Search

Your search keyword '"Zhang, Qisheng"' showing total 837 results
Start Over Author "Zhang, Qisheng"
837 results on '"Zhang, Qisheng"'

201. Tuning the Excited State of Tetradentate Pd(II) and Pt(II) Complexes through Benzannulated N‐Heteroaromatic Ring and Central Metal.

Author

Li, Guijie, Guo, Hua, Fang, Xiaoli, Yang, Yun‐Fang, Sun, Yulu, Lou, Weiwei, Zhang, Qisheng, and She, Yuanbin

Subjects
PLATINUM, EXCITED states, QUANTUM efficiency, METALS, MOLECULAR spectra, CHARGE transfer, ORGANIC light emitting diodes
Abstract

Comprehensive Summary: A series of tetradentate Pd(II) and Pt(II) complexes containing fused 5/6/6 metallocycles with phenyl N‐heteroaromatic benzo[d]imidazole (pbiz), benzo[d]oxazole (pboz) or benzo[d]thiazole (pbthz)‐containing ligands was developed. Systematic studies by experiments and theoretical calculations reveal that both the central metal and the benzannulated N‐heteroaromatic ring have significant influence on the electrochemical, photophysical and excited‐state properties of the Pd(II) and Pt(II) complexes. In identical condition, compared to pbiz‐based Pd(II) and Pt(II) complexes, the corresponding metal complexes with pboz and pbthz‐containing ligand show significant red‐shift emission spectra. Pd(II) complexes exhibit blue‐shift emission spectra in comparison with the corresponding Pt(II) complexes. The Pt(II) complexes possess more metal‐to‐ligand charge transfer (3MLCT) character in their T1 states, which enables the Pt(II) complexes to have much higher quantum efficiencies (ΦPL) and shorter excited‐state lifetimes (τ), resulting in large radiative decay rates (kr). Especially, Pt(pbiz) has a ΦPL of 94% with a τ of 4.0 μs in 5 wt% doped PMMA film at room temperature. Pt(pbiz)‐doped green organic light‐emitting diode (OLED) using 26mCPy as host demonstrated a peak external quantum efficiency (EQE) of 21.6% and a maximum brightness (Lmax) of 55481 cd/m2, which still maintained an EQE of 16.5% and 10.8% at 1000 and 10000 cd/m2, respectively. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

202. Effects of temperature on paocai bacterial succession revealed by culture-dependent and culture-independent methods

Author

Yao Tang, Wang Meng, Zhang Qisheng, Wang Dongdong, Shen Wenxi, Shuliang Liu, Wen Qin, Chen Gong, and Li Heng

Subjects
DNA, Bacterial, Hot Temperature, Weissella, Lactococcus, DNA, Ribosomal, Polymerase Chain Reaction, Microbiology, 03 medical and health sciences, Culture Techniques, RNA, Ribosomal, 16S, Lactobacillus, Leuconostoc, Food science, 030304 developmental biology, 0303 health sciences, biology, 030306 microbiology, Lactobacillus brevis, food and beverages, General Medicine, biology.organism_classification, Random Amplified Polymorphic DNA Technique, Cold Temperature, carbohydrates (lipids), Leuconostoc mesenteroides, Fermentation, Food Microbiology, Fermented Foods, Lactobacillus plantarum, Food Science
Abstract

Paocai is a widely consumed Chinese traditional fermented vegetable product. To understand the effect of temperature on paocai fermentation flora, the bacterial community structure of paocai fermented at 10 °C, 15 °C, 25 °C and 35 °C was analyzed by culture-dependent and culture-independent methods. The results showed that increasing the fermentation temperature in a certain range is beneficial for rapid paocai acid production and shortening of the maturity period. Illumina Miseq sequencing was performed on 56 samples at different fermentation process temperatures using a culture-independent method. A total of 1,964,231 high-quality reads of 16S rRNA V3-V4 regions were obtained, and they were divided into 405 operational taxonomic units (OTUs) and identified as 213 bacterial genera. The bacterial diversity decreased with the progression of fermentation, and some spoiled samples had an increased diversity. The culture-independent method found that at 10 °C, Lactococcus appeared at the start of fermentation, Leuconostoc and Weissella appeared in the middle of fermentation, and Lactobacillus and Leuconostoc dominated fermentation in the late stage. At 15 °C, Lactococcus started fermentation, Leuconostoc appeared in the middle stage, and Lactobacillus was dominant in the late stage. At 25 °C, Lactococcus started fermentation, Weissella and Lactobacillus appeared in the middle stage, and Lactobacillus dominated fermentation in the late stage. Finally, at 35 °C, Lactococcus, Weissella, and Lactobacillus started fermentation, Weissella and Lactobacillus appeared in the middle stage, and Lactobacillus dominated fermentation in the late stage. A total of 647 strains of bacteria were isolated by culture-dependent methods and were divided into 12 genera and 19 species by randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) and 16S ribosomal RNA gene (rDNA) sequencing technology. More types of bacteria were isolated in the early stage of fermentation. At 10 °C, Lactococcus lactis began fermentation, and Lactobacillus brevis and Leuconostoc mesenteroides dominated acid production in the middle and late stages of paocai fermentation. At 15 °C, L. lactis initiates fermentation, while Lactobacillus plantarum dominates the acid fermentation of paocai. At 25 °C and 35 °C, there were a large number of Enterobacteriaceae bacteria in the start-up fermentation stage, and L. plantarum was dominant after 1–2 days of fermentation. Redundancy analysis (RDA) found that the lower the temperature, the more bacterial species that are produced, and the higher the temperature and the longer the time, the more obvious are the effects of L. plantarum on paocai. The results of dominant bacteria studied by culture-dependent and culture-independent methods are similar. The results indicate that most of the dominant microorganisms in the paocai fermentation system are culturable. This discovery can provide data and physical support for modernization and regulation of different types of paocai production.

