To compare the biodegradation of di-n-methyl pathalate by free and immobilized microbial cells. Methods The enrichment and isolation technique was used to isolate the microorganism. The PAV-entrapment method was utili...To compare the biodegradation of di-n-methyl pathalate by free and immobilized microbial cells. Methods The enrichment and isolation technique was used to isolate the microorganism. The PAV-entrapment method was utilized to immobilize the microorganisms. The scanning electron microscophy (SEM) was used to observe the growth and distribution of microbial cells immobilized inside the PVA bead gels. The GC/MS method was used to identify the main intermediates of DMP degradation. Results The microbial cells could grow quite well in PVA gel. The metabolic pathway did not change before and after immobilization of the microbial cells. The degradation rate of immobilized cells was higher than that of free cells. Conclusion The immobilized microbial cells possess advantages than free cells when applied to the biodegradation of toxic organic pollutants.展开更多
The change of electrical performances of silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) andSi bipolar junction transistor (BJT) was studied as a fumction of reactor fast neutron radiation fluence. Af...The change of electrical performances of silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) andSi bipolar junction transistor (BJT) was studied as a fumction of reactor fast neutron radiation fluence. After neutron irradia-tion, the collector current Ic and the current gain β decrease, and the base current Ib increases generally for SiGe HBT. Thehigher the neuron irradiation fluence is, the larger Ib increases. For conventional Si BJT, Ic and Ib increase as wellas β decreases much larger than SiGe HBT at the same fluence. It is shown that SiGe HBT has a larger anti-radiationthreshold and better anti-radiation perrormance than Si BJT. The mechanism of performance changes induced by irradiationwas preliminarily discussed.展开更多
High temperature vaccum evaporation is a recycling technology that includes a selective material recovering process. The fundamental research on a process of disassembling and recovering selected materials from Ni Cd ...High temperature vaccum evaporation is a recycling technology that includes a selective material recovering process. The fundamental research on a process of disassembling and recovering selected materials from Ni Cd batteries was conducted using self designed experimental apparatus. An effective recycling technology based on the evaporation phenomenon of batteries and the elements of cadmium under the laboratory condition was studied. The results show that: (1)Ni/Cd can be effectively recovered by vacuum distillation at appropriate temperature, pressure and time, and high purity cadmium (>99%) can be obtained through the process; (2)the effective distillatory temperature should be at the range of 5731 173 K; (3)the higher the evaporation temperature, the lower the purity of cadmium in condensate展开更多
A new process of enriching germanium from coal ash was developed.The process involves in mixing the coal ash and ammonium chloride and then roasting the mixture to produce germanium chloride that is then absorbed by d...A new process of enriching germanium from coal ash was developed.The process involves in mixing the coal ash and ammonium chloride and then roasting the mixture to produce germanium chloride that is then absorbed by dilute hydrochloric acid and hydrolyzed to germanium oxide.The germanium recovery reached to 80.2% at the optimum condition:mass ratio of NH4Cl/coal ash is 0.15,roasting temperature 400℃ and roasting time 90min.展开更多
The procedure of nebulization was studied with the introduction of ethanol into a lower power argon ICP. It was found that as ethanol introduced, the physical properties of solutions changed, which results in an impro...The procedure of nebulization was studied with the introduction of ethanol into a lower power argon ICP. It was found that as ethanol introduced, the physical properties of solutions changed, which results in an improvement on the nebulization efficiency. An empirical relationship between the concentration of the aerosol and the solution properties (viscosity, density, and surface tension) is presented.展开更多
To separate the cadmium and nickel resources in waste Ni-Cd batteries,a self-designed vacuum distillation recycling system was studied under laboratory conditions.The effects of system temperature,operating pressure,...To separate the cadmium and nickel resources in waste Ni-Cd batteries,a self-designed vacuum distillation recycling system was studied under laboratory conditions.The effects of system temperature,operating pressure,and time on the separation of Ni and Cd were studied respectively.The mechanism of vacuum thermal recycling was also discussed.Results show that vacuum distillation is a very effective separation method for waste Ni-Cd batteries.At a Constant pressure,the increase of temperature can improve the separating efficiency of Cd.When the temperature is 1173K,Cadmium can evaporate completely from the samples during 3h at 10Pa,The reduction of pressure in a certain range is effective to the separating of Cd from Ni-Cd batteries by vacuum distillation.展开更多
