On the basis of the structural and electronic properties of 14 different cyclic nitramine molecules, two types of formulas are employed to predict their electric spark sensitivity. One contains the minimum Mulliken ch...On the basis of the structural and electronic properties of 14 different cyclic nitramine molecules, two types of formulas are employed to predict their electric spark sensitivity. One contains the minimum Mulliken charges of nitro group, the ratio of hydrogen to oxygen, and the ratio of carbon to oxygen; the other contains the lowest unoccupied molecular orbital energy, the ratio of hydrogen to oxygen, and the ratio of carbon to oxygen. Using these two types of formulas, we calculate the electric spark sensitivity of these 14 cyclic nitramine molecules, and compare them with the experimental data and previous theoretical values. And our investigations show that the former type of formula is better than the latter on predicting the electric spark sensitivity for cyclic nitramine molecules.展开更多
The machine tool is one of the new products developed and produced by the Shanghai No.8 Machine Tool Plant. It adopts a lift adjustable wiretrame and molybdenum filament tensioning mechanism with large cutting thickne...The machine tool is one of the new products developed and produced by the Shanghai No.8 Machine Tool Plant. It adopts a lift adjustable wiretrame and molybdenum filament tensioning mechanism with large cutting thickness and high machining precision. It is equipped with an advanced IBM-PC 386 microcomputer-controlled system, with strong performance and CRT display. Man/展开更多
The DK7763A digital-controlled electric spark wire cutter, developed by the Tianjin Tianyi Digital-controlled Machinery Holdings Co. Ltd, is used in processing large modules and large precision parts. In 1995 it was a...The DK7763A digital-controlled electric spark wire cutter, developed by the Tianjin Tianyi Digital-controlled Machinery Holdings Co. Ltd, is used in processing large modules and large precision parts. In 1995 it was awarded the title of state-level new product. It has a T-type body,rational Structure and展开更多
Ignition energy is one of tbe important parameters of flammable materials, and evaluating ignition energy precisely is essential to the safety of process industry and combustion science and technology. By using electr...Ignition energy is one of tbe important parameters of flammable materials, and evaluating ignition energy precisely is essential to the safety of process industry and combustion science and technology. By using electric spark discharge test system, a series of electric spark discharge experiments were conducted with the capacitor-stored energy in the range of 10 J, 100 J, and 1000 J, respectively. The evaluation method for energy consumed by electric spark, wire, and switch during capacitor discharge process has been studied respectively. The resistance of wire, switch, and plasma between electrodes has been evaluated by different methods and an optimized evaluation method has been obtained. The electric energy consumed by wire, electric switch, and electric spark-induced plasma between electrodes were obtained and the energy structure of capacitor-released energy was analyzed. The dynamic process and the characteristic parameters (the maximum power, duration of discharge process) of electric spark discharge process have been analyzed. Experimental results showed that, electric spark-consumed energy only accounts for 8%-14% of the capacitor-released energy. With the increase of capacitor-released energy, the duration of discharge process becomes longer, and the energy of plasma accounts for more in the capacitor-released energy. The power of electric spark varies with time as a damped sinusoids function and the period and the maximum value increase with the capacitor-released energy.展开更多
An ESZ KTTV instrument of a new,relatively simple construction has been applied to determination of electric spark sensitivity of 29 polynitro arenes,expressed as spark energy,EES,required for 50-percent initiation pr...An ESZ KTTV instrument of a new,relatively simple construction has been applied to determination of electric spark sensitivity of 29 polynitro arenes,expressed as spark energy,EES,required for 50-percent initiation probability.The thermal stability thresholds,Tmax,were calculated from the published Arrhenius parameters of monomolecular thermal decomposition of the studied compounds,predominantly obtained under the conditions of the Russian manometric method.An approximate relationship has been found between the ln EES values and threshold Tmax values.In the sense of this relationship,the compounds studied fall into several sub-groups.The reason of the said diversification lies in the decomposition reaction rate at the temperature of onset of their thermal decomposition.It has been found that in each sub-group increasing thermal stability of polynitro arenes is accompanied by increasing electric spark sensitivity of these substances.This fact must be taken into account if we deal with the problem of electric spark energy transfer into the reaction centre of the molecule.展开更多
基金the National Natural Science Foundation of China (Nos. 11176020 and 10976019)
文摘On the basis of the structural and electronic properties of 14 different cyclic nitramine molecules, two types of formulas are employed to predict their electric spark sensitivity. One contains the minimum Mulliken charges of nitro group, the ratio of hydrogen to oxygen, and the ratio of carbon to oxygen; the other contains the lowest unoccupied molecular orbital energy, the ratio of hydrogen to oxygen, and the ratio of carbon to oxygen. Using these two types of formulas, we calculate the electric spark sensitivity of these 14 cyclic nitramine molecules, and compare them with the experimental data and previous theoretical values. And our investigations show that the former type of formula is better than the latter on predicting the electric spark sensitivity for cyclic nitramine molecules.
