介绍新型WXJ25型微电子相敏轨道电路接收器的工作原理，技术条件及维修标准。

The working principle, technical specification and maintenance standard of the new WXJ25 phase-sensitive track circuit receiver were introduced in this paper.

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本文简单介绍了LVDT、相敏检波器和三角波发生器的工作原理及自行设计的一种实用的LVDT相敏检波读出电路。

The principles of the LVDT, the phase-sensitive detector and the triangular wave generator are briefly illustrated in this paper. A practical LVDT readout.

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调查引起果农职业性花粉过敏的主要致敏源，并与春季花粉过敏症相鉴别。

To investigate the main allergen on fruiter with occupational pollen allergy and analyze the difference between that and other spring pollen allergy.

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