南美白对虾(Penaeus vannamei)视神经节和脑免疫细胞化学研究

应用抗脊椎动物5-羟色胺、神经肽Y、β-内啡肽、P物质、生长抑素、胰高血糖素、催乳素抗体和SABC免疫细胞化学方法,对南美白对虾视神经节和脑进行了免疫细胞化学研究。结果表明,前4种抗体呈现免疫阳性反应：5-羟色胺免疫阳性细胞分布于视神经节的视神经层、视外髓、视内髓和视端髓;前脑前中细胞群,中脑嗅叶内侧细胞群、嗅叶外侧细胞群以及前脑中部的前端神经髓质呈免疫阳性反应。神经肽Y免疫阳性细胞分布于视神经节的4个神经髓;前脑前中群细胞和前脑中部的前端神经髓质也呈阳性反应。P物质免疫阳性细胞位于前脑前中群。β-内啡肽免疫阳性细胞仅分布干后脑后侧群。4种免疫阳性物质特异性的分布模式,为其可能参与调节神经内分泌活动提供了形态学证据。     

Stability evaluation and protection of slope for Laosongling-Yanji Highway

The authors analyzed the engineering geological characteristics of the slope of the study area （ K75 ＋ 840-K76 ＋ 340）. Two typical cross-sections have been chosen to analyze the failure modes after the excavation of the highway. Different types of the failure modes have been calculated and analyzed. The results show that some dealing methods have been advised to ensure the stability of the slopes.     

Nonlinear consolidation of vertical drains with coupled radial-vertical flow considering time and depth dependent vacuum pressure

The system of vacuum pressure combined with vertical drains to accelerate soil consolidation is one of the most effective ground improvement methods. The consolidation theories of soft soil improved by vertical drains including void ratio–dependent compressibility and permeability have been widely applied in practice to predict the consolidation behavior. In this paper, analytical solutions of the consolidation of vertical drains are derived incorporating the loss and propagating stage of vacuum pressure. In addition, special solutions are obtained for the cases of instantaneous surcharge loading and staged surcharge loading, based on the general solution. The solution is verified by ignoring the propagating stage of vacuum pressure formation and comparing it with an existing solution. The effects of vacuum pressure loss and propagating stage combined with other parameters are investigated through the ratio between excess pore water pressure and surcharge loading.     

Numerical modeling of vertical drains with advanced constitutive models

The water flow into a vertical drain under an embankment loading is axisymmetric problem and therefore, the vertical drain system must be converted into equivalent plane strain model. The matching is achieved by manipulating the drain spacing and/or soil permeability according to relatively simple rules. This paper investigates the verification of matching approaches by comparing 2D plane strain and 3D unit cell results when complex constitutive models are used in the finite element analyses. The numerical results showed that the match was found to be satisfactory but not perfect. A full-scale plane strain analysis is subsequently applied to an embankment case history taken from Haarajoki, Finland, stabilized vertical drains and compared with field measurements.     

Consolidation of vertical drain with depth-varying stress induced by multi-stage loading

An explicit analytical solution is developed for the consolidation of vertical drain with both radial and vertical drainage by adopting a depth-varying stress induced by multi-stage loading. The well resistance and smear effect are also considered. The smear effect is described by three decay patterns of horizontal permeability towards drains within the smeared zone, including a reduced constant pattern, a linear decay pattern and a parabolic decay pattern. A parameter analysis is performed to investigate the consolidation behavior of the vertical drain. The convergence of the proposed series solution is discussed.     

考虑井阻时空变化的竖井地基非线性固结解析解

软土固结过程中展现出明显的非线性压缩和渗透特性,同时竖井的淤堵效应常导致井阻在固结过程中随深度和时间不断演化,但目前能考虑井阻随时空演化的竖井地基非线性固结解析解还很鲜见。通过引入孔隙比与有效应力及孔隙比与渗透系数间的半对数模型描述了土体的非线性固结特性,建立了能同时考虑井阻随时空变化和涂抹影响的竖井地基非线性固结模型,并采用分离变量法获得了固结模型的解析解。将特定参数下固结解的计算结果与实测数据、已有的竖井地基固结解答进行了对比分析以验证其可靠性。最后,对竖井地基的非线性固结性状开展了大量计算分析。结果表明：竖井渗透系数随深度线性衰减越明显则地基固结速率越慢;外荷载一定时,随着软土压缩指数c_c与渗透率指数c_k之比的增大,竖井地基固结速度减慢;在c_c /c_k值不变的情况下,外荷载增加,地基固结速率加快。在涂抹区的3种径向渗透系数变化模式中,抛物线变化模式下的地基固结速度最快,线性变化模式下的地基固结速度次之,恒定模式下的地基固结速度最慢,且这种性状并不因为考虑井阻变化或土体非线性固结特性而发生改变。     

Estimation of the hydraulic conductivity of soils improved with vertical drains

In this study, some limitations associated with modeling the hydraulic conductivity of soil improved with vertical drains are discussed. In addition, some limitations of conventional methodologies for deducing the hydraulic conductivity from oedometer or Rowe cell tests are investigated. An alternative approach for estimating the hydraulic conductivity in soils improved by vertical drains is discussed. This methodology will allow for simpler finite element modeling of consolidation due to vertical drains. The effectiveness of this technique has been demonstrated using a field study.     

Sex-different effects of tributyltin on brain aromatase,estrogen receptor and retinoid X receptor gene expression in rockfish (Sebastiscus marmoratus)

Since the brain plays important roles in reproduction, the brain aromatase (Cyp19b), estrogen receptor (ER), retinoid X receptor (RXR) α and peroxisome proliferator-activated receptor γ were examined in rockfish after TBT exposure (1, 10, and 100 ng L⁻¹). The results showed that the Cyp19b expression was elevated in the male rockfish, while no effect was produced in the females. Inconsistently, serum testosterone and 17β-estradiol showed no change in the males, while an increase of testosterone and a decrease of 17β-estradiol were observed in the females. TBT affected the ER expression in the males depending on the concentrations, however, no change was observed in the females. In addition, TBT elevated the RXRα expression in the males but produced an opposite effect in the females. In conclusion, TBT might have had sex-different effects on the brain Cyp19b, ER and RXR expression in rockfish, indicating a complex endocrine disrupting effect of TBT.     

环渤海排污口临近海域水交换能力研究

将环渤海主要入海排污口按位置划分至31个归并点,并定义了影响距离的概念,用于衡量各归并点所代表的排污口临近海域的水交换能力。在渤海三维水动力模型的基础上,利用质点追踪的方法研究了各归并点的30d影响距离。此外,通过在夏季(7月)大潮、夏季小潮、冬季(1月)大潮、冬季小潮4个时间段释放质点以研究季节和潮汐对30d影响距离的作用。结果表明:不同排污口邻近海域的水交换能力差异显著;与小潮相比,大潮期间排污口邻近海域水交换能力更强,因此大潮期间排污有助于污染物扩散;不同季节污染物扩散方向不同,与季风有关。据此海洋环境保护部门可根据不同海区水交换能力的差异调整排污量。