We present an analysis of the xF_3(x,Q^2) structure function and Gross-Llewellyn Smith(GLS) sum rule taking into account the nuclear effects and higher twist correction. This analysis is based on the results presented...We present an analysis of the xF_3(x,Q^2) structure function and Gross-Llewellyn Smith(GLS) sum rule taking into account the nuclear effects and higher twist correction. This analysis is based on the results presented in[N.M. Nath, et al., Indian J. Phys. 90(2016) 117]. The corrections due to nuclear effects predicted in several earlier analysis are incorporated to our results of xF_3(x,Q^2) structure function and GLS sum rule for free nucleon, corrected upto next-next-to-leading order(NNLO) perturbative order and calculate the nuclear structure function as well as sum rule for nuclei. In addition, by means of a simple model we have extracted the higher twist contributions to the nonsinglet structure function xF_3(x,Q^2) and GLS sum rule in NNLO perturbative orders and then incorporated them to our results. Our NNLO results along with nuclear effect and higher twist corrections are observed to be compatible with corresponding experimental data and other phenomenological analysis.展开更多
With three theoretical models of nuclear effects on gluon distribution functions,the differentialcross sections and the total cross sections for associate production of J/ψ and γ with large P_T in high energyp-Fe co...With three theoretical models of nuclear effects on gluon distribution functions,the differentialcross sections and the total cross sections for associate production of J/ψ and γ with large P_T in high energyp-Fe collisions are calculated.展开更多
An improved formula considering the deformation effect for the α-decay half-lives is proposed based on WKB barrier penetrability.Using the quadrupole deformation values of the daughter nuclei obtained from the WS4 an...An improved formula considering the deformation effect for the α-decay half-lives is proposed based on WKB barrier penetrability.Using the quadrupole deformation values of the daughter nuclei obtained from the WS4 and FRDM models in the improved formula,the root mean square deviation(RMSD)between the calculated results and experimental data decreased from 0.456 to 0.413 and 0.415,respectively.Although the improved formula did not significantly reduce the overall RMSD,it produced results that better matched the experimental values for nuclei with larger deformations.Additionally,eXtreme Gradient Boosting(XGBoost)models were employed to further reduce the deviations between the calculated α-decay half-lives and experimental data,with the corresponding RMSDs decreasing from 0.413 to 0.295 and from 0.415 to 0.302,respectively.Furthermore,the improved empirical formula and XGBoost models were used to predict the α-decay half-lives of nuclei with Z=117,118,119,and 120.The results suggest that N=184 is the magic number.展开更多
Extended quark distribution functions are presented obtained by fitting a large amount of experimental data of the l-A DIS process on the basis of an improved nuclear density model. The experimental data of l-A DIS pr...Extended quark distribution functions are presented obtained by fitting a large amount of experimental data of the l-A DIS process on the basis of an improved nuclear density model. The experimental data of l-A DIS processes with A≥ 3 in the region 0.0010 ≤ x ≤ 0.9500 are quite satisfactorily described by using the extended formulae. Our knowledge of the influence of nuclear matter on the quark distributions is deepened.展开更多
An anomalous isotope effect exists in many heavy element isotope systems （e.g., Sr, Gd, Zn, U）. This effect used to be called the ＂odd--even isotope effect＂ because the odd mass number isotopes behave differently ...An anomalous isotope effect exists in many heavy element isotope systems （e.g., Sr, Gd, Zn, U）. This effect used to be called the ＂odd--even isotope effect＂ because the odd mass number isotopes behave differently from the even mass number isotopes. This mass-indepen- dent isotope fractionation driving force, which originates from the difference in the ground-state electronic energies caused by differences in nuclear size and shape, is cur- rently denoted as the nuclear field shift effect （NFSE）. It is found that the NFSE can drive isotope fractionation of some heavy elements （e.g., Hg, T1, U） to an astonishing degree, far more than the magnitude caused by the con- ventional mass-dependent effect （MDE）. For light ele- ments, the MDE is the dominant factor in isotope fractionation, while the NFSE is neglectable. Furthermore, the MDE and the NFSE both decrease as temperatures increase, though at different rates. The MDE decreases rapidly with a factor of 1/T2, while the NFSE decreases slowly with a factor of 1/T. As a result, even at high temperatures, the NFSE is still significant for many heavy element isotope systems. In this review paper, we begin with an introduction of the basic concept of the NSFE, including its history and recent progress, and follow with the potential implications of the inclusion of the NFSE into the kinetic isotope fractionation effect （KIE） and heavy isotope geochronology.展开更多
