摘要:
Insert into T1select * from T2 where NOT EXISTS (select 1 from T1 X where X.GUID=T2.GUID); 阅读全文
posted @ 2018-11-09 14:41
kakaisgood
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摘要:
设电阻R1,R2,R3,...,Rn总电阻R1/R=1/R1+1/R2+1/R3+...+1/Rn假设Rm为最小电阻则1/R=1/R1+1/R2+1/R3+...+1/Rn>1/Rm即 R<Rm1/R=1/R1+1/R2+1/R3+...+1/Rn<=1/Rm+1/Rm+1/Rm+...+1/Rm= 阅读全文
posted @ 2018-11-09 10:29
kakaisgood
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