Towards implanted deep brain stimulation(D B S):The human brain i s a complex network of 86 billion neurons and 85 billion nonneuronal cells and they are coordinated in a well-defined ratio(1:1)which is required for d...Towards implanted deep brain stimulation(D B S):The human brain i s a complex network of 86 billion neurons and 85 billion nonneuronal cells and they are coordinated in a well-defined ratio(1:1)which is required for desired body functions.The connectivity among neuronal cells secretes neurotransmitters(e.g.,dopamine)to establish a perfect connection between the brain and a peripheral system i.e.,motor coordination.展开更多
Accurate regulation of two-dimensional materials has become an effective strategy to develop a wide range of catalytic applications.The introduction of heterogeneous components has a significant impact on the performa...Accurate regulation of two-dimensional materials has become an effective strategy to develop a wide range of catalytic applications.The introduction of heterogeneous components has a significant impact on the performance of materials,which makes it difficult to discover and understand the structure-property relationships at the atomic level.Here,we developed a novel and efficient ensemble learning classifier with synthetic minority oversampling technique(SMOTE) to discover all possible arsenene catalysts with implanted heteroatoms for hydrogen evolution reaction(HER).A total of 850 doped arsenenes were collected as a database and 140 modified arsenene materials with different doping atoms and doping sites were identified as promising candidate catalysts for HER,with a machine learning prediction accuracy of 81%.Based on the results of machine learning,we proposed 13 low-cost and easily synthesized two-dimensional Fe-doped arsenene catalytic materials that are expected to contribute to high-efficient HER.The proposed ensemble method achieved high prediction accuracy,but millions of times faster to predict Gibbs free energies and only required a small amount of data.This study indicates that the presented ensemble learning classifier is capable of screening high-efficient catalysts,and can be further extended to predict other two-dimensional catalysts with delicate regulation.展开更多
Ion implantation induced damage in GaSb and its removal by rapid thermal annealing(RTA)have been investigated by Raman spectroscopy.The evolution of the Raman modes as a function of implantation fluence,annealing temp...Ion implantation induced damage in GaSb and its removal by rapid thermal annealing(RTA)have been investigated by Raman spectroscopy.The evolution of the Raman modes as a function of implantation fluence,annealing temperature and time has been analyzed.Results indicate that a lattice quality that is close to as-grown GaSb has been obtained by annealing the implanted samples at 500℃for 45 s.However,consequent surface analyses by scanning electron microscope(SEM)and atomic force microscope(AFM)show that a heavily perturbed layer contains voids due to the outdifiusion of Sb atoms on the surface remains.Mechanism of the damage recovery and the structure of the implanted layer are discussed based on the experimental results.展开更多
AIM To determine the activities ofpolysaccharide extracts from Flammulina velutipes (Curt. ex Fr. ) Sing (FV), Lentinusedodes (LE) and Agaricus bisporus Sing (AB)on the proliferation of human hepatoma SMMC-7721 cells ...AIM To determine the activities ofpolysaccharide extracts from Flammulina velutipes (Curt. ex Fr. ) Sing (FV), Lentinusedodes (LE) and Agaricus bisporus Sing (AB)on the proliferation of human hepatoma SMMC-7721 cells in vitro and on mouse implanted S-180tumors in vivo.METHODS The polysaccharide extracts were isolated from the fruit bodies of FV, LE and AB by the methods of hot-water extraction, Sevag’sremoval of proteins, ethanol precipitation,trypsin digestion and ethanol fractionalprecipitation. Human hepatoma SMMC-7721 cells were treated with 50 mg/L Polysaccharide extracts, and the mitosis index, mitochondria activity and cell proliferation were detected at different times in both control and experimental groups. The mice with S-180 implanted tumors were injected with the polysaccharide extracts at 24 mg/ kg body weight for 9 d and the tumorweight was measured on the 15th day.RESULTS The mitosis index of hepatoma cells in vitro could be significantly decreased by treatment with the polysaccharide extracts fromthe three kinds of edible fungi (P < 0 .005 ). Thecell numbers and mitochondria activity of SMMC7721 cells treated with polysaccharide extracts were lower than those in control groups (P <0.005). The inhibition rates of polysaccharide extracts against implanted S-180 tumors in mice were 52.8%, 56.6% and 51 .9% respectivelycompared with that in c0ntrol gr0ups.CONCLUSI0N The POIysaccharide extractsfrom the three kinds of edible fungi could inhibitnot only the Cultured malignant cells in vitfO butalso impIanted Sl80 tum0r i0 vivo.展开更多
