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排序方式: 共有88条查询结果,搜索用时 15 毫秒
1.
介绍了新型精细化工产品过碳酸钠的性质、国内外生产现状、生产技术进展和应用情况.  相似文献   
2.
目的:建立HPLC法测定鹿骨片中硫酸软骨素钠的含量方法。方法:采用C18柱(250×4.6mm,5μm)为色谱柱;甲醇-0.004%庚烷磺酸钠溶液(20:80),用磷酸调节p H值至3.5为流动相;流速0.8m L·min-1;检测波长197nm。结果:该方法在0.0208mg·m L-1~0.2078mg·m L-1浓度范围内具有良好的线性关系,R=0.9999;平均回收率为99.80%,RSD(%)=0.35%。结论:该测定方法准确、可靠、重复性好,可作为鹿骨片的质量控制方法。  相似文献   
3.
目的:对比四种成盐剂对头孢噻肟钠成品质量的影响。方法:通过头孢噻肟酸与成盐剂反应制得头孢噻肟钠溶液,再滴加丙酮析出头孢噻肟钠固体。结果:由碳酸氢钠制得的头孢噻肟钠质量优于其他方法。结论:使用碳酸氢钠作成盐剂,滴加丙酮结晶,简化了工艺路线,并能有效地降低生产成本,减少环境污染,适合工业化生产。  相似文献   
4.
医学上常用的的苯酚 ,学生对它有弱酸性及在一定条件下能与金属钠产生氢气这一现象不易理解。通过对实验的改进 ,并让学生参与实验 ,最后结合理论开展教学活动 ,使教学达标 ,并取得良好的效果  相似文献   
5.
金属氧化物沉积法制备钛酸铋钠陶瓷的研究   总被引:1,自引:1,他引:0  
金属氧化物沉积法(MOD)成功地制备了Bi1/22Na1/2TiO3(NBT)基无铅压电陶瓷,样品的X射线衍射(XRD)结果显示其具有较好的结晶性,XRD指标化后的结果表明,晶胞参数的变化,在室温下是赝立方相。通过测量不同退火条件下陶瓷表观密度,得到NBT陶瓷采用MOD法的最大密度可在烧结温度约为1150℃左右。  相似文献   
6.
A wastewater evaporation-desalination pretreatment method was introduced to remove the Na^+ and K^+ salts in volatile organic compounds (VOCs) wastewater before it was fed into the incinerator. VOCs in the wastewater were volatilized in the evaporation system and then the vapor was combusted in an incinerator. Simulated phenol wastewater containing sodium chloride was evaporated and concentrated and sodium chloride was crystallized in different parameters. The experimental results showed that the higher initial concentration of sodium chloride increases the ratio of volatilization of VOCs, which was due to the effect of “salting out” (a decrease in the solubility of the nonelectrolyte in the solution, or more rigorously, an increase in its activity coefficient, caused by the salt addition (Furter and Cook, 1967)). When evaporation speed was increased from 1.67 ml/min to 2.73 ml/min, the total removal coefficient of sodium chloride was about 99.88%-99.99%. This pretreatment procedure eliminates the slag phenomenon caused by Na^+ and K^+ salts during wastewater incineration, so the incinerator could operate continuously, and the wastewater evaporation could increase the heat value of wastewater, and the operation cost would be reduced.  相似文献   
7.
Rapid and complete restoration of fluid balance after exercise is an important part of the recovery process, especially in hot, humid conditions, when sweat losses may be high. Rehydration after exercise can only be achieved if the electrolytes lost in sweat, as well as the lost water, are replaced. However, the amount of electrolytes lost in sweat is highly variable between individuals and although the optimum drink may be achieved by matching drink electrolyte intake with sweat electrolyte loss, this is virtually impossible in sport settings. The composition of sweat varies considerably not only between individuals, but also with time during exercise and it is further influenced by the state of acclimatization. A moderate excess of salt intake would appear to be beneficial as far as hydration status is concerned, without any detrimental effects on health, provided that fluid intake is in excess of sweat loss and that renal function is not impaired. To achieve effective rehydration following exercise in the heat, the rehydration beverage should contain moderately high levels of sodium (at least 50 mmol l -1 ), and possibly also some potassium. The addition of substrate is not necessary for rehydration, although a small amount of carbohydrate (< 2%) may improve the rate of intestinal uptake of sodium and water. The volume of beverage consumed should be greater than the volume of sweat lost to provide for the ongoing obligatory urine losses. Therefore, the palatability of the beverage is important. Many individuals may lose substantial amounts of sweat and will therefore have to consume large amounts of replacement fluids and this is more likely to be achieved if the taste is perceived as being pleasant. Water alone is adequate for rehydration purposes when solid food is consumed, as this replaces the electrolytes lost in sweat. However, there are many situations where intake of solid food is not possible or is deliberately avoided and, in these instances, the inclusion of electrolytes in rehydration beverages is essential. Where a second exercise bout has to be performed, replacement of sweat losses is an essential part of the recovery process. Exercise performance will be impaired if complete rehydration is not achieved.  相似文献   
8.
目的:比较用电极直接法测定血清和肝素钠抗凝血浆电解质浓度的差异,探讨肝素钠抗凝血浆代替血清检测电解质的可行性。方法:用深圳航创9886型电解质分析仪测定患者血清和肝素钠抗凝血浆的电解质浓度并进行统计分析。结果:血浆与血清钾、钠测定结果差异具有统计学意义,血浆与血清氯测定结果差异无统计学意义,但血浆与血清钾、钠、氯的测定结果具的很好的相关性,相关性系数(r)均≥0.975,且两种标本钾、钠、氯测定值平均偏倚均没有超出1/2 CLIA’88允许误差。结论:行肝素钠抗凝血浆代替血清测定钾、钠、氯是可行的,但应建立相应的换算体系。  相似文献   
9.
舒巴坦钠本身抑茵作用较弱,是一种竞争性、不可逆的β-内酰胺酶抑制剂药,通常与头孢哌酮钠、氨苄西林钠、阿莫西林钠、哌拉西林钠等联合应用;舒巴坦可防止耐药茵对青霉素类和头孢菌素类抗生素的破坏,舒巴坦与青霉素类和头孢菌素类抗生素具有明显的协同作用。国内通常采用中国药典2005年版相关物质的检测方法进行检测,经检测不同生产厂家的舒巴坦钠,在主成分峰保留时间的3倍停止后,通常在7倍左右还有其杂质,不能够完全洗脱,完成一个样品的杂质分析需要近50分钟。现采用梯度的洗脱方法,不仅缩短了检测的时间,还可对其杂质进行定性,为指导生产过程中的杂质控制,提供了可靠的数据。  相似文献   
10.
通过实验证明NO、NO2均能与Na2O2直接反应,并从化学热力学角度进行了分析  相似文献   
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