Nutrients in human milk,including minerals,relate growth and development of breast-fed infants.Tibetan mother-infant dyads possess unique characteristics on early nutrition due to their featured long-lasting lifestyle...Nutrients in human milk,including minerals,relate growth and development of breast-fed infants.Tibetan mother-infant dyads possess unique characteristics on early nutrition due to their featured long-lasting lifestyle.This study longitudinally investigated the relationship between the mineral composition in human milk and the Z-scores of infants among Tibetan mother-infant dyads during their first 6 months postpartum through a prospective cohort study.The results show that the minerals of Na,Mg,K,Ca,Cu,Zn,and Se were of higher levels in colostrum than other lactation stages.Several minerals were below the recommended values for infants according to Chinese dietary guidelines.Besides,a large proportion of infant Z-scores were below-2 as lactation period continued.Multivariate statistical analysis revealed that classifications and correlations in varying degrees were observed between minerals in human milk and infant Z-scores.These findings will be advantageous for research upon Chinese early nutrition and progress of tailor-made infant formula.展开更多
In this work,we employ electronic structure calculations and nonadiabatic dynamics simulations based on many-body Green function and BetheSalpeter equation(GW/BSE)methods to study excited-state properties of a zinc ph...In this work,we employ electronic structure calculations and nonadiabatic dynamics simulations based on many-body Green function and BetheSalpeter equation(GW/BSE)methods to study excited-state properties of a zinc phthalocyanine-fullerene(ZnPcC_(60))dyad with 6-6 and 5-6 configurations.In the former,the initially populated locally excited(LE)state of ZnPc is the lowest S1 state and thus,its subsequent charge separation is relatively slow.In contrast,in the latter,the S1 state is the LE state of C_(60)while the LE state of ZnPc is much higher in energy.There also exist several charge-transfer(CT)states between the LE states of ZnPc and C_(60).Thus,one can see apparent charge separation dynamics during excited-state relaxation dynamics from the LE state of ZnPc to that of C_(60).These points are verified in dynamics simulations.In the first 200 fs,there is a rapid excitation energy transfer from ZnPc to C_(60),followed by an ultrafast charge separation to form a CT intermediate state.This process is mainly driven by hole transfer from C_(60)to ZnPc.The present work demonstrates that different bonding patterns(i.e.5-6 and 6-6)of the C−N linker can be used to tune excited-state properties and thereto optoelectronic properties of covalently bonded ZnPc-C_(60)dyads.Methodologically,it is proven that combined GW/BSE nonadiabatic dynamics method is a practical and reliable tool for exploring photoinduced dynamics of nonperiodic dyads,organometallic molecules,quantum dots,nanoclusters,etc.展开更多
The molecular orientations of conjugated materials on the substrate mainly include edge-on,face-on,and end-on.Edge-on and face-on orientations have been widely observed,while end-on orientation has been rarely reporte...The molecular orientations of conjugated materials on the substrate mainly include edge-on,face-on,and end-on.Edge-on and face-on orientations have been widely observed,while end-on orientation has been rarely reported.Since in organic solar cells(OSCs)charge transport is along the vertical direction,end-on orientation with conjugated backbones perpendicular to the substrate is recognized as the ideal microstructure for OSCs.In this work,we for the first time obtained the preferential end-on orientation in a conjugated molecular dyad that contains a conjugated backbone as donor and perylene bisimide side units as acceptor.This was realized by introducing a fused-ring structure to replace linear terthiophenes with conjugated backbones,yielding F-MDPBI and L-MDPBI respectively.Surprisingly,a shifting trend of the molecular orientation from dominating edge-on in L-MDPBI to preferential end-on in F-MDPBI was observed.As a consequence,vertical charge carrier mobilities in F-MDPBI are one order of magnitude higher than those with preferential edge-on orientation,so single-component OSCs based on this molecular dyad as a single photoactive layer provided a power conversion efficiency of 4.89% compared to 1.70% based on L-MDPBI with preferential edge-on orientation.展开更多
ELECTRON transfer plays a crucial role in energy transformation of natural biological systemssuch as the photosynthetic process by which plants convert solar energy into chemical energy.This is achieved in photosynthe...ELECTRON transfer plays a crucial role in energy transformation of natural biological systemssuch as the photosynthetic process by which plants convert solar energy into chemical energy.This is achieved in photosynthesis by a series of electron transfers which occur after light is ab-sorbed. Among the various factors which influence the efficiency of electron transfer struc-tural effect is one of the important features to be considered. In recent years, numerous syn-thetic model dyads in which electron donor and electron acceptor are covalently linked by dif-ferent spacers have been designed and synthesized in an effort to understand how the展开更多
