Characteristics of π−,\bar p,and antinuclei frompp collisions

An investigation of inclusivepp→π^?+? in terms of the covariant Boltzmann factor (BF) including the chemical potential μ indicates a) that the temperatureT increases less rapidly than expected from Stefan's law, b) that a scaling property holds for the fibreball velocity of π^? secondaries, leading to a multiplicity law like ～E _cm ^1/2 at high energy, and c) that μ_π is related to the quark mass: μ_π=2m _q ?m _π the quark massm _q determined by \(T_{\pi ^ - } \) at \(\bar pp\) threshold beingm _q =3T_π?330 MeV. Because ofthreshold effects \(T_{\bar p}< T_{\pi ^ - } \) , whereas \({{\mu _p } \mathord{\left/ {\vphantom {{\mu _p } {\mu _{\pi ^ - } }}} \right. \kern-0em} {\mu _{\pi ^ - } }} \simeq {3 \mathord{\left/ {\vphantom {3 2}} \right. \kern-0em} 2}\) as expected from the quark contents of \(\bar p\) and π. The antinuclei \(\bar d\) and \({{\bar t} \mathord{\left/ {\vphantom {{\bar t} {\overline {He^3 } }}} \right. \kern-0em} {\overline {He^3 } }}\) observed inpp events are formed by coalescence of \(\bar p\) and \(\bar n\) produced in thepp collision. Semi-empirical formulae are proposed to estimate multiplicities of π^?, \(\bar p\) and antinuclei.     

XeF和KrF的热催化合成及KrF在含氟高能氧化剂NFBF合成中的应用

本文介绍了一种以氟气和惰性气体为原料合成 Kr F2 和 Xe F2 的热催化合成方法并对合成机理和条件作了简单的讨论 ,利用合成的 Kr F2 作为氟化剂合成了含氟高能氧化剂 NF4BF4,纯度约为 93%,其红外光谱和拉曼光谱基本与文献值吻合。元素分析结果表明产品 NF4BF4中含 B5.8%(mass) ,自由氟原子含量为 9.95%(mass) ,与理论值基本一致 ,此结果也间接证明了 Kr F2 质量的可靠性。粉末状的 Xe F2 经升华 -再结晶纯化后可得纯净晶体产品。     

2-(1,11-十一亚甲基)-5-取代亚氨基-△~3-1,3,4-噻二唑啉的合成及杀菌活性

通过环十二酮与 N -取代氨基硫脲的缩合反应 ,合成了一系列 N -取代环十二酮缩氨基硫脲 ,经Mn O2 氧化关环 ,得到 1 5种未见文献报道的标题化合物 ,其结构经 IR,1 3C NMR,元素分析的确证 .初步实验表明 ,部分化合物具有一定的杀菌活性     

Pu（^7Fg）＋H2（X^1∑g^＋,0,0）的分子反应动力学

基于PuH_2分子基态(X~7A_1)的分析势能函数，用准经典的Monte-Carlo轨线法 对Pu(~7Fg)+H_2(X~1∑_g~+，0，0)的分子反应动力学过程进行了计算。结果表明 ：Pu(~7F_g)与H_2(X~1∑_g~+，0，0)碰撞是弹性碰撞。     

SiO_2负载钼催化剂的合成及其催化乙烯二聚、同系化和歧化的反应性能

从单核及双核二甲胺钼络合物出发,制备了SiO_2负载的钼催化剂。程序升温分解实验(TPDE)及红外测试表明,双核钼络合物与SiO_2作用生成双钼中心物种,此物种可催化乙烯的二聚反应。280℃活化后此双钼中心物种变成单钼中心物种,单钼物种只催化乙烯的同系化及歧化反应。     

A Novel Cu-Mo／ZSM-5 Catalyst for NOx Catalytic Reduction with Ammonia

The Cu-Mo/ZSM-5 catalysts with different Cu/Mo ratios were prepared by wet impregnation method, and their catalytic performance for selective catalytic reduction of NOx was studied. The results showed that Cu-Mo/ZSM-5 is a very effective catalyst for NOx catalytic reduction with ammonia, especially when Cu/Mo molar ratio is about 1.5. It not only exhibited the extremely high catalytic activity, but also showed good stability for 02. The bulk phase structure of Cu-Mo/ZSM-5 catalysts was determined by XRD technique, and the results indicated that there is a maximum dispersion for Cu species when Cu/Mo molar ratio is 1.5, and an interaction between Cu and Mo along with HZSM-5 may be present in Cu-Mo/ZSM-5, which may possibly result in a special structure favorable for the catalytic reduction of NOx over Cu-Mo/ZSM-5 catalyst.     

Durch Bromierung ausgelöste Umlagerung tertiärer Allylalkohole: Der Einfluss eines Fluor-Substituenten auf Reaktionsgeschwindigkeit und Reaktionsverlauf

Rearrangement of Tertiary Allyl Alcohols Induced by Bromination: The Effect of a Fluorine Substituent on the Rate and the Outcome of the Reaction The allyl alcohol bearing a methyl and a t-butyl group at the hydroxylated position was found to undergo a rearrangement when treated with bromine (or N-bromosuccinimide) in an aqueous medium and to afford a product mixture containing two regioisomeric ketones and one oxirane. Introduction of an additional methyl group or a fluorine atom at the non-terminal olefinic center led to a more selective discrimination between potential migratory groups. As the result of an exclusive t-butyl shift only one product, a ketone, was formed in both cases. Whereas the reaction rate was only slightly affected by the additional methyl group, it was substantially decreased by the fluorine atom.     

用高效疏水色谱法对多种脲变α-淀粉酶折叠中间体的研究

用高效疏水色谱法对用脲变性的α-淀粉酶的体外折叠中间体进行了分离，发现脲变α-淀粉酶折叠至少有19个中间体，而且，这些中间体在色谱流出液中可稳定一周．这一结论已由电泳、离子交换色谱和体积排阻色谱法证实．此外，还用紫外吸收光谱和荧光发射光谱研究了这些折叠中间体与天然α-淀粉酶构象之间的差异．     

氢谱在甾醇类化合物定量和纯度分析中的应用

用^1HNMR谱可定量确定繁茂膜海绵(Hymeniacidon perleve)中分离得到的结构类似的甾醇类化合物的含量，这种方法是对鉴定分析组成复杂而性质很相近的天然甾醇化合物的新思路。