Molecular systematics of pikas (genus Ochotona) inferred from mitochondrial DNA sequences

The phylogenetic relationships among worldwide species of genus Ochotona were investigated by sequencing mitochondrial cytochrome b and ND4 genes. Parsimony and neighbor-joining analyses of the sequence data yielded congruent results that strongly indicated three major clusters: the shrub-steppe group, the northern group, and the mountain group. The subgeneric classification of Ochotona species needs to be revised because each of the two subgenera in the present classification contains species from the mountain group. To solve this taxonomic problem so that each taxon is monophyletic, i.e., represents a natural clade, Ochotona could be divided into three subgenera, one for the shrub-steppe species, a second for the northern species, and a third for the mountain species. The inferred tree suggests that the differentiation of this genus in the Palearctic Region was closely related to the gradual uplifting of the Tibet (Qinghai-Xizang) Plateau, as hypothesized previously, and that vicariance might have played a major role in the differentiation of this genus on the Plateau, On the other hand, the North American species, O. princeps, is most likely a dispersal event, which might have happened during the Pliocene through the opening of the Bering Strait. The phylogenetic relationships within the shrub-steppe group are worth noting in that instead of a monophyletic shrub-dwelling group, shrub dwellers and steppe dwellers are intermingled with each other. Moreover, the sequence divergence within the sister tars of one steppe? dweller and one shrub dweller is very low. These findings support the hypothesis that pikes have entered the steppe environment several times and that morphological similarities within steppe dwellers were due to convergent evolution. (C) 2000 Academic Press.

Phylogenetic relationships within mammalian order Carnivora indicated by sequences of two nuclear DNA genes

Phylogenetic relationships among 37 living species of order Carnivora spanning a relatively broad range of divergence times and taxonomic levels were examined using nuclear sequence data from exon1 of the IRBP gene (approximate to1.3 kb) and first intron

Effects of molecular structures on the olfactory responses of phospholipid membranes to four alcohols

In order to understand the relationship between phospholipid molecular structures and their olfactory responses to odorants, we designed and synthesized four phosphatidylcholine analogues with different long hydrocarbon (CH) chains and selected three natural phospholipids with different head-groups. By using interdigital electrodes (IEs) as olfactory sensors (OSs), we measured the responses of the Ifs coated with these seven different lipid membranes to four alcohol vapors in a gas flow system. The Ifs voltage changes were recorded and the voltage-relative saturate vapor pressure (V-P/P degrees) curves were also plotted. It was found that with a methyl (-CH3) placed at the C-8 position in the 18-carbon chain, the olfactory responses could be improved about ten times and with conjugated double bonds (C=C) in the long chains, the sensitivity could be increased by 3 similar to 4 orders of magnitude. As to head-groups, choline is preferred over ethanolamine and serine in phospholipid structures in terms of high olfactory sensitivity: These results are expected to be useful in further designing and manufacturing lipid-mimicking OSs. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.

Enhanced fiber Bragg grating sensor demodulation technique using cascade wavelength division multiplex couplers

An enhanced technique for interrogating fiber Bragg grating wavelength shift using cascade wavelength division multiplexer (WDM) couplers was proposed and demonstrated. Three WDM couplers which show a linear filter function over the expected wavelength range are employed and cascaded to track Bragg wavelength shifts. Compared with single WDM demodulator. sharper spectral slope is obtained and considerable linear filter range is kept. The static and dynamic strain sensor demodulation experiments demonstrated that the simple passive technique improves the sensitivity approximately two times and keeps 5nm linear demodulation range based on our devices. The cascade WDM coupler demodulation system has high scan rate which can be used to monitor fast vibration.

黄土丘陵沟壑区退耕地土壤种子库特征与季节动态

采用野外样线取样与室内萌发相结合的方法研究了黄土高原丘陵沟壑区退耕地种子库的组成、密度、分布特征、季节动态、种子库类型。结果表明,土壤种子库中共发现50种植物的种子,隶属15个科,39个属,主要物种组成与密度季节间差异不显著;在演替过程中土壤种子库的物种数量与密度随退耕年限的增加表现出:增加-减少-增加的趋势,同时阳坡种子库密度波动较阴坡剧烈;土壤种子库密度年内变化范围为1 067~14 717粒/m2,土壤种子库平均密度是夏季>秋季>春季;研究区域退耕地土壤种子库类型属于以猪毛蒿为优势种,并具有其他一年生、多年生草本植物与灌丛种子的没有显著的季节动态的持久种子库,是物种适应黄土丘陵沟壑区特有生态环境条件的繁殖更新策略;从土壤种子库的物种组成、密度、类型来看,黄土丘陵沟壑区退耕地具有一定的自然恢复潜力。

