共查询到20条相似文献,搜索用时 62 毫秒
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(以姓氏笔划为序 )马紫峰 上海交通大学化学化工学院化工系主任、教授、博导。田伟生 中科院上海有机所资源化学与甾体化学联合实验室主任、研究员。印 杰 上海交通大学化学化工学院院长、教授、博导。叶建农 华东师范大学副校长、教授、博导。李和兴 上海师范大学生命与环境科学学院院长、教授。钟建江 华东理工大学生物反应器工程国家重点实验室主任、长江特聘教授、博导。李良君 上海化工研究院新型材料研究室主任、高级工程师。陈芬儿 复旦大学教授、博导。张 勇 上海交通大学化学化工学院副院长、教授、博导。宣利江 中科… 相似文献
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<正> 一九八○年十二月十二日在北京召开了第一次理事会议。到会理事六十一人。选出了常务理事二十一人,组成了常务理事会。同日召开了常务理事会。选举了理事长、副理事长、秘书长等人选,批准了编委会组成人员名单。常务理事二十一人:彭涛、李书华、李文渊、杜明霞、毕可鸿、王师俊、孙万亭、彭必先、付辉玢、朱文烈、杨绪增、林雨和、邱玉成、马成良、刘林生、王承忠、邓汉民、王维华、李守志、郭大梁、曾国爱 相似文献
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亚硫酸钙和硫酸钙混合物共沉淀实验研究 总被引:2,自引:1,他引:1
亚硫酸钙和硫酸钙的沉淀物是钙基脱硫的必然产物,目前对于这两者的沉淀缺乏研究。文章用亚硫酸钠、硫酸钠和氯化钙溶液配制亚硫酸钙和硫酸钙的混合溶液,分别研究了25、45、55℃下,钙离子浓度为0.04M时,不同比例的亚硫酸钙和硫酸钙过饱和溶液的共沉淀过程中各离子的浓度变化,并探讨了温度、硫酸钙对亚硫酸钙沉淀晶型、热力学参数的影响。试验结果表明,在低浓度条件下,经过50h可沉淀完全,亚硫酸钙和硫酸钙共沉淀时形成混晶。混晶中硫酸根离子占了总比例20%,并得到了亚硫酸钙和硫酸钙共沉淀时的溶度积,从溶度积中求得沉淀过程的焓变。硫酸根离子的存在提高了钙离子平衡浓度,容易结垢,同时硫酸根离子的存在大大减小了亚硫酸根的离子浓度,不利于脱硫,因此必须控制双碱法过程中的氧化率在20%以下。 相似文献
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不同钙肥对苹果品质的影响及其作用机理 总被引:2,自引:0,他引:2
研究了不同钙肥对红富士苹果果实品质和Ca^2+-ATPase(钙泵)活性的影响。结果表明,喷钙后单果重增加,果形指数增大,Vc含量提高,可溶性固形物和花青苷含量增大,但果实的叶绿素和可滴定酸含量下降。不同钙肥间,喷巨金钙的效果最好,其次为氨基酸钙,再次为翠康钙宝,最后为钙宝2000。钙肥对Ca^2+-ATPase活性影响极为显著,其活性明显高于对照,而不同钙肥问的变化趋势与果实品质的变化趋势相同。 相似文献
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Zhi Pan Andrew Avila Lauren Gollahon 《International journal of molecular sciences》2014,15(2):2672-2694
Previously, we reported that endoplasmic reticulum calcium stores were a direct target for paclitaxel initiation of apoptosis. Furthermore, the actions of paclitaxel attenuated Bcl-2 resistance to apoptosis through endoplasmic reticulum-mediated calcium release. To better understand the calcium-regulated mechanisms of paclitaxel-induced apoptosis in breast cancer cells, we investigated the role of extracellular calcium, specifically; whether influx of extracellular calcium contributed to and/or was necessary for paclitaxel-induced apoptosis. Our results demonstrated that paclitaxel induced extracellular calcium influx. This mobilization of extracellular calcium contributed to subsequent cytosolic calcium elevation differently, depending on dosage. Under normal extracellular calcium conditions, high dose paclitaxel induced apoptosis-promoting calcium influx, which did not occur in calcium-free conditions. In the absence of extracellular calcium an “Enhanced Calcium Efflux” mechanism in which high dose paclitaxel stimulated calcium efflux immediately, leading to dramatic cytosolic calcium decrease, was observed. In the absence of extracellular calcium, high dose paclitaxel’s stimulatory effects on capacitative calcium entry and apoptosis could not be completely restored. Thus, normal extracellular calcium concentrations are critical for high dose paclitaxel-induced apoptosis. In contrast, low dose paclitaxel mirrored controls, indicating that it occurs independent of extracellular calcium. Thus, extracellular calcium conditions only affect efficacy of high dose paclitaxel-induced apoptosis. 相似文献
