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Localization of normalized solutions for saturable nonlinear Schr?dinger equations

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Science China Mathematics 2023年第11期66卷 2495-2522页

作者： Xiaoming Wang zhi-qiang Wang Xu Zhang School of Mathematics&Computer Science Shangrao Normal UniversityShangrao 334001China College of Mathematics and Statistics Fujian Normal UniversityFuzhou 350117China Department of Mathematics and Statistics Utah State UniversityLoganUT 84322USA School of Mathematics and Statistics Central South UniversityChangsha 410083China

In this paper,we study the existence and concentration behavior of the semiclassical states with L2-constraints for the following saturable nonlinear Schr?dinger equation:-ε2Δv+Γ(I(x)+v^(2))/(1+I(x)+v^(2))v=λv for x∈*** a negatively large coupling constantΓ,we show that there exists a family of normalized positive solutions(i.e.,with the L2-constraint)whenεis small,which concentrate around local maxima of the intensity function I(x)asε→*** also consider the case where I(x)may tend to-1 at infinity and the existence of multiple *** proof of our results is variational and the novelty of the work lies in the development of a new truncation-type method for the construction of the desired solutions.

关键词： saturable nonlinear Schrodinger equation normalized solutions semiclassical states local maximum potential

The stable planar conformation of the γ-butyrolactone ring in solution

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Chinese Chemical Letters 2010年第2期21卷 187-190页

作者： zhi qiang Feng Cheng Lie Yin Institute of Materia Medica Chinese Academy of Medical Sciences Beijing 100050 China Department of Chemistry Beijing Normal University Beijing 100875 China

The conformations ofγ-butyrolactone ring in solution were deduced on the basis of ~1H NMR spectra of geminal protons of the butyrolactone ring.A series of optically pure(Z)-(-)-4-(1 -alkoxyl-1 -carbalkoxy-methylene)-... 详细信息

关键词： β-Methylene-γ-butyrolactone Planar conformation Envelope conformation

Achieving strength-ductility synergy in a non-equiatomic Cr_(10)Co_(30)Fe_(30)Ni_(30)high-entropy alloy with heterogeneous grain structures

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Rare Metals 2022年第8期41卷 2864-2876页

作者： Chen-Liang Chu Wei-Ping Chen Jun-Chen Liu qiang Chen zhi-qiang Fu Guangdong Key Laboratory for Advanced Metallic Materials Processing South China University of TechnologyGuangzhou510641China Southwest Technology and Engineering Research Institute Chongqing400039China

Cold rolling and post-deformation annealing(PDA)heat treatments were used to produce heterogeneous grain structures(HGS)in a single-phase face-centered cubic(fcc)Cr_(10)Co_(30)Fe_(30)Ni_(30)high-entropy alloy(HEA).The microstructural evolution and microstructure-property relationship of the HEA were systematically studied under different *** could be achieved in PDA-treated samples at 875℃for 20 s and at 900℃for 20 s(PDA-900-20 s).PDA-900-20 s sample exhibits the most excellent combination of strength and ductility,showing a tensile yield strength of~590 MPa,an ultimate strength of~706 MPa and a total elongation of~23.9%.Additionally,compared with the homogenized counterpart exhibiting homogenous grains,PDA-900-20 s sample displays a notable increment of~413%in yield strength and simultaneously maintains a good *** dominated strengthening mechanisms in PDA-900-20 s sample are grain-boundary strengthening and heterogeneous deformation-induced(HDI)strengthening,whereas the good ductility is mainly resulted from the HDI ***,the present study provides an effective and simple pathway to overcome the strength-ductility tradeoff of typical fcc HEAs through heterogeneous microstructure.

