The photon scanning tunneling microscope and its applications

A simple photon scanning tunneling microscope (PSTM) is described. Its lateral resolution (similar to 10nm with a maximal scanning range of 10 mu m x 10 mu m ) is much better than that of a conventional optical microscope. Its principle, the fiber optic tip fabrication and PSTM images of different samples such as mica, HDPE and LiNbO3 are presented.

Aluminum induced crystallization of strongly (111) oriented polycrystalline silicon thin film and nucleation analysis

A polycrystalline silicon thin film was fabricated on glass substrate by means of aluminum induced crystallization (AIC). Al and alpha-Si layers were deposited by magnetron sputtering respectively and annealed at 480A degrees C for 1 h to realize layer exchange. The polycrystalline silicon thin film was continuous and strongly (111) oriented. By analyzing the structure variation of the oxidation membrane and lattice mismatch between gamma-Al2O3 and Si, it was concluded that aluminum promoted the formation of (111) oriented silicon nucleus by controlling the orientation of gamma-Al2O3, which was formed at the early stage of annealing.

液滴在超疏水表面上的电场启动以及碰撞的实验研究

液滴操纵和控制是实现微全分析系统(μTAS)和芯片上的实验室(lab-on-a-chip)功能的基础,基于液滴操控的显示及微透镜已经成功应用。目前电润湿启动液滴方法简单、响应时间快,引起越来越多的关注。另一方面超疏水表面上的液滴具有低摩擦、低粘附的特性,借由这种原理制作的微流器件可以实现微量液体传输。为了更好的利用超疏水表面的特性,就需要研究液滴运动规律,以及表面特性的影响。

Pool Boiling on Wire in Microgravity - What Have We Learned

In the past years, steady pool boiling of degassed R113 on thin platinum wires has been studied systematically in our lab, including experiments in long-term microgravity aboard RS-22, in short-term microgravity in the Drop Tower Beijing / NMLC, and in normal gravity on the ground. Slight enhancement of nucleate boiling heat transfer is observed in microgravity, while dramatic changes of bubble behaviors are much evident. The value of CHF in microgravity is lower than that in normal gravity, but it can be predicted well by the Lienhard-Dhir correlation, although the dimensionless radius in the present case is far beyond its initial application range. The scaling of CHF with gravity is thus much different from the traditional viewpoint. Considering the influence of the Marangoni effects, the different characteristics of bubble behaviors in microgravity have been explained. A new bubble departure model has also been proposed, which can predict the whole observation both in microgravity and in normal gravity.

路易斯碱催化的烯胺不对称还原研究

手性胺不仅是许多天然产物和手性药物的重要结构单元，而且也是非常有用的拆分试剂、手性配体和手性催化剂。亚胺和烯胺的不对称催化还原是制备手性胺的最直接有效的方式之一，手性有机小分子催化的亚胺不对称还原已取得了很大的进展，但到目前为止，有机小分子催化的烯胺不对称还原极少见文献报道。 本研究以廉价的三氯氢硅为氢源、DMF 等路易斯碱为催化剂实现了烯胺的高效还原。通过反应条件的优化，各种烯胺底物在0.1 eq. DMF 催化下、12 个小时内可以获得非常高的收率（>93%）。 在本课题组前期研究的基础上，我们筛选并设计了一系列以手性哌啶酸和叔丁基亚磺酰胺为母体的有机小分子路易斯碱催化剂，它们能催化三氯氢硅对(Z)-N-苄氧羰基-1-苯基丙烯胺的不对称还原，获得很高的收率和中等的对映选择性，并且具有很好的底物普适性。另外，通过机理方面的研究，我们推测在反应过程中一分子烯胺先捕获一个质子而转变为亚胺正离子，然后受到路易斯碱活化的三氯氢硅中的富电氢原子进攻该亚胺正离子得到还原产物。 另外，本文列出了在此课题进展中所发现的一些新反应，并且试图去阐释这些反应的作用机理。 Catalytic enantioselective reduction of imines and enamines represents one of the most straightforward and efficient methods for the preparation of chiral amines, which are not only important building blocks of many natrural products and chiral drugs, but also can serve as useful resolution reagents, chiral ligands and chiral catalysts. By now, asymmetric reduction of enamines catalyzed by organocatalysts has scarcely been reported, although organocatalyzed enantioselective reduction of imines has already gained great progress. In this study, we report the DMF-catalyzed reduction of enamines with high yields using HSiCl3 as the reducing agent. Under the optimized reaction conditions, various enamines can be reduced in the presence of 0.1 eq. DMF with high yields (>93%) in 12 hours. We screened a set of Lewis base organocatalysts derived from chiral pipecolinic acid and tert-butanesulfinamide for the reduction of (Z)-N-Cbz-1- phenylpropenamine, including newly designed ones and some of those previously developed in our lab. However, only moderate stereoselectivities, albeit high yields were obtained. As for the mechanism, we speculate that the enamine firstly engages a proton to form an iminium species, which is then attacked by the nucleophlic hydrogen of HSiCl3 activated by Leiws base. During the above studies, we have also discovered some new reactions, for which feasible mechanisms were proposed.

