Project Teaching and Practice in College English Teaching

At present, a new teaching model - Project Approach rises in English education. Project teaching is a student-centered, inquiry-centered practice, with project activities centered learning model. Project teaching students focus on learning strategies to help students become independent learners, to improve students＇ motivation to help students learn practical ability, communication skills, collaboration skills, creative thinking skills and the ability to solve practical problems. Project-based learning in the late 1990s was introduced in China. Within ten years, research project studying abroad connotation, significance and theoretical foundation, extension are applied research to classroom practice. However, most of the research object of the project is teaching primary and secondary students, higher education, adult education and general higher education students in science and engineering students. Research related to the field of English teaching is not much; the theory is applied to the case of teaching practice rarely. Therefore, this article introduced the project teaching college English classroom, through the implementation of the teaching aims to stimulate the enthusiasm of the students, so that students learn more explicit goals, enhance self- confidence and motivation to learn, to develop their creativity, initiative and independent learning and the purpose of learning ability.

Arctic sea ice volume export through the Fram Strait: variation and its effect factors

Arctic sea ice export is important for the redistribution of freshwater and sea ice mass.Here,we use the sea ice thickness,sea ice velocity,and sea ice concentration(SIC)to estimate the exported sea ice volume through the Fram Strait from 2011 to 2018.We further analyse the contributions of the sea ice thickness,velocity and concentration to sea ice volume export.Then,the relationships between atmospheric circulation indices(Arctic Oscillation(AO),North Atlantic Oscillation(NAO),and Arctic Dipole(AD))and the sea ice volume export are discussed.Finally,we analyse the impact of wind-driven oceanic circulation indices(Ekman transport(ET))on the sea ice volume export.The sea ice volume export rapidly increases in winter and decreases in spring.The exported sea ice volume in winter is likely to exceed that in spring in the future.Among sea ice thickness,velocity and SIC,the greatest contribution to sea ice export comes from the ice velocity.The exported sea ice volume through the zonal gate of the Fram Strait(which contributes 97%to the total sea ice volume export of the Fram Strait)is much higher than that through the meridional gate(3%)because the sea ice flowing out of the zonal gate has the characteristics of a high thickness(mainly thicker than 1 m),a high velocity(mainly faster than 0.06 m/s)and a high concentration(mainly higher than 80%).The AD and ET explain 53.86%and 38.37%of the variation in sea ice volume export,respectively.

Spatial-temporal variations in net primary productivity in the Arctic from 2003 to 2016

The area of Arctic sea ice has dramatically decreased, and the length of the open water season has increased;these patterns have been observed by satellite remote sensing since the 1970 s. In this paper, we calculate the net primary productivity(NPP, calculated by carbon) from 2003 to 2016 based on sea ice concentration products,chlorophyll a(Chl a) concentration, photosynthetically active radiation(PAR), sea surface temperature(SST), and sunshine duration data. We then analyse the spatiotemporal changes in the Chl a concentration and NPP and further investigate the relations among NPP, the open water area, and the length of the open water season. The results indicate that(1) the Chl a concentration increased by 0.025 mg/m^3 per year;(2) the NPP increased by 4.29 mg/(m^2·d) per year, reaching a maximum of 525.74 mg/(m^2·d) in 2016;and(3) the Arctic open water area increased by 57.23×10^3 km^2/a, with a growth rate of 1.53 d/a for the length of the open water season. The annual NPP was significantly positively related to the open water area, the length of the open water season and the SST.The daily NPP was also found to have a lag correlation with the open water area, with a lag time of two months.With global warming, NPP has maintained an increasing trend, with the most significant increase occurring in the Kara Sea. In summary, this study provides a macroscopic understanding of the distribution of phytoplankton in the Arctic, which is valuable information for the evaluation and management of marine ecological environments.

p53 mutation regulates PKD genes and results in co-occurrence of PKD and tumorigenesis

Objective: Polycystic kidney disease(PKD) is the major cause of kidney failure and mortality in humans. It has always been suspected that the development of cystic kidney disease shares features with tumorigenesis, although the evidence is unclear.Methods: We crossed p53 mutant mice(p53N236S, p53S) with Werner syndrome mice and analyzed the pathological phenotypes.The RNA-seq, ss GSEA analysis, and real-time PCR were performed to dissect the gene signatures involved in the development of disease phenotypes.Results: We found enlarged kidneys with fluid-filled cysts in offspring mice with a genotype of G3mTerc^(-/-)WRN^(-/-)p53^(S/S)(G3TM).Pathology analysis confirmed the occurrence of PKD, and it was highly correlated with the incidence of tumorigenesis. RNA-seq data revealed the gene signatures involved in PKD development, and demonstrated that PKD and tumorigenesis shared common pathways, including complement pathways, lipid metabolism, mitochondria energy homeostasis and others. Interestingly, this G3TM PKD and the classical PKD1/2 deficient PKD shared common pathways, possibly because the mutant p53S could regulate the expression levels of PKD1/2, Pkhd1, and Hnf1b.Conclusions: We established a dual mouse model for PKD and tumorigenesis derived from abnormal cellular proliferation and telomere dysfunction. The innovative point of our study is to report PKD occurring in conjunction with tumorigenesis. The gene signatures revealed might shed new light on the pathogenesis of PKD, and provide new molecular biomarkers for clinical diagnosis and prognosis.