The maize pollens were implanted with seven different doses of 30 keV N+ beam respectively, The genomic DNA polymorphism from treated pollens were analyzed with 104 primers by using RAPD respectively. The results show...The maize pollens were implanted with seven different doses of 30 keV N+ beam respectively, The genomic DNA polymorphism from treated pollens were analyzed with 104 primers by using RAPD respectively. The results showed that N^+ beam-induced mutation of maize pollens can result in the change of their DNA bases. The mutation is not properly random and its frequency increases with a rise in 30 keV N+ beam doses. It is conformed with A-G transformation, which is one of the most important factors in DNA bases induced by N+ beam.展开更多
Radiation-induced defect annealing in He^+ ion-implanted 4 H-SiC via H^+ ion irradiation is investigated by Raman spectroscopy. There are 4 H-SiC wafers irradiated with 230 keV He^+ ions with fluences ranging from 5.0...Radiation-induced defect annealing in He^+ ion-implanted 4 H-SiC via H^+ ion irradiation is investigated by Raman spectroscopy. There are 4 H-SiC wafers irradiated with 230 keV He^+ ions with fluences ranging from 5.0×10^(15) cm^(-2)to 2.0×10^(16) cm^(-2) at room temperature. The post-implantation samples are irradiated by 260 keV H^+ ions at a fluence of 5.0×10^(15) cm^(-2) at room temperature. The intensities of Raman lines decrease after He implantation,while they increase after H irradiation. The experimental results present that the magnitude of Raman line increment is related to the concentration of pre-existing defects formed by He implantation. A strong new peak located near 966 cm^(-1), which is assigned to 3 C-SiC LO(Γ) phonon, is found in the He-implanted sample with a fluence of 5.0×10^(15) cm^(-2) followed by H irradiation. However, for the He-implanted sample with a fluence of2.0×10^(16) cm^(-2) followed by H irradiation, no 3 C-SiC phonon vibrations are found. The detailed reason for H irradiation-induced phase transformation in the He-implanted 4 H-SiC is discussed.展开更多
We report on a study of terahertz(THz) generation using implanted In Ga As photomixers and multi-wavelength quantum dot lasers. We carry out In Ga As materials growth, optical characterization, device design and fabri...We report on a study of terahertz(THz) generation using implanted In Ga As photomixers and multi-wavelength quantum dot lasers. We carry out In Ga As materials growth, optical characterization, device design and fabrication, and photomixing experiments. This approach is capable of generating a comb of electromagnetic radiation from microwave to terahertz. For shortening photomixer carrier lifetime, we employ proton implantation into an epitaxial layer of lattice matched In Ga As grown on InP. Under a 1.55 μm multimode In GaAs/In GaAsP quantum dot laser excitation, a frequency comb with a constant frequency spacing of 50 GHz generated on the photomixer is measured, which corresponds to the beats of the laser longitudinal modes. The measurement is performed with a Fourier transform infrared spectrometer. This approach affords a convenient method to achieve a broadband multi-peak coherent THz source.展开更多
Rapid thermal annealing (RTA) of Si^+-implanted SI-GaAs was studied in an annealing system using a halogen lamp heater.Good electrical properties in activated layers were achieved. We found that the co-implantation of...Rapid thermal annealing (RTA) of Si^+-implanted SI-GaAs was studied in an annealing system using a halogen lamp heater.Good electrical properties in activated layers were achieved. We found that the co-implantation of phosphorus (P^+) with Si^+ intoSI-GaAs can improve the mobility of ion implanted layer. Hall mobility of 4600～4700 cm^2/V. s and activation efficiencies of75～85% were obtained. These results are better than those obtained from the samples without P^+ co-implantation. Deep leveltransient spectroscopy (DLTS) measurements showed that the number of deep levels and their concentrations decreased. Wethink that the P atoms occupy the As vacancies and enhance the activation efficiency and the average Hall mobility. GaAsMESFETs with 0.5 W output power and associated gain of 3.5 dB at 6 GHz were obtained by this method.展开更多