The performance of organic solar cells(OSCs)is mainly related to the bulk heterojunction(BHJ)microstructure of specific active layer systems,which is often in a metastable state.A promising strategy to address the abo...The performance of organic solar cells(OSCs)is mainly related to the bulk heterojunction(BHJ)microstructure of specific active layer systems,which is often in a metastable state.A promising strategy to address the abovementioned shortcomings of BHJs is to develop single-component active layer materials.Owing to the single-component small molecule materials with defined chemical structures generally exhibit poor absorption spectra,herein we first introduced narrow bandgap Y-series acceptors into the molecular skeleton of single-component materials,and designed two molecular dyads,SM-Et-1Y and SM-Et-2Y.The optical bandgaps(E_g~(opt)s)of the two dyads are 1.364 and 1.361 eV,respectively,which are much smaller than those of previously reported single-component molecules.Consequently,the SM-Et-2Y-based single-component OSCs(SCOSCs)showed a power conversion efficiency(PCE)of 5.07%,superior to SM-Et-1Y(2.53%),which is one of the highest PCEs reported for SCOSCs to date.Moreover,both SM-Et-1Y-and SM-Et-2Y-based devices exhibited excellent photo-stability,retaining over 90%of their initial performance after 250 h of continuous illumination.Our results provide a deeper understanding of the molecular backbone and a guiding principle for the rational design or selection of non-fullerene single-component materials with suitable donor/acceptor ratios.展开更多
Methyl 9 ethylenedioxpyropheophorbide d was prepared from methyl pyropheophorbide a by protection of cyclic ketone with ethylene glycol, and oxidation with OsO 4 in vinyl group at 2 position. The terminal alky...Methyl 9 ethylenedioxpyropheophorbide d was prepared from methyl pyropheophorbide a by protection of cyclic ketone with ethylene glycol, and oxidation with OsO 4 in vinyl group at 2 position. The terminal alkyne was introduced into chlorin chromophore by Grignard reaction, and the enediyne moiety was constructed by a palladium catalyzed coupling reaction with (Z) chloroenynes.展开更多
Three novel symmetrical 4.4'-difluoro-4-bora-3a,4a-diaza-sindacene(BODIPY) derivatives were synthesized via a general and efficient protocol. These BODIPY dyads bear a diverse aryl linker bridge in the middle and t...Three novel symmetrical 4.4'-difluoro-4-bora-3a,4a-diaza-sindacene(BODIPY) derivatives were synthesized via a general and efficient protocol. These BODIPY dyads bear a diverse aryl linker bridge in the middle and two BODIPY units at the termini. The photophysical properties of these dyads were investigated by ultravioletvisible(UV-Vis) absorption and emission spectroscopy. And their electrochemical properties were studied by cyclic voltammetry. The absorption of these dyads showed slightly blue shift and the intramolecular charge transfer(ICT) state under,vent ultrafast direct surface crossing to the ground state with high degree of rotational freedom. The results will be useful for the further functionalization of these novel symmetrical BODIPY derivatives.展开更多
A notation of the eigentensors of an arbitrary second-order tensor had been introduced by HUANG Yong-nian (1992). By using this notation an explicit solution of homogeneous linear ordinary differential equations with ...A notation of the eigentensors of an arbitrary second-order tensor had been introduced by HUANG Yong-nian (1992). By using this notation an explicit solution of homogeneous linear ordinary differential equations with constant coefficients had been given. Recently, it is found that these eigentensors are dyads. By using these dyads the tensor calculations can be simplified greatly.展开更多
Creativity is designative for the mankind,distinguishing it among the other species.Everyone is born with the affinity to speculate the perceived reality—overlaying it by his own imagination,inventing a playful use f...Creativity is designative for the mankind,distinguishing it among the other species.Everyone is born with the affinity to speculate the perceived reality—overlaying it by his own imagination,inventing a playful use for the encountered items and refreshing extant ideas by new approaches,creating new mental outcome.The perceived world is not enough for the human mind,which challenges the given reality,animated by the need for questing and creatively exploring beyond it.As a result,the history of humanity is a history of realized inventions and different visions.If the creativity is an organic part of the human nature,why are so few mature people creative?展开更多
We analyze the success of Konstantin Stanislavski's method of emotion memory in Western acting schools. We propose a path that, counter-intuitively, connects the emotional distress related to this method with an atta...We analyze the success of Konstantin Stanislavski's method of emotion memory in Western acting schools. We propose a path that, counter-intuitively, connects the emotional distress related to this method with an attachment to it. A chain of psychological steps explains this dynamic: the delegation of power from the actor to the director, emotional suffering during the training, rise of feelings within the dyad, and eventually rise of satisfaction. Our argument draws especially on interdisciplinary research on athlete-coach relationships in sports psychology while also suggesting wider application to educational psychology and psychotherapy.展开更多
