四溴化碳-二苯胺成像体系光化学反应的研究

研究了CBr_4-二苯胺(DPA)自由基光敏体系的光化学过程。在250-400nm区,CBr_4的光分解速度随波长的增加而下降。分别用CBr_4、DPA及CBr_4-DPA电荷转移复合物吸收光谱最大值对应的光254、284及333nm辐照CBr_4-DPA体系,发现333nm光辐照有最大的反应速度,证明此体系光激发阶段,CBr_4-DPA生成的基态电荷转移复合物是主要的光敏物质。     

自由基照相体系的ESR波谱研究

本文用自旋捕获剂t-BuNO(2-甲基2-亚硝基丙烷)与ESR技术结合的方法研究了CBr_4-φ_2NH、CBr_4-LCV及CBr_4-LMG体系的光化学过程。从ESR谱的超精细结构及其随组分浓度的变化,证实了上述体系中除有Br~·外,还分别形成了自由基。由这些体系在避光条件下的UV谱,证明溶液中存在(HX…CBr_4)型的部分电荷转移络合物。因此,上述自由基照相体系的光引发反应既包括CBr_4的光解,又包括(HX…CBr_4)~*的光解。     

苝四羧酸多联体化合物的合成及其光谱特性研究

本文合成了８个四羧酸多联体化合物;测定了这些化合物的吸收光谱、荧光光谱．研究了由供电子分子键连的多联体分子的光谱特性及其分子体系内稳态荧光猝灭机理．首次从吸收光谱和荧光光谱上分析和考察了四羧酸多联体化合物分子体系内的光致电子转移反应．     

Yb:NaY(WO4)2激光晶体的光谱性能

采用提拉法生长出了Yb：NaY(WO4)2晶体,给出了晶体生长的最佳工艺参数：拉速0．5～4mm／h,转速30～40r／min,冷却速率18℃／h。由TG-DTA分析得到晶体的熔点为1209℃。测试了该晶体的Raman光谱、吸收光谱和荧光光谱,计算了吸收光谱和荧光光谱中的有关参数。结果表明：该晶体发射波长为1010nm,在848,968nm附近有较强、较宽的吸收峰,适合于LD泵浦。     

pH灵敏化合物的合成及其光谱性能

以醛酮缩合原理,设计并合成了2,5-双(4-羟基-苯亚甲基)环己酮,研究发现其溶液的光谱性能对pH值有一定的依赖性。化合物的紫外吸收光谱强度随着溶液的pH变化,而当溶液体系由酸性变为碱性时,紫外吸收光谱发生红移,表现出的结果就是溶液颜色发生变化。化合物的荧光光谱强度,在碱性条件下pH值的增加有20倍以上的增大。研究表明该化合物可作为pH的探针使用。     

一种仿绿松石材料的鉴定

对近期市场上出现的一种绿松石的仿制品进行常规宝石学特征、红外吸收光谱、X荧光能谱、紫外-可见光光谱研究。研究结果表明:该绿松石仿制品为硅孔雀石,莫氏硬度为4,密度为2.3g/cm3,整体呈蓝色,宝石显微镜下可见蓝色斑点,结构致密。红外吸收光谱显示硅孔雀石的特征吸收光谱。X荧光能谱测试蓝色部位主要含有Cu、Si,黑色部位还含有Mn。紫外-可见光光谱测试具有635~700nm的宽吸收。该样品的蓝色主要由Cu引起。     

Yb∶NaY(WO_4)_2激光晶体的光谱性能

采用提拉法生长出了Yb∶NaY(WO4 ) 2 晶体 ,给出了晶体生长的最佳工艺参数 :拉速 0 .5～ 4mm/h ,转速 3 0～ 40r/min ,冷却速率 18℃ /h。由TGDTA分析得到晶体的熔点为 12 0 9℃。测试了该晶体的Raman光谱、吸收光谱和荧光光谱 ,计算了吸收光谱和荧光光谱中的有关参数。结果表明 :该晶体发射波长为 10 10nm ,在 848,968nm附近有较强、较宽的吸收峰 ,适合于LD泵浦     

环双(百草枯对苯撑)-双2-萘甲酸三缩四乙二醇酯二元超分子给受体体系光诱导电子转移研究

本文利用核磁氢谱、吸收光谱和荧光光谱证明了环双(百草枯对苯撑)(CBPQT)与双2-萘甲酸三缩四乙二醇(N-P4-N)在乙腈溶液中能够形成1∶1的二元超分子给受体体系.瞬态吸收光谱的研究表明该超分子体系中光诱导电子转移的速率kCS>1.0×108s-1,电子回传的速率kCR=1.26×103s-1,光诱导电子转移所生成电荷分离态的寿命长达794μs.     

