金属钕工业生产中氧化钕利用率的探讨

在氟化体系氧化物电解金属钕的工业产中,针对Ｍｄ２Ｏ３在熔盐中溶解度低的情况下,尤其是以氟酸铈矿提取的ｎｄ２Ｏ３为原料电解时易发生沉底现象时,采取调整熔盐配比和适当提高氧化钕利用率的方法,可改善金属钕产品的表面质量,防止熔盐夹杂,降低产品中的碳含量,并可达到减少炉渣（废旧溶盐）生成、稳定炉况生产和节能降耗的目的。     

Laser skin resurfacing with the Q-switched Nd:YAG laser

BACKGROUND: Recent studies have shown that char-free pulsed carbon dioxide lasers are useful in the treatment of rhytids. Other infrared lasers have also been observed to induce changes in the skin. OBJECTIVE: In this pilot study, we evaluated the rhytid resurfacing capability of the Q-switched neodymium:yttrium-aluminum-garden (QS Nd:YAG) laser at 1064 nm as compared with char-free carbon dioxide lasers at 10,600 nm. METHODS: Three lasers were used in the study: The QS Nd:YAG laser, the SilkTouch carbon dioxide laser, and the UltraPulse carbon dioxide laser. Eleven subjects were treated in either the periorbital or perioral region with the QS Nd:YAG laser on one side of the face, and both of the char-free pulsed carbon dioxide lasers on the other side. The subjects were evaluated at posttreatment days 7, 30, 60, and 90 for improvement of rhytids, healing, pigmentary changes, and erythema. RESULTS: All 11 patients treated with the char-free carbon dioxide lasers improved. Nine of 11 patients treated with the QS Nd:YAG laser were improved. Healing (complete reepithelialization) was noted to occur 3-6 days earlier in sites treated with the QS Nd:YAG than in sites treated with char-free carbon dioxide lasers. Pigmentary changes were not observed in any treatment site. Erythema was observed at 1 month after treatment in all areas treated with the char-free carbon dioxide lasers, but only three patients treated with the QS Nd:YAG exhibited erythema. These were the same three QS Nd:YAG-treated patients whose clinical improvement was comparable with that of the char-free carbon dioxide lasers. CONCLUSION: The Q-switched Nd:YAG laser may play a role in the treatment of rhytids.     

Magnetomechanical Properties of the Alloy Nd2Fe14B

We have studied the elastic and inelastic properties of the polycrystalline ferromagnet Nd₂Fe₁₄B in the temperature range 20–550 °C. We used the low-frequency (80 Hz) internal friction method to measure the Curie point of Nd₂Fe₁₄B. We observe an internal friction peak at T ≈ 280 °C. The nature of this peak is explained in terms of the magnetoelastic saturation concept.__________Translated from Poroshkovaya Metallurgiya, Nos. 3–4(442), pp. 87–93, March–April, 2005.     

Phase Equilibria in the Nd ― Re ― B System

XRD has been applied to component interaction in the Nd ― Re ― B system. Isothermal sections have been constructed for the phase diagram at 600°C (a region >33 at.% boron) and 800°C (>33 at.% boron). It is confirmed that it contains the previously known borides Nd₂Re₃B₆ (Pr₂Re₃B₆ structure type) and Nd₈Re_{13 − x} B₁₂ (Pr₈Re_{13 − x} B₁₂ structure type). Two new ternary compounds are reported: ∼NdRe₄B₄ considered to have a tetragonal incommensurate structure and ∼Nd₅Re₂B₆, whose structure is unknown.

     

Phase Equilibria in the Nd ― Re ― B System

Powder Metallurgy and Metal Ceramics - XRD has been applied to component interaction in the Nd ― Re ― B system. Isothermal sections have been constructed for the phase diagram at...     

An evaluation of the bactericidal effect of the Nd:YAP laser

The aim of this in vitro study was to compare the efficacy of a classical irrigant with that of a laser in disinfecting a contaminated root canal. Thirty canals of extracted single-root teeth were prepared with files to size #20. The teeth were sterilized with Germispad (Spad, France) for 30 min and then inoculated with Streptococcus mitis ATCC 33399. By randomization, the teeth were divided into six groups of five teeth each. In the first group, teeth were neither inoculated nor prepared. This was the sterility control group (1). In the second group (2) teeth were inoculated without any preparation: as positive controls. The third group was inoculated and then hand-instrumented with files to size #30 with 5.25% NaOCl as irrigant. This was the hand instrumentation group. The other groups were prepared with hand instrumentation with files to size #30, using sterile water as an irrigant, and the canal was then lased with different frequencies as follows: group 4, frequency of 5 Hz and power of 260 mJ; group 5, frequency of 10 Hz and power of 310 mJ; and group 6, frequency of 30 Hz and power of 300 mJ. After experimentation, the residual colonies were counted. The results indicated that (i) the treatment with NaOCl and manual instrumentation effectively inhibited the growth of Streptococcus mitis ATCC 33399; and (ii) the antibacterial effect of the Nd:YAP laser depended on the frequency. Only a frequency of 30 Hz of the Nd:YAP laser inhibited the growth of Streptococcus mitis ATCC 333999.     

Er或Nd组合着色的新型陶瓷变色颜料的研究

用高温固相反应合成出了新型陶瓷光致变色颜料 ,此陶瓷颜料主要用 Er与 Nd作发色剂 ,并添加其它金属氧化物组合着色而成。