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
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
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
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
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
In order to harness wind energy with high coefficients, horizontal axis wind turbines (HAWT), like propeller-type wind turbines, have an advantage in terms of practical utilization because of their scale merit. Howeve...In order to harness wind energy with high coefficients, horizontal axis wind turbines (HAWT), like propeller-type wind turbines, have an advantage in terms of practical utilization because of their scale merit. However, large size and high tip-speed ratio are inherently related to material strength problems and low frequency noise emissions to the environment. In contrast to HAWT, we will discuss a flapping-type turbine driven at low speed. The flapping turbine works using lift force like the HAWT, but employs a new wind turbine concept in the present report. The concept involves the unique flapping motion of a wind blade mounted on a Chebyshev-dyad linkage by which the wing transforms wind energy into mechanical rotation. Both static and dynamic numerical estimates are developed to optimize all fundamental parameters of this linkage in order to obtain the desired torque. In this paper, the results of primitive optimization for determining the fundamental characteristics of motion and the trajectory of the wind turbine blade are demonstrated in order to obtain smooth rotation of the generator-driving shaft. It is also shown that the present turbine can be driven at low speed with a suitable energy conversion rate. Moreover, the practicality of operating slow flapping-type wind turbines is demonstrated, focusing on usage near residential areas or, e.g., on rooftops owing to lower noise. The feasibility of “figure eight” trajectory diversity is discussed along with geometrical parameters. Assuming one-blade motion with a variable trajectory for optimization, the smooth motion and required torque at slow rotation speeds are studied.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.
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.
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.
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.
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In order to harness wind energy with high coefficients, horizontal axis wind turbines (HAWT), like propeller-type wind turbines, have an advantage in terms of practical utilization because of their scale merit. However, large size and high tip-speed ratio are inherently related to material strength problems and low frequency noise emissions to the environment. In contrast to HAWT, we will discuss a flapping-type turbine driven at low speed. The flapping turbine works using lift force like the HAWT, but employs a new wind turbine concept in the present report. The concept involves the unique flapping motion of a wind blade mounted on a Chebyshev-dyad linkage by which the wing transforms wind energy into mechanical rotation. Both static and dynamic numerical estimates are developed to optimize all fundamental parameters of this linkage in order to obtain the desired torque. In this paper, the results of primitive optimization for determining the fundamental characteristics of motion and the trajectory of the wind turbine blade are demonstrated in order to obtain smooth rotation of the generator-driving shaft. It is also shown that the present turbine can be driven at low speed with a suitable energy conversion rate. Moreover, the practicality of operating slow flapping-type wind turbines is demonstrated, focusing on usage near residential areas or, e.g., on rooftops owing to lower noise. The feasibility of “figure eight” trajectory diversity is discussed along with geometrical parameters. Assuming one-blade motion with a variable trajectory for optimization, the smooth motion and required torque at slow rotation speeds are studied.
