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Phase diagram,correlations,and quantum critical point in the periodic Anderson model

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Chinese Physics B 2018年第3期27卷 362-367页

作者： Jian-Wei Yang Qiao-ni chen Department of Physics Beijing Normal University Beijing 100875 China

Periodic Anderson model is one of the most important models in the field of strongly correlated electrons. With the recent developed numerical method density matriX embedding theory, we study the ground state properties of the periodic Anderson model on a two-dimensional square lattice. We systematically investigate the phase diagram away from half filling. We find three different phases in this region, which are distinguished by the local moment and the spin-spin correlation functions. The phase transition between the two antiferromagnetic phases is of first order. It is the so-called Lifshitz transition accompanied by a reconstruction of the Fermi surface. As the filling is close to half filling, there is no difference between the two antiferromagnetic phases. From the results of the spin-spin correlation, we find that the Kondo singlet is formed even in the antiferromagnetic phase.

关键词： periodic Anderson model Kondo singlet states density matrix embedding theory

Influence of topography,soil properties and plant community on the biomass of Abies georgei *** seedlings in Southeast Tibet

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Journal of Mountain Science 2022年第9期19卷 2664-2677页

作者： ZHANG Xin-sheng ZHOU chen-ni LU Jie Institute of Tibet Plateau Ecology Tibet Agricultural&Animal Husbandry UniversityNyingchi 860000China Key Laboratory of Forest Ecology in Tibet Plateau Tibet Agricultural&Animal Husbandry UniversityMinistry of EducationNyingchi 860000China Linzhi National Forest Ecosystem Observation&Research Station of Tibet Nyingchi 860000China Key Laboratory of Alpine Vegetation Ecological Security in Tibet Nyingchi 86000China

Biomass of seedlings at different developing stages of growth is important information for studying the response of species to site *** objectives of this study was to explore the distribution characteristics of AGB(above-ground biomass)and BGB(below-ground biomass)of Abies georgei *** seedlings of different ages,and investigate the effects of topography(slope aspect,altitude),plant community characteristics(crown density,species diversity,etc.),and soil properties(soil physical and chemical properties)on the biomass and its *** in five age classes(1–2,3–4,5–6,7–8,and 9–10 years old)were collected by full excavation from 6 elevations(3800 m,3900 m,4000 m,4100 m,4200 m,4300 m)on the north and south slopes of Sejila Mountain in Tibet.15seedlings of each age class were investigated at one *** individual effects of seedling age(SA)and the interaction effects of SA,slope aspect(SL),and elevation(EG),namely,SL×EG,SL×SA,EG×SA,and SL×EG×SA,had significant effects on the AGB of the seedlings(pnificantly affected by SA(p<0.001).The AGB and BGB of the seedlings showed a binomial growth trend with the increase in seedling age,and had an allometric relationship at different elevations,α(allometric exponential)varied from 0.913 to 1.046 in the northern slope,and from 1.004 to 1.268 in the southern *** biomass of seedlings on the northern slope was remarkably affected by stand factors,with a contribution rate of 47.8%,whereas that on the southern slope was considerably affected by soil factors with a contribution rate of 53.2%.The results showed that age was the most important factor affecting seedling *** allometric pattern of seedling biomass was relatively stable,but in a highaltitude habitat,*** *** seedlings increased the input of *** seedling biomass allocation and its influencing factors is useful for evaluating plants’ability to acquire resources and surviv

关键词： Biomass allocation Allometric relationship Stand characteristic Soil factors Abies georgei var.smithii seedlings Sejila Mountain,Tibet

Production of Functional Materials Derived from Regenerated Silk Fibroin by Utilizing 3D Printing and Biomimetic Enzyme-induced Mineralization

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Chinese Journal of Polymer Science 2024年第3期42卷 299-310,I0005页

作者： ni chen Fei-Yu Luo Gong-Wen Yang Jin-Rong Yao Xin chen Zheng-Zhong Shao State Key Laboratory of Molecular Engineering of Polymers Laboratory of Advanced Materials and Department of Macromolecular ScienceFudan UniversityShanghai 200433China

