一维气温时间序列的多重分形研究

采用武汉１９５１－１９７０年日平均气温序列作多重分形分析，从计算ｑ阶分数维Ｄｑ着和，得到了多重分形谱ｆ（ａ）曲线，反映了大气运动确定是一个层次分明的过程，具有多标度结构。     

超压泥岩盖层封闭性演化规律及其研究意义

为了研究超压泥岩盖层封闭性演化规律,在超压形成与演化分析的基础上,通过超压演化规律的定量研究,对超压泥岩盖层封闭性演化规律进行了定量研究,结果表明超压泥岩盖层封闭性演化是按阶段进行的,每一次超压释放表明上一次封闭性演化阶段的结束,下一次封闭性演化阶段的开始,每一次演化过程中封闭性逐渐增强,在超压释放期封闭性降至最低点。研究超压泥岩盖层封闭性演化规律不仅可以准确评价目前封闭能力和预测封闭能力演化,而且还可以研究封闭油气的有效性。实例应用结果表明,古龙凹陷嫩一、二段超压泥岩盖层目前已刚刚结束第3阶段演化,开始第4阶段演化,具6.0 MPa的超压。随着演化进行,超压值将继续增大,封闭性继续增强。嫩一、二段超压盖层封闭性演化史与青山口组源岩生烃史匹配关系较好,可封闭住青山口组源岩生成的大量油气,有利于青山口组源岩生成的油气在萨、葡、高油层中聚集和保存。     

海量车载激光扫描点云数据的快速可视化方法

当前车载激光扫描系统的数据量往 往 达 到 数 十 gb 乃 至 tb 级,海 量 激 光 点 云 数 据 的 加 载 与 查 询 对传统可视化方法提出了挑战。本文设计了一种基于内外存调度的三维可视化方法,突破了物理内存对显示数据量的限制。该方法首先利用双层四叉树索引数据结构实现外存储器上的点云数据管理与快速调度,基于该索引动态加载外存储器上的点云数据到内存,从而快速获取海量数据中的实时数据块;然后,利用多线程分时加载双层四叉树索引数据结构,实现激光点云数据外存到内存的实时传输与绘制。实验结果表明,本文方 法不受点云数据量与物理内存大小限制,海量点云可视化效果流畅,适用于台式计算机或网络环境下的海量激光点云数据的调度管理与实时可视化。     

Effect of Radiation on the Nonlinear Stability Zones of the Lagrangian Equilibrium Points

The nonlinear stability zones of the triangular Lagrangian points are determined numerically and the effect of radiation of primaries is considered, in addition to the known effect of mass distribution, using the photogravitational restricted threeq243u06317v15/xxlarge8208.gif" alt="dash" align="MIDDLE" BORDER="0">body problem model. It is found that radiation also has a considerable effect reducing the stability zones. In cases of resonances, these zones are reduced to negligible size for some parameter values within the linear stability regions.     

Gaseous and Particulate Oxidation Products Analysis of a Mixture of α-pinene + β-pinene/O3/Air in the Absence of Light and α-pinene + β-pinene/NOx/Air in the Presence of Natural Sunlight

The gas and particle phase reaction products of a mixture of the atmospherically important terpenes q77024008/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-pinene and q77024008/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-pinene with the atmospheric oxidants O₃ and OH/NO_x were investigated using both gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography (HPLC) for identification and quantification of reaction products. The nighttime oxidation of a mixture of q77024008/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-pinene and q77024008/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-pinene in the presence of O₃/air, and the daytime oxidation of a mixture of q77024008/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-pinene + q77024008/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-pinene with NO_x air in the presence of natural sunlight were carried out in the University of North Carolina's large outdoor smog chamber (190 m³) located in Chatham County, North Carolina. Mass balances for gaseous and aerosol reaction products are reported over the course of the reaction. More than twenty-nine products were identified and/or quantified in this study. On average, measured gas and particle phase products accounted for q77024008/xxlarge8764.gif" alt="sim" align="MIDDLE" BORDER="0">74 to q77024008/xxlarge8764.gif" alt="sim" align="MIDDLE" BORDER="0">80% of the reacted q77024008/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-pinen/q77024008/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-pinene mixture carbon. Measurements show that a number of reaction products were found in both O₃ and NO_x system [pinonaldehyde, pinic acid, pinonic acid, pinalic-3-acid, 4-hydroxypinalic-3-acid, 4-oxonopinone, 1-hydroxy-nopinone, 3-hydroxy-nopinone, and nopinone]. Pinonic acid, pinic acid, pinalic-3-acid, 4-hydroxypinalic-3-acid, and 10-hydroxypinonic acid were observed in the early stage in the aerosol phase and may play an important role in the early formation of secondary aerosols.     

