Chiral Bis-sulfoxide Phosphine Ligands and Asymmetric Catalysis

近年来,作为既能提供手性源和又能与金属配位的手性片段,手性亚砜在配体设计及金属不对称催化反应中的研究,逐渐引起有机化学工作者的关注。过去几年,我们一直致力于基于手性叔丁基亚砜片段的手性亚砜膦、双亚砜和亚砜烯等配体的设计和探索其在过渡金属催化的不对称反应中的应用[1]。最近,我们发展了两类手性双亚砜膦配体L1和L2,其中:L1配体的两个亚砜在钯催化烯丙基取代反应中表现双功能特性(提供配位原子和氢键受体)[2a-b],成功实现了1,3-非对称烯丙基醇酯底物的动态动力学转化;L2配体在铑催化的芳基硼酸对γ,β-不饱和a-酮酰化合物的不对称共轭加成[2c-d],表现出优秀的1,4-选择性、对映选择性和..

Oxidation and degradation of 2,4-dichlorophenol in water by UV-H_2O_2 system

研究了用UV-H2O2体系对水中2,4-二氯酚氧化降解。结果表明,UV-H2O2体系中H2O2的投加量主要由UV光强度和有机物初始浓度来确定,酸性和中性条件下有利于UV-H2O2体系对2,4-二氯酚的降解;最佳反应温度在20～25℃;UV-H2O2光氧化技术适用于低浊度水的深度处理,降解效果以浊度6 NTU为分界点。在Fenton试验中,向质量浓度为20mg/L的2,4-二氯酚溶液加入2.0mg/L的Fe2+,同时把H2O2的投加量减为0.204mg/L,pH值3.0左右,此时UV-H2O2-Fenton体系对2,4-二氯酚的氧化效率大大提高,比单纯Fenton体系的降解率提高1倍,达到95.6%。用UV-Fenton体系去除有机污染物在效果和经济上均具有明显的优越性。The oxidation and degradation of 2,4-dichlorophenol in water by UV-H2O2 system was studied.The results indicated that,the dosage of H2O2 in UV-H2O2 system mainly depended on the strength of UV radiation and the initial concentration of organic contaminants,acid and neutral conditions were in favor of the degradation of 2,4-dichlorophenol by UV-H2O2 system;the optimal reaction temperature was ranged between 20-25 ℃;UV-H2O2 photo-oxidation technology was only available for the advanced treatment of low-turbidity water with a critical limitation of 6 NTU turbidity.In the Fenton experiment,under the condition that,2.0 mg/L of Fe2+ was added into the 2,4-dichlorophenol solution with the mass concentration of 20 mg/L,the dosage of H2O2 decreased to 0.204 mg/L,the pH value was about 3.0,the efficiency of the UV-H2O2-Fenton system on 2,4-dichlorophenol oxidation was improved greatly;the degradation rate of 2,4-dichlorophenol by the said system was twice higher than by Fenton system only,reached 95.6%.It was proved that UV-Fenton system had obvious superiority both in effect and in economic benefits for removal of the organic contaminants.国家自然科学基金项目(29977015);; 瑞典政府国际发展署(SIDA)资助项目(20040231

A High-Precision Method for Determining the FBG Peak Wavelength Shift Based on FBG Actual Reflection Spectrum Match

针对目前光纤布拉格光栅(fbg)解调方案中采用低分辨率CCd测量fbg峰值波长时存在的问题,提出一种采用基于fbg实际反射谱构建基函数匹配CCd测量获得的有限测量点确定fbg峰值波长偏移量的新方法。分别在理论和实测上对这种方法的有效性和可行性进行了研究,证明这种采用fbg实际反射谱函数匹配有限测量数据的方法比采用特定函数拟合测量数据的方法能够更准确地获得fbg峰值波长的偏移量。实现了在CCd采样点数少、光谱分辨率较低的情况下对fbg峰值波长偏移量的高精度确定,有效地提高了实际工程应用中基于低成本CCd解调fbg峰值波长及其微小偏移量的准确性。Referring to the problems in using low-resolution charge coupled device(CCD) to measure fiber Bragg grating(FBG) peak wavelength,a high-precision method for determining the FBG peak wavelength shift by matching basis function based on the FBG actual reflection and sampling data measured by CCD is proposed.The effectiveness and feasibility of the new method are studied theoretically and experimentally.It is proved that compared with fitting sampling data by specific functions,the matching method based on FBG actual reflection spectrum can determine FBG peak wavelength shift more accurately.In the case of few sampling data and low resolution of CCD measurement,the high-precision determination of FBG peak wavelength shift is achieved.The accuracy of demodulation of FBG peak wavelength shift using low-cost CCD in the practical applications is improved effectively.国家自然科学基金(61077031);国家质检总局科技计划项目(2010IK077)资助课

