Effects of host starvation on the symbiotic dinoflagellates from the sea anemone Stichodactyla mertensii

Many tropical cnidarians, including anemones and corals, contain symbiotic dinoflagellates known as zooxanthellae. Photosynthesis by symbiotic dinoflagellates benefits the animal host and the proficiency of host metabolism also plays an important role in the nutrient status of the photosynthetic dinoflagellates. We aimed to determine the responses of symbiotic dinoflagellates to host starvation. The ultrastructure and some physiological indicators of symbiotic dinoflagellates (Symbiodinium sp., zooxanthellae) were examined in starved sea anemones (Stichodactyla mertensii; 3‐, 45‐ and 280‐day starvation). The cell size of zooxanthellae was not affected by starving the host; however, the ultrastructure and other physiological indicators of the zooxanthellae were affected. The photochemical efficiency of symbiotic dinoflagellates from anemones after 280 days of starvation was significantly (P < 0.01) higher than that of symbiotic dinoflagellates from anemones after 3‐ and 45‐day starvation. The number of symbiotic dinoflagellates from anemones decreased with increasing starvation duration. Generally, the chlorophyll a and c content of symbiotic dinoflagellates decreased significantly with longer anemone starvation. The tentacles of 3‐day starved anemones contained the most zooxanthellae, some of which were dividing and still enclosed within one periplast, and some had split entirely within one host vacuole. Moreover, each cell from 3‐day starved anemone contained up to five or six more mitochondria than those from 45‐ to 280‐day starved anemones. More lipid granules appeared in the zooxanthellae from 45‐ to 280‐day starved anemones. Pyrenoids, lobed accumulation bodies and calcium oxalate crystals existed in the symbiotic dinoflagellates from anemones at different starvation stages, which suggested that their existence had no correlation with host starvation. These findings contribute to an improved mechanistic understanding of the symbiotic relationship between zooxanthellae and anemones.     

Cloning and characterization of a delta-6 desaturase encoding gene from Nannochloropsis oculata

A gene(NANOC-D6D) encoding a desaturase that removes two hydrogen atoms from fatty acids at delta 6 position was isolated from a cDNA library of Nannochloropsis oculata(Droop) D.J.Hibberd(Eustigmatophyceae).The unicellular marine microalga N.oculata synthesizes rich long chain polyunsaturated fatty acids(LCPUFAs),including eicosapentaenoic acid(20:5n-3,EPA).The deduced protein contains 474 amino acids that fold into 4 trans-membrane domains.The neighbor-joining phylogenetic tree indicates that NANOC-D6D is ...     

CINRAD/SA雷达充电开关组件芯片级故障诊断技术

充电开关组件是发射机回扫充电电路关键组件,通过充电变压器完成对人工线的充电,它直接决定了人工线高压的稳定性和准确性,是影响发射机输出功率大小和稳定的关键因素之一。根据改进后开关组件线路图,总结出充电开关组件主通道、充电控制信号、故障监控信号流程和与此相关的故障树图。在此基础上,依据实际测试的发射机充电开关组件关键点波形或电平,研究出规范化的充电开关组件芯片级故障诊断流程,列举了依据充电开关组件芯片级故障诊断流程,解决了充电开关组件主通道充电赋能驱动电路芯片损坏导致无充电脉冲信号,引起无人工线高压和发射机输出功率故障,以及修复充电控制电路的充电电流传感器故障导致人工线电压过高,发射机束流报警。充电开关组件故障维修效果表明:充电开关组件芯片级故障诊断流程可以快速定位充电开关组件故障点到芯片,方法简洁,操作规范,雷达技术保障人员容易掌握,能满足国家级、省级雷达测试维修平台和雷达站器件(芯片)级维修需求,为发射机人工智能故障诊断提供借鉴,可有效缩短雷达故障维修时间,提高雷达业务运行可用性指标。     

49种大气科学类期刊创刊及更名情况分析

收集、整理49种大气科学类期刊的创刊、中外文刊名变更、刊期变更、期刊网站等情况,并分析了存在的问题。结果表明:1)49种期刊中,《气象学报》创刊最早,《气象科技进展》创刊最晚,创刊、复刊的高峰期是20世纪70、80年代。2)25种期刊变更过刊名,其中18种期刊在2000年之后更名;著录参考文献时,应注意正确著录更名期刊的中外文刊名。3)25种期刊更改过刊期,其中20种期刊由季刊变更为双月刊。4)38种期刊建有自主网站,但尚需加强网站维护。     

城市低碳消费模式的选择

从全球气候变暖、资源枯竭以及发达国家完成了工业化与城市化进程3个方面,分析了低碳消费产生的社会历史背景;根据低碳经济的内涵,提出了城市低碳消费模式选择的"科学、节约、环保、愉悦"原则。城市低碳消费模式具体体现在生产性和非生产性两大领域,前者是指从事物质资料和有形产品的生产部门,后者是指第三产业、政府管理与公共服务、居民生活3个部门。建设低碳城市,必须树立正确的消费观念,并从社会、经济、制度、法律、政策等多个层面开展工作。     

以西柏坡为龙头的红色文化产业集群建设

红色文化产业集群化发展是全球文化产业发展到一定阶段的客观趋势,是当前经济文化一体化浪潮的必然结果。本文在对河北省红色文化产业发展的条件和存在问题进行分析之后,提出了河北省红色文化产业集群建设的总体思路和发展模式,以期推动河北省红色文化产业的发展。     

