The reaction of triphenylphosphine with AgNO3 yielded an unusual nitrate anion bridging one-dimensional infinite chain [Ag(PPh3)NO3] in which the silver(I) atom is three-coordinated by one P atom of triphenylphosphine...The reaction of triphenylphosphine with AgNO3 yielded an unusual nitrate anion bridging one-dimensional infinite chain [Ag(PPh3)NO3] in which the silver(I) atom is three-coordinated by one P atom of triphenylphosphine and two O atoms of two bridging nitrate anions to form a scalene triangle. The complex [Ag(PPh3)NO3] crystallizes in the monoclinic system, space group P21/c with a = 10.281(2), b = 18.596(5), c = 9.180(2) , = 90.60(1), V = 1755.1(7) 3, Z = 4, Mr = 432.15, Dc = 1.635 g/cm3, F(000) = 864 and = 1.254 mm-1. The final R = 0.0606 and wR = 0.1400 for 2188 observed reflections with I > 2(I) out of 3057 unique ones (Rint = 0.0539). IR and elemental analysis of the complex are characterized.展开更多
The reaction of MoO2(acac)2 with 2-amino-6-methyl-pyridine (amp) in the mixed solvent of DMF (N,N-dimethylformamide) and water affords the title complex [H-amp]4- [Mo8O26(DMF)2]2H2O which was characterized by elementa...The reaction of MoO2(acac)2 with 2-amino-6-methyl-pyridine (amp) in the mixed solvent of DMF (N,N-dimethylformamide) and water affords the title complex [H-amp]4- [Mo8O26(DMF)2]2H2O which was characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction analysis with the following crystallographic data: C30H54Mo8N10O30, Mr = 1802.35, monoclinic, P21/n, a = 8.631(1), b = 24.260(3), c = 13.351(2) ? b = 104.688(3), V = 2704.2(7) 3, Z = 2, Dc = 2.213 g/cm3, m =1.890 mm-1 and F(000) = 1760. The final R = 0.0281 and wR = 0.0620 for 4935 observed reflections with I > 2s(I). X-ray structure analysis has confirmed the existence of g-[Mo8O26]4- anion in the molecule. Eight MoO6 distorted octahedra share edges with short terminal MoO bonds from 1.691(3) to 1.749(2) ? medium bonds from 1.868(2) to 1.965(2) ?and long bonds from 2.059(2) to 2.450(2) ? In the terminal site there exist two DMF ligands bound to the Mo atom through O atoms with the MoODMF bond length of 2.166(3) ? affording a bond strength of 0.433. A three-dimensional network structure was formed through hydrogen bonds.展开更多
Under the new market environment, the office needs to carefully study the problems existing in the management of administrative affairs, and make plans in combination with the demand and development to innovate and op...Under the new market environment, the office needs to carefully study the problems existing in the management of administrative affairs, and make plans in combination with the demand and development to innovate and optimize them. To effectively promote the modernization of office work is very beneficial to the realization of development goals and has far-reaching significance.展开更多
Modern mechanical manufacturing technology and precision machining technology have a positive role in promoting the whole industrial production. However, with the development of modern science and technology, the actu...Modern mechanical manufacturing technology and precision machining technology have a positive role in promoting the whole industrial production. However, with the development of modern science and technology, the actual requirements of modern mechanical manufacturing technology and precision machining technology are gradually improving, forcing the current enterprises to make appropriate adjustments in combination with the actual requirements of modern industrial production. Therefore, under the requirements of current production management, this paper makes a comprehensive analysis and exploration of the relationship between modern mechanical manufacturing technology and precision processing technology, further combs out the practical problems existing in the whole industrial production of modern mechanical manufacturing technology and precision processing technology, and judges the relevant contents involved in the modern mechanical manufacturing and processing technology, in order to promote the transformation of industrial production mode and improve the overall quality of industrial production management in our country.展开更多
With the overall improvement and steady development of Chinas science and technology, mechanical automation technology has been widely used in Chinas current mechanical manufacturing industry. Mechanical automation te...With the overall improvement and steady development of Chinas science and technology, mechanical automation technology has been widely used in Chinas current mechanical manufacturing industry. Mechanical automation technology can improve the steady development of industrial enterprises and help enterprises to realize intelligent, intensive and systematic production management work pattern analysis under the current product production cycle structure. At the same time, the comprehensive management of production, implementation of production technology and production speed in the production process of the enterprise can be comprehensively controlled, thus effectively improving the quality of product production management within the enterprise and effectively shortening the actual cycle of product production. Therefore, based on the implementation of the existing mechanical automation technology, this paper analyzes the effective application of mechanical automation technology in the mechanical manufacturing industry, analyzes the main problems existing therein, and puts forward various measures and means accordingly, so as to provide certain assistance for the application of mechanical automation technology in the mechanical manufacturing industry.展开更多
In this paper, a periodic Holling Ⅱ predator-prey model with impulsive effect is investigated. By applying the Floquet theory of linear periodic impulsive equation,some sufficient conditions are obtained for the line...In this paper, a periodic Holling Ⅱ predator-prey model with impulsive effect is investigated. By applying the Floquet theory of linear periodic impulsive equation,some sufficient conditions are obtained for the linear stability and instability of trivial and semi-trivial periodic solutions. Moreover, we use standard bifurcation theory to show the existence of coexistence states which arise near the semi-trivial periodic solution. As an application, we also examine some special case of the system to confirm our main results.展开更多
基金NNSFC (No. 20001007 20131020) and Natural Science Foundation of the Chinese Academy of Sciences (KJCX2-H3) and Fujian Province (2000F006)
文摘The reaction of triphenylphosphine with AgNO3 yielded an unusual nitrate anion bridging one-dimensional infinite chain [Ag(PPh3)NO3] in which the silver(I) atom is three-coordinated by one P atom of triphenylphosphine and two O atoms of two bridging nitrate anions to form a scalene triangle. The complex [Ag(PPh3)NO3] crystallizes in the monoclinic system, space group P21/c with a = 10.281(2), b = 18.596(5), c = 9.180(2) , = 90.60(1), V = 1755.1(7) 3, Z = 4, Mr = 432.15, Dc = 1.635 g/cm3, F(000) = 864 and = 1.254 mm-1. The final R = 0.0606 and wR = 0.1400 for 2188 observed reflections with I > 2(I) out of 3057 unique ones (Rint = 0.0539). IR and elemental analysis of the complex are characterized.