萘酰亚胺类新型手性荧光染料的设计合成及其应用

本文利用较温和的反应条件制备了两个新型萘酰亚胺类手性荧光染料NNH、NNM,测试了其吸收光谱、荧光光谱和圃二色光谱.研究了化舍物NNH与扁桃酸的作用,利用荧光光谱实现了对不同构型的扁桃酸的识别.采用荧光和圆二色两种手段考察了化舍物NNM对pH值的响应,结果表明两种方法得到的pKa值吻合.     

掺钕钆镓石榴石晶体的激光性能

采用提拉法生长了Nd：Gd3Ga3O12（Nd：GGG）晶体。切割后的样品经过端面抛光,测试了荧光光谱、吸收光谱和激光性能。荧光光谱表明：晶体的最强的荧光发射峰位于1062nm,是Nd^3＋的4^F3/2-4^I11/2谱项导致的荧光发射。由吸收光谱发现：Nd：GGG晶体的最强吸收峰位于808nm,表明该晶体适合于激光二极管泵浦．并且吸收峰强度随掺杂离子浓度的增加而增加。激光性能测试结果表明：激光二极管泵浦时光-光转换效率为33.＋8％,斜效率为57.8％。     

自由基照相的光显影研究

非银盐感光材料与卤化银感光材料相比具有很高的分辨力,但灵敏度较低,限制了它的应用范围。因此,如何提高非银盐感光材料的灵敏度一直是非常活跃的研究领域。Sprague和Fotland对红光显影及其机理进行了研究。本文研究了无色结晶紫(LCV),四濞化碳(CBr_4),和2-(对-二甲胺基苯乙烯基)-喹啉(2SQ)自由基照相体系的红光显影,主要研究了各组分浓度,自由基产生剂,2SQ衍生物对红光显影的影响。 2SQ参照文献[4]合成。4-(对-二甲胺基苯-1,3-丁二烯基)-喹啉(4SBQ)和4-(间-硝基苯乙烯基)-喹啉(4SNQ)由日本感光色素研究所赠送。三溴甲基苯砜(TBMS)由北京     

Spectral radiance reconstruction from trichromatic camera responses based on orthogonal test and regularized algorithm

Reconstruction of spectral information based on multi‐channel image system is a significant problem in color reproduction, detection, and recognition. A spectral radiance reconstruction from trichromatic digital camera responses is researched in this article. The mapping relationship between the trichromatic imaging system response and the incident spectral radiance is analyzed. Then, in order to remove the ill‐posedness of the problem, a regularized constraint solution model of spectral radiance reconstruction matrix is established. And the spectral radiance can be reconstructed by spectral radiance reconstruction matrices and trichromatic imaging system response. Finally, the spectral radiance reconstruction matrix is estimated by the system radiometric calibration experiment. The input radiance is offered by a LCD display. A 3‐factor and 9‐level orthogonal test is designed for the calibration experiment, and a test set of 24 colors is used for precision analysis. The results show that the average relative mean error of our method is 8.69%, it is lower than that of Wiener filtering method by 2.84%. The method can reconstruct spectral radiance information effectively.     

