Genome sequencing and analysis of Aspergillus oryzae

The genome of Aspergillus oryzae, a fungus important for the production of traditional fermented foods and beverages in Japan, has been sequenced. The ability to secrete large amounts of proteins and the development of a transformation system have facilitated the use of A. oryzae in modern biotechnology. Although both A. oryzae and Aspergillus flavus belong to the section Flavi of the subgenus Circumdati of Aspergillus, A. oryzae, unlike A. flavus, does not produce aflatoxin, and its long history of use in the food industry has proved its safety. Here we show that the 37-megabase (Mb) genome of A. oryzae contains 12,074 genes and is expanded by 7-9 Mb in comparison with the genomes of Aspergillus nidulans and Aspergillus fumigatus. Comparison of the three aspergilli species revealed the presence of syntenic blocks and A. oryzae-specific blocks (lacking synteny with A. nidulans and A. fumigatus) in a mosaic manner throughout the genome of A. oryzae. The blocks of A. oryzae-specific sequence are enriched for genes involved in metabolism, particularly those for the synthesis of secondary metabolites. Specific expansion of genes for secretory hydrolytic enzymes, amino acid metabolism and amino acid/sugar uptake transporters supports the idea that A. oryzae is an ideal microorganism for fermentation.     

环氧树脂胶粘剂粘结的Al2O3/Al层状复合材料

以环氧树脂胶粘剂为粘结剂,采用简单的常温模压方法,在5 MPa下经常温固化制备了Al2O3/Al层状复合陶瓷材料,考察了环氧树脂和固化剂质量比为1∶0.7、1∶0.8、1∶0.9和1∶1.0时胶粘剂的粘结强度.结果显示:当环氧树脂和固化剂的质量比为1∶0.8时,胶粘剂的粘结强度最大;在粘结接头中间添加不同表面研磨处理的铝薄片后,当进行单向研磨时环氧树脂胶粘剂的粘结强度较大.层状复合材料的显微结构显示,该复合材料的层间结合紧密;力学性能测试表明,该复合材料的抗弯强度虽比氧化铝稍低,但断裂韧性和断裂功得到了较大的提高,这得益于裂纹扩展过程中形成的多裂纹特征.     

基于旋转折变型长周期光纤光栅的压力传感器

利用CO2激光脉冲以单侧入射方式在普通单模光纤上写出了一种折射率沿光栅轴向呈旋转分布的长周期光纤光栅．横向负载实验表明,对于折变旋转度为270°的旋转折变型长周期光纤光栅,谐振峰幅值的横向负载灵敏度为0．44dB／（g-mm^-1）,是普通长周期光纤光栅的7倍;而且由于旋转变化的折射率结构降低了光栅的原始双折射,使得这种光栅在各圆周方向上谐振波长对横向负载都不敏感．利用这一特性可用于制作体积小、操作简单、成本低廉的高灵敏度光强型压力传感器．     

高铬白口铸铁抗磨粒磨损耐磨性与断裂韧性的研究

本文研究了两种基体组织状态及碳化物体积分数对高铬白口铸铁抗磨粒磨损耐磨性、断裂韧性K_(IC)、K_(Id)及亚临界裂纹扩展速率da/dN的影响。结果表明:高铬白口铸铁耐磨性与磨损系统有关;而其断裂韧性及亚临界裂纹扩展速率与基体组织状态、碳化物体积分数及其形态与分布有关。综合研究结果,从高铬白口铸铁耐磨性与断裂韧性最优化角度考虑,如果用软磨料,宜选用马氏体基体;采用硬磨料,则宜选用奥氏体基体。     

合成推理的插值实现

在对采用合成推理规则进行模糊推理的机制进行分析的基础上 ,给出了利用插值法也可以得到相同结果的原理 .在此基础上用实际例子说明了采用插值法实现合成推理的方法 ,结果表明采用插值法可以等效地实现合成推理 .     

