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Effect of Triisopropanolamine on the Compressive Strength and Early Hydration of Cement at Low Temperature

Journal of Wuhan University of Technology(Materials Science) 2020年第3期35卷 611-619页

作者： ZHANG Feng BAI Yin CAI Yuebo CHEN bo ning Fengwei State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing Hydraulic Research InstituteNanjing 210029China

Triisopropanolamine (TIPA) was used as an early strength component to study its effects on mortar strength, cement paste setting time and early hydration characteristic of cement. And the early strength mechanism of TIPA at low temperature of 5 ℃ was also discussed. The results showed that, at 5 ℃, the incorporation of TIPA promoted the condensation of cement paste, shortened the initial and final setting time, and accelerated the strength development of specimens at all ages, among which the strength after 3 d increased significantly. The 1, 3, 7, and 28 d compressive strength ratios of the mortars mixed with 1% TIPA could reach 196%, 179%, 160% and 110% respectively, and the mortar strength after 3 d exceeded that of the contrast sample cured at 20 ℃. Under low temperature condition, TIPA could promote the hydration reaction of cement, shorten the induction period and advance the acceleration period. Furthermore, the maximum heat release rate and cumulative heat release quantity would be all increased, and the cumulative heat release of the cement mixed with TIPA hydrated for 12 h and 7 d increased 73% and 38% respectively. TIPA could shorten the nucleation and crystal growth (NG) stage and increase its hydration degree significantly, so it promoted cement hydration reaction. Additionally, the hydration reaction rates in phase boundary reaction (I) phase and diffusion reaction (D) phase were increased, and the duration of I process was prolonged, thereby the development of specimen strength would be accelerated. TIPA did not obviously change the types of hydration products, but increased the content of Ca(OH)2 in the samples and the degree of cement hydration. After hydration to 7 d, large amounts of hydration products, whose surface was smooth, were formed and bonded into sheets, and the structural density of samples improved significantly.

关键词： low temperature triisopropanolamine compressive strength hydration mechanism

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Broadcast encryption schemes based on RSA

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The Journal of China Universities of Posts and Telecommunications 2009年第1期16卷 69-75页

作者： MU ning-bo HU Yu-pu OU Hai-wen The Ministry of Education Key Laboratory of Computer Networks and Information Security Xidian University Xi'an 710071 China Key Laboratory of Information Security and Secrecy Beijing Institute of Electronic Science and Technology Beijing 100070 China

Three broadcast schemes for small receiver set using the property of RSA modulus are presented. They can solve the problem of data redundancy when the size of receiver set is small. In the proposed schemes, the center uses one key to encrypt the message and can revoke authorization conveniently. Every authorized user only needs to store one decryption key of a constant size. Among these three schemes, the first one has indistinguishability against adaptive chosen ciphertext attack （IND-CCA2） secure, and any collusion of authorized users cannot produce a new decryption key but the sizes of encryption modulus and ciphertext are linear in the number of receivers. In the second scheme, the size of ciphertext is half of the first one and any two authorized users can produce a new decryption key, but the center can identify them using the traitor tracing algorithm. The third one is the most efficient but the center cannot identify the traitors exactly.

关键词： broadcast encryption traitor tracing authorization revocation RSA

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Quadratic Stabilization of Switched Uncertain Linear Systems: A Convex Combination Approach

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IEEE/CAA Journal of Automatica Sinica 2019年第5期6卷 1116-1126页

作者： Yufang chang Guisheng Zhai bo Fu Lianglin Xiong the School of Electrical and Electronic Engineering Hubei University of TechnologyWuhan 430068China the Department of Mathematical Sciences Shibaura Institute of TechnologySaitama 337-8570Japan the School of Mathematics and Computer Science Yunnan Minzu UniversityKunming 650500China

We consider quadratic stabilization for a class of switched systems which are composed of a finite set of continuoustime linear subsystems with norm bounded uncertainties. Under the assumption that there is no single quadratically stable subsystem, if a convex combination of subsystems is quadratically stable, then we propose a state-dependent switching law, based on the convex combination of subsystems, such that the entire switched linear system is quadratically stable. When the state information is not available, we extend the discussion to designing an outputdependent switching law by constructing a robust Luenberger observer for each subsystem.