几种中药材的化学成分及其定性定量检测方法研究

本论文由四部分组成。第一部分报道了佛手参提取物的化学成分研究，建立了活性成分含量测定的高效液相测定和指纹图谱研究，采用液质联用技术鉴定了主要色谱峰；第二部分报道了丹参及其复方制剂的特征图谱研究；第三部分探讨了两面针生物碱的电喷雾质谱裂解规律，并采用液质联用技术分离鉴定了提取物中的多种生物碱。第四部分概述了液质联用在药物代谢研究中的运用。 第一部分包括第一、第二和第三章。第一章针对佛手参（Gymnadeniaconopsea）块茎的甲醇提取物，采用大孔树脂和反相硅胶柱层析等各种分离方法，共分离鉴定出4 个化合物，通过波谱分析将它们的结构确定为dactylorhin B (1)、loroglossin (2)、dactylorhin A (3)和militarine (4)。这4 个化合物均是首次从佛手参中分离得到的琥珀酸葡萄糖苷类成分。第二章采用高效液相色谱法对西藏、四川、河北、青海和尼泊尔等不同地区产的十个佛手参样品进行腺嘌呤核苷和对羟基苯甲醇的定量分析，结果表明这2 个成份可视为佛手参的特征成分，但也注意到产地不同该2 个特征成分的含量也有所不同。第三章采用标准中药指纹图谱相似度计算软件，以10 个佛手参样品HPLC 图谱的平均值为相似性评价对照模板，对10 个样品进行了相似度评价，并经液质联用分析指认了7 个共有峰，分别为腺嘌呤核苷(1)、对羟基苯甲醇(2)、对羟基苯甲醛(3) 、dactylorhin B(4) 、loroglossin(5)、dactylorhin A(6)和militarine(7)。 第二部分包括第四、第五、第六和第七章。第四章运用电喷雾质谱检测了对照药材和五个不同产地的丹参药材中脂溶性和水溶性成分，系统地探讨了多种成分的电喷雾质谱规律，并以对照药材为标准建立了特征指纹图谱。五个产地的药II材通过与对照药材相对比，采用聚类分析的方法，得到了定性的鉴别与判断。并采用液质联用技术对丹参药材提取液中的化学成份进行分析，推测了九个特征峰，并对六样品的液相色谱图进行了聚类分析。第五章探讨了三七皂苷的电喷雾质谱电离和裂解规律，并采用电喷雾质谱法对三七标准药材，血通片中的皂苷成分进行了分析。第六章运用电喷雾质谱研究复方丹参片提取液的特征图谱，并和单味药材丹参和三七的特征图谱进行了对比研究。并运用HPLC-ESI MSn 分析鉴定了复方丹参片提取液中的化学成分，推测了12 个色谱峰。第七章总结了电喷雾质谱和液质联用技术在丹参药材，三七药材及复方丹参制剂中的运用的优势和局限性。 第三部分（第八章）研究了两面针生物碱中二氢白屈菜红碱(1)、二氢两面针碱(2)、8-酮基二氢白屈菜红碱(3)、8-丙酮基二氢两面针碱(4)、两面针碱(5)、和1,3-二(8-二氢两面针碱)丙酮(6)等六个苯并菲啶型生物碱的电喷雾质谱裂解规律，其中二氢两面针碱和二氢白屈菜红碱，8-丙酮基二氢两面针碱和8-酮基二氢白屈菜红碱是两对二个甲氧基分别在C-9 和C-10，C-10 和C-11 的同分异构体。实验结果表明，在相同的碰撞能下，这类位置异构体的ESI MS2 质谱二级碎片离子的相对峰度存在很大差异，这可以用于区分该类同分异构体，采用液-质联用可以对两面针的总生物碱提取物中的这些同分异构体加于区分。同时在本实验采用的液相色谱条件下，多种生物碱得到较好的分离，通过和对照品的保留时间，紫外吸收光谱及电喷雾质谱图对照，鉴定了11 个主要色谱峰。 第四部分（第九章）对液质联用技术在药物代谢中的运用进行了综述。 This dissertation consisted of four sections. The first two sections elaborated thephytochemical investigation of the rhizomes Gymnadenia conopsea R. Br., methoddevelopment for rapid identifying and qutifying the chemical condtituent of thistibetant medicine, and the chemical fingerprint analysis of rhizomes of G. conopsea,Salviae miltiorrhiza and P. notoginseng. The third section studied the fragmentationmechanism of six alkaloids from Zanthoxylum nitidium and method development forrapid identifying varieties of alkaloids from the extract of this herbal medicine. Thefourth section reviewed HPLC- MS method in drug metabolism studies. The first section consisted of chapters 1, 2, 3. Chapter 1 elaborated the phytochemicalinvestigation of Gymnadenia conopsea R. Br. Four succinate derivative esters wereisolated from the methanol extract of the rhizomes of G. conopsea through repeatedcolumn chromatography on normal and reversed phase silica gel, their structures weredetermined by ESI-MS, 1D and 2D NMR evidence. They were firstly discoveredfrom this species. In chapter 2, a high-performance liquid chromatography.diodearray detection (HPLC-DAD) method has been firstly developed for quantitation oftwo characteristic constituents, adenosine and 4-hydroxybenzyl alcohol, from theextract of rhizomes of G. conopsea. All 10 samples of G. conopsea contained differentamount of adenosine and 4-hydroxybenzyl alcohol. Adenosine and the4-hydroxybenzyl alcohol can be applied in identification and quality control for theroots of G. conopsea. In chapter 3, a high-performance liquid chromatography.diodearray detection.tandem mass spectrometry (HPLC-DAD-MSn) method has