Implantations of 100 keV In ions to high dose of 6 ×1016 In/cm2 were performed into a-axis oriented crystals of Al2O3 held at a liquid nitrogen temperature. The implantation produced about 80nm thick amorphous su...Implantations of 100 keV In ions to high dose of 6 ×1016 In/cm2 were performed into a-axis oriented crystals of Al2O3 held at a liquid nitrogen temperature. The implantation produced about 80nm thick amorphous surface layer. Isothermal annealing in flowing Ar gas ambient was done at the temperatures of 600, 700, 800, and 900℃ . Rutherford backscattering and channeling (RBS-C), scanning electron microscope (SEM) and reflection high energy electron diffraction (RHEED) have been employed to investigate the annealing behaviors.The indium shows anomalous diffusion in amorphous layer. The migration of indium was composed of two parts: (a) some broadening of In profile corresponding to diffusion within the amorphous layer, (b) segregation of In to surface to form In2O3 which appears as islands on the surface. When the ambient is made oxygen free, the segregated In is lost by evaporation at the surface.展开更多
·AIM:To establish a new method to record visual evoked potential of rats and this method was applied to retinal cone degeneration (RCD) and congenital stationary night blindness (CSNB) rats to see whether it is f...·AIM:To establish a new method to record visual evoked potential of rats and this method was applied to retinal cone degeneration (RCD) and congenital stationary night blindness (CSNB) rats to see whether it is feasible.·METHODS:After anesthesia,the rats scalp surface was exposed and two stainless screws were implanted at 4mm in front of and 8mm behind Bregma.The front one was reference electrode and the latter one was recording electrode.The ground electrode was joined to the tail.And we recorded VEP of scotopic adaptation and photopic adaptation (The stimulus intensity of light :0.011,0.035,0.11,0.35,1.1 and 3.5cd·s/m2.They were all overlapped for 100 times.There were 2-5minutes intervals between different intensities.The frequency of stimulation was 1Hz and time course was 300 milliseconds).A week later,we recorded the VEP again in the same conditions.·RESULTS:The rats who were implanted with electrodes could live longer.When they were recorded,there was no disturbance and the waveforms were very clear and steady.There was no difference between the waveforms recorded by conventional method and those by implanted electrodes while the amplitude of new method was larger than conventional.We could get the same conclusion in RCD and CSNB rats.·CONCLUSION:Since the electrodes can be kept on the scalp for a longer time,we can not only observe dynamic changes of VEP but also observe the long-duration patho-logical changes in the rats.Because the positions of recording and reference electrodes were fixed,the system error can be reduced and the repeatability of experiments increased.·展开更多
Hydrogen contents and its depth profiles, obtained by nuclear reaction induced by fluorine ion, have been investigated for a series of thermal annealed amorphous silicon and implanted amorphous carbon (diamond-like ca...Hydrogen contents and its depth profiles, obtained by nuclear reaction induced by fluorine ion, have been investigated for a series of thermal annealed amorphous silicon and implanted amorphous carbon (diamond-like carbon) films. For dual layer amorphous silicon films, it is shown that hydrogen of either a-Si:H or a-SiNx:H sublayer moves obviously at different annealing conditions. For diamond-like carbon (DLC) films, measurements show that, by argon implantation, hydrogen contents decrease obviously with the increase of implanting dose. The decrease of hydrogen contents results in the decrease of diamond- like (SP3) and graphite-like (SP2) components of DLC films. But, the ratios of SP2 and SP3 increased, and the resistivities decrease with the increase of implanting dose.展开更多
