地基设计基本原则的探讨

地基设计是整个建（构）筑物设计中的重要组成部分，它关系到建（构）筑物的安全及其功能能否正常发挥。本文着重分析探讨了在地基设计中应遵循的原则及注意事项。以保证建（构）筑物的安全和正常使用，充分发挥地基的作用。     

Accelerated vibratory fatigue test by ultrasonic frequency at cryogenic temperature

The fatigue test is a time-consuming experiment. The accelerated fatigue testing technique is a dream for all researchers. In our laboratory, a vibratory fatigue testing machine was built, which works at 20 kHz for R = −1 and permits to carry out tests at cryogenic temperature. This is an automatic machine controlled by a PC computer. By using this apparatus, it is easy to save time by 400 to 500 times and a lot of liquid air (nitrogen or helium).

A titanium alloy, Ti6A14V (TA6V PQ french mark), was tested in liquid nitrogen (77 K) with this machine for S---N curve. At the same time, other fatigue tests were performed in SEP (Société Européenne de Propulsion) in conventional fatigue for the same material and the same conditions except the frequency. The comparison shows that the results are coherent.     

马来酸及其酐和衣康酸与PP熔体接枝反应机理的研究

以马来酸酐作对照，用热分析、流变、化学分析等方法，研究了马来酸和衣康酸在非隔氧条件下与ＰＰ熔体催化接枝反应的特点和规律，阐述了单体结构－单元反应相对速率－－接枝产物结构之间的关系，提出了３种接枝物的结构模型。     

照相材料的稳定与保存

本文讨论了影响照相材料稳定与保存的几个因素以及为保持照相材料最佳稳定性、保存性而采取的几种有效方法。     

“镍”催化酰氯和有机锡试剂交叉偶联反应的研究

镍络合物催化酰氯与有机锡试剂交叉偶联合成有机酮的反应,其反应选择性强,反应彻底,转化率高,工艺简单。在有机锡过量的情况下,对不同催化剂的催化活性和包括投料比,反应温度,反应时间,反应溶剂等反应条件进行了考察。     

管外上升R－113流体的沸腾换热试验

详细介绍了Ｒ－１１３流体管外上升流动的沸腾换热试验，包括试验台架、流量计和温度测量的修正，以及试验数据。拟合的换热关系式为ｑ＝５２８（Ｔｗ─Ｔｓ）１．３３。     

An efficient numerical approach, for determining the dispersioncharacteristics of dual-mode elliptical-core optical fibers

Based on vectorial formulations which combine the surface integral equation method and the finite-element method, a novel numerical approach is proposed for calculating the dispersion coefficients of dual-mode elliptical-core fibers with arbitrary refractive index profiles. By differentiating the original formulations involving the propagation constant β and the guided mode fields H_x and H_y once and twice with respect to the normalized frequency V, the new formulations for {dβ/dV, dH_x/dV, dH_y/dV} and for {d²β/dV², d² H_x/dV², d²H_y/dV² } are obtained respectively. Once {β, H_x, H_y } is solved through the eigenvalue procedure which dominates the computing time, only a few matrix manipulations are required to obtain {dβ/dV, dH_x/dV, dH_y/dV} and {d²β/dV², d²H_x/dV² , d²H_y/dV²}. Some numerical examples are examined to see the influence of different refractive index distributions with dips on the dispersions of the four nondegenerate LP ₁₁ modes for elliptical-core fibers