been firstly developed for chemical fingerprint analysis of rhizomes of G. conopsea andrapid identification of major compounds in the fingerprints. Comparing the UV andMS spectra with those of authentic compounds, seven main peaks in the fingerprintswere identified as adenosine, 4-hydroxybenzyl alcohol, 4-hydroxybenzyl aldehyde,dactylorhin B, loroglossin, dactylorhin A and militarine. The Computer AidedSimilarity Evaluation System for Chromatographic Fingerprint of TraditionalChinese Medicine (CASES) was employed to evaluate the similarities of 10 samplesof the rhizomes of G. conopsea collected from Sichuan, Qinghai and Hebei provincesand Tibet autonomous region of China, and Nepal. These samples from differentsources had similar chemical fingerprints to each other. The second section consisted of chapters 4, 5, 6 and 7. In chapter 4，both thecharacteristic spectra of liposoluble tanshinones and aqueous-soluble salvianolic acidswere established by the electrospray ionization mass spectrometry (ESI MS)technique and the differences between standard and crude rhizomes of Salviaemiltiorrhiza Bge. from 5 sources were analyzed. The law of electrospray ion trap mass(ESI ITMS) of typical tanshinones and salvianolic acids is studied.The analysis of the chemical constituent of rhizomes of Salviae miltiorrhiza Bge. byliquid chromatography coupled with mass spectrum (LC/MS) technique wasestablished，and the distances among standard herb and crude herb from 5 sourceswere calculated by clustering analysis. According the DAD spectra and MS2 data，9tanshinones could be speculated. In chapter 5, the character spectra of total saponinsin P. notoginseng extracts were established by ESI ITMS and selective ion monitoring(SIM) technology. The law of notoginsenosides by ESI MS2 was studied. In chapter 6,the characteristic spectra of Compound Danshen Tablet established and compared byESI-MS and HPLC/DAD/MS, 6 known tanshinones and 3 saponins were speculated.In chapter 7, the advantage and disadvantage of the strategy, using the ESI ITMS andLC/MS techniques for study of characteristic spetra of danshen and Compound Danshen Tablet, were summerized. The third section (chapter 8) studied the fragmentation mechanism of six alkaloids,dihydronitidine, dihydrochelerythrine, 8-acetonyl dihydronitidine,8-acetonyldrochelerythrine, nitidine and 1,3-bis (8-dihydronitidinyl)-acetone, by ESIMSn. Tandem mass spectrometry experiments indicated that different substitutionsites of the methoxyl groups at C-9 and C-10 or at C-10 and C-11 determined thedifferent abundances of the MS2 fragmentation ions using the same collision energy.According to the different abundances of MS2 product ions, positional isomericbenzo[c] phenanthridine alkaloids can be differentiated. Moreover, ten constituents inthe crude alkaloids extract from the roots of Zanthoxylum nitidium were rapidlyidentified by high-performance liquid chromatography coupled with tandem massspectrometry (HPLC-MSn), through comparing the retention times and ESI MSn spectra with the authentic standards. The fourth section (chapter 9) is a review on HPLC-MS method development in drug metabolism studies.