Critical-sized bone defects, commonly encountered in clinical orthopedic surgery, present a significant challenge. One of the promising solutions is to prepare synthetic bone substitute materials with precise structural control, mechanical compatibility, and enhanced osteogenic induction performance, nevertheless the successful preparation of such materials remains difficult. In this study, a two-step technique,integrating an extrusion-based printing process with biomimetic mineralization induced by alkaline phosphatase(ALP), was developed. Initially,a pre-cured hydrogel of regenerated silk fibroin(RSF) with a small quantity of hydroxypropyl cellulose(HPC) and ALP was prepared through heating the mixed aqueous solution. This pre-cured hydrogel demonstrated thixotropic property and could be directly extruded into predetermined structures through a 3D-printer. Subsequently, the 3D-printed RSF-based materials with ALP underwent biomimetic in situ mineralization in calcium glycerophosphate(Ca-GP) mineralizing solution, utilizing the polymer chains of RSF as templates and ALP as a trigger for cleaving phosphate bonds of Ca-GP. The resulting 3D-printed RSF-mineral composites including hydrogel and sponge possessed adjustable compression modulus of megapascal grade and variable hydroxyapatite content, which could be controlled by manipulating the duration of the mineralization ***, these 3D-printed RSF-mineral composites demonstrated non-cytotoxicity towards rat bone marrow mesenchymal stem cells. Therefore, they may hold great potential for applications involving the replacement of tissues characterized by osteoinductivity and intricate structures.

关键词： Silk protein Alkaline phosphatase Extrusion-based printing Biomineralization

Influence of Rashba spin–orbit coupling on Josephson effect in triplet superconductor/two-dimensional semiconductor/triplet superconductor junctions

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Chinese Physics B 2022年第7期31卷 490-497页

作者： Bin-Hao Du Man-ni chen Liang-Bin Hu Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials School of Physics and Telecommunication EngineeringSouth China Normal UniversityGuangzhou 510631China

We study theoretically Josephson effect in a planar ballistic junction between two triplet superconductors with pwave orbital symmetries and separated by a two-dimensional(2D)semiconductor channel with strong Rashba spin–orbit *** triplet superconductors,three types of orbital symmetries are *** use Bogoliubov–de Gennes formalism to describe quasiparticle propagations through the junction and the supercurrents are calculated in terms of Andreev reflection *** features of the variation of the supercurrents with the change of the strength of Rashba spin–orbit coupling are investigated in some *** is found that for the three types of orbital symmetries considered,both the magnitudes of supercurrent and the current-phase relations can be manipulated effectively by tuning the strength of Rashba spin–orbit *** interplay of Rashba spin–orbit coupling and Zeeman magnetic field on supercurrent is also investigated in some detail.

关键词： Josephson effect Rashba spin–orbit coupling triplet superconductor 0-πtransitions

Resolution enhancement of optical scanning holography with a spiral modulated point spread function

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Photonics Research 2016年第1期4卷 1-6页

作者： ni chen Zhenbo Ren Haiyan Ou Edmund Y.Lam Department of Electrical and Electronic Engineering The University of Hong Kong Institute of Applied Physics University of Electronic Science and Technology of China

In optical scanning holography, one pupil produces a spherical wave and another produces a plane wave. They interfere with each other and result in a fringe pattern for scanning a three-dimensional object. The resolution of the hologram reconstruction is affected by the point spread function(PSF) of the optical system. In this paper, we modulate the PSF by a spiral phase plate, which significantly enhances the lateral and depth resolution. We explain the theory for such resolution enhancement and show simulation results to verify the efficacy of the approach.

关键词： PSF Resolution enhancement of optical scanning holography with a spiral modulated point spread function

TaARR1, a cytokinin response regulator gene in Triticum aestivum, is essential in plant N starvation tolerance via regulating the N acquisition and N assimilation

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Journal of Integrative Agriculture 2019年第12期18卷 2691-2702页

作者： YANG Meng-ya chen Jia-qi TIAN He-yang ni chen-yang XIAO Kai College of Agronomy Hebei Agricultural University/Key Laboratory of Crop Growth Regulation of Hebei Province

