Strong magneto chiral effects in absorption of phenylalanine bridged chiral zinc bis porphyrin O,O C 2 Phe C 2 (TPP) 2Zn 2 were demonstrated through the comparison of natural circular dichroism and magnetic circular d...Strong magneto chiral effects in absorption of phenylalanine bridged chiral zinc bis porphyrin O,O C 2 Phe C 2 (TPP) 2Zn 2 were demonstrated through the comparison of natural circular dichroism and magnetic circular dichroism spectra of enantiomers. Magneto chiral circular dichroism spectra expressed as difference between the absorption coefficients of the left circularly polarized and right circularly polarized light are given. The observed intensive magneto chiral effect was suggested to be related with the chiral exciton coupling between two zinc porphyrin chromophores of the enantiomers. [WT5HZ]展开更多
This study is to reveal the effect of interlayer lattice registry on the formation of collapsed double wall carbon nanotubes (DWCNTs). It is found that collapsed carbon nanotubes can be energetically unstable, metasta...This study is to reveal the effect of interlayer lattice registry on the formation of collapsed double wall carbon nanotubes (DWCNTs). It is found that collapsed carbon nanotubes can be energetically unstable, metastable or stable, depending mainly on the diameter of the CNT. A fully collapsed DWCNT can adopt different structural morphologies, such as a straight ribbon, a warping ribbon or a twisted ribbon, depending on the chirality of the CNT, which is similar to single wall carbon nanotubes (SWCNTs). Different from SWCNTs, this study also shows some unique phenomena in the formation of collapsed DWCNTs. A fully collapsed DWCNT can have different combinations of the interlayer lattice registry effect within the inner and outer tube, thus the outer tube can influence the formation of the collapsed CNT via lattice registry effect, sometimes even dominates the twist of the CNT.展开更多
The uncertainties of background contributions to J = 0 partial wave πK scattering phase shifts are carefully studied. We firstly point out that the circular cuts exhibit different characters in S1/1 and S3/2 waves. W...The uncertainties of background contributions to J = 0 partial wave πK scattering phase shifts are carefully studied. We firstly point out that the circular cuts exhibit different characters in S1/1 and S3/2 waves. While the former contributes negatively to the scattering length parameter, the latter contributes positively, i.e., has a wrong sign. This fact indicates that short range force contribu tions to the phase shift are non-negligible in the exotic channel. Nevertheless, it is verified that the κ pole will be affected only slightly with respect to the theoretical uncertainty in estimating the left hand cut contributions.展开更多
Embodiment theories proposed that the comprehension of language involves sensory-motor simulation in the brain.The present study examined the brain response to motor compatibility effect in comprehending action-relate...Embodiment theories proposed that the comprehension of language involves sensory-motor simulation in the brain.The present study examined the brain response to motor compatibility effect in comprehending action-related linguistic materials for participants learning Chinese as a second language(L2).In this study,participants are required to read action-related sentences describing an agent performing two manual actions simultaneously or sequentially by manipulating temporal conjunctions.The sentences with simultaneous actions are marked by Chinese parallel structure一边……一边……(“while”)showing non-congruent motor condition while the sequential action sentences are marked by先……然后……(“after”)showing congruent motor condition.Event-Related Potentials(ERPs)were recorded with the second verb phrase.A larger fronto-central late positivity was observed for the sentences with simultaneous actions rather than the sentences with sequential actions due to body constraints,revealing that late L2 Chinese learners integrate embodied knowledge while processing action-related complex sentence despite demanding more cognitive resources,and longer processing time.展开更多
Avian brood parasitism is a model system for studies of coevolution and ecological interactions between parasites and their hosts. However, recent work may have led to misconceptions concerning the Brown-headed Cowbir...Avian brood parasitism is a model system for studies of coevolution and ecological interactions between parasites and their hosts. However, recent work may have led to misconceptions concerning the Brown-headed Cowbird (Molothrus ater), the most widely studied brood parasitic bird in the world, and its effects on host species. Potential misconceptions about this species that could affect management issues are as follows: cowbird populations are increasing; cowbirds are relatively new to North America; recently exposed hosts are defenseless against parasitism; cowbirds have caused widespread declines of songbirds; and cowbird control is always effective in increasing the size of endangered host populations. Potential coevolutionary misconceptions are that cowbirds are typically 'host tolerant'; cowbirds evict host nestmates; and the mafia effect is widespread. It is important to clarify these issues because such misconceptions could hinder our understanding of parasite-host interactions, and thus obscure the direction of basic research and of management efforts taken to limit cowbird impacts on endangered species. We discuss these issues and suggest future research directions to enhance our understanding of this fascinating species.展开更多