钻井废水可生化性研究及处理技术探索

钻井废水是油气井开采钻探过程中产生的废水，钻井废水成分复杂，有机物浓度高、色度高、悬浮物浓度高，水质变化大，排放点分散，不经处理排放会污染环境，破坏生态。随着石油工业的不断发展和国家环保法律法规的日益严格，钻井废水的治理也越来越受到重视。如何采用经济有效的方法处理废弃钻井液，对油气井开采业的可持续发展具有重要意义。本论文以遂宁磨153 井的钻井废水为主要研究对象，在对废水进行絮凝沉降预处理和生物法处理探索的基础上，针对钻井废水可生化性差的特点，采用水解酸化和Fenton 试剂改善钻井废水的可生化性，对反应过程进行了比较详细的考察，对可生化性改善的机理进行了探索。主要研究结论如下：1 用PFS 和PAC 配制的混合混凝剂对钻井废水COD 的去除效果比较显著，在最佳条件下COD 的去除率可达75%，且絮体沉降速度较快，出水pH 保持中性；2 水解酸化法处理钻井废水可显著改善废水的可生化性。经48 小时水解酸化处理，钻井废水的理论BOD5可提高约22 倍，表观BOD5/COD值由0.004 提高到0.034。用接触氧化反应器处理经水解酸化处理后的废水，处理效果比较稳定，COD平均去除率达35.5%；3 研究了Fenton反应中各影响因子对废水COD去除率、BOD5/COD的影响并分析其作用机制，确定了最佳条件：初始pH为4.0，H2O2/Fe2+(摩尔浓度比)为20，H2O2/COD（质量浓度比）为1，反应时间为2 个小时。此条件下，废水的COD去除率约为40%，BOD5/COD值从0.002～0.003 提高至0.15～0.2，可生化性得到很大提高。本论文的主要创新点在于：1 以成分复杂、水质变化大的气井钻井废水为研究对象，从理论BOD 和表观BOD 两方面对水解酸化过程中废水可生化性的变化进行了分析；2 对Fenton 试剂改善钻井废水可生化性的过程、主要影响因素进行了比较详细的考察。本论文的研究成果，可为生物法处理钻井废水的深入研究提供理论依据。Drilling wastewater is produced in the process of oil-gas well drilling,because of its complicated composition, high concentrate of organic compound andsuspended solid, high chroma, levity of water quality and decentralization ofdischarge point, it pollutes environment seriously if discharged without treatment.With the development of petroleum industry and the issuing of more strict laws forenvironmental protection, it has been paid more and more attention on drillingwastewater treatment. It is of great importance for the sustainable development ofoil-gas well drilling to treat drilling wastewater by economical and effective methods.In this paper, drilling wastewater of Mo No.153 well in Suining was studied asthe main object. On the basis of research on pre-treatment with flocculant andbiological treatment, and according to the character of poor biodegradability, thedrilling wastewater was treated by hydrolytic acidification and Fenton’s reagent toimprove its biodegradability. The process and mechanism of biodegradabilitychanging were investigated. The primary conclusions are:1 It is effective to treat drilling wastewater with mixing PFS and PAC asflocculant. The removal rates of COD came up to 75% under optimal conditions, thesedimentation rate of flocculation is rapid, and the pH value of treated water remainedneutral;2 The biodegradability of drilling wastewater was highly improved afterhydrolytic acidification process. The theoretic BOD5 of drilling wastewater increasedby 22 times and its detected BOD5/COD ratio increased from 0.004 to 0.034 afterhydrolytic acidification for 48 hours. The wastewater after hydrolytic acidificationwas treated by biological contact oxidation reactor. Stable treatment performance was achieved, and the average removal rates of COD came up to 35.5%;3 The effects of various affection factors on the removal efficiency of COD andBOD5/COD radio in treating drilling wastewater by Fenton’s reagent wereinvestigated and the mechanism was analyzed. The optimal conditions were: initialpH of solution was 4.0, the molar ratio of H2O2 and Fe2+ was 20, the concentrationratio of H2O2 and COD was 1 and the reaction time was 120 min. Under the aboveconditions, the removal efficiency was about 40% and the ratio of BOD5 and CODincreased from 0.002 ¡« 0.003 to 0.15 ¡« 0.2. The biodegradability of drillingwastewater was greatly improved.The innovations of this thesis are:1 The drilling wastewater was taken as the research object which hascomplicated composition and variational water quality, and the changes ofbiodegradability were analyzed from theoretic BOD and detected BOD aspects duringhydrolytic acidification process;2 The biodegradability changing process and primary affection factors of drillingwastewater treating by Fenton’s reagent were investigated.The results of this study could provide theoretic foundation for further researchon biological treatment of drilling wastewater.

