Nafion-玻碳修饰电极阴极溶出伏安法测定痕量铋的研究

研究并提出在HNO_3-NaCl-硫脲(Tu)体系中,Nafion/玻碳(Gc)修饰电极阴极溶出伏安法测定痕量鉍的方法。表明Tu具络合协同作用,使Nation阳离子交换能力提高。本法检出限为5×10~(-9)mol/L Bi~(3+)(td:5min),电极表面易于再生,文中研究了电极过程机理,计算得[Bi(Tu)_6]~(3+)在Nafion膜中的分配系数(K_D),扩散系数(D)和选择性系数(K_H~[Bi(Tu)_6~+]~(3+))分别为7.57×10~5,5.9×10~(-11)cm~2/s及3.39。

PHASE-SEPARATION IN ANHYDRIDE-CURED EPOXY-RESIN CONTAINING PHENOLPHTHALEIN POLY(ETHER ETHER KETONE)

Dynamic mechanical analysis and scanning electron microscopy were used to study phase separation of three blends of anhydride-cure bisphenol-A-type epoxy resin with phenolphthalein poly(ether ether ketone). Phase separation was observed for all the blends. The overall compatibility and the resulting morphology of the cured blends are dependent on the choice of cure agent. The phenomena have been discussed from the points of view of both thermodynamics and kinetics. The effects of the choice of hardener on phase separation are considered to be primarily due to differences between the chemical natures of the hardeners.

网间交联型增韧环氧树脂/蓖麻油聚氨酯互穿网络聚合物的动态力学性能和形态结构

以增韧环氧树脂(TEP)和蓖麻油聚氨酯[PU(CO)]形成的互穿网络聚合物(IPN),两网络间具有一定数量的交联点,在一定组成下,该IPN的tanδ-T曲线半峰宽达100℃,tanδ最大值接近1,阻尼性能良好。形态研究表明,该IPN既有增韧环氧树脂本身的两相结构,又有IPN的两相结构。

A~NB~(8-N)型晶体中的化学键和硬度

我们在晶体化学键的研究中得出这样的结论,晶体硬度正象其他宏观量一样,是其微观特性的宏观反映,我们通过对一些晶体的研究比较,给出了AB型晶体化学键参数和硬度之间的定量关系一经验公式,并对六十多种晶体的硬度进行了计算,结果和实验测定值符合很

Cloning and recombinant expression of a crustin-like gene from Chinese shrimp, Fenneropenaeus chinensis

Antimicrobial peptides or proteins (AMPs) are proved to be one of the most important humoral factors to resist pathogen infection. As an antimicrobial protein, crustin had been described in invertebrates as a component of the innate immune system. A crustin-like gene (CruFc) was cloned from haemocytes of Chinese shrimp Fenneropenaeus chinensis by 3' and 5'-RACE PCR. The full-length cDNA consists of 523 with 405 bp open reading frame encoding 134 amino acids and the deduced peptide contains a putative signal peptide of 17 amino acids. The sequence also contains a whey-acidic protein (WAP) domain at the C-terminal. Transcripts of CruFc were mainly detected in haemocytes and gill by RT-PCR analysis. In addition, another full-length cDNA named CshFc was also cloned from haemocytes of Chinese shrimp and its inferred amino acid sequence lacks the WAP-type 'four-disulfide core' domain. The fusion proteins containing CruFc and CshFc were, respectively, produced and the antimicrobial assays revealed that the recombinant CruFc could inhibit the growth of grain-positive bacteria in vitro but the recombinant CshFc could not inhibit at the same conditions. The difference of antimicrobial activity between recombinant CruFc and CshFc provides the evidence that the four-disulfide core domain of crustin may play an important role in its biological function. (c) 2006 Elsevier B.V. All rights reserved.

A preliminary study on thermoluminescence characteristics of sediments from the North Pacific

Thirty-eight surficial deposit samples were collected from the equatorial North Pacific, and the natural thermoluminescence (TL) characteristics of both bulk and clay fraction samples ( < 2 mu m fractions) were studied by the FJ427 - Al automatic TL Dosimeter for the first time. With the measurements of clay mineral composition, element composition by XRD and ICP, the correlations between TL intensity and sedimentary environment proxies were analyzed, such as water depth, ratio of FeO to Fe2O3 contents, LOI, and major clay mineral concentration, and it was found the bulk sample's TL signal was stronger than the clay ones. Usually, increase in the clay components may result in the decrease of TL intensity. From the shape of TL curves, the pelagic sediments can be divided into two groups: the majority group has two glow peaks, in general, the first peak is broad and flat, but the second narrow and sharp; the minority group only has a single peak because the first is absent. The peak centers of TL curves are almost fixed, falling in the temperature sections 230 similar to 260 and 390 similar to 405 degrees C respectively. Lorentz model packed in the Origin 7.5 was chosen to deal with the TL curves. From the processing results, three parameters ( H, C and A), corresponding to the height, center, and kurtosis of TL curve, were obtained to describe the curve characteristics. The correlations between TL curve parameters and sedimentary environment proxies were also calculated. On the basis of the above work, the relationship between TL characteristics and sediment type, mineral composition, sedimentary environment of surface sediments was discussed in the study area, and a conclusion is: sediments from the environment of shallower water, higher organic contents and weaker reductivity have stronger TL signals.