吲哚生物碱Desbromoarborescidine A 的全合成及烯胺C-亚磺酰化反应研究

从新几内亚核桃木的树皮中分离得到的吲哚类喹诺里西定生物碱10-Desbromoarborescidine A，因发现其具有阻滞钙离子通道的活性而倍受关注。10-Desbromoarborescidine A由A、B、C、D四个环组成，只有一个手性中心，是吲哚生物碱中结构较简单的一种，常作为此类生物碱全合成方法的模型化合物。但迄今为止，能高效而简便的实现手性10-Desbromoarborescidine A不对称全合成方法线路不多，大多数以不对称诱导的方式建立其手性中心，手性催化的方式仅有一例金属催化。从逆合成分析可知，Desbromoarborescidine A的全合成可以通过亚胺不对称催化还原进行关键的手性中心构建，而本课题组在之前的研究中通过手性有机小分子催化剂的发展，已将三氯硅烷氢转移还原亚胺发展成了一类简便实用、高效、高对映选择性并具有优良底物适应范围的不对称催化反应，我们希望以这一反应作为关键手段，发展一条Desbromoarborescidine A及其类似物不对称合成新路线。 根据我们设计的新路线，首先成功合成了其关键中间体，然后我们进行了关键的不对称催化尝试。用本实验室已有的高性能有机小分子催化剂虽得到了较好的对应选择性，但是产率很低。同时，为了验证整条线路的可行性，我们也用消旋的中间体进行拉通线路的尝试。但不幸的是，在脱除保护基时遇到了很大困难。尝试换不同的保护基，或改变脱保护基的顺序，都未能成功合成目标产物。究其原因可能是由于吲哚的特殊性造成的，吲哚类亚胺与常规的芳香亚胺有较大的差异，其NH基团无论保护还是不保护，对与其2位相联接的C=N双键均有很大的影响，导致其不对称催化还原难以进行。另外，由于所设计的还原产物含有处在吲哚苄位的胺基，稳定性较差，造成保护基脱除困难。 烯胺C-亚磺酰化反应是本课题组最近发现的一个新反应，之前未见文献报道。本研究对该反应进行了反应条件优化和底物扩展，发现带Cbz，Ac，COt-Bu，CO2Et，Bz等保护基的一系列环状和非环状烯胺在亚磺酸钠、DMAc和MeSiCl3的共同作用下能高效高产率生成β-胺基烯基亚砜类新化合物，为合成多官能团化的烯基亚砜新化合物提供了一条简便实用的途径。 The main constituent of Dracontomelum mangiferum B1, indoloquinolizidine alkaloid 10-Desbromoarborescidine A, has drawn great attention due to its calcium channel blocking activity. Its molecular structure is relatively simple compared with the other alkaloids of the same type, which has only one chiral center, albeit with four cycles A, B, C, and D. This compound is often used as a model target for exploring different strategies for the total synthesis of indole alkaloids. Nevertheless, so far there still lack practical and highly efficient methods for the asymmetric total synthesis of 10-Desbromoarborescidine A. Most of the current available methods rely on stoichiometric asymmetric synthesis for the construction of the chiral center. There is only one example reporting utilization of asymmetric catalysis, but with transition metal complex as the catalyst. Our retrosynthetic analysis shows that catalytic asymmetric reduction of imine could be used as the key step for the construction of the chiral center of Desbromoarborescidine A. Since in the previous studies our group has developed the asymmetric reduction of imines by trichlorosilane into a practical and highly efficient and enantioselective method using newly designed chiral organocatalysts, we hope to apply this method to develop a novel synthetic route for the total synthesis of Desbromoarborescidine A and its analogues in this study. According to the newly designed synthetic route, we first accomplished the synthesis of the key intermediates which was then examined for the critical asymmetric catalysis. The asymmetric reduction using the highly efficient organocatalysts, developed in our lab afforded high ee but poor yield. We tried different reaction conditions to improve the yield, but failed to get any good results. Simultaneously, to vertify the feasibility of the synthetic route we designed, we also tired to go through the route toward the racemic synthesis of Desbromoarborescidine A. But unfortunately, protection and deprotection proved to be big hurdles. All the different protection groups and different sequences of protection and deprotection we tried failed to get us through the designed synthetic sequence and furnish the final product. Most likely, the indole part is the culprit behind the failures.The NH group of the indole, no matter protected or not, may impact the catalytic asymmetric reduction of C-N double bond connected with 2-C. Additionally, the reduction product we designed contains an amino group in the β-position of the indole, which may cause problems due to its instability. C-sulfenylation of enamines is a novel reaction discovered recently by our group, which has not been seen before in the literature. In this study, optimization of the reaction conditions and exploration of the substrate scope were further undertaken for this reaction, which reveal that a series of enamines with N-Cbz, Ac, COt-Bu, CO2Et protection groups could all undergo smooth C-sulfinylations with the comined use of sodium benzene sulphinate, DAMc and MeSiCl3, efficiently furnishing the β-amino vinylsulfoxide products in high yield, affording a practical and highly efficient methods for synthesis of functional vinylsulfoxides.

