ESTIMATION OF THE RADIATION-INDUCED DAMAGE IN PTFE BY DEPRESSION OF THE MELTING AND CRYSTALLIZATION TEMPERATURES

The radiation induced depression of the melting and crystallization temperatures of PTFE irradiated at various temperatures followed by heat treatment at 380-degrees-C, and their relationship to structural changes, were investigated. The G(-units) values obtained in this work are different from those of samples which have not undergone heat treatment and seem to be more closely associated with radiation induced branched structures.

STUDIES ON THE REACTIONS OF TRANSITION-METAL HYDRIDES WITH HETEROCUMULENES .6. REACTION OF CP2ZR(H)CL WITH RNCS (R=C6H5, 2-C10H7, C-C6H11 AND N-C4H9)

The novel NS-containing zirconacycle complexes Cp2ZrCl[SC(H)NR] (1a, R = C6H5; 1b, R = 2-C10H7; 1c, R= C-C6H11; 1d; R = n-C4H9) were obtained by insertion reactions of Cp2Zr(H)Cl with RNCS. 1(a-d) could react further with Cp2Zr(H)Cl to yield a sulphur-bridging compleX (Cp2ZrCl)2S (2) and a Schiff base RN=CH2. The crystal structure of la has been determined by X-ray analysis.

四苯基卟啉及其金属配合物的裂解色谱研究

四苯基卟啉及其铁、锰等金属配合物是一类具有较大分子量、非挥发性的卟啉衍生物。由于结构和性能上的特点,这类物质成为有机合成中一种新型催化剂。关于这类物质的裂解研究尚未见有文献报道。本文用裂解色谱法(PGC)考察了它们的热裂解

CRYSTALLIZATION KINETICS OF MIXTURES OF POLY(EPSILON-CAPROLACTONE) AND POLY(STYRENE-CO-ACRYLONITRILE)

The crystallization kinetics in mixtures of poly(epsilon-caprolactone) (PCL) and poly(styrene-co-acrylonitrile) (SAN) has been investigated as the function of composition and crystallization temperature. The isothermal growth rates of PCL spherulites decrease with increasing concentration of SAN. Because of the miscibility of PCL/SAN mixtures, the radial growth rates of the spherulites are described by a kinetic equation including the interaction parameter and the free energy for the formation of crystal nuclei. The interaction parameter obtained from the fitting of the kinetic equation with experimental data is in good agreement with that obtained from melting point depression. Folding surface free energies decrease with the increase of SAN concentration. In light of these results, it is suggested that, for the PCL/SAN mixtures, the noncrystallizable SAN polymer reduces the mobility of crystallizable PCL polymer so that the growth rates decrease with the increase of noncrystallizable component fraction.

用于核磁共振波谱仪三调探头电路的设计

本文叙述了用于核磁共振谱仪的单线圈三调谐探头电路的设计。单线圈三调谐探头电路同时提供三个通道不同频率信号的发射和接收,氢(~1H)通道,碳(~13C)通道,氘通道三调谐电路如图1所示.氢通道的等效电路如图2a所示,碳通道等效电路如图2b所示,氘(~2D)

STUDY OF THE CHLORINATION REACTION OF Li2CO3 WITH NH4Cl

The chlorination reaction of Li2CO3 with NH4Cl has been studied in detail by a series of thermal analysis methods. When NH4Cl/Li2CO3 mole ratio equals 4, Li2CO3 can be transformed into LiCl quantitatively in a stream of Ar gas flow. All residual NH4Cl is decomposed completely at 400 degrees C and carried away from the reaction cell by Ar gas.Analysis by X-Ray diffraction and Ion Chromatography show that there are almost no NH4Cl remained in The LiCl product. It is interested that the chlorination reaction can be applied to the determinations of phase diagram by thermal analysis method and the preparation of Al-Li alloy by electrolysis in molten salt.

