高校社科类课程的自主学习实践

自主学习是适应高校学生和社科类课程的特征,以激发学生的学习积极性和提高其综合素质为目的而采取的以学生探索讲述为主、教师根据学生需要加以引导为辅的立体式教学模式。这种新模式包括引学导探、探索自学、构建讲述、归纳总结和教学评价五个阶段,在这五个阶段中,教师发挥着引导者、组织者和监督者的作用

The Role of Microorganisms in the Geochemical Iron Cycle

铁元素虽然只在地壳含量中位列第4,但却是地球上分布最广的变价金属元素之一,微生物介导的铁循环及其与生源要素碳、氮、氧和硫等耦合的氧化还原反应是微生物地球化学循环的重要驱动力.由于铁循环过程中氧化态三价铁Fe(Ⅲ)在环境p H条件下大多以不溶状态存在,因而由其参与的地球化学循环进程通常较为缓慢.研究表明,微生物在铁元素的地球化学循环过程中起着举足轻重的作用,并在该过程中参与矿物的生成与转化.近年来的最新研究发现,参与地球化学铁循环的微生物之间,微生物与矿物之间,以及矿物介导的微生物之间存在着多样的相互作用,而含铁矿物介导的微生物胞外电子传递机制是其中最受瞩目的研究热点.本文综述了微生物介导的地球..

DDEFL1的结构和功能研究进展

DDEFL1又称为ASAP3(、ACAP4或UPLC1,属于小G蛋白家族中Arfs家族的一种ArfGAP。人的肝和肺是DDEFL1表达水平较高的两个组织[1]。了解DDEFL1的结构及功能,可以为肝癌或其它癌症患者提供一种新的基因治疗方案

Microbial Degradation of Petroleum Hydrocarbons by Acinetobacter sp. BZ-15,Isolated from Contaminated Soil

本研究旨在从土壤中筛选高效石油烃降解菌株,并对其系统分类和降解特性进行研究,为石油污染的原位修复奠定基础.该研究从滨州油井溢油污染土壤样品中分离得到一株高效石油烃降解菌株BZ-15,对菌株BZ-15进行形态观察、16S r RNA基因序列分析及系统发育树分析;对该菌株的生长特性进行研究;通过GC-MS分析其对原油组分中不同碳原子饱和烃的降解特性;同时研究吐温-20对其生长及降解特性的影响;对该菌株中的烷烃羟化酶基因alk M进行了克隆.结果表明,菌株BZ-15为不动杆菌属(Acinetobacter sp.)细菌,在LB培养基中其代时为3.25 h,添加吐温-20代时为2.67 h,吐温-20..

Purification efficiency of four combinations of aquatic macrophytes on eutrophic water body in winter

