低温自蔓延燃烧法制备纳米Sm2O3

将溶胶-凝胶法（sol—gel）和低温燃烧技术（LCS）相结合，成功开发了一种以溶胶-凝胶为前驱体的燃烧合成Sm2O3纳米粉体的技术．利用XRD，TEM，AFM等方法对合成产物进行了表征，并考察了制备条件对Sm2O3纳米粉体尺寸和形貌的影响．     

Suitable internal control genes for qRT-PCR normalization in cotton fiber development and somatic embryogenesis

The mechanisms of cotton fiber development and somatic embryogenesis have been explored sys-tematically with microarray and suppression subtractive hybridization. Real-time RT-PCR provides the simultaneous measurement of gene expression in many different samples,with which the data from microarray or others can be confirmed in detail. To achieve accurate and reliable gene expression re-sults,normalization of real-time PCR data against one or several internal control genes is required,which should not fluctuate in different tissues during various stages of development. We assessed the gene expression of 7 frequently used housekeeping genes,including 18S rRNA,Histone3,UBQ7,Actin,Cyclophilin,Gbpolyubiquitin-1 and Gbpolyubiquitin-2,in a diverse set of 21 cotton samples. For fiber developmental series the expression of all housekeeping genes had the same down tendency after 17 DPA. But the expression of the AGP gene(arabinogalactan protein) that has high expression level at the later fiber development stage was up-regulated from 15 to 27 DPA. So the relative absolute quanti-fication should be an efficient and convenient method for the fiber developmental series. The expres-sion of nonfiber tissues series varied not so much against the fiber developmental series. And three best control genes Histone3,UBQ7 and Gbpolyubiquitin-1 have to be used in a combinated way to get better normalization.     

柠檬酸发酵液的活性炭吸附处理法

提出了用活性炭吸附处理柠檬酸发酵液的工艺条件及流程。探讨了湿度、通量、停留时间、再生碱液浓度等对吸附、脱附操作的影响。解决了萃取法制柠檬酸操作时的界面污物现象，为充实该法制柠檬酸提供了依据。     

Multiple transgenes Populus xeuramericana ''''Guariento'''' plants obtained by biolistic bombardment

A JERF36 regulation gene, a selection marker gene (NPT-II), and the foreign genes levansucrase (SacB), Vitreoscilla hemoglobin (vgb), and Binary coleopterus insect resistance (BtCry3A OC-I) were co-transferred into Populus xeuramericana 'Guariento' using biolistic bombardment; 25 kanamycin resistant plants were obtained. The results of PCR and Southern hybridization showed that the foreign genes had been integrated into the genome of P. xeuramericana 'Guariento' and 5 genes were all transferred into 7 poplar plants. The results of a BtCry3A ELISA experiment indicated that the BtCry3A gene was expressed in the 7 transgenic poplar plants, and these plants grew well on coastal saline land.     

Validation of MODIS aerosol products by CSHNET over China

The Chinese Sun Hazemeter Network (CSHNET) provides the necessary ground-based observation to validate and assess the applicability of MODIS aerosol optical depth (AOD) products over different ecological and geographic regions in China for the first time. The validation results show that the comprehensive utilization ratio and applicability of MODIS products varied very much over different regions and seasons from August 2004 to July 2005. On the Tibetan Plateau, the comprehensive utili- zation ratio of MODIS data was low: MODIS products only accounted for 16% of the ground-based observation; on average, 31% to 45% of MODIS products fell within the retrieval errors issued by NASA. A similar result was found in northern desert areas with the ratio of MODIS to observation ranging from 15% to 55%, with 7% to 39% of MODIS products within errors. In the remote northeast corner of China, low ratios of MODIS to observation were also found ranging from 14% to 46%, with 49% to 69% of MODIS within errors. The forested sites exhibited moderate ratios of MODIS to observation ranging from 46% to 65%, with 30% to 59% of MODIS within errors. This was similar to numbers observed at sites along eastern seashore of China and inland urban sites with the ratio of MODIS to observation between 63% to 75%, with 25% to 67% of MODIS within errors for sites along eastern seashore of China and 43% to 78%, with 35% to 75% of MODIS within errors for inland urban sites. The ratio of MODIS to observation over agricultural areas ranged from 61% to 89%; 59%-88% of MODIS fell within the retrieval errors. At homogeneous and well vegetated areas, the comprehensive utilization ratio of MODIS products was over 80% and above 70% of MODIS products fell within the retrieval errors in growing season.     

