Effects of Diet with"Lianhuang"Additive of Chinese Herb Medicine on Growth Performance and Metabolic Rates of Dietary Nutrients in Donglan Black Chicken

[Objectives]The study was conducted to evaluate the effects of diet with"Lianhuang"additive of Chinese herbal medicine(LACHM)on growth performance and metabolic rates of dietary nutrients in Donglan black chickens(DBCs).[Methods]80 DBCs aged 1 d were blocked into 4 groups randomly and assigned to 6 replicates in each group with 20 chicks in each replicate.Group A as control group fed basal diet.Groups B,C and D as treatment groups consumed the basal diet added with 0.25%,0.50%and 1.00%of LACHM,respectively during the test period of 70 d.In the end of feeding test,24 DBCs with similar body weight from each group were chosen out and used for a metabolism test to determine the metabolic rates of dietary nutrients from each treatment.The metabolism test was conducted as the same design as the feeding test and the DBCs from each group were fed the same diet as previous test.[Results]The ADG of chickens in the test increased by 5.00%-9.15%(P<0.05)except the stage of 50-70 d,and the individual average body weight(IABW)at 70 d in group B also increased by 4.86%(P<0.05).Compared with group A,the ADG of group C in the stages of 36-49,1-49 and 1-70 d and the IABW in the end of 70 d increased by 5.90%,2.66%,2.68%and 2.57%(P>0.05),respectively.The ADFI in the stage of 36-49 d from group A was 6.04%more than that from group B(P<0.01),and 5.12%and 4.13%more than those from groups C and D(P<0.05),respectively,and the ADFI of group A in the stage of 1-49 d was still 2.86%more than that from group C(P<0.05).However,no differences in ADFI were found in other stages in the test among the 4 groups(P>0.05).The F/G in the stages of 22-35 and 1-70 d from group B was 6.32%and 3.41%lower than those from group A(P<0.05),respectively,and even 11.43%and 7.31%lower in the stages of 36-49 and 1-49 d from group B than those from group A(P<0.01),respectively.The F/G of group C in the stage of 36-49 d was also 10.15%lower than that of group A(P<0.05),and still 5.29%lower than that from group A in 1-49 d(P<0.01),but no differences were found in other stages between the two groups(P>0.05).The metabolic rates of MD,CP,CF,NFE,CA,TE,Ca and P in the 3 treatment diets for group B,C and D all increased to some extent.Among them,the increasing extents of diets with 0.25%and 0.50%of LACHM for groups B and C were much greater.Therefore,the diet with 0.25%of LACHM could improve the growth performance and metabolic rates of dietary nutrients in DBCs significantly.[Conclusions]This study provides a theoretical reference for the effects of traditional Chinese medicine additives on the growth and metabolic rates of DBCs.

High-performance terahertz modulators induced by substrate field in Te-based all-2D heterojunctions

High-performance active terahertz modulators as the indispensable core components are of great importance for the next generation communication technology.However,they currently suffer from the tradeoff between modulation depth and speed.Here,we introduce two-dimensional(2D)tellurium(Te)nanofilms with the unique structure as a new class of optically controlled terahertz modulators and demonstrate their integrated heterojunctions can successfully improve the device performances to the optimal and applicable levels among the existing all-2D broadband modulators.Further photoresponse measurements confirm the significant impact of the stacking order.We first clarify the direction of the substrate-induced electric field through first-principles calculations and uncover the unusual interaction mechanism in the photoexcited carrier dynamics associated with the charge transfer and interlayer exciton recombination.This advances the fundamental and applicative research of Te nanomaterials in high-performance terahertz optoelectronics.

Drag reduction characteristics of recirculation flow at rocket base in an RBCC engine under ramjet/scramjet mode

To reduce the drag generated by the recirculation flow at the rocket base in a RocketBased Combined Cycle(RBCC)engine operating in the ramjet/scramjet mode,a novel annular rocket RBCC engine based on a central plug cone was proposed.The performance loss mechanism caused by the recirculation flow at the rocket base and the influence of the plug cone configuration on the thrust performance were studied.Results indicated that the recirculation flow at the rocket base extended through the entire combustor,which creates an extensive range of the"low-kineticenergy zone"at the center and leads to an engine thrust loss.The plug cone serving as a surface structure had a restrictive effect on the internal flow of the engine,making it smoothly transit at the position of the large separation zone.The model RBCC engine could achieve a maximum thrust augmentation of 37.6%with a long plug cone that was twice diameter of the inner isolator.However,a shorter plug cone that was half diameter of the inner isolator proved less effective at reducing the recirculation flow for a supersonic flow and induced an undesirable flow fraction that diminished the thrust performance.Furthermore,the effectiveness of the plug cone increased with the flight Mach number,indicating that it could further broaden the operating speed range of the scramjet mode.

在线课程质量观和质量要素的质性研究--基于专家、实践者和学习者的视角

本文采用扎根理论研究方法,通过对学术专家、实践者和学习者三类相关群体的访谈,调查高等教育和继续教育在线课程相关人群关于在线课程的质量观与对质量构成的认识,探索在线课程质量框架与要素,以期为促进人们对在线课程质量的共识,为改进和优化现有在线课程质量标准提供参考。研究通过对20位受访者累计22万字访谈文本的编码分析,发现四种质量观--服务质量观、系统性质量观、目标性质量观和增值性质量观,并定义出设计开发与实施运行两大类的九个在线课程质量要素--课程目标、课程内容、学习过程、学习支持服务、学习评价、媒体与技术环境、实施效果、改进发展和社会影响。其中,课程目标、学习内容与实施效果被定义为核心要素。本文基于TF-IDF关键词统计方法对三类群体的在线课程质量观差异进行了分析,并结合已有远程教育质量观和在线课程质量标准相关成果对本研究发现和定义的在线课程质量观、质量框架和质量要素进行了讨论与反思。

可控氧化方法制备的锰氧化物中隐藏的金属-绝缘体转变研究（英文）

氧在调节复杂氧化物中的相结构和功能方面扮演着重要的角色,比如高温超导体、庞磁电阻、催化等,人们急需在这些功能氧化物中实现有效且可控的氧含量调控.在此工作中我们通过改变气体氛围温度来精确的调控氧化活性,从而实现一种新的化学辅助的高质量外延薄膜的制备方法.以钙钛矿锰氧化物La_(0.5)Sr_(0.5)MnO_3(LSMO)为例,通过调控薄膜样品中氧的化学计量比,我们首次发现了该体系中隐藏的由相竞争产生的金属-绝缘体转变.氧组分引起的Mn离子间的交换相互作用以及载流子浓度的变化可能是此相转变产生的原因,这与第一性原理计算十分符合.不同于传统的阳离子掺杂,有效的阴离子(O^(2-), S^(2-)等)调节提供了一种新的实现复杂氧化物外延薄膜中调控相结构和功能的技术手段.