Environment, Energy and Sustainable Development

918

In other words, under the condition of

μ

>+

ng

+

,

there will be formed into a finite number of the

central region (see in Fig. 3).

Because in the first case, the center area keeps

shrinking, tends to zero, and finally cross with

the axes of intersect at a point; while in the sec-

ond case, the center area keeps increasing, under

the constraint of the total area, it can’t be enlarged

unlimitedly. Accordingly, whatever conditions,

eventually there will be formed into a finite number

of the central region.

Expansion formula of the formula given above

is:

:

:l

n:

:

**

*

s

:l

n

t

tt

::

cc

:l

n

:l

n

m

c

m

12

:

n

:l

n

12

:

t

…

:

:

…

:l

n

m

12

:

t

(14)

From

se

c

rt

1

1

tt

*

, we get:

l

n

.

*

sr

t

c

11

r

t