In this work,the results of an experimental study of the impulse characteristic of practical ground electrodes consisting of horizontal conductors of various lengths and full-scale tower footings were reported.These e...In this work,the results of an experimental study of the impulse characteristic of practical ground electrodes consisting of horizontal conductors of various lengths and full-scale tower footings were reported.These electrodes were installed at an outdoor test site having nonuniform soil,with equipment facilities for generating low-and high-magnitude impulse currents.The tests on the horizontal electrode were used to determine the effective length,the voltage and current distribution along the electrode length and the effect of the injection point along the electrode.The tests on the tower footings were used to determine impulse resistance and demonstrate its non-linear variation with current magnitude.Computer simulations of the test electrodes using the electromagnetic field method showed good agreement with the measured result.展开更多
The combination of CrO4^2-anion and N,N′-dimethylformamide(DMF)-containing solvent helps to stabilize an atom-precise ultrasmall Ag6 kernel into a 52-nuclei silver shell,giving a core-shell Ag6@Ag52 wheel-like struct...The combination of CrO4^2-anion and N,N′-dimethylformamide(DMF)-containing solvent helps to stabilize an atom-precise ultrasmall Ag6 kernel into a 52-nuclei silver shell,giving a core-shell Ag6@Ag52 wheel-like structure(SD/Ag58b).The solution behavior and photocurrent response property were investigated in details.展开更多
In the present study the first 20 microatoms of the periodic table are named as bioatoms, since they are needed for biochemical functions and services to life itself. The rationale behind this project is the detailed ...In the present study the first 20 microatoms of the periodic table are named as bioatoms, since they are needed for biochemical functions and services to life itself. The rationale behind this project is the detailed analysis of the ionization energy of the electrons in the inside of the bioatoms and their orderly arrangement at specific positions. Such position of the electrons is harmonized with the succession of their energy values in their logarithmic curves. The compelling arrangement of each electron at a particular place would not be feasible in the absence of an energy offset, which is a proton. The latter would hold electrons on their proper position. These fundamental aspects of our project receive such strong support from the quantum theory, according to which it is the electromagnetic interaction between electrons and protons by the exchange of photons, which hold them together in the atoms. According to our proposed model, the protons of the aforementioned proton—electron twins, are distributed on distinct positions which are the junctions of a primary network, coupled with their electrons, in a secondary network. The geometry and distance of the protons, in the plexus, is constant and is calculated at 8, 42 ?. This was estimated by a mathematical analysis of the proposed model, as discussed further. Our study has shown that electrons in the specific positions are moving in a symmetrical oscillation in the length of a channel, in vacuum, under the Coulomb forces. Moreover, the chemical evidence suggests that electrons, in an atom, have their own separate orbit, and that these orbits are closely interrelated.展开更多
GC-FID methods for the analysis of Petroleum hydrocarbons were developed and optimised. Contamination of soil from the Niger Delta was investigated about 40 days after crude oil spillage from the Shell Petroleum margi...GC-FID methods for the analysis of Petroleum hydrocarbons were developed and optimised. Contamination of soil from the Niger Delta was investigated about 40 days after crude oil spillage from the Shell Petroleum marginal well head. Soil samples and controls were collected at depths of 0 - 15 cm, 15 - 30 cm and 30 - 60 cm. Samples were analysed using gas chromatography fitted with a flame ionisation detector. Penetration and migration of C10-C26 and C26-C34 hydrocarbons through the soil layers were assessed by cluster analysis to determine the spatial distribution, penetration and similarity of these compounds over the contaminated area. The results also indicated elevated levels of total hydrocarbon contents when compared with the reference sites. Recommendations are made to carefully monitor and remediate the environment.展开更多
