We suggest a mathematical route which has the capability to obtain quantitative information of solid residues on a substrate of aluminum, in which the evaporation of the deposited micro-drops has the form of coffee ri...We suggest a mathematical route which has the capability to obtain quantitative information of solid residues on a substrate of aluminum, in which the evaporation of the deposited micro-drops has the form of coffee rings. In this job, the glycine aminoacid was used as probe molecule. We suppose that the number of moles present on the study sample is proportional to the Raman signal and to the experimental parameters of the used Raman system. Then, the mass and the number of molecules can be determined with these data. We showed that the mathematical expression is simple and elegant for its implementation. On the other hand, we have applied and demonstrated that the technique of principal component analysis (PCA) can be used to obtain quantitative information of the sample. Our results show quantitative analysis of glycine residues between 10-11 to 10-15 g.展开更多
Nine C2-symmetric chiral disulfonamldes were designed and synthesized from L-valine, L-phenylalanine and L-leucine respectively via one-pot ring opening of aziridines. The application of these disulfonamides as catal... Nine C2-symmetric chiral disulfonamldes were designed and synthesized from L-valine, L-phenylalanine and L-leucine respectively via one-pot ring opening of aziridines. The application of these disulfonamides as catalyst in the addition of diethyl zinc to benzaldehyde in three reagent systems: Ligand-Ti(OiPr)4-Et2Zn; Ligand-Ti(OiPr)4-H2O-Et2Zn; Ligand-Et2Zn was also described.展开更多
The title complex of [(Yb(Pro)2(H2O)5Cl3]n has been synthesized. Its IR spectrum from 4000 to 400 cm-1 has been measured and the possible structure of the complex was proposed. The molecular and crystal structure has ...The title complex of [(Yb(Pro)2(H2O)5Cl3]n has been synthesized. Its IR spectrum from 4000 to 400 cm-1 has been measured and the possible structure of the complex was proposed. The molecular and crystal structure has been determined by four-circle X-ray diffractometer. The crystal is monoclinic with space group P21. The unit cell parameters are as follows: a=0.8268(l) nm, b=1.0980(3) nm, c =1.1965(4) nm, β=106.97(2)°, V=1.04120(5) nm3, z=2. Positicnal and anisotropic thermal parameters have been corrected by least sqare method and the final deviation R is 0.0812. The prolines exist in two forms in the complex. One form of proline serves as bridging group connecting neighboring Yb atoms, so that the complex form a one-dimensional chain of infinitive length. Another form of proline coordinates with Yb atom through one oxygen atom of the carboxyl group. In addition there are five water moleculers coordinating to each Yb atoms. The coordination number of Yb is eight, forming a distorted trigonal-dodecahedral arrangement. The three Cl-anions are in the neighbourhood of NH+2 cations.展开更多
By adding suitable amount of amino acid L-cysteine to acidic solution in contac t with sphalerite or pyrite,the activity of Thiobacillus Ferrooxidans is la rgely enhanced. But,at comparable higher concentration of L-c...By adding suitable amount of amino acid L-cysteine to acidic solution in contac t with sphalerite or pyrite,the activity of Thiobacillus Ferrooxidans is la rgely enhanced. But,at comparable higher concentration of L-cysteine,a delete rious effect on bacterial activity was found,which can be due to the toxic effe ct of this amino acid at higher concentrations to microbes. The addition of L-m ethionine would be great inhibition to the bioleaching no matter how much it was applied,which indicates that L-methionine is harmful for bioleaching. The qui te different effect on bioleaching between L-cysteine and L-methionine lies in that L-cysteine has a SH group which is useful in helping metal sulfide biolea ching by Thiobacillus ferrooxidans.展开更多
文摘We suggest a mathematical route which has the capability to obtain quantitative information of solid residues on a substrate of aluminum, in which the evaporation of the deposited micro-drops has the form of coffee rings. In this job, the glycine aminoacid was used as probe molecule. We suppose that the number of moles present on the study sample is proportional to the Raman signal and to the experimental parameters of the used Raman system. Then, the mass and the number of molecules can be determined with these data. We showed that the mathematical expression is simple and elegant for its implementation. On the other hand, we have applied and demonstrated that the technique of principal component analysis (PCA) can be used to obtain quantitative information of the sample. Our results show quantitative analysis of glycine residues between 10-11 to 10-15 g.
文摘 Nine C2-symmetric chiral disulfonamldes were designed and synthesized from L-valine, L-phenylalanine and L-leucine respectively via one-pot ring opening of aziridines. The application of these disulfonamides as catalyst in the addition of diethyl zinc to benzaldehyde in three reagent systems: Ligand-Ti(OiPr)4-Et2Zn; Ligand-Ti(OiPr)4-H2O-Et2Zn; Ligand-Et2Zn was also described.
文摘The title complex of [(Yb(Pro)2(H2O)5Cl3]n has been synthesized. Its IR spectrum from 4000 to 400 cm-1 has been measured and the possible structure of the complex was proposed. The molecular and crystal structure has been determined by four-circle X-ray diffractometer. The crystal is monoclinic with space group P21. The unit cell parameters are as follows: a=0.8268(l) nm, b=1.0980(3) nm, c =1.1965(4) nm, β=106.97(2)°, V=1.04120(5) nm3, z=2. Positicnal and anisotropic thermal parameters have been corrected by least sqare method and the final deviation R is 0.0812. The prolines exist in two forms in the complex. One form of proline serves as bridging group connecting neighboring Yb atoms, so that the complex form a one-dimensional chain of infinitive length. Another form of proline coordinates with Yb atom through one oxygen atom of the carboxyl group. In addition there are five water moleculers coordinating to each Yb atoms. The coordination number of Yb is eight, forming a distorted trigonal-dodecahedral arrangement. The three Cl-anions are in the neighbourhood of NH+2 cations.
文摘By adding suitable amount of amino acid L-cysteine to acidic solution in contac t with sphalerite or pyrite,the activity of Thiobacillus Ferrooxidans is la rgely enhanced. But,at comparable higher concentration of L-cysteine,a delete rious effect on bacterial activity was found,which can be due to the toxic effe ct of this amino acid at higher concentrations to microbes. The addition of L-m ethionine would be great inhibition to the bioleaching no matter how much it was applied,which indicates that L-methionine is harmful for bioleaching. The qui te different effect on bioleaching between L-cysteine and L-methionine lies in that L-cysteine has a SH group which is useful in helping metal sulfide biolea ching by Thiobacillus ferrooxidans.
