The Relation between Atmospheric Intraseasonal Oscillation and Summer Severe Flood and Drought in the Changjiang-Huaihe River Basin

The intraseasonal oscillation (ISO) is studied during the severe flood and drought years of the Changjiang-Huaihe River Basin with the NCEP/NCAR reanalysis data and the precipitation data in China. The results show that the upper-level (200 hPa) ISO pattern for severe flood (drought) is characterized by an anticyclonic (cyclonic) circulation over the southern Tibetan Plateau and a cyclonic (anti-cyclonic) circulation over the northern Tibetan Plateau. The lower-level (850 hPa) ISO pattern is characterized by an anticyclonic (cyclonic) circulation over the area south of the Changjiang River, the South China Sea, and the Western Pacific, and a cyclonic (anticyclonic) circulation from the area north of the Changjiang River to Japan. These low-level ISO circulation patterns are the first modes of the ISO wind field according to the vector EOF expansion with stronger amplitude of the EOF1 time coefficient in severe flood years than in severe drought years. The analyses also reveal that at 500 hPa and 200 hPa, the atmospheric ISO activity over the Changjiang-Huaihe River basin, North China, and the middle-high latitudes north of China is stronger for severe flood than for severe drought. The ISO meridional wind over the middle-high latitude regions can propagate southwards and meet with the northward propagating ISO meridional wind from lower latitude regions over the Changjiang-Huaihe River Basin during severe flood years, but not during severe drought years.

Long-term effects of pattern scan laser pan-retinal photocoagulation on diabetic retinopathy in Chinese patients: a retrospective study

●AIM:To evaluate the long-term effects of pattern scan laser(PASCAL)pan-retinal photocoagulation(PRP)on diabetic retinopathy(DR)in Chinese patients.●METHODS:In this retrospective study,we evaluated clinical data of 29 patients(53 eyes)with severe non-proliferative DR(SNPDR)or proliferative DR(PDR)who received PRP and follow-up at our hospital from 2008 to 2013.Sixteen patients(29 eyes)received PASCAL PRP and 13 patients(24 eyes)received 100-ms conventional laser PRP.●RESULTS:After long-term follow-up(mean,min-max days:719.8,290-1666 for PASCAL PRP vs 743.5,240-1348 for conventional PRP,P=0.569),patients receiving PASCAL PRP required fewer photocoagulation sessions than the conventional PRP group(2.6±1.0 vs 3.9±0.9,P<0.01).Best corrected visual acuity(BCVA)was reduced slightly in PASCAL PRP group while reduced significantly in conventional PRP group.At last visit,24 eyes in the PASCAL group(88.9%)and 21 eyes in the conventional group(91.7%)were improved or stable.Two eyes in PASCAL PRP group(7.4%)and 3 eyes in the conventional PRP group(12.5%)developed vitreous hemorrhage or vitreous fibrovascular proliferation.●CONCLUSION:PASCAL PRP is as effective and may be more conducive to maintaining visual acuity with less treatment sessions for DR treatment compared to conventional laser PRP.

Experimental and Computational Investigations on Severe Slugging in A Catenary Riser

Severe slugging can occur in a pipeline-riser system at relatively low liquid and gas flow rates during gas-oil transportation, possibly causing unexpected damage to the production facilities. Experiments with air and water are conducted in a horizontal and downward inclined pipeline followed by a catenary riser in order to investigate the mechanism and characteristics of severe slugging. A theoretical model is introduced to compare with the experiments. The results show that the formation mechanism of severe slugging in a catenary riser is different from that in a vertical riser due to the riser geometry and five flow patterns are obtained and analyzed. A gas-liquid mixture slug stage is observed at the beginning of one cycle of severe slugging, which is seldom noticed in previous studies. Based on both experiments and computations, the time period and variation of pressure amplitude of severe slugging are found closely related to the superficial gas velocity, implying that the gas velocity significantly influences the flow patterns in our experiments. Moreover, good agreements between the experimental data and the numerical results are shown in the stability curve and flow regime map, which can be a possible reference for design in an offshore oil-production system.

