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1.
[目的]分析丹东地区春播期低温冷害的气候特征及演变规律.[方法]利用丹东地区4个测站1961~2010年4月下旬至5月上旬日平均气温资料以及亚洲极涡面积和太阳黑子等特征量,对春播期低温冷害的成因背景进行分析.[结果]丹东地区4月下旬发生低温冷害的频率高于5月上旬,1980、1988和2010年出现了严重的低温冷害.[结论]线性倾向趋势分析表明,1961~2010年丹东地区低温日数呈增加趋势. 相似文献
2.
[目的]探讨河西走廊中西部风能资源的时空分布特征及储量.[方法]利用河西走廊中西部10个气象观测站1955-2007年风速气象资料和2007年1~12月专用风塔精细资料,研究了该区域内风能资源的分布特征及其储量.[结果]河西走廊中西部环魔风速相对较稳定,气候特征分布上无明显跳跃式变化;风能资源分布存在明显的地域性差别,瓜州县和玉门市附近存在1个风能大值区;区域内风能普遮较高,10m高度层内瓦能密度在100w/m2以上,大部分地方在140w/m2左右,大值地带在200w/m2以上;垂直方向上风能随高度呈线性增长,平均每升高10m风能约增加15w/m2,50m层风能普遮大于240w/m2.河西走廊中西部风能存在明显的日、年变化,3-5月是风能密集阶段;距地面高度10m处风能在10:00前后处于低值,从11:00以后不断增大,到18:00前后达到日最大,然后逐渐减小.区域内年有效风速时数普遥在6200 h以上,大值区接近7600 h.[结论]为河西走廊中西部风能的开发利用提供了理论依据. 相似文献
3.
根据2005~2009年湘西主要产烟区烟叶收购统计数据,分析了烟叶生长期主要气候事件(春寒、倒春寒、5月低温、连阴雨、雨季结束时间、日最高气温≥35℃高温的日数、日最高气温≥35℃连续天数、干旱)对烟叶产质量的影响.结果表明,湘西主要产烟区出现在3月中旬的春寒或倒春寒天气过程可能对烟叶的产质量造成严重影响;4月轻度春寒或倒春寒,轻度5月低温对烟叶产质量的负面影响较小;在雨季结束日期不明显的年份,8月份的干旱有利于烟叶产质量的提高;7、8月份高温期间,温度、湿度、日照、云量、日较差等综合气象因素可能是湘西高品质烟叶生产的重要因素;日最高气温≥35℃的高温日数偏少对烟叶产质量有负面影响,日数偏多则有利于烟叶产质量的提高;5月低温与重度连阴雨同时出现时,烟叶的产质量严重下降,6月连阴雨对烟叶的产质量影响较小,7月连阴雨有助于烟叶的生长. 相似文献
4.
利用山东省90个气象观测站逐日气温资料,采用中值和Hampel提出的一种新的极端事件检测方法,检测并分析了山东极端冷暖天气气候事件的变化特征.结果表明,极端高温日数无显著变化,极端暖日数趋于上升;极端冷事件显著减少,具有明显的年代变化特征,20世纪60年代为极端冷(暖)事件的高发期,70~80年代中期均有所减少;90年代中期以后为极端暖事件高发期,而极端冷事件急剧减少.在空间分布上,山东省大部分地区极端冷事件趋于减少,而极端暖事件发生频率的变化则呈现出东部沿海地区增加、鲁西南和鲁西北减少的径向分布特征.在20世纪80年代中期全球明显变暖背景下,山东省极端暖事件的线性变化正趋势范围明显变大,大部分地区的极端低温日数的变化趋于平缓,极端冷日数仍以迅速减少为主要趋势. 相似文献
5.
