Search

Your search keyword '"Sun, Changcheng"' showing total 126 results
Start Over Author "Sun, Changcheng"
126 results on '"Sun, Changcheng"'

11. Research on the coordinated development of tourism-urbanization-ecological environment——Taking Chongqing as an example

Author

Qing Yang, Zhang Fengtai, Wu Jianfeng, Sun Changcheng, Yang Xingyu, and Xiao Yuedong

Subjects
Environmental sciences, GE1-350
Abstract

The article analyzes the comprehensive development levels of the three subsystems of Chongqing's tourism, urbanization and ecological environment from 2000 to 2017, and the temporal evolution characteristics of the coordinated development of the three. The results show that: (1) The comprehensive evaluation index of Chongqing's tourism industry system and urbanization system is on the rise; the comprehensive ecological environment index showed an upward trend before 2008, and fluctuated greatly after 2008. (2) The degree of coupling and coordination of the three systems in Chongqing City generally shows a transformational trend of maladjustment recession-intermediate transition-coordination improvement. In the future, Chongqing should continue to deepen institutional reforms and continue to develop new tourism markets; improve transportation, promote enterprise transformation and upgrading, implement policies for talent introduction; strengthen the construction of environmental protection talents and capital investment, and vigorously develop ecological industries

Published
2021
Full Text
View/download PDF

18. Alpha rhythm of electroencephalography was modulated differently by three transcranial direct current stimulation protocols in patients with ischemic stroke

Author

Chen, Yuanyuan, Wang, Chunfang, Song, Peiqing, Sun, Changcheng, Zhang, Ying, Zhao, Xin, and Du, Jingang

Subjects
Behavioral Neuroscience, Psychiatry and Mental health, Neuropsychology and Physiological Psychology, Neurology, Biological Psychiatry
Abstract

The heterogeneity of transcranial direct current stimulation (tDCS) protocols and clinical profiles may explain variable results in modulating excitability in the motor cortex after stroke. However, the cortical electrical effects induced by different tDCS protocols remain unclear. Here, we aimed to compare rhythm changes in electroencephalography (EEG) induced by three tDCS position protocols and the association between tDCS effects and clinical factors in stroke. Nineteen patients with chronic ischemic stroke underwent four experimental sessions with three tDCS protocols [anodal (atDCS), cathodal (ctDCS), and bilateral (bi-tDCS)] and a sham protocol, according to a single-blind randomized crossover design. Resting-state EEG was acquired before and after each protocol. First, a paired-sample t-test was used to examine the difference in spectral power between pre- and post-stimulation. Then, linear and quadratic regression models were used separately to describe the association between the clinical factors of stroke and changes in spectral power which was significantly different between pre- and post-tDCS. Finally, repeated measures analysis of variance with lesion hemisphere, stimulation protocol, and the location was performed to investigate the effects of tDCS over time. The induced effect of tDCS was mainly reflected in the alpha rhythms. The alpha power was increased by atDCS, especially low-alpha (8–10 Hz), in localized areas of the central and distant areas of the frontal and parietal lobes. Bi-tDCS also affected alpha power but in a smaller area that mainly focused on high-alpha rhythms (10–13 Hz). However, ctDCS and sham had no significant effects on any EEG rhythm. The clinical factors of time since stroke and motor impairment level were related to the change in high-alpha induced by atDCS and bi-tDCS following quadratic regression models. The above-mentioned modulation effect lasted for 20 min without attenuation. In conclusion, our findings provide evidence that the alpha rhythm of EEG is modulated differently by different tDCS protocols and that high alpha is affected by clinical characteristics such as post-stroke time and motor deficits, which is of great significance for understanding the modulation effect of different tDCS protocols on stroke and the guidance of protocols to promote motor recovery following stroke.

