平潭大屿岛上台湾相思长势的时空差异性

为了探讨台湾相思群落生长发育与气候特征的关系,选用11个位于大屿靠海一侧不同地点的台湾相思群落研究对象。通过2016年4—12月对台湾相思标记枝条的生长状况进行长期监测。观测结果表明:11个样点受盐害叶片占比为1.16%~51.48%,受虫害叶片占比为30.27%~59.78%。植株大多受到盐害与虫害的干扰,花数量和花蕾数量处于一个较低的水平。由植物生长状况与气候特征的相关性结果可知,风向和风力随月份变化而变化,12月风力最高达5.93m/s。月份和风向与受盐害叶片占比、受虫害叶片占比均呈现极显著相关性。在开展海岛植被生态修复时,需要注重冬季养护、病虫害防治和筛选抗风、耐盐雾的海岛适生物种。国家海洋局海洋公益性行业科研专项“海岛植物物种多样性保护及生态优化技术研究与应用”(201505009-5

基于乡村核心—边界理念的城郊渔村更新策略探究——以厦门市欧厝村更新规划为例

乡村振兴政策的提出强化了乡村规划的引导作用,为乡村建设和发展指明了方向。然而,尽管当前对于乡村规划实践的关注较多,但针对乡村规划理论的探索较少,导致乡村规划未能达到振兴乡村的目的,乡村规划更多地沦为一种市场资本单向往乡村渗透的扩张工具。本文将核心—边缘理论引入乡村规划理念的探索,提出强化核心、开放边界的乡村核心—边界理念,使乡村在保留特质的基础上适应时代发展。在实证研究方面,本文以厦门市欧厝村为例,将理论与实际案例相结合,在分析作业方式、文化认同、聚落形态三方面凸显的问题的基础上,以乡村核心—边界理念为指导,从产业、文化与空间三方面提出较为系统的振兴策略,为类似的村落规划与发展提供借鉴

Isolation of Embryo Sac Cells of Lettuce(Lactuca sativa)

用酶解和解剖方法分离了莴苣的卵细胞,助细胞,中央细胞和合子。莴苣子房先在酶液中酶解40~50MIn,然后在不含酶的分离液中用解剖针解剖子房。在解剖出的胚囊中,可看到卵细胞,两个助细胞和中央细胞的轮廓。将胚囊的合点端切破,轻轻挤压胚囊的珠孔端,四个细胞即可逸出。在最佳条件下,90MIn可从40个子房中分离出29个胚囊,进一步从中分离出11个卵细胞。分离出的胚囊细胞用显微操作仪收集备用。莴苣卵细胞的成功分离为进行离体受精探索创造了条件。Viable egg cells,synergids,central cells and zygotes of lettuce (Lactuca sativa L.) were isolated using enzymatic digestion and mechanical dissection.The ovaries were digested in enzymatic solution for 40-50 min,and then transported into the isolation solution without enzymes to dissect.In the dissected embryo sacs,the outline of an egg cell,two synergids and a central cell could be observed.When dissected embryo sacs were sliced from the chalazal end,four cells could be released by gently pushing its micropylar end.In optimal condition,29 embryo sacs and 11 egg cells could be isolated from 40 ovaries during 90 min.The isolated egg cells could be collected using micromanipulator for preparation of molecular biology of egg cell of lettuce.The isolation of egg cell of lettuce will make a great chance for in vitro fertilization in a dicot plant.国家自然科学基金(30970275

聚碳硅烷纤维氧化交联机理的研究

对聚碳硅烷(PCS)原丝在不同氧化交联温度区间生成的逸出产物进行红外、核磁和GC-MAS分析,并结合交联丝的红外分析,推测氧化交联的机理。结果表明,PCS的氧化交联主要是其Si—H氧化生成Si—OH,后者进而彼此缩合生成Si—O—Si交联结构;氧化交联温度高于150℃时,其部分Si—CH3也开始氧化生成Si—OH并进而交联;同时,在氧化交联过程还发生PCS侧链的热裂解,所形成小分子也通过Si—OH彼此结合,形成较大分子,且其分子量随交联温度的提高而提高。因此,要及时排除氧化交联过程废气,以免逸出产物黏附在纤维表面而导致粘结

固/液态聚碳硅烷共混制备碳化硅纤维的研究

以超支化液态聚碳硅烷(LPCS)与固态聚碳硅烷(纯PCS)的共混物作先驱体,熔融纺丝;所得原丝再在热空气气氛中氧化交联,在高温氮气气氛中热裂解,得到碳化硅纤维。研究表明,15%(质量分数)LPCS的加入,可使纯PCS先驱体的纺丝温度,从285℃降低到225℃;纺丝性能和纤维表面质量明显提高;还可以提高氧化交联的效率,降低交联温度,从而减少纤维部分融并、粘结的弊端;虽然纤维的室温力学强度有所降低,但抗氧化性能提高,1400℃氧化交联后,力学性能几乎不变;而纯PCS的力学性能却降为原来的50%

含氟聚硅氧烷的结构与性能研究

以含氢硅油、丙烯酸全氟己基乙基酯(APHEE)为原料,氯铂酸为催化剂,采用硅氢加成合成了含氟聚硅氧烷.通过红外光谱仪、光学接触角测量仪、差式扫描量热仪对产物结构进行表征分析,探讨了不同组分比例对产物性能的影响,并研究了不同固化剂对产物固化性能的影响及不同阻聚剂对产物储存稳定性的影响.结果表明:APHEE组分比例越大,含氟聚硅氧烷的憎水憎油性能越好.异辛酸铅的固化活性最大,添加N,N-二甲基甲酰胺的产物储存稳定性最好

