Electromagnetic decay of the 1.7- and 2.43-MeV levels in ^9Be

The 1.7- and 2.43-MeV levels in ⁹Be were populated with the reaction ¹¹B(d, α)⁹Be* by bombarding thin boron on carbon foils with 1.7-MeV deuterons. The alpha particles were analyzed in energy with a surface-barrier counter set at the unique kinematically determined angle and the recoiling ⁹Be nuclei at 90^o were analyzed in rigidity with a magnetic spectrometer, in energy by a surface-barrier counter at the spectrometer focus, and in velocity by the time delay between an alpha and a ⁹Be count. When a pulse from the spectrometer counter was in the appropriate delayed coincidence with a pulse from the alpha counter, the two pulses were recorded in a two-dimensional pulse height analyzer. Most of the ⁹Be* decay by particle breakup. Only those that gamma decay are detected by the spectrometer counter. Thus the experiment provides a direct measurement of Γ_rad/Γ. Analysis of 384 observed events gives Γ_rad/Γ = (1.16 ± 0.14) X 10^-4 for the 2.43-MeV level. Combining this ratio with the value of Γ_rad = 0.122 ± 0.015 eV found from inelastic electron scattering gives Γ = (1.05 ± 0.18) keV. For the 1.7-MeV level, an upper limit, Γ_rad/Γ ≤ 2.4 = 10^-5, was determined.

Cr2+:ZnSe中红外激光器

Cr2+掺杂II-VI族化合物在中红外波段的输出，在气体检测、遥感、通信、眼科医学、神经外科等领域有着重要的应用前景。目前已经获得了最大1.7 W的连续输出功率，18.5 W的平均脉冲功率，1100 nm的调谐范围和最窄4 ps的脉宽。对Cr2+:ZnSe连续、脉冲、随机纳米激光器以及其它的Cr2+掺杂II-VI族化合物激光器的最新的国内外研究进展进行了综述。

Upconversion luminescence from E-2 state of Cr3+ in Al2O3 crystal by infrared femtosecond laser irradiation

Visible upconversion luminescence was observed in Cr3+: Al2O3 crystal under focused femtosecond laser irradiation. The luminescence spectra show that the upconversion luminescence originates from the E-2-(4)A(2) transition of Cr3+. The dependence of the fluorescence intensity of Cr3+ on the pump power reveals that a two-photon absorption process dominates in the conversion of infrared radiation to the visible emission. It is suggested that the simultaneous absorption of two infrared photons produces the population of upper excited states, which leads to the characteristic visible emission from E-2 state of Cr3+.

Cr^4＋，Nd3＋共掺的钆镓石榴石（Cr，Nd：GGG）的光谱性能与光谱参数的研究

用提拉法生长了掺铬、钕的钆镓石榴石(Cr^4+，Nd^3+:GGG)晶体，研究了室温下的吸收光谱和荧光光谱性质，以及晶体中Cr离子浓度对Nd离子光谱性质的影响。应用Judd—ofelt理论计算了强度参数Ωt(t=2，4，6)，自发辐射跃迁几率、荧光分支比和辐射辱命等光谱参数。应用McCumber理论计算^4F3/2→^4I11/2能级跃迁的受激发射截面。结果表明：Cr^3+在300～900nm之间较强地增加了吸收截面，尤其是伴随Cr^3+→Nd^3+有效的能量转移。Cr^4+在1．06μm附近的吸收减弱了

《中国植物志》第52卷2分册(红树林科.海桑科.石榴科.玉蕊科)

1、红树科和海桑科是中国植物志的一部分，1980年开始编著，1983年出版，本文记载红树科6属13种1变种，6属中除山红树属和竹节树属是内陆种类，其余4属均是组成红树林的主要树种，红树科的木杬属、角果木属、秋茄树属和红树属它们的树皮都含有丰富单宁为侵染皮革和染料的主要原料，又是防风防浪护堤的海岸防护林的主要树种及盐土指示植物，木材大都坚硬，纹理密微，在药用方面有止痛等作用。海桑科与红树科的生态习性极为相似也是构成红树林的主要树种和海岸防林不可缺少的种类，本文记载中国有2属4种。以上两科均详细叙述它们的形态、生态习性和经济用途。2、通过研究多年搜集的标本和资料，报导石榴科和玉蕊科的种类、分布和经济用途。石榴原产地中海沿岸至伊朗及其邻近地区，汉时张骞出使西域引入我国栽培，是我国第一批有文字记载的外来经济树种之一，既可食用和药用，又供观赏，综述历代文献，描述其形态演变，对研究外来（特别是地中海沿岸）经济植物的驯化有重要的意义。玉蕊科是有代表性的热带植物群，我国种类虽不多，但其发现对论证我国植物区系的热带亲缘的理论提供了直接的证据，故有一定的科学意义。

