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Tomographic Imaging of the India-Asia Plate Collisional Tectonics and Mantle Upwelling Beneath Western Tibet

Acta Geologica Sinica(English Edition) 2020年第4期94卷 1159-1166页

作者： ZHENG Hongwei LI Tingdong HE Rizheng YANG hui niu xiao ZOU Changqiao Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China Chinese Academy of Geological Sciences Beijing 100037China Institute of Geophysics China Earthquake AdministrationBeijing 100081China Southern University of Science and Technology Shenzhen 518055China

To better understand the lithosphere mantle collision tectonics between the India plate and Asia plate, we determine three dimensional P wave velocity structure beneath western Tibet using 27,439 arrival times from 2,174 teleseismic events recorded by 182 stations of Hi-CLIMB Project and 16 stations in the north of Hi-CLMB. Our tomographic images show the velocity structure significantly difference beneath northern and southern Qiangtang, which can further prove that the Longmu Co-Shuanghu ophiolitic belt is a significant tectonic boundary fault zone. There are two prominent high velocity anomalies and two prominent low velocity anomalies in our images. One obvious high velocity anomalies subduct beneath the Tibet at the long distance near 34°N, whereas it is broke off by an obvious low velocity anomaly under the IYS. We interpret them as northward subducting Indian lithosphere mantle and the low velocity anomanly under IYS likely reflects mantle material upwelling triggered by tearing of the northward subduction Indian lithosphere. The other prominent high velocity anomaly was imaged at a depth from 50 km to 200 km horizontal and up to the northern Qiangtang with its southern edge extending to about 34°N through Hoh Xil block. We infer it as the southward subducting Asia lithosphere mantle. The other widely low velocity anomaly beneath the Qiangtang block lies in the gap between the frontier of India plate and Asia plate, where is the channel of mantle material upwelling.

关键词： seismic tomography southward subduction of Asia lithosphere mantle northward subduction of Tibet lithosphere mantle Longmu Co-Shuanghu tectonic boundary zone

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Bose-Einstein condensates in an eightfold symmetric optical lattice

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Chinese Physics B 2020年第5期29卷 400-405页

作者： Zhen-xia niu Yong-Hang Tai Jun-Sheng Shi Wei Zhang Department of Physics Renmin University of ChinaBeijing 100872China Yunnan Key Laboratory of Optoelectronic Information Technology Yunnan Normal UniversityKunming 650500China Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices Renmin University of ChinaBeijing 100872China

We investigate the properties of Bose-Einstein condensates(BECs)in a two-dimensional quasi-periodic optical lattice(OL)with eightfold rotational symmetry by numerically solving the Gross-Pitaevskii *** a stationary external harmonic trapping potential,we first analyze the evolution of matter-wave interference pattern from periodic to quasiperiodic as the OL is changed continuously from four-fold periodic to eight-fold *** also investigate the transport properties during this evolution for different interatomic interaction and lattice depth,and find that the BEC crosses over from ballistic diffusion to ***,we focus on the case of eightfold symmetric lattice and consider a global rotation imposed by the external trapping *** BEC shows vortex pattern with eightfold symmetry for slow rotation,becomes unstable for intermediate rotation,and exhibits annular solitons with approximate axial symmetry for fast *** results can be readily demonstrated in experiments using the same configuration as in ***.122110404(2019).

关键词： quasicrystals Bose-Einstein condensates quantum transport vortex and soliton

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Super-Resolution Track-Density Imaging Reveals Fine Anatomical Features in Tree Shrew Primary Visual Cortex and Hippocampus

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Neuroscience Bulletin 2018年第3期34卷 438-448页

作者： Jian-Kun Dai Shu-xia Wang Dai Shan Hai-Chen niu Hao Lei National Center for Magnetic Resonance in Wuhan State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathe-matics Chinese Academy of Sciences Wuhan 430071 China Institute of Neuroscience Chinese Academy of SciencesShanghai 200031 China Xuzhou Medical University Xuzhou 221004 China Britton Chance Center for Biomedical Photonics Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 China