A full-relaxation optimization of molecule and the Dreiding force field are employed to obtain the geometry parameters and the conformational energy surfaces of meso or racemic dyad of poly(acrylic acid) (PAA) and pol...A full-relaxation optimization of molecule and the Dreiding force field are employed to obtain the geometry parameters and the conformational energy surfaces of meso or racemic dyad of poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA). Three different carbonyl-bond orientations of side-groups resulted in the differences in depth of potential wells in their energetic contours for a meso or a racemic dyad. These discrepancies are interpreted as a result of various fine structures corresponding to grid search conformations as well as thereby different interactions. The analysis on the most stable conformations of PMAA confirmed that the ester groups are nearly perpendicular to the plane defined by the two adjacent skeletal bonds but may possibly change their relative orientations to meet the requirement of lower energy during the conformational state transition. For each polymer, two global energy maps of a meso and a racemic dyad were finally constructed from the superposition of energy data for the three kinds of side-group orientations by the Boltzmann factors. From an ensemble average, the proposed scheme with three rotational isomeric states (RIS) allowed us to access the experimentally unperturbed dimensions of PAA chain via the configurational statistical mechanics. Although the calculation was based on the short-range, local interactions, it was interested to note that the experimental characteristic ratios just fell within the range calculated for atactic chains.展开更多
The ground and excited state properties of the [60]fullerene, diphenylbenzothiadiazole-triphenylamine (PBTDP-TPA) dyad and fullerene-diphenylbenzothiadiazole-triphenylamine (fullerene-PBTDP-TPA) triad were investi...The ground and excited state properties of the [60]fullerene, diphenylbenzothiadiazole-triphenylamine (PBTDP-TPA) dyad and fullerene-diphenylbenzothiadiazole-triphenylamine (fullerene-PBTDP-TPA) triad were investigated theoretically using density functional theory with B3LYP functional and 3-21G basis set and time-dependent density functional theory with B3LYP functional and STO-3G basis set as well as 2D and 3D real space analysis methods. The 2D site representation reveals the electron-hole coherence on excitation. The 3D transition density shows the orientation and strength of the transition dipole moment, and the 3D charge difference density gives the orientation and result of the intramolecular charge transfer. Also photoinduced intermolecular charge transfer (ICT) in PBTDP-TPA-fullerene triad are identified with 2D and 3D representations, which reveals the mechanisms of ICT in donor-bridge-acceptor triad on excitation. Besides that we also found that the direct superexchange ICT from donor to acceptor (tunneling through the bridge) strongly promotes the ICT in the donor-bridge-acceptor triad.展开更多
Dyad and triad census summarize much of the network level structural information of a given directed network. They have been found very useful in analyzing structural properties of social networks. This study aims to ...Dyad and triad census summarize much of the network level structural information of a given directed network. They have been found very useful in analyzing structural properties of social networks. This study aims to explore crisis communication network by following dyad and triad census analysis approach to investigate the association of microlevel communication patterns with organizational crisis. This study further tests hypothesis related to the process of data generation and tendency of the structural pattern of transitivity using dyad and triad census output. The changing communication network at Enron Corporation during the period of its crisis is analyzed in this study. Significant differences in the presence of different isomorphism classes or microlevel patterns of both dyad and triad census are noticed in crisis and non-crisis period network of Enron email corpus. It is also noticed that crisis communication network shows more transitivity compared to the non-crisis communication network.展开更多
A new copper phthalocyanine-fullerene dyad (CuPc-C-60) was synthesized by Diels-Alder adduct of corresponding CuPc and C-60. The chemical structure of this compound was characterized by elemental analysis, MS, IR, UV-...A new copper phthalocyanine-fullerene dyad (CuPc-C-60) was synthesized by Diels-Alder adduct of corresponding CuPc and C-60. The chemical structure of this compound was characterized by elemental analysis, MS, IR, UV-VIS and NMR.展开更多
Nowadays the number of cores that are integrated into NoC (Network on Chip) systems is steadily increasing, and real application traffic, running in such multi-core environments requires more and more bandwidth. In th...Nowadays the number of cores that are integrated into NoC (Network on Chip) systems is steadily increasing, and real application traffic, running in such multi-core environments requires more and more bandwidth. In that sense, NoC architectures should be properly designed so as to provide efficient traffic engineering, as well as QoS support. Routing algorithm choice in conjunction with other parameters, such as network size and topology, traffic features (time and spatial distribution), as well as packet injection rate, packet size, and buffering capability, are all equivalently critical for designing a robust NoC architecture, on the grounds of traffic engineering and QoS provision. In this paper, a thorough numerical investigation is achieved by taking into consideration the criticality of selecting the proper routing algorithm, in conjunction with all the other aforementioned parameters. This is done via implementation of four routing evaluation traffic scenarios varying each parameter either individually, or as a set, thus exhausting all possible combinations, and making compact decisions on proper routing algorithm selection in NoC architectures. It has been shown that the simplicity of a deterministic routing algorithm such as XY, seems to be a reasonable choice, not only for random traffic patterns but also for non-uniform distributed traffic patterns, in terms of delay and throughput for 2D mesh NoC systems.展开更多
