降低G级油井水泥初始稠度的控制措施

通过优化油井水泥熟料、油井水泥粉磨工艺、控制比表面积、SO3含量，有效降低油井水泥初始稠度。通过对水泥成品存储条件和存储时间的研究，确定了适宜的水泥出厂时间及后续工地的储存条件，保证了产品使用满足工地需求。     

工业化建造的政策路径研究——基于政府角色分析

基于政府角色,分析对比四个发达国家的工业化建造的政策路径。通过对我国近20年工业化建造相关政策的统计,总结我国工业化建造发展的政策特征;依据现存问题提出政策建议,以期为我国推广工业化建造提供指引。     

一种激光眼组织切割系统设计及实验

针对医生手工进行白内障手术,病人术后视力恢复效果取决于医生手术熟练度的问题,提出了一种激光眼组织切割光路运动系统。系统采用直线电机带动平面镜运动的形式改变光路,利用聚焦透镜实现激光对样品单点切割。建立了白内障手术中碎核、撕囊扫描轨迹的数学模型,通过MATLAB仿真验证扫描轨迹数学模型的正确性。最后以透明塑料为样品模拟眼球实验,结果表明此系统可以实现给定轨迹切割,为激光眼组织切割设备研发提供了一种新方案。     

西湖凹陷中央背斜带中北部花港组储层成岩相测井识别

基于测井资料对未取心井区域的成岩相进行人工智能识别成为必然的趋势。利用岩心铸体薄片与扫描电镜资料,划分西湖凹陷中央背斜带中北部花港组储层成岩相,总结了六种典型成岩相类型,各类成岩相所对应的测井响应差异明显。结果表明,测井系列自然伽马、补偿中子、声波时差、深侧向电阻率、浅侧向电阻率和密度等为成岩相判别敏感曲线。对比岩心薄片资料表明,概率神经网络模型可以准确识别未取心井段的成岩相,识别准确率可达到90%以上。     

A multi-regional structural path analysis of the energy supply chain in China's construction industry

The construction industry in China exerts significant environmental impacts and uses considerable resources because of rapid urbanization. This study conducted a structural path analysis (SPA) based on the multi-regional input–output table to quantify environmental impact transmission in the entire supply chain. Results indicated that the direct resource input (the first stage) along with on-site construction (the zeroth stage) consumed the highest amount of energy in the supply chain and accounted for approximately 50% of total energy consumption. Regional analysis showed that energy consumption in the construction industry at the provincial level was self-sufficient. Sectoral analysis demonstrated that the direct inputs from the sectors of “manufacture of non-metallic mineral products” and “smelting and pressing of metals” generated the most important energy flows, whereas the sectors of “production and distribution of electric power and heat power” and “extraction of petroleum and natural gas” significantly but indirectly influenced energy use. Sensitivity analysis exhibited that the system boundary of SPA could be narrowed down into the first two upstream stages that contained nearly 50% of energy flow information or expanded toward the first five upstream stages that represented 80% of total energy consumption.     

Variable neighborhood search for the pharmacy duty scheduling problem

In this paper, we study on the Pharmacy Duty Scheduling (PDS) problem, where a subset of pharmacies should be on duty on national holidays, at weekends and at nights in order to be able to satisfy the emergency drug needs of the society. PDS problem is a multi-period p-median problem with special side constraints and it is an NP-Hard problem. We propose four Variable Neighborhood Search (VNS) heuristics. The first one is the basic version, BVNS. The latter two, Variable Neighborhood Decomposition Search (VNDS) and Variable Neighborhood Restricted Search (VNRS), aim to obtain better results in less computing time by decomposing or restricting the search space. The last one, Reduced VNS (RVNS), is for obtaining good initial solutions rapidly for BVNS, VNDS and VNRS. We test BVNS, VNRS and VNDS heuristics on randomly generated instances and report the computational test results. We also use VNS heuristics on real data for the pharmacies in central İzmir and obtain significant improvements.     

Existence and construction of Hamiltonian paths and cycles on conforming tetrahedral meshes

This paper addresses the existence and construction of Hamiltonian paths and Hamiltonian cycles on conforming tetrahedral meshes. The paths and cycles are constrained to pass from one tetrahedron to the next one through a vertex. For conforming tetrahedral meshes, under certain conditions which are normally satisfied in finite-element computations, we show that there exists a through-vertex Hamiltonian path between any two tetrahedra. The proof is constructive from which an efficient algorithm for computing Hamiltonian paths and cycles can be directly derived.     

A model to estimate the path loss in areas with foliage of trees

This paper presents an empirical model to predict attenuation in forest environments considering parameters related to vegetation. Typically, environmental parameters are only included in theoretical models, but they are more difficult to apply. The developed model uses tree density, average tree canopy diameter and foliage density as input parameters. The foliage density is very difficult to determine since it depends on the characteristics of trees. A simple metric of this parameter was obtained by measuring the background light silhouetted by the canopy. The model was developed with measurements obtained in different forest environments for two frequencies within the UHF band (Ultra High Frequency). A procedure was also applied to extend the operating frequency range of the model.     

Analysis of the extended stress-based forming limit curve considering the effects of strain path and through-thickness normal stress

In this study, an approach based on the modified Marciniak–Kuczynski (M–K) method for computation of an extended stress-based forming limit curve (FLC) is presented. The extended stress-based FLC is built based on equivalent plastic stress versus mean stress. This curve has some advantages in comparison with the conventional FLC. This new criterion is much more strain path independent than the conventional FLC. The effect of strain path on the predicted extended stress-based FLC is reexamined. For this purpose, two types of pre-straining on the sheet metal have been loaded. Moreover, the plane stress state assumption is not adopted in the current study. The influence of a through-thickness compressive normal stress is also investigated theoretically. The verifications of the theoretical FLCs are performed by using some available published experimental data.