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31.
Cell division during regeneration in Hydra 总被引:1,自引:0,他引:1
32.
W. Wang C. Sprague M. Yokoyama H. S. Park 《Cellular and molecular life sciences : CMLS》1973,29(7):871-872
Zusammenfassung Es wird eine Radial-Immun.-Diffusionsmethode verwendet, um durch Vergleich der IgM-Antikörper im Nabelschnurblut zu bestimmen, ob im den homologen mütterlichen Proben eine asymptotische Infektion stattgefunden hat. Es ergab sich, dass das benutzte Verfahren nicht zur Klärung der gestellten Frage geeignet ist.
This study was supported by a Kapiolani Maternity Hospital Research Grant and the Mrs. Lois A. Mayer Family Fund.
Acknowledgment. The authors indebted to Mrs.L. Hann, MT (ASCP) for her technical assistance and Mr.V. T. Oi for his critical review of this paper. 相似文献
This study was supported by a Kapiolani Maternity Hospital Research Grant and the Mrs. Lois A. Mayer Family Fund.
Acknowledgment. The authors indebted to Mrs.L. Hann, MT (ASCP) for her technical assistance and Mr.V. T. Oi for his critical review of this paper. 相似文献
33.
The volcanic layer may be only 200 m thick at 45 degrees N and oxidation of titanomagnetite may be responsible for the decrease in amplitude of the magnetic anomalies away from the ridge axis. 相似文献
34.
35.
Hydrogen is a promising energy carrier that can potentially facilitate a transition from
fossil fuels to sustainable energy sources without producing harmful by-products. Prior to realizing
a hydrogen economy, however, viable hydrogen storage materials must be developed. Physical
adsorption in porous solids provides an opportunity for hydrogen storage under low-stringency
conditions. Physically adsorbed hydrogen molecules are weakly bound to a surface and, hence, are
easily released. Among the various surface candidates, porous carbons appear to provide efficient
hydrogen storage, with the advantages that porous carbon is relatively low-cost to produce and is
easily prepared. In this review, we summarize the preparation methods, pore characteristics, and
hydrogen storage capacities of representative nanoporous carbons, including activated carbons,
zeolite-templated carbon, and carbide-derived carbon. We focus particularly on a series of
nanoporous carbons developed recently: metal–organic framework-derived carbons, which exhibit
promising properties for use in hydrogen storage applications. 相似文献
36.
Haislip JB Nysewander MC Reichart DE Levan A Tanvir N Cenko SB Fox DB Price PA Castro-Tirado AJ Gorosabel J Evans CR Figueredo E MacLeod CL Kirschbrown JR Jelinek M Guziy S de Ugarte Postigo A Cypriano ES LaCluyze A Graham J Priddey R Chapman R Rhoads J Fruchter AS Lamb DQ Kouveliotou C Wijers RA Bayliss MB Schmidt BP Soderberg AM Kulkarni SR Harrison FA Moon DS Gal-Yam A Kasliwal MM Hudec R Vitek S Kubanek P Crain JA Foster AC Clemens JC Bartelme JW Canterna R Hartmann DH Henden AA Klose S 《Nature》2006,440(7081):181-183
Gamma-ray bursts (GRBs) and their afterglows are the most brilliant transient events in the Universe. Both the bursts themselves and their afterglows have been predicted to be visible out to redshifts of z approximately 20, and therefore to be powerful probes of the early Universe. The burst GRB 000131, at z = 4.50, was hitherto the most distant such event identified. Here we report the discovery of the bright near-infrared afterglow of GRB 050904 (ref. 4). From our measurements of the near-infrared afterglow, and our failure to detect the optical afterglow, we determine the photometric redshift of the burst to be z = 6.39 - 0.12 + 0.11 (refs 5-7). Subsequently, it was measured spectroscopically to be z = 6.29 +/- 0.01, in agreement with our photometric estimate. These results demonstrate that GRBs can be used to trace the star formation, metallicity, and reionization histories of the early Universe. 相似文献
37.
Metallic transport in polyaniline 总被引:2,自引:0,他引:2
Despite nearly three decades of materials development, the transport properties in the 'metallic state' of the so-called conducting polymers are still not typical of conventional metals. The hallmark of metallic resistivity--a monotonic decrease in resistivity with temperature--has not been obtained at temperatures over the full range below room temperature; and a frequency dependent conductivity, sigma(omega), typical of metals has also not been observed. In contrast, the low-temperature behaviour of 'metallic' polymers has, in all previous cases, exhibited an increase in resistivity as temperature is further decreased, as a result of disorder-induced localization of the charge carriers. This disorder-induced localization also changes the infrared response such that sigma(omega) deviates from the prediction of Drude theory. Here we report classic metallic transport data obtained from truly metallic polymers. With polyaniline samples prepared using self-stabilized dispersion polymerization, we find that for samples having room-temperature conductivities in excess of 1,000 S cm(-1), the resistivity decreases monotonically as the temperature is lowered down to 5 K, and that the infrared spectra are characteristic of the conventional Drude model even at the lowest frequencies measured. 相似文献
38.
T. Kashimoto D. Park R. P. Ebstein M. Goldstein M. Levitz S. Yaverbaum 《Cellular and molecular life sciences : CMLS》1974,30(11):1363-1364
Résumé Les auteurs décrivent une méthode radioimmunologique de dosage de la DH utilisant un anticorps lié de façon covalente à des billes de verre. La technique a été appliquée à la mesure de la DH dans les surrénales et différentes régions du cerveau de buf. Les principaux avantages de cette méthode sont sa relative facilité d'emploi, sa précision et sa haute spécificité.
This work was supported by USPHS Grants Nos. MH-02717, NS-06801 and CA-02071 and NSF Grant No. GB-27603.Acknowledgements: The authors wish to express their appreciation for the technical assistance of Susan Kadner and William P. Vann. 相似文献
This work was supported by USPHS Grants Nos. MH-02717, NS-06801 and CA-02071 and NSF Grant No. GB-27603.Acknowledgements: The authors wish to express their appreciation for the technical assistance of Susan Kadner and William P. Vann. 相似文献
39.
Most recently produced wind generators use variable-speed systems for high-efficiency operation and low mechanical stress.In this study of a variable-speed standalone system that uses a synchronous machine,a power converter for the system was developed and tested.The maximum power points were approximated in a line according to the wind speed changes,and the linear approximation MPPT algorithm was used to determine the duty ratio that corresponds to the intersection point of the observed power and linearized line using the power generated from the generator at a point.With the fabricated converter,it was verified that the voltage,current and theta were normal with the varied load current. 相似文献
40.
LEE Jun-Hee PARK Su-A PARK KoEun KIM Jae-Hyun KIM Kyung-Shik LEE Jihye Kim WanDoo 《科学通报(英文版)》2010,55(1):94-98
In this paper, we design and fabricate a 3D scaffold using rapid prototyping (RP) technology for tissue engineering. The scaffold should have a three-dimensional interconnected pore network. We fabricate a polycaprolactone (PCL) scaffold with interconnecting pores and uniform porosity for cell ingrowth using a 3D plotting system. In order to keep the three dimensional shape under mechanical loading while implanted, we design an oscillating nozzle system to increase elastic modulus and yield strength of PCL ... 相似文献