A Tentative Observation Design for Investigating the Morphology of Dark Matter in the Universe

Unlike the luminous objects observed, dark matter does not emit light but can be only detected by its gravitational effect. Modern cosmology considers that most matter in Universe is dark matter. However, it is still not clear what the dark matter was. Two origins have been proposed by astrophysicists, astrophysics candidates and particle physics candidates. The most differences are their morphology, the former are compact objects and the latter are dispersed. Under Einstein’s theory of general relativity, light bends as it passes near a compact object, creating a convergence effect like a lens. When background light source, intervening lense and the observer lie on a straight line, the brightness of the background source will be significantly magnified. In astrophysics, this effect is called microlensing. If compact dark matter is abundant in the universe, it is possible to frequently observe “microlensing” events when observing high redshift objects, i.e. the objects temporarily brighten for a certain time. The microlensing technique has been applied to study the dark matter in halo of Milky Way. The difficulty occurs when applying to study the cosmic dark matter as the crossing time of cosmic microlensing events is too long for observations. Apparent superluminal jets in bright quasars are idea background objects, significantly enhancing the efficiency of cosmic microlensing survey. Here, we tentatively designed an observational experiment to study the morphology of dark matter in Universe via statistics of microlensing events towards luminous quasars with apparent superluminal jets.

白蚁消化系统转化和降解木质纤维素酶研究进展

木质纤维素是地球上最丰富的有机聚合物,白蚁是古老但进化最成功的高效木质纤维素降解者之一。了解白蚁降解高度抗性植物聚合物的机制对工业上生物质能源转化和生物仿生设计有重要的借鉴和指导价值。白蚁和其共生微生物产生的木质纤维素酶在其转化利用木质纤维素上发挥着重要作用。本文从来源作用方面对白蚁自身及其肠道原虫、细菌和真菌产生的纤维素酶、木聚糖酶和漆酶等酶研究概况进行了总结,对其存在的问题和前景进行了展望。本综述有助于全面了解白蚁消化系统木质纤维素酶的基因种类、来源、分布、表达以及酶活性和功能。