若干材料的微裂纹、相变和各向异性与负膨胀关系的研究

对陶瓷材料的微裂纹、相变和各向异性与负膨胀关系作了研究，以实验结果为依据，列举了一些具有负膨胀性能的材料。实验结果表明，陶瓷材料的这些性能对它的热膨胀有一定的影响     

低膨胀陶瓷的结构特征

董青石、钛酸铝、β-锂辉石、β-锂霞石及NZP等低膨胀陶瓷均有一个方向的轴膨胀为负值,本文对这些负的轴膨胀及低膨胀的结构特征进行了分析归纳,并根据结构特征指出改善低膨胀陶瓷低强度的一个有效方法。     

锰基反钙钛矿化合物负/零热膨胀性质的研究进展

近零热膨胀材料在变温环境下具有高的尺寸稳定性，不易产生热应力，可保证相关器件或构件具有高的精密性和稳定的使用寿命，因此其在航空航天、微电子、光学、精密仪器仪表等领域具有重要应用价值。锰基反钙钛矿化合物Mn₃AX(A=金属或半导体元素，X=N或C)由于具有宽温区、各向同性、易调控的负或近零热膨胀性质，近年来引起广泛关注。Mn₃AX化合物具有丰富的磁结构，此类化合物负或近零热膨胀性质与其磁相变和晶格-自旋强关联特性密切相关。因此，通过优化组分可改变其磁结构及磁相变过程，进而有效调控其热膨胀行为并获得其它功能物性。综述并评价了国内外研究者在Mn₃AX反常热膨胀行为调控方面所做的实验和理论工作。对锰基反钙钛矿化合物反常负/零热膨胀性质实验上的有效调控和机制上的深入分析，对揭示反常热膨胀的物理起源具有重要意义，能够积极推动这类材料走向应用。旨在总结目前本领域的研究进展，着重介绍了锰基反钙钛矿化合物负/零热膨胀性质的调控策略与机理研究，也对本领域未来的研究趋势进行了展望。     

湿法纺丝凝固负牵伸的研究

采用膨口胀大比的测量、沸水收缩率、X射线衍射、电子探针、孔隙率及机械性能的测试等分析测试手段,系统研究了凝固负牵伸对聚丙烯腈(PAN)纺丝液的膨胀效应、初生纤维聚集态结构和性能的影响,初步揭示了膨胀效应和凝固取向的产生机理及其对初生纤维结构与性能的影响。研究发现:随着凝固负牵伸的降低,PAN纺丝液的膨口胀大比减小,初生纤维的凝固取向、结晶度和晶粒尺寸均增加,其截面形状趋于规整,内部结构变得均匀致密、内部缺陷减少。     

专利信息

一种高压陶瓷电容器介质本发明是关于高压陶瓷电容器介质的配方组成,它采用常规的高压陶瓷电容器介质制备方法来制备得到无铅高压陶瓷电容器介质,其特征在于所述介质配方包括(重量比):BaTiO365%～98%、SrTiO31%～15%、Bi2O3·3TiO20.05%～30%、CaZrO30.03%～6%、Nb2O50.01%～1%。其耐压高,可达8KV/mm以上,电容温度变化率小,使用过程中性能稳定性好,安全性高。低膨胀或负膨胀复相陶瓷及其制备方法一种低膨胀或负膨胀复相陶瓷极其制备方法,采用湿化学法制备前驱体,微波低温煅烧的合成工艺获得化学式为:(Zr1-xAx)(W2-yMoy)O8-δ固溶体…     

玻璃成分的设计与调整(十九)

5.9 耐热微晶玻璃成分 微晶玻璃是通过玻璃析晶得到的多晶体,晶体尺寸小于10μm,晶相体积含量在50%以上.选择合适的玻璃成分与玻璃析晶温度制度,可以得到低膨胀或负膨胀的微晶,使微晶玻璃具有很高的耐热震性能,用于直接在明火上加热的炊具和餐具.     

