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：研究目的:为了同时预测固体氧化物燃料电池(SOFC)的电压、温度动态特性和设计控制器,建立SOFC的控制相关动态辨识模型。创新要点:为了建立SOFC更精确的最小二乘支持向量回归机(LSSVR)动态模型,采用遗传算法(GA)优化LSSVR的参数。所建GA-LSSVR模型可同时预测SOFC的电压和温度动态特性。研究方法:1.分析SOFC的电化学和能量平衡子模型。2.利用所选择的最优LSSVR参数,建立了SOFC的GA-LSSVR动态辨识模型。通过仿真分析和比较,验证了所建模型的有效性(图3和4)。3.利用所建模型的预测结果,与模拟退火算法优化最小二乘支持向量回归机(SAA-LSSVR)和5折交叉验证最小二乘支持向量回归机(5FCV-LSSVR)模型的预测结果进行了比较,表明所建立的GA-LSSVR模型具有较高的预测精度(表3和4)。重要结论:通过比较SAA-LSSVR和5FCV-LSSVR模型的预测结果,发现所建GA-LSSVR模型具有较好的预测性能和精度。基于所建立的GA-LSSVR模型可进行有效的多变量控制器设计。

摘要：Zero-dimensional perovskite materials,characterized by broadband emission caused by self-trapped excitons,are promising materials for stimuli-responsive and photo-writeable ***,existing research is focused on the effects of structural phase transitions on photophysical properties,and lacks in-depth understanding of the mechanisms of self-trapped excitons ***,we demonstrate that the dehydration reaction in zero-dimensional antimony halide clusters significantly enhances the self-trapped excitons emission without inducing structural phase transition,resulting in a substantial increase in photoluminescence(PL)quantum yield from 3.5%to 91.4%.In-situ X-ray diffraction and PL techniques were employed to shed light on the relationship between the crystal structure and radiative recombination,demonstrating the introduction of rich lattice distortion during the dehydration ***-dependent PL spectra and transient absorption spectra suggest that the lattice distortion causes the moderate electron-phonon coupling strength and high exciton binding energy,facilitating self-trapped excitons to relax from the non-radiative recombination singlet state to the radiative recombination triplet state,corresponding to the enhanced emission *** a proof of concept,several switchable PL applications have been established in scenarios such as anti-counterfeiting,rewritable luminescent paper,and humidity *** finding elucidates the emission mechanism of self-trapped excitons and provides a novel avenue for designing switchable luminescent materials.

摘要：为给沥青路面电磁感应自修复技术提供参考依据,通过掺加钢丝绒制备了可用于感应加热的密实型沥青混合料小梁,研究其裂缝感应热自愈合性能。对不同类型、不同掺量钢丝绒的混合料试件进行了电磁感应加热试验,研究了感应加热试件的升温速率,并进一步开展了裂缝自愈合能力试验以及混合料的路用性能试验,对混合料进行了综合优化设计。研究结果表明:电磁感应加热是对混合料中的沥青加热而非集料加热,热量由沥青胶结料转移到集料中,加热迅速,能耗低;加热温度不能高于100℃,否则混合料会膨胀松散;钢丝绒越长,掺量越高,密实型钢丝绒沥青混合料试件的电磁感应平均加热速率越高;2~#钢丝绒(6.5mm)掺量为4%的试件在顶面加热至90℃时表现出最佳的愈合率(96.7%),顶面加热至75℃时同样具有理想的愈合率(95.4%),且此温度下能够节约能耗和避免试件松散;2~#钢丝绒(3.5mm)掺量为2%的密实型沥青混合料具有最优良的路用性能;结合混合料路用性能和感应热自愈合能力分析,2~#钢丝绒(3.5mm)掺量为4%的密实型沥青混合料在顶面电磁感应加热到75℃时具有94.6%的理想自愈合率和良好的路用性能,且能耗经济。

摘要：边坡锚杆通常先假定锚杆长度,通过试算边坡体的安全系数来进行锚杆设计。这种方法过程繁琐,且设计的方案为可行性方案而非最优方案。而应用可靠度反分析方法设计边坡锚杆,可获得满足边坡稳定可靠性条件下的最优设计方案。首先,用有限元法计算边坡体的安全系数,然后,利用响应面法拟合边坡的极限状态方程,最后通过遗传算法反演边坡的锚杆长度,从而建立一种基于可靠度指标体系下边坡锚杆设计的新方法。并以某停车场边坡支护加固工程为算例,将该方法与传统的边坡锚杆设计方法进行对比,结果表明:建立的边坡锚杆反演设计方法是一种合理、有效、快速的设计方法。

摘要：对数据库系统即时修改数据的高效实时分析需求推动了数据库系统向同时支持OLTP业务和OLAP业务两种场景的HTAP数据库系统的快速发展.面对众多的HTAP数据库系统,为了推动HTAP数据库系统的公平比较和健康发展,定义和实现相应的评测基准来评估HTAP数据库系统的新特性至关重要.首先,分析HTAP数据库系统的关键特征并抽象总结HTAP数据库系统实现的关键技术.然后,提炼出HTAP数据库系统的设计难点和构建HTAP评测基准的挑战,并基于此提出HTAP评测基准应考虑的设计维度,包括数据生成、负载生成、评价指标和一致性模型支持性.对比现有HTAP评测基准在设计维度和实现技术上的差异,总结评测基准在不同设计维度上的优劣.此外,运行已公开的典型评测基准,展示并分析它们对HTAP数据库系统关键特征的评测能力以及对不同HTAP数据库系统的横向对比的支持能力.最后,总结对HTAP评测基准的能力需求和未来的一些研究方向,指出语义一致的负载控制和新鲜数据访问度量是HTAP数据库系统评测基准定义的关键问题.

