瞬变电磁法在公路隧道地下水预报中的应用

针对某高速公路隧道掌子面临近富水断层F4-3的地质背景，为探明掌子面前方地下水发育情况，利用瞬变电磁法开展超前地质预报工作。通过多测线、多方位的探测方式，综合分析各方位测线的探测结果，预报掌子面前方地下水的发育段落及空间分布情况。预报结果表明： 1）YK90+755~ +811段地下水发育； 2）YK90+755~+811段富水部位主要位于开挖方向的左右两侧。最后通过超前钻孔验证，瞬变电磁探测富水区域和超前水平钻孔探测出水位置基本一致，较准确地预测了地下水的发育段落。实际开挖后富水情况与瞬变电磁预报富水段落及地下水空间分布基本吻合，取得了较好的预报效果。     

多层结构卤化银微晶的设计及制备

卤化银乳剂的分辨率随卤化银微晶尺寸的减小而提高，但感光度急剧下降。研究表明：卤化银微晶的结构对感光度的影响很大。讨论了多层结构卤化银微晶的设计原理，用自动双注仪制备出多层结构卤化银微晶。     

几种箱梁腹板弧形段竹胶板模板施工工艺比较

针对目前桥梁箱梁腹板弧形段施工中常见的几种施工工艺,进行了综合分析比较,得出采用10 mm竹胶板作为腹板弧形段面板,采用单根钢管制作成钢托横格栅支撑结构的箱梁腹板弧形段竹胶板模板施工工艺作为箱梁弧形段施工的最佳工艺,并期望在桥梁施工中能够普及推广.     

Carbon flows in Baltic Sea food webs — a re-evaluation using a mass balance approach

The brackish Baltic Sea has been seen as particularly suitable for studies of food webs. Compared to fully marine ecosystems, it has low species diversity, which means fewer trophic linkages to analyse. The Baltic Sea is also one of the best-studied areas of the world, suggesting that most data requirements for food web models should be fulfilled. Nevertheless, the influence of physical and biological factors on trophic interactions and biogeochemical patterns varies spatially in the Baltic Sea, adding considerable complexity to food web studies. Food web structure and processes can be described and compared quantitatively between areas by estimating the flow of matter or energy through the organisms. Most such models have been based on carbon, though studies of complementary flows of other elements limiting production, such as nitrogen and phosphorus would be desirable. However, since ratios between carbon and other elements are used in calculating these flows, it is crucial, as a first step, to quantify the flows of carbon as accurately as possible.In this study, we used the EcopathII software (ver 3.1) to analyse models of carbon flow through the food webs in the three main areas of the Baltic Sea; the Baltic proper, Bothnian Sea and Bothnian Bay. A previously published study on carbon flow in the Baltic Sea [Elmgren, R. 1984. Trophic dynamics in the enclosed, brackish Baltic Sea. Rapp. P.-V. Reun. — Cons. Int. Explor. Mer. (183) 152–169.] was complemented with the data on respiration and flow to detritus [Wulff, F., Ulanowicz, R. 1989. A comparative anatomy of the Baltic Sea and Chesapeeake Bay ecosystems. In: F. Wulff, J.G. Field, K.H. Mann (Eds.), Flow Analysis of Marine Ecosystems: Theory and Practice. New York: Springer-Verlag.] in order to present complete mass balance models of carbon. The purpose of re-evaluating previous models with new analytic tools was to check how well their carbon flows balance, and to provide a basis for improved mass balance models using more recent data, including nutrients other than carbon.The resulting mass balance networks for the Baltic proper, Bothnian Sea and the Bothnian Bay were shown to deviate from steady state. There was an organic carbon surplus of 45, 25 and 18 g C m⁻² year⁻¹ in the pelagic zones of the Baltic proper, Bothnian Sea and Bothnian Bay, respectively. The Ecopath network analysis confirmed that the overall carbon flow was highest in the Baltic proper, somewhat lower in the Bothnian Sea and much lower in the Bothnian Bay. The only clear differences in food web structure between the basins was that the average trophic level was lower for demersal fish in the Bothnian Sea and higher for macrofauna in the Bothnian Bay, compared to the other basins. The analysis showed weakness in our current understanding in Baltic Sea food webs and highlighted areas where improvements could be made with more recent data.     

