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Cosmic Ray-driven Bioenergetics for Life in Molecular Clouds
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作者 FENG Lei 《天文学报》 CAS CSCD 北大核心 2024年第6期26-31,共6页
According to models such as panspermia or the Nebula-Relay hypothesis,the ancestors of life on Earth once lived in molecular clouds.Then what are the energy source and bioenergetics for such lifeforms?A new bioenerget... According to models such as panspermia or the Nebula-Relay hypothesis,the ancestors of life on Earth once lived in molecular clouds.Then what are the energy source and bioenergetics for such lifeforms?A new bioenergetic mechanism powered by cosmic ray ionization of hydrogen molecules is proposed and its relation with the origin of chemiosmosis is also discussed in this paper.Based on this mechanism,the Last Universal Common Ancestor may be a type of lifeform that utilizes hydrogen molecules as donors of electron transport chains. 展开更多
关键词 ASTROBIOLOGY ASTROCHEMISTRY interstellar medium(ISM) NEBULAE cosmic ray
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Isolation of Leptospirillum ferriphilum by single-layered solid medium 被引量:10
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作者 柳建设 谢学辉 +3 位作者 肖升木 王秀美 赵文杰 田卓力 《Journal of Central South University of Technology》 EI 2007年第4期467-473,共7页
According to physiological and biochemical characteristics of Leptospirillum ferriphilum, a strain of object bacteria was isolated successfully. Bacteria were enriched by selective liquid medium and plated on designed... According to physiological and biochemical characteristics of Leptospirillum ferriphilum, a strain of object bacteria was isolated successfully. Bacteria were enriched by selective liquid medium and plated on designed single-layered agar solid medium. Colony was cultured and bacteria were collected. The morphologies of the object bacteria were observed using crystal violet staining, scanning electron microscope(SEM) and transmission electron microscope (TEM). The result of 16S rDNA identification shows that this bacterium belongs to Leptospirillum ferriphilum and it is named as Leptospirillum ferriphilum strain D1. These results indicate that this new single-layered agar solid medium is efficient and physiological-biochemical characteristics show that the optimum simple for isolation of Leptospirillum ferriphilum. Additionally, initial pH value and its growth temperature are 1.68 and 40℃. 展开更多
关键词 Leptospirillum ferriphilum ISOLATION purification solid medium BIOLEACHING concentrate chalcopyrite
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Process Intensification of VOC Removal from High Viscous Media by Rotating Packed Bed 被引量:9
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作者 李沃源 毋伟 +3 位作者 邹海魁 初广文 邵磊 陈建峰 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第3期389-393,共5页
The removal of a volatile organic compound (VOC) from high viscous liquid was carried out in a rotat-ing packed bed (RPB) in this study. The mixed liquid of syrup and acetone was used as simulated high viscous polymer... The removal of a volatile organic compound (VOC) from high viscous liquid was carried out in a rotat-ing packed bed (RPB) in this study. The mixed liquid of syrup and acetone was used as simulated high viscous polymer solution with acetone as the volatile compound. The influence of the rotating speed of RPB, liquid viscos-ity, liquid flow rate, vacuum degree, and initial acetone content in the liquid on acetone removal efficiency was in-vestigated. The experimental results indicated that the removal efficiency increased with increasing rotating speed and initial acetone content in the viscous liquid and decreased with increasing liquid viscosity and flow rate. It was also observed that acetone removal efficiency increased with an increasing vacuum degree and reached 58% at a vacuum degree of 0.1 MPa. By the comparison with a flash tank devolatilizer, it was found that acetone removal ef-ficiency in RPB increased by about 67%. 展开更多
关键词 polymer devolatilization rotating packed bed high viscosity mass transfer volatile organic compound
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Characterization of Sub-100nm MOSFETs with High K Gate Dielectric
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作者 朱晖文 刘晓彦 +2 位作者 沈超 康晋锋 韩汝琦 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2001年第9期1107-1111,共5页
The short-channel performance of typical 70nm MOSFETs with high K gate dielectric is widely studied by using a two dimensional(2-D) device simulator.The short-channel performance is degraded from the fringing field a... The short-channel performance of typical 70nm MOSFETs with high K gate dielectric is widely studied by using a two dimensional(2-D) device simulator.The short-channel performance is degraded from the fringing field and lower the source/drain junction resistance.The sidewall material is found very useful to eliminate the fringing-induced berrier lowing effect. 展开更多
关键词 high K materials gate dielectrics MOSFET
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Polarization and absorption principle of corona virus in the electric field