摘要：Depletion calculation is important for studying the transmutation efficiency of minor actinides and longlife fission products in accelerator-driven subcritical reactor system(ADS). Herein the Python language is used to develop a burnup code system called IMPC-Burnup by coupling FLUKA, OpenMC, and ORIGEN2. The program is preliminarily verified by OECD-NEA pin cell and IAEAADS benchmarking by comparison with experimental values and calculated results from other studies. Moreover,the physics design scheme of the CIADS subcritical core is utilized to test the feasibility of IMPC-Burnup program in the burnup calculation of ADS system. Reference results are given by the COUPLE3.0 program. The results of IMPC-Burnup show good agreement with those of COUPLE3.0. In addition, since the upper limit of the neutron transport energy for OpenMC is 20 MeV, neutrons with energies greater than 20 MeV in the CIADS subcritical core cannot be transported; thus, an equivalent flux method has been proposed to consider neutrons above 20 MeV in the OpenMC transport calculation. The results are compared to those that do not include neutrons greater than 20 MeV. The conclusion is that the accuracy of the actinide nuclide mass in the burnup calculation is improved when the equivalent flux method is used. Therefore, the IMPC-Burnup code is suitable for burnup analysis of the ADS system.

摘要：通过调查分析,发现目前社会工作专业核心课程设置相对统一,分支课程设置比较分散,专业实习与国际标准差距明显。学生对社会工作专业课程和专业教材的满意度达到中等水平,对专业实习的认同度比较低。学生所在年级、进入大学之前和目前对社工的了解程度等个人因素,学校类型、专业实习时间等学校因素对专业课程、专业教材和专业实习的评价有显著影响。这主要与社会工作专业的助人特质和我国社会工作发展现状有关。如何完善社会工作实习机制、规范社会工作教材编制,是增强学生专业课程认同的关键。

摘要：MAPK信号通路中的MKKs家族基因在水稻生长发育和防御信号传导中起承上启下的作用,并参与调控多种生物学过程。本研究通过生物信息学分析,鉴定了水稻中的MKKs基因,并构建了它们的系统发育树,揭示了MKKs家族基因的保守性和多样性。利用基因编辑技术,编辑日本晴水稻品种中Os MKK4基因,成功获得了6种该基因不同突变类型的材料,其粒长、粒宽和千粒重均较野生型显著降低。单倍型分析结果表明,Os MKK4基因的单倍型有明显的籼粳分化,主要为Glu^(14)粳型和Leu^(14)籼型。含有Glu^(14)粳型稻的平均粒长较低,平均粒宽和千粒重较高。此外,将Kasalath中带有Leu^(14)单倍型的Os MKK4基因导入日本晴,导致DHX(CSSL)的粒长、粒宽和千粒重较日本晴显著降低;与Kasalath相比,代换系的粒宽和千粒重显著增加。本研究探索了Os MKK4基因的重要单倍型对水稻籽粒的影响,为更精确的分子设计育种提供基因资源和策略。

摘要：Polyl(lactide),PLA,suffers from bitleness and low heat deflection temperature(HDT),which limits its application as an engineering *** this work,poly(L-lactide)/poly(D-lactide)/ethylene-vinyl acetate glycidyl methacrylate random copolymer(PLLA/PDL A/EVM-GMA=1/1/x)composites were prepared by melt blending,and the in situ formed EVM-g PLA copolymers improved the compatibility between PLA and ***,the blends were subjected to a two-step annealing process during compression molding,*** annealing at 120℃ to rapidly form a certain amount of stereocomplex(sc)crystallites as nucleation sites,and then annealing at 200℃ to guide the formation of new *** differential scanning calorimetry(DSC)and wide angle X-ray dffrction(WAXD)measurements confirmed the formation of highly stereocomplexed PLA *** results showed that the PLLA/PDLA blend with 20 wt%of EVM-GMA had a notched impact strength up to 65 kJ/m2 and an elongation at break of 48%,while maintaining a tensile strength of 40 ***,dynamic mechanical analysis(DMA)and heat deflection tests showed that the PLA composite had an HDT up to 142℃ which is 90℃ higher than that of normal PLA *** electron microscopy(SEM)confirmed the fine dispersion of EVM-GMA particles,which facilitated to understand the toughening ***,the highly stereocomplexed PLA composites simultaneously exhibited excellent chemical and hydrolysis ***,these fascinating properties may extend the application range of sc PLA material as an engineering bioplastic.