A series of sphere-rod shape amphiphiles were designed and synthesized by connecting the rod-like oligofluorenes with different lengths (OF,) to the different positions of the spherical [60]fullerene (C60) through...A series of sphere-rod shape amphiphiles were designed and synthesized by connecting the rod-like oligofluorenes with different lengths (OF,) to the different positions of the spherical [60]fullerene (C60) through a rigid linkage. The conjugates were characterized by IH-NMR, 13C-NMR, FTIR, EA and MALDI-TOF mass spectrometry. The optical and electronic properties of the conjugates were studied by UV-Vis absorption spectroscopy, fluorescence spectrometry, and cyclic voltammetry. The results from UV-Vis absorption spectroscopy and cyclic voltammetry indicated that the energy profiles of C60 and OFn remained unchanged when different lengths of OFn were attached to C60. The electron affinities of the OFn-C60 conjugates were close to that of C60, while slight electronic interaction was found between the two individual chromophores (C60 and OFn) in their ground states. The fluorescence spectra exhibited a complete fluorescence quenching in the toluene solution, suggesting an effective energy transfer from OFn to C60. It presents a systematic study on the self- assembly, structure-property relationship, and potential technical applications of the conjugates.展开更多
Two dyads of eosin and porphyrin linked with a semi-rigid (-CH2phCH2-) or flexible (-(CH2)4-) bridge and their reference model compounds were synthesized and characterized The intermoleccular interaction and intramole...Two dyads of eosin and porphyrin linked with a semi-rigid (-CH2phCH2-) or flexible (-(CH2)4-) bridge and their reference model compounds were synthesized and characterized The intermoleccular interaction and intramolecular photoinduced singlet energy transfer and electron transfer were studied by their absorp tion spectra,fluorescence emission,excitation spectra and fluorescence lifetime The model compounds,ethyl ester of eosm (EoEt) and porphyrin (PorEt),could form complexes in the ground state.When the eosin moieties in dyads were excited,they could transfer some singlet energy to the porphyrins; in the meantime,they could also ndsce electron transfer between two chromophores.Exciting the porphyrin moieties in dyads could induce electron transfer from eosin moieties to porphyrin moieties.The efficiencies (EnT,ET) and rate constants (kEnT,kET) were related to the polarity of solvents and mutual orientation of the two chromophores in dyads.展开更多
Group living provides various advantages to individuals in regards to protection avoidance,intergroup competition,productive success and social information.Stable one-male units(OMUs)consist of relationships between t...Group living provides various advantages to individuals in regards to protection avoidance,intergroup competition,productive success and social information.Stable one-male units(OMUs)consist of relationships between the adult females and the resident male as well as the relationships among adult females.Based on continuous observation of a reproductive group of golden snub-nosed monkeys(Rhinopithecus roxellana)in the Qinling Mountains,we analyzed the relationships among adult individual dyads within 4 OMUs.The results indicated that in golden snub-nosed monkey societies,females not only had no strong tendency to build a relationship with the resident male in the OMU but also had no strong tendency to build relationships with other females in the OMU.In comparison with hamadryas(Papio hamadryas)and gelada baboons(Theropithecus gelada),the relationships within golden snub-nosed monkeys OMUs showed neither the star-shaped pattern observed in hamadryas baboons nor the net-shaped pattern observed in gelada baboons.We concluded that the relationships within golden snub-nosed monkey OMUs indicated a third pattern in nonhuman primate societies.Future research is required to determine the potential mechanisms for such a pattern.展开更多
Two donor-σ-acceptor molecular systems incorporating tetrathiafulvalene(TTF)and tetraphenylpor-phyrin(TPP)units,TTF-TPP(dyad 1)and TTF-TPP-TTF(triad 2),were synthesized.Both dyad 1 and triad 2 and their synthetic int...Two donor-σ-acceptor molecular systems incorporating tetrathiafulvalene(TTF)and tetraphenylpor-phyrin(TPP)units,TTF-TPP(dyad 1)and TTF-TPP-TTF(triad 2),were synthesized.Both dyad 1 and triad 2 and their synthetic intermediates have been characterized by 1H nuclear magnetic resonance(1H NMR)and mass spectro-graphy(MS).Their ultraviolet and visible spectroscopy(UV-Vis)and cyclic voltammetry(CV)showed negligible intramolecular charge transfer interaction in their ground states.Theirfluorescence intensity was strongly quenched compared with TPP,which implied the photoinduced electron transfer occurred from the TTF unit to the TPP unit in the excited state.On the other hand,theirfluorescence intensity could be modulated by sequential oxidation of the TTF unit using chemical methods,which exhibited their potential application influorescence molecular switch.展开更多
基金supported by the National Natural Science Foundation of China(32272316)Beijing Innovation Team of Livestock Industry Technology System(BAIC05-2022)Guangxi Science and Technology Project(AD20297088).
