问题 问答题 简答题

什么叫剂油比?剂油比的大小对催化裂化反应有些什么影响?

答案

参考答案:

剂油比(C/O)=催化剂循环量(t/h)/总进料量(t/h)

由于催化剂活性中心的存在,大大提高了反应速度。

因此,提高剂油比就是相对增加了活性中心。

同时,由于催化剂循环量的增加,使待生剂和再生剂的炭差减小,相应提高了催化剂的有效活性中心,使反应的转化深度提高。当剂油比提高时,转化率增加,气体、汽油和焦炭都增加。

特别是焦炭与转化率的比值增加显著。这是由于剂油比增加使待生剂上的烃类吸附量增加,汽提时间短而造成焦炭产率增加。

单项选择题

The majority of successful senior managers do not closely follow the classical rational model of first clarifying goals, assessing the problem, formulating options, estimating likelihood of success, making a decision, and only then taking action to implement the decision. Rather, in their day-by-day tactical activities, these senior executives rely on what is vaguely termed "intuition" to manage a network of interrelated problems that require them to deal with ambiguity, inconsistency, novelty, and surprise; and to integrate action into the process of thinking.

Generations of writers on management have recognized that some practicing managers rely heavily on intuition. In general, however, such writers display a poor grasp of what intuition is. Some see it as the opposite of rationality; others view it as an excuse of capriciousness.

Isenberg’s recent research on the cognitive processes of senior managers reveals that managers’ intuition is neither of these. Rather, senior managers use intuition in at least five distinct ways. First, they intuitively sense when a problem exists. Second, managers rely on intuition to perform well-learned behavior patterns rapidly. This intuition is not arbitrary or irrational, but is based on years of painstaking practice and personal experience that build skills. A third function of intuition is to synthesize isolated bits of data and practice into an integrated picture, often in an "Aha!" experience. Fourth, some managers use intuition as a check on the results of more rational analysis. Most senior executives are familiar with the formal decision analysis models and tools, and those who use such systematic methods for reaching decisions are occasionally suspicious of solutions suggested by these methods which run counter to their sense of the correct course of action. Finally, managers can use intuition to bypass in-depth analysis and move rapidly to find out a plausible solution. Used in this way, intuition is an almost instantaneous cognitive process in which a manager recognizes familiar patterns.

One of the implications of the intuitive style of executive management is that "thinking" is inseparable from acting. Since managers often "know" what is right before they can analyze and explain it, they frequently act first and explain later. Analysis is invariably tied to action in thinking/acting cycles, in which managers develop thoughts about their companies and organizations not by analyzing a problematic situation and then acting, but by acting and analyzing in close concert.

Given the great uncertainty of many of the management issues that they face, senior managers often initiate a course of action simply to learn more about an issue. They then use the results of the action to develop a more complete understanding of the issue. One implication of thinking/acting cycles is that action is often part of defining the problem, not just of implementing the solution. (454 words)

According to the text, senior managers use intuition in all of the following ways EXCEPT()

A. to speed up the creation of a solution to a problem

B.to identify a problem or bring together different facts

C. to initiate clear goals and in the end attain them

D.to evaluate possible solutions to a problem

单项选择题