含氧/蒸汽气氛中煤高温分解产物分布及反应性

在流化床反应器中考察了含氧/水蒸气气氛中煤在850 ℃下的热解特性,包括产物分布特性及生成的半焦与焦油的反应性,研究了温度、过量空气比(Equivalence ratio: ER)和水蒸气/煤比(S/C, 质量比)的影响。结果表明,随热解温度、ER和S/C质量比的增加,气体产率增加,而半焦和焦油产率减少。O₂的加入使CO₂、CO含量明显增加,H₂含量降低。O₂和水蒸气的加入使半焦的比表面积显著增加,半焦气化活性增强,但半焦在900 ℃和 ER 为0.22的条件下出现轻微石墨化,降低了其气化活性。同时,反应气氛中含有O₂和水蒸气对焦油的性质有显著影响,与单纯的N₂气氛相比,O₂和水蒸气的存在使热解焦油中单环芳烃、酮类、酚类、脂肪烃都明显减少,这对于焦油的进一步裂解及重整更加有利。     

TiO2制备方法对光催化分解十二烷基苯磺酸钠的影响

本文以TiCl4为前体，采用沉淀法、气相沉积法和溶胶-凝胶法分别制备了TiO2光催化剂，比较了它们在十二烷基苯磺酸钠（SDBS）光解反应中的催化活性。结果表明，以日光灯作光源时，气相沉积法获得的催化剂效果最好；以500W紫外线高压汞灯作光源时，沉淀法获得的催化剂活性最高，100ml初始化学需氧量（COD）为381mg/L的SDBS溶液，在0.1g催化剂作用下，室温光照8h,COD去除率可达98.8%。在沉淀法制备的催化剂上，SDBS溶液的催化光解为一级反应。     

TiO_2制备方法对光催化分解十二烷基苯磺酸钠的影响

本文以TiCl4 为前体 ,采用沉淀法、气相沉积法和溶胶 凝胶法分别制备了TiO2 光催化剂 ,比较了它们在十二烷基苯磺酸钠 (SDBS)光解反应中的催化活性。结果表明 ,以日光灯作光源时 ,气相沉积法获得的催化剂效果最好 ;以 5 0 0W紫外线高压汞灯作光源时 ,沉淀法获得的催化剂活性最高 ,10 0ml初始化学需氧量 (COD)为381mg/L的SDBS溶液 ,在 0 .1g催化剂作用下 ,室温光照 8h ,COD去除率可达 98 8%。在沉淀法制备的催化剂上 ,SDBS溶液的催化光解为一级反应     

红外光谱法检定安息香光照分解产物

将红外光谱的基本原理和实验技术应用于光化学反应过程及产物结构的测定研究中。通过实验结合实验原理，可直观地观察到安息香在光化分解反应中前后光谱的变化，以及在不同溶剂所得不同产物的实验结果。有助于理解光化学反应机理，掌握红外光谱实验技术。     

明胶氧化产物的分子量分布

氧化明胶是最近二十年来开发并逐步完善起来的一个照相明胶的新品种.文献中Moll^[1]等做过氧化明胶的制备及性质的研究.Maskasky^[2]做过氧化明胶对卤化银晶形的调变作用的研究.明胶的氧化深度对于明胶卤化银乳剂微晶性能有重要的影响.然而,深度的氧化是否会导致明胶分子量分布的变化,文献中还没有有关报道.     

二叔丁基过氧化物分解产物的气相色谱法测定

采用气相色谱法考察了二叔丁基过氧化物分解温度与分解量之间的关系,研究了二叔丁基过氧化物分解产物的组成。实验发现：作为主要热分解产物的峰面积与二叔丁基过氧化物的量之间在２２．９１～１１４．９３μｇ范围内呈线性关系。测定未知浓度的过氧化物试样,有较好的精密度。     