岷江柏种子的形态和发芽特征与贮藏生理动态研究

岷江柏(Cupressus chenggiana S. Y. Hu)是我国川甘地区特有的珍稀濒危乔木，一般生长在干旱的河谷区，在涵养水源和保护水 土等方面起着重要的作用。本文选择4个岷江柏种群，采用了野外调查和室内实验相结合的研究方法，调查岷江柏种群结实状况， 分析种子和球果形态特征，阐明种子发芽的基本特征，研究岷江柏种子贮藏过程中几个生理指标的动态变化特点，目的是为岷江柏 种苗繁育、自然更新能力评估以及珍稀濒危机制分析提供理论依据。研究得出如下结论：1.岷江柏球果呈椭球形，长为1.5～ 2.2cm,宽为1.5～1.9cm，质量为1.7～4.2g，球果鳞片数量为8～11片，球果内种子数量一般在40～70粒。岷江柏种子为椭圆形，长 为3.58～4.02mm，宽为3.10～3.15mm，厚为0.96～1.11mm，千粒重为3.1～3.5g。岷江柏的结实率很低，并且有显著的地理差异和 大小年差异。2. 岷江柏种子发芽温度范围是5℃～30℃,其中种子的适宜发芽温度范围是10℃～25℃。种子最适发芽温度随着贮藏 时间的增加而变化。在适宜温度范围内，种子发芽周期为20d。温度对种子的发芽势和T50有显著影响，对种子发芽率没有显著影响 ；光照有利于种子发芽；岷江柏种子的发芽特征是岷江柏保护种子资源、防止物种濒危的一种环境适应，有助于岷江柏种子提高发 芽率和幼苗的存活率。岷江柏种子是一种耐贮藏的正常性种子，在短期贮藏过程中，贮藏温度和种子含水量对于种子生理指标和种 子发芽没有显著影响。3. 岷江柏种子在短期贮藏过程中，千粒重没有显著变化；含水量都经历了先下降，再稳定的过程；粗脂肪 含量和可溶性糖含量逐渐降低；可溶性蛋白含量和丙二醛含量逐渐增加；脯氨酸含量在贮藏1～7个月时变化差异不明显，但是贮藏 7～10个月后显著增加。岷江柏种子的各个生理指标之间的相关性差异不显著。4. 岷江柏球果和种子的形态特征存在显著的地理差 异。岷江柏种子的发芽能力的地理性差异不大，种群间差异不大。岷江柏种群的地理差异由种群特征、生境特征和气候特征共同决 定。5. 在岷江柏的人工繁育中，对于刚刚采集的种子，发芽温度在15℃～25℃比较适合，其中以25℃最佳；而对于短期贮藏(4～ 10个月)后的种子，发芽温度在10℃～25℃均可，以15℃～20℃为最佳。野外播种的最适时间为4～6月，6～9月的间歇性干旱和降 水波动可能是限制岷江柏自然更新的因素之一。在短期贮藏过程中，种子可以采用常规室温贮藏，可以节约成本。Cupressus chenggiana is a specific and endangered plant in Sichuan and Gansu provinces of China, and it usually grows in dry valley and plays an important role in water supply and soil and water conservation in the dry valley of alpine and canyon region of southwest China. The research selected four Cupressus chenggiana populations and used the methods of the field investigation and the lab experiments. The fruiting characters of Cupressus chenggiana populations, the morphological characters of seeds and cones, the germination characters of seeds and the store physiological dymatics of several factors of seeds have been studied in order to give some theoretical advices on the artificial propagation and the ability of natural regeneration and the endangered principle of Cupressus chenggiana in the paper. The main results may be clarified as follows: 1. The cones of Cupressus chenggiana are ellipsoidal, length ranged from 1.5 to 2.2cm, with ranged from 1.5 to 1.9 cm, weight ranged from 1.7 to 4.2g, the number of cone squama ranged from 8 to 11, and the seed number of per cone ranged from 40 to 70. The seeds of Cupressus chenggiana are elliptical, length ranged from 3.58 to 4.02 mm, width ranged from 3.10 to 3.15 mm, thickness ranged from 0.96 to 1.11 mm, and the weight of 1000 seeds ranged from 3.1 to 3.5g. The fruiting rate of Cupressus chenggiana is very low, and the fruiting period of Cupressus chenggiana has the geographical differences and the big or small year differences. 