Photocoupling Reactions of Haloaromatic Hydrocarbons With Aromatic Compounds——Synthesis and Mechanism

An effective method of synthesizing polyaromatic hydrocarbons with high selectivity was developed through our research work on the photocoupling reactions between several haloaromatic hydrocarbons and aromatic compounds. The structures of polyaromatic hydrocarbons synthesized were determined by IR, UV, ~1H NMR, MS and elemental analysis, and the crystal structure of 3-(1-naphthyl)-coumarin was established by an crystallographic analysis. Further study of the regioselectivity, orientational effect of substituents, solvent effect, sensitizing and quenching effect supported the proposed mechanism of this type of reaction involving election transfer process under excited triplet state.     

光子加速器的理论研究

研究了光子加速器(即利用等离子体中的朗谬尔波实现光脉冲频率上转换)所涉及的基本物理问题.文中导出了在存在朗谬尔波的条件下,光脉冲频率对于等离子体本底密度及电子密度扰动的依赖关系,并就最大频率转换、光脉冲俘获、波的加速位相(accelerating phase)以及位相滑动(phase slippage)效应进行讨论.     

稳态自洽密度分布的三参量解族

本文利用严格的解析方法求得了激光等离子体中稳态自洽密度分布的三参量解族。讨论几种特殊情况,指出Lee等人给出的平台型密度分布只是其中的一种特殊情况。 关键词：     

温离子对动力迥旋损失锥不稳定性的作用

本文详细研究了温离子对动力论迴旋损失锥(DCLC)不稳定性的作用,并与温离子抑制流体近似下DCLC模的理论进行了比较,发现由于(1)磁漂移共振耗散可以激发负能的DCLC波;(2)另一种新的正能波可以因共振获得能量而增长;因此当流体近似DCLC模被少量温离子所抑制的同时,动力论DCLC模仍然是不稳定的。所以要抑制动力论DCLC不稳定性需要注入更多的温离子,本文给出了定量的结果。 关键词：     

非晶态Fe87-xSixB13合金的磁化强度、电阻与温度的关系

本文研究了非晶态Fe_87-xSi_xB₁₃(x=0,9.6,14.5)合金的饱和磁化强度、电阻率与温度的关系。得到样品的居里温度T_C和晶化温度T_cr随Si含量的增加而明显提高。低温下的热磁关系符合布洛赫的T^3/2定律,计算出自旋波劲度系数D从x=0时的62meV·A²增加到x=14.5时的111meV·A²。从D值和Handrich理 关键词：     

(Tb,Dy)Fe2金属间化合物的巨大磁致伸缩

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体外培养三个人体肝癌细胞系的建立及其特征

从两例男性和一例女性肝癌患者获得的临床手术标本,经离体培养建成三系细胞,分别定名为:BEL-7402,BEL-7404和BEL-7405,在建系过程中(从第2代起),陆续对它们的生物学特征进行观察,细胞群体的倍增时间为20—26小时,动物异种移植能形成肿瘤结节,它们不仅在形态上均为上皮样细胞,且在电子显微镜下亦均显示上皮细胞所具有的桥粒和张力原纤维,它们的超显微结构显示与正常人肝细胞不同,而与临床肝癌细胞相似,三系细胞的染色体数均为不足三倍体值,均有一个异常长的近端着丝点染色体,但在BEL-7405系细胞中尚有微小的近端着丝点染色体和染色体断片的存在,免疫荧光间接法检测三系细胞内的AFP均显示阳性反应,LDH同功酶谱显示与成年人肝不同,而与人胚肝和临床肝癌相近似,即趋向于以LDH-1(H-型)比LDH-5(M-型)的酶活力高,上述几方面观察的结果,表明三系人肝癌均属生长迅速、分化较差的上皮样恶性细胞。     

千周和兆周范围的马氏体相变内耗以及预马氏体相变内耗

在千周和兆周两个频段分别测量了含Cd为46.1at％,47.5at％,50.0at％和52.5at％的AuCd合金中与马氏体转变有关的内耗和杨氏模量。实验结果表明,在千周范围,由于马氏体转变引起的Q^-1(内耗)是静滞后型的。Q^-1峰的形成可以用弹性软化及界面位错的静滞后阻尼机制来解释。而兆周范围的超声衰减是与频率有关的,表明尚有共振型及弛豫型阻尼的成份。此外,实验还观察到AuCd合金的等温马氏体转变Q^-1峰以及预马氏体相变Q^-1峰。 关键词：     

DEVELOPMENT AND IDENTIFICATION OF CHINESE SPRING Ta1 kr ph1b PLANTS AND THEIR USE ON GENETIC TRANSFER OF DESIRABLE GENES FROM Aegilops

Chinese Spring Tal kr phlb plants were developed by hybridizing Tal common wheat and Chinese Spring phlb mutant and backcrosses. When Chinese Spring Tal kr phlb plants were crossed with some wild species of Triticeae, much more seeds of wide hybridization can be obtained without artificial emasculation and pollination because of the existence of Tat and kr genes. The homoeologous chromosomes between common wheat and the wild species of Triticeae can also pair and exhibit cross-over in the hybrid F1 plants because of the existence of the phlb gene. So that more alien desirable genes can be transferred to common wheat rapidly. Therefore, Chinese Spring Tal kr phlb plants become a powerful tool for wide hybridization and transferring alien desirable genes to common wheat.     

FORMATION AND MAGNETIC PROPERTIES OF Dy2Fe17-xMnxC(x = 0-17) PREPARED BY ARC-MELTING

We report on alloys formed by replacing iron with manganese in the compound Dy₂Fe₁₇C_1.0 Samples were characterized by X-ray diffraction and magnetic measure-ments, The 2:17-type structure can be crystallized in the whole range of manganese substitution. The Curie temperature of the series of Dy₂Fe_17-xMn_xC_1.0(x= 0-17) drops down considerably from 515K for x = 0 to about 20K for compounds with high manganese concentration, and the compensation point was observed in a narrow range of x≈4-6. The rapid decrease of the magnetization shows that the manganese substitution is not a simple magnetic dilution to the transition-metal sublattice mo-ment, it indicates that the moment of Mn may be antiparallel to that of Fe. The field dependence of the magnetization of Dy₂Fe_17-xMn_xC_1.0 may indicate the existence of the nonlinear magnetic structure for the samples with high Mn conoentrations.