新生大鼠海马神经元体外分散培养技术研究

在实验室建立了分散的新生大鼠海马神经细胞体外培养模型。该模型属原代培养,在体外能直接观察神经元的生长发育。研究表明：该模型稳定性好,差异性小;培养神经细胞可存活１个月以上,１４ｄ左右细胞生长最为丰满,且四周晕光明显,神经突起多而粗大,分枝互成网络;１４ｄ以后生长减缓。由于在此模型培养的条件下,既不存在血脑屏障问题,又容易控制条件,便于在细胞和分子水平上深入研究神经细胞的形态学、生理学、生化代谢及药理学等方面的问题,特别适合在体外进行神经药理学的研究。     

地震计线性误差精确测试

利用同步测试标准地震数据采集器标定电流的地震计线性误差测试方法,避免了标定信号输出电流波动对地震计线性误差测试的影响,按DB/T 21—2007规定的方法进行数据处理,并判定结果是否符合DB/T 22—2007的要求。实际测试表明,该方法测试精度可以达到0.000 5%,满足测试线性偏差小于0.01%的需要,且操作简单,无额外设备要求,可行性高,可在固定地震台站、野外等条件下使用,具有较大的应用价值。     

基于Google Earth的气象多参数综合显示系统

利用Google Earth平台,将天气过程中的雷电、红外云图、MICAPS高空图以及TMPA降水资料,通过编写KML/KMZ文件,建立了气象多参数综合显示系统。该系统平台的建立,可在三维空间中真实动态地再现天气的发生发展及演变过程。此平台将有利于灾害性天气成灾过程和物理机制的研究。     

Study on the urban heat island effects and its relationship with surface biophysical characteristics using MODIS imageries

This study assesses surface urban heat island (UHI) and its associated surface physical characteristics using remote sensing approaches. TERRA/MODIS images acquired in 2005 in three different seasons were selected to generate land surface tem-perature and surface characteristics for the Changsha-Zhuzhou-Xiangtan metropolitan area in China. The intensity of urban heat is-land effects and its seasonal variations were examined. The result showed that UHI effects were significant both in the summer and the spri...     

鄱阳湖洲滩湿地植物演替对土壤微生物量的影响

湿地植物演替对土壤微生物量具有显著影响,但不同土壤理化环境下的植物演替对湿地土壤微生物量影响的具体差异还不清楚。以鄱阳湖土壤理化性质不同的4个碟形子湖(包括相对肥沃的东湖和白沙湖以及相对贫瘠的蚌湖和大湖池)为研究对象,运用空间代替时间的方法,在泥滩带、湿生植被带(苔草)和挺水植被带(南荻或芦苇)采集0～10 cm表层土壤,分析不同土壤理化性质条件下植物群落演替对土壤微生物量的影响。采用土壤微生物量碳(MBC)和微生物熵(qMB)指示土壤微生物量。蚌湖、大湖池、东湖和白沙湖洲滩湿地表层土壤MBC的平均值分别为1077.27、888.29、942.45和1162.46 mg/kg,土壤qMB的平均值分别为6.07%、6.17%、3.60%和3.79%。在泥滩—苔草—南荻植物演替洲滩,土壤MBC先增加后减少;但是在泥滩—苔草—芦苇植物演替洲滩,土壤MBC持续增加。植物演替没有显著改变土壤qMB。尽管植物的生长会增加所有洲滩湿地的土壤MBC,但增加的幅度在相对贫瘠的蚌湖和大湖池明显强于相对肥沃的东湖和白沙湖。蚌湖和大湖池的土壤qMB也显著高于东湖和白沙湖。在植被演替梯度上,洲滩湿地土壤MBC和...     

Erosion probability model of base-soil particle migration into a granular filter under local flow

To avoid soil erosion, lters often are installed in the downstream cross section of dams. However, the probability of piping failure and the lter effect both are related to the soil pore network. Previous erosion probability models for a base soil- lter system do not consider the effect of local ow. Therefore, in this study, an improved erosion probability model is established, in which the deviation between the main ow direction of the soil and the local ow direction in the lter was considered based on a previous model. The improved model was validated by numerical simulation. The erosion probability was found to affect the reasonable evaluation of lter effects and the optimal selection of lter thickness. The controlling con- striction size in a granular lter was increased to Dc* Dc5 with a lter thickness of 59 Dm.     

物联网技术在地震受困人员应急搜救中的应用研究

为能在搜救地震受困人员时,实时监测灾区情况,增强实时性及降低搜救误差,研究物联网技术在地震受困人员应急搜救中的应用,设计基于物联网的地震应急搜救系统,采用RFID识读器将采集的数据通过互联网传输至数据处理中心服务器上,再反馈至灾区信息处理子系统中的监测防御模块中,若出现异常情况则开启射频模块,命令现场报警装置响应报警应急搜救信号;通过蚁群算法获取最优搜救路线,及时搜救地震受困人员。实验结果表明,设计系统可有效搜救地震受困人员,且系统的吞吐率高达90%,搜救准确率均值高达97.6%,耗时均值仅为0.88 h,具有较高的搜救准确率和搜救效率。     