Participation of singlet oxygen in photosensitized oxidation of 1,4-dienoic systems and photooxidation of soybean oil

Sensitized photooxidation of a model 1,4-diene, 4cis, 7cis-undecadiene, was shown to yield 4-hydroperoxy-5trans,7cis-undecadiene and 5-hydroperoxy-3trans,7cis-undecadiene as initial products. Further irradiation (in the presence of the sensitizer) caused the isomerization of 4-hydroperoxy-5trans,7cis-undecadiene to 4-hydroperoxy-5trans,7trans-undecadiene. Oxidation of 4cis,7cis-undecadiene with chemically formed singlet oxygen gave the same initial products as the photosensitized oxidation. 5-Hydroperoxy-3trans,7cis-undecadiene is, however, not formed in the radical autoxidation of the diene. It is concluded that singlet oxygen is the reactive intermediate in the photooxidation. Comparison with this model reaction suggests that the photooxidation of refined soybean oil in propanol also proceeds via singlet oxygen: the photooxidations of both 4,7-undecadiene and soybean oil are inhibited by β-carotene and by triethylamine, but unlike radical chain autoxidation, they are not inhibited by 2,6-di-t-butyl-4-methylphenol. Also soybean oil can act as a sensitizer for the photooxidation of 4,7-undecadiene. Chlorophyl-like sensitizers are probably unimportant in the well refined soybean oil used in this work. The observed photooxidation of the skipped dienoic components of soybean oil, which is probably due to some other, unidentified sensitizer(s), absorbing below 500 nm, can be avoided by using a yellow filter. Presented in part in the symposium “Oxidation Chemistry,” New Chemical Society Meeting, Manchester, April 1972.     

Oxidation of all‐cis‐7,10,13,16,19‐docosapentaenoic acid ethyl ester. Hydroperoxide distribution and volatile characterization

The isomeric hydroperoxide distribution and the composition of volatiles generated by oxidation of all‐cis‐7,10,13,16,19‐docosapentaenoic acid ethyl ester (DPA Et) were determined. DPA Et was prepared by using seal blubber oils as raw material and purified by urea complexation and reverse‐phase high‐performance liquid chromatography (HPLC). The DPA Et of over 96% purity thus obtained was dissolved in methanol and subsequently divided into two portions. One portion was added with methylene blue and exposed to a tungsten bulb light at 5 °C for photosensitized oxidation. The other portion was added with 2,2'‐azobis (2,4‐dimethylvaleronitrile) as an azo‐radical initiator and kept in the dark at room temperature for autoxidation. Positional isomers of hydroperoxides generated by autoxidation or photosensitized oxidation of DPA Et were separated by normal‐phase HPLC and detected by a fluorescence detection system as well as UV absorption. The peak components were identified by gas chromatography‐mass spectrometry (GC‐MS). Eight isomeric hydroperoxides, including certain amounts of 7‐, 10‐, 11‐, 13‐, 14‐, 16‐, 17‐, and 20‐hydroperoxy docosapentaenoate, were generated by autoxidation of DPA Et. The photosensitized oxidation of DPA Et yielded not only the above eight hydroperoxide isomers but also two additional isomeric hydroperoxides, 8‐ and 19‐hydroperoxy docosapentaenoate, which are characteristic hydroperoxide isomers generated by singlet oxygen‐mediated oxidation. Volatiles formed by autoxidation of DPA Et at 50 °C were collected and analyzed by solid‐phase micro‐extraction and GC/GC‐MS. A number of aldehydes, ketones, alcohols, acids, furans and hydrocarbons were identified. The formation mechanisms of certain volatiles are discussed.     

Electrochemiluminescence of 9,10-diphenylanthracene-halogen ion systems

Influence of halide ions (Cl^?, Br^?, I^?) on the electrochemiluminescence (ecl) of 9,10-diphenplanthracene (DPA) is studied by using controlled-potential double-step method. It is confirmed that the ecl begins to appear at the anodic potential corresponding to the potential of the first anodic half-wave potential of each halide ion and that, passing through an intensity maximum, it disappears at more positive potential. Similarly, when the cathodic potential is changed, the ecl appears at the first cathodic half-wave potential of DPA and disappears at more negative potential than the second half-wave potential of DPA. These facts indicate that the ecl must be due to the reaction between oxidised species of halide ions (presumably trihalide ions) and monovalent DPA anion radicals. The mechanism for the formation of the excited singlet state of DPA is reasonably explained by assuming a reaction scheme containing a mono-halogenated DPA radical as an intermediate.     

