水热合成技术的研究和应用：Ⅳ.钛酸锶晶体粉末的制备

本文以Ｓｒ（ＯＨ）２和ＴｉＯ（ＯＨ）２作为水热合成ＳｒＴｉＯ３晶体粉末的前驱物，讨论并选定制备前驱物的化工原料，并对水热合成ＳｒＴｉＯ３晶体粉末的条件：ＫＯＨ浓度、温度和时间进行了考察。结果表明１５０－２００℃，１ｈ均可有效合成。２００℃下水热２０－６０ｍｉｎ产物的Ｘ光衍射征峰高无明显差别；水热介质中ＫＯＨ浓度从０．１－１．０ｍｏｌ／Ｌ区域内对合成无大的影响；最后初步讨论了ＳｒＴｉＯ３晶体粉末的合     

La_（1－x）Sr_xMn_（1－y）Cr_yO_3高温化学稳定性的研究

ＳＯＦＣ（固体氧化物燃料电池）中，尽量降低阴极材料与固体电解质（ＹＳＺ）之间在运行温度（１０００℃）时的化学反应，是降低电地内部能量损失的重要环节。本文从阴极材料的合成方法入手，讨论了Ｌａ＿（１－ｘ）ＳｒＭｎＯ＿３与ＹＳＺ之间在１４００℃的反应机制，研究了降低反应倾向的方法。发现向阴极材料中引入部分Ｃｒ￣（３＋）能获得很高的化学稳定性。     

水热法制备Y2O3—CeO2—ZrO2超细陶瓷粉末

采用共沉淀－水热法制备了Ｙ２Ｏ３－ＺｒＯ２（ＹＺ）和Ｙ２Ｏ３－ＣｅＯ２－ＺｒＯ２（ＹＣＺ）超细陶瓷粉末（１０ｎｍ左右）。Ｘ射线衍射分析表明，二元钇和锆及三元钇、铈和锆的共沉淀氢氧化物，经水热处理后均可获得四方相复合氧化物，在１７０￣２５０℃温度下进行水热处理，随着处理温度的提高，其氢氧化物的脱水速率加快，脱水更加完全，粉末粒度增大，有机添加剂如聚乙烯醇对水热产物可起到一定的分散作用。     

海洋锰结核的试验研究：Ni（Ⅱ）在H2O—NH3—SO2—MnO2体系中的行为

在用亚硫酸铵（ＮＨ４）２ＳＯ３浸出海洋锰结核中有价金属时发现镍从浸出液中损失，本试验就是研究这种损失的原因，在下列体系中，对Ｎｉ（Ⅱ）的行为进行研究：ａ．ＮＨ３－（ＮＨ４）２ＳＯ３－Ｈ２Ｏ；ｂ．ＮＨ３－用氧部分氧化的（ＮＨ４）２ＳＯ３－Ｈ２Ｏ；ｃ．ＮＨ３－用ＭｎＯ２部分氧化的（ＮＨ４）２ＳＯ３－Ｈ２Ｏ，在ＮＨ３－（ＮＨ４）２ＳＯ３溶液用ＭｎＯ２氧化时，加入的Ｎｉ（Ⅱ）形成晶状沉淀：Ｎｉ０．７５Ｍｎ     

ZrO_2－Y_2O_3超细粉末的研制

以ＺｒＯ２－Ｙ２Ｏ３超细粉末为研究对象，通过Ｘ射线衍射、差热分析（ＤＴＡ）、透射电镜和扫描电镜观察等方法，对共沉淀法制备的超细粉末进行了物相、粒度分析，并对该粉料压形烧结后进行了组成、密度、显微结构的测试分析。探讨了分散剂、盐溶液浓度、ｐＨ值、灼烧温度等条件对粉末烧结性能的影响，对用分散剂代替无水乙醇脱水工艺控制粉末团聚体做了研究尝试，得出了制备超细粉末的最佳工艺条件并制得了粒度为２０ｎｍ的ＺｒＯ２－Ｙ２Ｏ３超细粉。     