Dehydration for a solid coordination network based on CuII-(py)2C(OH)2 trimers

Abstract de congreso: Póster presentado en 12th International Conference on Materials Chemistry (MC12), 20 - 23 July 2015, York, United Kingdom

Preparação e Avaliação da Atividade Catalítica de Polímeros de Condensação de Metilpiridinas e Tereftalaldeído em Reações de Nitroaldol e Cicloadição Heterodipolar [3+2]

Nesse estudo, foram preparadas bases poliméricas derivadas de 2,6-dimetilpiridinas e tereftaladeído utilizando a 2,4,6-trimetilpiridina como agente de reticulação. As resinas foram sintetizadas sob aquecimento convencional e purificadas por precipitação em metanol, apresentando rendimentos variando de 59 a 95%. Os copolímeros produzidos foram caracterizados por análise termogravimétrica (TGA), ressonância nuclear magnética de núcleo de hidrogênio (RMN-1H) e espectroscopia na região do infravermelho com técnica de ATR (FTIR - ATR), além de sua atividade básica. A capacidade catalítica do material produzido foi avaliada em reações nitroaldólicas, do tipo Henry, tanto em aquecimento convencional quanto com o uso de reator de micro-ondas. Não sendo observada atividade catalítica significativa para as resinas testadas, nestas reações. O material polimérico produzido também foi testado como suporte para cobre na catálise de reações de cicloadição heterodipolar do tipo [3+2] com benzilazida e propiolato de etila, para a formação de triazóis, processadas em reator de micro-ondas e sob aquecimento convencional. A reação mostrou-se regiosseletiva e processos de reciclo do catalisador se mostrou eficiente em reações consecutivas

New chiral E- and Z-isomers of the 1R,4R-2-arylidene-p-menthane-3-ones in induced cholesteric and ferroelectric liquid crystals

A novel pair of the E- and Z-isomeric 1R,4R-2-(4-heptyloxyphenyl)-benzylidene-p-menthan-3-ones has been prepared and the influence of distinctions in their molecular geometry on macroscopic properties of liquid crystal systems with the induced supra-molecular helical structure has been studied. The significantly lower helical twisting power of the chiral Z-isomer in comparison with that of E- one has been confirmed in the case of induced cholesteric systems based on 4-pentyl-4-cyanobiphenyl. The phase behavior and ferroelectric characteristics have been investigated for smectic-C* compositions based on the eutectic mixture of the homological 4-hexyloxyphenyl-4'-hexyloxy- and 4-hexyloxyphenyl-4'-octyloxybenzoates containing the novel isomeric chiral dopants. The spontaneous polarisation of the opposite signs induced by the isomeric chiral components has been revealed for the compositions studied. Distinctions in phase states, absolute values of the spontaneous polarization, smectic tilt angle and rotation viscosity of the systems obtained are discussed.

Ferroelectric liquid crystal mixtures containing chiral ether and ester compounds with the 2-arylidene-p-menthan-3-one skeleton

Some 1R,4R-2-(4-phenylbenzylidene)-p-menthane-3-one derivatives containing the ether or ester linking group between benzene rings of the arylidene fragment have been studied as chiral dopants in ferroelectric liquid crystal systems based on the eutectic mixture (1:1) of two phenylbenzoate derivatives CmH2m+1OC6H4COOC6 H4OCnH2n+1 (n = 6; m = 8, 10). The ferroelectric properties of these compositions (spontaneous polarization, rotation viscosity, smectic tilt angle as well as quantitative characteristics of their concentration dependences) were compared with those for systems including chiral dopants containing no linking group. Ferroelectric parameters of the induced ferroelectric compositions studied have been shown to depend essentially on the presence of the linking group between benzene rings and its nature as well as on the number of the benzene rings in the rigid molecular core of the chiral dopants used. For all ferroelectric liquid crystal systems studied, the influence of the chiral dopants on the thermal stability of N*, SmA and SmC* mesophases has been quantified. The influence of the linking group nature in the dopant molecules on the characteristics of the systems studied is discussed taking into account results of the conformational analysis carried out by the semi-empirical AM1 and PM3 methods.

