化学刻蚀法制备多孔硅的表面形貌研究

本工作首先采用化学刻蚀法制备出各种特征的多孔硅，然后通过扫描电镜（ＳＥＭ）技术，对多孔硅的表面形貌进行了表征，并分析了多孔硅表面微结构的形成过

Cloning and heterologous expression of a novel GH10 xylanase gene from Hypocrea orientalis EU7-22

木聚糖酶是降解半纤维素最主要的酶,对于开发可再生生物能源具有重要的应用价值。分别以东方肉座菌(HyPOCrEA OrIEnTAlIS)Eu7-22的基因组dnA和C dnA为模板,利用染色体步移和PCr技术首次克隆获得该菌gH10家族木聚糖酶Ⅲ的基因(XynⅢ),并对其进行生物信息学分析。结果表明:该基因全长1283 bP(gXynⅢ),含有3个内含子;CdS序列为1044 bP(CXynⅢ),编码347个氨基酸,n端含有一个16 AA的信号肽序列;XynⅢ氨基酸序列与TrICHOdErMA PSEudOkOnIngII的EndOXylAnASE具有较高的同源性。经生物信息学分析,XynⅢ成熟蛋白可能含有18个n-糖基化位点,其理论等电点(P I)为6.14,蛋白质分子质量为36.55 ku,属于亲水性蛋白;SWISS-MOdEl建模预测,XynⅢ成熟蛋白中含有11个α螺旋,其核心结构为8个β折叠片围成一个柱状结构。同时将编码成熟蛋白的基因片段MXynⅢ与P PIC9k质粒连接构建表达载体后转化毕赤酵母,对重组子表达产物进行酶活检测显示该基因能在毕赤酵母中表达有生物活性的XynⅢ并分泌到胞外,发酵液中的木聚糖酶活在诱导培养168 H后可达到127.5 Iu/M l。Endo-1,4-xylanase( E.C.3.2.1.8) is the major enzyme to the conversion of hemicelluloses into xylo-oligosaccharide.In this research,a novel GH10 xylanase Ⅲ( xyn Ⅲ) gene was cloned from Hypocrea orientalis EU7-22 by chromosome walking and PCR.The results showed that the DNA fragment( 1283 bp) encoding xynⅢ( gxynⅢ) contained three introns.The CDS of xynⅢ( cxynⅢ) encoded 331 amino acids of putative mature protein and a 16 aa signal in N terminator.The amino acid sequence of xynⅢ is highly homologous with the endoxylanase of Trichoderma pseudokoningii.The bioinformatics analysis showed that the theoretical isoelectric point and the molecular weight of putative mature protein of XYNⅢ were 6.14 and 36.55 ku,respectively.It is a soluble hydrophilic protein containing 18 N-glycosylation sites.The 3D structure predicted with SWISS-Model showed that XYNⅢ protein contained11 alpha helices and 8 extended strands.A recombinant plasmid p PIC9K-xynⅢ was constructed and then transformed into Pichia pastoris.The transformant identified by PCR was induced to produce XYNⅢ enzyme with 1% methanol.And after 168 hours induced expression,the produced crude enzyme was detected to reach a high enzymatic activity of 127.5 IU / m L.国家自然科学基金(21303142;31170067); 福建省海洋高新产业发展专项项目(闽海洋高新[2014]25号); 厦门市海洋经济发展专项资金项目(14GZP59HJ29

Research Progress of α-Glucuronidase, an Enzyme for Degrading Hemicellulose Side-Chain

半纤维素是自然界中最丰富的可再生资源之一,将半纤维素降解为单糖并转化为燃料或化学品一直是科学界研究的热点。半纤维素是由木糖基主链以及α-葡萄糖醛酸等侧链共同组成的异质多聚体。α-葡萄糖醛酸酶是半纤维素完全降解过程中的关键酶之一,能够水解4-O-甲基葡萄糖醛酸与木糖之间的α-1,2-糖苷键。本文综述了α-葡萄糖醛酸酶的分类、催化机制及晶体结构、酶学性质和基因克隆表达等方面的研究进展,同时对该研究进行了展望。Hemicellulose is one of the most abundant renewable resources in nature.The bioconversion of hemicellulose into biofuels or chemicals is a research hotspot in the world.Hemicellulose consists of a backbone of xylan residues and some branches like glucuronic acid.α-Glucuronidase, which is capable to hydrolysis the α-1,2-glycosidic bond between xylan and glucuronic acid, is one of the key enzyme to degrade hemicellulose completely.The recent research progresses on catalysis mechanism, structure, charaterization, and gene cloning of α-glucuronidase are summarized in this paper.国家自然科学基金(31170067;21303142); 国家重点基础研究发展计划(973计划;2010CB732201); 福建省自然科学基金(2012J05029); 农业部“引进国际先进农业科学技术”项目(2013-Z70

