Variations of Hydrodynamics and Submarine Groundwater Discharge in the Yellow River Estuary Under the Influence of the Water-Sediment Regulation Scheme

The “Water-Sediment Regulation Scheme” (WSRS) is critically important to the hydrologic evaluation of the Yellow River estuary since a huge pulse of water and sediment are delivered into the sea during a short period. We used the natural geochemical tracers radium (²²³Ra, ²²⁴Ra, ²²⁶Ra) and radon (²²²Rn) isotopes as well as other hydrological parameters to investigate the mixing variations and submarine groundwater discharge (SGD) in the Yellow River estuary under the influence of the 2013 WSRS. Dramatically elevated radium and radon isotopic activities were observed during this WSRS compared with activities measured during a non-WSRS period. Radium “water ages” indicated that the offshore transport rate nearly tripled when the river discharge increased from 400 to 3400 m³/s. We calculated the SGD flux in the Yellow River estuary based on a radium mass balance model as well as radium and radon time-series models. The SGD flux was estimated at 0.02~0.20 m/day during a non-WSRS period and 0.67~1.22 m/day during the 2013 WSRS period. The results also indicate that large river discharge tends to lead more intense SGD along the river channel direction with a large amount of fresh SGD.     

基于动态极值理论和Copula函数的极端海平面高度预测建模

全球气候变化背景下,海平面上升是一个潜在的重大风险,为防范气候灾害,应对极端气象海洋事件,需客观、定量地对未来极端海平面变化进行科学预测。为此,基于Copula函数和动态极值分析理论,综合考虑平均海平面变化(包括垂直陆地运动和基准的局地变化)与潮、涌、浪等其他气候变化的增水对极端海平面高度的影响,采用DREAM方法改进Bayes推断对动态极值模型的参数空间估计问题,提出一种新的模型对未来极端海平面高度变化进行预测,旨在改进传统模型存在的不确定性问题,并运用该模型对气候变化背景下厦门地区未来35年的海平面变化情景进行了模型应用和实验模拟。     

新疆额尔宾山花岗岩侵位年龄和成因及其对南天山洋闭合时代的限定

额尔宾山花岗岩岩体位于南天山晚古生代侵入岩带,对该花岗岩进行锆石U-Pb定年获得296.1±1.8Ma的年龄,为早二叠世。岩石主量元素分析结果表明,该花岗岩的Si O2含量为66.96%~67.3%,富碱(Na2O+K2O=7.53%~7.97%),K2O/Na2O1(1.15~1.27),属高钾钙碱性系列岩石;Al2O3为15.56%~15.62%,Al2O3K2O+Na2O+Ca O,属于过铝型。岩石稀土元素配分模式呈现轻稀土元素(LREE)富集((La/Yb)N=27.03~30.62)、重稀土元素(HREE)亏损((LREE/HREE)=18.2~20.1)、具有中等程度的负Eu异常(δEu=0.64~0.68)。微量元素判别结果显示,其具有I-A型花岗岩过渡的特征。结合区域地质背景综合分析,初步认定该岩体可能形成于南天山同碰撞向后碰撞构造体制转换时期,据此可以推测南天山洋盆闭合时限至少应该在早二叠世以前。     

New variogram modeling method using MGGP and SVR

A critical step for kriging in geostatistics is estimation of the variogram. Traditional variogram modeling comprise of the experimental variogram calculation, appropriate variogram model selection and model parameter determination. Selecting of the variogram model and fitting of model parameters is the most controversial aspect of geostatistics. Shapes of valid variogram models are finite, and sometimes, the optimal shape of the model can not be fitted, leading to reduced estimation accuracy. In this paper, a new method is presented to automatically construct a model shape and fit model parameters to experimental variograms using Support Vector Regression (SVR) and Multi-Gene Genetic Programming (MGGP). The proposed method does not require the selection of a variogram model and can directly provide the model shape and parameters of the optimal variogram. The validity of the proposed method is demonstrated in a number of cases.     

