节能温度、供热气象指数及供热参数研究   总被引：2，自引：1，他引：1  

王保民  张德山  汤庆国  李迅  孔玉斌  张姝丽  杨世燕  陈正洪  胡江林  王志斌 《气象》2005,31(1):72-74

对北京市2001～2002年采暖季的室内外气象一热力试验数据进行科学分析,求出实际条件下不同环境温度、风速、辐射等气象条件下的节能温度,提出了供热气象指数及等级划分标准,推算出总供热量、供回水温度差及通过控制回水温度而知供水温度等供热参数,并已在北京市供热作业中投入应用,为实时供热调度提供了参考依据,是节能、增效、减污的基础。  相似文献   

城市热岛强度订正与供热量预报   总被引：7，自引：2，他引：5  

陈正洪  胡江林  张德山  王保民  汤庆国  王志斌  杨宏青 《气象》2005,31(1):69-71

利用公主坟自动气象站(供热区)和北京市观象台(郊区)间1997～2001年4个冬季逐月(11月～3月)逐日4次气温差值,研究了城市热岛变化特征,结合其他研究提出了北京市各供热区城市热岛强度订正原则和初步结果。对北京市2001～2002年采暖季的室内外气象-热力试验数据进行科学分析,求出不同环境温度条件下单位面积供热量模式,按此模式运行则存在较大节能空间。  相似文献   

2002年西北太平洋和南海热带气旋路径主客观预报评价   总被引：3，自引：2，他引：1  

许映龙  刘震坤  董林  顾华 《气象》2005,31(6):43-46

利用目前中央气象台热带气旋路径实时业务预报中使用的各种主客观预报产品资料,对2002年西北太平洋和南海热带气旋路径实时业务预报中的主客观预报进行对比分析检验。结果显示：虽然在整体上主观预报要优于客观模式的结果,但客观模式的预报能力已接近主观预报,有时甚至还好于主观预报,特别是48小时以上时效的客观模式较主观预报具有一定的优势;而在客观模式中,全球模式优于台风模式;热带气旋路径数值模式产品的使用对提高热带气旋路径业务预报水平具有十分重要的作用。  相似文献   

RAMS模式在山谷城市模拟性能的检验   总被引：1，自引：0，他引：1  

杨胜朋  吕世华  陈玉春  奥银焕  余晔  王长友 《中国沙漠》2009,29(6):1212-1220

 利用2005年冬季兰州边界层试验的观测数据,分别从边界层结构、近地面温度和风速、地表通量等几个方面检验了RAMS在山谷城市的模拟性能。RAMS模式能很好地捕捉边界层结构特征,模拟的白天混合层高度和夜间稳定边界层高度和观测值非常一致。模式能较好地模拟近地面温度和地表通量的日变化特征。对模拟偏差进行统计分析,结果显示RAMS对近地面温度和风速的模拟结果是可以接受的:近地面温度的平均偏差为-1.73 ℃,RMSE为2.16 ℃,风速的平均偏差为0.35 m·s-1,RMSE和RMSVE分别为1.61 m·s-1和3.15 m·s-1。研究表明,RAMS适合作为研究兰州山谷城市大气边界层的工具。  相似文献   

TESTING OF ENERGY DISSIPATING CLADDING CONNECTIONS     

J.&#x;P. PINELLI  C. MOOR  J. I. CRAIG  B. J. GOODNO 《地震工程与结构动力学》1996,25(2):129-147

Properly designed precast concrete cladding could potentially provide lateral stiffness, ductility, and energy dissipation for an overall building structure, especially during earthquakes. This paper describes a set of advanced connections that take advantage of the interaction between facade panels and structure (mainly due to horizontal interstorey drift) to dissipate energy, thereby reducing the response of the main structure. The results of an experimental program to characterize the hysteretic behaviour of advanced connections are presented. Design equations for the advanced connections are then calibrated against the test results, and the corresponding design charts are presented. It is anticipated that this research will lead to innovative ways of viewing the entire cladding system of a building.  相似文献   

