STUDY OF THE REACTION K-p → πo Λ

It is shown that at high energy all available data for differential and integrated cross sections and the Λ-polarization in the reaction K^-p → π^o Λ can be fitted by using a simple Regge pole model with phenomenological residue functions. The characteristics of helicity and helicity non-flip amplitudes are also examined.     

合金元素韧化或脆化FeAl金属间化合物的微观机制

通过测量二元FeAl以及含B，Zr或Si的FeAl合金的正电子寿命谱参数，计算合金基体和缺陷处的价电子密度.结果表明，当Al原子和Fe原子结合形成FeAl合金时，Al原子提供价电子与Fe原子的3d电子形成局域的共价键.FeAl合金基体的价电子密度很低，FeAl合金中金属键和共价键共存.FeAl合金晶界缺陷的开空间大于Fe空位或Al空位的开空间，FeAl合金晶界处的金属键合力很弱.在FeAl合金中加入少量的B，一部分B原子以间隙方式固溶到FeAl基体中，增加基体的价电子密度；另一部分B原子偏聚到FeAl合金的晶界上，也增加了晶界处的价电子密度.在FeAl合金中加入Zr，增加了合金中的金属键成分，使基体中的价电子密度增加，增强了基体中金属键合力.Zr原子的加入还降低了FeAl合金的有序度，使合金晶界容易弛豫，晶界缺陷的开空间变小.Zr原子在晶界附近出现，还增加了晶界处的价电子密度.在FeAl中加入B或Zr有利于提高合金的韧性.在FeAl合金中加入Si，晶界处的Si原子与邻近的原子形成强的共价键，使得在晶界处参与形成金属键的价电子密度降低.在FeAl中加入Si使合金更脆. 关键词：     

THEORETICAL INVESTIGATION OF THE ISOSPIN VIOLATING HADRONIC TRANSITIONS Ψ'→Ψ(11P1)+π° AND T"→T(11P1)+π°

The isospin violating processes Ψ'→Ψ(1¹P₁)+π° and T"→T(1¹P₁)+π° are investigated in the framework of the multipole expansion in quantum chromodynamics. Using the rate of Ψ'→Ψ+π° as an input to determine the isospin violating vertex, we obtain the following branching ratios for the processes BR(Ψ'→Ψ(1¹P₁)+π°)～10^-6-10^-5, BR(T"→T(1¹P₁)+π°)～10^-5-10^-3 for M₁1_p1=1/9(5M₁3_p2+3M₁3_p1+M₁3_p0). These are too small to be detected in the present experiments.     

应用于双原子分子转动谱的ab公式的微观机制

此文给出了著名的核谱的ａｂ公式应用于双原子分子转动谱时的微观机制。     

THE DUAL ABSORPTIVE MODE AND πP ELASTIC SCATTERING REVISITED

Using the Regge pole phase rule for contrilbutions to both amplitudes the DAM is applied to ^πp elastic scattering in the p_lab≥10 GeV/c and |t|≤0.8(GeV/c)² region. It is found that the DAM has a mixed success in describing ^πp scattering. The p contribution to both amplitudes is in accord with the DAM while the f-non-flip contribution does not have a peripheral zero.The Pomeron imaginary part is in accord with the DAM with a non-negligible Pomeron phase so that the DAM approximation Rep=O is unsatisfactory. There is also a Pomeron-flip contribution contrary to the expectation of the model. The O-flip contribution is taken into account and a small f-flip contribution i s also required.     

Pd(OAc)2与有机膦在氯代烷中的反应机理

应用电子自旋捕获技术(EPR-ST)研究了Pd(OAc)₂与有机膦dppm(二,二苯基膦甲烷)及dppe(二,二苯基膦乙烷)在氯代烷中反应生成新奇配合物PdCl₂[PPh₂CHClPPh₂]这一新反应的反应机理,所用捕获剂为PBN和POBN,得到EPR实验谱并进行了模拟.提出了反应机理并进行了讨论.反应经过dppm的均裂、夺氯、夺氢后生成新配体[PPh₂CHClPPh₂],然后发生配位取代和配位反应,生成新的配合物PdCl₂[PPh₂CHClPPh₂].并对影响反应的因素进行了探讨,溶剂效应在此类自由基反应中起重要作用,其极性对反应的发生影响很大,主要是对过渡态1及2的影响.Pd(OAc)₂在反应中既是反应物还是引发剂,在反应中起分子诱导作用.     

THE DECAY ρ→ππ IN LATTICE GAUGE THEORY

The hadronic decays are studied by using an improved Hamiltonian including 2-link interactions. We find that the formulation is effective for studying hadronic decays as well as mass spectrum. In the intermediate coupling region,the decay width of ρ meson is found to be of the right order of magnitude.     

一种新的反应机制——轻稀土金属薄膜与Si衬底的反应机理研究

以La,Ce为例对轻稀土金属与Si的薄膜反应机理进行了研究。在超高真空(UHV)下,用电子束蒸发制备样品,继之以恒温电阻炉退火,并利用俄歇深度分析、X射线衍射和二次离子质谱等手段对各种等温或等时退火样品进行了分析。发现在200—400℃范围内,轻稀土金属与Si的薄膜反应存在极限,且这一极限不是稳定的化学相。文中提出一种反应模式,并以此导出反应机制,解释了实验结果。 关键词：     

菌紫质光电作用的分子机制

本文介绍了一种新型的生物分子光电功能材料─-细菌视紫红质,对其结构、光电功能和光化学性质作了简单介绍,着重对其光电作用机理从分子生物学角度进行了阐述,对其在光电器件、神经网络和仿视觉功能系统方面的实际应用给出了几个例子。     

