有机物对黄河水中重金属与沉积物相互作用的影响

研究了在黄河水中溶液 p H值对 Cu( )、Zn( )和 Cd( )分别与转化沙和未转化沙相互作用的离子交换率 E( % )的影响 ,并研究了当甘氨酸存在时对上述相互作用的离子交换百分率的改变 .结果表明 :当沉积物分别为转化沙和未转化沙时 ,其对重金属的吸附作用的影响是不同的 ,且实验结果与理论推测和实际是一致的 ;甘氨酸的存在对不同金属离子分别与转化沙和未转化沙相互作用的离子交换率 E( % ) -p H曲线的影响各不相同     

新疆伊犁谷地重塑黄土抗拉强度试验研究

为研究伊犁黄土抗拉强度变化特征及拉张裂缝形成过程,采用自行研制的土体拉伸强度测定仪,并借助粒子图像测速(PIV)系统、核磁共振(NMR)技术及扫描电镜(SEM),对不同干密度、不同含水率的伊犁重塑黄土进行室内试验.结果表明:重塑黄土抗拉强度与含水率和干密度密切相关,随着含水率的下降,黄土抗拉强度呈上升趋势,且存在一个界限含水率wc=18%(塑限含水率附近).NMR和SEM试验分别从水分赋存形态及微观结构角度揭示了含水率变化对伊犁黄土抗拉强度的影响机制.当含水率高于wc时,含水率降低对应毛细自由水的大量脱失,此阶段基质吸力的提高和少量黏粒的凝聚促使抗拉强度缓慢增加;当含水率小于等于wc时,结合水的迅速降低导致黄土中大量黏粒凝聚,重新胶结了黄土颗粒,部分填充了孔隙,且水膜物化作用力增强,从而促使抗拉强度的迅速提升.     

探针N-戊基-N'-(对氨基苯磺酸钠)硫脲快速测定血清样品中蛋白质含量的光谱法研究

研究了N-戊基-N'-(对氨基苯磺酸钠)硫脲(APT)与人血清白蛋白(HSA)体系的三维荧光光谱,证明了两者可以发生相互作用,APT的加入导致HSA疏水微环境极性和构象的变化.考察了△λ值,pH值、离子强度、试剂加入顺序及APT用量等因素对APT与HSA体系的同步荧光强度的影响.在最佳实验条件下,体系的同步荧光强度与H...     

我国近海热带气旋迅速加强活动特征及其与 ENSO 的关系

利用 1949?2006 年西北太平洋热带气旋资料, 对强度迅速加强过程(12小时热带气旋中心附近最大风速增值≥10 m/ s) 发生在我国近海范围内的热带气旋进行了统计分析。总结了近海迅速加强热带气旋地理分布特点、发生时间和强度分布特征, 以及近海迅速加强热带气旋活动与 ENSO 的关系, 并简要分析了ENSO 以及近海热带气旋起源位置对近海迅速加强热带气旋活动的影响机制。     

1949—2008年热带气旋对中国沿海商船航线的影响频次

为分析西北太平洋(含南中国海域)热带气旋对中国沿海商船航线影响频次的时间和空间分布规律,利用CMA提供的1949-2008年热带气旋最佳路径资料,采用统计和趋势分析等方法进行分析研究.结果表明,热带气旋对中国沿海商船航线的影响频次存在较明显的盛衰周期性波动,其中盛期持续时间(6年左右)只有衰期持续时间(12年左右)的一半左右;每年8月西北太平洋热带气旋对中国沿海商船舫线的影响最为频繁,7月份所生成的热带气旋对中国沿海商船航线造成影响的可能性最大.热带气旋对中国沿海商船航线的影响主要集中在海南至台湾海峡一带沿海水域,其中影响次数最多的为海南省以东18°N-21°N沿海水域,影响频次最高区域有明显的向北漂移的趋势.     

Fe~+催化N_2O与H_2反应的理论探究

采用密度泛函理论(DFT)B3LYP与耦合簇(CCSD)方法,研究了气相中四重态和六重态势能面上Fe+催化N2O氧化H2的微观机理.采用分子轨道理论和自然键轨道理论(NBO)对反应势能面进行分析,并通过自旋-轨道耦合(SOC)计算,讨论了势能面的交叉情况和自旋翻转的可能性.用Kozuch提出的能量跨度模型,确定了整个反应的决速过渡态(TDTS)和决速中间体(TDI),最后计算了催化剂的转化频率(TOF),以评价催化剂的性能.     

