濮阳市0 cm地温变化特征及成因分析   总被引：5，自引：1，他引：4  

贾金明  朱腾冉  王惠芳  谢若梅  钟天华  田国卫 《气象科技》2009,37(3):330-335

利用线性分析方法和相关分析方法,分析了濮阳近50年地面温度的变化倾向率及成因。月平均地面温度变化趋势具有明显的阶段性,12月至翌年4月呈升温趋势,5～11月呈降温趋势,其变化倾向率分别为0．01～0．32℃／10a和-0．04～-0．83℃／10a,年平均地面温度变化倾向率为-0．23℃／10a;各月地面平均最高温度的变化倾向率,11月为0．01℃／10a,其余月份则为-0．46～-2．16℃／10a,年变化倾向率为～0．23℃／10a;各月地面平均最低温度的变化倾向率,11月为-0．02℃／10a,其余月份则为0．09～0．76℃／10a,年变化倾向率为0．34℃／10a;各月平均地气温差的变化倾向率为-0．17～-0．66℃／10a,年变化倾向率为-0．35℃／10a。当地地面平均最高温度呈逐年递减趋势,地面平均最低温度呈逐年递增趋势,地面平均最高温度的递减趋势远大于平均最低温度的递增趋势,因此,年平均地面温度呈逐年递减趋势。地气温差逐年递减,大气稳定度增强,不利于近地层污染物和水汽扩散,由此带来轻雾日数增多,空气污染加重。日照时数减少,地面受太阳直接辐射减少,是地面温度趋降的直接原因,空气湿度和降水量趋增、空气污染加重等要素的变化,是地面温度趋降的间接原因。  相似文献   

濮阳棉铃虫气象预报模式的建立与应用   总被引：1，自引：0，他引：1  

吴建河  徐巧真  张志芳  谢若梅  钟天华  田国卫   《气象与环境科学》2009,32(4):33-36

根据濮阳市气象条件的变化对棉铃虫特别是对棉铃虫虫源影响的特点,按照棉铃虫繁育规律,将棉铃虫周年活动期划分为秋季预蛹期、越冬期、春季羽化期、夏季危害期4个阶段;分阶段选取有昆虫学、统计学意义的气象因子,通过归一化处理和加权组合,组成棉铃虫气象指数,建立多时效、归一化棉铃虫气象预报模式和分析、评价指标.  相似文献   

鄂托克旗自动站与人工观测风速记录的差异分析     

刘永红  谢金明  段启勇 《山东气象》2010,30(3):67-68

利用鄂托克旗气象观测站2007年1-12月人工站和自动站平行观测的风速、风向资料,统计比较了人工站与自动站风速观测值和极值。结果表明：受观测仪器系统偏差和观测取值时间差异的影响,人工站比自动站的日平均风速偏小0．4m．S-1。风向完全相符的接近40％,2个以上方位的不相符率为4％。  相似文献   

两类极区平流层异常增温的特征及其与850hPa温度的关系   总被引：1，自引：0，他引：1  

谢再红  李忠贤  倪东鸿 《气象与减灾研究》2010,33(4):16-22

采用NCEP/NCAR逐日再分析资料,将冬季极区平流层增温分为两种类型:Ⅰ型和Ⅱ型,并分析了两种类型增温的特征、机制及其与850hPa温度的关系。结果表明,波动强迫的强度和对流层的热量能否向上到达平流层是决定两类平流层异常增温的两个主要因素。Ⅰ型平流层增温期间,对流层也表现出了明显的增温特征,850hPa与平流层温度距平场呈现相当正压结构,极区和中纬度异常表现为反位相的振荡,呈现典型的北极涛动的特征;Ⅱ型平流层异常增温期间,增温异常仅局限在平流层范围内,平流层的中低层与高层呈现反位相的距平分布,850hPa温度距平场呈现无规则的分布特征。  相似文献   

