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Bounding surface model for ballast with additional attention on the evolution of particle size distribution

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Science China(Technological Sciences) 2014年第7期57卷 1352-1360页

作者： SUN YiFei XIAO Yang ju wen School of Civil Mining and Environmental Engineering University of Wollongong College of Civil and Transportation Engineering Hohai University College of Civil Engineering Chongqing University China Nuclear Industry Huaxing Construction Company Limited

Particle size distribution significantly influences the mechanical response of the ballast under low confining ***,particle breakage usually occurs and unfavorably degrades the particle size distribution of the ballast when sufficient load is *** model the triaxial stress-strain behavior and its associated evolution of particle size distribution of the ballast,a specific bounding surface model is *** proposed model is based on the traditional bounding surface plasticity and a modified particle breakage index,which correlates the initial gradation and the ultimate gradation together with the current *** of the experimental results from the triaxial compression tests shows that the proposed model can predict the strain softening and volumetric expansion of the ballast under relatively lower confining *** is also able to simulate the strain hardening and volumetric compression of the ballast under relatively higher confining *** importantly,the proposed approach was observed to have a great potential in predicting the evolution of the particle size distribution of the ballast.

关键词： bounding surface ballast particle breakage particle size distribution triaxial test

Studies on a Cationically Modified Quaternary Ammonium Salt of Lignin

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Chemical Research in Chinese Universities 2007年第4期23卷 479-482页

作者： YANG Ai-li JIANG wen-ju College of Architecture and Environment Sichuan University Chengdu 610065 P. R. China

A new quaternary ammonium salt monomer was synthesized and a quaternary amination of lignin（ noted as QL）, with the monomer was carried out by grafting copolymerization. The products were characterized by Fourier Transform Infrared spectroscopy（ FTIR）. The experimental results indicate that the yield of the monomer was 99.06%, and the conversion of the monomer and the grafting yield of QL were 93.69% and 185.78%, respectively. The feasibility of QL as the flocculant to be applied in color removal of five artificial dyes, erioehrome black T（dye A）, gongo red（dye B ）, direct fast black G （dye C ）, cuprofix blue green B （dye D ）, and acid black ATT （dye E ） was examined. Results show that OL exhihits the favorable flocculation nerformance and high stability.

关键词： Quaternary ammonium salt of lignin(QL) Cationic monomer Grafting copolymerization Flocculation

Effective Elastic Properties of 3-Phase Particle Reinforced Composites with Randomly Dispersed Elastic Spherical Particles of Different Sizes Dedicated to Professor Karl Stark Pister for his 95th birthday

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Computer Modeling in Engineering & Sciences 2021年第12期129卷 1305-1328页

作者： Yu-Fu Ko Jiann-wen Woody ju Civil Engineering and Construction Engineering Management California State UniversityLong BeachCA 90840-5101USA Civil and Environmental Engineering University of CaliforniaLos AngelesCA 90095-1593USA

Higher-order multiscale structures are proposed to predict the effective elastic properties of 3-phase particle reinforced composites by considering the probabilistic spherical particles spatial distribution,the particle interactions,and utilizing homogenization with ensemble volume average *** matrix material,spherical particles with radius a1,and spherical particles with radius a2,are denoted as the 0th phase,the 1st phase,and the 2nd phase,***,the two inhomogeneity phases are different particle sizes and the same elastic material *** higher-order(in ratio of spherical particle sizes to the distance between the centers of spherical particles)bounds on effective elastic properties of 3-phase particle reinforced proposed Formulation II and Formulation I derive *** a special case,i.e.,particle size of the 1st phase is the same as that of the 2nd phase,the proposed formulations reduce to 2-phase *** theoretical predictions demonstrate excellent agreement with selected experimental *** addition,several numerical examples are presented to demonstrate the competence of the proposed frameworks.

关键词： Particle reinforced composites micromechanics spherical particle interactions ensemble volume average homogenization probabilistic spatial distribution higher-order bounds multiscale

YIELD SURFACES AND PLASTIC FLOW OF 45 STEEL UNDER TENSION-TORSION LOADING PATHS

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维普期刊数据库

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Acta Mechanica Solida Sinica 2012年第4期25卷 348-360页

作者： Guijuan Hu Keshi Zhang Shihong Huang Jiann-wen Woody ju Key Laboratory of Disaster Prevention and Structural Safety Guangxi UniversityNanning 530004China Guangxi Polytechnic of Construction Nanning 530004China Department of Civil and Environmental Engineering University of CaliforniaLos AngelesCA 90095-1593USA

