986 resultados para 7140-240
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本文采用接枝共聚方法合成功能高分子型钆化合物活性材料,研究了它们的结构和某些性能,结果表明这些活性材料的结构和性能对钆离子选择电极性能有较大的影响。
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芳香聚酰亚胺一直在电子、复合材料及粘接剂等领域广泛地应用。最近,聚酰亚胺膜已用于气体的分离过程。这是因为芳香聚酰亚胺是具有高玻璃化温度的玻璃态聚合物,它对小分子比大分子有更大的选择透过性,高选择性是与玻璃态聚合物的僵硬主链,对不同尺寸的分子提供筛分作用相连系的。新开发的芳香聚酰亚胺膜是用联苯四甲酸二酐与芳香二胺缩聚制备的聚酰亚胺溶液制造的。这种中空纤维状的膜是由一个多孔结构支撑的一个很薄的外表面组成的。它可通过聚合物溶液采用干——湿法过程纺丝而成,经溶剂交换干燥,外层的致密部分由计算可知厚度低于0.1μm。它对H_2与CO、CH_4.N_2及其它气体的分离有高度的选择性。由于它具有聚酰亚胺特有的耐高温性能,所以可以在很广的气体加工条件下使用。这种膜对水蒸气有很高的透过性,因而也可用于有机蒸气的脱水,或空气干燥。此膜对水蒸气的透过速度为乙醇的100~200倍。30%的乙醇水溶液,经一次膜分离,浓度可提高到99%。空气干燥系统可产出达到-50℃露点的空气。
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本文介绍用高效液相色谱(HPLC)分析豆油中脂肪酸组成的方法。油脂经皂化后,不需萃取,直接形成脂肪酸的苯乙酮酯,通过梯度淋洗,使分离时间大大缩短。此方法可以直接应用到生物样品。
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Year-round induction of sporogenesis of Laminaria saccharina was performed by mechanically blocking the transport of the putative sporulation inhibitors produced by the blade meristem and culturing the plants in constant short days. Sporogenesis was successfully induced by removal of the blade meristem, either by cultivating distal blade fragments or by performing a transverse cut in the frond. The earliest sorus formation after artificial induction was 10 days. The age of the sporophytes used for induction was 6-11 months or 2 years in tank-grown or field-collected sporophytes, respectively. Zoospores were successfully released in all cases. Thus, by year-round artificial induction of sporogenesis, (1) sporeling production of L. saccharina and thereafter sporophyte cultivation could be achieved without seasonal limitation, and (2) the life cycle of L. saccharina (from spore to spore) could be completed within 8 months under controlled conditions. (C) 2004 Elsevier B.V. All rights reserved.
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Effect of temperature and irradiance on growth and reproduction of Enteromorpha prolifera that bloomed offshore along the Qingdao coast in summer 2008, was studied. It was showed that E. prolifera propagated mainly asexually with specific growth rate (SGR) of 10.47 at 25A degrees C/40 mu mol m(-2)s(-1). Under this condition, gametes with two flagellate formed and released in 5 days. At the beginning of the development, the unicell gamete divided into two cells with heteropolarity, and then the apical cell developed into thalli primordial cells, whereas the basal cell developed into rhizoid primordial cells. In 8-day culture, the monoplast gamete developed into juvenile germling of 240 mu m in length. Unreleased gametes can develop directly within the alga body. E. prolifera could either reproduce through lateral branching or fragmenting except apomixis revealed by Microscopic observation. On aged tissue of E. prolifera, although the degraded pigments partially remained in faded algal filaments, numerous vegetative cells could still divide actively in the algal tissues.