[目的]研究沈阳沈北新区蔬菜大棚生产期气候变化及气象灾害对策.[方法]利用沈阳沈北新区近38年气象观测资料,采用常规数理统计方法,分析沈北新区蔬菜大棚生产期气候变化,并探讨气象灾害天气的应对措施.[结果]近38年来,沈北新区光照条件一般,冬季平均日照时数较短(551 h),呈缓慢减少趋势,但降幅并不明显;沈北新区蔬菜大棚生产期气温倾向率0.371 ℃/10 a,冬季气温倾向率0.313℃/10 a,气温虽呈升高趋势,但波动幅度较大,让生产管理难以控制;较寒冷期(11~3月)历年降水量、阴天日数呈增加趋势,对蔬菜大棚生产影响较大;低温寡照阴天是该区冬季气候特点,对发展蔬菜大棚产业不利,冬季增加取暖措施有望正常发展.[结论]研究结果可为当地设施农业的发展提供科学依据. 相似文献
6.
[目的]比较黔东南两次冰冻灾害.[方法]利用黔东南自动站的气象资料,分析了2010年12月31日-2011年1月10日冰冻灾害的出现时间、影响范围、灾害强度,并与2008年1月的冰冻灾害进行比较.[结果]黔东南2011年1月冰冻灾害天气起始时间较早,影响范围大,来势过猛,气温下降较低,气温有间隙性升温,后续冷空气较弱,冰冻灾害逐渐减轻;而2008年1月冰冻灾害起始时间较晚,持续时间较长,后续冷空气逐渐增强,气温逐渐下降,并伴有持续性降雨(雪),冰冻灾害逐渐加重.可见,2011年冰冻灾害不如2008年严重.[结论]研究结果可为冰冻灾害的预报预警及相应对策的制定提供科学依据. 相似文献
7.
白先达 《Canadian Metallurgical Quarterly》2011,39(11)
[目的]研究桂林地区冰雹天气及其预报方法.[方法]针对桂林地区的冰雹发生情况,结合桂林新一代多普勒天气雷达的观测资料,总结分析影响桂林地区冰雹的天气形势和雷达回波特征,探索冰雹天气的短时临近预报方法.[结果]桂林地区每年都会出现1~2次冰雹,冰雹发生受地形影响明显,地理分布极不均匀;时间分布比较集中,主要发生在春季,且多发生在下午到傍晚时分.新一代多普勒天气雷达探测冰雹十分有效,桂林地区冰雹的回波单体强度≥50 dBz,回波顶高≥10 km,垂直液态水含量≥40 kg/m<'2>,常配合有中气旋,冰雹很强的时候,还会出现三体散射特征.冰雹的预报以短时临近预报为主.[结论]该研究为冰雹的预报、人工消雹和减灾防灾工作提供参考. 相似文献
8.
[目的]研究沈阳地区近58年积温变化趋势及其对农业生产的影响.[方法]利用沈阳地面气温资料,应用气候统计学方法,分析了近58年沈阳≥0℃、≥10℃积温变化趋势,并探讨了积温变化对农业生产的影响.[结果]近58年来,沈阳地区气温≥10℃初日提前约10 d,终日推后不明显,持续日数延长13 d,≥0℃积温增加343℃;≥10℃初日提前约9 d,终日推后8 d,持续日数延长16 d,≥10℃积温增加370℃;后20年平均值与前20年相比,≥0℃、≥10℃持续日数均延长9 d,≥0℃、≥10℃积温分别平均增加196、202℃.另外,沈阳地区热量的增加对当地农业生产有一定影响.[结论]该研究可为当地掌握热量资源变化特征及调整农业布局提供理论依据. 相似文献
9.
[目的]分析鲁西北灰霾天气特征及影响因素.[方法]根据德州市11个县市1970~2009年灰霾和日照时数资料,对鲁西北灰霾天气的日、月、季、年变化及其原因进行分析,并讨论灰霾对日照时数的影响.[结果]一日中09:00~14:00出现灰霾频率最多,不同季节日变化不一致;一年中12月出现灰霾日数最多(200 d),其次为1月(161 d),8月最少(20 d).从季节上来看,秋、冬季灰霾出现多,分别占全年的23%、40%;春、夏季出现少,分别占18%、20%.年际变化上,1970~1979年鲁西北灰霾出现日数最少(110 d),趋势倾向率为2.27 d/a;2000~2009年最多(724 d),倾向率为16.35 d/a.灰霾日数的区域分布,德城区最多,其次为夏津,最少为禹城.灰霾日数的年际变化多与大气中的污染物浓度有关,月、季变化多受天气形势和气象条件控制.[结论]该研究为灰霾的预防及其影响评估提供科学依据. 相似文献
10.
