Hydrothermal synthesis and luminescent properties of Y2O3:Tb3+ and Gd2O3:Tb3+ microrods

One-dimensional (1D) Y2O3:Tb3+ and Gd2O3:Tb3+ microrods have been successfully prepared through a large-scale and facile hydrothermal method followed by a subsequent calcination process in N-2/H-2 mixed atmosphere. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (IR), thermogravimetric analysis (TGA), energy-dispersive X-ray spectra (EDX). scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), photoluminescence (PL) and cathodoluminescence (CL) spectra as well as kinetic decays were used to characterize the samples. The as-formed products via the hydrothermal process could transform to cubic Y2O3:Tb3+ and Gd2O3:Tb3+ with the same morphology and slight shrinking in size after a postannealing process.

Synthesis and chain-length dependent properties of monodisperse oligo(9,9-di-n-octylfluorene-2,7-vinylene)s

A series of monodisperse oligo(9,9-di-n-octylfluorene-2,7-vinylene)s (OFVs) with fluorene units up to 11 has been synthesized following a divergent approach. Chain length was found to affect not only photophysical properties but also thermal properties. Absorption and photoluminescence spectra are red-shifted with increasing chain length. The effective conjugated length has been extrapolated to be as long as 19 fluorene vinylene units, indicative of a well-conjugated system. With the number of fluorene units > 5, the oligomers exhibit nematic mesomorphism. Glass transition temperature (T-g) and clearing point temperature (T-c) increase with increasing molecular length and with those of OFV11 up to 71 and 230 degrees C, respectively. The oligomers can form uniform films by solution casting for fabrication of light-emitting diodes. With a device structure of ITO/ PEDOT:PSS/OFV11/Ca/Al, a current efficiency of 0.8 cd.A(-1) at a brightness of 1300 cd.m(-2) along with a maximum brightness of 2690 cd.m(-2) have been realized. This performance is notably superior to that of the corresponding polymer.

Synthesis of poly(epsilon-caprolactone)-b-poly(gamma-benzyl-L-glutamic acid) block copolymer using amino organic calcium catalyst

A biodegradable two block copolymer, poly(epsilon-caprolactone)-b- poly(gamma-benzyl-L-glutamic acid) (PCL-PBLG) was synthesized successfully by ring-opening polymerization of N-carboxyanhydride of gamma-benzyl-L-glutamate (BLG-NCA) with aminophenyl-terminated PCL as a macroinitiator. The aminophenethoxyl-terminated PCL was prepared via hydrogenation of a 4-nitrophenethoxyl-teminated PCL, which was novelly obtained from the polymerization of c-caprolactone (CL) initiated by amino calcium 4-nitrobenzoxide. The structures of the block copolymer and its precursors from the initial step of PCL were confirmed and investigated by H-1 NMR, FT-IR, GPC, and FT-ICRMS analyses and DSC measurements.

Flexural fatigue behavior of injection-molded composites based on poly(phenylene ether ketone)

Flexural fatigue tests were conducted on injection-molded short fiber composites, carbon fiber/poly(phenylene ether ketone) (PEK-C) and glass fiber/PEK-C (with addition of polyphenylene sulfide for improving adhesion between matrix and fibers), using four-point bending at stress ratio of 0.1. The fatigue behavior of these materials was presented. By comparing the S-N curves and analyzing the fracture surfaces of the two materials, the similarity and difference of the failure mechanisms in the two materials were discussed. It is shown that the flexural fatigue failure of the studied materials is governed by their respective tensile properties. The matrix yielding is main failure mechanism at high stress, while at lower stress the fatigue properties appear fiber and interface dominated. (C) 1997 John Wiley & Sons, Inc.

