New developments of HIF injector

The ultra-high intensity heavy-ion beam is highly pursued for heavy-ion researches and applications.However,it is limited by heavy-ion production of ion source and space-charge-effect in the low energy region.The Heavy-ion Inertial Fusion(HIF)facilities were proposed in 1970s.The HIF injectors have large cavity number and long total length,e.g.,there are 27 injectors in HIDIF and HIBLIC is 30 km in length,and the corresponding HIF facilities are too large and too expensive to be constructed.Recently,ion acceleration technologies have been developing rapidly,especially in the low energy region,where the acceleration of high intensity heavy-ions is realized.Meanwhile,super-conducting(SC)acceleration matures and increases the acceleration gradient in medium and high energy regions.The length of HIF injectors can be shortened to a buildable length of 2.5 km.This paper will present a review of a renewed HIF injector,which adopts multi-beam linac-based cavities.

Enhanced Anomalous Hall Effect of Pt on an Antiferromagnetic Insulator with Fully Compensated Surface

We report a significantly enhanced anomalous Hall effect(AHE)of Pt on antiferromagnetic insulator thin film(3-unit-cell La_(0.7)Sr_(0.3)MnO_(3),abbreviated as LSMO),which is one order of magnitude larger than that of Pt on other ferromagnetic(e.g.Y_(3)Fe_(5)O_(12))and antiferromagnetic(e.g.Cr_(2)O_(3))insulator thin films.Our experiments demonstrate that the antiferromagnetic La_(0.7)Sr_(0.3)MnO_(3)with fully compensated surface suppresses the positive anomalous Hall resistivity induced by the magnetic proximity effect and facilitates the negative anomalous Hall resistivity induced by the spin Hall effect.By changing the substrate’s temperature during Pt deposition,we observed that the diffusion of Mn atoms into Pt layer can further enhance the AHE.The anomalous Hall resistivity increases with increasing temperature and persists even well above the Neel temperature(T_(N))of LSMO.The Monte Carlo simulations manifest that the unusual rise of anomalous Hall resistivity above T_(N)originates from the thermal induced magnetization in the antiferromagnetic insulator.

Double stimulus-responsive palladium catalysts for ethylene polymerization and copolymerization

The external stimulus response strategy has been evolved rapidly in the field of olefin polymerization.In this work,we modularly synthesized three types of double stimulus responsiveα-diimine palladium catalysts,combining redox regulation and other regulation together,such as light,Lewis acid and alkali cations.The catalytic activities and the molecular weight of polyethylene products can be regulated for 4 times in ethylene polymerization.These palladium complexes were also used for the copolymerization reaction of ethylene and polar monomers,such as methyl 10-undecylenate and methyl acrylate,effectively regulating the catalytic activities,the molecular weight and polar monomer incorporation of the prepared copolymers.The research on these dual-regulated palladium complexes makes full use of prepared catalysts and provides new inspirations for regulating olefin polymerization.

Synthesis of Ultra-High-Molecular-Weight Polyethylene by Transition-Metal-Catalyzed Precipitation Polymerization

Ultra-high-molecular-weight polyethylene(UHMWPE)plays an important role in many important fields as engineering plastics.In this contribution,a precipitation polymerization strategy is developed by combination of highly active phosphino-phenolate nickel catalysts with polymer-insoluble solvent(heptane)to access UHMWPE(Mn up to 8.3×10^(6)g mol^(-1))with good product morphology,free-flowing characteristics,and great mechanical properties.Compared with the academically commonly used aromatic solvent(toluene),the utilization of heptane offers simultaneous enhancement in important parameters including activity,polymer molecular weight,and catalyst thermal stability.This system can also generate polar functionalized UHMWPE with molecular weight of up to 1.6×10^(6)g mol^(-1)in the copolymerization of ethylene with polar comonomers.More importantly,this precipitation polymerization strategy is generally applicable to several representative transition metal catalyst systems,leading to UHMWPE synthesis with good product morphology control.

Uncovering hydrothermal treatment of per-and polyfluoroalkyl substances

Per-and polyfluoroalkyl substances(PFAS),consisting of at least one perfluoroalkyl group(CnF2nt1),are a class of synthesized organic compounds with hydrogen atoms partially or entirely replaced by fluorine atoms[1].Short-chain PFAS refers to the perfluoroalkane and-alkyl sulfonic acids(PFSAs)with less than six carbon atoms and the perfluoroalkyl carboxylic acids(PFCAs)with less than eight carbon atoms,while long-chain PFAS include the PFSAs with more than six carbon atoms and the PFCAs with more than eight carbon atoms[2].