In the ionisation of Rydberg hydrogen atoms near a metal surface, the electron will escape from the nucleus and arrive at the detector in a time sequence. This probability flux train relies on the initial electron wav...In the ionisation of Rydberg hydrogen atoms near a metal surface, the electron will escape from the nucleus and arrive at the detector in a time sequence. This probability flux train relies on the initial electron wave packet irradiated by the laser pulse. For simplicity, the laser pulse is usually simplified to a delta function in energy domain, resulting in a sharp initial arrival time with an exponentially decaying tail at the detector. Actually and semiclassically, the initial outgoing wave should be modeled as an ensemble of trajectories propagating away from the atomic core in all directions with a range of launch times and a range of energies. In this case, each pulse in the pulse train is averaged out rather than a sharp profile. We examine how energy and time averaging of the electron wave packet affects the resolution of escaping electron pulses and study the energy dependence of the arrival time for each pulse in the ionisation train. An optimization condition for the laser pulse shape to generate narrow ionisation electron pulse in the train is obtained. The ionisation rates with various excitation energy are calculated also, which show the excitation to higher N Rydberg states will narrow the electron pulse as well.展开更多
The radiation effects of the metal-oxide-semiconductor （MOS） and the bipolar devices are characterised using 8 MeV protons, 60 MeV Br ions and 1 MeV electrons. Key parameters are measured in-situ and compared for th...The radiation effects of the metal-oxide-semiconductor （MOS） and the bipolar devices are characterised using 8 MeV protons, 60 MeV Br ions and 1 MeV electrons. Key parameters are measured in-situ and compared for the devices. The ionising and nonionising energy losses of incident particles are calculated using the Geant4 and the stopping and range of ions in matter code. The results of the experiment and energy loss calculation for different particles show that different incident particles may give different contributions to MOS and bipolar devices. The irradiation particles, which cause a larger displacement dose within the same chip depth of bipolar devices at a given total dose, would generate more severe damage to the voltage parameters of the bipolar devices. On the contrary, the irradiation particles, which cause larger ionising damage in the gate oxide, would generate more severe damage to MOS devices. In this investigation, we attempt to analyse the sensitivity to radiation damage of the different parameter of the MOS and bipolar devices by comparing the irradiation experimental data and the calculated results using Geant4 and SRIM code.展开更多
We perform a research of the influence of atomic electrons correlation to some characteristics of the (e,2e) process on helium. The Hilleraas type J-matrix approach was used for numerical calculations.
The ionisation of Rydberg helium atoms in an electric field above the classical ionisation threshold has been examined using the semiclassical method, with particular emphasis on discussing the influence of the core s...The ionisation of Rydberg helium atoms in an electric field above the classical ionisation threshold has been examined using the semiclassical method, with particular emphasis on discussing the influence of the core scattering on the escape dynamics of electrons. The results show that the Rydberg helium atoms ionise by emitting a train of electron pulses. Unlike the case of the ionisation of Rydberg hydrogen atom in parallel electric and magnetic fields, where the pulses of the electron are caused by the external magnetic field, the pulse trains for Rydberg helium atoms are created through core scattering. Each peak in the ionisation rate corresponds to the contribution of one core-scattered combination trajectory. This fact further illustrates that the ionic core scattering leads to the chaotic property of the Rydberg helium atom in external fields. Our studies provide a simple explanation for the escape dynamics in the ionisation of nonhydrogenic atoms in external fields.展开更多
The 1^10^＋ 1^1（-1）^＋and 1^1（2）^＋ states of the helium atom in the magnetic field regime between 0 and 100 a.u. are studied using a full configuration-interaction （CI） approach. The total energies, derivatives...The 1^10^＋ 1^1（-1）^＋and 1^1（2）^＋ states of the helium atom in the magnetic field regime between 0 and 100 a.u. are studied using a full configuration-interaction （CI） approach. The total energies, derivatives of the total energy with respect to the magnetic field and ionisation energies are calculated with Hylleraas-like functions in spherical coordinates in low to intermediate fields and Hylleraas Caussian functions in cylindrical coordinates in intermediate to high fields, respectively. In intermediate fields, the total energies and ionisation energies are determined in terms of Hermite interpolation, based on the results obtained with the two above-mentioned basis functions. Calculations show that the current method can produce lower total energies and larger ionisation energies, and make the two ionisation energy curves obtained with the two above-mentioned basis functions join smoothly in intermediate fields. Comparisons are also made with previous works.展开更多