Validation of WRF model on simulating forcing data for Heihe River Basin

The research of coupling WRF (Weather Research and Forecasting Model) with a land surface model is enhanced to explore the interaction of the atmosphere and land surface; however, regional applicability of WRF model is questioned. In order to do the validation of WRF model on simulating forcing data for the Heihe River Basin, daily meteorological observation data from 15 stations of CMA (China Meteorological Administration) and hourly meteorological observation data from seven sites of WATER (Watershed Airborne Telemetry Experimental Research) are used to compare with WRF simulations, with a time range of a whole year for 2008. Results show that the average MBE (Mean Bias Error) of daily 2-m surface temperature, surface pressure, 2-m relative humidity and 10-m wind speed were ?0.19 °C, ?4.49 hPa, 4.08% and 0.92 m/s, the average RMSE (Root Mean Square Error) of them were 2.11 °C, 5.37 hPa, 9.55% and 1.73 m/s, and the average R (correlation coefficient) of them were 0.99, 0.98, 0.80 and 0.55, respectively. The average MBE of hourly 2-m surface temperature, surface pressure, 2-m relative humidity, 10-m wind speed, downward shortwave radiation and downward longwave were ?0.16 °C, ?6.62 hPa, ?5.14%, 0.26 m/s, 33.0 W/m² and ?6.44 W/m², the average RMSE of them were 2.62 °C, 17.10 hPa, 20.71%, 2.46 m/s, 152.9 W/m² and 53.5 W/m², and the average R of them were 0.96, 0.97, 0.70, 0.26, 0.91 and 0.60, respectively. Thus, the following conclusions were obtained: (1) regardless of daily or hourly validation, WRF model simulations of 2-m surface temperature, surface pressure and relative humidity are more reliable, especially for 2-m surface air temperature and surface pressure, the values of MBE were small and R were more than 0.96; (2) the WRF simulating downward shortwave radiation was relatively good, the average R between WRF simulation and hourly observation data was above 0.9, and the average R of downward longwave radiation was 0.6; (3) both wind speed and rainfall simulated from WRF model did not agree well with observation data.     

1965—2017年东江中上游流域气温变化特征分析

利用东江中上游江流域8个气象站1965—2017年逐日气温资料,采用线性趋势分析、小波分析和Mann-Kendall突变检验等方法分析了东江中上游流域气温的变化特征。结果表明：1965—2017年东江中上游流域年平均气温以0.17 ℃/(10 a)速率显著上升;秋季平均气温上升最显著,冬季、夏季次之,春季不显著;年高温日数以3 526 d/(10 a)的速率显著增多。年与季平均气温和年高温日数均存在突变,各气象站年与季平均气温均大致呈自南向北依次递减分布。上游的高温日数略多于中游。各气象站年平均气温上升趋势均显著,春、夏季均以连平为中心上升幅度最大,秋季为上升趋势最明显的季节,冬季以连平为中心上升趋势最显著。各气象站年高温日数增多趋势均显著,增幅最大为连平,最小为龙川。年平均气温存在4、8—9、13—14、18—19 a的周期变化,高温日数存在2、6、10—11、25—26 a的周期变化。     

旋转等离子体系统的稳定性条件

本文从完整的MHD方程出发严格推导了一个旋转等离子体系统相对于平衡态作小振动的稳定性条件。该系统具有粘性、可压缩性、有自引力。同前人的工作相比较,由于本文用能量方程代替了近似关系(如绝热关系等),所以结果更加合理并具有普遍性。在一般情况下,前人的结果可以认为是本文结果的特例。同时本文还对文献[1]的稳定性充要条件提出疑义。     

Geochemical Characteristics and Sources of Some Chemical Components in Sediments of Zhuiiang（Pearl） River Estuary

Sediment cores with length of 25 - 45cm at 12 stations in Zhujiang(Pearl) River Estuary were sampled in summer of 1999. Chemical components (Al2O3 , Fe2O3, CaO, TiO2, Cu, Pb, Cr, Zn, Co, Ni, V, Ba, Sr and Y) and grain sizes were analyzed. Sediments in Zhujiang River Estuary are characterized by relatively coarse grain size. The grain sizes of the sediments in the area outside the estuary are relatively finer than those in the north part of the estuary but coarser than those in the middle of Lingdingyang and have a trend similar to the spatial distribution trend of some chemical components such as Fe2O3, Al2O3, TiO2, V, Cu, Ni, Zn and Y. This showed that grain size is an important factor that controls the spatial distribution and depth profile of chemical elements in the Zhujiang River Estuary. Frequent re-suspension, re-transportation and redistribution of settled sediment on estuary floor could be deduced from the spatial distributions and depth profiles of chemical components. Except for CaO and Sr, the chemical components always enrich at the west side of, in the middle of, and at the north side of, the estuary. Fe2O3, Al2O3, Ti, V, Cr, Ni, Zn, Cu and Y in Zhujiang River Estuary sediments mainly result from rock and soil weathering except that parts of Cr, Ni, Zn Cu and Y are anthropogenic. CaO and Sr in sediments originate from marine source. Although Co as well as Pb derives from anthropogenic sources, human activities related to Co might differ from the activities related to Pb.