火焰原子吸收法测定琼脂中钙,铁

本文研究了琼脂中钙铁的火焰原子吸收分析法。讨论了分析测定中的一些因素的影响和基本元素的干扰及其消除方法，建立了一种快速、精确的用火焰原子吸收法测定琼脂中钙和铁的方法。通过回收率试验及与经典方法测得的结果比较，证明用火焰原子吸收法测定琼脂中钙和铁是可行的。     

钙矾石碳化反应速控步骤活化能

用静态法测定钙矾石碳化率ｘ与时间ｔ的关系曲线，采用初始反应数值测定控制步骤基元反应活化能。结果表明：在通常条件下钙矾石极易被碳化，要防止碳化必须设法毒化钙矾石对水的吸附中心。     

饲料中钙镁的原子吸收测定法研究

研究了用火焰原子吸收法测定饲料中钙镁的方法，确定了方便快速地测定饲料中钙镁的条件，方法的回收率98%-107%,RSD低于6.9%，结果满意。     

FAAS法测定“三合宜”核桃粉中钙、锌、铁、铜和锰

采用硝酸－－高氯酸混酸为溶剂，湿法消解，氯化镧消除磷对钙的干扰，用火争原子吸收法测定钙和锌等六种营养元素，分析结果表明，方法简便快速，结果满意。     

水中总硬度及钙和镁的测定

报告了应用火焰原子吸收光谱法测定水样中钙和镁浓度的技术过程，并与EDTA法进行了比较。     

珍珠水解液中钙离子含量的离子选择电极测定方法

用离子选择电极法分别对标准溶液中钙离子含量，电极检测性能及pH值对离子选择电极的影响等进行了一系列测定和讨论，提出了离子选择电极测定珍珠水解液中钙离子含量的方法．同时将离子选择电极法和原子吸收法测定样品的结果加以了比较．该方法所用仪器易普及，适用于中小型企业进行产品的测试．     

空气—乙炔火焰原子吸收光谱法测定痕量铝

文研究了空气－乙炔火焰原子吸收光谱法测定铝的方法，利用铝对钙的干扰效应和微量进样技术间接测定了化学试剂中的痕量铝。实验表明，该法具有样品用量少，精密度好，简便实用的优点。。     

钢中微量钙的原子吸收分光光度法测定(空气──乙炔火焰)

本文研究了在空气－乙炔火焰中原子吸收测定钙的条件、干扰及其消除。采用混合释放 剂，及空白与试液都以标准加入法测定、扣除空白值的方法测定钢中微量钙。方法简便快速， 具有一定实用价值。     

火焰原子光谱法快速测定指甲中的钙镁钾

建立了非完全消化-火焰原子光谱法快速测定指甲中钙、镁、钾的分析方法。在低温下用浓硝酸消解样品,可获得均匀、透明的样品溶液。用发射法测定钙、钾,以吸收法测定镁。以Sr2+作为钙的释放剂及钾的消电离剂。对样品处理条件、化学干扰、试液与空白溶液粘度一致性、背景吸收干扰及检出限进行了考察。测定结果的相对标准偏差小于2.2%,测定结果与灰化法一致,相对误差小于±1.2%。方法简便、准确。     

消解乳化技术-火焰原子光谱法测定天然橡胶中微量元素

在低温下用浓硝酸消解天然橡胶样品,以甲基异丁基酮溶解消解产物,并制成乳浊液.加入氯化锂溶液作为钠、钾的消电离剂及加入La3 作为钙、镁的释放剂.用火焰原子发射光谱法测定钠、钾、钙,以火焰原子吸收光谱法测定镁.建立了消解乳化技术-火焰原子光谱法测定天然橡胶中钠、钾、钙、镁的分析方法.对消解产物的溶解性质、溶剂及乳化剂的选择、试液与空白溶液物理性质的一致性,背景吸收干扰及检出限进行了考察.测定结果的相对标准偏差小于3.7%,加标回收率96.7%～104.7%.     