99Tc is a fission product, and it has high fission yield (6%) and very long half-life (2.1×105 a). With the movement of nucleus, the concentration of 99Tc is increasing in the circumstance. So it's important ...99Tc is a fission product, and it has high fission yield (6%) and very long half-life (2.1×105 a). With the movement of nucleus, the concentration of 99Tc is increasing in the circumstance. So it's important to measure the concentration of 99Tc in the circumstance, and accelerator mass spectrometry (AMS) might be the best method for 99Tc measurement. The 93Nb is used for AMS instrument normalization, sample matrix. And we used the difference of energy loss and deducting the isotope to measure the 99Tc in a series of standard samples. And the results show that the AMS is the feasible measurement method.展开更多
AIM： To identify a multi serum protein pattern as well as single protein markers using surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry （SELDI-TOF-MS） for detection and differentiation ...AIM： To identify a multi serum protein pattern as well as single protein markers using surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry （SELDI-TOF-MS） for detection and differentiation of liver fibrosis （F1-F2）, liver cirrhosis （F4） and hepatocellular carcinoma （HCC） in patients with chronic hepatitis C virus （HCV）. METHODS： Serum samples of 39 patients with F1/F2 fibrosis, 44 patients with F4 fibrosis, 34 patients with HCC were applied to CM10 arrays and analyzed using the SELDI-TOF ProteinChip System （PBS-Ⅱc; Ciphergen Biosystems） after anion-exchange fractionation. All patients had chronic hepatitis C and histologically confirmed fibrosis stage/HCC. Data were analyzed for protein patterns by multivariate statistical techniques and artificial neural networks. RESULTS： A 4 peptide/protein multimarker panel （7486, 12843, 44293 and 53598 Da） correctly identified HCCs with a sensitivity of 100% and specificity of 85% in a two way-comparison of HCV-cirrhosis versus HCV-HCC training samples （AUROC 0.943）. Sensitivity and specificity for identification of HCC were 68% and 80% for random test samples. Cirrhotic patients could be discriminated against patients with F1 or F2 fibrosis using a 5 peptide/protein multimarker pattern （2873, 6646, 7775, 10525 and 67867 Da） with a specificity of 100% and a sensitivity of 85% in training samples （AUROC 0.976） and a sensitivity and specificity of 80% and 67% for random test samples. Combination of the biomarker classifiers with APR/score and alfa-fetopotein （AFP） improved the diagnostic performance. The 6646 Da marker protein for liver fibrosis was identified as apolipoprotein C-I. CONCLUSION： SELDI-TOF-MS technology combined with protein pattern analysis seems a valuable approach for the identification of liver cirrhosis and hepatocellular carcinoma in patients with chronic hepatitis C. Host probably a combination of different serum markers will help to identify liver cirrhosis and early-stage hep展开更多
文摘In this work,the results of an experimental study of the impulse characteristic of practical ground electrodes consisting of horizontal conductors of various lengths and full-scale tower footings were reported.These electrodes were installed at an outdoor test site having nonuniform soil,with equipment facilities for generating low-and high-magnitude impulse currents.The tests on the horizontal electrode were used to determine the effective length,the voltage and current distribution along the electrode length and the effect of the injection point along the electrode.The tests on the tower footings were used to determine impulse resistance and demonstrate its non-linear variation with current magnitude.Computer simulations of the test electrodes using the electromagnetic field method showed good agreement with the measured result.
基金supported by the National Natural Science Foundation of China(21822107,21571115,21827801,21671172)the Natural Science Foundation of Shandong Province(JQ201803,ZR2017MB061)+2 种基金the Taishan Scholar Project of Shandong Province of Chinathe Qilu Youth Scholar Funding of Shandong Universitythe Fundamental Research Funds of Shandong University(104.205.2.5)
文摘The combination of CrO4^2-anion and N,N′-dimethylformamide(DMF)-containing solvent helps to stabilize an atom-precise ultrasmall Ag6 kernel into a 52-nuclei silver shell,giving a core-shell Ag6@Ag52 wheel-like structure(SD/Ag58b).The solution behavior and photocurrent response property were investigated in details.