Analysis of genes differentially expressed during initial cellular dedifferentiation in cotton

The early phase of phytohormone induction is a vital stage of somatic embryogenesis. This phase includes a key process for acquiring cellular totipotency through cellular dedifferentiation. To unravel the molecular mechanism of cellular dedifferentiation in cotton, we constructed a cDNA library using the suppression subtractive hybridization method. A total of 286 differential cDNA clones were sequenced and identified. Among these clones, 112 unique ESTs were significantly up-regulated during the early phase of phytohormone induction, and 40.2% of the ESTs were first identified. GST was highly ex- pressed from 6 to 24 h after induction with phytohormone treatment. PRPs were predominantly ex- pressed and exhibited distinct expression patterns in different treatments, suggesting that they are closely related to cellular dedifferentiation in cotton. Putative GhSAMS, GhSAMDC, GhSAHH and GhAC03 involvement in SAM metabolism was identified in this library. The analysis of qRT-PCR showed that two remarkable increased expressions of the four SAM-related genes happened during the early phase of phytohormone induction, and that a highly positive correlation existed between GhSAMS and GhSAHHo The highest expression level of GhSAMS might be associated with its reentry into the cell cycle. The histological observations further showed that some cells accomplished cellular dedifferentiation and division within 72 h in 2,4-D treatment, and that cellular dedifferentiation might be regulated through two alterations in SAM-dependent transmethylation activity in cotton. In addition, the expression patterns of differential genes in different treatments disclosed the complicated interaction between 2, 4-D and kinetin.     

High-precision measurement of mercury isotope ratios of atmospheric deposition over the past 150 years recorded in a peat core taken from Hongyuan,Sichuan Province,China

High-precision 210Pb dating technology was applied to a peat core with a time span of about 150 years that was taken from Hongyuan, Sichuan Province, China. The concentrations of total mercury (Hg) and stable isotope compositions of mercury in the peat core were measured using a LUMEX 915 instrument and multi-collector inductively coupled plasma mass spectrometer, respectively. Total mercury (Hg) concentrations in the peat core had a clearly increasing trend from the bottom to top of the core while δ 202Hg ...     

求同存异的非局部图像去噪

非局部方法是近年来图像恢复领域最重要的方法之一,这类方法的关键在于如何理解和描述自然图像的自相似性质.本文通过对自相似性质的深入分析,提出描述自相似性质的两个原则：1）＂两方向＂原则：利用隐含在图像中的两方向相关结构.2）＂求同存异＂原则：利用相似性的同时保持各相似块之间的相对差异.然后利用奇异值分解建立了一种符合这两个原则的非局部图像去噪模型.该模型能获得很好的去噪效果.     

二氧化碳-水体系动态溶解平衡的探索性研究

通过恒温水浴振荡器使静态溶解平衡的二氧化碳-水体系中的流体产生回旋运动,以此研究流体的流速对二氧化碳-水体系静态溶解平衡的影响,从而归纳出了二氧化碳和水的动态溶解平衡状态。采用示踪法测出振荡器不同振荡频率对应的流体的回旋流动线速度,进而计算流体的雷诺准数以考察流体运动状态。实验结果表明,流体的流动引起二氧化碳-水体系远离原有静态溶解平衡。在常温25.5℃下,原有静态饱和状态下溶解在水中的二氧化碳的量约有6.55%被解吸出来,亨利系数可产生高达15%的偏差。     

一类图构形的Orlik-Solomon代数及Tutte多项式

研究得到了n-秩轮图及其导出图构形的Orlik-Solomon代数的计算公式,n-秩轮图关于某条边的删除B_n以及n-秩轮图的Tutte多项式的一般表达式,并计算了n-秩轮图（n=5,6）的双变量着色多项式,举例说明图的双变量着色多项式与Tutte多项式是不相同的。