杭黄高铁现浇梁卸架钢楔块设计计算

为了使杭黄高铁32m现浇箱梁卸架钢楔块受力安全可靠,设计承载能力为200k N的钢楔块,通过详细分析计算钢楔块上下底板、钢楔块腹板、钢楔块拉杆套筒、钢楔块拉杆四个主要受力构件,确保钢楔块各项力学指标达标。     

钢锚板式钢-混凝土组合索塔锚固体系黏结滑移性能影响因素分析

在研究钢锚板式钢-混凝土组合索塔锚固体系极限承载力时,发现钢锚板与塔柱混凝土之间的黏结滑移是一种主要破坏形式.影响钢锚板式钢-混凝土组合索塔锚固体系钢-混凝土黏结性能的主要因素有混凝土强度、钢锚板厚度、钢锚板穿孔钢筋(PBL剪力键)数量和位置、隔板数量和位置.通过数值模拟方法,对钢锚板式钢-混凝土组合索塔锚固体系的黏结...     

运营盾构隧道加固后衬砌-钢环复合体系力学性能研究

通过运营盾构隧道-钢环复合体系有限元数值分析,不仅对比了加固前后衬砌受力结果的差异,还揭示了加固后钢环、钢牛腿、钢拉条、衬砌与钢环间界面的应力分布规律。结果表明：(1)钢环加固后,钢环与衬砌形成复合体系共同承载,能明显改善衬砌受力,运营盾构隧道承载力得到了提高。其中,隧道最大弯矩降低了32.2%～71.3%,最大轴力降低了21.9%。(2)钢环、钢牛腿、钢拉条的应力均小于钢板屈服强度,但各构件连接处应力较大,需合理选择构件的尺寸保证工程的安全性和经济性。(3)隧道拱顶和钢牛腿与钢环连接处附近的界面应力为拉应力,隧道钢环加固时可考虑相应措施提高该位置界面的抗拉承载力。     

公路波形钢腹板钢-混组合箱梁振动特性的影响参数

为了研究结构参数对波形钢腹板钢-混组合箱梁振动特性的影响,文章以某波形钢腹板组合简支梁为工程背景,利用ANSYS有限元软件建立了波形钢腹板钢-混组合箱梁的三维模型,采用理论公式对有限元模型的正确性进行了验证,随后,分析了波形钢腹板的类型、钢底板的厚度以及波形钢腹板的厚度对波形钢腹板钢-混组合箱梁振动特性的影响。研究结果表明:波形钢腹板的类型对波形钢腹板钢-混组合箱梁振动频率的影响较小,可以忽略不计,波形钢腹板钢-混组合箱梁振动频率随波形钢腹板的厚度和钢底板的厚度的增加而增大,该研究为波形钢腹板钢-混组合箱梁的合理设计和振动频率的计算提供有利的参考依据。     

钢栈桥设计与施工技术

结合沙颍河太和县颖河一桥钢栈桥、钢平台、钢围堰的施工,分析了钢栈桥的应用形式,阐述了钢栈桥的结构设计及施工要点,为今后同类工程提供经验。     

漳州后石电厂输煤栈桥结构设计特点

本文介绍漳州后石电厂输煤栈桥结构设计特点 ,包括柱、钢桁架、柱与钢桁架的连接、钢梁与钢桁架的连接、钢 -砼组合构件及围护结构     

不同节点形式钢框架受力性能研究进展

节点形式对钢框架受力性能会产生不同程度的影响,对半刚接钢框架、延性节点钢框架、装配式钢框架和空间钢框架的受力性能研究进行综述,通过理论、有限元及试验的研究方法分析不同节点形式对钢框架力学性能的影响,并介绍了不同节点形式钢框架的受力特性。介绍了ANSYS、SAP2000和ABAQUS三种有限元分析软件的模拟方法,并针对不同节点钢框架的特点对有限元模拟单元的优缺点及适用范围进行归纳总结。对不同节点钢框架的静力性能和抗震性能研究现状进行总结,最后对不同节点形式钢框架的力学性能研究趋势进行了展望。     

整体钢平台模架装备技术研发及应用

整体钢平台模架装备是超高建筑物和构筑物建造的关键.基于传统整体钢平台模架、智能控制整体钢平台模架的发展历程,重点论述了内筒外架支撑式整体钢平台模架装备、临时钢柱支撑式整体钢平台模架装备、劲性钢柱支撑式整体钢平台模架装备、钢梁与筒架交替支撑式整体钢平台模架装备、钢柱与筒架交替支撑式整体钢平台模架装备的技术发展.同时对整体钢平台模架装备的一体化技术进行了介绍.整体钢平台模架装备的理论基础与技术体系可为今后该技术的应用提供参考和借鉴.     

