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971.
972.
Qiuhua Wu Ning Li Lihua Yang Ranxiao Tang Ruihuan Bian Tao Feng 《Mikrochimica acta》2007,157(3-4):189-192
A novel method for the determination of nucleic acid at nanogram levels was developed based on the measurement of resonance
light scattering (RLS) signals of 3,3′-dichlorobenzidine (DCB). In the Britton-Robinson buffer (pH 2.21), the weak light scattering
of DCB was greatly enhanced by addition of calf thymus DNA (ctDNA), the maximum RLS peak is at 346 nm and the enhanced intensity
of RLS is in proportion to the concentration of ctDNA. The linear range is 0.05–5 μg mL−1 for ctDNA, and the detection limit is 14 ng mL−1 (3σ). DNA in synthetic samples was analyzed with satisfactory results. 相似文献
973.
UNIQUENESS OF VISCOSITY SOLUTIONS OF FULLY NONLINEAR SECOND ORDER PARABOLIC PDE''''S 总被引:1,自引:0,他引:1
This paper investigates the maximum principle for viscosity solutions of fully nonlinear, second order parabolic, possibly degenerate partial differential equations. Using this maximum principle the anthor prove that viscosity solutions of initial and bo unoary value problem for parabolic equations are unique. 相似文献
974.
975.
976.
Juan Xie Yong Jing Hao Zhao Zhou Xiao Cai Meng Lan Yao Li Bian Yu Wei 《Research on Chemical Intermediates》2014,40(5):1937-1946
In this work, ZnO particles with different morphologies were successfully prepared by a simple solution route at low temperature. The products were characterized by SEM, EDS, XRD, TEM, HRTEM, SAED, TG–DTA and UV–Vis DRS. To further understand the formation processes of these ZnO particles, XRD analyses of the intermediates and concentration measurements of Zn(II) remaining in the reaction solution were made at regular intervals throughout the reactions. A possible formation mechanism is discussed. Photocatalytic activity of the as-prepared ZnO powders, evaluated by degradation of pentachlorophenol under UV irradiation, is found to be closely related to the particle morphology. 相似文献
977.
Xiang‐Cheng Bian Li Chen Jun‐Sheng Wang Yu‐Zhong Wang 《Journal of polymer science. Part A, Polymer chemistry》2010,48(5):1182-1189
A series of thermotropic liquid crystalline polyesters containing phosphorus and aromatic ether groups (TLCP‐AEs) were synthesized from p‐acetoxybenzoic acid (p‐ABA), terephthalic acid (TPA), 4,4′‐oxybis(benzoic acid) (OBBA), and acetylated 2‐(6‐oxid‐6H‐dibenz(c,e) (1,2) oxaphosphorin 6‐yl) 1,4‐benzenediol (DOPO‐AHQ). The chemical structure and the properties of TLCP‐AEs were characterized by Fourier‐transform spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1H NMR), differential scanning calorimetry (DSC), X‐ray diffraction (XRD), thermogravimetry analysis (TGA), scanning electronic microscopy (SEM), polarizing optical microscopy (POM), limiting oxygen index, and UL‐94 tests, respectively. The results showed that TLCP‐AEs had low and broad mesophase temperatures (230–400 °C). TLCP‐AEs also showed excellent thermal stability; their 5%‐weight‐loss temperatures were above 440 °C and the char yields at 700 °C were higher than 45 wt %. All TLCP‐AE polyesters exhibited high flame retardancy with a LOI value of higher than 70 and UL‐94 V‐0 rating. The SEM observation revealed that TLCP‐AEs had good fibrillation ability. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1182–1189, 2010 相似文献
978.
The fast parallel restoration (FPR) scheme is proposed to achieve the fast setup of restoration label switched path (LSP) in the distributed optical networks. The scheme is derived by dividing the whole restoration LSP into several segments of sub-LSP and triggering each sub-LSP along the new route to finish the signaling procedure concurrently, and subsequently merging all sub-LSPs into a whole LSP. The theoretical analysis and simulation results show that the FPR scheme outperforms the other two typical restoration schemes in terms of connection setup time. 相似文献
979.
尽管类比不能代替论证,但可以为理解新知识、概念和规律提供依托,做为一种"从特殊推到特殊的科学方法"在物理学中有着广泛的应用.现将中学物理解题中常见的类比推理方法归纳整理如下. 相似文献
980.
Isolation and purification of recombinant human plasminogen Kringle 5 by liquid chromatography and ammonium sulfate salting‐out 下载免费PDF全文
In this work, a novel method was established to isolate and purify Human plasminogen Kringle 5 (HPK5) as a histidine‐tagged fusion protein expressed in Escherichia coli BL21 (DE3). This method consisted of sample extraction using a Ni‐chelated Sepharose Fast‐Flow affinity column, ammonium sulfate salting‐out and Sephadex G‐75 size‐exclusion column in turn. The purity analysis by SDS–PAGE, high‐performance size‐exclusion and reversed‐phase chromatographies showed that the obtained recombinant fusion HPK5 was homogeneous and its purity was higher than 96%; the activity analysis by chorioallantoic membrane model of chicken embryos revealed that the purified recombinant HPK5 exhibited an obvious anti‐angiogenic activity under the effective range of 5.0–25.0 µg/mL. Through this procedure, about 19 mg purified recombinant fusion HPK5 can be obtained from 1 L of original fermentation solution. Approximate 32% of the total recombinant fusion HPK5 can be captured and the total yield was approximately 11%. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献