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作者 梁震 肖登明 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2008年第2期202-205,共4页
The polarization and absorption principle of corona virus in the electric field is presented. It is expressed by the mathematic differential equation based on the physical model. According to the parameters of the dip... The polarization and absorption principle of corona virus in the electric field is presented. It is expressed by the mathematic differential equation based on the physical model. According to the parameters of the dipole moment of virus, the electric field force exerted by the external electric field can be calculated. According to the parameters of size, mass and elastic modular, etc., the moment of inertia of virus can be calculated. According to the viscosity of tissues, the resistant force when virus rotates can be calculated. According to the balance condition of relaxation polarization, when the drive force equals to the resistant force, the rotating or swaying frequency of virus can be calculated. According to the heat producing condition such as friction, the temperature rising of virus can be calculated. When the temperature exceeds a certain threshold, virus would be inactivated. Through the calculation, it is found that the movement type of the virus depends on the intensity and frequency of the external electric field, which are the effects of "intensity widows" and "frequency windows". It also gives approximate calculation of the temperature rising of the virus according to this model. The vitro experiment confirms the reasonability of this model. The electric fields of different densities of a certain frequency are applied to the solution of avian infectious bronchitis virus. Through the toxicity experiment of the SPF chicken embryo, it is found that the toxicity is decreased exceedingly with a certain intensity of the applied voltage. EID50 decreases from 6.70/0.2 mL to 2.66/0.2 mL. It is proved that the avian infectious bronchitis virus can be inactivated with a certain low frequency and low-density electric field. 展开更多
关键词 POLARIZATION ABSORPTION corona virus electric field
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Syntheses of Coumarins in Environmentally Friendly Ionics Liquids
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作者 Sanita Pavlovica Andris Zicmanis 《Journal of Chemistry and Chemical Engineering》 2014年第3期243-249,共7页
Syntheses of 3-substituted coumarins by the condensation reaction of salicylaldehyde with activated methylene compounds (ethyl cyanoacetate, malonic acid) are discussed in media of ionic liquids--(2-hydroxyethyl)a... Syntheses of 3-substituted coumarins by the condensation reaction of salicylaldehyde with activated methylene compounds (ethyl cyanoacetate, malonic acid) are discussed in media of ionic liquids--(2-hydroxyethyl)ammonium carboxylates (formates, acetates, lactates) without utilization of any other catalysts. The dependence of yields of the reaction product is investigated on the structure of ionic liquids (their cations, anions, total polarity and pseudo-pH values). 3-Substituted coumarins are prepared in high yields in media of these environmentally friendly ionic liquids which serve simultaneously as reaction media and as catalysts. The mentioned ionic liquids are prepared by reactions of corresponding hydroxyethyl-amines with carboxylic acids, and their quantitative analyses being made by potentiometric titration of ionic liquids with perchloric acid in 100% acetic acid. 展开更多
关键词 COUMARIN condensation reaction ionic liquid potentiometric titration.
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典型金属离子对漆酶催化降解溴代阻燃剂四溴双酚A的影响研究 被引量:2
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作者 冯义平 沈梦瑶 +1 位作者 张伊健 高士祥 《环境科学学报》 CAS CSCD 北大核心 2020年第6期2082-2089,共8页
研究了自然环境、垃圾渗滤液及工业废水中广泛存在的金属离子对真菌漆酶(Trametes versicolor)酶活性以及对漆酶催化降解典型溴代阻燃剂四溴双酚A(TBBPA)的影响.金属离子包括Na^+、K+、Zn^2+、Cd^2+、Cu^2+、Hg^2+、Fe^2+、Fe3+、Pb^2+... 研究了自然环境、垃圾渗滤液及工业废水中广泛存在的金属离子对真菌漆酶(Trametes versicolor)酶活性以及对漆酶催化降解典型溴代阻燃剂四溴双酚A(TBBPA)的影响.金属离子包括Na^+、K+、Zn^2+、Cd^2+、Cu^2+、Hg^2+、Fe^2+、Fe3+、Pb^2+、Al3+能抑制漆酶酶活性和降低TBBPA的降解转化率,抑制效应随着金属离子浓度的升高而增大;Ca^2+、Mg^2+、Mn^2+则对漆酶活性和TBBPA去除率均没有显著影响.金属离子的抑制作用主要是通过干扰漆酶的电子传递过程产生的.其中,Fe^2+和Hg^2+的抑制效应尤为明显,而二者的抑制机制不同,Fe^2+竞争消耗O2,Hg^2+则通过与漆酶结构中氨基酸络合,改变其构型从而抑制其活性.此外,通过加入介体物质2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)、2,2,6,6-四甲基哌啶-氮-氧化物(TEMPO)等物质能够显著提高金属离子存在下漆酶对TBBPA的去除率. 展开更多
关键词 TBBPA 漆酶 降解转化 金属离子 介体物质
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Conceptual design of an experiment to study dust destruction by astrophysical shock waves
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作者 M. J.-E. Manuel T. Temim +6 位作者 E. Dwek A. M. Angulo E X. Belancourt R. E Drake C. C. Kuranz M. J. MacDonald B. A. Remington 《High Power Laser Science and Engineering》 SCIE CAS CSCD 2018年第3期9-14,共6页
