Reactive compatibilization of polyamide 6 with isocyanate functionalized ethylene-propylene copolymer

Reactive compatibilization of ethylene-propylene copolymer functionalized with allyl (3-isocyanato-4-tolyl) carbamate (TAI) isocyanate (EPM-g-TAI) and polyamide 6 (PA6) was investigated in this paper, FTIR analysis revealed the evidence of a chemical reaction between the end groups of PA6 and EPM-g-TAI. Thermal, rheological, morphological, and mechanical properties of the resultant system were examined, DSC analysis indicated that the crystallization of PA6 in Pa6/EPM-g-TAI blends was inhibited, due to the chemical reaction that occurs at the interface of PA6 and EPM-g-TAI. Rheological measurement showed that complex viscosity and storage modulus of PA6/EPM-g-TAI were both dramatically enhanced compared to those of PA6/EPM at the same blending composition. After examining the morphology of both blending systems, smaller particile sizes, more homogeneous distribution of domains and improved interfacial adhesion between matrix and domains were observed in the compatibilized system. Mechanical properties such as tensile strength. Young's modulus, flexural strength and modulus, as well as notched and un-notched impact strength of PA6/EPM-g-TAI blends were also found to improve gradually with increasing the content of grafted TAI.

Amplified immunoassay of human IgG using real-time biomolecular interaction analysis (BIA) technology

An automated biomolecular interaction analysis instrument (BI-Acore) based on surface plasmon resonance (SPR) has been used to determine human immunoglobulin G (IgG) in real time. Polyclonal anti-human IgG antibody was covalently immobilized to a carboxymethyldextran modified gold film surface. The samples of human IgG prepared in HBS buffer were poured over the immobilized surface. The signal amplification antibody was applied to amplify the response signal. After each measurement, the surface was regenerated with 0.1 mol/L H3PO4. The assay was rapid, requiring only 30 min for antibody immobilization and 20 min for each subsequent process of immune binding, antibody amplification and regeneration. The antibody immobilized surface had good response to human IgG in the range of 0.12-60 nmol/L with a detection limit of 60 pmol/L. The same antibody immobilized surface could be used for more than 110 cycles of binding, amplification and regeneration. The results demonstrate that the sensitivity, specificity and reproducibility of amplified immunoassay using real-time BIA technology are satisfactory.

Polymer/silica nanoscale hybrids through sol-gel method involving emulsion polymers. 1. Morphology of poly(butyl methacrylate)/SiO2

In this article, we report on an approach of using an emulsion polymerized polymer in preparing organic-inorganic nanocomposites through a sol-gel technique. By mixing a polymer emulsion with prehydrolyzed tetraethoxysilane transparent poly(butyl methacrylate)/SiO2, nanocomposites were prepared as shown by TEM. AFM, FTIR, and XPS results show that there is a strong interaction between polymer latex particles and the SiO2 network. Comparison of the emulsion method with a traditional solution method shows that nanocomposites can be prepared by both methods, but there is some difference in their morphology and properties.

Stimulated emission in the film of polymer/dye blend

Optically pumped stimulated emission behavior in an organic film was demonstrated in this study. The gain material consists of a laser dye perylene doped into polystyrene (PS) matrix in an appropriate weight ratio. The sample was transversely pumped by the three harmonic output of a mode-locked Nd:YAG laser. The change of the emission spectra showed a clear threshold action and gain narrowing phenomenon when increasing the excitation intensity. Three emission peaks were observed below the excitation threshold, which are locate at 446, 475 and 506 nm, respectively. However, only the gain narrowing peak centered at 475 nm could be detected above the threshold. The spectra narrowing observed results from the amplified spontaneous emission (ASE) in the gain material. (C) 2000 Elsevier Science S.A. All rights reserved.

Comparison of different methods for variable selection

In chemistry for chemical analysis of a multi-component sample or quantitative structure-activity/property relationship (QSAR/QSPR) studies, variable selection is a key step. In this study, comparisons between different methods were performed. These methods include three classical methods such as forward selection, backward elimination and stepwise regression; orthogonal descriptors; leaps-and-bounds regression and genetic algorithm. Thirty-five nitrobenzenes were taken as the data set. From these structures quantum chemical parameters, topological indices and indicator variable were extracted as the descriptors for the comparisons of variable selections. The interesting results have been obtained. (C) 2001 Elsevier Science B.V. All rights reserved.

