30 results on '"Zhen Bi"'
Search Results
2. DC–DC circuit fault diagnosis based on GWO optimization of 1DCNN-GRU network hyperparameters
- Author
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Li, Zhen-Bi, primary, Feng, Xue-Yan, additional, Wang, Li, additional, and Xie, Yi-Chen, additional
- Published
- 2023
- Full Text
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3. Iron-dependent nitrate reduction by anammox consortia in continuous-flow reactors: A novel prospective scheme for autotrophic nitrogen removal
- Author
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Wenjing Zhang, Ge Song, Yong Huang, and Zhen Bi
- Subjects
Environmental Engineering ,Denitrification ,010504 meteorology & atmospheric sciences ,Iron ,chemistry.chemical_element ,010501 environmental sciences ,Waste Disposal, Fluid ,01 natural sciences ,Bacteria, Anaerobic ,chemistry.chemical_compound ,Ammonia ,Nitrate ,Environmental Chemistry ,Ammonium ,Autotroph ,Nitrite ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Autotrophic Processes ,Nitrates ,Pollution ,Nitrogen ,chemistry ,Anammox ,Environmental chemistry ,Oxidation-Reduction - Abstract
Anammox bacteria are chemolithotrophic organisms growing on the conversion of ammonium and nitrite with bicarbonate as the sole carbon source. Meanwhile, anammox bacteria display a metabolic versatility to sustain their metabolism. However, there is less attention on the Fe0/Fe2+-dependent autotrophic denitrification by anammox consortia. In this study, the autotrophic nitrate reduction using different valence of iron (Fe0, Fe2+ and Fe0+ Fe2+, respectively) as electron donors by anammox consortia were firstly explored in continuous feeding mode. Results revealed anammox consortia showed high adaptability to the niche wherein containing nitrate and iron. They could generate nitrite and ammonium from iron-dependent nitrate reduction, and hence support their central metabolism. During 60-days operation, the maximum nitrate and total nitrogen removal efficiency reached 88.43% and 80.77%, respectively, with coexistence of Fe0 and Fe2+. The expression of key functional genes involved in nitrate reduction (including narG, napA and nrfA) in 16S rRNA level revealed the coupling of dissimilatory nitrate reduction to nitrite, dissimilatory nitrite reduction to ammonia (DNRA), and anammox processes possibly play pivotal role in nitrogen loss under Fe0/Fe2+ condition. Meanwhile, abiotic reduction by Fe0/Fe2+ also contributed nitrate reduction to provide nitrite and ammonium for anammox consortia. Activities of two vital enzymes hydrazine dehydrogenase (HDH) and nitrate oxidoreduetase (NAR) also inferred higher microbial activities with co-existence of Fe0 and Fe2+. The present study confirms and further extends the versatile metabolisms of Anammox consortia, also it can help to circumvent the accumulation of nitrate produced by anammox process itself and increase the quality of discharge.
- Published
- 2019
4. m6A methylation modulates adipogenesis through JAK2-STAT3-C/EBPβ signaling
- Author
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Nana Chen, Xinxia Wang, Yizhen Wang, Ruifan Wu, Fengqin Wang, Zhen Bi, Guanqun Guo, Youhua Liu, and Yuanling Zhao
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0301 basic medicine ,Gene knockdown ,biology ,Chemistry ,MRNA modification ,Biophysics ,Methylation ,Biochemistry ,Cell biology ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Structural Biology ,Adipogenesis ,Transcription (biology) ,hemic and lymphatic diseases ,030220 oncology & carcinogenesis ,Genetics ,biology.protein ,Phosphorylation ,Demethylase ,STAT3 ,Molecular Biology - Abstract
N6-methyladenosine (m6A), the most abundant internal mRNA modification in eukaryotes, plays a vital role in regulating adipogenesis. However, its underlying mechanism remains largely unknown. Here, we reveal that deletion of m6A demethylase FTO in porcine and mouse preadipocytes inhibits adipogenesis through JAK2-STAT3-C/EBPβ signaling. Mechanistically, FTO deficiency suppresses JAK2 expression and STAT3 phosphorylation, leading to attenuated transcription of C/EBPβ, which is essential for the early stage of adipocyte differentiation. Using dual-luciferase assay, we validate that knockdown of FTO reduces expression of JAK2 in an m6A-dependent manner. Furthermore, we find that m6A "reader" protein YTHDF2 directly targets m6A-modified transcripts of JAK2 and accelerates mRNA decay, which results in decreased JAK2 expression and inactivated JAK2-STAT3-C/EBPβ signaling, thereby inhibiting adipogenesis. Collectively, our results provide a novel insight into the molecular mechanism of m6A methylation in post-transcriptional regulation of JAK2-STAT3-C/EBPβ signaling axis and highlight the crucial role of m6A modification and its modulators in adipogenesis.
