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Discrete numerical modeling of granular materials considering crushability

Journal of Mountain Science 2017年第4期14卷 758-770页

作者： QIAN Jian-gu gu Jian-bo gu xiao-qiang HUANG Mao-song Key Laboratory of Geotechnieal and Underground Engineering of Ministry of Education Tongji UniversityShanghai 200092China Department of Geotechnical Engineering Tongji UniversityShanghai 200092China

The aim of this study is to numerically investigate the influence of particle breakage on the mechanical behavior of granular materials using a discrete element method(DEM). To enable particle crushing, non-crushable elementary particles are boned together to represents the granular aggregates which can be crushed when the external force exceeds its strength. The flaw of the aggregate was also modeled by randomly distributed void. Single particle crushing tests were carried out to determine the distribution of particle strength. The results of single particle crushing tests illustrate that the simulated single particle fracture strength and pattern agree well with the Weibull's distribution *** oedometer tests, drained monotonic and cyclic triaxial tests were also carried out to investigate the crushing of the aggregates and the associated mechanical behaviors. The effect of confining pressure on the crushing of aggregates and the mechanical behavior was also analyzed. It was found that the peak stress and dilation decrease significantly when particle crushing was *** deformation behavior of the specimen is essentially controlled by two factors: particle rearrangement-induced dilation and particle crushing-induced contraction. The increase of permanent strain and the reduction of dilation were observed during cyclic loading and they tend to reach a stable state after a certain number of cycles. The crushing of aggregate is most significant in the first two cycles. The results also indicated that for the same axial strain the volumetric strain and the bound breakage in the cyclic loading tests are significantly larger than that in the monotonic loading tests,especially at high cyclic stress ratio.

关键词： DEM simulation Granular materials Crushing Monotonic and Cyclic triaxial test

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Hierarchically 1D CdS decorated on 2D perovskite-type La_(2)Ti_(2)O_(7) nanosheet hybrids with enhanced photocatalytic performance

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Rare Metals 2021年第5期40卷 1067-1076页

作者： Liang Mao xiao-Yan cai Ming-Shan Zhu School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221116China Jiangsu Province Engineering Laboratory of High Efficient Energy Storage Technology and Equipment China University of Mining and TechnologyXuzhou 221116China School of Environment Jinan UniversityGuangzhou 511443China

In this paper,a heterojunction of hierarchically one-dimensional(1D)cadmium sulfide(CdS)nanowires decorated on the two-dimensional(2D) La_(2)Ti_(2)O_(7) (LTO)has been fabricated by a simple two-step hydrothermal *** structure,morphology and surface chemical composition of CdS/LTO were studied by a variety of characterizations,in which the X-ray photoelectron spectroscopy(XPS)results showed a strong interaction between CdS and LTO through S-O *** typeⅡband alignment of CdS/LTO for favorable electron transfer from CdS to LTO and hole transfer from LTO to CdS was clarified by ultraviolet-visible(UV-Vis)diffuse reflectance spectroscopy and Mott-Schottky(M-S)plot *** the absence of any co-catalyst,H2 production from water splitting and Rhodamine B(RhB)decomposition in aqueous solution were carried out to evaluate the photocatalytic activities,showing that the photocatalytic performance of CdS/LTO was superior to that of pure LTO and CdS under visible light and simulated *** optimal CdS content in the CdS/LTO system was determined to be 7.5 wt%.The present results show an effective pathway to design a 1D/2D heterojunction photocatalyst in the face of overwhelming problems of energy crisis and environmental pollution.

