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Search Results: 1 - 10 of 90496 matches for " 龙黎红 "
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崩滑灾害位移曲线典型类型及其形成机制
曹洋兵, 晏鄂川, , 王琪
地质科技情报 , 2014,
Abstract: 通过整理分析大量的崩塌滑坡位移-时间曲线发现,孕育期地表位移时序曲线典型类型主要有稳定型、渐进型和突发型3类,其中稳定型分为蠕滑稳定型和波动稳定型2亚类,渐进型分为三阶段渐进型、振荡渐进型和多台阶渐进型3亚类;孕育期地下位移时序曲线典型类型主要有单滑裂面型和多滑裂面型2类,并发现滑带处位移时序曲线与地表的具有相似的演化规律;从孕育、成灾到形成崩滑堆积体的全过程位移时序曲线典型类型只有生长型一类。基于崩塌滑坡滑裂面上锁固段数量、位置和强度,结合变形状态空间区划效应及外界因素对锁固段的加卸载特征,对孕育期地表典型位移时序曲线形成机制进行了探讨。
The ecological sensitivity evaluation in Yellow River Delta National Natural Reserve
黄河三角洲国家级自然保护区生态敏感性评价

宋晓,李晓文,白军,,郑钰,焦松松
生态学报 , 2009,
Abstract: Based on the grid analysis of GIS, with the combination of habitat suitability assessment and human interference analysis, the ecological sensitivity evaluation model was established. Firstly, the endangered water-birds in Yellow River Delta NNR were prioritized as a database according to IUCN 2007 Red List, and the habitat preference was identified and evaluated through literatures review and field survey. By establishing GIS-based 200m×200m girding system, the existing habitat was evaluated on landscape-level, and a Comprehensive Habitat Suitability Index (CHSI) was developed and calculated by habitat suitability assessment model. Based on CHSI, the habitat suitability was evaluated and graded. Secondly, the typical species Cranes was selected from the established database as indicator species and the habitat loss rate of indicator species associated with anthropogenic interference (roads and oil wells) was also analyzed on 200m×200m grids by GIS. Finally, on the basis of results from habitat suitability evaluation and human interference analysis, ecological sensitivity analysis was conducted by Overlying Operation. The results showed that: the ecological sensitivity of study area was quite high on the whole; the overall distribution was high in the coastal region low in the inland region, ranking in five classes of extreme sensitivity, fair sensitivity, moderate sensitivity, sensitivity and no sensitivity. In the area, extreme sensitivity zone and fair sensitivity zone accounted for about 55.74% in all, moderate sensitivity zone was about 16.2%, sensitivity zone and no sensitivity zone accounted for 22.81% and 5.19%, respectively. In addition, compared with existing function zones of reserve and combined with the research results, related suggestions for adjusting function zones were proposed aiming at enhancing the conservation efficacy of critical habitats.