New (1R,4R)-2-arylidene-p-menthan-3-ones with a bridging ester group in the arylidene fragment. Synthesis and behavior in liquid-crystalline systems

(1R,4R)-2-(4-Hydroxybenzylidene)- and (1R,4R)-2-(4′-hydroxybiphenyl- 4-yl)methylene-p-menthan-3-ones were synthesized by condensation of (-)-menthone with O-tetrahydropyran-2-yl derivatives of 4-hydroxybenzaldehyde and 4′-hydroxy-4-formylbiphenyl, respectively, in a DMSO - base medium followed by the removal of the protective group. The reactions of these hydroxy derivatives with 4-alkylbenzoic, 4-alkyloxybenzoic, trans-4-alkylcyclohexane-4- carboxylic, and 4′-alkylbiphenyl-4-carboxylic acids afforded three series of new chiral esters. Compounds containing the arylidene moiety with three benzene rings were found to exhibit liquid-crystalline properties. The characteristic features of these compounds are discussed based on the results of studies by polarizing microscopy, differential scanning calorimetry, and small-angle X-ray scattering. It was found that the mesomorphic compounds under study can form a smectic A mesophase, twist grain boundary mesophases (TGBA), and blue phases in a wide temperature range. Upon dissolution of certain of chiral compounds in 4′-cyano-4-pentylbiphenyl, a rather high twisting power and the thermal stabilizing effect on mesophases were observed.

竹叶青(Trimeresurus stejnegeri)蛇毒五种磷脂酶A_(2)的分离纯化和氨基酸序列分析

用超细Sephadex G-75凝胶色谱和C4反相高效液相色谱从竹叶青(Trimeresurus stejnegeri)蛇毒中分离纯化5种磷脂酶A_(2),并分别命名为PLA_(2)-Ⅰ(SWISS-PROT,P82892)、Ⅱ(SWISS-PROT,P82893)、Ⅲ(SWISS-PROT,P82894)、Ⅳ(SWISS-PROT,P82895)、Ⅴ(SWISS-PROT,P82896)。SDS-PAGE测定它们的分子量分别为14.0、15.8、15.0、14.0和14.0kDa。等电聚焦电泳测得PLA_(2)-Ⅰ、Ⅱ、Ⅲ呈碱性,等电点大于8.8;PLA_(2)-Ⅳ和Ⅴ呈酸性,等电点分别为5.2和4.7。PLA_(2)-Ⅳ和Ⅴ有水解卵磷脂活性。用自动Edman降解法测定了PLA_(2)-Ⅴ的全部氨基酸序列和PLA_(2)-Ⅰ、Ⅱ、Ⅲ、Ⅳ的N-端部分氨基酸序列。PLA_(2)-Ⅴ由122个氨基酸残基组成,有14个Cys,并与其它来源的PLA_(2)的氨基酸序列进行了比较。

~(14)C标记1,2,7,8-TCDD在鲤体内分布及代谢的初步研究

利用14C标记1,2,7,8-四氯代二苯并二噁英(1,2,7,8Tetrachloro[U—14C]dibenzodioxin,14C1,2,7,8TCDD)初步研究了其在鲤体内的分布和代谢规律。14C1,2,7,8-TCDD溶解于丙酮/植物油中,腹腔暴露。暴露1、2、4、8、12d后取样,肝脏、胆汁、腹腔脂肪等消化制样后用液闪仪测量放射性活度。肝脏和胆汁内的放射性活度同步变化,都是第8d达到峰值后下降。腹腔脂肪内1—2d放射性明显高于随后取样的样品。肝和腹腔脂肪的分布量之比呈现“S”型变化趋势。暴露4d

孵化温度对中华鳖4种同工酶和肌肉蛋白基因表达的影响

应用聚丙烯酰胺梯度凝胶电泳 ,对不同温度 (常温 30～ 33℃和低温 2 2～ 2 4℃ )人工孵化的幼鳖肝、肌、肾、心、脑等不同组织的乳酸脱氢酶 (LDH)、异柠檬酸脱氢酶 (IDH)、葡萄糖 6 磷酸脱氢酶 (G 6 PD)和酯酶(EST)等 4种同工酶和肌肉蛋白进行分析研究。结果发现 :不同温度孵化的中华鳖同工酶表达无差异。LDH和IDH的基因表达有组织特异性 ,但不存在遗传多态性 ;G 6 PD和EST同工酶具有遗传多态性。低温孵化的个体的肌肉蛋白有别于常温孵化个体的特异蛋白带。

锦鲤4个人工雌核发育家系的微卫星标记研究

利用Crooijmansetal (1997)分离的包含CA重复单元的普通鲤鱼 (CyprinuscarpioL .)的 8个微卫星DNA标记 ,对从锦鲤 (CyprinuscarpioL .)的红白、大正和昭和 3个不同品系中所获得的 4个不同人工雌核发育家系的 2 0尾个体进行PCR扩增。电泳结果表明 ,8对引物在 2 0尾个体中均能重复稳定地扩增出相应的同源序列。随引物不同 ,各等位基因数为 1～ 11个 ,大小在 6 8～ 2 6 4bp。在MFW 4、MFW7、MFW 19、MFW 2 0、MF