Model of production planning and scheduling in shop floor based on collaboration and competition

The planning and scheduling in real shop floor is actually achieved by coordination between different persons. In this process, cooperation is mainstream, but competition also exists, for example, the competition between different groups, operators with the same skill, etc. In multi-agent based shop floor management and control system, this competition and cooperation relation must be embodied. The general process of shop floor production planning and scheduling is studied, and a colored Petri-net model for the competition and cooperation process of three main agents in such system to achieve shop floor production planning and scheduling is presented. The evaluating method of bids in bidding process that especially embodies the competition relationship is also presented. This colored Petri-net model gives a clear illustration of this complex coordination process to system designers, effectively promotes the cooperative development. Foundation item: Supported partly by the Hi-tech Program of China (China 863) (No. 863-511-943-009) and the National Natural Science Foundation of China(No. 59990470) Biography: Liu Shi-ping(1971-), male, Ph. D. candidate, research direaction: CIMS, intelligent manufacturing.     

Preparation of the selenomethionine derivative of tabtoxin resistance protein

In order to obtain phase information for the X-ray diffraction of tabtoxin resistance protein (TTR) crystal using the MAD phasing method, a selenomethionine (Se-Met) derivative of TTR was overexpressed in E. coli strain M15, with pQE-30 plasmid, through IPTG induction in M9 medium containing Se-Met. The product was purified to an estimated homogeneity of greater than 95% according to SDS-PAGE, by a Ni-NTA metal affinity followed by a Mono Q anion exchange column chromatography. The successful substitution of Se-Met for methionine (Met) was confirmed by MALDI-TOF and ESI-Quadrupole Mass Spectrometry analysis. The derivative crystal was obtained using similar conditions as those for the native.     

Plasmonic biosensors and nanoprobes based on gold nanoshells

Gold nanoshells (GNSs), consisting of a dielectric core coated with gold, have gained extensive attention as they show readily tunable optical properties and good biocompatibility. As highly sensitive and label-free optical biosensors with wide applications, GNSs have been investigated in many fields including drug delivery, immunoassay, cancer treatment, biological sensing and imaging. Taking advantage of the adjustability of the local surface plasmon resonance (LSPR) and the sensitivity of the surfaceenhanced Raman scattering (SERS) signal of GNSs, we have developed diverse applications including plasmonic biosensors and nanoprobes based on GNSs. In this review we introduce plasmonic and electromagnetic properties and fabrication methods of GNSs. We describe research progress in recent years, and highlight several applications of GNSs developed by our group. Finally we provide a brief assessment of future development of GNSs as plasmonic materials that can be integrated with complementary analytical techniques.     

轻烧白云石粉料制备纳米级片状氢氧化镁

以轻烧白云石粉料和氨水为原料,采用水热法合成了纳米级氢氧化镁。通过SEM和XRD表征方法,研究了水热反应温度、表面活性剂的种类和氨水添加量对氢氧化镁晶体形貌的影响。结果表明：水热温度为180℃时晶体的生长方向发生改变,极性较弱的[001]面对应的衍射峰增强;添加阴离子表面活性剂十二烷基苯磺酸钠制得的氢氧化镁分散性较好;以弱电解质氨水做沉淀剂,随着氨水添加量的增加,氢氧化镁的颗粒大小变得更加均匀,当镁离子和氨水的物质的量比为3∶7时颗粒大小最均匀。     

远源地下水入侵阿拉善高原沙漠:酸溶物Sr同位素证据

选取北方西－东向气候剖面上物质组成相似的四个沙漠（塔克拉玛干、巴丹吉林、腾格里和毛乌素）,测定其地表沙酸溶物87Sr/86Sr比值、Ca2+和Sr2+浓度。Ca2+和Sr2+浓度相关性极好,在降雨量低的塔克拉玛干沙漠中最高,向东逐渐降低,在降雨量多的毛乌素沙漠中最低。降雨量是控制阳离子浓度变化的主导因素。酸溶物87Sr/86Sr比值在四个沙漠中有不同于阳离子变化的区域特征。塔克拉玛干沙漠酸溶物87Sr/86Sr比值在0.71以下,巴丹吉林和腾格里沙漠的大于0.7112,而毛乌素沙漠的在0.71-0.7112之间变化。塔克拉玛干和毛乌素沙漠地表沙酸溶物87Sr/86Sr比值仅受气候变化的制约。巴丹吉林和腾格里沙漠除了受气候因素影响外还受其它因素的制约,最可能的就是远源地下水。经计算,远源地下水对巴丹吉林沙漠的影响份额为47%,对腾格里沙漠为44%,接近气候因素的影响。