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61.
逼近Banach空间中渐近非扩张映象的不动点   总被引:10,自引:0,他引:10       下载免费PDF全文
设E是一致凸Banach空间,C是E的非空闭凸子集, T:C→C是具有不动点的渐近非扩张映象. 该文证明了, 在某些适当的条件下, 由下列修改了的Ishikawa迭代程序所定义的序列{x\-n},\$\$x\-\{n+1\}=t\-nT\+n(s\-nT\+nx\-n+(1-s\-n)x\-n)+(1-t\-n)x\-n,\$\$弱收敛到T的不动点, 其中{t\-n},{s\-n}是区间\[0,1\]中满足某些限制的实数列.  相似文献   
62.
变加速直线运动黑洞中Weyl中微子的Hawking辐射   总被引:1,自引:0,他引:1       下载免费PDF全文
吴双清  曾瑜  蔡勖  闫沐霖 《物理学报》2003,52(6):1340-1345
利用推广的乌龟坐标变换法研究了作变加速直线运动的Kinnersley黑洞中Weyl中微子的量子 热效应,导出了局部的事件视界面方程和Hawking温度以及中微子的热辐射谱.结果表明视界 的位置和温度不仅随时间变化,而且明显依赖于方位角. 关键词: Hawking辐射 Weyl中微子 动态Kinnersley黑洞 广义乌龟坐标变换  相似文献   
63.
郭恒  苏运波  李和平  曾实  聂秋月  李占贤  李志辉 《物理学报》2018,67(4):45201-045201
以临近空间高超声速飞行器以及航天器再入大气环境飞行过程"黑障"问题的研究为背景,进行了多相交流电弧放电实验装置的物理设计,建立了六相交流电弧等离子体实验平台(MPX-2015),在背景压力为500 Pa的亚大气压条件下获得了最大直径和长度分别达到14.0 cm和60.0 cm的等离子体射流.研究了工作气体流量、真空腔压强、电极间距以及弧电流等因素对等离子体自由射流和冲击射流特性的影响规律.结果表明:在实验参数范围内,真空腔压强对等离子体的射流特性影响最为显著,等离子体自由射流的长度和直径以及冲击钝体条件下的鞘套有效工作长度和厚度均随着压强的降低而增大;提高沿电极环缝注入的工作气体流量或弧电流亦有利于等离子体鞘套尺寸的增加.上述工作有助于进一步开展临近空间飞行器与其周围复杂介质环境间复杂的气动热效应和"黑障"问题的研究.  相似文献   
64.
Ito  Yoichiro  Clary  Robert  Witten  Jacob J.  Zeng  Yun 《Chromatographia》2012,75(19):1091-1097

A new preparative column for the vortex counter-current chromatograph was fabricated by making many (966) cylindrical separation units to a high-density polyethylene disk and then threading them with 6–40 taps. The resulting column had a total capacity of 364 mL. The performance of this vortex column was examined with three different two-phase solvent systems each using a set of suitable test samples: hexane–ethyl acetate–methanol–0.1 M hydrochloric acid (1:1:1:1, v/v) for the separation of DNP-amino acids; 1-butanol–acetic acid–water (4:1:5, v/v) for the separation of dipeptides; and hexane–acetonitrile–water (20:15:2, v/v) for the separation of Sudan dyes. Most of the separations show high partition efficiency of over a thousand theoretical plates, as expected based on the results previously obtained in preliminary separations with a small column. Overall, the results of the present study suggest that further improvement of the partition efficiency can be obtained by the modifying column configuration.

  相似文献   
65.
Recently, thioredoxin reductase as a target for treatment of tumors has attracted the attention of scientists. 1,2‐[Bis(1,2‐benzisoselenazolone‐3(2 H)‐ketone)]ethane (ethaselen, BBSKE, PCT: CN02/00412), designed and synthesized previously, is an effective thioredoxin reductase inhibitor; presently it is in phase II clinical trials, targeting gastric cancer, lung cancer and colon cancer. To seek more novel and effective anticancer drugs, we have developed many selenazole‐based compounds. Evaluation of the thioredoxin reductase inhibitory effect and investigation of the mechanism of anticancer drugs require abundant thioredoxin reductase, but since commercial thioredoxin reductase is expensive its use is often limited. Therefore, the preparation of thioredoxin reductase is necessary. Base on the above investigation, in this work we have prepared thioredoxin reductase and evaluated selenazole‐based compounds, and found that 44 compounds have high inhibitory effect on thioredoxin reductase with IC50 < 10 µ m , of which 16 compounds have IC50 values below 1 µ m . This is helpful in investigating and elucidating the mechanism of this kind of compound. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
66.

Abstract  

The title compounds 1-(4-aryl-5-triazolyl-2-thiazolyl)-3,5-diaryl-2-pyrazoline derivatives (3ac) were synthesized by reacting 3,5-diaryl1-thiocarbamoyl -2-pyrazoline 1 with 2-bromo-1-aryl-2-(1H-1,2,4-triazol-1-yl) ethanones 2 in boiling ethanol. Their structures were characterized by IR, 1H-NMR, MS spectroscopic data and elementary analyses. The structure of compound (3a), C26H18Cl2N6S, was conclusively established with X-ray crystal structure analysis. It crystallizes in the Orthorhombic space group Pna2(1), with a = 17.8160(5), b = 18.9125(7), c = 14.7926(4), α = 90°, β = 90°, γ = 90°and Dc = 1.379 mg/m3 for Z = 8, V = 4984.3(3) ?, μ(Mo–Kα) = 0.372 mm, λ = 0.71070 ?, the final R = 0.0527 and wR = 0.1307 for 43309 observed reflections with I > 2σ(I). The structure is stabilized by weak C–H···N intramolecular hydrogen bonds and C–H···Cg p-ring intermolecular interactions and gives support to molecular packing stability in the unit cell.  相似文献   
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In the postgenome era, biology and medicine are rapidly evolving towards quantitative and systems studies of complex biological systems. Emerging breakthroughs in microfluidic technologies and innovative applications are transforming systems biology by offering new capabilities to address the challenges in many areas, such as single-cell genomics, gene regulation networks, and pathology. In this review, we focus on recent progress in microfluidic technology from the perspective of its applications to promoting quantitative and systems biomolecular analysis in biology and medicine.  相似文献   
70.
In Western blotting, a suitable loading control is indispensable for correcting errors in the total amount of loaded protein. Immunodetection of housekeeping proteins and total protein staining have traditionally been used as loading control methods. Direct Blue 71 (DB71) staining—a novel, sensitive, dye‐binding staining method compatible with immunodetection—may offer advantages over these traditional loading control methods. Three common neuroscientific samples (human plasma, human oligodendrocytes, and rat brain) were employed to assess DB71 staining as a loading control method for Western blotting. DB71, CBB, one traditional housekeeping protein, and one protein of interest were comparatively assessed for reliability and repeatability and linear dynamic range over 2.5–40 μg of protein loaded. DB71's effect on the reliability and repeatability and linear dynamic range of immunoreaction were also assessed. Across all three sample types, DB71 was either equivalent or superior to CBB and housekeeping protein‐based methods in terms of reliability and repeatability and linear dynamic range. Across all three sample types, DB71 staining did not impair the reliability and repeatability or linear dynamic range of immunoreaction. Our results demonstrate that the DB71 staining can be used as a destaining‐free alternative loading control method for Western blotting.  相似文献   
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