Deprecated: Method ReflectionProperty::setAccessible() is deprecated since 8.5, as it has no effect since PHP 8.1 in /var/www/html/plugins/system/falangdriver/falangdriver.php on line 534
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Deprecated: Using null as the key parameter for array_key_exists() is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/cbPluginHandler.php on line 323

Deprecated: Using null as the key parameter for array_key_exists() is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/cbPluginHandler.php on line 323

Deprecated: Using null as the key parameter for array_key_exists() is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/cbPluginHandler.php on line 323

Deprecated: Using null as the key parameter for array_key_exists() is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/cbPluginHandler.php on line 323

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什么是功率因数？如何如何测量？


Deprecated: Using null as the key parameter for array_key_exists() is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/cbPluginHandler.php on line 323

Deprecated: Using null as the key parameter for array_key_exists() is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/cbPluginHandler.php on line 323
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25 Oct 2020 12:57 #148 by btt
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功率因数：在直流电路里，电压乘电流就是有功功率。但在交流电路里，电压乘电流是 视在功率，而能起到作功的一部分功率（即有功功率）将小于视在功率。有功功率与视在功 率之比叫做功率因数，以 COSΦ表示，其实最简单的测量方式就是测量电压与电流之间的 相位差，得出的结果就是功率因数。

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 234

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 237

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 239

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 189

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 237

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 239

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Deprecated: Using null as the key parameter for array_key_exists() is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/cbPluginHandler.php on line 323

Deprecated: Using null as the key parameter for array_key_exists() is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/cbPluginHandler.php on line 323

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/src/Menu/AbstractMenu.php on line 164

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 189

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 237

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 239
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Deprecated: Method ReflectionProperty::setAccessible() is deprecated since 8.5, as it has no effect since PHP 8.1 in /var/www/html/plugins/system/falangdriver/falangdriver.php on line 100

Deprecated: Method ReflectionProperty::setAccessible() is deprecated since 8.5, as it has no effect since PHP 8.1 in /var/www/html/plugins/system/falangdriver/falangdriver.php on line 100
mysqli object is already closed (500 Whoops, looks like something went wrong.)

Error

HTTP 500 Whoops, looks like something went wrong.

mysqli object is already closed

Exception

Error

in /var/www/html/libraries/vendor/joomla/database/src/Mysqli/MysqliDriver.php (line 318)
  1. */
  2. public function disconnect()
  3. {
  4. // Close the connection.
  5. if (\is_callable([$this->connection, 'close'])) {
  6. $this->connection->close();
  7. }
  9. parent::disconnect();
  10. }
in /var/www/html/libraries/vendor/joomla/database/src/Mysqli/MysqliDriver.php -> close (line 318)
  1. */
  2. public function disconnect()
  3. {
  4. // Close the connection.
  5. if (\is_callable([$this->connection, 'close'])) {
  6. $this->connection->close();
  7. }
  9. parent::disconnect();
  10. }
in /var/www/html/libraries/vendor/joomla/database/src/DatabaseDriver.php -> disconnect (line 496)
  1. *
  2. * @since 2.0.0
  3. */
  4. public function __destruct()
  5. {
  6. $this->disconnect();
  7. }
  9. /**
  10. * Alter database's character set.
  11. *
DatabaseDriver->__destruct()

Stack Trace

Error 
Error:
mysqli object is already closed

  at /var/www/html/libraries/vendor/joomla/database/src/Mysqli/MysqliDriver.php:318
  at mysqli->close()
     (/var/www/html/libraries/vendor/joomla/database/src/Mysqli/MysqliDriver.php:318)
  at Joomla\Database\Mysqli\MysqliDriver->disconnect()
     (/var/www/html/libraries/vendor/joomla/database/src/DatabaseDriver.php:496)
  at Joomla\Database\DatabaseDriver->__destruct()

Deprecated: Method ReflectionProperty::setAccessible() is deprecated since 8.5, as it has no effect since PHP 8.1 in /var/www/html/plugins/system/falangdriver/falangdriver.php on line 100

Deprecated: Method ReflectionProperty::setAccessible() is deprecated since 8.5, as it has no effect since PHP 8.1 in /var/www/html/plugins/system/falangdriver/falangdriver.php on line 100