To investigate equilibrium mercury(Hg)and lead(Pb)isotope fractionation caused by the nuclear volume effect(NVE)in crystals,the electron densities at nuclei(i.e.,|Ψ(0)|2)for Hg-or Pb-bearing crystalline compounds wer...To investigate equilibrium mercury(Hg)and lead(Pb)isotope fractionation caused by the nuclear volume effect(NVE)in crystals,the electron densities at nuclei(i.e.,|Ψ(0)|2)for Hg-or Pb-bearing crystalline compounds were investigated by using the relativistic spin orbit zeroth-order regular approximation(ZORA)method with a three-dimensional periodic boundary condition based on the density functional theory(DFT).Many isotope fractionation factors of crystalline compounds are provided for the first time.Our results show,even at1000℃,NVE-driven Hg and Pb isotope fractionation are meaningfully large,i.e.,range from 0.12‰to 0.49‰(202Hg/^(198)Hg),from-0.20‰to 0.17‰(208Pb/^(206)Pb)and from-0.08‰to 0.06‰(207Pb/^(206) Pb)relative to Hg0 vapor and Pb0 vapor,respectively.Specifically,the fractionations range from-0.06‰to-0.20‰(208Pb/^(206)Pb)and from-0.02‰to-0.08‰(207Pb/^(206)Pb)for Pb2+-bearing species,from 0.10‰to 0.17‰(208Pb/^(206)Pb)and from 0.04‰to 0.06‰(207Pb/^(206)Pb)for Pb4+-bearing species in crystals.All calculated Hg-bearing species in crystals will enrich heavier isotope(202Hg)relative to Hg0 vapor.Meanwhile,Pb4+-bearing species enrich heavier Pb isotopes(208Pb and 207Pb)than Pb^(2+)-bearing species in crystals,which the enrichment can be up to 0.37‰(208-Pb/^(206)Pb)and 0.14‰(207Pb/^(206)Pb)at 1000℃,due to their NVEs are in opposite directions.The NVE-driven MIFs of Hg isotopes,which are compared to the Hg202-Hg198baseline,are up to-0.158‰(ΔNV199Hg),-0.024‰(ΔNV200Hg)and-0.094‰(ΔNV201Hg)relative to Hg0 vapor at5000 C.For all studied Hg-bearing species in crystals,the MIFs of two odd-mass isotopes(i.e.,ΔNV199Hg andΔNV201Hg)will be changed proportionally and their ratio(i.e.,ΔNV199Hg/ΔNV201Hg)will be a constant 1.67.The NVE can also cause mass-independent fractionations for 207Pb and 204 Pb compared to the baseline of 208Pb and 206Pb.The largest NVEdriven MIFs are 0.043‰(ΔNV207Pb)and-0.040‰(ΔNV204Pb)among all the studied species relative to Pb0 vapor at 5000 C.The magnitudes of odd-mass isotope MIF(ΔNV207Pb)and even-mass isotope MIF(ΔNV204Pb)are almost the same but with opposite signs,leading to the MIF ratio of them(i.e.,ΔNV207Pb/ΔNV204Pb)is-1.08.展开更多
It is well-known that the equilibrium isotope fractionation of mercury(Hg)includes classical massdependent fractionations(MDFs)and nuclear volume effect(NVE)induced mass-independent fractionations(MIFs).However,the ef...It is well-known that the equilibrium isotope fractionation of mercury(Hg)includes classical massdependent fractionations(MDFs)and nuclear volume effect(NVE)induced mass-independent fractionations(MIFs).However,the effect of the NVE on these kinetic processes is not known.The total fractionations(MDFs+NVEinduced MIFs)of several representative Hg-incorporated substances were selected and calculated with ab initio calculations in this work for both equilibrium and kinetic processes.NVE-induced MIFs were calculated with scaled contact electron densities at the nucleus through systematic evaluations of their accuracy and errors using the Gaussian09 and DIRAC19 packages(named the electron density scaling method).Additionally,the NVE-induced kinetic isotope effect(KIE)of Hg isotopes are also calculated with this method for several representative Hg oxidation reactions by chlorine species.Total KIEs for 202 Hg/^(198)Hg ranging from−2.27‰to 0.96‰are obtained.Three anomalous^(202)Hg-enriched KIEs(δ^(202)Hg/^(198)Hg=0.83‰,0.94‰,and 0.96‰,)caused by the NVE are observed,which are quite different from the classical view(i.e.,light isotopes react faster than the heavy ones).The electron density scaling method we developed in this study can provide an easier way to calculate the NVE-induced KIEs for heavy isotopes and serve to better understand the fractionation mechanisms of mercury isotope systems.展开更多
1 Introduction In deeper study of HTSC, it is found that Y<sub>1</sub>Ba<sub>2</sub>Cu<sub>3</sub>O<sub>7-δ</sub> has an unusualproperty of absorbing hydrogen. The abso...1 Introduction In deeper study of HTSC, it is found that Y<sub>1</sub>Ba<sub>2</sub>Cu<sub>3</sub>O<sub>7-δ</sub> has an unusualproperty of absorbing hydrogen. The absorption process could be described by a gen-eral equation （x/2） H<sub>2</sub> + Y<sub>1</sub>Ba<sub>2</sub>Cu<sub>3</sub>O<sub>7-δ</sub>→H<sub>x</sub>Y<sub>1</sub>Ba<sub>2</sub>Cu<sub>3</sub>O<sub>7-δ</sub>.A structural analysis indicates that absorbed hydrogen is located on the Cu-Osurface and its state change with temperature. As an isotope of hydrogen,deuterium can have simlar effects. Therefore we have experimentally studied展开更多
A dynamic model of DNA molecules which takes into account the interaction of the nearestbase pairs between the different strands is presented.The nonlinear effect and phase transition aresimulated by the nuclear trans...A dynamic model of DNA molecules which takes into account the interaction of the nearestbase pairs between the different strands is presented.The nonlinear effect and phase transition aresimulated by the nuclear transport theory and the method of fractorial moment in high energy physics,re-spectively.The results show that the nonlinear interaction of the nearest base pairs between the differentstrands may play a rule in DNA molecules.展开更多
In this study,we investigated the motion,shape,and delayed radiation intensity of a radioactive cloud by establishing a volume-source model of delayed radiation after high-altitude nuclear explosions.Then,the spatial ...In this study,we investigated the motion,shape,and delayed radiation intensity of a radioactive cloud by establishing a volume-source model of delayed radiation after high-altitude nuclear explosions.Then,the spatial distribution of electron number density at different moments on the north side of the explosion point generated by delayed γ-rays and delayed β-rays from the radioactive cloud under the influence of the geomagnetic field was calculated by solving chemical reaction kinetics equations.The impact of radio communication in the different frequency bands on the process of atmospheric ionization was also studied.The numerical results of the high-altitude nuclear explosion (120 km high and with a 1 megaton equivalent at 40°N latitude) indicated that the peak of electron number density ionized delayed γ-rays is located at a height of approximately 100 km and that of electron number density ionized delayed β-rays is about 90 km high.After 1 min of explosion,the radio communication in the medium frequency (MF) and high-frequency (HF)bands was completely interrupted,and the energy attenuation of the radio wave in the very high-frequency (VHF)band was extremely high.Five minutes later,the VHF radio communication was basically restored,but the energy attenuation in the HF band was still high.After 30 min,theVHF radio communication returned to normal,but its influence on the HF and MF radio communication continued.展开更多
