美法两公司组成铀氢锆堆燃料合资公司

【美国《核燃料》1995年7月31日刊报道】 美国通用原子公司(GA)和法国原子燃料研究制造公司(Cerca)7月20日宣布,这两家公司组成一个为GA所建的一些铀氢锆研究堆(Triga)制造燃料的法国合资公司。

Co_3O_4 nanoparticles assembled on polypyrrole/graphene oxide for electrochemical reduction of oxygen in alkaline media

The development of highly efficient catalysts for cathodes remains an important objective of fuel cell research. Here, we report Co3O4 nanoparticles assembled on a polypyrrole/graphene oxide electrocatalyst （Co3O4/Ppy/GO） as an efficient catalyst for the oxygen reduction reaction （ORR） in alkaline media. The catalyst was prepared via the hydrothermal reaction of Co2＋ ions with Ppy-modified GO. The GO, Ppy/GO, and Co3O4/Ppy/GO were characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The incorporation of Ppy into GO nanosheets resulted in the formation of a nitrogen-modified GO po-rous structure, which acted as an efficient electron-transport network for the ORR. With further anchoring of Co3O4 on Ppy/GO, the as-prepared Co3O4/Ppy/GO exhibited excellent ORR activity and followed a four-electron route mechanism for the ORR in alkaline solution. An onset potential of -0.10 V vs. a saturated calomel electrode and a diffusion limiting current density of 2.30 mA/cm^2 were achieved for the Co3O4/Ppy/GO catalyst heated at 800 ℃; these values are comparable to those for noble-metal-based Pt/C catalysts. Our work demonstrates that Co3O4/Ppy/GO is highly active for the ORR. Notably, the Ppy coupling effects between Co3O4 and GO provide a new route for the preparation of efficient non-precious electrocatalysts with hierarchical porous structures for fuel cell applications.

Formation Mechanism and Binding Energy for Body-Centered Cubic Structure of He^＋9 Cluster

The formation mechanism for the body-centered cubic structure of cluster is proposed and its total energy curve is calculated by the method of a Modified Arrangement Channel Quantum Mechanics. The energy is the function of separation R between the nuclei at the center and an apex of the body-centered cubic structure. The result of the calculation shows that the curve has a minimal energy . The binding energy of with respect to was calculated to be 0.8857 a.u. This means that the cluster ofmay be formed in the body-centered cubic structure of .

RADIOIMMUNOTOXICOLOGICAL EFFECT OF ENRICHED URANIUM ON CENTRAL AND PERIPHERAL IMMUNE CELLS AND THE PROTECTIVE ACTION OF IL－1 AND IL－2

Accumulation of enriched 235U-UO2F2 in the body had injurious effects on theimmune function of central and peripheral immune cells. After an intravenousinjection of beaU--UO,F,, the spontaneous ’H--TdR incorporation in thymocytes andbone marrow cells decreased, with the thymocytes damaged more markedly. Theproliferation ability of spleen T and B lymphocytes were both inhibited, with Blymphocytes inhibited more severely. In spleen B lymphocytes the IL-- 1 production andIL--2 consumption were diminished. The inhibition of spleen B lymphocyteproliferation by 'U-- UOZFZ was partially restored by adding exogenous IL-- 1 or IL--2to the cultured lymphocytes obtained from 'U injected mice.

Fe,N,S-doped porous carbon as oxygen reduction reaction catalyst in acidic medium with high activity and durability synthesized using CaCl_2 as template

Proton exchange membrane fuel cells suffer from the sluggish kinetics of the oxygen reduction reaction(ORR)and the high cost of Pt catalysts.In the present work,a high‐performance ORR catalystbased on Fe,N,S‐doped porous carbon(FeNS‐PC)was synthesized using melamine formaldehyderesin as C and N precursors,Fe(SCN)3as Fe and S precursors,and CaCl2as a template via a two‐stepheat treatment without a harsh template removal step.The results show that the catalyst treated at900℃(FeNS‐PC‐900)had a high surface area of775m2/g,a high mass activity of10.2A/g in anacidic medium,and excellent durability;the half‐wave potential decreased by only20mV after10000potential cycles.The FeNS‐PC‐900catalyst was used as the cathode in a proton exchangemembrane fuel cell and delivered a peak power density of0.49W/cm2.FeNS‐PC‐900therefore hasgood potential for use in practical applications.