利用宣城市2010年气象资料,分析了气候特征及其影响.结果表明,2010年全市平均年降水量正常略偏多,除绩溪、宁国较常年偏少外,其余各县偏多;入梅、出梅期偏迟,梅雨日数和全市平均梅雨量较常年偏多.全市年平均气温比常年偏高,高温日数多于常年.主要气象灾害是7月3~23日降水强度大、持续时间长的全市梅雨型暴雨洪涝灾害以及3月上旬末和12月15~16日低温雨雪冰冻灾害,其对工农业生产造成严重影响.农业方面病虫害迁入量小,较常年偏轻;受气象灾害影响,油菜、茶叶、棉花减产,但水稻产量增加,气候上属正常年景. 相似文献
11.
The report is concerned with a study of fine structures of brain capillaries in 9 embryos received during medical abortions from schizophrenic mothers. The authors established some traits in the ultrastructure of endothelial cells in most of the studied cases--an increase of the surface of endothelial cells at the expense of a tortuosity of their plasmatic membranes and a formation of growths, vacuolization of the cytoplasma. There were also some changes in the structure of basal membranes. In 2 cases there were also peculiar pathological changes in the vascular endothelium: granules of an unknown nature in the endothelial cells and a focal lysis of the plasmatic membranes of endothelial cells. 相似文献
12.
刘社平 《Canadian Metallurgical Quarterly》2011,39(10)
[目的]验证不同除草剂的除草效果,为直播冬油菜田的杂草防除提供借鉴.[方法]使用不同剂量25%胺苯磺隆可湿性粉剂和10.8%高效氟吡甲禾灵乳油在直播冬油菜田间进行单用和混用除草试验.[结果] 25%胺苯磺隆可湿性粉剂在冬油菜4~5叶期使用可以有效防除田间的阔叶杂草;25% 胺苯磺隆可湿性粉剂18.0~22.5 g/hm<'2>+400 ml/hm<'2>的10.8%高效氟吡甲采灵乳油可以有效防除油菜田间的阔叶和禾本科杂草,总防效达90%以上,且可以比人工除草节省成本1 100元、hm<'2>.[结论] 25%胺苯磺隆与10.8%高效氟吡甲未灵乳油混用可以更好地防除冬油菜田间杂草. 相似文献
13.
V. G. Lisienko G. K. Malikov M. V. Morozov V. V. Belyaev V. A. Kirsanov 《Russian Journal of Non-Ferrous Metals》2013,54(4):287-291
A mathematical model of the Vanyukov furnace, which makes it possible to predict the behavior of an object in the emergency operational mode (upon the disconnection of the oxygen supply) and develop an effective system of additional heating which damps the consequences of the emergency mode and lowers the costs for the renovation of the furnace operation, is created. It is shown how solidification upon cooling the furnace with time is simulated using the enthalpy and porosity method. The mathematical model is adopted for existing production conditions, which are weakly defined. The energy characteristics of the mode for the solidifying furnace bath, which ensures its holding for a long time in the ready state to rapid firing, are found. Thus, the problem of excessively expensive furnace firing after prolonged production stoppage is solved in the conjugated statement with a calculation of the heating system of the overbath space. 相似文献
14.
The anatomic relationship of the 2 major vessels of the left coronary groove was studied in 140 dogs. Five basic patterns of disposition were observed: 1) circumflex artery superficial from its origin to the caudodorsal cardiac margin, coronary vein deep and not visible (22%); 2) coronary vein superficial from the ventral interventricular septum to the caudodorsal cardiac margin, circumflex artery deep and not visible (15%); 3) circumflex artery and coronary vein both superficial and running parallel with each other along the groove (8%); 4) coronary vein crossing circumflex artery at some point along the groove (44%); and 5) circumflex artery crossing coronary vein at some point along the groove (11%). These variations were found to influence certain experimental modifications of the left circumflex blood flow in the dog. 相似文献
15.