Accurate and reliable nuclear data libraries are essential for calculation and design of advanced nuclea systems. A 1200 fine group nuclear data library Hybrid Evaluated Nuclear Data Library/Fine Group(HENDL/FG with n...Accurate and reliable nuclear data libraries are essential for calculation and design of advanced nuclea systems. A 1200 fine group nuclear data library Hybrid Evaluated Nuclear Data Library/Fine Group(HENDL/FG with neutrons of up to 150 Me V has been developed to improve the accuracy of neutronics calculations and anal ysis. Corrections of Doppler, resonance self-shielding, and thermal upscatter effects were done for HENDL/FG Shielding and critical safety benchmarks were performed to test the accuracy and reliability of the library. The dis crepancy between calculated and measured nuclea parameters fell into a reasonable range.展开更多
The radiological environmental impact assessment of the nuclear industry in China has been completed. The effective dose equivalents to the critical groups are mainly within the fluctuation range of the average naturh...The radiological environmental impact assessment of the nuclear industry in China has been completed. The effective dose equivalents to the critical groups are mainly within the fluctuation range of the average naturhl background radiation dose in the provinces, and below the dose limits. The annual average collective effective dose equivalent from the nuclear industry is approximately 23 man·Sv. According to the nuclear power planning of China, it is estimated that the annual collective effective dose equivalent from the nuclear fuel cycle and the application of radioisotopes is 59 man·Sv in 2000 a.展开更多
This paper introduces a nuclear calamity evaluation expert system which is applied to comprehensive evaluation of damage effects of nuclear calamities. It contains hardware environment, overall structure, logical step...This paper introduces a nuclear calamity evaluation expert system which is applied to comprehensive evaluation of damage effects of nuclear calamities. It contains hardware environment, overall structure, logical steps and reasoning models, concerning the expert system.展开更多
Cytoplasmic effects are important agronomical phenomena that have generated widespread interest in both theory and application. In the present study, five high yield rice cultivars（Oryza sativa L. ssp. japonica） in ...Cytoplasmic effects are important agronomical phenomena that have generated widespread interest in both theory and application. In the present study, five high yield rice cultivars（Oryza sativa L. ssp. japonica） in large-scale cultivation in northeast China were determined to possess Oryza sativa L. ssp. indica-type cytoplasm using cytoplasmic subspecies-specific molecular markers. This was confirmed by cytoplasmic genome-wide single nucleotide polymorphisms（SNPs） and functional gene sequencing. Two of these five japonica cultivars were core breeding parents with high yield and the other three were super-high-yield varieties registered by the Ministry of Agriculture of China. We constructed nuclear substitution lines to further demonstrate whether and how this indica-type cytoplasm contributed to yield improvement by comparing yield components. The results showed that under the same japonica nuclear background, the lines with indica-type cytoplasm had a significant decrease in tillers in exchange for increased grain number per panicle compared with their recurrent parents. Our results implied that botanical basis of this cytoplasmic effect was to reduce the plant＇s branching differentiation to produce more floral organs under the constant nutrition. Our findings open another door for the utilization of inter-subspecific hybridization for the improvement of rice cultivar.展开更多
We are reviewing Freeman Dyson’s paper which alleged that detection of gravitons via LIGO, or by outer space experiments (due to probabilistic calculations which we review in the document), an impossibility. The disa...We are reviewing Freeman Dyson’s paper which alleged that detection of gravitons via LIGO, or by outer space experiments (due to probabilistic calculations which we review in the document), an impossibility. The disagreement we have with Dr. Dyson is that his probability calculations are taking place in almost infinite spatial domains, which renders the detection protocols, using his probability scheme, impossible. After we summarize the Dyson outer space arguments, and how Dyson got them, we will refer the reader to the very strain calculation done in the referenced PRD article, so cited, as to how a nuclear weapon could generate GW, and then afterwards, refer the reader to a 2nd paper, of how Tokamaks could detect GW/ Gravitons, as detectable by the 3DSR effect. Nowhere are we suggesting DETONITION of a nuclear device to generate GW! The reader is referred to another Li et al. PRD article, 2008, as to 3DSR, as to how detection of GW/Gravitons could occur due to something other than the Gertenshehtein effect, in this paper, i.e. they can look it up, and then in a 2nd follow up paper learn how a Tokamak could be utilized to have a finite sized geometry, for using the 3DSR effect for GW generation. The first paper highlights how if one assumes that only by use of infinite spatial geometry, and by using only the Gertenshehtein effect, that indeed one can convince oneself as to not bothering with the very real prospects of earthbound generation of Gravitons and GW, and that in doing so, GW research will be strictly limited, even with the outstanding results of LIGO, which in no way should be criticized. The entire analysis makes the case that foundational research as to the nature of GRAVITY means moving beyond the mental limitations place on GW/Graviton research by Dyson’s 2009 paper.展开更多