基金This work was supported by the Natural Science Foundation and the Youth Science Foundation of Guangxi province
文摘The reaction of MoO2(acac)2 with 2-amino-6-methyl-pyridine (amp) in the mixed solvent of DMF (N,N-dimethylformamide) and water affords the title complex [H-amp]4- [Mo8O26(DMF)2]2H2O which was characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction analysis with the following crystallographic data: C30H54Mo8N10O30, Mr = 1802.35, monoclinic, P21/n, a = 8.631(1), b = 24.260(3), c = 13.351(2) ? b = 104.688(3), V = 2704.2(7) 3, Z = 2, Dc = 2.213 g/cm3, m =1.890 mm-1 and F(000) = 1760. The final R = 0.0281 and wR = 0.0620 for 4935 observed reflections with I > 2s(I). X-ray structure analysis has confirmed the existence of g-[Mo8O26]4- anion in the molecule. Eight MoO6 distorted octahedra share edges with short terminal MoO bonds from 1.691(3) to 1.749(2) ? medium bonds from 1.868(2) to 1.965(2) ?and long bonds from 2.059(2) to 2.450(2) ? In the terminal site there exist two DMF ligands bound to the Mo atom through O atoms with the MoODMF bond length of 2.166(3) ? affording a bond strength of 0.433. A three-dimensional network structure was formed through hydrogen bonds.
文摘Under the new market environment, the office needs to carefully study the problems existing in the management of administrative affairs, and make plans in combination with the demand and development to innovate and optimize them. To effectively promote the modernization of office work is very beneficial to the realization of development goals and has far-reaching significance.
文摘Modern mechanical manufacturing technology and precision machining technology have a positive role in promoting the whole industrial production. However, with the development of modern science and technology, the actual requirements of modern mechanical manufacturing technology and precision machining technology are gradually improving, forcing the current enterprises to make appropriate adjustments in combination with the actual requirements of modern industrial production. Therefore, under the requirements of current production management, this paper makes a comprehensive analysis and exploration of the relationship between modern mechanical manufacturing technology and precision processing technology, further combs out the practical problems existing in the whole industrial production of modern mechanical manufacturing technology and precision processing technology, and judges the relevant contents involved in the modern mechanical manufacturing and processing technology, in order to promote the transformation of industrial production mode and improve the overall quality of industrial production management in our country.
文摘With the overall improvement and steady development of Chinas science and technology, mechanical automation technology has been widely used in Chinas current mechanical manufacturing industry. Mechanical automation technology can improve the steady development of industrial enterprises and help enterprises to realize intelligent, intensive and systematic production management work pattern analysis under the current product production cycle structure. At the same time, the comprehensive management of production, implementation of production technology and production speed in the production process of the enterprise can be comprehensively controlled, thus effectively improving the quality of product production management within the enterprise and effectively shortening the actual cycle of product production. Therefore, based on the implementation of the existing mechanical automation technology, this paper analyzes the effective application of mechanical automation technology in the mechanical manufacturing industry, analyzes the main problems existing therein, and puts forward various measures and means accordingly, so as to provide certain assistance for the application of mechanical automation technology in the mechanical manufacturing industry.
基金This research is supported by the National Natural Science Foundation of China (10171106).
文摘In this paper, a periodic Holling Ⅱ predator-prey model with impulsive effect is investigated. By applying the Floquet theory of linear periodic impulsive equation,some sufficient conditions are obtained for the linear stability and instability of trivial and semi-trivial periodic solutions. Moreover, we use standard bifurcation theory to show the existence of coexistence states which arise near the semi-trivial periodic solution. As an application, we also examine some special case of the system to confirm our main results.