Poly(epsilon-capralactone)/poly(ethylene oxide) diblock copolymer .2. Nonisothermal crystallization and melting behavior

The nonisothermal crystallization behavior and melting process of the poly(epsilon-caprolactone) (PCL)/poly(ethylene oxide) (PEG) diblock copolymer in which the weight fraction of the PCL block is 0.80 has been studied by using differential scanning calorimetry (DSC). Only the PCL block is crystallizable, the PEO block with 0.20 weight fraction cannot crystallize. The kinetics of the PCL/PEO diblock copolymer under nonisothermal crystallization conditions has been analyzed by Ozawa's equation. The experimental data shows no agreement with Ozawa's theoretical predictions in the whole crystallization process, especially in the later stage. A parameter, kinetic crystallinity, is used to characterize the crystallizability of the PCL/PEO diblock copolymer. The amorphous and microphase separating PEO block has a great influence on the crystallization of the PCL block. It bonds chemically with the PCL block, reduces crystallization entropy, and provides nucleating sites for the PCL block crystallization. The existence of the PEO block leads to the occurrence of the two melting peaks of the PCL/PEO diblock copolymer during melting process after nonisothermal crystallization. The comparison of nonisothermal crystallization of the PCL/PEO diblock copolymer, PCL/PEO blend, and PCL and PEO homopolymers has been made. It showed a lower crystallinity of the PCL/PEO diblock copolymer than that of others and a faster crystallization rate of the PCL/PEO diblock copolymer than that of the PCL homopolymer, but a slower crystallization rate than that of the PCL/PEO blend. (C) 1997 John Wiley & Sons, Inc.

Morphological, thermal, and mechanical properties of polypropylene/polycarbonate blend

This work deals with the effect of compatibilizer on the morphological, thermal, rheological, and mechanical properties of polypropylene/polycarbonate (PP/ PC) blends. The blends, containing between 0 to 30 vol % of polycarbonate and a compatibilizer, were prepared by means of a twin-screw extruder. The compatibilizer was produced by grafting glycidyl methacrylate (GMA) onto polypropylene in the molten state. Blend morphologies were controlled by adding PP-g-GMA as compatibilizer during melt processing, thus changing dispersion and interfacial adhesion of the polycarbonate phase. With PP-g-GMA, volume fractions increased from 2.5 to 20, and much finer dispersions of discrete polycarbonate phase with average domain sizes decreased from 35 to 3 mu m were obtained. The WAXD spectra showed that the crystal structure of neat PP was different from that in blends. The DSC results suggested that the degree of crystallization of PP in blends decreased as PC content and compatibilizer increased. The mechanical properties significantly changed after addition of PP-g-GMA. (C) 1997 John Wiley & Sons, Inc.

Genetic model of the hydrate system in the fine grain sediments in the northern continental slope of South China Sea

Gas hydrate samples were obtained firstly in China by drilling on the northern margin of South China Sea (SCS). To understand the formation mechanism of this unique accumulation system, this paper discusses the factors controlling the formation of the system by accurate geophysical interpretation and geological analysis, based on the high precision 2-D and 3-D multichannel seismic data in the drilling area. There are three key factors controlling the accumulation of the gas hydrate system in fine grain sediment: (1) large volume of fluid bearing methane gas Joins the formation of gas hydrate. Active fluid flow in the northern South China Sea makes both thermal gas and/or biogenic gas migrate into shallow strata and form hydrate in the gas hydrate stability zone (GHSZ). The fluid flow includes mud diapir and gas chimney structure. They are commonly characterized by positive topographic relief, acoustic turbidity and push-down, and low reflection intensity on seismic profiles. The gas chimneys can reach to GHSZ, which favors the development of BSRs. It means that the active fluid flow has a close relationship with the formation and accumulation of gas hydrate. (2) The episodic process of fracture plays an important role in the generation of gas hydrate. It may provide the passage along which thermogenic or biogenic gas migrated into gas hydrate stability zone (GHSZ) upward. And it increases the pore space for the growth of hydrate crystal. (3) Submarine landslide induced the anomalous overpressure activity and development of fracture in the GHSZ. The formation model of high concentration gas hydrate in the drilling sea area was proposed on the basis of above analysis.