Thermal conductivity of graded spherical composites with contact resistance

The effective thermal conductivity of graded composites with contact resistance on the inclusion surface is investigated. As an example, we have considered the graded composite media with a spherical particle embedded in a homogeneous matrix, where the thermal conductivity of spherical inclusion is an exponential function k(i) = c exp(betar) (where r is the inside distance of a point in particle from the center of the spherical particle in a spherical coordinate). For both heat contact resistance and perfect contact cases, we have given a reasonable effective medium approximation to calculate the effective conductivity. (C) 2003 Elsevier B.V. All rights reserved.

A hybrid coupled ocean-atmosphere model and ENSO prediction study

A hybrid coupled ocean-atmosphere model is designed, which consists of a global AGCM and a simple anomaly ocean model in the tropical Pacific. Retroactive experimental predictions initiated in each season from 1979 to 1994 are performed. Analyses indicate that: (1) The overall predictive capability of this model for SSTA over the central-eastern tropical Pacific can reach one year, and the error is not larger than 0.8 degrees C. (2) The prediction skill depends greatly on the season when forecasts start. However, the phenomenon of SPB (spring prediction barrier) is not found in the model. (3) The ensemble forecast method can effectively improve prediction results. A new initialization scheme is discussed.

退耕还林还草地鼠害治理——大林姬鼠种群年龄结构的研究

对采自青海省退耕还林还草地88只大林姬鼠Apodemus specivsus标本的体重和胴体重等7项生长指标进行了主成分分析，确定了各项指标时鼠体生长的代表性大小。结果表明：体重和胴体重是最具有代表性的生长指标，井根据体重将大林姬鼠划分为5个年龄组。为厦时掌握退耕还林还草地鼠类种群动态进而对其进行有效防治提供有力的证据。

国产赖草属的叶表皮特征与组群划分

对国产赖草属15个种的叶片表皮进行了光镜观察,发现下表皮呈现的微形态差异可以把国产类群划分为3个群体,并参照各群体所具的外部形态特征,3个群体应分别属于前人组群划分中的3个组,即多穗组(sect.Leymus)、少穗组(sect.Aphanoneuron(Nevski)Tzvelev)和单穗组(sect.Anisopyrum(Griseb.)Tzvelev).同时,根据叶表皮性状的递变趋势,分析了3个国产组的亲缘关系.结果表明:多穗组最原始,单穗组最高级,少穗组演化居中;单穗组与少穗组亲缘关系直接,与多穗组关系间接.

The effect of land management on carbon and nitrogen status in plants and soils of alpine meadows on the Tibetan plateau

Large-scale grassland rehabilitation has been carried out on the severely degraded lands of the Tibetan plateau. The grasslands created provide a useful model for evaluating the recovery of ecosystem properties. The purposes of this research were: (1) to examine the relative influence of various rehabilitation practices on carbon and nitrogen in plants and soils in early secondary succession; and (2) to evaluate the degree to which severely degraded grassland altered plant and soil properties relative to the non-disturbed native community. The results showed: (1) The aboveground tissue C and N content in the control were 105-97 g m(-2) and 3.356gm(-2), respectively. The aboveground tissue C content in the mixed seed treatment, the single seed treatment, the natural recovery treatment and the severely degraded treatment was 137 per cent, 98 per cent, 49 per cent and 38 per cent, respectively, of that in the control. The corresponding aboveground tissue N content was 109 per cent, 84 per cent, 60 per cent and 47 per cent, respectively, of that in the control. (2) Root C and N content in 0-20 cm depths of the control had an 2 2 average 1606 gm(-2) and 30-36 gm(-2) respectively. Root C and N content in the rehabilitation treatments were in the range of 26-36 per cent and 35-53 per cent, while those in the severely degraded treatment were only 17 per cent and 26 per cent of that in the control. (3) In the control the average soil C and N content at 0-20 cm was 11307 gm(-2) and 846 gm(-2), respectively. Soil C content in the uppermost 20 cm in the seeded treatments, the natural recovery treatment and the severely degraded treatment was 67 per cent, 73 per cent and 57 per cent, respectively, while soil N content in the uppermost 20cm was 72 per cent, 82 per cent and 79 per cent, respectively, of that in the control. The severely degraded land was a major C source. Restoring the severely degraded lands to perennial vegetation was an alternative approach to sequestering C in former degraded systems. N was a limiting factor in seeding grassland. It is necessary for sustainable utilization of seeding grassland to supply extra N fertilizer to the soil or to add legume species into the seed mix. Copyright (c) 2005 John Wiley & Sons, Ltd.

