SN 1987A: an investigation of the bolometric luminosity evolution and the interior neutron star

In this paper the contributions of various radioactive substances (⁵⁶Co, ⁵⁷Co, ⁴⁴Ti and ²²Na) in the envelope of the supernova SN 1987A to the evolution of the bolometric luminosity are calculated and the several types of radiation, which may probably exist in the interior neutron star, as well as their contributions to the bolometric luminosity are investigated. After comparison of the results of calculation with the observation of CTIO and ESO, it is believed that after about 900 days the nuclear decay energy is no longer the unique energy source which determines the bolometric luminosity evolution of SN 1987A, that the radiation coming from the interior neutron star begins to play a dominating role in the bolometric luminosity evolution and that the most important mechanism of radiation of the neutron star is accretion.     

基于Partial-EIV模型的TLS姿态估计方法

推导了基于乘性姿态角误差的观测方程,顾及其系数矩阵也含有误差的特点提出一种利用整体最小二乘原理估计姿态参数的新思路。该问题的系数矩阵中同时存在随机元素和固定元素且存在结构性特征,故引入Partial-EIV模型,设计了一种符合其系数矩阵结构特点的新模型。最后通过两组仿真实验将其与已有姿态估计方法进行对比,得出结论:基于Partial-EIV模型的整体最小二乘解法解算精度高于常规最小二乘法;其解算效果与基于乘性姿态角误差的最小二乘法基本一致。表明本文提出的方法正确有效。     

九道岭煤矿贯通测量方案设计与新方法研究

设计了两套九道岭煤矿副井与西风井之间-700m水平大巷贯通测量方案,并从精度和工程预算等方面分析了其优缺点,选出最优方案。讨论了井下导线加测陀螺边的优点,提出测陀螺边的最佳位置为2i/（2m＋1）L （L为导线全长,适用等边直伸型导线）,最佳条数为1～2条。     

线性模型的泛最小二乘法

本文首先针对线性模型提出了泛最小二乘法,在设计矩阵不加限制的情形下,得到了参数的泛最小二乘估计量。该方法既发扬了最小二乘法的优点,又克服了它的一些不足,它包含了常见的岭估计和最小二乘估计法;其次讨论了泛最小二乘法的理论依据;接着研究了泛最小二乘估计量的一些统计性质,并与最小二乘估计进行比较,在一定意义上前者优于后者;然后讨论了平衡参数的选取问题;最后,给出一个应用,说明了泛最小二乘法的有效性和可行性。     

基于相态识别的S波段双线偏振雷达最优化定量降水估测方法研究

为了提高雷达定量降水估测的精度,本文利用雨滴谱数据、实际雨量以及不同偏振参量建立起的降水估测公式,参考CSU-ICE算法降水估测模型,建立了一种基于相态识别的S波段双线偏振雷达最优化定量降水估测算法(简称HCALIQ)。利用广东珠海S波段双线偏振雷达数据和华南密集的地面自动站网的雨量,以两次华南夏季典型的降水过程为例,对该最优化算法的估测效果进行了统计分析,并进一步与CSU-ICE方法、传统的R(Z_H)方法进行了比较。结果表明:以地面雨量计为标准,HCA-LIQ最优化算法表现出与雨量计较强的相关性且有着较好的稳定性。雷达相对地面雨量计小时雨量估测的偏差分布与离雷达的距离关系不大。按过程分类的结果显示,强对流云降水时,两种最优化算法要明显优于传统的R(Z_H)方法;混合云降水时,最优化算法的效果并不比R(Z_H)方法好;HCA-LIQ最优化算法比CSU-ICE算法效果更佳。按雨强分类统计时发现,与传统的R(Z_H)方法相比,HCA-LIQ最优化算法对小雨的估测偏差降低了23%,对中雨的估测偏差相当,对大雨、暴雨的估测偏差分别降低了71%、68%。     

Comparing an estimate of seabirds at risk to a mortality estimate from the November 2004 Terra Nova FPSO oil spill

On 21 November 2004, about 1000 barrels of crude oil were accidentally released from the Terra Nova FPSO (floating production, storage and offloading) onto the Grand Banks, approximately 340 km east-southeast of St. John's, Newfoundland. We estimated the number of vulnerable seabirds (murres (Uria spp.) and dovekies (Alle alle)) at risk from this incident by multiplying observed densities of seabirds with the total area covered by the slick, estimated at 793 km(2). A mean density of 3.46 murres/km(2) and 1.07 dovekies/km(2) on the sea surface was recorded during vessel-based surveys on 28 and 29 November 2004, with a mean density of 6.90 murres/km(2) and 13.43 dovekies/km(2) combining those on the sea and in flight. We calculated a mean of 9858 murres and dovekies were at risk of being oiled, with estimates ranging from 3593 to 16,122 depending on what portion of birds in flight were assumed to be at risk. A mortality model based on spill volume was derived independently of the risk model, and estimated that 4688 (CI 95%: 1905-12,480) birds were killed during this incident. A low mortality estimate based strictly on spill volume would be expected for this incident, which occurred in an area of relatively high seabird densities. Given that the risk and mortality estimates are statistically indistinguishable, we estimate that on the order of 10,000 birds were killed by the Terra Nova spill.     

大气环境氮同位素示踪及生物监测

大气中氮的转化、迁移和沉降等大气过程与地表氮的生物地球化学循环密切相关。氮同位素对大气氮源和氮的大气化学过程的定量研究已引起广泛关注。本文对大气不同氮源的同位素特征、氮在大气过程中的同位素分馏机制以及如何定量化大气氮过程的方法进行了简要阐述,并介绍了苔藓氮同位素作为一种新的研究手段在示踪大气氮源和大气氮过程等方面取得的新进展。对国内开展的有关大气氮同位素以及苔藓氮同位素方面的工作进行了重点介绍。     

内蒙古兴和县二道河治理工程设计

本文通过工程实例分析了内蒙古兴和县前、后河和二道河的气象水文工程地质环境及其特点,对河道的治理进行了论述,提出了治理设计、施工技术要点,水土保持和环境保护的保障措施,得出投资概算与防洪效益是合理的结论。     

强壮前沟藻Amphidinium carterae Hulburt生消过程中水体总吸收特性研究

基于2011年7月藻类培养实验期间的实测数据研究了强壮前沟藻Amphidinium carterae Hulburt生消过程中水体的总吸收特性。结果表明,强壮前沟藻本次培养周期共21天,前15天为生长期,之后进入消亡期;整个生消过程中水体吸收光谱变化明显,未见440nm 波段浮游藻类蓝光吸收峰,但675nm 波段红光吸收峰突出,消亡期总吸收系数的日变化明显大于生长期,总吸收系数与叶绿素浓度的时间序列变化趋势一致;总吸收系数的波段关系良好,但不同生长时期相同波段的拟合曲线存在显著差别,消亡期的拟合曲线普遍高于生长期,且整体看来随波长增加,两曲线逐渐接近,到667、678nm 波段时几乎重合;特征波段(440、675nm)的总吸收系数与叶绿素浓度存在较好的乘幂函数关系,拟合曲线与藻种的生长阶段有关,决定系数均在0.98以上。