FIRST RECORD OF AN EYE DISEASE IN THE BOWHEAD WHALE (BALAENA MYSTICETUS)

Bowheadwhale(Balaenamysticetus)isahighlyvaluedspecies,andofimportancetotheAlaskancoastEskimoswhoharvestitastheirtraditionalfoodresource.Itisknownastheicewhalebecauseitspendsmuchofitslifeintheice.ItwassurprisingtofindacaseofeyediseaseintheeyespecimensfromthebowheadwhalesharvestedinthecoldenvironmentatBarrow,Alaska,USA.Somebasicinformationispasentedbelow.Bowheadwhale96B14washarvestedbywhalingcaptainJacobAdamsonSeptember16,1996.ThisWhalewasafemalewithbodylengthof8.33m.Thecorneaofbotheyeswas…     

箭竹生长及开花的气象条件研究

通过对我国历史上箭竹开花及王朗自然保护区箭竹生长气象条件的研究认为，箭竹开花多在冬暖夏凉的年份；箭竹的生长量可由气象因素的变化来进行预测。研究结果可为保护大熊猫提供一定的气象依据。     

红外传感器用于断层气体测量

介绍新型红外气体观测仪的结构、主要技术指标、优缺点以及解决其不足之处的方法;通过分析红外气体观测仪在台站试验中取得的观测数据,探索出一种将红外气体传感技术应用于断层气观测的新方法。     

基于广义回归神经网络的GPS高程转换

为提高GPS高程转换的精度,采用广义回归神经网络(GRNN)进行拟合。将控制点的X、Y坐标作为网络输入,高程异常作为网络输出,采用实验数据训练网络,训练完成的网络作为模型进行高程异常预测。结果表明,GRNN方法具有较高的GPS转换精度。     

天顶对流层延迟计算方法研究

依据精密单点定位（PPP）原理编写天顶对流层延迟估计程序,分别利用所编程序和GAMIT软件进行实测数据解算,将所得数据与IGS网站提供数据进行对比分析,结果显示PPP与双差法估计对流层延迟都有较高精度;但在双差法解算过程中发现,无远距离测站参与解算会影响对流层延迟估计的精度。     

基于位移强度概念分析大坝变形规律

为改变以单个监测点为研究对象分析大坝变形规律的方法,提出位移强度概念,并以此作为分类标准,借鉴决策树算法,根据大坝所有监测点的坐标建立模型,计算并分析大坝在某一方向上的整体变形规律。     

基于BP神经网络的地质灾害细网格预报模型

地质灾害成因复杂,其中以气象因素、地质地貌因素引发的地质灾害最为常见.以金华地区为例,通过对金华市地质地貌条件及其对地质灾害点的调查,将全区划分为4个地质灾害隐患风险等级的网格区域.在此基础上利用金华中尺度气象资料,采用BP神经网络模型,建立地质灾害细网格预报模型,对该模型进行模拟和预报试验.结果表明,合理的隐患风险等级分区能使预报模型更符合科学规律,而采用分布较细的中尺度资料作为预报因子能进一步提高预报精度.模型的预报结果达到一定的可信度,为防灾减灾工作提供了科学依据.     

BL Andromedae and GW Tauri: close binary stars in a key evolutionary stage

A photoelectric light curve of BL And is presented along with the first CCD light curve of GW Tau. Both objects are short-period eclipsing binaries and were observed in 2003 or 2004. Photometric elements were computed using the latest version of the Wilson–Van Hamme code. The results reveal that BL And is a semidetached system with the primary component filling its Roche lobe and the secondary one almost filling but still detached, while GW Tau is a marginal-contact binary system with a small degree of contact ( f = 10.9 per cent) and a large temperature difference of about 3100 K. All available eclipse times, including new ones, were analysed for each system. It was found that the orbital period of BL And is decreasing at the rate of  d P /d t =−2.36 × 10⁻⁸ (±0.09) d yr⁻¹  while that of GW Tau may be decreasing or oscillating. We think period decrease is more probable. The derived configuration and secular period decrease for BL And combined with the asymmetry of the light curve indicate that this system may evolve from the present semidetached phase into a contact stage, with mass transfer from the primary component to the secondary one through the L ₁ point, or that it might just undergo the broken stage predicted by the theory of thermal relaxation oscillations. In contrast, GW Tau is a marginal-contact binary in poor thermal contact and may be at the beginning of the contact phase.     

The potential of FAST in detecting celestial hydroxyl masers and related science topics

The Five-hundred-meter Aperture Spherical radio Telescope(FAST) will make contributions to studies of Galactic and extragalactic masers. This telescope, with construction finished and now undergoing commissioning, has an innovative design that leads to the highest sensitivity of any single dish radio telescope in the world. FAST's potential for OH megamaser research is discussed, including the sky density of masers detectable in surveys. The scientific impact expected from FAST maser studies is also discussed.     

More than two hundred and fifty thousand spectroscopic binary or variable star candidates discovered by LAMOST

About 786.4 thousand stars were observed by LAMOST twice or more during the first stage of its spectroscopic survey. The radial velocity differences for about 256 thousand targets are larger than10 km s^-1 and they are possible spectroscopic binary or variable candidates(SBVCs). It is shown that most SBVCs are slightly metal poorer than the Sun. There are two peaks in the temperature distribution of SBVCs around 5760 K and 4870 K, while there are three peaks in the distribution of the gravitational acceleration at 2.461, 4.171 and 4.621 cm s^-2. The locations of SBVCs on the [Fe/H]-T, [Fe/H]-log g, log g-T and H-R diagrams are investigated. It is found that the detected SBVCs could be classified into four groups. The first group has higher log g～4.621 and lower T ～ 4870 K which are mainly cool red dwarf binaries. The second group of SBVCs has logg around 4.171 cm s^-2 that includes binaries and pulsating stars such as δSet and γ Dor variables. The gravitational accelerations of the third group of SBVCs are higher and some of them are below the zero-age main sequence. They may be contact binaries in which the primary components are losing energy to the secondaries in the common envelopes and are at a special stellar evolutionary stage.The last group is composed of giants or supergiants with log g around 2.461 cm s^-2 that may be evolved pulsating stars. One target(C134624.29+333921.2) is confirmed as an eclipsing binary with a period of 0.65 days. A preliminary analysis suggests that it is a detached binary with a mass ratio of 0.46. The primary fills its critical Roche lobe by about 89%, indicating that mass transfer will occur between the two components.