关键词： Cadmium sulfide Lanthanum titanium oxide Heterojunction H_(2)production Dyes degradation

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A semi-transparent selective undo algorithm for multi-user collaborative editors

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Frontiers of Computer Science 2021年第5期15卷 53-69页

作者： Weiwei cai Fazhi HE xiao LV Yuan CHENG School of Computer Science Wuhan UniversityWuhan 430072China Department of Computer Engineering Naval University of EngineeringWuhan 430072China School of Information Management Wuhan UniversityWuhan 430072China

Multi-user collaborative editors are useful computer-aided tools to support human-to-human *** multi-user collaborative editors,selective undo is an essential utility enabling users to undo any editing operations at any *** editors usually adopt operational transformation(OT)to address concurrency and consistency ***,it is still a great challenge to design an efficient and correct OT algorithm capable of handling both normal do operations and user-initiated undo operations because these two kinds of operations can interfere with each other in various *** this paper,we propose a semi-transparent selective undo algorithm that handles both do and undo in a unified framework,which separates the processing part of do operations from the processing part of undo *** proofs are provided to prove the proposed algorithm under the well-established *** analysis and experimental evaluation are conducted to show that the proposed algorithm outperforms the prior OT-based selective undo algorithms.

关键词： human-centric collaboration collaborative editing systems selective undo concurrency control replication consistency

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Study of the relationship between the content of the rare earth element Eu in rice plants and in Nilaparvata lugens （Hemiptera： Delphacidae）

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Insect Science 2012年第1期19卷 13-20页

作者： Min Yang Jin-cai Wu Hai-Nan gu School of Plant Protection Yangzhou UniversityYangzhouChina Indooroopilly Science Centre Department of Primary Industries and FisheriesQueensland 4068Australia

The current study investigated changes in the content of the rare earth element Europium （Eu） in roots, shoots and leaves of rice plants and in Nilaparvata lugens Stal （Hemiptera： Delphacidae） using an Eu marker and hydroponic culture. The results showed that N. lugens infestation significantly reduced Eu content in roots, shoots and leaves of two rice varieties, Shenyou 1 and Xieyou 963. The Eu content in roots, shoots and leaves of the susceptible variety, Shenyou 1, was significantly higher than that in the resistant variety, Xieyou 963. The Eu content ofN. lugens fed on Shenyou 1 was significantly higher than of those fed on Xieyou 963. In addition, the Eu level was elevated at a higher density ofN. lugens infestation. Eu content in the bodies ofN. lugens was related to their weight and honeydew excretion, with a significant positive correlation. Thus, Eu content in the bodies ofN. lugens can be considered an index of the amount of phloem sap taken in by N. lugens because the amount of honeydew excretion is proportional to the amount of phloem sap consumed. The ratios of Eu content in N. lugens to that in roots, shoots and leaves of rice plants were elevated at a higher N. lugens infestation density. That ratio was maximal in leaves, was intermediate in shoots and was minimal in roots. There was no significant difference in ratios between the two plant varieties. An Eu marker may be useful in the screening of resistant varieties and in the study of the mechanisms of resistance.

关键词： markers Nilaparvata lugens rare earth element Eu rice

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Giant magnetoresistance in antiferromagnetic Mn2Au-based tunnel junction

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Science China(Physics,Mechanics & Astronomy) 2020年第9期63卷 111-117页

作者： Xing-Tao Jia xiao-Lin cai Yu Jia School of Physics and Electronic Information Engineering Henan Polytechnic UniversityJiaozuo 454000China International Laboratory for Quantum Functional Materials of Henan School of PhysicsZhengzhou UniversityZhengzhou 450001China Key Laboratory for Special Functional Materials of Ministry of Education School of Materials Science and EngineeringHenan UniversityKaifeng 475004China

Recent studies on the electrical switching of tetragonal antiferromagnet(AFM)via Neél spin-orbit torque have paved the way for the economic use of antiferromagnetic *** most difficult obstacle that presently limits the application of antiferromagnetic materials in spintronics,especially in memory storage applications,could be the small and fragile magnetoresistance(MR)in the AFM-based *** this study,we investigated the spin transports in Mn2Au-based tunnel junctions based on the first-principle scattering *** MRs more than 1000%are predicted in some Fe/MgO/Ag/Mn2Au/Ta junctions that are about the same order as that in an MgO-based ferromagnetic tunnel junction with same barrier *** interplay of the spin filtering effect,the quantum well resonant states,and the interfacial resonant states could be responsible for the unusual giant and robust MRs observed in these Mn2Au-based junctions.