OM Horbatiuk 《Canadian Metallurgical Quarterly》1998,(4):25-27
The study was made of labyrinthine changes induced by lasix dehydration. Changes indicative of Meniere's disease were identified at comparison of the findings obtained by audiological lasix test, caloric optokinetic reactions. Four types of the nystagmic response in the bithermal lasix-test were determined. These reactions are helpful for more precise staging of the disease. 相似文献
16.
The substantia nigra pars reticulata (SNpr) is a critical site for the control of epileptic seizures. Potentiation of the inhibitory GABAergic input from the striatum to the SNpr suppresses primary or secondary generalized seizures in the rat. The purpose of this study was to examine the possible involvement of the excitatory glutamatergic input from the subthalamic nucleus to the SNpr in the control of both the electroencephalographic and the motor components of amygdala-kindled seizures in the rat. Microinjections of either an N-methyl-D-aspartate (NMDA) antagonist in the substantia nigra or a GABAA agonist in the subthalamic nucleus, significantly reduced motor seizures but did not modified the afterdischarges. These results provide evidence for the involvement of the subthalamo-nigral projection in the modulation and the propagation of the motor components of amygdala-kindled seizures. 相似文献
17.
The objectives of this study were to develop a system to calculate the economic consequences of accidents and to account for the economic consequences of all accidents during 1 year in a district. A total population injury survey was done in an area with a population of over 41,000. All accidents (N = 4926) occurring within a 12-month period and requiring medical care were noted. The costs (calculated at 1991 prices) to the health care service (outpatient care, including primary health care and hospital care) were SEK 23.7 million (US $3.59 million), to trade and industry SEK 79.7 million (US $12.08 million), and for health insurance SEK 9.1 million (US $1.38 million). The cost for society of uninsured people is not possible to estimate using loss of production. However, the time lost from "normal activities" was registered. If this time is valued at the same price as working hours, a welfare cost of SEK 43.1 million (US $6.53 million) should be added. In a forthcoming paper, an assessment of the cost-effectiveness of interventions against accidents will be published. 相似文献
18.
A two-level model is presented for explaining the development of the topographically ordered retinotectal connections of the visual system of the frog. The columnar structure of the tectum were taken into account explicitly. Simulations suggest that the self-excitatory intracolumnar connections play an important role in the formation of the topography. In the case of self-excitation the system is able to recognize the topology of the visual field by the continuity of the object's movement. 相似文献
19.
With the help of microionophoretic stimulation of individual neurons of the arcuate region of the hypothalamus and the registration of its activity, changes in the sensitivity to dopamine during several stages of the sexual cycle of rats was studied. It was shown that in the 1st half of the day of proestrus the majority of neurons of the arcuate region, in correspondance to the increase in the level of estrogens in the blood plasma during this phase of the cycle, were activated by microionophoretic injections of dopamine. In the 2nd half of the day of proestrus, when the level of estrogens is minimal, and in the Diestrous-2 stage, it was observed that among registered neurons, those activated by dopamine were the most inhibited. 相似文献
20.
AV Chalyshev 《Canadian Metallurgical Quarterly》1998,29(3):92-104
Dietary character of ruminants in the north is principally different between "nonselective" (cattle, sheep) and "selective" (reindeer, moose) species. Due to the developed polyfunctioning, forestomach in ruminants, primarily rumen and reticulum, are involved in the homeostasis formation in enteral and interior mediums, nutrients deposition and recirculation. That provides efficiency in utilization of deficient in nutrients forage and body reserves of wild ruminants during the winter. The original functional organization of absorption processes and nutrients recirculation across the multilayer epithelium of forestomach also promotes realization of the two levels metabolism during the year and adaptation of wild ruminants to season dynamics of nutrition. 相似文献