Influence of Reaction Parameters on the Hydrogenolysis of Hydroxymatairesinol Over Carbon Nanofibre Supported Palladium Catalysts

The density functional theory (DFT/B3LYP) calculations were applied to investigate the interaction of a Pt₆ particle with the ZSM-5 zeolite framework. The electronic structure of the metal particle is strongly affected by the interaction with basic framework oxygens and acid sites of the zeolite support. Adsorption on basic sites (E_ads = 6 kcal/mol) favors the formation of the electron enriched metal cluster. Interaction of the platinum cluster with the acid site characterized by stabilization energy of 47 kcal/mol results in oxidation of the metal particle and suppression of Brønsted acidity of the support. The hypothesis is put forward that the oxidized platinum particle can function as an active site for the alkane isomerisation on platinum supported high silica zeolites.     

Effect of hydrogen spillover on the hydrogenation of 1-hexene over diluted carbon molecular sieve supported Pt catalyst

Pt supported on a carbon molecular sieve (Pt/CMS) was prepared by pyrolysis of polyfurfuryl alcohol containing pre-reduced Pt particles. The catalysts were characterized by hydrogen chemisorption, XRD, N₂ adsorption/desorption and TEM. Hydrogen chemisorption showed that not all the Pt particles were exposed to H₂ molecules. Oxidation treatment made Pt particles more accessible to H₂. Catalyst activity was evaluated by hydrogenation of 1-hexene. Hydrogen spillover was demonstrated by diluting Pt/CMS with activated carbon or hydrogen type zeolite Y. The initial conversion of 1-hexene was increased from 86.5% to 98.5% and to 100% when Pt/CMS was diluted with activated carbon and hydrogen type zeolite, respectively. The high initial conversion was sustained for 6 h in the presence of diluents while the conversion decreased quickly for Pt/CMS alone.     

The flexible surface or the rigid surface?

In this paper we discuss aspects of the concept described by Somorjai as the flexible surface, and whether some surfaces can be considered to be inflexible, or rigid. We present STM results which appear to manifest both types of behaviour for surfaces, depending on their oxidation state. Copper metal surfaces can be classed as flexible, showing facile reconstruction in the presence of oxygen, whereas an oxidised Pd(110) surface shows no apparent diffusivity, even at 500 K. We go on to show data for a bulk oxide which indicates that sub-stoichiometry in the sample induces an element of flexibility in the surface, especially during reaction with oxygen. Finally, this is related to the direct observation of spillover on model catalysts of Pd nanoparticles supported on TiO₂. It must be recognised that flexibility relates to surface diffusivity and hence length- and time-scales. Surfaces which appear inflexible at short times may be flexible at long times. In relation to catalysis then, surface flexibility depends on the relationship between the time-scale of diffusive events on the surface and the catalytic turnover number.     

Aromatization of n-butane over new LD-HBS catalysts. Effect of the gallium oxide support

It is shown that even pure quartz, other silicas or aluminas can enhance the aromatization activity of a ZSM-5 zeolite. Incorporation of gallium oxide onto these supports increases further the production of aromatics. The use of supported gallium oxide co-catalyst obtained by co-evaporation of a colloidal silica and a Ga salt has led to extremely high aromatization performance for the hybrid catalyst.     

技术溢出与最优R&D补贴策略

针对R&D补贴对私人创新的激励问题,按照R&D和产量博弈的合作情况,将双寡头企业分为三种组织类型.最优R&D补贴率总是随着技术溢出的增加而增加.通过R&D补贴,完全不合作与半合作可以获得相同结果,而且当技术成果完全共享时,成本降低幅度达到最大值.从利润最大化角度,企业愿意完全合作,但是这将导致社会福利水平最低.     

FDI对物流业技术溢出效应的实证研究——以河南省为例

首先利用Malmquist指数方法测算物流业全要素生产率(TFP),并将其分解成技术进步指数与技术效率指数;然后利用脉冲响应函数和格兰杰检验分别动态模拟FDI对技术进步的影响程度,以及FDI与技术进步的因果关系.结果表明:FDI对物流业生产率的溢出机制主要是通过对技术进步的提升表征出来的;物流业FDI对技术进步的影响,其格兰杰检验不通过,说明外商直接投资在物流业的技术溢出效应不显著.     

内禀安全：网络安全能力体系化构建方法

目前主流的网络安全防护体系是外嵌的,安全体系与业务体系分离,安全产品相互孤立,在防护能力上难以高效应对越来越复杂的网络安全挑战。网络安全从外向内进行强基,势在必行。将网络安全的业务场景归纳为组织、厂商、监管和威胁四方视角,各视角具有不同的业务目标。从四方视角的共性和个性出发,系统性归纳网络安全生态的能力需求,提出内禀安全方法论。内禀安全能力是指ICT组件原生支撑监测、防护和溯源等安全功能的能力。内禀安全能力对网络安全具有基础支撑作用,本身不是最终的安全功能实现,与现有的“内生安全”“内设安全”等方法论所针对的问题不同。内禀安全强调网络组件内在的安全赋能禀赋,有两种方式可以发掘这种禀赋,一是通过先天安全能力激活,二是外嵌能力内化,对外在逻辑上表现出自体免疫。此类组件的优势之一在于业务与安全的内聚,能够透明化感知安全态势、定制化配置安全策略、贴身化执行安全保护;优势之二在于将业务功能与安全功能进行合并封装,简化整体工程架构,降低网络管理复杂度。进一步提出了内禀安全支撑能力框架,对符合内禀安全理念的安全能力进行归纳和枚举,将安全支撑能力分为采集、认知、执行、协同和弹复5类,并进一步介绍各类能力的子类型和基础ICT技术。基于该框架,介绍了典型安全业务场景在内禀安全理念下的增强实现。     

A mathematical model for vehicle routing problem under endogenous uncertainty

In this study, a multistage stochastic programming (SP) model is presented for a variant of single-vehicle routing problem with stochastic demands from a dynamic viewpoint. It is assumed that the actual demand of a customer becomes known only when the customer is visited. This problem falls into the category of SP with endogenous uncertainty and hence, the scenario tree is decision-dependent. Therefore, nonanticipativity of decisions is ensured by conditional constraints making up a large portion of total constraints. Thus, a novel approach is proposed that considerably reduces the problem size without any effect on the solution space. Computational results on some test problems are reported.     

Personalized Cancer Immunotherapy via Transporting Endogenous Tumor Antigens to Lymph Nodes Mediated by Nano Fe3O4

While immunotherapy has a tremendous clinical potential to combat cancer, immune responses generated by conventional cancer immunotherapy remain not enough to completely eliminate tumors, mainly due to the tumor's immunosuppressive microenvironment and heterogeneity of tumor immunogenicity. To improve antitumor immune responses and realize personalized immunotherapy, in this report, endogenous tumor antigens (ETAs) that dynamically present on tumor cells are transported to lymph nodes (LNs). Based on the hypothesis that nano Fe₃O₄ (≈10 nm) could serve as the nanocarrier for transporting ETAs from the tumor to LNs, we wondrously find that Fe₃O₄ has a tremendous potential to improve cancer immunotherapy, because of its excellent protein‐captured efficiency and LNs‐targeted ability. To ensure the optimal ETAs‐bound efficiency of Fe₃O₄, a core–shell formulation (denoted as Ce6/Fe₃O₄‐L) is developed and specific release of Fe₃O₄ in tumor is enabled. These findings provide a simple and general strategy for boosting cytotoxic T‐cell response and realizing personalized cancer immunotherapy simultaneously.