F19的转动能谱

本文用转动微扰的方法,计算了F¹⁹的能级。结果与实验大致符合。把F¹⁹看做大变形核并把它的低激发能谱解释为转动能级是没有什么矛盾的。     

Nonlinear Optical Loop MirrorUsed to Compensate the Second Order Distortion in Analog Link

1.IntroductionErbium-doPedfiberamplifiers(EDFA)nowareappliedwide1yinanalogAMCATVtransPOrtanddistributionnetworkwhentheCATVcarrierfrequenciesarehighenough,thesystemlinearityiswellmaintainedbyEDFA(inabsenceofFMmodulatonbythelightsource)-ForadirectIymodulateddistributedfeedback(DFB)laser,thefrequencychirping,whichisalwaysserious,candegradeorupgradethedistortionaccordingtothedifferentgainsloPeofEDFAatlightsourcewavelength['J-UsuaIIy,thegainti1tiscon-sideredasunchangeable,theonlywayto…     

关于低压火花放电特性的一些研究

本文从理论和实验两方面,对低压火花放电特性作一些探讨。采用Laplace变换法,分析了线路在引燃、充电和放电三个过程中的过渡过程;探讨了火花与电弧互相转换的条件,以及线路参数对谱线光强的影响。从而对低压火花放电特性有一个较全面的、概略的认识。     

p型α-多孔SiC的光致发光光谱研究

用UV光照射和不用UV条件下形成的p型α-PSC的PL光谱，2.35eV，2.50eV和2.70eV及3.4eV附近的发射峰已被观察到.研究了不同的制备条件下形成的p型α-PSC的PL谱的稳定性和不同的能量的光激发引起PL谱的差别.结果表明，在电化学腐蚀过程中制备条件对PSC的PL谱有很大的影响，前者在低能区有较强的光发射而后者则在高能区有较强的光发射；前者的光谱稳定性较好而后者发射光谱强度则随时间的增加而减少.对产生这些差别的原因进行了深入讨论. 关键词：     

Effect of upward ion on field-aligned currents in the near-earth magnetotail

A 3-dimensional resistive MHD simulation was carried out to study the effect of the upward ions on the field-aligned currents (FACs) in the near-earth magnetotail. The simulation results show that the up-flow ions originating from the nightside auroral oval would drift into the center plasma sheet along the magnetic field lines in the plasma sheet boundary, and have an important effect on the field-aligned currents. The main conclusions include that: 1) the upward-ions mainly affect the field-aligned currents in the near-earth magnetotail (inside 15 Re); 2) the generated FACs in the near-earth region have two types, i.e., Region 1 FAC in the high-latitude and Region 2 FAC in the low-latitude; 3) FACs increase with the enhancement of the upward ion flux; 4) with the same flux of the upward ions, FACs enhance with the increase of the velocity of the up-flow ions; 5) the intensification of FACs is also closely related with the latitude of the upward ions, and the ions from the closed field line region generate larger FACs; 6) the generation of FACs is closely related with B _y created by the upward ions. Supported by the National Natural Science Foundation of China (Grant Nos. CNSF-40474058 and CNSF-40536030)     

The effect of olefinic terminal chains on the mesomorphic properties of 4,4′-disubstituted diphenyldiacetylenes

New diphenyldiacetylenes of the type with A, B = H and/or F; m = 0, 1; n = 1–4; and X = C _n H_2n+1, F, CF₃ or CN were synthesized and their mesomorphic properties determined by hot stage polarizing microscopy and DSC. When m = 0, all of these compounds showed only a nematic phase except when X = CF₃ when both nematic and smectic A phases were seen. Both clearing and melting temperatures were higher than those reported for substitution with the corresponding alkyl chains but the much larger increase in clearing temperatures produced considerably wider nematic phases. Eutectic mixtures of a few of these olefins yielded nematic materials also having much wider temperature ranges and higher clearing temperatures than the eutectic mixtures of the alkyl compounds, while retaining their high birefringence and low viscosities. Such materials are of interest for beam-steering devices. Four of the diacetylenes with m = 1 (A, B = H) were also prepared (X = C₆H₁₃, F, n= 2, 3). When X was C₆H₁₃ (n=2), the nematic range was smaller in the 2- than in the 1-olefin but wider than in the alkyl series. When X=F, either no nematic phase or a monotropic one was observed, whereas the 1-olefins gave a much wider nematic phase. Both transition temperatures were lower than those for the corresponding 1-olefin and alkyl analogues. The compound with X=C₆H₁₃ and n=2 had a melting temperature below room temperature.     

ON INVERSES AND ALGEBRAIC LOOPS OF CO-H-SPACES

In this paper we study the properties of homotopy inverses of comultiplications and Mgebraic loops of co-H-spaces based on a wedge of spheres. We also investigate a method to construct new comultiplications out of old ones by using a group action. We are primarily interested in the algebraic loops which have inversive, power-associative and Moufang properties for some comultiplications.     

采用柠檬酸合成高分散铜催化剂用于选择氢解反应

A highly dispersed Cu catalyst supported on silica was prepared by an incipient wetness impregnation method with citric acid.The synthesis was studied by nitrogen physisorption,X-ray diffraction,and temperature-programmed reduction by comparing with a reference prepared without citric acid.The catalyst precursor obtained after impregnation was X-ray amorphous.The precursor was readily transformed to crystalline CuO upon calcination.The CuO particles were of uniform size in a highly dispersed state and can be reduced to Cu at a lower temperature.The activity of the Cu catalyst obtained was an order of magnitude higher than that of the reference for the hydrogenolysis of methyl laurate to dodecanol.     

苯甲酸分子印迹聚合物的制备及其吸附性能

以苯甲酸为模板分子,4-乙烯基吡啶为功能单体,乙二醇二甲基丙烯酸酯为交联剂,采用本体聚合法制备了高选择性识别的分子印迹聚合物。利用合成的聚合物作为吸附剂填充制备气体浓缩针装置,并用于挥发性有机化合物(VOCs)的气相色谱分析。实验结果表明:60℃下恒温聚合反应6h,模板分子、功能单体、交联剂的物质量比为1∶4∶20,预聚合时间为3h,溶剂为乙腈,模板分子为苯甲酸时,合成的分子印迹聚合物对苯系物的吸附量最大。     

THE δ^－－PROBLEM FOR HOLOMORPHIC （0,2）－FORMS ON PSEUDOCONVEX DOMAINS IN SEPARABLE HILBERT SPACES AND D.F.N. SPACES

This paper shows that the δ^--problem for holomorphic (0, 2)-forms on Hilbert spaces is solv-able on pseudoconvex open subsets. By using this result, the authors investigate the existence ofthe solution of the δ^--equation for holomorphic(0, 2)-forms on pseudoconvex domains in D.F.N.spaces.