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In this study, at proper dosage of ultraviolet (UV) irradiation (180 sec: 36,000 erg/mm(2)), sperm chromosomes of left-eyed flounder, Paralichthys olivaceus, were inactivated, while spermatozoa maintained ability to move and inseminate eggs. Gynogenetic haploids were detected by morphological observation, chromosome counting, and flow cytometer analysis. The ultrastructure of treated sperm was observed under scanning electronic microscope (SEM) and transmission electronic microscope (TEM). The results showed that after being irradiated at lower dosage of irradiation (0-180 sec: 0-36,000 erg/mm(2)), the surface structure of spermatozoa was not affected by UV irradiation, while the inner structures including membrane system and karyoplasm denseness of treated spermatozoa were little changed. However, obvious changes were observed in their membrane system, mitochondria, and nucleus if the dosage of irradiation increased to 240 sec: 48,000 erg/mm(2) or 300 sec: 60,000 erg/mm(2). The sperm survival rates did not change at the lower dosages of the UV irradiation (0-180 sec: 0-36,000 erg/mm(2)) but decreased as the irradiation dosage increased. The motility of treated sperm was lower than that of control group in general but did not change with UV irradiation dosage increasing at the certain range of 0-300 sec: 0-60,000 erg/mm(2).
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The Zenisu deep-sea channel originates on the Izu-Ogasawara island arc, and disappears in the Shikoku Basin of the Philippine Sea. The geomorphology, sedimentary processes, and the development of the Zenisu deep-sea channel were investigated on the basis of swath bathymetry, side-scan sonar imagery, submersible observations, and seismic data. The deep-sea channel can be divided into three segments according to the downslope gradient and channel orientation. They are the Zenisu Canyon, the E-W fan channel, and the trough-axis channel. The sediment fill is characterized by turbidite and debrite deposition and blocky-hummocky avalanche deposits on the flanks of the Zenisu Ridge. In the Zenisu Canyon and the Zenisu deep-sea channel, sediment transport by turbidity currents generates sediment waves (dunes) observed during the Shinkai 6500 dive 371. The development of the Zenisu Canyon is controlled by a N-S shear fault, whereas the trough-axis channel is controlled by basin subsidence associated with the Zenisu Ridge. The E-W fan channel was probably affected by the E-W fault and the basement morphology.