The encysted dormant embryo proteome of Artemia sinica

The possibility of the brine shrimp Artemia to produce dormant embryo (cysts) in diapause is a key feature in its life history. In the present study, we obtained a proteomic reference map for the diapause embryo of Artemia sinica using two-dimensional gel electrophoresis with a pH range of 4-7 and a molecular weight range of 10-100 kDa. Approximately 233 proteins were detected, and 60 of them were analyzed by capillary liquid chromatography tandem mass spectrometry (LC-MS/MS). Of these, 39 spots representing 33 unique proteins were identified, which are categorized into functional groups, including cell defense, cell structure, metabolism, protein synthesis, proteolysis, and other processes. This reference map will contribute toward understanding the state of the diapause embryo and lay the basis and serve as a useful tool for further profound studies in the proteomics of Artemia at different developmental stages and physiological conditions.

南海西北部陆架潮频内波生成过程的数值模拟

我国南海海水运动复杂、海底地形多变，是内波的多发区域。目前关于南海内波的报道、观测和研究主要集中在Luzon海峡到南海东北部东沙群岛附近海域。2005年4月16日始，中国科学院海洋研究所和中国海洋石油总公司联合在海南岛东部的文昌站进行了为期近半年的连续定点海洋调查，观测资料清楚地表明，这一海域陆架上长期存在着比较规则的潮频内波现象。 从航天图片和SAR卫星图片上捕捉到的信息来看，南海西北部陆架上（文昌站附近海域）有些潮频内波并非从Luzon海峡传播而来，而极有可能是局地正压潮与陆坡作用生成的。本文用数值模拟的方法来证明这一观点。 首先，我们从Reynolds方程组出发，用差分方法和有限元方法建立了一个连续层结海水中正压潮与海底地形相互作用生成潮频内波的二维非线性数值模式。我们用该模式研究了正压潮流流经下降地形、上升地形、凸起地形、凹陷地形等几种典型的海底地形时生成内波的过程，探讨了该数值模式中各个参数对生成内波的影响。 然后，我们从文昌站海洋科学调查的温盐深数据资料中提取了该海区的密度、跃层厚度和强度等海洋环境参数；用调和分析法从海流流速、流向数据中提取了正压潮潮流成分及各潮流分量的速度、振幅、方向等与数值模式相关的信息。我们把这些从实测资料中提取出的海洋环境和潮流信息应用到内波生成的非线性数值模式中，模拟了文昌站附近海域正压潮流与陆坡作用生成内波的过程。模拟结果表明，南海局地潮流与陆坡作用足以生成能够被SAR捕捉到的大振幅内波。从而我们可以断定，南海西北部陆架上有些潮频内波是天文潮与陆坡作用生成，然后传播到陆架上的。