水热合成技术的研究和应用：V.锆酸锶,锆酸钡晶体粉末的制备研究

采用碱性前驱物Ｂａ（ＯＨ）２或Ｓｒ（ＯＨ）２及两性前驱动ＺｒＯ（ＯＨ）２，水热合成了ＢａＺｒＯ３和ＳｒＺｒＯ３晶体粉末，一系列实验结果表明，在水热温度为１５０～２００℃，ＫＯＨ浓度为０．１～０．８ｍｏｌ／Ｌ，时间２０～６０ｍｉｎ的条件下，均能有效合成。在相同的碱度下，延长水热时间或提高温度有利于ＳｒＺｒＯ３，ＢａＺｒＯ３晶体粉末的合成，晶化，晶体长大和提高晶体完整性，推荐合成条件：在０．２ｍｏｌ／     

ITO超细粉末的研制

应日本ＳＥＩ公司的要求，通过大量的试验，研究出制备超细ＩＴＯ粉末（Ｉｎ２Ｏ３－ＳｎＯ２）的独工艺，使一次平均粒径达０．２～０。．３μｍ，比日本目前平均粒径１～３μｍ小约一个数量级。用它制备的透明电极ＩＴＯ薄膜，相对深度（Ｒ．Ｄ值）高达９５％～９８％，高于日本市场要求的技术水平，本工艺具有极好的再现性，大大地简化了工序，减少了玷污。为工业生产透明电极材料ＩＴＯ超细粉末创造了条件。     

SiC陶瓷常压烧结研究

研究了ＳｉＣ粉末粒度、助剂Ａｌ２Ｏ３＋Ｙ２Ｏ３加入量和Ａｌ２Ｏ３与Ｙ２Ｏ３的配比等因素对ＳｉＣ陶瓷材料性能的影响。结果表明，添加Ａｌ２Ｏ３＋Ｙ２Ｏ３助剂可实现ＳｉＣ陶瓷的低温（１８５０℃）常压烧结。ＳｉＣ粉末粒度是影响可烧结性的重要因素之一，助剂加入量为２０％，Ａｌ２Ｏ３与Ｙ２Ｏ３之比为１：１时材料性能较好。     

ZG00Cr32Ni31Mo4Cu2Nb钢钝化膜的电子能谱分析

采用ＡＥＳ俄歇电子能谱和ＸＰＳ－Ｘ光电子能谱相结合的方法,对新型ＺＧ００Ｃｒ３２Ｎｉ３１Ｍｏ４Ｃｕ２Ｎｂ钢在９５℃４０％Ｐ２Ｏ５,１％Ｈ２ＳｉＦ６,２％ＨＦ,４％Ｈ２ＳＯ４,０．０５％Ｃｌ＾－１介质中形成的钝化膜进行了分析。试验结果表明,新型钢在该介质中,形成以Ｃｒ２Ｏ３、ＭｎＯ３为主的氧化物膜,而Ｎｉ、Ｃｕ富集在膜的底部,可进一步提高膜的稳定性。     

25—20型铬镍奥氏体不锈钢的成分优化和组织性能研究

研究了碳，铬，铌对铬－镍奥氏体不锈钢在沸腾８ＮＨＮＯ３－０．４２ＭＦｅ＾３＋－０．８３ＭＳＯ＾２－４－１．３ＭＮａ＾＋介质中均匀腐蚀和晶间腐蚀的影响；提出了耐蚀材料００Ｃｒ２５Ｎｉ２０Ｎｂ的最佳成分，评价了敏化条件对００Ｃｒ２５Ｎｉ２０Ｎｂ冲击专访韧性，显微组织的影响。采用硝酸法（ＧＢ１２２３－７５Ｘ法）检验了敏化条件与晶间腐蚀行为的关系。结果表明，６５０℃是该钢析出Ｍ２３Ｃ６的最敏感温度，达到晶     

Manufacture of Bulk Amorphous Crystal and Micro-Crystal for Pr60Cu(20-x)Ni10Al10Fex and Characteristics of Its Magnetic Apparatus

Bulk amorphous crystal and microcrystal for Pr60Cu(20-x)Ni10Al10Fex (x=0, 8, 15, 20) with the diameter of Φ 2～6 mm were manufactured by electric arc smelting, high frequency heating and copper mold upper suction casting, and its structure was analyzed by X-ray diffract meter. It showed soft magnetic characteristic gradually when Fe content in it was up to 8%. The material was applied to magnetic-electric sensor as key component, output signal of which was measured with the change of Fe content. It shows that the signal changes from weak to strong with the increase of Fe content and presents the largest peak value when Fe is replaced by Cu completely.     