Role of street patterns in zone-based traffic safety analysis

Although extensive analyses of road segments and intersections located in urban road networks have examined the role of many factors that contribute to the frequency and severity of crashes, the explicit relationship between street pattern characteristics and traffic safety remains underexplored. Based on a zone-based Hong Kong database, the Space Syntax was used to quantify the topological characteristics of street patterns and investigate the role of street patterns and zone-related factors in zone-based traffic safety analysis. A joint probability model was adopted to analyze crash frequency and severity in an integrated modeling framework and the maximum likelihood estimation method was used to estimate the parameters. In addition to the characteristics of street patterns, speed, road geometry, land-use patterns, and temporal factors were considered. The vehicle hours was also included as an exposure proxy in the model to make crash frequency predictions. The results indicate that the joint probability model can reveal the relationship between zone-based traffic safety and various other factors, and that street pattern characteristics play an important role in crash frequency prediction.

THE RECOGNITION AND TRACKING OF SEVERE CONVECTIVE CLOUD FROM IR IMAGES OF GMS

It is very important to locate and track weather systems which cause severe calamity,such as severeconvective clouds (SCC),in nowcasting. In this paper the recognition and tracking of SCC is studied withGMS IR images using computer image techniques. As an IR image preprocessing, a SCC futerlng algorithm is put forward that combines a segment smoothing filtering and a removal procedure by thresholds. To the filtered SCCs the T algorithm and IP algorithm of contour coding method are applied to extract the contour line and its initial point. The description of SCCs includes four characteristic quanti-ties, i. e. center of gravity, cloud size, moment invariant M and R-shaped descriptor. Pattern recosnitionand pattern matching techniques are used to track the SCCs. Two procedures of rough and fine matchingare given. The former procedure include the setting of searching area and recognition of area and the latter is composed by the matching of shape descriptor R and moment invariant M and the analysis of correlative brightness temperature analysis.

Pain Management and Factors Associated with Its Severity among Post Surgical Patients Admitted in the Intensive Care Unit at Muhimbili National Hospital, Tanzania

Background: Pain is the common experience among post operative patients admitted to the intensive care unit. Inadequate management can lead to undesired complications which can increase risk for morbidity and mortality. Objective: The aim of this study was to assess pain management and factors associated with its severity among post surgical patients admitted in intensive care unit at MNH. Method: A prospective study was conducted from October 2017 to February 2018 involving a total of 123 post operative patients aged 18 years and above admitted to the surgical and obstetric intensive care units. Structured questionnaires were used to obtain the required perioperative information. Severity of pain was assessed by using the Numerical Rating Scale (NRS). Data was analyzed using SPSS version 23.0. Frequency, percentages, tables and charts were used to summarize the study findings. Bivariate analysis and multivariate logistic regression were done. P-value of Results: The prevalence of severe post operative pain within 24 and 72 hours was 32.1% and 41.5% respectively. Pre operative use of analgesia (OR: 2.66, CI: 1.15 - 6.12, P value = 0.02), abdominal surgery (OR: 4.12 CI: 1.12 - 15.88, P value = 0.03) and thoracic surgeries (OR;7.42, CI: 1.54 - 35.88, P value = 0.01) was significantly associated with severe pain. Age, sex, ASA class, duration of surgery, and level of education did not show significant association with pain severity. Opioids prescribed postoperatively were pethidine (70.7%), morphine (11.4%) and fentanyl (11.4%). Other analgesics used were paracetamol (60.2%) and diclofenac (22%). Conclusion: The magnitude of post operative pain was high. Pre operative uses of analgesia, abdominal and thoracic surgery were the factors associated with severe pain. Pethidine and paracetamol were the most prescribed drugs, however the prescription pattern used was inadequate to control pain.

