Impacts of external forcing on the 20th century global warming

The impacts of external forcing,including natural and anthropogenic,on the 20th century global warming were assessed with the use of the Grid Atmospheric Model of IAP/LASG Version 1.1.0,fol-lowing the standard coordinated experiment design of the Climate Variability and Predictability(CLIVAR) International Climate of the Twentieth Century Project(C20C) ,Phase II. The results indicate that external forcing plays an important role in the evolution of the land surface air temperature on in-terannual,decadal,and interdecadal time scales,and contributes greatly to the global warming in the following two periods:the early twentieth century between the 1910s and the 1940s and the late twen-tieth century after the 1970s. External forcing also has strong impact on the regional temperature change during the two warming periods except for parts of the Eurasia and the North America conti-nents. In the cooling period,however,the impact of internal variability is dominant.     

一种新颖的Keggin型磷钼酸盐化合物(C10H10N3)3PMo12O40的合成与结构表征

首次合成了一个新的多金属簇化合物,通过元素分析、IR光谱、UV-VIS-NIR反射光谱、ESR谱以及单晶X-射线衍射对其进行了表征,晶体学参数为：三斜晶系,P-1空间群,a=11.5499(17)A,b=12.9776(16)A,c=20.3895(25)A,α=90.72(1)°,β=91.35(1)°,γ=111.43(1)°,V=2843.40(1237)A³,化学组成为(C₁₀H₁₀N₃)₃PMo₁₂O₄₀。Keggin型聚阴离子[PMo₁₂O₄₀]^3-与质子化的2,2′-二吡啶胺之间形成一个三维超分子网状结构。部分质子化的2,2′-二吡啶胺间因π-π作用诱导按Z型链规则排列。将(C₁₀H₁₀N₃)₃PMo₁₂O₄₀应用于电极修饰,在ClO₃^-的电催化还原反应中表现出优良的性能。     

DEX1, a plasma membrane-localized protein, functions in microspore development by affecting CalS5 expression in Arabidopsis thaliana

Microsporogenesis in flowering plants plays important roles in sexual reproduction. It has been reported that DEFECTIVE IN EXINE FORMATION1 (DEX1) is essential for exine pattern formation in Arabidopsis thaliana. However, the functions of DEX1 in regulating microspore development are largely not understood. In this study, we show that DEX1 is strongly expressed in the tapetum by using RNA in situ hybridization. dex1 microspores were degenerated and aborted after release from the tetrads. The callose wall in tetrads was thinner in the dex1 mutant than in the wild type, suggesting that DEX1 affects callose formation at the tetrad stage during anther development. RT-PCR and real-time PCR analyses showed that CalS5, which plays an important role in callose synthesis during microspore development, was greatly down-regulated in dex1 plants. DEX1 encodes a membrane protein with one transmembrane domain, one intracellular domain and one extracellular domain. Collectively, our results demonstrate that DEX1 is essential for microspore development, possibly by regulating the expression of CalS5.     

微机在广告图形设计中的应用

来文介绍用微型计算机输入广告图形的一种方法。此方法是将广告图形转换成一种编码,微处理机用该编码进行广告图形的控制。     

洛界公路周口至项城水泥混凝土路面破损原因探析

根据对河南省洛阳-界首公路的交通及路面现场调查结果系统分析了水泥混凝土路面的破损原因.     

六阶极窄带宽高温超导滤波器的研制

文中研制了一款极窄带宽的六阶高温超导滤波器,成功实现了相对带宽小于1‰的多阶高温超导滤波器的设计与制作.文中给出了极窄带宽高温超导滤波器的等效电路、理论曲线、耦合矩阵、设计过程、模拟仿真结果以及滤波器的物理电路结构,有效解决了极窄带滤波器的设计、材料与加工精度的技术难题,研制的高温超导滤波器使用蒸镀于0.5mm厚度的氧化镁(MgO)基片上的DyBa2Cu3O7双面高温超导薄膜加工制作,滤波器工作频率约为900MHz,相对带宽为0.58‰,滤波器的实际损耗小于0.6dB,带外抑制达到70dB以上,其测试曲线与模拟仿真结果很好的吻合,文中的试验结果标志着多阶高温超导滤波器可以实现的最窄带宽达到了一个新的高度.     

