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A Middle Pleistocene Glaciation Record from Lacustrine Sediments in the Western Tibetan Plateau and Discussion on Climate Change

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Acta Geologica Sinica(English Edition) 2023年第2期97卷 623-635页

作者： ZHAO Zhenming ji Wenhua fu Chaofeng Xi'an Center China Geological SurveyXi'an 710054China Key Laboratory of Western Mineral Resources and Geological Engineering Ministry of Education of China and Chang'an UniversityXi'an 710054China State Key Laboratory of Loess and Quaternary Geology Institute of Earth and EnvironmentCASXi'an 710075China

The Tibetan Plateau is an important area for studying global climate change,but the answers to many scientific problems remain ***,we present new information from the lacustrine sedimentary record in the western Tibetan Plateau,related to the third most-recent *** sediment data,including sporopollen,particle size,total organic carbon,mass susceptibility,CaCO_(3),CaSO_(4),BaSO_(4)contents and chronological data,were reconstructed and revealed that climate and environmental conditions obviously and distinctly changed between 600 and 700 thousand years *** comparison,the data obtained from the Guliya ice core in this area also corresponds to the global glacial climatic characteristics recorded in basin sediments in the eastern and southeastern regions of the plateau and to the information obtained from ice cores in the Antarctic and Arctic *** this study,we conclude that the main reason for the glaciations and new tectonic movement must be a geomagnetic polarity reversal 774 thousand years ago(from Matuyama to Brunhes).Indeed,the results of this study suggest that the described reversal event might have influenced the current global climate pattern and will continue to impact climatic changes in the future.

关键词： glacial record global climate change geomagnetic polarity reversal middle Pleistocene western Tibetan Plateau

Damage Spreading in Neural Network with Local Connection and Cycle Stored Patterns

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Chinese Physics Letters 1996年第9期13卷 644-647页

作者： ji Dao-yun CHEN Tian-lun Department of Physics Nankai UniversityTianjin 300071

The simulation results of damage spreading show the happening of dynamical chaotic-frozen phase transition in a one-dimensional system,a neural network with cycle stored patterns and local *** chaotic phase,the averag... 详细信息

关键词： behavior chaotic dynamical

A New Sufficient Degree Condition for a Graphic Sequence to Be Forcibly k-Edge-Connected

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Acta Mathematicae Applicatae Sinica 2022年第1期38卷 223-228页

作者： jian-hua YIN ji-yun GUO School of Science Hainan UniversityHaikou 570228China

A graphic sequence π =(d1, d2,..., dn) is said to be forcibly k-edge-connected if every realization of π is k-edge-connected. In this paper, we obtain a new sufficient degree condition for π to be forcibly k-edgeconnected. We also show that this new sufficient degree condition implies a strongest monotone degree condition for π to be forcibly 2-edge-connected and a conjecture about a strongest monotone degree condition for π to be forcibly 3-edge-connected due to Bauer et al.(Networks, 54(2)(2009) 95-98), and also implies a strongest monotone degree condition for π to be forcibly 4-edge-connected.

关键词： graphic sequence forcibly k-edge-connected graphic sequence a strongest monotone degree condition

Nitrogen release and re-adsorption dynamics on crop straw residue during straw decomposition in an Alfisol

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Journal of Integrative Agriculture 2021年第1期20卷 248-259页

作者： LI ji-fu ZHONG Fang-fang Engineering Research Center of Ecology and Agricultural Use of Wetland Ministry of Education/College of AgricultureYangtze UniversityJingzhou 434025P.R.China

Returning crop straw to the field not only improves the nitrogen(N) supplying capacity and N retention of soil but also decreases the amount of rural organic waste and prevents air pollution. Therefore, understanding the mechanisms of the N release and re-adsorption dynamics on crop straw residue during straw decomposition in agricultural soil is important, and this understanding can help us strengthen N fertilizer management during the crop growth period. An on-farm incubation experiment was conducted in the jianghan Plain in Central China under flooded conditions using the nylon mesh bag method. Results showed that the decomposition rate of crop straw was much faster at the beginning of the incubation stage, whereas it was steady during the later stage with no observed differences among the three types of crop straw. After 120 d of incubation, the cumulative decomposition proportion of rice straw, wheat straw and rape straw was 72.9, 56.2, and 66.9%, respectively. The proportion of N that released from the three crop straws was 52.0, 54.4 and 54.9%, respectively. The zeta potentials and Brunauer, Emmett and Teller(BET) surface area of the rice, wheat and rape straw residues increased gradually as the decomposition period progressed. The water adsorption capacity of the rice straw was significantly affected during the decomposition period. The saturated water adsorption capacity of rice straw was the highest at 30 d of decomposition(4.17 g g^–1) and then decreased slightly. The saturated water adsorption of wheat and rape straws reached the lowest value at 30 d and then gradually increased and became stable. All the results demonstrated that crop straw and straw residue can re-adsorb NH4^+ ions from the surrounding solution. The re-adsorption was affected by the decomposition period and concentration of exogenous NH4^+ and was independent of the crop species via the combined efforts of physical and chemical adsorption, ion exchange and water retention on residue su

关键词： adsorption decomposition nitrogen(N) Alfisol straw substrate

Dual Thermal-and p H-responsive Polypeptide-based Hydrogels

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Chinese Journal of Polymer Science 2017年第10期35卷 1243-1252页

作者： fan-dong meng yun-xia ni si-fan ji xiao-hui fu yu-han wei 孙静李志波 School of Polymer Science and Engineering Qingdao University of Science and Technology Qingdao 266042 China

