基础有机化学教学中课程思政的探索与实践

课程思政是将思想政治教育与课程理论相结合,在向学生传授基础知识的同时,传递正确的价值观和社会观,树立爱国主义思想。本文对基础有机化学课程与思想政治教育相结合的方式进行了探索和实践,将思政教育与基础有机化学知识融于趣味性的小故事中,使学生在学习理论知识的同时,培养正确的思想观念,树立远大的人生理想。

西北大学化学一流专业建设的探索与实践

在长期的教学实践中,西北大学化学专业科学合理地设定专业定位与人才培养目标,以教师队伍建设为抓手,持续提高教学质量;以教材建设为根基,擦亮专业育人底色;以课程建设为统领,着重提高学生学术素养;以一流的教学管理为保障,建立人才培养长效机制,在专业建设中形成了鲜明的特色。本文从专业定位、师资队伍建设、教材建设、课程建设、教学管理等方面介绍西北大学化学一流专业建设的举措及成效。

A positive correlation between local photocurrent and grain size in a perovskite solar cell

Developing an interplay between the local morphological character and its local photovoltaic(PV)parameters in a perovskite thin film is essential for guiding the construction of highly-efficient perovskite solar cells(PSCs). To achieve a higher PSC performance, great efforts have been devoted to the growth of larger perovskite grains;however, how the gain size can influence the PSC performance in a working device remains unclear. Herein, using laser-scanned confocal microscopy coupled with a photocurrent detection module, we realize local photocurrent, photoluminescence(PL) intensity and PL lifetime mappings directly in a working PSC. For perovskite grains of various sizes(from ~500 nm to a few micrometers), their local photocurrent exhibit a statically positive correlation with the grain size, but anti-correlated with the grain’s local PL intensity. This result suggests that a larger perovskite grain likely has fewer defects and more importantly better interfacial contact with the charge collection layers and thus leads to higher charge collection efficiency, and the optimum grain size is found to be ≥2 μm.Our result provides important guidance to the growth and control of perovskite microstructures toward the further improvement of PSC performance.

Canopy structure:An intermediate factor regulating grassland diversity-function relationships under human disturbances

Grasslands are one of the largest coupled human-nature terrestrial ecosystems on Earth,and severe anthropogenic-induced grassland ecosystem function declines have been reported recently.Understanding factors influencing grassland ecosystem functions is critical for making sustainable management policies.Canopy structure is an important factor influencing plant growth through mediating within-canopy microclimate(e.g.,light,water,and wind),and it is found coordinating tightly with plant species diversity to influence forest ecosystem functions.However,the role of canopy structure in regulating grassland ecosystem functions along with plant species diversity has been rarely investigated.Here,we investigated this problem by collecting field data from 170 field plots distributed along an over 2000 km transect across the northern agro-pastoral ecotone of China.Aboveground net primary productivity(ANPP)and resilience,two indicators of grassland ecosystem functions,were measured from field data and satellite remote sensing data.Terrestrial laser scanning data were collected to measure canopy structure(represented by mean height and canopy cover).Our results showed that plant species diversity was positively correlated to canopy structural traits,and negatively correlated to human activity intensity.Canopy structure was a significant indicator for ANPP and resilience,but their correlations were inconsistent under different human activity intensity levels.Compared to plant species diversity,canopy structural traits were better indicators for grassland ecosystem functions,especially for ANPP.Through structure equation modeling analyses,we found that plant species diversity did not have a direct influence on ANPP under human disturbances.Instead,it had a strong indirect effect on ANPP by altering canopy structural traits.As to resilience,plant species diversity had both a direct positive contribution and an indirect contribution through mediating canopy cover.This study highlights that canopy structure is an important intermediate factor regulating grassland diversity-function relationships under human disturbances,which should be included in future grassland monitoring and management.

