冬小麦土壤深松保墒增产效应试验研究   总被引：1，自引：0，他引：1       下载免费PDF全文

霍治国  白月明  李光华  温民  陈林 《应用气象学报》2000,(Z1)

采用土壤深松 45cm、30 cm处理打破犁底层 ,1 996～ 1 998年连续进行 2个年度的冬小麦保墒、增产效应田间试验 .试验结果表明 :土壤深松处理后可减少冬小麦全生育期 0～ 1 0 0 cm的作物耗水量 ,促进根系对 1 0 0～ 2 0 0 cm土层土壤水分的利用 ,提高冬小麦的产量耗水比 .土壤深松处理能明显增加 0～ 30 cm土层的土壤湿度和含水量 ,降低 0～ 50 cm土层的土壤容重 .有利于冬小麦根系、茎、叶的生长发育和总生物量的累积 .土壤深松 45cm处理 2年平均冬小麦增产 7.0 % ,土壤深松 30 cm处理第一年增产 7.7% .冬小麦土壤深松保墒增产效应的适宜深松深度为 30 cm.  相似文献   

永暑礁站风的气候统计分析   总被引：1，自引：0，他引：1  

杨彩福  郭湘平  张朝峰  常治国 《海洋通报》2000,19(2):15-19

统计分析永暑礁站最近１０ａ资料,得出该站的风向是以北至东和南至西为主。西南季风期一般为６～９个月,东北季风期１１月至次年４月,少数年份有提前或者推后一个月的现象;东北季风期的平均风速较大,西南季风期的风速很不稳定,风速不稳定指数最大月也是１２级以上大风最多月。  相似文献   

基于随机森林方法的遥感影像分类方法     

赵志国 《北京测绘》2021,35(9):1173-1176

通过研究随机森林方法,针对上海、辽宁、陕西、福建四个地区的中分辨率成像光谱仪(MO-DIS)影像数据,建立五个时间序列的训练集,通过随机森林机器学习方法,学习一年内目标区域的时序变化规律,从而获取更为精确的分类效果,并对比研究该算法对于上述四个地区识别方法的优劣.实验结果显示随机森林分类法在没有海部的地区识别效果能够达到90％以上,使用训练集数据量越大,识别率越高,数据量达到一年左右后,识别率只有微小波动.通过预测图像像素点与验证图像像素点对比进行精度评价,取得了不错的大尺度植被分类结果.  相似文献   

河西走廊中西部干旱区极端暴雨个例分析   总被引：1，自引：0，他引：1  

孔祥伟  陶健红  刘治国  傅朝  吉惠敏 《高原气象》2015,34(1):70-81

利用常规、自动气象观测站资料、卫星资料及NCEP 1°×1°再分析资料,对2012年6月4 5日河西走廊中西部干旱区极端暴雨天气过程的影响系统配置、中尺度特征、水汽输送、不稳定能量等方面进行了诊断分析。结果表明:此次暴雨发生在地面冷锋过境后,降温冷凝作用明显,对流层高层存在强抽吸作用,中层高原低涡受其下游弱脊阻挡较长时间维持在暴雨区上空,低层存在切变线,高低空系统的耦合提供了中尺度对流系统发生、发展的有利条件;水汽主要来自对流层中低层东、西两路及高层南路三支水汽输送通道,西路水汽输送强度最大,东路水汽输送受小高压影响显著,暴雨开始后6 h才完整建立,暴雨中心整层大气可降水量达到了该地区夏季平均值的两倍多;通过降温、增湿作用近地面出现对流不稳定能量,自由对流高度较低;涡旋云系的冷空气侵入处,不断激发出6个β中尺度的对流单体,暴雨中心玉门两次受其中4个单体的影响,产生短时强降水。  相似文献   

应用Winding-Number算法快速确定中国地震地理位置名称     

任枭  殷翔  徐志国  孙丽 《地震地磁观测与研究》2011,32(4):145-151

应用Winding-Number算法,快速确定中国地震地理位置名称(精确到县市区一级),查询过程具有准确性、高效性和误差小等特点.根据实际要求,将地名查询程序应用到F-E分区程序,可得到中国地震地理位置详细名称,顺应地震观测报告的出版要求,为地震基础科学研究提供便利.  相似文献   

利用宽频带数字地震资料测定地震震级的方法研究   总被引：5，自引：4，他引：1  

刘瑞丰  任克新  张立文  韩雪君  徐志国  孙丽  任枭  刘敬光 《地震地磁观测与研究》2011,32(3):1-8

在国际地震学与地球内部物理学联合会(IASPEI)新推荐震级标度在中国地震台网中心应用的基础上,提出中国地震台网地震震级测定方法.研究指出,地方性震级ML与不同地区的地震波衰减特性具有密切关系,区域性特征明显,为保证中国地方性震级的一致性,宜沿用中国传统测定方法.建议:用IASPEI新推荐的短周期体波震级mb和宽频带体...  相似文献   

