镍铬合金烤瓷全冠腐蚀性分析

对不同两地加工厂生产的镍铬合金烤瓷熔附金属全冠(porcelain-fused-to-metal crown,PFM冠)进行了为期一年的体外腐蚀性对比研究、分析该产品应用近30年来烤瓷全冠中镍的析出量及其市场的规范化程度.将两厂家生产的镍铬PFM冠样品共40个,随机分为4组(10天组、1月组、6月组、12月组),分别浸泡于ISO/TR10271标准(37℃,pH 6.8)配制的人工唾液中,于10天、1月、6月、12月用电感耦合等离子体发射光谱仪(ICP-AES)测定浸提液中析出的镍离子浓度,同步采用X射线能量散谱仪(EDS)、正置式金相显微镜分析、观察样品元素构成及金相显微组织结构.结果显示两厂样品的镍离子析出量在一年组差异具有统计学意义(F=9.360,P=0.000).能谱分析显示两厂样品主要成分都为Ni、Cr、Mo,但含量不同;其金相结构均为树枝状共晶结构,但B厂样品较A厂夹杂物多,枝晶粗、排列紊乱、晶间相多.一年内两厂的镍铬合金烤瓷冠在抗腐蚀性能方面存在差异性,远期效果有待进一步观察.     

高纯铝再结晶晶界面的择尤取向

相比于传统的晶体择尤取向（晶体织构,简称织构）,晶界面择尤取向是一个新的科学问题.系统地研究晶界面择尤取向的形成规律和演化机制对合理调控显微组织结构以显著改善材料的各种使用性能具有非常重要的科学意义和应用价值.本文利用基于体视学原理和电子背散射衍射技术的晶界特征分布五参数表征分析方法,研究了冷轧变形高纯铝（99.99%）再结晶晶界面的择尤取向问题.结果表明,在再结晶及晶粒长大过程中,晶界面择尤取向由最初的{2 2 3}晶面转变为{1 1 1}晶面,最后取向在{1 0 0}晶面上.分析指出,冷轧变形高纯铝再结晶组织中,小角度晶界（取向差介于2°~15°）是其晶界构成的主体部分;在晶粒长大过程中,晶体织构由{1 1 0}〈1 1 2〉黄铜织构为主转变为以{0 1 1}〈1 0 0〉高斯织构和{0 2 3}〈1 0 0〉织构共存为主,受晶面能和晶体织构的影响,小角度晶界一般择尤取向于可形成能量较低的倾侧型小角度晶界所对应的晶面上.这是导致高纯铝再结晶晶界面择尤取向随晶粒长大而发生上述规律性变化的主要原因.     

铋层状化合物Na0.5Ho0.5-xYbxBi4Ti4O15陶瓷材料的上转换发光、铁电、介电性能研究

采用传统的固相烧结法,制备了Na0.5Ho0.5-xYbxBi4Ti4O15铋层状结构陶瓷.经X射线衍射（XRD）表征,新合成材料为单相结构,且扫描电子显微镜下的表面和断面图像均为层状,说明合成材料为新型铋层状材料.室温时,在可见光波长范围内,有2个峰,分别为546 nm处的绿光峰和656 nm处的红光峰,分别对应于Ho3＋离子的5F4＋5S2→5I8和5F5→5I8跃迁.为研究其机理,测试了变功率条件下的发光强度,经计算,绿光和红光发射均为双光子过程.研究陶瓷样品在变温（-130~270°C）条件下的发光性能时,发现红光与绿光的强度比值与温度呈线性关系,该材料有望应用于光学温度传感器领域.经介电性能测试发现当Ho：Yb=1：9时,样品的居里温度为686.4°C.研究铁电性能发现当Ho：Yb=3：2时,剩余极化Pr为9.3μC/cm2,矫顽场强为Ec=82 k V/cm,表明具有一定的铁电性能.以上研究结果表明,制得的新材料是一种具有优异光学性能的多功能材料.     