Retrospective analysis of diversity and species composition of marine macroalgae of Hainan Island (China)

Retrospective analysis of diversity and species composition of marine macroalgae of Hainan Island in the period 1933–1992 is presented in this paper. There are two extensive sample collection periods of benthic macroalgae: the early collection (EC) covers a period between the early 1930s and the 1980s before considerable urbanization and reef degradation took place and a late collection (LC) was performed in 1990/1992 during a phase of rapid urbanization. Analysis of data also including an earlier published inventory of green algae covering the same collection sites (Titlyanov et al. 2011a) revealed that the marine flora of the island comprises 426 taxa in total, with 59% red algae, 18% brown algae and 23% green algae. In total 59 species of red algae, 11 species of brown algae and 37 species of green algae sampled during the LC are new records for Hainan Island. Considerable floristic changes between EC and LC became evident. In the LC there were significantly more filamentous, tubular or fine blade-like, and often epiphytic, green and red algae with a high surface-to-volume ratio. Additionally a reduction of green, brown and red algal species with larger fleshy or foliose thalli and a low surface-to-volume ratio was observed. It is assumed that the changes reflect the degradation of the coral reef ecosystem around Hainan, which was damaged by human activities especially in the 1950s–1970s.     

Seismic Stability of Gravity Retaining Structures by Pseudo-Dynamic Method

An analytical expression of a gravity retaining wall's seismic stability against sliding and overturning is proposed in this article. The derivation, aiming at the cohesionless soil with inclined backfill surface and nonvertical wall back, is based on limit equilibrium analysis and the pseudo-dynamic method. The variations of the sliding and overturning stability safe factors with the horizontal seismic acceleration are investigated for different seismic amplification factors, soil friction angles, wall friction angles, vertical seismic acceleration coefficients, wall back inclination angles, and backfill surface inclination angles. The results indicate that the soil friction and horizontal seismic action significantly impact the seismic stability. The increase of vertical earthquake action changes the curvature of stability factor curves. The wall friction and back inclination strengthen the gravity retaining wall's resistance to sliding and overturning failure while the backfill surface inclination plays a negative role in the seismic stability. We also found that the seismic stability safe factors calculated by the proposed method are larger but more reasonable than those by the Mononobe-Okabe method.     

低空无人机视频影像可量测立体模型构建技术

提出了一种利用无人机快速获取的视频数据的可量测立体模型构建方法。首先,通过无人机飞行平台快速获取视频数据,基于改进平板摄像机智能标定技术,获取摄像头的内方位元素,结合摄像机内方位参数、视频帧率、飞行高度、速度、影像分辨率等参数实现了基于实时视频流的关键帧影像自适应自动提取算法,并对提取关键帧影像进行畸变差改正;其次,通过对校正后的影像进行光束法空中三角测量加密处理,计算视频关键帧影像的外方位元素信息。最后,利用北京地区的试验数据进行了验证分析。结果表明利用能快速实现可量测立体模型构建,具有较高的量测精度,能有效的提高应急测绘条件下的灾情地理信息获取,为灾情评估和辅助决策提供依据。     

Protective effects of C-phycocyanin on alcohol-induced acute liver injury in mice

Excessive alcohol consumption leads to liver disease. Extensive evidence suggests that C-phycocyanin (C-PC), a chromophore phycocyanobilin derived from Spirulina platensis, exerts protective effects against chemical-induced organ damage. In this study, we investigated whether C-PC could protect against ethanol-induced acute liver injury. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), total cholesterol (CHOL), low-density lipoprotein (LDL), liver homogenate malondialdehyde (MDA), superoxide dismutase (SOD) content were measured, and pathological examination of liver sections were examined. C-PC showed obvious inhibitory effects on serum ALT, AST, TG, CHOL, LDL and MDA, and SOD content significantly increased in the liver. The structure of hepatic lobules was clear, liver sinus returned to normal, and liver cell cords were arranged in neat rows. Cloudiness, swelling, inflammatory cell infiltration and spotty necrosis of liver cells were significantly reduced. Therefore, C-PC can significantly protect against ethanol-induced acute liver injury.