Objective To investigate the annual effective doses from indoor radon received by academic staff in the Faculty building. Methods Measurements of indoor radon concentrations were performed in the Arts and Sciences Fac...Objective To investigate the annual effective doses from indoor radon received by academic staff in the Faculty building. Methods Measurements of indoor radon concentrations were performed in the Arts and Sciences Faculty of Dokuz Eylul University for two surveys of about 1 month duration respectively using the SSNTD （Solid State Nuclear Track Detectors） method with LR115 detectors. Time integrated measurements comprised different locations inside the faculty building： classrooms, toilets, canteen and offices. Homes of academic staff were also tested for radon. Results The aritthmetic mean radon concentration is 161 Bq m-3 with a range between 40 and 335 Bq m-3 in the Faculty. Six offices and three classrooms have a radon concentration above 200 Bq m-3. The results show that the radon concentration in classrooms is generally higher than in offices. Based on the measured indoor radon data, the annual effective doses received by staff in the Faculty were estimated to range from 0.79 to 4.27 mSv, according to UNSCEAR methodology. The annual effective doses received by staff ranged from 0.78 to 4.20 mSv in homes. On average, the Faculty contributed 56% to the annual effective dose. Conclusion Reported values for radon concentrations and corresponding doses are within the ICRP recommended limits for workplaces.展开更多
The mystery of superconductivity has intrigued scientists for 110 years now. The author in 2014 specifically predicted the superconductivity in carbon, sulfur and hydrogen compounds and generally predicted carbonaceou...The mystery of superconductivity has intrigued scientists for 110 years now. The author in 2014 specifically predicted the superconductivity in carbon, sulfur and hydrogen compounds and generally predicted carbonaceous, hydrogeneous and sulfurous compounds in 2005 with reference to scattering to asymmetric orbital motions and associated spin and orbital exchanges between nuclei and electrons. The emphasis was in 2005 upon stronger electron and nuclear interactions and electron-phonon effects. But here the author develops more the un-gerade parity of the p and f orbitals and their contributions to the superconductivity at lower pressures and higher temperatures. On the bases of such, the role of parity from the origin and inflation of the Universe is noted and dark and bright energies and matters in the mature Universe are reasoned. Moreover, the superconductors are all reasoned by positive and negative nuclear magnetic moments (NMMs) with availability of un-gerade parities of p and f subshells and their orbitals. In addition to superconductivity, such positive and negative NMMs by Little Effect is presented for explaining Pomeranchuk Effect and thereby further explaining superconductivity and superfluidity of <sup>3</sup>He. On the bases of successes of Little Effect via positive and negative NMMs, in particular negative NMMs of <sup>3</sup>He, the superconductivity in twisted graphene is explained and also its recently discovered Pomeranchuk Effect.展开更多
Probing in-medium nucleon-nucleon （NN） cross section σ1/NN（α） in heavy ion collisions has been investigated by means of the isospin-dependent quantum molecular dynamics （IQMD） with the isospin- and momentum-de...Probing in-medium nucleon-nucleon （NN） cross section σ1/NN（α） in heavy ion collisions has been investigated by means of the isospin-dependent quantum molecular dynamics （IQMD） with the isospin- and momentum-dependent interaction （IMDI（T））. It is found that there are the very obvious medium effect and the sensitive isospin-dependence of nuclear stopping R on the in-medium NN cross section α1/NN（α） in the nuclear reactions induced by halo-neutron projectile and the same-mass stable projectile. However, R induced by the neutron-halo projectile is obviously lower than that induced by the corresponding stable projectile. In particular, there is a very obvious dependence of R on the medium effect of σ1/NN（α） in the whole beam energy region for the above two kinds of projectiles. Therefore, the comparison between the results of R＇s in the reactions induced by the neutron-halo projectile and the corresponding same-mass stable projectile is a more favourable probe for extracting the information of σ1/NN（α） because of adding a new judgement.展开更多
基金Support from DAE-BRNS,India,as Major Research Project under Sanction No.2012/37P/36/BRNS/2018 dated 24 Nov.2012
文摘We present an analysis of the xF_3(x,Q^2) structure function and Gross-Llewellyn Smith(GLS) sum rule taking into account the nuclear effects and higher twist correction. This analysis is based on the results presented in[N.M. Nath, et al., Indian J. Phys. 90(2016) 117]. The corrections due to nuclear effects predicted in several earlier analysis are incorporated to our results of xF_3(x,Q^2) structure function and GLS sum rule for free nucleon, corrected upto next-next-to-leading order(NNLO) perturbative order and calculate the nuclear structure function as well as sum rule for nuclei. In addition, by means of a simple model we have extracted the higher twist contributions to the nonsinglet structure function xF_3(x,Q^2) and GLS sum rule in NNLO perturbative orders and then incorporated them to our results. Our NNLO results along with nuclear effect and higher twist corrections are observed to be compatible with corresponding experimental data and other phenomenological analysis.
