The Fangshan landslide was a rainfall-induced landslide that occurred in a volcanic area in the Fangshan scenic spot, Nanjing, Jiangsu, China. On 25 October 2016, after approximately 10 days of continuous rainfall, a shallow landslide rapidly developed, which triggered slow movement of deep mudstone rock. According to the characteristics of the landslide body, measures such as anti-slide piles, anchor cables and drainage were used to reinforce the landslide. Active drainage measures included arranging plant growth zones at the trailing edge of the landslide, and passive drainage measures included arranging pumping wells at the trailing edge of the landslide. It is worth emphasizing that the Fangshan landslide was the first example of a landslide in Jiangsu Province, China that was treated by actively lowering the water pressure. After landslide treatment from 16 May 2017 to 21 January 2018, the Fangshan landslide tended to be stable. However, the stable landslide was reactivated by the rise in groundwater level caused by rainfall and pumping well damage and underwent accelerated downward sliding in July 2020. The Fangshan landslide has caused great damage to the roads and buildings of Fangshan scenic spot, with a direct loss of RMB 6 million and an indirect loss of RMB 95 million. This article discusses the development process of the shallow soil landslide and the underlying deep mudstone rock landslide. The influence of groundwater level variation on the deformation of the shallow soil landslide and deep mudstone rock landslide of the Fangshan landslide are also discussed.
Highly functionalized xanthenes possess an impressive range of bioactivities and daunting synthetic challenge due to their unique ring systems and stereocenters. Here, we report an unprecedented ketyl radicals‐induced skeletal rearrangement reaction of spirodihydrobenzofurans, enabled by zero‐valent iron as reducing agents via photoredox catalysis, facilitating the facile preparation of various highly functionalized xanthenes. The features of this protocol include high chemo‐ and regioselectivity, exceptionally mild conditions, a broad substrate scope, scalability to gram‐scale quantities, and consistent delivery of good to excellent yields. Mechanistic studies rationalize the function of this zero‐valent iron‐based reactivity in radical generation. Notably, this reaction was applied to the first asymmetric total synthesis of the complex polycyclic xanthene ent‐myrtucomvalones E‐F. Moreover, this work led to the discovery of an agent with highly effective antiosteosarcoma activity in vitro and in vivo, potentially paving the way for the development of new xanthene‐based candidates for osteosarcoma treatment.
With the development of the semiconductor devices, advanced technology node requires both tight critical dimension (CD) control and enough photo process window. In many circumstances, the unstable substrate can have great influence on photo CD, causing large variation in the performance of device. Although there have been intensive studies on this topic, we attempt to discuss the physical mechanism underneath within this paper, and to illustrate the phenomenon observed in the function layers. This paper is to investigate the contributions of several different factors on photo CD variation and discuss the possible controlling methods. Different substrate deposition methods and various surface treatment methods are applied in our experiment and the corresponding influence on CD variations are investigated. Results indicate that the surface treatments play important roles in controlling CD variation. The underlying mechanism is discussed.
Using sunflower oil as the oil matrix, the antioxidant effects and types of interactions of three natural components, α-tocopherol, β-carotene and epigallocatechin gallate (EGCG), were investigated and the kinetic model of oxidation reaction was established. The results showed that the ability of the three antioxidants to scavenge DPPH radicals was ranked as EGCG > β-carotene > α-tocopherol in the concentration range of 0~100 mg/kg. 15 samples were obtained by combining two of three natural components. When the concentration ratios of β-carotene and EGCG were 1:20 and 1:7.5, α-tocopherol and EGCG were 1:13.3, 1:6, and 1:2, and α-tocopherol and β-carotene were 1:0.2 and 1:0.05, the type of interaction was synergistic, while the rest of the samples showed antagonistic effects. The sample with a 1:13.3 concentration of α-tocopherol and EGCG showed the longest induction period, the lowest oxidation rate constant, the highest activation energy, the best oxidative stability, and the longest shelf life at different temperatures. This compounded natural antioxidant was the most favorable for the stability of sunflower oil. This provides some theoretical basis for the development and application of compounded natural antioxidants in vegetable oils.
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