Recovery of Ni-Cd batteries was studied by a self-designed vacuum-aided recovering system under laboratory condi-tions. The fundamental research on a process of disassembling and recovering selected materials from Ni-...Recovery of Ni-Cd batteries was studied by a self-designed vacuum-aided recovering system under laboratory condi-tions. The fundamental research on a process of disassembling and recovering selected materials from Ni-Cd batterieswas conducted. The impacts of temperature, pressure and time were studied respectively. The mechanism of vac-uum thermal recovering was also discussed. The results show that: Ni-Cd batteries can be recovered effectively by vacuum-aided recovering system at 573～1173 K. At constant pressure, the increase of temperature can improve theseparating efficiency of cadmium. When the temperature is 1173 K, the cadmium can evaporate completely fromthe residue during 3 h at 10 Pa. The reduction of pressure in the certain range is effective to separate cadmium byvacuum distillation. Distillation time is a very important factor affecting separation of cadmium.展开更多
Changes of the average brightness and non-uniformity of dark output images, and quality of pictures captured under natural lighting for the color CMOS digital image sensors irradiated at different electron doses have ...Changes of the average brightness and non-uniformity of dark output images, and quality of pictures captured under natural lighting for the color CMOS digital image sensors irradiated at different electron doses have been studied in comparison to those from the γ-irradiated sensors. For the electron-irradiated sensors, the non-uniformity increases obviously and a small bright region on the dark image appears at the dose of 0.4 kGy. The average brightness increases at 0.4 kGy, increases sharply at 0.5 kGy. The picture is very blurry only at 0.6 kGy, showing the sensor undergoes severe performance degradation. Electron radiation damage is much more severe than γ radiation damage for the CMOS image sensors. A possible explanation is presented in this paper.展开更多
The change of electrical performances of 1 MeV electron irradiated silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) and Si bipolar junction transistor (BJT) was studied. After electron irradiation, bot...The change of electrical performances of 1 MeV electron irradiated silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) and Si bipolar junction transistor (BJT) was studied. After electron irradiation, both the collector current IC and the base current IB changed a little, and the current gainβ decreased a little for SiGe HBT. The higher the electron irradiation fluence was, the lower the IC decreased. For conventional Si BJT, IC and IB increased as well asβ decreased much larger than SiGe HBT under the same fluence. The contribution of IB was more important to the degradation ofβ for both SiGeHBT and Si BJT. It was shown that SiGe HBT had a larger anti-radiation threshold and better anti-radiation performance than Si BJT. The mechanism of electrical performance changes induced by irradiation was preliminarily discussed.展开更多
Microorganisms have a number of applications in the nuclear industry, which would benefit from the use of radiation-resistant microorganisms. Environmentally isolated bacteria have shown to be resistant to gamma ir- r...Microorganisms have a number of applications in the nuclear industry, which would benefit from the use of radiation-resistant microorganisms. Environmentally isolated bacteria have shown to be resistant to gamma ir- radiation up to a dose of 30,000 Gy. It has also been reported that the presence of ionizing radiation may induce ra- dio-resistance in bacteria. Recent demonstrations of the removal and immobilization of inorganic contaminants by microbial transformations, sorption and mineralization show the potential of both natural and engineered microor- ganisms as bioremedial tools. This review is to provide an overview of the application of radiation-resistant bacteria to decontamination of metal and radionuclide.展开更多
The probability of 5He particle emission has been affirmed theoretically [J.S. Zhang, Science in China G47 (2004) 137]. In order to describe the 5He emission, the theoretical formula of the double-differential cross s...The probability of 5He particle emission has been affirmed theoretically [J.S. Zhang, Science in China G47 (2004) 137]. In order to describe the 5He emission, the theoretical formula of the double-differential cross section of emitted 5He is to be established. Based on the pick-up mechanism, used for calculating the formula of d, t, 3He, α emissions, the theoretical formula of double-differential cross section of 5 He is obtained, which is expressed in the form of Legendre coefficients. In the case of low incident energies, the configuration [J.S. Zhang, Science in China G47 (2004)137; J.S. Zhang, Commun. Theor. Phys. (Beijing, China) 39 (2003) 83] is the dominant part in the reaction processes.The calculated result indicates that the forward peaked angular distribution of the composite particle emission is weaker than that of the emitted single nucleon due to pick-up nucleon from the Fermi sea. As an example, the reactions of n + 14N have been calculated, and the Legendre coefficients of d, t, 3He, α, 5He emissions are obtained respectively.The results show that the forward tendency is decided by the average momentum per nucleon in the emitted composite particles. The larger the average momentum is, the stronger the forward tendency is.展开更多
基金the National Natural Science Foundation of China (Grant No. 29637010).
