The underlying problem is that DB2 processes recursion by essentially producing one level of recursion at a time ( breadth first), while Oracle uses depth first. 在底层,DB2处理递归时采用的方法是逐层递归(广度优先),而Oracle采用的是深度优先的方法。
The effect of forage grass on runoff and sediment reductions was studied by using different flows scouring experiment, and analyzed mechanism of regulating runoff in slope from the duration of producing runoff, velocity and depth of runoff. 通过坡面放水模拟径流冲刷试验,研究了不同放水流量下草地减水减沙效应,并从起流历时、径流流速、径流深度等方面分析了草地调控水沙的机理。
This paper presents a new application of this type machines for producing teeth of tapered depth By use of this new method, the second order tooth surface contact conditions can be effectively ensured, and a reference contact point according to requirements can be arbitrarily appointed. 本文给出这类机床上加工收缩齿的一种新的应用。应用该法能有效地保证二阶齿面接触条件,且可根据要求任意指定接触基准点。
First the transient temperature fields in tooth surface by pulsed line-source laser producing are studied. The temperature rises in the direction of depth and the radius are analyzed. 先讨论了激光线源作用于牙齿表面时产生的瞬态温度场,得到了深度和光斑半径方向上的温升情况。