Interatomic diffusion in Pd-Pt core-shell nanoparticles

Pt monolayer-based core-shell catalysts have garnered significant interest for the application of low temperature fuel cell technology as their use may enable a decreased loading of Pt while still providing sufficient current density to meet volumetric requirements. One promising candidate in this class of materials is a Pd@Pt core-shell catalyst, which shows enhanced activity toward oxygen reduction reaction(ORR). One concern with the use of Pd@Pt, however, is the durability of the core-shell structure as Pd atoms are thermodynamically favored to migrate to the surface. The pathway of the migration has not been systematically studied. The current study explores the stability of this structure to thermal annealing and probes the effect of this heat treatment on the catalyst surface structure and its oxygen reduction activity. It was found that surface alloying between Pd and Pt occurs at temperatures as low as 200 °C, and significantly alters the structure and ORR catalytic activity in the range of 200–300 °C. Our results shed lights on the thermal induced interatomic diffusion in all core-shell and thin film structures.

Facile synthesis of Zn_2GeO_4 nanorods toward improved photocatalytic reduction of CO_2 into renewable hydrocarbon fuel

Zn2GeO4 nanorods were prepared by a surfactant-assisted solution phase route.The as-prepared products were characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM),inductively coupled plasma atomic emission spectrometer(ICP-AES),UV-vis diffuse reflection spectroscopy and photoluminescence(PL) spectroscopy.The possible formation mechanism of Zn2GeO4 nanorods was discussed.It was supposed that the CTA+ cations preferentially adsorb on the planes of Zn2GeO4 nanorods,leading to preferential growth along the c-axis to form the Zn2GeO4 rods with larger aspect ratio and higher surface area,which showed the improved photocatalytic activity for photoreduction of CO2.The photoluminescence(PL) property of Zn2GeO4 nanorods was investigated through the emission spectra.

Could It Happen： Global Warming Leads to the Extinction of Mankind？

The upcoming COP23 at Bonn of the UN and its UNFCCC must outline how its COP21 objectives are to be promoted by means of concrete international and national management. Only a massive replacement of fossil fuels and wood coal by solar power parks, can wind power and atomic power save mankind from the grave threats of global warming. This paper presents a tentative estimation of what is involved with regard to the fulfilment of COP21 ＇s GOAL II--decarbonisation to 30-40 per cent of 2005 level of emissions.

Irradiation Testing of Coated Particle Fuel at HANARO

TRISO （Tri-structural iso-tropic）-coated particle fuel is being developed to support the development of a VHTR （very high temperature reactor） in Korea. From August 2013, the first irradiation testing of coated particle fuel was begun to demonstrate and qualify TRISO fuel for use in the VHTR in HANARO （high-flux advanced neutron application reactor） at KAERI （Korea Atomic Energy Research Institute）. This experiment is currently undergoing under an atmosphere of a mixed inert gas without on-line temperature monitoring and control combined with on-line fission product monitoring of the sweep gas. The irradiation device contains two test rods, one contains nine fuel compacts and the other five compacts and eight graphite specimens. Each compact has 263 coated particles. After a peak bum-up of about 4% and a peak fast neutron fluence of about 1.7 × 1021 n/cm2, PIE （post irradiation examination） will be carried out at KAERI＇s irradiated material examination facility. This paper describes the characteristics of coated particle fuels, and the design of the test rod and irradiation device for the coated particle fuels, and discusses the technical results of irradiation testing at HANARO.