1 Introduction Virtually all cardiovascular diseases including arrhythmias,valve disease,coronary artery disease and heart failure(HF)are increasingly common with advancing age.^([1])Age and disease-related changes in...1 Introduction Virtually all cardiovascular diseases including arrhythmias,valve disease,coronary artery disease and heart failure(HF)are increasingly common with advancing age.^([1])Age and disease-related changes in the heart including fibrosis in the atrial and ventricular myocardium and conduction system,scar tissue from myocardial infarction or other cardiomyopathic processes,increased inflammatory cytokines and changes to ion channels are just some of the factors that predispose older adults to arrhythmias.^([2]).展开更多
The PA1010 was implanted with 450 keV N+ ions to three doses of 5× 1014 cm-2 , 2.5× 1015 cm-2 and 1.25 × 1016 cm-2. The friction and wear behaviors of the ion implanted PA1010 disks rubbing with two cer...The PA1010 was implanted with 450 keV N+ ions to three doses of 5× 1014 cm-2 , 2.5× 1015 cm-2 and 1.25 × 1016 cm-2. The friction and wear behaviors of the ion implanted PA1010 disks rubbing with two ceramic (ZrO2 and Si3N4) balls were studied using a pin-on-disk tribometer under dry friction. The results shows that the wear resistance of PA1010 is increased with the increasing implantation doses. The adhesion, plastic deformation and plow groove are wearing mechanisms for un-implanted PA1010, while abrasive wear for implanted PA1010.展开更多
As ion implanted damage of silicon was removed by Rapid ThermalAnnealing(RTA)using Model KST-1 RTA appakatus.Removal ofdamage and dopant redistribution were investigated by RutherfordBackscattering Spectra(RBS)and Ext...As ion implanted damage of silicon was removed by Rapid ThermalAnnealing(RTA)using Model KST-1 RTA appakatus.Removal ofdamage and dopant redistribution were investigated by RutherfordBackscattering Spectra(RBS)and Extended Resistance.Sheet resistanceand carrier Hall mobility was mesaured by Van der Panw method.展开更多
Buried Si<sub>3</sub>N<sub>4</sub> layer is formed by hitrogen ion implanted silicoh with high energy （400Key） and high dose (1×10<sup>18</sup>/cm<sup>2</sup>). T...Buried Si<sub>3</sub>N<sub>4</sub> layer is formed by hitrogen ion implanted silicoh with high energy （400Key） and high dose (1×10<sup>18</sup>/cm<sup>2</sup>). The unimplanted single crystal zone is used as seed crystal. Seed inducing recrystallization is carried out by autoscanning Nd: YAG CW laser annealing. We got a large area SOI structure sample.展开更多
Mo ions are implanted into aluminium with a high ion flux and high dose at elevated temperatures of 300℃,400℃and 500℃.X-ray diffraction spectra show that the Al12Mo phases are formed.Rutherford backscattering spect...Mo ions are implanted into aluminium with a high ion flux and high dose at elevated temperatures of 300℃,400℃and 500℃.X-ray diffraction spectra show that the Al12Mo phases are formed.Rutherford backscattering spectroscopy indicates that a profile of Mo appears in Al around the depth of 550nm and with an atomic concentration of~7%,when Mo is implanted to the dose of 3×10^(17)/cm^(2) with an ion flux of 45μA/cm^(2)(400℃).If the dose increases to 1×10^(18)/cm^(2) at the same ion flux,the penetration of Mo ions in Al can reach a depth of 2μm,which is greater than the ion project range Rp(52.5nm).The results show that anomalous diffusion takes place.Owing to the intense atom collision cascades,the diffusion coefficient increases greatly with the increase of the ion flux and dose.The Mo diffusion coefficients in Al are calculated.The Mo retained dose in A1 increases obviously with the increase of the ion flux.展开更多
In this paper, damages and annealing effects of X,Y and Z cut LiNbO-3 implanted by 350keV high energy Ti (1.5 x 10<sup>17</sup> / cm<sup>2</sup>) are studied. The surface damages of X,Y cut pla...In this paper, damages and annealing effects of X,Y and Z cut LiNbO-3 implanted by 350keV high energy Ti (1.5 x 10<sup>17</sup> / cm<sup>2</sup>) are studied. The surface damages of X,Y cut plates are nearly amorphous, but the surface damage of Z cut does not reach saturation. Radiation damage is mainly due to Nb moving atoms and Ti atoms occupy the interstitial sites. By annealing the sample at 1000℃, most damage is removed from the boundary between implanted layer and LiNbO<sub>3</sub> base to surface.展开更多