Centre symmetric quadruple pattern-based illumination invariant measure

A centre symmetric quadruple pattern-based illumination invariant measure(CSQPIM)is proposed to tackle severe illumination variation face recognition.First,the subtraction of the pixel pairs of the centre symmetric quadruple pattern(CSQP)is defined as the CSQPIM unit in the logarithm face local region,which may be positive or negative.The CSQPIM model is obtained by combining the positive and negative CSQPIM units.Then,the CSQPIM model can be used to generate several CSQPIM images by controlling the proportions of positive and negative CSQPIM units.The single CSQPIM image with the saturation function can be used to develop the CSQPIM-face.Multi CSQPIM images employ the extended sparse representation classification(ESRC)as the classifier,which can create the CSQPIM image-based classification(CSQPIMC).Furthermore,the CSQPIM model is integrated with the pre-trained deep learning(PDL)model to construct the CSQPIM-PDL model.Finally,the experimental results on the Extended Yale B,CMU PIE and Driver face databases indicate that the proposed methods are efficient for tackling severe illumination variations.

用Apache&MySQL&PHP构建高校教务管理系统

为高效率、高质量地完成教务管理工作,使其更加规范化、科学化、现代化,运用Apache&MySQL&PHP组合平台构建了一种基于Web的高校教务信息管理系统,描述了该系统的总体结构及功能,并以成绩信息管理模块的构建过程为例,说明了数据库及程序的设计方法。该系统的建设和运用,能强化教学管理、提高工作效率,适应远程教育、异地教学及计算机、外语各种等级考试的需求。

GMS卫星红外云图强对流云团的识别与追踪

利用ＧＭＳ静止气象卫星探测所得到的红外云图资料，用计算机图象学技术来研究强对流云团的识别和追踪，以求能够准确、及时地发现并追踪象强对流云团这种能够造成强烈灾害的天气系统。对红外云图的图象处理，提出区域平滑滤波和阈值剔除相结合的强对流云团过滤算法，对于过滤出的强对流云团，应用图象处理中轮廓编码法的Ｔ算法和ＩＰ算法提取出它的边界、边界初始点。强对流云团的描述包括其重心、特征面积、矩特征量以及Ｒ形状描绘子等特征量。由描述强对流云团的特征量，应用模式识别和模式匹配技术对强对流云团进行追踪。给出粗对比分析和细对比分析两个模式匹配过程，粗对比分析包括搜索区设定和面积识别两步，而细对比分析由Ｒ形状描绘子匹配。

重证肺炎中医证候分布规律及症状特点研究

目的:基于文献,分析重症肺炎证候分布规律及主要证型的症状特点。方法:采用计算机检索和人工检索相结合方法,检索1981—2008年6月重症肺炎的相关文献,运用频数描述、logistic回归分析和聚类分析方法进行分析。结果:共收集合格文献29篇,55条记录。结果显示,频率较高的证型依次为亡阳证(28.1%)、气阴两虚证(21.8%)、亡阴证(18.75%)、肺热腑实证(18.75%)、厥证(15.62%)、脱证(12.5%)、痰热壅肺证(12.5%)。结合专业知识和聚类结果,筛选痰热壅肺证、阴竭阳脱证、肺热腑实证、热入心包证作为重症肺炎的主要证型,并对证型的主、次症进行了筛选。结论:文献分析总结出了重症肺炎证型分布规律及主要证型症状特点,为进一步研究提供了参考。

GIS中局部放电与气体分解产物关系的试验

SF6分解气体检测法,因其不受电磁噪声和振动干扰,同时也适用于过热故障的检测等优点,成为对GIS设备进行局部放电检测诊断的重要手段,应用前景广阔。为填补现有文献中关于GIS设备局部放电与SF6分解产物关系的研究空白,在实验室建立了一套能够检测SF6分解气体产物的GIS局部放电研究平台,利用长期加压法研究了局部放电类型、放电严重程度以及气体压强对SF6气体分解产物体积分数的影响以及分解产物体积分数随时间的变化趋势。研究结果表明:在尖刺放电、悬浮放电、沿面放电3种类型中,GIS设备中均产生SOF2+SO2气体与HF气体,上述两种分解气体可作为检测GIS设备局部放电的特征气体;随着局部放电严重程度的加重,SOF2+SO2气体与HF气体体积分数增大,SF6气体分析法比较适用于检测较为严重的放电缺陷;随着SF6气体压强的增大,局部放电产生的SOF2+SO2气体和HF气体的产气速率有下降的趋势。

