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Zhou X, Jiang L, Lei S, Tian WQ, Wu G. Micromechanism in Self-Lubrication of TiB2/Al Composite. ACS APPLIED MATERIALS & INTERFACES 2015; 7:12688-12694. [PMID: 26010553 DOI: 10.1021/acsami.5b02906] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The authors discovered the self-lubrication behavior of TiB2/Al composite and pointed out that the materials responsible for the self-lubrication behavior comes from the oxidation of TiB2. Atomic/friction force microscopy and first-principles calculations have been employed to study the self-lubrication microscopic mechanism of TiB2/Al composite. Atomic force microscopy confirms the existence of a soft film with nanometer thickness on the TiB2 surface, which was attributed to H3BO3 film. Friction measurements revealed much smaller friction force on this H3BO3 nanofilm than that on Al matrix. The detailed structure and interactions among H3BO3 molecules and between the H3BO3 sheet and substrate were explored by density functional theory based calculations. The details of adsorption of H3BO3 sheet on TiB2 and TiO2 surface were scrutinized and the potential of the relative movement between H3BO3 sheets were scanned and compared with that of graphite. The generation of H3BO3 film, the strong chemical adsorption of H3BO3 film on the surface of the composite, the strong hydrogen bonding in H3BO3 film, and small potential in the relative slide between H3BO3 sheets warrant the good self-lubricant properties of TiB2/Al metal matrix composites.
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Wang D, Han D, Li XB, Xie SY, Chen NK, Tian WQ, West D, Sun HB, Zhang SB. Determination of formation and ionization energies of charged defects in two-dimensional materials. PHYSICAL REVIEW LETTERS 2015; 114:196801. [PMID: 26024189 DOI: 10.1103/physrevlett.114.196801] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Indexed: 06/04/2023]
Abstract
We present a simple and efficient approach to evaluate the formation energy and, in particular, the ionization energy (IE) of charged defects in two-dimensional (2D) systems using the supercell approximation. So far, first-principles results for such systems can scatter widely due to the divergence of the Coulomb energy with vacuum dimension, denoted here as L_{z}. Numerous attempts have been made in the past to fix the problem under various approximations. Here, we show that the problem can be resolved without any such assumption, and a converged IE can be obtained by an extrapolation of the asymptotic IE expression at large L_{z} (with a fixed lateral area S) back to the value at L_{z}=0. Application to defects in monolayer boron nitride reveal that defects in 2D systems can be unexpectedly deep, much deeper than the bulk.
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Hu YY, Gu J, Li WQ, Yang L, Feng JK, Tian WQ. From Graphene to Carbon Nanotubes: Variation of the Electronic States and Nonlinear Optical Responses. Chemphyschem 2015; 16:2151-8. [PMID: 25951233 DOI: 10.1002/cphc.201500173] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Indexed: 11/11/2022]
Abstract
From the same piece of graphene sheet, (3, 3) and (6, 0) carbon nanotube clips were obtained on the basis of the different manners of rolling. The nature of the electronic state varies differently with different manners of rolling and is significantly affected by zigzag edges. The intermediate structures formed during the rolling process were functionalized with fluorine and oxygen atoms to investigate the electronic states and nonlinear optical (NLO) responses. Passivation of the intermediate structures with fluorine neither changes the nature of electronic states and nor improves the NLO responses. In constrast, passivation with oxygen enhances the NLO properties and changes the electronic states of the structures upon passivating at the open zigzag edges.
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Wang MQ, Zhou X, Tian WQ, Goddard JD. Electronic and optical properties of the five most stable C96 isomers. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2015.02.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Sun XL, Fan LX, Yang YJ, Guo Z, Tian WQ, Lei S. Synthesis of One-Dimensional Schiff Base Polymers that Contain an Oligothiophene Building Block on the Graphite Surface. Chemistry 2015; 21:6898-905. [DOI: 10.1002/chem.201406287] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Indexed: 11/05/2022]
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Xie SY, Li XB, Tian WQ, Chen NK, Wang Y, Zhang S, Sun HB. A novel two-dimensional MgB6 crystal: metal-layer stabilized boron kagome lattice. Phys Chem Chem Phys 2015; 17:1093-8. [DOI: 10.1039/c4cp03728f] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Based on first-principles calculations, we designed for the first time a boron-kagome-based two-dimensional MgB6 crystal, in which two boron kagome layers sandwich a triangular magnesium layer.