Use of Thorium in the Generation IV Molten Salt Reactors and Perspectives for Brazil

Interest in thorium stems mainly from the fact that it is expected to have a substantial increase in uranium prices. So, advanced fuel cycles which increase the reserves of nuclear materials are interesting, particularly, the use of thorium is to produce the fissile isotope ^233U. Thorium is three to five times more abundant than uranium in the earth＇s crust. Additionally, thoria produces less radiotoxicity than the UO2, because it produces fewer amounts of actinides. ThO2 has higher corrosion resistance, besides being chemically stable, and the burning of Pu in a reactor based in thorium also decreases the inventories of Pu from the current fuel cycles. There are some ongoing projects in the world, taking into consideration the proposed goals for Generation IV reactors, namely： sustainability, economics, safety and reliability, proliferation resistance and physical protection. Some developments on the use of thorium in reactors are underway, with the support of the IAEA （International Atomic Energy Agency） and some govern like molten salt reactor. In this paper, we discuss the future importance of thorium, particularly for Brazil, which has large mineral reserves of this strategic element, the characteristics of the molten salt reactor and the experience of the IPEN （Instituto de Pesquisas Energ6ticas e Nucleares） in the purification of thorium compounds.

英语新闻标题的特点

对于绝大多数人来说,报纸是有价值的新闻载体,同时还有其他价值.由于它兼有篇章型和语言风格的广泛多样性内容,因此报纸是语言学习的一种好材料.报纸是语言学习的源泉,它在我们通常语言学习资料中是难以找到的,它能帮助我们熟悉语言,并能帮助我们学会许多不同的交流技巧.报纸也会帮助我们获得认知并了解文化价值.如果我们在语言学习中没有接触报纸,那么我们在英语国家如英国和美国生活和旅游就会碰到很多困难.

一九八六年日本能源法研究所研究计划

1986年3月19日日本能源法研究所召开了理事会,对于1986年度的研究计划进行了审议并做出决定。下面是日本能源法研究所《日本能源法研究所月报》1986年5月号(总第41号)刊载的该所各研究组1986年度的研究课题。一。

Nonlinear dynamical behavior of Xenon atoms along dislocation lines in UO_(2+x) nuclear fuel

Experimental results showed that there are a few Xenon atom bubbles connected by the dislocation line in the UO2+x nuclear fuel, and the largest radius of bubbles is about 45 nm. This phenomenon is in contrast to traditional bubble formation mechanism. This phenomenon is very important in understanding the properties of nuclear fuel. In this work, we apply a time- dependent microscopic atom transport equation and take into account stress coherent potential in the boundary of the dislocation. Using the equation, we numerically solved the stress coherence effect and studied the transfer properties of Xenon atoms along the dislocation line. Our numerical results show that the transport of the Xenon atoms along the dislocation changes nonlinearly with the external driving energy, and reaches at the saturation values. It explains the growth limit of Xenon atom bubbles that is in agreement with the experiment results.

Highly dispersed L1_(0)-PtZn intermetallic catalyst for efficient oxygen reduction

Highly active and durable electrocatalysts with minimal Pt usage are desired for commercial fuel cell applications.Herein,we present a highly dispersed L1_(0)-PtZn intermetallic catalyst for the oxygen reduction reaction(ORR),in which a Zn-rich metal–organic framework(MOF)is used as an in situ generated support to confine the growth of PtZn particles.Despite requiring high-temperature treatment,the intermetallic L1_(0)-PtZn particles exhibit a small mean size of3.95 nm,which confers the catalysts with high electrochemical active surface area(81.9 m^(2)g_(Pt)^(-1))and atomic utilization.The Pt electron structure and binding strength between Pt and oxygen intermediates are optimized through ligand effect and compressive strain.These advantages result in ORR mass activity and specific activity of 0.926 A mg_(Pt)^(-1) and 1.13 mA cm^(-2),respectively,which are 5.4 and 4.0 times those of commercial Pt/C.The stable L10structure provides the catalysts with superb durability;only a halfwave potential loss of 11 mV is observed after 30,000 cycles of accelerated stress tests,through which the structure evolves into a more stable PtZn-Pt core-shell structure.Therefore,the development of a Zn-based MOF as a catalyst support is demonstrated,providing a synergy strategy to prepare highly dispersed intermetallic alloys with high activity and durability.