2. Seed germination temperature is between 5℃ and 30℃, while the suited temperature is between 10℃ and 25℃. The optimum temperature of seed germination will change as the store time of seeds changes logner. The cycle of seed germination can persist 20 days in the range of the suited temperature. The germination temperatures have significant influences on the germination potential and T50, but have no significant infuluences on the germination rate. The photoperiod is in favor of seed germination. The characters of Cupressus chenggiana seed germination represent a kind of environmental adaptability to protect the seed sources and endangered species, and it can give help to increase the germination rate of seeds and the livability of seedings. The seeds of Cupressus chenggiana are a kind of orthodox seeds that can endure the long time storage. In the short time storage, the store temperatures and the moisture contents of seeds have no significant infuluences on the physiological factors and the germination of seeds, but the store time has significant influences on the physiological factors of seeds. 3. In the short store course of Cupressus chenggianna seeds, the 1000 seed weight has no significant variation; The moisture content descends at the beginning of the storage, but has no significant variation later; The crude fat content and the soluble sugar content descend gradually; The soluble protein content and MDA content increase gradually; The praline content has no significant variation after 1～7 months storage, but increase significantly after 7～10 months storage. The correlations of different physiological factors are not significant. 4. The morphological characters of cones and seeds of four populations exist significant differences. The germination of Cupressus chenggiana seeds has no significant geographical variation. The geographical variation of Cupressus chenggiana populations can be ascribed to the population characters, climate and environment. 5. In the course of artificial propagation of Cupressus chenggiana, it is favored that the germination temperature of newly collected seeds is between 15℃ and 25℃, while the optimum temperature is 25℃. After the short storage ranged from 4 months to 10 months, it is favored that the germination temperature is between 10℃ and 25℃, while the optimum temperature is ranged from 15℃ to 20℃. The field sowing optimum time is between April and June, and the interval drought and fallrain fluctuation between July and September may be one of the reasons that restrict natural regeneration of Cupressus chenggiana. In the short storage, seeds can be stored in the condition of room temperature.

