2019-02-01

封面图展示的是位于斯洛伐克布拉迪斯拉发的斯洛伐克理工大学化学与食品技术学院门前矗立着的由卡洛·拉科创作的德米特里·门捷列夫的雕塑和他的元素周期表柱。从图中可以看到，这些柱从雕塑的头部向外辐射展开。2019年是门捷列夫首次发表这一有关化学元素的组织原则与预测工具表150周年。

This sculpture by Karol Lacko of Dmitri Mendeleev and the columns of his periodic table, radiating outward from his head, stands in front of the Faculty of Chemical and Food Technology of the Slovak University of Technology in Bratislava, Slovakia. This year marks the 150th anniversary of Mendeleev's initial publication of the table as organizing principle and predictive tool.

2019-02-08

数千年来，安第斯山脉的农民种植着各种各样色彩缤纷的当地特产马铃薯，如封面图中展示的“母狮”“蒂尼卡”和“塔曼娜”等品种。地方品种和野生物种拥有的遗传多样性，有可能是开发新的马铃薯品种的关键，这也是帮助农民适应气候变化及其他挑战所必需的。

For thousands of years, Andean farmers have cultivated colorful landraces of domesticated potatoes, such as lioness, tunica, and tarmeña shown in this arrangement. Landraces and wild species hold genetic diversity that could be key to developing new potato varieties, which are needed to help farmers adapt to climate change and other challenges.

2019-02-15

封面图展示的是在冬雪中的一只北美野兔，它们会从棕色的皮毛蜕换成白色的皮毛，从而在积雪覆盖的环境中保持伪装。在一些动物物种中已经进化出了这种季节性的适应能力，但随着积雪持续时间的减少，这可能会导致伪装的不匹配性。关注生态和进化基因组学的高登研究会议将于2019年7月14—19日在美国新罕布什尔州举行。

In winter, snowshoe hares (Lepus americanus) molt from brown to white coats to maintain camouflage in snow-covered environments. This seasonal adaptation has evolved in several animal species and can result in camouflage mismatch as snow duration decreases. The Gordon Research Conference on Ecological and Evolutionary Genomics will be held from 14 to 19 July 2019 in Manchester, New Hampshire.

2019-02-22

封面上描绘的是在绝对零度以上仅仅几十亿分之一度的温度下产生的分子，表现出奇异的量子性质。钾-铷分子的经典气体具有化学反应性（图中上半部分）；当气体被冷却到低温时，集合量子效应会控制分子的运动和碰撞，抑制反应性，并能够使稳定的简并分子气体形成（图中下半部分）。

Molecules produced at just a few billionths of a degree above absolute zero display exotic quantum properties. A classical gas of potassium-rubidium molecules is chemically reactive (top); when the gas is cooled to low temperatures, collective quantum effects govern how molecules move and collide, suppressing reactivity and enabling formation of a stable, degenerate molecular gas (bottom).