高强Q960钢高温后力学性能试验研究

为了研究高强Q960钢在火灾后的力学性能,对过火温度为300~900℃的高强Q960钢试件进行了稳态拉伸试验,得到其在自然冷却和浸水冷却条件下的应力-应变曲线、弹性模量、屈服强度和极限强度.结果表明:600℃是高强Q960钢强度发生明显变化的临界温度,将试验结果与普通Q235钢、Q345钢和高强Q460钢、Q690钢、S960钢进行比较,发现不同种类钢材经历高温后的力学性能退化程度并不相同;根据试验结果,建立了高强Q960钢高温后力学性能折减系数随温度变化的拟合公式,拟合结果与试验结果吻合较好.     

美国在役核电厂安全壳钢衬里锈蚀及修复技术研究进展

通过美国混凝土安全壳钢衬里锈蚀的一些典型案例说明了钢衬里的锈蚀特征,论述了钢衬里的锈蚀机理,介绍了国外学者对钢衬里锈蚀后力学性能变化、钢衬里局部锈蚀对安全壳完整性和易损性的影响进行的研究,最后论述了钢衬里锈蚀检测和修复技术.分析表明,安全壳钢衬里锈蚀包括由涂层失效引起的钢衬里内表面锈蚀和安全壳混凝土中的异物吸水导致的外...     

Profiling iron corrosion coating on iron grains in a zerovalent iron system under the influence of dissolved oxygen

Rapid oxidation of Fe(0) by O(2) occurred when Fe(0) grains were bathed in 0.54 mM FeCl(2) solution saturated with dissolved oxygen (DO), forming a substantial corrosion coating on Fe(0) grains. A sonication method was developed to strip the corrosion coating off the iron grains layer by layer. The transformation of the constituents and the morphology of the corrosion coating along its depth and over reaction time were investigated with composition analysis, X-ray diffraction and scanning electron microscopy. Results indicate that the sonication method could consistently recover >90% iron oxides produced by the Fe(0)-DO redox reaction. Magnetite (Fe(3)O(4)) and lepidocrocite (gamma-FeOOH) were identified as the corrosion products. Initially, lepidocrocite was the preferential product in the presence of DO. As the oxide coating thickened, the inner layer transformed to magnetite, which retained as the only stable corrosion product once DO was depleted. The study confirms the phase transformations between gamma-FeOOH and Fe(3)O(4) within a stratified corrosion coating. The sonication technique exemplifies a new approach for investigating more complicated processes in Fe(0)/oxides/contaminants systems.     

住户铁制开关箱

针对当前建筑市场上住户铁制开关箱合格产品不足10％，危害住户安全用电的问题。介绍了开关箱是住户安全用电的把门神，在选择时要引起足够的重视。就住户铁制开关箱存在的各种缺陷，可能出现的问题进行了分析，并对合格铁制开关箱的标准要求进行了简述，得出了一种简便易行鉴别开关箱的方法。     

自然铁研究进展

自然铁在自然界的形成与保存都需要苛刻的条件,因此国内外关于自然铁的报道较少,国内对自然铁的研究更是比较薄弱,尚未形成统一的研究方法,也未形成分类标准及成因体系,因此在对自然铁的研究上往往出现会参照对比困难的情况。笔者通过大量阅读文献,回顾了自然铁的研究现状,并总结了其产状和成因类型。     

铸铁件补焊技术

针对铸铁件的焊接特点,给出几种不同的焊接方法,并通过对冲床床身裂纹和对铸造天轮裂纹的修复实例,介绍了采用一定工艺措施的手工电弧焊焊接修复铸铁件,以获得高质量焊缝的工艺方案。     