利用含纤维素原料发酵产氢的研究

本文从新鲜大熊猫粪便和实验室保存的沼气发酵富集物中筛选得到 4 株厌氧纤维素分解菌B5、C3、D3-2、D4-1，利用这4 株菌预处理秸秆，然后将预处理后的秸秆用本实验室保存的厌氧产氢菌来发酵进行生物产氢。同时还比较研究了：○1 用1% H2SO4、25% NH3 · H2O和12% NaOH对秸秆进行化学预处理；○2 用厌氧纤维素分解菌对秸秆进行生物预处理；○3 化学与生物组合预处理对秸秆发酵生物产氢的影响。实验结果表明：12% NaOH和生物组合预处理后的秸秆发酵产氢效果最好，其产氢量为21.04 mL g-1，是未经预处理秸秆的75 倍；最高氢气浓度为57.3%，是未经预处理秸秆的96 倍；其产氢的最适pH 为4.5 ~ 6.0，最佳底物浓度为45 ~ 55 g L-1；其发酵过程中的挥发性脂肪酸（VFAs）以乙酸和丁酸为主。 本实验筛选到的 4 株厌氧纤维素分解菌株中，B5 和D4-1 在降解纤维素的同时还具有直接以纤维素为底物产氢的功能，因此本文分别对菌株B5 和D4-1 以及二者的组合菌株B5+D4-1 直接利用秸秆为基质发酵生物产氢做了初步探索研究。结果发现：组合菌株发酵产氢的效果以及对秸秆纤维素和半纤维素的降解率要比单菌株好。菌株B5+D4-1 发酵，秸秆的产氢量为11.4 mL g-1，分别是B5 和D4-1 单菌株的1.6 倍和3.1 倍；组合菌株B5+D4-1 发酵的最大氢气浓度为31.6%，分别是B5 和D4-1 单菌株的1.3 倍和2.4 倍。在发酵过程中，组合菌株B5+D4-1 对秸秆纤维素和半纤维素的最高降解率分别为35.0%和11.8%，分别是菌株B5 的1.2 倍和1.1 倍，是菌株D4-1的1.5 倍和1.3 倍。菌株B5，D4-1 以及组合菌株B5+D4-1 发酵过程产生的挥发性脂肪酸（VFAs）均以乙酸为主。菌株B5 单独发酵过程中只检测到乙酸和丁酸，菌株D4-1 单独发酵以及组合菌株B5+D4-1 发酵过程检测到有乙醇、乙酸和丁酸。 The fermentative bio-hydrogen production by anaerobic hydrogen bacteria preserved in our laboratory from the straw which had been pretreated by four anaerobic cellulolytic decomposition strains of B5, C3, D3-2, D4-1 which were isolated and screened from giant panda’s excrement and biogas fermentation enrichments conserved in our laboratory was studied. Besides, the impact of chemical(1% H2SO4、25% NH3·H2O and 12% NaOH), biological (cellulolytic strains of B5, C3, D3-2, D4-1) and chemical-biological combination pretreatment on bio-hydrogen production from straw by fermentation was also comparatively studied. The experiments showed that the best results of bio-hydrogen production were obtained from the straw with 12% NaOH-biological combination pretreatment method, its capability of bio-hydrogen production was 21.04 mL g-1, which was 75 times higher than the straw without pretreatment; the maximum concentration of H2 was 57.3%, which was 96 times higher than the straw without pretreatment; its optimum pH range was 4.5 ~ 6.0, and its optimum range of substrate concentration was 45 ~ 55 g L-1; In the process of fermentation, the main composition of VFAs were acetate and butyrate. Among the four strains of B5, C3, D3-2, D4-1, B5 and D4-1 have the function of hydrogen-producing by cellulose used as substrate when it decompose cellulose, so the preliminary exploration and research on fermentative bio-hydrogen production by B5, D4-1 and B5+D4-1 which directly used straw as substrate was carried out. The results showed that the combination strains of B5+D4-1 was strikingly better than either B5 or D4-1 strain in the fermentative hydrogen production. The hydrogen-production capability of B5+D4-1 was 11.4 mL g-1 which was respectively 1.6 times and 3.1times higher than B5 and D4-1; the maximum hydrogen concentration of B5+D4-1 was 31.6% which was respectively 1.3 times and 2.4 times higher than B5 and D4-1. In the process of fermentation, the maximum degradation rate of cellulose and hemicellulose in straw was respectively 35.0% and 11.8% by B5+D4-1, which was 1.2 times and 1.1 times higher than B5, and was 1.5 times and 1.3 times higher than D4-1 respectively. The Volatile Fattty Acids(VFAs) generated in the process of fermentation with strains of B5, D4-1 and B5+D4-1 were all mainly acetate. Acetate and butyrate were detected in the process of fermentation with B5, ethonal, acetate and butyrate were detected in the process of fermentation with D4-1 and B5+D4-1.

