Cerium promoted Pd/HZSM-5 catalyst for methane combustion

A series of Pd/HZSM-5 (Si/Al-2 = 165) catalysts without and with additives of oxides of La, Ce, Sm, Nd and Tb were prepared by the impregnation method, and characterized by XRD, Raman spectra, N-2-adsorption, CO-chemisorption, O-2-TPD and CH4-TPR techniques. The catalysts were investigated for low-temperature CH4 combustion, and CeO2 was found to have a significant promoting effect on the activity of Pd/HZSM-5. Pd-Ce/HZSM-5 showed the best methane combustion activity and the improved thermal/hydrothermal reaction stability among tested catalysts. The characterization results of catalysts indicated that CeO2 can effectively promote the formation of crystalline PdO and weaken the bond strength of PdO on Pd-Ce/HZSM-5, resulting in that Pd-Ce/HZSM-5 possessed lower temperatures for oxygen desorption and CH4 reduction than Pd/HZSM-5. This could be ascribed to the covalent property and large oxygen storage/supplying capacity of CeO2. lt is believed that more active PdO species on Pd/HZSM-5 for low-temperature methane combustion process could be effectively promoted due to the introduction of CeO2. (c) 2006 Elsevier Ltd. All rights reserved

A comparison of different practical indices for assessing carbohydrate quality among carbohydrate-rich processed products in the US.

Healthier carbohydrate (carb)-rich foods are essential for health, but practical, validated indices for their identification are not established. We compared four pragmatic metrics, based on, per 10g of carb:(a) ≥1g fiber (10:1 carb:fiber), (b) ≥1g fiber and <1g free sugars (10:1:1 carb:fiber:free sugars), (c) ≥1g fiber and <2g free sugars (10:1:2 carb:fiber:free sugars); and (d) ≥1g fiber and, per each 1 g of fiber, <2g free sugars (10:1 carb:fiber, 1:2 fiber:free sugars; or 10:1|1:2). Using 2013-2016 National Health and Nutrition Examination Survey /Food and Nutrient Database for Dietary Studies, we assessed, overall and for 12 food categories, whether each metric discriminated carb-rich products higher or lower (per 100g) in calories, total fat, saturated fat, protein, sugar, fiber, sodium, potassium, magnesium, folate, and 8 vitamins/minerals. Among 2,208 carb-rich products, more met 10:1 (23.2%) and 10:1|1:2 (21.3%), followed by 10:1:2 (19.2%) and 10:1:1 (16.4%) ratios, with variation by product sub-categories. The 10:1 and 10:1|1:2 ratios similarly identified products with lower calories, fat, free sugars, and sodium; and higher protein, fiber, potassium, magnesium, iron, vitamin B6, vitamin E, zinc and iron. The 10:1:2 and 10:1:1 ratios identified products with even larger differences in calories and free sugars, but smaller differences in other nutrients above and lower folate, thiamine, riboflavin, and niacin; the latter findings were attenuated after excluding breakfast cereals (~9% of products). These novel findings inform dietary guidance for consumers, policy, and industry to identify and promote the development of the healthier carb-rich foods

Investigation of the effective components of the flowers of Trollius chinensis from the perspectives of intestinal bacterial transformation and intestinal absorption

Context: The flowers of Trollius chinensis Bunge (Ranunculaceae), used for respiratory tract infections, mainly contain flavonoids, phenolic acids, and alkaloids; however, the effective components are debatable because of their unclear in vivo activities. Objective: This study investigates the effective components from the perspectives of biotransformation and absorption. Materials and methods: Both single person derived- and multiple people-derived intestinal florae were used to investigate the biotransformation of aqueous extract of the flowers of T. chinensis (AEOF) at the concentrations of 15.0, 30.0, and 60.0 mg/mL, respectively, for 72 h. Both human colon adenocarcinoma cell line (Caco-2) monolayers and everted gut sacs were employed to evaluate the intestinal absorption of the intestinal bacterial transformed AEOF at the concentrations of 10, 20, and 30 mg/mL, respectively, for 180 min. Results: 2″-O-β-l-Galactopyranosylorientin, orientin, vitexin, quercetin, veratric acid, proglobeflowery acid, and trolline in AEOF were not transformed by intestinal bacteria, while isoquercetin and trollioside were completely transformed. The Papp values of 2″-O-β-l-galactopyranosylorientin, orientin, and vitexin calculated based on the experimental data of intestinal absorption were at the levels of 10−5, whereas those of veratric acid, proglobeflowery acid, and trolline were at 10−4. The mass ratio of flavonoids to phenolic acids to alkaloids changed from 16:10:7 to 9:12:8 before and after absorption. Discussion and conclusion: The dominant position of flavonoids was replaced by phenolic acids after absorption. In addition to flavonoids which are usually considered as the dominant effective ones, phenolic acids and alkaloids should be also very important for the efficacy of these flowers

