滁州市生态系统服务价值分析及趋势预测

为促进区域生态经济可持续发展,基于4期TM影像数据,采用Costanza的生态系统服务价值(ESV)计算模型与敏感性指数,对研究区2000—2015年土地利用变化信息及其对ESV的影响进行研究,最后利用灰色GM(1,1)模型,预测了滁州市在2015—2025年间的发展趋势。结果表明:滁州市ESV 2000—2005年增加了4.40×108~元,2005—2015年减少5.16×10~8元;在2000—2015年间,滁州市生态系统单项服务价值总体减少,减少量为7.7×10~7元。从各县市情况来看,各县市的ESV比例均在10%～21%,其中明光市ESV量占比最高,超过20%。15年间,价值变化率最大的是市辖区,为-15.53%。预测结果表明,到2025年研究区ESV将减少到2.175 6×10~(10)元。研究结果可为滁州市科学利用土地提供理论依据。     

GM(1,1)模型和马尔柯夫模型在流域旱涝灾害预测中的运用

试用中央气象局推荐的旱涝标准对已知流域降水资料进行旱涝分级,并综合运用GM(1,1)模型和马尔柯夫模型对流域旱涝灾害发生的时间进行预测.经检验,两模型可预测流域旱涝灾害发生的时间及其概率,并具有较高的精度.     

基于时间序列疏系数模型的太阳辐射年际变化趋势预测

利用1961—2016年山东省济南市太阳年总辐射量观测数据,通过模型识别和统计检验,对比分析时间序列模型AR(5)和ARIMA((1,2,4),1,0)的拟合结果。残差检验结果表明,疏系数模型ARIMA ((1,2,4),1,0)可用于预测地表太阳年总辐射量,预测结果显示2017—2025年济南市地表太阳辐射的年际变化整体呈增长趋势。对比多元线性回归模型结果,时间序列疏系数模型误差较小,预测准确度相对较高。     

NGINAR(1)模型的Bayes估计及预测

先利用Bayes方法研究NGINAR(1)模型的参数估计问题, 再利用条件分布预测方法进行模型预测. 模拟结果表明, Bayes估计效果优于条件最小二乘估计和Yule Walker估计, 且条件分布预测方法比条件期望预测方法更适用于整数值序列.     

NGINAR(1)模型的Bayes估计及预测

先利用Bayes方法研究NGINAR(1)模型的参数估计问题, 再利用条件分布预测方法进行模型预测. 模拟结果表明, Bayes估计效果优于条件最小二乘估计和Yule Walker估计, 且条件分布预测方法比条件期望预测方法更适用于整数值序列.     

基于灰色GM(1,1)模型的桩基沉降预测研究

简述现有桩基沉降预测方法存在的不足,结合桩基沉降的特点,引入灰色预测GM(1,1)模型,建立基于灰色GM(1,1)模型的单桩及群桩沉降预测研究模型,并给出其建模的原理及建模的过程。最后,通过工程实例,进行实证分析,研究表明该模型具有良好的适应性,能更好地反映桩基沉降变形的规律,提高预测的精度,具有良好的工程应用价值和推广前景。     

基于GM(1,1)模型的空气质量变化趋势预测及分析

在掌握区域空气环境质量现状资料的基础上,运用具有适用性广,预测准确率高等优点的灰色系统预测模型对大连市未来五年空气中SO2的浓度变化趋势进行预测,对其模型的精度和可行性进行了分折和检验,并与目前常用的指数平滑法的预测结果进行了对比。研究结果表明:建立基于GM(1,1)模型的大气质量变化趋势预测模型是可行的,其模型的平均相对误差比指数平滑法减少了44％,因此预测精度高,能够满足预测要求。     

氯代苯和部分氯代酚的生物活(或毒)性定量研究

在分子拓扑理论的基础上,根据分子中成键原子i价层电子结构特征和所处的化学环境,提出一个新的计算顶点原子价点价δYi方法:δY i=mi Z(i-hi)+ΣLi×L[()]j/n2i[L(i+1)/pi],以δYi为基础构建了价连接性指数mYt,通过逐步回归法对化合物的拓扑参数进行筛选,所得最佳参数与氯代苯和部分氯代酚的生物活(或毒)性进行定量构效关系研究(QSAR)。结果表明:2D(Two-dimensional)指数mYt和3D(Threedimensional)指数QC对这些化合物的生物活(或毒)性具有良好的结构选择性,且所建模型具有良好的预测能力、较好的可靠性和稳健性。     

灰色GM(1,1)模型在山区耕地预测中的应用研究

以云南楚雄1999-2005年耕地面积数据为试验资料,运用灰色GM(1,1)模型分析探讨耕地面积的变化状况.初步结果表明:楚雄耕地面积的动态变化结果符合客观实际的变化规律,未来几年,楚雄拼地面积仍呈递减的趋势.     