组合白腐真菌预处理木质纤维素原料的研究

木质纤维素原料种类多、分布广、数量巨大，通过燃料乙醇生产技术、厌氧沼气发酵技术将其转化成乙醇、沼气等二次能源，一定程度上可以缓解化石能源的不断消耗所带来的能源危机，也解决了农林废弃物引起的环境污染问题。其中以木质纤维素原料生产燃料乙醇，还可以避免以淀粉类和糖类原料生产燃料乙醇时带来的“与人争粮”等一系列问题。因此具有重要的经济效益、环境效益和社会效益。 然而，木质纤维素原料结构致密，木质素包裹在纤维素、半纤维素外围，导致其很难被降解利用，必须进行适当的预处理，去除木质素，打破原有的致密结构，利于原料的后续利用。因此，预处理成为木质纤维素原料能源化利用的关键。而目前预处理环节的费用过于昂贵，于是寻找一种高效、低成本的预处理方法是当今研究的热点。 本论文采用组合白腐真菌对木质纤维素原料进行生物预处理研究，与其他物理化学法相比，该法有着专一性较强、反应温和、不造成环境污染、成本低等优势。白腐真菌主要通过分泌木质素降解酶对木质素进行降解，从而破坏原料的致密结构，提高后续利用效率。所以木质素降解酶酶活的高低是影响原料预处理效果的一个关键因素。于是本论文首先通过将白腐真菌进行组合的方式提高木质素降解酶（漆酶，Lac）酶活；接着对组合菌的菌株相互作用机理进行研究，阐明组合菌Lac 酶活提高的原因，为菌株组合提高Lac 酶活这种方法的应用提供理论依据，同时也为后续组合白腐真菌预处理木质纤维素原料提供指导；进一步采用固态发酵和木质素降解酶两种方式对木质纤维素原料进行预处理研究，最大化去除木质素成分，破坏原料的致密结构；最终对预处理后原料的酶解糖化进行初步研究，为原料后续的能源化应用奠定基础。具体研究结果如下： （1） 以实验室保存的三株主要分泌Lac 的白腐真菌为出发菌株，筛选得到一组Lac 酶活明显提高的组合菌55+m-6，其中菌株55 为Trametes trogii sp.，m-6 为Trametes versicolor sp.，组合后Lac 酶活较单菌株分别提高24.13倍和4.07 倍。组合菌的最适产酶条件为pH 6.5、C/N 16:1、Tween 80 添加量为0.01%，在该条件下组合菌的Lac 酶活峰值比未优化时提高4.11倍。 （2） 对组合菌55+m-6 菌株间相互作用机理进行研究，发现菌株之间不存在抑制作用；平板培养时，菌丝交界处Lac 酶活最高并分泌棕色色素；液体培养时，菌株m-6 对组合后Lac 酶活的提高起着更为重要的作用：菌株m-6的菌块、过滤灭菌胞外物以及高温灭菌胞外物均能明显刺激菌株55 的Lac产生；菌株55、m-6 进行组合后，同工酶种类未发生增减，但有三种Lac同工酶浓度有所提高；对菌株胞外物进行薄层层析和质谱分析，结果表明组合前后菌株胞外物中各物质在浓度上存在较大的变化。推测组合菌Lac酶活的明显提高，主要是由于菌株m-6 胞外物中的一些物质能刺激菌株55 分泌大量Lac 进行代谢，且这些刺激物质并非菌株m-6 特有，菌株55自身也可以代谢生成，但是适当的浓度才能刺激Lac 的大量分泌。 （3） 将组合菌55+m-6 用于固态发酵预处理木质纤维素原料，发现其对玉米秆的降解程度最大，在粉碎度40 目、含水率65%的最优处理条件下，处理至第15d，秸秆失重率为41.24%，其中木质素、纤维素、半纤维素均有降解，且Lac 和纤维素酶（CMC）酶活以及还原糖量均达到峰值。 （4） 对玉米秆进行木质素降解酶预处理，发现Lac/1-羟基苯并三唑（HBT）系统对玉米秆木质素的降解效果最好，在最优处理条件时，即HBT 用量0.2%、处理时间1d、Lac 用量50U/g，木质素降解率可达12.60%。预处理后玉米秆的致密结构被破坏，比表面积增大，利于后续酶与纤维素、半纤维素成分的结合。 （5） 对预处理后的玉米秆进行酶解糖化，其中组合菌固态发酵预处理后玉米秆的糖化率比对照高4.33 倍；Lac/HBT 系统预处理后玉米秆的糖化率比对照高2.99％，糖化液中主要含有木糖、葡萄糖两种单糖。 There are many kinds and large quantities of lignocellulosic biomass widely distributed on the earth. They can be converted into secondary energy such as fuel ethanol, biogas, et al., which can relieve the energy crisis caused by consumption of fossil energy resources and solve the problem of environmental pollution caused by agriculture and forestry waste. Meanwhile, the production of fuel ethanol from lignocellulosic biomass can ensure food supply to human kind instead of starch- and sugar-containing raw materials. So the energy conversion of lignocellulosic biomass contributes considerable economic, environment and social benefits. However, lignocellulosic biomass has the compact structure, in which lignin surrounds cellulose and hemicellulose, so it must be pretreated before energy usage and pretreatment is one of the most critical steps in the energy conversion of lignocellulosic biomass. At present, the cost of pretreatment is too expensive, so looking for an efficient and low-cost pre-treatment method is one of recent research hot spots. In this research, combined white rot fungi pretreatment method was used, which had some advantages in low cost, high specificity, mild reacting conditions and friendly environmental effects compared with the other physical and chemical methods. White rot fungi secrete lignin degrading enzymes to degrade the content of lignin and damage the contact structure of lignocellulosic biomass, so the activity of the lignin degrading enzymes is the key factor to the degradation effect of raw materials. Firstly, the combined fungi with high laccase activity were screened; secondly, the interaction mechanism between strains was studied, and the cause of higher laccase activity after strains combination