关键词： Convex combination limear matrix inequalities (LMIs) norm bounded uncertainties output-dependent switching, quadratic stabilization state-dependent switching switched uncertain linear systems(SULS)

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Steganography in low bit-rate speech streams based on quantization index modulation controlled by keys

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Science China(Technological Sciences) 2017年第10期60卷 1585-1596页

作者： HUANG YongFeng TAO HuaiZhou XIAO bo chang ChinChen Department of Electronic Engineering Tsinghua University Department of Information Engineering and Computer Science Feng Chia University

Since low bit-rate speech codecs used for voice over internet protocol （VolP）, such as iLBC （internet low bit-rate codec）, G.723.1 and G.729A, have less redundancy due to high compression, it is more challenging to embed information in low bit-rate speech streams of VolP. In this study, a new method is proposed for steganography in low bit-rate speech streams of VolP. The core idea of this method is setting up a graph model for the codebook space of the quantizer. Based on the graph model, the method realises a quantization index modulation （QIM）-controlled algorithm for partitioning the codebook space. It can be proved that this method can minimize signal distortion while steganography taking place. Taking into account codeword partition balance and partition diversity, the proposed steganographic algorithm was based on QIM controlled by secret keys, i.e., mapping the ways of codebook division into secret keys, thereby significantly improving the undetectability and robustness of VolP steganography. Performance measurements and steganalysis experiments showed that the proposed QIM-controlled steganographic algorithm was more secure and robust than the QIM algorithm, the conventional RANDOM algorithm and the original codebook algorithm.

关键词： Steganography VoIP QIM graph theory QIM-controlled

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Advanced electrosynthesis of hydrogen peroxide on oxidized carbon electrocatalyst

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Journal of Energy Chemistry 2019年第7期28卷 10-11页

作者： chang-Xin Zhao bo-Quan Li Qiang Zhang Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical Engineering Tsinghua University

Hydrogen peroxide(H2O2)is one of the 100 most important chemicals involved in multiple chemical processes including paper and textile manufacturing,waste degradation,and pharmaceutical production[1].Compared with the current industrial process to produce H2O2 following the anthraquinone oxidation/reduction method,electrochemical reduction of oxygen to H2O2 through a two-electron pathway constitutes an environmental friendly alternative route[2-4].Unfortunately,the electrogeneration of H2O2 from two-electron reduction of oxygen feedstock is kinetically sluggish and therefore requires electrocatalysts with high reactivity,high selectivity,and good stability[5,6].

关键词： Hydrogen peroxide electrosynthesis Oxygen reduction reaction Carbon nanotubes Electrocatalysis Oxygen functional groups

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Eye movement evidence in investigative identification based on experiments

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Journal of Safety Science and Resilience 2023年第3期4卷 316-328页

作者： chang Sun ning Ding Dongzhe Zhuang Xinyan Liu Public Security Behavioral Science Lab People's Public Security University of ChinaBeijing 100091China

Investigative identification is a routine criminal investigative procedure,the results of which can be used as evidence in ***,some suspects often deny their involvement in the case,and some witnesses may withhold information or misrepresent it,all of which may lead to a miscarriage of *** study created a stressful environment and conducted a simulated crime experiment to explore whether eye movement data can be an effective feature for distinguishing perpetrators,innocents,and *** eye movement features—such as the total fixation duration,number of fixations,and first fixation duration—within an area of interest were collected from 83 participants sorted into informed,involved,and innocent *** results revealed the following:(1)compared with the object and scene stimuli,subjects with different identities were more likely to exhibit significant differences in eye movement data for the involved and irrelevant *** total fixation duration and the number of fixations can provide a reference for judging whether someone is involved in a case,and the first fixation duration effect was not obvious.(2)Using machine learning algorithms to predict subjects’identities through eye movement features,it was demonstrated that the involved portrait-object-scene model had the best predictive effect.(3)Multiple algorithmic models were used to distinguish subjects’identities,and the highest accuracy of 92.7%was achieved for the informed×innocent group,88%for the innocent×suspect group(including the informed and involved groups),and 84.5%for the involved *** eye movement analysis method can provide a reference for criminal investigators to distinguish between the perpetrator,insider,and innocent,and offer a novel approach to determining the direction of further investigation and uncovering and verifying case clues.

关键词： Eye movement Investigative identification Repeated measures ANOVA Machine learning

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PSR J1614-2230 May Include Hyperons

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Chinese Physics Letters 2011年第8期28卷 352-355页

作者： YU Zi DING Wen-bo BAO Tmurbagan LIU ning-ning The College of Science Nanjing Forestry UniversityNanjing 210037 Department of Physics Bohai UniversityJinzhou 121000 College of Physics and Electronic Engineering Nanyang Normal UniversityNanyang 473061 Department of Basic Course Nanjing Institute of TechnologyNanjing 211167

In the framework of the relativistic mean field theory,it is found that recently discovered PSR J1614-2230 with mass of 1.97±0.04Mʘmay include hyperons when the weakly interacting light boson(WILB)is *** describe PSR J1614−2230 with the equation of state(EOS)including hyperons,the characteristic scale of the WILB(g^(2)/μ^(2))should lie in the range of 13–46(24–46)GeV^(−2) with the weak(strong)hyperon-hyperon(YY)*** measurements of inertial momentum and the total neutrino luminosity of the neutron star could be used to further constrain the characteristic scale of the *** more stringent constraint on the WILB is given,the mass measurement of the neutron star could not exclude any soft EOS.

