船舶风荷载算法的比较研究

分析研究了国内外几种港口工程规范中关于船舶风荷载计算的方法特点并应用同一算例进行了计算结果间的对比分析,评价了O ptim oor软件的可用性。     

科学与人文：分离还是整合？

本文从自然科学和人文学术两种文化相互分离的一些现象入手，讨论了自然科学在若干问题上的作用界限，以及重文轻理和重理轻文问题，进布针对上述两种文化的整合（就社会而言）和向文理兼通境界的追求（就个人而言），作了若干独特的分析，讨论了若干可能的途径。     

电力电子与绿色能源

介绍了绿色能源的概念,以风力发电为重点介绍了电力电子技术在绿色能源发展中的应用以及分布式发电在绿色能源系统方面的应用.     

高原公路水土流失预测

以香日德-花石峡高原项目区土壤侵蚀现状为例,结合3种土壤侵蚀的特点,按照水土保持技术规范,提出分区、分类的高原公路水土流失预测方法,并详细分析预测结果,提出相应的监测和治理建议.     

车门密封胶条力学性能衰变分析

按照国家标准的规定,检测自然条件使用的密封胶条样品的硬度和拉伸性能(拉伸强度、拉断伸长率),从自然老化的角度分析了密封胶条老化前后力学性能变化规律,从性能保持率的角度分析了密封胶条的劣化程度,最后基于密封胶条拉断伸长率的数据,构建了6阶拉格朗日插值多项式,对车门密封胶条使用寿命进行了预测,结果显示其使用寿命是185个月。     

Corrosion fatigue load frequency sensitivity analysis

This paper presents experimental assessment of crack growth rates of S355J2+N steel in a corrosion fatigue environment similar to what is experienced on offshore wind farm monopile structures under various cyclic load frequencies in order to assess the effect of cyclic frequency of the applied loading within a frequency range pertinent to the structure. Fatigue crack propagation behaviour in this test programme is evaluated through fatigue tests on six compact tension test specimens in air and in laboratory simulated seawater under free corrosion condition. Fatigue crack lengths were monitored by back face strain (BFS), DCPD and ACPD. A regression model was derived through the BFS method to express strain values as a function of crack length to width ratio. The effectiveness of BFS method is particularly demonstrated in the simulated marine environment. Within the range of test frequencies, crack growth rates in simulated seawater when compared to the equivalent air test revealed environmental reduction factors of 2 and 4 at lower and higher values of stress intensity factors respectively. Significant difference in the results of the seawater test frequencies is discussed.     

Crack growth direction effects on corrosion-fatigue behaviour of offshore wind turbine steel weldments

In this study corrosion-fatigue tests have been conducted on fracture mechanics specimens extracted from an S355 G10+M structural steel welded plate. The tests have been performed on compact tension specimens with the crack tip located in the heat affected zone. The corrosion-fatigue test results from this study have been compared with the data available on the base metal as well as air tests on the same material. Moreover, the obtained results have been compared with the corrosion-fatigue data available in the literature on a wide range of steels and also the fatigue trends for welded joints in free-corrosion condition recommended in the BS7910 Standard. The effect of the specimen orientation, with respect to the weld region, is also examined in this study and it has been found that higher corrosion-fatigue crack growth rates are generally observed in the tests with 0° orientation. The results have also shown that the corrosive environment has significant effects on the fatigue crack growth acceleration at the beginning of the tests; however, as the crack propagates, the environmental damage effect on crack growth behaviour becomes less pronounced. The results presented in this study are discussed in terms of improvement in the structural integrity assessment of offshore wind turbine monopiles.     

A hybrid heuristic strategy for liquefied natural gas inventory routing

As liquefied natural gas (LNG) steadily grows to be a common mode for commercializing natural gas, LNG supply chain optimization is becoming a key technology for gas companies to maintain competitiveness. This paper develops methods for improving the solutions for a previously stated form of an LNG inventory routing problem (LNG-IRP). Motivated by the poor performance of a Dantzig-Wolfe-based decomposition approach for exact solutions, we develop a suite of advanced heuristic techniques and propose a hybrid heuristic strategy aiming to achieve improved solutions in shorter computational time. The heuristics include two phases: the advanced construction phase is based on a rolling time algorithm and a greedy randomized adaptive search procedure (GRASP); and the solution improvement phase is a series of novel MIP-based neighborhood search techniques. The proposed algorithms are evaluated based on a set of realistic large-scale instances seen in recent literature. Extensive computational results indicate that the hybrid heuristic strategy is able to obtain optimal or near optimal feasible solutions substantially faster than commercial optimization software and also the previously proposed heuristic methods.     

碱激发煤制气残渣地质聚合物的制备及性能

煤制天然气残渣（CSNGS）是一种可用于制备地质聚合物的潜在新原料，然而关于用该工业废渣制备地质聚合物的报道却很少。采用机械球磨手段对煤制天然气残渣进行活化改性，分别以氢氧化钠（NaOH）溶液和氢氧化钾（KOH）溶液为激发剂，在不同条件下制备煤制气残渣地质聚合物，并对其强度进行对比。然后，通过X射线粉末衍射仪（XRD）、扫描电镜（SEM）、能谱分析（EDS）以及红外光谱（FT-IR）等微观试验手段对比研究了2种煤制气残渣地质聚合物的微观结构和强度形成机理，并分析了激发剂中不同碱金属阳离子对地质聚合物性能的影响。研究发现，随着热养护温度的升高，2种煤制气残渣中晶体峰强降低，地质聚合物的硅铝比（Si/Al）升高，地质聚合物的强度增加。研究还发现，在适当的热养护条件下，当激发剂浓度在6~9 mol·L^-1时，2种煤制气残渣地质聚合物均可以获得较高的力学强度。由SEM分析可知，较高的热养护温度和适当的激发剂浓度可以生成大量的水化硅铝酸钠凝胶（N-A-S-H）或水化硅铝酸钾凝胶（K-A-S-H），使地质聚合物的微观结构变得更加致密，从而使试件具备良好的力学性能。此外，NaOH溶液对煤制气残渣的碱激发效果要优于KOH溶液，这不仅是因为钠离子与负离子的结合能力强于钾离子，更有效地保证了地质聚合物骨架中的电荷平衡；而且与钾离子相比，钠离子更容易形成具有2个或3个SiO₄四面体桥接单个AlO₄四面体的地聚合物凝胶，这使材料形成了更加致密均匀的微观结构。研究结果表明：地质聚合物最高强度分别为36.1 MPa（NaOH）和27.8 MPa（KOH），因此，以煤制天然气残渣为原料制备地质聚合物具有很高的研究和应用价值。     

The North Norfolk Coastline: A Complex Legacy

The North Norfolk coast is a naturally eroding coastline that has been subject to various management strategies over time, many of which have impeded its natural evolution. The Kelling to Lowestoft-Ness Shoreline Management Plan underpins management of the North Norfolk coast, advocating policies of managed realignment and no active intervention for much of this coastline. Implementation of these policies would give rise to significant loss of housing in North Norfolk during the course of this century. This has caused intense conflict between local communities and coastal planners, with the former feeling abandoned to the vagaries of natural coastal processes. Coastal planners need to work closely with local communities to implement a long-term vision for a sustainable coast. The issues of conflicting land-use planning policies and compensation for affected communities must be addressed. The wider implications of current management strategies are not fully understood and may, in some cases, be unsustainable.