无机盐热力学平衡模式的简化及其应用   总被引：2，自引：1，他引：1       下载免费PDF全文

李树  王体健  谢旻  庄炳亮 《应用气象学报》2010,21(1):89-94

利用查表法简化无机盐热力学平衡模式ISORROPIA,对温度、相对湿度、总氨(NH3+NH4+)、总氮(HNO3+NO3-)和总硫(H2SO4+SO42-)等5个影响因子进行分档,建立不同组合情况下硫酸盐、硝酸盐、铵盐等物种平衡浓度的查算表。在区域气候化学模式系统(RegCCMS)中,分别用查算表检索法和直接耦合热力学平衡模式的方法模拟我国2003年1月和7月硝酸盐气溶胶的浓度分布。结果表明:查表法既能显著提高计算效率,在无机盐模拟性能方面又与直接耦合法保持较好的一致性,在气溶胶气候效应研究方面具有良好的应用前景。  相似文献   

Aliphatic alkanes and polycyclic aromatic hydrocarbons in atmospheric PM₁₀ aerosols from Baoji, China: Implications for coal burning   总被引：1，自引：0，他引：1  

Mingjie Xie  Gehui Wang  Shuyuan Hu  Qingyou Han  Yajuan Xu  Zhongchao Gao 《Atmospheric Research》2009,93(4):840-848

Normal alkanes and PAHs in atmospheric PM₁₀ aerosols collected during 2008 winter and spring in Baoji, a mid-scale inland city of China, were determined on a molecular level. Concentrations of n-alkanes ranged from 232 to 3583 ng/m³ with an average of 1733 ng/m³ in winter and from 124 to 1160 ng/m³ with an average of 449 ng/m³ in spring, while PAHs in the PM₁₀ samples were 594 ± 405 and 128 ± 82 ng/m³ in the two seasons. Molecular compositions showed that CPI (odd/even) values of n-alkanes were close to unity for all the samples especially in winter, and diagnostic ratios of PAHs (e.g., Phe/(Phe + Ant), CPAH/ΣPAHs and IcdP/(IcdP + BghiP)) were found similar to those in coal burning smoke with a strong linear relationship (R² ≥ 0.85) between PAHs and fossil fuel derived n-alkanes, demonstrating that coal burning is the main source of n-alkanes and PAHs in the city, especially in winter due to house heating. Concentrations of the determined compounds in Baoji are much higher than those in Chinese mega-cities, suggesting that air pollution in small cities in the country is more serious and need more attention.  相似文献   

西藏南部晚始新世打拉埃达克质花岗岩及其构造动力学意义   总被引：9，自引：7，他引：2  

谢克家  曾令森  刘静  高利娥 《岩石学报》2010,26(4):1016-1026

打拉二云母花岗岩岩体位于雅拉香波穹隆的东南,侵入到中生代以前的变质岩系(眼球状花岗质片麻岩和石榴黑云母片麻岩)和特提斯沉积岩(页岩和砂岩)中,主要由石英、斜长石、钾长石、黑云母和白云母组成,形成于～44.3Ma。打拉二云母花岗岩地球化学特征表明:打拉花岗岩具有高Al_2O_3(16.0%～17.0%)、Na_2O/K_2O(1.2)以及A/CNK比值(1.05),表明打拉花岗岩为富钠过铝质花岗岩;轻稀土(LREE)富集,重稀土(HREE)相对亏损,HREE中的Ho到Lu元素有变平的特征((Ho/Lu)_N=1.11～1.46);具有微弱或无Eu异常,Eu/Eu~*=0.87～0.95;较高的初始Sr同位素比值(~(87)Sr/~(86)Sr(i)=0.71754～0.71785)和较低的初始Nd比值(ε_(Nd)(i)=-9.15～-12.4)。打拉花岗岩具有高Sr含量(为355×10~(-6)～416×10~(-6))和Sr/Y的比值(59.1～71.5)、高La/Yb比值、低Y及HREE亏损的特征,与埃达克质花岗岩类似。上述特征表明打拉花岗岩是在较高压力条件下,以角闪岩为主的深部岩石部分熔融的结果。  相似文献   