猪场废水短程硝化反硝化-厌氧氨氧化脱氮研究

畜禽废水是农村水环境污染的主要来源之一，其处理的难点在于脱氮。传统生物脱氮法具有能耗高、需大量外加碳源等缺点，开发低成本、高效率的新型生物脱氮技术具有重要意义。 本研究将短程硝化反硝化和厌氧氨氧化两种脱氮新技术结合，让前者为后者创造去除可降解COD、降低总氮负荷、调整pH、调整氨氮和亚硝酸盐氮浓度比例等进水条件，而后者可在无需外加碳源的条件下进一步脱氮，二者结合可成为高氨氮、低C/N废水脱氮的新途径。 试验以低碳氮比猪场废水为研究对象，首先进行了短程硝化反硝化预处理研究，同时启动并运行调控厌氧氨氧化反应器，最后以经过短程硝化反硝化预处理的猪场废水为进水，进行厌氧氨氧化脱氮考察。实验表明：（1）短程硝化反硝化作为厌氧氨氧化的预处理工序是可行的。猪场废水通过短程硝化反硝化，可以达到基本去除可生化COD、部分脱氮、控制出水氨氮和亚硝酸盐氮浓度之比在1︰1左右、pH在7.5～8.0的目的， COD和总氮平均去除率分别为64.3%、49.1%,出水可达到厌氧氨氧化反应的进水要求。（2）采用模拟废水启动厌氧氨氧化反应器，经过5个月左右的运行调控，反应器启动成功并稳定运行，最高总氮去除率为87.1%，总氮容积去除率最高达到0.14kg/m3.d；整个稳定阶段，氨氮、亚硝酸盐氮、硝酸盐氮的变化量之比为1︰1.21︰0.33。（3）经过短程硝化反硝化预处理的猪场废水厌氧氨氧化脱氮效果稳定，氨氮、亚硝酸盐氮、总氮、COD的平均去除率分别为93.0%、99.4%、84.6%、18.1%，处理效果与模拟废水处理系统相比无明显变化。（4）经过短程硝化反硝化预处理后，猪场废水中残留有机物成分在厌氧氨氧化反应过程中无显著变化，主要为酯类和烷烃类物质；残留有机物对厌氧氨氧化效果无明显影响。（5）采用PCR技术进行特殊功能菌种检测，结果表明模拟废水处理系统和猪场废水处理系统的菌群中均含有厌氧氨氧化菌和好氧硝化菌；通过blast比对，厌氧氨氧化菌扩增序列与未培养的Planctomycetales菌和Candidatus Brocadia fulgida菌16S rRNA部分序列相似性分别为95％、90%。（6）MPN法菌种计数结果显示，模拟废水处理系统和猪场废水处理系统的菌群中均含有硝化细菌、亚硝化细菌和少量反硝化菌，实验条件下的微生物系统是一个厌氧氨氧化菌与好氧硝化菌、反硝化菌共存的系统。 Poultry wastewater is one of the main source of water pollution in rural areas，and nitrogen removal is the most difficult part in treating poultry wastewater. There are some disadvantages in traditional nitrogen removal, such as high energy consumption and more additional organic carbon. It is important to develop ecolomical and efficient technologyies. Shortcut nitricfication/denitrification, as a pretreatment process, was combined with Anammox in this research, so that part of total nitrogen and most degradable COD could be removed by the former, and further nitrogen removal could be implemented by the latter. The combination of the two technologies was a new approach to treat wastewater with high ammonium and low C/N. Piggery wastewater with low C/N was treated in lab-scale experiment. Firstly, shortcut nitrification/denitrification was investigated, and Anammox reactor was started up successfully at the same time. Then piggery wastewater after pretreatment was treated by Anammox. The results showed :(1) It was feasible to take nitrification/denitrification as the pretreatment process of Anammox. By using this process, part of total nitrogen and COD were removed, the ratio of ammonium and nitrite reached around 1︰1 and the pH was about 7.8, which were favorable for Anammox. The average removal percentage of COD and total nitrogen were about 64.3% and 49.1%, respectively. (2) Simulated wastewater was used to start up Anammox reactor. The reactor was started up successfully within 5 months and stable performance was achieved. The highest nitrogen removal reached 87.1% and the biggest volumetric total nitrogen removal rate reached 0.14kg/m3.d. The average ratio of ammonium, nitrite and nitrate was 1:1.21:0.33. (3)Taking the effluent of shortcut nitrification/denitrification as the influent, the nitrogen removal efficiency of Anammox was stable, and the the average removal percentage of ammonium, nitrite, total nitrogen and COD were 93.0%, 99.4% , 84.6% and 18.1%, respectively, which had little difference with that by using simulated wastewater..(4) After pretreatment, the residual organic carbon in piggery wastewater showed no obvious change during the Anammox process, and the main organic compounds were saturated hydrocarbon and ester, which had no obvious negative effect on Anammox process.(5) By PCR technology, the existence of Anammox bacteria was confirmed and the aerobic nitrifying bacteria was found to coexist as well. The result of blast showed that the identities of Anammox bacterium to part of 16S rRNA sequence of uncultured Planctomycetales bacterium and Candidatus Brocadia fulgida bacterium were 95% and 90%, respectively.（6）By MPN method, nitrite oxidizer, ammonium oxidizer and denitrification bacteria were detected in both simulated and piggery wastewater treatment system of Anammox, and the microorganism system was composed of Anammox bacteria，aerobic bacteria and denitrification bacteria together.

