CINRAD/CC雷达接收机特性曲线异常诊断

依据新一代天气雷达接收机系统工作原理及接收系统特性曲线关键点参数测量方法,结合对CINRAD/CC新一代天气雷达系统特性曲线异常故障的分析,提出了接收系统特性曲线异常故障诊断流程及处理方法,该方法在排除CINRAD/CC新一代天气雷达接收机特性曲线异常的故障实践中得到验证,结果表明:采用这种诊断流程和处理方法不仅快捷、有效,还具有规范性和稳定性,可为雷达技术保障人员处理各种型号新一代天气雷达接收机特性曲线异常故障提供借鉴.     

海陆交互相沉积岩页岩气生储特征——以鲁西南含煤区为例

鲁西南含煤区是山东重要的煤炭生产和储存区,也是山东省古生代海陆交互相沉积岩发育和保存较好的地区之一,本次以石炭-二叠纪海陆交互相沉积泥页岩为研究目标,对泥页岩沉积环境和发育特征、有机地化特征、岩石物性特征、含气性特征等方面进行分析研究,发现山西组和太原组是鲁西含煤区海陆交互相沉积岩最为发育层位,暗色泥页岩厚度100～2...     

Long-term trend of oceanic surface carbon in the Northwest Pacific from 1958 to 2017

Contrasting decrease and increase trends of sea surface temperature（SST） have been documented in the western Subarctic（WSA） and the rest of the Northwest Pacific（NWP） from 1958 to 2017, respectively. Consequently, more（less） total carbon dioxide（TCO₂） due to ocean cooling（warming） is transported to the surface, which leads to increase（decrease） of oceanic surface partial pressure of carbon dioxide（pCO₂）. With the combined influence of the rising atmospheric carbon dioxide（C...     

The response law of far-field seismic ground motion of the Wenchuan earthquake and its damaging mechanism in the Loess Plateau

A series of housing collapses and other serious damage was caused by the 2008 Wenchuan M_S 8.0 earthquake in the seismic intensity Ⅵ areas of the Loess Plateau, which is hundreds of kilometers away from the epicenter, and which showed a remarkable seismic intensity anomaly. The seismic disasters are closely related to the seismic response characteristics of the site, therefore, the systematic study of the far-field seismic response law of the Wenchuan earthquake in the Loess Plateau is of great significance to prevent the far-field disaster of great earthquake. In this paper, the seismic acceleration records of several bedrock stations and loess stations from the seismogenic fault of the Wenchuan earthquake to the Loess Plateau were collected, and the attenuation law of ground motion along the propagation path and the characteristics of seismic response on the loess site are studied, and the mechanism of amplification effect of ground motion is analyzed based on the dynamic feature parameters of the loess site obtained through the HVSR method. Taking a typical loess site of thick deposit as the prototype, a series of shaking table tests of dynamic response of loess site models with different thicknesses were carried out. Amplification effect, spectral characteristics of acceleration in model sites were analyzed under the action of a far-field seismic wave of the Wenchuan earthquake. The results show that seismic attenuation on the propagation path along the NE strike of the seismogenic fault to the Loess Plateau is slower than that in other directions, and the predominant period range of ground motion on bedrock site of the Loess Plateau presents broadband characteristics. Because the natural periods of loess sites with thick deposits are within the predominant period range of bedrock input wave, loess sites appear significant amplification effect of ground motion, the horizontal acceleration of ground motion exceeds 0.1 ?g, the seismic intensity reaches 7°. The thicker the loess deposit is, the more significant the change of spectral characteristics of ground motion on loess sites, and the narrower the predominant period range of ground motion becomes, and the closer it is to the natural period of loess sites. Therefore, for some old houses on thick loess sites, the poor seismic performance and strong seismic response eventually led to their collapses and damages because their natural periods are very close to the predominant period of ground motion of the Wenchuan earthquake on thick loess sites; For these damaged high-rise buildings, the resonance effect might be the main reason for their damages because their natural periods are included in the predominant period range of ground motion of the Wenchuan earthquake on thick loess sites.These research results would provide a basis for seismic disasters prediction and evaluation and seismic design of construction engineering in the Loess Plateau.     

好氧降解对垃圾土沉降影响试验及沉降模型

好氧降解作用对垃圾土沉降变形特性的定量评价是预测和评估好氧降解稳定化的重要基础。以武汉市典型生活垃圾组成配比人工制作的垃圾土为样本,开展了不同通风条件下垃圾土沉降特性试验,分析了好氧通风频率对沉降变形的影响。试验结果表明：厌氧条件沉降速率趋于稳定后,好氧通风可显著提高垃圾土的沉降速率;上、中、下3层垃圾在高通风频率下垃圾土沉降比低通风频率下沉降效率分别提高了145%、150%、100%;建立了厌氧-好氧联合型沉降模型,通过与试验监测得到的沉降值对比,初步验证了模型的可靠性。研究结果为好氧通风过程中垃圾土沉降稳定性评估提供了理论依据。     

Creep characteristics of calcareous coral sand in the South China Sea

Acta Geotechnica - In recent years, a series of lands have been built or enlarged on the top of some natural coral reefs by the means of reclamation in the South China Sea (SCS). The reclamation...     

广东长排铀矿床成矿流体特征

长排铀矿床位于广东长江铀矿田内,矿体主要赋存在北北西向硅化断裂带内及其两侧的蚀变花岗岩中。流体包裹体显微测温和激光拉曼光谱分析表明,成矿流体为中低温、中低盐度的含CO2、CH4和H2的流体。铀成矿期流体包裹体均一温度多集中于120~250 ℃,盐度为04%~102%。氢、氧同位素分析表明,成矿流体可能来源于深部,后期有大气降水的加入。成矿期方解石的δ13C值大多数集中于-91‰~-82‰,以深源碳为主。综合分析认为,长排铀矿床属于中低温热液脉型铀矿床。成矿流体经历了沸腾作用,使CO2等挥发分逃逸,这可能是长排铀矿床铀矿沉淀、富集的主要原因。     

Characterization of SNAP-25 gene from marine teleostean, Lateolabrax japonicus

The t-SNARE protein SNAP-25 (synaptosome-associated protein of 25 kDa) plays an essential role in regulating fusion between the vesicle and plasma membranes during exocytosis. To clone and characterize SNAP-25 gene, the first step in the functional study of SNARE proteins in marine teleostean, was to obtain the cDNA of sea perch SNAP-25 (SPsn25) by RT-PCR and RACE-PCR amplification of a Japanese sea perch. The full-length cDNA of 831bp contains a CDS of 615 bp, coding 204 amino acid residues, and a 5′UTR of 219bp. Bioinformatic analysis revealed that SPsn25 corresponds with SNAP-25a isoform and shares 91.1% identity with SNAP-25a of a goldfish and a zebrafish. The SPsn25 expression in both mRNA and protein levels in the Japanese sea perch had been identified through semi-quantitative RT-PCR and Western Blot assay. Together, these data again confirmed the nerve tissue specificity of the fish SNAP-25 gene expression.