Lacustrine organic matter and the Holocene paleoenvironmental record of Lake Albano (central Italy)

A combined bulk and detailed geochemical study of the sedimentary organic matter in Lake Albano, central Italy, provides critical data to track the response of this aquatic system to the environmental changes of variable amplitude that occurred during the Holocene. Rockq4/xxlarge8208.gif" alt="dash" align="MIDDLE" BORDER="0">Eval pyrolysis of this predominantly laminated, organic carbonq4/xxlarge8208.gif" alt="dash" align="MIDDLE" BORDER="0">rich sedimentary sequence shows changes in hydrogen and oxygen indices that are related to variations in the dominance of the primary producers. These variations are further confirmed by the pigments and the carbon isotopic composition of bulk organic matter showing that cyanobacteria dominated the lake waters during the early and late Holocene whereas diatoms have been the main producers during the middle Holocene. Sharp decreases in productivity, 2–3 centuries long, are identified at ca. 8.2, 6.4 and 3.8 ka. B.P. Changes in temperature and/or effective moisture are suggested as the most probable causes, although human impact cannot be ruled out for the latest part of the Holocene.     

Hubbert’s petroleum production model: an evaluation and implications for World Oil Production Forecasts

Following Hubbertq363778431537157/xxlarge8217.gif" alt="rsquo" align="BASELINE" BORDER="0">s successful prediction of the timing of US peak oil production, Hubbertq363778431537157/xxlarge8217.gif" alt="rsquo" align="BASELINE" BORDER="0">s model has been used extensively to predict peak oil production elsewhere. However, forecasts of world and regional peak oil and natural gas production using Hubbertq363778431537157/xxlarge8217.gif" alt="rsquo" align="BASELINE" BORDER="0">s methodology usually have failed, leading to the implicit belief that such predictions always will fail and that we need not worry about finite resources. A careful examination of Hubbertq363778431537157/xxlarge8217.gif" alt="rsquo" align="BASELINE" BORDER="0">s approach indicates that the most important reasons for his success in the US were stable markets, the high growth rate of demand, ready availability of low cost imports, and a reasonable estimate of easily extractable reserves. This analysis also shows that his model cannot predict ultimate oil reserves and that it should be considered an econometric model. Building on Hubbertq363778431537157/xxlarge8217.gif" alt="rsquo" align="BASELINE" BORDER="0">s vital insight, that cheap fossil fuel reserves are knowable and finite, one can state that for world peak oil production, political constraints should be much more important than resource constraints.     

The Phase Space Structure Around L4 in the Restricted Three-Body Problem

The phase space structure around L ₄ in the restricted three-body problem is investigated. The connection between the long period family emanating from L ₄ and the very complex structure of the stability region is shown by using the method of Poincaréq0103/xxlarge8217.gif" alt="rsquo" align="BASELINE" BORDER="0">s surface of section. The zero initial velocity stability region around L ₄ is determined by using a method based on the calculation of finite-time Lyapunov characteristic numbers. It is shown that the boundary of the stability region in the configuration space is formed by orbits suffering slow chaotic diffusion.     

The production of circumstellar26Al by massive stars

We investigate the production of²⁶Al during hydrogen burning and its ejection by massive single and binary stars. Effects of convection and rotation are studied. We discuss the importance of RSGs, LBVs and WR stars to the total Galactic²⁶Al production, and the detection probability of the²⁶Al decay in individual objects as P Cygni,q477833ntt/xxlarge947.gif" alt="gamma" align="MIDDLE" BORDER="0"> Velorum andq477833ntt/xxlarge951.gif" alt="eegr" align="MIDDLE" BORDER="0"> Carinae.     

Theoretical visibility curves of late type stars

Theoretical visibility curves are presented for one carbon and one oxygen star. We aim to show the importance of measurements at wavelengths across the band.