The new toothpastes

Total genomic DNA sampled from 20 oral squamous cell carcinomas (SCCs) and from four SCC cell lines, was examined for genomic imbalances using comparative genomic hybridisation (CGH). Gains and losses of DNA copy number aberrations (CNAs) were found in the primary tumours, but also in the cell lines at a varying number. The patterns of CNAs proved to be rather peculiar in oral SCCs, gains of genetic material clearly dominating compared with losses, and a rather high uniformity of these patterns was an impressive finding. Hypersomies of whole chromosomes, e.g. numbers 17 and 19 or of whole chromosome arms, e.g. 20q, were particularly evident. The segments most frequently gained in oral SCCs were 3q26-q27, 5p15 and 9q34 (16 of 20 tumours each), as well as 1p36.3, 8q24, 10q26, 19 and 20q (15/20 each). Among the 15 tumours with more than 10 CNAs, all showed these imbalances. 11q13 was a band often involved in increases (14/20 tumours), but in several tumours was involved in amplification of DNA copy number. Several other chromosomal segments over represented in more than 60% of the tumours, as, for example, 12q24, 15q22-q24, 16p13.2 and 17q (14/20 tumours each), 6q26-qter, 7p22, 12p12.2-p13, 14q31-q32.2 (13/20) and 1q32-q41, 2q37, 16q23-q24 (12/20 each). In contrast, loss of material affected only a few chromosomal segments, as, for example, 3p12 (12 of the 20 tumours), 5q21 (10/20), 6q13 (8/20). The peculiarities of these findings, in some respect, differ from those found in other epithelial tumours, suggesting a high impact of environmental factors in the generation and progression of these tumours.     

Dynamic Response of Compacted CG, DM, and CG-DM Blends

The cyclic behavior of 9.5 mm (3/8 in.) minus curbside-collected crushed glass (CG) blended with dredged material (DM), classified as an organic silt by the Unified Soil Classification System, was evaluated using a cyclic triaxial testing program. Tests were performed on 100% CG and 100% DM specimens, and 20/80, 40/60, 60/40, and 80/20 CG-DM blends (dry CG content is reported first). The specimens were compacted to a dry unit weight equivalent to 95% of the maximum dry density based on ASTM D1557. For each material, a minimum of three specimens was tested at cyclic stress ratios of 0.20, 0.35, and 0.45. The DM used in this study exhibited significant plasticity, which would be expected to display cyclic softening behavior according to liquefaction susceptibility criteria proposed by Boulanger and Idriss in 2006. However, the high density of the material resulted in transitional behavior between cyclic mobility and cyclic softening. These findings suggest that as long as the CG, DM, and CG-DM blends are compacted, they should not be susceptible to strength loss or large strain under cyclic loading.     

Biosynthesis of polyunsaturated fatty acids in the developing brain: II. Metabolic transformations of intracranially administered [3-(14)C] Eicosatrienoic acid, evidence for lack of delta8 desaturase

[3-(14)C] Eicosatrienoic acid (delta11,14,17) chemically synthesized from [-(14)C] linolenic acid was injected intracranially into 14-day old rats and sacrificed 8 hr later. The analysis of brain fatty acids by radio-gas liquid chromatography before and after ozonolysis showed that the tetraene fraction consisted of a desaturated product, delta5,11,17-20:4, and its elongated product, delta7,13,16,19-22:4. Both of these products, with a combined total of 61% of the total radioactivity recovered in the tetraene fraction, contain a nonmethylene interrupted double bond system and, therefore, are unsuitable for further desaturation. The other two components, delta6,9,12,15-18:4 and delta8,11,14,14-20:4, must have been formed from delta9,12,15-18:3, formed by retroconversion of the starting material 20:3, followed by desaturation and elongation. These results suggest a lack of delta8 desaturase in the developing brain, leading to formation of delta5,11,14,17-20:4 rather than delta8,11,14,17-20:4. However, the nonmethylene interrupted doulbe bond isomer does not restrict chain elongation.     