Diffusion-weighted magnetic resonance imaging（d MRI） is widely used to study white and gray matter（GM） micro-organization and structural connectivity in the brain. Super-resolution track-density imaging（TDI） is an image reconstruction method for d MRI data, which is capable of providing spatial resolution beyond the acquired data, as well as novel and meaningful anatomical contrast that cannot be obtained with conventional reconstruction methods. TDI has been used to reveal anatomical features in human and animal brains. In this study, we used short track TDI（st TDI）, a variation of TDI with enhanced contrast for GM structures, to reconstruct directionencoded color maps of fixed tree shrew brain. The results were compared with those obtained with the traditional diffusion tensor imaging（DTI） method. We demonstrated that fine microstructures in the tree shrew brain, such as Baillarger bands in the primary visual cortex and the longitudinal component of the mossy fibers within the hippocampal CA3 subfield, were observable with st TDI,but not with DTI reconstructions from the same d MRI *** possible mechanisms underlying the enhanced GM contrast are discussed.

关键词： Track-density imaging Diffusion tensor imaging Tree shrew Primary visual cortex Hippocampus

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Phase equilibrium data prediction and process optimizationin butadiene extraction process

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Chinese Journal of Chemical Engineering 2024年第7期71卷 1-12页

作者： Baowei niu Yanjie Yi Yuwen Wei Fuzhen Zhang Lili Wang Li xia xiaoyan Sun Shuguang xiang Institute of Process System Engineering College of Chemical EngineeringQingdao University of Science and TechnologyQingdao 266042China

In response to the lack of reliable physical parameters in the process simulation of the butadiene extraction,a large amount of phase equilibrium data were collected in the context of the actual process of butadiene production by *** accuracy of five prediction methods,UNIFAC(UNIQUAC Functional-group Activity Coefficients),UNIFAC-LL,UNIFAC-LBY,UNIFAC-DMD and COSMO-RS,applied to the butadiene extraction process was verified using partial phase equilibrium *** results showed that the UNIFAC-DMD method had the highest accuracy in predicting phase equilibrium data for the missing ***-RS-predicted multiple systems showed good accuracy,and a large number of missing phase equilibrium data were estimated using the UNIFAC-DMD method and COSMO-RS *** predicted phase equilibrium data were checked for *** NRTL-RK(non-Random Two Liquid-Redlich-Kwong Equation of State)and UNIQUAC thermodynamic models were used to correlate the phase equilibrium *** device simulations were used to verify the accuracy of the thermodynamic model applied to the butadiene extraction *** simulation results showed that the average deviations of the simulated results using the correlated thermodynamic model from the actual values were less than 2%compared to that using the commercial simulation software,Aspen Plus and its *** average deviation was much smaller than that of the simulations using the Aspen Plus database(>10%),indicating that the obtained phase equilibrium data are highly accurate and *** best phase equilibrium data and thermodynamic model parameters for butadiene extraction are *** improves the accuracy and reliability of the design,optimization and control of the process,and provides a basis and guarantee for developing a more environmentally friendly and economical butadiene extraction process.

关键词： Butadiene extraction Phase equilibrium data Prediction methods Thermodynamic modeling Process simulation

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Stimulated by retinoic acid gene 8 （Stra8） plays important roles in many stages of spermatogenesis

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Asian Journal of Andrology 2018年第5期20卷 479-487页

作者： Hai-Tao Ma Chang-Min niu Jing xia Xue-Yi Shen Meng-Meng xia Yan-Qiu Hu Ying Zheng Department of Histology and Embryology School of Medicine Yangzhou University Yangzhou 225001 China Jiangsu Key Laboratory of Experimental and Translational Noncoding RNA Research Yangzhou 225001 China Clinicial Medical College Yangzhou University Yangzhou 225001 China