Published
2022

21. Subacute oral toxicology and toxicokinetics of pterostilbene, a novel Top1/Tdp1 inhibiting anti-tumor reagent.

Author

Sun, Changcheng, Li, Ying, Zhang, Yutian, Huang, Haoyan, Chen, Huili, Chen, Jiaqin, Han, Luyao, Chen, Xiang, Chen, Xijing, and Zhang, Yongjie

Subjects
*TOXICOLOGY, *FOOD consumption, *ANTINEOPLASTIC agents, *BODY weight, *FEMALES, *MALES
Abstract

This study evaluated the subacute toxicity and toxicokinetics of a potential anti-cancer drug candidate, pterostilbene, in rats. Animals were orally administered at two repeated doses of 200 and 500 mg/kg for 28 days. No mortality was observed during the 28 days of continuous administration of pterostilbene. Body weight and food consumption in each group increased steadily, while no significant difference was found. Liver weight in the 500 mg/kg female, but not male group increased with mild cytoplasmic vacuoles observed in histopathological study. Toxicokinetics was assessed by measuring plasma concentrations of pterostilbene on the first and 28th day of administration using UPLC–MS/MS. Toxicokinetic parameters showed that AUC0–t significantly increased in all animals, while the increase in females was greater than males. System exposure of pterostilbene appeared to be linear within the administrated dose range. In conclusion, our findings suggested a minimal subacute toxicity profile of pterostilbene, which could strongly support further development of this compound as a novel anti-cancer agent. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

45. Method of fuzzy pattern recognition in one-demotion range profile recognition based on scatter central

Author

Cui Mengda, Xi Ze-min, and Sun Changcheng

Subjects
Engineering, business.industry, Feature vector, Information processing, Process (computing), Pattern recognition, Fuzzy logic, law.invention, Dimension (vector space), law, Feature (machine learning), Range (statistics), Computer vision, Artificial intelligence, Radar, business
Abstract

Scatter central feature of high resolution range profile (HRRP) is sensitive to radar incident angles. So there are two problems that may influence the result of HRRP recognition, the recognition templates cannot be made full use of, and there is no reasonable order to arrange the feature vector. In this paper, a new method is proposed based on fuzzy information processing, and the training and recognition process is illuminated. Compared with other algorithms, the most important difference is that the dimension of the feature vector is no longer fixed. So the feature vector contains more target information and can be used more flexibly. At last, the feasibility of this algorithm is verified through experiment.

Published
2015

49. New Insight into the In Situ SO 2 Poisoning Mechanism over Cu-SSZ-13 for the Selective Catalytic Reduction of NO x with NH 3.

Author

Qiu, Yu, Fan, Chi, Sun, Changcheng, Zhu, Hongchang, Yi, Wentian, Chen, Jiazhe, Guo, Luyao, Niu, Xiaoxue, Chen, Jianjun, Peng, Yue, Zhang, Tao, and Li, Junhua

Subjects
CATALYTIC reduction, POISONING, FOURIER transform infrared spectroscopy, ULTRAVIOLET spectroscopy, ZEOLITE catalysts
Abstract

To reveal the nature of SO2 poisoning over Cu-SSZ-13 catalyst under actual exhaust conditions, the catalyst was pretreated at 200 and 500 °C in a flow containing NH3, NO, O2, SO2, and H2O. Brunner−Emmet−Teller (BET), X-ray diffraction(XRD), thermo gravimetric analyzer (TGA), ultraviolet Raman spectroscopy (UV Raman), temperature-programmed reduction with H2 (H2-TPR), temperature-programmed desorption of NO+O2 (NO+O2-TPD), NH3-TPD, in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS), and an activity test were utilized to monitor the changes of Cu-SSZ-13 before and after in situ SO2 poisoning. According to the characterization results, the types and generated amount of sulfated species were directly related to poisoning temperature. Three sulfate species, including (NH4)2SO4, CuSO4, and Al2(SO4)3, were found to form on CZ-S-200, while only the latter two sulfate species were observed over CZ-S-500. Furthermore, SO2 poisoning had a negative effect on low-temperature selective catalytic reduction (SCR) activity, which was mainly due to the sulfation of active sites, including Z2Cu, ZCuOH, and Si-O(H)-Al. In contrast, SO2 poisoning had a positive effect on high-temperature SCR activity, owing to the inhibition of the NH3 oxidation reaction. The above findings may be a useful guideline to design excellent SO2-resistant Cu-based zeolite catalysts. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results