福建沿海热带气旋的时空分布特征及其影响分析

福建沿海受热带气旋影响严重,研究分析其强度规律及时空特征等要素对福建沿海防灾减灾工作具有重要的意义。基于福建省1945-2019年登陆型热带气旋及2004-2019年影响型热带气旋数据资料,对福建沿海地区热带气旋的活动规律、时空分布特征及灾害损失情况进行统计分析。结果表明：福建省登陆型热带气旋频数年际分布大致呈现“增-减-增-减-增-减”变化,而强度年际分布呈现相反趋势。影响型热带气旋频数整体呈现减小趋势,预计未来几年继续减小。登陆型热带气旋在8月份登陆次数最多,其中以登陆强度为台风的热带气旋次数最多。福州市为登陆次数最多的城市,75年共登陆39次,且登陆强度呈现标准正态分布；宁德市登陆型热带气旋强度整体最大。从防灾角度出发,热带气旋由海域向陆域移动过程中,强度逐渐减小,且严重灾情在北部出现的频数较南部高。     

我国近海热带气旋迅速加强活动特征及其与ENSO的关系

利用1949—2006年西北太平洋热带气旋资料,对强度迅速加强过程(12小时热带气旋中心附近最大风速增值≥10m/s)发生在我国近海范围内的热带气旋进行了统计分析。总结了近海迅速加强热带气旋地理分布特点,近海迅速加强热带气旋的时间、强度分布特征,以及近海迅速加强热带气旋活动与ENSO的关系,并简要分析了ENSO以及近海热带气旋起源位置对近海迅速加强热带气旋活动的影响机制。     

福建沿海热带气旋的时空分布特征及其影响分析

基于福建省1945—2019年登陆型及影响型热带气旋数据资料,对福建沿海地区热带气旋的活动规律、时空分布特征及灾害损失情况进行统计分析. 发现登陆型热带气旋频数年际分布呈现“增-减-增”的变化趋势,而强度年际分布呈现相反趋势. 影响型热带气旋频数整体呈现减小趋势,预计未来几年继续减小. 福州市为登陆次数最多的城市,且登陆强度呈现标准正态分布. 从防灾角度出发,热带气旋由海域向陆域移动过程中,强度逐渐减小,且严重灾情在北部出现的频数较南部高.     

PLLA-PEG1000-PLLA三嵌段共聚物的红外变温研究

以左旋丙交酯(LLA)与聚乙二醇(PEG1000)开环共聚制备的HO-PLLA-PEG-PLLA-OH三嵌段共聚物为样品,采用FTIR,X-Ray,DSC等对样品的结构与性能进行了初步表征.然后以变温红外光谱法在0～185℃范围内对其温敏性谱带做了研究.结果发现,当升温至T=95℃左右时,一些吸收谱带的强度增强(如:在920cm-1,1215cm-1,1294cm-1等附近的谱带),当继续升温至T=165℃时,这些吸收谱带的强度减弱或消失,自然降温至30℃后,这些吸收谱带强度又增强,这种变化与DSC表征一致,因此应归属于结晶相关谱带.同时还观察到:在样品的冷结晶温度区域附近,756cm-1的吸收带强度,在实验条件下发生了不可逆转变.     

Interdecadal variation of tropical cyclone activity in association with summer monsoon, sea surface temperature over the western North Pacific

Based on geographic division over the western North Pacific (WNP), the interdecadal relationships between summer monsoon, sea surface temperature (SST) and tropical cyclones activity (including number, track and intensity) are examined. In the past several decades, the western Pacific subtropical high (WPSH) and tropical westerlies contribute to the interdecadal variation of TC number in the northwest and southeast of WNP respectively. The increased TC occurrence density to the east of Philippines related to TC track appears during the 1990s, in terms of both steer flow induced by WPSH and genesis location. From the interdecadal viewpoint, the tendency of TC intensity, measured by averaged accumulated cyclone energy, does well agree with that of SST, implying that SST plays an important role in TC intensity. Supported by Special Scientific Research Project for Public Interest (Grant No. GYHY200806009) and National Basic Research Program of China (Grant No. 2009CB421505)     

Effect of remote sea surface temperature change on tropical cyclone potential intensity

The response of tropical cyclone activity to global warming is widely debated. It is often assumed that warmer sea surface temperatures provide a more favourable environment for the development and intensification of tropical cyclones, but cyclone genesis and intensity are also affected by the vertical thermodynamic properties of the atmosphere. Here we use climate models and observational reconstructions to explore the relationship between changes in sea surface temperature and tropical cyclone 'potential intensity'--a measure that provides an upper bound on cyclone intensity and can also reflect the likelihood of cyclone development. We find that changes in local sea surface temperature are inadequate for characterizing even the sign of changes in potential intensity, but that long-term changes in potential intensity are closely related to the regional structure of warming; regions that warm more than the tropical average are characterized by increased potential intensity, and vice versa. We use this relationship to reconstruct changes in potential intensity over the twentieth century from observational reconstructions of sea surface temperature. We find that, even though tropical Atlantic sea surface temperatures are currently at a historical high, Atlantic potential intensity probably peaked in the 1930s and 1950s, and recent values are near the historical average. Our results indicate that--per unit local sea surface temperature change--the response of tropical cyclone activity to natural climate variations, which tend to involve localized changes in sea surface temperature, may be larger than the response to the more uniform patterns of greenhouse-gas-induced warming.     

