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本文利用楚雄市1971-2007年37年的年降水量和相对湿度等资料,计算了楚雄市降水距平百分率并分析了37年来楚雄市干湿变化,结果表明楚雄市降水呈波动的状态,楚雄市降水量的近10年平均值有所增加,通过计算发现楚雄冬、春季节比较干燥,夏、秋季节比较湿润,楚雄市多数年份的气候属于干旱型.通过城市与郊区的对比分析发现城市降水量和相对湿度有别于郊区,原因是下垫面性质的不同,提出了针对楚雄市的干旱防御措施. 相似文献
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利用楚雄市气象站1987-2007年观测资料中的风向资料来统计代表冬季的1月和代表夏季的7月的风向频率,冬夏两季节的盛行风向风呈90度角.据此从季风角度结合楚雄市的居住区分布现状提出适宜楚雄市居住区和工业区布局的模式及总体布局.利用楚雄市2006年环境监测污染物二氧化硫、二氧化氮和可吸入颗粒物日浓度资料和同步风资料分别分析风向风速与二氧化硫、二氧化氮和可吸人颗粒物浓度的关系,它们的浓度随风速风向的变化而变化. 相似文献
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黄伟峰 《中山大学学报论丛》1990,(4)
讨论了广州雾日的时空变化.研究指出,由于广州近地层气温较高,加上城市热岛和干岛效应的影响,年平均雾日较少.34年的资料表明,广州平均雾日为4.8天,春季最多,冬季次之,夏季最少.1～4月为雾季,雾一股出现在清晨5～7时.50年代至70年代雾日增加,80年代开始雾日有减少的趋势.广州的雾可以分成4种类型:即辐射雾(占24％),锋面雾(占14％),平流雾(占14％)和平流辐射雾(占48％).最后指出,雾是稳定的象征,它与大气温度层结有密切的关系。 相似文献
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对临沧站1961—2010年的雷暴日数进行统计分析。结果表明:临沧属于雷暴多发区,雷暴日数年际变化大,近50 a平均年雷暴日数为75.46 d,最多年为100 d,最少年为40 d;近50 a年雷暴日数呈显著减少趋势,减少率为5.75 d/10 a;临沧雷暴日数的季节性变化十分明显,夏季最多,占全年46.94%,冬季最少,占全年4.12%;4—10月是雷暴高发期,占全年89.40%。临沧多年平均雷暴初、终日分别为2月3日、11月15日,年雷暴持续期平均为286.94 d。 相似文献
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基于南充气象站1951年至2005年的逐日地面气候资料,分别统计整理出南充1951~2005年平均温度、平均最高温度、平均最低温度、极端最高温度、极端最低温度、高温天气(日最高温度≥35℃)日数、低温天气(日最低温度≤0℃)日数、降水量、雨日和最大日降水量等气候要素。应用线性倾向估计、小波分析、R/S分析、灾变灰预测等方法对南充极端气候变化进行了研究探讨,并在此基础上尝试预测了未来南充极端气候变化的情形。研究表明:南充极端气候变化具有明显的多尺度振荡特征,并且振荡分量具有明显的年际、年代际变化。极端温度气候的变化特征具有地域特殊性,与全球变暖的趋势不一致。极端高温在年际尺度上均表现为降温为主要特征的变化趋势,季节内尤其以夏秋季差异明显。极端低温在年际尺度上表现为有升有降,但幅度都不大。季节内以冬季变化有所差异。极端降水气候的变化特征受地形和环流特征影响,总体表现越发的不稳定。夏季降水量变化特征较之其它季节极不稳定,而雨日变化除冬季外,其余季节呈一致的减少趋势。汛期雨日骤减,而降水量则成波动上升的趋势。这将增加汛期强降水事件的发生概率,给嘉陵江流域的防汛工作增加难度。年最大日降水量在近年来呈现出密集峰值区,这是强降水事件的先兆信号。未来年极端最低气温将继续上升,"暖冬"事件可能增多。汛期降水量将会增加,由于雨日持续减少,汛期降水将多以"强降水事件"出现,加重汛期洪涝灾害。 相似文献
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楚雄市城市发展对气候的影响分析 总被引：1，自引：0，他引：1
何萍 《楚雄师范学院学报》2005,20(3):64-68
利用云南楚雄市气象观测站资料与其郊区南华气象观测站资料进行对比分析，发现了楚雄市的城市气候的一些年变化和日变化规律。结果表明，进入二十世纪80年代以来，随着城市的发展，楚雄市城市气候变化日趋突出，并且有明显的季节性。 相似文献
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徐州市降水特征及频率分析 总被引：1，自引：0，他引：1
基于1991—2009年徐州市降水资料,分析了近19年来徐州市降水量的年际和年内变化特征,并采用皮尔逊Ⅲ型频率曲线分析降水频率．结果表明：徐州市多年平均年降水量为857．6mm,总体降水量基本平稳;降水异常年份偏多,旱涝出现频数相当;年内降水量分配不均,降水集中性强,主要集中于6-8月,占全年降水量的61．9％;通过降... 相似文献
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《滁州学院学报》2015,(5):5-14
为揭示滁州市1952—2012年的降水变化规律,利用其逐日降水量数据,对滁州市年、季、月降水量的变化特征进行分析。结果表明:滁州市年降水量变化比较明显,降水倾向率为10.232mm/10a;四季中春季降水量减少和夏冬降水量增加的趋势较为明显,且春夏降水较多,秋冬较少;各月降水量7月份最多,12月份最少,且分布不均。年降水日数总体呈减少趋势,气候倾向率为-6.628d/10a;四季平均降水强度和降水日数分别呈总体增加和减少趋势,同时春秋两季以中雨为主,夏季主要是暴雨,冬季以小雨和中雨为主;十二个月中2个月以小雨为主,5个月以中雨为主,1个月以大雨为主,4个月以暴雨为主。 相似文献
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用气候倾向趋势分析、相关性分析、距平和方差分析等数理统计方法对楚雄州辖区内10个县气象观测站近50年（1961-2010年）的气温、降雨资料,按年度、春季、夏季、秋季和冬季5个时段,分析了楚雄全区域,中部、西部、南部和东北部区域的气温、降雨量、降雨日数的演变。结果表明：近50年来楚雄州气温升高明显,暖冬现象突出,春季升温快,年降雨量和大雨降雨日数增加,秋季降雨量和年降雨日数减少,年降雨量变率增大;尤其是近15年楚雄10县（市）平均气温16．4℃,较前30年增高了0．2℃;大雨以上的降雨天数平均增加了1～3天,其中,暴雨、大暴雨日数明显增多,年总降雨日数和小雨日数明显减少,春季降雨量增加,秋季降雨量减少,相当年份雨季提前结束1个月左右,雨季呈缩短趋势变化。 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
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Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
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Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献