PMBP与P350对Nd(Ⅲ)的协同萃取

1-苯基-3-甲基-4-苯甲酰基吡唑酮-5(PMBP,以HA代表)作为一种优良的β—二酮类酸性螯合萃取剂,迄今已用于50多种元素的萃取分离、分析,它与其它试剂对金属的协同萃取也有报道。为研究不同中性磷萃取剂和无机酸介质对PMBP协同萃取稀土的影响,本文以盐酸体系中Nd(?)为被萃金属离子,选择甲基膦酸二甲庚酯(P350,以B代表)与PMBP组成新协同萃取体系,

HIPS/TiO_2复合材料的电子显微学研究

高抗冲聚苯乙烯树脂(HIPS)在实际应用中,往往要加入着色剂进行着色,钛白粉(TiO_2)是一种通用的白色着色剂。然而着色剂的加入对材料的力学性能有较大影响。本文对着色后的HIPS/TiO_2复合材料进行了电子显微学研究,明确了TiO_2影响HIPS力学性能的原因。 HIPS/TiO_2复合材料超薄切片的透射电子显微镜结果表明,TiO_2在样品中的分布很不均匀,局部区域TiO_2严重堆积(图1a)。扫描电子显微镜对HIPS/TiO_2冲击断面的组成观察得到了同样的结果(图1b。TiO_2在材料内部的堆积区域形成材料力学性能的弱点,材料受外力作用时首先从这些弱点处断裂,

Ce~(3+)在xMF_(2-y)YF_3体系中发射峰位置的变化

本文讨论了Ce~(3+)在xMF_2-yYF_3(M=Ca、Sr、Ba;x=0、1、2、y=0、1、2、)体系中的光谱行为及与其取代阳离子、邻位阳离子和 YF_3组分含量的变化关系,并与 Eu~(2+)的光谱行为进行了比较。

DRY-WEIGHT AND CHEMICAL-COMPOSITION (CHN) IN RELATION TO POPULATION-DENSITY OF CULTIVATED TISBE-HOLOTHURIAE (COPEPODA, HARPACTICOIDA)

CARBON

Bifurcation of Pacific North Equatorial Current at the surface

The grid altimetry data between 1993 and 2006 near the Philippines were analyzed by the method of Empirical Orthogonal Function (EOF) to study the variation of bifurcation of the North Equatorial Current at the surface of the Pacific. The relatively short-term signals with periods of about 6 months, 4 months, 3 months and 2 months are found besides seasonal and interannual variations mentioned in previous studies. Local wind stress curl plays an important role in controlling variation of bifurcation latitude except in the interannual timescale. The bifurcation latitude is about 13.3A degrees N in annual mean state and it lies at the northernmost position (14.0A degrees N) in January, at the southernmost position (12.5A degrees N) in July. The amplitude of variation of bifurcation latitude in a year is 1.5A degrees, which can mainly be explained as the contributions of the signals with periods of about 1 year (1.2A degrees) and 0.5 year (0.3A degrees).

牙鲆生长相关性状遗传力估计

遗传力是数量遗传学的重要参数，对鱼类良种选育具有重要意义。可靠的遗传力估计值可以为合理制定育种计划提供宝贵信息，同时可以预测选择反应。本文按照10×3因子设计方法，10尾雄鱼与3尾雌鱼两两授精，产生10个父系半同胞、3个母系半同胞及30个全同胞家系，以微卫星分子标记为家系鉴定手段，对40日龄牙鲆生长相关性状遗传力进行了估计；同时，初步探讨了因子交配设计及人工控制条件下，亲本对子代遗传贡献率差异及有效群体大小。主要结论包括：1.初步筛选的14个微卫星位点中，有9个（Po91、Po1、Po56、Po20、Poli23、Po89、Poli121、Po42、Po13）在亲本中呈现中、高度多态性：平均等位基因9.4个；平均亲本特异性等位基因4个。用5个位点（Po91、Po1、Po56、Po20、Poli23）为346个子代中的227个个体找到所属家系；继续用另外4个位点（Po89、Poli121、Po42、Po13）分型，成功鉴定72个个体。鉴定率约86%，其中，亲本特异性等位基因的存在使鉴定效率大大提高。以上9个位点可为该群体良种选育工作提供技术支持。2. 发生降解的DNA与完整的DNA，在相同引物、相同PCR体系、相同模板浓度下扩增的带型一致。该结果证实了微卫星分型对降解的DNA同样稳定。3. 亲本对子代的遗传贡献率存在差异。雄亲的贡献率为5.8—14.3%，除3号、9号子代数较少，5号、6号子代数较多外，其它父本基本一致；母本对子代的贡献率差异较大（18.5%—50.6%），这与人工授精前雌亲发育状况、卵子质量检测结果基本一致，在一定程度上说明，母本尤其是卵子质量对鱼类早期存活具有较大影响。4. 家系内子代数目的不平衡导致实际有效群体大小下降。Ne=7.44，比理论有效群体大小（9.23）下降约19%。但与自然交配相比（有效群体下降可达75%），人工控制下的交配在一定程度上可有效限制遗传多样性的下降。5. 基于父本方差组分，40日龄生长相关性状遗传力估计值（h2s±S.E.）为（0.157±0.052）－（0.440±0.137）。加性遗传方差在表型方差中所占的比例，在一定程度上表明该牙鲆群体生长性状具有一定的选择力度。

