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Search Results: 1 - 10 of 286809 matches for " <br>梁捷宁 "
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Turbulence Influenced by Mesoscale Motions in the Stable Boundary Layer over Complex Terrain of the Loess Plateau
黄土高原复杂地形受中尺度运动影响的稳定边界层湍流特征

LIANG Jiening,ZHANG Lei,BAO Jing,ZHAO Shiqiang,HUAGN Jianping,Zhang Wu,<br>,张镭,鲍婧,赵世强,黄建平,张武
大气科学 , 2013,
Abstract: Turbulent characteristics in the stable boundary layer are evaluated by using data collected by the eddy covariance approach at the Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL). The influence of mesoscale motions in the averaging time is the chief reason for the large scattering of turbulent fluxes obtained by using the eddy covariance technique. The time interval to define the turbulence ranges from several tens of seconds to several minutes. The multiresolution cospectra of the heat flux reveal a gap scale from 112.4 s to 449.9 s for strong stability when gradient Richardson number (Ri) is greater than 0.3. The motions at averaging time scales greater than the gap scale lead to large random heat flux errors and may even change the sign of heat flux cospectra. The gap scale for momentum flux occurs between 112.4 s and 224.9 s. In a weak wind regime in which the submeso velocity scale is greater than the mean flow, standard deviation of vertical velocity depends systematically on the submeso velocity scale and increases with increasing submeso velocity scale at an average rate of approximately 0.1. The standard deviation of vertical velocity correlates well with the generalized velocity scale, and approaches to zero with the generalized velocity scale vanishing. The standard deviations of w, u, and v normalized by friction velocity equal 1.35, 2.54, and 2.21 respectively. Analysis of turbulent kinetic energy reveals that persistent turbulence exists even under condition of Ri > 0.3. Stationarity time based on turbulent kinetic energy changes with stability ranged from 133.5 s to 856.2 s during December 7-11, 2008.
Boundary Layer Height Estimate in Summer over the Lanzhou Suburb in the Yuzhong Area Using Lidar Measurement and Numerical Model
利用激光雷达结合数值模式估算兰州远郊榆中地区夏季边界层高度

ZHAO Shiqiang,ZHANG Lei,WANG Zhiting,WANG Tengjiao,ZHANG Lei,LIANG Jiening,<br>赵世强,张镭,王治厅,王腾蛟,张磊,
气候与环境研究 , 2012,
Abstract: The atmospheric boundary layer over the Lanzhou suburb in the Yuzhong area was analyzed at the Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL). Micro Pulse Lidar (MPL-4B) data was retrieved by the wavelet transform method and a simulation was performed using the Weather Research Forecast (WRF) model with its two boundary layer parameterizations schemes: YSU and MYJ. The results showed that the Lidar retrieval data and the simulated boundary layer height were in agreement. The WRF with YSU scheme reflected the convection boundary layer well; the WRF with MYJ scheme showed good results in simulating the dynamic boundary layer. The boundary layer over SACOL started to develop around 0800 LST and reached its maximum height at 1700 LST. The analysis showed that the thermic convection boundary layer can reach an altitude of more than 2 km, and the dynamic boundary layer can reach 1.5 km. The thermic convection boundary layer decreases faster than the dynamic boundary layer.
基于专利信息的国内外钢铁产业技术创新能力评价
Technology Innovation Capacity Assessment for Steel and Iron Enterprises or Research Institutions: Based on the Data of Patents

