Application of transparent soil model tests to study the soil-rock interfacial sliding mechanism

When transparent soil technology is used to study the displacement of a slope, the internal deformation of the slope can be visualized. We studied the sliding mechanism of the soil-rock slope by using transparent soil technology and considering the influence of the rock mass Barton joint roughness coefficient, angle of the soil mass, angle of the rock mass and soil thickness factors on slope stability. We obtained the deformation characteristics of the soil and rock slope with particle image velocimetry and the laser speckle technique. The test analysis shows that the slope sliding can be divided into three parts: displacements at the top, the middle, and the bottom of the slope; the decrease in the rock mass Barton joint roughness coefficient, and the increase in soil thickness, angles of the rock mass and soil mass lead to larger sliding displacements. Furthermore, we analyzed the different angles between the rock mass and soil thickness. The test result shows that the displacement of slope increases with larger angle of the rock mass. Conclusively, all these results can help to explain the soil-rock interfacial sliding mechanism.     

Preface of “Earthquake,volcanism, and physical oceanography”

Marine Geophysical Research -     

Analyses of egg size,otolith shape,and growth revealed two components of small yellow croaker in Haizhou Bay spawning stock

The geographic al variations in life history characteristic s of small yellow cro aker Larimich thys polyactis,caused by experienced different environmental conditions,have been observed in China seas.Previous studies based on spatial distribution,migration route,and body morphometrics suggested a complex stock structure.In this study,to clarify the source of a spawning stock,we investigated the reproduction strategy and inter-structure of the Haizhou Bay(HZB)spawning stock in the middle Yellow Sea from both egg survey and adult otolith increment analysis.Egg and adult samples were collected from three surveys during spawning season in 2013.Distinct spatial and temporal variations were detected in egg distribution and size,and otolith shape analy sis of adult fishes revealed two morphotypes with different increment growth using random forest cluster.The results indicate the existence of two components within the same spawning stock in HZB from different wintering grounds,and accordingly special protection should be required for this stock given the significance to maintain connectivity between adj acent subpopulations.     

Effects of stocking density on the growth and immunity of Atlantic salmon salmo salar reared in recirculating aquaculture system (RAS)

Atlantic salmon reared in recirculating aquaculture system (RAS) may lead to inappropriately high stocking density, because fish live in a limited space. Finding the suitable stocking density of Atlantic salmon reared in RAS is very important for RAS industry. In this paper, the influence of stocking density on growth and some stress related physiological factors were investigated to evaluate the effects of stocking density. The fish were reared for 220 days at five densities (A: 24 kg/m³; B: 21 kg/m³; C: 15 kg/m³; D: 9 kg/ m³ and E: 6 kg/m³ ). The results show that 30 kg/m³ might be the maximum density which RAS can afford in China. The stocking densities under 30 kg/m³ have no effect on mortality of Atlantic salmon reared in RAS. However, the specific growth rate (SGR), final weight and weight gain in the high density group were significantly lower than the lower density groups and middle density groups. Moreover, feed conversion rate (FCR) had a negative correlation with density. Plasma hormone T₃ and GH showed significant decrease with the increase of the stocking density of the experiment. Furthermore, thyroid hormone (T₃), GH (growth hormone) activities were decreased with stocking density increase. However, plasma cortisol, GOT (glutamic oxalacetic transaminase) and GPT (glutamic pyruvic transaminase) activities were increase with stocking density increase. And the stocking density has no effects on plasma lysozyme of Atlantic salmon reared in RAS. These investigations would also help devise efficient ways to rear adult Atlantic salmon in China and may, in a way, help spread salmon mariculture in China.

     

大地水准面高的计算及其在海底地形反演中的应用

为充分挖掘海洋重力数据在反演海底地形中的应用潜力,尝试探索利用大地水准面高反演海底地形的技术途径,并以夏威夷—皇帝海山链拐点所在海区作为反演试验区进行验证。首先采用Belikov列推法计算伴随(缔和)勒让德函数,利用EIGEN-6C4地球重力场模型解算获取了分辨率为1'的大地水准面高格网数值模型;然后通过综合分析反演比例函数和转换函数特点、研究海区大地水准面高与海底地形的相干特性以及大地水准面高本身尺度特征,获得了利用大地水准面高反演海底地形的频段范围;最终以试验海区大地水准面高为数据输入,构建了相应的海底地形模型(BNT模型),并与ETOPO1等海深模型进行比对分析。试验结果表明:BNT模型检核差值在一倍均方差范围检核点数量占比70.60%,相比正态分布更加集中;BNT模型检核精度低于ETOPO1等海深模型;海深模型检核精度随着水深增加不断提升,水深小于1 000 m时,海深模型相对误差出现较大发散现象;计算海域ETOPO1模型精度最高,GEBCO模型和DTU10模型检核精度相当。     

决口海堤水波传播模拟和分析研究Ⅱ:2D传播

应用经验证的SWASH数学模型,分析了海堤决口中心线沿线实测水深分布规律和保护区淹没水量与淹没面积。对不同特征水深进行验证,进而探讨不同波要素对不同形式的海堤决口堤后特征水深分布情况以及波浪传播距离与时间的关系;分析了物理模型试验中海堤决口宽度以及不同波要素对堤后洪水波演进的影响;计算了不同决口深度和宽度对洪水波传播的影响,建立堤后水体淹没水量和淹没面积分布公式。成果可供我国沿海城市和地区在风暴潮和台风浪作用下海堤决口风险图绘制参考。     

