For IIS 6 you should not enter an url for the keepalive.
The AppKeepAlive is making a periodic server side web request of your site home page on a background thread. It does this to keep the site from being shut down by IIS due to lack of traffic.
The error indicates it cannot retrieve the home page url. It is either not able to resolve the host name to the ip address or possibly blocked at the firewall. You'll need to either solve that problem or disable the keep alive.
The application start and a few other things logged are localized by resource files, it just means that a Chinese visitor made the first request that started the application after it was shutdown by IIS because of lack of traffic the first request that came next was a web browser with the language preference set to Chinese so the application start event was logged with Chinese localization
Hope it helps,
Joe