反钙钛矿Mn_3AN(C)化合物中的负热膨胀与磁相转变（英文）

负热膨胀材料在诸多工业领域拥有广阔应用价值,在此类材料中,锰基反钙钛矿化合物近年来被广泛研究。本工作对具有负膨胀效应的Mn3AN(C)(A=主族或过渡族元素)化合物进行了综述与评论。讨论了该化合物特殊热膨胀行为及与磁结构和磁相转变的关系,指出其特殊磁结构是Mn3AN(C)化合物中产生磁容积效应的重要因素,Fermi能级处的电子态密度与磁相转变具有强关联性。由负热膨胀材料Mn3AN与金属铜组成的金属基复合材料显示有低热膨胀和近零热膨胀行为,可通过改变Mn3Cu0.5A0.5N(A=Ni,Sn)的混合含量,调控金属铜的热膨胀系数。     

钛酸铝材料反常热膨胀特性的分析研究

铁稳定钛酸铝材料在８５０￣９５０℃之间热膨胀有一个特殊变化,即出现反常负膨胀。本研究通过对试样的热膨胀分析、Ｘ－ＲＡＹ分析和ＳＥＭ分析,探明了造成这一变化的原因。     

湿纺凝固负拉伸对初生纤维结构与性能的影响

研究了凝固负拉伸对聚丙烯腈(PAN)纺丝液的膨胀效应、初生纤维聚集态结构和性能的影响,初步揭示了膨胀效应和凝固取向的产生机理及其对初生纤维结构与性能的影响;指出溶剂与水之间的传质速率差是控制初生纤维结构进而控制其性能的最关键因素,它决定了原液细流表面凝固层的组成及结构,而凝固速率反映了凝固层的生长速度。研究发现:随着凝固负拉伸的降低,PAN纺丝液的挤出胀大比减小,其传质速率差与凝固速率均下降,初生纤维的凝固取向、结晶度和晶粒尺寸均增加,其截面形状趋于圆形,内部结构变得均匀致密、缺陷减少,从而使断裂强度得以提高。     

ZrW2O8微波合成、表征及负膨胀行为研究

采用湿化学－微波合成工艺制备了具有负膨胀行为的ＺｒＷ２Ｏ８粉体,Ｘ射线衍射和Ｒａｍａｎ光谱分析结果表明,合成产物是基本单一的立方结构的ＺｒＷ２Ｏ８。用ＳＥＭ观察了样品的形貌,热膨胀仪测定了样品从室温到８００℃的膨胀行为,其膨胀系数的平均值为－７．９×１０＾－６Ｋ＾－１。     

微波消解-ICP-OES法测定黑芝麻中的18种矿质元素

采用HNO3/H2O2湿法微波消解制样,利用全谱直读电感耦合等离子原子发射光谱法(ICP-OES),全面详细地分析测定了黑芝麻中的矿质元素,共检出Ca、P、S、Mg、K、Al、Si、Fe、Na、Zn、Se、Sr、Cu、Mn、Ba、B、Ti、Cr等18种矿质元素,RSD值在1.21%～10.1%,其中13种元素在5%以内。黑芝麻中所含人体常量元素Ca、P、S、Mg、K、Na等的质量分数分别为1.79%,1.08%,0.59%,0.43%,0.41%和0.009 1%;微量元素Fe、Zn、Se、Cu、Mn、B、Cr、Sr、Si、Al等的含量分别为18.6,4.55,3.87,1.74,1.62,0.91,3.21,78.8,125.8 mg/100 g,未检出Pb、Hg、Cd、As以及Ni、Co、Mo等元素。     

Phase-mineral and chemical composition of coal fly ashes as a basis for their multicomponent utilization. 4. Characterization of heavy concentrates and improved fly ash residues

The phase-mineral and chemical composition of heavy concentrates (HCc) and improved fly ash residues (IFAs) recovered from five fly ashes (FAs) produced in four large Spanish thermo-electric power stations was characterized. The HCs were separated by sink-float separation in bromoform, while the IFAs are residues after the isolation of ceramic cenosphere, salt, magnetic, char and heavy concentrates. The HCs recovered are in the range 0.02–0.28% and their phase-mineral composition (in decreasing order of significance) commonly includes aluminosilicate glass, hematite, magnetite, larnite, quartz, periclase, mullite, corundum, lime, char, melilite, rutile, plagioclase, wollastonite, ferrian spinel, and anhydrite. Numerous accessory minerals of Ba, Ce, Cl, Cr, Cu, F, Fe, La, Mn, P, Pb, Th, Ti, Y, and Zr, are also typical components of HCs. These fractions are enriched in As, Ca, Cr, Cu, Gd, Mg, Mn, Mo, Fe, Ni, Pb, S, Se, Ti, V, Zn, and Zr in comparison with the FAs. The IFAs isolated are in the range 71.5–97.1% and their phase-mineral composition (in decresing order of significance) normally includes aluminosilicate glass, mullite, quartz, char, kaolinite, plagioclase, cristobalite, wollastonite, hematite, anhydrite, K-feldspar, melilite, and corundum. The contents of most elements in IFAs are similar to FAs as Ag, Ba, Cl, Cs, Ge, Mo, S, Sb, and Sc are significantly depleted in these residues. The IFAs have an improved composition in comparison with the FAs because they are: more homogeneous and finer-grained products; abundant in pozzolan and inert constituents; and depleted in harmful components. Some genetic features, properties, possible environmental concern, and potential utilization directions related to the HCs and IFAs are described. A basis for the advanced, multicomponent, wasteless, and environmentally safety utilization of various FAs is also discussed.     