An experimental analysis on the subsequent yield-surfaces evolution using multiple specimens is presented for a 45 steel after a prescribed pre-strain loading in three different directions respectively, and the yielding is defined by a designated offsetting strain. The size of the subsequent yield surface is found smaller than the initial yield surface; the negative cross effects are observed in the normal loading direction, its shape is not a Mises circle but has a rather blunt nose in loading direction and flat in the opposite. These results strongly depend on the loading path and the prescribed offset plastic strain. The plastic flow direction to the subsequent yield surface is investigated, and it is found that the plastic flow direction deviates from the normal flow rule. The deviation differs from preloading case to preloading case. And the plastic flow direction would have a larger deviation from the normal of the yield surface, if the subsequent yield was defined by a smaller offset strain. Furthermore, the experiments are simulated using the Chaboche model, and the results show that it can rationally predict yield-surface only when yield is defined by a fairly large offset strain.

关键词： subsequent yield surface plastic flow direction multiple specimen methods offsetstrain

Partial organic substitution weakens the negative effect of chemical fertilizer on soil micro-food webs

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Journal of Integrative Agriculture 2022年第10期21卷 3037-3050页

作者： LIU Han-wen ZHANG Xiao-ke ZHANG Gui-zong KOU Xin-chang LIANG wen-ju Institute of Applied Ecology Chinese Academy of SciencesShenyang 110016P.R.China University of Chinese Academy of Sciences Beijing 100049P.R.China School of Geographical Science Northeast Normal UniversityChangchun 130024P.R.China

Soil biotic communities play vital roles in enhancing soil nutrient cycling and soil ***-term excessive nitrogen(N)application is disadvantageous to the stability of soil food webs and affects arable soil health and sustainable *** organic substitution is essential to improve soil health and alleviate the disadvantages of excessive chemical ***,the biological effects of various organic amendments on soil micro-food webs are poorly *** order to explore the effects of various organic amendments including stover,biochar and manure on soil micro-food webs(microbial and nematode communities),a field plot experiment with maize having five treatments viz.,100%urea(100%N),70%urea(70%N),70%urea plus stover(Stover),70%urea plus cattle manure(Manure)and 70%urea plus biochar(Biochar)was *** treatment increased the carbon(C)to N use efficiency of soil microbes,which contributed to the retention of soil C,while Biochar treatment elevated soil organic C(SOC)and soil p ***,Biochar treatment mitigated the negative effects of soil acidification on the soil micro-food web and reduced the abundance of plant ***,the biological effect of organic amendments was distinguished from chemical fertilization(100%N and 70%N)through principal co-ordinates *** relationships among soil properties,microbial and nematode biomass in the 100%N treatment were diminished in treatments where chemical fertilizer was *** bottom-up effects on soil food webs were observed in organic substitution *** conclusion,organic amendments improved soil fertility by regulating soil microbial and nematode communities in the cropland ecosystem,alleviated the negative effects of chemical fertilizer on the micro-food webs and controlled the trophic cascades among soil biota.

关键词： microbial community nematode community soil micro-food webs organic substitution chemical fertilizer soil health

CAVITATION CHARACTERISTICS OF HIGH VELOCITY FLOW WITH AND WITHOUT AERATION ON THE ORDER OF 50m/s

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Journal of Hydrodynamics 2007年第4期19卷 429-433页

作者： DONG Zhi-yong CHEN Lei ju wen-jie School of Civil Engineering and Architecture Zhejiang University of Technology Hangzhou 310032 China

Experimental study of cavitation characteristics with and without aeration was conducted at the flow velocity 50m/s in the non-circulating type water tunnel in the Hydraulics Laboratory at Zhejiang University of Technology. Variations of pressure and cavitation number with air concentration, pressure waveforms as well as cavitation erosion level of concrete specimen with and without aeration were obtained. The effects of cavitation control by aeration were analyzed.