计算机应用型人才培养的探索与实践

本论文主要介绍具有一般地方工科院校和行业特色的计算机科学与技术专业应用型人才培养模式的探索与实践。为适应计算机技术的高速发展和社会对人才的需求变换,本论文主要探索主动适应市场需求的应用型人才培养模式。     

Spatial variability of cyanobacterial community composition in Sanya Bay as determined by DGGE fingerprinting and multivariate analysis

The cyanobacterial communities in the surface and bottom waters of Sanya Bay were investigated on April 24 and 25,2010.Flow cytometry showed that the total cyanobacterial abundance in the surface and bottom layers ranged from 0.7×10 4 to 2.38×10 4 cells mL-1 and from 1×10 4 to 1.8×10 4 cells mL-1,respectively.Cyanobacterial diversity was analyzed using a molecular fingerprinting technique called denaturing gradient gel electrophoresis(DGGE),followed by DNA sequencing.The results were then interpreted through multivariate statistical analysis.Differences in the compositions of cyanobacterial communities were observed in the surface and bottom waters at the same station,with some bands obtained from both the surface and bottom layers,whereas some bands were present only in one layer.The predominant cyanobacterial species of the excised DGGE bands were related to Synechococcus or Synechococcus-like species(56.2%).Other phylogenetic groups identified included Chroococcidiopsis(6.3%),Cyanobium(6.3%) and some unclassified cyanobacteria(31.2%).A redundancy analysis(RDA) was conducted to reveal the relationships between the cyanobacterial community composition and environmental factors.Analysis results showed that the spatial variations in the cyanobacterial community composition in surface waters was significantly related to chlorophyll a(Chla),the biochemical oxygen demand(BOD),nitrate and phosphate(P<0.05).Meanwhile,the spatial variations in the bottom waters was significantly affected by nitrate,nitrite,and phosphate(P<0.05).Environmental parameters could explain 99.3% and 58.3% of the variations in the surface and bottom layers,respectively.     

正电子谱学技术在功能材料微结构表征中的应用

特殊功能材料是一些具有优良电学、磁学、学、热学、学、力学、化学、物医学功能,在各类高科技领域到泛应用.正电子湮没技术是一种对材料微结构特别有效探测技术,特别是对各种缺陷、空位和微孔尤为灵敏,通过正电子湮没寿命谱、多普勒展宽谱和慢正电子束技术,通过分析正电子湮没参数可以获材料从表面到内部缺陷分布信息和随外部物理和化学条件变化、引起微结构变化.本文选取几种特殊材料正电子湮没实验结果来分析材料内部微结构,表明正电子湮没谱学是一种独特研究微观结构方法.     

用同位素稀释法测定牛肝和人血清中的锌和硒

结合阴离子交换树脂分离及巯基棉分离技术,采用同位素稀释-电感耦合等离子体质谱法测量了国际比对样品CCQM-K49牛肝样品和人血清样品中的锌和硒。结果表明,对于待测元素含量较高的样品,不经分离,高倍稀释可有效减少基体的干扰;而对待测元素含量较低的样品,则必须经过分离才能准确测量。CCQM-K49牛肝样品中锌和硒的质量分数分别为(179.8±1.2)×10^-6和(2.067±0.027)×10^-6,BW3215人血清标准物质中锌的质量分数为(1.164±0.024)×10^-6,国际比对IMEP-17人血清样品中硒的质量分数(0.0780±0.0014)×10^-6,测量结果均与比对的中心值接近,符合检测的要求。