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Probing proton halo of the exotic nucleus ^(2.)S by elastic electron scattering

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Science china(physics,Mecha{2.cs & Astronomy) 2004年第1期47卷 42-51页

作者： WANG Zaijun1 & ren zhongzhou1’2.1. {2. of {3., nanjing university, nanjing 2.0008, china 2. Center of Theoretical Nuclear {3., National Laboratory of Heavy-Ion Accelerator at Lanzhou, Lanzhou 73.000, china Correspondence should be addressed to ren zhongzhou (email: zren@*** zren99@***) Received June 16, 2.03 department of physics Nanjing University Nanjing 210008 China Center of Theoretical Nuclear physics National Laboratory of Heavy-Ion Accelerator at Lanzhou Lanzhou 730000 China

Elastic electron scattering on the exotic light nucleus 2.S is investigated in the plane wave Born approximation. The variation of the squared form factors of 2.S with momentum transfer is compared with that of 3.S. It is found that the behavior of the form factors near the second minimum (with a moderate momentum transfer) is sensitive to the alteration of the charge density distribution of halo protons in 2.S. This indicates that elastic electron scattering can be a good probe of the structure of proton-halo nuclei.

关键词： elastic electron scattering, cross section, form factor, proton-halo nucleus.

Effects of different concentrations of nicotinamide on hematopoietic stem cells cultured in vitro

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World Journal of Stem Cells 2024年第2期16卷 163-175页

作者： Yan ren Yan-ni Cui Hong-Wei Wang The Second Clinical Medical College Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina department of Hematology The Second Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina department of Hematology Key Laboratory of Molecular Diagnosis and Treatment of Blood Diseases in Shanxi ProvinceTaiyuan 030001Shanxi ProvinceChina

BACKGROUND In vitro expansion to increase numbers of hematopoietic stem cells(HSCs)in cord blood could improve clinical efficacy of this vital ***(NAM)can promote HSC expansion ex vivo,but its effect on hematopoietic stem and progenitor cells(HSPCs,CD{2.^(+)CD{2.)and functional subtypes of HSCs-shortterm repopulating HSCs(ST-HSCs,CD{2.^(+)CD{2.CD45RACD49f^(+))and long-term repopulating HSCs(LT-HSCs,CD{2.^(+)CD{2.CD45RACD49f^(+)CD90^(+))is not yet *** a sirtuin 1(SIRT1)inhibitor,NAM participates in regulating cell adhesion,polarity,migration,proliferation,and ***,SIRT1 exhibits dual effects by promoting or inhibiting differentiation in different tissues or *** propose that the concentration of NAM may influence proliferation,differentiation,and SIRT1 signaling of *** To evaluate the effects and underlying mechanisms of action of different concentrations of NAM on HSC proliferation and *** CD{2.^(+)cells were purified from umbilical cord blood using MacsCD{2. beads,and cultured for 10-12.d in a serum-free medium supplemented with cytokines,with different concentrations of NAM added according to experimental *** cytometry was used to detect phenotype,cell cycle distribution,and apoptosis of the cultured ***-time polymerase chain reaction was used to detect the transcription levels of target genes encoding stemness-related factors,che mokines,components of hypoxia pathways,and antioxidant ***-dihydro-fluorescein diacetate probes were used to evaluate intracellular production of reactive oxygen species(ROS).Determination of the effect of different culture conditions on the balance of cytokine by cytometric bead *** Compared with the control group,the proportion and expansion folds of HSPCs(CD{2.^(+)CD{2.)incubated with 5 mmol/L or 10 mmol/L NAM were significantly increased(all Pnificantly

关键词： Hematopoietic stem cells nicotinamide Concentration Proliferation Differentiation Sirtuin 1

Accurate studies on the full vibrational energy spectra and molecular dissociation energies for some electronic states of N_(2.molecule

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Science china(physics,Mecha{2.cs & Astronomy) 2005年第4期48卷 385-398页