美国豆科牧草在黄土高塬沟壑区引种试验研究
闫晓玲,杨莉,,慕志,张丽娟
人民黄河 , 2006,
Abstract: ?对美国豆科牧草多年生香豌豆、犹他甜苕子、美丽鹧鸪豆在黄土高塬沟壑区的适应性及种子处理、育苗、栽培技术进行了试验研究,结果表明:多年生香豌豆的适应性强,具有抗旱、抗盐碱、生长迅速、产草量大、营养价值高等优点,可在本区大面积推广;美丽鹧鸪豆、犹他甜苕子在黄土高塬沟壑区适应性较差,难以推广种植.
超声波提取脐橙皮黄酮类化合物的工艺研究
黄运,高兴强,伟伟,中儿
食品科学 , 2009,
Abstract: ?采用超声波提取,通过l9(34)正交试验设计,探讨了提取条件对脐橙皮中黄酮提取率的影响。结果表明,脐橙皮中黄酮类化合物提取最佳的工艺条件为超声波功率为125w、乙醇体积分数为60%、料液比为1:35、超声波作用时间60min,黄酮类化合物的提取率为49.3mg/g。
黄河三角洲国家级自然保护区生态敏感性评价
宋晓,李晓文*?,白军,聪?,郑钰?,焦松松?
生态学报 , 2009,
Abstract: 基于gis下的网格分析,建立了结合生境适宜性评价和人为干扰特征分析的生态敏感性评价模型。首先建立被列为世界自然保护联盟(iucn)红色名录濒危等级(截止到2007)的水禽数据库,并结合相关文献及实地调查,识别评价所选物种的生境需求。再基于gis下的200m×200m网格系统,依据生境适宜性评价模型,从景观水平上进行生境现状评价,提出“综合生境适宜性的概念”并计算综合生境适宜性指数,再根据综合指数进行生境适宜性评价;然后从已建立的数据库中选取典型物种鹤类作为指示种,同样基于200m×200m的网格,借助gis技术分析研究区内的人为干扰因子(道路和油井)造成的生境损失;最后在以上的研究基础上,将生境适宜性评价和人为干扰特征分析的结果叠加运算进行生态敏感性分析。结果表明:研究区生态敏感性整体上较高,总的分布规律是靠近沿海的区域敏感性较高,内陆区域的敏感性较低;并按生态敏感度的高低,将研究区划分为极敏感区、敏感区、较敏感区、一般敏感区和不敏感区5个等级,其中极敏感区和敏感区面积共占研究区面积的55.74%,较敏感区约占16.26%,一般敏感区和不敏感区各占22.81%和5.19%。此外,为更有效地保护重要生境,对照保护区现有的功能分区,并结合评价结果,讨论了功能分区调整的相关建议。
铁纳米粒子/碳纤维/环氧树脂基复合材料的制备和吸波性能
王永辉,赛义德,黄昊,薛方,,董星
材料研究学报 , 2015,
Abstract: ?用直流电弧等离子体法制备fe纳米粒子,用作微波吸收剂。用γ-氨丙基三乙氧基硅烷(kh550)对fe纳米粒子的表面改性,然后按不同比例与环氧树脂均匀混合。在混合物中添加碳纤维后制备出fe纳米粒子/碳纤维/环氧树脂基功能/结构一体化吸波复合材料,研究了吸收剂的添加量和浓度梯度、碳纤维以及平板结构等因素对其在2-18ghz范围内吸波性能的影响。结果表明,碳纤维促进了结构体内电磁波的多重反射与吸收,在低频段出现反射损耗峰并提高吸波性能;随着fe纳米粒子含量的提高吸波能力逐渐增强,吸收峰向低频移动;在环氧树脂的固化过程重力导致fe纳米粒子浓度呈梯度分布,使平板状复合材料正、反两面的吸波性能出现差异,吸收剂浓度的梯度分布有利于电磁波的进入和吸收。
基于最大后验概率的单视频时间超分辨率重建算法
,廖宇,陈为,,李军,向军
计算机应用 , 2014,
Abstract: ?任何视频摄像设备均具有一定的时间分辨率限制,时间分辨率不足会造成视频中存在运动模糊和运动混叠现象。针对这一问题常用的解决方法是空间去模糊和时间插值,然而这些方法无法从根本上解决问题。提出一种基于最大后验概率(map)的单视频时间超分辨率重建方法,该方法通过重建约束来确定条件概率模型,然后利用视频自身具有的时间自相似先验信息得到先验信息模型,最后求得基于最大后验概率的估计值,即通过对单个低时间分辨率视频重建来得到高时间分辨率视频,从而有效解决由于相机曝光时间过长所造成的“运动模糊”和相机帧率不足引起的“运动混叠”现象。通过理论分析与实验,证明了所提方法的有效性。
基于松动区理论的高速铁路浅埋隧道初支变形处理方法
The Initial Support Deformation Treatment of High Speed Railway Shallow Buried Tunnel Based on Excavation Disturbed Zone Theory
 [PDF]

