46 research outputs found
Pore structure characterization of Chang-7 tight sandstone using MICP combined with N2GA techniques and its geological control factors
Understanding the pore networks of unconventional tight reservoirs such as tight sandstones and shales is crucial for extracting oil/gas from such reservoirs. Mercury injection capillary pressure (MICP) and N(2) gas adsorption (N(2)GA) are performed to evaluate pore structure of Chang-7 tight sandstone. Thin section observation, scanning electron microscope, grain size analysis, mineral composition analysis, and porosity measurement are applied to investigate geological control factors of pore structure. Grain size is positively correlated with detrital mineral content and grain size standard deviation while negatively related to clay content. Detrital mineral content and grain size are positively correlated with porosity, pore throat radius and withdrawal efficiency and negatively related to capillary pressure and pore-to-throat size ratio; while interstitial material is negatively correlated with above mentioned factors. Well sorted sediments with high debris usually possess strong compaction resistance to preserve original pores. Although many inter-crystalline pores are produced in clay minerals, this type of pores is not the most important contributor to porosity. Besides this, pore shape determined by N(2)GA hysteresis loop is consistent with SEM observation on clay inter-crystalline pores while BJH pore volume is positively related with clay content, suggesting N(2)GA is suitable for describing clay inter-crystalline pores in tight sandstones
Public awareness, emotional reactions and human mobility in response to the COVID-19 outbreak in China- A population-based ecological study
This work is supported by the West China Hospital COVID-19 Epidemic Science and Technology Project (No. HX-2019-nCoV-014 to Dr Song, No. HX-2019-nCoV-019 to Dr Zhang), Sichuan University Emergency Grant (No. 2020scunCoVyingji1002 to Dr Song, No. 2020scunCoVyingji1005 to Dr Zhang), and Emergency Grant form Science & Technology Department of Sichuan Providence (No. 2020YFS0007 to Dr Zhang). Publisher Copyright: © 2020 Cambridge University Press. All rights reserved.Background: The outbreak of COVID-19 generated severe emotional reactions, and restricted mobility was a crucial measure to reduce the spread of the virus. This study describes the changes in public emotional reactions and mobility patterns in the Chinese population during the COVID-19 outbreak. Methods: We collected data on public emotional reactions in response to the outbreak through Weibo, the Chinese Twitter, between January 1st and March 31st, 2020. Using anonymized location-tracking information, we analyzed the daily mobility patterns of approximately 90% of Sichuan residents. Results: There were three distinct phases of the emotional and behavioral reactions to the COVID-19 outbreak. The alarm phase (January 19th�26th) was a restriction-free period, characterized by few new daily cases, but enormous public negative emotions (the number of negative comments per Weibo post increased by 246.9 per day, 95%CI: 122.5�371.3), and a substantial increase in self-limiting mobility (from 45.6% to 54.5%, changing by 1.5% per day, 95%CI: 0.7%�2.3%). The epidemic phase (January 27th�February 15th) exhibited rapidly increasing numbers of new daily cases, decreasing expression of negative emotions (a decrease of 27.3 negative comments per post per day, 95%CI:-40.4�-14.2), and a stabilized level of self-limiting mobility. The relief phase (February 16th�March 31st) had a steady decline in new daily cases and decreasing levels of negative emotion and self-limiting mobility. Conclusions: During the COVID-19 outbreak in China, the public�s emotional reaction was strongest before the actual peak of the outbreak and declined thereafter. The change in human mobility patterns occurred before the implementation of restriction orders, suggesting a possible link between emotion and behavior.Peer reviewe
Proteomic analysis of tumor necrosis factor-α resistant human breast cancer cells reveals a MEK5/Erk5-mediated epithelial-mesenchymal transition phenotype
Soil, grain and water chemistry in relation to human selenium responsive diseases in Enshi District, China
