弱冻胶调剖剂在孤岛油田污水中成胶性能评价     

宋岱锋  张岩  薄纯辉  李楠  陈辉 《海洋地质译丛》2011,(2):62-64,90

应用孤岛油田现场聚合物和美国进口复合有机铬交联剂TIORCOWC684进行了一系列的室内评价实验。实验结果表明,宝莫聚合物均具有较好的初始黏度、且形成的弱冻胶体系强度高;弱冻胶主段塞选取聚合物浓度2500--3000mg／L,交联剂浓度300--600mg／L,成胶强度较高,且胶体不易脱水;弱冻胶封口段塞聚合物浓度为4000mg／L,交联剂浓度300--900mg／L,胶体强度较大、韧性好,满足封口的要求;同时评价了封口段塞的耐盐性能,结果表明该体系随盐类矿化度的增加体系强度有增加趋势。  相似文献   

曹妃甸填海工程阻断浅滩潮道初期老龙沟深槽的地形变化     

尹延鸿  褚宏宪  李绍全  胡刚  毕世普  袁红明 《海洋地质前沿》2011,(5):1-6

通过研究1992、1997、2006年的测深资料,对比分析了横切老龙沟深槽口门处的地形横剖面和大致沿老龙沟深槽轴线的地形纵剖面,可知在此期间深槽内的水深有变浅和淤积的趋势.总体看来,老龙沟深槽的淤积厚度在0.61～4.8 m之间,并且老龙沟深槽轴线也有自东向西迁移的趋势.自2004年曹妃甸填海工程的通岛公路阻断浅滩潮道...  相似文献   

舟山凉潭岛填海工程对水动力及海床演变影响的模拟预测分析     

吴仁豪  童元正  张旭锋  赵晟  孙健  娄建富  王海平 《热带海洋学报》2011,(4)

用一个三维(ECOMSED)模式对舟山凉潭岛填海工程前后的潮流场变化进行模拟,做出预测。潮流场模拟结果与实测基本吻合。经分析可知,工程对潮流的影响主要在围堤的东南角小范围内:工程后流速明显减小,造成淤积现象,但淤积程度不大,1年后的淤积为13cm左右,5年后的淤积为0.8—1.2m左右。工程对较深水层的潮流运动影响很小。通过对施工期间产生的悬浮物在涨落潮时的分布模拟可知,涨潮时,悬浮物从工程区域的一个悬浮物源不断排出,主要对工程附近及其上游地区造成一定的影响;落潮时,悬浮物主要影响工程外围及其下游地区,整个落潮期间悬浮物能影响的范围比涨潮期间要大。总体上工程对该附近海域的潮流场及冲淤影响很小。  相似文献   

降雨诱发浅层黄土泥流的研究进展、存在问题与对策思考     

辛鹏  吴树仁  石菊松  王涛  石玲 《地质论评》2015,61(3):485-493

降雨诱发的浅层黄土泥流规模小、流速快、冲击力强、发育范围广、难以防御、致灾频率高,近两年造成了大量人员伤亡,急需开展其形成机制与强度的研究。黄土物质组成与水敏性、坡体形态对降雨入渗—积水的响应、黄土斜坡对降水入渗的力学响应机制、富水黄土粘滞性流动特性是制约浅层黄土泥流形成的四种主要因素,分析这四种因素的对浅层黄土泥流形成的制约作用需解决斜坡降雨入渗的水文过程、非饱和土的力学效应及水土耦合的机制等前沿问题。本文对影响泥流形成的各因素研究的最新进展进行了综述,同时讨论了研究中的核心问题,并提出了相应的对策与方案,认为可从三方面开展研究:(1)定量描述泥流体积扩容特征,建立浅层黄土泥流启动与流动模式;(2)分析泥流与原状黄土物质成分、组成结构差异,开展黄土非饱和增湿力学变形试验,监测0°~60°单面坡与坡肩平缓斜坡的降雨入渗过程,研究坡体形态对雨水汇聚、入渗及基质吸力变化的控制特征,揭示泥流流体运动过程中水土响应机制;(3)对浅层黄土泥流物理力学模型进行解析,讨论泥流流动能量转化特征,建立降雨诱发泥流灾害的强度计算模型,为降雨泥流灾害危险性定量计算提供理论支撑。  相似文献   