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rpoS 基因编码RpoS因子(RNA聚合酶的σ亚基),能增强细菌细胞对外界不良环境的抗逆性和适应能力。我们从鳗弧菌(Vibrio anguillarum)M3 Fosmid 文库中得到rpoS 基因序列,全长999bp,同源分析发现与大肠杆菌(Escherichia coli)有71%的相似性,与霍乱弧菌(Vibrio cholerae )有78%的相似性。为了研究rpoS在鳗弧菌中的作用,我们利用in-frame deletion技术构建了rpoS 基因的非极性缺失突变株,同时利用细菌的接合转移,以低拷贝克隆质粒pSUP202为载体,构建了突变株的互补株。 在TSB培养基中,rpoS 基因的缺失减缓了鳗弧菌对数期的生长,但是对稳定期的生长没有影响。对数期鳗弧菌在1M蔗糖(渗透压胁迫)和5%(v/v)乙醇中的生长减缓,而在18%(v/v)乙醇中的生长及42℃热击时的存活率相对于野生型没有变化。不同生长时期的鳗弧菌对15mM H2O2的反应有所不同,rpoS 的缺失使对数期的鳗弧菌对15mM H2O2的反应更加敏感。在rpoS基因互补株中,上述表型几乎恢复到野生型水平。 我们通过感染实验发现,rpoS 基因的缺失使鳗弧菌的LD50提高了20倍。 RpoS的突变对鳗弧菌的泳动和胞外酶的产生也有影响。突变株泳动圈直径是野生型的73.8%,在明胶平板和酪蛋白平板上的透明圈直径分别为野生型的61%和69%。通过azocaseion检测胞外产物ECP酶活发现,突变株的酶活是野生型的35.5%。 以上数据表明了RpoS在鳗弧菌对数期应对外界不良环境时起到了重要作用,同时参与了鳗弧菌的致病过程。
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本研究以中国对虾为材料,以杂交育种和选择育种为目标,进行了系统的中国对虾杂交育种试验、生长性状遗传参数试验及其分子遗传连锁图谱的构建工作。结果表明以不同地理群体杂交作为基础群体,然后采用系统的选择育种方法可以获得较好的选择效果。构建的遗传连锁图谱为中国对虾分子辅助育种提供一定的基础。这些试验结果为中国对虾合理系统的育种工作提供了理论基础和数据支持。其具体结果如下: 1. 试验对中国对虾黄渤海水域乳山湾群体(WYP)和朝鲜半岛南海群体(WKN)的2个群体及其杂交后代不同月龄生长情况和存活率进行了研究,测量体长(TL)、头胸甲长(CL)、头胸甲宽(CW)、第2、3腹节高(HST)、第2、3腹节宽(WST)、体重(BW)和存活率共7个性状,计算各项指标的杂种优势率,并对各性状进行了方差分析和多重比较。其3月龄生长情况和存活率研究结果表明,存活率在乳山湾群体(WYP♀)× 朝鲜半岛南海群体(WKN♂)杂交后代出现杂种劣势外,其他指标都表现出不同程度的杂种优势(4.37%~23.96% )。除了存活率外,杂交后代生长性状均显著高于亲本,乳山湾群体(WYP♀)×朝鲜半岛南海群体(WKN♂)杂交后代高于朝鲜半岛南海群体(WKN♀)× 乳山湾群体(WYP♂)杂交后代,黄渤海水域乳山湾群体高于朝鲜半岛南海群体后代。为确定测量性状与中国对虾体重的相关程度,建立了用体长(X1),头胸甲宽(X2),第2、3腹节宽(X3),头胸甲长(X4),第2、3腹节高(X5)估计体重的多元回归方程:Y = -2.056 + 0.03X1 + 0.076X2 + 0.078X3 + 0.033X4 + 0.043X5。 2. 中国对虾黄渤海水域乳山湾群体(WYP)和朝鲜半岛南海群体(WKN)2个群体及其杂交后代在4月龄时期的6个生长指标和存活率的杂种优势范围在0.514%到14.95%之间,WYP♀×WKN♂杂交后代在这7个指标中都高于WKN♀×WYP♂杂交后代。5月龄杂交后代也表现出一定程度的杂种优势,其范围在-9.000%~19.090%之间,但头胸甲长、第2、3腹节处高和存活率3个指标出现杂种劣势。不同杂交组合各个阶段生长发育情况和存活率在杂种优势表现出一定的规律。随着月龄的增加,WKN♀×WYP♂杂交后代杂种优势率有所增加,而WYP♀×WKN♂杂交后代的却有所降低。ANOVA分析结果表明,杂交后代在存活率方面与双亲差异不显著。4月龄的分析结果发现杂交后代在WST和BW这2个指标上存在显著差异。LSD多重比较结果显示,WYP♀×WKN♂杂交后代在BW指标上与亲本存在显著差异,在WST指标方面与其他3个组合的后代差异显著。5月龄的数据分析结果发现,杂交后代除体重存在显著差异外,其他各项指标差异均不显著。LSD多重比较结果发现,WKN♀×WYP♂杂交后代体重与其亲本WKN存在显著差异。 3. 