An improved optical flow method to estimate Arctic sea ice velocity(winter 2014-2016)

Sea ice velocity impacts the distribution of sea ice,and the flux of exported sea ice through the Fram Strait increases with increasing ice velocity.Therefore,improving the accuracy of estimates of the sea ice velocity is important.We introduce a pyramid algorithm into the Horn-Schunck optical flow(HS-OF)method(to develop the PHS-OF method).Before calculating the sea ice velocity,we generate multilayer pyramid images from an original brightness temperature image.Then,the sea ice velocity of the pyramid layer is calculated,and the ice velocity in the original image is calculated by layer iteration.Winter Arctic sea ice velocities from 2014 to 2016 are obtained and used to discuss the accuracy of the HS-OF method and PHS-OF(specifically the 2-layer PHS-OF(2 LPHS-OF)and 4-layer PHS-OF(4 LPHS-OF))methods.The results prove that the PHS-OF method indeed improves the accuracy of sea ice velocity estimates,and the 2 LPHS-OF scheme is more appropriate for estimating ice velocity.The error is smaller for the 2 LPHS-OF velocity estimates than values from the Ocean and Sea Ice Satellite Application Facility and the Copernicus Marine Environment Monitoring Service,and estimates of changes in velocity by the 2 LPHS-OF method are consistent with those from the National Snow and Ice Data Center.Sea ice undergoes two main motion patterns,i.e.,transpolar drift and the Beaufort Gyre.In addition,cyclonic and anticyclonic ice drift occurred during winter 2016.Variations in sea ice velocity are related to the open water area,sea ice retreat time and length of the open water season.

Thinner Sea Ice Contribution to the Remarkable Polynya Formation North of Greenland in August 2018

In August 2018,a remarkable polynya was observed off the north coast of Greenland,a perennial ice zone where thick sea ice cover persists.In order to investigate the formation process of this polynya,satellite observations,a coupled iceocean model,ocean profiling data,and atmosphere reanalysis data were applied.We found that the thinnest sea ice cover in August since 1978(mean value of 1.1 m,compared to the average value of 2.8 m during 1978-2017) and the modest southerly wind caused by a positive North Atlantic Oscillation(mean value of 0.82,compared to the climatological value of-0.02) were responsible for the formation and maintenance of this polynya.The opening mechanism of this polynya differs from the one formed in February 2018 in the same area caused by persistent anomalously high wind.Sea ice drift patterns have become more responsive to the atmospheric forcing due to thinning of sea ice cover in this region.

4-Formyl-2-(2H-benzotriazol-2-yl)-phenol: an ESIPT chromophore

In the present work, excited state intramolecular proton transfer(ESIPT) emission properties of a new benzotriazole derivative 4-formyl-2-(2H-benzotriazol-2-yl)-phenol(C1) were studied. 4-Formyl-2-(2H-benzotriazol-2-yl)-methoxy-benzene(C2), 4-formyl-2-(2H-benzotriazol-2-yl)-phenyl acetate(C3) and 4-methyl-2-(2H-benzotriazol-2-yl)-phenol(C4) were used as the reference molecules.1H NMR chemical shift of hydroxy group in C1 was located at more down field than that of C4 or p-hydroxy-benzaldehyde(C5), respectively. C1 showed two absorption bands in the range of 260–400 nm zones in various solvents, while C2 and C3 exhibited single absorption band. The equal molar mixtures of C2/C5 or C3/C5 showed single absorption band.C2 and C3 displayed single fluorescence emission band in various solvents, while C1 exhibited dual emission bands in some strong polar solvents. Furthermore, the second emission band in these strong polar solvents showed the large Stokes shift. The results show that the second emission band of C1 was produced by ESIPT. C2 and C3 could not undergo ESIPT due to no hydroxy group. The geometry optimization calculation of enol and keto forms in the ground and excited states of C1 provided tough theoretical evidences of ESIPT.

为什么股权分置改革未能提高营利能力?

基于科斯定理的视角,股权分置改革降低了上市公司进行控制权转让(transfer of corporate control)的交易成本,理论上可以提高上市公司的营利能力,但以往研究并没有发现上市国有企业营利能力在股权分置改革后显著提高。本文认为,紧随股权分置改革发生的应对金融危机的一揽子计划(以下简称一揽子计划)加剧了上市国有企业的过度投资,掩盖了股权分置改革对营利能力的改善效果。本文以2002~2010年A股非金融行业上市公司为样本,采用双重匹配和直接计算一揽子计划对上市国有企业营利能力的影响两种方法来调整一揽子计划的影响,发现和该解释一致的经验证据:①在调整一揽子计划的影响前,股权分置改革后上市国有企业的营利能力没有显著提高;②在调整一揽子计划的影响后,股权分置改革显著提高了上市国有企业的营利能力;③股权分置改革后上市公司营利能力的提高源于代理问题的有效缓解。