大气激光通信ATP系统设计及精跟踪子系统仿真

分析了影响大气激光通信ATP系统的环境因素,总结出ATP系统应该采用自适应光学系统和四象限体制来设计,并重点分析了精跟踪系统及给出MATLAB仿真.提出一套详细的设计方案,同时对于应用中的实际问题,提出相应的解决措施.     

Comparison of the performances of Ti/SnO2-Sb, Ti/SnO2-Sb/PbO2, and Nb/BDD anodes on electrochemical degradation of azo dye

In this paper, the preparation conditions of antimony-doped SnO₂ and PbO₂ electrode were optimized for the degradation activity of AO7 dye solution. The results showed that when the doping content of Sb is 8 mol %(SnO₂-Sb(0.08)), the SnO₂ electrode exhibited best activities for the decolorization and mineralization of AO7. The concentration of NaF in electroplating solution had a noticeable effect on PbO₂ electrode for the decolorization of AO7 solution, but little influence on the COD removal rate. The anodic stability tests showed that the electrode prepared in the solution containing 0.10 g l⁻¹ NaF (PbO₂-F(0.10)) was best for environmental application. The comparison of SnO₂-Sb(0.08), PbO₂-F(0.10) and Boron-doped Diamond (BDD) electrodes revealed that a more rapid decolorization rate was obtained on SnO₂-Sb(0.08) and PbO₂-F(0.10) electrodes in dilute AO7 solutions, while higher COD removal rate of concentrated AO7 solutions was on BDD and SnO₂-Sb(0.08) electrodes. The effect of concentration of Na₂SO₄ on the degradation rate of AO7 was very notable on BDD electrode for its highest overpotential of oxygen evolution reaction. In the chloride-containing medium, the decolorization was accelerated greatly but the completed mineralization of AO7 was inhibited with the increasing of chloride ions concentration when these high-overvoltage anodes were used Published in Russian in Elektrokhimiya, 2008, vol. 44, No. 7, pp. 865–875. The text was submitted by the authors in English.     

DNA分子结构的多态性研究 (Ⅱ) 吖啶橙凝聚体变化诱导的质粒DNA大分子构象的研究

利用吸收光谱和荧光光谱方法,研究了吖啶橙（ＡＯ）与质粒ＤＮＡ水溶液、以及含胶束介质的吖啶橙与质粒ＤＮＡ溶液体系的相互结合作用及减色效应。结果表明：吖啶橙对质粒ＤＮＡ的吸收光谱有减色效应;含十二烷基硫酸钠（ＳＤＳ）的ＡＯ水溶液体系中,随着ＳＤＳ浓度的增加,其光谱结果表现为由凝聚态向单体的转化。而在含十二烷基硫酸钠（ＳＤＳ）的ＡＯ与质粒ＤＮＡ溶液体系中,吖啶橙凝聚态随ＳＤＳ浓度的增加,对ＡＯ与质粒ＤＮＡ相互结合产生协同的减色效应,使质粒ＤＮＡ空间结构发生缩拢。进一步采用电泳法研究了ＡＯ凝聚态可能对质粒ＤＮＡ构象的影响,结果表明：在ＡＯ与质粒ＤＮＡ溶液体系中,ＡＯ浓度的增加对质粒ＤＮＡ构象未产生影响;而在含有ＳＤＳ的ＡＯ与质粒ＤＮＡ的溶液体系中,由于ＳＤＳ对ＡＯ凝聚态的解聚作用,以及ＳＤＳ对质粒ＤＮＡ减色效应的协同作用,使得质粒ＤＮＡ的构象发生变化,诱导质粒ＤＮＡ形成超螺旋构象     

Ionic bonding of lanthanides,as influenced by d‐ and f‐atomic orbitals,by core–shells and by relativity

Lanthanide trihalide molecules LnX₃ (X = F, Cl, Br, I) were quantum chemically investigated, in particular detail for Ln = Lu (lutetium). We applied density functional theory (DFT) at the nonrelativistic and scalar and SO‐coupled relativistic levels, and also the ab initio coupled cluster approach. The chemically active electron shells of the lanthanide atoms comprise the 5d and 6s (and 6p) valence atomic orbitals (AO) and also the filled inner 4f semivalence and outer 5p semicore shells. Four different frozen‐core approximations for Lu were compared: the (1s²–4d¹⁰) [Pd] medium core, the [Pd+5s²5p⁶ = Xe] and [Pd+4f¹⁴] large cores, and the [Pd+4f¹⁴+5s²5p⁶] very large core. The errors of Lu? X bonding are more serious on freezing the 5p⁶ shell than the 4f¹⁴ shell, more serious upon core‐freezing than on the effective‐core‐potential approximation. The Ln? X distances correlate linearly with the AO radii of the ionic outer shells, Ln³⁺‐5p⁶ and X^?‐np⁶, characteristic for dominantly ionic Ln³⁺‐X^? binding. The heavier halogen atoms also bind covalently with the Ln‐5d shell. Scalar relativistic effects contract and destabilize the Lu? X bonds, spin orbit coupling hardly affects the geometries but the bond energies, owing to SO effects in the free atoms. The relativistic changes of bond energy BE, bond length R_e, bond force k, and bond stretching frequency v_s do not follow the simple rules of Badger and Gordy (R_e～BE～k～v_s). The so‐called degeneracy‐driven covalence, meaning strong mixing of accidentally near‐degenerate, nearly nonoverlapping AOs without BE contribution is critically discussed. © 2015 Wiley Periodicals, Inc.     