华南农田下垫面地气交换和能量收支的观测研究   总被引：12，自引：1，他引：11  

郭晓峰  康凌  蔡旭晖  朱彤 《大气科学》2006,30(3):453-463

利用2004年11月至12月在广东省惠州地区进行的湍流连续观测资料,分析非均匀农田近地面层的基本气象要素特征以及水汽和CO2的浓度与通量输送规律,作为今后深入探讨地表非均匀性效应的基础.通过各辐射分量和感热、潜热与土壤热通量的特征分析,研究能量收支的基本状况,并讨论了造成显著能量"不平衡"的原因.观测的基本结果是:(1)近地面1.8 m高度处以北风为主,风速大多低于2 m/s,正午入射太阳辐射约700 W/m2;CO2浓度的日变化范围为600～900 mg/m3,水汽为5～25 g/m3.(2)各气象要素呈现明显的日变化,当地温度日较差约10℃,相对湿度始终高于50%.CO2和水汽的浓度在夜间较白天高,二者的日平均值为713.7 mg/m3和15.9 g/m3;利用涡旋相关法,测得二者的通量在白天高于夜间,日平均值为25.3 mg·m-2·s-1和-4.7×10-2mg·m-2·s.当地的日平均波文(Bowen)比仅为0.04,这主要是由于当地的高湿度造成的.(3)当地存在显著的能量"不平衡"现象,正午时的差额热通量可高达150 W/m2,这可能与平均垂直运动输送的作用、观测误差以及通量和辐射观测的"源地"不匹配等原因有关.研究结果与荒漠、城市和稻田下垫面的观测事实进行了定量比较.  相似文献   

冲击荷载下玄武岩纤维水泥土吸能及分形特征     

马芹永  高常辉 《岩土力学》2018,39(11):3921-3928

为研究玄武岩纤维对水泥土冲击破坏过程中能量吸收及碎块块度分布特征的影响,采用Φ50 mm变截面霍普金森压杆（split Hopkinson pressure bar,简称SHPB）试验装置对不同玄武岩纤维掺量的水泥土进行了冲击压缩和动态劈裂试验,分析了冲击荷载作用下玄武岩纤维掺量与水泥土吸收能、破坏形态和分形维数 的关系,试验结果表明：随着玄武岩纤维掺量的增加,水泥土吸收能呈先增大后减小的趋势,超过最佳掺量后,由于纤维-纤维薄弱面的存在,水泥土吸收能减少;冲击破坏后水泥土破碎块度分布是具有统计意义上的分形,冲击压缩试验中水泥土破碎块度平均粒径随玄武岩纤维掺量的增加而不断增大,对应的 值总体上呈现不断减小的趋势;在动态劈裂试验中,玄武岩纤维掺量在0～2.0%范围内,水泥土破碎块度平均粒径呈现上升趋势, 值不断减小,玄武岩纤维掺量超过2.0%后,平均粒径有所降低,对应 值增大。玄武岩纤维水泥土吸收能和 值之间有着密切的联系,冲击压缩试验中,吸收能在分形维数为2.20～2.26范围内呈先增大后减小的趋势,而在动态劈裂试验中,吸收能在分形维数为1.85～2.20范围内总体呈现下降趋势,两者具有一定的负相关性;合适掺量的玄武岩纤维对水泥土动态特性起着积极作用,通过试验得出玄武岩纤维的合适掺量为1.5%～2.0%。  相似文献   

三类边坡失稳判据的统一性   总被引：2，自引：0，他引：2  

涂义亮  刘新荣  钟祖良  杜立兵  王鹏 《岩土力学》2018,39(1):173-180

将热力学理论中材料破坏的能量机制引入边坡工程中,推导了强度折减过程中边坡的能量方程,利用FLAC3D二次开发了能量的计算程序,并应用于某经典边坡算例中。通过与Spencer法的计算结果对比发现：强度折减法中边坡的稳定性与能量变化关系紧密,由此提出了4种新的失稳判据--能量突变失稳判据,且4种能量突变失稳判据理论上是统一的。通过对比发现：动能突变判据与数值计算收敛性判据、重力势能降突变判据与特征点垂直位移突变判据、耗散能增量突变判据与塑性区贯通判据分别存在对应关系,证明了常见的3类失稳判据也是统一的。通过算例试算发现,3类判据判定结果不相等主要是由收敛标准和网格精度等人为因素造成的,本质上是因为数值计算是一种近似解。工程应用中,可通过3类失稳判据判定结果的一致性来自评安全系数的计算精度,一致性越好,精度越高。提高计算精度的根本办法是严格收敛标准和精细网格划分,但应同时兼顾数值计算的时长,从而实现计算效率最大化。  相似文献   

