2010年大同市主要天气气候事件及特征

2010年,大同市年平均气温较常年偏高0.2℃,春季气温为1971年以来历史同期次低值,夏季气温为次高值;年降水量418.9mm,比常年偏多5%,秋季降水量为1971年以来历史同期第二多。年内,极端天气气候事件频发,多项气象要素突破极值。冬春季持续低温致春播延期、作物发育推迟;夏季全市高温破历史纪录,阶段性干旱明显,局地冰雹及洪涝灾害偏多;秋季连阴雨天气造成涝灾及作物贪青晚熟,春季全市出现大范围大风沙尘天气,给社会经济和人民生活带来较大的损失和影响,其中干旱、冰雹及洪涝造成的损失较为严重。     

《中国近现代史纲要》教学效果问卷分析——以吉林农业科技学院为例

问卷分析表明,本校《中国近现代史纲要》教改比较成功,尤其是一周时事工作历深受学生喜欢。目前存在的问题集中表现在不能激发学生的学习兴趣,因此,提高教师素质,增强学生的主体地位是解决问题的有效措施。     

基于GLDAS-2数据的中国极端降水事件时空变异性研究

全球气候变化导致极端降水事件频发,为了做好应对极端事件的准备,利用GLDAS-2.0数据集进行可靠性分析后,提取9个极端降水指标,使用M-K检验方法分析了1948—2014年中国极端降水事件时空变化特征及其突变趋势。结果表明：全国发生极端降水事件的频率增高,西北、西南和中南地区的年降水量增强趋势明显,连续湿润天数变少,强降水变多,其中西北地区变化最为明显;西北地区中西部,中南与西北、华东的两个交界范围,极端降水相关指标突变趋势明显。结果显示西北地区中西部,西南和中南交界地区以及中南和华东交界地区发生极端降水的频率高,应提前做好应对各种自然灾害的准备。     

降雨对河岸生态系统杨树树干液流及其环境控制的影响

降雨能够改变土壤水分状况进而促进林木蒸腾,然而场降雨量及其持续时间对林木树干液流及其环境控制机制的影响尚不明确。为此,在华北半干旱半湿润区的北京市顺义区共青林场,选取位于河岸生态系统不受土壤水分胁迫的欧美杨(Populus×euramericana)人工林为研究对象,在2019年和2021年生长季,使用TDP热扩散法测量树干液流,同步监测气象及土壤含水量等环境因子。根据对该区长期(2016—2017年、2019年和2021年)降雨数据统计分析结果,将2次降雨脉冲间隔超22.5 h的事件划分2场独立的降雨事件。按照降雨事件雨量及历时,将其中位数±1.5倍标准误的事件定义为常见事件,而将累积概率大于90%的事件定义为极端事件。结果表明:(1)太阳辐射是唯一显著控制该杨树人工林生长季树干液流的环境因子(偏相关系数r_p=0.539),饱和水汽压差、风速和土壤含水量均与树干液流不相关(p>0.533),降雨事件发生前后这一环境控制特征没有发生变化;(2)雨后树干液流随着场降雨量的增加而降低(R²=0.78,p=0.004),但与降雨事件历时无显著相关关系;(3)树干液流在常见降雨事件和极端事件后,在半小时尺度上随时间变化无显著差异(p≥0.264),但4类降雨事件后主导的环境控制因子却不完全相同,太阳辐射和饱和水汽压差总能显著促进半小时尺度的树干液流(r_p≥0.374),而土壤含水量仅在常见和极端的强降雨历时事件后,显著促进雨后半小时尺度液流(r_p≥0.215)。风速显著抑制常见场降雨量事件后半小时尺度的树干液流(r_p=-0.258),却能显著促进常见和极端场降雨历时事件后半小时尺度的树干液流(r_p≥0.183)。研究成果为进一步深入揭示降雨特征对树干液流及其生物物理控制机制的影响,以及改进气候变化下生态水文过程的模拟与评估提供参考。     

横坡垄作下雨型对褐土坡面细沟侵蚀过程的影响

雨型对细沟侵蚀过程起关键作用,而横垄坡面具有独特的细沟侵蚀特征。为定量研究雨型对横垄坡面细沟侵蚀过程的影响,以褐土横垄坡面为研究对象,设计了降雨动能、降雨量和平均雨强相同的4种雨型,采用可同时调节垄向和坡面坡度的土槽进行模拟降雨,分析了各雨型下细沟发育形态、产流产沙特征和细沟水流的水动力特性等。结果表明:雨型间细沟沟头溯源、沟壁崩塌和沟底下切侵蚀速率的不同导致细沟形态具有明显差异,增加-减弱型、减弱-增加型和减弱型的沟宽和沟深较增加型分别增加158.8%和38.9%,115.7%和-27.8%,21.6%和-33.3%,相应宽深比的增加率分别为14.9%,60.4%,82.6%。雨型间的细沟径流量和侵蚀量均差异显著,径流量为增加-减弱型>减弱-增加型>减弱型>增加型,而侵蚀量为增加-减弱型>减弱型>减弱-增加型>增加型。4种雨型下产沙率与径流率之间均符合幂函数关系,但增加-减弱型、减弱型和减弱-增加型方程中的指数较增加型(0.54)分别增加2.52,2.46,1.46倍。雨型间差异最大的水力学参数为雷诺数,侵蚀动力参数则为水流功率;增加-减弱型、减弱-增加型和减弱型的雷诺数和水流功率较增加型分别显著增加107.0%和106.8%,42.2%和41.9%,16.6%和16.7%。研究结果有助于深入理解横坡垄作对坡面细沟侵蚀过程的作用机制,并为横坡垄作措施的合理利用提供依据。     

