Orlicz空间非负下鞅微分从属不等式

本文在Orlicz空间中推广了Burkholder关于非负下鞅与其微分从属的不等式.     

完全交替结构乙烯-丙烯共聚物的制备与表征

对顺-1,4含量为100%的高顺式聚异戊二烯(HCPI)进行加氢反应,得到了序列结构高度规整的乙烯-丙烯交替共聚物(alt-EP).所用的HCPI有适当的分子量(Mn=41×104)和极窄的分子量分布(Mw/Mn=1.02).HCPI的加氢反应以环烷酸镍和三异丁基铝为催化剂,在60℃和4.0MPa氢压的条件下反应3h,加氢产物的加氢度为100%.GPC测试结果显示所得乙烯-丙烯交替共聚物保持了窄分布的特点,表明HCPI加氢后未发生交联和降解反应;NMR,FTIR和广角X射线衍射测试结果表明此乙烯-丙烯交替共聚物具有高度规整的序列结构,为完全交替结构的乙烯-丙烯共聚物.并通过TGA和DSC对乙烯-丙烯交替共聚物的热性能进行了表征.     

The influence of minimal subgroups on the structure of a finite group

We study the detailed structure of a finite group under the assumption that all minimal subgroups of the generalized Fitting subgroup of some normal subgroup of are well-suited in .

     

Preparation of alpha-phosphono lactams via electrophilic phosphorus reagents: an application in the synthesis of lactam-based farnesyl transferase Inhibitors

Conversion of N-alkyl lactams to the corresponding alpha-phosphono lactams has been investigated through procedures that involve formation of the lactam enolate and reaction with a phosphorus electrophile. With N-octylpyrrolidinone, the enolate could be trapped efficiently on oxygen by reaction with diethyl phosphorochloridate, and the resulting vinyl phosphate rearranges smoothly to the desired phosphonate upon treatment with additional LDA. Attempts to apply the same protocol to N-farnesyl lactams met with limited success. Studies with an isolated alpha-phosphono N-farnesyl lactam have shown that the farnesyl group is not stable to the excess of strong base required for rearrangement of a vinyl phosphate. However, a series of N-farnesyl lactams and imides was converted to the desired phosphonates through formation of the lactam enolate, reaction with diethyl phosphorochloridite, and subsequent oxidation of the phosphorus intermediate to the P(V) state.     

Release and enrichment of 44 elements during coal pyrolysis of Yima coal, China

The coal samples were collected from Yima coal district, China. The pyrolysis experiments were carried out in a simulated bed quartz reactor with a heating rate of 20 °C/min. The 44 elements in raw coal and chars were determined by inductively coupled-plasma mass spectrometry instrument (ICP-MS). The release and enrichment behavior of 44 trace elements during coal pyrolysis of Yima coal was studied.

According to the transformation behaviors, chemical features and thermal features under different pyrolysis temperatures, the 44 elements can be categorized to 4 groups: light elements (Li and Be), nonmetal elements (Se, As, B, etc.), heavy metal elements (including 24 elements, Cu, V, Co, etc.) and rear earth elements (REE) (14 elements). The results showed that (1) the higher pyrolysis temperatures, the higher release ratio and release ratio of REE are very low; (2) the enrichment ratios of the elements in chars increase by the sequence of nonmetal elements < light elements < heavy metal elements < REE. The nonmetal elements, light elements and a few heavy metal elements will be emitted out from coal during coal pyrolysis and they will pollute environment.     

甲壳素——一类新的液晶性多糖

"将甲壳素的结构与纤维素进行了比较, 并根据结构和链刚性指出其形成液晶态的可能性。简要介绍了制备液晶性甲壳素衍生物所必须的一些主要的化学修饰途径。叙述了15 种甲壳素衍生物的溶致液晶行为以及结构因素对它们液晶临界行为的影响。介绍了甲壳素衍生物形成的主要液晶态织构, 如指纹状织构、交替偏振场织构、条带织构和滴状织构, 以及甲壳素衍生物? 二氯乙酸溶液的热致相转变。综述了甲壳素的成纤性和液晶纺丝。     

有限群的最大子群的性质对群结构的影响

有限群G的一个子群称为在G中是π-拟正规的若它与G的每一个Sylow-子群是交换的.G的一个子群H称为在G中是c-可补的若存在G的子群N使得G=HN且H∩N≤HG=CoreG(H).本文证明了:设F是一个包含超可解群系u的饱和群系,G有一个正规子群H使得G/H∈F.则G∈F若下列之一成立:(1)H的每个Sylow子群的所有极大子群在G中或者是π-拟正规的或者是c-可补的;(2)F*(H)的每个Sylow子群的所有极大子群在G中或者是π-拟正规的或者是c-可补的,其中F*(H)是H的广义Fitting子群.此结论统一了一些最近的结果.     

百焦耳级KrF准分子激光实验

介绍闪光Ⅱ号加速器泵浦的百焦耳级氟化氢激光研制情况，给出了激光器的构造和主要性能。在二极管电压为８４０ｋＶ，电流为２００ＫＡ条件下，获得了１５７Ｊ的最大激光能量，峰值功率为２．０ＧＷ。研究了激光输出能量随Ｆ２和Ｋｆ气体浓度的变化规律．     

Effect of source location on particle dispersion in displacement ventilation rooms

A proposed computer model for predicting aerosol particle dispersion in indoor spaces was validated with experimental data found in the literature, and is then used to study the effect of the area and point source locations on particle dispersion in displacement ventilation （DV） rooms. The results show that aerosol source location has a strong impact on the spatial distribution and removal rate of indoor particles. Particle removal performance depends strongly on ventilation efficiency and particle deposition rate on indoor surfaces. Important consideration for both relative ventilation efficiency and deposition rate consists of the position of the aerosol source relative to the main airflow pattern and the occupied zone.