央视新闻主流价值的传播创新分析——以#2019正能量天团#为例

2019年年末,央视新闻通过“两微一端”等多个渠道上线了#2019正能量天团#系列人物短片,让正能量的暖流涌进人们心中。本文拟结合央视新闻推出的这一系列人物短片,对其传播创新进行分析,为新时期主流媒体如何创新主流价值的传播提供一些可行的参考意见。

小金团簇的基态结构和能量

应用遗传算法和Gupta势对小金团簇的结构进行了优化计算 ,分析讨论了基态结构和能量随团簇尺寸的变化规律 ,发现Au13 为二十面体以及Ann 在n≥ 16时呈现非晶无序结构的特征 .

镍小团簇的基态结构和能量

采用Gupta势来描述Nin 团簇中原子之间的相互作用 ,用模拟自然界生物进化的遗传算法优化计算了Nin 团簇 (n =2～ 2 3)的基态结构和能量 ,给出了结构和能量随原子数目的变化规律 ,并讨论了其相对稳定性。

狭义相对论效应物理本质的初步探讨

本文以四个物理假设为前提,其中假设一、二决定了惯性系内回路光速的测值恒为C的结论:再加上假设三、四,它们共同决定了物体运动时产生的具体物理变化,即钟慢、尺缩、质速关系等。在本文假设下,如果采用与狭义相对论相同的校钟方法,参照任一惯性系对上述动体效应的观测结果与狭义相对论的结论相同。

Inhibiting effect of[HOEmim][BF_4]and[Amim]Cl ionic liquids on the cross-linking reaction of bituminous coal

In order to reduce the hazard of coal spontaneous combustion,the cross-linking reaction between O-containing functional groups of coal should be inhibited.So the inhibitory effect of an ionic liquid(IL) on the cross-linking reaction was studied.The O-containing functional groups change the weight loss and H_2O,CO_2,CO yields of bituminous coal before and after[H0Emim][BF_4]and[Amim]Cl pre-treatment and were detected by Fourier Transform Infrared spectroscopy(FT1R) and Thermo Gravimetric(TC) analysis.The results show that | AmimjCI has a weaker ability to inhibit the cross-linking reaction of bituminous coal compared to[HOEmim][BF_4].Besides,based on Quantum Chemistry calculation,it was found that the different inhibiting effects of |H0Emim][BF_4]and[Amim]Cl are greatly related to their anions and the H linked with C2 atom on the imidazole ring.The H-donor ability of coal will be enhanced by[HOEmim][BF_4]leading to a weaker cross-linking reaction of coal.

Surface chemistry of MXene quantum dots:Virus mechanism-inspired mini-lab for catalysis

Scientific research is currently more interdisciplinary.Researchers have parsed the surface structure of virus,constructed the interaction model of virus-receptors,offering the clues for studying efficient targeted drugs.Likewise,catalysis is also highly relevant to modern human life.Exploring the surface structure and physicochemical properties of catalysts is of great significance for the design of efficient catalysts.Great progresses have been made for endowing specific physicochemical properties of catalysts through controlling the size of materials and coordination chemistry of active sites,particularly at nanometer scale since Sir John Meurig Thomas and Tao Zhang’s early ground-breaking contribution,with casting on a very surface issue.Herein,functional regulation renders the emerging MXene quantum dots(MQDs)excel in contrast to the typical carbon-based quantum dots.In fact,similar to the interaction of virus-receptors model,the surface functional groups decorated MQDs provide a mini-lab to afford a variety of adjustments,involved with the type modification and electronic structure tuning of groups as well as their arrangement,together with the interaction between the groups and active materials/support,ultimately for packaging or designing high-activity catalysts.

Adsorption of cadmium ions from aqueous solutions by activated carbon with oxygen-containing functional groups

The adsorption of aqueous cadmium ions(Cd(Ⅱ)) have been investigated for modified activated carbon(AC-T)with oxygen-containing functional groups.The oxygen-containing groups of AC-T play an important role in Cd(Ⅱ) ion adsorption onto AC-T.The modified activated carbon is characterized by scanning electron microscopy,Fourier transform infrared spectroscopy(FT-IR) and X-ray photoelectron spectroscopy(XPS).The results of batch experiments indicate that the maximal adsorption could be achieved over the broad pH range of 4.5 to 6.5.Adsorption isotherms and kinetic study suggest that the sorption of Cd(Ⅱ) onto AC-T produces monolayer coverage and that adsorption is controlled by chemical adsorption.And the adsorbent has a good reusability.According to the FT-IR and XPS analyses,electrostatic attraction and cation exchange between Cd(Ⅱ) and oxygen-containing functional groups on AC-T are dominant mechanisms for Cd(Ⅱ) adsorption.

Electron Acceleration and Bunch Generation by Intense Femtosecond Laser Pulse in Preplasma of a Target

We present analytical studies of electron acceleration in the low-density preplasma of a thin solid target byan intense femtosecond laser pulse.Electrons in the preplasma are trapped and accelerated by the ponderomotive forceas well as the wake field.Two-dimensional particle-in-cell simulations show that when the laser pulse is stopped by thetarget,electrons trapped in the laser pules can be extracted and move forward inertially.The energetic electron bunchin the bubble is unaffected by the reflected pulse and passes through the target with small energy spread and emittance.There is an optimal preplasma density for the generation of the monoenergetic electron bunch if a laser pulse is given.The maximum electron energy is inverse proportion to the preplasma density.