对2个野生群体——朝鲜半岛南海岸群体(WKN)和黄渤海群体(WYP)和3个养殖群体——朝鲜半岛群体的养殖一代(FKN),黄海1号(HH1)和即抗98(JK98)进行杂交试验的研究,结果表明JK98 (♀) WKN (♂)组合在存活率方面最高,其余的依次为WYP (♀) WKN (♂),WKN (♀) WYP (♂),FKN (♀)HH1 (♂) 和 WYP (♀) FKN (♂)。而在体重方面FKN(♀) HH1(♂)组合最高,其余的依次为WKN (♀) WYP (♂),WYP (♀) WKN (♂),WYP (♀)FKN (♂) 和 JK98 (♀)WKN (♂)。在所有生长性状方面,JK98 (♀) WKN (♂)在5个组合中是最低的。方差检测结果表明,TL、CL、HST、LL和BW这5个指标在不同组合间存在差异,而其他指标不存在差异。多重比较结果发现JK98 (♀)WKN (♂)组合的TL与其他组合间差异极显著,HST指标与WKN (♀) WYP (♂),FKN(♀) HH1(♂)和 WYP (♀) WKN (♂)这3个组合差异显著,BW指标与WKN (♀) WYP (♂) 和 FKN(♀) HH1(♂)差异显著。 4. 通过人工授精的方法建立了中国对虾21个半同胞家系,测量了中国对虾21个半同胞(46个全同胞)家系的TL、CL、CW、HST、WST、第1腹节长(FL)、第6腹节长(LL)。利用MTDFREML软件得到生长性状遗传力在0.15~0.35之间,属于中度遗传力范围。TL的遗传力为0.34±0.071,CL的为0.30±0.070,CW为0.35±0.077,WST为0.33±0.073,HST为0.33±0.073,FL的最低为0.15±0.044,LL的为0.24±0.059。各个性状间表现出高的正相关,其中CW和TL以及HST的遗传相关最大,FL和WST的遗传相关最小。 通过以上杂交育种和选择育种的研究,认为单纯的依靠杂交育种来改善中国对虾的育种工作可能具有一定的局限性。所以在实际的育种过程中,以中国对虾不同群体的杂交后代作为基础群体,并以此为基础进行系统的选择育种应该具有更大的潜力。 5. 本试验利用中国对虾F2群体和AFLP分子标记技术进行了遗传连锁图谱的构建。利用55对AFLP引物组合对F2家系的110个个体进行了研究,结果检测到532个符合作图策略的AFLP标记。利用卡方检验检测分离位点是否符合孟德尔分离定律。对于符合3:1比例的分离位点利用F2自交模型构建性别平均连锁图谱,对于符合1:1比例的分离位点利用拟测交理论分别构建中国对虾的雌性和雄性遗传连锁图谱。雌性、雄性和性别平均遗传图谱分别有28、35和44个连锁群,图谱实际长度分别为1090、1617和1772.1 cM。中国对虾遗传连锁图谱估计基因组长度为2420 cM,符合与人类基因组相比的对虾类基因组长度。中国对虾雄性遗传连锁图谱比雌性遗传连锁图谱长32.6%,这可能说明中国对虾不同性别存在不同的重组率。通过皮尔逊相关系数检测认为AFLP标记在中国对虾图谱上分布均匀。本文利用AFLP标记构建的中国对虾遗传连锁图谱为中国对虾基因组研究和遗传改良提供一定的基础,同时也应该开发微卫星等共显性标记,为遗传连锁图谱的整合提供条件。
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基因组大片段BAC文库是进行生物遗传学和基因组学研究必不可少的基础工具。为了深入开展栉孔扇贝(Chlamys farreri)和凡纳滨对虾(Litopenaeus vannamei)基因组学研究、阐明其基因组的结构与功能、图位克隆重要功能基因、构建高密度物理图谱并最终实现与已有遗传连锁图的整合,本研究在植物基因组BAC文库构建技术的基础上,针对海洋生物的特点进行了大胆的改革与尝试,最终成功构建了C. ferrari和L. vannamei两种重要海水养殖动物的基因组BAC文库。 本文构建的栉孔扇贝基因组BAC文库,由BamHI文库和MboI文库构成。其中BamHI文库含有73,728个BAC克隆,空载率约为1%,平均插入片段约为110 kb,覆盖栉孔扇贝单倍体基因组约8倍;MboI文库共有7,680个克隆组成,平均插入片段大小约为145 kb,插入率为100%,覆盖栉孔扇贝单倍体基因组约1.1倍。两个栉孔扇贝基因组BAC文库共由81,408个克隆组成,平均插入片段约为113 kb,覆盖率约为栉孔扇贝单倍体基因组大小的9.1倍。 将栉孔扇贝基因组BAC文库的192个384微孔培养板中的73,728个BAC克隆以4 x 4点阵形式制备了高密度DNA薄膜,用于对感兴趣的基因及DNA序列的筛选。高密度DNA薄膜的覆盖率约为栉孔扇贝单倍体基因组的8.3倍。针对栉孔扇贝先天免疫系统通路的6个重要功能基因,根据栉孔扇贝cDNA序列以及异缘物种DNA序列设计了Overgo探针。利用Overgo探针对高密度DNA薄膜杂交筛选的结果显示,平均每个基因检测到7.3个潜在阳性克隆。 本研究所构建的凡纳滨对虾基因组HindIII酶切BAC文库共有102,528个BAC克隆,存放于267个384微孔培养板中,平均插入片段大小约为101 kb,空载率约为5%,覆盖L. vannamei单倍体基因组约5倍。将其中240个384微孔培养板中的92,160个BAC克隆以4 x 4的矩阵排列形式制作了5张高密度凡纳滨对虾DNA薄膜,约覆盖整个对虾单倍体基因组的4.5倍。针对6个与对虾免疫、生殖生理有关的重要功能基因设计了Overgo探针,杂交筛选出20个阳性克隆,平均每个基因有3.3个潜在阳性克隆。 以上筛选结果不仅为进一步研究这些功能基因的结构与功能、表达与调控,揭示它们在扇贝和对虾以及其他近缘种的免疫系统、抗逆和生殖生理过程中的作用机理打下了基础,同时也间接验证了栉孔扇贝和凡纳滨对虾基因组BAC文库将成为基因筛选、基因的结构与功能分析、基因图位克隆、物理图谱构建以及大规模全基因组测序等方面的有力工具。