陕西强沙尘暴、特强沙尘暴天气气候特征分析

从陕西1954—2003年所有沙尘暴记录所对应的3次或4次定时能见度观测资料中挑出最小能见度小于500m的作为强沙尘暴记录,小于200m的作为特强沙尘暴记录。然后挑取在一次过程中有3个或3个以上气象站出现强沙尘暴的过程共41次作为强沙尘暴过程,有3个或3个以上气象站出现特强沙尘暴的过程共6次作为特强沙尘暴过程。分析结果表明,20世纪90年代是陕西强沙尘暴、特强沙尘暴过程最少的时期。陕西强沙尘暴过程主要发生在春季,冬季次之,其中春季4月最多,冬季2月最多。除春季、冬季外,6、11月也有发生。根据41次强沙尘暴过程出现前一日08时500hPa环流形势分析,将造成陕西强沙尘暴天气的环流形势及影响系统分为蒙古冷(横)槽型、脊前下滑槽型、短波槽东移型和西北气流型4类,其中蒙古冷(横)槽型是造成陕西强沙尘暴天气最多的一种形势,占总次数的44%。陕西6次特强沙尘暴过程的环流形势及影响系统全为蒙古冷(横)槽型。根据地面冷空气入侵陕西的路径分析,将造成陕西强沙尘暴天气的冷空气路径分为西路、西北路、北路三条。

广东前汛期强对流天气分类流型及物理量阈值

本文利用常规高空、地面和自动站观测资料,对2004-2013年广东前汛期分类强对流天气的影响系统及其位置和动态的详细分析和比较,归纳总结了不同类型强对流天气与影响系统之间的有机联系和显著区别,结果表明:大范围短时强降水大部分在高空槽影响下伴有纬向型切变线和低空急流,而区域性短时强降水更依赖于地面低槽的发展;大范围混合强对流天气多数与径向型切变线密切相关,低槽发展所带来的不稳定能量积蓄和冷锋的触发易使对流天气更强烈发展。建立了不同类型强对流天气的流型,总结了各流型天气系统特点和简化物理量指标及阈值,为今后广东强对流天气分析和分类预报提供了明确的思路和参考依据。

大兴安岭火烧迹地主要目的树种的天然更新

对不同火烧方式、火烧强度、林分组成、坡向、坡位、郁闭度、土壤厚度、下木盖度、地被物盖度、林龄等条件下的样地的天然更新情况进行了调查。结果表明:地表火火烧迹地的天然更新效果好于树冠火火烧迹地;中度火烧迹地好于重度火烧迹地;发生火烧的林分比未发生火烧的林分天然更新效果好。

退化红壤不同治理模式对土壤肥力的影响

采取4种不同治理模式对福建省长汀县花岗岩区红壤严重侵蚀地进行治理，1992年对各治理模式及相应对照的土壤化学性质、土壤微生物、土壤酶活性、土壤呼吸作用进行研究，结果表明，治理后土壤细菌、真菌、放线菌数量及微生物总数明显增加，土壤水解性酶和氧化还原酶活性及土壤呼吸作用强度得到显著的加强，土壤养分贮量和速效养分供应强度得到明显改善，土壤肥力得到不同程度的恢复。表明采用合适的生物措施，辅以必要的工程措施，是改善严重退化红壤肥力有效途径之一。