Discussion on the mechanism of the calcium absorption in the human body

The present article discusses a new mechanism of calcium absorption in the human body. The mechanism is revealed as follows. First, after food is digested in the stomach, calcium ions (Ca2+) are released. The small intestine secretes amino acid or short peptide chain with small molecular weight automatically, which are called chelating agent; when the calcium ions from the stomach get to the small intestine, the reaction of the chelating agent with the calcium ions occurs, producing the neutral amino acid calcium chelate. Then, this kind of calcium chelate with small molecular weight is absorbed as a whole into the tissues of the small intestine. After being absorbed, in the cell the calcium chelate can break down its chelating bond automatically and decompose into the amino acid and calcium ion again. Finally, the calcium ion goes into blood through portal vein and is transferred to the organs and also deposits on the bone. The reason for the body抯 calcium insufficiency, which has no linear relation with the calcium intake amount, is the lack of the amino acid secreted by the small intestine. The main barrier that influences the calcium absorption is anion pollution. The calcium absorptivity of the body has nothing to do with the solubility of the calcium source out of the body. A new kind of calcium supplement agent——glycine calcium chelate——is synthesized, whose molecular weight is 206.06 (containing a molecular water). If the glycine calcium chelate is used to make calcium supplement agent, about 20 mg calcium element (converted from the glycine calcium chelate, the same below, no longer indicated) per day for one person, 50 mg at most, is enough to maintain the positive balance of calcium metabolism.     

3种口服钙制剂在兔体内生物利用度的比较

利用原子吸收分光光度法测定兔血清中钙的浓度来比较补钙剂G、葡萄糖酸钙、天门冬氨酸钙3种口服钙制剂在兔体内的生物利用度.结果表明,3种钙制剂间无显著性差异(P>0.05),它们对兔体内钙行为的影响是一致的.     

Mycorrhizal weathering of apatite as an important calcium source in base-poor forest ecosystems

The depletion of calcium in forest ecosystems of the northeastern USA is thought to be a consequence of acidic deposition and to be at present restricting the recovery of forest and aquatic systems now that acidic deposition itself is declining. This depletion of calcium has been inferred from studies showing that sources of calcium in forest ecosystems namely, atmospheric deposition and mineral weathering of silicate rocks such as plagioclase, a calcium-sodium silicate do not match calcium outputs observed in forest streams. It is therefore thought that calcium is being lost from exchangeable and organically bound calcium in forest soils. Here we investigate the sources of calcium in the Hubbard Brook experimental forest, through analysis of calcium and strontium abundances and strontium isotope ratios within various soil, vegetation and hydrological pools. We show that the dissolution of apatite (calcium phosphate) represents a source of calcium that is comparable in size to known inputs from atmospheric sources and silicate weathering. Moreover, apatite-derived calcium was utilized largely by ectomycorrhizal tree species, suggesting that mycorrhizae may weather apatite and absorb the released ions directly, without the ions entering the exchangeable soil pool. Therefore, it seems that apatite weathering can compensate for some of the calcium lost from base-poor ecosystems, and should be considered when estimating soil acidification impacts and calcium cycling.     

氯化钙/膨胀石墨混合吸附剂导热性能测试

为改善吸附剂的导热特性,制备了一种新型的混合吸附剂,并通过平行热线法对7种不同的吸附剂样品,包括颗粒状氯化钙、粉末状氯化钙、散状氯化钙/膨胀石墨混合吸附剂以及固化氯化钙/膨胀石墨混合吸附剂等,进行了导热系数测量.实验结果表明:由氯化钙/膨胀石墨组成的散状混合吸附剂,其导热系数比纯粉末状氯化钙提高了22.5%;固化氯化钙与膨胀石墨混合吸附剂比纯粉末状氯化钙吸附剂导热系数提高了23倍以上.     

