Fundamentals of hydrogen storage processes over Ru/SiO2 and Ru/Vulcan

Hydrogen adsorption and desorption over Ru/SiO₂ and Ru/Vulcan are investigated in terms of hydrogen storage and release characteristics by both dynamic and static experiments. Ru particle dispersions as a function of metal loading were determined by HR-TEM and volumetric chemisorption experiments. Vulcan was more accommodating for spillover hydrogen than SiO₂. High Ru dispersions, i.e., small particle sizes, favored the amount of hydrogen spillover to Vulcan, as revealed by temperature programmed desorption (TPD) of hydrogen. TPD of hydrogen under He flow experiments over Ru/SiO₂ and Ru/Vulcan materials revealed a low temperature process (up to 200 °C) attributed to desorption of weakly bound hydrogen from Ru metal surface. A high temperature process (above 450 °C) was attributed to diffusion of hydrogen from the support to the Ru particle and desorption at the Ru sites. Hydrogen adsorbs strongly on Ru metal, as indicated by the initial heats of H₂ adsorption measured as 100 kJ/mol over 1 wt% Ru/Vulcan by adsorption calorimetry. At higher coverages, heat of adsorption of hydrogen was measured as 10 kJ/mol. Low heat of adsorption of hydrogen at high coverages indicate multilayer weak adsorption of hydrogen over the storage material, which can desorb at lower temperatures.     

Pd-modified CuO–ZnO–ZrO2 catalysts for CH3OH synthesis from CO2 hydrogenation

The Pd-modified Cu–ZnO–ZrO₂ quaternary catalysts for CO₂ hydrogenation to CH₃OH was investigated. The effect of Pd on CZZ were characterized systematically to illustrate the interaction between Pd and CZZ. The addition of Pd results in an increase in the crystalline sizes of Cu and a higher reduction temperature of bulk CuO. A suitable amount of Pd addition is crucial for the modification of surface Cu sites. 1.0Pd-CZZ shows the highest selectivity for CH₃OH and 0.5Pd-CZZ exhibits the highest intrinsic CH₃OH STY. Excess amount of Pd loadings (1.0% and 1.4%) would result in surface Cu aggregation, and exhibit decreased intrinsic CH₃OH STY. By correlating the characterization and the catalytic performance results, it is inferred that both the independent Cu site and the Cu site with strong interactions are responsible for CH₃OH production. This work would provide molecular insight into the modification of intrinsic surface sites for CH₃OH synthesis from CO₂.     

人工智能驱动的6G网络：智慧内生

为了满足智能适配人-机-物深度互联需求,第六代移动通信系统（6G）将基于全频谱、面向全场景、支撑全业务,其核心组成是智慧内生,也是驱动5G演进的趋势。探讨了人工智能驱动的6G智慧内生网络的特征与组成,描述了智慧内生网络的关键技术和产业应用现状,介绍了国内外相关进展和标准化工作,也对未来的挑战进行了展望。     

Hierarchically Responsive Tumor-Microenvironment-Activated Nano-Artificial Virus for Precise Exogenous and Endogenous Apoptosis Coactivation

Targeting apoptotic pathways in tumor cells is recognized as a potent anticancer strategy. However, monotherapies that target a single apoptotic pathway often do not meet expectations and the nonspecific and uncontrolled activation of apoptotic pathways can overshadow potential application prospects. Here, a novel tumor-microenvironment-activated nano-artificial virus (TMAN) with hierarchically responsive capacity is fabricated and loaded with the plasmid encoding tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and mitochondria-targeted red fluorescent phototoxic protein (KillerRed) simultaneously for precise and controllable exogenous and endogenous apoptosis coactivation. The inert TMAN is endowed with in vivo longevity and undergoes orderly acidity-triggered deshielding of a masking layer, enzyme-responsive charge-reversal, and oxidative stress-sensitive structural fragmentation in the tumor extra/intracellular microenvironment to exert precise tumor recognition, deep penetration, cellular internalization, rapid endosomes escape, and effective gene release ability, leading to the effective and tumor-specific delivery of payloads. Given the virtues of TMAN, a favorable collaboration of TRAIL-triggered exogenous apoptosis and mitochondria-targeted KillerRed induced endogenous apoptosis is achieved synchronously under the control of light irradiation, thus remarkably improving antitumor efficacy with minimal toxicity. Taken together, this strategy highlights the significance of exogenous and endogenous apoptosis coactivation in cancer treatments and offers a promising paradigm for precise exo/endogenous dual-augmented antitumor therapy.     