作者： ren Weiyi1,2. SUN Weiguo1, HOU Shilin3.& FENG Hao4 1. Institute of {2., College of Chemical Engineering, Sichuan university, Chengdu 610065, {3. 2. Institute of Theoretical {2., Xihua Normal university, Nanchong 63.002. {3. 3. department of {2., {3. Oceanography university, Qingdao 2.6003. {3. 4. College of {2., Sichuan university, Chengdu 610065, {3. Institute of physics College of Chemical Engineering Sichuan University Chengdu China Institute of Theoretical physics Xihua Normal University Nanchong China department of physics China Oceanography University Qingdao China College of physics Sichuan University Chengdu China

It is usually very difficult to directly obtain molecular dissociation energy De and all accurate high-lying vibrational energies for most diatomic electronic states using modern experimental techniques or quantum theories, and it is also very difficult to give accurate analytical expression for diatomic molecular dissociation energy. This study proposes a new analytical formula for obtaining accurate molecular dissociation energy based on the LeRoy and Bernstein’s energy expression in dissociation limit. A set of full vibrational energy spectra for some electronic states of N2.molecule are studied using the algebraic method (AM) suggested recently, and the corresponding accurate molecular dissociation energies are evaluated using the proposed new formula and high-lying AM vibrational energies. The results show that the AM spectra and the new theoretical dissociation energies agree excellently with experimental data, and thereby providing a new physical approach to generating accurate dissociation energies for electronic states of diatomic molecules.

关键词： vibrational energy, dissociation energy, nitrogen molecule, algebraic method.

Toughened (Ti_(0.2.Zr_(0.2.Hf_(0.2.Nb_(0.2.Ta_(0.2.)B_(2.–SiC composites fabricated by one-step reactive sintering with a unique SiB_(6) additive

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Journal of Advanced Ceramics 2024年第1期13卷 86-100页

作者： Wei Hao Xinzhe Lu Ling Li Tao Wang Guoliang ren Huangyue Cai Xiaofeng Zhao Dongyun Wang Na ni Zhejiang Provincial Key Laboratory of Urban Rail Transit Intelligent Operation and Maintenance Technology&Equipment Zhejiang Normal UniversityZhejiang 321004China Key Lab of Education Ministry for Power Machinery and Engineering School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

High-entropy diboride has been arousing considerable interest in recent ***,the low toughness and damage tolerance limit its applications as ultra-high-temperature structural *** we report that a unique SiB_(6) additive has been first incorporated as boron and silicon sources to fabricate a high-entropy boride(Ti_(0.2.Zr_(0.2.Hf_(0.2.Nb_(0.2.Ta_(0.2.)B_(2.–SiC composite though one-step boro/carbothermal reduction reactive sintering.A synergetic effect of high-entropy sluggish diffusion and SiC secondary phase retarded the grain growth of the(Ti_(0.2.Zr_(0.2.Hf_(0.2.Nb_(0.2.Ta_(0.2.)B_(2.–51SiC *** small grain size was beneficial to shorten the diffusion path for mass transport,thereby enhancing the relative density to~99.3..These results in an increase of fracture toughness from~5.2.in HEBS-1900 to~7.7 MPa·m^(1/2. in HEBS-2.00,which corresponded to a large improvement of 48%.The improvement was attributed to a mixed mode of intergranular and transgranular cracking for offering effective pinning in crack propagation,resulting from balanced grain boundary strength collectively affected by improved densification,solid solution strengthening,and incorporation of SiC secondary phase.