栉孔扇贝和海湾扇贝免疫防御特性的比较研究

贝类养殖作为我国传统的海水养殖产业，在我国沿海地区的经济发展中起重要作用。但由于近年来养殖扇贝病害的不断发生，不仅造成了巨大的经济损失，而且直接威胁到现有养殖产业的生存和发展。目前认为，机体抗病能力的下降是发生流行性死亡的主要原因之一。因此，深入研究扇贝免疫防御特性，能更好地了解和解决贝类养殖中的病害问题。本文比较了健康状态和重金属污染以及高温胁迫下海湾扇贝和栉孔扇贝部分免疫指标的变化，并对同龄不同大小的栉孔扇贝的部分免疫指标进行了比较，以期更好的了解贝类的防御机制，为扇贝病害防治提供资料。研究结果如下: 用流式细胞仪技术对血细胞死亡率、细胞吞噬率和呼吸爆发进行了测定，发现健康状态下两种扇贝的细胞死亡率相差不大，海湾扇贝为4.83%，栉孔扇贝为4.95%；细胞吞噬率差异显著(P<0.05)，海湾扇贝为26.73%，栉孔扇贝为19.89%；呼吸爆发的基础值相差也不大，海湾扇贝为1.94，栉孔扇贝为1.56。另外用免疫化学方法对健康状态下栉孔扇贝和海湾扇贝血淋巴和肝胰腺中SOD、ACP活性和MDA含量也进行了测定与比较。发现在血淋巴和肝胰腺中，两种扇贝SOD活性均存在显著差异(P<0.05)，其中海湾扇贝分别为995.43和113.99，栉孔扇贝分别为446.64和40.6；血淋巴和肝胰腺中ACP活性差异显著(P<0.05)，海湾扇贝分别为90.19和432.36，栉孔扇贝分别为73.26和146.63；血淋巴中和肝胰腺中MDA含量差异不显著(P>0.05)，海湾扇贝分别为3.37和92.46，栉孔扇贝分别为2.17和28.96。实验结果说明，海湾扇贝对细菌等异物的吞噬和杀灭能力以及机体自身的抗氧化能力高于栉孔扇贝，这为海湾扇贝比栉孔扇贝具有更高的抗逆性提供了证据。 用相同的方法对不同浓度(0, 0.2, 0.3, 0.5 mg L-1) Pb2+溶液浸泡后的栉孔扇贝和海湾扇贝的血细胞死亡率、细胞吞噬率和呼吸爆发进行了检测，同时测定了Pb2+处理后肝胰腺中SOD、ACP活性和MDA含量的变化。结果表明，栉孔扇贝的血细胞死亡率与对照组相比有上升趋势，且随着Pb2+浓度的增加而显著增加，而海湾扇贝在相同条件Pb2+的胁迫下，血细胞的死亡率明显低于栉孔扇贝。栉孔扇贝各实验组细胞吞噬率均低于对照组，而海湾扇贝在低浓度的Pb2+浸泡后，细胞的吞噬率与对照组相比有所降低，但随着浓度的继续增加，细胞的吞噬率反而上升，甚至略高于对照组。栉孔扇贝血细胞的呼吸爆发在Pb2+胁迫后较对照组有所升高，但随着浓度的增加，呼吸爆发有下降的趋势，而海湾扇贝的呼吸爆发随着Pb2+浓度的增加而显著增加。对两种扇贝体液免疫指标的测定发现，各实验组SOD的活性均比对照组高，且海湾扇贝的SOD活性高于栉孔扇贝；随着Pb2+浓度的增加，各实验组ACP的活性一直呈上升趋势，且海湾扇贝的ACP活性也高于栉孔扇贝；Pb2+处理后MDA的含量均显著增加，其中栉孔扇贝MDA含量的增幅明显高于海湾扇贝。该结果说明，Pb2+对两种扇贝的免疫系统都有一定的影响，但相同剂量的Pb2+对两种扇贝的毒害程度不同，海湾扇贝对Pb2+的耐受性似乎高于栉孔扇贝。 对海湾扇贝和栉孔扇贝的升温刺激实验发现，当养殖水体的温度从18℃缓慢升高到30℃后，栉孔扇贝在第三天开始出现大量死亡现象，而海湾扇贝未出现死亡。因而本文只对升温前后的海湾扇贝进行了细胞死亡率、吞噬率和呼吸爆发的测定和比较。结果发现，与升温前相比，血细胞的死亡率在温度升高后略有增加，但差异不显著(P>0.05)；而细胞吞噬率在温度升高后显著下降；通过对呼吸爆发积聚的活性氧（Reactive Oxygen Species，ROS）的测定发现，升温后血细胞的ROS含量显著高于升温前(P<0.05)。该结果表明，高温会影响血细胞的功能，使机体的免疫防御能力下降，从而导致病害的发生。 另外，本文对同龄不同大小的栉孔扇贝的血细胞吞噬率以及血淋巴和肝胰腺中SOD、ACP活性和MDA含量进行了测定与比较。结果发现: 小扇贝的血细胞吞噬率略高于大扇贝，分别达到了22.82和20.96；在血淋巴及肝胰脏中，两组扇贝SOD酶的活性均差异显著(P<0.05)，小扇贝分别为613.88和102.01，大扇贝分别为356.15和50.22；血淋巴中小扇贝ACP的活性极显著的高于大扇贝(P<0.01)，分别为44.3和2.91，但肝胰腺中大扇贝和小扇贝ACP的活性相差不大，大扇贝为455.75，小扇贝为485.33；大扇贝和小扇贝血淋巴和肝胰脏中MDA含量相差不大，大扇贝分别为2.67和31.83，小扇贝分别为3.17和35.33。该结果说明，小扇贝对细菌等异物的吞噬和杀灭能力以及机体自身的抗氧化能力高于大扇贝，这为生长与抗逆性相颉抗提供了依据。

Synthesis, crystal structure and biological activities of N '-(4-methoxybenzylidene)-2-(1H-1,2,4-triazol-1-yl) acetohydrazide

The title compound, N'-(4-methoxybenzylidene)-2-(1H-1,2,4-triazol-1-yl)acetohydrazide, was synthesized and its structure was confirmed by means of IR, MS,H-1 NMR and elemental analysis. The single crystal structure of the title compound was determined by X-ray diffraction. The preliminary biological test shows that the synthesized compound has a low antifungal activity.

中国虎耳草属（虎耳草科）二新种——班玛虎耳草和丁青虎耳草

记载了中国虎耳草属Saxifraga新种，即班玛虎耳草S.banmaensisJ．T Pan和丁青虎耳草sdingqingensis J．T Pan。其中，班玛虎耳草仅见于青海班玛，与小伞虎耳草S．umbellulata Hook．f ＆ Thoms．近缘，但其萼片先端具软骨质短尖头，花瓣线形，非提琴状长圆形至提琴形，基部无爪，可资区别。丁青虎耳草见于西藏丁青，与近加拉虎耳草S．llonakhensis W W Smith相似，但其萼片3脉，于先端汇合成1疣点，花瓣具8痂体和4—5脉，基部截形或近耳形，可以区别。此两种均系中国特有种，隶属于莲座状亚组subsect．Rosulares Gornall。