Experimental and numerical investigations on the intact and damage survivability of a floating–moored oscillating water column device     

《Applied Ocean Research》2017

This paper investigates the intact and damage survivability of a floating–moored Oscillating Water Column (OWC) device using physical model experiments and Computational Fluid Dynamics (CFD) simulations. Different extreme wave conditions have been tested using irregular and regular wave conditions. The device was moored to the tank floor via four vertical taut lines and the effect of the mooring line pre–tension on the device response was studied. It was found that the instantaneous position of the floating device was a key factor in the survivability analysis such that a certain irregular wave train that might not include the largest wave could induce the maximum response. Reducing the pre–tension minimized the maximum surge, but significantly increased the maximum tension due to mooring slack events causing snatch loads. A design regular wave with a period equal to the peak period and a height of 1.9–2.0 times the significant wave height could reasonably predict the same maximum line tension as the irregular sea state, but a smaller wave height was required to achieve the maximum surge. A single failure in the mooring system increased the maximum tension by 1.55 times the intact tension. For a damaged mooring system, using the same design regular wave condition derived from the survivability analysis with an intact mooring system could result in overestimating the maximum tension by more than 20% in comparison to the tension from the irregular sea state, but a smaller regular wave height or a different regular wave condition representing another sea state could lead to the same maximum tension. This highlighted the importance of investigating survival conditions with a damaged mooring system instead of simply using the same conditions derived for the intact mooring system.  相似文献   

Depositional evolution of a progradational to aggradational,mixed-influenced deltaic succession: Jurassic Tofte and Ile formations,southern Halten Terrace,offshore Norway     

《Marine and Petroleum Geology》2017

Predicting the hydrodynamics, morphology and evolution of ancient deltaic successions requires the evaluation of the three-dimensional depositional process regime based on sedimentary facies analysis. This has been applied to a core-based subsurface facies analysis of a mixed-energy, clastic coastal-deltaic succession in the Lower-to-Middle Jurassic of the Halten Terrace, offshore mid-Norway. Three genetically related successions with a total thickness of 100–300 m and a total duration of 12.5 Myr comprising eight facies associations record two initial progradational phases and a final aggradational phase. The progradational phases (I and II) consist of coarsening upward successions that pass from prodelta and offshore mudstones (FA1), through delta front and mouth bar sandstones (FA2) and into erosionally based fluvial- (FA3) and marine-influenced (FA4) channel fills. The two progradational phases are interpreted as fluvial- and wave-dominated, tide-influenced deltas. The aggradational phase (III) consists of distributary channel fills (FA3 and FA4), tide-dominated channels (FA5), intertidal to subtidal heterolithic fine-grained sandstones (FA6) and coals (FA7). The aggradational phase displays more complex facies relationships and a wider range of environments, including (1) mixed tide- and fluvial-dominated, wave-influenced deltas, (2) non-deltaic shorelines (tidal channels, tidal flats and vegetated swamps), and (3) lower shoreface deposits (FA8). The progradational to aggradational evolution of this coastal succession is represented by an overall upward decrease in grain size, decrease in fluvial influence and increase in tidal influence. This evolution is attributed to an allogenic increase in the rate of accommodation space generation relative to sediment supply due to tectonic activity of the rift basin. In addition, during progradation, there was also an autogenic increase in sediment storage on the coastal plain, resulting in a gradual autoretreat of the depositional system. This is manifested in the subsequent aggradation of the system, when coarse-grained sandstones were trapped in proximal locations, while only finer grained sediment reached the coastline, where it was readily reworked by tidal and wave processes.  相似文献