关键词： high-entropy diboride silicon hexaboride boro/carbothermal reduction reactive sintering fracture toughness

Quantum statistical entropy corresponding to cosmic horizon in five-dimensional spacetime

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Science china(physics,Mecha{2.cs & Astronomy) 2008年第2期51卷 140-146页

作者： ZHAO ren1,2.& ZHANG ShengLi1 1 {2. of Applied {3., Xi’an Jiaotong university, Xi’an 710049, china 2.{2. of {3., Shanxi Datong university, Datong 03.009, china department of Applied physics Xi’an Jiaotong University Xi’an China department of physics Shanxi Datong University Datong China

The generalized uncertainty relation is introduced to calculate the quantum statis-tical entropy corresponding to cosmic horizon. By using the new equation of state density motivated by the generalized uncertainty relation, we discuss entropies of Bose field and Fermi field on the background of five-dimensional spacetime. In our calculation, we need not introduce cutoff. There is no divergent logarithmic term in the original brick-wall method. And it is obtained that the quantum statistical en-tropy corresponding to cosmic horizon is proportional to the area of the horizon. Further it is shown that the entropy corresponding to cosmic horizon is the entropy of quantum state on the surface of horizon. The black hole's entropy is the intrinsic property of the black hole. The entropy is a quantum effect. In our calculation, by using the quantum statistical method, we obtain the partition function of Bose field and Fermi field on the background of five-dimensional spacetime. We provide a way to study the quantum statistical entropy corresponding to cosmic horizon in the higher-dimensional spacetime.

关键词： quantum statistical entropy generalized uncertainty relation high-dimensional spacetime

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Science china Chemistry 2004年第6期47卷 466-479页

作者： SONG Huajie1,2. XIAO Heming1 & DONG Haishan2.1. department of Chemistry, nanjing university of Science and Technology, {2. 2.0094, {3. 2. Institute of Chemical Materials, {3. Academy of Engineering physics, Mianyang 62.900, {3. department of Chemistry Nanjing University of Science and Technology Nanjing China Institute of Chemical Materials China Academy of Engineering Physics Mianyang China

The symmetry-adapted perturbation theory (SAPT) that has the ability in decompo- sition of the total interaction energy into physically meaningful components is used to provide a more fundamental understanding of intermolecular forces. This work was motivated by the diffi- culty of standard SAPT in computing the intermolecular interactions for large energetic dimer systems. SAPT based on Kohn-Sham orbitals (SAPT(DFT)) proves computationally efficient for these large systems, but has been shown to perform poorly for interaction energy components. The deficiencies of SAPT(DFT) result from wrong asymptotical behaviors of commonly used exchange-correlation potentials. To remove the deficiencies, two asymptotic corrections by means of van Leeuwen and Baerends (LB) model potential and Fermi-Amaldi (FA) type potential were applied into three small test systems comprising He2. HF2.and (N2.2.and a set of larger ni- tramide dimers at several separations. The results showed that when utilizing newly developed frequency-dependent density susceptibilities (FDDS) technique for computing dispersion energy, the FA asymptotic correction is very effective to circumvent these deficiencies in SAPT(DFT) and yields a good accuracy over the LB correction. The FA corrected SAPT(DFT) approach is capa- ble of correctly predicting all the quantitative trends in binding energies for all test cases and substantially reduces computational cost as compared with the standard SAPT calculations. The successful application of the approach to nitramide dimer demonstrates that it potentially pro- vides a good means to calculate accurately intermolecular forces in larger system such as en- ergetic systems.

关键词： intermolecular interaction, density functional theory (DFT), symmetry adapted perturbation theory (SAPT), asymptotic correction, frequency-dependent density susceptibilities (FDDS).

Calculations of β-decay half-lives of proton-rich nuclei

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Science china(physics,Mecha{2.cs & Astronomy) 2012年第12期55卷 2397-2406页

作者： ni dongdong {2. {3. ZHI QiJun department of physics Nanjing UniversityNanjing 210093China Kavli Institute for Theoretical physics china Beijing 100190China Center of Theoretical Nuclear physics National Laboratory of Heavy-Ion AcceleratorLanzhou 730000China GSI Helmholtzzentrum für Schwerionenforschung DarmstadtGermany School of physics and Electronic Science Guizhou Normal UniversityGuiyang 550001China

