COⅠ条形码辅助分析雷州半岛红树林区鱼类的物种多样性

于2014年3月至2015年7月从我国雷州半岛红树林区采集成鱼和幼鱼样本共1720尾,在依据Fish Base等鱼类形态分类系统进行鉴定的基础上,利用COⅠ条形码技术确认存在94个物种,分属11目33科72属。结果表明:红树林区鱼类种群极其丰富,其中鲈形目(Perciformes)鱼类物种最多,为59种,占总物种数的62.77%,其次是鲱形目(Clupeiformes)和鲻形目(Mugiliformes),分别占6.38%和5.32%。鲈形目中又以虾虎鱼科(Gobiidae)为优势类群,含29种(占30.85%)。按生态类群分:海洋洄游鱼类最多,占物种总数的32.98%,其次为海洋偶见鱼类、两侧洄游鱼类,分别占22.34%、17.02%,以虾虎鱼类物种为主的红树林定居鱼类约占11%。本研究表明红树林生态系统是许多海水、淡水和洄游性鱼类在特定生活阶段的重要栖息地和育幼场所。另外,COⅠ条形码技术可有效快捷地鉴定出红树林海域的鱼类。     

拉萨河源头水域中浮游生物、鱼类资源调查与分析

拉萨河是西藏重要的河流之一,流经多个县市,拉萨河的生态性调查和环境保护对西藏的社会和经济发展重要意义。本调查在拉萨河上游11个乡镇分别进行断面取点调查,对各乡镇境内拉萨河段进行浮游生物与鱼类取样统计分析。本次调查中,共检出浮游植物76个种类,其中硅藻门48种,占总种类数的63.2%;绿藻门12种,占总种类数的15.8%;蓝藻门6种,占总种类数的7.9%;金藻门4种,占总种类数的5.3%;隐藻门3种,占总种类数的3.9%;黄藻门和裸藻门各1种,分别占总种类数的1.3%;共检出浮游动物4大类50种,其中原生动物24种,占总种数的48%;轮虫12种,占总种数的24%;枝角类10种,占总种数的20%;桡足类4种,占总种数的8%;共发现1目2科5属的鱼类5种,均为鲤形目,本地鱼类有3种,占总数的60%,外来种有2种,占到总数的40%,其中拉萨裸裂尻鱼(Schizopygopsis younghusbandi Regan)和双须叶须鱼[Ptychobarbus dipogon(Regan)]为雅鲁藏布江特有鱼类。本次调查采集到的外来鱼种有棒花鱼和鳅鱼两种。经本次调查,西藏拉萨河源头流域,生物多样性略贫乏,尤其是鱼类种类较少。而鱼类保护工作面临的两大挑战就是外来鱼种入侵以及过度捕捞而造成的鱼类资源减少。     

Fitness‐related consequences shed light on the mechanisms of covering and sheltering behaviors in the sea urchin Glyptocidaris crenularis

We know of no comparative assessment on the benefits and costs of long‐term covering and sheltering behaviors in sea urchins. The present study investigated the long‐term effects of conditions suitable for sheltering and covering behaviors on fitness‐related traits of sea urchins Glyptocidaris crenularis. In general, conditions suitable for covering and sheltering behaviors significantly affected the fitness‐related traits of G. crenularis in a long‐term laboratory study of 31 months. Glyptocidaris crenularis kept in conditions suitable for sheltering behavior (bricks with openings) showed significantly lower test size, body weight, organ (test, lantern, gonad and gut) weights, gonad index and slower gonad development than those kept in conditions suitable for covering behavior (presence of shells) and the control conditions (without conditions for covering and sheltering). However, the index of maximum pressure resistance of the test was significantly higher in G. crenularis kept in the sheltering conditions than those in the covering and control conditions. The present study provides new insight into the mechanisms of covering and sheltering behaviors and has implications for the conservation and aquaculture of sea urchins.     

Criteria of Acceptance for Constant Rate of Strain Consolidation Test for Tropical Cohesive Soil

In this study, the rapid consolidation equipment (RACE) was developed as an alternative device to the conventional consolidation test using Oedometer, consuming merely a few hours for the whole precedure to determine the consolidation characteristics of cohesive soil. RACE operates based on the constant rate of strain (CRS) consolidation theory, which is a continuous loading method of testing, requiring a good estimation of the loading rate such that it is ideal for the achievement of steady state condition during testing. The steady state condition is achieved when the c _v values from drained and undrained face of CRS converged with the c_v from Oedometer test. A slightly modification has been made on the normal constant rate of strain (CRS) test by proposing a direct back pressure system to the specimen using a tube to saturate the soil sample. This research has produced a set of criteria for determining the suitable rate for the rapid consolidation test based on the ratio of normalized strain rate, β, and proposed a new coefficient in terms of a ratio of β to clay fraction (CF), as a part of new criteria for testing a fine soil. Four types of sample were tested with different rates of strain using the RACE and their results were compared with those conducted using the Oedometer on the same soil type, from which fairly good agreements were evident in many specimens. It was found from the study that the minimum value of normalized strain rate, β, for the CRS test is 0.005 and for the u _a /σ _v ratio is suggested as 0.01. Also, the maximum β/CF for soils with clay friction lower and higher than 50 % are 0.008 and 0.001, respectively. The minimum β/CF value for both conditions is 0.0001.     

