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Search Results: 1 - 10 of 180576 matches for " 陈三雄 "
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硅酸及其盐的研究xx聚硅酸溶液中的酸强度与分子结构的关系
毛延?,王国,,戴安邦?
无机化学学报 , 1987,
Abstract: 本文利用无机酸系列的酸强度(pka值)与羟基上氧原子的亲电子超离域度s0(e)成线性关系的规律性,找出聚硅酸系列的相应线性方程为:pka=-90.28+11.35s0(e)并由此推测低聚硅酸溶液中可能存在的硅酸结构:在三聚硅酸溶液中主要存在着六元平面环的三聚体;在四聚硅酸中则主要存在着三种环状的四聚体.
露天开采矿区土壤重金属污染状况评价
,谢莉,家栋,张金池*,廖建文
南京林业大学学报(自然科学版) , 2012, DOI: 10.3969/j.jssn.1000-2006.2012.03.013
Abstract: 对广东大宝山矿区土壤cd、pb、zn、cu含量进行了测试与分析,采用单因子污染指数法和内梅罗综合指数法对土壤重金属污染状况进行了评价。结果表明,大宝山矿区土壤中重金属含量差异较大,但都要明显高于广东省土壤重金属背景值。27个土壤样品中,cd和cu的单因子污染指数都大于1,超标率达100%,有21个土壤样品的pb和zn的单因子污染指数大于1,超标率为77.8%。从综合污染指数来看,27个土壤样品的综合污染指数在5.74~157.23之间,所有样品的综合污染指数都要大于3,表明矿区土壤已受到重金属严重污染,其中以cd、cu的污染最为严重。
浙江安吉主要林地类型土壤渗透性
刘道平,,张金池,谢莉,姜姜
应用生态学报 , 2007,
Abstract: 对浙江安吉县龙王山地区主要植被类型的土壤渗透性进行了研究.结果表明,不同土地利用类型的土壤渗透性存在很大差别.根据土壤渗透能力可将8种植被类型分为4类:第1类,落叶阔叶林,土壤渗透能力极强;第2类,草地、松林、灌木林和茶园,土壤渗透能力强;第3类,毛竹林和常绿阔叶林,土壤渗透较强;第4类,裸露地,土壤较紧实,土壤结构较差,土壤通透性不佳,渗透能力弱.经主分量分析,得到表征渗透性能综合参数α和表征根系特征的综合参数β,构建了回归方程:α=0.1708eβ-0.3122.土壤理化性质、植被根系显著地影响土壤渗透性能.植被根系提高土壤入渗性能的实质是≤1mm细根能有效地改善土壤性状.
利用RNA-seq技术分析淹水胁迫下转BnERF拟南芥差异表达基因
吕艳艳,, , 张唯, 戚存扣
植物学报 , 2015, DOI: 10.3724/SP.J.1259.2015.00321