We study the influence of the chiral phase transition on the chiral magnetic effect. The azimuthal charge-particle correlations as functions of the temperature are calculated. It is found that there is a pronounced cu...We study the influence of the chiral phase transition on the chiral magnetic effect. The azimuthal charge-particle correlations as functions of the temperature are calculated. It is found that there is a pronounced cusp in the correlations as the temperature reaches its critical value for the QCD phase transition. It is predicted that there will be a drastic suppression of the charge-particle correlations as the collision energy in RHIC decreases to below a critical value. We show then the azimuthal charge-particle correlations can be the signal to identify the occurrence of the QCD phase transitions in RHIC energy scan experiments.展开更多
Some structural factors to the design of polymer-supported Chiral Catalysts arediscussed, and some new approaches for designing of polymer-supported catalysts arereviewed in this paper
Based on the global color symmetry mode/ （GCM）, a method for obtaining the quark loop effects on the dressed gluon propagator in GCM is developed. In the chiral limit, it is found that the dressed gluon propagator c...Based on the global color symmetry mode/ （GCM）, a method for obtaining the quark loop effects on the dressed gluon propagator in GCM is developed. In the chiral limit, it is found that the dressed gluon propagator containing the quark loop effects in the Nambu-Goldstone and Wigner phases are quite different. In solving the quark self-energy functions in the two different phases and subsequent study of bag constant one shouM use the above dressed gluon propagator as input. The above approach for obtaining the current quark mass effects on the dressed gluon propagator is quite general and can also be used to calculate the chemical potential dependence of the dressed gluon propagator.展开更多
The chiral magnetic effect (CME) refers to a charge separation along a strong magnetic field due to an imbalanced chirality of quarks from interactions with the vacuum topological gluon field. This chiral anomaly is a...The chiral magnetic effect (CME) refers to a charge separation along a strong magnetic field due to an imbalanced chirality of quarks from interactions with the vacuum topological gluon field. This chiral anomaly is a fundamental property of quantum chromodynamics (QCD) and, therefore, an observation of the CME would have far-reaching impact on our understanding of QCD and Nature. The measurements of the CME-sensitive azimuthal correlator Δγ observable in heavy-ion collisions are contaminated by a major background induced by elliptic flow anisotropy. Several novel approaches have been carried out, including a dedicated isobar collision program, to address this flow-induced background. Further background effects, arising from nonflow correlations, have been studied. While the isobar data are consistent with zero CME signal with an upper limit of 10% of the measured Δγ, the Au+Au midcentral data suggest a positive CME signal on the order of 10% of the measured Δγ with a significance of ~2 standard deviations. Future increased statistics and improved detector capability should yield a firm conclusion on the existence (or the lack) of the CME in relativistic heavy-ion collisions.展开更多
文摘Strong magneto chiral effects in absorption of phenylalanine bridged chiral zinc bis porphyrin O,O C 2 Phe C 2 (TPP) 2Zn 2 were demonstrated through the comparison of natural circular dichroism and magnetic circular dichroism spectra of enantiomers. Magneto chiral circular dichroism spectra expressed as difference between the absorption coefficients of the left circularly polarized and right circularly polarized light are given. The observed intensive magneto chiral effect was suggested to be related with the chiral exciton coupling between two zinc porphyrin chromophores of the enantiomers. [WT5HZ]
基金Project (10542001) supported by the National Natural Science Foundation of China
文摘This study is to reveal the effect of interlayer lattice registry on the formation of collapsed double wall carbon nanotubes (DWCNTs). It is found that collapsed carbon nanotubes can be energetically unstable, metastable or stable, depending mainly on the diameter of the CNT. A fully collapsed DWCNT can adopt different structural morphologies, such as a straight ribbon, a warping ribbon or a twisted ribbon, depending on the chirality of the CNT, which is similar to single wall carbon nanotubes (SWCNTs). Different from SWCNTs, this study also shows some unique phenomena in the formation of collapsed DWCNTs. A fully collapsed DWCNT can have different combinations of the interlayer lattice registry effect within the inner and outer tube, thus the outer tube can influence the formation of the collapsed CNT via lattice registry effect, sometimes even dominates the twist of the CNT.
基金The project supported in part by National Natural Science Foundations of China under Grant Nos. 10575002, 10421503, and 10491306.Acknowledgments It is a pleasure to thank Prof. Han-Qing Zheng for valuable discussions and a careful reading of the manuscript.
文摘The uncertainties of background contributions to J = 0 partial wave πK scattering phase shifts are carefully studied. We firstly point out that the circular cuts exhibit different characters in S1/1 and S3/2 waves. While the former contributes negatively to the scattering length parameter, the latter contributes positively, i.e., has a wrong sign. This fact indicates that short range force contribu tions to the phase shift are non-negligible in the exotic channel. Nevertheless, it is verified that the κ pole will be affected only slightly with respect to the theoretical uncertainty in estimating the left hand cut contributions.