Selenium deficiency (Keshan Disease) and toxicity diseases in humans occur within 20 km of each other in Enshi District in China and have been linked to environmental levels of Se. Low concentrations of Se are associated with Jurassic siltstones and sandstones, whereas high concentrations occur in areas underlain by Permian carbonaceous strata. Although these broad relationships between Se in the environment and the human population have been established previously, not all villages underlain by the carbonaceous strata suffer Se toxicity problems and the precise controls on Se distribution and availability have not been quantified. In the present study, soil, grain, drinking water and human hair samples are examined to determine the controls on Se availability in 3 Se environments in Enshi District. Five low-Se and Keshan Disease villages, 5 high-Se and no toxicity villages and 5 high-Se and toxicity villages were selected for the study. Results show that the majority of samples in the low-Se villages are deficient or marginal in Se, and that Se availability to plants is inhibited by adsorption onto organic matter and Fe oxyhydroxides in soil. Therefore, remediation strategies involving the application of Se fertiliser direct to the soil may not increase plant Se levels as expected. In the high-Se villages, localised lithological variations result in considerable ranges in Se concentrations in all sample types. Deficient and excessive levels of Se are recorded in samples from the same village. Selenium bioavailability in the high-Se toxicity villages is controlled by the total soil Se concentration and pH. A greater proportion of the Se is plant available in villages where the carbonaceous strata are interbedded with limestone. Villagers should be advised to avoid planting crops in these areas if possible
Review of Key Technologies for Offshore Floating Wind Power Generation
In recent years, due to the global energy crisis, increasingly more countries have recognized the importance of developing clean energy. Offshore wind energy, as a basic form of clean energy, has become one of the current research priorities. In the future, offshore wind farms will be developed in deep and distant sea areas. In these areas, there is a new trend of floating offshore wind platforms replacing fixed wind power platforms, due to their low cost, ease of installation, and independence from the water depth. However, the stability of offshore floating platforms is poor and their power fluctuations are significant; furthermore, they are more prone to failure because of sea wind, waves, and currents. This paper summarizes and analyzes the current research progress and critical technical issues of offshore floating wind power generation, such as stability control technology, integrated wind storage technology, wind power energy management, and long-distance transmission of electricity for floating wind power generation at sea. Finally, future research directions for key offshore wind power technologies are presented
Synthesis and Antitumor Activity of a Series of Novel 1-Oxa-4-azaspiro[4,5]deca-6,9-diene-3,8-dione Derivatives
A series of novel 1-oxa-4-azaspiro[4.5]deca-6,9-diene-3,8-diones were designed and synthesized by using 4-aminophenol and α-glycolic acid or lactic acid as starting materials in three or four steps. The key step is the metal-catalyzed oxidative cyclization of the amide to 1-oxa-4-azaspiro[4.5]deca-6,9-diene-3,8-diones (10a and 10b), the reaction conditions of which are investigated and optimized. The anticancer activity of 17 1-oxa-4-azaspiro[4.5]deca-6,9-diene-3,8-dione derivatives was evaluated. Preliminary results showed that 15 compounds have moderate to potent activity against human lung cancer A549, human breast cancer MDA-MB-231, and human cervical cancer HeLa cancer cell lines. Among them, compounds 11b and 11h were the most potent against A549 cell line with 0.18 and 0.19 µM of IC50, respectively; compounds 11d, 11h, and 11k showed the most potent cytotoxicity against MDA-MB-231 cell line with 0.08, 0.08, and 0.09 µM of IC50, respectively, while the activities of 11h, 11k, and 12c against HeLa cell line were the most potent with 0.15, 0.14, and 0.14 µM of IC50, respectively. Compound 11h is a promising candidate for further development, which emerged as the most effective compound overall against the three tested cancer cell lines
Room- and Low-Temperature Crystallographic Study of the Ambient Pressure Organic Superconductor (Bisethylene dithiotetrathiofulvalene) 4
Review of key technologies for offshore floating wind power generation
Review