SF_6分解产物的氦离子色谱分析方法

本发明公开了一种SF6分解产物的氦离子色谱分析方法,采用包括一根硅胶柱、一根第一Porapak Q柱、一根第二Porapak Q柱以及一根Gaspro毛细柱的4根色谱柱联用对样品进行组分分离,采用包括第1阀、第2阀、第3阀、第4阀在内的4个阀进行切割组分分离控制,采用第一PDD检测器和第二PDD检测器对分离后的样品分别进行分析测试。本发明分析方法能够同时准确检测传统分析方法不能准确检测的SF6分解产物,如H2,O2,N2,CO,CH4,CO2,COS,H2S,SOF2,CS2等化合物,通过全面准确的对SF6分解产物进行分析,从而准确判断SF6气体绝缘设备内部运行情况,保障电气设备安全运行。     

极性单体阴离子型聚合反应产物的分子量分布

关于任意官能度多官能团引发剂瞬时引发并有单体链终止的阴离子型聚合反应体系,本工作通过非稳态动力学分析,求得了分子量分布函数和平均聚合度的一般表示式,讨论了单体的最大消耗量和聚合物的官能度分布问题,建立了从反应的初始条件和单体转化率计算产物的各种分子参数的方法。上述理论结果适用于甲基丙烯酸甲酯等极性单体在极性溶剂中的阴离子型聚合反应。数值计算的结果表明:当引发剂的官能度为2时,除了少数例外,所得聚合物的分子量分布一般具有双峰。     

Fe-Mn催化剂的费托合成产物分布动力学

在固定床反应器上进行了Fe-Mn超细粒子催化剂F -T合成反应动力学研究。以碳化物机理为基础推导出简化的F -T合成产物生成动力学模型 :　RCnH2n 2 =kHC5PH2 (1-α)αn在温度 5 76～ 6 10K ,压力 1 5～ 2 5MPa ,空速 2 5 0 0～ 45 0 0h-1和原料气H2 /CO比为 2 0的条件下进行动力学试验 ,通过模型拟合 ,求得动力学方程参数 :　kHC5=kHC5(5 80K)exp[EaR(1T - 15 80 ) ]其中 ,kHC5(5 80K) =2 82× 10 -6mol/ (mlcat·MPa·s) ,Ea=6 6 0 7kJ/mol结果表明 ,该模型与实验值拟合较好 ,链增长几率α与温度和反应器内H2 /CO比具有简单的关系 :α =1/ (1 ρRHC)。     

焦化蜡油催化裂化产物氮分布的研究

催化裂化（FCC）原料正向重质化和多样化发展,如何利用催化裂化装置加工焦化蜡油（CGO）成为各炼油厂扩大FCC原料来源和挖潜增效的重要途径。与直馏蜡油（VGO）相比,CGO突出的特点心0是碱性氮化物的质量分数高。中国由于受加氢装置和氢源的限制,CGO一般不加氢而采用直接掺炼的方法,这样不仅存在CGO催化裂化转化过程中FCC催化剂碱氮中毒严重的问题,而且还存在反应后由于部分含氮化合物会直接或间接进入汽油、柴油馏分中,影响产物安定性等问题。为此,对CGO催化裂化转化过程中氮化物的研究引起了研究者的重视。     

用ISS研究负载型催化剂中活性组分与载体间的相互作用

Low energy (1.5 KeV) ISS is a surface sensitive technique for identification of element on the top layer of material. The energy losses of primary particle during the collision in low energy ISS technique are assumed to be completely kinetic, i.e. the electronic interaction energy transfer is generally small and will be neglected. In this paper, however, the electronic effect is measurable for certain supported oxide or halide catalysts by improved experimental technique. The shift of scatter- ing He~+ peak due to electronic effect is remarkable and different for Mo in MoO_3/TiO_2, MoO_3/γ-Al_2O_3, MoO_3/SiO_2 and Cu in CuO/γ-Al-2O_3, CuCl/γ-Al_2O_3. The corresponding “mass increment” was calculated by the binary collision approach. We find out that the “mass increment” may characterize the interaction between active component and carrier in supported catalysts. Thus, low energy ISS is not only a good tool for surface elemental analysis but also an effective probe for chemical information of surface species.     

