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Comparison of Hydration Properties between Cement-GGBS-fly ash Blended Binder and Cement-GGBS-steel slag Blended Binder

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Journal of Wuhan University of Technology(Materials Science) 2014年第2期29卷 273-277页

作者：王强阎培渝 yang jianwei Department of Civil Engineering Tsinghua University

The hydration properties of cement-GGBS-fly ash blended binder and cement-GGBS-steel slag blended binder were compared. The experimental results show that the hydration rate of cement-GGBS- steel slag blended binder is higher than that of cement-GGBS-fly ash blended binder within 28 days, but lower than the latter after 28 days. The hydration of cement-GGBS-steel slag blended binder tends to produce more Ca（OH）2 than the hydration of cement-GGBS-fly ash blended binder, especially at late ages. Cement-GGBS- steel slag mortar exhibits higher strength than cement-GGBS-fly ash mortar within 28 days, but at late ages, it exhibits similar compressive strength with eement-GGBS-fly ash mortar and even slightly lower bending strength than cement-GGBS-fly ash mortar. Cement-GGBS-steel slag paste has finer early pore structure but coarser late pore structure than cement-GGBS-fly ash paste. Cement-GGBS-steel slag paste can get satisfied late pore structure and cement-GGBS-steel slag mortar can get satisfied late strength as compared with pure cement paste and pure cement mortar, respectively.

关键词： steel slag fly ash GGBS hydration

Convergence of compressible Navier-Stokes-Maxwell equations to incompressible Navier-Stokes equations

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Science China Mathematics 2014年第10期57卷 2153-2162页

作者： yang jianwei WANG Shu Institute of Applied Physics and Computational Mathematics College of Mathematics and Information Science North China University of Water Resources and Electric Power College of Applied Sciences Beijing University of Technology

The combined quasi-neutral and non-relativistic limit of compressible Navier-Stokes-Maxwell equations for plasmas is *** well-prepared initial data,it is shown that the smooth solution of compressible Navier-Stokes-Maxwell equations converges to the smooth solution of incompressible Navier-Stokes equations by introducing new modulated energy functional.

关键词： Navier-Stokes-Maxwell equations incompressible Navier-Stokes equations asymptotic limit mod-ulated energy function

Two-Scale Picard Stabilized Finite Volume Method for the Incompressible Flow

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Advances in Applied Mathematics and Mechanics 2014年第5期6卷 663-679页

作者： Jianhong yang Gang Lei jianwei yang Department of Mathematics Baoji University of Arts and SciencesBaoji 721013China Department of Computer and Science Baoji University of Arts and SciencesBaoji 721007China

In this paper,we consider a two-scale stabilized finite volume method for the two-dimensional stationary incompressible flow approximated by the lowest equalorder element pair P_(1)−P_(1)which do not satisfy the inf-sup *** two-scale method consist of solving a small non-linear system on the coarse mesh and then solving a linear Stokes equations on the fine *** of the optimal order in the H1-norm for velocity and the L^(2)-norm for pressure are *** error analysis shows there is the same convergence rate between the two-scale stabilized finite volume solution and the usual stabilized finite volume solution on a fine mesh with relation h=O(H^(2)).Numerical experiments completely confirm theoretic ***,this method presented in this paper is of practical importance in scientific computation.

关键词： Incompressible flow stabilized finite volume method inf-sup condition local Gauss integral two-scale method

Influence of initial alkalinity on the hydration of steel slag

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Science China(Technological Sciences) 2012年第12期55卷 3378-3387页

作者： WANG Qiang yang jianwei YAN PeiYu Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry Department o(Civil Engineering Tsinghua UniversityBeijing 100084China