2023 Descuento MDPIIn recent years, due to the global energy crisis, increasingly more countries have recognized the importance of developing clean energy. Offshore wind energy, as a basic form of clean energy, has become one of the current research priorities. In the future, offshore wind farms will be developed in deep and distant sea areas. In these areas, there is a new trend of floating offshore wind platforms replacing fixed wind power platforms, due to their low cost, ease of installation, and independence from the water depth. However, the stability of offshore floating platforms is poor and their power fluctuations are significant; furthermore, they are more prone to failure because of sea wind, waves, and currents. This paper summarizes and analyzes the current research progress and critical technical issues of offshore floating wind power generation, such as stability control technology, integrated wind storage technology, wind power energy management, and long-distance transmission of electricity for floating wind power generation at sea. Finally, future research directions for key offshore wind power technologies are presented.State Key Laboratory of Alternate Electrical Power System with Renewable Energy SourcesGuangdong Basic and Applied Basic Research FoundationCentral Universities (China)National Natural Science Foundation of ChinaMinisterio de Ciencia e Innovación (España)Depto. de Arquitectura de Computadores y AutomáticaFac. de InformáticaInstituto de Tecnología del Conocimiento (ITC)TRUEpubDescuento UC
Optimization strategy of power purchase and sale for electricity retailers in a two-tier market
Against the backdrop of the gradual advancement of China's electricity market reform, the number of Power Trading Companies in China has been increasing year by year, and as of October 2022, the number has reached more than 10,000. As an important hub connecting the electricity market and users, electricity retailers face double risks from downstream user load fluctuations and electricity market price fluctuations. Therefore, a reasonable power purchase and sale strategy is very important for an electricity retailer. In this study, a block bidding mechanism is adopted to optimize the clearing of the medium-to long-term market and a DA-RBF neural network is established for spot electricity price forecasting model based on numerical feature similarity to improve the accuracy of electricity price forecasting. Furthermore, the model considers the differences in user demand responses and investigates the optimal power purchase and sale strategy, guided by differentiated time-of-use electricity pricing. The case study analysis demonstrated that the proposed power purchase and sale optimization strategy yields favorable results, improving profitability and enhancing the stability of the power system
Metabolism, Pharmacokinetics, and Bioavailability of ZB716, a Steroidal Selective Estrogen Receptor Downregulator (SERD)
ZB716 is a selective estrogen receptor downregulator (SERD) with excellent oral bioavailability and superior efficacy. In this study, we investigate the in vitro and in vivo metabolism and the pharmacokinetics of ZB716 by incubation with liver microsomes, liver cytosol, and by orally dosing rodents. Metabolic products were identified and quantified by a combination of liquid chromatography and tandem +mass spectrometry. The metabolic profile of ZB716 showed fulvestrant and ZB716- sulfone as the two major oxidative metabolites. ZB716 also underwent some degree of sulfation and glucuronidation in vitro. The major oxidative metabolites of ZB716 were found in rat plasma, feces, and urine samples. No sulfation and glucuronidation metabolites from ZB716 were found in plasma. Limited amounts of sulfate conjugates and glucuronides of ZB716 were detected in feces. The glucuronidation on 3-OH position of fulvestrant was the main metabolite found in urine, suggesting that this specific site of phase 2 metabolism is blocked in ZB716 and formation of glucuronide 3-fulvestrant must be preceded by metabolic transformation of ZB716 to fulvestrant. The pharmacokinetic study of ZB716 showed a half-life (t1/2) at 17.03 hour, the area under curve value (AUC) of 1451.82 ng/ml*h, and the maximum plasma concentration (Cmax) at 158.12 ng/mL reached at 2 h after a single dose of 10 mg/kg by oral gavage. Overall this study elucidated important metabolic characteristics of ZB716, an oral SERD that has demonstrated superior bioavailability and efficacy in preclinical studies conducted so far