文摘The machine tool is one of the new products developed and produced by the Shanghai No.8 Machine Tool Plant. It adopts a lift adjustable wiretrame and molybdenum filament tensioning mechanism with large cutting thickness and high machining precision. It is equipped with an advanced IBM-PC 386 microcomputer-controlled system, with strong performance and CRT display. Man/
文摘The DK7763A digital-controlled electric spark wire cutter, developed by the Tianjin Tianyi Digital-controlled Machinery Holdings Co. Ltd, is used in processing large modules and large precision parts. In 1995 it was awarded the title of state-level new product. It has a T-type body,rational Structure and
基金supported by the National Natural Science Foundation of China(Grant No.11572044)the National Key Research and Development Program of China(Grant No.2017YFC0804705)
文摘Ignition energy is one of tbe important parameters of flammable materials, and evaluating ignition energy precisely is essential to the safety of process industry and combustion science and technology. By using electric spark discharge test system, a series of electric spark discharge experiments were conducted with the capacitor-stored energy in the range of 10 J, 100 J, and 1000 J, respectively. The evaluation method for energy consumed by electric spark, wire, and switch during capacitor discharge process has been studied respectively. The resistance of wire, switch, and plasma between electrodes has been evaluated by different methods and an optimized evaluation method has been obtained. The electric energy consumed by wire, electric switch, and electric spark-induced plasma between electrodes were obtained and the energy structure of capacitor-released energy was analyzed. The dynamic process and the characteristic parameters (the maximum power, duration of discharge process) of electric spark discharge process have been analyzed. Experimental results showed that, electric spark-consumed energy only accounts for 8%-14% of the capacitor-released energy. With the increase of capacitor-released energy, the duration of discharge process becomes longer, and the energy of plasma accounts for more in the capacitor-released energy. The power of electric spark varies with time as a damped sinusoids function and the period and the maximum value increase with the capacitor-released energy.
基金The research was carried out under the auspices of the Ministry of Education,Youth & Sports of the Czech Republic as a part of its research project No.MSM0021627501
文摘An ESZ KTTV instrument of a new,relatively simple construction has been applied to determination of electric spark sensitivity of 29 polynitro arenes,expressed as spark energy,EES,required for 50-percent initiation probability.The thermal stability thresholds,Tmax,were calculated from the published Arrhenius parameters of monomolecular thermal decomposition of the studied compounds,predominantly obtained under the conditions of the Russian manometric method.An approximate relationship has been found between the ln EES values and threshold Tmax values.In the sense of this relationship,the compounds studied fall into several sub-groups.The reason of the said diversification lies in the decomposition reaction rate at the temperature of onset of their thermal decomposition.It has been found that in each sub-group increasing thermal stability of polynitro arenes is accompanied by increasing electric spark sensitivity of these substances.This fact must be taken into account if we deal with the problem of electric spark energy transfer into the reaction centre of the molecule.