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1.
本文论述了如何从布尔代数的公理系统出发,建立相应的几何公理系统。因为布尔代数就是一个有补分配格。从这一点出发,首先定义几何中的点对应于代数中的元素。然后,再确定点集对应于代数中半序子集合时满足的几何性质。进一步,就是建立几何子空间,使它对应布尔代数中的有补格。最后,确定集合内各点之间的一种几何关系,使这个关系与可分配格相对应。用这样的方法使几何公理系统与布尔代数公理系统一致。本文的立足点是布尔代数公理系统中的集合、元素,并、交和补等仅是作为数学术语,可以不考虑它的其他任何性质。  相似文献   

2.
在pH=8.0的氨-氯化铵缓冲溶液和组成为OP乳化剂、正丁醇、正庚烷和水的微乳液中,以2-(5-溴-2吡啶偶氮)-5-二乙氨基酚为显色剂,通过测定铜(Ⅱ)、镍(Ⅱ)配合物共存体系的吸光度A,及加入乙二胺掩蔽铜(Ⅱ)后镍(Ⅱ)配合物的吸光度A1,得到铜(Ⅱ)配合物的吸光度A2=A-A1,从而求出铜(Ⅱ)、镍(Ⅱ)含量,用于Cu-Ni合金镀液中铜(Ⅱ)、镍(Ⅱ)的测定,效果良好.  相似文献   

3.
本文采用笔者新近合成的新有机试剂2-(5-溴-2-噻唑偶氮)-5-二乙氨基苯酚(5-Br-TADAP)作显色剂,在表面活性剂OP存在下,与痕量铜(Ⅱ),钴(Ⅱ)、镍(Ⅱ)在最佳条件下形成有色三元胶束增溶配合物。用CPA-矩阵法和共轭梯度法(CG)同时计算分光光度测定三组分含量,前者取得了满意的结果。对两种计算方法进行了比较和讨论。在处理吸收光谱相似的多组分体系时,从所测结果的准确度和精密度看。CPA优于CG。  相似文献   

4.
研究发现:在阴离子表面活性剂十二烷基硫酸钠(SDS)存在下,以混酸-氢氧化钠缓冲液控制酸度,利用镍与4-(5-氯-2-吡啶偶氮)-1,3-二胺基苯(5-Cl-PADAB)生成紫红色络合物的吸收光谱,可直接光度法测镍。该体系稳定性好,摩尔吸光系数为1.22×105L·mol-1·cm-1,镍量在0~15μg·25mL-1范围内符合比耳定律  相似文献   

5.
甘氨酸席夫碱Ni(Ⅱ)复合物法不对称合成丝氨酸   总被引:1,自引:0,他引:1  
秦为民  曹飞  周华  李振江  韦萍 《化学试剂》2005,27(11):643-644,670
采用甘氨酸席夫碱Ni(Ⅱ)复合物法不对称合成光学纯的D-和L-丝氨酸。以2-N-(N'-苄基)脯氨酰-氨基-二苯甲酮甘氨酸席夫碱Ni(Ⅱ)复合物与聚甲醛反应,生成2-N-(N'-苄基)脯氨酰-氨基-二苯甲酮丝氨酸席夫碱Ni(Ⅱ)复合物,经水解生成D-或L-丝氨酸,对映体过量值(e.e.)达到98%,重结晶后e.e.为99.5%,并对手性辅基2-N-(N;-苄基)脯氨酰-氨基-二苯甲酮进行了回收,回收率为85%~95%。  相似文献   

6.
不对称席夫碱Cu(Ⅱ)配合物的合成和催化性能研究   总被引:1,自引:0,他引:1  
用2,4-二羟基苯乙酮、二胺基硫脲与取代水杨醛反应,合成了3种不对称席夫碱配体及其Cu(Ⅱ)配合物,通过元素分析、1HNMR、IR、UV-vis、MS等手段对配体及其配合物进行了组成和结构表征,并研究了不对称席夫化合物对双氧水的催化分解性能。结果表明,合成得到的不对称席夫碱Cu(Ⅱ)配合物对催化H2O2分解具有较好的催化性能。  相似文献   

