267 resultados para 7140-240


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At room temperature, the Bi3+ ion shows broad band characters of its luminescence in Ca2B2O5, M3B2O6 ( M=Ca,Sr ) and SrB4O7. The maxima of the Bi3+ S-1(0)-->P-3(1) absorption bands are located in the range of 240-300nm, but the energy variation of the corresponding P-3(1)-->S-1(0) emissions is very large. The maxima of these emission bands change from 350nm in Ca3B2O6;Bi3+ to 586nm in SrB4O7:Bi3+. The Stokes shift of the Bi3+ luminescence increases from 6118 cm-1, in Ca2B2O5:Bi3+, to 24439 cm-1, in SrB4O7:Bi3+. The emission intensity of the Bi3+ luminescence increases with the decreasing Stokes shift. It has been found that in Ca2B2O5, the Bi3+ ion could transfer its excitation energy to the R3+ ions ( R=Eu, Dy, Sm, Tb ) , but in, Ca3B2O6 and Sr3B2O6, only Bi3+-->Eu3+ was observed. No energy transfer from Bi3+ to R3+ was detected in SrB4O7.

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The radiation-induced loss of weight of F-46 was found to be proportional to irradiation dose and affected markedly by irradiation temperature.

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报道了采用新型酞菁铜衍生物:三特戊基苯氧基对羧基苯氧基酞菁铜(ttc~CuPc)制备LB膜ttc-CuPc/硬脂酸(C_(18))/n-Si光伏电池的结果。测量了电池的光照I—V、暗I—V和光谱响应等特性。在辐照度为100mW/cm~2AMC混合光照射下电池的I_(sc)为240μA/cm~2,V_(oc)为0.33V,观察到反常二极管整流效应并进行了讨论。

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The system of Ca-Sr-Cu-O have been investigated. Two new compounds with compositions Sr3Cu5O8+alpha and CaSrCu3O5+alpha have been discovered. Both are orthorhombic with a = 6.489, b = 11.280, c = 12.240 angstrom for CaSrCu3O5+alpha and a = 3.950, b = 11.479, c = 13.420 angstrom for Sr3Cu5O8+alpha. The X-ray powder data for CaSrCu3O5+alpha, Sr3Cu5O8+alpha, Sr2CuO3 and SrCuO2 are presented. The oxidation state of Cu ion and oxygen contents are analyzed by iodometric titration. Sr0.5Ca0.5CuO2 that has a similar structure with SrCuO2 has been found and its X-ray data are presented also.

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血色素蛋白分子空间结构庞大,电活性中心不易暴露;同时这些分子在电极上吸附强烈而造成电极的钝化,因而其在普通电极上的电子转移速率很低,得不到有效的电流响应。将吩噻嗪染料亚甲蓝等媒介体吸附到

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本文采用接枝共聚方法合成功能高分子型钆化合物活性材料,研究了它们的结构和某些性能,结果表明这些活性材料的结构和性能对钆离子选择电极性能有较大的影响。

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芳香聚酰亚胺一直在电子、复合材料及粘接剂等领域广泛地应用。最近,聚酰亚胺膜已用于气体的分离过程。这是因为芳香聚酰亚胺是具有高玻璃化温度的玻璃态聚合物,它对小分子比大分子有更大的选择透过性,高选择性是与玻璃态聚合物的僵硬主链,对不同尺寸的分子提供筛分作用相连系的。新开发的芳香聚酰亚胺膜是用联苯四甲酸二酐与芳香二胺缩聚制备的聚酰亚胺溶液制造的。这种中空纤维状的膜是由一个多孔结构支撑的一个很薄的外表面组成的。它可通过聚合物溶液采用干——湿法过程纺丝而成,经溶剂交换干燥,外层的致密部分由计算可知厚度低于0.1μm。它对H_2与CO、CH_4.N_2及其它气体的分离有高度的选择性。由于它具有聚酰亚胺特有的耐高温性能,所以可以在很广的气体加工条件下使用。这种膜对水蒸气有很高的透过性,因而也可用于有机蒸气的脱水,或空气干燥。此膜对水蒸气的透过速度为乙醇的100~200倍。30%的乙醇水溶液,经一次膜分离,浓度可提高到99%。空气干燥系统可产出达到-50℃露点的空气。

