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Your search keyword '"Shen, Shigang"' showing total 450 results
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450 results on '"Shen, Shigang"'

23. TEMPO as Hydrogen Atom Transfer Catalyst in Enhancing Iminyl Radical Cyclization of O-Acetyl Oxime toward Phenanthridines and Isoquinolines

Author

Liu, Zi-Xuan, Li, Hao-Yuan, Shen, Shigang, Yang, Xiu-Long, and Niu, Xiaoying

Abstract

Herein, we present a strategy for promoting the cyclization of ortho-aryl or orthoalkenyl arylketone oxime ethers C–N bonds using TEMPO as a direct hydrogen atom transfer (HAT) catalyst. The reaction employs a green solvent and requires no introduction of metal additives. It only needs catalytic amount of TEMPO to drive the reaction. Gram-scale reaction yields the corresponding products with satisfactory yields, providing a novel and efficient method for the synthesis of phenanthridine and isoquinoline derivatives.

Published
2024
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29. Determination of Organic Carbon Content of Corn Stalk: A Casestudy in Laiyuan County, Hebei Province

Author

Liu Zhuohan, Shen Shigang, Dong Jiangxue, Yao Na, Wu Qianwen, and Fu Zhaowei

Subjects
Environmental sciences, GE1-350
Abstract

Organic carbon is an important component of straw, which plays an important role in the hydrothermal conditions, physical and chemical properties of straw. In order to discuss the transformation of corn straw in straw and the influence on straw fertility, this paper selects 6 villages in Laiyuan County, Hebei Province as the study area, and uses straw organic carbon analyzer to determine the organic carbon content of straw samples before and after corn straw treatment in the study area. The results show that: The organic carbon content of corn straw in Laiyuan County is 50.62%~55.01%, with an average of 53.46%. In Laiyuan County, the organic carbon content is high in the northern townships, low in the western townships and low in the southern townships. From the spatial distribution of organic carbon content of straw, the organic carbon content of corn straw in the northern area of Laiyuan County is high, while the organic carbon content in the western area is low. The conversion of corn straw in straw and its effect on straw fertility are related to the type of straw, the amount of straw and the planting method.

Published
2023
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45. Protecting Rural Large Old Trees with Multi-Scale Strategies: Integrating Spatial Analysis and the Contingent Valuation Method (CVM) for Socio-Cultural Value Assessment.

Author

Yao, Na, Gu, Chenxi, Qi, Jinda, Shen, Shigang, Nan, Bo, and Wang, Hongjie

Subjects
CONTINGENT valuation, RURAL poor, WILLINGNESS to pay, SOCIAL bonds, U.S. dollar, TREES
Abstract

Governments are faced with the unique challenge of implementing large-scale and targeted protection against the global decline of large old trees. Incorporating socio-cultural values and encouraging public involvement are important parts of conservation policy. However, current studies on the socio-cultural valuation of large old trees are still limited, and how rural residents perceive the human-related value of large old trees remains largely unknown. Using a quantitative, spatial analysis and the contingent valuation method (CVM), we tried to explore a multi-scale socio-cultural valuation and protection framework based on a case study of Baoding City and Xiongan New Area in North China. The results showed that (1) the scattered large old trees in the study area were generally at a relatively younger stage, showing normal growth performance but having poor living environments. Some 96.99% of the trees resided in the countryside. Their distribution showed an agglomerative pattern with several clusters. (2) The species richness was relatively lower than that reported in urban areas. The species diversity had an obvious high–low gradient from the mountain to plain areas. Most endemic species were found in habitats of the village fringe (VF) and government/community/institutional ground (GC). (3) The mean willingness to pay (WTP) for the socio-cultural value of scattered large old trees was CNY 132.48 per year per person (1 US dollar equals about 7.2 CNY) of all the respondents, and CNY 84.30 per year per person with regard to farmers, which is relatively higher than that reported in large cities. (4) Economic income, gender, age, education level, place of residence, diameter at breast height, and tree habitat were factors that significantly influenced the WTP, among which economic income was the most significant. (5) The importance ranking of socio-cultural value connotations perceived by rural residents was as follows: spiritual attachment and homesickness > fengshui > social bond > witnessing history > education > creative inspiration. (6) The annual gross value was estimated to be CNY 349 million in the study area, and CNY 169,500 for a single tree on average. Based on the case study, a conceptual framework for socio-cultural value assessment and multi-scale protection of large old trees was proposed, which can provide references for the improvement of current conservation policies from both quantitative and qualitative perspectives, and give insights into rural revitalization strategies in China. [ABSTRACT FROM AUTHOR]

Published
2024
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