Federal Motor Vehicle Safety Standards (FMVSS) for fuel system integrity set limits for fuel spillage during and after crashes to reduce the occurrence of deaths and injuries from fire. FMVSS 301 and 303 respectively specify post-crash limits for liquid fuels and compressed natural gas (CNG). These limits have been used as a benchmark for setting leakage limits for hydrogen, based on energy equivalence, in industry standards and proposed or enacted international regulations. However the properties of hydrogen with regard to leak behavior and combustion are very different from those of liquid fuels or CNG. Gasoline will pool and dissipate slowly. CNG and hydrogen will rise and dissipate more rapidly. Hydrogen has a much wider range of flammability in air than most fuels, including CNG: 4% to 75% for hydrogen versus 5% to 15% for CNG. Therefore, a research program was developed and executed to assess the safety of the proposed allowable leak rate for hydrogen, through leak and ignition experiments in and around vehicles and vehicle compartment simulators.

关键词：代用燃料；燃烧；死亡；消防安全；可燃性

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A system for non-venting thermal control for spacesuits was built by integrating two previously developed technologies, namely NASA's Spacesuit Water Membrane Evaporator (SWME), and Creare's flexible version of the Lithium Chloride Absorber Radiator (LCAR). This SEAR system was tested in relevant thermal vacuum conditions. These tests show that a 1 sq m radiator having about three times as much absorption media as in the test article would be required to support a 7 hour spacewalk. The serial flow arrangement of the LCAR of the flexible version proved to be inefficient for venting non-condensable gas (NCG). A different LCAR packaging arrangement was conceived wherein the Portable Life Support System (PLSS) housing would be made with a high-strength carbon fiber composite honeycomb, the cells of which would be filled with the chemical absorption media. This new packaging reduce the mass and volume impact of the SEAR on the Portable Life Support System (PLSS) compared to the flexible design. A 0.2 sq m panel with flight-like honeycomb geometry is being constructed and will be tested in thermal and thermal vacuum conditions. Design analyses forecast improved system performance and improved NCG control. A flight-like regeneration system also is also being built and tested. Design analyses for the structurally integrated prototype as well as the earlier test data show that SEAR is not only practical for spacesuits but also has useful applications in spacecraft thermal control.

关键词：蒸发器；便携式生命保障系统；航天服

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A low voltage,low power up-conversion mixer is presented here for 2.4GHz wireless sensor networks (WSN).It was based on a double-balanced Gilbert cell type.The current-reuse technique was used to reduce the power consumption and negative-resistance compensation technique was used to improve the conversion gain.The mixer was designed in 0.18μm RF CMOS technology,and was simulated with Cadence SpectreRF.The simulation results indicate that the conversion gain is 6.37dB,the noise figure is 15.36dB and the input 1dB compression point is -10.3dBm,while consuming 1mA current for operating voltage at 1V.

关键词：混频器；电流再利用；低电压；低功耗

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OH Laser Induced Fluorescence (LIF) and picosecond (ps), broadband Coherent Anti-Stokes Raman Spectroscopy (CARS) are used for time-resolved temperature and time-resolved, absolute OH number density measurements in lean H2-air, CH4-air, C2H4-air, and C3H8-air mixtures in a nanosecond (ns) pulse discharge cell/plasma flow reactor. The premixed fuel air flow in the reactor, initially at T0 = 500 K and P = 100 torr, is excited by a repetitive ns pulse discharge in a plane-to-plane geometry (peak voltage 28 kV, discharge gap 10 mm, estimated pulse energy 1.25 mJ/pulse), operated in burst mode at 10 kHz pulse repetition rate. In most measurements, burst duration is limited to 50 pulses, to preclude plasma-assisted ignition. The discharge uniformity in air and fuel air flows is verified using sub-ns-gated images (employing an intensified charge-coupled device camera). Temperatures measured at the end of the discharge burst are in the range of T = 550 600 K, using both OH LIF and CARS, and remain essentially unchanged for up to 10 ms after the burst. Time-resolved temperature measured by CARS during plasmaassisted ignition of H2-air is in good agreement with kinetic model predictions. Based on CARS measurement, vibrational nonequilibrium is not a significant factor at the present conditions. Time-resolved, absolute OH number density, measured after the discharge burst, demonstrates that OH concentration in C2H4-air, C3H8-air, and CH4 is highest in lean mixtures. In H2-air, OH concentration is nearly independent of the equivalence ratio. In C2H4-air and C3H8-air, unlike in CH4- air and in H2-air, transient OH-concentration overshoot after the discharge is detected. In C2H4-air and C3H8-air, OH decays after the discharge on the time scale of 0.02 0.1 ms, suggesting little accumulation during the burst of pulses repeated at 10 kHz. In CH4-air and H2-air, OH concentration decays within 0.1 1.0 ms and 0.5 1.0 ms, respectively, showing that it may accumulate during the burst.

关键词：荧光；动力学；激光；低温；混合物

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The ultimate goal of this project is to develop a viable C-coating process of the current collector in order to improve the overall power performance of the electrode of Li-ion batteries. During this third-year period, the performance of different thickness of carbon coating on Al foil is compared. The result shows that only the samples with sufficient thickness to form conductive channel on the surface would give a positive effect on the performance. Scale up of this coating process is further developed to make 1.5 m long C-coated tape by a contentious process followed with a special batch thermal process called roll-calcination. The same positive effects seen on small samples have been reproduced.