- Published
- 2019
5. Significant inhibition of re-emerged and emerging swine enteric coronavirus in vitro using the multiple shRNA expression vector
- Author
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Zhiquan Li, Dongyan Huang, Yuxin Tang, Wang Gong, Suxian Luo, Zhen Bi, Deping Song, Hao Li, Kai Li, Dan Lei, Fanfan Zhang, and Yu Ye
- Subjects
0301 basic medicine ,China ,Small interfering RNA ,Genes, Viral ,Swine ,viruses ,030106 microbiology ,Multi-resistance strategy ,Multiple short hairpin RNAs ,medicine.disease_cause ,Article ,Swine enteric coronavirus ,Small hairpin RNA ,03 medical and health sciences ,RNA interference ,Virology ,medicine ,Animals ,RNA, Small Interfering ,Gene ,Coronavirus ,Swine Diseases ,Pharmacology ,Expression vector ,biology ,Porcine epidemic diarrhea virus ,Alphacoronavirus ,Genetic Therapy ,biology.organism_classification ,030104 developmental biology ,Viral replication ,RNA Interference ,Coronavirus Infections - Abstract
Swine enteric coronaviruses (SECoVs), including porcine epidemic diarrhea virus (PEDV), swine acute diarrhea syndrome coronavirus (SADS-CoV), and porcine deltacoronavirus (PDCoV) have emerged and been prevalent in pig populations in China for the last several years. However, current traditional inactivated and attenuated PEDV vaccines are of limited efficacy against circulating PEDV variants, and there are no commercial vaccines for prevention of PDCoV and SADS-CoV. RNA interference (RNAi) is a powerful tool in therapeutic applications to inhibit viral replication in vitro. In this study, we developed a small interfering RNA generation system that expressed two different short hairpin RNAs (shRNAs) targeting the M gene of PEDV and SADS-CoV and the N gene of PDCoV, respectively. Our results demonstrated that simultaneous expression of these specific shRNA molecules inhibited expression of PEDV M gene, SADS-CoV M gene, and PDCoV N gene RNA by 99.7%, 99.4%, and 98.8%, respectively, in infected cell cultures. In addition, shRNA molecules significantly restricted the expression of M and N protein, and impaired the replication of PEDV, SADS-CoV, and PDCoV simultaneously. Taken together, this shRNAs expression system not only is proved to be a novel approach for studying functions of various genes synchronously, but also developed to test aspects of a potential therapeutic option for treatment and prevention of multiple SECoV infections., Highlights • Two potential targets of antiviral molecules for the treatment of three swine enteric coronaviruses replication are tested. • The multiple-shRNA expression vector was constructed to effectively inhibit PEDV, SADS-CoV, and PDCoV. • A shRNA-based multiple-resistance antiviral strategy, significantly affecting viral replication, was evaluated in vitro.
