Microstructure and magnetic properties of anisotropic Nd-Fe-B magnets prepared by spark plasma sintering and hot deformation

Bulk anisotropic Nd-Fe-B magnets were prepared from hydrogen-disproportionation-desorption-recombination（HDDR） powders via spark plasma sintering（SPS） and subsequent hot deformation. The influence of sintering temperature on the structure and magnetic properties of the spark plasma sintered Nd-Fe-B magnets were studied. The remanence Br, intrinsic coercivity Hcj, and the maximum energy product（BH）max, of sintered Nd-Fe-B magnets first increase and then decrease with the increase of sintering temperature, TSPS, from 650 °C to 900 °C. The optimal magnetic properties can be obtained when TSPS is 800 °C. The Nd-Fe-B magnet sinter treated at 800 °C was subjected to further hot deformation. Compared with the starting HDDR powders or the SPS treated magnets, the hot-deformed magnets present more obvious anisotropy and possess much better magnetic properties due to the good c-axis texture formed in the deformation process. The anisotropic magnet deformed at 800 °C with 50% compression ratio has a microstructure consisting of well aligned and platelet-shaped Nd2Fe14 B grains without abnormal grain growth and exhibits excellent magnetic properties parallel to the pressing axis.

Effects of gallium on electrochemical discharge behavior of Al-Mg-Sn-In alloy anode for air cell or water-activated cell

In order to evaluate the electrochemical properties of aluminum alloy anode under high current densities in alkaline electrolyte, the galvanostatic discharge, potentiodynamic polarization and hydrogen evolution tests of three experimental Al?Mg?Sn?In?(Ga) alloys were performed. The results show that the alloying element gallium improves the working potentials of experimental Al?Mg?Sn?In alloys under different discharge current densities. The average working potentials of the alloys containing gallium can reach?1.3 V under current density ranging from 650 to 900 mA/cm2, while those of alloy without Ga are only?1.0 V. Such phenomenon is attributed to the solid solution which can form amalgam with aluminum matrix. Such an amalgam can form the hydrolyzed species during the discharge process and lead to the corrosion infiltrating into aluminum matrix.

Reproducibility of splicer-based long-period fiber gratings for gain equalization

We fabricated long-period fiber gratings （LPFGs） using electric arc discharges. We observed that the fiber becomes slightly tapered due to longitudinal tension during the arc： this effect depends on the arc current and time length. We experimentally investigated how these characteristics can influence grating＇s performances, especially in view of employing the LPFG as gain equalizer for an erbium-doped optical amplifier. As expected, we found that the spectral response of the grating depends on the period A, the intensity of the perturbation, the grating length and the type of mode-coupling induced. Since this last parameter cannot be estimated directly from the transmission spectra, we propose a method to determine the modecoupling occurring in the device and to assess the index modulation induced by the electric arcs. This method combines both experimental and simulated data, and can be used to characterize LPFGs made-up by any method.

Safety and effective developing nuclear power to realize green and low-carbon development

This paper analyzes the role of nuclear power of China's energy structure and industry system. Comparing with other renewable energy the nuclear power chain has very low greenhouse gas emission, so it will play more important role in China's low-carbon economy. The paper also discussed the necessity of nuclear power development to achieve emission reduction, energy structure adjustment, nuclear power safety,environmental protection, enhancement of nuclear power technology, nuclear waste treatment, and disposal, as well as nuclear power plant decommissioning. Based on the safety record and situation of the existing power plants in China, the current status of the development of world nuclear power technology, and the features of the independently designed advanced power plants in China, this paper aims to demonstrate the safety of nuclear power. A nuclear power plant will not cause harm either to the environment and nor to the public according to the real data of radioactivity release, which are obtained from an operational nuclear plant. The development of nuclear power technology can enhance the safety of nuclear power. Further, this paper discusses issues related to the nuclear fuel cycle, the treatment, and disposal strategies of nuclear waste, and the decommissioning of a nuclear power plant, all of which are issues of public concern.

谁是影视创作中的“吃客”?

小时候,看电影是一件很愉快的事。花一、两根冰棍的钱,就可以进电影院。而更多的时候,连钱也不要,看免费的露天电影:天刚擦黑,甚至还没黑,场院上就早早的有人去占位置了。各种各样的马扎、木椅、小凳,摆了一溜。大人们闲闲地聊着天,小孩儿撒开了欢儿似地跑。等到天完全黑下来,满场就黑压压地都是人了,甚至连幕布的背面也坐了不少人。 《南征北战》、《多瑙河之波》、《卖花姑娘》……其实好些片子不止看了一遍两遍,可一放电影还是会再去。百看不厌的原因,当然与那时文化娱乐贫乏,没有更多的消遣有关,当然还有别的什么。记得那时每回看完电影,心里都有一种说不出的满足感,好像干涸的花,被细雨滋润了一样,好长时间后,还能品出点滋味来。于是就老盼着什么时候再放电影。否则大冬天的。