Microstructure and superconducting properties of single grains of Y-Ba-Cu-O containing Y-2411(M) and Y2O3

Y-Ba-Cu-O (YBCO) single grains have the potential to generate large trapped magnetic fields for engineering applications, and research on the processing and properties of this material has attracted interest world-wide over the past 20 years. In particular, the introduction of flux pinning centers to the large grain microstructure to improve its current density Jc, and hence trapped field, has been investigated extensively. Y2Ba 4CuMO2 [Y-2411(M)], where M = Nb, Ta, Mo, W, Ru, Zr, Bi and Ag, has been discovered recently to form very effective flux pinning centers due primarily to its ability to form nano-size inclusions in the superconducting phase matrix. However, the addition of the Y-2411(M) phase to the precursor composition complicates the melt-processing of single grains. The addition of Y2O3 to the precursor composition, however, broadens the growth window of single YBCO grains containing Y-2411 (M). We report an investigation of the microstructures and superconducting properties of single grains of this composition grown by top seeded melt growth (TSMG). © 2010 IEEE.

一种改进的高分辨率RFLPs 分析

国家自然科学基金和云南省自然科学基金资助

Species diversification in coastal aquaculture: production potentials of shrimp (Penaeus monodon) with mono and mixed sex tilapia

An experiment of 120 days of culture was conducted in brackishwater earthen ponds having an area of 0.2ha each. The hatchery produced shrimp (Penaeus monodon) post larvae were stocked in the 40m² fine meshed nylon net nursery enclosures were fed with commercial pellet feed. After two weeks of nursing, juveniles were allowed to spread in cultural pond by opening the fence. Fingerlings of three different strain of tilapia were stocked as shrimp and Strain-1 all male (monosex) (T1), shrimp and Strain-2 all male (T2), shrimp and Strain-3 mixed sex population (T3) @ 20.000/ha and 10.000/ha, respectively and shrimp only (monoculture) (T4) @ 20.000/ha. The shrimp and fish were fed with farm made feed consisting of a mixture of fishmeal 29%, MOC 15%, rice bran 30%, soybean meal 16%, wheat flour 9% and vitamin premix 0.1%. The average final weight of shrimp was 24.9±1.13g, 23.41±3.26g and 26.67±1.89g that stocked with tilapia in treatments T1, T2, and T3 respectively. The final average weight of shrimp in monoculture (T4) was 27.41±0.76g, apparently higher but insignificant in treatments. The survival of shrimp was 42.17%, 32.38%, 39.45% and 61.98% in treatments T1 T2, T3 and T4 respectively. The production of shrimp in concurrent culture was 193.67, 154.26 and 210.41kg/ha in T1, T2 and T3, respectively, while in monoculture (T4) was 339.77 kg/ha. The growth and survival of tilapia among the treatments was insignificant. The growth of monosex tilapia ranged 225.29 and 291.31g and survival 62.77 and 72.20% in T1 and T2, respectively, in mixed sex was 193.0g and 83.20% (T3). The production of tilapia monosex strains was 1676.69kg/ha (Strain-2 all male) and 1668.98 kg/ha (Strain-1 all male) while that of Strain-3 mixed sex population was 1622.92 kg/ha.

天花粉蛋白对体外无血清培养的人早期绒毛细胞滋养层细胞hCG，孕酮分泌的影响

本研究以体外无血清培养的人早期绒毛细胞滋养层细胞和绒毛组织培养为模型，测定了天花粉蛋白对滋养层细胞ｈＣＧ、孕酮分泌的影响，发现体外无血清培养的细胞滋养层细胞分泌的ｈＣＧ在天花粉蛋白浓度为０．１μｇ／ｍｌ即下降５０％，而后下降缓慢，８μｇ／ｍｌ以上方降为零，而绒毛组织培养在天花粉蛋白浓度为０．１μｇ／ｍｌ时ｈＣＧ下降近９０％，而后下降缓慢，至８μｇ／ｍｌ以上降到零，说明体外培养的细胞滋养层细胞中有两个群体，其中一个对天花粉蛋白敏感，另一个不敏感，尽管在形态上很难区别。孕酮的反应则不同，在细胞滋养层细胞和绒毛组织培养中，随天花粉蛋白浓度升高，孕酮分泌均缓慢下降，未出现两阶段下降过程。

Milkfish grow-out culture in ponds

Milkfish farming is regarded as the backbone of Philippine aquaculture. In 2001, nearly 50% of the Philippines' aquaculture production was milkfish cultured from brackishwater ponds. It has 3 major culture systems: extensive; semi-intensive and intensive. A brief outline is given of the stocking and feeding procedures, providing also some details as to investment costs and returns.

鱼类入侵的生态效应及管理策略

当前生物入侵已在全球范围内广受关注，鱼类入侵不仅会造成生物多样性不可弥补的消失，而 且其对入侵地生态环境和生态系统的破坏性影响更是深远而不可估量的。为减少鱼类入侵的负面影响，一是 要尽快开展预测预警研究，二是采用管理手段控制入侵的发生及发生后及时采取相应控制措施。综述了鱼类 入侵可能引起的各种效应，初步提出了鱼类入侵的管理策略。

四种底栖螺类饥饿代谢的研究

研究了四种常见优势底栖螺类的饥饿代谢(R,mgO2/ind.d)与温度(T,℃)、体重(Wd,mg dry-wt或Ww,mg wet-wt)的关系,并计算出三者间的复合关系,分别是:铜锈环棱螺,R=0.044Wd0.537e0.061T;长角涵螺,R=0.0004Ww0.9405·e0.0735T;纹沼螺,R=0.004Wd1.072e0.091T;短沟蜷,R=0.023Wd0.777e0.042T。

Improving photosynthesis of microalgae by changing the ratio of light-harvesting pigments

Changing the ratio of light-harvesting pigments was regarded as an efficient way to improve the photosynthesis rate in microalgae, but the underlying mechanism is still unclear. In the present study, a mutant of Anabeana simensis (called SP) was selected from retrieved satellite cultures. Several parameters related with photosynthesis, such as the growth, photosynthesis rate, the content of photosynthetic pigment, low temperature fluorescence spectrum (77K) and electron transport rate, were compared with those of the wild type. It was found that the change in the ratio of light-harvesting pigments in the mutant led to more efficient light energy transfer and usage in mutant than in the wild type. This may be the reason why the mutant had higher photosynthesis and growth rates.

Demonstration of directed XOR/XNOR logic gates using two cascaded microring resonators

Submitted by 张磊 (zhanglei@semi.ac.cn) on 2010-06-03T13:47:18Z No. of bitstreams: 1 Directed XOR_XNOR.pdf: 556366 bytes, checksum: c67167a8648c1242c1eec35d6cca24f6 (MD5)