文摘Embodiment theories proposed that the comprehension of language involves sensory-motor simulation in the brain.The present study examined the brain response to motor compatibility effect in comprehending action-related linguistic materials for participants learning Chinese as a second language(L2).In this study,participants are required to read action-related sentences describing an agent performing two manual actions simultaneously or sequentially by manipulating temporal conjunctions.The sentences with simultaneous actions are marked by Chinese parallel structure一边……一边……(“while”)showing non-congruent motor condition while the sequential action sentences are marked by先……然后……(“after”)showing congruent motor condition.Event-Related Potentials(ERPs)were recorded with the second verb phrase.A larger fronto-central late positivity was observed for the sentences with simultaneous actions rather than the sentences with sequential actions due to body constraints,revealing that late L2 Chinese learners integrate embodied knowledge while processing action-related complex sentence despite demanding more cognitive resources,and longer processing time.
文摘Avian brood parasitism is a model system for studies of coevolution and ecological interactions between parasites and their hosts. However, recent work may have led to misconceptions concerning the Brown-headed Cowbird (Molothrus ater), the most widely studied brood parasitic bird in the world, and its effects on host species. Potential misconceptions about this species that could affect management issues are as follows: cowbird populations are increasing; cowbirds are relatively new to North America; recently exposed hosts are defenseless against parasitism; cowbirds have caused widespread declines of songbirds; and cowbird control is always effective in increasing the size of endangered host populations. Potential coevolutionary misconceptions are that cowbirds are typically 'host tolerant'; cowbirds evict host nestmates; and the mafia effect is widespread. It is important to clarify these issues because such misconceptions could hinder our understanding of parasite-host interactions, and thus obscure the direction of basic research and of management efforts taken to limit cowbird impacts on endangered species. We discuss these issues and suggest future research directions to enhance our understanding of this fascinating species.
基金Supported by the National Natural Science Foundation of China under Grant Nos.10425521,10675007,10935001the Major State Basic Research Development Program under Grant No.G2007CB815000the Financial Support from China Postdoctoral Science Foundation No.20090460534
文摘We study the influence of the chiral phase transition on the chiral magnetic effect. The azimuthal charge-particle correlations as functions of the temperature are calculated. It is found that there is a pronounced cusp in the correlations as the temperature reaches its critical value for the QCD phase transition. It is predicted that there will be a drastic suppression of the charge-particle correlations as the collision energy in RHIC decreases to below a critical value. We show then the azimuthal charge-particle correlations can be the signal to identify the occurrence of the QCD phase transitions in RHIC energy scan experiments.
文摘Some structural factors to the design of polymer-supported Chiral Catalysts arediscussed, and some new approaches for designing of polymer-supported catalysts arereviewed in this paper
基金The project supported in part by National Natural Science Foundation of China under Grant Nos. 10575050 and 10135030 and the Research Fund for the Doctoral Program of Higher Education under Grant No. 20030284009.
文摘Based on the global color symmetry mode/ （GCM）, a method for obtaining the quark loop effects on the dressed gluon propagator in GCM is developed. In the chiral limit, it is found that the dressed gluon propagator containing the quark loop effects in the Nambu-Goldstone and Wigner phases are quite different. In solving the quark self-energy functions in the two different phases and subsequent study of bag constant one shouM use the above dressed gluon propagator as input. The above approach for obtaining the current quark mass effects on the dressed gluon propagator is quite general and can also be used to calculate the chemical potential dependence of the dressed gluon propagator.
文摘The chiral magnetic effect (CME) refers to a charge separation along a strong magnetic field due to an imbalanced chirality of quarks from interactions with the vacuum topological gluon field. This chiral anomaly is a fundamental property of quantum chromodynamics (QCD) and, therefore, an observation of the CME would have far-reaching impact on our understanding of QCD and Nature. The measurements of the CME-sensitive azimuthal correlator Δγ observable in heavy-ion collisions are contaminated by a major background induced by elliptic flow anisotropy. Several novel approaches have been carried out, including a dedicated isobar collision program, to address this flow-induced background. Further background effects, arising from nonflow correlations, have been studied. While the isobar data are consistent with zero CME signal with an upper limit of 10% of the measured Δγ, the Au+Au midcentral data suggest a positive CME signal on the order of 10% of the measured Δγ with a significance of ~2 standard deviations. Future increased statistics and improved detector capability should yield a firm conclusion on the existence (or the lack) of the CME in relativistic heavy-ion collisions.
