大板面高密度印制板的双面贴装技术

叙述了大板面双面混装工艺中对ＰＣＢ 的设计、制作以及元器件布局等方面的要求，分析了该工艺的特点和难点，并对可能造成故障的原因进行了较为详细的探讨，提出了相应的解决办法。

大面积大板面石材铺贴技术

杭州萧山国际机场石材地面施工面积为6.1万m2,板面尺寸为1.2m×1.2m×0.03m,理论重量每片140 kg。通过对石材生产、保管、施工等过程的细化控制和深化设计、石材各项物理指标分析、质量控制攻关等方式,使工程一次验收合格品率大大提高。

浅析大板面散热器焊缝无损检测技术

本大板面散热器真空钎焊工艺参数复杂、焊接难度大、产品合格率较低,鉴于此钎焊接头的检测是生产过程中必不可少的一个环节,无损检测在不破坏钎焊接头或在不影响钎焊接头使用的前提下进行的焊接缺陷检验是验证产品焊接质量的重要手段。本文旨在针对大板面散热器钎焊质量有效控制与评估,对其无损检测方法进行探究。

高难度PCB的生产与设计——从设计入手来增大PCB生产的可行性

近年来,小孔、细线、高层次、多重埋孔形式的高难度PCB已成为一种趋势。然而,受材料、设备及工艺的限制,如果一味追求高难度,必将大幅度增加PCB的造价、制造周期及工艺难度。

Analysis on cracking of deck pavement on Jiangyin Bridge

Based on four-year field inspection and investigation on deck pavement of mastic asphalt on Jiangyin Bridge, cracking causes of mastic asphalt are studied. Cracks of deck pavement are summarized on crack length and width to get a clear view of their propagations. Traffic surveys including traffic volume, axle load and vehicle speed were also conducted to assess their influences. Samples taken on-site were tested with pulling-out test and fatigue test to benchmark their properties. According to the inspection and tests results, it is concluded that the cracks are induced by rutting and fatigue. Lack of fatigue resistance, not well bonded to the steel deck and insufficient high temperature stability are supposed to be the main reasons as well as high density of low speed, excessively overloaded trucks.

季节性冰冻地区砼道面大板技术研究与基础处理

简要介绍了冰冻地区砼道面大板防冻胀的技术研究，提出了大板基础(防冻层)的技术要求，结构设计指标。供同仁参考。

蜂窝梁骨架楼面大板的可行性研究

以装配式楼面大板结构为对象,分析了蜂窝梁骨架的可行性。通过对楼板骨架中蜂窝梁的设计和计算,验证了蜂窝梁骨架的可行性;其构造简单、制作方便、防腐性能好且经济效益高;蜂窝梁结构增加了楼层净空高度,环境更加舒适。研究为蜂窝梁在实际工程中的应用提供参考。

Dynamic plastic response of clamped stiffened plates with large deflection

Study on the dynamic response, and especially the nonlinear dynamic response of stiffened plates is complicated by their discontinuity and inhomogeneity. The finite element method (FEM) and the finite strip method are usually adopted in their analysis. Although many useful conclusions have been obtained, the computational cost is enormous. Based on some assumptions, the dynamic plastic response of clamped stiffened plates with large deflections was theoretically investigated herein by a singly symmetric beam model. Firstly, the deflection conditions that a plastic string must satisfy were obtained by the linearized moment-axial force interaction curve for singly symmetric cross sections and the associated plastic flow rule. Secondly, the possible motion mechanisms of the beam under different load intensity were analysed in detail. For structures with plastic deformations, a simplified method was then given that the arbitrary impact load can be replaced equivalently by a rectangular pulse. Finally, to confirm the validity of the proposed method, the dynamic plastic response of a one-way stiffened plate with four fully clamped edges was calculated. The theoretical results were in good agreement with those of FEM. It indicates that the present calculation model is easy and feasible, and the equivalent substitution of load almost has no influence on the final deflection.