7.
用核黄素光照法测定了,8种大环铜(Ⅱ)、锰(Ⅱ)配合物的超氧化物歧化酶活性(SOD),结果表明,它们在1×10-4-1×10-7mol/L的浓度范围内均有50%以上抑制率,锰(Ⅱ)配合物表现出较铜(Ⅱ)配合物更低的SOD活性,对各模型化合物活性和结构的关系进行了探讨。  相似文献   

8.
山梨醇经脱水、酯化、硝酸酯化及皂化,合成了5 单硝酸异山梨醇酯。山梨醇脱水反应:山梨醇与硫酸质量比为1∶0014,二甲苯作带水剂,反应温度140℃,反应时间35h,得异山梨醇(Ⅰ),收率69%;酯化反应:异山梨醇、冰乙酸及对甲基苯磺酸的质量比为1∶049∶0034,溶剂S兼作带水剂,回流反应,得2 乙酸异山梨醇酯混合物(Ⅱ);在10℃,Ⅱ与硝酸质量比为1∶036,2h内进行硝酸酯化,得2 乙酸 5 硝酸异山梨醇酯混合物(Ⅲ);Ⅲ在50℃、pH=10~12条件下皂化15h,得5 单硝酸异山梨醇酯。总收率25%。  相似文献   

9.
何琴  程静茹 《广东化工》2012,39(9):154-155
在pH为9.60的硼砂-氢氧化钠缓冲溶液、十六烷基三甲基溴化铵(CTMAB)存在下,铜(Ⅱ)、镍(Ⅱ)、钙(Ⅱ)和镁(Ⅱ)与二甲酚橙(XO)发生灵敏的显色反应,所形成的络合物吸收光谱严重重叠,各组分间相互干扰。采用人工神经网络结合分光光度法,设计不经分离同时测定铜(Ⅱ)、镍(Ⅱ)、钙(Ⅱ)和镁(Ⅱ)含量的方法。结果表明:该方法具有良好的准确性,四种金属离子同时测定结果的相对误差绝对值均≤2.74%。  相似文献   

10.
以5-氯水杨醛、N,N′-二甲基乙二胺和多聚甲醛合成N,N′-二甲基-N,N′-二(3-甲酰基-5-氯水杨醛)乙二胺(1),化合物1与乙二胺、醋酸铜、高氯酸铅通过模板反应缩合制备了不对称大环铜(Ⅱ)配合物(2),用元素分析、红外光谱、电喷雾质谱对其进行结构表征,X射线单晶衍射分析配合物2晶体(CCDC:787806)属于三斜晶系,P-1空间群,铜(Ⅱ)离子与大环中两个亚胺氮原子、两个酚羟基的氧原子形成4配位。  相似文献   

11.
塑料成型加工过程的计算机模拟技术(Ⅱ)   总被引:1,自引:0,他引:1  
介绍挤出成型、吹塑成型和热成型及其它成型方式的数值模拟技术,阐述了目前存在的问题和发展趋势。  相似文献   

12.
Two methods were applied in simulating the height of a packed column required for the removal of NO and SO2 by absorption into Fe(II)-EDTA solutions. The first method used a double-stirred cell to simulate a packed column by matching the gas- and liquid-phase mass transfer coefficients of the two device. The second method used the differential mass balance including reaction kinetics. Data taken in an 8 cm diameter, 40 cm packed height column and in a double-stirred cell were employed in illustrating the methodology. The two methods of prediction were quite satisfactory.  相似文献   

13.
以实际工业装置为背景,建立了丙烯液相本体聚合连续搅拌釜式反应器的定态数学模型。通过模拟计算,考察了诸工艺参数──进料温度、进料流量、夹套冷却水人口温度和流量、丙烯蒸汽冷凝量、催化剂浓度以及反应器中的氢浓度对聚合反应釜反应结果的影响,并对其定态操作行为作了理论上的解释和分析。  相似文献   

14.
An unsteady - state model of concurrent-flow maize drying was developed. It consists of a set of four partial differential equations (PDE) which are solved by finite differences. The PDE model was verified by comparing it to the steady-state concurrent-flow dryer simulation. The model was used for the development of a process model which in turn is to be employed for the design of an automatic control system of a two-stage concurrent-flow dryer.  相似文献   

