中国海洋旅游安全事故时空特征分析

为预防和减少海洋旅游安全事故,运用卡方列联表分析与残差检验、时间强度指数、地理集中指数和不平衡指数分析中国海洋旅游安全事故的类型、特征与时空分布规律。研究发现：1）中国海洋旅游安全事故类型主要分为溺水、被困、交通事故、自杀、意外受伤、动物咬伤、疾病突发、火灾、食物中毒等9种。2）事故发生的主导因素存在类型差异,涉事旅游者个体特征、旅游活动与事故发生的关联性较高。3）事故在大（年）、中（月）、小（日）时间尺度分布呈现差异性和集中性。事故发生数量呈上升趋势,7―8月为高发期,5―6、10月为次发期,下午（T 14:00―18:00）为一日高发时段,上午（T 08:00―12:00）和晚上（T 18:00―21:00）为一日次发时段。4）事故在大（海洋旅游圈）、小（海洋旅游城市）、微（海洋旅游活动点）空间尺度分布呈现聚集性和不平衡性。其中,大空间尺度集中在闽台海峡西岸区域和环渤海区域,小尺度（闽台海峡西岸区域为例）集中在厦门、泉州和福州,微尺度集中在沙滩、海礁与海上区域。因此,建议从高发事故类型及其发生特征、时空分布规律等方面强化安全防控与监管工作,预防和减少海洋旅游安全事故发生。     

An approach to estimate Lower Jurassic seawater oxygen‐isotope composition using δ18O and Mg/Ca ratios of belemnite calcites (Early Pliensbachian,northern Spain)

Palaeotemperature estimates from the oxygen‐isotope compositions of belemnites have been hampered by not knowing ancient seawater isotope compositions well enough. We have tackled this problem using Mg/Ca as a proxy for temperature and here, we present a ~2 Ma record of paired Mg/Ca and δ¹⁸O measurements of Jurassic (Early Pliensbachian) belemnites from the Asturian basin as a palaeo‐proxy of seawater oxygen‐isotope composition. From the combined use of the two approaches, we suggest a δ¹⁸O_w composition of about ?0.1‰ for the Jamesoni–Ibex zones. This value may have been increased by about 0.6‰ during the Davoei Zone due to the effect of waters with a different δ¹⁸O_w composition. These findings illustrate the inaccuracy of using a globally homogeneous ice‐free value of δ¹⁸O_w = ?1‰ for δ¹⁸O_carb‐based palaeotemperature reconstructions. Our data suggest that previous palaeotemperatures calculated in the region from δ¹⁸O values of belemnites may have been underestimated as the seawater oxygen isotopic composition could have been higher.     

火焰发射光谱法测定水系沉积物中痕量铯

通过对火焰发射光谱法测定Ｃs的条件和共存元素的影响进行试验,选用适当的仪器工作条 件,试样中基体元素对Ｃs的干扰很小,可不经分防,直接测定水系沉积物中的Ｃs。方法的检出限为１ｕｇ／ｇ,对Ｃs一分别为１０．２ｕｇ／ｇ和３８．３ｕｇ／ｇ的样品测定１４次,ＲＳＤ为５．１％和４．４％。对水系沉积物国家标准物质进行测定,结果与标准值相符。     

含平流(advection)的热单温吸积流的径向结构

本文在小粘滞参数（α＝０．１）、低吸积率的条件下，借助含平流的热吸积流的自相似解，考虑非热正负电子对产生，采用分两个区域分别求解然后对接的方法，研究了含平流的热单温吸积流的径向结构．证实了热吸积流所具有的一些显著特征和基本性质，同时得到一些新的结果：含平流的热吸积流存在一个临界半径ｒｃｒ；明确指出含平流的热吸积流的辐射冷却率与中心天体的质量成平方反比关系；提出正负电子对过程对含平流的热吸积流的辐射过程有显著影响．     

吉林省浅层地热开发利用适宜性

本文对吉林省浅层地热开发利用的适宜性进行了论证。概括地阐述地质及水文地质条件、地热分类与其形成机制,指出浅层地热的特点和开发利用现状。全面地分析浅层地热开发利用的适宜条件,为浅层地热的利用发挥建设性作用。     

Rapid variability in S5 0716+714

S5 0716+714 is one of the targets in our long term blazar monitoring program carried out with the 1.56-m telescope at Sheshan Station of Shanghai Astronomical Observatory,China.We report a very rapid variability of ΔI = 0.611 ± 0.102 mag over 3.6 min detected in our monitoring program during the period from December 2000 to March 2007.The rapid variability suggests that the mass for the central black hole is log(M/M) = 7.68 8.38.     

The Relationship between Radio Luminosity and Core-Dominance Parameter for XBLs

In this work, we investigate the correlation between the luminosity and the core-dominance parameter for a sample of X-ray selected BL Lacertae objects (XBLs), and found that the extended luminosity is strongly anti-correlated with the core-dominance parameter while the core (or the total) luminosity is not correlated with the core-dominance parameter. If this is the case, then we can expect that the lower extended luminosity XBLs and their core luminosity is relatively higher. This can be explained by a relativistic beaming model since in this case, the viewing angle is smaller and the emissions dominate the extended emissions. Therefore, the anti-correlation is in fact the result of the relativistic beaming model.     

Beyond maximum entropy: Fractal pixon-based image reconstruction

We have developed a new Bayesian image reconstruction method that has been shown to be superior to the best implementations of other methods, including Goodnessof-Fit (e.g. Least-Squares and Lucy-Richardson) and Maximum Entropy (ME). Our new method is based on the concept of the pixon, the fundamental, indivisible unit of picture information. Use of the pixon concept provides an improved image model, resulting in an image prior which is superior to that of standard ME.