Enhanced spin-orbit torques in MnAl/Ta films with improving chemical ordering

We report the enhancement of spin-orbit torques in MnAl/Ta films with improving chemical ordering through annealing. The switching current density is increased due to enhanced saturation magnetization MS and effective anisotropy field HK after annealing. Both damplinglike effective field HD and fieldlike effective field HF have been increased in the temperature range of 50 to 300 K. HD varies inversely with MS in both of the films, while the HF becomes liner dependent on 1/MS in the annealed film. We infer that the improved chemical ordering has enhanced the interfacial spin transparency and the transmitting of the spin current in MnAl layer

A study of the problems associated with Dalangdian reservoir, China

There are over 2,300 lakes over 1 km2 in China (total area 80 000 km2). In addition there are approximately 87 000 reservoirs with a storage capacity of 413 billion m3. These form the main supply of drinking water as well as water for industrial and agricultural production and aquaculture. Because of a lack of understanding of the frailty of lake ecosystems and poor environmental awareness, human activities have greatly affected freshwater systems. This article focuses on the problems of one water supply reservoir, Dalangdian Reservoir, and considers options for improving its management. Dalangdian Reservoir is described and occurrence of algal genera given. The authors conclude with remarks on the future of the Dalangdian Reservoir

Black hole thermodynamics and modified GUP consistent with doubly special relativity

We study the black hole thermodynamics and obtain the correction terms for temperature, entropy, and heat capacity of the Schwarzschild black hole, resulting from the commutation relations in the framework of {\it Modified Generalized Uncertainty Principle} suggested by {\it Doubly Special Relativity}.Comment: 13 pages, 6 figures, minor revision, references adde

Online Power and Time Allocation in MIMO Uplink Transmissions Powered by RF Wireless Energy Transfer

Wireless energy transfer (WET) has been a promising technology to tackle the lifetime bottlenecks of energy-limited wireless devices in recent years. In this paper, we study a WET enabled multiple input multiple output (MIMO) system including a base station (BS) and a user equipment (UE), which has a finite battery capacity. We consider slotted transmissions, where each slot includes two phases, namely downlink (DL) WET phase and uplink (UL) wireless information transmission (WIT) phase. In the WET phase (a fraction τ of a slot), the BS transfers energy and the UE stores the received energy in the battery. In the WIT phase (a fraction 1 − τ of a slot), the UE transmits information to the BS by using the energy in the battery. Considering the power sensitivity α of the radio frequency (RF) to direct current (DC) conversion circuits, the BS transfers energy only if the UE received power is larger than α, and the downlink WET is formulated as a Bernoulli process. Based on the formulation, we propose an online power and time allocation algorithm to maximize the average data rate of uplink WIT. We also extend the proposed algorithm to multiple user systems. The numerical results show that the proposed algorithm outperforms the existing schemes in terms of average data rate, energy efficiency and outage probability

Simulation of overtopping and seepage induced dike failure using two-point MPM

Fluvial dikes are important engineering works for protecting river valleys from flooding, so the stability of them is of great importance. In this paper, we apply a two-point two-phase formulation of the Material Point Method (MPM) to investigate the dike stability problem under the action of overtopping flows. Such a method has been incorporated in the Anura3D software (www.anura3d.com). In the model, the behaviours of soil and water are analysed in a single framework, so the interactions between the two phases are fully dynamic. The computational results agree well with the laboratory experiments. Parametric studies have been carried out to examine the effectiveness of various dike stability measures. The two-point MPM shows encouraging capabilities for studying a broad range of phenomena involving strong soil/water interactions.We are grateful to the financial support by the Royal Academy of Engineering UK-China Urban Flooding Research Impact Programme (UUFRIP\100051) and the Royal Society-Newton Mobility Grant (EC\NSFC\191369)