文摘Nutrients in human milk,including minerals,relate growth and development of breast-fed infants.Tibetan mother-infant dyads possess unique characteristics on early nutrition due to their featured long-lasting lifestyle.This study longitudinally investigated the relationship between the mineral composition in human milk and the Z-scores of infants among Tibetan mother-infant dyads during their first 6 months postpartum through a prospective cohort study.The results show that the minerals of Na,Mg,K,Ca,Cu,Zn,and Se were of higher levels in colostrum than other lactation stages.Several minerals were below the recommended values for infants according to Chinese dietary guidelines.Besides,a large proportion of infant Z-scores were below-2 as lactation period continued.Multivariate statistical analysis revealed that classifications and correlations in varying degrees were observed between minerals in human milk and infant Z-scores.These findings will be advantageous for research upon Chinese early nutrition and progress of tailor-made infant formula.
基金support from the National Natural Science Foundation of China(No.21688102,No.21590801,and No.21520102005)support from Sichuan Science and Technology Program Grant(2020YJ0161)。
文摘In this work,we employ electronic structure calculations and nonadiabatic dynamics simulations based on many-body Green function and BetheSalpeter equation(GW/BSE)methods to study excited-state properties of a zinc phthalocyanine-fullerene(ZnPcC_(60))dyad with 6-6 and 5-6 configurations.In the former,the initially populated locally excited(LE)state of ZnPc is the lowest S1 state and thus,its subsequent charge separation is relatively slow.In contrast,in the latter,the S1 state is the LE state of C_(60)while the LE state of ZnPc is much higher in energy.There also exist several charge-transfer(CT)states between the LE states of ZnPc and C_(60).Thus,one can see apparent charge separation dynamics during excited-state relaxation dynamics from the LE state of ZnPc to that of C_(60).These points are verified in dynamics simulations.In the first 200 fs,there is a rapid excitation energy transfer from ZnPc to C_(60),followed by an ultrafast charge separation to form a CT intermediate state.This process is mainly driven by hole transfer from C_(60)to ZnPc.The present work demonstrates that different bonding patterns(i.e.5-6 and 6-6)of the C−N linker can be used to tune excited-state properties and thereto optoelectronic properties of covalently bonded ZnPc-C_(60)dyads.Methodologically,it is proven that combined GW/BSE nonadiabatic dynamics method is a practical and reliable tool for exploring photoinduced dynamics of nonperiodic dyads,organometallic molecules,quantum dots,nanoclusters,etc.
基金Beijing Natural Science Foundation,Grant/Award Number:JQ210065NSFC,Grant/Award Numbers:52073016,92163128+4 种基金Fundamental Research Funds for the Central Universities,Grant/Award Numbers:buctrc201828,XK1802-2The opening Foundation of State Key Laboratory of Organic-Inorganic Composites,Beijing University of Chemical Technology,Grant/Award Number:oic-202201006Jiangxi Provincial Department of Science and Technology,Grant/Award Numbers:20202ACBL213004,20212BCJ23035,jxsq2019102004,20203BBE53062Jiangxi Academy of Sciences,Grant/Award Numbers:2021YSBG22034,2021YSBG22033,2020-YZD-3Australian Research Council,Grant/Award Number:FT180100594。
文摘The molecular orientations of conjugated materials on the substrate mainly include edge-on,face-on,and end-on.Edge-on and face-on orientations have been widely observed,while end-on orientation has been rarely reported.Since in organic solar cells(OSCs)charge transport is along the vertical direction,end-on orientation with conjugated backbones perpendicular to the substrate is recognized as the ideal microstructure for OSCs.In this work,we for the first time obtained the preferential end-on orientation in a conjugated molecular dyad that contains a conjugated backbone as donor and perylene bisimide side units as acceptor.This was realized by introducing a fused-ring structure to replace linear terthiophenes with conjugated backbones,yielding F-MDPBI and L-MDPBI respectively.Surprisingly,a shifting trend of the molecular orientation from dominating edge-on in L-MDPBI to preferential end-on in F-MDPBI was observed.As a consequence,vertical charge carrier mobilities in F-MDPBI are one order of magnitude higher than those with preferential edge-on orientation,so single-component OSCs based on this molecular dyad as a single photoactive layer provided a power conversion efficiency of 4.89% compared to 1.70% based on L-MDPBI with preferential edge-on orientation.