- Published
- 2019
6. Simultaneous removal of ammonia and nitrate by coupled S0-driven autotrophic denitrification and Anammox process in fluorine-containing semiconductor wastewater
- Author
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Yan Yuan, Yong Huang, Xiang Li, and Zhen Bi
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Environmental Engineering ,Denitrification ,010504 meteorology & atmospheric sciences ,ved/biology ,ved/biology.organism_classification_rank.species ,chemistry.chemical_element ,010501 environmental sciences ,01 natural sciences ,Pollution ,Nitrogen ,Thiobacillus ,Ammonia ,chemistry.chemical_compound ,Denitrifying bacteria ,chemistry ,Wastewater ,Nitrate ,Anammox ,Environmental chemistry ,Environmental Chemistry ,Waste Management and Disposal ,0105 earth and related environmental sciences - Abstract
To achieve the simultaneous removal of NH4+-N and NO3−-N in F−-containing semiconductor wastewater by coupled S0-driven autotrophic denitrification and Anammox process, the effect of variable F− concentration on the Anammox process was investigated by batch experiments. The denitrifying ammonium oxidation (Deamox) reactor was then started-up to explore the feasibility of the coupling of Anammox and sulfur autotrophic denitrification (SADN) for the treatment of semiconductor wastewater. Short-term variation of F− concentration has an obviously effect on the activity of Anammox sludge, but didn't affect the nitrogen conversion rate. The activity of Anammox obviously decreased after long-term operation of the Deamox reactor when influent F− concentrations reached 552 mg/L. The sensitivity of Anammox bacteria to F− concentration is stronger than that of SADN bacteria. Total nitrogen removal efficiency of 98% and total nitrogen removal rate of 4.11 kg/(m3·d) were achieved in the Deamox reactor, when the F− was pre-treated by calcium ions. Moreover, the high-throughput 16S rRNA gene sequence analysis indicated that variation in F− concentrations could influence the structure and functional of microbial communities in the Deamox process. Candidatus Kuenenia, Thiobacillus and Sulfurimonas were main functional bacteria that achieved symbiotic.
- Published
- 2019
7. Mechanistic influence on uniformity of sheet resistance of AlGaN/GaN HEMT grown on Si substrate with the graded AlGaN buffer layers
- Author
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Jinbang Ma, Yachao Zhang, Yifan Li, Tao Zhang, Yixin Yao, Qian Feng, Zhen Bi, Jincheng Zhang, and Yue Hao
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Condensed Matter Physics ,Instrumentation ,Surfaces, Coatings and Films - Published
- 2022
8. Highly efficient of nitrogen removal from mature landfill leachate using a combined DN-PN-Anammox process with a dual recycling system
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Yuan Yi, Yong Huang, Xiang Li, Zhen Bi, Qing-tan Qiu, Yan Yuan, and Fan Wang
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0106 biological sciences ,Environmental Engineering ,Nitrogen ,chemistry.chemical_element ,Bioengineering ,010501 environmental sciences ,01 natural sciences ,Bioreactors ,010608 biotechnology ,Leachate ,Waste Management and Disposal ,Effluent ,Nitrosomonas ,0105 earth and related environmental sciences ,biology ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Airlift ,General Medicine ,Pulp and paper industry ,biology.organism_classification ,Nitrification ,Wastewater ,Anammox ,Denitrification ,Water Pollutants, Chemical - Abstract
An efficient and stable combined denitrification-partial nitrification-Anammox process with a dual recycling system was used to remove nitrogen from mature landfill leachate. After 155 d of operation, the NO3− as the PN-Anammox byproduct was almost treated with biodegradable organic carbon in raw wastewater in a pre-denitrification reactor by external recycling system. When raw landfill leachate with NH4+-N concentration of 1900 mg/L was treated, an integrated reactor with airlift recycling was combined with the PN and Anammox reactions to efficiently remove NH4+ from the inflow. The total nitrogen concentration of effluent stabilized at 20 mg/L and total nitrogen removal efficiency was 99%. The maximum NO2− production rate in the aerobic zone was 2.2 kg/(m3·d) and the maximum nitrogen removal rate in the anaerobic zone was 21.4 kg/(m3·d). The most common phyla among the nitrification and the Anammox functional bacteria were Nitrosomonas, Candidatus Kuenenia, and Candidatus Brocadia after landfill leachate treatment.