Photocurrent imaging of phase segregation in a ternary polymer blend induced via a non-solvent route

Control of phase separation length scales of polymers in a solution-processed film of binary (two-component) polymer blends is the most important step to realize significant photocharge generation and transport efficiencies leading to efficient solar cells. The dynamics of phase segregation becomes more complex in ternary (three-component) polymer blends. In the three-component blend, one component serves as sensitizer, and other two act as donor and acceptor polymer. The sensitizer absorbs photons and the energy is quickly transferred to the host donor. Subsequently, efficient charge transfer occurs at the host donor/acceptor interface. Depending on the relative amount of phase segregation between sensitizer/donor, sensitizer/acceptor and donor/acceptor, the different photophysical mechanisms (viz. energy transfer and charge transfer) are either boosted or suppressed. The correct kind of morphology should allow efficient energy transfer at the sensitizer/donor interface followed by efficient charge transfer at the donor/acceptor interface. We attempt to address these requirements by modulating the nanomorphology of a ternary blend via tailoring the non-solvent concentration in the ternary polymer blend solution. Here, we study the effect of non-solvent mixing and resultant film morphology is characterized by wide-field local photocurrent imaging and photoluminescence imaging in a confocal microscope set-up.     

Observations on the synthesis and structure of wide pore aluminum phosphate molecular sieves

The synthesis of wide pore 18-ring aluminum phosphates has been explored using several amines as templates. The systems studied in more detail involve the use of dipentylamine (DPTA), a combination of tributylamine (TBA) and dipentylamine and dipropylamine (DPA). In the latter two systems a thermally unstable phase with an XRD pattern similar to VPI-5 was obtained which has been identified as the H1 phase. In the DPTA system both thermally stable and unstable phases can be formed, depending on the reaction conditions used. By controlling the gel formation in the DPA system ALPO₄-8 was synthesized by hydrothermal methods. The products in the first two cases contain significantly higher amounts of the amine than has been reported in the synthesis of VPI-5. The structure of the thermally unstable H1 phase has been solved from X-ray powder data collected using a synchrotron X-ray source and shown to contain 6-coordinate aluminum in the 4-rings.     

Magnetic filed effect on sensitized photocrosslinking reaction of azidomethylated polytsyrene

Characteriscs curves for the lithographic sensitivity of poly(styrene-co-vinylblenzyl azide) (AZMA) with such sensitizer as 2,4-diisopentvlthioxanthone (DITX), 2-chlorothioxanthone (CTX), and Michier's ketone wer emeasured in the basence and in the presence of a magnetic filed. By the application of a magnetic field, the get fraction increases, and efficiency of photocrosslink formation increases by ≈ 45% (at 0.1 T) for AZMA/DITX and by ≈ 20% (at 0.5 T) for AZMS/CTX. Senstization mechanism was investigated by measuring UV, IR, and FT-IR spectra, and AZMS is found to be sensitized effectively by DITX and CTX through the triplet energy transfer, and to produce the triplet nitrene as an intermediate. The magnetic field effect on photocrosslink formation of AZMS/sensitizer systems is interpreted in term of the radical pair model of intermediate species which is formed by hydrogen abstraction of the nitrene from the sensitizer.     

Studies of the polymerization of diallyl compounds. XXXVIII. Telomerization of diallyl aromatic dicarboxylates in the presence of carbon tetrabromide

Radical telomerization of diallyl aromatic dicarboxylates, including diallyl phthalate (DAP) and diallyl terephthalate (DAT), was investigated in detail in the presence of CBr₄ as a telogen. Telomer yield could be accurately determined by a subsidiary GPC measurement in conjunction with a precipitation method. Telomerization kinetics of diallyl compound in the presence of CBr₄ was discussed and the chain transfer constant C_CBr4 (= k_tr/k_p) was estimated to be 57.9 and 53.8 for DAP and DAT, respectively, the values which correspond to those for one functional group of diallyl compound. The degree of polymerization was significantly dependent on conversion as consequences of the fast consumption of CBr₄ and the occurrence of crosslinking reaction. The rate of polymerization was enhanced with the added amount of CBr₄, being ascribable to the replacement of the degradative chain transfer by the chain transfer to CBr₄, the latter which yields active tribromomethyl radical in lieu of less active allyl radical. Gelation was delayed with an increase in the added amount of CBr₄. Preparation of telomer in high yield and its applicability are finally discussed.