was also preliminary clarified; under the guidance of the mechanism, lignocellulosic biomass was pretreated by the combined fungi; lastly, the enzymatic hydrolysis of pretreated lignocellulosic biomass was also preliminary studied; all of the researches could lay the foundation for the energy application of lignocellulosic biomass. The specific research results were as follows: (1) The combined fungi 55+m-6 with significant higher laccase activity were screened from the three white rot fungi stored in our lab which mainly secreted laccase. Strain 55 and strain m-6 were Trametes trogii sp. and Trametes versicolor sp., respectively. The laccase activity of combined fungi was 24.13 and 4.07-fold than strain 55 and strain m-6, respectively. The optimized condition for laccase production of the combined fungi in liquid medium was pH 6.5, C/N 16:1 and Tween 80 0.01%. In this optimized condition, the laccase activity of combined fungi was 4.11-fold higher comparing with which in non-optimized medium. (2) The interaction mechanism between strain 55 and strain m-6 was further studied, and no inhibition effect was observed. Brown pigment was secreted on the junction of the two strains on the plate, where the highest laccase activity was detected. Strain m-6 was much important to boost laccase activity of combined fungi in liquid medium, and strain 55 was stimulated by fungal plug, filter sterilized extracellular substances and high temperature sterilized extracellular substances of strain m-6 to produce laccase. The types of laccase isozymes did not change after combining strain 55 and strain m-6, but the concentrations of three types increased. Mass Spectrometry and TLC analysis of extracellular substances of each strain showed that concentration of some substances considerably changed after strains were combined. It was supposed that the cause of higher laccase activity of combined fungi was mainly due to some extracellular substances of strain m-6 with the appropriate concentration which stimulated laccase secretion of strain 55 and generated not only by strain m-6 but also by strain 55. (3) Combined fungi 55+m-6 were used to lignocellulosic biomass pretreatment with the type of solid-state fermentation. The highest degree of degradation of corn straw was obtained, including the rate of weight loss was 41.24% and the lignin, cellulose and hemicellulose were degraded partially under the optimized condition of 40 mesh, 65% water content on 15th day. Laccase, CMCase activities and content of reducing sugar reached the maximum value on that day. (4) Lignin degrading enzymes from combined fungi 55+m-6 were used for corn straw pretreatment. The most remarkable degradation of lignin in corn straw with Lac/1-hydroxybenzotriazole (HBT) system was observed, and the 12.60% lignin degradation was obtained under the optimized condition of 0.2% HBT, 50 U/g laccase for 1 d. After pretreated by Lac/HBT, the tight structure of corn straw was demolished and specific surface area increased, which had advantages for accessible of enzyme to cellulose and hemicellulose. (5) The corn straws pretreated by combined fungi 55+m-6 with the type of solid-state fermentation and Lac/HBT were used for enzymatic hydrolysis, and the saccharification rates of each pretreatment type were 4.33 times and 2.99% higher than CK, respectively. The enzymatic hydrolysis liquid of corn straw pretreated by Lac/HBT mainly contained xylose and glucose.

