推进课堂变革之合作学习在语文教学中的应用

现阶段，在我国社会快速发展和进步的过程中，国家整体的经济和科学技术水平得到了良好的提升，在这样的背景下，新课改理念提出，校园教学工作走上了改革的道路。因此，本文也力求能够推进课堂变革，实现校园教学效果的最大化，以小学校园语文教学工作为例，了解到合作学习在其中的应用，希望能够提高课堂教学质量，在合作学习的模式下，为学生综合素质的提升做出贡献。</jats:p

Chinese Public's Willingness to Pay for CO_2 Emissions Reduction: A Case Study from Four Provinces/Cities

利用非市场价值评估的方法——条件价值法,通过估算公众对CO_2减排政策的支付意愿,评估中国减缓气候变化政策的价值。利用从北京、上海、山东、福建4个省市收集的1653份有效调查问卷,建立支付意愿模型。结果表明,绝大部分参与者对CO_2减排政策持明显的支持态度,平均每人每年愿意支付201.86元人民币以支持减排行动。其中,北京地区的参与者CO_2减排的支付意愿最高,其次为福建和山东,上海参与者的支付意愿最低。模型显示,年轻、男性和中共党员参与者愿意支付较高的额度支持CO_2减排行动,收入水平高、对目前的生活状况满意、对气候变化问题有较好理解的参与者支付意愿也高。这一研究的政策启示是:中国低碳发展需要将公众对气候政策的支持意愿转化为切实的低碳行动,在设计碳税等减排机制时还要关注不同地区和收入群体在支付意愿和能力上的差异。The paper applies Contingent Valuation Method(CVM) to investigate the Chinese public's willingness to pay(WTP) for CO,emissions reduction policy.Face to face interviews were conducted to collect 1653 valid questionnaires from Beijing,Shanghai,Shandong Province and Fujian Province.A model was constructed to understand the factors that determined WTP.The results indicate that the Chinese public is willing to pay 201.86 CNY annually to support the policy in reducing greenhouse gas emissions.Participants from Beijing show the highest WTP,followed by participants from Fujian and Shandong,and those from Shanghai report the lowest WTP.The findings reveal that participants with higher income,higher satisfaction to current life,and being aware of climate issues are willing to pay more for CO:emissions reduction,and those who are young,male and members of the Communist Party also indicate a higher WTP.The results imply that translating the public's willingness to protect climate into actions should be taken into account in China's low carbon policy.There is a need to consider the difference of willingness to pay for emissions reduction among different social groups if the market-based mechanisms such as carbon tax would be designed to facilitate emissions reduction.教育部人文社会科学规划基金项目(09YJA790119

A novel evaluation method for epigenetic demethylation toxicity of contaminated aquatics based on EGFP reporter

PEgfP-C3质粒经过体外人工甲基化处理后,被转染进入HEPg2细胞以构建重组细胞株.以5-AzA为阳性去甲基化毒物与重组细胞共培养,通过亚硫酸氢钠测序法定量检测EgfP基因启动子区甲基化状态,通过实时定量PCr检测EgfP基因表达,借助流式细胞术和荧光摄片定量检测共培养细胞的绿色荧光强度,在dnA甲基化、EgfP基因MrnA表达、gfP蛋白等多个层次研究5-AzA染毒处理与其去甲基化能力和荧光表达改变的响应关系.对天津污染水产的去甲基化能力进行了实际样品测试.结果表明,5-AzA与重组细胞的dnA甲基化、基因表达、蛋白产物变化之间存在显著关联,具有较低的检出浓度和良好的重复性.天津污染海域的水产去甲基化能力较强.本文初步建立了一种污染物去甲基化表观遗传毒性评价方法.To study a novel evaluation method for demethylation epigenetic toxicity of pollutants based on an artificial recombinant pEGFP-C3 plasmid, pEGFP-C3 plasmid was methylated with M.SssⅠ in vitro first and then transfected into HepG2 cells.Taking 5-AZA as positive demethylation agent, the levels of methylation of the EGFP CMV promoter region, EGFP gene expression and green fluorescence intensity of the recombinant cell lines was quantified with sodium bisulfite sequencing assay, quantitative real-time quantitative PCR and flow cytometry at the time of 24 h after the cells co-cultured with 5-AZA gradients, respectively.A dose-respond relationship was explored between the cells’ response intensity at the former three levels and the co-cultured 5-AZA.The demethylation ability of the aquatic from polluted area of Tianjin basin was tested with this novel method.Good dose-respond relationships were found between DNA methylation of CMV promoter, EGFP gene expression, green fluorescence intensity of the recombinant cells and 5-AZA.The equation for green fluorescence intensity of the test cells and 5-AZA is y = 0.640lnx + 10.284 with R2 = 0.890.This method has a detection limit of 0.00004 μM 5-AZA and good repeatability with variation of 7.5%-23.9%.Almost half of the aquatic from the Tianjin basin was found demethylation ability positively with this method.国家自然科学基金(20907047);中国环境科学研究院中央级公益性科研院所基本科研业务专项基金(2008KYYW05)资