Interannual and interdecadal variabilities in SST anomaly over the eastern equatorial Pacific

The global sea surface temperature (SST) anomaly data from 1950 to 1996 were used to analyze spatial characters of interdecadal SST variations. A wavelet transform was made for the equatorial eastern Pacific SST anomaly time series. Results show that there are three remarkable timescale SST variations: 130-month interdecadal variation, 57-month interannual variation and 28-month quasi-2-a variation. Based on this result, an El Nino event was predicted in the early part of 1997.     

Linear relationship between the interdecadal and interannual variabilities of North China rainfall in rainy season

Interdecadai and interannuai timescales are dominant in the North China rainfall in rainy season (July and August). On the interdecadai timescale, the North China rainfall exhibited an abrupt decrease at the end of 1970s. In this study, we examined the effect of this abrupt rainfall decrease on the association between rainfall and circulation on the interannuai timescale, and found that the interdecadal variation does not change the physical mechanism responsible for the interannuai variation of North China rainfall.There is a linear relationship between the interdecadai and interannuai variabilities of North China rainfall in rainy season.     

Interannual and interdecadal variations in the North Atlantic Oscillation spatial shift

The spatial shift of the North Atlantic Oscillation (NAO) is analyzed by using the Twentieth Century Reanalysis version 2 dataset and identifying NAO action centers directly on winter mean sealevel pressure (SLP) anomaly maps. The spatial shift of the NAO is characterized by four NAO spatial shift indices: the zonal and meridional shifts of the NAO southern and northern action centers. It is found that the zonal and meridional shift trends of the NAO action centers move along a path of southwest-northwest direction. Spectral analysis shows that the four NAO spatial shift indices have periodicity of 2-6 years and the NAO index has periodicity of 2-3 years in terms of high-frequency variations. On a decadal time scale, the NAO spatial shift indices are closely (positively) related to the NAO index, which is in agreement with previous studies of the relationship between the NAO index and the spatial shift of the NAO pattern. However, there is no relationship between the NAO index and the meridional shift of the northern action center on an interannual time scale. The significant relationship between the NAO index and the interannual variability of NAO spatial shift indices is very likely to be associated with synopticscale Rossby wave breaking, which generates surface pressure anomalies and thus affects the phase and pattern of the NAO. The correlations of winter westerly winds over 90°W-0° and the NAO index and the NAO spatial shift indices have a ’+ - + -’ structure from the Equator to the North Pole. Although there is close correlation between the NAO spatial shift indices and the strength of the zonal winds in the North Atlantic region, the effect of the zonal winds on the NAO spatial shift differs at different latitudes. Hence, the role of the zonal winds is probably a result of the NAO spatial shifts.     

南盘江盆地中三叠统复理石的物源和沉积构造背景分析

利用数据统计分析方法,对岩石薄片数据、古水流数据、岩石化学数据等进行了统计分析,在此基础上研究了南盘江盆地中三叠统物源和沉积构造背景.结果表明:中三叠统南盘江盆地古水流方向为北西西方向;沉积物主要来源于盆地一侧的再旋回造山带;再旋回造山带应该在盆地的东南方向;沉积构造背景以大陆岛弧为主,兼有活动陆缘的性质.     

云南年降水多周期叠加与连续特大气象干旱关系及趋势预估研究

选用Morlet连续复小波变换(cmor)分析1959—2012年云南全省125个气象站的逐年站平均降水时间序列的多时间尺度周期分布特征,解析云南2009年以来降水异常特少导致连续特大干旱的成因,用各主周期的小波系数实部数据建立虚拟变量回归模型,模拟年降水距平的时间演变,预估未来5 a逐年降水趋势.结果表明:云南年降水存在明显的26、16~17、9~10、4 a 4个时间尺度不同的振荡主周期; 其中26 a周期最为明显,且最持续稳定,次明显的是9~10 a周期,也有持续稳定的特点;1992年前、后的振荡主周期差异明显;自2009年以来,4个不同时间尺度的主周期均进入或处于谷期,4个主周期谷底效应的叠加,是云南降水连续4 a异常偏少导致连续特大干旱的重要成因之一;云南的降水偏少时段可能在2014—2015年结束,以持续年降水异常偏少为特征的云南连续特大气象干旱也将可能随之结束.     