INTERACTION BETWEEN UPOSOMES AND MONOLAYERS IN THE PRESENCE OF CALCIUM

Abstract

The interaction between phospholipid vesicles (phosphatidylcholine : phosphatide acid, 90:10 w/w) and phosphatidylcholine : cholesterol (70:30, molar ratio) monolayers at air/water interfscks has been studied at. several concentrations of calcium cation ( Ca²⁺). The liposome vesicles were SUVs and MLVS.

The vesicles interact with the monolayers, rapidly causing a large increase in surface pressure. Limiting values of surface pressure, 2.07-6.99 mN.m-1 for SUVs, and 7.01-11.11 mN.m^?1 for MLVs, were reached in less than 40?min.

Calcium ion concentration affects the liposome size in MLVs, producing an increase of gyration radius. The SUVs are little influenced. The change in size can be due to a variation of liposome composition induced by calcium: cholesterol molecules can migrate from monolayer to liposomes and the redistribution of exchanged lipids in the outer bilayer can also explain the size variation.     

壳聚糖与尿素的相互作用及其应用研究进展

尿素能够显著破坏甲壳素/壳聚糖分子氢键结构和疏水相互作用,增加其临界胶束浓度,促进多糖大分子的溶解,并能减少其在溶液中的自聚集现象.碱-尿素水溶液可以作为一种新型的甲壳素/壳聚糖绿色溶剂,有望用于对刺激性要求较为苛刻的食品、生物医学等领域.壳聚糖衍生物特别是其与过渡金属离子的配合物具有良好的尿素吸附功能,可用于尿毒症患者血液中小分子毒物的吸附,对机体刺激性小且不吸附血清蛋白等生物大分子.有望成为血液灌流治疗法中清除尿素等小分子毒性物质的良好吸附剂.壳聚糖还可以作为包膜材料,制备壳聚糖包膜尿素,与普通的包膜尿素相比性能更为优越.     

THE PHOTOLYSIS OF TRYPTOPHAN IN THE PRESENCE OF OXYGEN

Abstract— Quantum yields for the destruction of tryptophan by a single 500 J flash in aqueous solution have been determined over the pH range 1–13 in both air-equilibrated and nitrogen-saturated conditions. When these quantum yields are compared with the quantum yields for radical formation and photoejection of electrons, it is found that there is good agreement only for the nitrogen-saturated case. In air-equilibrated solutions of tryptophan, there is a large disparity between the measured degradation quantum yields and those for photoejection of electrons and radical formation. Oxygen, therefore, is playing a major role in the photochemical decomposition and it is proposed that the major reaction which occurs, under normal atmospheric conditions, is the reaction of the lowest triplet excited state of tryptophan with oxygen.
Preliminary photolysis-product distributions against pH are discussed, and indicate that a total of nine major products are formed in the presence of oxygen.     

THE PHOTOPHYSICAL AND PHOTOCHEMICAL PROCESSES OF TRYPTOPHAN IN INTERACTION WITH POLYNUCLEOTIDES: LASER FLASH PHOTOLYSIS STUDY

Abstract— The influence of nucleotides or polynucleotides on the photophysics and the photochemistry of tryptophan (Trp) derivatives has been investigated in aqueous solutions using the 265 nm laser flash photolysis technique. In solutions containing mixtures of N -acetyltryptophanamide and uridine monophosphate (UMP) or mercurated dUMP, the Trp triplet and the hydrated electron (e_aq) are quenched at almost diffusion controlled rates by the nucleotides leading to uracil reduction. Lysyl-tryptophyl-α-lysine (Lys-Trp-Lys) forms stable complexes in solution with normal or mercurated poly(uridylic acid) [poly(U)]. In the Poly(rU)-Lys-Trp-Lys complex the Trp triplet state is completely quenched, whereas the Trp triplet formation quantum yield is enhanced in complexes with mercurated poly(U). In this last case, the 'heavy atom effect' is characterized by a shortening of the Trp triplet lifetime in agreement with low temperature experiments. Our results also show that photoionization of Trp does occur in the complexed state with both polymers. The e_aq lifetime is however longer with the complexed than with the free peptide.     