关键词： cavitation erosion aeration pressure change cavitation number the order of 50 m/s

Distribution of Soil Enzyme Activities and Microbial Biomass Along a Latitudinal Gradient in Farmlands of Songliao Plain,Northeast China

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Pedosphere 2008年第4期18卷 431-440页

作者： LIU Xiu-Mei LI Qi LIANG wen-ju JIANG Yong Key Laboratory of Terrestrial Ecological Process Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 （China） Graduate School of the Chinese Academy of Sciences Beijing 10004g （China）

Soil enzymes activities and microbial biomass have an important influence on nutrient cycling. The spatial distribution of soil enzymes activities and microbial biomass were examined along a latitudinal gradient in farmlands of Songliao Plain, Northeast China to assess the impact of climatic changes along the latitudinal transect on nutrient cycling in agroecosystems. Top soils （0-20 cm depth） were sampled in fields at 7 locations from north （Hallun） to south （Dashiqiao） in the end of October 2005 after maize harvest. The contents of total C, N, and P, C/N, available N, and available P increased with the latitude. The activities of invertase and acid phosphatase, microbial biomass （MB） C and N, and MBC/MBN were significantly correlated with latitude （P 〈 0.05, r^2 = 0.198, 0.635, 0.558, 0.211 and 0.317, respectively）, that is, increasing with the latitude. Significant positive correlations （P 〈 0.05） were observed between invertase activity and the total N and available P, and between acid phosphatase activity and the total C, C/N, available N, total P and available P. The urease, acid phosphatase, and dehydrogenase activities were significantly correlated with the soil pH and electrical conductivity （EC）（P 〈 0.05）. MBC and MBN were positively correlated with the total C, C/N, and available P （P 〈 0.05）. The MBC/MBN ratio was positively correlated with the total C, total N, C/N, and available N （P 〈 0.05）. The spatial distribution of soil enzyme activities and microbial biomass resulted from the changes in soil properties such as soil organic matter, soil pH, and EC, partially owing to variations in temperature and rainfall along the latitudinal gradient.

关键词： farmlands hydrolases latitudinal gradient microbial biomass soil organic matter

Nematode Diversity in Phaeozem Agroecosystems of Northeast China

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Pedosphere 2009年第5期19卷 597-605页

作者： LI Qi JIANG Yong LIANG wen-ju WANG He JIANG Si-Wei Key Laboratory of Terrestrial Ecological Process Institute of Applied Ecology Chinese Academy of Sciences Shenyang110016 (China) Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Beijing 100081(China)

The diversity and distribution patterns of soil nematode communities in phaeozem agroecosystems of Northeast China were assessed to evaluate nematode taxonomic diversity and functional diversity in relation to climatic condition and soil characteristics in human modified landscape. Along the latitudinal gradient, soil samples were collected from north （Hailun） to south （Gongzhuling） down to a depth of 100 cm with intervals of 030, 20-40, 40-60, 60-80, and 80-100 cm. The nematode abundance and taxonomic diversity （generic richness） were lower at Hailun than at other sites, and higher values of evenness were observed at Hailun and Harbin than at Dehui and Gongzhuling. Nematode faunal analysis revealed that soil food web at Hailun was sueeessionally more mature or structured, and the environment little disturbed, while at Harbin and Gongzhuling, the soil food web was degraded with stressed environment. The environmental variables relevant in explaining the patterns of nematode distribution and diversity in phaeozem agroecosystems, using canonical correspondence analysis （CCA）, were the mean annual temperature, total nitrogen, electrical conductivity, mean annual precipitation, and other soil properties. Among these variables, the mean annual temperature was a relatively important factor, which could explain 29.05% of the variations in nematode composition.

关键词： agricultural disturbance canonical correspondence analysis maize field nematode faunal analysis soil biodiversity

Nonreciprocal two-photon transmission and statistics in a chiral waveguide QED system

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Chinese Physics B 2022年第5期31卷 340-349页

作者： Lei Wang Zhen Yi Li-Hui Sun wen-ju Gu School of Physics and Optoelectronic Engineering Yangtze UniversityJingzhou 434023China

We study the nonreciprocal properties of transmitted photons in a chiral waveguide quantum electrodynamics(QED)system,including single-and two-photon transmissions and second-order *** the single-photon transmission,the nonreciprocity is induced by the effects of chiral coupling and atomic dissipation in the weak coupling *** vanishes in the strong coupling regime when the effect of atomic dissipation becomes *** the case of two-photon transmission,there exist two ways of going through the emitter:independently as plane waves and formation of bound *** the nonreciprocal behavior of plane waves,the bound state that differs in two directions also alters transmission *** addition,the second-order correlation of transmitted photons depends on the interference between plane wave and bound *** destructive interference leads to the strong antibunching in the weak coupling region,while the effective formation of bound state leads to the strong bunching in the intermediate coupling ***,the negligible interactions for left-propagating photons hardly change the statistics of the input coherent state.

关键词： chiral waveguide QED nonreciprocal transmissions nonreciprocal correlations