Practice of “Lesson for Garbage Separation” in Chikugo City, Fukuoka

In Chikugo City, Fukuoka, they have been practicing “lesson for garbage separation” at all elementary schools in the city. Cooperating with social studies classes in 4th grade, in all 19 classes in 4th grade in all 11 schools in Chikugo City, the lesson was conducted. “the test for garbage separation” was given to pupils before and after the class, we found that the average score 53 before the class was raised to 78 after the class. Considering “the class for garbage separation” as a operation for enlightening the public on environment of Local Government Unit, there are 2 points. 1.All of citizens can be the target. 2.The effect is measurable and beneficial

Fabrications and Characterizations of Porous Silicon by Tow-step Techniques I:Constant Current Application

本工作通过采用电化学极 -化学氧化两步法在 1:1氢氟酸和乙醇溶液中制备出孔径约为 1～ 2 μm ,厚度大经为 6～ 10 μm的多孔硅样品 .首先将 0 .0 3A/cm2 的恒电流施加到p( 10 0 )硅片一段时间 ,然后将该硅片浸到 2 0 %的硝酸溶液中氧化一段时间 .通过此方法获得的多孔硅结构再进一步用扫描电子显微镜和拉曼光谱仪进行表面形貌和光学性质的考察 .所有制备出的多孔硅结构均有光致发光现象 .老化的多孔硅样品 (在干燥器放置一年 )的光致发光谱峰强度明显增强 ,但分别经过苯乙烯和十六碳烯 ( 1)两种有机溶剂处理 1h后的老化多孔硅样品的光致发光强度却没有显著改变 .Porous silicon structures were formed by a two step technique consisting of electrochemical polarization and chemical oxidation processes in 1∶1 hydrofluoric acid and ethanol solutions. A constant current density of 0.03 A/cm 2 was applied to p type silicon wafers, followed by chemical treatment in 20% nitric acid solutions. These samples were then carefully examined by scanning electron microscope (SEM) and Raman spectrometer to study their surface morphologies and optical properties. After a year storage in a desiccator, the aged porous silicon samples were re examined by SEM and Raman spectrometer before and after treated with styrene and decene(1) organic solvents, respectively. It was found that the Raman intensities of the aged porous silicon samples were significantly enhanced. However, the treatments of the aged porous silicon samples with tow organic solvents did not alter their optical properties.作者联系地址：厦门大学!福建厦门361005,厦门大学化学系!福建厦门361005,厦门大学材料科学系!福建厦门361005,厦门大学化学系!福建厦门361005,厦门大学化学系!福建厦门361005,厦门大学分析测试中心!福建厦门361005Author's Address: Department of Chemistry, ** Department of Materials Science State Key Laboratory for Physical Chemistry of Solid Surfaces *** Center fo

Fabrications and Characterizations of Porous Silicon by Two-step Techniques II: Pulse Current Application

采用脉冲阳极 /阴极电流和化学氧化两步法分别在 1∶1的氢氟酸和乙醇溶液中及 2 0 %硝酸溶液中制备出孔径约为 0 .5～ 3μm ,厚度大约为 10～ 2 0 μm的多孔硅样品 ,将获得的多孔硅结构再进一步用扫描电子显微镜和拉曼光谱仪进行表面形貌和光学性质的考察 .与恒电流 -化学氧化两步法制得的多孔硅相比 ,用脉冲电流法得到的多孔硅的孔径范围较大 ,且多孔层较厚 .制备时加紫外光照显著提高了多孔硅的厚度 ,并发生“蓝移”现象 .用脉冲电流法制得的多孔硅在老化后 (在干燥器放置一年 )同样观察到光致发光明显增强 .Porous silicon structures were formed by two?step technique consisting of pulse current applications in 1∶1 hydrofluoric acid and ethanol solutions and chemical oxidation in 20% nitric acid solutions. Their surface morphologies and optical properties were characterized by scanning electron microscope (SEM) and Raman spectrometer, and compared with those obtained by constant current application. More uniform pore formation on p(100) silicon wafers was observed by pulse current application. Illumination with an ultraviolet lamp during the pulse current application accelerated the macropore formation, accordingly, the optical properties were changed.作者联系地址：厦门大学化学系!福建厦门361005,厦门大学化学系!福建厦门361005,厦门大学化学系!福建厦门361005,厦门大学固体表面物理化学国家重点实验室化学系!福建厦门361005,厦门大学化学系!福建厦门361005,厦门大学化学系分析测试中心!福建厦门361005Author's Address: 1. Dept. of Chem., 2. State Key Lab. for Phys. Chem. of Solid Surfaces, 3. Center for Instrumental Anal. and Measurements, Xiamen Univ., X

The Study on Children’s Waste Sorting in Shenyang City, China.