Research on the Distribution and Content of Water Ice in Lunar Pole Regions Using Clementine UVVIS Data     

孟治国  陈圣波  路鹏  汪自军  连懿  周超 《中国地质大学学报(英文版)》2011,(5)

Interest in the Moon started to increase at the beginning of the 21st century,and henceforth,more and more attention has been paid to the content and distribution of water ice in the lunar polar regions.The existence of water or ice in the regolith can apparently change its dielectric features.Therefore,in this article,the Dobson model is adopted and improved according to the Moon's environmental features,to construct the relationship between the volumetric water ice content and the dielectric constant.Ther...  相似文献   

Stable carbon and oxygen isotopic study of carbonate along a loess/paleosol section in Lantian County, Shaanxi Province, on the southeastern edge of the Chinese Loess Plateau     

Qian Xue  Zhiguo Rao  Suping Wang  Pingyu Zhang  Fahu Chen 《Environmental Earth Sciences》2011,64(1):237-246

Studies of carbonate carbon isotope of loess/paleosol (δ¹³C_carb) in the Chinese Loess Plateau (CLP) have shown δ¹³C_carb less negative in loess and more negative in paleosol, which is opposite to that of bulk organic matter. Although some mechanisms have been proposed to explain this inconsistency, few studies have been conducted to investigate how carbonate migration could affect the reliability of utilizing δ¹³C_carb as an effective indicator. Here, a loess/paleosol profile with a nodule horizon intercalated in the loess layer, located on the southeastern edge of the CLP, was investigated to understand the influence of carbonate eluviation and reprecipitation on δ¹³C_carb along the section. The mean grain size and magnetic susceptibility generally conform to the field observed loess/paleosol stratigraphy. However, carbonate content shows distinct differences in the two sides of the nodule horizon, clearly indicating eluviation along the section. The variation of carbon and oxygen isotopic compositions of soil carbonate (δ¹³C_SC and δ¹⁸O_SC) and nodule carbonate (δ¹³C_NC and δ¹⁸O_NC) along the profile does not present a clearly meaningful picture. Generally, δ¹³C_SC and δ¹⁸O_SC have a similar change trend along the profile and are positively correlated, but there is no apparent relationship between δ¹³C_NC and δ¹⁸O_NC. More importantly, δ¹⁸O_NC values fall in the range of δ¹⁸O_SC, whereas δ¹³C_NC values are much more positive than δ¹³C_SC. Detailed analyses of the data indicate migration of carbonate along the profile, which is an important factor that determines that loess/paleosol δ¹³C_carb could not be employed as a high-resolution paleovegetational and paleoenvironmental indicator in the CLP, at least on or below the glacial/interglacial scales.  相似文献   

Influence of Dietary Probiotic Bacillus TC22 and Prebiotic Fructooligosaccharide on Growth,Immune Responses and Disease Resistance against Vibrio splendidus Infection in Sea Cucumber Apostichopus japonicus     

ZHAO Yancui  MAI Kangsen  XU Wei  ZHANG Wenbing  AI Qinghui  ZHANG Yanjiao  WANG Xiaojie  LIUFU Zhiguo 《青岛海洋大学学报(英文版)》2011,(3):293-300

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Influence of temperature and frequency on microwave dielectric properties of lunar regolith simulant     

EDWARD Matthew Osei Jnr 《中国地理科学(英文版)》2011,21(1):94-101

The dielectric constant of the lunar regolith can directly influence the reflection coefficient and the trans-mission coefficient of the Moon′s surface, and plays an important role in the Moon research. In order to study the di-electric properties of the lunar regolith, the lunar regolith simulant was made according to the making procedure of the CAS-1 simulant made by Chinese Academy of Sciences. Then the dielectric constants of the lunar regolith simulant were measured with 85070E Aiglent Microwave Network Analyzer in the frequency ranging from 0.2 GHz to 20.0 GHz and at temperature of 25.1℃, 17.7℃, 13.1℃, 11.5℃, 9.6℃, 8.0℃, 4.1℃, -0.3℃, -4.7℃, -9.5℃, -18.7℃, -27.7℃, and -32.6℃, respectively. The Odelevsky model was employed to remove the influence of water in the air on the final effective dielectric constants. The results indicate that frequency and temperature have apparent influences on the dielectric constants of the lunar regolith simulant. The real parts of the dielectric constants increase fast over the range of 0.2 GHz to 3.0 GHz, but decrease slowly over the range of 4.0 GHz to 20.0 GHz. The opposite phenomenon occurs in the imaginary parts. The influences of the frequency and temperature on the brightness temperature were also estimated based on the radiative transfer equation. The result shows that the variation of the frequency and temperature results in great changes of the microwave brightness temperature emitting from the lunar regolith.  相似文献