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Sun X, Fan L, Zhou X, Tian WQ, Guo Z, Li Z, Li X, Lei S. Surface confined synthesis of porphyrin containing two-dimensional polymers: the effect of rigidity and preferential adsorption of building blocks. Chem Commun (Camb) 2015; 51:5864-7. [DOI: 10.1039/c5cc00659g] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The rigidity and affinity of building blocks to the surface show essential effects on the topology of the 2D polymers.
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Feng W, Zhou X, Tian WQ, Zheng W, Hu P. Performance improvement of multilayer InSe transistors with optimized metal contacts. Phys Chem Chem Phys 2015; 17:3653-8. [DOI: 10.1039/c4cp04968c] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Solid experimental investigations were performed to reveal the specific interface nature of thin-film InSe layered semiconductor/metals. Multilayer InSe transistors showed significantly increased mobilities in the contact sequence of Al, Ti, Cr, and In. The interface nature of the metal/thin-film InSe layered semiconductor was strong van der Waals epitaxial interactions, accompanied with d-orbital overlap.
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Liu F, Xiao P, Tian WQ, Zhou M, Li Y, Cui X, Zhang Y, Zhou X. Hydrogenation of Pt/TiO2{101} nanobelts: a driving force for the improvement of methanol catalysis. Phys Chem Chem Phys 2015; 17:28626-34. [DOI: 10.1039/c5cp05018a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Single-crystalline anatase TiO2 nanobelts with a dominant surface of the {101} facet were hydrogenated and used as active substrates of platinum for methanol oxidation reaction (MOR).
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Xin YP, Zan LS, Liu YF, Tian WQ, Wang HB, Cheng G, Li AN, Yang WC. Genetic diversity of Y-short tandem repeats in Chinese native cattle breeds. GENETICS AND MOLECULAR RESEARCH 2014; 13:9578-87. [PMID: 25501167 DOI: 10.4238/2014.november.14.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The aim of this study is to use Y-chromosome gene polymorphism method to investigate regional differences in genetic variation and population evolution history of the Chinese native cattle breeds. Six Y-chromosome short tandem repeat (Y-STR) loci (UMN0929, UMN0108, UMN0920, INRA124, UMN2404, and UMN0103) were analyzed using 1016 healthy and heterogenetic males and 90 females of 9 native cattle breeds (Qinchuan, Jinnan, Zaosheng, Luxi, Nanyang, Jiaxian, Dabieshan, Yanbian, and Menggu) in China. Allele frequency and gene diversity were calculated for the various populations. The results indicated that Y-STRs in the 6 loci have polymorphisms and genetic diversity in Chinese cattle populations. The genetic diversity analysis revealed that the Chinese cattle populations have a close genetic relationship. The analysis of INRA124, UMN2404, and UMN0103 loci revealed the original history of Chinese cattle because of which cattle belonging to Bos taurus or Bos indicus could be determined. Interestingly, a declining zebu introgression was displayed from South to North and from East to West in the Chinese geographical distribution, which implied that cattle population from various regions of China had been subjected to somewhat different evolutionary history. This conclusion supported other evidences such as earlier archaeological, historical research, and blood protein polymorphism analysis.