Broad beans were divided into six groups and implanted with N+ beam of 30 KeV, 8 × 1016/cm2 per time for various radiating times respectively. Besides the statistics of its vigor of germination, the M1 root-tip c...Broad beans were divided into six groups and implanted with N+ beam of 30 KeV, 8 × 1016/cm2 per time for various radiating times respectively. Besides the statistics of its vigor of germination, the M1 root-tip cells of these broad beans were systematically analyzed on their changes in mitotic percentage, morphology and behavior of chromosomes, along with the structure o f cytoskeletons, including microtubule and intermediate filament. Based on all results of these studies, our opinions have been expressed in the report on the mechanism of low-energy N+ beams effecting on higher dicotyledons such as broad beau.展开更多
Due to its superior mechanical and electrical properries,silicon carbide(SiC)is a technologically important material in the development of high-temperature,high-power,high-frequency electronic devices and in nuclear e...Due to its superior mechanical and electrical properries,silicon carbide(SiC)is a technologically important material in the development of high-temperature,high-power,high-frequency electronic devices and in nuclear energy and waste technologies.In the former cases,helium implantation can be used to introduce展开更多
基金Authors acknowledge respective affiliated institutions for providing facilities and support.
文摘Towards implanted deep brain stimulation(D B S):The human brain i s a complex network of 86 billion neurons and 85 billion nonneuronal cells and they are coordinated in a well-defined ratio(1:1)which is required for desired body functions.The connectivity among neuronal cells secretes neurotransmitters(e.g.,dopamine)to establish a perfect connection between the brain and a peripheral system i.e.,motor coordination.
基金supported by the National Key R&D Program of China(No.2021YFC2100100)the National Natural Science Foundation of China(No.21901157)the Shanghai Science and Technology Project(No.21JC1403400)。
文摘Accurate regulation of two-dimensional materials has become an effective strategy to develop a wide range of catalytic applications.The introduction of heterogeneous components has a significant impact on the performance of materials,which makes it difficult to discover and understand the structure-property relationships at the atomic level.Here,we developed a novel and efficient ensemble learning classifier with synthetic minority oversampling technique(SMOTE) to discover all possible arsenene catalysts with implanted heteroatoms for hydrogen evolution reaction(HER).A total of 850 doped arsenenes were collected as a database and 140 modified arsenene materials with different doping atoms and doping sites were identified as promising candidate catalysts for HER,with a machine learning prediction accuracy of 81%.Based on the results of machine learning,we proposed 13 low-cost and easily synthesized two-dimensional Fe-doped arsenene catalytic materials that are expected to contribute to high-efficient HER.The proposed ensemble method achieved high prediction accuracy,but millions of times faster to predict Gibbs free energies and only required a small amount of data.This study indicates that the presented ensemble learning classifier is capable of screening high-efficient catalysts,and can be further extended to predict other two-dimensional catalysts with delicate regulation.
基金the National Natural Science Foundation of China(No.61904175)Jiangsu Provincial Key Research and Development Program(No.BE2020033)。
文摘Ion implantation induced damage in GaSb and its removal by rapid thermal annealing(RTA)have been investigated by Raman spectroscopy.The evolution of the Raman modes as a function of implantation fluence,annealing temperature and time has been analyzed.Results indicate that a lattice quality that is close to as-grown GaSb has been obtained by annealing the implanted samples at 500℃for 45 s.However,consequent surface analyses by scanning electron microscope(SEM)and atomic force microscope(AFM)show that a heavily perturbed layer contains voids due to the outdifiusion of Sb atoms on the surface remains.Mechanism of the damage recovery and the structure of the implanted layer are discussed based on the experimental results.