Experimental verification of therapeutic doses for the superficially-placed tumor radiotherapy with heavy ions at HIRFL

Up to now, clinical trials of heavy-ion radiotherapy for superficially placed tumors have been carried out for six times and over 60 selected patients have been treated with 80—100 MeV/u carbon ions supplied by the Heavy Ion Research Facility in Lanzhou (HIRFL) at the Institute of Modern Physics, Chinese Academy of Sciences since November, 2006. A passive irradiation system and a dose optimization method for radiotherapy with carbon-ion beams have been developed. Experimental verification of longitudinally ...

Selective hydrogenation of citral catalyzed with palladium nanoparticles in CO2-in-water emulsion

CO2-in-Water (C/W) emulsion was formed by using a nonionic surfactant of poly (ethylene oxide)-poly (propylene oxide)-poly (ethylene oxide) (P123), and palladium nanoparticles were synthesized in situ in the present work. The catalytic performance of Pd nanoparticles in the C/W emulsion has been discussed for a selective hydrogenation of citral. Much higher activity with a turnover frequency (TOF) of 6313 h(-1) has been obtained in this unique C/W emulsion compared to that in the W/C microemulsion (TOF, 23 h(-1)), since the reaction was taking place not only in the surfactant shell but also on the inner surface of the CO2 core in the C/W emulsion. Moreover, citronellal was obtained with a higher selectivity for that it was extracted to a supercritical carbon dioxide (scCO(2)) phase as formed and thus its further hydrogenation was prohibited. The Pd nanoparticles could be recycled several times and still retain the same selectivity, but it showed a little aggregation leading to a slight decrease in conversion.

Effects of polymerization conditions on hydrophilic groups in aromatic polyamide thin films

For polyamide used in reverse osmosis (RO) membranes, the content of pendant acid groups is critical to its performance. In this work, FTIR was used to analyze the acid contents in the polyamide films prepared via interfacial polymerization of trimesic acid trichloride (TMC) in hexane and 1,3-phenylenediamine (MPDA) in water, and the effects of reaction conditions, including monomer concentrations, time, and temperature, were studied. It was found that more pendant acid groups are present in the polyramide film at higher TMC concentrations or lower MPDA concentrations, and longer reaction times and lower temperatures also favor the formation of the free acids. These results can be explained by the monomer diffusion in the interfacial polymerization process. This work may help the design and fabrication of RO membranes with different hydrophilicity and target performance.

Effective enhancement of peroxydisulfate electrochemiluminescence on C-60/DDAB films

Effective enhancement of electrochermluminescence (ECL) of peroxydisulfate on a C-60/didodecyldimethyl ammonium bromide (C-60/DDAB) film coated glassy carbon electrode (GCE) surface is reported in this paper. The C60/DDAB film gave lower cathodic current in the presence of peroxydisulfate than that from a bare GCE. To our surprise, electrochemiluminescent intensity from peroxydisulfate reduction was effectively enhanced on the C60/DDAB film, which was 50 times and 250 times higher than those from a DDAB film coated and bare GCE, respectively. Moreover, the ECL onset potential on the C60/DDAB film was about -0.9 V, which positively shifted 200 mV compared with that from the bare GCE. Dissolved oxygen and the applied potential also affected the electrochemiluminescent intensity. The presence of oxygen decreased the intensity, and the intensity reached maximum at the applied potential of -1.7 V. The unique property will greatly enrich ECL studies and applications based on fullerenes.

Determination of diphenhydramine by capillary electrophoresis with tris(2,2 '-bipyridyl)ruthenium(II) electrochemiluminescence detection

Tris(2,2'-bipyridyl)ruthenium(II) electrochemiluminescence detection in a capillary electrophoresis separation system was used for the determination of diphenhydramine. In this study, platinum disk electrode (300 mum in diameter) was used as a working electrode and the influence of applied potential and buffer conditions were investigated. Under optimal conditions: 1.2 V applied potential, pH 8.50, 15 kV separation voltage and 10 mmol l(-1) running buffer, the calibration curve of diphenhydramine was linear over the range of 4 x 10(-8) to 1 x 10(-5) Mol l(-1). This technique gave satisfactory precision, and relative standard deviations of migration times and chemiluminescence peak intensities were less than 1 and 6%, respectively. The technique was applied to animal studies for determination of diphenhydramine extracted from rabbit plasma and urine samples, and the extraction efficiency were between 92 and 98.5%.

Improvement of luminescence efficiency by electrical annealing in single-layer organic light-emitting diodes based on a conjugated dendrimer

In this paper, we study the effects of electrical annealing at different voltages on the performance of organic light-emitting diodes. The light-emitting diodes studied here are single-layer devices based on a conjugated dendrimer doped with 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole as the emissive layer. We find that these devices can be annealed electrically by applying a voltage. This process reduces the turn-on voltage and enhances the brightness and efficiency. We obtained an external electroluminescence quantum efficiency of 0.07% photon/electron and a brightness of 2900 cd m(-2) after 12.4 V electrical annealing, which are about 6 times and 9 times higher than un-annealing devices, respectively. The improved luminance and efficiency are attributed to the presence of a space charge field near the electrodes caused by charging of traps.