关键词： Mn2Au giant magnetoresistance tunnel junction

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Glucagon-like peptide-2 protects impaired intestinal mucosal barriers in obstructive jaundice rats

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World Journal of Gastroenterology 2015年第2期21卷 484-490页

作者： Jun Chen Jia-Tian Dong xiao-Jing Li Ye gu Zhi-Jian Cheng Yuan-Kun cai Department of General Surgery Shanghai Fifth People’s HospitalFudan University Department of Pathology Shanghai Fifth People’s HospitalFudan University Clinical Base of Emergency Shanghai Fifth People’s HospitalFudan University

AIM: To observe the protective effect of glucagon-like peptide-2(GLP-2) on the intestinal barrier of rats with obstructive jaundice and determine the possible mechanisms of action involved in the protective ***: Thirty-six Sprague-Dawley rats were randomly divided into a sham operation group, an obstructive jaundice group, and a GLP-2 group; each group consisted of 12 rats. The GLP-2 group was treated with GLP-2 after the day of surgery, whereas the other two groups were treated with the same concentration of normal saline. Alanine aminotransferase(ALT), total bilirubin, and endotoxin levels were recorded at 1, 3, 7, 10 and 14 d. Furthermore, on the 14 th day, body weight, the wet weight of the small intestine, pathological changes of the small intestine and the immunoglobulin A(Ig A) expressed by plasma cells located in the small intestinal lamina propria were recorded for each ***: In the rat model, jaundice was obvious, and the rats' activity decreased 4-6 d post bile duct ligation. Compared with the sham operation group, the obstructive jaundice group displayed increased yellow staining of abdominal visceral serosa, decreased small intestine wet weight, thinning of the intestinal muscle layer and villi, villous atrophy, uneven height, fusion, partial villous epithelial cell shedding, substantial inflammatory cell infiltration and significantly reduced Ig A expression. However, no significant gross changes were noted between the GLP-2 and sham groups. With time, the levels of ALT, endotoxin and bilirubin in the GLP-2 group were significantly increased compared with the sham group(P < 0.01). The increasing levels of the aforementioned markers were more significant in the obstructive jaundice group than in the GLP-2 group(P < 0.01).CONCLUSION: GLP-2 reduces intestinal mucosal injuries in obstructive jaundice rats, which might be attributed to increased intestinal Ig A and reduced bilirubin and endotoxin.

关键词： Intestinal mucosal barrier Glucagon-likepeptide-2

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Synthesis and Characterization of Poly (hydroxylethyl, octanediamine)-DL-aspartamide: a New Tissue Engineering Scaffolds

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Chinese Chemical Letters 2006年第2期17卷 191-194页

作者： gu Ping TANG xiao xiao SONG Da LI Department of Chemistry Zhejiang University Hangzhou 310028 Department of Medical Zhejiang University Hangzhou 310006

Poly （hydroxyethyl, octanediamine）-DL-aspartamide （PHOA） hydrogels were prepared by adding mixture of 1,8-octanediamine and ethanolamine to PA in DMF at room temperature. The properties of the hydrogels were inves... 详细信息

关键词： Octanediamine aspartamide hydrogel cell adhesion.

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Reproducibility of optical quality parameters measured at objective and subjective best focuses in a doublepass system

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International Journal of Ophthalmology(English edition) 2015年第5期8卷 1043-1050页

作者： Ai-Lian Hu Li-Ya Qiao Ye Zhang xiao-gu cai Lei Li Xiu-Hua Wan Beijing Institute of Ophthalmology Beijing Tongren Eye CenterBeijing Tongren HospitalCapital Medical UniversityBeijing Ophthalmology & Vision Science Key Lab

