摘要：
Poor reversibility of conversion and alloying reactions for Sb2S3 limits its application as high capacity anode for rechargeable lithium storage. Herein a facile high-efficiency plasma assisted milling (P-milling) was used to create Sb2S3-C hybrid nanostructure with disk-like Sb2S3 nanograins wrapped within ultrathin graphite nanosheets. Benefiting from the high structure stability and excellent Li+ ion diffusion kinetics in the graphite wrapped Sb2S3 nanostructure, highly reversible conversion and alloying reactions are maintained throughout the long-term cycles. The Sb2S3-C nanocomposite anode demonstrates a high stable capacity of 638.2 mA h g(-1) after 250 cycles at 200 mA g(-1) between 0.01 and 3.0 V vs. Li/Li+, with a high initial Coulombic efficiency of 78.3%. A reversible capacity of 496.1 mA h g(-1) is obtained after 500 cycles even at higher current rate of 1 A g(-1), much superior to those of the unmilled Sb2S3-C and P-milled Sb2S3 anodes. These demonstrate that P-milling could be a promising strategy to create high performance metal chalcogenide anode materials involved both conversion and alloying reactions toward lithium storage. (C) 2019 Elsevier Ltd. All rights reserved.
摘要：
To promote the application of biochar in environmental pollution decontamination especially the heavy metals amendment, the relationship between the adsorption mechanism and biochar pyrolysis conditions was investigated. Tobacco stem was pyrolyzed at 300-700 degrees C for various residence time of 2 h, 4 h and 6 h. The adsorption of lead, cadmium and copper in single solute was then analyzed for as-obtained biochars. The change of the crystal structures, the related functional groups, and the exchanged cations were determined to reveal the effect of pyrolysis conditions on the adsorption mechanisms of these three heavy metals. The change of crystal structure confirmed that precipitation was the main mechanism of lead adsorption and that the tobacco stem biochar obtained at 700 degrees C for around 2 h was excellent adsorbent for lead clearance, since high temperature pyrolysis could promote the formation of carbonates but they would be decomposed under long-time exposure. The alteration of surface functional groups and exchanged cations of both original and demineralized biochars followed an affinity order of Cu(II)>Cd(II)>Pb(II) to oxygen functional groups. The surface complexation should be the primary mechanism of copper adsorption. Thus, the tobacco stem biochars pyrolyzed at 400 degrees C for 4 h could be effective adsorbents for copper amendment. Despite of the important role of precipitation in its removal, cadmium favores the cation-Is interaction best, and the biochars derived from tobacco stem at 700 degrees C for the residence time of 4-6 h are good adsorbents for cadmium decontamination. (C) 2018 Elsevier Ltd. All rights reserved.
摘要：
Background: An epidemic can spread rapidly among a large number of people in a community within a short period of time. Some infectious diseases, including influenza, hand, foot and mouth disease, dengue and meningitis, are temporally limited by variations in the meteorological factors, such as sunshine, temperature, humidity, rainfall, atmospheric pressure, wind speed and so on. Therefore, it is necessary to predict the behavior of outbreak of these infectious diseases based on meteorological factors. Objective: Review various epidemic models related to meteorological factors. Results: We discuss two kinds of epidemic models: deterministic models and stochastic models. The deterministic models include switched SIR model, seasonal SIR model, periodic SEIR system and seasonal SEIQR model. And the stochastic models involve multiple regression models, auto-regressive moving average model, autoregressive distributed lag model, time series Poisson regression models and generalized additive models. Furthermore, we introduce the latest applications of these models, respectively. Conclusion: In our work, these deterministic models and stochastic models can successfully predict the diseases outbreak using meteorological factors, and they all are now widely used in the field. However, few meteorological factors are used in these models. With the development of Meteorological Science, large amounts of Meteorological factor data will be obtained. More key Meteorological factors causing an epidemic will be identified. Therefore, in the future, more key meteorological factors will be considered in models and they will further improve the accuracy of the forecast.
通讯机构：
[Zou, Xiufen] W;Wuhan Univ, Sch Math & Stat, Computat Sci Hubei Key Lab, Wuhan 430072, Peoples R China.