Failure mechanism and control technology of longwall coalface in large-cutting-height mining method

The stability control of longwall coalface is the key technology of large-cutting-height mining method.Therefore,a systematic study of the factors that affect coalface stability and its control technology is required in the development of large-cutting-height mining method in China. After the practical field observation and years of study,it was found that the more than 95% of failures in coalface are shear failure. The shear failure analysis model of coalface has been established,that can perform systematic study among factors such as mining height,coal mass strength,roof load,support resistance,and face flipper protecting plate horizontal force. Meanwhile,sensitivity analysis of factors influencing coalface stability showed that improving support capacity,cohesion of coal mass and decreasing roof load of coalface are the key to improve coalface stability. Numerical simulation of the factors affecting coalface stability has been performed using UDEC software and the results are consistent with the theoretical analysis. The coalface reinforcement technology of large-cutting-height mining method using the grouting combined with coir rope is presented. Laboratory tests have been carried out to verify its reinforcement effect and practical application has been implemented in several coal mines with good results.It has now become the main technology to reduce longwall coalface failure of large-cutting-height mining method.

The Role of Comprehensive Income as Financial Performance Predictor： Panel Evidence From Italy

The aim of this study is to investigate whether the comprehensive income （CI） and its individual components are useful in assessing the future cash flows for Italian listed companies. In addition, we verify whether the recent requirement of International Accounting Standard （IAS） 1 （r2011） of providing the other comprehensive income （OCI） separates in two sub-totals （recycling and non-recycling items groups） is useful to explain the expected cash flows. We consider a sample of 121 Italian non-financial companies listed on the Italian Stock Exchange for the testing period of 2008-2011, employing a fixed-effect regression model, and we test the relationship between the changes in the variables considered and not the relative absolute value reducing, in this way, the risk of not grasping a report if the independent variable and the response variable do not have the same sign. Our results stress that CI and the two new sub-aggregates are not relevant to explain future cash flows, while net income （NI） and OC1 as a whole seem to be more relevant to make explicit the future financial position. The study contributes, as a sort of post-implementation review, to the current debate on the ability of Cl to predict the future cash flows and on the real usefulness of the CI and the sub-aggregate identified by the IAS 1 revised as well.

Measurement and Prediction of Interfacial Area on a DistiIlation Tray

In this paper the modern electron optical equipment is used to translate the clear image of speed moving bubbles in bubbling liquid on a sieve tray into the digital information stored in computer, and the computer aided image processing technique is utilized to measure the bubble size distributions and interfacial areas under various operating conditions. And the dynamic behavior of bubbles in turbulent liquid is analyzed theoretically; the mechanism of bubble deformation and breakage is explored on the basis of Kolmogoroff′s isotropic turbulence hypothesis; the mathematical model for predicting the gas liquid interfacial area is proposed. The comparison between the simulated results and the experimental data shows that the model is higher in accuracy, simple in form and convenient in use.

Seismic analysis of a long-span continuous steel truss-arch bridge across the Yangtze River

In this paper, an FEM （Finite Element Method） model is established for the main span of the bridge, with the main box arch and suspender members modeled by beam elements, truss members by truss elements, and the orthotropic steel deck by plate elements. The natural frequencies and mode shapes are acquired by the eigen-parameter analysis. By input of a typical earthquake excitation to the bridge system, the dynamic responses of the bridge, including the displacement and accelerations of the main joints of the structure, and the seismic forces and stresses of the key members, are calculated by the structural analysis program, based on which the main laws of the seismic responses of the bridge are summarized, and the safety of the structure is evaluated.

Distribution of acceleration and empirical formula for calculating maximum acceleration of rockfill dams

To find the distribution patterns of dynamic amplification coefficients for dams subjected to earthquake, 3D seismic responses of concrete-faced rockfill dams with different heights and different shapes of river valley were analyzed by using the equivalent-linear model. Statistical analysis was also made to the seismic coefficient, and an empirical formula for calculating the maximum acceleration was provided. The results indicate that under the condition of the same dam height and the same base acceleration excitations, with the increase of the river valley width, the position of the maximum acceleration on the axis of the top of the dam moves from the center to the riversides symmetrically. For the narrow valleys, the maximum acceleration occurs in the middle of the axis at the top of the dam; for wide valleys the maximum acceleration appears near the riversides. The result negates the application of 2D dynamical computation for wide valleys, and shows that for the seismic response of high concrete-faced rockfill dams, the seismic coefficient along the axis should be given, except for that along the dam height. Seismic stability analysis of rockfill dams using pseudo-static method can be modified according to the formula.