Abstract: ?为探究淹水胁迫下BnERF调节的耐淹防御相关途径,应用RNA-seq技术,对淹水6小时后的拟南芥(Arabidopsisthaliana)野生型(WT)和转BnERF株系(E33)幼苗进行基因表达分析。结果表明,淹水3天后,E33表现出较强的耐淹性,地上部生长状况和根系发育均明显强于野生型。E33幼苗未淹水处理时相对于野生型单独上调的基因有9个,4个为膜结合蛋白,其中2个参与MAPK级联途径,其它5个参与氧化胁迫及水分调节途径;与未淹水野生型相比,无论是未淹水处理还是淹水6小时后的E33幼苗中缺氧响应、抗氧化防护及细胞、器官发育相关基因的表达量均上调。另外,淹水6小时后E33的差异基因并未完全覆盖淹水6小时后野生型的差异基因;E33幼苗中缺氧响应、氧化胁迫响应、能量的产生与转变、乙醇代谢途径中的基因以及乙烯响应因子基因的表达量都明显高于野生型。上述结果表明,BnERF直接或间接调节植物的淹水胁迫相关生理代谢途径,参与淹水胁迫的防御过程。
甘蓝型油菜雌性不育突变体FS-M1乳突细胞的细胞学观察
李春宏,, 新军, 戚存扣
植物学报 , 2012, DOI: 10.3724/SP.J.1259.2012.00036
Abstract: ?雌性不育突变体FS-M1是从甘蓝型油菜(Brassicanapus)品种宁油10号中发现的。为了从细胞学角度研究FS-M1的雌性不育机理,利用荧光显微镜、扫描和透射电子显微镜观察分析了FS-M1柱头乳突细胞的授粉行为和超微结构。结果表明:花粉粒能在FS-M1乳突细胞上附着和萌发形成花粉管,但花粉管无法穿越柱头乳突细胞;开花后的FS-M1乳突细胞迅速衰退而呈干瘪萎蔫状,在衰退过程中,FS-M1柱头乳突细胞的细胞器数量减少,细胞液泡化明显,高尔基体、内质网和线粒体等一些细胞器结构被逐渐破坏。因此,推测FS-M1的雌性不育性是由于柱头乳突细胞发育异常造成的。
敦煌西湖湿地生态系统现状、退化原因及综合修复对策
戚登臣,文业,张继强,,袁海峰
草业学报 , 2010,
Abstract: 通过对敦煌西湖湿地生态系统现状的实地调查和现有资料的分析,结果表明由于自然环境、人文和社会等复杂因素的多重影响,湿地生态系统日益恶化。在对湿地生态系统退化原因深入分析与研究的基础上,从控制人口数量、提高人口素质,调整产业结构、建设发展节水型城市,完善湿地生态系统科研监测体系,强化环境法规和相关政策建设等措施方面出发,提出了修复湿地生态系统的对策,实现敦煌西湖湿地生态系统可持续发展。
凸形钢箱拱肋截面荷载试验和有限元分析
吴庆,陈康明,宝春,中村?
交通运输工程学报 , 2012,
Abstract: 以宁波市东外环甬江大桥凸形钢箱拱肋截面为对象,应用预应力钢绞线的自平衡加载方式进行了14的拱肋节段缩尺模型荷载试验,采用板壳单元和实体单元建立了有限元模型,进行了非线性分析,研究了考虑初始缺陷和局部屈曲的凸形钢箱拱肋截面的受力特性、实际承载能力和局部失稳机理。研究结果表明各测点实测应力与截面平均应力较接近,根据测点实测应力与截面平均应力之间的关系可将凸形截面分成4类测点;有限元所得应力与实测应力趋势相同,数值相近;凸形钢箱拱肋截面的强度折减系数为0.94~0.98;纵向加劲肋和横隔板结构能有效防止凸形截面加劲板件的局部屈曲;在极限荷载作用下节段出现了凹凸的波节,由于各加劲板出平面位移过大而导致无法继续承载。
甘蔗宿根矮化病研究进展
徐景升?,许莉萍?,阙友,基?,如凯?