文摘To compare the biodegradation of di-n-methyl pathalate by free and immobilized microbial cells. Methods The enrichment and isolation technique was used to isolate the microorganism. The PAV-entrapment method was utilized to immobilize the microorganisms. The scanning electron microscophy (SEM) was used to observe the growth and distribution of microbial cells immobilized inside the PVA bead gels. The GC/MS method was used to identify the main intermediates of DMP degradation. Results The microbial cells could grow quite well in PVA gel. The metabolic pathway did not change before and after immobilization of the microbial cells. The degradation rate of immobilized cells was higher than that of free cells. Conclusion The immobilized microbial cells possess advantages than free cells when applied to the biodegradation of toxic organic pollutants.
文摘The change of electrical performances of silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) andSi bipolar junction transistor (BJT) was studied as a fumction of reactor fast neutron radiation fluence. After neutron irradia-tion, the collector current Ic and the current gain β decrease, and the base current Ib increases generally for SiGe HBT. Thehigher the neuron irradiation fluence is, the larger Ib increases. For conventional Si BJT, Ic and Ib increase as wellas β decreases much larger than SiGe HBT at the same fluence. It is shown that SiGe HBT has a larger anti-radiationthreshold and better anti-radiation perrormance than Si BJT. The mechanism of performance changes induced by irradiationwas preliminarily discussed.
文摘High temperature vaccum evaporation is a recycling technology that includes a selective material recovering process. The fundamental research on a process of disassembling and recovering selected materials from Ni Cd batteries was conducted using self designed experimental apparatus. An effective recycling technology based on the evaporation phenomenon of batteries and the elements of cadmium under the laboratory condition was studied. The results show that: (1)Ni/Cd can be effectively recovered by vacuum distillation at appropriate temperature, pressure and time, and high purity cadmium (>99%) can be obtained through the process; (2)the effective distillatory temperature should be at the range of 5731 173 K; (3)the higher the evaporation temperature, the lower the purity of cadmium in condensate
基金This project is financially supported by the National Nature Science Foundation of China (No. 59804004) and (No.50274046)
文摘A new process of enriching germanium from coal ash was developed.The process involves in mixing the coal ash and ammonium chloride and then roasting the mixture to produce germanium chloride that is then absorbed by dilute hydrochloric acid and hydrolyzed to germanium oxide.The germanium recovery reached to 80.2% at the optimum condition:mass ratio of NH4Cl/coal ash is 0.15,roasting temperature 400℃ and roasting time 90min.
文摘The procedure of nebulization was studied with the introduction of ethanol into a lower power argon ICP. It was found that as ethanol introduced, the physical properties of solutions changed, which results in an improvement on the nebulization efficiency. An empirical relationship between the concentration of the aerosol and the solution properties (viscosity, density, and surface tension) is presented.
文摘To separate the cadmium and nickel resources in waste Ni-Cd batteries,a self-designed vacuum distillation recycling system was studied under laboratory conditions.The effects of system temperature,operating pressure,and time on the separation of Ni and Cd were studied respectively.The mechanism of vacuum thermal recycling was also discussed.Results show that vacuum distillation is a very effective separation method for waste Ni-Cd batteries.At a Constant pressure,the increase of temperature can improve the separating efficiency of Cd.When the temperature is 1173K,Cadmium can evaporate completely from the samples during 3h at 10Pa,The reduction of pressure in a certain range is effective to the separating of Cd from Ni-Cd batteries by vacuum distillation.
