溶融动态核极化（dDNP）是一种将分子样品在超低温、强磁场以及微波照射下高度极化，然后经高温高压溶剂快速溶解后立即转移至NMR/MRI系统进行检测的灵敏度增强技术．溶融系统是实现这一过程的关键部分，其性能直接影响样品的溶融、转移效率以及样品极化度的保留程度．本文提出了基于双闭环PID控制算法的自动化溶融系统的控制方案，可在9 min以后达到目标压强1.7 MPa左右并使内部压强被动控制在1.5%以内．将研制的自动化溶融系统集成于自主开发的5 T dDNP仪器系统，可将-271℃的低温样品快速溶融，并于4 s内将其转移到距离11.2 m处的7 T NMR系统进行检测，获得了[1-¹³C]-丙酮酸钠在溶融态下¹³C NMR信号9 050倍的增强．自动化溶融系统简化了操作步骤，提高了实验的安全性和一致性．

Dissolution dynamic nuclear polarization (dDNP) involves polarizing the sample under microwave irradiation at a low-temperature and strong-magnetic field, dissolving it by solvent of high-temperature and high-pressure, then injecting it rapidly into an NMR/MRI for detection. The dissolution system serves as a pivotal component in the dissolving and injecting process, with its performance directly affecting the melting and transfer efficiency and the high polarization retention. We present an automated dissolution system using a dual-loop proportional-integral-derivative (PID) control algorithm that can reach the target pressure of ~1.7 MPa after 9 min and control the internal pressure within 1.5%. The system can dissolve a solid sample of -271 ℃ in the self-developed 5 T dDNP polarizer and transfer it to the 7 T NMR system at a distance of 11.2 m for detection in 4 s, yielding a 9050-fold enhancement of ¹³C NMR signal of sodium [1-¹³C]-pyruvate at the solvated state. In summary, this work developed an automated dissolution system that simplifies the operation steps, ensures detection consistency, and improves experimental safety.