低应变反射波法的桥梁桩基检测实例分析

结合桥梁桩基础工程检测实例,对低应变反射波法检测结果进行了综合对比分析,明确了该方法的优势和不足,探讨了低应变反射波法适宜的检测桩长与检测结果可靠性,以供工程实践参考。     

气举反循环钻进工艺在地热深井施工中的应用

结合工程实例,对气举反循环钻进工艺进行了介绍,描述了该工艺所用的设备与参数选取方法,并对其在地热深井施工中的应用效果进行了分析,总结了施工中出现的问题与解决策略,以更好的满足地热井的施工要求。     

城市人性空间解析

在当前的城市规划中注重物质空间的规划设计,但能同时关照到人的身体与心灵的设计才是人性化设计追求的目标。城市需要人性空间,人性空间是对日常生活与人的关怀与尊重,对宜人小尺度的推敲,以及对历史文脉的探求。其核心在于空间场所的塑造和历史文化的滋养,由物质空间与自然人文等多重维度共同构成。     

Research on quality improvement of the cross section cut by abrasive water jet based on secondary cutting

A manufacturing system comprises production processes and building services, both of which are supplied by different energy carriers as well as raw materials and water. These resources interact according to complex relationships and are converted into products for sale and waste flows. Holistic resource accounting allows the analyst to consider the dynamic relationships between these components, including the strong interdependence between energy and water, which has been called the energy-water nexus. Exergy analysis is a method that accounts for mass and both the quantity and quality of energy, while allowing analysis on a common basis, and for this reason, it is used increasingly to analyse resource consumption in manufacturing systems; however, it has rarely been used to consider water flows alongside energy and material flows. The main contribution of this paper is the presentation of modelling water flows in terms of exergy in the context of sustainable manufacturing. Using this technique in combination with previously developed exergy-based methods, the result is a truly holistic resource accounting method for factories based on exergy analysis that incorporates water flows. The method is illustrated using a case study of a food factory in which a 4.1% reduction in resource use is shown to be possible by employing anaerobic digester in an effluent water treatment process. The benefits of this technology option would have been underestimated compared to the benefits of waste heat capture if an analysis based on mass and energy balances alone had been used. The scientific value of this paper is the demonstration of the relatively high exergy content of effluent flows, which should therefore be regarded as potentially valuable resources. The analytical method presented is therefore of value to a wide range of industries beyond the food industry.     

基于Logvinovich原理射弹超空泡形态解析解研究

为快捷、简便地分析运动射弹的超空泡形态,利用Logvinovich原理、Riabouchinsky空泡闭合模型和射弹动力学方程,推导了射弹运动过程中空泡形态解析解和空泡参数的计算公式,得到了自然超空泡扩展的一些规律。计算结果与经验公式比较,吻合较好。算例分析表明:首尾压差对射弹速度影响较小,当射弹速度不小于100m/s,射弹在水中的深度不大于100m时,压差的影响可以忽略;完整空泡扩展时间非常短,且随着射弹运动时间增大而减小,逐渐趋于平缓;空泡数0.06、射弹速度60m/s左右时,超空泡开始蜕化为局部空泡。     

基于网络科学的团队协作模型及网络模式的识别

网络科学的出现为研究和解决团队系统中的问题提供了新的方法和思路,在其框架下可以将团队的整体表现看作参与者之间的互动结果。文章将网络科学应用于足球运动中,为足球球员组成的团队构建了一个传控网络模型,并对模型的网络模式进行了进一步的分析。     

Preparation and characterization of porous PDMS beads for oil and organic solvent sorption

In this article, poly (dimethyl siloxane) (PDMS) porous beads were prepared by suspension polymerization method using n‐octane and carbon tetrachloride (CCl₄) as diluents and pore formation agents. The apparent density, porosity and other characteristics were characterized. The absorption experiments showed that the porous PDMS beads exhibited more absorption capacity and faster absorption rate toward oils than the nonporous or oligoporous PDMS beads did, moreover they are of remarkable stability and recyclability, which could provide a path to absorb the oils floating on water. POLYM. ENG. SCI., 54:2965–2969, 2014. © 2014 Society of Plastics Engineers     

Differentiated Electric Behaviors of La2/3Cu3Ti4O12 Ceramics Prepared by Different Methods

Microstructure and electric behaviors of La_2/3Cu₃Ti₄O₁₂ (LCTO) ceramics prepared by the sol‐gel method (SG) and solid‐state method (SS) have been systemically investigated. The results indicated that LCTO‐SG ceramics sintered at 1105°C for 15 h showed larger grain size, higher density, and especially higher dielectric constant up to about 0.9–1.6 × 10⁴ at 10²~10⁵ Hz compared to LCTO‐SS ceramics. The higher dielectric constant of the LCTO‐SG ceramics might be due to the stronger internal barrier layer capacitor (IBLC) effect. More notably, compared with LCTO‐SS ceramics, two kinds of dielectric anomalies, one conduction activation energy value and same activation energies for the conduction and relaxation process in LCTO‐SS ceramics, the LCTO‐SG ceramics showed three kinds of dielectric anomalies, two values of conduction activation energy, and decrease in conduction activation energy with increasing temperature. The activation energies for the conduction and relaxation process in LCTO‐SG ceramics showed great difference below about 210°C, suggesting that the mechanism of electrical conduction and dielectric relaxation seem to be different in LCTO‐SG ceramics. These remarkable differences in electric behaviors of LCTO ceramics prepared by sol‐gel and solid‐state methods were firstly found and analyzed.     

Cationic microgel emulsion with a high solid content by a multistep addition method in inverse microemulsion polymerization

The multistep addition of a monomer and initiator was developed to successfully synthesize cationic polyacrylamide microgels with solid contents (SCs) greater than 35% and cationic monomer concentrations of 0–40 mol % by inverse microemulsion polymerization. Two feed methods, three‐step nonuniform addition and five‐step uniform addition, were implemented to obtain microgel emulsions with 37% SC. The former addition method was designed according to the solubilization limit of the microemulsion before step polymerization, and that of the latter was a constant based on the remaining surfactant weight in the reactor. The product properties in the intermediate processes of these two methods were compared by dynamic light scattering and viscosity measurement. The results show that the products here were translucent microemulsions instead of milky ones when they were synthesized by a semicontinuous polymerization. Also, the particle sizes of these two methods were almost the same; this indicated that the oscillation phenomenon in continuous polymerization at a high SC was avoided. With the former feed method, the risk and operation cost in the synthesis process could be cut down greatly. Moreover, the viscosity of the cationic microgel emulsion conformed to the Krieger–Dougherty equation with a greater value of intrinsic viscosity than that of a hard‐sphere system because of an electroviscous effect. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40585.