Supermassive Black Holes in Galactic Nuclei: Past, Present and Future Research

This review discusses the current status of supermassive black hole research, as seen from a purely observational standpoint. Since the early ‘90s, rapid technological advances, most notably the launch of the Hubble Space Telescope, the commissioning of the VLBA and improvements in near-infrared speckle imaging techniques, have not only given us incontrovertible proof of the existence of supermassive black holes, but have unveiled fundamental connections between the mass of the central singularity and the global properties of the host galaxy. It is thanks to these observations that we are now, for the first time, in a position to understand the origin, evolution and cosmic relevance of these fascinating objects.This revised version was published online in July 2005 with a corrected cover date.     

运动技术典范 福特ST的前世今生

<正>2002年,第一代福克斯ST车型一一福克斯ST搭载了代表当时福特先进发动机的代表2.0升自然吸气Duratec发动机,最大动力输出为170马力(约125千瓦),因此该车型也被称为福克斯S T170。2012年,作为福特旗下首款全球高性能车型,全新福克斯ST搭载了福特广受赞誉的2.0升EcoBoost发动机,输出动力比之前提升近50%,达到184千瓦。除了输出功率的提高和能吸引全球车迷的动     

勾起上海记忆的点心

<正>你记忆中的上海是什么样的?温情贤淑的女子?风情万种的万国建筑?又或者是那些一口一个的老上海点心?优雅与精致充满着这座城市,让我们用生煎馒头、桂花糖年糕、油墩子、排骨年糕这些上海人的"心头好"来启发潜藏在我们内心深处许久的上海记忆。     

如何爱上威士忌

威士忌是真正属于男人的酒,尘世的烟火气味掩饰不了它的天生神韵,如果你从心里接受了它,一生都会是它的信徒,因为它能渗透到你的生命里去。如何鉴别优质威士忌1色泽:拿酒杯时应该捏住杯子的下方杯脚,而不能托着杯壁。因为手指的温度会让杯中的酒发生微妙的变化。在灯光下仔细观察,可以在酒杯的背后衬上一张白纸作为背景。威士忌的颜色有很多种,从深琥珀色到浅琥珀色都有。酒的色泽和威士忌在橡木桶里存放时间的长短密切相关。一般来说,存放时间越长,威士忌的色泽就     

The influence of microgravity on invasive growth in Saccharomyces cerevisiae

This study investigates the effects of microgravity on colony growth and the morphological transition from single cells to short invasive filaments in the model eukaryotic organism Saccharomyces cerevisiae. Two-dimensional spreading of the yeast colonies grown on semi-solid agar medium was reduced under microgravity in the Σ1278b laboratory strain but not in the CMBSESA1 industrial strain. This was supported by the Σ1278b proteome map under microgravity conditions, which revealed upregulation of proteins linked to anaerobic conditions. The Σ1278b strain showed a reduced invasive growth in the center of the yeast colony. Bud scar distribution was slightly affected, with a switch toward more random budding. Together, microgravity conditions disturb spatially programmed budding patterns and generate strain-dependent growth differences in yeast colonies on semi-solid medium.     

Innovations in mission architectures for exploration beyond low Earth orbit

Through the application of advanced technologies and mission concepts, architectures for missions beyond Earth orbit have been dramatically simplified. These concepts enable a stepping stone approach to science driven; technology enabled human and robotic exploration. Numbers and masses of vehicles required are greatly reduced, yet the pursuit of a broader range of science objectives is enabled. The scope of human missions considered range from the assembly and maintenance of large aperture telescopes for emplacement at the Sun-Earth libration point L2, to human missions to asteroids, the moon and Mars. The vehicle designs are developed for proof of concept, to validate mission approaches and understand the value of new technologies. The stepping stone approach employs an incremental buildup of capabilities, which allows for future decision points on exploration objectives. It enables testing of technologies to achieve greater reliability and understanding of costs for the next steps in exploration.     

和味蕾谈一场恋爱 上海浪漫的情侣餐厅

<正>虽然只要爱对了人,每天都是情人节,但在有纪念意义的节日里,拥有一个难忘的夜晚是每个女孩子的梦想。所以,既然约会去了圣地,那么一家浪漫的情侣餐厅作为后续自然是标准化流程啦。     

上海马路 让心情由阴转晴

<正>很多人说,优雅精致的申城总有一种从骨子里散发出来的小资情怀。任时光流逝,上海一直在展现着它的魅力,并保存着它的精髓,就像上海总有几条马路,总可以让你的心情由阴转晴。     

不一样的浪漫 上海约会圣地

<正>每一年情人节,现代的牛郎和织女们都会为了选择合适的"鹊桥"相会而伤透脑筋。其实,上海不止高楼林立,上海还是一座浪漫的城市,让我们钩织一张浪漫地图,为你在平凡的每一天谱写一出浪漫的‘爱情偶像剧"。     

Post: Polar stratospheric telescope

The tropopause, typically at 16 to 18 km altitude at the lower latitudes, dips to 8 km in the polar regions. This makes the cold, dry and nonturbulent lower stratosphere accessible to tethered aerostats. Tethered aerostats can fly as high as 12 km and are extremely reliable, lasting for many years. In contrast to free-flying balloons, they can stay on station for weeks at a time, and payloads can be safely recovered for maintenance and adjustment and relaunched in a matter of hours. We propose to use such a platform, located first in the Arctic (near Fairbanks, Alaska) and, potentially, later in the Antarctic, to operate a new technology 6-meter, diluted aperture telescope with diffraction-limited performance in the near infrared. Thanks to the low ambient temperature (220 K), thermal emission from the optics is of the same order as that of the zodiacal light in the 2 to 3 micron band. Since this wavelength interval is the darkest part of the zodiacal light spectrum from optical wavelengths to 100 microns, the combination of high resolution images and a very dark sky make it the spectral region of choice for observing the redshifted light from galaxies and clusters of galaxies at moderate to high redshifts.Affiliated to the Astrophysics Division, Space Science Department, European Space Agency