摘要：Adsorption and activation of dinitrogen(N_(2)) is an indispensable process in nitrogen *** nitride species continue to attract attention as a promsing catalyst for ammonia ***,the detailed mechanisms at a molecular level between reactive nitride species and N_(2) remain unclear at elevated temperature,which is important to understand the temperature effect and narrow the gap between the gas phase system and condensed phase ***,the ^(15)N/^(14)N isotopic exchange in the reaction between tantalum nitride cluster anions Ta_(3)^(14)N_(3)^(-) and ^(15)N_(2) leading to the regeneration of ^(14)N_(2)/^(14)N^(15)N was observed at elevated temperature(393-593 K)using mass *** the aid of theoretical calculations,the exchange mechanism and the effect of temperature to promote the dissociation of N_(2) on Ta_(3)N_(3)^(-) were elucidated.A comparison experiment for Ta_(3)^(14)N_(4)^(-)/^(15)N_(2) couple indicated that only desorption of ^(15)N_(2) from Ta_(3)^(14)N_(4)^(15)N_(2)^(-) took place at elevated *** different exchange behavior can be well understood by the fact that nitrogen vacancy is a requisite for the dinitrogen activation over metal nitride *** study may shed light on understanding the role of nitrogen vacancy in nitride species for ammonia synthesis and provide clues in designing effective catalysts for nitrogen fixation.

摘要：This review summarizes a variety of experimentally identified gas‐phase catalytic cycles,all of which are mediated by atomic metal ions,bare metal clusters,metal oxide clusters or metal *** is placed on the latest advances in the unique catalytic reactivity of cluster‐confined single noble metal *** cycles discussed in this paper cover a wide range of inorganic and organic *** use of start‐of‐the‐art mass spectrometric instrumentation in conjunction with quantum chemistry calculations is also reported,as these techniques have determined the mechanistic details of the elementary steps of such catalytic *** important role of gas‐phase data in guiding the rational design of better‐performing catalysts in related condensed phase reactions is also *** particular,this review focuses on the following three topics:(1)the catalytic oxidation of carbon monoxide,(2)the catalytic functionalization of methane,and(3)catalytic decarboxylation.

摘要：以GX自治区WZ市2021年度大中型水库移民后期扶持政策实施情况监测评估项目为案例,基于10个移民村200户移民家庭的原始调查数据,采用灰色聚类-复相关-信息灵敏度法,构建了包括人均可支配收入等指标的评价指标体系;利用熵值法和环比评分法分别计算指标权重后,应用基于博弈论的组合赋权法确定了评价指标的主客观组合权重;结合调查数据及官方统计数据确定指标分级标准,利用综合评分法计算移民的生产生活水平指数,并运用该指数对样本村水库移民生产生活水平进行了实证评价。结果表明,采用本文方法构建的指标体系和评价模型相对合理、有效,评价结果符合实际,可为水库移民后期扶持效果评价及其他相关评价工作提供参考。

摘要：民族音乐是永儒布艺术创作的根基。潮尔、马头琴及蒙古族民歌,是永儒布交响乐的主要创作源泉。他的交响乐作品体现出丰厚的民族风格底蕴,具有史诗性和哲理性的审美本质。尊崇自然、敬畏生命和爱恋家园,既是永儒布交响乐作品的核心内容,也是其交响乐作品所体现的典型的审美情结。向民族文化传统寻根,创作立意与民族传统紧密相连,是永儒布交响乐创作中的基本遵循。

摘要：Joint inversion based on a correlation constraint utilizes a linear correlation function as a structural *** linear correlation function contains a denominator,which may result in a singularity as the objective function is optimized,leading to an unstable inversion *** improve the robustness of this calculation,this paper proposes a new method in which a sinusoidal correlation function is employed as the structural constraint for joint inversion instead of the conventional linear correlation *** structural constraint does not contain a denominator,thereby preventing a *** with the joint inversion method based on a cross-gradient constraint,the joint inversion method based on a sinusoidal correlation constraint exhibits good *** application to actual data demonstrates that this method can process real data.

摘要：提出了一种简单、快速、高效的基于草绘设计的概念模型创建方法.该方法模仿传统的纸笔草绘设计方式,允许用户自由地在笔式用户界面上勾画特征笔划,然后根据笔划的形状和位置关系采用基于特征的实体建模方法构造不同的扫描特征体素.在此基础上,采用了基于意图捕捉的特征添加及切削机制创建复杂的实体模型,给出了一些关键算法的实现过程.实验结果表明:该方法能够较好地应用到联机三维概念模型快速创建过程中.

摘要：对位芳纶等高性能纤维通常以机织或无纬布的形式用于制备轻量化、高性能的柔性防弹织物及其增强复合材料。为探索不同混杂方式对复合材料抗侵彻性能的影响,基于对位芳纶纤维设计了平纹叠层织物(P)和5层衬垫贯穿接结角联锁织物(T);通过将两者进行混杂叠层并采用浸胶方式施加改性酚醛树脂后制备成复合材料,再通过弹道实验得到靶板的弹道极限速度,并对靶板的损伤形貌进行了对比分析。研究发现:三维贯穿接结角联锁织物增强复合材料的弹道极限速度比纯平纹织物增强复材高出35.9%;将T作为迎弹面,P作为背弹面进行简单叠层,P与T混杂比为1∶3的靶板的弹道极限速度最高,比单纯平纹叠层增强复合材料提高了16.4%。

摘要：共价有机框架(COFs)因其比表面积大、稳定性高和可设计性强等优点而引起了人们的广泛关注.卟啉是一种具有大π共轭体系、易于修饰和良好吸光性能的功能基元.卟啉基COFs吸光范围广,活性位点多,电子-空穴分离能力强,在光催化领域应用广泛.综述了卟啉基COFs在光催化还原二氧化碳、光催化分解水、光催化有机转化和光催化还原六价铀的研究进展,最后讨论了卟啉基COFs在光催化领域的前景和面临的挑战.

摘要：应用遗传算法对锯齿型板翅式换热器的结构进行了优化设计.以预定的传热量、两侧压降、体积等设计要求为适应度函数,通过对设计变量构成的种群个体进行适应度评估以及选择、交叉、变异等遗传操作,得到符合设计约束的换热器最优结构参数(如翅高、翅长、间距,以及长、宽、高等).此外,对10次计算得到的设计参数进行了统计分析.结果表明:相关结构参数的不确定度很小,应用遗传算法可以快速方便地对紧凑式换热器的几何结构参数作出符合设计要求的选择.

摘要：In order to enhance the glutathione peroxidase（GPX） catalytic activity of the selenium-containing single-chain variable fragments（Se-scFv）, a novel human scFv was designed on the basis of the structure of human antibody and optimized via bioinformatics methods such as homologous sequence analysis, three-dimensional（3D） model building, binding-site analysis and docking. The DNA sequence of the new human scFv was synthesized and cloned into the expression vector pET22b（＋）, then the scFv protein was expressed in soluble form in Escherichia coli BL21（DE3） and purified by Ni2＋-immobilized metal affinity chromatography（IMAC）. The serine residue of scFv in the active site was converted into selenocysteine（Sec） with the chemical modification method, thus, the human Se-scFv with GPX activity was obtained. The GPX activity of the Se-scFv protein was characterized. Compared with other Se-scFv, the new human Se-scFv showed similar efficiency for catalyzing the reduction of hydrogen peroxide by glutathione. It exhibited pH and temperature dependent catalytic activity and a typical ping-pong kinetic mechanism.