文摘ELECTRON transfer plays a crucial role in energy transformation of natural biological systemssuch as the photosynthetic process by which plants convert solar energy into chemical energy.This is achieved in photosynthesis by a series of electron transfers which occur after light is ab-sorbed. Among the various factors which influence the efficiency of electron transfer struc-tural effect is one of the important features to be considered. In recent years, numerous syn-thetic model dyads in which electron donor and electron acceptor are covalently linked by dif-ferent spacers have been designed and synthesized in an effort to understand how the
基金supported by the National Natural Science Foundation of China(52061135206,22279094)the Fundamental Research Funds for the Central Universities。
文摘The performance of organic solar cells(OSCs)is mainly related to the bulk heterojunction(BHJ)microstructure of specific active layer systems,which is often in a metastable state.A promising strategy to address the abovementioned shortcomings of BHJs is to develop single-component active layer materials.Owing to the single-component small molecule materials with defined chemical structures generally exhibit poor absorption spectra,herein we first introduced narrow bandgap Y-series acceptors into the molecular skeleton of single-component materials,and designed two molecular dyads,SM-Et-1Y and SM-Et-2Y.The optical bandgaps(E_g~(opt)s)of the two dyads are 1.364 and 1.361 eV,respectively,which are much smaller than those of previously reported single-component molecules.Consequently,the SM-Et-2Y-based single-component OSCs(SCOSCs)showed a power conversion efficiency(PCE)of 5.07%,superior to SM-Et-1Y(2.53%),which is one of the highest PCEs reported for SCOSCs to date.Moreover,both SM-Et-1Y-and SM-Et-2Y-based devices exhibited excellent photo-stability,retaining over 90%of their initial performance after 250 h of continuous illumination.Our results provide a deeper understanding of the molecular backbone and a guiding principle for the rational design or selection of non-fullerene single-component materials with suitable donor/acceptor ratios.
文摘Methyl 9 ethylenedioxpyropheophorbide d was prepared from methyl pyropheophorbide a by protection of cyclic ketone with ethylene glycol, and oxidation with OsO 4 in vinyl group at 2 position. The terminal alkyne was introduced into chlorin chromophore by Grignard reaction, and the enediyne moiety was constructed by a palladium catalyzed coupling reaction with (Z) chloroenynes.
基金the National Natural Science Foundation of China
文摘Three novel symmetrical 4.4'-difluoro-4-bora-3a,4a-diaza-sindacene(BODIPY) derivatives were synthesized via a general and efficient protocol. These BODIPY dyads bear a diverse aryl linker bridge in the middle and two BODIPY units at the termini. The photophysical properties of these dyads were investigated by ultravioletvisible(UV-Vis) absorption and emission spectroscopy. And their electrochemical properties were studied by cyclic voltammetry. The absorption of these dyads showed slightly blue shift and the intramolecular charge transfer(ICT) state under,vent ultrafast direct surface crossing to the ground state with high degree of rotational freedom. The results will be useful for the further functionalization of these novel symmetrical BODIPY derivatives.
文摘A notation of the eigentensors of an arbitrary second-order tensor had been introduced by HUANG Yong-nian (1992). By using this notation an explicit solution of homogeneous linear ordinary differential equations with constant coefficients had been given. Recently, it is found that these eigentensors are dyads. By using these dyads the tensor calculations can be simplified greatly.
文摘Creativity is designative for the mankind,distinguishing it among the other species.Everyone is born with the affinity to speculate the perceived reality—overlaying it by his own imagination,inventing a playful use for the encountered items and refreshing extant ideas by new approaches,creating new mental outcome.The perceived world is not enough for the human mind,which challenges the given reality,animated by the need for questing and creatively exploring beyond it.As a result,the history of humanity is a history of realized inventions and different visions.If the creativity is an organic part of the human nature,why are so few mature people creative?
文摘We analyze the success of Konstantin Stanislavski's method of emotion memory in Western acting schools. We propose a path that, counter-intuitively, connects the emotional distress related to this method with an attachment to it. A chain of psychological steps explains this dynamic: the delegation of power from the actor to the director, emotional suffering during the training, rise of feelings within the dyad, and eventually rise of satisfaction. Our argument draws especially on interdisciplinary research on athlete-coach relationships in sports psychology while also suggesting wider application to educational psychology and psychotherapy.