- Published
- 2018
9. FTO regulates adipogenesis by controlling cell cycle progression via m6A-YTHDF2 dependent mechanism
- Author
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Yuanling Zhao, Ruifan Wu, Zhen Bi, Yizhen Wang, Xinxia Wang, Fengqin Wang, Qin Jiang, Min Cai, Youhua Liu, Yongxi Yao, and Qing Liu
- Subjects
0301 basic medicine ,Gene knockdown ,biology ,Chemistry ,MRNA modification ,Cyclin-dependent kinase 2 ,nutritional and metabolic diseases ,Cell Biology ,Cell cycle ,Cell biology ,03 medical and health sciences ,030104 developmental biology ,Downregulation and upregulation ,Adipogenesis ,biology.protein ,Demethylase ,Gene silencing ,Molecular Biology - Abstract
N6-methyladenosine (m6A) is the most prevalent internal mRNA modification in eukaryotes. Loss of m6A demethylase FTO increases m6A levels and inhibits adipogenesis of preadipocytes. However, its underlying mechanism remains elusive. Here, we demonstrated that silencing FTO inhibited adipogenesis of preadipocytes through impairing cell cycle progression at the early stage of adipogenesis. FTO knockdown markedly decreased the expression of CCNA2 and CDK2, crucial cell cycle regulators, leading to delayed entry of MDI-induced cells into G2 phase. Furthermore, the m6A levels of CCNA2 and CDK2 mRNA were significantly upregulated following FTO knockdown. m6A-binding protein YTHDF2 recognized and decayed methylated mRNAs of CCNA2 and CDK2, leading to decreased protein expression, thereby prolonging cell cycle progression and suppressing adipogenesis. Our work unravels that FTO regulates adipogenesis by controlling cell cycle progression in an m6A-YTHDF2 dependent manner, which provides insights into critical roles of m6A methylation in adipogenesis.
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- 2018
10. Investigation on the relationship between dislocation type and the annihilation mechanism of GaN-on-Si
- Author
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Jinbang Ma, Yachao Zhang, Yifan Li, Yixin Yao, Tao Zhang, Qian Feng, Zhen Bi, Lansheng Feng, Jincheng Zhang, and Yue Hao
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science ,Condensed Matter Physics - Published
- 2022
11. A novel method of simultaneous NH4+ and NO3− removal using Fe cycling as a catalyst: Feammox coupled with NAFO
- Author
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Yong Huang, Xiang Li, Heng-wei Liu, Yan Yuan, Peng-bin Yang, Zhen Bi, and Yi Yuan
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Environmental Engineering ,Chemistry ,Microbial diversity ,0208 environmental biotechnology ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Pollution ,020801 environmental engineering ,Catalysis ,Anammox ,Yield (chemistry) ,Oxidizing agent ,Environmental Chemistry ,Cycling ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Nuclear chemistry - Abstract
The feasibility of using Feammox coupled with nitrate-dependent Fe(II) oxidizing (NAFO) to cause the simultaneous conversion of NH4+ and NO3− was explored by inoculation with Feammox sludge and the use Fe cycling as catalyst. After 61 days operation, the simultaneous conversion of NO3− and NH4+ occurred with the presence of interconversion between Fe(III) and Fe(II). The conversion ratio of NH4+ to NO3− stabilized at 0.9–1. The results of isotopic tracing and microbial diversity analysis indicated that NH4+ was first oxidized to NO2− by Fe(III), then NO3− was reduced to NO2− and N2 by the Fe(II) produced in Feammox process, and finally, the NO2− produced in NAFO process underwent an Anammox process with the remaining NH4+ to yield N2. The results showed the simultaneous continuous conversion process of NO3− and NH4+ with limited Fe as a catalyst was a coupled process of Feammox, Anammox, and NAFO under the anaerobic conditions.