Effects of Si and Ce on the microstructure and hydrogen storage property of Ti_(26.5)Cr_(20)V_(45)Fe_(8.5)Ce_(0.5) alloy

In this paper,the effects of Si and Ce on the microstructure and hydrogen storage property of Ti26.5 Cr20V45Fe8.5Ce0.5 alloy were studied,respectively.First of all,effects of Si on the microstructure and hydrogen storage properties of Ti26.5Cr20(V45Fe8.5)1-xSixCe0.5(x=0,0.5,1.0,1.5 and 2.0 at%)alloys were studied by X-ray diffraction,scanning electron microscopy and P-C isotherm measurements.As the Si addition increases,the hydrogen absorption capacities of alloys decrease but the equilibrium pressure incre...     

热压烧结ZrB2／B4C陶瓷材料的组织与性能

以B4C、C、ZrO2为主要原料,采用反应热压法制备ZrB2／B4C陶瓷材料。通过对ZrB2／B4C陶瓷材料的显微组织及力学性能的综合分析,发现第二相ZrB2含量为20wt％时,材料具有较好的综合力学性能,相对密度为99．3％,维氏硬度为36．1GPa,抗弯强度为533．3MPa,断裂韧性为6．95MPa·m^1/2,比纯B4C陶瓷材料的性能均有所提高。材料为穿晶和沿晶断裂的混合断裂模式。     

Electron microscopy of gastric mucosal innervation in rats

Summary Electron microscopy of the rat stomach has shown vagal innervation of gastric epithelial cells with contact points. Unmyelinated axons of diameter 0.06 and 0.20 m were demonstrated passing in the connective tissue between epithelial cells.     

ArF准分子激光晶化非晶硅薄膜微结构研究

利用ArF准分子激光对非晶硅薄膜的表层进行晶化后,采用拉曼光谱(Raman)、透射电镜(TEM)、场发射扫描电子显微镜(FE-SEM)等实验方法研究不同激光能量密度下晶化层硅薄膜微结构变化。实验结果表明:随激光能量密度的增大,薄膜结晶度增大,晶化层厚度加厚;晶粒尺寸则是先增大,直到激光能量密度增大到210 mJ/cm~2后,晶粒尺寸开始减小并且均匀性逐渐变差。最佳的激光能量密度范围为120～180 mJ/cm~2,这时薄膜表面晶化层晶粒比较均匀致密,薄膜质量较好。     

不同分子量膜对清络通痹水提液梯度纯化对比研究

目的通过考察不同梯度分子量膜对中药水提液物理化学性质的影响,探索中药水提液复杂体系在膜分离过程中的规律。方法测定以0．2μmAl2O3无机陶瓷膜和5万、1万、6千分子量PS膜纯化清络通痹水提液前后各样品的pH、浊度、粘度、电导率、青藤碱含量、总固含物量等指标。结果清络通痹水提液在膜分离前后的pH、浊度、粘度、电导率及青藤碱含量等方面表现出不同的特征。结论膜纯化前后样品的各指标变化趋势呈现一定的相关性。     

Teratogenic effects of cadmium on Bufo arenarum during gastrulation

Developing Bufo arenarum embryos were treated during gastrulation with cadmium chloride in concentrations ranging from 6x10(-7) to 1.5x10(-5)M Cd++ at 20 and 30 degrees C. Initial failures at gastrulation result mainly in axial incurvations, microcephaly, hydropsy and abnormal tail formation. The higher temperature has a dual effect: at high concentrations of Cd early malformations are significantly increased; whereas, at low concentrations the higher temperature prevents alterations.     

Polyoxin fungicides: Demonstration of insecticidal activity due to inhibition of chitin synthesis

Summary Polyoxin A, a selective inhibitor of chitin synthetase, was found to be insecticidal when injected into the abdomen of grasshoppers nymphs, with an LD₅₀ of 1.26±0.20 g per insect. Symptomatology and the absence of any toxicity toward adult insects indicate that toxicity is due to interference with cuticle deposition.Acknowledgment. I thank Henry Bork for his expert technical assistance.     