SIASUN-RH06A弧焊机器人控制系统的开发与研制

本文介绍了新松机器人公司最新开发的弧焊机器人控制的研制情况.该系统可完成机器人对多个弧焊工作站的协调控制,最多为12个运动轴.为便于国内用户使用,实现了中文界面功能键驱动的新型编程示教盒,是一种便于使用和维护的弧焊机器人控制系统.该系统已用于新松机器人公司的6kg工业机器人产品中。

基于视觉的机器人激光焊接质量检测技术研究

视觉检测技术是随着计算机视觉技术和光电技术的飞速发展，而出现的一种新的检测技术。检测被测目标时，把图像当作检测和传递信息的手段或载体，从图像中提取有用的信号，它是以现代光学为基础，融光电子学、计算机图像学、信息处理、计算机视觉等科学技术为一体的现代检测技术。现代激光自动化焊接技术是由激光、计算机、机器人、数控和精密机床等相结合的综合高新技术,此项技术已成为工业生产自动化的关键技术，拥有普通加工技术所不能比拟的优势。为了克服机器人焊接过程中各种不确定因素对焊接质量的影响，提高机器人作业的智能化水平和工作可靠性，要求焊接机器人系统不仅能实现空间焊缝的实时跟踪，而且还能实现焊接参数的在线调整和焊缝质量的实时控制，即焊接机器人焊接过程的自主化和智能化。本文的研究依托于中国科学院知识创新工程方向性项目“全自动激光拼焊成套装备生产线”，旨在探索立体视觉检测系统的实现及其在激光拼焊工程中的应用的问题。从理论和实践两个方面，对其中的若干关键技术，如视觉检测系统创新设计、数学模型、量化误差、摄像机标定、结构光条纹中心线提取、焊前特征检测、溶池边缘提取、焊后缺陷图像匹配算法、三维重建和表面孔的视觉定位等进行了研究。主要研究成果如下： 1．提出了一种可以用于焊前跟踪，焊后检测，以及焊接过程中对激光溶池进行监测的多功能激光视觉检测装置。推导了检测系统在不考虑像平面安装倾斜角度时和考虑像平面安装倾斜角度时检测点坐标的计算公式以及量化误差公式，分别针对由于数模转换量化误差、安装角度倾斜误差、安装高度误差三个方面引起的量化误差，分析其关于行，列，以及不同倾斜角度的影响分布规律。并对于各种情况进行了仿真，对于各种误差分布特征进行了分析，提出了检测奇异点的情况和数学模型的局限性。以上工作为实现焊缝三维信息的高精度提取奠定了基础。 2．对于摄像机的标定技术进行了研究，结合工程实际，利用zhang的标定法和matlab标定工具包，对于摄像机进行了标定；针对检测相机视场较小，标定采集范围不易调整和相机的畸变主要发生在视场边缘等特征，在保证要求的精度范围之内，提出一种基于标定靶的标定方法，实验证明该方法的标定与测量精度能够满足工程需要。 3．研究了现有的条纹中心提取算法过程，提出了基于OTSU阈值的多次高斯拟合平均法和基于OTSU阈值的质心平均法计算激光条纹中心坐标。该法对条纹的噪声，散斑和被测工件表面漫反射有很强的抵制作用，因此具有很强的鲁棒性。实验表明，与传统方法相比，具有更高的提取精度。同时为了适应激光条纹被工件表面调制后发生的角度变化，以及硬件安装带来的激光线型条纹倾斜，提出了一种自适应方向模板法，可以解决特殊倾斜角度时的激光条纹中心线提取问题。三个仿真试验验证了方法的可行性。 4．提出了一套在线实时进行焊前检测的图形处理算法，可以实现焊缝宽度，焊前错配和焊缝中心位置检测。通过工程实验提取了各指标的检测结果，并验证了算法的正确性。 5．提出了一种基于数学形态学的激光拼焊溶池边缘检测算法，对于激光拼焊中的溶池图像进行边缘提取，基于真实图像进行了实验研究表明，提取边缘效果可以达到单像素。 6．对焊后表面形貌检测的图像实时处理算法进行了研究。提出了一套在线实时进行焊后焊缝表面缺陷检测的图形处理算法,可以进行焊缝宽度，错配，凹度，凸度，咬边，焊接倾角，过高七种表面焊接缺陷的匹配识别；对于整个焊缝的表面形貌进行三维重建。通过等厚板焊接和不等厚板焊接两种试验，验证了算法的合理性和鲁棒性。提出了一种基于randon变换的错配和兴趣区域快速检测算法。对于表面孔的检测算法进行了探讨，主要针对孔的检测中的噪声和表面反射，研究了腐蚀膨胀对于表面孔定位和大小的检测影响。 7．研究了以普通6R机器人进行焊缝视觉检测的工作视野，即焊缝视觉检测空间，提出了一种生成焊缝视觉检测空间的解算法；以此检测视野为依托，探索了在视觉检测视野中进行焊缝视觉检测的初始位置规划问题，提出了一种初始位置规划算法；仿真结果证明了算法的正确性。