Retrospective analysis of nonradiation complications in dogs undergoing radiation therapy

Dogs receiving radiation can develop complications unrelated to the radiation treatment. No study to date has described these complications in clinical patients undergoing multiple radiation therapy treatments. The purpose of this retrospective case‐control study was to characterize the incidence and type of complications that occur in these dogs. A secondary goal was to evaluate whether patient and treatment characteristics could be identified to predict the risk of these complications. Medical records of 268 dogs receiving at least one radiation treatment at a single institution, between September, 2004 and June, 2007 were reviewed. Age, breed, gender, body weight, tumor type, tumor location, number of treatments, pre‐treatment blood work abnormalities, and whether chemotherapy, glucocorticoids, or nonsteroidal anti‐inflammatory drugs were given were collected. Number, type, and severity of nonradiation complications were recorded. Complications attributed to the tumor or to the radiation were excluded. Statistical analyses were performed to determine whether demographic and clinical characteristics were associated with development of a complication. General anesthesia was used for all treatments. Complications occurred in 101 (37%) cases including diarrhea, vomiting, cough, and loss of appetite, which were typically mild. Seventeen dogs (6%) developed severe complications. Eight dogs (3%) died from their complication. Dogs that developed complications were younger, received more treatments, had leukocytosis, received glucocorticoids, and were less likely to have thrombocytopenia. On multivariate analysis, number of treatments and leukocytosis were significantly associated with complications. Findings indicate that nonradiation complications are common in dogs receiving radiotherapy under general anesthesia. In this population, complications were usually mild or self‐limiting.     

Impact of short‐term climate effects and sea ice coverage variation on Japanese scallop aquaculture in Saroma Lake,Japan

Saroma Lake is the southernmost lagoon exhibiting seasonal sea ice coverage in the Northern hemisphere and one of the most important aquaculture areas for Japanese scallops (Mizuhopecten yessoensis). Under conditions of adequate food and appropriate temperature, scallops grow well from the time of ice melting in April to harvesting starting in July. However, over the past decade, Saroma Lake frequently has not been completely covered by ice in winter, and the production of Japanese scallops has shown significant changes. Therefore, this study integrated data from satellite remote sensing, buoys, and in situ observations with climatic events [the winter East Asian Monsoon (EAM) and El Niño/La Niña–Southern Oscillation events] to investigate the impact of ice coverage variations on scallop growth in Saroma Lake between 2007 and 2015. Daily ice conditions were detected using Moderate Resolution Imaging Spectroradiometer false colour images and an unsupervised classification method. The results indicated that EAM strongly influenced the ice coverage variation in Saroma Lake through their effects on temperature during winter. Ice coverage variations show a strong correlation with water temperature and spring phytoplankton blooms, which are the two most important environmental factors for scallop growth. In addition, extreme climate events could cause water temperature anomalies (as in 2015) which are unfavourable for scallop growth. Monitoring ice conditions should be considered when developing plans and management strategies for scallop aquaculture in Saroma Lake.     

深秋季台风“海燕”(1330)引发广西特大暴雨的水汽和螺旋度分析

为了探讨深秋季台风暴雨的形成机制,利用CMA热带气旋最佳路径数据、NCEP/NCAR再分析资料、区域自动气象站资料和中国气象数据网提供的降水资料,采用天气学分析及诊断等方法,对引发广西特大暴雨的深秋季台风“海燕”(1330)进行了分析。结果表明：广西特大暴雨期间水汽输送完全靠台风环流本身,但其水汽辐合层伸展到较高的高度。广西的降雨开始于东边界水汽输入达到最大值之后开始减小、南边界由水汽输出转为水汽输入且开始出现明显突增现象时,最强降雨时段发生在南边界水汽输入达到峰值前后。冷空气侵入前期,增强了台风的斜压性,对暴雨起积极作用,但后期冷空气的加强完全破坏台风的暖心结构,使台风迅速填塞同时暴雨也很快结束。相对风暴螺旋度正值中心与强降雨落区有很好的对应关系,并且有至少6 h的提前量。深秋季台风暴雨预报应重点关注水汽辐合高度和冷空气的作用,而相对风暴螺旋度在台风暴雨预报中有非常好的指示意义。     

基于格网的河北省精细化暴雨洪涝灾害风险区划

基于IPCC最新风险评估理论模型,以高精度地理信息数据、长序列均一化气象资料和2010基准年社会经济数据等资料为基础,运用统计建模方法,从气象致灾因子危险性、暴露度和脆弱性3个方面对河北地区暴雨洪涝灾害进行精细化风险评估与区划,并根据区划结果提出防御措施。结果显示：滦河流域下游以及沿海诸河流域的暴雨洪涝风险最高;平原地区的暴雨洪涝灾害风险普遍高于山区,流域下游风险高于上游,河道周边风险高于远离河流的区域。