国外深水钢悬链线立管研究发展现状

介绍国外在新型深水立管系统--钢悬链线立管关键技术方面的研究发展现状,论述浮体一、二阶运动对钢悬链线立管疲劳寿命的影响、浮体升沉运动对钢悬链线立管触地点疲劳寿命的影响;钢悬链线立管与海底相互作用机制的实验研究及结果;钢悬链线立管涡致振动与疲劳的研究现状.并简要论述钢悬链线立管触地点问题的研究结论.     

The black water around the Changjiang (Yangtze) Estuary in the spring of 2003

The Changjiang (Yangtze) Estuary is located in the East China Sea shelf with shallow water. Affected by the tide mixing and the runoff of the Changjiang River and the Qiantang River, the turbidity is very high. Generally, the water-leaving radiance is high in the turbid water because of the large particle scattering. Based on the in-situ data and ocean color remote sensing data of SeaWiFS, it was found that there was a black water region with the normalized water-leaving radiances less than 0.5 mW/(cm2·μm2·...     

夏季长江口外海区域上升流现象的数值研究

基于Blumberg等(1996)的ECOMSED模式,对长江口外海区域夏季的上升流现象进行了数值模拟.模式综合考虑径流,风应力,环流,热通量和M_2,S_2,K_1,O_1四个主要分潮的作用,从而提高长江口外海区域上升流模拟的准确性和可靠性,并通过各种控制实验分析了其动力机制,进一步说明本区域影响上升流的主要因子.数值实验表明,长江口外水下河谷的南边(杭州湾口门中心东侧),上升流主要是由向北流动的台湾暖流通过底Ekman效应和陆坡的抬升共同作用产生的.夏季偏南风对长江口外水下河谷西侧上升流的产生有一定影响,但作用不大.此外,潮汐潮流对上升流的产生也起着一定的作用,但在本文关注的上升流区潮作用影响不大.     

Elastic-plastic analysis for pile-anchor supporting system of deep foundation pit

By using numerical analysis methods to simulate the deep excavation, a lot of analyses are established on the basis of two-dimensional plane strain, ignoring the fact that foundation pit possesses three dimensions. For soil constitutive relation, people always take linear and nonlinear model, without considering the plastic behavior of soil. Using plastic-elastic hardening model to simulate constitutive relation of soil characteristics, the authors carried out mechanical analysis for pit excavation and support. The results show that the analysis for the stress state of pile anchor system is an effective way which provides theoretical basis for calculation of soil displacement.     

盐度、pH胁迫对茂名海域文昌鱼磷酸酶活性的影响

实验测定了茂名海域文昌鱼在 96 h 时间间隔内耐受盐度的极限值为:最低 17.24,最高46.24;耐受 pH 的极限值为最低 5.0,最高10.0.通过实验前后文昌鱼体重及酸碱磷酸酶活性的变化对比,找出茂名海域文昌鱼较适合生长的盐度及 pH 范围分别为:28.0～32.0及7.5～8.5.     

六盘山植物区系基本特征的初步分析

六盘山位于陕甘宁交接地区,属于半湿润气候向半干旱气候的过渡带,是黄土高原生物多样性最丰富的地区之一,有维管植物836种,隶属于93科,359属。本区属于泛北极植物区、中国-日本森林植物亚区、华北植物地区的黄土高原亚地区。全部种子植物可分为13个分布区类型和12个变型,以北温带分布类型为主,与其他植物区系联系广泛,但特有属较贫乏。六盘山与小陇山、太白山和中条山的属相似性系数较高,均达60%以上,表明几座山体处于相似的生物气候背景之下,地理隔离性不明显。与贺兰山的属相似性系数低于60%,因为贺兰山位于干旱的荒漠与半荒漠区,可能有地理隔离作用。     

Estimation and prediction of plastic waste annual input into the sea from China

Marine plastic debris has been a pervasive issue since the last century, and research on its sources and fates plays a vital role in the establishment of mitigation measures. However, data on the quantity of plastic waste that enters the sea on a certain timescale remain largely unavailable in China. Here, we established a model using material flow analysis method based on life cycle assessment to follow plastic product from primary plastic to plastic waste with statistical data and monitoring data from accurate sources. This model can be used to estimate and forecast the annual input of plastic waste into the sea from China until 2020. In 2011, 0.547 3–0.751 5 million tons of plastic waste entered the seas in China, with a growth rate of 4.55% per year until 2017. And the amount will decrease to0.257 1 to 0.353 1 million tons in 2020 under the influence of governmental management. The amount of plastic waste discharged from coastal areas calculated in this study was much larger than that from river, thus it is suggested to strengthen the governance and control of plastic waste in coastal fishery activities in China in order to reduce the amount of marine plastic waste input.     

Soil Organic Carbon Contents and Stocks in Coastal Salt Marshes with Spartina alterniflora Following an Invasion Chronosequence in the Yellow River Delta,China

Plant invasion alters the fundamental structure and function of native ecosystems by affecting the biogeochemical pools and fluxes of materials and energy. Native(Suaeda salsa) and invasive(Spartina alterniflora) salt marshes were selected to study the effects of Spartina alterniflora invasion on soil organic carbon(SOC) contents and stocks in the Yellow River Delta. Results showed that the SOC contents(g/kg) and stocks(kg/m~2) were significantly increased(P 0.05) after Spartina alterniflora invasion of seven years, especially for the surface soil layer(0–20 cm). The SOC contents exhibited an even distribution along the soil profiles in native salt marshes, while the SOC contents were gradually decreased with depth after Spartina alterniflora invasion of seven years. The natural ln response ratios(Ln RR) were applied to identify the effects of short-term Spartina alterniflora invasion on the SOC stocks. We also found that Spartina alterniflora invasion might cause soil organic carbon losses in a short-term phase(2–4 years in this study) due to the negative Ln RR values, especially for 20–60 cm depth. And the SOCD in surface layer(0–20 cm) do not increase linearly with the invasive age. Spearman correlation analysis revealed that silt + clay content was exponentially related with SOC in surface layer(Adjusted R~2 = 0.43, P 0.001), suggesting that soil texture could play a key role in SOC sequestration of coastal salt marshes.     

桂林柑桔主要病虫害发生的气象条件分析

通过桂林地区柑桔主要病虫害发生发展的气象条件分析,找出了病虫害的发生发展与气象条件的关系很密切。     

新疆伊吾县马依当地区二叠纪地层的发现及其意义

在新疆伊吾煤矿一带1:5万区域地质矿产调查中,首次在原定石炭系上统妖魔梁组中发现大量透镜状钙质结核,并具明显的陆相冲积扇沉积特征;通过该地层的大量孢粉鉴定属为二叠世晚期,故将原石炭系上统妖魔梁组更名改为库莱组。其时代定为晚二叠世。并初步探讨了它的地质意义。