- Published
- 2018
12. Effects of salinity on the denitrification efficiency and community structure of a combined partial nitritation- anaerobic ammonium oxidation process
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Yan Yuan, Xin Liu, Yi Yuan, Chongjun Chen, Yong Huang, Shan-shan Xu, Zhen Bi, Xiang Li, and Heng-wei Liu
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Salinity ,Environmental Engineering ,Denitrification ,Nitrogen ,0208 environmental biotechnology ,chemistry.chemical_element ,Bioengineering ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,chemistry.chemical_compound ,Bioreactors ,RNA, Ribosomal, 16S ,Nitration ,Ammonium Compounds ,Botany ,Waste Management and Disposal ,0105 earth and related environmental sciences ,biology ,Renewable Energy, Sustainability and the Environment ,General Medicine ,biology.organism_classification ,020801 environmental engineering ,Microbial population biology ,chemistry ,Anammox ,Environmental chemistry ,Oxidation-Reduction ,Bacteria ,Transformation efficiency - Abstract
The effects of salinity changes on nitrogen transformation efficiency and recoverability were studied by using a partial nitration (PN)- anaerobic ammonium oxidation (Anammox) integrated reactor. The changes of microbial community structure and population abundance during the increase and decrease of salinity were also analyzed by 16S rRNA gene high-throughput sequencing. The results showed that when the salinity was increased to 1.35%, the combined PN-Anammox process achieved the maximum stimulated and total nitrogen removal rate (TNRR) arrived at 1.1kg/(m3·d). When the salinity was higher than 1.35%, the activities of AOB and Anammox bacteria began to be inhibited. When the salinity reached 2.4%, the TNRR decreased to 60%. TNRR was fast restored, when salinity was reduced to 0.11%. The genes of AOB and Anammox bacteria indicated that the TNRR of the reactor was restored after salinity inhibition, but the functional microbial community structure and abundance had relatively large, irreversible changes.
- Published
- 2018
13. Effects of the pretreatment of Si substrate before the pre-deposition of Al on GaN-on-Si
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Yachao Zhang, Yifan Li, Zhen Bi, Jincheng Zhang, Yue Hao, Jinbang Ma, Tao Zhang, Yixin Yao, and Qian Feng
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Work (thermodynamics) ,Materials science ,Morphology (linguistics) ,Photoluminescence ,business.industry ,Surface finish ,Condensed Matter Physics ,Root mean square ,Full width at half maximum ,Quality (physics) ,Si substrate ,Optoelectronics ,General Materials Science ,Electrical and Electronic Engineering ,business - Abstract
In this work, we report a method that the Si substrate is pre-treated in the atmosphere of high temperature AlN before the depositon of Al to improve the quality of GaN-on-Si, which is studied by few people. Compared to the untreated sample, the pre-treated one exhibits smoother surface morphology with a root mean square roughness (RMS) value of 0.580 nm and the full width at half maximum (FWHM) of GaN (102) plane also decreases from 1484 arcsec to 1303 arcsec. Moreover, we give an explanation for the extra shoulder peaks in the photoluminescence (PL) spectrum. This enhancement of quality and surface morphology of GaN can be attributed to the improvement of surface flatness of Si substrate, which contributes to the conversion of AlN to two-dimensional growth mode, leading to a smoother surface of GaN. And the reason for the improvement of Si substrate is also investigated in this work.