An improved method for calculating colony forming ability in soft agar with special reference to malignancy

Summary We examined the correlation between the tumorigenicity and the growth capacity in soft agar of various malignant cell lines. The colony forming rates were calculated in (a) 0%, (b) 0.15%, (c) 0.30%, and (d) 0.40% soft agar medium. An approximate value for the colony forming capacity, y, was then established for the formula (x=concentration of soft agar, f(x)=rate of appearance of colony forming cells with x% soft agar medium).We would like to thank Miss Kimiko Tabuchi for her expert technical assistance during the course of these investigations.     

稀土Ho3＋/Yb3＋共掺SrBi4Ti4O15高温铁电陶瓷的上转换发光及其温度传感特性

Sr Bi4Ti4O15是一种具有高居里温度（Tc）、高机械品质因数和大电阻率的铋层状结构铁电、压电多功能材料,通过掺入稀土离子的手段,可使其具有上转换发光的特性,并且可以在一定程度上改善其电学性能.在本文中,同时将Ho3＋和Yb3＋对A位的Bi进行取代,其中Ho3＋的取代量为0.06 mol-1,Yb3＋的取代范围为0≤x≤0.3,采用传统的固相烧结法制备了Sr Bi3.94-xHo0.06YbxTi4O15陶瓷.主要通过控制Ho3＋离子的量不变,调节Yb3＋离子的浓度来研究不同稀土离子掺杂量对Sr Bi4Ti4O15陶瓷的形貌、上转换发光特性、以及介电性能的影响.在使用980 nm的红外激光器对Sr Bi3.94-xHo0.06YbxTi4O15陶瓷进行激发下,从上转换发光图谱中可以观察到三个峰,分别为峰位在547 nm附近较强的绿色发光、659附近以及759 nm处的较弱的红色发光.同时可以看到,随着Yb3＋浓度的增加,绿色上转换发光的强度表现出先增强,后减弱的规律,且当Yb3＋取代量为x=0.15时,绿色上转换发光强度达到最大值.通过研究上转换发光强度与激发光功率的关系得到,绿色和红色上转换发光均为双光子吸收过程.在研究Sr Bi3.79Ho0.06Yb0.15Ti4O15样品上转换发光与温度的关系时,可以观测到随着温度的增加,547 nm处的绿色上转换发光和659 nm处的红色上转换发光的强度均随之减弱,且I659 nm与I547 nm的荧光强度比与温度存在线性关系,利用这种温度与上转换发光强度的关系,可将Sr Bi3.94-xHo0.06YbxTi4O15陶瓷应用于光学温度传感器.     

Protective effect of vitamins against trichothecene toxicity towardsSaccharomyces cerevisiae

Summary Several trichothecene mycotoxins were shown to inhibit the growth ofSaccharomyces cerevisiae. This effect was most pronounced with the macrocyclic trichothecenes, especially verrucarin A. Much less growth inhibition was observed with T-2 toxin. Verrucarol, diacetoxyscirpenol, acetyl T-2 toxin, HT-2 toxin, T-2 tetraol and neosolaniol were inactive at a concentration of 75 g of toxin per disc. Incubation ofS. cerevisiae with verrucarin A together with vitamins resulted in a decrease in toxicity. Pyridoxine-HCl, Ca-pantothenate, thiamine-HCl and -tocopheryl acetate were amongst the most potent of the vitamins tested which reversed growth inhibition, overcoming the inhibitory potential of the toxins.9 December 1986The authors thank Dr J. Behrend, Makor Company, Israel, for a generous gift of verrucarin A and roridin A.     