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本文在实验室条件下,系统地研究了温度盐度对栉孔扇贝胚胎和幼虫的单一和组合效应。受精卵孵化的适宜温度范围为16.0-22.0 ℃,适宜盐度范围为27.5-32.5‰。随着胚胎发育,胚体对度盐度的适应范围增广。胚胎孵化的适宜温--盐区域为16.0 ℃/27.2‰-24.4 ℃/33.6‰。水温超过26.0 ℃时,幼虫存活率显著下降,其生长的适宜温度范围为16.0-26.0℃。幼虫存活的适宜盐度范围为27.0-42.0‰,生长的适宜盐度范围为27.0-39.0‰。在120小时实验中,幼虫存活的适宜温--盐区域是10.0 ℃/16.3‰-27.0 ℃/42.0‰,生长的适宜的温--盐区域是21.5 ℃/26.1‰-27.0 ℃/36.0‰。在240小时实验中,幼虫存活的适宜温--盐区域是10.0 ℃/23.4‰-26.9 ℃/42.0‰,生长的适宜的温--盐区域是14.2 ℃/20.5‰-27.6 ℃/38.8‰。温度盐度对胚胎和幼虫的影响都很大,相比较而言,盐度的影响大于温度。温--盐对胚胎发育和幼虫存活的组合效应极其显著。随着幼虫的生长发育,温--盐对幼虫生长的组合效应逐渐表现出显著性,幼虫生长的适应范围增大。
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Sea water samples were collected in the East China Sea in March and April, 2005, and three-dimensional fluorescence of dissolved organic matter was measured by fluorescence excitation-emission matrix spectroscopy. The position, number and intensity of fluorescence peak in the spectra and the relations of the peaks were analyzed to determine the type, distribution and origin of the fluorescence dissolved organic matter. Seven types of fluorescence peaks were detected from the samples. There are protein-like fluorescence peaks B with Ex(max)/Em(max) = 275/300 nm, D with Ex(max)/Em(max) = 225/295-305 nm, T with Ex(max)/Em(max) = 280/345 nm, and S with Ex(max)/Em(max) = 225-240/320-350 nm, two humic-like peaks A with Ex(max)/Em(max) = 250-255/410-455 nm and C 335-345/410-440 ran, and marine humic peak M with Ex(max)/Em(max) = 305 nm/400-420 nm. Peaks B, S and A appeared in all surveyed area. Peaks T and D appeared in the north of the surveyed area. Peaks M and C only appeared in a few stations. In the surface layer, the source of the fluorescence dissolved organic matter might be the fresh water outflow of the Yangtze River, while the fluorescence dissolved organic matter in the middle layer had double sources from the Yangtze River and the phytoplankton. The good correlationships of different fluorescence peaks showed the same source or some relationship between the protein-like and the humic-like fluorescence dissolved organic matter.