鲁西新太古代济宁群含铁岩系形成时代——SHRIMP U-Pb锆石定年   总被引：12，自引：7，他引：5  

王伟  王世进  刘敦一  李培远  董春艳  颉颃强  马铭株  万渝生 《岩石学报》2010,26(4):1175-1181

济宁群以隐伏的地质体分布于华北克拉通鲁西地区,以往被划归古元古代。近年来在济宁群的钻探和地球物理研究中,发现存在较大规模条带状硅铁建造,其形成时代引起地学界极大关注。本文对济宁群变质碎屑沉积岩和长英质火山岩进行了锆石SHRIMP年龄测定。含砾绿泥绢云千枚岩的碎屑锆石年龄主要集中在～2.7Ga,可靠的最年轻碎屑锆石年龄为2.61±0.01Ga。变质长英质火山岩岩浆锆石年龄为2.56±0.02Ga。研究表明,济宁群形成于新太古代晚期,而不是以往认为的古元古代。华北克拉通条带状铁建造主要形成于新太古代晚期。济宁群在岩石组合、变质作用方面与鞍山、冀东以及五台地区同时代含硅铁建造的表壳岩系有差别,但是与本溪南芬铁矿的岩石组合有相似之处。这些可能为我国的隐伏太古宙BIF铁矿的研究与勘探提供了重要依据。  相似文献   

Analytical solution for one-dimensional consolidation of clayey soils with a threshold gradient     

Kang-He Xie  Kun WangYu-Lin Wang  Chuan-Xun Li 《Computers and Geotechnics》2010

General approximate analytical solutions are developed for one-dimensional consolidation with consideration of the threshold gradient under a time-dependent loading. A comparison is made between the present solution and some available numerical solutions for a particular case, and the results show that the approach employed in this article is reasonable. The influence of the threshold gradient and the loading period on consolidation behaviour is investigated, and the results show that the moving boundary of seepage moves downward gradually. The greater the threshold gradient is, the slower the boundary moves. The excess pore pressure will not be completely dissipated at the end of consolidation, and the larger the threshold gradient is, the greater the residual excess pore pressure is. The average degree of consolidation considering the threshold gradient defined by settlement is different from that defined by pore pressure. Moreover, the greater the threshold gradient is, the larger the average degree of consolidation in terms of strain, whereas the smaller the average degree of consolidation in terms of stress. It is also shown that the longer the loading period is, the longer the time moving boundary takes to reach the bottom of the layer, and the greater the average degree of consolidation is.  相似文献   

A formation mechanism for hematite-rich spherules on Mars     

Chaojun Fan  Hongjie Xie  Steve Ackley 《Planetary and Space Science》2010,58(3):401-410

Gray crystalline hematite on Mars has been detected in three regions, Sinus Meridiani, Aram Chaos, and Valles Marineris, first by the Thermal Emission Spectrometer (TES) onboard the Mars Global Surveyor (MGS) orbiter, and then confirmed by other instruments. The hematite-rich spherules were also detected by the Mars Exploration Rover (MER) Opportunity at Meridiani Planum (Sinus Meridiani). Formation mechanisms of the hematite-rich spherules have been discussed widely since then. Here, we argue for an alternative formation mechanism, that is, the spherules originally formed at Valles Marineris due to the interaction of volcanic deposits and acidic hydrothermal fluids, and then were transported to and deposited at Meridiani Planum and Aram Chaos as alluvial/fluvial sedimentary deposits with other materials such as sulfates and rock fragments during the wash-out flows from Valles Marineris to Meridiani Planum and Aram Chaos. Diagenesis of the hematite-rich spherules may have also been a possible mechanism following sediment transport and emplacement. The hypothesis is consistent with available relevant information to date and provides an insight into the understanding of Martian surficial processes.  相似文献