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New measurements of the photoneutron reaction on 181 Ta have been conducted with the AIST-LCS ͑laser Compton scattering͒ beam in the 7.8ՇE͓MeV͔Շ12 energy range. The major advantage of the present ␥-ray experiment is its intense peaking in the energy window of astrophysical interest, i.e., close to the neutron threshold. Details on photon beams from the laser Compton scattering, neutron counting, and experimental determination of the 181 Ta photoneutron cross section are given. The present experimental data are in good agreement with the IAEA evaluation. Reaction rate calculations in the Hauser-Feshbach statistical model are performed and confronted with the experimental data. The data provide constraints on the low-energy tail of the dipole strength function. It is found that among the three different models for the E1-strength considered, only the microscopic quasiparticle random phase approximation model can reproduce the extra strength observed in the 181 Ta(␥,n) 180 Ta reaction at energies of about 8.5 MeV. Such an experiment helps to improve the determination of the corresponding stellar photodisintegration rate of

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Highly concentrated solutions composed of lithium bis­(fluorosulfonyl)­imide (LiFSI) and sulfolane (SL) are promising liquid electrolytes for lithium metal batteries because of their high anodic stability, low flammability, and high compatibility with lithium metal anodes. However, it is still challenging to obtain the stable lithium metal anodes in the concentrated electrolytes due to their poor wettability to the conventional polyolefin separators. Here, we report that the highly concentrated 1:2.5 LiFSI/SL electrolyte coupled with a three-dimensionally ordered macroporous polyimide (3DOM PI) separator enables the stable lithium plating/stripping cycling with an average Coulombic efficiency of ca. 98% for over 400 cycles at 1.0 mA cm–2. The 3DOM PI separator shows good electrolyte wettability and large electrolyte uptake due to its high porosity and polar constituent of the imide structure, allowing superior cycling performance in the highly concentrated solution, compared with the polyolefin separators. Electrochemical and spectroscopic analyses reveal that the superior cycling stability in the concentrated electrolyte is attributed to the formation of highly stable and Li+ ion conductive solid electrolyte interphase (SEI) layer derived from FSI– anions, which reduces the side reactions of SL with lithium metal, prevents the growth of lithium dendrites, and suppresses the increase in cell impedance over long-term cycling. Our findings demonstrate that polar and porous separators could effectively improve the affinity to the concentrated electrolytes and allow the formation of the anion-derived SEI layer by increasing the salt concentration of the electrolytes, achieving the long-term stable lithium metal anode.

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The development of NMR/MRI REBa2Cu3Oy (REBCO, RE = Rare Earth) magnets is undergoing all over the world. However, a screening current-induced magnetic field (SCMF) is a serious problem for NMR/MRI magnets wound with REBCO tapes. The reduction of SCMF is strongly desired, and the estimation of SCMF is also desired at the design stage of REBCO magnets. In order to evaluate a SCMF, a finite element method (FEM) or a boundary integration method is needed so far, and a high-level simulation technique is required. In this paper, we develop an easy method to estimate a SCMF without any high-level simulation technique. In the developed method, an inductance of a winding turn is calculated and then a screening current is estimated according to the magnetic field penetrating into the winding turn. The SCMF is obtained from the estimated screening current. The SCMFs computed by the proposed method were compared with measurements and simulation results of the FEM. The results agreed well, but we can see a large difference. However, the SCMFs by the proposed method are enough accurate so that we know the SCMFs at the design stage without using a high-level simulation technique.

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Current slow-freezing methods are too inefficient for cryopreservation of three-dimensional (3D) tissue constructs. Additionally, conventional vitrification methods use liquid nitrogen, which is inconvenient and increases the chance of crosscontamination. Herein, we have developed polyampholytes with various degrees of hydrophobicity and showed that they could successfully vitrify cell constructs including spheroids and cell monolayers without using liquid nitrogen. The polyampholytes prevented ice crystallization during both cooling and warming, demonstrating their potential to prevent freezing-induced damage. Monolayers and spheroids vitrified in the presence of polyampholytes yielded high viabilities post-thawing with monolayers vitrified with PLL-DMGA exhibiting more than 90% viability. Moreover, spheroids vitrified in the presence of polyampholytes retained their fusibilities, thus revealing the propensity of these polyampholytes to stabilize 3D cell constructs. This study is expected to open new avenues for the development of off-the-shelf tissue engineering constructs that can be prepared and preserved until needed.