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Fluorescence excitation-emission spectroscopy (EEMS) was employed to analyze the 3-dimensional fluorescence of dissolved organic matter in the East China Sea after diatom red tide dispersion. The relationships between fluorescence peak intensity, and salinity and chlorophyll-a were discussed. The centers of protein-like fluorescence peaks dispersed at Ex(max)/Em(max) = 270-280/290-315 nm (Peak B), 220-230/290-305 nm (Peak D), 230-240/335-350 nm(Peak S)and 280/320 nm(Peak T). Two humic-like peaks appeared at 255-270/435-480 nm (Peak A) and 330-350/420-480 nm(Peak C). High tyrosine-like intensity was observed in diatom red tide dispersion area, and tryptophan-like fluorescence was also found which was lower. High FIB/FIS showed that diatom red tide produced much tyrosine-like matter during dispersion. Peaks S, A and C had positive correlation with one another, and their distributions were similar, which decreased with distance increasing away from the shore. Good negative correlations between peaks S, A and C and salinity suggested that Jiangsu-Zhejiang coastal water was the same source of then-L Correlations between fluorescence peak intensity and chlorophyll-a were not remarkable enough to clear the relationship between fluorescence and living algal matter. It was supposed that the living algal matter contributed little to the fluorescence intensity of algal dispersion seawater.
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The nitric oxide synthase (NOS) activity in the haemocytes of shrimps Fenneropenaeus chinensis (Osbeck) and Marsupenaeus japonicus (Bate) was Studied after white spot syndrome virus (WSSV) infection to determine its characteristics in response to virus infection. First, the NOS activity in haemocytes of shrimps was determined by the means of NBT reduction and changes in cell conformation. And the variations of NOS activity in shrimps after challenge with WSSV intramuscularly were evaluated through the analysis Of L-citrulline and total nitrite/nitrate (both as NO derivates) concentrations. The result showed that NOS activity in the haemocytes of F chinensis increased slightly from 0 to 12 h postchallenge, indicated by the variations Of L-Citrulline (from 11.15 +/- 0.10 to 12.08 +/- 0.64 mu M) and total nitrite/nitrate concentrations (from 10.45 +/- 0.65 to 12.67 +/- 0.52 mu M). Then it decreased sharply till the end of the experiment (84 h postchallenge), the concentrations Of L-Citrulline and total nitrite/nitrate at 84 It were 1.58 +/- 0.24 and 2.69 +/- 0.70 mu M, respectively. The LPS-stimulated NOS activity kept constant during the experiment. However, in M. japonicus, the NOS activity kept increasing during the first 72 It postchallenge, the concentrations Of L-Citrulline and total nitrite/nitrate increased from 7.82 +/- 0.77 at 0 h to 10.79 +/- 0.50 mu M at 72 h, and from 8.98 +/- 0.43 at 0 h to 11.20 +/- 0.37 mu M at 72 h, respectively. Then it decreased till the end of the experiment (216 h postchallenge), and the concentrations of L-Citrulline and total nitrite/nitrate at 216 h were 5.66 +/- 0.27 and 4.68 +/- 0.16 mu M, respectively. More importantly, an apparent increase of I-PS-stimulated NOS activity was observed in M japonicus at 48 h postchallenge, which was about 4 times higher than that in the control group of health shrimps. In correspondence with the difference of NOS activity between the two species of shrimps, the Cumulative mortalities of the shrimps were also different. All shrimps of F. chinensis in the mortality experiment died in 66 h, much more quickly than M. japonicus, Whose accumulative mortality reached 100% after 240 h. Data here reported let us hypothesize that NOS activity in the haemocytes of shrimps F chinensis and M. japonicus responses to WSSV infection differently, and this might be one of the reasons for the different susceptibility of F chinensis and M. japonicus to WSSV infection. (c) 2005 Elsevier Inc. All rights reserved.
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The dye C.I. Acid Blue 80 (AB80) was easily degraded by TiO2-P25 assisted photocatalysis in aqueous dispersion under irradiation of sunlight. The optimal reaction conditions were [TiO2] = 2.0 g/L, pH = 10, [H2O2] = 5 mmol/L. The photocatalytic reaction followed pseudo-first order kinetics. The adsorption of AB80 onto TiO2 was in accord with Langmuir equation.