基金The project supported in part by the National Natural Science Foundation of Chinathe Doctoral Program Foundation of Institution of Higher Education of Chinathe Provincial Natural Science Foundation of Hebei
文摘With three theoretical models of nuclear effects on gluon distribution functions,the differentialcross sections and the total cross sections for associate production of J/ψ and γ with large P_T in high energyp-Fe collisions are calculated.
基金supported by the Joint Funds for the Innovation of Science and Technology,Fujian province(Nos.2021Y9190 and 2021Y9210)National Natural Science Foundation of China(No.12475121)National Key R&D Program of China(Nos.2023YFA1606503 and 2024YFE0109804).
文摘An improved formula considering the deformation effect for the α-decay half-lives is proposed based on WKB barrier penetrability.Using the quadrupole deformation values of the daughter nuclei obtained from the WS4 and FRDM models in the improved formula,the root mean square deviation(RMSD)between the calculated results and experimental data decreased from 0.456 to 0.413 and 0.415,respectively.Although the improved formula did not significantly reduce the overall RMSD,it produced results that better matched the experimental values for nuclei with larger deformations.Additionally,eXtreme Gradient Boosting(XGBoost)models were employed to further reduce the deviations between the calculated α-decay half-lives and experimental data,with the corresponding RMSDs decreasing from 0.413 to 0.295 and from 0.415 to 0.302,respectively.Furthermore,the improved empirical formula and XGBoost models were used to predict the α-decay half-lives of nuclei with Z=117,118,119,and 120.The results suggest that N=184 is the magic number.
基金Supported by Natural Science Foundation of China (100775061, 10505016, 10575119)CAS Knowledge Innovation Project(KJCX-SYW-N02)+1 种基金Major State Basic Research Developing Program of China (2007CB815004)Natural Science Foundationof Hebei Province in China (A2005000535, 103143)
文摘Extended quark distribution functions are presented obtained by fitting a large amount of experimental data of the l-A DIS process on the basis of an improved nuclear density model. The experimental data of l-A DIS processes with A≥ 3 in the region 0.0010 ≤ x ≤ 0.9500 are quite satisfactorily described by using the extended formulae. Our knowledge of the influence of nuclear matter on the quark distributions is deepened.
基金funding support from the973 Program(2014CB440904)Chinese NSF projects(41225012,41490635,41530210)
文摘An anomalous isotope effect exists in many heavy element isotope systems （e.g., Sr, Gd, Zn, U）. This effect used to be called the ＂odd--even isotope effect＂ because the odd mass number isotopes behave differently from the even mass number isotopes. This mass-indepen- dent isotope fractionation driving force, which originates from the difference in the ground-state electronic energies caused by differences in nuclear size and shape, is cur- rently denoted as the nuclear field shift effect （NFSE）. It is found that the NFSE can drive isotope fractionation of some heavy elements （e.g., Hg, T1, U） to an astonishing degree, far more than the magnitude caused by the con- ventional mass-dependent effect （MDE）. For light ele- ments, the MDE is the dominant factor in isotope fractionation, while the NFSE is neglectable. Furthermore, the MDE and the NFSE both decrease as temperatures increase, though at different rates. The MDE decreases rapidly with a factor of 1/T2, while the NFSE decreases slowly with a factor of 1/T. As a result, even at high temperatures, the NFSE is still significant for many heavy element isotope systems. In this review paper, we begin with an introduction of the basic concept of the NSFE, including its history and recent progress, and follow with the potential implications of the inclusion of the NFSE into the kinetic isotope fractionation effect （KIE） and heavy isotope geochronology.