Experimental Study on Rock Mechanics Parameters-A Case of the Sand Conglomerate Reservoir in M2 Well Area

This paper presents the acoustic characteristics tested on 20 groups of cores (20 vertical samples and 60 horizontal samples) from the sand conglomerate reservoir in Baikouquan and lower Wuerhe Formation (two wells in the M2 well area). The average values of dynamic modulus of elasticity and Poisson's ratio of rocks from Baikouquan Formation are 32.1 GPa and 0.2055 respectively, and those of lower Wuerhe Formation are 28.4 GPa and 0.2425 respectively. The three axis rock mechanics test device is used to test the stress-strain curves of the corresponding rock samples. The sand-conglomerate samples in this area generally have good brittleness characteristics; the static modulus of elasticity and Poisson's ratio of the corresponding rock samples are 13.7GPa and 0.2858 respectively, and those of rocks from lower Wuerhe Formation are 14.9GPa and 0.2565, respectively. In general, there is a good correlation between P&S wave velocity, and poor correlation in the dynamic and static mechanical parameters

Experimental Study on Rock Mechanics Parameters-A Case of the Sand Conglomerate Reservoir in M2 Well Area

This paper presents the acoustic characteristics tested on 20 groups of cores (20 vertical samples and 60 horizontal samples) from the sand conglomerate reservoir in Baikouquan and lower Wuerhe Formation (two wells in the M2 well area). The average values of dynamic modulus of elasticity and Poisson's ratio of rocks from Baikouquan Formation are 32.1 GPa and 0.2055 respectively, and those of lower Wuerhe Formation are 28.4 GPa and 0.2425 respectively. The three axis rock mechanics test device is used to test the stress-strain curves of the corresponding rock samples. The sand-conglomerate samples in this area generally have good brittleness characteristics; the static modulus of elasticity and Poisson's ratio of the corresponding rock samples are 13.7GPa and 0.2858 respectively, and those of rocks from lower Wuerhe Formation are 14.9GPa and 0.2565, respectively. In general, there is a good correlation between P&S wave velocity, and poor correlation in the dynamic and static mechanical parameters

pi-Extended Nonfullerene Acceptors for Efficient Organic Solar Cells with a High Open-Circuit Voltage of 0.94 V and a Low Energy Loss of 0.49 eV

A combination of high open-circuit voltage (V-oc) and short-circuit current density (J(sc)) typically creates effective organic solar cells (OSCs). Y5, a member of the Y-series acceptors, can achieve high V-oc of 0.94 V with PM6 but low J(sc) of 12.8 mA cm(-2). To maintain the high V-oc while increasing the J(sc) of devices, we developed a new nonfullerene acceptor, namely, BTP-C2C4-N, by extending the conjugation of a Y5 molecule with a naphthalenebased end acceptor. In comparison with Y5-based devices, PM6:BTP-C2C4-N-based devices exhibited significantly higher J(sc) of 18.2 mA cm(-2) followed by a high V-oc. To further increase the photovoltaic properties of BTP-C2C4-N analogues, BTP-C4C6-N and BTP-C6C8-N molecules with better processability and film morphology are obtained by adjusting the alkyl branched chain length. The optimized OSCs based on BTP-C4C6-N with a moderate alkyl branched chain length exhibited the best PCE of 12.4% with a high V-oc of 0.94 V and J(sc) of 20.7 mA cm(-2). Notably, the devices achieved a low energy loss of 0.49 eV (0.51 eV for Y5 system) accompanied by a small nonradiative energy loss. The results indicate that nonfullerene acceptors with extended terminal motifs and optimized branched chain lengths can effectively enhance the performance of OSCs and reduce energy loss.Funding Agencies|National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [21822503, 51973043, 21721002, 51961135103]; Ministry of Science and Technology of ChinaMinistry of Science and Technology, China [2016YFA0200700]; Youth Innovation Promotion Association; Datong Coal Mine Group; Chinese Academy of SciencesChinese Academy of Sciences; Swedish Research Council VRSwedish Research Council [2018-06048]; Swedish Strategic Research Foundation through a Future Research Leader program [FFL 18-0322]</p