2024-03-01
封面圖上是詹姆斯·韋布空間望遠(yuǎn)鏡拍攝到的獵戶座星云條狀區(qū)域紅外圖像,它將獵戶星云中含有冷分子氣體的部分(左下)與含有熱等離子體的部分(右上)分隔開(kāi)來(lái)。后者被來(lái)自大質(zhì)量恒星(位于圖像之外)的紫外線輻射電離。強(qiáng)烈的紫外線輻射場(chǎng)將該區(qū)域年輕恒星周圍的原行星盤加熱后,分散了行星形成所需的氣體。
This JWST infrared imageshows the Orion Bar, whichseparates parts of the OrionNebula containing cool molecularg a s ( l o w e r l e f t ) f r om t h o s econtaining hot plasma (upperright). The latter are ionized byultraviolet radiation from massivestars (located beyond the image).The strong ultraviolet radiationfield heats protoplanetary disksa r o u n d y o u n g s t a r s i n t h i sregion, dispersing the gas neededfor planet formation.
2024-03-08
封面圖展示的是一條粗鯊(粗皮棘鮫科),它屬于深海鯊魚的一個(gè)小科,只有5 個(gè)物種。其中3 個(gè)物種因過(guò)度捕撈而面臨滅絕的威脅。由于它們生長(zhǎng)緩慢、幼仔很少,再加上以鯊魚卵為食的特殊飲食習(xí)慣,使得這群深海鯊魚很容易受到過(guò)度捕撈的影響,因而非常有必要為它們提供躲避人類活動(dòng)的庇護(hù)所。
Rough sharks (Oxynotidae)are a small family of deepwatersharks consisting of five species.Three species are threatened withextinction from overfishing. Theirslow growth and few young,combined with an unusual dietof shark eggs, make this groupof deepwater sharks susceptibleto overfishing, which highlightsthe need to provide refuge fromhuman activities.
2024-03-15
封面展示的是在2024年2 月8 日, 熔巖流的前緣摧毀了冰島格林達(dá)維克鎮(zhèn)附近的一條道路。該地區(qū)一系列破壞性的火山噴發(fā)和地面破裂事件造成了重大社會(huì)問(wèn)題。超快速巖漿流可以在地下發(fā)生而無(wú)須噴發(fā), 就像2023 年11月10 日影響格林達(dá)維克的第一起事件一樣。
T h e l e a d i n g e d g e o f alava flow destroys a road on 8February 2024 near the town ofGrindavík, Iceland. A series ofdamaging eruptions and groundfracturingepisodes in the areaprovide a major societal challenge.Ultrarapid magma flow can occurin the subsurface without aneruption, as in the first of theevents that influenced Grindavíkon 10 November 2023.
2024-03-22
封面圖展示的是一只熱帶袖蝶,它表現(xiàn)出了多種表示警戒的斑紋,它們?cè)谶x擇配偶時(shí)也會(huì)使用這些斑紋。研究人員現(xiàn)已將詩(shī)神袖蝶喜歡紅色的行為偏好與一種特定基因聯(lián)系起來(lái)了,該基因通過(guò)雜交與其他具有相似顏色的物種進(jìn)行共享。
T r o p i c a l H e l i c o n i u sbutterflies display a diversityof warning patterns that theyalso use during mate choice.Researchers have now linkedbehavioral preferences for the redcolors of Heliconius Melpomene(shown here) to a specific gene,which has been shared with otherspecies with similar colors throughhybridization.
(陶 陶 編譯)