通讯作者E-mail: [email protected][中文文摘]选择10种耐低温的水生植物构建4种植物组合,研究了冬季低温环境下不同水生植物组合对富营养化水体的净化效果。结果表明:组合1〔常绿水生鸢尾(Iris hexagonus Hybrid)+羊蹄(Rumex japonicus)+金叶"金钱蒲"(Acorus gramineus"Ogan")+反曲灯心草"蓝箭"(Juncus inflexus"BlueArrows")〕4种植物均能在试验富营养化水体中茂盛生长,且对TN、NOx-N、NH4-N和TP的去除率分别为47.8%、52.2%、32.4%和70.1%;组合2〔常绿水生鸢尾+羊蹄+金叶"金钱蒲"+大苞萱草(Hemerocallis middendorfii)〕4种植物也都能在试验富营养化水体中存活,并且有一定量的生长,对TN、NOx-N、NH4-N和TP的去除率分别为44.2%、58.5%、34.6%和67.8%;而未种植物的对照对TN、NOx-N、NH4-N和TP的去除率分别为40.0%、25.9%、27.3%和64.5%;组合1和2对富营养化水体有较好的净化效果。组合3和组合4中由于吊兰(Chlorophytum comosum)和三穗薹草(Carex tristachya)等植物长势较差,仅对NOx-N具有较明显去除能力,对其他指标去除效果不明显。通过这些水生植物在富营养化水体中生长特性和对营养元素的去除能力,发现冬季组合1和2的净化效果较好,是低温条件下适宜的浮床植物组合形式。[英文文摘]Ten species of low temperature-tolerant aquatic macrophytes were chosen to construct four combinations of aquatic macrophytes to study their purification efficiency on eutrophic water body in winter.In non-macrophyte treatment (CK),the removal efficiency of water total nitrogen (TN) ，nitrite nitrogen ( NOx-N) ,ammonium nitrogen (NH4-N),and total phosphorus (TP) was 40.0%,25.9%,27.3%, and 64.5%,respectively.Combination 1 (Iris hexagonus Hybrid + Rumex japonicas + Acorus gramineus“Ogan”+ Juncus inflexus“Blue Arrows”) grew luxuriantly in the test eutrophic water body,and performed best in decreasing water TN,NOx-N,NH4-N,and TP,with the removal efficiency being 47.8%,52.2%,32.4%，and 70.1%,respectively. Combination 2 ( I． hexagonus Hybrid + R． japonicas + A． gramineus “Ogan”+ Hemerocallis middendorfii) could survive and had definite growth amount in the test eutrophic water,and the removal efficiency of water TN,NOx-N,NH4-N,and TP was 44.2%,58.5%,34. 6% and 67.8%,respectively.In contrast,both the combination 3 ( R.japonicas + Lolium perenne + Chlorophytum comosum + Juncus pallidus R.Br. “Javelin”) and the combination 4 (R.japonicas + L. perenne + C.comosum + Carex tristachya) only had an obvious efficiency in removing NOx-N but less efficiency in removing TN,NH4-N,and TP,due to the poor growth of C.comosum and C.tristachya.It was suggested that combinations 1 and 2 had better purification efficiency on eutrophic water body,being the suitable combination forms of aquatic macrophytes floating-bed under low temperature in winter.国家自然科学基金项目(50809063)资

HYDROLOGICAL OBSERVATION IN AN EVERGREEN BROAD LEAVED FOREST IN THE WUYI MOUNTAINS

[中文文摘]对武夷山甜槠林成熟林水文学效应的研究结果表明：观测期间，年大气降水量2678.78ｍｍ，林内雨量2182.04ｍｍ，林冠截留量为496.74ｍｍ；林内雨中，穿透雨量2082.08ｍｍ，树干茎流99.96ｍｍ；到达甜槠林地作用面的林内雨量中，被地表枯枝落叶层截留的雨量为159.84ｍｍ，地表径流量11.6ｍｍ，地下渗流量109.32ｍｍ，其余林内雨量形成土壤含水量增量并由地表物理蒸发、根系吸收以及植物蒸腾所消耗；甜槠林地o~20０ｃｍ土层水分初渗率78.6ｍｍ·ｍｉｎ－１，稳渗率１５．５ｍｍ·ｍｉｎ－１，达到稳渗历时４５ｍｉｎ，地表枯枝落叶最大持水量5.2ｍｍ，土壤蓄水量154.0ｍｍ。与国内其它地区不同类型的森林相比较，武夷山甜槠林具有较强的水文学效能。[英文文摘]Hydrological observations were made in a 76 year old Castanopsis eyrei forest of the Wuyi Mountains.The results are as follows:(1)In the study period during 1993～1994,annual gross precipitation,net precipitation (throughfall was 208204mm and stemflow was 9996mm)and interception loss were 267878mm,218204mm and 49674mm respectively.Interception rate was 1845%.(2)Net precipitation,the part of gross precipitation appearing on the forest floor,was redistributed through different routes.The part absorbed by litter layer was an annual amount of 15984mm,and accounting for 733%.The parts as surface runoff and below ground drainage were annual amounts of 116mm and 10932mm respectively,and accounting for0.53% and 5.01%,respectively.The rest was kept in soil and then lost to the atmosphere by means of ground physical evaporation or plant transpiration as absorbed by the roots.Its amount was 190128mm,and accounting for 87.13%.(3) The initial infiltration rate and stable infiltration rate for the soil layer of 0～20cm were 786mm·min-1 and 155mm·min-1 respectively.The time needed to arrive at the stable state was 45min.Water storage capacity of soil was 15041t·hm-2.The maximum water holding capacity of litter layer was 52mm.福建省自然科学基金,武夷山自然保护区管理局资