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Xu L, Zhou X, Tian WQ, Gao T, Zhang YF, Lei S, Liu ZF. Surface-Confined Single-Layer Covalent Organic Framework on Single-Layer Graphene Grown on Copper Foil. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201400273] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Xu L, Zhou X, Tian WQ, Gao T, Zhang YF, Lei S, Liu ZF. Surface-Confined Single-Layer Covalent Organic Framework on Single-Layer Graphene Grown on Copper Foil. Angew Chem Int Ed Engl 2014; 53:9564-8. [DOI: 10.1002/anie.201400273] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Indexed: 11/08/2022]
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Xie SY, Li XB, Tian WQ, Wang D, Chen NK, Han D, Sun HB. Slide Fastener Reduction of Graphene-Oxide Edges by Calcium: Insight from Ab Initio Molecular Dynamics. Chemphyschem 2014; 15:2707-11. [DOI: 10.1002/cphc.201402057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 03/28/2014] [Indexed: 11/08/2022]
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Le YQ, Gu J, Tian WQ. Nitrogen-fixation catalyst based on graphene: every part counts. Chem Commun (Camb) 2014; 50:13319-22. [DOI: 10.1039/c4cc01950d] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Hu YY, Sun SL, Tian WT, Tian WQ, Xu HL, Su ZM. Inside Cover: Influence of Spiral Framework on Nonlinear Optical Materials (ChemPhysChem 5/2014). Chemphyschem 2014. [DOI: 10.1002/cphc.201490021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Hu YY, Sun SL, Tian WT, Tian WQ, Xu HL, Su ZM. Influence of spiral framework on nonlinear optical materials. Chemphyschem 2014; 15:929-34. [PMID: 24677788 DOI: 10.1002/cphc.201301149] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Indexed: 11/10/2022]
Abstract
A series of spiral donor-π-acceptor frameworks (i.e. 2-2, 3-3, 4-4, and 5-5) based on 4-nitrophenyldiphenylamine with π-conjugated linear acenes (naphthalenes, anthracenes, tetracenes, and pentacenes) serving as the electron donor and nitro (NO2 ) groups serving as the electron acceptor were designed to investigate the relationships between the nonlinear optical (NLO) responses and the spirality in the frameworks. A parameter denoted as D was defined to describe the extent of the spiral framework. The D value reached its maximum if the number of NO2 groups was equal to the number of fused benzene rings contained in the linear acene. A longer 4-nitrophenyldiphenylamine chain led to a larger D value and, further, to a larger first hyperpolarizability. Different from traditional NLO materials with charge transfer occurring in the one-dimensional direction, charge transfer in 2-2, 3-3, 4-4, and 5-5 occur in three-dimensional directions due to the attractive spiral frameworks, and this is of great importance in the design of NLO materials. The origin of such an enhancement in the NLO properties of these spiral frameworks was explained with the aid of molecular orbital analysis.
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Xu L, Zhou X, Yu Y, Tian WQ, Ma J, Lei S. Surface-confined crystalline two-dimensional covalent organic frameworks via on-surface Schiff-base coupling. ACS NANO 2013; 7:8066-8073. [PMID: 23924203 DOI: 10.1021/nn403328h] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We performed a co-condensation reaction between aromatic aldehyde and aromatic diamine monomers on a highly oriented pyrolytic graphite surface either at a solid/liquid interface at room temperature or in low vacuum with moderate heating. With this simple and moderate methodology, we have obtained surface-confined 2D covalent organic frameworks (COFs) with few defects and almost entire surface coverage. The single crystalline domain can extend to more than 1 μm(2). By varying the backbone length of aromatic diamines the pore size of 2D surface COFs is tunable from ∼1.7 to 3.5 nm. In addition, the nature of the surface COF can be modified by introducing functional groups into the aromatic amine precursor, which has been demonstrated by introducing methyl groups to the backbone of the diamine. Formation of small portions of bilayers was observed by both scanning tunneling microscopy (STM) and AFM, which clearly reveals an eclipsed stacking manner.
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Li W, Zhou X, Tian WQ, Sun X. A new scheme for significant enhancement of the second order nonlinear optical response from molecules to ordered aggregates. Phys Chem Chem Phys 2013; 15:1810-4. [DOI: 10.1039/c2cp43536e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Li SJ, Zhou X, Tian WQ. Theoretical Investigations on Decomposition of HCOOH Catalyzed by Pd7 Cluster. J Phys Chem A 2012; 116:11745-52. [DOI: 10.1021/jp308819j] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Fan YY, Fu GW, Fu CZ, Zan LS, Tian WQ. A missense mutant of the PPAR-γ gene associated with carcass and meat quality traits in Chinese cattle breeds. GENETICS AND MOLECULAR RESEARCH 2012; 11:3781-8. [PMID: 22930427 DOI: 10.4238/2012.august.17.4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The peroxisome proliferator-activated receptor gamma (PPAR-γ) is a key molecule in adipocyte differentitation; it transactivates multiple target genes in lipid metabolic pathways. Using PCR-SSCP and DNA sequencing, we evaluated a potential association of an SNP (72472 G﹥T in exon7) of the bovine PPAR-γ gene with carcass and meat quality traits in 660 individuals from five Chinese indigenous cattle breeds, Qinchuan (QC), Luxi (LX), Nanyang (NY), Jiaxian (JX), and Xianan (XN). This 72472 G﹥T mutation identified a missense mutation, Q448H. Two alleles were named C and D. Allele frequencies of PPAR-γ-C/D in the five breeds were 0.7815/0.2185, 0.9/0.1, 0.7442/0.2558, 0.7051/0.2949, and 0.8333/0.1667 for QC, NY, JX, LX, and XN, respectively. Except for the XN breed, all breeds were in Hardy-Weinberg equilibrium at this locus. The polymorphism information content was low for NY and XN (0.16 and 0.24, respectively), while it was moderately high for QC, JX, and LX (0.28, 0.31 and 0.33, respectively). Correlation analysis showed significant association of this missense mutation with carcass length, backfat thickness and water holding capacity in the QC breed. Animals with the genotype CD had significantly greater carcass length than those with genotypes CC and DD, while animals with genotype CC had significantly greater backfat thickness than those with genotypes CD and DD. Animals with genotype CC had lower water holding capacity than those with the genotypes CD and DD. In conclusion, this locus is a candidate for a major quantitative trait locus affecting production traits and could be used for beef breeding selection.