- Published
- 2021
14. Nitrate removal by anammox biomass with intracellular carbon source as electron donors via DNRA pathway
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Jiti Zhou, Zhen Bi, Chao Wang, and Sen Qiao
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Nitrogen ,chemistry.chemical_element ,Biomass ,Electrons ,010501 environmental sciences ,01 natural sciences ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,Bioreactors ,0302 clinical medicine ,Nitrate ,Ammonium Compounds ,030212 general & internal medicine ,Ecosystem ,0105 earth and related environmental sciences ,General Environmental Science ,Nitrates ,biology ,Metabolism ,biology.organism_classification ,Carbon ,chemistry ,Acetylene ,Anammox ,Environmental chemistry ,Degradation (geology) ,Oxidation-Reduction ,Bacteria - Abstract
In this work, a novel nitrate (NO3−) reduction pathway by anaerobic ammonium oxidation (anammox) biomass was firstly discovered with the intracellular carbon sources as the only electron donors. And the possible reaction mechanism was deduced to be intracellular dissimilatory nitrate reduction to ammonium (DNRA) pathway according to the experimental results. In batch experiments, without any external electron donors, NO3−-N (about 50 mg/L) was reduced to N2 within 48 h, and a small amount of NO2−-N was detected (the maximum of 2 mg/L) with the anammox biomass concentration of 4400 mg/L. Acetylene (4.46 mmol/L) addition resulted in obvious NH4+ accumulation during NO3− degradation by anammox biomass, since acetylene mainly interfered in hydrazine (N2H4) generation from NH4+ and NO. Without HCO3− addition, the NO3−-N degradation rate was slower than that with HCO3− addition. Simultaneously, glycogen contents inside anammox biomass decreased to 133.22 ± 1.21 mg/g VSS and 129.79 ± 1.21 mg/g VSS with and without HCO3−, respectively, from 142.20 ± 0.61 mg/g VSS. In the long-term experiment, anammox biomass stably degraded NO3−-N without external electron donors addition, and the maximum removal efficiency of NO3−-N reached 55.4%. The above results indicated the anammox bacteria utilized the DNRA pathway to reduce NO3− to NO2− and further NH4+, then normal anammox metabolism would continue to convert the produced NO2− and NH4+ to N2. The intracellular stored carbon sources (e.g., glycogen) were supposed to be electron donors for NO3− degradation. This capability would enhance the viability and living space of anammox bacteria in different natural ecosystems, and make it plausible that complete nitrogen removal could be implemented only by the anammox process.
- Published
- 2021
15. Numerical study of suppression mechanism of two types of grooves on the TLV
- Author
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Xueming Shao, Lingxin Zhang, and Zhen Bi
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Environmental Engineering ,Materials science ,020209 energy ,Flow (psychology) ,Ocean Engineering ,02 engineering and technology ,Mechanics ,01 natural sciences ,010305 fluids & plasmas ,Vortex ,Tip clearance ,Axial compressor ,Cavitation ,0103 physical sciences ,Turbomachinery ,0202 electrical engineering, electronic engineering, information engineering ,Groove (engineering) ,Casing - Abstract
In the tip clearance flow, the dominant vortex is the tip leakage vortex (TLV), which has a significant impact on the hydraulic and cavitation performance of axial flow machinery. Thus, the suppression methods of the TLV are necessary in turbomachinery. Casing groove is an effective and economical technique among many control methods. However, its mechanism is still not completely understood. In order to reveal the effect mechanism of the casing groove on the TLV, numerical investigations of gap flow with groove configurations are carried out. A NACA0009 hydrofoil with tip gap is selected as the research object. Two typical groove types (vertical groove and horizontal groove) are applied on the solid wall respectively. Efforts are made to analyze the difference of velocity distributions between the two groove cases and the smooth wall case. Combing with the vortex stability theory, the suppression mechanisms of the two types of casing groove are distinguished and uncovered. For the vertical groove, the TLV intensity is reinforced via the secondary leakage vortex (SLV) at first, and then the supply of the axial momentum in the TLV center is cut off, leading to a less stable TLV. For the horizontal groove, the dissipation effect caused by viscosity on the TLV is strong, resulting in a weakened TLV.