To clarify the functions and mechanism of stimulated by retinoic acid gene 8 （Stra8） in spermatogenesis, we analyzed the testes from Stra8 knockout and wild-type mice during the first wave of spermatogenesis. Comparisons showed no significant differences in morphology and number of germ cells at 11 days postpartum, while 21 differentially expressed genes （DEGs） associated with spermatogenesis were identified. We speculate that Stra8 performs many functions in different phases of spermatogenesis, such as establishment of spermatogonial stem cells, spermatogonial proliferation and self-renewal, spermatogonial differentiation and meiosis, through direct or indirect regulation of these DEGs. We therefore established a preliminary regulatory network of Stra8 during spermatogenesis. These results will provide a theoretical basis for further research on the mechanism underlying the role of Stra8 in spermatogenesis.

关键词： differentiation meiosis proliferation spermatogenesis spermatogonia Stra8

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Dynamical nonlinear excitations induced by interaction quench in a two-dimensional box-trapped Bose-Einstein condensate

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Chinese Physics B 2024年第2期33卷 209-215页

作者：牛真霞高超 Department of Physics Zhejiang Normal UniversityJinhua 321004China Key Laboratory of Optical Information Detection and Display Technology of Zhejiang Zhejiang Normal UniversityJinhua 321004China

Manipulating nonlinear excitations,including solitons and vortices,is an essential topic in quantum many-body physics.A new progress in this direction is a protocol proposed in[***.2043256(2020)]to produce dark solitons in a one-dimensional atomic Bose–Einstein condensate(BEC)by quenching inter-atomic *** by this work,we generalize the protocol to a two-dimensional BEC and investigate the generic scenario of its post-quench *** an isotropic disk trap with a hard-wall boundary,we find that successive inward-moving ring dark solitons(RDSs)can be induced from the edge,and the number of RDSs can be controlled by tuning the ratio of the after-and before-quench interaction strength across different critical *** role of the quench played on the profiles of the density,phase,and sound velocity is also *** to the snake instability,the RDSs then become vortex–antivortex pairs with peculiar dynamics managed by the initial density and the after-quench *** tuning the geometry of the box traps,demonstrated as polygonal ones,more subtle dynamics of solitons and vortices are *** proposed protocol and the discovered rich dynamical effects on nonlinear excitations can be realized in near future cold-atom experiments.

关键词： Bose-Einstein condensate quench interaction soliton vortex

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Effect of the frequency of high-angle grain boundaries on the corrosion performance of 5wt%Cr steel in a CO2 aqueous environment

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International Journal of Minerals,Metallurgy and Materials 2018年第3期25卷 315-324页

作者： hui-bin Wu Tao Wu Gang niu Tao Li Rui-yan Sun Yang Gu Collaborative Innovation Center of Steel Technology University of Science and Technology Beijing Beijing 100083 China National Engineering Research Center of Advanced Rolling University of Science and Technology Beijing Beijing 100083 China Survey and Design Institute of Jilin Oilfield Company Jilin 138000 China

The corrosion behavior of 5 wt%Cr steel tempered at different temperatures was investigated by immersion testing and electrochemical testing in a CO_2 aqueous environment. When the tempering temperature exceeded 500℃, the corrosion rate increased. The corrosion layers consisted of Cr-rich compounds, which affected the corrosion behaviors of the steels immersed in the corrosive solution. The results of electrochemical experiments demonstrated that 5 wt%Cr steels with different microstructures exhibited pre-passivation characteristics that decreased their corrosion rate. Analysis by electron back-scattered diffraction showed that the frequency of high-angle grain boundaries(HAGBs) and the corrosion rate were well-correlated in specimens tempered at different temperatures. The corrosion rate increased with increasing HAGB frequency.