15.
Stability constants of Copper(II), Nickel(II), Cobalt(II), Zinc(II), Uranyl(II) and Thorium(IV) adipates have been determined by paper electrophoresis. Adipic acid (0.005 mol dm?3) was added to the background electrolyte: 0.1 mol dm?3 HClO4. The proportions of (CH2)4COOH COO? and (CH2)4C2O=2 were varied by changing the pH of the electrolyte. These anions yielded the complexes Zn(CH2)4COOH COO+, Co(CH2)4COOH COO+, Ni(CH2)4COOH COO+, Th(CH2)4COOH COO3+, Th[(CH2)4COOH COO]4, Cu(CH2)4 C2O4 and UO2[(CH2)4(C2O4)]2?2, whose stability constants are found to be 102.8, 102.8, 103.2, 105.2, 1015.3, 102.7 and 1011.8 respectively (μ = 0.1, temp. 40°C).  相似文献   

16.
应用严格的热力学模型研究了带有侧线返回进料的氢同位素低温精馏塔的分离特性.根据氢同位素低温精馏体系的特点,以平衡级模型为基础建立了氢同位素低温精馏稳态模拟模型,确定了模型方程适宜的求解方法.塔的一股侧线出料流股经过一个平衡反应器完成平衡反应后,作为内部进料流股,与原外部进料混合后重新进入精馏塔内进行分离操作.通过对带有侧线返回进料的塔的计算模拟阐明了这一侧线流股对塔分离特性的影响.在平衡反应器内,HD部分分解为H2和D2,塔顶产品中H2的浓度增加了8.635%,塔底D2的浓度增加了11.327%.  相似文献   

17.
《Drying Technology》2013,31(10):1895-1917
ABSTRACT

The present study proposes the development of a complete mathematical modelling transfer phenomena involving at the same time heat, mass and momentum transfer during the drying process of clay. Clay is a generic example of colloid materials forming particulate gels. That can be considered as bi-constituent, homogeneous, isotropic, and highly deformable. The model was numerically solved by the finite difference method and validated by comparison of the numerical results with a previous set of experiments data. The simulation has allowed the determination of spatio-temporal evolution within the solid of different variables: temperature fields, moisture contents, displacement, deformation and stresses. The parametric sensibility has been analyzed in the case of thermophysical properties and the external heat transfer coefficient. Various values of external conditions have been analyzed.  相似文献   

18.
ABSTRACT

Hydration of lead(II) acetylacetonate and its solvation by trioctylphosphine oxide and chloroform, were studied by solvent extraction and compared with those of zinc(II) acetylacetonate. The results suggest that the 6s2 lone electron pair of the PbII ion in the chelate is stereochemically active.  相似文献   

19.
The present study proposes the development of a complete mathematical modelling transfer phenomena involving at the same time heat, mass and momentum transfer during the drying process of clay. Clay is a generic example of colloid materials forming particulate gels. That can be considered as bi-constituent, homogeneous, isotropic, and highly deformable. The model was numerically solved by the finite difference method and validated by comparison of the numerical results with a previous set of experiments data. The simulation has allowed the determination of spatio-temporal evolution within the solid of different variables: temperature fields, moisture contents, displacement, deformation and stresses. The parametric sensibility has been analyzed in the case of thermophysical properties and the external heat transfer coefficient. Various values of external conditions have been analyzed.  相似文献   

20.
Paper electrophoresis has been used for the study of the equilibria in mixed ligand complex systems in solution. The method is based on the migration of a spot of a metal ion, with the complexants added in the background electrolyte (0.1 M perchloric acid), at a fixed pH. The concentration of one of the complexants [A] is kept constant, while that of second ligand [L] is varied. A graph of—log [L] against mobility is used to obtain information on the formation of the mixed ligand complex, and to calculate the stability constant. Using this technique, the values of overall stability constant of the complex metal—tartarate—nitrilotriacetate have been found to be 1012.25, 105.98, 10?3.56, and 103.74 for Cu(II), Ni(II), Co(II), UO2(II) and Th(IV) complexes, respectively at μ = 0.1 and temp. = 40°C.  相似文献   

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