基金supported by National Natural Science Foundation of China (NSFC) projects (41703012)Qinghai Science and Technology projects (2018-ZJ-956Q)+2 种基金the supports of the Strategic Priority Research Program (B) of CAS (XDB18010100, XDB41000000)pre-research Project on Civil Aerospace Technologies No. D020202 funded by the Chinese National Space AdministrationNSFC projects (41530210)。
文摘To investigate equilibrium mercury(Hg)and lead(Pb)isotope fractionation caused by the nuclear volume effect(NVE)in crystals,the electron densities at nuclei(i.e.,|Ψ(0)|2)for Hg-or Pb-bearing crystalline compounds were investigated by using the relativistic spin orbit zeroth-order regular approximation(ZORA)method with a three-dimensional periodic boundary condition based on the density functional theory(DFT).Many isotope fractionation factors of crystalline compounds are provided for the first time.Our results show,even at1000℃,NVE-driven Hg and Pb isotope fractionation are meaningfully large,i.e.,range from 0.12‰to 0.49‰(202Hg/^(198)Hg),from-0.20‰to 0.17‰(208Pb/^(206)Pb)and from-0.08‰to 0.06‰(207Pb/^(206) Pb)relative to Hg0 vapor and Pb0 vapor,respectively.Specifically,the fractionations range from-0.06‰to-0.20‰(208Pb/^(206)Pb)and from-0.02‰to-0.08‰(207Pb/^(206)Pb)for Pb2+-bearing species,from 0.10‰to 0.17‰(208Pb/^(206)Pb)and from 0.04‰to 0.06‰(207Pb/^(206)Pb)for Pb4+-bearing species in crystals.All calculated Hg-bearing species in crystals will enrich heavier isotope(202Hg)relative to Hg0 vapor.Meanwhile,Pb4+-bearing species enrich heavier Pb isotopes(208Pb and 207Pb)than Pb^(2+)-bearing species in crystals,which the enrichment can be up to 0.37‰(208-Pb/^(206)Pb)and 0.14‰(207Pb/^(206)Pb)at 1000℃,due to their NVEs are in opposite directions.The NVE-driven MIFs of Hg isotopes,which are compared to the Hg202-Hg198baseline,are up to-0.158‰(ΔNV199Hg),-0.024‰(ΔNV200Hg)and-0.094‰(ΔNV201Hg)relative to Hg0 vapor at5000 C.For all studied Hg-bearing species in crystals,the MIFs of two odd-mass isotopes(i.e.,ΔNV199Hg andΔNV201Hg)will be changed proportionally and their ratio(i.e.,ΔNV199Hg/ΔNV201Hg)will be a constant 1.67.The NVE can also cause mass-independent fractionations for 207Pb and 204 Pb compared to the baseline of 208Pb and 206Pb.The largest NVEdriven MIFs are 0.043‰(ΔNV207Pb)and-0.040‰(ΔNV204Pb)among all the studied species relative to Pb0 vapor at 5000 C.The magnitudes of odd-mass isotope MIF(ΔNV207Pb)and even-mass isotope MIF(ΔNV204Pb)are almost the same but with opposite signs,leading to the MIF ratio of them(i.e.,ΔNV207Pb/ΔNV204Pb)is-1.08.
基金This paper is supported by Chinese NSF project(42130114)the strategic priority research program(B)of CAS(XDB41000000)the pre-research Project on Civil Aerospace Technologies No.D020202 funded by Chinese National Space Administration(CNSA)。
文摘It is well-known that the equilibrium isotope fractionation of mercury(Hg)includes classical massdependent fractionations(MDFs)and nuclear volume effect(NVE)induced mass-independent fractionations(MIFs).However,the effect of the NVE on these kinetic processes is not known.The total fractionations(MDFs+NVEinduced MIFs)of several representative Hg-incorporated substances were selected and calculated with ab initio calculations in this work for both equilibrium and kinetic processes.NVE-induced MIFs were calculated with scaled contact electron densities at the nucleus through systematic evaluations of their accuracy and errors using the Gaussian09 and DIRAC19 packages(named the electron density scaling method).Additionally,the NVE-induced kinetic isotope effect(KIE)of Hg isotopes are also calculated with this method for several representative Hg oxidation reactions by chlorine species.Total KIEs for 202 Hg/^(198)Hg ranging from−2.27‰to 0.96‰are obtained.Three anomalous^(202)Hg-enriched KIEs(δ^(202)Hg/^(198)Hg=0.83‰,0.94‰,and 0.96‰,)caused by the NVE are observed,which are quite different from the classical view(i.e.,light isotopes react faster than the heavy ones).The electron density scaling method we developed in this study can provide an easier way to calculate the NVE-induced KIEs for heavy isotopes and serve to better understand the fractionation mechanisms of mercury isotope systems.
