Longitudinal investigation of mineral composition in human milk and its correlation with infant anthropometric outcomes among Tibetan mother-infant dyads during the first 6 months postpartum

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.

Dyads方法综合曲柄滑块机构

本文在用Dyads的方法综合平面铰链四连杆机构的基础上,提出了综合曲柄滑块机构的矢量方程.用这一方程可解决综合曲柄滑块机构实现刚体导向的问题.

Photoinduced Intramolecular Charge Transfer in Donor-acceptor Dyad and Donor-bridge-acceptor Triad

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.

GW/BSE Nonadiabatic Dynamics Simulations on Excited-State Relaxation Processes of Zinc Phthalocyanine-Fullerene Dyads:Roles of Bridging Chemical Bonds

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.

Self-assembled donor-acceptor hole contacts for inverted perovskite solar cells with an efficiency approaching 22%: The impact of anchoring groups

Self-assembled molecules(SAMs) have shown great potential in replacing bulk charge selective contact layers in high-performance perovskite solar cells(PSCs) due to their low material consumption and simple processing. Herein, we design and synthesize a series of donor-acceptor(D-A) type SAMs(MPA-BTCA, MPA-BT-BA, and MPA-BT-RA, where MPA is 4-methoxy-N-(4-methoxyphenyl)-N-phenylaniline;BT is benzo[c][1,2,5]-thiadiazole;CA is 2-cyanoacrylic acid, BA is benzoic acid, RA is rhodanine-3-propionic acid) with distinct anchoring groups, which show dramatically different properties. MPA-BTCA with CA anchoring groups exhibited stronger dipole moments and formed a homogeneous monolayer on the indium tin oxide(ITO) surface by adopting an upstanding self-assembling mode. However, the MPA-BT-RA molecules tend to aggregate severely in solid state due to the sp~3 hybridization of the carbon atom on the RA group, which is not favorable for achieving a long-range ordered self-assembled layer.Consequently, benefiting from high dipole moment, as well as dense and uniform self-assembled film,the device based on MPA-BT-CA yielded a remarkable power conversion efficiency(PCE) of 21.81%.Encouragingly, an impressive PCE approaching 20% can still be obtained for the MPA-BT-CA-based PSCs as the device area is increased to 0.80 cm^(2). Our work sheds light on the design principles for developing hole selecting SAMs, which will pave a way for realizing highly efficient, flexible, and large-area PSCs.

Design and Synthesis of Acceptor-Donor-Acceptor Type Non-Fullerene Acceptors Using Oxindole-Based Bridge for Polymer Solar Cells Applications

Two acceptor-donor-acceptor(A-D-A)type non-fullerene acceptors(namely WH1 and WH7)containing the oxindole-based bridge are designed and synthesized for polymer solar cells(PSCs)applications.The bridge unit is introduced through a precursor(6-bromo-1-octylindoline-2,3-dione)that contains both bromine and carbonyl and provides the feasibility of the Pd-catalyzed cross-coupling reaction and the Knoevenagel condensation,respectively.This facile synthetic approach exhibits the potential to gain high performance non-fullerene acceptors through extendingπ-conjugated backbone with strong light-absorbing building blocks.The synthesis and properties of WH1 and WH7 are demonstrated with different endcap units,then PSCs are fabricated using PBDB-T:WH1 and PBDB-T:WH7 as the active layers,and attain an average power conversion efficiency(PCE)of 2.58%and 6.24%,respectively.Further device physics studies afford the deep insight of structure variation influence on the device performance.This work provides a facile non-fullerene acceptor design strategy and shows how structure variations impact the PSC performance.

Dyad and Triad Census Analysis of Crisis Communication Network

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.

Donor-acceptor conjugated copolymer with high thermoelectric performance:A case study of the oxidation process within chemical doping

The doping process and thermoelectric properties of donor-acceptor(D-A)type copolymers are investigated with the representative poly([2,6-4,8-di(5-ethylhexylthienyl)benzo[1,2-b;3,3-b]dithiophene]3-fluoro-2-[(2-ethylhexyl)-carbonyl]thieno[3,4-b]thiophenediyl))(PTB7-Th).The PTB7-Th is doped by Fe Cl;and only polarons are induced in its doped films.The results reveal that the electron-rich donor units within PTB7-Th lose electrons preferentially at the initial stage of the oxidation and then the acceptor units begin to be oxidized at a high doping concentration.The energy levels of polarons and the Fermi level of the doped PTB7-Th remain almost unchange with different doping levels.However,the morphology of the PTB7-Th films could be deteriorated as the doping levels are improved,which is one of the main reasons for the decrease of electrical conductivity at the later stage of doping.The best electrical conductivity and power factor are obtained to be 42.3 S·cm^(-1);and 33.9μW·mK^(-1),respectively,in the doped PTB7-Th film at room temperature.The power factor is further improved to 38.3μW·mK^(-1);at 75℃.This work may provide meaningful experience for development of D-A type thermoelectric copolymers and may further improve the doping efficiency.