基于模糊理论的沥青路面热风加热多参数优化

为了优化就地热再生热风加热参数，提高热风加热沥青路面的加热效果，基于有限元方法，建立了热风加热装置加热沥青路面的模型，模拟计算了热风加热沥青路面的过程，通过试验验证了仿真模型及参数设置的正确性。采用正交试验设计方法研究了热风温度、热风速度、出风孔离地高度对加热效果的影响。提出了基于模糊理论的热风加热效果评价方法，引入综合模糊评价指标代替沥青路面温度场、对流换热系数和加热过程中的能量利用率等单一评价指标对沥青路面加热效果进行评价，采用独立性权系数法确定了各指标的权重系数，仿真分析验证了综合模糊指标评价方法的有效性。结果表明：在加热装置的设计参数范围内，热风温度对沥青路面表面温度及分布均匀性影响最大，热风速度对换热系数影响最大，出风孔离地高度对能量利用率影响最大。以沥青路面温度场、对流换热系数和能量利用率等单一指标为优化目标获得的最佳加热参数组合，仅能保证各自指标最优，但其他指标较差；以综合模糊评价指标E_CFI为优化目标得到的最佳热风加热参数组合，可以同时获得较好的沥青路面温度场、对流换热系数和能量利用率。研究方法和结论为沥青路面热风加热参数的选择和加热效果的评价提供了一种有效可行的途径。     

大跨波形钢腹板小箱梁顶推施工技术研究

针对传统预应力混凝土箱梁顶推施工速度慢、工期长及跨径受限制等问题,引入波形钢腹板和Φ21.8大直径预应力束,设计了大跨波形钢腹板小箱梁,提出了波形钢腹板箱梁预制组拼顶推和临时钢斜撑相结合的施工方案,实现了大跨度梁桥顶推跨径和顶推速度的突破,其成果可供类似的设计和施工参考。     

基于傅立叶级数混凝土箱梁腹板竖向正应力的弹性计算

2004版桥规关于竖向预应力的计算公式实际是计算的平均竖向压应力,没有充分考虑到预加力的局部扩散效应。把竖向预应力作为不连续荷载,以傅立叶级数形式展开,导出竖向预加力作用下无限狭长矩形薄板竖向正应力弹性解析公式,该公式可用于预应力混凝土箱梁腹板竖向正应力的计算。     

钢轨轨腰水平脆断敏感性评定

通过采用锯切口法测定了几种进口高强度钢轨轨腰残余应力，阐述了残余应力对轨腰水平脆断的影响。并以切口尖端应力强度因子Ｋ１和轨腰材料断裂韧性Ｋ１作为判据，对这些钢轨轨腰脆断敏感性进行了评定。     

Biological effects of Mississippi River nitrogen on the northern gulf of Mexico—a review and synthesis

The Mississippi River currently delivers approximately 1.82 Tg N year⁻¹ (1.3×10¹¹ mol N year⁻¹) to the northern Gulf of Mexico. This large input dominates the biological processes of the region. The “new” nitrogen from the river stimulates high levels of phytoplankton production which in turn support high rates of bacterial production, protozoan and metazoan grazing, and fisheries production. A portion of the particulate organic matter produced in the pelagic food web sinks out of the euphotic zone where it contributes to high rates of oxygen consumption in the bottom waters of the inner shelf, resulting in the development of an extensive zone of hypoxia each summer. In spite of the significance of this river system to the coastal ocean of the northern gulf, we do not have an adequate understanding of the inputs, processing and ultimate fates of river nitrogen. Here we review available literature on this important system and propose a conceptual model showing how biological processes evolve in the river plume between the point of discharge and the point where plume waters are fully diluted by mixing with oceanic water.     

28000吨多用途船船型开发研究

２８０００吨多用途船是我所与大连造船厂共同开发研究，并由大连造船厂设计、建造的新型大舱口出口货船，是近年来国际上首次出现的此种吨位的经济型多用途货船，其主要技术指标达到国际先进水平。目前，２８０００吨多用途船已成为大连造船厂重要的系列名牌产品，并被船东命名为“梦幻型”系列。从已交付使用的４艘船舶来看，该型船性能优异，赢得了良好的国际信誉和可观的经济效益。介绍本船船型开发研究中所进行的线型设计、优化试验、节能装置试验以及原型和安装前置导管尾部伴流场测试研究的一些成果，可供今后研究设计新船参考。