关键词：
*Assembly;*Dynamics;*HIV-like particle;*Mathematical model
摘要：
In vitro, the recombinant HIV-1 Gag protein can generate spherical particles with a diameter of 25-30 nm in a fully defined system. It has approximately 80 building blocks, and its intermediates for assembly are abundant in geometry. Accordingly, there are a large number of nonlinear equations in the classical model. Therefore, it is difficult to compute values of geometry parameters for intermediates and make the mathematical analysis using the model. In this work, we develop a new model of HIV-like particle assembly in vitro by using six-fold symmetry of HIV-like particle assembly to decrease the number of geometry parameters. This method will greatly reduce computational costs and facilitate the application of the model. Then, we prove the existence and uniqueness of the positive equilibrium solution for this model with 79 nonlinear equations. Based on this model, we derive the interesting result that concentrations of all intermediates at equilibrium are independent of three important parameters, including two microscopic on-rate constants and the size of nucleating structure. Before equilibrium, these three parameters influence the concentration variation rates of all intermediates. We also analyze the relationship between the initial concentration of building blocks and concentrations of all intermediates. Furthermore, the bounds of concentrations of free building blocks and HIV-like particles are estimated. These results will be helpful to guide HIV-like particle assembly experiments and improve our understanding of the assembly dynamics of HIV-like particles in vitro. (C) 2017 Elsevier Inc. All rights reserved.
摘要：
Aim and Objective: Protein malonylation is a newly discovered post-translational modification. Malonylation is known to closely be associated with type 2 diabetes and to play its regulatory role in fatty acid oxidation and the associated genetic disease. Identifying protein malonylations might lay a solid foundation to explore malonylation function. Due to the limitations of experimental techniques, it is a great challenge to fast and accurately identify malonylation sites. Methods: We proposed a computational method to predict malonylation sites and to analyze malonylation pattern. We firstly extracted protein segments so that the lysine is at the center of each segment. Then, each segment was encoded by the pseudo amino acid compositions. The support vector machine classifier trained by a training dataset was built to distinguish malonylation sites from non-malonylation ones. Results: The leave-one-out test on the training dataset reached the accuracy of 0.7733, and the independent test on the testing dataset got 0.8889. Furthermore, the classifier also successfully identified 144 of 160 putative malonylation sites. Analyses on the differences between malonylation and non-malonylation segments implicated that lysine malonylation should follow a specific pattern, e.g. lysine with its neighbors being Glycine and Alanine might be more likely to be malonylated. Therefore, the proposed method is expected to be a promising tool to identify malonylation sites.
摘要：
A novel quantitative analysis method of genetic relationship of species is presented, which is based on the network composed of 20 nodes corresponding to 20 amino acids and edges corresponding to their interactions. The degree of genetic relationship of species is determined by the distance of the vectors which consist of 40 elements corresponding to the out-degrees and in-degrees of 20 nodes. Compared with the classical methods, it avoids choosing the four reference directions corresponding to four bases of DNA sequence, whose optimal angles are very difficult to get. Moreover, our method is efficient because it only computes the distance of vectors. In contrast, much time is spent for the classical methods on computing the eigenvalue of matrix, which has large sizes for long DNA sequence. The contrast experiments show that this approach is superior to the classical methods.
摘要：
We obtain a blue phosphor, Ba9Lu2Si6O24:Eu2+ (BLS:Eu2+), which shows a strong emission peak at 460 nm and a weak tail from 460 to 750 nm. A 610 nm red emission is observed for the first time in this kind of rhombohedral structure material, which is much different from the same crystal structure of Ba9Sc2Si6O24:Eu2+ and Ba9Y2Si6O24:Eu2+. The luminescence properties and decays from 10 to 550 K are discussed. The new red emission arises from a trapped exciton state of Eu2+ at the Ba site with a larger coordination number (12-fold). It exhibits abnormal luminescence properties with a broad bandwidth and a large Stokes shift. Under the 400 nm excitation, the external quantum efficiency of BLS:Eu2+ is 45.4%, which is higher than the 35.7% for the commercial blue phosphor BAM:Eu2+. If the thermal stability of BLS:Eu2+ can be improved, it will show promising applications in efficient near-UV-based white LEDs.