Lithium Salt of NH_2-substituted Graphene Nanoribbon with Twofold Donor-acceptor Framework: Large Nonlinear Optical Property

Based on graphene, a new class of second-order nonlinear optical（NLO） material, the lithium salt of NH2-substituted graphene nanoribbon with the twofold donor（D）/acceptor（A） mode, was reported. Eight stable 2Li-2NH2-GNR lithium salts, especially cis lithium salts, display considerably large β0 values. The combination of NH2-substituting and cis Li-doping makes β0 greatly increased from 0（GNR） to 1.2×105―2.9×105 a.u.（cis-2Li- 2NH2-GNRs）. Our largest β0 value（2.9×105 a.u.） for cis-2Li-1,3-2NH2-AGNR is comparable to the record value of 1.7×105 a.u. for a long donor-acceptor polyene.

Synthesis of a Novel Copper Phthalocyanine-Fullerene Dyad

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.

Numerical Performance Assessment of a Flapping-Type Vertical Axis Wind Turbine with Chebyshev-Dyad Linkage

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.

教师工作坊网络研修的“重要他人”研究——人类发展生态学的视角

随着信息技术的迅猛发展以及"国培计划"等政府项目的实践推动,教师工作坊网络研修成为当前我国中小学教师远程培训的一种创新模式。该文从人类发展生态学角度出发,将"重要他人"概念引入教师工作坊网络研修,并对其角色来源进行了分析,认为坊主、学伴、管理者等是学员"重要他人"的主要可能来源,他们对学员积极参与培训、保持研修动力、增强归属感,以及扩大研修影响力等有重要作用;在此基础上分析了学员与"重要他人"的人际关系类型和特征,阐述了教师工作坊网络研修中的三类关系(观察的双向关系、联动的双向关系和重要的双向关系)及其转化;最后,鉴于"重要他人"对学员参与教师工作坊研修和推进教师专业发展的重要意义,对培训机构提出了一些相应建议。

卟啉-蒽醌化合物分子内光诱导电子传递的光谱研究

合成了以不同长度柔韧碳链相连的三种卟啉(Por)-蒽醌(AQ)二元化合物Por-C_n-AQ(n=1,4,10),主要通过稳态荧光光谱和瞬态荧光光谱研究了它们的分子内光诱导电子传递情况,并结合密度泛函理论(DFT)对分子内电子转移机理进行了初步探讨.结果表明:共价相连的卟啉-蒽醌二元化合物在光激发下能够发生从卟啉组分到蒽醌组分的分子内光诱导电子传递;连接链性质对电子传递速率有直接的影响.实验和理论计算结果表明卟啉-蒽醌之间的分子内电子转移很可能是通过超交换机理进行的.

酵母基因内含子中二聚体寡核苷酸转录调控位点的统计分析

对高效和低效转录酵母基因内含子序列中寡核苷酸的出现频率进行对照分析 ,结果显示高效和低效内含子序列的结构有差异 ,而且高效转录内含子序列含有较多潜在的转录因子结合位点 .观察实验获得的转录调控位点 ,发现许多调控位点不是相邻接的寡核苷酸 ,而是由一对保守寡核苷酸构成 ,这对寡核苷酸被一段长度固定的非保守区域间隔开 .于是对此形式的二聚体寡核苷酸 (dyad)在高效和低效内含子序列中出现的频率进行统计比较分析 ,抽提出在高效内含子组出现的频率显著高于在低效内含子组出现频率的二聚体寡核苷酸 ,分析这些二聚体寡核苷酸在两组内含子序列中的分布特征 ,并对照实验结果 。

C_(60)富勒烯-哌啶硫代荒酸酯稠合体的合成与三线态特征

C60 富勒烯与 2 (哌啶 -硫代荒酸酯 ) 1,3 丁二烯通过Diels Alder环加成反应得到C60 富勒烯 -哌啶硫代荒酸酯稠合体 ,运用现代波谱技术等确定了产物结构 ;用半经验方法PM3和AM1计算预测环加成反应性和C60 富勒烯 -哌啶硫代荒酸酯稠合体的性能 .激光光解时间分辨技术初步探究了单加成的C60 富勒烯 -哌啶硫代荒酸酯稠合体 (C60 PX)三线态特征以及与四 ( 2 噻吩基 ) -四硫富瓦烯 (TT TTF)分子间的光诱导电子转移反应 .