文摘1 Introduction In deeper study of HTSC, it is found that Y<sub>1</sub>Ba<sub>2</sub>Cu<sub>3</sub>O<sub>7-δ</sub> has an unusualproperty of absorbing hydrogen. The absorption process could be described by a gen-eral equation （x/2） H<sub>2</sub> + Y<sub>1</sub>Ba<sub>2</sub>Cu<sub>3</sub>O<sub>7-δ</sub>→H<sub>x</sub>Y<sub>1</sub>Ba<sub>2</sub>Cu<sub>3</sub>O<sub>7-δ</sub>.A structural analysis indicates that absorbed hydrogen is located on the Cu-Osurface and its state change with temperature. As an isotope of hydrogen,deuterium can have simlar effects. Therefore we have experimentally studied
文摘A dynamic model of DNA molecules which takes into account the interaction of the nearestbase pairs between the different strands is presented.The nonlinear effect and phase transition aresimulated by the nuclear transport theory and the method of fractorial moment in high energy physics,re-spectively.The results show that the nonlinear interaction of the nearest base pairs between the differentstrands may play a rule in DNA molecules.
文摘In this study,we investigated the motion,shape,and delayed radiation intensity of a radioactive cloud by establishing a volume-source model of delayed radiation after high-altitude nuclear explosions.Then,the spatial distribution of electron number density at different moments on the north side of the explosion point generated by delayed γ-rays and delayed β-rays from the radioactive cloud under the influence of the geomagnetic field was calculated by solving chemical reaction kinetics equations.The impact of radio communication in the different frequency bands on the process of atmospheric ionization was also studied.The numerical results of the high-altitude nuclear explosion (120 km high and with a 1 megaton equivalent at 40°N latitude) indicated that the peak of electron number density ionized delayed γ-rays is located at a height of approximately 100 km and that of electron number density ionized delayed β-rays is about 90 km high.After 1 min of explosion,the radio communication in the medium frequency (MF) and high-frequency (HF)bands was completely interrupted,and the energy attenuation of the radio wave in the very high-frequency (VHF)band was extremely high.Five minutes later,the VHF radio communication was basically restored,but the energy attenuation in the HF band was still high.After 30 min,theVHF radio communication returned to normal,but its influence on the HF and MF radio communication continued.
基金supported by the Natural Science Foundation of China(Nos.11405204 11305205 and 10675123)Special Program for Informatization of Chinese Academy of Sciences(No.XXH12504-1-09)the National Special Program for ITER(No.2014GB1120001)
文摘Accurate and reliable nuclear data libraries are essential for calculation and design of advanced nuclea systems. A 1200 fine group nuclear data library Hybrid Evaluated Nuclear Data Library/Fine Group(HENDL/FG with neutrons of up to 150 Me V has been developed to improve the accuracy of neutronics calculations and anal ysis. Corrections of Doppler, resonance self-shielding, and thermal upscatter effects were done for HENDL/FG Shielding and critical safety benchmarks were performed to test the accuracy and reliability of the library. The dis crepancy between calculated and measured nuclea parameters fell into a reasonable range.
文摘The radiological environmental impact assessment of the nuclear industry in China has been completed. The effective dose equivalents to the critical groups are mainly within the fluctuation range of the average naturhl background radiation dose in the provinces, and below the dose limits. The annual average collective effective dose equivalent from the nuclear industry is approximately 23 man·Sv. According to the nuclear power planning of China, it is estimated that the annual collective effective dose equivalent from the nuclear fuel cycle and the application of radioisotopes is 59 man·Sv in 2000 a.
文摘This paper introduces a nuclear calamity evaluation expert system which is applied to comprehensive evaluation of damage effects of nuclear calamities. It contains hardware environment, overall structure, logical steps and reasoning models, concerning the expert system.
基金supported by the National Natural Science Foundation of China (31371587 and 31430062)the Cultivation Plan for Youth Agricultural Science and Technology Innovative Talents of Liaoning Province (2014046)+1 种基金the China Postdoctoral Science Foundation Grant (2014M560221)the Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT), China
文摘Cytoplasmic effects are important agronomical phenomena that have generated widespread interest in both theory and application. In the present study, five high yield rice cultivars（Oryza sativa L. ssp. japonica） in large-scale cultivation in northeast China were determined to possess Oryza sativa L. ssp. indica-type cytoplasm using cytoplasmic subspecies-specific molecular markers. This was confirmed by cytoplasmic genome-wide single nucleotide polymorphisms（SNPs） and functional gene sequencing. Two of these five japonica cultivars were core breeding parents with high yield and the other three were super-high-yield varieties registered by the Ministry of Agriculture of China. We constructed nuclear substitution lines to further demonstrate whether and how this indica-type cytoplasm contributed to yield improvement by comparing yield components. The results showed that under the same japonica nuclear background, the lines with indica-type cytoplasm had a significant decrease in tillers in exchange for increased grain number per panicle compared with their recurrent parents. Our results implied that botanical basis of this cytoplasmic effect was to reduce the plant＇s branching differentiation to produce more floral organs under the constant nutrition. Our findings open another door for the utilization of inter-subspecific hybridization for the improvement of rice cultivar.