垃圾渗滤液场外硝化－原位反硝化脱氮协同填埋场温室气体减排

垃圾卫生填埋是国内外城市垃圾的主要处置方法。垃圾渗滤液是渗入填埋场垃圾的降水混合垃圾降解过程中产生的物质而形成的混合物，是垃圾填埋场向环境排放的主要污染物。渗滤液由于其所含高浓度有机和无机污染物，且其中很多物质有生物毒性或难生物降解，难于治理。特别是到填埋晚期，渗滤液中高浓度的氨氮更是增加了治理的难度。渗滤液场外硝化－原位反硝化是填埋场氮管理的新途径。本文利用从环境中筛选出优势硝化功能菌对渗滤液中的高浓度氨氮进行生物硝化，经硝化后的渗滤液回灌至以垃圾柱模拟的生物反应器填埋场，在填埋场内实现原位反硝化。 上述目标通过以下两部分来实现： 第一部分：渗滤液场外硝化。首先从污水厂的硝化污泥中富集并筛选出硝化功能菌，在模拟氨氮废水中优化。将驯化的硝化功能菌接种于连续式完全混合反应器（CSTR）进行高氨氮渗滤液硝化研究。在200余天的连续运行中，反应器硝化和有机物去除效果良好。在最大氨氮负荷和有机物负荷分别为0.65 g N l-1 d-1 和3.84 g COD l-1 d-1时，氨氮和COD去除率分别高于99%和57%。实验过程中发现，游离氨（FA）和溶解氧（DO）浓度对反应器中亚硝酸盐的积累影响很大。 第二部分：渗滤液原位反硝化。本文利用一个垃圾填充柱模拟生物反应器填埋场，研究了硝化渗滤液回灌对垃圾降解的影响，和回灌的硝化渗滤液中TON（总氧化态氮）对填埋场生物反应器产甲烷作用的影响。最后利用变性梯度凝胶电泳（DGGE）分析了硝化渗滤液回灌对垃圾填埋场菌群结构的影响。结果表明：回灌的TON被完全还原，反硝化为主要反应，最大TON负荷为28.6 mg N kg-1 TS d-1。当垃圾柱TON负荷大于11.4 mg N kg-1 TS d-1时，出现了产甲烷抑制，抑制作用随TON负荷的增加而加强。在此过程中，反硝化逐渐代替产甲烷作用成为填埋场内垃圾降解的主要反应，且更多产生的是清洁的氮气，而非温室气体甲烷。直到实验结束时，回灌硝化渗滤液的垃圾柱的甲烷产量仅相当于对照的2.5%，并且回灌的硝化渗滤液还加速了填埋场垃圾的降解与稳定。通过DGGE进行菌群结构分析发现，由于TON对填埋场的长期作用，反硝化菌增多而产甲烷菌减少。 Landfill still remains the chief method for MSW management around the world. Leachate is a mixture of rainfall permeating through landfill and organic and inorganic matters generated during decomposition of the wastes in the landfills, characterized as highly complicated and refractory wastewater. Ex-situ nitrification and sequential in-situ denitrification represents a novel approach to nitrogen management at landfills. In the present paper, nitrification was carried out in a continuous stirred tank reactor (CSTR) inoculated with nitrifying bacteria which were isolated from municipal WWTP of Chengdu city. The nitrified leachate from CSTR was recirculated to a lab-scale municipal solid waste (MSW) column where in-situ denitrification took place. The above object was achived through two parts as following: First, ex-situ nitification of leachate. After acclimated in simulated wastewater for 3 month, nitrifying bacteria isolated from WWTP nitrifying sludge were added to the CSTR for nitrification. The results over 200 days showed that the maximum nitrogen loading rate (NLR) and the maximum organic loading rate (OLR) was 0.65 g N l-1 d-1 and 3.84 g COD l-1 d-1, respectively. The ammonia and COD removal was over 99% and 57%, respectively. Moreover, the effects of free ammonia (FA) and dissolved oxygen (DO) on nitrification were investigated. Second, in-situ denitrification was studied in a municipal solid waste (MSW) column. Variation of nitrified leachate and its effects on the decomposition of municipal solid waste (MSW) were studied in a lab-scale MSW column to which nitrified leachate was recirculated. Additionally, DGGE was employed to investigate the microbial community of both MSW columns. The results suggested: complete reduction of total oxidized nitrogen (TON) was obtained with maximum TON load of 28.6 mg N kg-1 TS d-1 and denitrification was the main reaction responsible. Methanogenesis inhibition was observed while TON load was over 11.4 mg N kg-1 TS d-1 and the inhibition was enhanced with the increase of TON load. Denitrification gradually took over methanogenesis to become the main reaction responsible for decomposition of MSW while nitrogen gas, a clean byproduct, was generated instead. Till the end of the experiment, the average weekly methane production in the denitrification column was as low as 2.5% of that of the control, and the rate of decompition and stability of MSW was accelerated by the recirculation of the nitrified leachate.Owing to long term exposure of nitrified leachate to landfill, denitrifying bacteria increased and methanogen decreased.

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.