2016年6月23日江苏阜宁EF4级龙卷天气分析

2016年6月23日,江苏省盐城市阜宁县发生了历史罕见的EF4级龙卷,导致99人死亡,846人受伤,并有大量建筑物被损毁。文章利用观测资料对产生强龙卷的天气背景和中尺度特征进行了分析,发现：阜宁龙卷发生在我国东部龙卷最高发的地区和季节,产生龙卷的天气尺度背景为典型的梅雨期暴雨环流,产生龙卷的中尺度对流系统发生在地面暖锋南侧,这里也是高低空急流耦合的区域,与高空急流相伴的动力强迫特征明显,大气热力不稳定条件为中等偏强;产生阜宁龙卷的中尺度对流系统与美国大部分强龙卷相似,为块状的离散单体对流模态,且具有经典超级单体的钩状回波和强中气旋特征,并伴有龙卷涡旋特征（tornado vortex signature,TVS）;龙卷位于钩状回波顶端,主要发生在中气旋底高高度低于1 km期间。     

Rainfall-induced landslide susceptibility assessment at the Chongren area (China) using frequency ratio,certainty factor,and index of entropy

The main objective of the study was to evaluate and compare the overall performance of three methods, frequency ratio (FR), certainty factor (CF) and index of entropy (IOE), for rainfall-induced landslide susceptibility mapping at the Chongren area (China) using geographic information system and remote sensing. First, a landslide inventory map for the study area was constructed from field surveys and interpretations of aerial photographs. Second, 15 landslide-related factors such as elevation, slope, aspect, plan curvature, profile curvature, stream power index, sediment transport index, topographic wetness index, distance to faults, distance to rivers, distance to roads, landuse, NDVI, lithology and rainfall were prepared for the landslide susceptibility modelling. Using these data, three landslide susceptibility models were constructed using FR, CF and IOE. Finally, these models were validated and compared using known landslide locations and the receiver operating characteristics curve. The result shows that all the models perform well on both the training and validation data. The area under the curve showed that the goodness-of-fit with the training data is 79.12, 80.34 and 80.42% for FR, CF and IOE whereas the prediction power is 80.14, 81.58 and 81.73%, for FR, CF and IOE, respectively. The result of this study may be useful for local government management and land use planning.     

国产资源三号测绘卫星DSM数据质量评价--以高海拔山区为例

为了评价国产资源三号测绘卫星DSM数据精度,在顾及地貌类型的情况下,以涵盖平原、台地、丘陵等地貌的高海拔山区为研究案例,并以1∶1万实测地形图DEM为假定真值,以90m分辨率SRTM DEM为评价参照,从高程精度和地形描述精度两个方面,对15m分辨率ZY-3DSM进行精度评价分析。研究结果表明:ZY-3DSM高程精度优于SRTM DEM,前者高程中误差仅为后者的1/6;就地形描述精度来讲,ZY-3DSM与SRTM DEM相比,其地形描述精度更接近理论值,前者RMS Et实际值仅为理论值0.99倍,而后者的实际值却是理论值5.13倍。由此看来,ZY-3DSM数据精度整体上高于SRTM DEM。     

The buckling of GRP hemi-ellipsoidal dome shells under external hydrostatic pressure

The paper reports on a theoretical and an experimental investigation into six GRP hemi-ellipsoidal dome shells, which were tested to destruction under external hydrostatic pressure. All six domes were of oblate shape and of three different aspect ratios. Each aspect ratio consisted of two dome shells, one made from two layers of glass fibre and one made from three layers of glass fibre. The theoretical analysis was via the finite element method where a non-linear theory was used which allowed for both geometrical and material non-linearity. Comparison between theory and experiment was good.     

铜在牙鲆(Paralichthys olivaceus)组织蓄积、分配及排放的研究

采用暴露实验方法 ,研究了海水中Cu在牙鲆 (Paralichthysolivaceus)内脏、肌肉、鳃组织内吸收、积累和排放规律 ,海水中总有机碳 (TOC)浓度、配体种类对铜吸收的影响及其与海水表观络合容量 (ACuCC)的关系。结果表明 ,Cu浓度为 0 .5mg/L时 ,各组织内Cu蓄积量随暴露时间增加而增大 ,第 1 3天均达吸收平衡 ,此时Cu蓄积量 (mg/kg)为内脏 971 .89>肌肉 2 0 4 .99>鳃 90 .0 4。染毒 1 3天牙鲆在清洁海水中排放结果表明 :随排放时间增加各组织Cu蓄积量下降 ,第 8天接近排放平衡。此时各组织Cu排出率为 :肌肉 89% >鳃 86.5 % >内脏团 83.7%。海水中TOC浓度、种类对牙鲆Cu蓄积有明显影响 ,当TOC浓度相同时 ,孔石莼分泌物比牙鲆分泌物更能降低Cu在牙鲆组织内吸收和蓄积量 ;当TOC种类相同时 ,随TOC浓度升高 ,各组织铜蓄积量均明显下降 ,表明海水TOC能降低牙鲆组织对Cu的吸收和积累。ACuCC随TOC浓度增加有明显上升趋势 ,并与TOC浓度呈线性相关。