碱度对杂原子介孔分子筛相转变的影响

在十六烷基三甲基溴化铵、正硅酸乙酯、氢氧化钠体系中添加不同铝源、钛源制备杂原子介孔MCM-48分子筛。通过调变母液的碱度,经水热晶化在不同杂原子源合成体系中按不同次序分别得到杂原子M41S系列的六方相(MCM-41)、立方相(MCM-48)和层状相(MCM-50)产物,其中立方相产物出现在较窄的碱度区间。合成过程中硅源正硅酸乙酯在不同碱度下的缩聚产物硅酸根多聚体或低聚体和水解产物乙醇的含量是生成立方相产物的关键因素,而杂原子源中的异丙醇会削弱碱度对产物相态的影响。在此相变规律基础上,对于不同杂原子源采用合适的母液碱度获得高杂原子含量的n(Si)∶n(Al)=20的Al-MCM-48分子筛和n(Si)∶n(Ti)=50的Ti-MCM-48分子筛。

杂原子介孔分子筛Co-MCM-41的合成及表征

采用水热法成功合成了介孔分子筛Co-MCM-41,并考察了晶化时间、晶化温度、p H值、陈化时间对合成介孔分子筛Co-MCM-41的影响。确定较适宜的合成条件为晶化温度110℃,晶化时间48 h,p H值10-11,陈化时间1 h,Co-MCM-41热稳定性研究表明,当焙烧温度增加到900℃,介孔结构出现坍塌。

双杂原子介孔材料的合成及催化应用

在强酸性条件下,采用沸石前驱体溶液与表面活性剂自组装的方法,合成了双杂原子掺杂的介孔催化材料Sn/Ti-MS-1.表征结果显示,Sn/Ti-MS-1具有介孔结构,骨架中含有TS-1沸石的结构单元.在苯酚和2,3,6-三甲基苯酚的双氧水氧化反应中,焙烧前后的Sn/Ti-MS-1均表现出了良好的催化反应活性,表明其钛物种具有良好的热稳定性,并且在大分子氧化反应中具有明显的优势.同时,这种Sn/Ti双杂原子介孔材料显示了较快的催化反应速率.

原子核的有限大小对原子能级的影响

本文用微扰理论的方法讨论了原子核的有限大小对原子能缓的影响，并对介原子进行了具体分析，得到了对较重元素的介原子其体积效应不可忽视的结论。

双色激光场中μ^3He的电离行为

为了探究双色激光对于电离行为的影响,数值求解了一维含时的Schrdinger方程,着重分析双色激光场的相对相位、倍频对介原子μ3He的电离影响。结果表明:双色激光场的相干作用可以使介原子μ3He电离率(较单色激光作用下介原子μ3He的电离率而言)大大增加,且双色激光的3倍频参数对电离的控制较2倍频强;介原子μ3He电离率随倍频激光间相对相位灵敏的变化,从而可以在μ子催化聚变反应中引入合适的双色激光,电离μ3He,使μ子重生,参加下一轮催化反应。

光学概论

O431 99020701光学势在K原子中的应用=Applications of opticalpotential to K atom[刊,中]/游阳明,刘宝方(河北省沧州师范专科学校.河北省,沧州(061000)),宁平治(南开大学.天津(300071))//哈尔滨理工大学学报.—1998,3(4).—82—84通过对K原子的Klein-Gordon方程的数值求解,得到了一组K原子能级,由此计算的能级跃迁与实验数据基本吻合,有力地支持了光学模型在介原子中应用的正确性,进一步证明了核子间的强相互作用为吸引力,其大小在(200-20)MeV数量级。表2参5(吴淑珍)O431

院士风采

张文裕1910.1.9～1992.11.5高能物理学家。福建惠安人。1931年毕业于燕京大学。1938年获英国剑桥大学博士学位。中国科学院高能物理研究所研究员、所长、名誉所长。

Antikaon Condensation and In-medium Kaon and Antikaon Production in Protoneutron Stars

Antikaon condensation and kaon and antikaon production in protoneutron stars are investigated in a chiral hadronic model （also referred to as the FST model in this paper）. The effects of neutrino trapping on protoneutron stars are analyzed systematically. It is shown that neutrino trapping makes the critical density of K^- condensation delay to higher density and fifo condensation not occur. The equation of state （EOS） of （proto）neutron star matter with neutrino trapping is stiffer than that without neutrino trapping. As a result, the maximum masses of （proto）neutron stars with neutrino trapping are larger than those without neutrino trapping. If hyperons are taken into account, antikaon does not form a condensate in （proto）neutron stars. Meanwhile, the corresponding EOS becomes much softer, and the maximum masses of （proto）neutron stars are smaller than those without hyprons. Finally, our results illustrate that the Q values for K^＋ and K^- production in （proto）neutron stars are not sensitive to neutrino trapping and inclusion of hyperons.