Effect of the Cryogenic Treatment on Polyamide and Optimization of Its Parameters for the Enhancement of Wear Performance

Polyamide (PA) is generally used in automotive applications in which the extensive mechanistic situations lead the material to wear. To deal with this situation, attempts are made to treat this material cryogenically using liquid nitrogen. The material is treated at different temperatures (?80, ?140 and ?185?°C) for stipulated time period (4, 8, 12, 16, 20 and 24?h) in the cryostat. Cryo-treated samples are then allowed to attain the ambient temperature and tested for studying the effect of cryogenic treatment. Selected material is also studied simultaneously for thermal ageing. The mechanical, thermal and structural properties of ??un-treated?? and ??cryo-treated?? PA are studied in a comparative manner. Mechanical properties like wear performance and tensile properties are evaluated. The morphological changes due to cryo-treatment are investigated using scanning electron microscopy. Structural characterization by X-ray diffraction and Fourier transform infrared spectroscopy revealed the change in % crystallinity, which is found to be the most important parameter responsible for enhancement of wear performance. In a similar way, thermal changes are also studied by using differential scanning calorimeter. Experimental data is evaluated for the polymer with improved structural, mechanical and thermal properties in order to get optimized parameters for the cryo-treatment.     

A comparison of the microstructures of As-cast and laser surface melted Ti-8Al-4Y

A Ti-8 at. pct Al-4 at. pct Y alloy has been cast in small quantities and subjected to laser surface melting treatments in an effort to produce a uniform distribution of fine-scale dispersoids by internal oxidation. The microstructures of both as-cast and laser-modified material have been characterized using transmission electron microscopy, energy dispersive X-ray spectroscopy, and convergent beam electron diffraction, and the identity and distribution of second phase dispersoids established. An ability to refine significantly the dendritic structure of the as-cast alloy by laser surface treatment is demonstrated. The matrix phase of the modified alloy is martensitic α′, in contrast to the α phase of the as-cast material. The interdendritic phase observed in both as-cast and laser-modified material and the fine-scale dispersed particles (50 to 70 nm) in the as-cast alloy are shown to be rich in Y, with a structure consistent with that of the oxide Y₂O₃. Dispersoids within the laser modified zone are typically 8 to 20 nm in diameter and show a tendency to form preferentially at interlath boundaries of the martensite. The origins of these structures and their potential effects on the mechanical properties of the alloy are discussed briefly.     

Outcomes of vitrectomy for retained lens fragments

PURPOSE: Retained lens fragments after cataract surgery is an infrequent, but potentially serious surgical complication. The aim of this study is to evaluate outcomes after vitrectomy has been performed for removal of retained lens material. METHODS: A retrospective review was conducted to evaluate all cases of pars plana vitrectomy for removal of retained lens fragments performed at Wills Eye Hospital from April 1991 through August 1994. RESULTS: A total of 121 eyes of 121 patients underwent pars plana vitrectomy with removal of retained lens material over the 3 1/2-year period. Visual acuity on presentation was 20/200 or worse in 95 eyes (79 percent). Visual acuity after vitrectomy was 20/40 or better in 82 eyes (68 percent). The postoperative visual acuity was 20/50 to 20/400 in 21 eyes (17 percent), and counting fingers or worse in 18 eyes (15 percent). Nineteen eyes (16 percent) had retinal detachment (RD), 8 were noted at the time of vitrectomy and 11 occurred after vitrectomy. Of the 19 eyes with RD, visual acuity was 20/200 or worse in 12 (63 percent) and counting fingers or worse in 6 (32 percent) at the time of last follow-up. The use of posterior segment phacofragmentation was associated with higher rate of RD, but the difference did not reach statistical significance. Major causes of poor final visual outcome included RD (6 eyes), cystoid macular edema (4 eyes), and glaucoma (2 eyes). CONCLUSION: The timing of vitrectomy did not have a statistically significant impact on visual outcome. Neither the type of intraocular lens nor the timing of lens implantation significantly altered the final visual acuity. Most eyes with retained lens fragments do well after vitrectomy, with the majority recovering good vision. However, the risk of RD is increased, and visual outcome may be adversely affected if RD occurs.     