Plant N starvation response is closely associated with the N signaling components that involve transduction of the low-N cues. In this study, we functionally characterized Ta ARR1, a cytokinin(CK) response regulator gene in Triticum aestivum, in mediating the N starvation adaptation in plants. Ta ARR1 harbors two conserved domains specified by plant ARR family members;subcellular localization analysis indicated its target onto nucleus after endoplasmic reticulum assortment. Ta ARR1 displayed modified expression upon the N starvation stressor, showing upregulated expression in roots and leaves over a 27-h N starvation treatment and whose induced transcripts were gradually recovered along with progression of the N recovery treatment. The tobacco lines overexpressing Ta ARR1 displayed improved low-N stress tolerance, displaying enlarged phenotype, increased biomass and N accumulation, and enhanced glutamine synthetase(GS) activities compared with wild type(WT) following the N starvation treatment. Expression analysis on genes encoding the nitrate transporter(NRT) and GS proteins in nicotiana tabacum revealed that Nt NRT2.2 and Nt GS3 are upregulated in expression in the N-deprived transgenic lines, whose expression patterns were contrasted to other above family genes that were unaltered on transcripts between the transgenic lines and WT. Transgene analysis validated the function of Nt NRT2.2 and Nt GS3 in regulating N accumulation, GS activity, growth traits, and N use efficiency in plants. These results suggested the internal connection between the Ta ARR1-mediated N starvation tolerance and the modified transcription of distinct N acquisitionand assimilation-associated genes. Our investigation together indicates that Ta ARR1 is essential in plant N starvation adaptation due to the gene function in transcriptionally regulating distinct NRT and GS genes that affect plant N uptake and assimilation under the N starvation condition.

关键词： wheat(Triticum aestivum L.) cytokinin response regulator gene expression N starvation functional characterization

Mechanism of low thermal conductivity of xonotlite-silica aerogel nanoporous super insulation material

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Journal of University of Science and Technology Beijing 2008年第5期15卷 649-653页

作者： Hailong Yang Wen ni Deping chen Guoqiang Xu Tao Liang Li Xu Civil and Environmental Engineering School University of Science and Technology Beijing Beijing 100083 China

In an effort to incorporate the low thermal conductivity of the silica aerogel and the superior structure strength of the xonotlite,a composite material of these two was produced. It was synthesized under vacuum condition and dried by supercritical drying technique. The thermal conductivity of the new material,which is at 298K with the gas pressure ranging from 1.01×10^5 to 1×10^-2 Pa,was measured using the transient hot-strip method. The mechanism of the low thermal conductivity was studied. The results indicate that the low thermal conductivity mainly results from the significant decrease of gaseous thermal conductivity of the new material due to the restriction of the motion of gas molecules in its fine structures. The formation of the fine structures is because the new material takes the pore structure of the silica aerogel which consists of mainly nanometer-sized pores.

关键词： silica aerogel xonotlite nanometer-sized pore super insulation thermal conductivity

Clinical and oncologic findings of extraprostatic extension on needle biopsy in de novo metastatic prostate cancer

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Asian Journal of Andrology 2020年第4期22卷 427-431页

作者： Jun-Ru chen Jin-Ge Zhao Sha Zhu Meng-ni Zhang ni chen Jian-Dong Liu Guang-Xi Sun Peng-Fei Shen Hao Zeng Department of Urology Institute of UrologyWest China HospitalSichuan UniversityChengdu 610041China Department of Pathology West China HospitalSichuan UniversityChengdu 610041China

This study aimed to explore the clinical and oncologic findings in patients with de novo metastatic prostate cancer(mPCa)and extraprostatic extension(EPE)on *** retrospectively evaluated data on 630 patients with de novo mPCa between January 2009 and December 2017 in the West China Hospital(chengdu,China),including evaluating the relationships between EPE and other variables and the association of EPE with survival outcomes by the Chi-square test,Kaplan–Meier curves,and the Cox proportional-hazards *** was found in 70/630 patients,making a prevalence of 11.1%.The presence of EPE on biopsy was associated with higher Gleason scores and higher incidence of neuroendocrine differentiation(NED),intraductal carcinoma of the prostate(IDC-P),and perineural invasion(Pni).Compared with those without EPE,patients with EPE had shorter castration-resistant prostate cancer-free survival(CFS;median:14.1 vs 17.1 months,P=0.015)and overall survival(OS;median:43.7 vs 68.3 months,P=0.032).According to multivariate analysis,EPE was not an independent predictor for *** analyses demonstrated that patients with favorable characteristics,including negative NED or IDC-P status,Eastern Cooperative Oncology Group(ECOG)scorenicopathological features and poorer CFS and *** data suggest that EPE may be an indicator of poor prognosis,particularly in patients,otherwise considered likely to have favorable survival outcomes.

关键词： extraprostatic extension metastatic prostate cancer prevalence prognosis

Management, Democracy and Redistribution： Reformation of Official Vehicles＇ Use Under Multiple Logic Contradiction

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公共行政评论 2012年第5期5卷 178-182页

作者： Xing ni Zhaocang chen The Institutional Turn and Intellectual Consensus of Anti-corruption in China