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本文介绍用高效液相色谱(HPLC)分析豆油中脂肪酸组成的方法。油脂经皂化后,不需萃取,直接形成脂肪酸的苯乙酮酯,通过梯度淋洗,使分离时间大大缩短。此方法可以直接应用到生物样品。

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Year-round induction of sporogenesis of Laminaria saccharina was performed by mechanically blocking the transport of the putative sporulation inhibitors produced by the blade meristem and culturing the plants in constant short days. Sporogenesis was successfully induced by removal of the blade meristem, either by cultivating distal blade fragments or by performing a transverse cut in the frond. The earliest sorus formation after artificial induction was 10 days. The age of the sporophytes used for induction was 6-11 months or 2 years in tank-grown or field-collected sporophytes, respectively. Zoospores were successfully released in all cases. Thus, by year-round artificial induction of sporogenesis, (1) sporeling production of L. saccharina and thereafter sporophyte cultivation could be achieved without seasonal limitation, and (2) the life cycle of L. saccharina (from spore to spore) could be completed within 8 months under controlled conditions. (C) 2004 Elsevier B.V. All rights reserved.

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Effect of temperature and irradiance on growth and reproduction of Enteromorpha prolifera that bloomed offshore along the Qingdao coast in summer 2008, was studied. It was showed that E. prolifera propagated mainly asexually with specific growth rate (SGR) of 10.47 at 25A degrees C/40 mu mol m(-2)s(-1). Under this condition, gametes with two flagellate formed and released in 5 days. At the beginning of the development, the unicell gamete divided into two cells with heteropolarity, and then the apical cell developed into thalli primordial cells, whereas the basal cell developed into rhizoid primordial cells. In 8-day culture, the monoplast gamete developed into juvenile germling of 240 mu m in length. Unreleased gametes can develop directly within the alga body. E. prolifera could either reproduce through lateral branching or fragmenting except apomixis revealed by Microscopic observation. On aged tissue of E. prolifera, although the degraded pigments partially remained in faded algal filaments, numerous vegetative cells could still divide actively in the algal tissues.

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In this study, at proper dosage of ultraviolet (UV) irradiation (180 sec: 36,000 erg/mm(2)), sperm chromosomes of left-eyed flounder, Paralichthys olivaceus, were inactivated, while spermatozoa maintained ability to move and inseminate eggs. Gynogenetic haploids were detected by morphological observation, chromosome counting, and flow cytometer analysis. The ultrastructure of treated sperm was observed under scanning electronic microscope (SEM) and transmission electronic microscope (TEM). The results showed that after being irradiated at lower dosage of irradiation (0-180 sec: 0-36,000 erg/mm(2)), the surface structure of spermatozoa was not affected by UV irradiation, while the inner structures including membrane system and karyoplasm denseness of treated spermatozoa were little changed. However, obvious changes were observed in their membrane system, mitochondria, and nucleus if the dosage of irradiation increased to 240 sec: 48,000 erg/mm(2) or 300 sec: 60,000 erg/mm(2). The sperm survival rates did not change at the lower dosages of the UV irradiation (0-180 sec: 0-36,000 erg/mm(2)) but decreased as the irradiation dosage increased. The motility of treated sperm was lower than that of control group in general but did not change with UV irradiation dosage increasing at the certain range of 0-300 sec: 0-60,000 erg/mm(2).

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The Zenisu deep-sea channel originates on the Izu-Ogasawara island arc, and disappears in the Shikoku Basin of the Philippine Sea. The geomorphology, sedimentary processes, and the development of the Zenisu deep-sea channel were investigated on the basis of swath bathymetry, side-scan sonar imagery, submersible observations, and seismic data. The deep-sea channel can be divided into three segments according to the downslope gradient and channel orientation. They are the Zenisu Canyon, the E-W fan channel, and the trough-axis channel. The sediment fill is characterized by turbidite and debrite deposition and blocky-hummocky avalanche deposits on the flanks of the Zenisu Ridge. In the Zenisu Canyon and the Zenisu deep-sea channel, sediment transport by turbidity currents generates sediment waves (dunes) observed during the Shinkai 6500 dive 371. The development of the Zenisu Canyon is controlled by a N-S shear fault, whereas the trough-axis channel is controlled by basin subsidence associated with the Zenisu Ridge. The E-W fan channel was probably affected by the E-W fault and the basement morphology.