, 王唤, 邸成
Hans Journal of Civil Engineering (HJCE) , 2015, DOI: 10.12677/HJCE.2015.41004
Abstract:
高速铁路浅埋隧道开挖断面较大,围岩强度低,隧道开挖后难以形成承载拱,常引起地表塌陷、初期支护变形过大、掉块、开裂等现象。当初期支护变形侵入二次衬砌限界后,为确保后续施工正常进行以及二次衬砌质量,需对这一部分初期支护进行拆换,并采取相应的加强措施。为确定隧道开挖对围岩的扰动作用,以某高速铁路浅埋隧道初支变形为例,进行无支护开挖条件下围岩应力的数值模拟,利用开挖外轮廓径向分布的特定临界破坏点的集合求出各施工阶段松动区范围。以此为依据,结合相似工程处理措施,最终确定了后续开挖过程中的初期支护型式,后续施工的各项监测指标均满足设计要求。工程实践证明,考虑了一定安全储备的松动区分析方法是可行且有效的。
Featured by larger excavated section and lower strength of surrounding rock, it’s not easy for HSR (High Speed Railway) shallow buried tunnel to form load-bearing arch after excavation, thus always prone to surface subsidence, and resulting in serious deformation, chipping and cracking of the ini-tial support. To ensure normal subsequent construction and the quality of secondary lining, the de-formed part of the initial support intruding into the secondary lining needs to be replaced and rein-forced. In order to determine the impact of tunnel excavation on surrounding rock, taking the initial support deformation of a certain HSR shallow buried tunnel for example, this paper carries out stress numerical simulation of surrounding rock in the case of support-free excavation, and finally works out the scope of disturbed zone in each construction stage, by determining the set of specific critical failure points radially distributed along the outer excavation contour. On this basis, combin-ing the treatment measures of similar projects, the initial support modal suitable for subsequent excavation can be determined, and all the monitoring indicators during subsequent construction can meet the design requirements. Engineering practices has proved that the disturbed zone analysis method considering certain emergency capacity is effective and feasible.
Inhibitory Activity Screening of Endophytic Fungi from Polygala tenuifolia Willd
远志内生真菌抑菌活性筛选

WANG Yu-Jun,CUI Jin-Long,SU Hong,FAN Li,
王玉君
,崔晋,,

微生物学通报 , 2009,
Abstract: 从10月份采集的栽培和野生远志(Polygala tenuifolia Willd) 的根、茎、叶中分离内生真菌85株, 其中自栽培远志分离33株, 野生远志分离52株, 共鉴定76株, 隶属于23个属。通过对14种指示菌进行生长抑制试验, 发现远志内生真菌对枯草芽孢杆菌、宋内氏痢疾杆菌、大肠杆菌、白色念珠菌和九州镰孢霉等5种指示菌抑制效果较好。经鉴定, 它们属于镰孢霉属, 交链孢霉属, Aphanocladium等属, 对单核细胞增生李斯特菌、蜡样芽孢杆菌、普通变形杆菌、致病性大肠埃希氏菌、小孢拟盘多毛
Perpendicular all-optical control of interactional optical spatical soliton pair
光致异构聚合物中相互作用光学空间孤子对的垂直光调控

Li Yang-Gang,She Wei-Long,Wang Hong-Cheng,
扬钢
,佘卫,

物理学报 , 2007,
Abstract: In photoisomerization polymer, the perpendicular optical control of the optical spatial soliton interaction is simulated by numerical method. Under control, the properties of two interacting solitons are damaged, the signal beam can give birth to phenomena such as the two beams to join together, or to detach and so on. We also give a physical explanation of the phenomena, that they are determined by the difference in the initiatial phases of the beams, the incident position of control-beam and so on. The effect of perpendicular optical control of interaction solitons can be applied to optical interlinkage, optical waveguide and so on.
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