投加溶胞菌群对剩余污泥消化影响的初步研究

活性污泥法是目前世界上普遍应用的污水生物处理工艺，其在运行过程中产生大量的剩余污泥。由于剩余污泥处理费用巨大及污泥最终处置对环境具有潜在危害问题，污泥的处理和处置已经成为水处理领域关注的焦点。本文利用实验室筛选的溶胞菌群，在好氧消化的同时对污泥进行前处理，促进剩余污泥的破解与溶胞，再通过两相厌氧处理对污泥进行进一步消化，以研究投加溶胞菌对剩余污泥消化的影响。 本研究中溶胞菌污泥减量化技术分为两个部分，第一，污泥在溶胞菌作用下的好氧消化与污泥传统好氧消化的对比研究，利用取自成都三瓦窑污水处理厂剩余污泥，向好氧污泥消化反应器中投加溶胞菌，检测各项污泥指标，并通过同传统好氧污泥消化对比，以研究溶胞菌对污泥好氧消化的影响。第二， 经过溶胞菌处理后好氧消化的剩余污泥进行两相厌氧处理研究。通过建立好氧溶胞联合两相厌氧消化系统的来处理剩余污泥，并与相同条件运行的两相厌氧消化系统做对比，检测运行过程中系统中物质成分变化，研究了其处理能力和运行稳定性，探索了两相厌氧消化系统中的发酵类型差别，验证了好氧溶胞对剩余污泥的破解效果。 研究结果表明：污泥在溶胞菌作用下的好氧消化效果和消化效率均优于传统好氧消化。在溶胞菌群存在的情况下，剩余污泥的TSS和VSS去除率达到40%和53%，远高于传统好氧消化的12%和20%。污泥经过溶胞及好氧消化后，TCOD去除率达到54.4%。经过溶胞菌处理后的剩余污泥再进入两相厌氧处理系统，进入厌氧处理系统的剩余污泥的VSS／TSS比值约为0.62。在两相厌氧处理水力停留时间(HRT)为8d时，溶胞处理污泥厌氧消化后VSS去除率达到55.17%，对照组两相厌氧系统的VSS去除率平均值为18.53%。经过溶胞处理的两相厌氧系统的污泥减量了能力远高于对照组。两相厌氧系统的pH值和碱度说明系统运行较为稳定。产酸相的有机酸中乙酸含量高于丙酸和丁酸，说明发酵末端产物以乙酸为主。在20天的试验周期内，污泥溶胞处理后、两相厌氧系统产甲烷相产气量累积产气量为1.2L，对照组只有375ml。气体中甲烷含量都在55%左右。该研究结果表明，好氧溶胞对污泥有破解能力，溶胞处理对两相厌氧中产酸相水解污泥细胞有明显的促进作用，提高了产酸相的水解酸化能力和效率。该研究对于利用生物溶胞途径提高污泥消化效率具有重要意义。 The actived sludge process has been used more and more extensively, but the procedure will lead to a large quantity of excess sludge. The treatment of Excess activated sludge has becomes a focuses not only for it is a seriously negative effect on environment but also for the costly disposal comes subsequently. The cell lysing bacterium was keeped in our lab to joined in the digestion of the excess activated sludge which was carrying at the same time with pre-processing of sludge to investigated the influence of cell lysing bacterium on excess sludge. There are two part in the method of cell lysing bacterium digesting sludge technology, the first, comparison of excess sludge digestion between anaerobic Cell-lysing Pretreatment and Conventional Aerobic Process. The sludge which was collected from San Wanyao disposal plant in Chengdu was thrown into the aerobic process system with cell-lysing bacterium, then, the indexes were detected to compare the difference between the cell-lysing bacterium in aerobic process and the traditional method to determine the influence of cell-lysing bacterium on aerobic process ; The second, the research on the sludge which was pro-treated with cell-lysing and aerobic digestion in the diphase of anaerobic digestion system. The system of cell-lysing combined with diphase of anaerobic digesting was created to compare to the diphase of anaerobic digested system, the changes of mass constituent was detected to study the ability and steady of disposal. Moreover, the research explored the difference among the types of fermentation. The efficacious of aerobic process was been proved. The result shows that the digesting rate of aerobic process with cell-lysing bacterium was higher than the traditional process. The ratio of sludge is reach to 40%~53%, which was far more effectively than the traditional process rate of 12%~20%. The TCOD of sludge which was treated with cell lysing bacterium and Aerobic Process is reach to 54.4%. Then, the sludge was thrown into the diphase of anaerobic digesting system. VSS／TSS of sludge is 0.62, HRT is 6d, the reduction of VSS is reach to 40.8%. The pH and alkalinity indicate the steady running of the diphase anaerobic digest system. In the acerbity phasing, the content of acetic acid was more than butanoic acid and propanoic acid in organic acid, it is demonstrated that the main composition of final production of fermentation was Acetic Acid. During the 20d of experiment, methylhydride phasing of diphase anaerobic digest system produced 1.2L methylhydride, however, there is only 375ml in CK, the content of methylhydride in all gas phase was around the rate of 55%. The average ratio of VSS was 18.53% in CK diphase anaerobic digest system which was far more unavailable than the mass sludge rate of 55.17%. Results demonstrated that aerobic cell-lysing digested the sludge, the treat of cell-lysing could obviously promoted the hydrolyzeing of sludge cell in the acerbity phasing, which improved the ability and rate of hydrolization and acidification. This study is significant in inhenceing the rate of sludge digestion in the method of cell-lysing bacterium.