We investigate the half-lives of β + /EC(electron capture) decay using the proton-neutron quasiparticle random-phase approximation(pnQRPA) with a δ-form Gamow-Teller residual *** particle-hole and particle-particle residual interactions are consistently introduced in dealing with the pnQRPA matrix *** sensitivity of the calculated half-lives to some physical quantities used in the calculations is *** are performed for even-even neutron-deficient isotopes ranging from Z = 10 to Z = *** agreement between experiment and theory is achieved especially for the nuclei far from stability,and the results of our calculations are discussed with comparison with other theoretical *** on the β-decay half-lives of some very neutron-deficient nuclei are also given for reference in future experiments.

关键词： proton-rich nuclei β-decay half-lives quasiparticle random-phase approximation

Simple Formula of β^+-Decay Half-Lives of Nuclei Far From β-Stable Line

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Communications in Theoretical physics 2007年第12期48卷 1072-1080页

作者： ZHANG Xiao-Ping~1 ren Zhong-Zhou~(1,2.and ZHI Qi-Jun~1~1 department of {2.,{3. university,{3. 2.0008,china~2.Center of Theoretical Nuclear {2.,National Laboratory of Heavy-Ion Accelerator,Lanzhou 73.000,china department of physics Nanjing University Nanjing 210008 China Center of Theoretical Nuclear physics National Laboratory of Heavy-Ion Accelerator Lanzhou 730000 China

We generalize the formula of β^+-decay half-lives [***.C 78 (2.06) 0143.5] to include all availabledata of nuclei far from the β-stable line. Good agreement with experimental data is obtained by taking into accountthe even-odd (e-o) *** is shown that the e-o effect on β^+-deeay half-life is apparent for the allowed β^+-transition,whereas it is not apparent for the first and second forbidden *** demonstrates that the allowed β^+-transitionis more sensitive to the nuclear even-odd effect than the forbidden β^+-*** underlying {3. is *** formula can be used to predict the β^+-decay half-lives of the nuclei far from β-*** is useful to experimentalphysicists for analyzing the data of β^+-decay.

关键词： β^+-decay half-lives formula even-odd effect

The optical near-field speckles and their first order statistics on the basis of the integral equations of electromagnetic field

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Science china(physics,Mecha{2.cs & Astronomy) 2004年第3期47卷 365-380页

作者： CHENG Chuanfu1, 2. SONG Hongsheng2. LIU Chunxiang2. ren Xiaorong2. ZHANG ningyu{2. TENG Shuyun1 & XU Zhizhan1 1. Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P. O. Box 800-2.1, Shanghai 2.1800, {{2. 2. department of physics, Shandong Normal university, Jinan 2.0014, {{2. {2. Shandong Institute of Architecture and Engineering, Jinan 2.0014, {{2. Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghaichina department of physicsShandong Normal {2.Jinan{3. Shandong Institute of Architecture and EngineeringJinanchina

From Helmholtz equation of the harmonic electromagnetic waves, the integral equations of the light field at the medium boundaries are obtained by use of the Green's theorem and are discretized into linear equation set with the values of the light field and its derivative as the unknowns. On solving the linear equation set, we realize the rigorous computations of the light fields at the boundaries. Then the intensities of the light waves scattered by the random self-affine fractal surfaces in the optical near-field are calculated, and the propagation characteristics, the evolutions of the contrast and the intensity probability density function of the near-field speckles are studied in detail. The near-field speckles are much different from the conventional speckles in the diffraction regions and in the imaging systems. There are obvious local fluctuations in the intensity distributions of the near-field speckles and such fluctuations disappear after propagating a distance of one wavelength from the medium surfaces. For the random surfaces with smaller lateral correlation lengths, the speckle contrasts approach the saturation values and the speckle fields approach Gaussian distribution within the near-field, while for the random surfaces with larger lateral correlation lengths, such evolutions become comparatively slow.

关键词： speckle, near-field optics, first order statistics, Green's function.