荧光能量转移体系在生化分析中的应用-吖啶橙(AO)-中性红(NR)荧光探针测定DNA研究

本文简述了以荧光能量转移体系测定ＤＮＡ方法的发展过程,对近几年这一领域的新成果作了介绍;同时对吖啶橙（ＡＯ）－中性红ＮＲ为荧光探针测定ＤＮＡ的条件进行分析,证明了该法具有灵敏度高、线性范围宽、检出限低、选择性好、抗干扰能力强等,该法为微量ＤＮＡ定量分析提供了一个新的途径。     

The alternant hydrocarbon pairing theorem and all-valence electrons theory. An approximate LCOAO theory for the electronic absorption and MCD spectra of conjugated organic compounds, part 2

An approximate linear combination of orthogonalized atomic orbitals (LCOAO) all-valence electrons theory is described, based on a previously suggested partitioning of the Fock operator. Kinetic energy and penetration terms are evaluated explicitly in a L?wdin OAO basis, while two-electron repulsion terms are treated according to the conventional neglect of differential overlap (NDO) approximation. One-electron and penetration integrals are parameterized explicitly to predict approximate alternant pairing symmetry for the π-systems of benzene and napthalene. Application of the resulting LCOAO theory to a variety of alternant and non-alternant hydrocarbons demonstrates significant improvements in the prediction of MCD B-terms and transition moment directions, particularly for alternant (4N+2)- or 4N-perimeter π-systems for which traditional NDO procedures fail. Received: 27 May 1997 / Accepted: 28 August 1997     

Chemical alteration of poly(vinyl fluoride) Tedlar induced by exposure to vacuum ultraviolet radiation

In this study the chemical alteration of poly(vinyl fluoride) Tedlar^® by vacuum ultraviolet radiation (VUV) (115-400 nm) has been examined using X-ray photoelectron spectroscopy (XPS). The initial F/C atom ratio of 0.34 decreases to 0.17 after a 2-h exposure. The F/C atom ratio is further reduced to a steady-state value of approximately 0.04 after a 24-h exposure. Similarly, the O/C atom ratio is reduced from 0.08 to 0.05 and then to 0.02 during these two exposures. As the F and O are removed by VUV exposure, the C concentration increases from 70.5 to 82.0 and then to 94.6 at.% thus forming a graphitic or amorphous carbon-like layer which erodes more slowly than the virgin Tedlar surface. Exposure of the VUV-damaged surface to O₂ results in chemisorption of O, indicating that reactive sites are formed during the chemical erosion by VUV. Further exposure to VUV removes this chemisorbed oxygen but a subsequent exposure to air at atmospheric conditions causes a three-fold increase in O chemisorbed at the surface. Comparison of XPS data indicates that the mechanisms of chemical alteration by VUV radiation and hyperthermal (∼5 eV) atomic oxygen (AO) are similar.     

激光二极管端面泵浦的调Q内腔倍频Nd：YAG激光器

报道了用两个１．５Ｗ激光二极管偏振耦合端面泵浦的声光调Ｑ内腔倍频Ｎｄ：ＹＡＧ激光器。输出５３２ｎｍ绿光重复频率１ＫＨｚ时，最大峰值功率为２．２３ＫＷ，最窄脉宽为１８ｎｓ，平均功率４０ｍＷ。最高重复频率３０ＫＨｚ。重复频率１５ｋＨＺ时，最高平均率１２８ｍＷ。对声光调Ｑ内倍频Ｎｄ：ＹＡＧ激光器的动态特性进行了理论分析及计算。     

Evaluation of energy transfer and utilization efficiency of azo dye removal by different pulsed electrical discharge modes

The degradation of an azo dye, acid orange 7 （AO7）, caused by different high voltage pulsed electrical discharge modes （spark, streamer and corona discharge） induced by the various initial conductivities was investigated. A new type of pulsed high voltage source with thyratron switch and Blumlein pulse forming net （BPFN） was used. The typical discharge waveforms of voltage, current, power, pulse energy and the pictures of spark, streamer and corona discharge modes were presented. The results indicated that pulsed electrical discharges led to complete decolorization and substantial decrease of the chemical oxygen demand （COD） of the dye solution. The main intermediate products were monitored by GC-MS. The discharge modes changed from spark to streamer and to corona discharge, and the streamer length decreased with the liquid conductivity increasing. At a constant input power, the peak voltage, peak current, peak power and energy per pulse of the three discharge modes ranked in the following order： spark 〉 streamer 〉 corona. The effective energy transfer efficiency of AO7 removal was higher for spark discharge （57.2%） than for streamer discharge （40.4%） and corona discharge （27.6%）. Moreover, the energy utilization efficiency of AO7 removal for spark discharge was 1.035×10^9 mol/J, and for streamer and corona discharge they were 0.646×10^-8 and 0.589×10^-8 mol/J. Both the energy transfer efficiency and the energy utilization efficiency of spark discharge were the highest.