综合研究型有机化学实验教学模式的探索

在有机化学实验中开设综合研究型实验,加强了学生的化学实验技能。对开设实验的特点、教学模式,进行了大胆的探索,取得了初步效果。     

有机化学实验教学改革探索

高校有机化学实验对培养学生良好的化学实验技能和实验素质起着重要的作用,但其“教、学、考”几方面均存在一系列问题,我们应加强实验教学体系建设、转变传统的实验教学方式、推行多向度的实验成绩考核方法、开放式实验室等措施,才能更好地激发学生的学习兴趣,提高学生的实验探究能力和创新能力.     

民族地方高校应用化学专业中有机化学实验教学改革初探

民族地方高校应用化学专业中有机化学实验教学,普遍存在着学生实验操作技能和动手能力薄弱、教学内容陈旧、教学方式不利于学生主体性的发挥等问题。调整教学内容、采取新型特色的教学方式、改革实验成绩考核方式,培养学生的有机实验操作技能,提高学生的科学素养是有效解决这些问题的途径。     

Effects of organic solvents on two retinal pigment epithelial lipofuscin fluorophores,A2E and all-trans-retinal dimer

Gene and drug therapies are being developed to alleviate vision loss in patients with Stargardt’s disease and age-related macular degeneration (AMD). To evaluate the therapeutic effects of these treatments, organic solvents are routinely used to extract and quantify bisretinoid lipofuscin constituents, such as N-retinylidene-N-retinyl-ethanolamine (A2E) and all-trans-retinal dimer (ATR-dimer). By high-performance liquid chromatography (HPLC), we found that A2E and ATR-dimer were both altered by tetrahydrofuran (THF) and chloroform, but were stable in dimethyl sulfoxide (DMSO) or methanol (MeOH). In addition, cyclohexane and ethanol (EtOH) did not alter ATR-dimer, whereas an alteration of A2E occurred in EtOH. On the basis of these findings, we designed processes II–IV, generated by modifications of process I, a routine method to measure bisretinoid compounds in vivo. Extra amounts of either ATR-dimer or A2E in mouse eyecups were released by processes II–IV versus process I. Efforts to clarify the effects of organic solvents on lipofuscin pigments are important because such studies can guide the handling of these fluorophores in related experiments.     

葡萄果肉和葡萄皮有机酸含量的高效液相法测定

采用Hibar column RT250mm×4.6mm,5μm色谱柱,以磷酸盐缓冲溶液(pH=2.5)为流动相,流速1mL/min,检测波长214nm,柱温30度.建立葡萄果肉和葡萄皮中富马酸、酒石酸、柠檬酸、苹果酸等有机酸的高效液相色谱分析方法.其中富马酸、酒石酸、柠檬酸和苹果酸的线性范围分别为0.1～100 mg/L、5～600 mg/L、15～1500 mg/L、10～1000 mg/L;回收率分别为119.3、89.2、99.4、101.6;检出限分别为0.000625mg/L、0.1 mg/L、0.2mg/L、0.1 mg/L.     

添加物对金线莲离体培养生长量的影响

以两个金线莲品种（Anoectochilus formosanus、A．roxburghii）为试验样本,通过培养基中添加不同的有机物及活性炭进行试验,结果表明培养基中添加适宜的有机物质能显著增加这两种金线莲培养植株的单株鲜重及干物质含量;添加活性炭也可以显著增加这两种金线莲植株的单株鲜重。     

合理运用多媒体技术辅助教学

随着科技的发展,社会的进步,计算机已步入社会的各个领域并发挥着巨大的作用。在课堂上多媒体技术辅助教学以其丰富的想象、鲜明的色彩、活泼可爱的动画形象,把学生带入积极思维、深化知识、理解重难点的情景中,同时,还将教学的重、难点融入新颖别致的娱乐形式中,使教师教得轻松,学生学得愉快。可多媒体技术毕竟只是辅助教学的一种手段,它也有其局限性,也不是万能,只有合理运用,才能发挥它的积极作用。     

Black limestone used in Lombard architecture

Black limestone samples from the quarries of Varenna (Lecco, I), Cene (Bergamo, I) and Riva di Solto (Bergamo, I) and widely used in Lombard architecture have been studied in terms of mineralogical, petrographic and chemical properties in order to provide a detailed characterisation and allow an unambiguous determination of their provenance. The inorganic and organic fractions have been separated from each other, and investigated using X-ray powder diffraction, atomic absorption, Hg-porosimetry, high performance liquid chromatography, gas chromatography, nuclear magnetic resonance and Fourier transform infrared spectroscopy. The occurrence of specific mineral phases, some binary chemical patterns (Fe/Mn, Zn/Sr, Zn/Co and Na/Cd) and the carbon chain relative molecular masses has proven to be useful markers to characterise unequivocally the materials studied.     

退耕还湖后菜子湖湿地土壤剖面有机碳分布变化

退耕还湖是我国长江中下游地区湿地生态恢复的重要举措,土壤有机碳是评价湿地生态功能恢复的重要组成部分。本文选取菜子湖区不同退耕年限(2、5、8、10、20a)和退耕后不同植被群落(苔草、芦苇和酸模)湿地土壤为研究对象,揭示退耕还湖后退耕年限和植被类型对湿地土壤有机碳恢复的影响。结果表明:随退耕年限的增加,湿地土壤有机碳含量逐渐增加,但土壤有机碳密度随退耕年限增加呈"升高―降低―升高"的趋势,总体比油菜地高出61.5%~82.3%;不同植被类型下土壤剖面(0~55 cm)有机碳含量表现为:芦苇(8.90g/kg)苔草(8.84g/kg)酸模(5.84g/kg),芦苇土壤剖面有机碳含量随土层深度增加而变化幅度小于苔草和酸模;不同植被类型下土壤剖面(0~55 cm)有机碳密度呈现出芦苇(7.92 kg/m2)苔草(7.42 kg/m2)酸模(5.01 kg/m2)。结果分析表明退耕还湖后菜子湖湿地植被恢复和理化性质变化促进土壤有机碳含量及其密度变化,而苔草、芦苇和酸模土壤剖面土壤有机碳恢复不一致,芦苇对土壤剖面有机碳密度提升能力最强。