A novel laboratory experimental design is described that will investigate the processing of dust grains in astrophysical shocks. Dust is a ubiquitous ingredient in the interstellar medium(ISM) of galaxies; however, it... A novel laboratory experimental design is described that will investigate the processing of dust grains in astrophysical shocks. Dust is a ubiquitous ingredient in the interstellar medium(ISM) of galaxies; however, its evolutionary cycle is still poorly understood. Especially shrouded in mystery is the efficiency of grain destruction by astrophysical shocks generated by expanding supernova remnants. While the evolution of these remnants is fairly well understood, the grain destruction efficiency in these shocks is largely unknown. The experiments described herein will fill this knowledge gap by studying the dust destruction efficiencies for shock velocities in the range ~10–30 km/s(μm/ns), at which most of the grain destruction and processing in the ISM takes place. The experiments focus on the study of grain–grain collisions by accelerating small(~1 μm) dust particles into a large(~5–10 μm diameter) population; this simulates the astrophysical system well in that the more numerous, small grains impact and collide with the large population. Facilities that combine the versatility of high-power optical lasers with the diagnostic capabilities of X-ray free-electron lasers, e.g., the Matter in Extreme Conditions instrument at the SLAC National Accelerator Laboratory, provide an ideal laboratory environment to create and diagnose dust destruction by astrophysically relevant shocks at the micron scale. 展开更多
关键词 laboratory astrophysics shock waves dust destruction
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Comparative Study on the Dielectric Properties Between Living and Non-living from Human and Animal Livers
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作者 WANG Hang HE Yong +5 位作者 SHI Xue-tao YOU Fu-sheng WANG Hui CAI Zhan-xiu ZHU Jian-bo DONG Xiu-zhen 《Chinese Journal of Biomedical Engineering(English Edition)》 CSCD 2016年第1期12-17,共6页
The data of d ieleclric properties of hum an tissues m ably com es from an in al tissues or hum an corpse at present U p to now, there has not been a report of dielectric properties of human living liver. This paper ... The data of d ieleclric properties of hum an tissues m ably com es from an in al tissues or hum an corpse at present U p to now, there has not been a report of dielectric properties of human living liver. This paper aims to studying the dielectric properties of hum an living liver and corn paring the results with those of an in al living liver as well as the human non-livhg liver. In vitro measurements of living and non-living livers from human and rabbitare shown in the range of 10 Hz to 100 MHz. Analysis of the conductivity, perm ittivity and characteristic param eters from the data were made. The conductivity of three kinds of liver were markedly different at low frequency: 0.06 S/m (living rabbit liver), 0.13 S/m (living hum an liver) and 0.24 S/m (non-living hum an liver); The Cole param eters that best characterize the liver of hum an and rabbit are RO, fc1,△R I and R ∞ ;The Cole param eters that best characterize the living and non-living liver ofhum an are RO, fc1,△R I,△R2 and R ∞. In conclusion,we can't substitute the dielectric properties of anin al or hum an corpse liver for the living human liver. The results suggest that the study on the dielectric properties of living hum an tissues has great sign ificance. 展开更多
关键词 living tissues dielectric properties LIVER characteristic param eters Cole-Cole models
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BIOCONVECTION IN A NON-DARCY POROUS MEDIUM SATURATED WITH A NANOFLUID AND OXYTACTIC MICRO-ORGANISMS
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作者 S. SHAW P. K. KAMESWARAN M. NARAYANA P. SIBANDA 《International Journal of Biomathematics》 2014年第1期91-105,共15页
The aim of this paper is to present a continuum model for bioconvection of oxytactic micro-organisms in a non-Darcy porous medium and to investigate the effects of bio- convection and mixed convection on the steady bo... The aim of this paper is to present a continuum model for bioconvection of oxytactic micro-organisms in a non-Darcy porous medium and to investigate the effects of bio- convection and mixed convection on the steady boundary layer flow past a horizontal plate embedded in a porous medium filled with a water-based nanofluid. The governing partial differential equations for momentum, heat, oxygen and micro-organism conser- vation are reduced to a set of nonlinear ordinary differential equations using similarity transformations that are numerically solved using a built-in MATLAB ODE solver. The effects of the bioconvection parameters on the nanofluid fluid properties, nanoparticle concentration and the density of the micro-organism are analyzed. A comparative anal- ysis of our results with those previously reported in the literature is given. Among the significant findings in this study is that bioconvection parameters highly influence beat, mass and motile micro-organism transfer rates. 展开更多
关键词 BIOCONVECTION non-Darcy porous medium oxytactic micro-organisms nanofluid.
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