关键词： High-entropy alloy Heterogeneous grain structures Hetero-deformation-induced hardening Mechanical properties Strengthening mechanism

Measuring the Distance of VX Sagittarii with SiO Maser Proper Motions

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Chinese Journal of Astronomy and Astrophysics 2007年第4期7卷 531-538页

作者： Xi Chen zhi-qiang Shen Ye Xu Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 Department of Earth Sciences National Taiwan Normal University 88 Sec. 4 Ting-Chou Rd. Taipei 116 Taiwan

We report on 43 GHz v=1, J=1-0 SiO maser proper motions in the circumstellar envelope of the M-type semi-regular variable star VX Sgr, observed by Very Long Baseline Array （VLBA） at 3 epochs during 1999 April-May. Applying the statistical parallax analysis to these proper motions, we estimated a distance of VX Sgr of 1.57±0.27kpc, which is consistent with that based on the proper motions of H20 masers, or on the assumption that VX Sgr belongs to the Sgr OB1 association. At this distance, VX Sgr can be classified as a red supergiant. Comparing the statistical parallax method with those of model fitting and annual parallax, we think that the statistical parallax method may be a good way of estimating SiO maser distances at present.

关键词： methods: statistical - masers -stars: individual (VX Sgr)- stars: distances

A Composite Model for GHz Peaked Spectra of Radio Sources

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Chinese Journal of Astronomy and Astrophysics 2005年第6期5卷 563-570页

作者： Jun Yang Xiang Liu zhi-qiang Shen National Astronomical Observatories/Urumqi Observatory Chinese Academy of Sciences Urumqi 830011 Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 Graduate University of the Chinese Academy of Sciences Beijing 100049

GHz-Peaked Spectrum （GPS） radio sources are powerful and compact sources with convex spectra. With increasing observational findings, it has been realized that either Synchrotron Self-Absorption （SSA） alone or Free-Free Absorption （FFA） alone is not enough to account for all the spectral features. We present a model consisting of an SSA region partially covered by FFA plasma, and derive a composite spectral formula. By applying the model to a sample of 19 GPS sources having strong absorption, it is found that the external FFA process makes the SSA peak frequency linearly shift to a higher （observed） peak frequency. The shift indicates that the FFA does play a role at the frequency close to the observed peak frequency.

关键词： radio continuum: galaxies -- galaxies: active -- quasars: general

Risk Assessment of Highways Affected by Debris Flows in Wenchuan Earthquake Area

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Journal of Mountain Science 2013年第2期10卷 173-189页

作者： CUI Peng XIANG Ling-zhi ZOU qiang Institute of Mountain Hazards and Environment/Key Laboratory of Mountain Hazards and Earth Surface Process Chinese Academy of Sciences Chongqing Jiaotong University Graduate University Chinese Academy of Sciences College of Environmental and Resource Southwest University of Science and TechnologyChina

Since the Wenchuan earthquake in China on May 12th, 2008, highways in earthquake-affected areas have been frequently interrupted by debris flows. We analyzed the hazard effect modes and damage processes along highways and developed three key indexes, scale of debris flows, deposits on highways and river blockage, to describe quantitatively the highway disasters. By combining the empirical methods and the actual terrain conditions, we proposed new methods to determine the value of hazard indexes. In addition, we used the economic value and resistance of highway as vulnerability assessment indexes, then determined the specific subindexes for the subgrade, bridges and culverts, and developed a way for the quantified vulnerability zoning. Moreover, we proposed the assessment and mapping methods for highway risk. The risk is described into 5 grades： extremely low risk, low risk, middle risk, high risk and extremely high risk. We applied these methods in a case study carried out on provincial highway S3o3 from Yingxiu Town to Wolong Town, in Wenchuan County. Analysis of debris flow risk for the whole highway, showed that the total length of highway in extremely low risk area was 28.26 km, 4.83 km in low risk area, 8.0 km in middle risk area, 3.65 km in high risk area, and 3.06 km in extremely high risk area. The assessment results are consistent with the field survey data which reflected the disaster situation. This risk method can be used objectively to evaluate the debris-flow risk along highways, and is useful for highway reconstruction in mountainous areas suffering from active debris flows.