We conducted a survey on the waste disposal situation and elementary school children’s waste sorting in Shenyang city, China, to check if the “class on waste” in elementary schools that we undertake in Japan is effective also in China. China’s population of 1,307.6 million (2005) accounts for 20% of the world population. Accompanying China’s economic progress, the waste problem is now a major issue. Also, local governments’ waste disposal costs are increasing every year. In this study, we researched the outline of waste disposal based on the case examples in Shenyang city, Liaoning province, an inland area of China. Furthermore, we conducted a questionnaire survey on how elementary school students considered and actually practiced waste sorting as citizens. The result revealed that the children’s enthusiasm for study on the environment and waste sorting was strong, but information supply by the government and education at school were insufficient

南海中深层动力格局与演变机制研究进展

南海是连接印度洋-太平洋的最大边缘海,在季风、海峡水交换以及复杂地形影响下,南海环流呈现出独特的三层结构以及远强于大洋的混合特征.理论与观测表明,南海内潮、内孤立波以及强风等过程是强混合的动力来源.在南海强混合作用下,南海发育了活跃的中深层动力系统,一方面促进了南海与大洋之间的水体交换,另一方面调控上层风生环流,使得南海环流显著区别于其他热带与副热带海盆.南海活跃的中深层环流所具有的物质搬运能力又显著影响着南海的地质沉积、生物地球化学循环等过程.中国对深海研究持续投入,在南海中深层环流动力学研究方面取得了显著的成果,文章就该方面进行总结,并对南海深海环流未来研究设想进行初步探讨

Power-law singularity precursor and prediction of catastrophic rupture in heterogeneous media under compression

灾变破坏是岩石类非均匀脆性材料破坏的一种典型形式，其发生时伴随着大量能量的突然释放，具有极大的破坏性。大地震的发生往往也属于这种破坏类型。在灾变破坏点附近，许多物理量（如应变、位移、声发射事件数、能量释放率等）呈现出加速的演化行为，并且其变化率在破坏点处遵循幂律规律发散到无穷大。这种演化曾被类比于相变的临界现象来加以研究。但不同于经典的临界现象，灾变破坏的幂律指数呈现出许多新的特点。此外，确定临界幂律奇异性指数的特征，对于准确地建立灾变预测方法至关重要。 本文通过大理岩和花岗岩试样的准静态单轴压缩实验，发现灾变岩样的响应函数R = du/dU在灾变破坏前呈现出临界幂律奇异性，其中u是试样的整体压缩量，U是试验机输出的位移。实验发现，R的临界幂律奇异性指数在−1和−1/2之间分布。在理论上阐明了响应函数R的临界幂律奇异性是灾变破坏能量准则的必然结果，而临界幂律奇异性指数的分布范围可由幂函数近似来导出。 基于临界幂律奇异性指数的分布范围，将响应函数和加载过程关联起来，提出了一个灾变预测方法，来实时的计算破坏点的上界及相应的预测区间。随着加载的进行和破坏点的临近，预测点逐渐向破坏点移动，包含真实破坏点的预测区间也逐渐缩小。 通过数字散斑相关方法测量了试样的表面位移场和应变场，采用条带分析方法研究了位移场和应变场的时空演化，观察到了灾变破坏前试样表面的应变局部化现象。实验发现，所有条带的平均位移分量构造的局部响应函数在灾变破坏前均出现临界幂律奇异性，临界幂指数介于−1和−1/2之间。破裂带附近垂直于破裂带方向的条带平均正应变构造的局部响应函数也呈现出临界幂律奇异性，临界幂指数接近−1。这种临界幂律奇异性具有跨尺度的特征，即对于包含破裂带的不同大小的平均窗口而言均会出现临界幂律奇异性，但临界幂指数随着平均窗口的增大而增大。这表明宏观物理量的临界幂律奇异性来源于局部化区域内响应量的加速演化。利用条带平均量构造的局部响应函数对灾变破坏点进行了实时预测，结果表明，随着加载的进行，预测值逐渐减小并向真实的灾变破坏点靠拢。靠近破裂带的、面积较小的计算区域，得到的实时预测值较小；远离破裂带的、面积较大的区域，得到的实时预测值较大。由此可以为灾变破坏的区域预测提供基础。 利用汶川地震震前4期GPS非连续观测站数据和同震的位移数据重构了龙门山破裂带附近的应变增量场，结果表明，在汶川地震前垂直破裂带方向的压应变增量分量呈现局部化现象。利用GPS连续观测站构成的三角网格，计算了垂直破裂带方向的响应函数，结果表明，汶川地震前响应函数具有临界幂律奇异性。临界幂指数接近−1。这说明汶川地震具有幂律前兆。基于此，将建立的实时预测方法应用于对汶川地震发震时间的后验性预测，实时地给出了发震时间的上界及预测区间。随着采样的进行，预测值逐渐向真实值靠拢，包含真实发震时间的预测区间也逐渐缩小。</p