Angew Chem Int Ed Engl
September 2024
Herein, we describe an innovative approach to the asymmetric electrochemical α-alkylation of aldehydes facilitated by a newly designed bifunctional chiral electrocatalyst. The highly efficient bifunctional chiral electrocatalyst combines a chiral aminocatalyst with a redox mediator. It plays a dual role as a redox mediator for electrooxidation, while simultaneously providing remarkable asymmetric induction for the stereoselective α-alkylation of aldehydes.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
October 2023
It is of great practical significance to identify service blind area, scientifically select park construction areas, and clarify the priority of parks' construction based on the co-ordination of supply-demand evaluation. With the urban parks within the Taiyuan Ring Expressway as the research subjects, we estimated the accessibility range and the service pressure of each park by using the application programming interface of Gaode map route planning and point of interest data to characterize their supply and demand levels. We identified the service blind areas of parks by overlay analysis, and used the location-allocation (LA) model to purposefully supply park green space.
View Article and Find Full Text PDFPM and ozone co-pollution, which are harmful to not only human health but also the social economy, has become the pivotal issue in air pollution prevention and synergistic control, especially in Beijing-Tianjin-Hebei and its surrounding areas and "2+26" cities. It is necessary to analyze the correlation between PM and ozone concentration and explore the mechanism of PM and ozone co-pollution. In order to study the characteristics of PM and ozone co-pollution in Beijing-Tianjin-Hebei with its surrounding area, ArcGIS and SPSS software were used to analyze the correlation between air quality data and meteorological data of the "2+26" cities in Beijing-Tianjin-Hebei and its surrounding areas from 2015 to 2021.
View Article and Find Full Text PDFCamptotheca acuminata (C. acuminata), is belongs to a monotypic genus endemic to southwestern China and listed as the first class national protected plant in China in 1999 (Wen, et al. 2020).
View Article and Find Full Text PDFBioorg Med Chem
October 2022
Electrochemical C(sp) - H oxygenation of phenols derivatives were accomplished using HO as the sole oxygen source. Thus, selectively oxidative 4-cresols to 4-acylphenols derivatives proved viable with the aid of indirect electrolysis, through metal- and external oxidant free environmental-friendly and safe electrocatalytic conditions. Advances of this strategy were proved by its ability to transform various sulfonamides with excellent site and regioselectivity.
View Article and Find Full Text PDFThe highly enantioselective copper-catalyzed propargylic amination of propargylic esters with amine hydrochloride salts has been realized for the first time using copper salts with chiral N,N,P-ligands. This method features a broad substrate scope and wide functional group tolerance, generating propargylic amines in good to excellent yields with high enantioselectivities (up to 99% ee). The utility of the approach was demonstrated by late-stage functionalization of marketed pharmaceuticals.
View Article and Find Full Text PDFA highly enantioselective copper-catalyzed propargylic amination starting from benzylic allylic amines has been developed with a new chiral N,N,P ligand. A series of -tethered 1,6-enynes were synthesized in good to excellent yields with excellent enantioselectivities. Utilization of transition metal-catalyzed cycloisomerization of 1,6-enynes provides several enantioselectively enriched chiral five-membered N-heterocycles efficiently.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
June 2019
The effects of single and combined pollution of enrofloxacin and Cu on the digestive enzymes of earthworms were studied, based on the actual pollution of caused by the application of livestock feces in farmland soil. Results showed that single enrofloxacin (0.1-4 mg·kg, 28 d) did not affect protease, but inhibited cellulase and alkaline phosphatase, with an induced effect on acid phosphatase.
View Article and Find Full Text PDFTo investigate the characteristics of PM emissions in Anyang, the PM emission inventory from industrial sources of Anyang in 2016 was established based on reasonable estimation method and emission factor. The spatial distribution analysis was carried out using Geographic Information System (GIS) technology. Based on the industry's typical ultra-low emission transformation and coal pressure reduction requirements, three scenarios were set to estimate the PM emission reduction potential of industrial sources from Anyang in 2020.
View Article and Find Full Text PDFReports of decreasing PM concentrations in some developed countries and regions, as well as the trends of annual average concentrations of PM in the 74 key cities of China from 2013 to 2016 were analyzed. The cities were categorized based on PM concentration ranges and the regions where they are located. The average annual declining rates of PM concentration were calculated for these categories.
View Article and Find Full Text PDFUnder solvothermal conditions, a robust Pb2+-based coordination polymer (CP), [Pb(TDC)]n (1), where H2TDC is thiophenedicarboxylic acid, has been achieved. Structural analysis reveals that 1 crystallizes in the monoclinic space group C2/c, where the Pb2+ ions show quadrangular prism coordination geometry. CP 1 represents a 3D coordination network based on a TDC2- ligand as bridges and quadrangular prismatic PbO8 units as nodes, among which the PbO8 units are extended through edge-sharing to form a 2D layer in the bc plane.
View Article and Find Full Text PDFObjective: To observe the effects of navel-warming therapy on clinical efficacy in patients with yang-deficiency tympanites based on regular treatment of western medication.
Methods: One hundred and twenty cases of yang-deficiency tympanites were randomly divided into a navel-warming therapy group and a western medication group, sixty cases in each one. The regular treatment of western medicine was applied in the western medication group, including oral administration of antiviral drug and diuretics as well as intravenous drip of hepatic protector.
To develop a new pattern of air pollution control that is based on the integration of "concentration control, total amount control, and quality control", and in the context of developing national (2011-2015 air pollution control plan for key areas) and (Environmental protection plan of Zibo municipality for the "12th Five-Year Plan" period), a simulation of atmospheric dispersion of air pollutants in Zibo City and its peripheral areas is carried out by employing CALPUFF model, and the atmospheric environmental capacity of SO2, NO(x) and PM10 is estimated based on the results of model simulation and using multi-objective linear programming optimization. The results indicates that the air pollution in Zibo City is significantly related to the pollution sources outside of Zibo City, which contributes to the annual average concentration of SO2, NO2 and PM10 in Zibo City by 26.34%, 21.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
December 2011
This study selected 90 samples from different brands of red wine. In order to eliminate the impact of spectral curve's baseline, the first derivatives of all of spectral curves were calculated and the principal component analysis was carried out on the first derivative spectra. The result showed that the contribution rate of the first two principal components was over 80 percent.
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