关键词：碳涂层电流收集器；化学汽相淀积；锂离子二次电池；蓄电池

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As a first step towards a microscopic understanding of single-Pt atom-dispersed catalysts on non-conventional TiN supports, we present density- functional theory (DFT) calculations to investigate the adsorption properties of Pt atoms on the pristine TiN(100) surface, as well as the dominant influence of surface defects on the thermodynamic stability of platinized TiN. Optimized atomic geometries, energetics, and analysis of the electronic structure of the Pt/TiN system are reported for various surface coverages of Pt. We find that atomic Pt does not bind preferably to the clean TiN surface, but under typical PEM fuel cell operating conditions, i.e. strongly oxidizing conditions, TiN surface vacancies play a crucial role in anchoring the Pt atom for its catalytic function. Whilst considering the energetic stability of the Pt/TiN structures under varying N conditions, embedding Pt at the surface N-vacancy site is found to be the most favorable under N-lean conditions. Thus, the system of embedding Pt at the surface N-vacancy site on TiN(100) surface could be a promising catalyst for PEM fuel cells.

关键词：燃料电池；原子吸附；计算缺陷

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Various modes of severe plastic deformation (SPD), such as high-pressure torsion (HPT) at cryogenic temperature, equal channel angular pressing (ECAP) and dynamic channel-angular pressing (DCAP), have been applied for nanostructuring of Ni, and the thermal stability of the structure obtained has been studied. The nanocrystalline structure with average grain sizes of 80 nm and the microhardness of 6200 MPa is produced by HPT in liquid nitrogen. DCAP and ECAP result in the submicrocrystalline structure of a mixed type, with ultra-fine grains separated by high-angle boundaries along with deformation bands and coarse cells with low-angle dislocation boundaries. The thermal stability of the structures obtained by ECAP and DCAP is approximately the same, and it is higher than after the HPT at cryogenic temperature.

关键词：电极材料；纳米晶体；塑性形变

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Fuel cells are a promising technology as an alternative for portable power applications, because they offer higher power densities, do not include moving parts, and thus are free of noise and vibrations. At the current state of development, fuel cell systems cannot effectively use hydrocarbon fuels unless they have been processed, or reformed, into a syngas consisting of hydrogen, carbon monoxide, and other species. Conventional reforming technologies utilize catalysts which may have strict requirements on fuel purity and operating conditions. The development of a robust non-catalytic technique has the advantage of using a variety of logistics fuels. In this project, conversion of various fuels was demonstrated in two different non-catalytic reactors. The conversion of butanol and Jet-A were demonstrated in a filtration reactor consisting of a packed bed of spheres. A second reactor, consisting of counterflowing channels, has the advantage of stationary reactions zones and the ability to operate continuously. Conversion of heptane was demonstrated in this reactor and a computational study was conducted to understand the scaling of the reactor for various applications. These results show the promise of non-catalytic technologies for the reforming of a wide range of fuels.

关键词：一氧化碳；燃烧；燃料电池；燃料系统

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Space solar sheet (SSS) being currently under development is a quite unique and Japan's original devise for generating electricity in space. There are two kinds of SSS: one is a film-type SSS using transparent polymer film and the other is glass-type SSS (G-SSS) using a coverglass. Space solar sheet basically possesses 15 paper-like Ⅲ-Ⅴ multi-junction solar cells connected in five series and three parallel rows. The cells are laminated with the transparent polymer film or coverglass. To realize G-SSS, features of flexibility, toughness (not crack easily) and high radiation tolerance are inevitably required for the coverglass. Optical degradation of the coverglass caused by space radiation is particularly important since it decreases the amount of transmitted sunlight falling on solar cells and degrades the cell output power. Hence, we evaluated a radiation tolerance of a new coverglass for G-SSS.

关键词：太阳能电池；辐射测量；太阳能电板

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Michigan State University, in East Lansing, was selected by the U.S. Department of Energy to design and establish the Facility for Rare Isotope Beams (FRIB), a cutting-edge research facility to advance the understanding of rare nuclear isotopes and the evolution of the cosmos. The research conducted at FRIB will involve experimentation with intense beams of rare isotopes within a well-shielded target cell that will result in activation and contamination of components. The target cell is designed to be hands-on accessible after shutdown and a brief cooldown period. Personnel are expected to have hands-on access to the tops of shielded component modules with the activated in-beam sections buried under the shielding. The modules are carefully designed to include steel shielding for protecting personnel during these hand-on operations. However, as the facility develops greater levels of activation and contamination, the facility design foresees that a bridge-mounted servomanipulator may need to be added to the cell to perform the disconnecting of services to the component assemblies. Dexterous remote handling and exchange of the modularized activated components is completed at a shielded window workstation with a pair of master-slave manipulators. The primary components requiring exchange or maintenance are the production target, the beam momentum compensation wedge, the beam dump, and the beam focusing and bending magnets. This paper provides an overview of the FRIB Target Facility remote-handling and maintenance design requirements, concepts, and techniques.

关键词：加速器；光束转储；同位素；磁铁

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