文摘AIM To determine the activities ofpolysaccharide extracts from Flammulina velutipes (Curt. ex Fr. ) Sing (FV), Lentinusedodes (LE) and Agaricus bisporus Sing (AB)on the proliferation of human hepatoma SMMC-7721 cells in vitro and on mouse implanted S-180tumors in vivo.METHODS The polysaccharide extracts were isolated from the fruit bodies of FV, LE and AB by the methods of hot-water extraction, Sevag’sremoval of proteins, ethanol precipitation,trypsin digestion and ethanol fractionalprecipitation. Human hepatoma SMMC-7721 cells were treated with 50 mg/L Polysaccharide extracts, and the mitosis index, mitochondria activity and cell proliferation were detected at different times in both control and experimental groups. The mice with S-180 implanted tumors were injected with the polysaccharide extracts at 24 mg/ kg body weight for 9 d and the tumorweight was measured on the 15th day.RESULTS The mitosis index of hepatoma cells in vitro could be significantly decreased by treatment with the polysaccharide extracts fromthe three kinds of edible fungi (P < 0 .005 ). Thecell numbers and mitochondria activity of SMMC7721 cells treated with polysaccharide extracts were lower than those in control groups (P <0.005). The inhibition rates of polysaccharide extracts against implanted S-180 tumors in mice were 52.8%, 56.6% and 51 .9% respectivelycompared with that in c0ntrol gr0ups.CONCLUSI0N The POIysaccharide extractsfrom the three kinds of edible fungi could inhibitnot only the Cultured malignant cells in vitfO butalso impIanted Sl80 tum0r i0 vivo.
文摘The maize pollens were implanted with seven different doses of 30 keV N+ beam respectively, The genomic DNA polymorphism from treated pollens were analyzed with 104 primers by using RAPD respectively. The results showed that N^+ beam-induced mutation of maize pollens can result in the change of their DNA bases. The mutation is not properly random and its frequency increases with a rise in 30 keV N+ beam doses. It is conformed with A-G transformation, which is one of the most important factors in DNA bases induced by N+ beam.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11005130,11475229 and 91026002the Strategic Priority Research Program of Chinese Academy of Sciences under Grant No XDA03010301
文摘Radiation-induced defect annealing in He^+ ion-implanted 4 H-SiC via H^+ ion irradiation is investigated by Raman spectroscopy. There are 4 H-SiC wafers irradiated with 230 keV He^+ ions with fluences ranging from 5.0×10^(15) cm^(-2)to 2.0×10^(16) cm^(-2) at room temperature. The post-implantation samples are irradiated by 260 keV H^+ ions at a fluence of 5.0×10^(15) cm^(-2) at room temperature. The intensities of Raman lines decrease after He implantation,while they increase after H irradiation. The experimental results present that the magnitude of Raman line increment is related to the concentration of pre-existing defects formed by He implantation. A strong new peak located near 966 cm^(-1), which is assigned to 3 C-SiC LO(Γ) phonon, is found in the He-implanted sample with a fluence of 5.0×10^(15) cm^(-2) followed by H irradiation. However, for the He-implanted sample with a fluence of2.0×10^(16) cm^(-2) followed by H irradiation, no 3 C-SiC phonon vibrations are found. The detailed reason for H irradiation-induced phase transformation in the He-implanted 4 H-SiC is discussed.
基金supported in part by NSERC. HCL thanks the support by the National Ma jor Basic Research Pro jects (2011CB925603)Shanghai Municipal Ma jor Basic Research Pro ject (09DJ1400102)
文摘We report on a study of terahertz(THz) generation using implanted In Ga As photomixers and multi-wavelength quantum dot lasers. We carry out In Ga As materials growth, optical characterization, device design and fabrication, and photomixing experiments. This approach is capable of generating a comb of electromagnetic radiation from microwave to terahertz. For shortening photomixer carrier lifetime, we employ proton implantation into an epitaxial layer of lattice matched In Ga As grown on InP. Under a 1.55 μm multimode In GaAs/In GaAsP quantum dot laser excitation, a frequency comb with a constant frequency spacing of 50 GHz generated on the photomixer is measured, which corresponds to the beats of the laser longitudinal modes. The measurement is performed with a Fourier transform infrared spectrometer. This approach affords a convenient method to achieve a broadband multi-peak coherent THz source.