Virus removal by iron coagulation-microfiltration

This study was undertaken to determine virus removal efficiency by iron coagulation followed by microfiltration (MF) in water treatment using the MS2 bacteriophage (25 nm diameter) as a tracer virus. Results from these bench-scale studies were used to propose a mechanism for virus removal by iron coagulation–MF. Ferric chloride was used as coagulant, and the dosages were 0, 2, 5, and 10 mg/L as Fe(III) with pH adjusted during mixing to 6.3, 7.3 and 8.3. In the absence of iron-coagulation and with less than 2 mg/L Fe, MF alone achieved less than a 0.5 log removal of MS2 virus. However, iron-coagulation pretreatment dramatically improved virus removal, especially in the 5–10 mg/L Fe dose range, ultimately achieving more than 4-log removal at pH 6.3 with 10-mg/L Fe dose. For the 5 and 10 mg/L Fe dosages, decreasing pH in the 8.3–6.3 range resulted in significantly greater virus removal. For 0 and 2 mg/L iron dosages, decreasing pH in the 8.3–6.3 range also improved virus removal, but to a lesser extent. The experimental data indicates negatively charged MS2 viruses first adsorbed onto the positively charged iron oxyhydroxide floc particles before being removed by MF. MS2 viruses were not inactivated in iron or aluminum coagulation as evidenced by the fact that their concentrations before and after coagulation, settling, and re-suspension of the coagulated sludge were not statistically different.     

“热熨斗”与重型起重机

预制构件建筑在荷兰的流行意味着这个国家使用了很多重型塔式起重机。Will North将荷兰市场与其周边国家的市场做了比较后．介绍了一座获奖建筑施工中预制构件的优点。     

静脉铁剂相关低磷血症

静脉铁剂常用于口服铁剂治疗效果不佳或无法耐受口服铁剂的缺铁性贫血患者。某些静脉铁剂(如羧基麦芽糖铁、异麦芽糖酐铁、蔗糖铁、多聚麦芽糖铁等)通过升高成纤维细胞生长因子23导致低磷血症,大多数患者表现为轻度低磷,症状缺乏特异性。反复长期使用静脉铁剂可能导致骨软化和骨折等严重结果。本文对该病进行综述,旨在提醒临床医生重视静脉铁剂相关低磷血症。     

Electrochemical peroxidation using iron nanoparticles and anodic iron dissolution to remove selenium from oil refinery wastewater

Experimental results for selenium removal from oil refinery wastewater applying the electrochemical peroxidation process (ECP) using either graphite electrodes with iron nanoparticles (nZVI) or carbon steel electrodes with anodic iron dissolution (AD) on laboratory scale are presented. Operating parameters were: current density, iron‐selenium molar ratio and treatment time. It was found that when applying ECP and nZVI, selenium removal reached 93%. On the contrary, when the ECP and AD process was applied, selenium removal only reached 64%. Therefore, the ECP process and use of iron nanoparticles could be a feasible technology to remove selenium from oil refinery wastewater.     

利用铁尾矿制造建筑用砖

简述了我国铁尾矿的资源状况，介绍了用铁尾矿制作各种建筑用砖的各种研究成果。指出铁尾矿制砖是铁尾矿综合利用的一种有效途径。     

Cation exchange during subsurface iron removal

Subsurface iron removal (SIR), or in-situ iron removal, is an established treatment technology to remove soluble iron (Fe²⁺) from groundwater. Besides the adsorptive-catalytic oxidation theory, it has also been proposed that the injection of O₂-rich water onsets the exchange of adsorbed Fe²⁺ with other cations, such as Ca²⁺ and Na⁺. In sand column experiments with synthetic and natural groundwater it was found that cation exchange (Na⁺-Fe²⁺) occurs during the injection-abstraction cycles of subsurface iron removal. The Fe²⁺ exchange increased at higher Na⁺ concentration in the injection water, but decreased in the presence of other cations in the groundwater. Field results with injection of elevated O₂ concentrations (0.55 mM) showed increased Fe removal efficacy; the operational parameter V/Vi (abstraction volume with [Fe]<2 μM divided by the injection volume) increased from an average 7 to 16, indicating that not the exchangeable Fe²⁺ on the soil material is the limiting factor during injection, but it is the supply of O₂ to the available Fe²⁺.