Smart hydrogels have received increasing attention for their great potential for the applications in many fields. Herein, we report a facile approach to prepare a class of dual-responsive hydrogels assembled from synthetic statistical/block thermal-responsive copoly（L-glutamate）s copolymerized with poly（ethylene glycol）, which were prepared by ring-opening polymerization（ROP） and post-modification strategy. The incorporation of oligo（ethylene glycol）（OEG） and glutamic acid residues offers the gels with thermal-and p H-responsive properties simultaneously. We have systematically studied the influence of both temperature and p H on the gelation behaviors of these copolymers. It is found that the increase of glutamic acid content and solution p H values can significantly suppress the gelation ability of the samples. Circular dichroism（CD） results show that the α-helix conformation appears to be the dominant secondary conformation. More interestingly, the gelation property of the block copolymer with statistical thermal-responsive copoly（L-glutamate）s shows greater dependence on p H as compared to that with block segments due to the distinct morphology of the self-assemblies. The obtained hydrogels exhibit p H-dependent and thermal-responsive gelation behaviors, which enable them as an ideal smart hydrogel system for biomedical applications.

关键词： links chains bonds hierarchical ferric tensile hydrogel healing polymerization fabricate

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Finite NPDM-groups

Acta Mathematica Sinica,English Series 2021年第2期37卷 306-314页

作者： jian ji CAO Xiu yun GUO School of Applied Mathematics Shanxi University of Finance and EconomicsTaiyuan 030006P.R.China Department of Mathematics Shanghai UniversityShanghai 200444P.R.China

In this paper the classification is given for finite groups in which the normalizer of every non-normal cyclic subgroup of order divided by the minimal prime of |G| is a maximal subgroup.

关键词： Normalizer cyclic subgroup maximal subgroup

Fission law of solitary waves propagating over sharply variable topography

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Journal of Hydrodynamics 2020年第4期32卷 727-734页

作者： Da-lin Tan ji-fu Zhou Xu Wang Key Laboratory for Mechanics in Fluid Solid Coupling Systems Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Sciences University of Chinese Academy of SciencesBeijing 100049China

The fission of solitary waves propagating over variable topography is *** previous theories,to predict the number and the amplitudes of disintegrated solitons in the wave packet generated from a solitary wave,the parameters of the water environment and the incident solitary wave are ***,it is difficult to measure these parameters in the ocean because of their temporal and spatial *** this paper,a fission law,in the form of the expressions of the number and the amplitudes of the disintegrated solitons,is derived from the partial information available on the wave *** analysis shows that the law is suitable fbr describing the fission of both surface and internal solitary waves and is also applicable to the cases of wave damping and wave *** between the model output and the results from laboratory experiments,numerical simulations and field observations available in the literature demonstrate that the fission law can efficiently estimate the number and the amplitudes of solitons in the wave packet generated by a solitary wave.

关键词： Fission law solitary wave packet wave breaking

In-situ ZrB2-hBN ceramics with high strength and low elasticity

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Journal of Materials Science & Technology 2020年第13期47卷 186-193页

作者： ji Zou Guo-Jun Zhang Zheng-Yi fu State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan430070China School of Metallurgy and Materials University of BirminghamB152TTBirminghamUK State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Institute of Functional MaterialsDonghua UniversityShanghai 201620China

ZrB2 ceramics with various hexagonal BN(hBN)additions up to 37 vol%were reactively densified by spark plasma sintering using powder mixtures containing ZrB2,ZrN and ***-boron based additives effectively promoted the densification process,ZrB2 ceramics reached>99%relative density at 2000℃and an applied pressure of 60 MPa with only 5 vol%in-situ formed hBN,whereas the relative density of pure ZrB2 was only 91.2%at the same *** thehBN contents,the morphology of hBN grains gradually changed from quasi-spherical to flake dominated,which has substantial influence on their mechanical ***-situ ZrB2-10 vol%hBN ceramics demonstrated high flexural strength of 597±22 MPa,relatively low Young’s modulus of 406 GPa and good machinability,especially for the impressively large strain to failure(1.47×10^-3)which is superior to most of their counterparts in the ZrB2 based particulate reinforced ceramics.

关键词： ZrB2 Reactive sintering Spark plasma sintering Boron nitride containing ceramics Mechanical property

Distributed Fiber Birefringence Measurement Using Pulse-CompressionФ-OTDR

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Photonic Sensors 2021年第4期11卷 402-410页

作者： Yongxiang CHEN yun fu ji XIONG Zinan WANG Key Lab of Optical Fiber Sensing&Communications University of Electronic ScienceTechnology of ChinaChengdu 611731China

In this paper,a novel birefringence measurement method through the Rayleigh backscattered lightwave within single-mode fiber is proposed,using a single chirped-pulse with arbitrary state of *** analysis is carried out in detail,then pulse-compression phase-sensitive optical time domain reflectometry(PC-O-OTDR)with polarization-diverse coherent detection is employed to verify this method.A 2 km spun single-mode fiber is tested with 8.6cm spatial resolution,and the average birefringence of the fiber under test is measured as 0.234rad/m,which is consistent with previous literatures about single-mode ***,the relationship between the measured birefringence and the spatial resolution is also studied for the first time,and the results show that spatial resolution is crucial for fiber birefringence measurement.

关键词： Birefringence Rayleigh scattering pulse-compression phase-sensitive optical time-domain reflectometiy coherent detection polarization-diverse receiver