文摘Rapid thermal annealing (RTA) of Si^+-implanted SI-GaAs was studied in an annealing system using a halogen lamp heater.Good electrical properties in activated layers were achieved. We found that the co-implantation of phosphorus (P^+) with Si^+ intoSI-GaAs can improve the mobility of ion implanted layer. Hall mobility of 4600～4700 cm^2/V. s and activation efficiencies of75～85% were obtained. These results are better than those obtained from the samples without P^+ co-implantation. Deep leveltransient spectroscopy (DLTS) measurements showed that the number of deep levels and their concentrations decreased. Wethink that the P atoms occupy the As vacancies and enhance the activation efficiency and the average Hall mobility. GaAsMESFETs with 0.5 W output power and associated gain of 3.5 dB at 6 GHz were obtained by this method.
文摘Implantations of 100 keV In ions to high dose of 6 ×1016 In/cm2 were performed into a-axis oriented crystals of Al2O3 held at a liquid nitrogen temperature. The implantation produced about 80nm thick amorphous surface layer. Isothermal annealing in flowing Ar gas ambient was done at the temperatures of 600, 700, 800, and 900℃ . Rutherford backscattering and channeling (RBS-C), scanning electron microscope (SEM) and reflection high energy electron diffraction (RHEED) have been employed to investigate the annealing behaviors.The indium shows anomalous diffusion in amorphous layer. The migration of indium was composed of two parts: (a) some broadening of In profile corresponding to diffusion within the amorphous layer, (b) segregation of In to surface to form In2O3 which appears as islands on the surface. When the ambient is made oxygen free, the segregated In is lost by evaporation at the surface.
基金National Natural Science Foundation of China (No.30371517,30571999)
文摘·AIM:To establish a new method to record visual evoked potential of rats and this method was applied to retinal cone degeneration (RCD) and congenital stationary night blindness (CSNB) rats to see whether it is feasible.·METHODS:After anesthesia,the rats scalp surface was exposed and two stainless screws were implanted at 4mm in front of and 8mm behind Bregma.The front one was reference electrode and the latter one was recording electrode.The ground electrode was joined to the tail.And we recorded VEP of scotopic adaptation and photopic adaptation (The stimulus intensity of light :0.011,0.035,0.11,0.35,1.1 and 3.5cd·s/m2.They were all overlapped for 100 times.There were 2-5minutes intervals between different intensities.The frequency of stimulation was 1Hz and time course was 300 milliseconds).A week later,we recorded the VEP again in the same conditions.·RESULTS:The rats who were implanted with electrodes could live longer.When they were recorded,there was no disturbance and the waveforms were very clear and steady.There was no difference between the waveforms recorded by conventional method and those by implanted electrodes while the amplitude of new method was larger than conventional.We could get the same conclusion in RCD and CSNB rats.·CONCLUSION:Since the electrodes can be kept on the scalp for a longer time,we can not only observe dynamic changes of VEP but also observe the long-duration patho-logical changes in the rats.Because the positions of recording and reference electrodes were fixed,the system error can be reduced and the repeatability of experiments increased.·
文摘Hydrogen contents and its depth profiles, obtained by nuclear reaction induced by fluorine ion, have been investigated for a series of thermal annealed amorphous silicon and implanted amorphous carbon (diamond-like carbon) films. For dual layer amorphous silicon films, it is shown that hydrogen of either a-Si:H or a-SiNx:H sublayer moves obviously at different annealing conditions. For diamond-like carbon (DLC) films, measurements show that, by argon implantation, hydrogen contents decrease obviously with the increase of implanting dose. The decrease of hydrogen contents results in the decrease of diamond- like (SP3) and graphite-like (SP2) components of DLC films. But, the ratios of SP2 and SP3 increased, and the resistivities decrease with the increase of implanting dose.
文摘1 Introduction Virtually all cardiovascular diseases including arrhythmias,valve disease,coronary artery disease and heart failure(HF)are increasingly common with advancing age.^([1])Age and disease-related changes in the heart including fibrosis in the atrial and ventricular myocardium and conduction system,scar tissue from myocardial infarction or other cardiomyopathic processes,increased inflammatory cytokines and changes to ion channels are just some of the factors that predispose older adults to arrhythmias.^([2]).