文摘In the present study the first 20 microatoms of the periodic table are named as bioatoms, since they are needed for biochemical functions and services to life itself. The rationale behind this project is the detailed analysis of the ionization energy of the electrons in the inside of the bioatoms and their orderly arrangement at specific positions. Such position of the electrons is harmonized with the succession of their energy values in their logarithmic curves. The compelling arrangement of each electron at a particular place would not be feasible in the absence of an energy offset, which is a proton. The latter would hold electrons on their proper position. These fundamental aspects of our project receive such strong support from the quantum theory, according to which it is the electromagnetic interaction between electrons and protons by the exchange of photons, which hold them together in the atoms. According to our proposed model, the protons of the aforementioned proton—electron twins, are distributed on distinct positions which are the junctions of a primary network, coupled with their electrons, in a secondary network. The geometry and distance of the protons, in the plexus, is constant and is calculated at 8, 42 ?. This was estimated by a mathematical analysis of the proposed model, as discussed further. Our study has shown that electrons in the specific positions are moving in a symmetrical oscillation in the length of a channel, in vacuum, under the Coulomb forces. Moreover, the chemical evidence suggests that electrons, in an atom, have their own separate orbit, and that these orbits are closely interrelated.
文摘GC-FID methods for the analysis of Petroleum hydrocarbons were developed and optimised. Contamination of soil from the Niger Delta was investigated about 40 days after crude oil spillage from the Shell Petroleum marginal well head. Soil samples and controls were collected at depths of 0 - 15 cm, 15 - 30 cm and 30 - 60 cm. Samples were analysed using gas chromatography fitted with a flame ionisation detector. Penetration and migration of C10-C26 and C26-C34 hydrocarbons through the soil layers were assessed by cluster analysis to determine the spatial distribution, penetration and similarity of these compounds over the contaminated area. The results also indicated elevated levels of total hydrocarbon contents when compared with the reference sites. Recommendations are made to carefully monitor and remediate the environment.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10774162)
文摘In the ionisation of Rydberg hydrogen atoms near a metal surface, the electron will escape from the nucleus and arrive at the detector in a time sequence. This probability flux train relies on the initial electron wave packet irradiated by the laser pulse. For simplicity, the laser pulse is usually simplified to a delta function in energy domain, resulting in a sharp initial arrival time with an exponentially decaying tail at the detector. Actually and semiclassically, the initial outgoing wave should be modeled as an ensemble of trajectories propagating away from the atomic core in all directions with a range of launch times and a range of energies. In this case, each pulse in the pulse train is averaged out rather than a sharp profile. We examine how energy and time averaging of the electron wave packet affects the resolution of escaping electron pulses and study the energy dependence of the arrival time for each pulse in the ionisation train. An optimization condition for the laser pulse shape to generate narrow ionisation electron pulse in the train is obtained. The ionisation rates with various excitation energy are calculated also, which show the excitation to higher N Rydberg states will narrow the electron pulse as well.
基金Project supported by the National Basis Research Program of China (Grant No. 61343)
文摘The radiation effects of the metal-oxide-semiconductor （MOS） and the bipolar devices are characterised using 8 MeV protons, 60 MeV Br ions and 1 MeV electrons. Key parameters are measured in-situ and compared for the devices. The ionising and nonionising energy losses of incident particles are calculated using the Geant4 and the stopping and range of ions in matter code. The results of the experiment and energy loss calculation for different particles show that different incident particles may give different contributions to MOS and bipolar devices. The irradiation particles, which cause a larger displacement dose within the same chip depth of bipolar devices at a given total dose, would generate more severe damage to the voltage parameters of the bipolar devices. On the contrary, the irradiation particles, which cause larger ionising damage in the gate oxide, would generate more severe damage to MOS devices. In this investigation, we attempt to analyse the sensitivity to radiation damage of the different parameter of the MOS and bipolar devices by comparing the irradiation experimental data and the calculated results using Geant4 and SRIM code.
