A strategy to prepare ultrafine dispersed Fe2O3 nanoparticles

In this article, a novel strategy was applied to prepare dispersed ultrafine alpha-Fe2O3 nanoparticles. The initial Fe(OH)(3) nanoparticles were synthesized by the reaction of NaOH and FeCl3 in alcohol. With the new-formed nanoparticles as nuclei, NaCl crystallized and encapsulated the particles into solid cages. As a result, the nanoparticles were prevented from aggregating and growing. The composite of Fe(OH)(3) and NaCl was calcined and then washed by water to obtain the pure alpha-Fe2O3 nanoparticles.

New titanium complexes with two beta-enaminoketonato chelate ligands: Syntheses, structures, and olefin polymerization activities

New titanium complexes with two nonsymmetric bidentate beta-enaminoketonato (N,O) ligands (4a-e), [(Ph)NC(R-2)C(H)C(R-1)O](2)TiCl2, have been synthesized. X-ray crystal structure reveals that complex 4a has a C-2-symmetric conformation with a distorted octahedral geometry around the titanium center. With modified methylaluminoxane (MMAO) as a cocatalyst, complexes 4a-e are active catalysts for ethylene polymerization at room temperature, producing high molecular weight polyethylenes bearing linear structures. The 4a,b/MMAO catalyst systems exhibit the characteristics of a quasi-living polymerization of ethylene, producing polyethylenes with narrow molecular weight distributions. Moreover, the 4a-d/MMAO catalyst systems are also capable of promoting the quasi-living copolymerization of ethylene with norbornene at room temperature, yielding high molecular weight alternating copolymers with narrow molecular weight distributions. The quasi-living nature of the catalysts allows the synthesis of new A-B polyethylene-block-poly(ethylene-conorbornene) diblock copolymer.

Tb~(3+)离子4f~75d组态能级的电子云扩大效应

研究了电子云扩大效应对Tb3+离子5d能级的影响.利用光谱理论,将电子云扩大效应比率β同Tb3+离子4f75d组态的自旋允许和禁阻跃迁能级的能级差联系起来,通过复杂晶体化学键理论确定了化学键的共价性、相应键体积极化率以及配体离子的有效电荷与β的线性关系,同时得到了对β有影响并与Tb3+离子自身相关的因子.

Hydrogen peroxide biosensor based on microperoxidase-11 entrapped in lipid membrane

A highly catalytic activity microperoxidase-11 (MP-11) biosensor for H2O2 was developed to immobilizing the heme peptide in didodecyldimethylammonium bromide (DDAB) lipid membrane. The enzyme electrode thus obtained responded to H2O2 without electron mediator or promoter, at a potential of +0.10 V versus Ag \ AgCl. A linear calibration curve is obtained over the range from 2.0 x 10(-5) to 2.4 x 10(-3) M. The biosensor responds to hydrogen peroxide in 15 s and has a detection limit of 8 x 10(-7) M (S/N = 3) Providing a natural environment with lipid membrane for protein immobilization and maintenance of protein functions is a suitable option for the design of biosensors.

Reactive reinforcement of the interface of poly(ether sulfone)/poly(phenylene sulfide) polymer blend by PMR-POI

The effect of polymerization of monomer reactant-polyimide (POI) as the interfacial agent on the interface characteristics, morphology features, and crystallization of poly(ether sulfone)/poly(phenylene sulfide) (PES/PPS) blends were investigated using a scanning electron microscope, FTIR, WAXD, and XPS surface analysis. It was found that the interfacial adhesion was enhanced, the particle size of the dispersed phase was reduced, and the miscibility between PES and PPS was improved by the addition of POI. It was also found that POI was an effective nucleation agent of the crystallization for PPS.

Analysis of poly (arylene phosphonate) cyclic oligomer by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MAIDI-TOF-MS) was used for analysis of poly(arylene phosphonate) cyclic oligomers. A comparison was made by using 1,8,9-dithranol, 2,5-dihydroxybenzoic acid and retinoic acid as the matrix. The result showed that the retinoic acid produced the strongest ion signals under the conditions used. Different salts of metals were used as the cationization agents to examine the effect on the cyclic oligomers. It was found that the salts could produce metal-cyclic oligomer cation spectra and lithium was the stronger one than those of silver so, the suitable matrix and cationization agent for the new cyclic oligmer were obtained. They were very effective for the analysis of poly(arylene phosphonate) cyclic oligomer.