关键词： interaction weakly momentum

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Fabrication and analysis of nano-structured thermal spraying feeds

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中国有色金属学会会刊：英文版 2004年第Z1期14卷 83-87页

作者： YE Xiong-lin MA Shi-ning LI chang-qing National Key Laboratory for Remanufacturing Academy of Armored Force Engineering Beijing 100072 China National Key Laboratory for Remanufacturing Academy of Armored Force Engineering Beijing 100072 China National Key Laboratory for Remanufacturing Academy of Armored Force Engineering Beijing 100072 China

A kind of thermal spray nanostructured Al2O3 and TiO2 feeds fabricating technology was *** nanogranules prepared by spray drying were heat treated in order to be dense, and there were two sintering technologies used, i.e. high temperature electric furnace sintering and high velocity flame sintering, respectively. The results indicate feeds phase components using high temperature electric furnace sintering at 1 200 ℃,1 300 ℃ and 1 400 ℃ do not change, and grain sizes of nano-Al2O3 and TiO2 grow little at 1 200 ℃ and 1 300 ℃,while grain sizes of nano-Al2O3 and TiO2 grow obviously, and the grain size of nano-TiO2 is larger than 100 nm at 1400 ℃. Phase components of the feeds using high velocity flame sintering change, where α-Al2O3 changes to γ-Al2O3 and rutile TiO2 changes to brookite TiO2, though grain size of nano-Al2O3 does not grow and is less than 100 nm because cooling velocity is too quick. Compared with these two heat treatment technology, the technology using electric furnace to treat nanostructured Al2O3 and TiO2 feeds is more suitable.

关键词： nanostructured feeds thermal spray heat treatment

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Experimental study of an ellipsoidal particle in tube Poiseuille flow

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Journal of Hydrodynamics 2020年第3期32卷 616-622页

作者： Yuan-feng Cui Xiang-ting chang Hai-bo Huang Department of Modern Mechanics University of Science and Technology of ChinaHefei 230026China

Behaviors of a prolate ellipsoid inside circular tube Poiseuille flow are studied experimentally. In the study, Reynolds number Re ∈ (100,700) and the confinement ratio D/A ∈ (1.2,2.8) are considered, where D is the diameter of the tube and A is the length of the major axis of the ellipsoid. Two typical stable motion modes are identified, namely, the horizontal, and inclined modes. Then another inclined mode (inclined mode II) is found at high Reynolds number (Re ∈ (1000,3200)) and small D/A, and the inclined angle of ellipsoid increases with the increase of Re. The possible mechanism is explained. Our experiment shows that the lagging velocity U increases as Re increases. Further numerical analysis using FLUENT shows that due to the increase of U, the moment acting on the particle would make the inclined angle of the particle increase.

关键词： Ellipsoidal particle Poiseuille flow circular tube experiment

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Interactive method research of dual mode information coordination integration for astronaut gesture and eye movement signals based on hybrid model

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Science China(Technological Sciences) 2023年第6期66卷 1717-1733页

作者： ZHUANG HongChao XIA YiLu WANG ning LI WeiHua DONG Lei LI bo School of Mechanical Engineering Tianjin University of Technology and EducationTianjin 300222China School of Information Technology Engineering Tianjin University of Technology and EducationTianjin 300222China School of Automotive Engineering Harbin Institute of Technology(Weihai)Weihai 264209China Tianjin Institute of Aerospace Mechanical and Electrical Equipment Tianjin 300458China School of Mechatronics Engineering Harbin Institute of TechnologyHarbin 150000China

The lightweight human-robot interaction model with high real-time,high accuracy,and strong anti-interference capability can be better applied to future lunar surface exploration and construction *** on the feature information inputted from the monocular camera,the signal acquisition and processing fusion of the astronaut gesture and eye-movement modal interaction can be *** with the single mode,the human-robot interaction model of bimodal collaboration can achieve the issuance of complex interactive commands more *** optimization of the target detection model is executed by inserting attention into YOLOv4 and filtering image motion *** central coordinates of pupils are identified by the neural network to realize the human-robot interaction in the eye movement *** fusion between the astronaut gesture signal and eye movement signal is performed at the end of the collaborative model to achieve complex command interactions based on a lightweight *** dataset used in the network training is enhanced and extended to simulate the realistic lunar space interaction *** human-robot interaction effects of complex commands in the single mode are compared with those of complex commands in the bimodal *** experimental results show that the concatenated interaction model of the astronaut gesture and eye movement signals can excavate the bimodal interaction signal better,discriminate the complex interaction commands more quickly,and has stronger signal anti-interference capability based on its stronger feature information mining *** with the command interaction realized by using the single gesture modal signal and the single eye movement modal signal,the interaction model of bimodal collaboration is shorter about 79%to 91%of the time under the single mode *** of the influence of any image interference item,the overall judgment accuracy of the proposed model can be maintained a

关键词： human-robot interaction gesture and eye movement hybrid model YOLOv4 CBAM

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