Status Analysis and Consideration of Medical Education System in China and Abroad

This paper concludes five current medical education systems by investigating medical education status in both China and abroad. They are: 5+3 years British system, 6-year German system, 6-year Russian system, “4+4” years American system, and 5+3+3 years Chinese system. Based on the five systems, this paper analyzes the current situation of medical postgraduate student education of the Great Britain, Germany, U.S.A, France, and China. In the last part of this paper, a careful consideration on Chinese medical education is made. Authors of this paper suggest that China should gradually call off multi-level medical education; take 8-year, 5-year, and 5+4 years education as the principal modes of medical education. Students should be offered medical doctor’s degree and positioned as diplomates after the 8-year medical education. Students who finish the 5-year medical education will be awarded the bachelor’s degree and work as general practitioner. Students decide to receive another 4 years medical education after finishing the 5-year one will be granted medical doctor’s degree (diplomate or general practitioner). The 3-year medical postgraduate education should be gradually abolished.Key words: Medical education; Postgraduate education; Education syste

Ball-milled FeP/graphite as a low-cost anode material for the sodium-ion battery

Phosphorus is a promising anode material for sodium batteries with a theoretical capacity of 2596 mA h g-1. However, phosphorus has a low electrical conductivity of 1 x 10-14 S cm-1, which results in poor cycling and rate performances. Even if it is alloyed with conductive Fe, it still delivers a poor electrochemical performance. In this article, a FeP/graphite composite has been synthesized using a simple, cheap, and productive method of low energy ball-milling, which is an efficient way to improve the electrical conductivity of the FeP compound. The cycling performance was improved significantly, and when the current density increased to 500 mA g-1, the FeP/graphite composite could still deliver 134 mA h g-1, which was more than twice the capacity of the FeP compound alone. Our results suggest that by using a low-energy ball-milling method, a promising FeP/graphite anode material can be synthesized for the sodium battery

Spatiotemporal characteristics of the time of emergence for anthropogenic tropospheric temperature changes based on the CMIP6 multi-model results

In the 20th century, with the intensification of human activities, the Earth is experiencing unprecedented warming. However, there are certain differences in the sensitivity of temperature changes to anthropogenic forcings in different regions and at different altitudes of the troposphere. The time of emergence (TOE) is the key point at which the anthropogenic climate change signal exceeds from the internal climate variability serving as a noise. It is a crucial variable for climate change detection, climate prediction and risk assessment. Here, we systematically analyzed the spatiotemporal characteristics of the TOE of temperature changes over the past century by calculating the signal-to-noise ratio (SNR) based on the selected CMIP6 multi-model outputs. The results show that the temperature TOE, particularly in the lower and middle troposphere, shows distinct latitude dependence, displaying an "M-type" distribution from the Antarctic to the Arctic: it first appears in low-latitudes, followed by high-latitudes, and last appears in the two mid latitude bands. For the tropics, the TOE of tropospheric temperatures becomes earlier with increasing altitude: the TOE of air temperatures at the surface, mid-tropospheric 500hPa and upper-tropospheric 200hPa occurs in 1980±15, 1965±20, and 1930±30, respectively. The TOEs of tropospheric temperatures in eastern equatorial Pacific are 10~30 years later than those in the western equatorial Pacific. For the regional TOEs of surface air temperature diverse differences exist on land and ocean in various latitudes of two hemispheres

Binder-free and carbon-free 3D porous air electrode for Li-O2 batteries with high efficiency, high capacity, and long life

Pt-Gd alloy polycrystalline thin film is deposited on 3D nickel foam by pulsed laser deposition method serving as a whole binder/carbon-free air electrode, showing great catalytic activity enhancement as an efficient bifunctional catalyst for the oxygen reduction and evolution reactions in lithium oxygen batteries. The porous structure can facilitate rapid O2 and electrolyte diffusion, as well as forming a continuous conductive network throughout the whole energy conversion process. It shows a favorable cycle performance in the full discharge/charge model, owing to the high catalytic activity of the Pt-Gd alloy composite and 3D porous nickel foam structure. Specially, excellent cycling performance under capacity limited mode is also demonstrated, in which the terminal discharge voltage is higher than 2.5 V and the terminal charge voltage is lower than 3.7 V after 100 cycles at a current density of 0.1 mA cm−2. Therefore, this electrocatalyst is a promising bifunctional electrocatalyst for lithium oxygen batteries and this depositing high-efficient electrocatalyst on porous substrate with polycrystalline thin film by pulsed laser deposition is also a promising technique in the future lithium oxygen batteries research

Weighted Differentiation Composition Operator from Logarithmic Bloch Spaces to Zygmund-Type Spaces

Let H() denote the space of all holomorphic functions on the unit disk of ℂ, u∈H() and let  n be a positive integer, φ a holomorphic self-map of , and μ a weight. In this paper, we investigate the boundedness and compactness of a weighted differentiation composition operator φ,unf(z)=u(z)f(n)(φ(z)),f∈H(), from the logarithmic Bloch spaces to the Zygmund-type spaces

County-level CO2 emissions and sequestration in China during 1997–2017

With the implementation of China’s top-down CO2 emissions reduction strategy, the regional differences should be considered. As the most basic governmental unit in China, counties could better capture the regional heterogeneity than provinces and prefecture-level city, and county-level CO2 emissions could be used for the development of strategic policies tailored to local conditions. However, most of the previous accounts of CO2 emissions in China have only focused on the national, provincial, or city levels, owing to limited methods and smaller-scale data. In this study, a particle swarm optimization-back propagation (PSO-BP) algorithm was employed to unify the scale of DMSP/OLS and NPP/VIIRS satellite imagery and estimate the CO2 emissions in 2,735 Chinese counties during 1997–2017. Moreover, as vegetation has a significant ability to sequester and reduce CO2 emissions, we calculated the county-level carbon sequestration value of terrestrial vegetation. The results presented here can contribute to existing data gaps and enable the development of strategies to reduce CO2 emissions in China

Capillary-Induced Ge Uniformly Distributed in N-Doped Carbon Nanotubes with Enhanced Li-Storage Performance

Germanium (Ge) is a prospective anode material for lithium-ion batteries, as it possesses large theoretical capacity, outstanding lithium-ion diffusivity, and excellent electrical conductivity. Ge suffers from drastic capacity decay and poor rate performance, however, owing to its low electrical conductivity and huge volume expansion during cycling processes. Herein, a novel strategy has been developed to synthesize a Ge at N-doped carbon nanotubes (Ge at N-CNTs) composite with Ge nanoparticles uniformly distributed in the N-CNTs by using capillary action. This unique structure could effectively buffer large volume expansion. When evaluated as an anode material, the Ge at N-CNTs demonstrate enhanced cycling stability and excellent rate capabilities

A germanium/single-walled carbon nanotube composite paper as a free-standing anode for lithium-ion batteries

Paper-like free-standing germanium (Ge) and single-walled carbon nanotube (SWCNT) composite anodes were synthesized by the vacuum filtration of Ge/SWCNT composites, which were prepared by a facile aqueous-based method. The samples were characterized by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Electrochemical measurements demonstrate that the Ge/SWCNT composite paper anode with the weight percentage of 32% Ge delivered a specific discharge capacity of 417 mA h g−1 after 40 cycles at a current density of 25 mA g−1, 117% higher than the pure SWCNT paper anode. The SWCNTs not only function as a flexible mechanical support for strain release, but also provide excellent electrically conducting channels, while the nanosized Ge particles contribute to improving the discharge capacity of the paper anode