胶州湾及其邻近海域的浮游植物－种类组成与数量变化

研究胶州湾浮游植物的物种组成与时空分布的特点，对于了解该湾生态系统的现状与历史变化趋势以及生态系统对自然条件变化和人类干扰的响应具有重要意义。 本文根据2004年每月一次采集的浮游植物样品，分析了胶州湾浮游植物的物种组成和优势种的时空分布情况。调查发现浮游植物共142种，分属于6门53属，其中硅藻门40属113种，占总物种数的79.6%；甲藻门10属24种，占总物种数的16.9%；其它为金藻门1属2种，裸藻1属1种，绿藻1属2种。浮游植物丰度周年波动范围为11.12－14602.39×104cells/m3，全年平均为1857.55×104cells/m3。全年丰度最高的藻为环纹劳德藻(Lauderia annulata)，出现在2月份，而全年的丰度最高值也出现在2月份。在胶州湾中，硅藻所占比例最大，平均为97.44%，最高为99.95%，最低为82.55%。浮游植物的丰度的周年变化：有两个高峰，分别出现在2月份和10月份，是典型的温带海域双高峰的分布形式。 胶州湾浮游植物的优势种分析，采用Kikvidze等（2002）提出的确定优势种数量的计算方法，再依据各物种的优势度排序最终确定优势种。其中在多样性最低的6月和10月，优势种数目均为1种，分别为丹麦细柱藻（Leptocylindrus danicus）和中肋骨条藻（Skeletonema costatum）。而在多样性指数较低的1月、2月，优势种数目分别为2和3；而在物种多样性比较高的5月、7月、11月，由于分布相对比较分散，所以优势种数量较多。这说明这个方法可以较好地完成对胶州湾浮游植物群落分析时确定优势种的目标。优势种出现频率较多的种类为中肋骨条藻（1、3、4、5、8、10、11、12月）、洛氏角毛藻(Chaetoceros lorenzianus)（7、8、9、11、12月）、尖刺拟菱形藻(Pseudonitzschia pungens)（2、3、5、7月）、加拉星杆藻(Asteronella kariana)（1、2、3、5月）、密联角毛藻(Chaetoceros densus)（5、11、12月）、扭鞘藻(Streptothece thamesis)（7、8、9月）、夜光藻(Noctiluca scintillancs)（4、5、7月）、奇异菱形藻(Nitzschia paradoxa)（5、11、12月）,对这些种的时空分布进行了分析。 对2004年胶州湾的浮游植物数据进行分层聚类分析后，发现可以将胶州湾划分为三个海区：湾南与湾外海区、湾中西部海区、湾东海区。

扇贝裙多肽的制备与分析

海洋生物是新型的肽类次级代谢物的丰富来源，现已从多种生物中发现一系列高活性的抗肿瘤、抗病毒、抗微生物及心血管疾病的活性多肽。以栉孔扇贝裙为原料，利用酶解的方法制备肽混合物，对其进行分离分析，获得高附加值的混合肽制品。通过一系列酶反应动力学研究，进行最佳用酶及其酶解最佳条件的选择。酶解条件为：酶浓度2500单位/每克样品，酶解温度45 ℃， 使用537酸性蛋白酶和1398中性蛋白酶先后于pH3和pH7左右作用共计5个小时。对所得胨肽混合物进行超滤，分级纯化，选择分子量介于600与4000道尔顿之间的混合肽，测定其氨基酸的组成，含有18种氨基酸，其中天门冬氨酸、谷氨酸、甘氨酸含量最高。通过SDS-PAGE对主要成分进行分离并确定分子量大小，电泳结果显示：混合肽主要含有三至五种多肽成分，分子量介于1000至3000道尔顿之间。通过质谱分析得到验证，并确定五种多肽的分子量分别为1714.32、 1857.97、 2034.53、 2474.77、 2492.80道尔顿。

Identification of quantitative trait loci for growth-related traits in the Pacific abalone Haliotis discus hannai Ino

The locations and effects of quantitative trait loci (QTL) were estimated for nine characters for growth-related traits in the Pacific abalone (Haliotis discus hannai Ino) using a randomly amplified polymorphic DNA (RAPD), amplification fragment length polymorphism (AFLP) and SSR genetic linkage map. Twenty-eight putatively significant QTLs (LOD > 2.4) were detected for nine traits (shell length, shell width, total weight, shell weight, weight of soft part, muscle weight, gonad and digestive gland weight, mantle weight and gill weight). The percentage of phenotypic variation explained by a single QTL ranged from 8.0% to 35.9%. The significant correlations (P < 0.001) were found among all the growth-related traits, and Pearson's correlation coefficients were more than 0.81. For the female map, the QTL for growth were concentrated on groups 1 and 4 linkage maps. On the male map, the QTL that influenced growth-related traits gathered on the groups 1 and 9 linkage maps. Genetic linkage map construction and QTL analysis for growth-related traits are the basis for the marker-assisted selection and will eventually improve production and quality of the Pacific abalone.