咬合重建对牙齿重度磨耗患者咀嚼运动模式的影响

目的探讨咬合重建修复对不同类型的牙齿重度磨耗患者咀嚼运动模式的影响。方法选择29例牙齿重度磨耗进行咬合重建修复的患者,根据后牙咬合支持状态分成后牙支持完全组(试验Ⅰ组,15例)和后牙支持不全组(试验Ⅱ组,14例),分别测量修复前、过渡修复1个月及永久修复1个月后咀嚼运动时嚼肌、颞肌前束和颞肌后束的表面肌电图,并选择15例正常人作为对照组,分析咀嚼周期、咀嚼运动活动期与间歇期比值及肌电积分值的变化。结果修复前,试验Ⅰ组和Ⅱ组患者的咀嚼周期与对照组之间无统计学差异(P>0.05);试验Ⅱ组活动期与间歇期比值明显高于对照组,而颞肌前束的肌电积分值低于对照组(P<0.05)。过渡修复及永久修复后,试验Ⅰ组和Ⅱ组的咀嚼周期有逐步缩短的趋势。过渡修复时,Ⅰ组患者活动期与间歇期比值和肌电积分值较修复前均有下降(P<0.05);Ⅱ组患者活动期与间歇期比值较修复前下降(P<0.05),肌电积分值的变化则不明显(P>0.05)。永久修复后,Ⅰ组患者活动期与间歇期比值和肌电积分值较过渡修复时的变化均无统计学意义(P>0.05);Ⅱ组患者活动期与间歇期比值较过渡修复时进一步下降,肌电积分值则明显提高(P<0.01)。结论咬合重建修复能明显改善重度磨耗患者咀嚼运动循环模式,提高咀嚼肌活动强度。

广西区域极端特大暴雨成因个例分析

利用常规观测资料、FY-2E卫星观测资料、雷达探测资料以及自动站雨量资料等,对2010年6月28日广西极端特大暴雨过程进行分析;结果表明:①暴雨灾害具有区域小、降雨时段集中、过程雨量大、短历时降雨强及引发次生灾害特别重等特点;②亚欧中高纬度500hPa呈两脊一槽型、200hPa南亚高压脊线贯穿广西上空及西南季风活跃是暴雨的环流背景;高空低涡、地面干线是主要天气系统配置,属低涡暴雨型;③强不稳定能量及层结的存在、850hPa以下低层辐合、700hPa附近明显涡旋、整层大气上升运动、850hPa以下层高湿及水汽强烈辐合是主要物理量特征;④中尺度低压、低涡及气流辐合等是中尺度对流触发条件。FY-2E红外云图上对流云团生成、合并对强降雨有重要指示意义,暴雨发生在云团合并发展阶段,FY-2E的TBB值小于200K可以作为短历时强降雨的指标。低质心雷达回波产生的列车效应和地形作用是造成强降雨的重要因素,低层辐合、高层辐散导致的强烈上升运动,有利于强对流的发展与维持。

大脑中动脉严重狭窄或闭塞卒中类型分析

目的探讨大脑中动脉严重狭窄或闭塞患者卒中类型特点及其发病机制。方法经TCD确诊的大脑中动脉狭窄或闭塞患者,依据头部CT和(或)MRI所示梗死灶进行卒中分型。结果169例大脑中动脉严重狭窄或闭塞患者,卒中类型各亚型以腔隙性脑梗死(LI)最为常见,占38.46%,其次为分水岭梗死(WI)占19.23%。流域性脑梗死、弥散性多发点状脑梗死、半卵园中心梗死与MCA严重狭窄或闭塞程度有关。结论大脑中动脉严重狭窄或闭塞患者卒中类型以腔隙型脑梗死、分水岭梗死为主。卒中类型多种多样,血管检查应该作为缺血性脑血管病的常规检查。

湖北省极端短时强降水MCS类型及特征分析

重点利用新一代天气雷达、常规探空和地面中尺度观测等资料,在详细分析湖北省2008-2015年62例极端短时强降水中尺度对流系统演变过程的雷达回波特征基础上,研究归纳了湖北省6类极端短时强降水MCS模态,其中包括4类线状(尾随层状云、平行层状云、后向扩建类、邻近层状云类)和2类非线状(涡旋状类和层状云环绕类)MCS模态。初步研究表明:(1)4类线状MCS的模态和环境风相对对流线分量的垂直分布与早期的研究结果基本一致。(2)非线状的涡旋状类MCS模态典型特征是大范围层状云降水包裹着螺旋式涡旋对流回波带,多形成于西南涡前切变线附近,主要与西南涡前鄂西山地平原过渡带边界层中尺度涡旋系统的触发和组织有关。(3)湖北省后向扩建类MCS常出现在山脉迎风坡一侧,与中尺度地形对冷池的阻挡、冷池对MCS的组织作用等有关。(4)涡旋状MCS持续时间较长、范围较大,而层状云环绕类MCS维持时间较短。

基于CFD的海洋立管系统严重段塞流数值模拟

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