近红外光谱快检技术在口岸安全监管领域的应用展望

近红外快速检测技术在全球范围内作为一项新兴的快速检测手段,已在农业、食品、饮料、石油、材料、制药、医学、动植物检疫及其工业化过程等领域得到了广泛应用。该文结合近红外光谱快速检测原理及其应用现状,针对口岸安全监管中的商品智能归类、材料成分快速鉴定、动植物产品快速检疫鉴定、商品装卸载过程的在线监测等需求,提出引入近红外光谱检测技术应用于口岸安全监管领域的设想,力求为实现口岸贸易安全与贸易便利化双重目标奠定科技基础,并给出了近红外在口岸安全监管研究方面的应用展望。     

幂指数小于2的无标度网络的性质

很多现实的复杂网络都具有无标度特性,其节点度具有幂律分布的规律。主要讨论幂指数γ<2的无标度网络的性质,指出当γ<2时,网络中最小度的节点数以及网络的平均度都与网络大小N有某种数量关系。通过与γ≥2的无标度网络对比,该类特殊网络呈现出不同的性质和行为,网络的边与节点相比呈现快速增长,具有更大的平均度,网络中有更多的边,网络不再稀疏。     

高性能简单结构聚(噻吩-喹喔啉)类给体光伏材料

<正>近年来,聚合物太阳能电池(PSCs)以其重量轻、价格低廉、可通过印刷方式制备大面积柔性器件等潜在优势,得到了学术界和工业界的广泛关注,也是世界各国在新能源部署上的重要研究方向之一.窄带非富勒烯受体(如2,2’-[[6,6,12,12-四(4-己基苯基)-6,12-二氢二硫代[2,3-d:2’,3’-d’]-s-吲哚诺[1,2-b:5,6-b’]二噻吩-2,8-二基]双[亚甲基(3-氧代-1H-茚-2,1(3H)-二亚甲基)]]双[丙胺](ITIC)、2,2’-((2Z,2’Z)-((4,4,9,9-四(对己基苯)-4,9-二氢-S-引达省并二噻吩-2,7-二基)双(甲基亚基))-双-(3-氧代-2,3-二氢-1H-茚-2,1-二亚甲基))二丙二腈(IDIC))对于推动聚合物太阳能电池的发展起着至关重要的作用.     

Positivity in electron-positron scattering:testing the axiomatic quantum field theory principles and probing the existence of UV states

We consider the positivity bounds on dimension-8 four-electron operators and study two related phenomenological aspects at future lepton colliders.First,if positivity is violated,probing such violations will revolutionize our understanding of the fundamental pillars of quantum field theory and the S-matrix theory.We observe that positivity violation at scales of 1-10 TeV can potentially be probed at future lepton colliders even if one assumes that dimension-6 operators are also present.Second,the positive nature of the dimension-8 parameter space often allows us to either directly infer the existence of UV-scale particles together with their quantum numbers or exclude them up to certain scales in a model-independent way.In particular,dimension-8 positivity plays an important role in the test of the Standard Model.If no deviations from the Standard Model are observed,it allows for simultaneous exclusion limits on all kinds of potential UV-complete models.Unlike the dimension-6 case,these limits apply regardless of the UV model setup and cannot be removed by possible cancellations among various UV contributions.This thus consists of a novel and universal test to confirm the Standard Model.We demonstrate with realistic examples how all the previously mentioned possibilities,including the test of positivity violation,can be achieved.Hence,we provide an important motivation for studying dimension-8 operators more comprehensively.     

平面无穷方格网络上的热传导问题

讨论了平面无穷方格网络上的热传导问题，并将结果推广到其他形状的无穷网络上。     

Constraining qqtt operators from four-top production:a case for enhanced EFT sensitivity

Recently, experimental collaborations have reported 0(10) upper limits on the signal strength of fourtop production at the LHC. Surprisingly, we find that the constraining power of four-top production on the qqtt type of operators is already competitive with the measurements of top-pair production, even though the precision level of the latter is more than two orders of magnitude better. This is explained by the enhanced sensitivity of the four-top cross section to qqtt operators, due to multiple insertion of operators in the squared amplitude, and to the large threshold energy of four-top production. We point out that even though the dominant contribution beyond the standard model comes from the O(C~4/Λ~8) terms, the effective field theory expansion remains valid for a wide range of underlying theories. Considering the possible improvements of this measurement with higher integrated luminosity, we believe that this process will become even more crucial for probing and testing the standard model deviations in the top-quark sector, and will eventually provide valuable information about the top-quark properties,leading to significant improvements in precision top physics.     

基于关联数据课程学习平台的研究与实现

研究语义Web技术,提出了基于关联数据的课程学习平台模型.用关联数据描述课程知识体系、课程教学资源以及文献资源,并将它们语义连接起来.阐述了原型系统的实现方法,并通过原型系统的构建和应用,提高网络学习的效率.     

基于小波包分析和SVM的在线手写签名鉴别

针对在线手写签名难以提取有效特征的实际情况,提出用小波包分解和单支重构来构造能量特征向量的方法,直接利用各频段成分能量的变化来反映签名的动态特征。给出了衡量各特征识别能力的Fisher准则,并且基于该准则剔除了识别能力差的特征,优化了特征空间。用该方法构造的特征向量能突出反映签名的动态特征。然后采用SVM对签名进行识别。实验证明:采用本文方法识别的正确率高达99.38%,错误拒绝率FRR=0.25%,错误接受率FAR=1.0%,其性能令人满意。     

本地财务独董治理效率研究—基于信息成本的视角

经济地理学越来越多地被应用到微观公司领域,地理邻近具有信息优势,方便学习、创新、咨询与监督。论文从信息成本的视角,研究了财务独立董事地理邻近性对公司治理效率的影响。研究结果表明:本地财务独董比非本地财务独董更能抑制盈余管理,从而具有更高的财务治理效率。进一步研究表明信息成本越高,本地财务独董治理效率更高。     

制冷系统模拟仿真技术的应用与发展

文中对仿真技术在制冷系统领域的发展现状进行了综述,并对其未来发展趋势进行了展望。