We analyze, both analytically and numerically, the effectiveness
of cloaking an infinite cylinder from observations by electromagnetic
waves in three dimensions. We show that, as truncated approximations
of the ideal permittivity and permeability tensors tend towards
the singular ideal cloaking fields, so that the anisotropy ratio tends to
infinity, the D and B fields blow up near the cloaking surface. Since
the metamaterials used to implement cloaking are based on effective
medium theory, the resulting large variation in D and B will pose a
challenge to the suitability of the field averaged characterization of "
and 碌. We also consider cloaking with and without the SHS (softand-
hard surface) lining, shown in [6] to be theoretically necessary
for cloaking in the cylindrical geometry. We demonstrate numerically
that cloaking is significantly improved by the SHS lining, with both
the far field of the scattered wave significantly reduced and the blow
up of D and B prevented.
標簽:
effectiveness
analytically
numerically
cloaking
上傳時間:
2017-03-30
上傳用戶:zxc23456789
TLC2543是TI公司的12位串行模數轉換器,使用開關電容逐次逼近技術完成A/D轉換過程。由于是串行輸入結構,能夠節省51系列單片機I/O資源;且價格適中,分辨率較高,因此在儀器儀表中有較為廣泛的應用。
TLC2543的特點
(1)12位分辯率A/D轉換器;
(2)在工作溫度范圍內10μs轉換時間;
(3)11個模擬輸入通道;
(4)3路內置自測試方式;
(5)采樣率為66kbps;
(6)線性誤差±1LSBmax;
(7)有轉換結束輸出EOC;
(8)具有單、雙極性輸出;
(9)可編程的MSB或LSB前導;
(10)可編程輸出數據長度。
TLC2543的引腳排列及說明
TLC2543有兩種封裝形式:DB、DW或N封裝以及FN封裝,這兩種封裝的引腳排列如圖1,引腳說明見表1
TLC2543電路圖和程序欣賞
#include<reg52.h>
#include<intrins.h>
#define uchar unsigned char
#define uint unsigned int
sbit clock=P1^0; sbit d_in=P1^1;
sbit d_out=P1^2;
sbit _cs=P1^3;
uchar a1,b1,c1,d1;
float sum,sum1;
double sum_final1;
double sum_final;
uchar duan[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};
uchar wei[]={0xf7,0xfb,0xfd,0xfe};
void delay(unsigned char b) //50us
{
unsigned char a;
for(;b>0;b--)
for(a=22;a>0;a--);
}
void display(uchar a,uchar b,uchar c,uchar d)
{
P0=duan[a]|0x80;
P2=wei[0];
delay(5);
P2=0xff;
P0=duan[b];
P2=wei[1];
delay(5);
P2=0xff;
P0=duan[c];
P2=wei[2];
delay(5);
P2=0xff;
P0=duan[d];
P2=wei[3];
delay(5);
P2=0xff;
}
uint read(uchar port)
{
uchar i,al=0,ah=0;
unsigned long ad;
clock=0;
_cs=0;
port<<=4;
for(i=0;i<4;i++)
{
d_in=port&0x80;
clock=1;
clock=0;
port<<=1;
}
d_in=0;
for(i=0;i<8;i++)
{
clock=1;
clock=0;
}
_cs=1;
delay(5);
_cs=0;
for(i=0;i<4;i++)
{
clock=1;
ah<<=1;
if(d_out)ah|=0x01;
clock=0;
}
for(i=0;i<8;i++)
{
clock=1;
al<<=1;
if(d_out) al|=0x01;
clock=0;
}
_cs=1;
ad=(uint)ah;
ad<<=8;
ad|=al;
return(ad);
}
void main()
{
uchar j;
sum=0;sum1=0;
sum_final=0;
sum_final1=0;
while(1)
{
for(j=0;j<128;j++)
{
sum1+=read(1);
display(a1,b1,c1,d1);
}
sum=sum1/128;
sum1=0;
sum_final1=(sum/4095)*5;
sum_final=sum_final1*1000;
a1=(int)sum_final/1000;
b1=(int)sum_final%1000/100;
c1=(int)sum_final%1000%100/10;
d1=(int)sum_final%10;
display(a1,b1,c1,d1);
}
}
標簽:
2543
TLC
上傳時間:
2013-11-19
上傳用戶:shen1230
The XML Toolbox converts MATLAB data types (such as double, char, struct, complex, sparse, logical) of any level of nesting to XML format and vice versa.
For example,
>> project.name = MyProject
>> project.id = 1234
>> project.param.a = 3.1415
>> project.param.b = 42
becomes with str=xml_format(project, off )
"<project>
<name>MyProject</name>
<id>1234</id>
<param>
<a>3.1415</a>
<b>42</b>
</param>
</project>"
On the other hand, if an XML string XStr is given, this can be converted easily to a MATLAB data type or structure V with the command V=xml_parse(XStr).
標簽:
converts
Toolbox
complex
logical
上傳時間:
2016-02-12
上傳用戶:a673761058