Carbon monoxide powered fuel cell towards H_(2)-onboard purification

Proton exchange membrane fuel cells(PEMFCs)suffer extreme CO poisoning even at PPM level(<10 ppm),owning to the preferential CO adsorption and the consequential blockage of the catalyst surface.Herein,however,we report that CO itself can become an easily convertible fuel in PEMFC using atomically dispersed Rh catalysts(Rh-N-C).With CO to CO_(2) conversion initiates at 0 V,pure CO powered fuel cell attains unprecedented power density at 236 mW cm^(-2),with maximum CO turnover frequency(64.65 s^(-1),363 K)far exceeding any chemical or electrochemical catalysts reported.Moreover,this feature enables efficient CO selective removal from H_(2) gas stream through the PEMFC technique,with CO concentration reduced by one order of magnitude through running only one single cell,while simultaneously harvesting electricity.We attribute such catalytic behavior to the weak CO adsorption and the co-activation of H_(2)O due to the interplay between two adjacent Rh sites.

SC-IrO_2 NR-carbon hybrid:A catalyst with high electrochemical stability for oxygen reduction

The enhanced electrochemical stability of the synthesized hybrid catalyst has been demonstrated by the introduction of the synergistic effect between carbon powder additive and the prepared catalyst.Single crystal IrO 2 nanorod (SC-IrO 2 NR) catalyst was prepared by a sol-gel method.The structure and performance of the catalyst sample were characterized by X-ray diffraction spectroscopy (XRD),scanning electron microscope (SEM),transmission electron microscope (TEM),rotating disk electrode (RDE) and cyclic voltammetry (CV) measurements.XRD patterns and TEM images indicate that the catalyst sample has a rutile IrO 2 single crystal nanorod structure.The onset potential for oxygen reduction reaction (ORR) of the SC-IrO 2 NR-carbon hybrid catalyst specimen is 0.75 V (vs.RHE) in RDE measurement.CV and RDE test results show that the SC-IrO 2 NR-carbon hybrid catalyst has a better electrochemical stability in comparison with the commercial Pt/C catalyst,with attenuation ratios of 17.67% and 44.60% for the SC-IrO 2 NR-carbon hybrid catalyst and the commercial Pt/C catalyst after 1500 cycles,respectively.Therefore,in terms of stability,the SC-IrO 2 NR-carbon hybrid catalyst has a promising potential in the application of the proton exchange membrane fuel cell.

Oxidative polymerization of hydroquinone using deoxycholic acid supramolecular template

Polyhydroquinone (PHQ) is a redox-active polymer with quinone/hydroquinone redox active units in the main chain and may have potential applications as a mediator in biosensors and biofuel cells. By the oxidative polymerization of hydroquinone (HQ), PHQ can be easily synthesized, but the reaction lacks control over the structure of the product. Deoxycholic acid (DCA) was introduced as a supramolecular template to control the reaction. The reaction rate is 14 times of that in deionized water and twice of that in buffer. The DCA template increases not only the reaction rate, but also the molecular weight of the polymer obtained. The template effect of DCA was attributed to the supramolecular assemblies of DCA formed in the solution. Cyclic voltammetry study indicated the resulting PHQ was redox-active. While the supramolecular assemblies of DCA provided a template for the oxidative polymerization of HQ, the protons released as a by-product of the oxidative polymerization of HQ in turn enhanced the self-assembly of DCA. As a result, DCA microfibers form and separate out of the solution.