 kg/t,降低了85.71%。2011年4月,选煤厂介耗降至0.18 kg/t,已低于国内吨原煤消耗的最低值,节省介质费用高达60.6万元。     

马来西亚动车组司机操纵台设计及其强度计算分析

本文介绍了一种仪表座采用悬臂式和中心底座结构的新型模块化设计形式的司机操纵台，对其结构及设备布置进行了阐述，并借助ANSYS软件对该结构的强度进行了计算分析。