Language-related hemispheric asymmetry in healthy subjects and patients with temporal lobe epilepsy as studied by event-related brain potentials and intracarotid amobarbital test

There are current attempts to replace the WADA test for pre-surgical evaluation of hemispheric language capabilities by one of the methods of functional brain imaging. Recent PET and fMRI studies using verbal cognitive tasks like verb generation, semantic monitoring or semantic ('deep') encoding of words showed asymmetries of activation in the fronto-lateral cortex. In a previous ERP study subjects were required to indicate whether pronounceable non-words and abstract geometric figures were presented for the first time ('new item') or whether they had been shown before ('old item'). Group analyses of this study showed significant material-specific hemispheric asymmetries with ERPs being more negative-going in recordings of the posterior part of the left hemisphere with verbal material (CP5/6) but more negative-going in recordings of the right hemisphere with the spatial material (P7/8). The aim of the present study was to test statistically ERP lateralization effects in individual healthy subjects as well as WADA-tested patients suffering from seizures of the mesio-temporal lobe (MTL). In all subjects ERP lateralization with verbal material was tested in the electrode pair CP5/6, and ERP lateralization with figures in the electrode pair P7/8. Statistical analyses of single trials showed that in 20 out of 24 subjects ERPs with verbal material started to be more negative-going in CP5 as compared to CP6 in the period between 100 and 200 ms after stimulus onset or the subsequent time epoch (200-300 ms). In one subject not CP5/6 but the closely adjacent electrode pair P7/P8 showed this verbal material-related hemispheric effect. In patients language dominance as indicated by ERPs was not always consistent with the data of the WADA test. In one patient with left MTL seizures ERPs with verbal material and figures were found to be significantly lateralized to the right hemisphere although the WADA test assigned this patient to have a language-dominant left hemisphere.     

高频燃烧-红外吸收法测定钎料中低碳

对高频燃烧-红外吸收法测定BAu20NiCrFeSiB钎料中低碳的实验条件进行了探讨,并考察了助熔剂和坩埚对空白值的影响。实验表明:当添加1.2g钨锡助熔剂,分析时间为40s、比较水平为3%时,测定效果最佳：采用由钨锡助熔剂与铁助熔剂制备的打底坩埚,空白值远低于试样含碳量且稳定。在没有BAu20NiCrFeSiB钎料标准样品的情况下,采用基体类似的镍基高温合金GH3128标准样品对仪器进行了校准。将方法用于实际样品中碳的测定,测得结果为0.0158%、0.0147%,平行测定11次的相对标准偏差不大于1.7%,加标回收率为97%~102%。     

Synthesis of a tetracyclic, conformationally constrained analogue of delta8-THC

A tetracyclic, conformationally constrained analogue of delta8-THC (2) has been synthesized in which a two carbon bridge exists between C2 and C2'. Two conceptually related syntheses of 2 are described, both of which employ 5,7-dimethoxy-4-oxo-1,2,3,4-tetrahydronaphthoic acid (11) as starting material. This substrate was converted to 5,7dimethoxy-2-propyl-1,2,3,4-tetrahydronaphthalene (7) and its 4-keto derivative (18). Demethylation of 11 and 18 provided the corresponding resorcinols, which were condensed with trans-p-menthadienol to afford cannabinoid 2, and a keto derivative (20). LiA1H4/A1C1(3) reduction of 20 provided 2. Cannabinoid 2 has relatively low affinity for the cannabinoid brain receptor (Ki = 703+/-98 nM).