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1.
[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   

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用统计学原理对泰安市所辖的5个气象观测站1971~2009年的大雾资料进行分析,得出时间分布特征:全市大雾主要出现在每年1、11和12月,平均雾日分别为2.2、2.9和3.0 d;空间分布特征:新泰大雾极差和标准差均最大,分别为57和15 d;肥城最小,分别为23和5 d.全市年最多雾日142 d,最少26 d,分别出现在1982年和1995年.一元线性回归法得出全市大雾日数呈减少趋势,气候变化率为8.7 d/10 a.  相似文献   

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利用北京地区1985~2008年逐日降水数据资料,运用IPCC极端天气气候事件指标确定方法计算得到北京地区暴雨天气指标在10.4~38.8mm波动,暴雨气候指标为日降水量≥27.5mm.以暴雨天气指标、暴雨气候指标和国家暴雨标准计算历年的暴雨日数和暴雨量,统计分析年降雨日数、暴雨日数和年降水量和暴雨量与作物洪涝受灾率的相关关系,得出年降雨日数和暴雨日数都不能真实地反映作物洪涝受灾率,而年降水量和暴雨量与作物洪涝受灾率则具有明显的线性正相关关系.以区域暴雨气候指标统计的暴雨量与作物洪涝受灾率相关程度最高,建议以暴雨量来预测评估洪涝灾害时,采用区城暴雨气候指标.  相似文献   

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利用重庆主城区近百余年降水资料,研究了不同级别雨目及其强度、贡献率的气候特征和长期变化趋势,并探讨了它们与各年代降水异常的关系.结果表明:重庆主城区降水日数近百余年为显著的线性增加趋势,而1961年以来却为显著的线性减少趋势.百年来降水日数的阶段变化十分明显,分为增→降→增→降4个阶段,其中20世纪60年代降水日数最多,20世纪20年代最少.小雨日数与降水日数的变化趋势比较一致.中雨、大雨和暴雨的线性趋势不明显,分别为弱的减、增、增趋势.降水强度阶段变化正好与降水日数相反.降水量异常与各级雨日日数、强度和贡献率密切相关.年降水最少的年代1892-1900年主要与大雨和暴雨日数显著偏少、暴雨强度偏弱有关.年降水最多的是20世纪10年代,主要是暴雨日数偏多引起暴雨的贡献率显著偏高.21世纪以来降水偏多主要与中雨日数偏多和暴雨强度偏强有关.  相似文献   

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利用漳州市1971~2000年30年地面降水观测资料,对漳州市暴雨的时空分布及其影响系统进行分析.结果表明,暴雨月时间分布呈现年头年尾少、年中多趋势,6~8月为暴雨高峰期;年平均暴雨日数和汛期3~10月暴雨日数地理分布呈现西南偏多、南北偏少特征;冬季暴雨日数分布呈现由南自北逐渐减少特征;暴雨落区与漳州地形特征紧密相关;暴雨主要在南支槽、西南急流、热带气旋影响的天气条件下发生.  相似文献   

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利用陕西省苹果产区近40 a 8月中旬至10月中旬逐日降雨量资料,提出了以连阴雨灾害指数L<,u>(L<,u>=N<,r≥3>/N<,R=0>)(N<,r≥3>为8月中旬至10月中旬雨日连续3 d以上的日数,N<,R=0>为8月中旬至10月中旬无降水日数)量化进行风险分析的方法.用此方法计算了苹果产区各地连阴雨气象灾害指数,分轻度、中度、重度3级对果区各地连阴雨气象灾害指数进行了分级、评价.结果表明,有13个县连阴雨气象灾害指数为轻度,有27个县连阴雨气象灾害指数为中度,有8个县连阴雨气象灾害指数为重度.此计算结果与陕西果区实际连阴雨影响基本一致,表明灾害指数方法是一种较好的风险分析方法.  相似文献   

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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   

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辽宁省由于特殊的地理位置、地形和气候条件,成为气象灾害发生较频繁、较严重的省份之一.其中由暴雨引发的渍涝灾害是最主要的灾害,它给国民经济和人民生命财产带来巨大损失.气候变暖导致了降水格局的变化,也使渍涝灾害发生频率增加.从分析诱发渍涝灾害发生因子入手,以气象条件为基础,分析了渍涝灾害发展趋势,并建立了渍涝等级预报指标,对气象防灾减灾具有重要的现实意义,也为气象更好地服务农业提供科学的参考依据.  相似文献   