Interannual variation of annual precipitation and urban effect on precipitation in the Beijing region

The large scale character of the interannual variation of precipitation and the urban effect on local annual precipitation anomaly are investigated in this paper based on the 1960-2000 annual precipitation observations at 20 stations in the Beijing region.The results show that:the annual precipitation in the Beijing region possesses the large scale variation character with the linear trend of-1.197/10 yr,which corresponds to a total reduction of 27.82 mm in annual precipitation in the 41 years;the local annual precipitation anomalies(percent of the normal 1960-2000)show a positive center near the urban area,i.e.urban precipitation island(UPI),whose intensity increases with the linear trend of 0.6621%/10 yr,opposite to the interannual trend of large scale precipitation over the Beijing region;changes in the UPI are also associated with the intensity of synoptic processes of precipitation,and when the synoptic processes are strong(wet years),the intensity of UPI strengthens,while the synoptic processes are weak(dry years),and the UPI disappears in the Beijing region.     

Interannual variation of annual precipitation and urban effect on precipitation in the Beijing region

The large scale character of the interannual variation of precipitation and the urban effect on local annual precipitation anomaly are investigated in this paper based on the 1960—2000 annual precipitation observations at 20 stations in the Beijing region. The results show that: the annual precipitation in the Beijing region possesses the large scale variation character with the linear trend of -1.197/10 yr, which corresponds to a total reduction of 27.82 mm in annual precipitation in the 41 years; the local annual precipitation anomalies (percent of the normal 1960—2000) show a positive center near the urban area, i.e. urban precipitation island (UPI), whose intensity increases with the linear trend of 0.6621%/10 yr, opposite to the interannual trend of large scale precipitation over the Beijing region; changes in the UPI are also associated with the intensity of synoptic processes of precipitation, and when the synoptic processes are strong (wet years), the intensity of UPI strengthens, while the synoptic processes are weak (dry years), and the UPI disappears in the Beijing region.     

贵金属/半导体异质结中的光致自旋电流效应研究

自旋电子材料因能同时对电子的自旋和电荷两个自由度实施操控,在构筑以低功耗、超高速、大容量和超宽带为特征的新一代信息处理技术中展现出巨大的应用潜力.然而,通过掺杂过渡金属元素和稀土离子而形成的传统稀磁半导体和钙钛矿锰氧化物往往因结构缺陷导致的居里温度不高、自旋磁矩和自旋极化率偏低等不足,阻碍了自旋电子材料的商业化应用.近年来,在高纯半导体上沉积贵金属薄膜所形成的贵金属/半导体异质结中,通过使用偏振光激发该类异质结可产生纯自旋电流.这种基于逆自旋霍尔效应(ISHE)、可在室温下运行的、非接触和非破坏型的自旋极化激励方法理论上可获得高于50%自旋极化率,引起了人们的广泛关注.文章主要介绍光致自旋电流形成机制和测试方法,以及入射光圆偏振度、光强、入射角度等参数对光致自旋注入效率的调控机理,介绍杂质介导和声子介导对光致自旋输运的贡献,最后提出增强光致自旋电子极化率的可行方案,可为揭示自旋载流子产生、注入和输运相关的自旋动力学核心科学问题以及研制高性能自旋电子器件提供有益的参考.     

新疆博斯腾湖流域气温降水变化特征分析

分析了博斯腾湖流域近51 a气温降水变化特征,结果表明:1)近51 a博斯腾湖流域平原区平均温度以0.313℃/10 a的速度上升,高于整个南疆地区,与全疆变化一致;流域山区增温趋势较快,平均以0.328℃/10 a的速度增温,冬季增温显著,暖冬趋势明显;2)近51 a平原区降水以2.639 mm/10 a的速度增加,年际变化比较大,降水量的增加显著于温度的增加.流域山区年平均降水量以13.045 mm/10 a的速度增加,相关系数为0.387;3)温度和降水在平原区没有明显相关性,但在山区温度高时降水量大,温度低时降水量小,呈现明显的正相关;4)平原区温度和降水用Mann-kendall方法检验没有达到突变水平,山区温度在1997年发生了由低向高的突变,降水在1990年发生了由低向高的突变.     

基于Visual MODFLOW的武威盆地地下水动态模拟及预测

采用Visual MODFLOW(VMOD)模型对武威盆地地下水动态进行数值模拟,预测规划年水资源配置方案下威武盆地地下水动态.模型识别与验证结果表明VMOD模拟效果良好,可用于研究区地下水系统采补平衡分析.水资源配置方案下的VMOD模型预测结果表明:各规划年地下水系统补、径、排空间格局总体趋势变化较小,山麓洪积扇井河混灌区南部地下水水位持续下降.至2020年,地下水位上升区间由盆地中部逐渐向东南方向移动,泉水溢出区地下水系统一定程度上得到恢复,地下水位整体下降情况逐步得到改善.