极化电位下高强钢腐蚀疲劳裂纹扩展的表征

研究了不同极化电位下高强钢在3.5%NaCl溶液中疲劳裂纹扩展速率的变化规律.在强阴极极化(-1100 mV～-1200 mV)和阳极极化(-200 mV～-400 mV)条件下,高强钢腐蚀疲劳裂纹扩展寿命明显缩短,而极化电位为-800 mV～-1000 mV时,高强钢腐蚀疲劳寿命延长.在Paris经验公式的基础上,引...     

Q235钢在察尔汗盐湖卤水中的电化学行为

采用电化学方法研究了Q235钢在盐湖卤水中电化学行为随浸泡时间的变化规律.结果表明,在浸泡前期腐蚀较快,随着浸泡的进行,钢表面覆盖微薄的腐蚀产物层,在高盐度的卤水环境中,腐蚀产物层可有效增加氧扩散的阻力,减缓腐蚀的进行.     

F-Si封闭剂对热喷涂15%Al-85%Zn合金涂层电化学行为的影响(英文)

大部分船体外壳通过喷漆、牺牲阳极和外加电流阴极保护方法来解决抗腐蚀问题。但是,这些传统的方法不是非常有效,因为船尾的船舵常暴露在严重的腐蚀环境中,例如潮汐、船行驶速度、气蚀和冲刷腐蚀。由于气泡的生成与破裂而产生的振荡波而导致的气蚀和冲刷腐蚀会对材料产生破坏。对热喷涂Al-Zn合金涂层进行了气蚀和电化学性能测试实验。然后,Al-Zn合金涂层表面涂刷F-Si封闭剂以提高Al-Zn涂层的耐海水电化学腐蚀和抗气蚀性能。结果表明,该封闭剂不但适用静态环境,而且适用于动态环境。     

硫酸盐还原菌模拟生物膜对907A钢腐蚀的影响

根据生物膜的结构特征,以硫酸盐还原菌和琼脂的混合物沉积于907A钢表面,形成人工模拟生物膜,采用微电极研究了模拟生物膜下溶解氧的分布情况,采用环境扫描电镜和能谱表征了模拟生物膜下907A钢在不同环境中的腐蚀情况。研究结果表明在人工模拟生物膜内,距离金属材料表面越近,溶氧量越低;金属材料的腐蚀情况受环境影响,当环境中富含还原性物质且SRB生长旺盛时,907A钢腐蚀严重,腐蚀产物以硫化铁为主,当环境中缺乏还原性物质且SRB生长不良时,907A钢的腐蚀产物以铁氧化物为主。     

Controlled,Parametric, Individualized, 2D,and 3D Imaging Measurements of Aerosol Deposition in the Respiratory Tract of Healthy Human Subjects: Preliminary Comparisons with Simulations

Preliminary comparisons of simulation results from existing extrathoracic (ET) models and a lung deposition model with individualized, two-dimensional and three-dimensional (3D) imaging measurements of aerosol deposition in the respiratory tract of healthy human subjects have been presented. In general, the ET models did not correspond well with each individual's experimental data. However, there is rather good agreement between simulated and experimental results for regional lung deposition comparable to those previously found in the literature. Comparisons of generational distributions are relatively poor. These preliminary results suggest not only the need for further developments in deposition modeling, but also the need for better methods for analyzing experimentally determined 3D deposition distributions for comparison to simulated results.

Copyright 2013 American Association for Aerosol Research     

Surface Composition and Morphology of Particles Dried Individually and by Spray Drying

This study investigates how the morphology of spray-dried particles is related to the formulation and properties of the components in the formulation. Further, the scale effects in comparisons of levitation-dried single particles and spray-dried particles in a lab-scale spray dryer have been addressed. The Drying Kinetics Analyzer^TM generates single particles from a levitated drop under simulated spray-drying conditions. A set of surface-active polymers (bovine serum albumin, hydroxypropyl methyl cellulose, and triblock co-polymer Poloxamer), in combination with lactose, were analyzed for their dynamic surface properties in solution, and their effect on particle morphology and surface composition were determined by low-vacuum SEM and XPS analyses. The morphology obtained in spray drying was reproduced in the single-particle drying. The surface compositions were also similar, but higher levels of surface-active materials were found at the surface of the single particles as compared to the spray-dried particles. Further, the adsorption rate of surface-active compounds at the drop surface estimated by dynamic surface tension was found to be an important parameter to estimate the surface composition at different drying scales. The particle morphology was primarily determined by the surface rheological properties of the feed solution and, to a lesser extent, by the surface composition.     