4,4',4",4"'-四羧基酞菁钴（II）高分子载体化及其催化硫醇的氧化反应

高分子催化剂的研究是高分子化学的重要课题之一。将金属酞菁高分子化，除有一般催化剂高分子化的特点之外，还有将催化活性中心用高分子骨架分隔开，以防生成催化活性低的二聚体，从而提高有效活性中心浓度的特殊意义。本论文研究了将4,4',4",4"'-四羧基酞菁钴（II）固载在接枝有高分子碱的二氧化硅上，合成双功能高分子催化剂。并结合2-羟基乙硫醇的氧化探索了其催化活性。以气相法4号白炭黑为载体，利用γ-氨丙基三乙氧基硅烷的水解反应，在白炭黑表面包裹聚γ-氨丙基硅氧烷。然后在DCCI脱水剂存在下，使CoPc(COOH)_4连接上述高分子载体上。通过红外光谱分析，表明产物中有酰胺键，证明是通过共价键连接，但亦不能排除有部分是以配位键结合的。用液相共辐照方法在硅胶H上接枝聚苯乙烯，对所得产物进行了表征，根据接枝的聚苯乙烯的重均分子量大于未接枝的聚苯乙烯，认为在液相单体中共辐照，其反应机理有可能与文献上研究硅胶与苯乙烯气相共辐照或预辐照接枝共聚的机理相似。在其它条件固定时，接枝率随着辐照时间的增加而增大。将接枝在硅胶H表面的聚苯乙烯进行氨甲基化，制得高分子碱载体。其结构通过元素分析和红外光谱证明与预想的相符。另外，用液相共辐照方法，在硅胶H上接枝苯乙烯与2-（或4-）乙烯基吡啶的共聚物，而文献上制取相同的载体是用化学方法进行的。与化学方法相比，辐照法有接枝率高，方法简便的优点。实验中观察到，在单体配比相同时，接枝率随剂量增加而增加，但到达最大值后又开始下降。同时，在剂量一定的情况下，随着单体中2-乙烯基吡啶含量的增加，接枝率下降接枝共聚物中聚比（2-乙烯基吡啶/苯乙烯）也比投料比低。对上述现象进行了初步解释，根据在γ-射线辐照时，2-乙烯吡啶比苯乙烯易于引发聚合，则随着单体中2-乙烯基吡啶含量的增加，未接枝聚合反应消耗了很多2-乙烯基吡啶单体，这样用于接枝聚合的单体量减少，造成接枝率下降，以及接枝共聚物中（2-乙烯基吡啶/苯乙烯）共聚比低于投料比的情况。用裂解色谱对未接枝的苯乙烯与2-乙烯基吡啶共聚物进行了表征，实验结果表明，共聚物中2-乙烯基吡啶的百分含量与裂解产物中2-乙烯基吡啶的百分含量之间有很好的线性关系，可以用来分析苯乙烯与2-乙烯基吡啶共聚物的组成。将CoPc(COOH)_4以共价或吸附形式接到上述高分子载体上分别合成出相应的含CoPc(CHHO)_4的高分子催化剂，其中对共价键结合的产物，用原子吸收光谱法定出了轱含量。结合2-羟基乙硫醇氧化反应，初步研究催化剂活性。所合成的高分子催化剂一般在少碱甚至无碱的情况下均有一定的催化活性。当反应在水溶液中进行，CoPc(COOH)_4负载在硅胶H上接枝的聚苯乙烯氨甲基化产物上，其催化活性优于含有吡啶基团的高分子载体。当反应在聚2-乙烯基吡啶的良溶剂，聚苯乙烯的劣溶剂乙醇中进行时，表面接枝不同共聚比苯乙烯与2-乙烯基吡啶的硅胶H为催化剂载体，其催化活性随着苯乙烯含量增加而下降。初步认为是苯乙烯含量增加，表面共聚物在乙醇中溶解性变差，空间阻碍增加，吸附CoPc(COOH)_4的能力及底物向活性中心扩散困难所致。影响固载在接枝共聚物上的金属酞菁催化剂，催化活性的因素很多。通过本工作初步认为含有碱性强的碱性基团和溶解性好的交链可能是合成具有理想催化活性剂的先决条件。关于所合成的高分子催化剂的催化活性尚有待于进一步的工作。