应用ICP-MS同时测定矿泉水中22种微量金属

研究结果表明应用ICP-MS可以同时测定饮用天然矿泉水中的Li、Be、B、Al、Ti、V、Cr、Mn、Co、Ni、Cu、Zn、Ge、As、Se、Sr、Mo、Ag、Cd、Sb、Ba、Pb、等微量金属元素.ICP-MS法具有快速、准确、处理简单、干扰少等优点.     

一种具有混合侧链的苯并菲类盘状液晶材料的合成及其液晶性能的表征

本研究采用邻苯二酚、溴代正戊烷和乙酰氯为原料合成了以苯并菲为基元的盘状液晶化合物2,6,10-三乙酯基-3,7,11-三戊氧基苯并菲,化合物的结构采用核磁手段1HNMR进行鉴定。采用偏光显微镜POM和DSC手段对该种化合物的相行为进行了研究,并且与合成过程中的中间体2,3,6,7,10,11-六戊氧基苯并菲的相行为进行了比较。     

Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons in Surface Sediments from the Upper Reach of Huaihe River

Based on the available toxicity data and the concentrations of polycyclic aromatic hydrocarbons (PAHs) in 16 surface sediments from upper reach of Huaihe River, overlapping areas of probability density curves and margin of safety (MOS₁₀) were used to estimate the ecological risk of eight PAHs to aquatic organisms. The results indicated that the overlapping areas of Pyr, Nap, Fla, Ant, Phe, Ace, BaP, and Flu were 0.38, 0.29, 0.16, 0.11, 0.07, 0.03, 0.03, and 0.01, respectively. The risk of Pyr was the highest while that of Flu was the lowest. The overlapping area of ΣPAH₈ was 0.72, higher than that of any individual PAHs due to their joint effect. The calculated MOS₁₀ for Nap, Ace, Flu, Phe, Ant, Fla, Pyr, and BaP were 6.86, 5.42, 19.0, 2.72, 0.93, 0.75, 0.03, and 63.0, respectively. The probabilities of Nap, Ace, Flu, Phe, and BaP surpassing the 10th percentile value of the toxicity data were 0.07%, 0.30%, 0.05%, 1.97%, and 0.01%, respectively, suggesting minimal risk to aquatic organisms. However, the probabilities of Ant, Fla, and Pyr exceeding this value were 11.3%, 12.9%, and 64.8%, indicating potential risks. Among the individual PAHs, the ecological risk from Pyr was the highest, followed by Fla, Ant, Phe, Ace, Nap, Flu, and BaP. Additionally, the combined ecological risk of ΣPAH₈ in the upper reach of Huaihe River was significantly higher than that of any individual PAH alone, which the probabilities of ∑PAH₈ in excess of the 10th percentile of the toxicity data were 99.4%.     