基金This work was supported by the Youth Science Foundation of Acedemia Sinica the China Postdoctoral Science Foundation, the National Natural Science Foundation of China, and Polymer Physics Laboratory,Academia Sinica
文摘A full-relaxation optimization of molecule and the Dreiding force field are employed to obtain the geometry parameters and the conformational energy surfaces of meso or racemic dyad of poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA). Three different carbonyl-bond orientations of side-groups resulted in the differences in depth of potential wells in their energetic contours for a meso or a racemic dyad. These discrepancies are interpreted as a result of various fine structures corresponding to grid search conformations as well as thereby different interactions. The analysis on the most stable conformations of PMAA confirmed that the ester groups are nearly perpendicular to the plane defined by the two adjacent skeletal bonds but may possibly change their relative orientations to meet the requirement of lower energy during the conformational state transition. For each polymer, two global energy maps of a meso and a racemic dyad were finally constructed from the superposition of energy data for the three kinds of side-group orientations by the Boltzmann factors. From an ensemble average, the proposed scheme with three rotational isomeric states (RIS) allowed us to access the experimentally unperturbed dimensions of PAA chain via the configurational statistical mechanics. Although the calculation was based on the short-range, local interactions, it was interested to note that the experimental characteristic ratios just fell within the range calculated for atactic chains.
基金This work was supported by the National Natural Science Foundation of China (No.10374040, No.20703064, and No.10505001) and the Postdoctoral Science Foundation of China (No.20060390017).
文摘The ground and excited state properties of the [60]fullerene, diphenylbenzothiadiazole-triphenylamine (PBTDP-TPA) dyad and fullerene-diphenylbenzothiadiazole-triphenylamine (fullerene-PBTDP-TPA) triad were investigated theoretically using density functional theory with B3LYP functional and 3-21G basis set and time-dependent density functional theory with B3LYP functional and STO-3G basis set as well as 2D and 3D real space analysis methods. The 2D site representation reveals the electron-hole coherence on excitation. The 3D transition density shows the orientation and strength of the transition dipole moment, and the 3D charge difference density gives the orientation and result of the intramolecular charge transfer. Also photoinduced intermolecular charge transfer (ICT) in PBTDP-TPA-fullerene triad are identified with 2D and 3D representations, which reveals the mechanisms of ICT in donor-bridge-acceptor triad on excitation. Besides that we also found that the direct superexchange ICT from donor to acceptor (tunneling through the bridge) strongly promotes the ICT in the donor-bridge-acceptor triad.
文摘Dyad and triad census summarize much of the network level structural information of a given directed network. They have been found very useful in analyzing structural properties of social networks. This study aims to explore crisis communication network by following dyad and triad census analysis approach to investigate the association of microlevel communication patterns with organizational crisis. This study further tests hypothesis related to the process of data generation and tendency of the structural pattern of transitivity using dyad and triad census output. The changing communication network at Enron Corporation during the period of its crisis is analyzed in this study. Significant differences in the presence of different isomorphism classes or microlevel patterns of both dyad and triad census are noticed in crisis and non-crisis period network of Enron email corpus. It is also noticed that crisis communication network shows more transitivity compared to the non-crisis communication network.
文摘A new copper phthalocyanine-fullerene dyad (CuPc-C-60) was synthesized by Diels-Alder adduct of corresponding CuPc and C-60. The chemical structure of this compound was characterized by elemental analysis, MS, IR, UV-VIS and NMR.
文摘Nowadays the number of cores that are integrated into NoC (Network on Chip) systems is steadily increasing, and real application traffic, running in such multi-core environments requires more and more bandwidth. In that sense, NoC architectures should be properly designed so as to provide efficient traffic engineering, as well as QoS support. Routing algorithm choice in conjunction with other parameters, such as network size and topology, traffic features (time and spatial distribution), as well as packet injection rate, packet size, and buffering capability, are all equivalently critical for designing a robust NoC architecture, on the grounds of traffic engineering and QoS provision. In this paper, a thorough numerical investigation is achieved by taking into consideration the criticality of selecting the proper routing algorithm, in conjunction with all the other aforementioned parameters. This is done via implementation of four routing evaluation traffic scenarios varying each parameter either individually, or as a set, thus exhausting all possible combinations, and making compact decisions on proper routing algorithm selection in NoC architectures. It has been shown that the simplicity of a deterministic routing algorithm such as XY, seems to be a reasonable choice, not only for random traffic patterns but also for non-uniform distributed traffic patterns, in terms of delay and throughput for 2D mesh NoC systems.