Alteration of early T lymphocyte count in patients with herpes genitalis

Summary Peripheral blood samples from 52 women, including 16 with herpes genitalis and 36 healthy persons, were studied to enumerate subpopulations of lymphocytes. It was found that the mean percentage of active T lymphocytes was significantly less in the patients with herpes genitalis than in the controls.Acknowledgment. This work was done at the Department of Obstetrics and Gynecology, Kansai Medical University and the authors are indebted to Professor I. Sawaragi for his support and encouragement. We also express our thanks to Dr James Monthony, Bio Rad Laboratories for his generous donation of immunobeads for this study.     

基于MATLAB的AA—HPA—AMPS—AM聚合物阻垢剂合成及其性能研究

通过溶液聚合方法,以过硫酸铵为引发剂,丙烯酸、丙烯酸羟丙酯、2-丙烯酰胺-2-甲基丙磺酸、丙烯酰胺为单体,合成AA-HPA-AMPS-AM聚合物.固定聚合物浓度为4 mg/L,分别考查反应时间、反应温度（X1）、引发剂用量（X2）、单体配比（AA：HPA以X3计、AMPS：AM以X4计）对聚合物阻CaCO3垢性能的影响,并设计了正交实验,得出当聚合物在80℃、引发剂用量为10%、M（AA）：M（HPA）为0.25、M（AMPS）：M（AM）为0.4时,阻CaCO3垢率最高为52.9%.为探究此聚合物是否有更高的阻垢性能,应用MATLAB对正交实验结果进行分析及验证,得知：聚合物阻CaCO3垢效率y与各影响因素X之间基本满足y=146.349 7-0.926 7x1-49.765 8x3-28.220 9x4.最佳聚合条件为x1=75、x3=0.15、X4=0.15,y为68.35%.     

Plasma estrogens in Pleurodeles waltlii. Comparison between diploid and triploid females]

Estrogens have been examined in the plasma of diploid and triploid newts Pleurodeles waltlii. Estradiol-17 beta (E2) and estrone (E1) were determined by radioimmunoassay, before and after enzymatic hydrolysis of the conjugates. Total (t) and unconjugated (u) E2 levels were positively correlated (E2u = 0.478 35 E2t + 0.579 98; r = 0.883), but no correlation was detected between E1 levels. No statistical difference was found for the estrogen levels between the different experimental lots of diploid newts (E2t = 7.5 +/- 0.37 ng/ml, E2u = 4.3 +/- 0.20 ng/ml, E1t = 2.19 +/- 0.08 ng/ml, E1t = 0.41 +/- 0.02 ng/ml) but every estrogen level was lower in the triploid group (E2t = 1.8 +/- 0.60, E2u = 1.0 +/- 0.18, E1t = 1.4 +/- 0.13, E1u = 0.3 +/- 0.04 ng/ml). This difference is discussed in relation to lower fertility of the triploid females.     

Oberflächenspannung und Schallgeschwindigkeit

Summary The preceding empirical relation was found between the surface tension of liquids, the specific weight of liquids, and the velocity of sound:=6.3 · 10^{–4 3/2}. In place of the vèocity of sound can be used, with suitable changes in the equation, the compressibility or, in the case of solid substances, the elasticity of the material in question. The range of validity of this relation is so large that it is possible by means of it to calculate the surface tension of solid substances and of gases.     

The impact on the performance of growth curve models of changes in parameter re-estimation period and other factors

A simulation model of a real electricity supply undertaking was used to provide a financial performance measure for growth curve forecasting models. The impact on financial performance was determined when changes were made in (1) the method of estimating the model parameters, (2) the period between re-estimations, (3) the growth curve fitted and (4) the amount of smoothing of the demand time-series. The response to variation of the parameter review period was found to behave surprisingly, in that it exhibited different signs for two different estimation methods. Changes in re-estimation period explained somewhat more of the variation in performance than did a change in growth curve. Correcting the demand series for conditions which were known to be abnormal improved performance.     

Beiträge zur Frage des Menotoxins

Summary Experiments on tadpoles showed that during menstruation the toxicity of the urine is increased. The authors regard this as a proof for the existence of a menotoxin.