中央气象台台风强度综合预报误差分析   总被引：6，自引：5，他引：1  

张守峰  余晖  向纯怡 《气象》2015,41(10):1278-1285

本文从总误差、逐年趋势、误差分布等方面对2001—2012年中央气象台（Central Meteorological Observatory, CMO）的台风（TC）强度综合预报水平进行分析,初步分析了强度迅速变化台风预报偏差大的原因。结果表明,强度预报水平没有明显改善,预报误差呈现逐年波动状态,强度稳定TC的预报误差最小,迅速加强TC的预报误差最大。24、96~120 h预报偏强的概率较大,而48~72 h预报偏弱的概率大。南海东北部等海域的预报误差较大,应在业务预报中特别予以关注。随着TC强度的逐渐增强,强度预报在120 h内预报偏强的可能性变大,而强度预报偏弱的可能性减小。根据误差分析结果,提出了一个强度概率预报方案,检验结果表明可在业务中参考使用。  相似文献   

STATISTICAL AND COMPOSITE ANALYSIS OF RELATIONSHIP BETWEEN THE NUMBER OF CONVECTIVE CORES AND THE CHARACTERISTICS OF TBB WITHIN THE TROPICAL CYCLONE CIRCULATION AND ITS INTENSITY     

曹钰  岳彩军  寿绍文 《热带气象学报(英文版)》2015,21(1):1-13

Based on the data(including radius of maximum winds) from the JTWC(Joint Typhoon Warning Center),the tropical cyclones(TCs) radii of the outermost closed isobar, TCs best tracks from Shanghai Typhoon Institute and the Black Body Temperature(TBB) of the Japanese geostationary meteorological satellite M1 TR IR1, and combining13 tropical cyclones which landed in China again after visiting the island of Taiwan during the period from 2001 to2010, we analyzed the relationship between the number of convective cores within TC circulation and the intensity of TC with the method of convective-stratiform technique(CST) and statistical and composite analysis. The results are shown as follows:(1) The number of convective cores in the entire TC circulation is well corresponding with the outer spiral rainbands and the density of convective cores in the inner core area increases(decreases) generally with increasing(decreasing) TC intensity. At the same time, the number of convective cores within the outer spiral rainbands is more than that within the inner core and does not change much with the TC intensity. However, the density of convective cores within the outer spiral rainbands is lower than that within the inner core.(2) The relationship described above is sensitive to landing location to some extent but not sensitive to the structure of TC.(3) The average value of TBB in the inner core area increases(decreases) generally with increasing(decreasing) of TC intensity, which is also sensitive to landing situation to some extent. At the same time, the average value of TBB within the outer spiral rainbands is close to that within the entire TC circulation, and both of them are more than that within the inner core. However, they do not reflect TC intensity change significantly.(4) The results of statistical composite based on convective cores and TBB are complementary with each other, so a combination of both can reflect the relationship between TC rainbands and TC intensity much better.  相似文献   

An equilibrium cloud-resolving modeling study of diurnal variation of tropical rainfall     

《Dynamics of Atmospheres and Oceans》2015

The diurnal variation of tropical rainfall is examined through the analysis of an equilibrium cloud-resolving model experiment. Model domain mean rain rate is defined as a product of rain intensity and fractional rainfall coverage. The diurnal variation of the mean rain rate is associated with that of fractional rainfall coverage because the diurnal variation of rain intensity is significantly weakened through the decrease in rainfall in early morning hours. The decrease in rainfall corresponds to the reduction in secondary circulations through the barotropic conversion from the perturbation kinetic energy to the mean kinetic energy under the imposed negative vertical gradient of westerly winds. The fractional rainfall coverage shows the diurnal signal with the maximum in the early morning hours primarily due to nocturnal infrared radiative cooling.  相似文献   