热带亚热带植物学报 , 2008, DOI: 10.3969/j.issn.1005-3395.2008.2.018
Abstract: 综述了近年来甘蔗宿根矮化病的检测、传播、防治及其致病菌leifsoniaxylisubsp.xyli的分类归属和致病机理等方面的研究进展,并探讨了研究策略。
结合面底部设开孔钢板的铰接空心板力学性能
Mechanical property of hinged voided slab with perforated steel plates at bottom of junction surface

吴庆,黄宛昆,宝春,陈康明,中村?}
- , 2017,
Abstract: 针对现有铰接空心板桥的薄弱部位――铰缝,提出一种在空心板与铰缝结合面底部设开孔钢板的空心板构造,通过开孔钢板改变结合面裂缝开展的路径,达到延缓空心板与铰缝结合面通缝形成的目的,并进行了8 m跨径的铰接空心板足尺模型试验。在试验和非线性有限元分析的基础上,与结合面底部带钢筋的铰接空心板试验进行了对比。分析结果表明:当试验荷载为100 kN(1.43倍车辆荷载)时,空心板跨中出现横向裂缝,空心板梁整体刚度降低,空心板受力状态由弹性阶段进入弹塑性阶段; 在试验荷载加至300 kN(4.29倍车辆荷载)为止的整个加载过程,未观察到空心板与铰缝结合面底部出现裂缝; 当结合面底部设门式钢筋时,裂缝沿结合面从下向上扩展,最终形成通缝,然而,当结合面底部设开孔钢板后,铰缝沿结合面开裂至开孔钢板下方后,裂缝的扩展需要绕过开孔钢板,使得开孔钢板下方铰缝混凝土开裂后,再沿开孔钢板上方结合面向上扩展,形成通缝; 铰缝开裂荷载由结合面设置钢筋的69 kN(0.99倍车辆荷载)提高到314 kN(4.49倍车辆荷载),提高了3.50倍; 铰缝形成通缝时的荷载由结合面设置钢筋的199 kN(2.84倍车辆荷载)提高到489 kN(6.99倍车辆荷载),提高了4.51倍。可见,在结合面底部设开孔钢板后,铰缝裂缝开展路径发生变化,延缓了空心板与铰缝结合面的开裂。
In view of the weakest point of hinged voided slab bridge, namely hinged joint, a kind of voided slab with perforated steel plates at the bottom of hinged joint-to-voided slab interface was put forward, the perforated steel plates were used to change the crack propagating path at the interface, so as to delay the formation of through crack at the hinged joint-to-voided slab interface, and the full-scale model experiment on 8 m-span hinged voided slab was conducted. Based on the experiment and nonlinear finite element(FE)analysis, the result was compared with the experiment result of hinged voided slab with gate-type steel bars at the bottom of interface. Analysis result shows that when the experiment load is 100 kN(1.43 times vehicle load),the lateral crack emerges in the mid-span of voided slab, the integral rigidity of voided slab decreases, and the stress state of voided slab comes into elastoplastic stage from elastic stage. The test load is applied up to 300 kN(4.29 times vehicle load), no crack is detected at the bottom of hinged joint-to-voided slab interface during the entire loading process. For hinged voided slab with gate-type steel bars at the bottom of hinged joint-to-voided slab interface, the crack extends from the bottom to the top along the interface, and then forms a through crack. However, for the hinged joint-to-voided slab interface with perforated steel plates, after the crack propagates along the interface to the bottom of perforated steel plate, the expansion of the crack needs to bypass the perforated steel plate, so that the joint concrete below the perforated steel plate cracks, and then the crack expands upward along the junction surface above the perforated steel plate until the formation of through crack. The joint cracking load increases from 69 kN(0.99 times vehicle load)for the interface with gate-type steel bars to 314 kN(4.49 times vehicle load), and increases by 3.50 times. The through-crack-formation load increases from 199 kN(2.84 times vehicle
Anatomy of Papilla Cells of a Female Sterile Mutant FS-M1 in Brassica napus
甘蓝型油菜雌性不育突变体FS-M1乳突细胞的细胞学观察

Chunhong Li,Sanxiong Fu,Xinjun Chen,Cunkou Qi,
李春宏
,,新军,戚存扣

植物学报 , 2012,
Abstract: The female sterile mutant FS-M1 was isolated from spontaneous mutation of Brassica napus ‘Ningyou10’. To understand the cellular mechanism of female sterility, we investigated the pollination response and ultrastructure of FS-M1 papilla cells by fluorescence microscope, scanning electron and transmission electron microscopy. Pollen grains could adhere to and germinate to produce pollen tubes on FS-M1 papilla cells, but the pollen tubes could not penetrate into papilla cells. FS-M1 papilla cells became withered and degenerated quickly after flowering. During the degeneration, the number of organelles was significantly decreased; vacuolization was obvious; some organelles such as dictyosome, endoplasmic reticulum, and mitochondria gradually became misshapen and degenerated. Therefore, female sterility in FS-M1 may have resulted from defects in papilla cells.
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