Energy dispersion of complex non-isolated vortices

Energy dispersion is a fundamental scientific problem in the study of natural disasters such as typhoons, heavy rain and earthquakes. The problem has been addressed by both multi-discipline research and forecast studies. The dynamics of isolated circular vortex energy dispersion have been solved. However, the disastrous results of typhoons and heavy rain often occur due to non-isolated circular vortices, the dynamics of which are explored in this paper. The energy dispersion characteristics of non-isolated vortices with complex structural patterns are examined using a linearized nondivergent barotropical vorticity equation model. In the initial field, a tropical cyclone (TC) vortex and a meso-scale vortex coexist, forming a complex structural pattern. An analytic solution based on a Fourier transform and simulations using a two-dimensional model show the following. (1) A wave train of TC-G-D may be created by the energy dispersion where the line connecting the three member centers of the wave train is parallel to the x axis in the case of an initial TC vortex without a meso-scale vortex. (2) A wave train of TC-G-D may also be created by energy dispersion. However, the line connecting the three member centers of the wave train would no longer be parallel to the x axis. Instead, they would form a triangle in the presence of the initial TC vortex with the meso-scale vortex. (3) There is a nonlinear relationship between the initial intensity of the meso-scale vortex and the base angle of the triangle. These results have the potential to be applied in the field of typhoon forecasting.     

主成分分析在线性模型与非线性模型的应用研究

为了解主成分分析在线性模型与非线性模型预报中的应用效果,在2001—2011年热带气旋历史观测资料基础上,采用主成分分析方法,结合线性回归模型和神经网络模型,开展西北太平洋热带气旋的强度预报技术研究试验．根据提取的主要影响因子构造线性回归模型与BP神经网络的输入样本进行不同样本的台风强度预测．计算结果表明,主成分分析通过降低线性回归模型和BP神经网络模型的维数,减少自变量之间的复共线性,减小模型的预报平均绝对误差．     

船舶绕避中热带气旋领域的研究

为提高船舶绕避热带气旋(TC)的安全性,针对由于TC警报区域信息不完整以及TC预报误差所致的TC周围危险区域不确定性导致TC中心未来落入概率圆概率过小问题,提出TC领域的概念及其确定方法.该方法参考航海技术中船舶领域的概念,借鉴了多位远洋船长绕避TC的丰富经验,给出了确定TC领域的实例.实验结果表明,该方法可较为迅速、有效地确定船舶绕避TC距离或TC中心附近危险区域,为选择绕避TC方案提供重要的科学定量分析的参考.     

西北太平洋热带气旋气候特征及其变化研究的若干进展

为了对我国气象工作者全面了解和参与热带气旋的研究有所帮助,在大量阅读和调研的基础上,介绍了近20年西北太平洋热带气旋活动在季节、年际和年代际尺度上研究的若干主要成果.重点阐述了EN-SO与热带气旋的关系,温室效应热带气旋的数值模拟和观测研究等的最新动态.     

影响文昌地区的热带气旋气候分析

本文研究了1959～2005年西太平洋和南海热带气旋影响文昌地区的规律,总结了热带气旋的时间和空间的分布特征,分析了登陆和影响文昌的热带气旋的气候概况,分析了海南发射场热带气旋季节和强度分布,简要介绍了国内外热带气旋可用的信息资源,为海南发射场建设和气象保障提供了基础。     

热带气旋与海洋暖涡间的海-气相互作用

采用区域海?气耦合模式WRF-sbPOM, 设计敏感性试验, 通过控制海洋暖涡(WCR)的有无以及暖涡与热带气旋(TC)的相对位置, 对理想性TC与WCR间的海-气相互作用进行模拟研究。结果表明, 当TC经过WCR后, 因为WCR区域较厚的暖水使海表温度在TC经过后并没有明显的降低, 削弱了海?气间的负反馈机制, 所以TC强度增大。但受作用时间、气旋强度以及WCR处较强流速的影响, TC强度增大的程度不同, 移动速度较慢的TC有明显增强, 移动速度较快的TC增强不明显。同时TC向海洋中输入大量的机械能, 与WCR的反气旋式环流发生相互作用, WCR的形状由最初的圆形变为椭圆形, 热容量损失约30%, 动能损失约60%。     

Increasing destructiveness of tropical cyclones over the past 30 years

Theory and modelling predict that hurricane intensity should increase with increasing global mean temperatures, but work on the detection of trends in hurricane activity has focused mostly on their frequency and shows no trend. Here I define an index of the potential destructiveness of hurricanes based on the total dissipation of power, integrated over the lifetime of the cyclone, and show that this index has increased markedly since the mid-1970s. This trend is due to both longer storm lifetimes and greater storm intensities. I find that the record of net hurricane power dissipation is highly correlated with tropical sea surface temperature, reflecting well-documented climate signals, including multi-decadal oscillations in the North Atlantic and North Pacific, and global warming. My results suggest that future warming may lead to an upward trend in tropical cyclone destructive potential, and--taking into account an increasing coastal population--a substantial increase in hurricane-related losses in the twenty-first century.