Characterization of Cu/CeO2/γ-Al2O3 Thin Film Catalysts by Thermal Desorption Spectroscopy

Thermal desorption spectroscopy (TDS) under ultra high vacuum (UHV) condition has been used to investigate the desorption characteristics of Cu/CeO₂/γ-Al₂O₃ thin film catalysts coated onto the microchannel of a microreactor. TDS results demonstrate that surface desorption profiles and chemical properties (acid–base and redox properties) are remarkably influenced by the catalyst composition, i.e. the loading of copper and ceria. The enhanced basicity with the increase of ceria loading and the decrease of copper loading is evident from the shifted desorption maximum of CO₂ in TDS spectra. Three oxygen species, ranging from weakly bound oxygen desorbed at low temperature to the strongly held lattice oxygen desorbed at high temperature, are easily discernible and clearly identified by O₂ TDS spectra, depending on the catalyst compositions. The concomitant thermal desorption of O₂, CO₂, and H₂O at low temperature indicates the unique chemical properties of copper/ceria catalyst with appropriate copper and ceria contents. The observed low-temperature feature is ascribed to the role of porthole of copper/ceria interfacial area for several desorbed species. The weakly bound oxygen species is attributed to the enhanced abundance of copper/ceria interfacial anionic vacancies created by the intimate contact between copper and ceria entities and its impact on steam reforming of methanol (SRM) reaction is tentatively discussed in terms of reverse oxygen spillover.     

基于需求价格弹性的电价交叉补贴理论问题研究

妥善处理电价交叉补贴是推进电力体制改革的关键问题。为深入分析电价交叉补贴的影响机理,将需求价格弹性纳入电价交叉补贴的理论模型,提出了基于“开口”形态的电价交叉补贴分类标准。研究发现：相对于地区间交叉补贴,不同用户间电价交叉补贴对我国电价的扭曲更为严重;“普惠制”和“助推物价”两个特征导致了中国电价交叉补贴的效益“溢出”问题。为准确把握处理电价交叉补贴的关键问题提供了理论支撑。     

Characterization of Italian cheeses ripened under nonconventional conditions

Four Italian cheeses (Casciotta di Urbino, Barricato San Martino, Vento d’Estate, and Ubriaco di Raboso) nonconventionally ripened under different plant materials (walnut leaves, herbs, hay, and wine by-products, respectively) were compared for compositional, microbiological, biochemical, and volatile profile characteristics. Mean values for gross composition were rather similar. Because primary starters were not used for manufacture, the endogenous lactic acid bacteria were mainly present (7.0 to 9.0 log₁₀ cfu/g). Except for Lactobacillus paracasei and Leuconostoc mesenteroides, which were commonly identified in 3 cheeses, Lactococcus lactis, Enterococcus sanguinicola, Lactobacillus brevis, Enterococcus durans/Enterococcus faecium, Lactobacillus plantarum, and Weissella cibaria/Weissella confusa were variously found in the 4 cheeses. Random amplification of polymorphic DNA-PCR analysis showed the biodiversity among the strains, and the species of lactobacilli were in part grouped according to their origin. As shown by the principal component analysis of reverse-phase fast protein liquid chromatography data for the pH 4.6-soluble fractions and by the determination of free AA, the secondary proteolysis of Barricato San Martino and Vento d’Estate mainly differed from the other 2 cheeses. Purge-and-trap and solid-phase microextraction were coupled with gas chromatography-mass spectrometry to determine volatile compounds. Vento d’Estate showed the highest levels of almost all chemical classes, and Casciotta di Urbino was characterized by a very low level of volatile components. Esters, ketones, and terpenes were the chemical classes that mainly differentiated the cheeses. Several volatile compounds seemed to be released directly from the plant materials used for ripening, especially terpenes for Vento d’Estate cheese. The lowest level of volatile free fatty acids was found in Casciotta d’Urbino, in which rennet paste was not used during manufacture. The highest concentration of free fatty acids, especially butyric and caproic acids, was found in Vento d’Estate cheese.     

利用芝麻内源性蛋白酶破乳的影响因素探究

通过电泳和体积排阻-高效液相色谱探究芝麻内源性蛋白酶的水解性质,在内源性蛋白酶最适的水解条件下,探究水解时间、破乳pH、固形物含量、粒径大小、蛋白质含量对破乳的影响。结果发现,芝麻粗油体中内源性蛋白酶在pH 4、50℃条件下水解速度相对最快,且在此条件下水解4 h后,破乳p H为5时破乳率高达97%。但是综合风味和破乳率的增长速度,发现2 h水解时间为最佳,破乳率可达87%。粗油体固形物含量在50%时破乳率最高。粒径越小、蛋白质含量越高,越难以破乳。实验结果为利用芝麻内源性蛋白酶进行水酶法提油提供了工艺基础。