研究生对生成性课堂的参与(笔谈)——厦门大学教育研究院“高等教育研究方法”第十三次课反思

\"高等教育研究方法\"这门课具有研究型课堂的特征。其第十三次课的主题是对反思日志做一次元研究。反思日志是学习\"高等教育研究方法\"课的重要工具,它不仅是课堂教学的缩影,而且是课堂时效的呈现,更是学生自我成长的印证。反思日志勾勒着整个课堂进程的图景,反映着学生的收获、困惑、不足以及对自己未来改进方向的认识等。第十三次课以生成式教学引导学生主动参与课堂,通过对反思日志重新审视,让学生成为思考的主体、学习的主体、研究的主体,实现自我成长、自我发现、自我唤醒的课堂教学改革目标

Mental health of elderly victims in relocation sites four months after the 5·12 earthquake

目的评估5.12地震后4个月安县板房区老年人的心理健康状况,并探讨其影响因素。方法利用自编受灾情况调查问卷、中国心理健康量表(老年版)(CMHI-E)、幸福感量表(MUNSH)和流调中心用抑郁量表(CES-D),调查绵阳市两个安置板房区290位老年人。结果灾区老年人的心理健康水平和幸福感水平均低于对照样本(P<0.001);抑郁水平高于对照样本(P<0.001);心理健康得分和幸福感正相关(r=0.61,P<0.01);心理健康得分和抑郁得分负相关(r=-0.59,P<0.01)。多元回归分析显示影响灾区老年人心理健康的主要因素有亲属遇难人数、财产损失状况和年龄。结论重灾区老年人的心理健康状况较差,幸福感水平较低,抑郁程度较高。遇难的亲属越多、年龄越大、财产损失越严重,老人的心理健康状况越差

Semantic Memory in Patients with Mild Cognitive Impairment

轻度认知损伤(Mildcognitive impairment,MCI)是介于正常老化与痴呆之间的过渡阶段,表现为与年龄和教育程度不相称的认知功能减退。本文回顾了近期有关MCI语义记忆的研究,分析比较了各研究的实验任务及结果,得出MCI患者存在一定程度的由多种原因造成的语义记忆损伤,语义记忆测验对MCI的早期筛查和转归预测有重要作用。最后指出将来的研究需要将包括语义记忆成分在内的多种认知测验相结合,以便及早发现有可能发展为痴呆的危险个体并开展相应干预

轻度认知损伤的语义记忆研究述评

轻度认知损伤(Mildcognitive impairment,MCI)是介于正常老化与痴呆之间的过渡阶段,表现为与年龄和教育程度不相称的认知功能减退。本文回顾了近期有关MCI语义记忆的研究,分析比较了各研究的实验任务及结果,得出MCI患者存在一定程度的由多种原因造成的语义记忆损伤,语义记忆测验对MCI的早期筛查和转归预测有重要作用。最后指出将来的研究需要将包括语义记忆成分在内的多种认知测验相结合,以便及早发现有可能发展为痴呆的危险个体并开展相应干预

Semantic Memory in Patients with Mild Cognitive Impairment

轻度认知损伤(Mildcognitive impairment,MCI)是介于正常老化与痴呆之间的过渡阶段,表现为与年龄和教育程度不相称的认知功能减退。本文回顾了近期有关MCI语义记忆的研究,分析比较了各研究的实验任务及结果,得出MCI患者存在一定程度的由多种原因造成的语义记忆损伤,语义记忆测验对MCI的早期筛查和转归预测有重要作用。最后指出将来的研究需要将包括语义记忆成分在内的多种认知测验相结合,以便及早发现有可能发展为痴呆的危险个体并开展相应干预