Research on a Recognition Algorithm for Offshore-Pipeline Defects during Magnetic-Flux Inspection

Pipeline-safety evaluation is an important problem for industry. On the basis of the magnetic-flux-leakage (MFL) method, this paper presents an automated inspection device for inspection of pipeline defects, analyzes the MFL-inspection theory and some defect-feature parameters, and gives a recognizing algorithm based on a dynamic wavelet-basis-function (WBF) neural network. This dynamic network utilizes a multiscale and multiresolution orthogonal wavelet and backward-propagating through signals and has more significant advantages than BP or other neural networks used in MFL inspection. It also can control the accuracy of the predicted defect profiles, possessing high-speed convergence and good approaching features. The performance that applies the algorithm based on the network for predicting a defect profile from experimental MFL signals is also presented.__________Translated from Defektoskopiya, Vol. 41, No. 4, 2005, pp. 34–43.Original English Text Copyright © 2005 by Jin Tao, Que Peiwen, Chen Liang, Li Liang.The text was submitted by the authors in English.     

毛皮类物料干燥特性模拟试验研究

采用正交试验法对不同干燥工况下毛皮物料干燥特性进行试验，给出了干燥曲线和干燥速率曲线，建立了干燥特性方程。试验方法具有通用性。通过正交分析，以干燥时间和能耗为目标给出最佳干燥工况。     

文渊阁与四库全书

《四库全书》是清朝乾隆年间编纂的一部大型丛书。“文渊阁”为《四库全书》藏书处，规制最为壮观。文渊阁位于文华殿以北，阁前有一长方形水池。阁制面阔六间，前后出廊造。阁虽采用六间建制，但作为楼梯间的西梢间面阔仅一廊步深，其余五间仍明间坐中（见“文渊阁地盘图”）。这种变通形式在清代建筑中较为奇特。阁采用歇山式琉璃瓦顶，黑心绿剪边做法。文渊阁外观两层，内实三层。阁之梁架结构大体以《工程做法·九檩楼房大木》为准。但改硬山顶为歇山顶，于腰檐部位增设暗层，上檐金柱改为落地通柱。     

明甪直天王殿松木斗拱振动台试验研究

以甪直保圣寺天王殿斗拱为参考对象,进行无缩尺松木斗拱模型的地震台试验研究。通过对斗拱的加速度与动力放大系数变化趋势、斗拱在振动过程中位移响应变化特征、斗拱变形最大时刻和各构件变形最大时刻的滑移位移和回转位移数值对比分析,得出以下结论：地震加速度用于衡量地震烈度,并不能直接反映斗拱试件的最大变形;振动频率的变化对斗拱回转变形的变化起重要作用,振幅是决定各构件水平滑移的主要因素;各构件变形最大值与斗拱整体变形最大值具有很强相关性,其中栌斗和华拱的回转变形对斗拱的整体变形而言,处于支配地位;斗拱的华拱连下昂部分主要起装饰作用,其榫卯连接节点位置在振动过程中较为薄弱,在对实际文物维护修缮过程中应引起重视并采取相关加固措施。     

Kilogram-scale synthesis of Mg-Al-CO3 LDHs nanosheets using a new two-stage reactor

A novel reactor with a two-stage reaction chamber was designed to kilogram-large-scale synthesized Mg-Al-CO₃ layered double hydroxide (Mg-Al-CO₃ LDHs) nanosheets. The effects of the reactant concentration and rotation speed of the dynamic structure on the crystal size and morphology were investigated. The results show that the size of Mg-Al-CO₃ LDH particles gained in typical condition is about 50 nm in length and 5.7 nm in thickness, and the size becomes larger as the reactant concentration or rotationl speed decreased. The possible reaction mechanism was explained by three critical factors of the reactor, N₂ gas and polyethylene glycol 2000.     

针状微胶囊Mg(OH)_2/EVA纳米复合材料的制备及性能研究

将自制针状微胶囊纳米氢氧化(镁Mg(OH)2)与乙烯-乙酸乙烯共聚(物EVA)经双螺杆挤出机熔融共混挤出造粒,然后利用注射机制成针状微胶囊Mg(OH)2/EVA纳米复合材料,对其力学性能、热稳定性和流变性能进行了研究。结果表明:纳米Mg(OH)2用量为4%时,复合材料的拉伸强度最大,加工流动性较好;在低温区时,纳米Mg(OH)2含量对复合材料的热稳定性能几乎没有影响,在高温区时,纳米Mg(OH)2的加入使其热稳定性略有提高。     

钢塑复合冲淤管的开发与应用

针对当前围堰造地与环境保护之间出现的问题,开发了一种钢塑复合冲淤管。经过工程试验证明这是一种切实可行的新技术,使用该产品做成的冲淤坝具有很好的冲淤能力。该产品的推广使用可减小围堰造地对环境的影响,加快冲淤速度,缩短围堰造地周期,节约造地成本。     

霞家河灌区续建配套与节水改造工程规划与研究

霞家河灌区是以一座中型水库为主要水源,利用灌区内小型水库、塘堰作调节,通过干渠相互沟通形成的长藤结瓜式灌溉系统,运行以来社会、经济效益巨大,但也存在工程布局不合理、水资源分配不优、工程老损失修等问题。在此提出了霞家河灌区续建配套与节水改造工程规划设计,同时对灌区工程规划设计的可行性进行了研究分析。     

GW286计算中心微机管理系统

本文详述了如何在GW286微机上利用DBASEⅢ软件对学生上机进行管理,以及如何完成上机课程表的排列、打印各种统计报表;此外,还介绍了实现DBASEⅢ与其他高级语言相互调用的方法。     

A comparison of techniques for preparing fish fillet for ICP-AES multielemental analysis and the microwave digestion of whole fish.

Four catfish fillet homogenate treatments before multielemental metal analysis by simultaneous inductively coupled plasma/atomic emission spectroscopy were compared in triplicate. These treatments were: nitric acid wet-ashing by Parr bomb digestion; nitric acid wet-ashing by microwave digestion; tetramethylammonium hydroxide/nitric acid wet digestion; and dry-ashing. The tetramethylammonium hydroxide/nitric acid method was imprecise (coefficients of variation > 20%). The dry-ashing method was fast and sensitive but had low recoveries of 50% for spiked Pb and Al and was not as precise as the Parr bomb or microwave treatments. The Parr bomb method was the most precise method but was less sensitive than the microwave method which had nearly the same precision. The microwave method was then adapted to homogenates of small whole fish < or = 3 cm in length. The whole fish homogenate required more vigorous digestion conditions, and addition of more acid after the evaporative step because of the presence of less oxidizable and acid-soluble components than fillet. The whole fish homogenate was also more heterogeneous than catfish fillet. A quality assurance protocol to demonstrate homogenate uniformity is essential. The use of a non-specialized microwave oven system allowed precise results for fillet and whole fish homogenates.