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Li W, Tian WQ, Sun X. Understanding of nonlinear optical properties of CS2 from a microscopic viewpoint. J Chem Phys 2012; 137:084315. [DOI: 10.1063/1.4748261] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Tian WQ. Modeling nonlinear optics of nanosystems with sum-over-states model. J Comput Chem 2011; 33:466-70. [DOI: 10.1002/jcc.21992] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 10/13/2011] [Accepted: 10/17/2011] [Indexed: 11/10/2022]
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Tian WQ, Wang HC, Song FB, Zan LS, Wang H, Wang HB, Xin YP, Ujan JA. Association between a single nucleotide polymorphism in the bovine chemerin gene and carcass traits in Qinchuan cattle. GENETICS AND MOLECULAR RESEARCH 2011; 10:2833-40. [PMID: 22095607 DOI: 10.4238/2011.november.17.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Qinchuan is a red or yellow draft and beef breed in China. In order to identify a predictor of carcass traits on the basis of associations between carcass traits and gene polymorphism, variation in the bovine chemerin gene was investigated using PCR-single-strand conformational polymorphism and DNA sequencing. An SNP of A868G located in exon 2 of the Bos taurus chemerin gene was detected in 716 samples of six breeds (Jiaxian red, Luxi, Nan yang, Qinchuan, Simmental and Luxi crossbred steers, and Xia'nan), all in China, and three genotypes (AA, AG and GG) were found. Based on the χ(2) test, the AA/AG/GG genotype frequencies of all six breeds were found to be in Hardy-Weinberg equilibrium. A possible association of A868G with some carcass traits was investigated in 106 Qinchuan cattle. Animals with the AG genotype were found to have significantly lower mean loin eye area and meat tenderness compared to those with the AA and GG genotypes. However, there was no significant association between any individual haplotype and backfat thickness, water holding capacity or marbling score. We suggest that A868G could be used as a molecular marker in marker-assisted selection for carcass traits.
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Li XM, Tian WQ, Dong Q, Huang XR, Sun CC, Jiang L. Substitutional doping of BN nanotube by transition metal: A density functional theory simulation. COMPUT THEOR CHEM 2011. [DOI: 10.1016/j.comptc.2010.12.026] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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50
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Liu LV, Tian WQ, Chen YK, Zhang YA, Wang YA. Theoretical studies on structures, 13C NMR chemical shifts, aromaticity, and chemical reactivity of finite-length open-ended armchair single-walled carbon nanotubes. NANOSCALE 2010; 2:254-261. [PMID: 20644802 DOI: 10.1039/b9nr00159j] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The geometries, chemical shifts, aromaticity, and reactivity of finite-length open-ended armchair single-walled carbon nanotubes (SWCNTs) have been studied within density functional theory. The widely used model of capping hydrogen atoms at the open ends of a SWCNT changes the chemical activity of the SWCNT and destabilizes the frontier molecular orbitals. The edge pi-orbital of the open ends enhances both pi- and sigma-aromaticity of the first belt of hexagons of carbon atoms at the open ends. The effect of the open ends on the structure and chemical reactivity of the SWCNT reaches only the first several layers of the hexagons of carbon atoms. Additions of carbene and dichlorocarbene to the nanotube reveal that the open ends have higher reactivities than the inner regions.
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