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目前,多数分析方法难以计算工业氢氧化钙中氧化钙、氢氧化钙和碳酸钙的含量。将蔗糖滴定法和热重分析相结合,对工业氢氧化钙中的氧化钙、氢氧化钙和碳酸钙做了分析。采用GB/T 5762—2012《建材用石灰石、生石灰和熟石灰化学分析方法》测定氢氧化钙中有效钙的含量。根据氢氧化钙和碳酸钙分解温度的差异,使用热重分析测定工业氢氧化钙中氢氧化钙和碳酸钙的含量。之后,将有效钙中的氢氧化钙部分扣除并换算,得到氧化钙的含量。实验得到氧化钙、氢氧化钙和碳酸钙这3种物质的含量,其余部分为杂质。该方法具有操作相对简单、测定成分种类较多的优点。 相似文献
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为阐明磁化条件下无机镁盐对碳酸钙溶解行为的影响规律,采用检测溶液电导率、pH和钙离子浓度等方法来考察磁化条件下不同种类镁盐(硫酸镁、硝酸镁、氯化镁和碳酸镁)对碳酸钙溶解行为的影响。结果表明,磁化条件下硫酸镁、硝酸镁和氯化镁对碳酸钙有促溶作用,作用最显著的是硫酸镁,其可使溶液钙离子浓度提高55.0%;碳酸镁对碳酸钙有阻溶作用,其可使溶液钙离子浓度减少36.0%。硫酸镁、硝酸镁和氯化镁对碳酸钙有促溶作用的原因在于溶液中镁离子产生的盐效应以及3种镁盐造成磁化碳酸钙溶液pH不同程度的减小。而碳酸镁对碳酸钙有阻溶作用的原因在于碳酸根产生的同离子效应和极化作用以及碳酸镁使磁化碳酸钙溶液pH增大。研究结果揭示了磁化溶液中不同镁盐对碳酸钙溶解行为的影响规律,可为利用镁盐调控碳酸钙溶解行为提供理论依据,并对强化磁化除垢效果有一定的参考意义。 相似文献
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R. J. Jandacek 《Lipids》1991,26(3):250-253
The solubilization of the calcium soaps of long chain fatty acids by liquid fatty acids was observed. The solubilities of
calcium palmitate, calcium laurate, and calcium oleate were 15.6, 22.8, and 53.3 wt%, respectively, in oleic acid at 40°C.
The formation of an acid-calcium soap complex was demonstrated by x-ray diffraction studies of calcium laurate, lauric acid,
and a mixture of these compounds that had been heated. Similar evidence was obtained for a calcium oleate-oleic acid complex.
The solubility of calcium oleate in a bile salt micellar system was enhanced by obeic acid. The solubilization of calcium
soaps by liquid fatty acids may explain the unexpectedly high bioavailability of some calcium soaps. 相似文献
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Effect of calcium silicate sources on geopolymerisation 总被引:2,自引:0,他引:2
Christina K. Yip 《Cement and Concrete Research》2008,38(4):554-564
Seven different calcium silicate materials were used to investigate the role of calcium in geopolymerisation. At low alkalinity, the compressive strength of matrices prepared with predominantly amorphous calcium silicates (blast furnace slag) or containing crystalline phases specifically manufactured for reactivity (cement) is much higher than when the calcium is supplied as crystalline silicate minerals. The compressive strength of matrices containing natural (crystalline) calcium silicates improves with increasing alkalinity, however the opposite trend is observed in matrices synthesised with processed calcium silicate sources. The difference in compressive strength between matrices synthesised using different calcium silicate sources is significantly reduced at high alkalinity. An insufficient amount of calcium is dissolved from crystalline calcium silicates at relatively low alkalinity to enable formation of calcium silicate hydrate in coexistence with the aluminosilicate geopolymeric gel, and this leads to the poor mechanical properties of such matrices. At high alkalinity, calcium plays a lesser role in affecting the nature of the final binder, as it forms precipitates rather than hydrated gels. Thus, the different calcium silicate sources will not have a major impact on the mechanical properties of these matrices. The effects of different calcium silicates on geopolymerisation are therefore seen to depend most significantly on two factors: the crystallinity of the calcium silicate source, and the alkalinity of the activating solution used. 相似文献