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Text steganography method based on automatic selection coding and dynamic word selection strategy [PDF]
, 2022 A text steganography method based on automatic selection coding and dynamic word selection strategy was proposed for the inflexible text coding method and candidate word increasing number leading to the low quality of generated steganographic text ...
Hui LI, Jiali JIN, Shuyu JIN, Weijiao MA
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Impact of rainstorm weather on urban road capacity [PDF]
, 2016 The rainstorm weather seriously affects the operation of urban traffic, and the surface gathered water and its obstruction to vision lead to a decrease of road capacity.
Ji, Xun +4 more
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New NDT method for ferromagnetic materials based on differential permeability [PDF]
, 2017 利用微分磁导率变化特性,提出了一种可对材料的宏观缺陷进行快速扫查的无损检测新方法。首先,将铁磁性材料置于偏置磁化场环境下,缺陷将导致内部磁通的畸; 变;其次,磁通畸变进一步体现在材料表面微分磁导率分布的差异性;再次,通过特殊设计的微分磁导率检测探头,对材料表面微分磁导率的分布进行扫查;最后,; 由磁导率分布差异获得材料内部的不连续性信息,从而实现对缺陷的无损检测。开展了系列验证实验,结果表明,相对于传统的漏磁检测方法,新方法具有磁化强度; 低、磁通泄漏少、检测信号稳定的特点。新方法正 ...
刘志天 +3 more
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Numerical simulation of high frequency guided wave testing for anchor bolt defects [PDF]
, 2023 Previous research has confirmed that only high-frequency guided waves larger than 1 MHz have the minimum attenuation detection mode for anchor bolt widely used in underground projects.
Changsuo ZHANG, Yanyu GUO, Yue ZHANG
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Dianci bileiqi, 2023 石墨接地体添加火花刺可以有效降低冲击接地电阻，为研究方框带外延线型石墨接地装置添加火花刺的降阻规律，从电磁场角度出发，建立了考虑电感效应、集肤效应和火花效应有限元分析模型，系统分析了火花刺的长度、位置和间距对方框带外延线石墨接地体冲击接地电阻的影响，并设计试验进行了验证。结果表明：方框带外延线型石墨接地装置射线端添加火花刺可以增加散流通道进而有效降低冲击接地阻抗。该试验条件下，受端部效应的影响，火花刺应布置在射线长度的1/3-7/10处；受屏蔽效应的影响，火花刺长度的最优值约为射线长度的0.1-0 ...
赵德辉 +5 more
doaj
Dianci bileiqi, 2022 笔者研究了引外接地在垂直双层土壤中有效长度，以验证GB 50065中所说变电站2 km范围内有低土壤电阻率地区时可采用引外接地的可行性。研究采用CDEGS软件进行仿真，结果表明辅助接地网的降阻效率随引外长度增加而减小，有效降阻的最大引外长度(η≥10%)在400～800 m之间。辅助接地网的降阻效率还受到两侧土壤电阻率比值k、接地导体材质、接地网边长以及接地导体半径等因素的影响。因此当辅助接地网距变电站主接地网2 km时已无实际效果。
周恬雅, 鲁志伟, 林忠宣, 董威
doaj
The Experimental Study on Flow Boiling Heat Transfer of Working Fluid R245fa in Horizontal Tube [PDF]
, 2017 设计了管内沸腾换热系数及总传热系数测定试验台架,对R245fa工质在内径6 mm水平光管内的流动沸腾换热特性进行试验研究。测试质流密度为50 ~; 150 kg /(m~2·s),工质蒸发温度为50, 60和70℃。结果表明:; 随着工质含汽率的增加,R245fa的流动沸腾换热系数呈先增大后降低趋势。对于304不锈钢套管式换热器,烟气与R245fa工质进行换热的总传热系数; 约在40 ~ 65 W/(m~2·K) 。A bench - scale facility was designed for ...
刘美丽 +4 more
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Study of degradation of methyl tert-butyl ether (MTBE) by UV/H2O2(UV/H2O2氧化降解甲基叔丁基醚(MTBE)的试验研究)
Zhejiang Daxue xuebao. Lixue ban, 2006 采用UV/H2O2技术对污染水体中的MTBE进行了氧化降解试验，考察了不同MTBE初始浓度，不同H2O2浓度，不同pH值，不同波长的紫外光对降解效果的影响，以及不同Cl-、HCO3-浓度的抑制作用.结果表明，在室温条件下，当紫外光波长为254 nm，H2O2为15 m mol/L，pH为3. 0时对起始浓度为1 m mol/L的MTBE具有较好的降解效果；反应60 min，MTBE去除率可达97.6%.实验证明，UV/ H2O2氧化技术是降解MTBE的一种有效方法.
HUQin-hai(胡勤海) +5 more
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Study on Method of Measuring Ionization Energy Loss of Time Projection Chamber Using UV Laser [PDF]
The time projection chamber (TPC) is a critical component in collider physics, dark matter research, and nuclear physics due to its high precision, low material budget, and superior particle identification (PID) capabilities.
CHANG Yue1, 2, QI Huirong2, 3, SHE Xin2, 3, ZHANG Jinxian2, 3, YU Chunxu1, ZHAO Guang2, 3, WU Linghui2, 3, DENG Zhi4, WANG Jianchun2, 3
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Effect of angle of slit on shedding vortex of slotted circular cylinder [PDF]
, 2017 开缝圆柱绕流作为钝体绕流研究的分支,具备很强的应用前景,但是对其复杂的流动现象的物理本质的理解仍不完善。本文采用流动显示技术和粒子成像测速技术(; PIV),探究缝隙对开缝圆柱流场结构的影响,在数据处理方面采用本征正交分解(POD)方法对开缝圆柱流场信息进行了重建。实验研究表明:; 在一定雷诺数范围内,开缝圆柱缝隙的存在从根本上改变了圆柱绕流近区尾流的结构;; 开缝圆柱脱落涡的脱落频率对开缝圆柱缝隙倾斜角具有一定的敏感性,随着缝隙倾斜角的增大其斯特劳哈尔数逐渐变大,对比发现开缝圆柱狭缝比(缝隙/直径)为;
刘志荣 +4 more
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