海蚀槽发育导致的软质海崖滑塌计算与分析

对福建省平潭岛东北部软质海崖进行现场调查和量测,在约1 km的岸线上发现9处滑塌,滑塌物的堆积距离、堆积高度和滑塌物体积均随海崖高度的增大而增大.滑塌包括剪切破坏和顶部破坏两种类型,剪切破坏的破坏面几乎完全垂直,顶部破坏的破坏面呈L形.针对这两种滑塌类型,分别建立理论计算模型.结果表明:经理论计算模型得到的海蚀槽最大槽深(蚀退距离)为0.51～1.30 m;海崖稳定性随槽深的增大而降低;海崖顶部破坏的滑塌临界水深为0.22～0.61 m.     

Annealing effect on InAs islands on GaAs(0 0 1) substrates studied by scanning tunneling microscopy

Post-annealing effects on InAs islands grown on GaAs(0 0 1) surfaces have been investigated by scanning tunneling microscopy (STM) connected to molecular beam epitaxy (MBE). It is found that for islands grown by 1.6 ML InAs deposition at 450 °C, post-annealing at 450 °C in an As₄ atmosphere causes dissolving of the InAs islands. In contrast, for larger islands obtained by 2.0 ML InAs deposition at 450 °C, the post-annealing leads to coarsening of the islands. The result can be explained in terms of a critical nucleus in heterogeneous nucleation.     

苦丁的经济价值与海南岛发展苦丁的可行性分析

苦丁即冬青科的大叶冬青，为高达２０ｍ的阔叶大乔木，其老叶嫩芽均可茶药两用，经济价值极高，本文介绍了苦丁的历史沿革，苦丁的药用功效和保健作用以及苦丁的植物学特征，并根据苦丁的生长习性和海南岛的各种自然条件分析了海南岛发展苦丁种植业的可行性，指出了几个应注意的问题．     

Cyclophanes—VII : Conformations of [2.2](2,5)furanoparacyclophane,[2.2](2,5)furano(1,4)naphthalenophane and [2.2](2,5)furano(9,10)anthracenophane. perpendicularity of aromatic moieties

Variable temperature NMR spectroscopy was used to study the conformational behavior of [2.2](2,5)furanoparacyclophane (1), [2.2](2,5)furano(1,4)naphthalenophane (2) and [2.2](2,5)furano(9,10)anthracenophane (3). While the method was useful in studying 1, it was not adequate for 2 and 3. Variable temperature UV absorption and fluorescence emission studies provided information on the conformations of 2 and 3. The UV absorption and emission spectra of 1 were blue-shifted relative to their ambient temperature spectra. Those of 2 were not shifted at all and those for 3 were red-shifted. The data is consistent with an anti-orientation of the aromatic rings in 2 both at ambient and low temperture. The aromatic rings in 3 are perpendicular to one another at low temperature and probably at room temperature as well. Exiplex bands were absent in the room temperature emission spectra of 1, 2 and 3 as well as the low temperature spectra of 2 and 3. An exciplex band was observed in the low temperature emission spectrum of 1.     

GC/MS profiling,in vitro anti-leptospiral and haemolytic activities of Boesenbergia rotunda (L.) Mansf. used as a medicinal plant by Nicobarese of Andaman and Nicobar Islands

Leaves of the plant Boesenbergia rotunda are used by the Nicobarese tribe of Andaman and Nicobar Islands, India, to prepare traditional medicine for treating fever, headache and body ache. In the present investigation, methanol fraction of these leaves were analysed by GC/MS that revealed the presence of 25 compounds. The anti-leptospiral activity of methanol crude extract was determined by both microdilution and macrodilution methods. The MICs of the extract were tested against 24 pathogenic leptospiral strains and ranged between 62.5–125 μg/mL in both microdilution and macrodilution. The range of MBCs was 250 and 500 μg/mL in macrodilution and microdilution respectively. The crude extract was subjected to cytotoxic studies and found to have negligible or no haemolytic activity, exhibiting IC₅₀ values of greater than 4 mg/mL. Further in vivo studies are needed to investigate the pharmacological and toxicological properties of Boesenbergia rotunda, before it can be considered as a new anti-leptospiral agent.     

舟山潮流能示范工程水轮机组选址与阵列优化

通过OpenTidalFarm开源代码建立浙江舟山潮流能示范工程海域的水动力数值模型,结合实测数据对其进行验证。模型中通过增加局部底摩擦的方法概化了潮流能水轮机对水动力环境的影响,利用迭代算法快速优化水轮机阵列。结果表明,阵列优化后的舟山潮流能示范工程水轮机组提取的潮流能比其初始布局时提高了15.2%,说明水轮机布局对潮流能提取量有很大的影响。     

Production of optically pure d-lactic acid by Nannochlorum sp. 26A4

Microalgae were screened from seawater for greenhouse gas CO₂ fixation and d-lactic acid production by self-fermentation and tested for their growth rate, starch content, and conversion rate from starch into d-lactic acid. More than 300 strains were isolated, and some of them were found to have suitable properties for this purpose. One of the best strains, Nannochlorum, sp. 26A4, which was isolated from Sakito Island, had a starch content of 40% (dry weight), and a conversion rate from consumed starch into d-lactic acid of 70% in the dark under anaerobic conditions. The produced d-lactic acid showed a high optical purity compared with the conventional one. The proposed new d-lactic acid production system using Nannochlorum sp. 26A4 should also be an effective technology for greenhouse gas CO₂ fixation and/or conversion into industrial raw materials.     

海南生态环境现状评价与变化分析

遥感和地理信息系统技术的发展为研究区域生态环境变化提供了有效手段,以1987年海南植被类型分布图、1988年河南省土壤侵蚀图和1998年的TM遥感资料为信息源,综合GIS参与监督分类及目视判读的方法,以GIS为工具提取生态因子信息并按景观生态类型进行了评价和分析对比,并以海南西部部分地区为例,进行了海南西部地区土地沙化／土地退化研究,表明海南生态环境质量由中部向外依次降低,森林生态环境好,部分园林和农田生态环境质量较差,土地沙化／土地退化在向着恢复逆转的方向发展。