关键词： Debris flow Highway disaster Hazardanalysis Vulnerability analysis Risk analysis Wenchuan earthquake

Simulation of γ spectrum-shifting based on the parameter adjustment of Gaussian function space

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Nuclear Science and Techniques 2013年第6期24卷 99-104页

作者： HUANG Hongquan SHAO qiang DING Weicheng fang fang GONG Dichen Applied Nuclear Techniques in Geosciences Key Laboratory of Sichuan Province Chengdu University of Technology Drilling Engineering Research institute of southwest Petroleum Engineering Company SINOPEC

Based on the statistical characteristics of energy spectrum and the features of spectrum-shifting in spectrometry,the parameter adjustment method of Gaussian function space was applied in the simulation of *** transient characteristics of energy spectrum were described by the Gaussian function space,and then the Gaussian function space was transferred by parameter adjustment ***,the spectrum-shifting in measurement of energy spectrum was *** applied example shows that the parameters can be adjusted flexibly by this method to meet the various requirements in simulation of energy *** method was one parameterized simulation method with good performance for the practical application.

关键词：高斯函数参数调整空间仿真基础 γ谱仿真应用函数空间模拟方法

High-pressure synergetic measurement station(HP-SymS)

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Chinese Physics B 2018年第7期27卷 8-19页

作者： Xiaohui Yu fangfei Li Yonghao Han fang Hong Changqing Jin zhi He qiang Zhou Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China

In the High-Pressure Synergetic Measurements Station （HP-SymS） of the Synergic Extreme Condition User Facility （SECUF）, we will develop ultrahigh-pressure devices based on diamond-anvil cell （DAC） techniques, with a target pressure up to 300 GPa. With the use of cryostat and magnet, we will reach 300 GPa4.2 K-9 T and conduct simultaneous measurements of the electrical-transport property and Raman/Brillouin spectrascopy. With resistance heating and laser heating, we will reach temperatures of at least 1000 and 3000 K, respectively, coupled with Raman/Brillouin spectroscopy measurements. Some designs of supporting devices, such as a femtosecond laser gasket-drilling device, electrode-deposition device, and the gas-loading device, are also introduced in this article. Finally, we conclude by providing some perspectives on the applications of the DAC in related research fields.

关键词： high pressure synergetic measurements diamond-anvil cell (DAC)

Deactivation Effect Caused by Catalyst-Cocatalyst Pre-contact in Propylene Polymerization with MgCl2-supported Ziegler-Natta Catalyst

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Chinese Journal of Polymer Science 2019年第10期37卷 1023-1030,I0005页

作者： Zhen Zhang Bai-Yu Jiang Biao Zhang zhi-Sheng Fu zhi-qiang Fan Ministry of Education Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University

Propylene slurry polymerization with a MgCl2-supported Ziegler-Natta catalyst containing internal electron donor was conducted after different durations of pre-contact of the catalyst with triethylaluminum cocatalyst. The number of active centers([C*]/[Ti])was determined by quenching the polymerization with 2-thiophenecarbonyl chloride and measuring sulfur content in the polymer. The pre-contact treatment caused selective deactivation of a part of active centers with low stereoselectivity and much lower activity in the initial stage of polymerization as compared with the polymerization run without the pre-contact stage. The active center concentration and polymerization activity decreased with prolonging of the pre-contact stage. The proportion of stereoselective active centers was increased by prolonging the pre-contact stage, so the isotacticity of produced polypropylene was enhanced. Release of active centers through catalyst particle fragmentation was significantly retarded, and the polymerization rate curve changed from decay type to induction type by the precontact treatment. In the induction period both non-stereoselective and stereoselective active centers were released and activated, resulting in gradual reduction of the polymer’s isotacticity in the first 5-10 min of polymerization. Selective deactivation of non-stereoselective active centers also took place in propylene polymerization using the catalyst without pre-contacting with the cocatalyst. In this case, the polymerization rate decayed with time after a short induction period of 2-5 min. Over reduction of the active center precursors with low stereoselectivity by triethylaluminum was considered as the reason for their deactivation during the pre-contact or the polymerization processes.

关键词： Propylene Polymerization Supported Ziegler-Natta catalyst Cocatalyst Pre-contact