Diatom assemblages in surface sediments from the South China Sea as environmental indicators

We studied diatom distribution from 62 samples from the uppermost 1 cm of sediment in the South China Sea (SCS), using grabs or box corers in three cruises between 2001-2007. Fifty six genera, 256 species and their varieties were identified. Dominating species included Coscinodiscus africanus, Coscinodiscus nodulifer, Cyclotella stylorum, Hemidiscus cuneiformis, Melosira sulcata, Nitzschia marina, Roperia tesselata, Thalassionema nitzschioides, Thalassiosira excentrica, and Thalassiothrix longissima. Most surface sediments in the SCS were rich in diatoms, except for a few coarse samples. Average diatom abundance in the study area was 104 607 valve/g. In terms of the abundance, ecology, and spatial distribution, seven diatom zones (Zones 1-7) were recognized. Zone 1 (northern continental shelf) is affected by warm currents, SCS northern branch of the Kuroshio, and northern coastal currents; Zone 2 (northwestern continental shelf) is affected by intense coastal currents; Zone 3 (Xisha Islands sea area) is a bat..

First record of genera Rutilaria and Trigonium(Bacillariophyta) and 11 diatom taxa(species and varieties) in South China Sea

Diatom taxa in samples collected from the uppermost 1-cm sediment of the South China Sea(SCS) during cruises in 2000,2001,and 2007 were investigated.Among them,two genera,Rutilaria and Trigonium,and 11 marine taxa(species and varieties) were described for the first time in China.The 11 taxa,Rutilaria radiata,Asterolampra grevillei,Biddulphia turrigera,Cocconeis cyclophora var.decora,Cocconeis ocellata,Dictyoneis marginata,Entogonia davyana,Tryblionella campechiana,Plagiogramma kinkeri,Plagiogramma nankoorense and Trigonium cf.contumax,were mainly extant species,although Rutilaria radiata and Entogonia davyana are fossils.Available data show that these species are mainly present in the eastern and western Pacific Ocean and the Indian Ocean.A large number of taxa newly recorded in this study were previously reported in the Philippines.The presence of these taxa in both locations is likely a result of seawater exchange in the SCS through the Bashi Channel.Taxonomic descriptions,habitats,and distributions of each..

基于核磁共振氢谱技术研究电针“内关”穴对心肌缺血再灌注损伤大鼠血清及心肌组织代谢物的影响

目的:基于核磁共振氢谱(1 H NMR)研究电针\"内关\"穴对心肌缺血再灌注损伤(MIRI)大鼠血清和心肌组织代谢物的影响,探讨电针\"内关\"穴对MIRI大鼠代谢模式的影响。方法:30只SD雄性大鼠随机分为对照组、模型组、电针组。对照组:不予电针,仅用鼠板束缚大鼠,每次20min,每日1次,持续7d;模型组予心肌缺血再灌注造模:至第7天后结扎冠状动脉左前降支40 min后恢复血流60 min;电针组(频率10Hz/50Hz,脉冲宽度0.5ms,强度1mA):每日电针双侧\"内关\"穴1次,时间20min,持续7d,于第7天电针后造模。造模结束后,收集3组大鼠的血清和心肌组织。利用1 H NMR进行代谢物检测并利用多元统计方法主成分分析(PCA)、正交偏最小二乘分析(OPLS-DA)进行模式识别。结果:与对照组相比,模型组大鼠血清的亮氨酸、异亮氨酸、缬氨酸、3-羟基丁酸、乳酸、丙氨酸、赖氨酸、醋酸盐、N-乙酰糖蛋白、丙酮、乙酰乙酸、琥珀酸、谷氨酰胺、多不饱和脂肪酸、肌酸、甘油磷酸胆碱、甘氨酸均浓度下降,低密度脂蛋白/极低密度脂蛋白、葡萄糖浓度上升;其中除丙酮、乙酰乙酸和多不饱和脂肪酸外,低密度脂蛋白/极低密度脂蛋白在电针后下降到接近对照组水平,其它代谢物浓度均在电针后上升到接近对照组水平,电针组大鼠血清的代谢模式更接近对照组。与对照组相比,模型组大鼠心肌组织的乳酸、丙氨酸、赖氨酸、谷氨酸、谷氨酰胺、天冬氨酸、甘油磷酸胆碱、肌酸、牛磺酸、甘氨酸、苏氨酸、腺苷一磷酸、烟酰胺腺嘌呤二核苷酸浓度下降,葡萄糖浓度明显上升;其中肌酸、甘油磷酸胆碱、烟酰胺腺嘌呤二核苷酸浓度在电针后上升,葡萄糖浓度在电针后下降;此外,电针组大鼠心肌组织苏氨酸、腺苷一磷酸浓度较模型组进一步下降;电针组大鼠心肌的代谢模式虽然有向对照组偏移的趋势,但与对照组差异还是较大。结论:电针\"内关\"穴可调节MIRI大鼠糖代谢、脂肪酸代谢、氨基酸代谢及能量代谢,对心肌具有一定的保护作用,但其具体的代谢通路及机制需要进一步研究。国家自然科学基金面上项目(No.81574080);;湖南省中医药管理局课题(No.201521);;湖南省高校创新平台开放基金项目(No.15k093