The influences of different alkaline conditions on the kinds and morphologies of steel slag＇s hydration products, Ca（OH）2 con- tent of hydration products, pore stiucture of hardened paste, non-evaporable water content of hydration products, and strength of steel slag mortar were investigated by changing the initial alkalinity of the hydration condition of steel slag. The results showed that increasing the initial alkalinity of hydration condition can promote the early hydration of steel slag＇s active com- ponents （e,g., C2S, C3S, and C12A7）, but it has little influence on their late-age hydration degree. The hydration degree of non-active components （e.g., RO phase and Fe304） of steel slag is very low even under strong alkaline condition with pH value of 13.8. The excitation effect of alkaline condition on the early hydration of steel slag is more obvious with the increase of pH value, but the kinds of steel slag＇s hydration products are not influenced by changing the alkaline condition. The amount of steel slag＇s hydration products is limited, so the strength of alkali-activated steel slag mortar is very low though the strong al- kaline condition significantly promotes the early hydration of steel slag. Steel slag is not an ideal raw material for alka- li-activated cementitious material.

关键词： steel slag alkalinity hydration cementitious material

Single event upset induced multi-block error and its mitigation strategy for SRAM-based FPGA

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Science China(Technological Sciences) 2011年第10期54卷 2657-2664页

作者： XING KeFei yang jianwei ZHANG ChuangSheng HE Wei Department of Instrument Science and Technology School of Mechatronics and Automation National University of Defense Technology Changsha 410073 China

According to the SRAM-based FPGA's single event effect problem in space application,single event upset induced multi-block error(SEU-MBE) phenomenon and its mitigation strategy are studied in the *** analyzing the place and route result,the paper points out that the essence of SEU-MBE is that some important modules exceed the safe internal *** approaches,area constraint method(ACM) and incremental route algorithm(IRA),are proposed,which can reduce the error rate by manipulating programmable switch matrix and interconnection points within FPGA route *** injection experiments indicate that error detection rate is above 98.6% for both strategies,and FPGA resources increment and performance penalty are around 10%.

关键词： SRAM-based FPGA single event upset induced multi-block error place and route

Grouting theories and technologies for the reinforcement of fractured rocks surrounding deep roadways

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Deep Underground Science and Engineering 2023年第1期2卷 2-19页

作者： Hongpu Kang Wenzhou Li Fuqiang Gao jianwei yang CCTEG Coal Mining Research Institute BeijingChina Coal Mining Branch China Coal Research InstituteBeijingChina State Key Laboratory of Coal Mining and Clean Utilization(China Coal Research Institute) BeijingChina

Grouting is an effective method to improve the integrity and stability of fractured rocks that surround deep *** years of research and practice,various theories and a complete set of grouting technologies for deep roadways with fractured rocks have been developed and are widely applied in Chinese coal mining *** paper systematically summarizes and analyzes the research results concerning the theory,design,materials,processes,and equipment for the grouting and reinforcement of fractured rocks surrounding deep ***,in terms of grouting methods,pregrouting,groutingwhile-excavation,and postgrouting methods are explored;in terms of grouting theory,backfill grouting,compaction grouting,infiltration grouting,and fracture grouting theories are *** addition,this paper also studies grouting borehole arrangement,water-cement ratio,grouting pressure,grouting volume,grout diffusion radius,and other grouting parameters and their determination *** this basis,this paper explores the physical and mechanical properties of organic and organic-inorganic composite grouting materials,and assess grouting reinforcement quality testing methods and *** as the field cases,the application of pregrouting in front of heading faces,groutingwhile-excavation,and postgrouting in the Kouzidong coal mine are then introduced,and the effects of the grouting reinforcements are *** paper proposes a development direction for grouting technology based on problems existing in the grouting reinforcement of fractured rocks surrounding deep roadways.