芳香环状聚膦酸酯齐聚物的基质辅助激光解吸电离飞行时间质谱分析

用基质辅助激光解吸电离飞行时间质谱方法对一系列芳香环状聚膦酸酯低聚物进行了结构分析。比较了不同基质及阳离子剂对芳香环状聚膦酸酯分析结果的影响。 1,8,9 蒽三酚基质仅对含有羰基基团聚膦酸酯环状齐聚物分析有效 ,而视黄酸基质则对所有聚膦酸酯环状齐聚物有效 ,是这类新型芳香环状齐聚物的适宜基质。环状聚膦酸酯齐聚物的阳离子剂分析表明 ,氯化锂是这种环状齐聚物的适宜的阳离子添加剂

The spectral properties of BaB8O13:Eu,Tb phosphors

The luminescence properties of BaB8O13:xEu,yTb phosphors which were synthesized in air atmosphere have been studied. The emissions of europium(III), terbium(III) and europium(II) have been observed in BaB8O13:xEu, yTb phosphors. Electron paramagnetic resonance (EPR) studies were carried out. The intensities of EPR peaks of europium(II) are increased if terbium(III) is increased in BaB8O13:Eu3+,yTb(3+) phosphors. So the valence state of europium is influenced by terbium(III). These phenomena can be explained by an electron transfer mechanism. We found a new kind of method to prepare trichromatic phosphor that two rare earth ions activated in a BaB8O13 matrix.

铕(Ⅱ)在氟化镁钾基质中的格位取代过程及价态稳定性

Eu~(2+)电子跃迁发射与其所处基质的晶场环境和化学键性质密切相关。实验证明,(d→ff→f)两种发射的竞争,取决于Eu~(2+)在基质中占据的晶格位置。 KMgF_3是一种典型的钙钛矿结构复合氟化物,是理想的激光基质材料。在这种基质中掺

波浪驱动式海洋要素垂直剖面测量系统关键技术

在海洋学研究、海洋生产和工程建设应用中，经常需要对特定区域的海水参数（如温度、盐度、深度和流速等）进行长期、定点、实时的垂直剖面测量。传统做法是，采用海洋观测站或海洋调查船只来投放并保证搭载平台的运行，这势必需要大量的人力、物力和财力。若采用海上浮标，则能源供给又成问题。如果能充分利用海上无时不在的波浪能，驱动测量平台运动携带传感器循环运行，并在运动过程中采集海洋要素，则是解决上述问题的一个很好的方案。 这里设计制作了一套波浪驱动式海洋要素垂直剖面测量系统，此系统由有效传递波浪能的锚泊系统、易于搭载传感器的往返测量平台、高度集成的数据采集与控制系统三部分构成。系统通过高效的波浪能传递装置，采用特殊的棘爪驱动结构，将测量平台驱动着步进下潜，当测量平台下潜到海底或事先设定的某一深度时，棘爪驱动结构彻底释放，则测量平台依靠自身的正浮力上浮，并在上浮过程中实现海洋要素的测量。这样测量平台就可以完全依靠水体的能量在水表面以下特定的深度循环往复运动，系统被驱动的最小波高为0.2m，连续工作时间不小于90天。论文系统论述了波浪驱动式海洋要素垂直剖面测量系统中的若干关键技术，这些技术包括基于波浪能驱动的系统整体设计，波浪能转化与传递技术，传感器搭载技术等，并对系统各部件和整机的性能试验情况进行了介绍和分析。论文最后对波浪驱动系统的技术设计和拓展应用进行了总结和展望。

哈氏弧菌种特异性分子标记的发现及其在哈氏弧菌快速诊断和免疫防治中的应用

哈氏弧菌是危害水产养殖业发展的重要病原菌之一，因而其免疫防治研究具有重要意义。论文发现了一个新的、编码未知功能蛋白的基因vhhP2，该基因只存在于哈氏弧菌中，具有很高的种特异性。根据此特点，建立了一种vhhP2 -PCR检测方法，并证明该方法可以快速准确地从动物血液、组织以及环境样品中检测哈氏弧菌。同时，对VhhP2进行了免疫原性检测，发现VhhP2作为亚单位疫苗具有良好的免疫保护效应。为了克服常规亚单位疫苗的缺点以及进一步提高VhhP2的免疫效应，利用表面展示技术将VhhP2蛋白定位到鱼类共生菌细胞表面，制成活体疫苗。免疫结果表明，这种表面展示型VhhP2能够大幅提高牙鲆对哈氏弧菌的抵抗能力。论文还利用VhhP2蛋白的分泌功能，将VhhP2与一株迟缓爱德华氏菌的免疫保护性抗原蛋白重组融合，制成交叉保护疫苗，并证明其对哈氏弧菌和迟缓爱德华氏菌均有一定的免疫作用。

Growing season ecosystem respirations and associated component fluxes in two alpine meadows on the Tibetan Plateau