Influence of future tropical cyclone track changes on their basin-wide intensity over the western North Pacific: Downscaled CMIP5 projections     

Chao Wang  Liguang Wu 《大气科学进展》2015,32(5):613-623

The possible changes of tropical cyclone(TC) tracks and their influence on the future basin-wide intensity of TCs over the western North Pacific(WNP) are examined based on the projected large-scale environments derived from a selection of CMIP5(Coupled Model Intercomparison Project Phase 5) models. Specific attention is paid to the performance of the CMIP5 climate models in simulating the large-scale environment for TC development over the WNP. A downscaling system including individual models for simulating the TC track and intensity is used to select the CMIP5 models and to simulate the TC activity in the future.The assessment of the future track and intensity changes of TCs is based on the projected large-scale environment in the21 st century from a selection of nine CMIP5 climate models under the Representative Concentration Pathway 4.5(RCP4.5)scenario. Due to changes in mean steering flows, the influence of TCs over the South China Sea area is projected to decrease,with an increasing number of TCs taking a northwestward track. Changes in prevailing tracks and their contribution to basin-wide intensity change show considerable inter-model variability. The influences of changes in prevailing track make a marked contribution to TC intensity change in some models, tending to counteract the effect of SST warming. This study suggests that attention should be paid to the simulated large-scale environment when assessing the future changes in regional TC activity based on climate models. In addition, the change in prevailing tracks should be considered when assessing future TC intensity change.  相似文献   

Identification and analysis of high-frequency oscillations in the eyewalls of tropical cyclones     

CHEN Shumin  Youyu LU  LI Weibiao  WEN Zhiping 《大气科学进展》2015,32(5):624-634

High-frequency oscillations, with periods of about 2 hours, are first identified by applying wavelet analysis to observed minutely wind speeds around the eye and eyewall of tropical cyclones(TCs). Analysis of a model simulation of Typhoon Hagupit(2008) shows that the oscillations also occur in the TC intensity, vertical motion, convergence activity and air density around the eyewall. Sequences of oscillations in these variables follow a certain order.  相似文献   

四川盆地低涡的月际变化及其日降水分布统计特征   总被引：2，自引：1，他引：1  

李超  李跃清  蒋兴文 《大气科学》2015,39(6):1191-1203

利用ERA-interim再分析资料和全国824个气象基准站的日降水资料,统计分析了1983年1月1日~2012年12月31日发生在四川盆地的低涡天气过程及其降水特征,结果表明:盆地涡初生位置主要位于盆地的西南部和东北部,盆地涡夏季出现最多,冬季出现最少,其中初生位置位于盆地西南部的低涡7月出现最多,12月和1月出现最少;位于东北部的低涡6月出现最多,1月出现最少;盆地涡具有明显的日变化,西南型盆地涡3~10月夜晚发生概率均大于白天,其他月份低涡夜发性不明显,而东北型盆地涡只在5~9月期间夜晚发生概率大于白天,其他月份低涡夜发性不明显;盆地涡生命史与对流程度具有相关性,对流发展有利于盆地涡长时间维持,然而,夏季西南型盆地涡即使对流没向上发展也能长时间维持;盆地涡夏季移出最多,尤其以7、8月最明显,冬季移出最少,7月前以偏东路径为主,7月后以东北路径为主;盆地涡频数的月际变化与川西高原西南涡源地的风场扰动移出有密切联系,九龙地区夏季风场扰动移出活跃,冬季移出不活跃。小金地区春季风场扰动移出活跃,冬季移出不活跃。九龙地区风场扰动移出对盆地涡频数的月际变化贡献明显,小金地区风场扰动移出对盆地涡频数的月际变化贡献不明显;夏半年(5~10月)西南型盆地涡和东北型盆地涡引起的日降水区域分布的月际变化特征不同,前者的日降水最大值中心随月份先由盆地东北部向西南部移动,之后再由盆地西南部向东北部折回,后者的日降水最大值中心会一直稳定维持在盆地的东北部达州地区。东北型盆地涡虽然出现频次低,但各月的日降水强度要远大于西南型盆地涡。  相似文献