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通过对广西博白县洪涝灾害的特征、灾害等级和灾害的成因进行分析,结果表明:博白县在1960~2009年50年中共发生洪劳灾害58次.平均每年1.2次,主要集中在4~9月,个别年份也发生在10月;2005~2009年为洪涝灾害发生最频繁阶段,每年3次,洪涝灾害的发生呈现明显增多和增强的趋势.6~8月的南流江水位与博白气象站的降水量相关显著,南流江水位有5、11、4年的周期变化.降水量随季节的转换而发生突变,降水强度也随季节的转换而有明显的差异,且县内南北地区的降水量有明显的差异.降水的变率大、过于集中和暴雨日数多且强度大是造成洪涝灾害的主要原因.  相似文献   

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[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   

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以重庆大学、重庆邮电大学和重庆理工大学为例,剖析重庆高校推进产学研合作的基本模式,已经取得的突出成绩,分析总结其基本经验.从完善政策法规体系、强化经济调控、建立组织机构、加强中介建设及开展国际产学研合作等方面,提出了深入推进重庆高校产学研合作的对策建议.  相似文献   

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The efficacy of treatment with cambendazole was tested in 1-year-old horses on a farm in Dubrovka, Ukraine. Thirty-five horses were treated. Their egg output was compared on the day of treatment and 14 days later with that of 33 untreated horses. Before treatment the mean number of eggs g-1 faeces was 614 in the controls and 766 in horses that had been treated. After 14 days the mean egg output in the controls was 580 and in the treated horses 369. This means a reduction of 54.5%. Only cyathostome larvae could be cultured from faeces collected after treatment. It can be concluded that benzimidazole resistance in cyathostomes is present in the Ukraine.  相似文献   

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We report the appearance of apoptotic cells in experimental myocardial infarction (rabbit heart) in in situ and in vitro preparations. Apoptosis was recognized by intravital staining with Hoechst 33342 (Ho342), by nick-end labeling (TUNEL) and by DNA laddering. A steady rise in the relative number of apoptotic cardiomyocytes (apoptotic index) was noted in in situ preparations. Apoptosis was first noted 6 h after the onset of ischemia with its highest value occurring after 72 h. Apoptotic nuclei were absent in remote areas of the left and right ventricles. Apoptotic nuclei within the infarcted area showed diminished intensity of Ho342 fluorescence. Three days after ischemia, a border zone adjacent to the infarcted area consisting of apoptotic macrophages was recognized. A novel finding was the appearance of apoptotic cardiomyocytes in the isolated perfused ischemic heart. Occurring as early as 50 min after the onset of ischemia, a high apoptotic index was present adjacent to the ligature placed around the coronary artery. This observation provides the opportunity to selectively examine factors leading to apoptosis in the ischemic heart under controlled experimental conditions.  相似文献   

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A prospective study of fractures in 231 children received at Khartoum North Teaching Hospital(KNTH) was carried out for a period of six months. The incidence of child fracture rated as one per day, then it increased from the age of 5 years onwards in boys and between 6 and 8 years in girls. Most injuries were sustained during the day time, especially between late afternoon and sunset. 82% of injured children presented to a medical facility, while 18% were taken to native healers first. Non-road traffic accidents accounted for 84% of the fractures mainly due to sports, domestic injuries and falls; whereas road traffic accidents were 16% and occurred mainly in pedestrians. Forty three percent of the fractures needed only first aid and splintage while 42% needed closed reduction. Thirty one percent of all patients were treated as inpatients. The long bones were affected in 91% of all fractures, the commonest site being the distal end of the forearm (26%), followed by supracondylar fracture of the humerus (15.6%). In the upper limb, left-sided fractures predominated. The epiphyseal injuries were 3.5% of all fractures, mainly at the distal radial epiphysis. Boys were commonly affected between 13-15 years of age. Open fractures constituted 9.8% of the series and were mainly due to traffic accidents in town dwellers, the most vulnerable bones were those of the leg and foot. Pathological fractures accounted for 2.2% and were due to bone cysts and osteogenesis imperfecta. The problem of child safety and the preventive measures need to be more stressed.  相似文献   

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It is a common opinion that general surgery is the first step for whoever approaches a surgical discipline, and that whoever practices training in general surgery should learn the rudiments of each surgical branch. The role of microsurgery in the training of the general surgeon has not been well-established. Clinical applications of microsurgery in general surgery are few and are rarely required, and have been connected strictly to restricted indications. However, we think that microsurgery could be very useful to the general surgeon because it allows the execution of experimental research on rats, the only possibility permitted by law. In these studies the microsurgeon can perform many times and in a short time the same surgical operation, thus improving his skill, and easily getting familiarity with surgical instruments and sutures.  相似文献   

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