Ti^(3+) self-doped TiO_(2) as a photocatalyst for cyclohexane oxidation under visible light irradiation

Most of TiO_(2) particles can be used as a photocatalyst for the selective oxidation of cyclohexane under ultraviolet light illumination.In this paper,Ti^(3+) self-doped TiO_(2) submicron-sized particles(i.e.,Ti^(3+)/TiO_(2) SMP)were used as a catalyst for visible-light driven photocatalytic cyclohexane oxidation.The microstructure and properties of the Ti^(3+)/TiO_(2) SMP were characterized by X-ray diffraction(XRD),UVevisible diffuse reflection(UVeVis DRS),scanning electron microscopy(SEM),electron paramagnetic resonance(EPR),solid-state photoluminescence spectroscopy(PLS)and X-ray photoelectron spectroscopy(XPS).The Ti^(3+)/TiO_(2) SMP exhibits good visible-light driven photocatalytic performances for cyclohexane oxidation with cyclohexanone as a dominate product.Effects of solvent,reaction temperature,reaction time and oxygen pressure on the formation of cyclohexanone were investigated.The cyclohexane oxidation over the Ti^(3+)/TiO_(2) SMP photocatalyst using carbon tetrachloride as a solvent under the optimal conditions presents a greater selectivity to cyclohexane(i.e.,95.1%).Based on the controlled experimental results with different radical scavengers,the hole(h^(+))is critical for the activation of cyclohexane.

全球价值链参与度和工资差距——基于我国在价值链中不同地位的考量

基于理论和实证的角度研究了我国在全球价值链中的参与度对处于价值链中不同地位的劳动力工资差异的影响。通过构建一个关于低技术国家的理论模型可以发现,对于在全球价值链中处于较高地位的行业,价值链的参与度对工资差距有放大效应。相反,对于在全球价值链中处于较低地位的行业,价值链的参与度对工资差距具有一定的收敛效应。使用WIOD等数据验证也支持了这一研究结论。

Expression and possible role of Smad3 in postnecrotizing enterocolitis stricture

Objective To investigate the expression of Smad3(mothers against decapentaplegic homolog 3)protein in postnecrotizing enterocolitis stricture and its possible mechanism of action.Methods We used immunohistochemistry to detect the expression characteristics of Smad3 and nuclear factor kappa B(NF-κB)proteins in human postnecrotizing enterocolitis stricture.We cultured IEC-6(crypt epithelial cells of rat small intestine)in vitro and inhibited the expression of Smad3 using siRNA technique.Quantitative PCR,western blotting,and ELISA were used to detect the changes in transforming growth factor-β1(TGF-β1),NF-κB,tumor necrosis factor-α(TNF-α),vascular endothelial growth factor(VEGF),and zonula occludens-1(ZO-1)messenger RNA(mRNA)and protein expressions in IEC-6 cells.CCK8 kit and Transwell cellular migration were used to detect cell proliferation and migration.Changes in epithelial-mesenchymal transition(EMT)markers(E-cadherin and vimentin)in IEC-6 cells were detected by immunofluorescence technique.Results The results showed that Smad3 protein and NF-κB protein were overexpressed in narrow intestinal tissues and that Smad3 protein expression was positively correlated with NF-κB protein expression.After inhibiting the expression of Smad3 in IEC-6 cells,the mRNA expressions of NF-κB,TGF-β1,ZO-1,and VEGF decreased,whereas the mRNA expression of TNF-αdid not significantly change.TGF-β1,NF-κB,and TNF-αprotein expressions in IEC-6 cells decreased,whereas ZO-1 and intracellular VEGF protein expressions increased.IEC-6 cell proliferation and migration capacity decreased.There was no significant change in protein expression levels of EMT markers E-cadherin and vimentin and also extracellular VEGF protein expression.Conclusions We suspect that the high expression of Smad3 protein in postnecrotizing enterocolitis stricture may promote the occurrence and development of secondary intestinal stenosis.The mechanism may be related to the regulation of TGF-β1,NF-κB,TNF-α,ZO-1,and VEGF mRNA and protein expression.This may also be related to the ability of Smad3 to promote epithelial cell proliferation and migration.