M olecular hydrogen (H 2 ) sorbents are appealing materials for storing hydrogen fuel onboard vehicles. The uptake and release of H 2 fuel in the sorbent materials can be fast and require less heat transfer. To use the H 2 sorbents at near ambient conditions, the binding energy of H 2 in these materials must be within certain range (e.g., 20Ϫ40 kJ/mol). 1,2 Theoretical studies predicted 3,4 that Kubaslike interactions between transition metal (TM) centers and coordinated H 2 could fall within this desirable energy range. Such predictions are consistent with recent experimental studies by using metalϪorganic frameworks (MOFs) with under-coordinated TM. 5Ϫ8 Attempts to anchor TM directly on carbon nanostructures, however, have not yet been successful. Recently, Hamaed et al. used organometallic precursor to successfully graft Ti onto the inner surface of mesoporous silica. 9 Though this work demonstrated the feasibility of individually dispersing Ti and the capability of binding multi-H 2 by dispersed Ti, mesoporous silica has a relatively small surface-to-volume ratio and may be too heavy for practical hydrogen storage. So far, no practical H 2 sorbent is available. Finding the right material for onboard storage is still a grand challenge. Concerning TM-based organometallic sorbents, several conditions are required at the same time: First, the substrate materials possess high surface-to-volume ratio and are lightweight. Second, the TM atoms are undercoordinated and well-exposed to accommodate multi-H 2 . Third, these unsaturated TM atoms, despite their high chemical reactivity, 10 do not form clusters. These require that the anchoring bonds between the TM atoms and the substrate are strong and the TM coverage is also optimized. Along the line of strengthening the anchoring bonds, several strategies have been suggested, such as functionalizing organic molecules, 11 employing defect sites in carbon materials, 12,13 and directly integrating metal atoms into the skeleton. 14,15 Alternatively, graphene oxide (GO) can be a potential substrate to covalently anchor TM atoms by simultaneously satisfying all these three conditions. GO has large surface-to-volume ratio and is intrinsically lightweight (condition 1). GO possesses ample O sites on the surfaces. Oxygen is the key in anchoring under-coordinated Ti (condition 2) and enhancing the TMϪ substrate binding (condition 3), as having been experimentally demonstrated on mesoporous silica. 9 Although GO has been routinely synthesized and extensively studied, 16Ϫ24 currently its precise atomic structures are still under intense investigation. In fact, the O content of GO can vary greatly, depending

Abstract-The smart grid introduces new privacy implications to individuals and their family due to the fine-grained usage data collection. For example, smart metering data could reveal highly accurate real-time home appliance energy load, which may be used to infer the human activities inside the houses. One effective way to hide actual appliance loads from the outsiders is Battery-based Load Hiding (BLH), in which a battery is installed for each household and smartly controlled to store and supply power to the appliances. Even though such technique has been demonstrated useful and can prevent certain types of attacks, none of existing BLH works can provide probably privacy-preserving mechanisms. In this paper, we investigate the privacy of smart meters via differential privacy. We first analyze the current existing BLH methods and show that they cannot guarantee differential privacy in the BLH problem. We then propose a novel randomized BLH algorithm which successfully assure differential privacy without considering realworld constraints, and further propose the Multitasking-BLHExp3 algorithm which adaptively update the BLH algorithm based on the context and the constraints. Results from extensive simulations show the efficiency and effectiveness of the proposed method over existing BLH methods.

A structural model of carbon nanocoils (CNCs) on the basis of carbon nanotubes (CNTs) was proposed. The Young’s moduli and spring constants of CNCs were computed and compared with those of CNTs. Upon elongation and compression, CNCs exhibit superelastic properties that are manifested by the nearly invariant average bond lengths and the large maximum elastic strain limit. Analysis of bond angle distributions shows that the three-dimensional spiral structures of CNCs mainly account for their unique superelasticity.

High-pressure air injection (HPAI) in light oil reservoirs has proven to be a valuable improved oil recovery (IOR) process and aroused more attention worldwide. In this research, laboratory experiments were performed to study the potential of HPAI application in Keke Ya oilfield (Tarim Basin, China). Test oil and actual reservoir core samples were taken from Keke Ya oilfield, and rock composition was prior analyzed through X-ray method. The thermal behaviors of oil-only, cuttings, and oilcuttings were studied by thermogravimetry/derivative thermogravimetry (TG/DTG), differential thermal analysis (DTA) tests, and also, rock composition and clay mineral type/relative content effects on light crude oil oxidation behavior were systematically investigated. The results show that Keke Ya oil has a favorable exothermic behavior, exhibiting apparent low-temperature oxidation (LTO), fuel deposition, and high-temperature oxidation (HTO) stages. An extended fuel deposition stage was observed by addition of cuttings. Smectite present in illite/smectite plays a positive role of catalyzing effects for oil oxidation in different reaction regions. In this study, it revealed that smectite is ranked first, illite or chlorite is ranked second, followed by kaolinite, in the aspect of catalytic ability for crude oil oxidation. The Arrhenius model was introduced for kinetics analysis. How these findings will provide guidelines to achieve high-performance HPAI projects is also discussed.