http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Di´az, M.J. (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
The multiple merger assembly of a hyperluminous obscured quasar at redshift 4.6
Dí,az-Santos, T.,Assef, R. J.,Blain, A. W.,Aravena, M.,Stern, D.,Tsai, C.-W.,Eisenhardt, P.,Wu, J.,Jun, H. D.,Dibert, K.,Inami, H.,Lansbury, G.,Leclercq, F. American Association for the Advancement of Scienc 2018 Science Vol.362 No.6418
<P><B>Mergers drive a powerful dusty quasar</B></P><P>Massive galaxies in the early Universe host supermassive black holes at their centers. When material falls toward the black hole, it releases energy and is observed as a quasar. Astronomers found a population of powerful distant quasars that are obscured by dust, but it has been unclear how they are formed. Díaz-Santos <I>et al.</I> observed the dust-obscured quasar WISE J224607.56-052634.9 at submillimeter wavelengths, finding three small companion galaxies connected to the quasar by bridges of gas and dust. They inferred that galaxy mergers can provide both the raw material to power a quasar and large quantities of dust to obscure it.</P><P><I>Science</I>, this issue p. 1034</P><P>Galaxy mergers and gas accretion from the cosmic web drove the growth of galaxies and their central black holes at early epochs. We report spectroscopic imaging of a multiple merger event in the most luminous known galaxy, WISE J224607.56−052634.9 (W2246−0526), a dust-obscured quasar at redshift 4.6, 1.3 billion years after the Big Bang. Far-infrared dust continuum observations show three galaxy companions around W2246−0526 with disturbed morphologies, connected by streams of dust likely produced by the dynamical interaction. The detection of tidal dusty bridges shows that W2246−0526 is accreting its neighbors, suggesting that merger activity may be a dominant mechanism through which the most luminous galaxies simultaneously obscure and feed their central supermassive black holes.</P>
-
Soda Pulping of Sunflower Stalks. Influence of Process Variables on the Resulting Pulp
Lo´pez, F.,Eugenio, M.E.,Di´az, M.J.,Nacimiento, J.A.,Garci´a, M.M.,Jime´nez, L. 한국공업화학회 2005 Journal of Industrial and Engineering Chemistry Vol.11 No.3
This paper discusses the influence of independent variables in the pulping of sunflower stalks [viz. the effects that the alkali concentration (5~15%), anthraquinone concentration (0~0.1%), temperature (125~175℃), time (30~90 min), and the liquid/solid ratio (4~8) have on the yield, holocellulose content, lignin content, and kappa number of the resulting pulp]. By using a central composite factorial design, equations relating each dependent variable to the different independent variables were derived; they reproduced the experimental results for the dependent variables with errors less than 15%. The Kappa number values were reproduced with errors less than 19%. This study confirms the feasibility of applying a soda-anthraquinone pulping process to sunflower stalks. Using a short time, a low liquid/solid ratio, a high temperature and anthraquinone concentration, and a medium-to-high alkali concentration (13.9%), we obtained values for holocellulose, lignin, and kappa number that differ by less than 13.7, 14.9, and 20.1%, respectively, from the optimum values (viz. 97.8%, 3.9%, and 14.9, respectively). However, the yield is 36.1% lower than the optimum value (68.7%). These conditions provide a pulp having acceptable properties. According to the results, paper sheets can be obtained that have characteristics similar to those obtained using similar alternative raw materials, and considerable savings should occur on operating costs.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