层流预混火焰PAHs形成的反应机理模型

本文着重讨论层流预混火焰中,碳黑的先驱多环芳烃(PAHs)形成的化学反应动力学机理。该机理包括101种组分、546个基元反应。通过与实验结果的比较表明,该模型能够较好地预报碳氢燃料预混火焰中PAHs的生成过程。计算结果还表明当量比和压力PAHs的生成与排放具有重要影响,且存在一个化学当量比,在此当量比下,PAHs的浓度达到极大值。     

A MICROSCOPIC MECHANISM OF LOW TEMPERATURE HELIUM RELEASE

⁴He ions of various energies and at various doses were implanted into three kinds of samples: TiH₂ films, high purity Ti pieces as-received and after hydrogenation. Thermal release of helium was monitored in situ by proton-enhanced backscattering. Low-temperature helium release was observed at T≤573K. Single jump model was used to calculate the active energies for the release. Based on the observations, a mechanism of helium cluster vacancy complex (He_mV_n-V_i) for low temperature helium release is proposed.     

Pd(OAc)2与有机双膦在氯代烷中的反应机理(Ⅱ)研究

在前文^[1,2]基础上,扩展了有机双膦系列.应用电子自旋捕获技术(EPR-ST)研究了Pd(OAc)₂与系列有机双膦dppm(二(二苯基膦甲烷))、dppe(二(二苯基膦乙烷))及dppp(二(二苯基膦丙烷))在氯代烷中反应的反应机理,所用捕获剂为PBN,得到EPR实验谱并进行了模拟.提出了反应机理并进行了讨论.并对影响反应的一些因素进行了探讨.Pd(OAc)₂在此反应中既是反应物又是引发剂,在反应中起分子诱导作用.当Pd(OAc)₂与非自由基物种有机双膦配体及氯代烷共存时,引发了自由基反应。     

槲皮素化学发光反应机理探讨

本文测量了槲皮素的化学发光光谱,λmax为520nm。研究了槲皮素的化学发光反应,反应过程的荧光,动力学特性及产物的纸色谱。首次提出了槲皮素-H2O2-KOH的一种可能的化学发光反应机理。     

Three-Body Amplitudes of the Process a2(1320) → π+π+π-

We analyze the decay amplitudes of the process a₂(1320) → π⁺π⁺π^- using the tensor analysis technique and show how to obtain three-body amplitudes. The derived amplitudes can describe both the resonance and the background contribution of the process.     

铝基矿物在钙基固硫过程中的固相反应机理分析

在高温电阻炉中对高硫煤掺入钙铝基添加剂后进行燃烧试验,分析了不同条件下煤中加入添加剂后固硫效率、固硫灰渣的矿物组成及微观形貌的变化特性;综合采用TG-FTIR-XRD研究了化学纯矿物CaO-A12O3-CaSO4体系中硫酸钙的高温热分解过程及产物组成.结果表明,A12O3的加入通过固相反应来影响钙基固硫效率,A12O3对固硫效率的影响并非呈单一性;低温下生成Ca-Al酸盐矿物削弱了固硫反应,而高温下CaSO4与灰中生成的含Ca、Al类矿物反应形成高温固硫物相硫铝酸钙并抑制其分解则提高了钙基固硫效率.     

氮丙啶衍生物的稳定性和固化反应机理的^13C—NMR研究

本文用~(13)C-NMR方法研究了间苯二甲酰二(2-甲基氮丙啶)和癸二酰二(2-甲基氮丙啶)的稳定性和固化反应机理。在常温下,这两种化合物均可缓慢重排为(口恶)唑啉,也可同空气中水发生水解反应。在重排和固化反应过程中,它们的N-CH和N-CH_2键断裂情况是不同的。     

AlPO4-5分子筛与NaF反应机理的研究

本文用XRD和³¹P NMR研究以Et₃N为模板剂合成的AlPO₄-5分子筛与NaF的反应机理。研究结果表明P、Al在AlPO₄-5分子筛中是严格有序交替排列的,且这种排列与合成中所用模板剂无关,并提出了上述反应的机理。     

桑色素荧光法测定痕量锗的反应机理研究

本文对桑色素荧光法测定痕量锗的反应机理进行了较为详细的研究。确定了该反应的络合比，用荧光法，紫外吸收法和红外吸收法确定了反应的位置，从而得到了桑色素荧光法测痕量锗的理论根据。     

THE SYMMETRIC STRUCTURE OF EXCITED STATES OF 13ΛC AND INVESTIGATIONS OF THE ANGULAR DISTRIBUTIONS OF 13C(K-,π-)13ΛC*

Based on the meth SU₃ × SU₂ supermultiplet classification,we studied the symmetric compon-ents of 10.4 and 16.4 MeV configuration of the ¹³_ΛC hypernucleus by calculating the hypernucleus by calculating the angular distribution of ¹³C(K^-,π^-)¹³_ΛC^* in the framework of DWIA, and analysed the effects of varying the parameters on the angular distributions.     

ON THE REACTION MECHANISM AND THE SELECTION RULE IN THE DOUBLE CHARGE EXCHANGE REACTION OF PIONS ON NUCLEI (DCX)-A STUDY OF THE CONNECTION BETWEEN THE 2β-DECAY AND DCX ON jP=O+ NUCLEI

It is shown that in the pion induced double charge exchange reaction on J^p=O⁺→O⁺ nuclei,there exists a possible new reaction mechanism π⁺(Δ⁰,Δ⁺⁺)π^- or π⁺(Δ^-,Δ⁺)π^- in so-called single step process,while that old speculative mechanism π⁺(N,Δ)π^- or π⁺(N,Δ)π^- is firbidden by a well-known selection rule which has been indicated in the theory of the nuclear 2β-decay.