合成环己酮乙二醇缩酮的催化剂研究进展

评述了近年来国内采用甲烷磺酸盐、对甲苯磺酸、氨基磺酸、强酸性阳离子交换树脂、磺化聚氯乙烯、六水三氯化铁、二水氯化亚锡、五水四氯化锡、四水氯化锰、硫酸铜、水合硫酸铁、十二水合硫酸铁铵、硫酸钛、四水硫酸锆、氯化锆、四水硫酸高铈、水合硝酸镧、活性炭固载硫酸镧、铌酸、树脂固载Lewis酸、壳聚糖硫酸盐、一水硫酸氢钠、碘、磷酸二氢钠、固体超强酸、杂多酸、分子筛和维生素C等固体酸催化合成环己酮乙二醇缩酮的实验结果。研究结果表明,固体酸能够代替硫酸作为合成环己酮乙二醇缩酮反应的催化剂。     

氯碱下游产品建设投资分析(续2)

介绍了20种氯碱下游产品--氯甲苯、氯乙酸、环氧氯丙烷、氯化苄、环氧丙烷、聚偏氯乙烯树脂、氯化聚氯乙烯树脂、氯化聚乙烯、甲基氯硅烷、三氯氢硅、氯化法钛白粉、三氯化磷、4,4'-二苯基甲烷二异氰酸酯、1,4-丁二醇、苯胺、环己酮、气相法白炭黑、甲基异丁基酮、对氨基苯酚、水合肼的市场前景、技术来源与建设投资.     

METAL EXTRACTION FROM NITRIC ACID SOLUTIONS BY (DIPHENYL-PHOSPHINYLMETHYL) PHENYLPHOSPHINIC ACID

ABSTRACT

The extraction of microquantities of Ca, Sr, Ba, Sc, Mn, Co, Cu, Zn, Ga, Cd, In, Pb, Bi, Zr, Hf, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, and U from HNO₃ solutions by (diphenylphosphinylmethyl)phenylphosphinic acid in organic diluents has been studied.

The effect of HNO₃ concentration in the aqueous phase and that of the extractant in the organic phase on the metal extraction are considered. (Diphenylphosphinylmethyl)phenylphosphinic acid possesses an extraordinary affinity for actinides and rare-earth elements. The extractive efficiency and selectivity of this compound toward rare-earth metal ions are compared with those of some multifunctional acidic and neutral organophosphorus extractants.     

全谱直读电感耦合等离子体原子发射光谱测定苦荞麦矿物元素

采用HNO3/H2O2湿法微波消解制样,采用全谱直读电感耦合等离子体原子发射光谱法（ICP-OES）,分析测定了苦荞麦中的矿物元素,共检出P、S、K、Mg、Ca、Si、Al、Fe、Na、Zn、Mn、B、Cu、Se、Ti、Cr、Ba、Sr等18种矿物元素。分析结果的RSD值在0.45%～9.09%之间,其中15种元素在5%以内。苦荞麦中所含P、S、K、Mg、Ca、Na等常量元素的质量分数分别为0.21%、0.21%、0.17%、0.098%、0.019%、0.0017%;微量元素Fe、Zn、Cu、Se、Cr、Si、Mn、B、Ti、Ba、Sr、Al等的含量（mg.kg-1）分别为37.4、16.5、3.67、1.38、0.44、121.6、6.90、4.88、0.63、0.22、0.12、49.9。     

Petrography and geochemistry of the Middle Devonian coal from Luquan, Yunnan Province, China

Coals from Luquan, Yunnan Province, China, have high contents of cutinite and microsporinite, with an average of 55 and 33.5 vol%, respectively, (on a mineral-free basis). The coals are classified as cutinitic liptobiolith, sporinite-rich durain, cutinite-rich durain, and sporinitic liptobiolith. These four liptinite-rich coals are often interlayered within the coal bed section and vary transversely within the coal bed. The vitrinite content varies from as low as 1.6-20.5% (mineral-free basis), and it is dominated by collodetrinite, collotelinite, and corpogelinite. The maceral composition may be attributed to the type of the peat-forming plant communities. Moreover, the Luquan coals are characterized by high contents of volatile matter, hydrogen, and oxygen, and the high values of the atomic hydrogen to carbon ratio as a result of the maceral composition. As compared with the common Chinese coals and the upper continental crust, the Luquan coals are enriched in Li, B, Cu, Ga, Se, Rb, Mo, Ba, Pb, Bi, and U, with averages of 99.9, 250, 111, 24.4, 4.55, 130, 58.8, 1276, 162, 3.85, and 34.1 μg/g, respectively. The SEM-EDX results show that V, Cr, Ga, and Rb occur mainly in clay minerals, and Cu and Pb are associated with clay minerals and pyrite, and Mo and U are mainly in clay minerals and organic matter. Barite and clay minerals are the main carrier of barium. The high B and U contents are probably resulted from deep seawater influence during coal formation.