From 30 June to 24 September in 2003 ecosystem respiration (Re) in two alpine meadows on the Tibetan Plateau were measured using static chamber- and gas chromatography- (GC) based techniques. Simultaneously, plant removal treatments were set to partition Re into plant autotrophic respiration (Ra) and microbial heterotrophic respiration (Rh). Results indicated that Re had clear diurnal and seasonal variation patterns in both of the meadows. The seasonal variability of Re at both meadow sites was caused mainly by changes in Ra, rather than Rh. Moreover, at the Kobresia humilis meadow site (K_site), Ra and Rh accounted for 54% and 46% of Re, respectively. While at the Potentilla fruticosa scrub meadow (P_site), the counterparts accounted for 61% and 39%, respectively. T test showed that there was significant difference in Re rates between the two meadows (t = 2.387, P = 0.022). However, no significant difference was found in Rh rates, whereas a significant difference was observed in Ra rates between the two meadows. Thus, the difference in Re rate between the two meadows was mainly attributed to plant autotrophic respirations. During the growing season, the two meadows showed relatively low Q(10) values, suggesting that Re, especially Rh was not sensitive to temperature variation in the growing season. Additionally, Re and Rh at the K_site, as well as Rh at the P_site was negatively correlated with soil moisture, indicating that soil moisture would also play an important role in respirations.

Morphological and reproductive response of Caragana microphylla to different stocking rates

Understanding the effect on host plants of defending against herbivores is important in grazing ecology and grassland management. In this study, the morphological and reproductive responses of Caragana microphylla Lam. to grazing sheep were investigated using a 15-year grazing experiment with six stocking rates in the Inner Mongolia steppe of China. Plant height, rachis length, leaflet size, and number of pods decreased significantly, whereas spine density and length increased significantly with increased stocking rate. Significant negative correlations were observed between production of vegetative and reproductive organs and defensive organs, indicating that it is costly for C. microphylla to defend against herbivores and that morphological miniaturization and a tradeoff between production and defense were main responses of C. microphylla to herbivores. (c) 2006 Elsevier Ltd. All rights reserved.

辽河盆地西部凹陷深部流体的地球化学特征与成藏效应

The main research area of this thesis is the Western Depression in the Liaohe Basin. Based on the drilling core observation and mud logging data, the features of the mantle–derived fluids and their effects on oil/gas generation in the Western Depression of the Liaohe Basin,was studied with comprehensive methods of volcanic petrology, sediment petrology, fluid geochemistry, sedimentlogy, and structural geology, and use of polarized light microscope, fluorescence microscope, electron microscope, fluid and melt inclusion test, and isotopic test of nature gas etc. The observation of drill cores in study area and other studies reveal that the main passageway of the volcanic eruption in the Cenozoic was the Xibaqian-Gaosheng fault, and the volcanic rocks of each stage were distributed around it. Mantle-derived fluid which affected on oil/gas generation formed later than the volcanic spew and those fluids entered into the depression through the Taian-Dawa fault and the Central fault. The volatile fraction analysis of the melt inclusion reveals the presence of two kinds of mantle fluids; they are hydrogen-rich fluid and carbon dioxide-rich fluid. These the two kinds of fluids were mainly distributed in olivine and pyroxene respectively. The hydrothermal veins development have multiple stages, from high temperature quartz vein to low temperature calcite vein and analcime vein, in which the fluid inclusion extremity component are methane and carbon dioxide, which indicate that when mantle-derived fluids ascended and entered into the basin, most of these fluids interacted with the organic matter in the basin even though some of these entered into atmosphere. The present isotopic test of the nature gas reveals the high 3He/4He value between the region of the Taian-Dawa fault and the Central fault, which also imply the feature of origin in mantle. This phenomenon indicates that the Mesozoic basement faults and the main Cenozoic faults had connected crust and the mantle during the basin evolution, so the mantle derived fluids could enter the basin along those faults. The main source rocks of the ES3 and ES4 members of the Shahejie Formation began to expel hydrocarbon at the end period of the ES1 member of the Shahejie Formation, and reached its peak during the period of the Dongying Formation deposition. During these periods, the mantle derived-fluids entered the basin constantly along the main faults, and supplied lots of hydrogen for hydrocarbon generation. Though the volcanic rocks and the mantle-derived fluids in the Eastern Depression were more developed than in the Western Depression, the source rocks and the deep fluids were not interacted better than the Western Depression because of the affection of structural evolution. In the Eocene, the Eastern Depression did not deposit the ES4 member of the Shahejie Formation, furthermore, the mantle-fluid formed in the Fangshengpao stage escaped to the atmosphere, which confined the later stage hydrocarbon generation capability.