文摘Recovery of Ni-Cd batteries was studied by a self-designed vacuum-aided recovering system under laboratory condi-tions. The fundamental research on a process of disassembling and recovering selected materials from Ni-Cd batterieswas conducted. The impacts of temperature, pressure and time were studied respectively. The mechanism of vac-uum thermal recovering was also discussed. The results show that: Ni-Cd batteries can be recovered effectively by vacuum-aided recovering system at 573～1173 K. At constant pressure, the increase of temperature can improve theseparating efficiency of cadmium. When the temperature is 1173 K, the cadmium can evaporate completely fromthe residue during 3 h at 10 Pa. The reduction of pressure in the certain range is effective to separate cadmium byvacuum distillation. Distillation time is a very important factor affecting separation of cadmium.
基金This project is financially supported by the Narional Natural Science Foundation of China(Nos 10375034 and 10075029) and the Basic Research Foundation of Tsinghua University (No. JC2002058).
文摘Changes of the average brightness and non-uniformity of dark output images, and quality of pictures captured under natural lighting for the color CMOS digital image sensors irradiated at different electron doses have been studied in comparison to those from the γ-irradiated sensors. For the electron-irradiated sensors, the non-uniformity increases obviously and a small bright region on the dark image appears at the dose of 0.4 kGy. The average brightness increases at 0.4 kGy, increases sharply at 0.5 kGy. The picture is very blurry only at 0.6 kGy, showing the sensor undergoes severe performance degradation. Electron radiation damage is much more severe than γ radiation damage for the CMOS image sensors. A possible explanation is presented in this paper.
基金This project is financially supported by the National Natural Science Foundation of China(No.10075029 and 69836020)National“863”Advanced Research Project of China(No.2002AA3Z1230).
文摘The change of electrical performances of 1 MeV electron irradiated silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) and Si bipolar junction transistor (BJT) was studied. After electron irradiation, both the collector current IC and the base current IB changed a little, and the current gainβ decreased a little for SiGe HBT. The higher the electron irradiation fluence was, the lower the IC decreased. For conventional Si BJT, IC and IB increased as well asβ decreased much larger than SiGe HBT under the same fluence. The contribution of IB was more important to the degradation ofβ for both SiGeHBT and Si BJT. It was shown that SiGe HBT had a larger anti-radiation threshold and better anti-radiation performance than Si BJT. The mechanism of electrical performance changes induced by irradiation was preliminarily discussed.
基金Supported by National Natural Science Foundation of China (Grant No. 50278045) and the Basic Research Fund of Tsinghua University (Grant No. JC2002054)
文摘Microorganisms have a number of applications in the nuclear industry, which would benefit from the use of radiation-resistant microorganisms. Environmentally isolated bacteria have shown to be resistant to gamma ir- radiation up to a dose of 30,000 Gy. It has also been reported that the presence of ionizing radiation may induce ra- dio-resistance in bacteria. Recent demonstrations of the removal and immobilization of inorganic contaminants by microbial transformations, sorption and mineralization show the potential of both natural and engineered microor- ganisms as bioremedial tools. This review is to provide an overview of the application of radiation-resistant bacteria to decontamination of metal and radionuclide.
文摘The probability of 5He particle emission has been affirmed theoretically [J.S. Zhang, Science in China G47 (2004) 137]. In order to describe the 5He emission, the theoretical formula of the double-differential cross section of emitted 5He is to be established. Based on the pick-up mechanism, used for calculating the formula of d, t, 3He, α emissions, the theoretical formula of double-differential cross section of 5 He is obtained, which is expressed in the form of Legendre coefficients. In the case of low incident energies, the configuration [J.S. Zhang, Science in China G47 (2004)137; J.S. Zhang, Commun. Theor. Phys. (Beijing, China) 39 (2003) 83] is the dominant part in the reaction processes.The calculated result indicates that the forward peaked angular distribution of the composite particle emission is weaker than that of the emitted single nucleon due to pick-up nucleon from the Fermi sea. As an example, the reactions of n + 14N have been calculated, and the Legendre coefficients of d, t, 3He, α, 5He emissions are obtained respectively.The results show that the forward tendency is decided by the average momentum per nucleon in the emitted composite particles. The larger the average momentum is, the stronger the forward tendency is.