基金financially supported by the International Science&Technology Cooperation Program of China(No.2010DFB70470)the Natural Science Foundation of Shanghai(No.10ZR1407600)
文摘A series of sphere-rod shape amphiphiles were designed and synthesized by connecting the rod-like oligofluorenes with different lengths (OF,) to the different positions of the spherical [60]fullerene (C60) through a rigid linkage. The conjugates were characterized by IH-NMR, 13C-NMR, FTIR, EA and MALDI-TOF mass spectrometry. The optical and electronic properties of the conjugates were studied by UV-Vis absorption spectroscopy, fluorescence spectrometry, and cyclic voltammetry. The results from UV-Vis absorption spectroscopy and cyclic voltammetry indicated that the energy profiles of C60 and OFn remained unchanged when different lengths of OFn were attached to C60. The electron affinities of the OFn-C60 conjugates were close to that of C60, while slight electronic interaction was found between the two individual chromophores (C60 and OFn) in their ground states. The fluorescence spectra exhibited a complete fluorescence quenching in the toluene solution, suggesting an effective energy transfer from OFn to C60. It presents a systematic study on the self- assembly, structure-property relationship, and potential technical applications of the conjugates.
基金Project supported by the National Natural Science Foundation of China
文摘Two dyads of eosin and porphyrin linked with a semi-rigid (-CH2phCH2-) or flexible (-(CH2)4-) bridge and their reference model compounds were synthesized and characterized The intermoleccular interaction and intramolecular photoinduced singlet energy transfer and electron transfer were studied by their absorp tion spectra,fluorescence emission,excitation spectra and fluorescence lifetime The model compounds,ethyl ester of eosm (EoEt) and porphyrin (PorEt),could form complexes in the ground state.When the eosin moieties in dyads were excited,they could transfer some singlet energy to the porphyrins; in the meantime,they could also ndsce electron transfer between two chromophores.Exciting the porphyrin moieties in dyads could induce electron transfer from eosin moieties to porphyrin moieties.The efficiencies (EnT,ET) and rate constants (kEnT,kET) were related to the polarity of solvents and mutual orientation of the two chromophores in dyads.
基金funded by grants from the Key Program of National Natural Science Fund(31130061)the Special Foundation of Shaanxi Academy of Sciences,China(2012K-01)+4 种基金the Youth Foundation of Shaanxi Academy of Sciences,China(2013K-35)the Western Light Talent Culture Project(2011DF05)the National Nature Science Foundation of China(30970444,30970168,30970379)the Research Fund for the Doctoral Program of Higher Education of China(20106101110005)the Cosmo Oil Eco Card Fund of Japan(2005–2012).
文摘Group living provides various advantages to individuals in regards to protection avoidance,intergroup competition,productive success and social information.Stable one-male units(OMUs)consist of relationships between the adult females and the resident male as well as the relationships among adult females.Based on continuous observation of a reproductive group of golden snub-nosed monkeys(Rhinopithecus roxellana)in the Qinling Mountains,we analyzed the relationships among adult individual dyads within 4 OMUs.The results indicated that in golden snub-nosed monkey societies,females not only had no strong tendency to build a relationship with the resident male in the OMU but also had no strong tendency to build relationships with other females in the OMU.In comparison with hamadryas(Papio hamadryas)and gelada baboons(Theropithecus gelada),the relationships within golden snub-nosed monkeys OMUs showed neither the star-shaped pattern observed in hamadryas baboons nor the net-shaped pattern observed in gelada baboons.We concluded that the relationships within golden snub-nosed monkey OMUs indicated a third pattern in nonhuman primate societies.Future research is required to determine the potential mechanisms for such a pattern.
基金supported by the National Natural Science Foundation of China(Grant Nos.21076078 and 20676036).
文摘Two donor-σ-acceptor molecular systems incorporating tetrathiafulvalene(TTF)and tetraphenylpor-phyrin(TPP)units,TTF-TPP(dyad 1)and TTF-TPP-TTF(triad 2),were synthesized.Both dyad 1 and triad 2 and their synthetic intermediates have been characterized by 1H nuclear magnetic resonance(1H NMR)and mass spectro-graphy(MS).Their ultraviolet and visible spectroscopy(UV-Vis)and cyclic voltammetry(CV)showed negligible intramolecular charge transfer interaction in their ground states.Theirfluorescence intensity was strongly quenched compared with TPP,which implied the photoinduced electron transfer occurred from the TTF unit to the TPP unit in the excited state.On the other hand,theirfluorescence intensity could be modulated by sequential oxidation of the TTF unit using chemical methods,which exhibited their potential application influorescence molecular switch.