Chinese characters encoding problem with XML

doc<-xmlRoot(xml)
doc[[1]]

doc1<-xmlRoot(xml,encoding="gb2312")
doc1[[1]]

XML is a good tool reading data from web within R.  But I wonder how could
get the encoding correctly.

library(XML)
url <- 'http://www.szitic.com/docc/jz-lmzq.html'
xml <- htmlTreeParse(url, useInternal=TRUE)
q <- "//tbody/tr/td"
dat <- unlist(xpathApply(xml, q, xmlValue))
df <- as.data.frame(t(matrix(dat, 4)))
dt<-as.character(df[15,1])

The first column of df is dates in Chinese.   dt is one of the Chinese
dates.
When I copied the content of dt into the email, it become the following:

dt

[1]
"2008å???㐀㄀㈀??\x8825æ???㔀∀ഀ਀㸀 

Indeed in R,  it looks like:

dt

[1] "2008\345\271\xb412\346\234\x8825\346\227\xa5"

and the color of the numbers differs a little.

getOption("encoding")

[1] "native.enc"

Sys.getlocale()

[1] "LC_COLLATE=Chinese (Simplified)_People's Republic of
China.936;LC_CTYPE=Chinese (Simplified)_People's Republic of
China.936;LC_MONETARY=Chinese (Simplified)_People's Republic of
China.936;LC_NUMERIC=C;LC_TIME=Chinese (Simplified)_People's Republic of
China.936"

Package:              XML
Version:              1.98-1
Date:                 2008/10/17

R version 2.8.0 (2008-10-20)
Windows Vista Basic, Simplified Chinese edition.

There is no problem using Chinese characters in R codes.

I wonder how could get the Chinese characters with XML.   Or is there any
methods which could help me convert the encoding of characters from UTF-8
to unicode in R?

Regards,
Wind

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