Cosserat生长弹性杆动力学的Gauss最小拘束原理

以自然界中具有生长、变形和运动特征的细长体为背景,用经典力学中的Gauss最小拘束原理研究生长弹性杆的动力学建模问题.在为生长弹性杆动力学建模提供新方法的同时,扩大了Gauss原理的应用范围.以Cosserat弹性杆为对象,分析弹性杆生长和变形的几何规则,表明生长应变和弹性应变是非线性耦合的;本构方程给出了截面的内力与弹性变形的线性关系;利用逆并矢,将经典力学中的Gauss原理和Gauss最小拘束原理用于生长弹性杆动力学,得到等价的两种表现形式,反映了时间和弧坐标在表述上的对称性,由此导出了封闭的动力学微分方程.给出了两种形式的最小拘束函数,表明生长弹性杆的实际运动使拘束函数取驻值,且为最小值.最后讨论了生长弹性杆的约束与条件极值等问题.

高管团队垂直对特征与企业创新研究

以我国A股上市公司为研究样本,从管理者背景特征视角,考察了高管团队垂直对这一结构特征对企业创新的影响。研究结果表明:高管团队性别垂直对特征对企业创新的影响不显著;高管团队年龄垂直对特征与发明专利、实用新型专利、专利总额以及创新投入均呈显著负相关关系;高管团队学历垂直对正向影响外观设计专利、专利总额以及创新投入;高管团队任期垂直对未对企业创新产出产生显著影响,但对创新投入产生了显著负向影响。区分产权性质后,上述关系在国有与非国有公司间存在显著差异。

痛抑郁二联征模型大鼠中缝背核不同水平5羟色胺表达差异

目的探讨痛抑郁二联征模型大鼠中缝背核(DRN)5羟色胺(5-HT)阳性细胞的分布特点。方法20只雄性SD大鼠随机分为对照组和模型组。模型组大鼠连续3d皮下注射利血平,每日1次,以诱发痛抑郁二联征模型。模型制作后第1天和第2天检测左后足机械缩足阈观察大鼠痛阈变化,模型制作后第2天旷场实验和高架O迷宫实验检测大鼠情绪变化,免疫荧光技术观察DRN前囟后6.8mm、7.3mm和7.8mm水平的5-HT表达。结果模型组大鼠经利血平注射后机械痛阈显著下降,并产生抑郁样行为。对照组的DRN前囟后6.8mm、7.3mm和7.8mm水平的5-HT阳性细胞表达量分别为106.00±10.21、96.67±24.50和195.67±2.33。模型组相应的表达量分别为61.67±14.53,72.33±34.35和53.67±26.77。除前囟后7.8mm水平模型组与对照组相比有显著性差异(P<0.05)之外,其他两个水平5-HT阳性细胞表达量模型组和对照组之间差异无显著性(P>0.05)。结论利血平诱导的痛抑郁二联征大鼠模型以及中缝背核5-HT表达的降低,可能主要与DRN前囟后7.8mm水平的5-HT阳性细胞数变化有关,而与前囟后6.8mm和后7.3mm水平无关。

TMT垂直对差异对创新绩效的影响——创新氛围的中介作用和行为整合的调节作用

基于社会心理和社会政治的双重视角下,从关系人口背景出发,研究高管团队(TMT)垂直对差异对创新绩效的影响,以及创新氛围的中介作用和行为整合的调节作用,以期更加全面地反映我国情境下TMT特征对创新绩效的影响。通过对有效样本的实证研究表明:TMT年龄、性别、教育和任期垂直对差异与创新绩效正相关。TMT垂直对差异对创新氛围有正向影响,创新氛围与创新绩效显著正相关,创新氛围能够部分中介TMT垂直对差异对创新绩效正向影响。行为整合能够正向调节TMT垂直对差异与创新氛围的关系,对营造创新氛围起到了良好的促进作用。

创业型企业高管团队垂直对差异与创业战略导向:产业环境和企业所有制的调节效应

在公司创业过程中,高管团队内部的构成及其运作状况会导致不同的创业战略导向,不同的产业经营领域和企业所有制也会产生差异性影响效应。本文选取2006-2010年我国中小企业板上市公司为研究样本,实证考察了创业型企业高管团队垂直对差异对创业战略导向的直接影响,以及产业环境和企业所有制如何对两者关系产生调节影响。层级多元回归分析结果表明,除教育背景测量指标外,高管团队年龄、性别和职业经历垂直对差异均对创业战略导向产生显著正向影响。分组多元回归分析结果表明:高管团队垂直对差异在动态型产业环境的影响效应大于稳定型产业环境;高管团队垂直对差异在国有企业的影响效应大于非国有企业。本文的结论对于创业型企业高管团队构建、创业战略导向结构设计,以及新业务产业经营领域和企业所有制选择等具有积极的借鉴与启示。