胜利减压渣油中钙的分布及特点

用吸附柱色谱法研究了胜利减压渣油中钙在4组分中的分布,结果表明大部分钙集中在柱残余质中,其余钙主要分布在芳香分、沥青质及苯不溶物中,通过阳离子交换、酸性水溶液萃取、乙醇萃取及红外分析考察了胜利减渣中钙化合物的某些特点。     

高温下表面活性剂与钠离子钙离子的作用机理

在高温条件下研究了表面活性剂SDBS和NPSS–10与Na+和Ca2+的静电作用机理:(1)SDBS浓度大于临界胶束浓度(cmc)时Na+作用较弱,Na+与胶束中的阴离子头基形成了离子对,屏蔽了离子头基的静电排斥力,在一定程度上降低了表面活性剂离子头基的极性,活性剂分子排列更加紧密。(2)NPSS–10浓度大于cmc时与Na+的作用较强,水化的氧乙烯基高温下部分失水和Na+与胶束中的阴离子头基形成了离子对的共同作用促使表面活性剂的极性降低,抗盐性能增加。(3)在Ca2+浓度较低时,SDBS与钙离子没有相互作用,无沉淀产生,原因是生成的烷基磺酸钙盐有一定的溶解度;在Ca2+浓度较高时,SDBS与Ca2+有强相互作用,电极电位发生显著变化,产生烷基磺酸钙盐沉淀。(4)在低浓度Ca2+溶液中,NPSS–10与Ca2+有较强的作用,无沉淀产生,NPSS–10中的氧乙烯基团与Ca2+形成络合物。在高浓度Ca2+溶液中,NPSS–10与Ca2+没有作用,这是因为NPSS–10在高Ca2+溶液中的极性减弱,再加上空间效应,使得磺酸基头与Ca2+的相互作用减小,形成离子对的能力减弱,避免了Ca2+与磺酸基头的作用产生沉淀,从而使它具有很强的抗Ca2+能力。     

酶解骨粉对低钙大鼠的补钙功效研究

为研究酶解骨粉对低钙大鼠的补钙效果，经过六周低钙饲养SD大鼠构建低钙模型，连续四周分别灌胃给予低钙大鼠200、400和800 mg/kg酶解骨粉溶液.对大鼠股骨进行HE染色分析，测定股骨力学指标、骨密度、干重灰重、骨钙和骨磷含量，并测定钙的表观吸收率.实验结果发现模型组大鼠骨小梁显著减少，骨髓腔明显扩大.给予酶解骨粉后大鼠骨小梁数量增加，骨髓腔面积减小.高剂量酶解骨粉组大鼠的骨密度提高了14.1%，股骨钙磷含量和钙表观吸收率也显著升高（p<0.05）.研究表明酶解骨粉能够促进低钙大鼠钙的吸收，提高大鼠骨密度，增加体内骨钙含量，或是一种潜在的补钙制剂.      

Development of calcium coke for CaC_2 production using calcium carbide slag and coking coal

A type of calcium coke was developed for use in the oxy-thermal process of calcium carbide production.The calcium coke was prepared by the co-pyrolysis of coking coal and calcium carbide slag, which is a solid waste generated from the chlor-alkali industry.The characteristics of the calcium cokes under different conditions were analyzed experimentally and theoretically.The results show that the thermal strength of calcium coke increased with the increase in the coking coal proportion, and the waterproof property of calcium coke also increased with increased carbonation time.The calcium coke can increase the contact area of calcium and carbon in the calcium carbide production process.Furthermore, the pore structure of the calcium coke can enhance the diffusion of gas inside the furnace, thus improving the efficiency of the oxy-thermal technology.     

利用电石渣和焦煤生产碳化钙用钙焦

A type of calcium coke was developed for use in the oxy-thermal process of calcium carbide production. The calcium coke was prepared by the co-pyrolysis of coking coal and calcium carbide slag, which is a solid waste generated from the chlor-alkali industry. The characteristics of the calcium cokes under different conditions were analyzed experimentally and theoretically. The results show that the thermal strength of calcium coke increased with the increase in the coking coal proportion, and the waterproof property of calcium coke also increased with increased carbonation time. The calcium coke can increase the contact area of calcium and carbon in the calcium carbide production process. Furthermore, the pore structure of the calcium coke can enhance the diffusion of gas inside the furnace, thus improving the efficiency of the oxy-thermal technology.     

过氧化钙在不同介质中的溶解性研究

本文研究了浓度、温度、时间、介对过氧化钙溶解性的影响。研究结果表明，过氧化钙溶于水，但在铵盐溶液中溶解量明显增加，是由于形成比氢氧化钙更易溶的钙盐或者难溶的钙盐所致。