SiO2包覆纳米CaCO3的透射电镜表征

在透射电子显微镜（TEM）电子衍射模式下，用适当孔径的物镜光阑选择非晶态SiO2的衍射区域，拍摄以溶胶一凝胶法制备的SiO2包覆纳米CaCO3的暗场像。与未经包覆SiO2的纳米CaCO3的暗场像作对比，可以看出经过SiO2包覆的纳米CaCO3粒子周围有一白色亮环，从而得到SiO3包覆层的暗场照片。用高分辨方法观察了包覆层与CaCO3粒子间的界面情况。     

溴碘化银薄片乳剂颗粒中碘离子分布对潜影分散的影响

碘溴化银乳剂薄片颗粒的潜影分散与碘离子在颗粒中的分布有关。本文用交叉光楔曝光技术测定了由次潜影造成的潜影分散,并根据所测出的潜影分散度和乳剂的表面感光度,对内、表敏的分布作了分析。结果表明,碘离子分布在颗粒边缘的乳剂,其表面潜影分散度要比碘离子均匀分布的颗粒更甚,后者且表现出内、表敏度竞争的现象。     

岩石的核磁共振自旋密度微成像

岩，心是油气储层的基本单元，其内部结构和渗流性质反映了油藏的基本特征．岩。心的精细描述是油藏描述、储层动态监测及设计强化采油方案的重要基础．本文利用核磁共振（NMR）自旋密度做成像，快速无损地观测到两类基本储油岩石——砂岩和灰岩的内部结构，提供了岩石渗透性、孔隙性及灰岩沉积环境等重要信息．1实验方法以自旋回波单片NMR成像脉冲序列为基础，设。P平面内样品的目施密度为P（。，v）．演化期t。，在。方向梯度场G。作用下，各处横向磁化矢量获得的相移为式中，7为共振核（在成像中一般为质子）的旋磁比，g为坐标位置·…     

不共轴光学系统自动优化中的有关问题

描述不共轴光学系统计算机优化中坐标变换与逆变换、“入瞳”与光线坐标、像面基准与质量函数定义的一致性问题。     

Low-level radiometric detection in LC using solvent segmentation and an effluent storage loop

Summary In this study a new approach is presented for on-line radiometric detection in reversed phase LC of medium to low polarity compounds labelled with¹⁴C. The test compounds,¹⁴C-carbaryl and¹⁴C-parathion, are extracted post-column into a non-water miscible liquid scintillation cocktail. The segmented two-phase system formed is introduced into the beta-detector without phase separation and collected in a capillary storage tube. After completion of the LC separation and detection process, the direction of the flow in the storage system is reversed and the segmented contents of the loop led at lower flow-rates through the beta-detector again. An enhanced signal, corresponding to the increase in counting time is obtained without measurable peak broadening. The lowest possible detection limit of the system is 9 counts per peak corresponding to subnanogram quantities of tested pesticides. Calibration curves are linear over at least 2 orders of magnitude and have the expected theoretical slopes. The reproducibility of the system is better than 4 % rel. S.D. An application to a recovery study of parathion shows the practical potential of this technique. Presented at the 15th International Symposium on Chromatography, Nürnberg, October 1984     

The regioselectivity of the formation of 2-pyrazolylthiazoles and their precursors from the reaction of 2-hydrazinothiazoles with 4,4,4-trifluoro-1-hetaryl-1,3-butanediones

Reaction of 2-hydrazinothiazoles 1 with 1-thienyl- and 1-furyl-1,3-butanediones 2a,b in methanol in the presence of hydrochloric acid mainly leads to a mixture of pyrazoles 3 and pyrazolines 4 or pyrazoles 3 and 5 in strong acidic conditions. Isomeric hydrazones 6 and pyrazolines 4 were formed and isolated in these reactions in the absence of hydrochloric acid. It has been shown that the regioselectivity in the reaction of diketones 2 with hydrazine 1 is governed by both the concentration of acid and the nature of substituents in the 1,3-diketones 2. Cyclization of hydrazones 6 is shown to occur under milder conditions than dehydration for pyrazolines 4. The new heterocyclic compounds were prepared and fully characterized by NMR spectra and by X-ray analysis for 3c.     

Antibody synthesis induced by endogenous internal images

In this study, immunization with a vaccine consisting of multiple F(abt’)₂ fragments of affinity-purified antitetanus toxoid antibodies covalently bound to a carrier protein successfully induced antitetanus toxoid antibodies. Further studies showed that this vaccine preparation contained no biologically detectable tetanus antigen. The induced antitetanus antibody (Ab1t’) titer was higher than the titer of antibodies binding control antigens. The immunizing F(abt’)₂ preparation did not elicit a secondary antitetanus response from mice primed with tetanus toxoid and, hence, appeared free of tetanus epitopes. The specificity of Ab1t’ was established by absorption and inhibition with antigen. Immunization with antitetanus F(abt’)₂ (Ab1t’) fragments appears to have elicited naturally occurring autologous antitetanus toxoid antibody (Ab1t’) through an idiotypic pathway. As predicted by network theory, anti-idiotype (Ab2) and antitetanus (Ab1t’) cycled reciprocally. Clonotypic characterization of Ab1t’ using isoelectric focusing and affinity immunoblotting showed increases in Ab1t’ titer to be the result of increased synthesis by limited subsets of antitetanus toxoid B-cell clones and not increased synthesis by multiple clones, as is characteristic of antigen-driven Ab1 responses. Many Ab1 and Ab1t’ clonotypes had identical pIs, suggesting that they either share V region genes or are the product of the same B-cell clones. These findings indicate that immunization with polyclonal multivalent Ab1 preparations can trigger active synthesis of antibodies with the same specificity. The results provide further evidence for naturally occurring idiotypic cascades that could be exploited for studies of catalytic antibodies.     

0.6~T人体核磁共振成象及其图象的彩色化处理

在0.6~τ超导磁体人体核磁共振成象设备上获得了横断、矢状、冠状各种断层的成象。采用了直接两维傅里叶变换成象方法,应用了自旋回波脉冲序列。由于人体心脏跳动和呼吸运动会造成图象模糊而使用心电延迟触发及呼吸门控方法。作者用一种相位调制光密度分割的方法将原始黑白灰度表示的核磁共振成象进行彩色化处理。提高了原图象低密度梯度区的清晰度,为进行医学图象诊断及判读解译提供了方便度。山了光学系统图,解释了光学信息处理方法。由所处理的人体核磁共振成象图片可以看出,在低密度梯给区更易辨认。参考文献10种。     

水溶性金属卟啉肿瘤靶向磁共振成像造影剂的研究

利用显微荧光－阿达玛变换三维图像分析研究了Ｃｕ－ＴＳＰＰ，Ｍｎ－ＴＳＰＰ，Ｃｕ－ＴＭＡＰ，Ｍｎ－ＴＭＡＰ４种水溶性金属卟啉人细胞间质进入肿瘤细胞内的富集过程，对金属卟啉的自旋－晶格驰豫性能（Ｒ１）的天空结果表明，Ｍｎ（Ⅱ）卟啉配合物的Ｒ１、值结Ｇｄ－ＤＴＰＡ提高１．５－２倍。