Published
2020

228. Flexibility Calculation of Like-U Type Flexure Hinge

Author

Zhang Qisheng, Li Ruiqin, and Ling Jingjing

Subjects
Physics::Computational Physics, business.industry, Mechanical Engineering, Computation, Hinge, Base (geometry), Structure (category theory), Structural engineering, Type (model theory), Physics::Classical Physics, Finite element method, Computer Science::Other, Castigliano's method, business, Mathematics, Variable (mathematics)
Abstract

A new like-U type flexure hinge structure is proposed, based on Castigliano’s second theorem and calculus theory. Taking the centrifugal angle parameters as the integration variable, and defining the intermediate parameters, it deduces the analytic computational formula for the like-U type flexure hinge flexibility. By changing the structural parameter of the flexure hinge, it is able to transform four different structure flexure hinges, and the deduced analytic computation formula can be applied to all of these four structures flexure hinges. After the twelve flexure hinges of different structures have been analyzed by applying finite-element method, it is found that the results are in good agreement with the results of analytic computation formula. Thus, the validity of the analytic computation formula is verified, realize accurate design and computation for such flexure hinges is realized, and the theoretical base for technical application of like-U type flexure hinge is provided.

Published
2015

230. Design and Implementation of the Detection Software of Wireless Microseismic Acquisition Station Based on Android Platform.

Author

Zhang, Qimao, Qiao, Shuaiqing, Zhang, Qisheng, and Liu, Shiyang

Subjects
REAL-time control, INTELLIGENT control systems, SEISMIC prospecting, CONSUMPTION (Economics), ENERGY consumption, SEISMIC response
Abstract

New energy acquisition devices are urgently required to address the increasing global energy consumption and increasing difficulty of energy exploitation. Devices for seismic exploration appear to be small in size, wireless and rapidly becoming more intelligent; hence, a traditional operating platform can no longer satisfy the demand of portable exploration device usage. This study investigates and develops hardware for a wireless microseismic acquisition station, then uses this hardware as a platform to address the distribution of wireless microseismic acquisition stations and deliver monitoring software based on the Android platform, which is portable, popular and has a large number of users. In large-scale field constructions, software can provide operators with visualised station layouts throughout the process, including positioning, ranging, angle measuring and network monitoring. It also offers a real-time network for monitoring small- and medium-sized microseismic acquisition station arrays under construction as well as other functions, such as intelligent control and real-time data monitoring of the status of the acquisition station. A drainage blast monitoring test is conducted on the system, showing positively monitored data and accurate results in the inverse operation. Moreover, the software and hardware are proven to be highly stable and portable through a post-construction test, which can help enhance the field construction efficiency. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

233. A Novel Antiparasitic Compound Kills Ring-Stage Plasmodium falciparum and Retains Activity Against Artemisinin-Resistant Parasites.

Author

Clements, Rebecca L, Streva, Vincent, Dumoulin, Peter, Huang, Weigang, Owens, Edward, Raj, Dipak K, Burleigh, Barbara, Llinás, Manuel, Winzeler, Elizabeth A, Zhang, Qisheng, and Dvorin, Jeffrey D

Subjects
PLASMODIUM falciparum, PARASITES, ANTIPARASITIC agents, COMMUNICABLE diseases, BIOCHEMICAL mechanism of action, LEAD compounds, ANTIMALARIALS, BIOCHEMISTRY, CELL culture, COMPARATIVE studies, DRUG resistance, FIBROBLASTS, PHENOMENOLOGY, RESEARCH methodology, MEDICAL cooperation, MOLECULAR structure, PROTOZOA, RESEARCH, EVALUATION research, PHARMACODYNAMICS
Abstract

Spreading antimalarial resistance threatens effective treatment of malaria, an infectious disease caused by Plasmodium parasites. We identified a compound, BCH070, that inhibits asexual growth of multiple antimalarial-resistant strains of Plasmodium falciparum (half maximal inhibitory concentration [IC50] = 1-2 µM), suggesting that BCH070 acts via a novel mechanism of action. BCH070 preferentially kills early ring-form trophozoites, and, importantly, equally inhibits ring-stage survival of wild-type and artemisinin-resistant parasites harboring the PfKelch13:C580Y mutation. Metabolomic analysis demonstrates that BCH070 likely targets multiple pathways in the parasite. BCH070 is a promising lead compound for development of new antimalarial combination therapy that retains activity against artemisinin-resistant parasites. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results