Intrinsic anomalous Hall effect across the magnetic phase transition of a spin-orbit-coupled Bose-Einstein condensate

We study theoretically the zero temperature intrinsic anomalous Hall effect in an experimentally realized 2D spin-orbit coupled Bose gas. For anisotropic atomic interactions and as the spin-orbit coupling strength increases, the system undergoes a ground state phase transition from states exhibiting a total in-plane magnetization to those with a perpendicular magnetization along the $z$ direction. We show that finite frequency, or ac, Hall responses exist in both phases in the absence of an artificial magnetic field, as a result of finite inter-band transitions. However, the characteristics of the anomalous Hall responses are drastically different in these two phases because of the different symmetries preserved by the corresponding ground states. In particular, we find a finite dc Hall conductivity in one phase but not the other. The underlying physical reasons for this are analyzed further by exploring relations of the dc Hall conductivity to the system's chirality and Berry curvatures of the Bloch bands. Finally, we discuss an experimental method of probing the anomalous Hall effect in trapped systems.Comment: 13 pages, 11 figure

Multi-scale input-output analysis of consumption-based water resources: Method and application

This work develops a method of multi-scale input-output analysis for the embodied water accounting of an economy. This method can distinguish between the different virtual water contents of imported and local products and is therefore capable of accurately estimating the virtual water that is embodied in trade. As a simplified model rather than a multi-regional input-output analysis, this method substantially minimizes the data requirements. With the support of averaged Eora global embodied water intensity databases for the world and Chinese economies, a three-scale embodied water input-output analysis of the Beijing economy in 2007 has been conducted. Dozens of virtual water flows that relate to the Beijing economy have been identified and analyzed. Only 15% of the total water resources embodied in Beijing's local final demand were from local water withdrawal; 85% were from domestically and internationally imported products. The virtual water import is revealed to play a more important role than physical water transfer in easing Beijing's water shortage. Since the average water use efficiency of the Beijing economy is much higher than that of the Chinese economy but somewhat lower that of the rest of the world, Beijing is suggested to shifting its imports to foreign countries to optimize global water use. The method developed can be useful for water saving strategies for multiple responsible entities holding different opinions, and it can be easily applied to the embodied water accounting of a sub-national or even smaller economic community

Asynchronously coupled resonant junctions for diplexers and multiport filtering networks

This paper proposes the use of asynchronously coupled resonator junctions in the design of diplexers. This is to ease the control and implementation of the external couplings at the common port of an all-resonator-based diplexer. A comparison study has been performed between a conventional diplexer and the proposed diplexer. To further explore the possibilities of the proposed junction technique, a four-port multi-port filtering networks was proposed and designed to function as a double diplexer. Good agreements have been achieved between the measurements of the prototype devices and the simulations

Ginkgo biloba preparation prevents and treats senile dementia by inhibiting neuro-inflammatory responses

Purpose: To study the effect of Ginkgo biloba preparation on senile dementia and the mechanism of its action.Methods: Sprague Dawley (SD) rat model of chronic cerebral hypoperfusion was produced by vascular occlusion (2-VO). The rats were administered Ginkgo biloba preparation via intra-gastric route 4 h after the operation, and then at 7:30 am every day at a dose of 100 mg/kg per day (0.5 mL/100 g, per day) for 28 days. One group of untreated model rats, and a reference group served as controls. Garcia composite score was used to evaluate the recovery of neurological function in the rats after operation. Morris water maze test was conducted to assess learning and memory abilities. Western blot was used to measure protein expressions of BACE1, TRP1 and RAGE. Serum levels of inflammatory factors IL1, IL6 and TNF were assayed by ELISA.Results: Garcia composite score showed that the neurological function of the SD rats was significantly impaired by the blockage of blood flow to the bilateral common carotid artery. However, neurological function was gradually recovered by treatment with Ginkgo biloba preparation. The escape latency and swimming distance of the rats were significantly shortened, and the number of platform crossings was gradually increased by the Ginkgo biloba preparation. With time, there was no significant difference in swimming speed between the groups. Western blot data showed that expression of BACE1, TRP1 and RAGE gradually decreased. Results from ELISA indicate that with time, Ginkgo biloba preparation decreased the expressions of IL-1, IL-6, and TNF in the reference group.Conclusion: The preventive and therapeutic effects of Ginkgo biloba preparation extract on senile dementia may be related to its inhibition of neuro-inflammatory reaction.Keywords: Alzheimer disease, Neuro-inflammatory reactions, Ginkgo biloba preparatio

Lasing- Encoded Microsensor Driven by Interfacial Cavity Resonance Energy Transfer

Microlasers are emerging tools for biomedical applications. In particular, whispering- gallery- mode (WGM) microlasers are promising candidates for sensing at the biointerface owing to their high quality- factor and potential in molecular assays, and intracellular and extracellular detection. However, lasing particles with sensing functionality remain challenging since the overlap between the WGM optical mode and external gain medium is much lower compared to internal gain inside the cavity. To overcome this problem, the concept of Förster resonant energy transfer (FRET) is exploited on WGM droplet microlaser by separating donor and acceptor molecules at the cavity- surface interface. It is first discovered that the interfacial FRET laser not only originates from conventional FRET but utilizes coherent radiative energy transfer (CRET) to excite acceptor molecules by inducing light- harvesting effect near the cavity interface. Simulations and experiments have revealed that the absorption spectrum of individual analyte plays a crucial role in interfacial FRET laser. Distinct lasing spectra can therefore distinguish molecules of different absorption properties upon binding. Finally, detection of small fluorescent molecules and photosynthetic protein is performed. The results presented here not only demonstrate the wide- ranging potential of microlaser external cavity implementation in molecular sensing applications, but also provide comprehensive insights into cavity energy transfer in laser physics.A novel concept is proposed to achieve active lasing- encoded biosensors by taking advantage of light- harvesting effect at the cavity interface, where interfacial molecular lasers based on cavity resonant energy transfer are demonstrated. This work marks a critical step of realizing whispering- gallery- mode (WGM) laser probes for biosensing, opening a new avenue in laser- based molecular sensing.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154969/1/adom201901596-sup-0001-SuppMat.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154969/2/adom201901596_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154969/3/adom201901596.pd