文摘We are reviewing Freeman Dyson’s paper which alleged that detection of gravitons via LIGO, or by outer space experiments (due to probabilistic calculations which we review in the document), an impossibility. The disagreement we have with Dr. Dyson is that his probability calculations are taking place in almost infinite spatial domains, which renders the detection protocols, using his probability scheme, impossible. After we summarize the Dyson outer space arguments, and how Dyson got them, we will refer the reader to the very strain calculation done in the referenced PRD article, so cited, as to how a nuclear weapon could generate GW, and then afterwards, refer the reader to a 2nd paper, of how Tokamaks could detect GW/ Gravitons, as detectable by the 3DSR effect. Nowhere are we suggesting DETONITION of a nuclear device to generate GW! The reader is referred to another Li et al. PRD article, 2008, as to 3DSR, as to how detection of GW/Gravitons could occur due to something other than the Gertenshehtein effect, in this paper, i.e. they can look it up, and then in a 2nd follow up paper learn how a Tokamak could be utilized to have a finite sized geometry, for using the 3DSR effect for GW generation. The first paper highlights how if one assumes that only by use of infinite spatial geometry, and by using only the Gertenshehtein effect, that indeed one can convince oneself as to not bothering with the very real prospects of earthbound generation of Gravitons and GW, and that in doing so, GW research will be strictly limited, even with the outstanding results of LIGO, which in no way should be criticized. The entire analysis makes the case that foundational research as to the nature of GRAVITY means moving beyond the mental limitations place on GW/Graviton research by Dyson’s 2009 paper.
基金supported by a grant of The Scientific and Technical Research Council of Turkey(TUBiTAK)
文摘Objective To investigate the annual effective doses from indoor radon received by academic staff in the Faculty building. Methods Measurements of indoor radon concentrations were performed in the Arts and Sciences Faculty of Dokuz Eylul University for two surveys of about 1 month duration respectively using the SSNTD （Solid State Nuclear Track Detectors） method with LR115 detectors. Time integrated measurements comprised different locations inside the faculty building： classrooms, toilets, canteen and offices. Homes of academic staff were also tested for radon. Results The aritthmetic mean radon concentration is 161 Bq m-3 with a range between 40 and 335 Bq m-3 in the Faculty. Six offices and three classrooms have a radon concentration above 200 Bq m-3. The results show that the radon concentration in classrooms is generally higher than in offices. Based on the measured indoor radon data, the annual effective doses received by staff in the Faculty were estimated to range from 0.79 to 4.27 mSv, according to UNSCEAR methodology. The annual effective doses received by staff ranged from 0.78 to 4.20 mSv in homes. On average, the Faculty contributed 56% to the annual effective dose. Conclusion Reported values for radon concentrations and corresponding doses are within the ICRP recommended limits for workplaces.
文摘The mystery of superconductivity has intrigued scientists for 110 years now. The author in 2014 specifically predicted the superconductivity in carbon, sulfur and hydrogen compounds and generally predicted carbonaceous, hydrogeneous and sulfurous compounds in 2005 with reference to scattering to asymmetric orbital motions and associated spin and orbital exchanges between nuclei and electrons. The emphasis was in 2005 upon stronger electron and nuclear interactions and electron-phonon effects. But here the author develops more the un-gerade parity of the p and f orbitals and their contributions to the superconductivity at lower pressures and higher temperatures. On the bases of such, the role of parity from the origin and inflation of the Universe is noted and dark and bright energies and matters in the mature Universe are reasoned. Moreover, the superconductors are all reasoned by positive and negative nuclear magnetic moments (NMMs) with availability of un-gerade parities of p and f subshells and their orbitals. In addition to superconductivity, such positive and negative NMMs by Little Effect is presented for explaining Pomeranchuk Effect and thereby further explaining superconductivity and superfluidity of <sup>3</sup>He. On the bases of successes of Little Effect via positive and negative NMMs, in particular negative NMMs of <sup>3</sup>He, the superconductivity in twisted graphene is explained and also its recently discovered Pomeranchuk Effect.
基金Project supported by the State Key Development Program for Basic Research of China （Grant No G2000077400）, the Major Program of the National Natural Science Foundation of China （Grant Nos 10435080 and 105350101）, the National Natural Science Foundation of China （Grant Nos 10447006 and 10575075）, the CAS Knowledge Innovation Project Program （Grant No KJCX2-SW-N02）.
文摘Probing in-medium nucleon-nucleon （NN） cross section σ1/NN（α） in heavy ion collisions has been investigated by means of the isospin-dependent quantum molecular dynamics （IQMD） with the isospin- and momentum-dependent interaction （IMDI（T））. It is found that there are the very obvious medium effect and the sensitive isospin-dependence of nuclear stopping R on the in-medium NN cross section α1/NN（α） in the nuclear reactions induced by halo-neutron projectile and the same-mass stable projectile. However, R induced by the neutron-halo projectile is obviously lower than that induced by the corresponding stable projectile. In particular, there is a very obvious dependence of R on the medium effect of σ1/NN（α） in the whole beam energy region for the above two kinds of projectiles. Therefore, the comparison between the results of R＇s in the reactions induced by the neutron-halo projectile and the corresponding same-mass stable projectile is a more favourable probe for extracting the information of σ1/NN（α） because of adding a new judgement.