,王兵<br>LIANG Xiaojie,WANG Bing
- , 2017,
Abstract: 摘要 在我国钢铁行业面临战略转型的大背景下,钢铁产业技术创新能力的提升至关重要。基于专利指标,建立了由创新方向、创新效率、创新质量三方面14个指标组成的钢铁产业创新能力评价体系,并采用密切值法对钢铁行业优势申请人的创新能力进行评价,从专利特征分析的角度对国内外钢铁产业的技术创新能力进行了实证研究和对比分析。研究发现,我国钢铁产业的专利数量增长很快,但与其他国家钢铁行业相比,我国钢铁产业高质量技术创新成果相对较少,创新活动后劲相对不足,且创新方向较为单一,合作力度较小,合作度有待进一步提升
黄土高原复杂地形上边界层低空急流对近地层湍流的影响
,张镭,田鹏飞,曹贤洁,王宏斌,闭建荣
地球物理学报 , 2014, DOI: 10.6038/cjg20140504
Abstract: 利用中尺度气象数值模式(WeatherResearchandForecastingModel,WRF)模拟风场,结合兰州大学半干旱气候与环境观测站(Semi-AridClimateandEnvironmentObservatoryofLanzhouUniversity,SACOL)湍流观测资料,分析了黄土高原复杂地形上稳定边界层低空急流对近地层湍流活动的影响.黄土高原复杂地形上稳定边界层低空急流的形成与地形作用引发的局地环流有关.低空急流对近地层湍流活动有强烈影响,剪切作用使小尺度湍涡活动加剧,湍动能增大,同时非平稳运动被压制.低空急流发生时,观测数据有87.3%是弱稳定情形(梯度理查森数小于0.25);而无低空急流时,对应时段的观测表明65.4%属于强稳定层结(梯度理查森数大于0.3),非平稳运动造成湍流功率谱在低频端迅速增大.与无低空急流和弱低空急流情形相比,强低空急流发生时,近地层湍动能增大1倍,湍动能在垂直方向上的传递增大1个量级,且方向向下,约为-3×10-3m3·s-3,湍流在上层产生并向下传递.
利用激光雷达结合数值模式估算兰州远郊榆中地区夏季边界层高度
赵世强,张镭,王治厅,王腾蛟,张磊,
气候与环境研究 , 2012, DOI: 10.3878/j.issn.1006-9585.2011.10170
Abstract: 用激光雷达资料,采用小波变化法反演兰州远郊榆中地区兰州大学半干旱气候与环境观测站(sacol)的边界层高度,并利用wrf中尺度数值模式,选取两种不同边界层参数化方案(ysu、myj)模拟了该地区边界层及其高度。分析表明激光雷达反演边界层高度与wrf模拟边界层高度结果基本一致;wrf选用ysu方案能较好反映热对流边界层,而myj方案对于动力作用边界层模拟较好。日出后08:00(北京时间,下同)sacol不稳定边界层开始发展,17:00达到最大高度。热对流边界层可以达到2km;动力作用边界层可达到1.5km,之后热对流边界层下降速度明显高于动力作用边界层。
SACOL黑碳和沙尘气溶胶辐射强迫分析 Analysis of radiative forcing of black carbon and dust aerosol over SACOL
衣娜娜,张镭,曹贤洁,,田鹏飞,李燕军
- , 2015,
Abstract: 利用兰州大学半干旱气候与环境观测站(SACOL)的太阳光度计资料、AREONET气溶胶光学特性资料,采用辐射传输模式SBDART分析了SACOL典型日个例沙尘气溶胶和黑碳气溶胶的长、短波辐射强迫,探讨了不同地表反照率和天顶角对气溶胶辐射强迫的影响.分析表明,沙尘和黑碳在地表的短波辐射强迫分别是-146.54,-60 W/m~2,长波辐射强迫分别是17.79,8.66 W/m~2,短波辐射强迫是长波的6倍多,沙尘辐射强迫是黑碳的2倍多;在大气层顶沙尘和黑碳短波辐射强迫是39.04,27.2 W/m~2,长波辐射强迫为12.19,5.0 W/m~2.短波辐射强迫随地表反照率的增加而增大,长波辐射强迫随地表反照率的增加线性减小.随天顶角减小,大气层顶的短波辐射强迫线性增加,地面短波辐射强迫对数减小,长波辐射强迫随天顶角的变化很小
口头表达的心理障碍及训练方法

心里发展与教育 , 1987,
Abstract: 随着教育实践的发展,对人才观、教学观的讨论日益深入;随着经体改、政体改的进一步施行,对人才素质提出了更全面、更具体、更迫切的要求;随着精神文明领域开放政策的贯彻,国际间文化交流日益频繁.在这一系列理论与实践的探索中都可以直接或间接地听到提高学生口头表达能力的呼声.实际上,从两年多前有人提出人才的七项标准,到今夏亚洲大专辩论会带来的巨大反响,都已经在广大师生中引起对培养口头表达能力的自觉要求与切实的重视.
“中学生听力发展”测试报告

心里发展与教育 , 1989,
Abstract: 我们“中学生语文能力发展与培养”课题组,经过两年的实验,基本上完成了对中学生语文能力结构的研究.听力,做为语文能力结构模型中“产品”一维的因素之一,它是由哪些能力构成?这些能力在不同年级有哪些差异?如何认识听力与其它一些因素的关系?能否尝试制定出听力测试量表?等等.为了给解答以上研究提供实验依据,为了对中学生听力培养的教学实践提供理论指导,我们于1988-1989学年度集中研究了听力培养问题,在三次综合统测的基础上,1988年11月份专门对听音辨义能力进行了统一测试.
教贵激疑——语文教学心理漫谈

心里发展与教育 , 1986,
Abstract: 语言文学是艺术,要上好传授语言文学知识,培养阅读与表达能力的语文课,同样是一种艺术.从美学观点来看“虎啸深山,鱼游漂底,驼走大漠,雁排长空,这就是它们的极致”,那么,语文课上得好坏的一个重要标准就是要看能否通过教师的教学启发了学生的思维,激发起学生的学习动机——教贵激疑.动机来自需要,需要是兴趣产生和发展的基础.
大黄苷元联合溶栓对血栓栓塞性脑缺血大鼠微血管基底膜损伤的保护作用
李建生,刘敬霞,王冬,刘轲,生旺,,苏静,,郭晓燕
中国中药杂志 , 2010,
Abstract: 目的:从大黄苷元联合尿激酶溶栓对脑缺血大鼠脑组织IgG,IV型胶原(CoLIV)和层粘蛋白(LN)变化的影响方面探讨其对脑缺血微血管基底膜损伤的保护作用。方法:大鼠随机分组,制备血栓栓塞性脑缺血动物模型,大鼠分别于缺血后3,6,9h经导管由区域动脉溶栓;动脉给药后24h,观察大鼠死亡率和脑组织颅内出血率,测定脑组织IgG,CoLIV和LN。结果:脑缺血9h溶栓可引起大鼠死亡率和脑出血率增高,联合用药可使其降低。模型6h和9h组大鼠脑组织IgG水平增高、CoLIV和LN表达降低;各用药9h组较模型组IgG降低、CoLIV和LN表达增强;联合用药9h组分别较两单一用药组IgG降低、CoLIV和LN表达增强。结论:脑缺血延迟溶栓可造成脑微血管基底膜损伤,引起颅内出血率和死亡率增高;大黄苷元联合溶栓对微血管基底膜损伤具有保护作用,可降低溶栓后的颅内出血率和死亡率。
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