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The plant growth regulator mepiquat chloride (MC) has been widely used to regulate cotton growth and development worldwide. However, little is known about whether MC application during cotton growing season affects defoliation efficiency of the harvest aids (TE), a novel product with the mixture of 10% thidiazuron and 40% ethephon. Here, a 3-year (2018–2020) field experiment was carried out in Hejian, Hebei province, China, involving six treatments as three different MC rates (MC free, farmers' practice-conventional amount, high MC amount) and two defoliant rates (0 ml ha−1 [CK] and 2250 ml ha−1 [TE]). High MC rate delayed cotton leaf abscission and decreased the defoliation percentage at 7 days after TE treatment, but hardly affected harvest aids efficacy at harvest time. The delay of leaf abscission was due to an increase in auxin and cytokinin concentration of cotton leaves in MC treatment. The MC treatment accelerated the natural maturation of cotton, achieving a higher boll-opening percentage before defoliant spraying, and increased cotton lint yield. Over the 3-year period, compared to CK, the defoliant application TE increased the defoliation percentage by 43.4%, the boll-opening percentage by 10.4%, and the cotton lint yield by 9.1% due to an increase in opened boll number per unit land area. We concluded that the optimal MC dose (about 200 g ha−1) would decrease the risk of reducing defoliation and achieve higher cotton lint yield. • Applying mepiquat chloride (MC) only delayed cotton leaf abscission in the early stage of defoliation. • MC application increased auxin and cytokinin concentration in cotton leaf. • Applying MC accelerated cotton maturation and achieved a higher boll-opening percentage. • The optimal MC dose decreased the risk of decreasing defoliation and enhanced cotton lint yield. [ABSTRACT FROM AUTHOR]

• At the steady state, the stress assessment of the reactor vessel in CiADS satisfies the requirements of ASME Code. • Adding a thermal insulation layer outside the reactor vessel may reduce the stress on vessel. • During the postulated ULOF accidents, the reactor vessel will not experience plastic deformation. • During the postulated UTOP accidents, the limit reactivity insertion to protect the reactor vessel from plastic deformation is 400 pcm. The China Initiative Accelerator Driven System (CiADS) was proposed by China Academy of Science since 2015. The subcritical reactor in CiADS is a liquid Lead Bismuth Eutectic (LBE) cooled fast reactor. When the reactor core is in operation, the LBE coolant will directly contact and corrode the inner surface of reactor vessel. Due to the high temperature, the corrosion will be more severe. If the stress on the reactor vessel exceeds the limit, the plastic deformation will occur, leading to the generation and expansion of defects and cracks, and the safety of the reactor will be affected. Therefore, evaluating the stress field of the reactor vessel under different operating conditions is a very important research project. In this paper, the finite element analysis software ADINA was applied to analyze the reactor vessel in CiADS, and the ASME Code was used as stress assessment standards. We can preliminarily prove that the stress assessments of the vessel during the postulated Unprotected Loss of Flow (ULOF) accidents satisfy the requirements of ASME Code. The limit reactivity insertion to protect the vessel from plastic deformation is 0.58$ in the postulated Unprotected Transient over Power (UTOP) accidents based on our current results. Therefore, we can preliminarily conclude that the current material selection and structural design of the reactor vessel in CiADS could survive most of the postulated transient accidents considering the stress effect. [ABSTRACT FROM AUTHOR]