多路谱仪放大器输出信号的读出与数据采集

A read-out and data acquisition system for the outputs of multi-channel spectroscopy amplifiers is introduced briefly in this paper.The 16-channel gating integrator/multiplexer developed by us and PXI-DAQ card are used to construct this system.A virtual instrument system for displaying,indicating,measuring and recording of output waveform is accomplished by integrating the PC,hardware,software together flexibly based on the Lab Windows/CVI platform in our read-out and data acquisition system.In this system,...中文文摘：简要介绍一个针对多路谱仪放大器的读出与数据采集方法与系统。该系统基于16通道门积分/选通输出电路和通用PXI-DAQ卡构建。利用Lab Windows/CVI平台构建虚拟仪器,灵活地将计算机、硬件、软件结合起来,设计了一个读出与数据采集系统。在该系统中,一个ADC通道可以面对16个谱仪放大器的输出,有效地提高了系统的集成度,降低了数据采集系统的成本。该设计为利用通用型谱仪放大器构建数百参数的信号读出与数据采集系统提供了一种新的方法。通过实验验证,证明该系统具有智能化、可靠性高、实时性强、成本低等优点。

基于数字锁相环的踢轨电源触发系统的设计

为了实现CSR踢轨电源的精确触发设计了基于数字锁相环的触发系统,数字锁相环的硬件由自主设计的高频鉴相器和NI公司的PXI插件PXI-6653和PXI-6280实现,并应用虚拟仪器Lab-VIEW构建软件,实现了对加速器高频频率的快速锁定并且相位可调,满足踢轨电源对触发系统的要求。

Largely deformed dinuclear system formed in F-19+Al-27 dissipative collision

Excitation functions are measured for different charge products of the F-19+(27) Al reaction in the laboratory energy range 110.25-118.75MeV in steps of 250keV at theta(lab) = 57 degrees, 31 degrees and -29 degrees. The coherence rotation angular velocities of the intermediate dinuclear systems formed in the reaction are extracted from the cross section energy autocorrelation functions. Compared the angular velocity extracted from the experimental data with the ones deduced from the sticking limit, it is indicated that a larger deformation of the intermediate dinuclear system exists.

Potential role of DNA-dependent protein kinase in cellular resistance to ionizing radiation

In this paper, we study the ability of DNA-PK-deficient (M059J) and -proficient (M059K) cells to undergo the rate of cellular proliferation, cell cycle distribution and apoptosis after 10 Gy X-ray irradiation, and the role of DNA-PK in radiosensitivity. The results showed that M059J cells exhibited hyper-radiosensitivity compared with M059K cells. A strong G2 phase arrest was observed in M059J cells post irradiation. Significant accumulation in the G2 phase in M059J cells was accompanied by apoptosis at 12 h. Altogether, the data suggested that DNA-PK may have two roles in mammalian cells after DNA damage, a role in DNA DSB repair and a second role in DNA-damaged cells to traverse a G2 checkpoint, by which DNA-PK may affect cellular sensitivity to ionizing radiation. 地址: [Li Ning; Zhang Hong; Wang Yanling; Hao Jifang] Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China; [Li Ning; Zhang Hong; Wang Yanling; Hao Jifang] Key Lab Heavy Ion Radiat Med Gansu Prov, Lanzhou 730000, Peoples R China; [Li Ning; Wang Yanling] Chinese Acad Sci, Grad Sch, Beijing 100039, Peoples R China; [Wang Xiaohu] Gansu Tumor Hosp, Dept Radiotherapy, Lanzhou 730050, Peoples R China