AIMTo evaluate intra-session repeatability and reproducibility of optical quality parameters measured at objective and subjective best focuses in a double-pass *** Chinese healthy adults (19 to 40 years old) meeting our inclusion criterion were enrolled in the study. After a basic eye examination, two methods of optical quality measurement, based on subjective and objective best focuses were performed using the Optical Quality Analysis System (OQAS) with an artificial pupil diameter of 4.0 *** each method, three consecutive measurements of the following parameters: the modulation transfer function cutoff frequency (MTFcutoff), the Strehl2D ratio, the OQAS values (OVs) at contrasts of 100%, 20%, 9% and the objective scatter index (OSI) were performed by an experienced examiner. The repeatability of each method was evaluated by the repeatability limit (RL) and the coefficient of repeatability (COR). Reproducibility of the two methods was evaluated by intra-class correlation coefficient (ICC) and the 95% limits of agreement (Bland and Altman analysis). Thirty subjects, seven females and twenty three males, of whom 15 right eyes and 15 left eyes were selected randomly for recruitment in the study. The RLs (percentage) for the six parameters measured at objective focus and subjective focus ranged from 8.44% to 15.13% and 10.85% to 16.26%, respectively. The CORs for the two measurement methods ranged from 8.27% to 14.83% and 10.63% to 15.93%, respectively. With regard to reproducibility, the ICCs for the six parameters of OQAS ranged from 0.024 to 0.276. The 95% limits of agreement obtained for the six parameters (in comparison of the two methods) ranged from -0.57 to 42.18 (MTFcutoff), -0.01 to 0.23 (Strehl2D ratio), -0.02 to 1.40 (OV100%), -0.10 to 1.75 (OV20%), -0.14 to 1.80 (OV9%) and -1.46 to 0.18 (OSI).CONCLUSIONMeasurements provided by OQAS with either method sh

关键词： optical quality double-pass system best focus repeatability reproducibility

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Highest Weight Representations of a Family of Lie Algebras of Block Type

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Acta Mathematica Sinica,English Series 2008年第4期24卷 687-696页

作者： xiao Qing YUE Yu cai SU Department of Mathematics Shanghai Jiao Tong University Shanghai 200240 P. R. China Department of Mathematics University of Science and Technology of China Hefei 230026 P. R. China

For an additive subgroup G of a field F of characteristic zero, a Lie algebra B（G） of Block type is defined with basis {Lα,i｜ α∈G, i∈Z＋} and relations [Lα,i, Lβ,j] = （β-α）Lα＋β,i＋j＋（αj-βi）Lα＋β,Lα＋β,i＋*** is proved that an irreducible highest weight B（Z）-module is quasifinite if and only if it is a proper quotient of a Verma module. Furthermore, for a total order λ on G and any ∧∈B（G）0^＊（the dual space of B（G）0 = span{L0,i｜i∈Z＋}）, a Verma B（G）-module M（∧,λ） is defined, and the irreducibility of M（A,λ） is completely determined.

关键词： Verma modules Lie algebras of Block type irreducibility quasifinite

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Investigation on the Coordination Mode of IL-Supported Diols Used as Phosphine-Free Ligands for Palladium Catalyzed Heck Reaction

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Chinese Journal of Chemistry 2013年第10期31卷 1250-1256页

作者： Yueqin cai Gonghua Song xiao Chen School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China Shanghai Key Laboratory of Chemical Biology Institute of Pesticides & Pharmaceuticals East China University of Science and Technology Shanghai 200237 China

The coordination mode of IL-supported diols used as phosphine-free ligands for palladium catalyzed Heck reaction has been investigated by tuning their compositions. The difference in coordination of these IL-supported diols with metal Pd in Heck reaction was related to the changes of the cation rings, leading to the different activities of Pd catalyst in the reaction. The experimental results indicated that the activities of Pd catalyst were affected mainly by n-electron density of the cation rings. Compared to pyridinium and piperidinium cations, imidazolium cations showed the best coordination to metal Pd. In the meantime, C-2 hydrogen and the length of alkyl side chains had impacts on the coordination as well.

关键词： homogeneous catalysis acylation Heck reaction phosphine-free ligands

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