A Survey on the Cultivation of College Students’ Audience Awareness in English Writing

The strength of audience awareness has a great influence on the content selection, expression and writing techniques of the article. Therefore, the cultivation of the students’ audience awareness in writing becomes one of the key factors that determine the qualities of the students’ compositions. This thesis conducts a questionnaire and interviews on college students from the four grades of Nanchang Normal University in order to reveal the college students’ cognitive status and attitude of audience awareness. Based on the status quo, this thesis analyzes the possible causes of this situation from two aspects: the teachers’ carelessness on audience awareness and overly concern with writing skills, and the students’ shortage of language ability and logical thinking ability and their excessive attention to writing skills. For these reasons, this thesis proposes corresponding countermeasures: in the English writing class, the reader's awareness should be emphasized; the theme of the article needs to be much closer to life; students are supposed to create imaginary readers in writing; the method of readers' feedback should be fully utilized. The use of these strategies will effectively help college students cultivate audience awareness in English writing

Characteristics of the Bohai Sea oil spill and its impacton the Bohai Sea ecosystem

In this paper, ENVISAT ASAR data and the Estuary, Coastal and Ocean Model was&nbsp; used to analyze and compare characteristics of the Bohai Sea oil spill. The oil&nbsp; slicks have spread from the point of the oil spill to the east and north-western&nbsp; Bohai Sea. We make a comparison between the changes caused by the oil spill on&nbsp; the chlorophyll concentration and the sea surface temperature using MODIS data,&nbsp; which can be used to analyze the effect of the oil spill on the Bohai Sea&nbsp; ecosystem. We found that the Bohai Sea oil spill caused abnormal chlorophyll&nbsp; concentration distributions and red tide nearby area of oil spill.</span

Semi-Numerical Simulation of Reionization with Semi-Analytical Modeling of Galaxy Formation

In a semi-numerical model of reionization, the evolution of ionization fraction is simulated approximately by the ionizing photon to baryon ratio criterion. In this paper we incorporate a semi-analytical model of galaxy formation based on the Millennium II N-body simulation into the semi-numerical modeling of reionization. The semi-analytical model is used to predict the production of ionizing photons, then we use the semi-numerical method to model the reionization process. Such an approach allows more detailed modeling of the reionization, and also connects observations of galaxies at low and high redshifts to the reionization history. The galaxy formation model we use was designed to match the low-$z$ observations, and it also fits the high redshift luminosity function reasonably well, but its prediction on the star formation falls below the observed value, and we find that it also underpredicts the stellar ionizing photon production rate, hence the reionization can not be completed at $z \sim 6$ without taking into account some other potential sources of ionization photons. We also considered simple modifications of the model with more top heavy initial mass functions (IMF), with which the reionization can occur at earlier epochs. The incorporation of the semi-analytical model may also affect the topology of the HI regions during the EoR, and the neutral regions produced by our simulations with the semi-analytical model appeared less poriferous than the simple halo-based models.Comment: 13 pages, 8 figures, RAA accepte

Laplacian eigenvalue distribution, diameter and domination number of trees

For a graph $G$ with domination number $\gamma$, Hedetniemi, Jacobs and Trevisan [European Journal of Combinatorics 53 (2016) 66-71] proved that $m_{G}[0,1)\leq \gamma$, where $m_{G}[0,1)$ means the number of Laplacian eigenvalues of $G$ in the interval $[0,1)$. Let $T$ be a tree with diameter $d$. In this paper, we show that $m_{T}[0,1)\geq (d+1)/3$. However, such a lower bound is false for general graphs. All trees achieving the lower bound are completely characterized. Moreover, for a tree $T$, we establish a relation between the Laplacian eigenvalues, the diameter and the domination number by showing that the domination number of $T$ is equal to $(d+1)/3$ if and only if it has exactly $(d+1)/3$ Laplacian eigenvalues less than one. As an application, it also provides a new type of trees, which show the sharpness of an inequality due to Hedetniemi, Jacobs and Trevisan