Influence of coastal wind on surface ozone and nitrogen oxides in suburban Shanghai     

Wenpo Shan  Peng Yang  Haixia Lu  Kefeng Ma  Zhixin Huang 《Asia-Pacific Journal of Atmospheric Sciences》2016,52(5):451-458

Surface ozone, NO, NO₂, and NO _x were measured at a coastal site (Shihua) and a nearby inland site (Zhujing) in suburban Shanghai for the whole year of 2009. More days with ozone pollution in a longer time range were observed at the coastal site than the inland site. The diurnal variations of NO _x concentrations were obviously higher at Zhujing station, while those of ozone concentrations were higher at Shihua station, indicating their different air pollution conditions. Coastal wind has significant influence on the levels and characteristics of the air pollutants. The ozone concentrations during maritime winds (MW) were much higher than those during continental winds (CW) at each of the site, while the NO and NO₂ concentrations were both opposite. The ozone concentrations at Shihua station were much higher than those at Zhujing station, while the NO and NO₂ concentrations were both opposite. The ozone concentrations at both of the two sites showed a distinct “weekend effects” and “weekdays effects” patterns during CW and MW, respectively. Correlation analysis of the pollutants showed that, the compounds during MW were more age than those during CW, and the compounds at Shihua were more age than those at Zhujing. The air pollutions at both of the two sites are mainly associated with the pollutants emitted in this region instead of long range transport.  相似文献   

南海海岛自动气象站防护应用技术探索     

甘志强  陆土金  高涛  井高飞  崔学林  黄斌 《气象科技》2016,44(6):913-917

立足海南及南海的自然条件,结合海岛自动气象站在南海高温、高湿、高盐雾、强辐射、强风等恶劣气候环境下使用情况,通过对历年来海岛自动气象站故障及失效模式的统计和分析,总结分析故障原因。根据设备维护人员多年气象设备保障工作积累总结的经验,从海岛自动气象站结构和防护要求出发,集成应用市场上优质材料、先进工艺和多种成熟、关键设备防护技术,形成一些气象设备防护的有效方法措施,以提高海岛自动气象站对海洋环境的适应性和性能,延长设备使用寿命。  相似文献   

硫酸参与的长江流域岩石化学风化速率与大气CO2消耗   总被引：4，自引：0，他引：4  

张连凯  覃小群  刘朋雨  黄奇波 《地质学报》2016,90(8):1933-1943

流域的岩石化学风化过程是全球碳循环中的重要环节。以往的流域水化学碳汇通量估算大多是基于碳酸的风化作用。而实际上,硫酸和碳酸一样,也参与了流域碳元素的地球化学循环,从而对全球碳循环过程产生影响。长江流域水体近几年出现酸化现象,大部分河段SO42-和Ca2+含量增高,其对应的岩石风化过程和大气CO2消耗速率也发生变化。文章对长江干流及主要支流2013年不同季节的离子组成进行监测,利用水化学平衡法和Galy估算模型,对长江流域岩石化学风化速率和CO2消耗通量进行了估算,对硫酸参与下的长江流域岩石风化和碳循环过程进行了分析。结果表明,长江流域水体离子主要来源于硅酸盐岩风化和碳酸盐岩风化。其中碳酸盐岩风化对河水离子贡献率为92%。在硅酸盐岩广泛分布的赣江流域,碳酸盐岩风化离子贡献也达85%。分析表明,硫酸参与了长江流域的岩石风化过程,对水体中离子产生一定影响。硫酸的参与加快了碳酸盐岩的化学风化速率,平均提高约30%,但是使流域大气CO2消耗速率降低。在不考虑蒸发岩溶蚀作用下,平均从516×103 mol/km2·a降至356×103 mol/km2·a,降低约31%。在各支流中,硫酸对乌江流域碳酸盐岩的风化和碳循环的影响最大,而对雅砻江的影响最小,这与乌江流域的含煤地层、矿床硫化物及大气酸沉降有关。  相似文献   

Projection of precipitation extremes for eight global warming targets by 17 CMIP5 models   总被引：1，自引：0，他引：1  

Xiaojun Guo  Jianbin Huang  Yong Luo  Zongci Zhao  Ying Xu 《Natural Hazards》2016,84(3):2299-2319

  相似文献   

Modification of strain wedge method for lateral soil-pile interaction in sandEI北大核心CSCD     

Yang Xiao-feng  Zhang Chen-rong  Huang Mao-song  Yuan Ju-yun 《岩土力学》2016,(10):2877-2884

A modified strain wedge (SW) method for analyzing the behavior of laterally loaded single piles in sand is proposed. The modified model assumes that the lateral displacements of a pile behind the three-dimensional passive soil wedge are nonlinear, which makes the horizontal soil strain variable with depths instead of a constant value in the original strain wedge model, and also employs two different hyperbolic models, one for describing horizontal stress increment-strain behavior of soil in the wedge, and the other for describing the shear stress-displacement property at the interface between soil and pile shafts. An example is analyzed to demonstrate the effectiveness of the modified method, and a good agreement is obtained. Finally, the effects of modifications on the lateral bearing capacity of pile shafts are discussed. The results show that the problem of overestimating the lateral bearing capacity of piles with strain wedge method can be ameliorated by introducing the assumption of nonlinear lateral displacements of piles. It makes the SW method more convenient and effective in analyzing the behavior of laterally loaded piles by introducing the new relationships of horizontal stress increment-strain and shear stress-displacement.  相似文献   