ANALYTIC METHOD FOR INVERSING THE OPEN BOUNDARY CONDITIONS IN A SEMI-CLOSED SEA AREA——CASE I FOR INVERSING THE TIDAL LEVELS AT OPEN BOUNDARY

In this paper, a computational case was employed to describe the computational procedure for inversing the tidal level open boundary conditions using an analytic method. The area for finding the solution is a circular area with a circular arc with the opening angle 60~-being the open boundary and the other circular arc being the solid wall boundary. Proceeding from the reestablished elliptic partial differential equation satisfied by the tidal level function, the extended spectrum method was used to derive the general solution of the equation for the sea of constant depth, and the impermeable solid wall condition (the second class boundary condition) and the adequately specified open boundary conditions were then applied to determine the undetermined coefficients of the general solution, thus obtaining the tidal level distribution function. In this way, both the first and second class boundary values at the solid wall boundary were obtained. With the above boundary values as the boundary conditions, the tidal level values at the open boundary were then inversed by means of the general solution of tidal wave equation. The validity of inversion method could be verified by comparing the inversed tidal level distributions with the originally specified open boundary values.     

海洋和除冰盐条件下混凝土结构的Cl-扩散行为及耐久性设计

研究了海洋和除冰盐条件下暴露7～18a的混凝土结构Cl-浓度分布规律,探讨了混凝土结构的耐久性设计.结果表明,在严酷环境条件下混凝土结构的Cl-扩散行为符合修正的Fick第二扩散定律,混凝土的最大水胶比和最小保护层厚度是保证结构工程使用寿命的重要耐久性设计参数.     

Auxiliary Degumming and Pressurized High Temperature Water Washing to Mitigate the Formation of Monochloropropanediols in Palm Oil

This study reports the benefits of auxiliary degumming (Aux.D) and pressurized high temperature (165 °C) water washing (PHTW) to mitigate the formation of monochloropropanediols (MCPD) during labscale physical refining of palm oil. Water-based degumming in combination with bleaching and deodorization are performed as the selected physical refining process. The mitigation concepts Aux.D and PHTW are integrated into the refining protocol and the ultimately observed MCPD levels in the fully refined oils are determined. Aux.D is performed by extracting the hydratable gum from pressed sunflower oil and using it as a degumming agent to further purify palm oil that has been previously subjected to centrifugation and water degumming. This approach enables the mitigation of 3-MCPD from the water washed reference 2.4–0.9 mg kg⁻¹ in ampoules. Even stronger mitigation is obtained when Aux.D is combined with bleaching and executed twice allowing a mitigation from the reference 1.9–0.6 mg kg⁻¹, in ampoules. PHTW is shown to decrease the 3-MCPD content of the refined oil from the reference 2.4–1 mg kg⁻¹, in ampoules and when combined with bleaching and executed twice showing a decrease from the reference 1.9–0.9 mg kg⁻¹. Practical applications: The benefits of these mitigation concepts are confirmed both in sealed ampoule tests and in deodorizer experiments at the lab scale. A combined application of Aux.D or PHTW with physical refining may represent new insights that can help to potentially further mitigate the formation of MCPD in physically refined palm oil beyond the limits achievable with current refining practices.     

A related key impossible differential attack against 22 rounds of the lightweight block cipher LBlock

LBlock is a new lightweight block cipher proposed by Wu and Zhang (2011) [12] at ACNS 2011. It is based on a modified 32-round Feistel structure. It uses keys of length 80 bits and message blocks of length 64 bits.In this letter, we examine the security arguments given in the original article and we show that we can improve the impossible differential attack given in the original article on 20 rounds by constructing a 22-round related key impossible differential attack that relies on intrinsic weaknesses of the key schedule. This attack has a complexity of 2⁷⁰ cipher operations using 2⁴⁷ plaintexts. This result was already published in Minier and Naya-Plasencia (2011) [9].