基金Project(2002AA331010) supported by the Hi-tech Research and Development Program of China project(BJ2000030) supported by the Natural Science Foundation of Jiangsu Province of China
文摘The PA1010 was implanted with 450 keV N+ ions to three doses of 5× 1014 cm-2 , 2.5× 1015 cm-2 and 1.25 × 1016 cm-2. The friction and wear behaviors of the ion implanted PA1010 disks rubbing with two ceramic (ZrO2 and Si3N4) balls were studied using a pin-on-disk tribometer under dry friction. The results shows that the wear resistance of PA1010 is increased with the increasing implantation doses. The adhesion, plastic deformation and plow groove are wearing mechanisms for un-implanted PA1010, while abrasive wear for implanted PA1010.
基金The Project Supported by Nationnl Natural Science Foundation of China
文摘As ion implanted damage of silicon was removed by Rapid ThermalAnnealing(RTA)using Model KST-1 RTA appakatus.Removal ofdamage and dopant redistribution were investigated by RutherfordBackscattering Spectra(RBS)and Extended Resistance.Sheet resistanceand carrier Hall mobility was mesaured by Van der Panw method.
基金The project supported by National Natural Science Foundation of Chinapartly by USTC Foundation
文摘Buried Si<sub>3</sub>N<sub>4</sub> layer is formed by hitrogen ion implanted silicoh with high energy （400Key） and high dose (1×10<sup>18</sup>/cm<sup>2</sup>). The unimplanted single crystal zone is used as seed crystal. Seed inducing recrystallization is carried out by autoscanning Nd: YAG CW laser annealing. We got a large area SOI structure sample.
基金Supported by The National Natural Science Foundation of China under Grant Nos.59671051 and 59871003the 863 High Technology Program of China(863-715-023-02-01).
文摘Mo ions are implanted into aluminium with a high ion flux and high dose at elevated temperatures of 300℃,400℃and 500℃.X-ray diffraction spectra show that the Al12Mo phases are formed.Rutherford backscattering spectroscopy indicates that a profile of Mo appears in Al around the depth of 550nm and with an atomic concentration of~7%,when Mo is implanted to the dose of 3×10^(17)/cm^(2) with an ion flux of 45μA/cm^(2)(400℃).If the dose increases to 1×10^(18)/cm^(2) at the same ion flux,the penetration of Mo ions in Al can reach a depth of 2μm,which is greater than the ion project range Rp(52.5nm).The results show that anomalous diffusion takes place.Owing to the intense atom collision cascades,the diffusion coefficient increases greatly with the increase of the ion flux and dose.The Mo diffusion coefficients in Al are calculated.The Mo retained dose in A1 increases obviously with the increase of the ion flux.
文摘In this paper, damages and annealing effects of X,Y and Z cut LiNbO-3 implanted by 350keV high energy Ti (1.5 x 10<sup>17</sup> / cm<sup>2</sup>) are studied. The surface damages of X,Y cut plates are nearly amorphous, but the surface damage of Z cut does not reach saturation. Radiation damage is mainly due to Nb moving atoms and Ti atoms occupy the interstitial sites. By annealing the sample at 1000℃, most damage is removed from the boundary between implanted layer and LiNbO<sub>3</sub> base to surface.
文摘Broad beans were divided into six groups and implanted with N+ beam of 30 KeV, 8 × 1016/cm2 per time for various radiating times respectively. Besides the statistics of its vigor of germination, the M1 root-tip cells of these broad beans were systematically analyzed on their changes in mitotic percentage, morphology and behavior of chromosomes, along with the structure o f cytoskeletons, including microtubule and intermediate filament. Based on all results of these studies, our opinions have been expressed in the report on the mechanism of low-energy N+ beams effecting on higher dicotyledons such as broad beau.
文摘Due to its superior mechanical and electrical properries,silicon carbide(SiC)is a technologically important material in the development of high-temperature,high-power,high-frequency electronic devices and in nuclear energy and waste technologies.In the former cases,helium implantation can be used to introduce