- Published
- 2021
16. Effects of the C/N ratio and bacterial populations on nitrogen removal in the simultaneous anammox and heterotrophic denitrification process: Mathematic modeling and batch experiments
- Author
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Masashi Takekawa, Satoshi Soda, Zhen Bi, Michihiko Ike, Jiti Zhou, Giri Park, and Sen Qiao
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Denitrification ,General Chemical Engineering ,Environmental engineering ,General Chemistry ,Anoxic waters ,Industrial and Manufacturing Engineering ,Denitrifying bacteria ,chemistry.chemical_compound ,Activated sludge ,chemistry ,Nitrate ,Anammox ,Environmental chemistry ,Environmental Chemistry ,Ammonium ,Nitrite - Abstract
A mathematic model was developed for describing the nitrogen and organic carbon removal via the simultaneous anaerobic ammonium oxidation (anammox) and heterotrophic denitrification (SAD) process. The model considered anammox bacteria, heterotrophic denitrifying bacteria, ammonium, nitrite, nitrate, and readily biodegradable carbon. The model parameters were calibrated by using the experimental data in the single batch reactors inoculated with anammox sludge of 190 mg-VSS/L and activated sludge of 110 or 220 mg-VSS/L for treating wastewater containing ammonium of 30 mg-N/L and nitrate of 40 mg-N/L. The rapid depletion of nitrate and acetate as the sole carbon source were observed in the reactor. Subsequently, the temporarily accumulated nitrite was removed with ammonium. The initial C/N ratio of 1.5–2.0 and the population ratio of heterotrophic denitrifying bacteria to anammox bacteria within 0.3–0.4 were suitable conditions for the batch SAD process. The sensitivity analysis of kinetic parameters revealed that the most influential parameters for the nitrogen and organic carbon removal were the half-saturation constants for nitrite of heterotrophic bacteria and anammox bacteria and the anoxic reduction factors of heterotrophic bacteria on the nitrate-reducing rate and the nitrite-reducing rate, which closely associated with nitrite accumulation in the SAD process.
- Published
- 2015
17. Inhibition and recovery of Anammox biomass subjected to short-term exposure of Cd, Ag, Hg and Pb
- Author
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Zhen Bi, Sen Qiao, Yingjun Cheng, Xin Tang, and Jiti Zhou
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chemistry.chemical_classification ,biology ,General Chemical Engineering ,Inorganic chemistry ,Biomass ,Dehydrogenase ,General Chemistry ,Industrial and Manufacturing Engineering ,Enzyme assay ,Heme C ,chemistry.chemical_compound ,Enzyme ,chemistry ,Anammox ,Toxicity ,biology.protein ,Environmental Chemistry ,IC50 ,Nuclear chemistry - Abstract
This study investigated the inhibitory effects of Cd, Ag, Hg and Pb on Anammox biomass by batch experiments. Inhibition effects and recovery performance were monitored in sequence over 24 h and 72 h experimental runs. The IC50 (the 50% inhibitory concentration of nitrogen removal rate) values were calculated as follows: 11.16 ± 0.42 mg/L for Cd; 11.52 ± 0.49 mg/L for Ag; 60.35 ± 2.47 mg/L for Hg. Pb caused only 7.19% decrease on nitrogen removal rate (NRR) even at a dose of 40 mg/L. Hence, the order of the inhibitory effect was determined as Cd > Ag > Hg > Pb. Furthermore, the crude enzyme (hydrazine dehydrogenase) activity and heme c concentration were also depressed under heavy metals exposure. Among four metals, Cd and Hg could exert sustained toxicity on Anammox biomass, but mal-effects of Ag and Pb could resume to a large extent after removing these two metals within 96 h.