基于层区带刻度区地质特点的资源评价方法适用性分析     

张雪峰  罗安湘  惠潇  赵彦德  王克  黄锦绣 《地质科技情报》2016,(4):59-65

针对新型的层区带刻度区进行资源评价方法的适应性研究是长庆四次资评一项重要内容。采用油藏规模序列法、油藏过程模型法、容积法和饱和探井法4种资源评价方法,对具不同成藏特点的刻度区进行了深入的方法适用性分析和参数研究。研究结果表明,过程类资源评价方法对低渗透、特低渗透连续性岩性油藏,在以储量提交单元作为统计单元进行油藏发现序列与规模序列模拟时,计算参数的合理性与计算结果认知度很难达到统一。而勘探程度类资源评价方法,在深入的地质分析基础上,选择合理适宜的关键参数,是可以求得较为可信的地质资源量。当然,评价者对评价对象的认识程度和对评价方法的掌握程度也影响着资源评价的结果。  相似文献   

委内瑞拉奥里诺科重油带沉积特征     

陈浩  陈和平  黄文松  孟征  万广峰 《地质科技情报》2016,(4):103-110

委内瑞拉奥里诺科重油带是世界上储量最大、开发程度最低的重油富集带。目前对油区主力储层的沉积特征及其演化规律认识并不明确。基于钻井岩心、测井、地震及生物化石等资料,结合盆地构造演化、构造特征、地层特征等因素的分析,重点研究了重油带主力储层的沉积演化特征。结果表明:重油带渐新统-中新统主力储层内主要发育12种岩相和6种岩相组合,其中以河流相岩相组合为主;地层由下到上可以划分出3个完整的海进海退沉积旋回(5个沉积单元);在探讨重油带主力储层沉积砂体平面演化规律的基础之上,建立了受河流控制、潮汐和沿岸流共同影响作用下形成的三角洲沉积模式,以期对类似油气聚集区的勘探、开发有所帮助。  相似文献   

多元时间序列分析的滑坡演化阶段划分          下载免费PDF全文

罗文强  李飞翱  刘小珊  黄丽 《地球科学》2016,41(4):711-717

滑坡的时间-位移曲线一般具有3个阶段特征,即初始变形阶段、等速变形阶段和加速变形阶段,不同演化阶段加速度具有不同的变化特点.目前往往是依据对加速度曲线特征的分析来人为划分演化阶段,缺少相应的理论支持和定量计算.针对上述问题,选取月降雨量、月库水位高程变化量对滑坡的累计位移建立多因素的时间序列预测模型.然后利用Chow分割点检验理论,以所建模型中F和LR统计量最大值点作为分割点对滑坡演化阶段进行划分.以新滩滑坡和三峡库区白水河滑坡为例,利用累计位移、降雨及库水位变化数据进行计算验证.结果表明,对多元时间序列模型进行Chow分割点检验可对滑坡的演化阶段进行准确划分,为滑坡的临滑预警预报提供重要判据.   相似文献   

CMIP5模式对中国近海海表温度的模拟及预估   总被引：2，自引：0，他引：2  

宋春阳  张守文  姜华  王辉  王大奎  黄勇勇 《海洋学报》2016,38(10):1-11

基于观测和再分析资料;利用多种指标和方法评估了国际耦合模式比较计划（CMIP5）中21个模式对中国近海海温的月、季节和年际变化模拟能力。多模式集合能够再现气候平均意义下近海海温的空间分布特征;但量值上存在一定的低估。在渤海和黄海;集合平均与观测差别比较明显。在年际尺度上;与观测数据对比;模式模拟海温与Niño3指数相关性较小。中国近海海表面温度在1960-2002年有明显的升高趋势;从2003年开始增温趋缓。评估结果表明;ACCESS1.0、BCC-CSM1.1、HadGEM2-ES、IPSL-CM5A-MR、CMCC-CM、FGOALS-g2、CNRM-CM5-2、INMCM4八个模式对中国近海海温的变化有较好的模拟能力。利用ACCESS1.0、INMCM4、BCC-CSM1.1、IPSL-CM5A-MR、CMCC-CM这5个模式结果对中国近海海温未来的变化进行了预估。在RCP4.5、RCP8.5情景下;未来近100年中国近海海温有明显升高趋势;最优模式多模式集合平均增温分别可达到1.5℃、3.3℃;净热通量变化和平流变化共同促进了东海升温。  相似文献   

Stability analysis of an ancient landslide considering shear strength reduction behavior of slip zone soil     

Xiao-ping?ChenEmail author  Hong-hu?ZhuEmail author  Jing-wu?Huang  Dong?Liu 《Landslides》2016,13(1):173-181

In this paper, the stability of an ancient landslide during the first impounding of a nearby reservoir is investigated through the analyses of the shear strength reduction behavior of slip zone soil. In view of the experimental observations, an empirical strain-dependent soil model is established and is then incorporated in finite element analyses. The numerical analysis results show that the failing sections progressively develop due to the soil strength declines from peak toward residual, and the shear zone propagates within the front slope. It is demonstrated in the numerical results that the toe weighting measure has a significant effect on restraining the shear displacements of the soils and preventing the progressive failure of the landslide. The field observations further confirmed the stability condition of the reinforced landslide.  相似文献