Studies on nitric oxide synthase activity in haemocytes of shrimps Fenneropenaeus chinensis and Marsupenaeus japonicus after white spot syndrome virus infection

The nitric oxide synthase (NOS) activity in the haemocytes of shrimps Fenneropenaeus chinensis (Osbeck) and Marsupenaeus japonicus (Bate) was Studied after white spot syndrome virus (WSSV) infection to determine its characteristics in response to virus infection. First, the NOS activity in haemocytes of shrimps was determined by the means of NBT reduction and changes in cell conformation. And the variations of NOS activity in shrimps after challenge with WSSV intramuscularly were evaluated through the analysis Of L-citrulline and total nitrite/nitrate (both as NO derivates) concentrations. The result showed that NOS activity in the haemocytes of F chinensis increased slightly from 0 to 12 h postchallenge, indicated by the variations Of L-Citrulline (from 11.15 +/- 0.10 to 12.08 +/- 0.64 mu M) and total nitrite/nitrate concentrations (from 10.45 +/- 0.65 to 12.67 +/- 0.52 mu M). Then it decreased sharply till the end of the experiment (84 h postchallenge), the concentrations Of L-Citrulline and total nitrite/nitrate at 84 It were 1.58 +/- 0.24 and 2.69 +/- 0.70 mu M, respectively. The LPS-stimulated NOS activity kept constant during the experiment. However, in M. japonicus, the NOS activity kept increasing during the first 72 It postchallenge, the concentrations Of L-Citrulline and total nitrite/nitrate increased from 7.82 +/- 0.77 at 0 h to 10.79 +/- 0.50 mu M at 72 h, and from 8.98 +/- 0.43 at 0 h to 11.20 +/- 0.37 mu M at 72 h, respectively. Then it decreased till the end of the experiment (216 h postchallenge), and the concentrations of L-Citrulline and total nitrite/nitrate at 216 h were 5.66 +/- 0.27 and 4.68 +/- 0.16 mu M, respectively. More importantly, an apparent increase of I-PS-stimulated NOS activity was observed in M japonicus at 48 h postchallenge, which was about 4 times higher than that in the control group of health shrimps. In correspondence with the difference of NOS activity between the two species of shrimps, the Cumulative mortalities of the shrimps were also different. All shrimps of F. chinensis in the mortality experiment died in 66 h, much more quickly than M. japonicus, Whose accumulative mortality reached 100% after 240 h. Data here reported let us hypothesize that NOS activity in the haemocytes of shrimps F chinensis and M. japonicus responses to WSSV infection differently, and this might be one of the reasons for the different susceptibility of F chinensis and M. japonicus to WSSV infection. (c) 2005 Elsevier Inc. All rights reserved.

Photocatalytic degradation of CI Acid Blue 80 in aqueous suspensions of titanium dioxide under sunlight

The dye C.I. Acid Blue 80 (AB80) was easily degraded by TiO2-P25 assisted photocatalysis in aqueous dispersion under irradiation of sunlight. The optimal reaction conditions were [TiO2] = 2.0 g/L, pH = 10, [H2O2] = 5 mmol/L. The photocatalytic reaction followed pseudo-first order kinetics. The adsorption of AB80 onto TiO2 was in accord with Langmuir equation.