文摘We perform a research of the influence of atomic electrons correlation to some characteristics of the (e,2e) process on helium. The Hilleraas type J-matrix approach was used for numerical calculations.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.10604045and11074104)the University Science and Technology Planning Program of Shandong Province of China(Grant No.J09LA02)the Discipline Construction Fund of Ludong University of China
文摘The ionisation of Rydberg helium atoms in an electric field above the classical ionisation threshold has been examined using the semiclassical method, with particular emphasis on discussing the influence of the core scattering on the escape dynamics of electrons. The results show that the Rydberg helium atoms ionise by emitting a train of electron pulses. Unlike the case of the ionisation of Rydberg hydrogen atom in parallel electric and magnetic fields, where the pulses of the electron are caused by the external magnetic field, the pulse trains for Rydberg helium atoms are created through core scattering. Each peak in the ionisation rate corresponds to the contribution of one core-scattered combination trajectory. This fact further illustrates that the ionic core scattering leads to the chaotic property of the Rydberg helium atom in external fields. Our studies provide a simple explanation for the escape dynamics in the ionisation of nonhydrogenic atoms in external fields.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10874133)
文摘The 1^10^＋ 1^1（-1）^＋and 1^1（2）^＋ states of the helium atom in the magnetic field regime between 0 and 100 a.u. are studied using a full configuration-interaction （CI） approach. The total energies, derivatives of the total energy with respect to the magnetic field and ionisation energies are calculated with Hylleraas-like functions in spherical coordinates in low to intermediate fields and Hylleraas Caussian functions in cylindrical coordinates in intermediate to high fields, respectively. In intermediate fields, the total energies and ionisation energies are determined in terms of Hermite interpolation, based on the results obtained with the two above-mentioned basis functions. Calculations show that the current method can produce lower total energies and larger ionisation energies, and make the two ionisation energy curves obtained with the two above-mentioned basis functions join smoothly in intermediate fields. Comparisons are also made with previous works.
文摘99Tc is a fission product, and it has high fission yield (6%) and very long half-life (2.1×105 a). With the movement of nucleus, the concentration of 99Tc is increasing in the circumstance. So it's important to measure the concentration of 99Tc in the circumstance, and accelerator mass spectrometry (AMS) might be the best method for 99Tc measurement. The 93Nb is used for AMS instrument normalization, sample matrix. And we used the difference of energy loss and deducting the isotope to measure the 99Tc in a series of standard samples. And the results show that the AMS is the feasible measurement method.
基金Supported by a research grant of the Jurgen Manchot Stiftung
文摘AIM： To identify a multi serum protein pattern as well as single protein markers using surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry （SELDI-TOF-MS） for detection and differentiation of liver fibrosis （F1-F2）, liver cirrhosis （F4） and hepatocellular carcinoma （HCC） in patients with chronic hepatitis C virus （HCV）. METHODS： Serum samples of 39 patients with F1/F2 fibrosis, 44 patients with F4 fibrosis, 34 patients with HCC were applied to CM10 arrays and analyzed using the SELDI-TOF ProteinChip System （PBS-Ⅱc; Ciphergen Biosystems） after anion-exchange fractionation. All patients had chronic hepatitis C and histologically confirmed fibrosis stage/HCC. Data were analyzed for protein patterns by multivariate statistical techniques and artificial neural networks. RESULTS： A 4 peptide/protein multimarker panel （7486, 12843, 44293 and 53598 Da） correctly identified HCCs with a sensitivity of 100% and specificity of 85% in a two way-comparison of HCV-cirrhosis versus HCV-HCC training samples （AUROC 0.943）. Sensitivity and specificity for identification of HCC were 68% and 80% for random test samples. Cirrhotic patients could be discriminated against patients with F1 or F2 fibrosis using a 5 peptide/protein multimarker pattern （2873, 6646, 7775, 10525 and 67867 Da） with a specificity of 100% and a sensitivity of 85% in training samples （AUROC 0.976） and a sensitivity and specificity of 80% and 67% for random test samples. Combination of the biomarker classifiers with APR/score and alfa-fetopotein （AFP） improved the diagnostic performance. The 6646 Da marker protein for liver fibrosis was identified as apolipoprotein C-I. CONCLUSION： SELDI-TOF-MS technology combined with protein pattern analysis seems a valuable approach for the identification of liver cirrhosis and hepatocellular carcinoma in patients with chronic hepatitis C. Host probably a combination of different serum markers will help to identify liver cirrhosis and early-stage hep