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rpoS 基因编码RpoS因子(RNA聚合酶的σ亚基),能增强细菌细胞对外界不良环境的抗逆性和适应能力。我们从鳗弧菌(Vibrio anguillarum)M3 Fosmid 文库中得到rpoS 基因序列,全长999bp,同源分析发现与大肠杆菌(Escherichia coli)有71%的相似性,与霍乱弧菌(Vibrio cholerae )有78%的相似性。为了研究rpoS在鳗弧菌中的作用,我们利用in-frame deletion技术构建了rpoS 基因的非极性缺失突变株,同时利用细菌的接合转移,以低拷贝克隆质粒pSUP202为载体,构建了突变株的互补株。 在TSB培养基中,rpoS 基因的缺失减缓了鳗弧菌对数期的生长,但是对稳定期的生长没有影响。对数期鳗弧菌在1M蔗糖(渗透压胁迫)和5%(v/v)乙醇中的生长减缓,而在18%(v/v)乙醇中的生长及42℃热击时的存活率相对于野生型没有变化。不同生长时期的鳗弧菌对15mM H2O2的反应有所不同,rpoS 的缺失使对数期的鳗弧菌对15mM H2O2的反应更加敏感。在rpoS基因互补株中,上述表型几乎恢复到野生型水平。 我们通过感染实验发现,rpoS 基因的缺失使鳗弧菌的LD50提高了20倍。 RpoS的突变对鳗弧菌的泳动和胞外酶的产生也有影响。突变株泳动圈直径是野生型的73.8%,在明胶平板和酪蛋白平板上的透明圈直径分别为野生型的61%和69%。通过azocaseion检测胞外产物ECP酶活发现,突变株的酶活是野生型的35.5%。 以上数据表明了RpoS在鳗弧菌对数期应对外界不良环境时起到了重要作用,同时参与了鳗弧菌的致病过程。