科尔沁沙地粗—细组分的碎屑锆石U- Pb年龄特征：对定量物源及区域构造- 岩浆演化事件的指示

追踪干旱—半干旱地区大型沙地的物源和风- 河流相互作用机制对于理解陆地景观格局演变、地表过程与地貌动态以及大气圈和岩石圈之间的联系至关重要。然而,目前科尔沁沙地的物源仍存在较大争议,且缺乏具有统计意义的锆石U- Pb年龄数据库。因此,本研究对科尔沁沙地地表风成沙进行多点取样,根据不同粒级(＜63 μm和＞63 μm)选取1500颗碎屑锆石进行U- Pb测年分析,并利用逆向蒙特卡罗模型对其物源进行定量约束。结果表明,从目视定性的角度看,科尔沁沙地的碎屑锆石U- Pb年龄谱特征非常相似。但定量重建结果显示沙地的物源整体上以中亚造山带的贡献为主(50. 5%~61. 3%),然而东南部体现出华北克拉通的绝对优势(~75. 8%)。科尔沁沙地的物源存在空间异质性,沙地西部和北部的锆石年龄谱极为相似,与南部锆石年龄特征显著不同。科尔沁沙地的碎屑锆石U- Pb年龄特征基本不受粒度分异的影响,但沙地东南部除外。本文认为,风与河流的协同作用及其由此导致的沉积分异和再循环作用解释了科尔沁沙地碎屑锆石的U- Pb年龄特征。结合区域构造演化历史,科尔沁沙地在~2. 5 Ga和~1. 85 Ga的U- Pb年龄峰值分别是前寒武纪华北克拉通的生长、拼合与碰撞过程中的两期构造事件的产物。此外,~1. 7 Ga的锆石年龄可能是对Columbia超大陆聚合与裂解的综合响应。古生代以来的锆石年龄峰值(500~400 Ma、300~250 Ma、130~110 Ma)记录了在古亚洲洋的俯冲闭合、蒙古- 鄂霍次克海俯冲碰撞和古太平洋的俯冲、回退的区域构造背景下多期区域构造- 岩浆事件。     

The selection of alkaline protease-producing yeasts fi＇om marine environments and evaluation of their bioactive peptide production

A total of 400 yeast strains from seawater, sediments, saltern mud, marine fish guts, and marine algae were obtained. The protease activity of the yeast cultures was estimated, after which four strains (HN3.11, N11b, YF04C and HN4.9) capable of secreting extracellular alkaline protease were isolated. The isolated strains were identified as Aureobasidium pullulans, Yarrowia lipolytica, Issatchenkia orientalis and Cryptococcus cf. aureus. The optimal pH of the protease activity produced by strains HN3.11, YF04C, and HN4.9 was 9.0, while that of the protease produced by strain N11b was 10.0. The optimal temperature for protease activity was 45°C for strains HN3.11, N11b, and YF04C, and 50°C for strain HN4.9. After digestion of shrimp (Penaeus vannamei) protein and spirulina (Arthospira platensis) protein with the four crude alkaline proteases, the filtrate from spirulina (Arthrospira platensis) powder digested by the crude alkaline protease of strain HN3.11 was found to have the highest antioxidant activity (61.4%) and the highest angiotensin I converting enzyme (ACE)-inhibitory activities (68.4%). The other filtrates had much lower antioxidant activity and ACE-inhibitory activities.     

Growth and feed efficiency of juvenile shrimp Litopenaeus vannamei fed formulated diets containing different levels of poultry by-product meal

This feeding trial was conducted to evaluate the potential of poultry by-product meal (PBM) as a protein source in the culture ofLitopenaeus vannamei. Seven isonitrogenous and isoenergetic diets were formulated to near to commercial diet with about 40% protein and 7.5% lipid. Fish meal was replaced by 0, 30%, 40%, 50%, 60%, 70% and 100% of PBM (diets 1-7). The diet with 100% fish meal was used as a control (diet 1). Post-larvae were reared in an indoor semi-closed re-circulating system. Each dietary treatment was tested in 4 replicate tanks (260 L) of 40 shrimp, arranged in a completely randomized design. The shrimps were hand-fed for three times a day to near-satiation (0700, 1200 and 1800) for 60d. Percentage weight gain, survival, feed conversion ratio (FCR), protein efficiency ratio (PER) and body composition of shrimps were measured. There were no significant differences (P>0.05) in growth performance among shrimps fed diets 1-5 (0-60% fish meal replacement). However, shrimps fed diet 7 (100% fish meal replacement) had significantly lower (P<0.05) growth than those fed diets 1-5 (0-60% fish meal replacement). Shrimp fed diets 2-4 (30%-50% fish meal replacement) showed significantly higher growth than those fed diets 6 and 7 (70% and 100% fish meal replacement, respectively). Survival ranged from 94.7% to 100.0% and did not differ significantly (P>0.05) among different experimental diets. No differences in body composition were found among shrimps fed different diets. These results showed that up to 70% of fish meal protein can be replaced by PBM without adversely affecting the growth, survival, FCR, PER and body composition of Litopenaeus vannamei.     

房产产权产籍系统中数据缓存的应用

针对房产产权产籍系统中由于大数据量图形数据传输所造成的性能过低的问题,本文首先分析了系统业务特点以及数据特点。在此基础上,利用业务数据访问相对集中的业务特点以及系统数据相对稳定的数据特点,着重研究缓存的内容选择、内容预取、替换策略和一致性维护策略等关键技术,并形成了详细的解决方案。实验表明,适当使用数据缓存技术能有效提高系统的性能。