ENTROPIC CONTRIBUTION TO THE INTERACTION PARAMETER xIN THE POLYMER／OLIGOMER SYSTEM： A LATTICE CLUSTER THEORY CONSIDERATION

Entropic contribution to the interaction parameter xeff in the model incompressible polymer/oligomer system is calculated by the lattice cluster theory (LCT). It is found that in the oligomer solvent, there exists a wide concentration range that the non-combinatorial “entropic interaction” term xeff φ1φ2 perceptibly counteracts the mean field combinary entropy ΔSMF. With the increase of the solvent size, both xeff and the ratio xefc φ1φ2/ΔSMF first reach their maximum and finally become trivially to zero. It is worth noting that no any demixing was found in the current calculation. This makes the controversial idea “entropically driven demixing” even elusive. However, we propose that further work on compressible polymer solution with structured monomer will witness the demixing owning to an increased configurational correlation.     

THE PHOTOLYSIS OF CYSTINE IN ACIDIC AQUEOUS SOLUTION

Abstract— Quantum yields of cysteine, ammonia, 1-amino,1'-oxo,2,2'-dithiodipropionicacid (AODT–DPA), alanine, alanine 3-sulphinic acid, cysteic acid, and serine have been determined in aqueous oxygenated and deaerated cystine solutions irradiated with 254 nm radiation. From the effect of methanol, ethanol and propanol-2 on the quantum yields of cysteine, ammonia, AODT-DPA and alanine, it is concluded that (a) the S–S bond is broken with high quantum efficiency, (b) C–S and C–N bonds do not undergo primary photolytic fission, and (c) all the AODT–DPA, but only about 12 per cent of the ammonia, is free-radical in origin. The production of pyruvic acid at the expense of AODT–DPA in irradiated cystine solutions containing alanine provides further evidence that AODT–DPA has free-radical precursors. Reaction schemes are proposed for the radical-induced production of keto acid and ammonia in oxygenated and deaerated solutions.     

INTERACTION BETWEEN TYROSINE AND DIVALENT SULFUR IN FLUORESCENCE QUENCHING AND IN THE PHOTOCHEMISTRY OF RIBONUCLEASE

Abstract— –Ribonuclease is inactivated in aqueous solution by u.v. light through different mechanisms according to whether divalent sulfur or aromatic amino acids are the primary light absorbers. At 284 nm, absorbed mainly by tyrosine, the presence of O₂ inhibits photoinactivation and H₂S formation, but does less so at 254 or 313 nm. Based on data with model substances containing disulfide groups a mechanism is indicated in which excited tyrosine is quenched through electron transfer to adjacent divalent sulfur within the protein. Disulfide compounds are shown to be very efficient quenchers of tyrosine fluorescence.     

电化法研究壳聚糖树脂与游离酸的相互作用

利用电化实验技术，跟踪观察交联壳聚糖树脂吸附低浓度游离酸的行为，讨论了酸和甲醇浓度等因素对吸附的影响，利用固-液相互作用方程，求取吸附剂一吸附质相互作用能。实验结果表明，交联壳聚糖树脂吸附低浓度游离酸的过程是遵循单分子层机制进行的，表观吸附速率常数随着吸附质浓度和外加甲醇含量的增大而减小，表观吸附速率常数与吸附剂一吸附质相互作用能（U）存在线性相关。     

INTERMEDIATES IN THE ROOM TEMPERATURE FLASH PHOTOLYSIS AND LOW TEMPERATURE PHOTOLYSIS OF PURINE SOLUTIONS

The flash photolysis of purine in acetonitrile and in water at different pH was studied. The transients produced on flash excitation of degassed aqueous solutions have been identified as the triplet excited state, the hydrated electron, a purine radical cation and radical anion on the basis of quenching experiments and comparison to transients observed in low temperature photolysis.