Toward Systemic Thinking in Managing Environmental Risks

1.Introduction The world today is strongly interconnected.Numerous interdependent and complex networks have been formed between environmental,economic,and social systems,through which people,resources,materials,goods,and information are exchanged at unprecedented speeds[1].At the same time,however,such networks are profoundly changing the global risk landscape and making the whole system more vulnerable[2].In particular,there is a growing concern about cascading and systemic risks.In such cases,a localized initial damaging event(e.g.,the coronavirus disease 2019(COVID-19)pandemic)can spread rapidly and globally,resulting in disruptive influences and countless societal costs[3].

Magnetic anisotropy manipulation and interfacial coupling in Sm_(3)Fe_(5)O_(12)films and CoFe/Sm_(3)Fe_(5)O_(12)heterostructures

The magnetic anisotropy manipulation in the Sm_(3)Fe_(5)O_(12)(SmIG)films and its effect on the interfacial spin coupling in the CoFe/SmIG heterostructures were studied carefully.By switching the orientation of the Gd_(3)Ga_(5)O_(12)substrates from(111)to(001),the magnetic anisotropy of obtained SmIG films shifts from in-plane to out-of-plane.Similar results can also be obtained in the films on Gd_(3)Ga_(5)O_(12)substrates,which identifies the universality of such orientation-induced magnetic anisotropy switching.Additionally,the interfacial spin coupling and magnetic anisotropy switching effect on the spin wave in CoFe/SmIG magnetic heterojunctions have also been explored by utilizing the time-resolved magneto-optical Kerr effect technique.It is intriguing to find that both the frequency and effective damping factor of spin precession in CoFe/SmIG heterojunctions can be manipulated by the magnetic anisotropy switching of SmIG films.These findings not only provide a route for the perpendicular magnetic anisotropy acquisition but also give a further path for spin manipulation in magnetic films and heterojunctions.

Transient Photoconductivity in LaRhO3 Thin Film

High-quality epitaxial LaRhO3(LRO) thin films on SrTiO3(110) single-crystalline substrates are fabricated by pulsed laser deposition and their photoconductivity properties are studied. The transient photoconductivity(TPC) effect is found in this semiconductor LRO film at room temperature. The magnitude of TPC increases almost linearly with the laser power intensities and the photon energies in visible light range. Moreover, the difference in the TPC results under two airflow conditions confirms that both intrinsic photoinduced carrier accumulation and extrinsic photoinduced heating effects contribute to the magnitude of TPC effect.

Optical spectroscopy study of Ca_3(Ru_(0.91)Mn_(0.09))_2O_7 single crystal in high magnetic fields

The magneto-optical spectrum, with magnetic fields up to 42 T, of double layered ruthenates Ca_3(Ru_(0.91)Mn_(0.09))_2O_7(CRMO) single crystal is studied. Both the temperature and magnetic field induced insulator-to-metal transitions(IMTs) are observed via magneto-optical properties of the crystal. The critical magnetic field(H//c) of IMT for CRMO is found to be as large as 35 T at 5 K. The fine structure of optical spectra identified the antiferromagnetic/ferro-orbital-ordering configurations of Ru 4d orbitals at low temperatures. Meanwhile, the configuration of orbital polarization of such double-layer CRMO single crystal is discussed. These results suggest that the orbital degree of freedom plays an important role in the field induced IMT of multi-orbital system.

Gradient Estimates for a Nonlinear Parabolic Equation with Diffusion on Complete Noncompact Manifolds

The authors obtain some gradient estimates for positive solutions to the following nonlinear parabolic equation:αu/αt=△u-b(x,t)u~σ on complete noncompact manifolds with Ricci curvature bounded from below,where 0<σ<1 is a real constant,and b(x,t) is a function which is C^2 in the x-variable and C^1 in the t-variable.

Planar-symmetry-breaking induced antisymmetric magnetoresistance in van der Waals ferromagnet Fe_(3)GeTe_(2)

Recently discovered magnetic van der Waals(vdW)materials provide an ideal platform to explore low-dimensional magnetism and spin transport.Its vdW interaction nature opens up unprecedented opportunities to build vertically stacked heterostructures with novel properties and functionalities.By engineering the planar structure as an alternative degree of freedom,herein we demonstrate an antisymmetric magnetoresistance(MR)in a vdW Fe_(3)GeTe_(2)flake with a step terrace that breaks the planar symmetry.This antisymmetric MR originates from a sign change of the anomalous Hall effect and the continuity of the current transport near the boundary of magnetic domains at the step edge.A repeatable domain wall due to the unsynchronized magnetization switching is responsible for this sign change.Such interpretation is supported by the observation of field-dependent domain switching,and the step thickness,temperature,and magnetic field orientation dependent MR.This work opens up new opportunities to encode magnetic information by controlling the planar domain structures in vdW magnets.

Epidemic transition of environmental health risk during China's urbanization

China has experienced rapid urbanization in recent decades along with dramatic economic growth.Previous studies have shown that urbanization has both positive and negative effects on health.However, there is a lack of research on the overall effects of urbanization on the epidemic transition of environmental health risks considering various pathways in China. In the present study, we studied the contributions of different aspects of urbanization in China to epidemic transitions using provincial and multi-year(1995, 2000, 2005, and 2010) panel data. Statistical models with fixed and random effects were developed to explore the impacts of different urbanization indicators on the overall epidemic transition of environmental health(general model) and the changes in cause-specific mortality rates of typical diseases(cause-specific models). The results show that the impacts of non-communicable diseases continue to grow during the urbanization process in China. The ratio of communicable disease-related mortality to non-communicable disease-related mortality continues to decrease over time. The general model shows that the improved medical conditions(coefficient = 0.0011, P = 0.037), the improved urban infrastructure(e.g., tap water supply)(coefficient = 0.00065, P < 0.001), and the rise in income(coefficient = 0.00027, P = 0.047) during the urbanization process are important factors that promote this overall epidemic transition. The cause-specific models show that the mechanisms behind the general model are complicated. More attention should be paid to non-communicable diseases in urban health management. Specific health policies for different diseases should incorporate the considerations of different impact pathways of urbanization.