On two species of spider crabs of the genus Doclea (Crustacea : Decapoda : Brachyura : Majidae : Pisinae) from China, one of which is new

A new species of spider crab, Doclea unidentata, is described from the South China Sea. Allied to D. brachyrhynchos Bleeker, 1856, and D. macracanthus Bleeker, 1856, it can easily be distinguished by its very short, unidentate rostrum. The identity of Doclea canalifera Stimpson, 1857, is resolved with the selection of a neotype, and it is here regarded as a senior subjective synonym of D. japonica Ortmann, 1893. The taxonomy of this species as well as the allied D. ovis (Fabricius, 1787) is also discussed.

水葫芦苗(Halerpestes cymbalaris)的生长特征研究

以调查统计的方法在中国科学院海北定位站研究了高寒湿地植物水葫芦苗无性系的生长特征、形态特征以及能量分配规律.结果表明:匍匐茎只有1条的水葫芦苗最多,占35.29%,匍匐茎有4条的水葫芦苗只占 8.82%.同一水葫芦苗无性系中,随着匍匐茎数目的增多,分株数、间隔子数、茎总长和匍匐茎比节间重变小.分株一般在第一级最高,末级较低;第1条匍匐茎的间隔子较长.随水葫芦苗匍匐茎数目的增多,用于无性繁殖的分株干重比例逐渐增加,用于有性繁殖的花的干重比例下降.水葫芦苗无性系这种生长特征、形态特征以及能量分配规律是其生物-生态学特性和所处高寒湿地 生境共同决定的.

海洋机器人动态定位的坐标变换与系统结构

本文给出海洋机器人的原理性流体动力学模型.动态定位的基本定义,海洋机器人既定向又定位的坐标变换与系统结构,和只定位不定向的坐标变换与系统结构.

温度、压力耦合背景下多相流体运移的数学模型研究

The Mathematical modeling of multiphase fluid flow is an important aspect of basin simulation, and also is a topic of geological frontier. Based on coupling relation of temperature, pressure and fluid flow, this dissertation discusses the modeling which conform to geological regularities of fluid migration. The modeling that is multi-field and multiphase includes heat transport equation, pressure evolvement equation, solution transport equation and fluid transport equation. The finite element method is effective numerical calculation methods. Author applies it to solve modeling and implements the finite element program, and the modeling is applied to Ying-Qiong Basin. The channels of fluid vertical migration are fault, fracture and other high penetrability area. In this thesis, parallel fracture model and columnar channel model have been discussed, and a characteristic time content and a characteristic space content been obtained to illustrate the influences of stratigraphic and hydrodynamic factors on the process. The elliptoid fracture model is established and its approximately solution in theory is gotten. Three kinds of modeling are applied to analyze the transient variation process of fluid pressure in the connected permeable formations. The elliptoid fracture model is the most similar geology model comparing with the other fracture models so the research on this fracture model can enhance the understanding to fluid pressure. In the non-hydrodynamic condition, because of the difference between water density and nature gas density, nature gas can migrate upon by float force. A one-dimension mathematical model of nature gas migration by float force is established and also applied to analyze the change in the saturation of gas. In the process of gas migration its saturation is non-continuous. Fluid flow is an important factor which influences the distribution of the temperature-field, the change of temperature can influence fluid property (including density, viscidity, and solubility),a nd the temperature field has coupling relations to the fluid pressure field. In this dissertation one-dimension and two-dimension thermal convection modeling is developed and also applied to analyze convective and conductive heat transfer. Author has established one-dimension and two-dimension mathematical modeling in which fluid is a mixture of water and nature gas based on the coupling relation between temperature and pressure, discussed mixture fluid convection heat transfer in different gas saturation, and analyzed overpressure form mechanism. Based on geothermal abnormity and pore pressure distribution in Dongfong 1-1, Yinggehai Basin, South China Sea, one-dimension mathematical modeling of coupling temperature and pressure is established. The modeling simulates the process that fluid migrates from deep to shallow and overpressure forms in shallow. When overpressure is so large that fractures appear and overpressure is released. As deep fluid flow to shallow, the high geothermal then forms in shallow. Based on the geological characteristics in Ya13-1, two-dimension mathematical modeling of coupling temperature and pressure is established. Fluid vertically flows in fault and then laterally migrates in reservoir. The modeling simulates the geothermal abnormity and pore pressure distribution in reservoir.