小麦抗条锈病分子标记辅助育种研究进展

小麦条锈病是小麦生产的主要病害之一。在中国，尤其是西北麦区，小麦条锈病是小麦生产面临的最严重问题。筛选和培育抗锈基因是防治小麦条锈病最为经济、安全、有效的方法。综述了分子标记辅助育种技术在小麦抗条锈病育种上的研究概况和发展运用。

青藏高原高寒灌丛CO2通量日和月变化特征

采用涡度相关法对青藏高原高寒灌丛CO2通量进行连续观测的结果表明,青藏高原高寒灌丛CO2通量呈明显的日和月变化特征.就日变化而言,暖季(7月)CO2通量峰值出现在12:00左右(-1.19 g CO2/(m2•h)-1),08:00～19:00时CO2净吸收,而20:00～07:00为CO2净排放; 冷季(1月)CO2通量变化振幅极小,除11:00～17:00时少量的CO2净排放以外(0.11 g CO2/(m2•h)-1左右),其余时段CO2通量接近于零.从月变化来看,6～9月为CO2净吸收阶段,8月CO2净吸收最大,6～9月CO2净吸收的总量达673 g CO2/m2; 1～5月及10～12月为CO2净排放,共排放446 g CO2/m2,4月CO2净排放最大.全年CO2通量核算表明,无放牧条件下青藏高原高寒灌丛是显著的CO2汇,全年CO2净吸收量达227 g CO2/m2.

高寒草甸地区陆面过程观测及耦合模式研究

对海北高寒草甸地区水热传输过程进行了系统观测,特别考虑了叶片气孔为非饱和水汽条件下的交换情况,结合修正的根系吸水公式,发展了一个多层陆气耦合模式.利用该模式对中国科学院海北高寒草甸生态试验站地区矮嵩草草甸陆气水热交换进行了数值模拟,分析了湍流交换的物理过程,给出了沿高度分布的各物理量.模拟结果与实测值吻合较好.

基于立体视觉的室外非结构化环境障碍物检测方法研究

随着智能机器人系统的发展，机器人的在线感知能力日益受到重视。障碍物检测能力是机器人在线感知能力的一个重要组成部分。因视觉传感器具有独特优势，基于视觉的障碍物检测方法成为目前关注的重点。 室外非结构化环境因结构复杂，机器人缺乏可有效利用的先验知识描述，导致众多障碍物检测系统在该环境中不能有效工作。本文采用全局-局部策略对场景进行由粗到精的分析，弥补室外非结构化环境先验知识不足的难题，提高机器人的在线感知能力。根据该策略，本文在基于视差图的障碍物检测系统框架中，引入视差投影图模块，提出了基于视差投影图的障碍物检测系统框架。该框架在视差投影图模块中全局分析场景视差分布水平，在立体匹配模块中局部分析场景前景目标的几何轮廓信息。依据该框架，针对实际应用中遇到的各种问题，提出了工作于室外非结构化环境的障碍物检测算法。该算法具有如下特点： 1、通过分析视差投影图的地面关联线信息，获得场景的视差分布水平。该信息一方面用来动态更改匹配算法的视差搜索范围，增强算法的实时性和鲁棒性；另一方面用来移除背景地表，简化障碍物分割过程； 2、采用双域滤波抑制噪声，获得清晰的边缘特征，降低立体匹配算法在深度不连续性区域的匹配难度； 3、借助逆向重投影的思想重采样扫描图像，在立体匹配前等效地实现了立体匹配过程中动态变更视差搜索范围的操作； 4、采用基于连通成分的扩散方法替代传统的SAD局部匹配算法，获得高质量的视差图，最终改善障碍物检测的精确性。 在室外非结构化环境中，本文对该算法进行了实验验证。通过设置不同的基线长度，验证了算法在不同的感知距离内的有效性。经实验证明，本算法在一定距离范围内能够有效的检测出障碍物。

黔西北炼锌地区河流重金属污染特征

黔西北地区铅锌矿的开发导致了后河严重的重金属污染。为此对河流水体、悬浮物和沉积物中重金属及其沿河流的分布规律进行了研究。结果表明，土法炼锌及其下游铅锌选矿都对河流造成污染，特别是选矿厂的尾矿直接注入河道，使河流沉积物中滞留有较多硫化物矿物。河流重金属的搬运迁移以悬浮质或泥沙推移等机构搬运为主。河流水体环境化学性质对沉积物中硫化物的氧化作用及其重金属向水体的释放起到一定抑制作用，但流水的淘洗和支流的混入过程等水文地球化学条件改变时可使氧化矿物表面的重金属释放返回水相，成为溶解态重金属。沉积物是河流重金属潜在的二次污染源。