Ordovician integrative stratigraphy and timescale of China

In this chapter, starting with a brief review of the research history and current status in the studies of the Ordovician chronostratigraphy in China, the subdivision of the Ordovician System, definition and recognition of its series and stage boundaries, and possible stratigraphic gaps are discussed in details in order to establish a multidisciplinary stratigraphic correlation through an integrated approach including lithostratigraphy, biostratigraphy, radiometric dating, chemostratigraphy and magnetostratigraphy. Being internationally accepted, the Ordovician System is now subdivided into three series and seven stages, in ascending order, Lower(Tremadocian, Floian), Middle(Dapingian, Darriwilian) and Upper series(Sandbian, Katian,Hirnantian). Three of the seven "Golden Spikes" defining the bases of the Ordovician stages, which were established in 1997–2007, are located in China. As a regionally applied chronostratigraphy, the Ordovician System was subdivided in China into Lower(Xinchangian, Yiyangian), Middle(Dapingian, Darriwilian) and Upper series(Neichiashanian, Chientangkiangian,Hirnantian). This scheme agrees largely with the standard international classification, which can actually be directly applied to China, except for some special circumstances where the Neichiashanian and Chientangkiangian stages of the Upper Ordovician are used. Based on the new studies in recent years and distinctions and differences recognized in the development of the Ordovician System in the constituent terranes of China, a new framework for correlation among the major Chinese palaeoplates or terranes, e.g. South China, North China(including Tarim and Qaidam) and Xizang(Tibet)-western Yunnan, has been established. However, it has been recognized herein that uncertainties still remain on defining the base of the Tremadocian,Dapingian and Katian, and on the correlation between different mega-facies. More specifically, for the Tremadocian, the precise correlation of its base will depend on the better-defined conodont taxonomy, while for the Dapingian and Katian, on the correlation between different mega-facies. It is worthwhile to note that the chemostratigraphic studies of the Ordovician System in China produced the carbonate δ13 C curves for the Darriwilian(Middle Ordovician) and Katian(Upper Ordovician), which show significant differences from the composite global curve. Record of the Ordovician isotopic dating is relatively rare in China, with only three reliable ages from zircons that are all from the upper Katian to Hirnantian of the Upper Ordovician.Abundant bentonite beds in the Upper Ordovician of South China will also provide unique opportunities to advance the isotopic dating and related researches. Studies on the Ordovician magnetostratigraphy need to be significantly enhanced in China, as currently all the available results are restricted to the Lower Ordovician of North China, although they can be correlated with those known from other parts of the world. The analysis of the durational unevenness of the seven stages in the Ordovician supports the possibility to further subdivide the long-durational Tremadocian, Darriwilian and Katian stages, each into two substages.     

东南丘陵山区深水水库两种浮床植物脱氮效率对比研究

为探究东南丘陵山区深水水库中生态浮床技术深度脱氮的效率及管理措施,以大型山谷型深水水库千岛湖为例,选取湿生植物空心菜(Ipomoea aquatica)和水生植物粉绿狐尾藻(Myriophyllum aquaticum),采用生态浮床技术,开展了原位模拟实验对比研究,探究不同营养盐浓度和光强下两种植物的生长状况与氮素去除效率。结果发现:(1)空心菜长势受营养盐和光照条件影响明显,添加氮磷后(TN=2.37 mg/L,TP=0.046 mg/L)的空心菜生物量是原位水体(TN=0.66 mg/L,TP=0.028 mg/L)的1.6倍,适当遮光有助于浮床植物生长,40%遮光条件下空心菜的生物量是不遮光条件下的1.5倍;而粉绿狐尾藻生长受营养盐和光照条件影响均较小。(2)空心菜对于水体氮素净化能力显著高于粉绿狐尾藻,在最佳条件下空心菜和粉绿狐尾藻对氮素的去除效率分别达到213.30和44.23 mg/(m²·d)。(3)空心菜去除氮主要以植物同化作用为主,占70%以上TN去除量,40%遮光环境通过明显提升空心菜同化吸收氮量和根系反硝化速率增强了氮的去除能力;粉绿狐尾藻同化吸收和反硝化脱氮作用各占50%左右,以遮光75%下脱氮效果最好。本研究表明,采用生态浮床技术能够强化深水水库的脱氮能力,空心菜更适合在氮浓度较高的水体生长,夏季为空心菜和粉绿狐尾藻浮床分别进行40%和75%的遮光处理将有更好的水质净化效果。因此,在滨岸湿地匮乏的深水水库实施多种植物搭配的生态浮床技术强化水体脱氮作用是一种行之有效的水质改善方法。     

Remote sensing retrieval of surface suspended sediment concentration in the Yellow River Estuary

Accurate assessment of surface suspended sediment concentration(SSSC) in estuary is essential to address several important issues: erosion, water pollution, human health risks, etc. In this study, an empirical cubic retrieval model was developed for the retrieval of SSSC from Yellow River Estuary. Based on sediments and seawater collected from the Yellow River and southeastern Laizhou Bay, SSSC conditions were reproduced in the laboratory at increasing concentrations within a range common to field observations. Continuous spectrum measurements of the various SSSCs ranging from 1 to 5700 mg/l were carried out using an Ava Field-3 spectrometer. The results indicated the good correlation between water SSSC and spectral reflectance(Rrs) was obtained in the spectral range of 726–900 nm. At SSSC greater than 2700 mg/L, the 740–900 nm spectral range was less susceptible to the effects of spectral reflectance saturation and more suitable for retrieval of high sediment concentrations. The best correlations were obtained for the reflectance ratio of 820 nm to 490 nm. Informed by the correlation between Rrs and SSSC, a retrieval model was developed(R2 = 0.992). The novel cubic model, which used the ratio of a near-infrared(NIR) band(740–900 nm) to a visible band(400–600 nm) as factors, provided robust quantification of high SSSC water samples. Two high SSSC centers, with an order of 103 mg/l, were found in the inversion results around the abandoned Diaokou River mouth, the present Yellow River mouth to the abandoned Qingshuigou River mouth. There was little sediment exchange between the two high SSSC centers due to the directions of the residual currents and vertical mixing.