3C_2S·3CaSO_4·CaF_2的性质及其对C_2S与C_3S形成的促进作用

本文对以氟、硫作矿化剂煅烧硅酸盐水泥熟料时出现的过渡相氟硫硅酸钙(3C_2S·3CaSO_4·CaF_2)的性质进行了研究,同时探讨了3CaS·3CaSO_4·Ca F_2对 C_3S 和 C_2S在不同温度及升温速率下的促进作用。     

碳酸盐建造天然储层及其在地质历史中的演化

流体分布特征及其在储层中的运移取决于岩石的储集性和层序内部结构。块状储层一般是礁或浮游生物建造,部分属地台底栖生物建造,其中流体可进行垂向和横向运移;层状储层是典型的底栖生物建造,具不同渗透性的岩层成互层状,以横向运移为主;岩性圈闭储层产于未补偿拗陷的沥青质-硅质、粘土-碳酸盐建造。层状储层遍及整个显生宙,但其相型、孔隙空间的组成及特征均有所改变。礁块储层的意义在地质历史中随其厚度及非均质性的增加均有所增长。在中生代末的浮游生物建造中常有块状储层。岩性圈闭储层自泥盆纪以来零星出现于较年轻的沉积中。     

氯化钡法分析混合碱的进一步探讨

用氯化钡法分析混合碱,当试样中混合碱含量为2g时(指500 ml待测液中碳酸钠和碳酸氢钠混合物的含量)结果准确,但当试样中混合碱含量大于2 g时,测定误差较大,可大于40％(相对误差)。这是由于BaCO_3吸附OH~-离子的结果,介绍了应用系数校正法,消除了这一误差,方法简便、准确、快速,相对误差可达0.2％以下。并对BaCO_3的吸附机理进行了初步的探讨。     

Cytosolic calcium in platelet activation

Experiments with permeabilised platelets, and with intact platelets loaded with fluorescent Ca²⁺-indicators, over the past several years have greatly extended our knowledge and understanding of cytosolic Ca²⁺ as a platelet activator and its interactions with other cytosolic regulators. This article outlines insights, gained from the use of the fluorescent dyes, into maintenance and restoration of basal [Ca²⁺]_i, mechanisms of receptor-mediated Ca²⁺-mobilisation and quantitation of [Ca²⁺]_i/response relations in intact human platelets.     

A novel pattern of fast calcium oscillations points to calcium and electrical activity cross-talk in rat chromaffin cells

Slow oscillations of cytosolic calcium ion concentration – – typically originate from release by intracellular stores, but in some cell types can be triggered and sustained by Ca²⁺ influx as well. In this study we simultaneously monitored changes in and in the electrical activity of the cell membrane by combining indo-1 and patch-clamp measurements in single rat chromaffin cells. By this approach we observed a novel type of spontaneous oscillations, much faster than those previously described in these cells. These oscillations are triggered and sustained by complex electrical activity (slow action potentials and spike bursts), require Ca²⁺ influx and do not involve release from intracellular stores. The possible physiological implications of this new pathway of intracellular signalling are discussed.Received 30 July 2004; received after revision 14 October 2004; accepted 1 November 2004     

环己烷氨基磺酸钙对叙利亚仓鼠原发性心肌病疗效观察

把BIO FID亚历山在叙利亚仓鼠分成5组,每组40只,雌雄各半,每天分别给予钦含0、275、1 100和2 200 mg/kg的环已烷氨基磺酸钙的水,连续处理90天。这些剂量没有引起动物任何病变,相反,这些动物的原发性心肌病表现出与上述剂量成明显负相关,提示利用环己烷氨基磺酸钙治疗人的某些心肌病值得进一步研究。     

In vitro study of poly(ethylene carbonate) as a drug-eluting stent coating

An in vitro feasibility study of the use of poly(ethylene carbonate) (PEC) as a biodegradable coating material for drug-eluting stents is reported, and the performance of PEC is compared with that of poly(lactic-co-glycolic acid) (PLGA). Scanning electron microscopy (SEM) images of PEC and PLGA discs after treatment with an alkaline KO2 solution as a superoxide source showed that the PEC maintained its integrity whereas holes and small particles appeared during the treatment of PLGA. Sirolimus and paclitaxel were loaded into PEC and PLGA in order to study drug release performance. Attenuated total reflectance–infrared (ATR– FTIR) spectroscopy of sirolimus, PEC and the sirolimus-loaded PEC coating showed that no chemical reaction occurred between sirolimus and PEC. The results of atomic force microscopy (AFM) revealed that the mean roughness (Ra) values of the bare metal stent (BMS) and the drugeluting stent (DES) were 2.3 nm and 1.0 nm, respectively. After balloon expansion experiments, no delamination or destruction of the PEC coating was observed. The drug release profile of sirolimus was different from that of paclitaxel when PEC was employed as the drug carrier, and the release curves of sirolimus were different when PEC and PLGA were used as drug carriers. All the experimental results demonstrated that PEC was one of the best potential stent-coating materials.     

水／乙二醇混合溶剂中微波辅助合成碳酸钙

在水/乙二醇混合溶剂中,通过微波辅助加热的方法,研究溶液过饱和度对碳酸钙成核生长的影响。分别采用扫描电子显微镜(SEM)、X-射线粉末衍射(XRD)对所得的样品进行了表征。结果表明,过饱和度的改变对碳酸钙形貌和晶型具有非常明显的影响,分别获得了菱面体状方解石、纤维捆扎状文石、松树枝状球霰石为主体的碳酸钙晶体。     

孔隙型小层间强非均质碳酸盐岩油藏注水优化方法

为改善伊拉克AHDEB复杂孔隙型碳酸盐岩油藏Khasib层小层间强非均质性导致水平井注水水窜、波及体积较小等问题,在油藏注水突破机理研究基础上,进行了注采评价优化方法研究。依据水平井井轨迹纵向穿行储层及生产特征情况,划分了3类特征井,并根据其不同生产阶段的生产特征定义了5个评价指标：历史生产因子(IDH)、剩余储量因子(IDR)、生产潜力因子(IDF)、注水需求因子(IDI)和提液生产因子(IDE),建立了单井注水生产分级雷达综合评价图版,定量表征了水平井在不同生产阶段的生产能力,结合地层压力变化数据可实时指导油藏注水优化。结果表明,该图版可以合理评价Khasib层单井注水开发效果,单井调整后生产效果良好,研究结果为实施“一井一策”的差异化精细注水提供有力支持。     

桑托斯盆地裂谷期构造演化对碳酸盐岩沉积的控制作用

为了研究桑托斯盆地不同构造背景下碳酸盐的沉积模式,对桑托斯盆地圣保罗台地的裂谷期构造演化、沉积充填特征、断裂特征及其对下白垩统碳酸盐岩沉积的控制作用进行了分析,得到基底的断裂、局部沉降及抬升活动是该地区构造演化的主控因素的结论。根据研究区内构造演化不同阶段的沉积特征,建立了圣保罗台地两种构造背景下的碳酸盐岩沉积模式:发育在裂谷晚期和坳陷期的孤立碳酸盐台地,发育在坳陷期的碳酸盐滩-礁复合沉积。对该区盐下油气勘探及储层预测具有重要意义。