Production of Neutral Top-Pion Associated with a Gauge Boson at LHC

In this paper, we study the production of the neutral top-pion （Πt^0） associated with a gauge boson at the LHC, i.e. pp →Πt^0V （V = g, W, Z, γ）. The cross section of pp→Πt^0g is at the level of 10^2 pb in the most parameter space. Such a process with the flavor-changing decay mode Πt^0→tc might provide viable signatures to detect rio at the LHC. The cross sections of other processes pp →→Πt^0W（Z,γ） distinguish the Higgs boson in the SM or MSSM from rio. are too small to detect Πt^0, which open a window to distinguish the Higgs boson in the SM or MSSM from Πt^0

Correspondence Between Oscillations and Emitted Photon Closed-Orbits in Spontaneous Emission Rate of an Atom Near a Dielectric Slab

We study the oscillations in the spontaneous emission rate of an atom near a dielectric slab. The emission rate is calculated as a function of system size using quantum electrodynamics. It exhibits multi-periodic oscillations. Four frequencies of the oscillations are extracted by Fourier transforms. They agree with actions of photon closed-orbits going away and returning to the atom. These oscillations are explained as manifestations of quantum interference effects between the emitted photon wave near the atom and the returning photon waves travelling along various closed-orbits.

Study on Production of Exotic 0^＋ Meson D＇^＊aj（2317） in Decays of ψ（4415）

The newly observed D^＊aj family containing D^＊aj（2317）, Daj（2460）, and Daj（2632） attracts great interests. Determining their structures may be an important task for both theorists and experimentalists. In this work we use a non-relativistic model （the harmonic oscillator model） to evaluate the production rate of D^＊aj （2317） from the decays of ψ（4415）. For a comparison, we a/so employ the widely adopted heavy quark effective theory to repeat the calculation. We lind that the rate is sizable and may be observed at BES III and CLEO, if it is a p-wave excited state of Da（1968）. Unfortunately, the other two members of the family cannot be observed through decays of charmonia, because of the constraints from the final state phase space.

Entanglement Dynamics of Atoms in Double Jaynes-Cummings Models with Kerr Medium

Entanglement dynamics of the atoms in the double Jaynes-Cummings models with the Kerr medium isstudied, and the effect of the Kerr medium on that is examined.The result shows that, the Kerr medium can control theentanglement dynamics of the atoms and repress entanglement sudden death.We can obtain the maximum entanglementbetween the atoms by strengthening the nonlinear interaction of the Kerr medium.

Ultra-slow Bright and Dark Optical Solitons in Cold Media

We present a systematic study on the formation of ultra-slow bright and dark optical solitons in highly resonant media. By investigating four life-time broadened atomic systems, i.e., three-state A-type and cascade-type schemes, and four-state N-type and cascade-type schemes, we show that the formation of such ultra-slow solitons in cold atomic systems is a fairly universal phenomenon.

Some Properties of $\pi$ Meson in Nuclear Matter with Finite Density

In the GCM we study some properties of meson as the Goldstone bosons in a nuclear matter with finite density. Using the effective action in a nuclear matter, we calculate the decay constant and mass as functions of the chemical potential. The relation between the chemical potential and the density of a nuclear matter is firstly given here. We find that and monotonously decrease as nuclear matter density increases. The result is consistent with the usual assumption that the chiral symmetry is gradually restored as the density of a nuclear matter increases.

Atomic Coherent Trapping and Properties of Trapped Atom

Based on the theory of velocity-selective coherent population trapping, we investigate an atom-laser system where a pair of counterpropagating laser fields interact with a three-level atom. The influence of the parametric condition on the properties of the system such as velocity at which the atom is selected to be trapped, time needed for finishing the coherent trapping process, and possible electromagnetically induced transparency of an altrocold atomic medium, etc., is studied.

Cavity Field Spectra of a Cascade Three-Level Atom Interacting with a Single-Mode Field with Kerr-Like Medium

The cavity field spectrum of a cascade three-level atom interacting with single-mode field with Kerr-like medium in the cavity is investigated. The numerical results for the initial field in pure number state, coherent state and squeezed vacuum state are calculated, respectively. It is found that the Kerr-like medium affects the spectral structure even though the initial field is in vacuum when the atom is in upper level. In the case of strong input field, the number state spectrum shows two peaks with different heights; and the superposition state spectrum shows a multipeak structure with an equal distance of two neighboring peaks. The spectral ＂central frequency＂ shifts away from the resonant frequency with the increasing of average photon number.