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本研究以中国对虾为材料,以杂交育种和选择育种为目标,进行了系统的中国对虾杂交育种试验、生长性状遗传参数试验及其分子遗传连锁图谱的构建工作。结果表明以不同地理群体杂交作为基础群体,然后采用系统的选择育种方法可以获得较好的选择效果。构建的遗传连锁图谱为中国对虾分子辅助育种提供一定的基础。这些试验结果为中国对虾合理系统的育种工作提供了理论基础和数据支持。其具体结果如下: 1. 试验对中国对虾黄渤海水域乳山湾群体(WYP)和朝鲜半岛南海群体(WKN)的2个群体及其杂交后代不同月龄生长情况和存活率进行了研究,测量体长(TL)、头胸甲长(CL)、头胸甲宽(CW)、第2、3腹节高(HST)、第2、3腹节宽(WST)、体重(BW)和存活率共7个性状,计算各项指标的杂种优势率,并对各性状进行了方差分析和多重比较。其3月龄生长情况和存活率研究结果表明,存活率在乳山湾群体(WYP♀)× 朝鲜半岛南海群体(WKN♂)杂交后代出现杂种劣势外,其他指标都表现出不同程度的杂种优势(4.37%~23.96% )。除了存活率外,杂交后代生长性状均显著高于亲本,乳山湾群体(WYP♀)×朝鲜半岛南海群体(WKN♂)杂交后代高于朝鲜半岛南海群体(WKN♀)× 乳山湾群体(WYP♂)杂交后代,黄渤海水域乳山湾群体高于朝鲜半岛南海群体后代。为确定测量性状与中国对虾体重的相关程度,建立了用体长(X1),头胸甲宽(X2),第2、3腹节宽(X3),头胸甲长(X4),第2、3腹节高(X5)估计体重的多元回归方程:Y = -2.056 + 0.03X1 + 0.076X2 + 0.078X3 + 0.033X4 + 0.043X5。 2. 中国对虾黄渤海水域乳山湾群体(WYP)和朝鲜半岛南海群体(WKN)2个群体及其杂交后代在4月龄时期的6个生长指标和存活率的杂种优势范围在0.514%到14.95%之间,WYP♀×WKN♂杂交后代在这7个指标中都高于WKN♀×WYP♂杂交后代。5月龄杂交后代也表现出一定程度的杂种优势,其范围在-9.000%~19.090%之间,但头胸甲长、第2、3腹节处高和存活率3个指标出现杂种劣势。不同杂交组合各个阶段生长发育情况和存活率在杂种优势表现出一定的规律。随着月龄的增加,WKN♀×WYP♂杂交后代杂种优势率有所增加,而WYP♀×WKN♂杂交后代的却有所降低。ANOVA分析结果表明,杂交后代在存活率方面与双亲差异不显著。4月龄的分析结果发现杂交后代在WST和BW这2个指标上存在显著差异。LSD多重比较结果显示,WYP♀×WKN♂杂交后代在BW指标上与亲本存在显著差异,在WST指标方面与其他3个组合的后代差异显著。5月龄的数据分析结果发现,杂交后代除体重存在显著差异外,其他各项指标差异均不显著。LSD多重比较结果发现,WKN♀×WYP♂杂交后代体重与其亲本WKN存在显著差异。 3. 对2个野生群体——朝鲜半岛南海岸群体(WKN)和黄渤海群体(WYP)和3个养殖群体——朝鲜半岛群体的养殖一代(FKN),黄海1号(HH1)和即抗98(JK98)进行杂交试验的研究,结果表明JK98 (♀)  WKN (♂)组合在存活率方面最高,其余的依次为WYP (♀) WKN (♂),WKN (♀) WYP (♂),FKN (♀)HH1 (♂) 和 WYP (♀) FKN (♂)。而在体重方面FKN(♀)  HH1(♂)组合最高,其余的依次为WKN (♀) WYP (♂),WYP (♀) WKN (♂),WYP (♀)FKN (♂) 和 JK98 (♀)WKN (♂)。在所有生长性状方面,JK98 (♀)  WKN (♂)在5个组合中是最低的。方差检测结果表明,TL、CL、HST、LL和BW这5个指标在不同组合间存在差异,而其他指标不存在差异。多重比较结果发现JK98 (♀)WKN (♂)组合的TL与其他组合间差异极显著,HST指标与WKN (♀) WYP (♂),FKN(♀)  HH1(♂)和 WYP (♀)  WKN (♂)这3个组合差异显著,BW指标与WKN (♀) WYP (♂) 和 FKN(♀)  HH1(♂)差异显著。 4. 通过人工授精的方法建立了中国对虾21个半同胞家系,测量了中国对虾21个半同胞(46个全同胞)家系的TL、CL、CW、HST、WST、第1腹节长(FL)、第6腹节长(LL)。利用MTDFREML软件得到生长性状遗传力在0.15~0.35之间,属于中度遗传力范围。TL的遗传力为0.34±0.071,CL的为0.30±0.070,CW为0.35±0.077,WST为0.33±0.073,HST为0.33±0.073,FL的最低为0.15±0.044,LL的为0.24±0.059。各个性状间表现出高的正相关,其中CW和TL以及HST的遗传相关最大,FL和WST的遗传相关最小。 通过以上杂交育种和选择育种的研究,认为单纯的依靠杂交育种来改善中国对虾的育种工作可能具有一定的局限性。所以在实际的育种过程中,以中国对虾不同群体的杂交后代作为基础群体,并以此为基础进行系统的选择育种应该具有更大的潜力。 5. 本试验利用中国对虾F2群体和AFLP分子标记技术进行了遗传连锁图谱的构建。利用55对AFLP引物组合对F2家系的110个个体进行了研究,结果检测到532个符合作图策略的AFLP标记。利用卡方检验检测分离位点是否符合孟德尔分离定律。对于符合3:1比例的分离位点利用F2自交模型构建性别平均连锁图谱,对于符合1:1比例的分离位点利用拟测交理论分别构建中国对虾的雌性和雄性遗传连锁图谱。雌性、雄性和性别平均遗传图谱分别有28、35和44个连锁群,图谱实际长度分别为1090、1617和1772.1 cM。中国对虾遗传连锁图谱估计基因组长度为2420 cM,符合与人类基因组相比的对虾类基因组长度。中国对虾雄性遗传连锁图谱比雌性遗传连锁图谱长32.6%,这可能说明中国对虾不同性别存在不同的重组率。通过皮尔逊相关系数检测认为AFLP标记在中国对虾图谱上分布均匀。本文利用AFLP标记构建的中国对虾遗传连锁图谱为中国对虾基因组研究和遗传改良提供一定的基础,同时也应该开发微卫星等共显性标记,为遗传连锁图谱的整合提供条件。