质量好的美缝剂，我们的主要原材料均来自国际化工行业的ZM的供应商，确保了产品的可靠性。
使用知道APP，立即抢鲜体验。你的手机镜头里或许有别人想知道的。我们会通过消息、等方式尽快将结果通知您。播放视频需要启用 JavaScript，推荐使用支持HTML5的访问。
Science, 20 AUGUST 2021, VOL 373, ISSUE 6557《科学》2021年8月20日，第373卷，6557期地球科学GeoscienceLarge-sample evidence on the impact of unconventional oil and gas development on surface waters非常规油气开发对地表水影响的大样本证据
我们的研究表明，冰川和积雪是HK河流的重要组成部分，对印度河流域的水文重要性大于恒河和雅鲁藏布江流域。除了一些例外情况和很大的不确定性外，预计到本世纪50年代，河流径流总量、冰川融化和流量的季节性都将增加。关键知识缺口严重影响不同径流成分的建模贡献、未来径流量和季节性。因此，需要基于野外观测和遥感的综合方法和模型去研究这些问题。▲ AbstractUnderstanding the response of Himalayan-Karakoram (HK) rivers to climate change is crucial for ~1 billion people who partly depend on these water resources. Policy-makers tasked with sustainable water resources management require an assessment of the rivers’ current status and potential future changes. We show that glacier and snow melt are important components of HK rivers, with greater hydrological importance for the Indus basin than for the Ganges and Brahmaputra basins. Total river runoff, glacier melt, and seasonality of flow are projected to increase until the 2050s, with some exceptions and large uncertainties. Critical knowledge gaps severely affect modeled contributions of different runoff components, future runoff volumes, and seasonality. Therefore, comprehensive field observation–based and remote sensing–based methods and models are needed.
▲ AbstractThe interfaces of perovskite solar cells (PSCs) are important in determining their efficiency and stability, but the morphology and stability of imbedded perovskite-substrate interfaces have received less attention than have top interfaces. We found that dimethyl sulfoxide (DMSO), which is a liquid additive broadly applied to enhance perovskite film morphology, was trapped during film formation and led to voids at perovskite-substrate interfaces that accelerated the film degradation under illumination. Partial replacement of DMSO with solid-state carbohydrazide reduces interfacial voids. A maximum stabilized power conversion efficiency (PCE) of 23.6% was realized for blade-coated p-type/intrinsic/n-type (p-i-n) structure PSCs with no efficiency loss after 550-hour operational stability tests at 60°C. The perovskite mini-modules showed certified PCEs of 19.3 and 19.2%, with aperture areas of 18.1 and 50.0 square centimeters, respectively.
Nd(IV):镧系的价除了Ce,Pr,Tb的之外都是很不稳定的，但是在剩下的元素中Nd,Dy相对更稳定。因此曾经有过NdO2与水溶液中Nd(IV)化合物的报道，虽然未能重复。将BaCeO3与Nd2O3共热，固体变黑，表明有少量Nd（lV）