关键词： deep roadways development direction field study fractured rocks grouting materials grouting methods high-pressure grouting

Theory,technology and application of grouted bolting in soft rock roadways of deep coal mines

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1463-1479页

作者： Hongpu Kang jianwei yang Pengfei Jiang Fuqiang Gao Wenzhou Li Jiafeng Li Huiyuan Chen Coal Mining Research Institute China Coal Technology and Engineering Group Co.Ltd.Beijing 100013China Coal Mining Branch China Coal Research InstituteBeijing 100013China State Key Laboratory of Intelligent Mining and Strata Control Beijing 100013China

The grouted bolt,combining rock bolting with grouting techniques,provides an effective solution for controlling the surrounding rock in deep soft rock and fractured *** has been extensively applied in numerous deep mining areas characterized by soft rock roadways,where it has demonstrated remarkable control *** article systematically explores the evolution of grouted bolting,covering its theoretical foundations,design methods,materials,construction processes,monitoring measures,and methods for assessing its *** overview encompassed several key elements,delving into anchoring theory and grouting reinforcement *** new principle of high pretensioned high-pressure splitting grouted bolting collaborative active control is introduced.A fresh method for dynamic information design is also *** discussion touches on both conventional grouting rock bolts and cable bolts,as well as innovative grouted rock bolts and cables characterized by their high pretension,strength,and sealing hole *** examination of the merits and demerits of standard inorganic and organic grouting materials versus the new inorganic–organic composite materials,including their specific application conditions,was ***,the article presents various methods and instruments to assess the support effect of grouting rock bolts,cable bolts,and grouting ***,it provides a foundation for understanding the factors influencing decisions on grouted bolting timing,the sequence of grouting,the pressure applied,the volume of grout used,and the strategic arrangement of grouted rock bolts and cable *** application of the high pretensioned high-pressure splitting grouted bolting collaborative control technology in a typical kilometer-deep soft rock mine in China—the soft coal seam and soft rock roadway in the Kouzidong coal mine,Huainan coal mining area,was ***,the existing problems in grouted bolting control

关键词： deep coal mine soft rock roadway grouted bolting rock bolt and cable grouting material high-pressure splitting grouting collaborative control technology

The energy-efficient implementation of an adaptive-filtering-based QRS complex detection method for wearable devices

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Journal of Semiconductors 2017年第10期38卷 15-21页

作者： Shudong Tian Jun Han jianwei yang Xiaoyang Zeng State Key Laboratory of ASIC and System Fudan University

Electrocardiogram（ECG） can be used as a valid way for diagnosing heart *** fulfill ECG processing in wearable devices by reducing computation complexity and hardware cost,two kinds of adaptive filters are designed to perform QRS complex detection and motion artifacts removal,*** proposed design achieves a sensitivity of 99.49% and a positive predictivity of 99.72%,tested under the MIT-BIH ECG *** proposed design is synthesized under the SMIC 65-nm CMOS technology and verified by post-synthesis *** results show that the power consumption and area cost of this design are of 160 μW and 1.09×10^5 μm^2,respectively.

关键词： ECG adaptive filter QRS motion artifacts R wave detection

Review of the Analysis and Suppression for High-frequency Oscillations of the Grid-connected Wind Power Generation System

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CES Transactions on Electrical Machines and Systems 2024年第2期8卷 127-142页

作者： Bo Pang Qi Si Pan Jiang Kai Liao Xiaojuan Zhu jianwei yang Zhengyou He the College of Electrical Engineering Southwest Jiaotong UniversityChengdu 610031China IEEE

High-frequency oscillation(HFO)of gridconnected wind power generation systems(WPGS)is one of the most critical issues in recent years that threaten the safe access of WPGS to the *** the WPGS can damp HFO is becoming more and more vital for the development of wind *** HFO phenomenon of wind turbines under different scenarios usually has different ***,engineers need to acquire the working mechanisms of the different HFO damping technologies and select the appropriate one to ensure the effective implementation of oscillation damping in practical *** paper introduces the general assumptions of WPGS when analyzing HFO,systematically summarizes the reasons for the occurrence of HFO in different scenarios,deeply analyses the key points and difficulties of HFO damping under different scenarios,and then compares the technical performances of various types of HFO suppression methods to provide adequate references for engineers in the application of ***,this paper discusses possible future research difficulties in the problem of HFO,as well as the possible future trends in the demand for HFO damping.

关键词： Damping method High-frequency oscillation Stability Wind power generation