Theoretical Studies on Expressions of Condensed-Phase Photoionization Cross Section

A set of general expressions for photoionization cross sections of atoms or molecules embedded in a medium and a dielectric influence function are derived based on Maxwell＇s equations and the Beer-Lambert＇s law in this work. The applications are performed for the photoionization process of solid gold both in the Clausius-Mossotti （virtual cavity） model and the Glauber-Lewenstein （real cavity） model firstly. The results show that the present theoretical expressions of photoionization cross section can be used to describe the photoionization process of atoms in condensed matter properly.

In-situ synthesized mesoporous TiO_2-B/anatase microparticles:Improved anodes for lithium ion batteries

Mesoporous TiO_2-B/anatase microparticles have been in-situ synthesized from K_2Ti_2O_5 without template.The TiO_2-B phase around the particle surface accelerates the diffusion of charges through the interface,while the anatase phase in the core maintains the capacity stability.The heterojunction interface between the main polymorph of anatase and the trace of TiO_2-B exhibits promising lithium ion battery performance.This trace of 5%(by mass) TiO_2-B determined by Raman spectra brings the first discharge capacity of this material to 247 mA · h ·g^(-1),giving 20%improvement compared to the anatase counterpart Stability testing at 1 C reveals that the capacity maintains at 171 mA·h·^(-1),which is better than 162 mA·h·g^(-1) for single phase anatase or 159 mA·h·g^(-1) for TiO_2-B.The mesoporous TiO_2-B/anatase rnicroparticles also show superior rate performance with 100 mA·h·g^(-1) at 40 C,increased by nearly 25%as compared to pure anatase.This opens a possibility of a general design route,which can be applied to other metal oxide electrode materials for rechargeable batteries and supercapacitors.

A Comparative Study of f_B within QCD Sum Rules with Two Typical Correlators up to Next-to-Leading Order

The B-meson decay constant fB is an important component for studying the B-meson decays, which can be studied through QCD sum rules. We make a detailed discussion on f B from two sum rules up to next-to- leading order, i.e. sum rules I and II, which are derived from the conventional correlator and the correlator with chiral currents respectively. It is found that these two sum rules are consistent with each other. The sum rules H involves less non-perturbative condensates as that of sum rules I, and in principle, it can be more accurate if we know the dimensionfour gluon condensate well. It is found that fB decreases with the increment of mb, and to compare with the Belle experimental data on fB, both sum rules I and H prefer smaller pole b-quark mass, mb= 4.68 ± 0.07 GeV. By varying all the input parameters within their reasonable regions and by adding all the uncertainties in quadrature, we obtain fB=172-25^＋23 MeV for sum rules I and fB =214-34^26 MeV for sum rules П.

Synthesis, characterization of triphenyltin grafted on SBA-15mesoporous silica and its catalytic performance for the synthesis of 4-methylacetophenone

The production of Ph3Sn–O–SBA-15(Ph3Sn SBA)was achieved by heating triphenyltin chloride and SBA-15in N-methylpyrrolidone at 190°C for 5 h using triethylamine as a catalyst.The composition,structure,and surface physical and chemical properties of Ph3Sn SBA were characterized using inductively coupled plasma-atomic emission spectroscopy(ICP-AES),13C,119Sn and29Si solid-state nuclear magnetic resonance(NMR)spectroscopy in situ pyridine infrared spectroscopy(Py-IR),N2adsorption–desorption isotherms,X-ray diffraction(XRD)and transmission electron microscopy(TEM).The results of ICP-AES and organic elemental analysis showed that the grafting yield of Sn was 17%(by mass)for Ph3Sn SBA.The elemental analysis and solid-state NMR results for Ph3Sn SBA were consistent with grafting of triphenyltin on SBA-15.The N2adsorption–desorption,XRD and TEM analyses showed that Ph3Sn SBA retained an ordered hexagonal mesoporous structure,resulting in decreases in the surface area,pore size and mesopore volume,and an increase in acidity as compared with SBA-15.The Hammett acidity function(H0)value and the number of acid sites for Ph3Sn SBA,obtained by the Hammett methods,were 2.77–3.30 and 2.07 mmol·g-1,respectively.The Friedel–Crafts acylation of toluene and acetic anhydride over Ph3Sn SBA was investigated.The yield of methylacetophenone(MAP)and the selectivity for 4-methylacetophenone(PMAP)were 79.56%and 97.12%,respectively,when the conditions were n(toluene):n(anhydride)=2.0:1.0 with 6%(by mass)catalyst,and heating under reflux for 5 h.The PMAP selectivity still reached 93.11%when Ph3Sn SBA was used for the fifth time under the same reaction conditions.