Effect of culture methods on individual variation in the growth of sea cucumber Apostichopus japonicus within a cohort and family

There is substantial individual variation in the growth rates of sea cucumber Apostiehopus japonicus individuals. This necessitates additional work to grade the seed stock and lengthens the production period. We evaluated the influence of three culture methods （free-mixed, isolated-mixed, isolated-alone） on individual variation in growth and assessed the relationship between feeding, energy conversion efficiency, and individual growth variation in individually cultured sea cucumbers. Of the different culture methods, animals grew best when reared in the isolated-mixed treatment （i.e., size classes were held separately）, though there was no difference in individual variation in growth between rearing treatment groups. The individual variation in growth was primarily attributed to genetic factors. The difference in food conversion efficiency caused by genetic differences among individuals was thought to be the origin of the variance. The level of individual growth variation may be altered by interactions among individuals and environmental heterogeneity. Our results suggest that, in addition to traditional seed grading, design of a new kind of substrate that changes the spatial distribution of sea cucumbers would effectively enhance growth and reduce individual variation in growth of sea cucumbers in culture.     

简易建筑物的雷电防护

通过对近年来简易建筑物所发生的一些雷灾事故,分析了简易建筑物雷电防护的必要性、可行性,并因陋就简地提出了实用、经济的雷电防护方案.     

Ultrastructure developments during spermiogenesis in Polydora ciliata (Annelida: Spionidae), a parasite of mollusca

Spionid worms of Polydora ciliata inhabit the shells of many commercially important bivalves and cause disease in molluscan aquaculture. Their sperm structure is closely related to their fertilization method. To give an insight into the sperm structure and spermatogenesis, ultrastructure details of the subcellular components of germ cells during spermiogenesis of Polydora ciliata are detected by transmission electron microscopy (TEM). In P. ciliata, during spermiogenesis, chromatin is regularly arranged as dense fibrils and becomes more condensed when the nucleus elongates. Microtubules do not surround the nucleus during its elongation. The Golgi phase is characterized by the formation of proacrosomal granules within the Golgi apparatus. The proacrosomal granules fuse to form a single, spherical acrosomal vesicle that migrates to the anterior pole of the cell. At the time of nuclear condensation, mitochondria become reduced in number but increased in size, causing deep indentation at the base of the nucleus. The mid-piece has a few mitochondria. The cap phase includes the spreading of the acrosomal granule over the surface of the nucleus of the differentiating spermatid. The acrosomal phase of spermiogenesis is typically associated with changes in the shape of the nucleus, acrosome and tail. The relationship of sperm ultrastructure to spermiogenesis in spionidae species was discussed.     

网格低潮面模型构建及精度分析

文章基于网格潮汐模型构建了网格低潮面(深度基准面)模型,分析了网格低潮面模型的精度影响因子,验证了网格低潮面模型的可行性和有效性.试验表明,网格低潮面模型精度优于20cm,在离岸较远的海区精度更高;基于网格低潮面模型的低潮面确定方法可以避免基准面确定需要设立验潮站获取(同步)潮位观测数据、沿岸低潮面(深度基准面)定义和算法存在差异以及基准面传递技术存在局限性的问题,尤其适合不易设立验潮站的海区的低潮面确定.     

海口东寨港自然保护区红树林变化及其与周边社区关联分析

利用1976—2021年共6期遥感影像获取了海口市东寨港红树林自然保护区范围内不同年代的湿地数据,基于转移矩阵、问卷调查和主成分分析,剖析了45年来保护区红树林的变化及其与周边社区的关系。结果显示：1)保护区内红树林面积由1976年的1 395.84 hm²增至2021年的1 589.28 hm²,期间呈“骤减缓升”之势。除1976—1985年红树林面积有减少外(减少了250 hm²,减少幅度为18%),其余时段红树林面积均为增长态势。2) 1976—2021年保护区红树林转出对象分别是淤泥质海滩(34.32 hm²)、河流(25.81 hm²)、海水养殖场(21.06 hm²)、其他用地(10.58 hm²)和洪泛湿地/内陆滩涂(8.26 hm²);转入为红树林的对象主要是淤泥质海滩(177.41 hm²)、河流(38.18 hm²)、其他用地(28.21 hm     

基于谷歌地图的地震信息可视化应用

针对禁核试北京国家数据中心地震核查监测数据产品的需求,设计并实现基于Google Maps的动态实时更新的可视化地震信息系统,系统良好的扩展性保证了其可随应用而不断更新变化。     

Assessing climate change impacts on the ecohydrology of the Jinghe River basin in the Loess Plateau,China

Abstract

Quantifying the impacts of climate change on the hydrology and ecosystem is important in the study of the Loess Plateau, China, which is well known for its high erosion rates and ecosystem sensitivity to global change. A distributed ecohydrological model was developed and applied in the Jinghe River basin of the Loess Plateau. This model couples the vegetation model, BIOME BioGeochemicalCycles (BIOME-BGC) and the distributed hydrological model, Water and Energy transfer Process in Large river basins (WEP-L). The WEP-L model provided hydro-meteorological data to BIOME-BGC, and the vegetation parameters of WEP-L were updated at a daily time step by BIOME-BGC. The model validation results show good agreement with field observation data and literature values of leaf area index (LAI), net primary productivity (NPP) and river discharge. Average climate projections of 23 global climate models (GCMs), based on three emissions scenarios, were used in simulations to assess future ecohydrological responses in the Jinghe River basin. The results show that global warming impacts would decrease annual discharge and flood season discharge, increase annual NPP and decrease annual net ecosystem productivity (NEP). Increasing evapotranspiration (ET) due to air temperature increase, as well as increases in precipitation and LAI, are the main reasons for the decreasing discharge. The increase in annual NPP is caused by a greater increase in gross primary productivity (GPP) than in plant respiration, whilst the decrease in NEP is caused by a larger increase in heterotrophic respiration than in NPP. Both the air temperature increase and the precipitation increase may affect the changes in NPP and NEP. These results present a serious challenge for water and land management in the basin, where mitigation/adaption measures for climate change are desired.

Editor Z.W. Kundzewicz; Associate editor D. Yang

Citation Peng, H., Jia, Y.W., Qiu, Y.Q., and Niu, C.W., 2013. Assessing climate change impacts on the ecohydrology of the Jinghe River basin in the Loess Plateau, China. Hydrological Sciences Journal, 58 (3), 651–670.     

基于OMR的2．16米望远镜积分视场单元方案

基于积分视场单元的三维成像光谱技术日趋成熟,并且与传统的狭缝光谱仪相比有许多明显的优势。2．16m望远镜的OMR光谱仪是采用平面光栅分光的低色散卡焦光谱仪器,可以考虑对其进行积分视场单元的升级优化。在不改变OMR光谱仪自身结构,不影响现有功能的同时,利用“微透镜阵列＋光纤束”的技术可以实现积分视场单元与OMR光谱仪的耦合。设计了两种方案,给出了升级积分视场单元后的空间分辨率和视场。