Stable High-Energy Density Super-Atom Clusters of Aluminum Hydride

With the concept of super-atom, first principles calculations propose a new type of super stable cage clusters AlnH3n that are much more energetic stable than the well established clusters, AlnHn＋2. In the new clusters, the aluminum core-frame acts as a super-atom with n vertexes and 2n A1-A1 edges, which allow to adsorb n hydrogen atoms at the top-site and 2n at the bridge-site. Using Al12H36 as the basic unit, stable chain structures, （Al12H36）m, have been constructed following the same connection mechanism as for （A1H3）n linear polymeric structures. Apart from high hydrogen percentage per molecule, calculations have shown that these new clusters possess large heat of formation values and their combustion heat is about 4.8 times of the methane, making them a promising high energy density material.

Structure characteristics and adhesive property of humic substances extracted with different methods

The structure characteristics and adhesive property of humic substance(HS) extracted with different methods were mainly studied by terms of elementary analysis,visible spectrum,FT-IR spectroscopy,viscosity,adsorption and pelletizing experiments.The results show that HSs extracted with new method(HS-a) own higher degree of aromatization and polymerization,larger relative molecular mass and more polar functional groups than HS extracted with usual method(HS-b).The viscosity of HS-b is about 30-40 mPa·s lower than that of HS-a.The maximum adsorption amounts of HS-a and HS-b onto iron concentrates are 9.11 mg/g and 8.08 mg/g,respectively.Meanwhile,HS-a has a better performance than HS-b in the practical application for pelletizing of iron concentrates.The difference in agglomeration behaviors with iron concentrates lies in the differences of the structure characteristics of HSs.With higher content of polar functional groups,larger relative molecular mass and viscosity of HSs,the agglomeration behavior is improved.

Effect of the surface properties of an activated coke on its desulphurization performance

Commercial coke was modified by H2O2 and/or NH3.H2O to obtain an activated coke containing additional oxygen functional groups and/or nitrogen functional groups. The aim of the modification was to enhance the SO2 adsorption capacity of the activated coke. Several techniques, including total nitrogen content measurements, SO2 adsorption, XPS and FTIR analysis, were used to characterize the coke samples. The XPS and FTIR spectra suggest the existence of -CONH2 groups in the H2O2 plus ammonia modified coke. The SO2 adsorption capacity of an activated coke increases slightly with an increase in H2O2 concentration during the modification process. The desulphurization performance of a modified coke is considerably enhanced by increasing the treatment temperature during ammonia modification. The amount of nitrogen in a coke modified by H2O2 plus NH3.H2O is the highest, and the SO2 adsorption capacity of the coke is also the highest (89.9 mg/gC). The NH3.H2O (only) modified sample has lower nitrogen content and lower desulphurization capacity (79.9 mg/gC). H2O modification gives the lowest SO2 adsorption capacity (28.9 mg/gC). The H2O2 pre-treatment is beneficial for the introduction of nitrogen onto the surface of a sample during the following ammonia treatment process.

Analysis of Carbon Functional Groups in Mobile Humic Acid and Recalcitrant Calcium Humate Extracted from Eight US Soils

Solid state 13C nuclear magnetic resonance （NMR） spectroscopy is a common tool to study the structure of soil humic fractions; however, knowledge regarding carbon structural relationships in humic fractions is limited. In this study, mobile humic acid （MHA） and recalcitrant calcium humate （CallA） fractions were extracted from eight soils collected from six US states and representing a variety of soils and ecoregions, characterized by this spectroscopic technique and analyzed for statistical significance at P 〈 0.05. We found that the abundances of COO and N-C=O functional groups in the MHA fractions were negatively correlated to soil sand content, but were positively correlated to silt, total N and soil organic carbon contents. In contrast, the abundances of the COO and N-C=O functional groups were only positively correlated to the content of clay in the CallA fractions, indicating that the two humic fractions were associated with different soil components. The two 13C NMR peaks representing alkyls and OCH3/NCH were negatively correlated to the peaks representing aromatics, aromatic C-O and N-C=O/COO. Comparison of the sets of data from 13C NMR spectroscopy and ultrahigh resolution mass spectrometry revealed that the aromatic components identified by the two methods were highly consistent. The comparison further revealed that protein in MHA was associated with, or bound to, the nonpolar alkyl groups, but a component competitively against （or complementary to） aromatic groups in the MHA composition. These observations provided insight on the internal correlations of the functional groups of soil humic fractions.

High-lying excited states in ^10Be from the ^9Be(^9Be,^10Be)^8Be reaction

A transfer-reaction experiment of ~9Be(~9Be,^(10)Be)~8Be was performed at a beam energy of 45 Me V.Excited states in ^(10)Be up to 18.80 Me V are produced using missing mass and invariant mass methods.Most of the observed high-lying resonant states,reconstructed from theα+~6He and t+~7Li decay channels,agree with the previously reported results.In addition,two new resonances at 15.6 and 18.8 Me V are identified from the present measurement.The 18.55 Me V state is found to decay into both the t + ~7Lig:s: and t + ~7Li?(0.478 MeV) channels, with a relative branching ratio of 0:93 ± 0:33. Further theoretical investigations are encouraged to interpret this new information on cluster structure in neutron-rich light nuclei.

A model for thermal annealing on forming In—N clusters in InGaNP

We develop a model for the effect of thermal annealing on forming In--N dusters in GalnNP according to thermodynamics. The average energy variation for forming an In--N bond in the model is estimated according to the theoretical calculation. Using the model, the added number of In--N bonds per mol of InGaNP, the added number of nearest-neighbor In atoms per N atom and the average number of nearest-neighbor In atoms per N atom after annealing are calculated. The different function of In--N clusters in InGaNP and InGaN is also discussed, which is due to the different environments around the In--N clusters.