关键词： chromium steel grain boundaries microstructure corrosion performance tempering temperature

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Research on Reservoir Landslide Thrust Based on Improved Morgenstern-Price Method

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Journal of Earth Science 2024年第4期35卷 1263-1272页

作者： Xuan Wang Xinli Hu Chang Liu Lifei niu Peng xia Jian Wang Jiehao Zhang Faculty of Engineering China University of GeosciencesWuhan430074China

The curve of landslide thrust plays a key role in landslide *** commonly used transfer coefficient method(TCM)and Morgenstern-Price method(MPM)are *** does not take into account the moment balance between *** MPM considers the moment balance,the calculation is complex,and it does not consider that the force between slices may be less than zero at the back edge of the *** rationality and feasibility of the improved MPM are verified by calculating the landslide stability coefficient and landslide thrust at different reservoir water *** paper studies the law of landslide thrust when the reservoir water level changes,and discusses the determination of design thrust,to provide a certain theoretical basis for the design of reservoir landslides.

关键词： reservoir transfer coefficient method Morgenstern-Price landslide thrust design thrust landslides

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Dynamic Changes of Chemical and Mechanical Properties of Moso Bamboo (Phyllostachys edulis) Culms under Different Storage Conditions

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Journal of Renewable Materials 2021年第5期9卷 1031-1043页

作者： hui Zhan Zhaohui niu Lixia Yu Maobiao Li Changming Wang Shuguang Wang Southwest Forestry University Kunming650224China APFNet Kunming Training Center Kunming650224China

The durability of bamboo based on its chemical and mechanical properties is a crucial consideration for the wood-based industry due to its vulnerability to insects and *** investigated the dynamic changes of chemical and mechanical properties of Phyllostachys edulis under air-dry and water storage conditions for 3,6 and 12 months *** chemical properties of *** bamboo culms varied with culm age but insignificantly with culm *** mechanical properties of *** culms showed an increasing trend with culm *** storage condition decreased the ash,SiO2 and lignin content,but increased the ethanol-benzene *** also created an anaerobic environment for bamboo culms in which only anaerobic respiration was possible contributing to reducing the content of soluble sugar and starch,thereby beneficial for decreasing the damage from insects and ***,the water storage conditions could maintain culm mechanical performance ***,the indigenous practice of local people to store bamboo culms in ponds has good science behind it and water storage practices of bamboo culms was recommended.

关键词： Phyllostachys edulis chemical properties mechanical properties storage conditions

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A study on the catalytic performance of carbide slag in transesterification and the calculation of kinetic parameters

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Science China(Technological Sciences) 2015年第2期58卷 258-265页

作者： LIU Meng Qi niu Sheng Li LU Chun Mei LI hui HUO Meng Jia School of Energy and Power Engineering Shandong University

The catalytic performance of carbide slag in transesterification is investigated and the reaction kinetic parameters are calculated. After being activated at 650℃, calcium compounds of carbonate and hydroxide in the carbide slag are mainly transformed into calcium oxide. The activated carbide slag utilized as the transesterification catalyst is characterized by X-ray diffraction （XRD）, attenuated total reflectance-Fourier transform infrared spectroscopy （ATR-FTIR）, nitrogen adsorption-desorption and the Hammett indicator method. Compared with the carbide slag activated at 700 and 800℃, the largest surface area of 22.63 m2g^-1, the smallest particle size of 265.12 nm and the highest catalytic efficiency of the carbide slag activated at 650℃ guarantee its capacity in catalyzing transesterification. Then, the influences of activated temperature （Ta）, molar ratio of methanol to oil （γ）, catalyst added amount （ζ）, reaction temperature （Tr） and reaction time （τ） on the catalytic performance are investi- gated. Under the optimal transesterification condition of Ta=650℃, γ=15, ζ=3%, Tr=60℃ and τ=-110 rain, the catalytic efficiency of 92.98% can be achieved. Finally, the kinetic parameters of transesterification catalyzed by the activated carbide slag are calculated, where activation energy （E） is 68.45 kJ mol^-1 and pre-exponential factor （k0） is 1.75×10^9 min^-1. The activated carbide slag shows better reused property than calcium hydroxide.

关键词： transesterification catalyst carbide slag kinetic parameters

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