The lock is activated by a magnetic key.

这个锁用磁性钥匙开。

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The key is using magnetic and electric fields, instead of matter, to construct the walls of an antimatter "bottle."

这套设备的关键之处在于使用了电磁场的而不是普通物质来捕捉反粒子，电磁场犹如一道墙，把反物质牢牢地束缚在“电磁瓶”内。

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Scientists believe magnetic structures, like sunspots hold an important key to understanding space weather.

科学家认为磁性结构如太阳黑子对理解空间天气有重要帮助。

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The magnetic properties of materials hold the key to major advances in technology.

ENGADGET: Cray's Jaguar supercomputer upgraded with NVIDIA Tesla GPUs, renamed Titan

Data is loaded onto any plastic card with a magnetic stripe an old hotel key card or an expired credit card would do as long as it carried the account data and correct access codes.

WSJ: Anatomy of a global bank cyber theft

Others loaded that data onto any plastic card with a magnetic stripe an old hotel key card or an expired credit card worked fine as long as it carried the account data and correct access codes.

WSJ: Global network of hackers steal $45m from ATMs