dynamicpipe理视图的连接string中的实例名称

我想运行以下查询::

SELECT S.* FROM sys.dm_exec_requests S JOIN sys.dm_exec_sessions R ON r.session_id = s.blocking_session_id 

它在我在SQL Server控制台中运行时工作。
但是我一直没能做到相同的代码。 我正在使用以下连接string:

 "Data Source=localhost\\sqlexpress;Initial Catalog=Master;Integrated Security = True" 

到目前为止,我在连接string中使用了sysMsSQLSystemResource来代替Master; 但我面临同样的错误,说有问题连接..实例名称可能是错误的..

我不断收到以下错误

 System.Data.SqlClient.SqlException (0x80131904): A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) 

 Data Source=(local)\sqlexpress 

我认为双\是逃跑