- Published
- 2014
18. A new fluorescent pH probe for extremely acidic conditions
- Author
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Jun-Ying Miao, Yu Xiao, Yu Xu, Bao-Xiang Zhao, Fu-Zhen Bi, and Zheng Jiang
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Models, Molecular ,Metal ions in aqueous solution ,Optical Imaging ,Imidazoles ,Molecular Conformation ,Analytical chemistry ,Protonation ,Hydrogen-Ion Concentration ,Photochemistry ,Biochemistry ,Fluorescence ,Photoinduced electron transfer ,Analytical Chemistry ,Absorbance ,chemistry.chemical_compound ,chemistry ,Coumarins ,pH indicator ,Drug Design ,Escherichia coli ,Proton NMR ,Environmental Chemistry ,Imidazole ,Spectroscopy ,Fluorescent Dyes - Abstract
A novel turn-off fluorescent probe based on coumarin and imidazole moiety for extremely acidic conditions was designed and developed. The probe with pKa=2.1 is able to respond to very low pH value (below 3.5) with high sensitivity relying on fluorescence quenching at 460 nm in fluorescence spectra or the ratios of absorbance maximum at 380 nm to that at 450 nm in UV-vis spectra. It can quantitatively detect pH value based on equilibrium equation, pH=pKa-log[(Ix-Ib)/(Ia-Ix)]. It had very short response time that was less than 1 min, good reversibility and nearly no interference from common metal ions. Moreover, using (1)H NMR analysis and theoretical calculation of molecular orbital, we verified that a two-step protonation process of two N atoms of the probe leaded to photoinduced electron transfer (PET), which was actually the mechanism of the fluorescence quenching phenomenon under strongly acidic conditions. Furthermore, the probe was also applied to imaging strong acidity in bacteria, E.coli and had good effect. This work illustrates that the new probe could be a practical and ideal pH indicator for strongly acidic conditions with good biological significance.
- Published
- 2014
19. Morphology control of ultrafine cuprous oxide powder and its growth mechanism
- Author
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Kang-gen Zhou, Zhen Bi, Yue-jun Wang, and Yan Cao
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Supersaturation ,Morphology (linguistics) ,Inorganic chemistry ,Metals and Alloys ,Nucleation ,Oxide ,Geotechnical Engineering and Engineering Geology ,Condensed Matter Physics ,Morphology control ,Crystal ,Truncated octahedron ,chemistry.chemical_compound ,chemistry ,Octahedron ,Materials Chemistry - Abstract
Four shapes of Cu2O particles as sphere, cube, truncated octahedron and octahedron were prepared via glucose reduction of Cu(II) under alkaline condition. The products were characterized by XRD and SEM. The effects of the precursor (CuO, Cu(OH)2), reaction temperature and glucose concentration on morphology of Cu2O particles were investigated, and the mechanism of morphology control was discussed on the basic theory of crystal nucleation and growth. It is found that the Cu+ supersaturation is remarkably influenced by the precursor kind, reaction temperature and glucose concentration, and the morphology of Cu2O particles can be controlled by the Cu+ supersaturation.
- Published
- 2010
20. Plasma-activated nitrogen-doped p-type ZnO thin films with multi-buffer-layers grown on sapphire (0001) by L-MBE
- Author
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Xun Hou, Jingwen Zhang, Xuming Bian, Xin’an Zhang, Dong Wang, Zhen Bi, and Yunpeng Peng
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Photoluminescence ,Chemistry ,business.industry ,Mechanical Engineering ,Doping ,Metals and Alloys ,Analytical chemistry ,Acceptor ,Semiconductor ,X-ray photoelectron spectroscopy ,Mechanics of Materials ,Materials Chemistry ,Sapphire ,Thin film ,business ,Molecular beam epitaxy - Abstract
Nitrogen-doped ZnO (ZnO:N) thin films with multi-buffer-layers, Mg0.1Zn0.9O / ZnO super-lattice structure, were grown on sapphire (0 0 0 1) by plasma-activated laser molecular beam epitaxy (L-MBE) using an atomic nitrogen source. High resolution X-ray diffraction (HR-XRD) measurement demonstrated that all the ZnO:N samples are (0 0 0 2) oriented and the residual strain along c-axial are effectively controlled. Room temperature (RT) Hall measurements indicate that the 200 °C sample shows a p-type behavior with a mobility of 4.08 cm2/V s and a carrier density of 1.47 × 1 0 17 cm−3. The 300 °C sample shows a weak p-type behavior with a mobility of 0.75 cm2/V s and a carrier density of 4.40 × 1 0 16 cm−3. However, the 200 °C sample is not stable and reverted back to n-type conductivity in about 5 days. The X-ray photoelectron spectra (XPS) of N1s display two peaks at 404 eV and 396 eV which are related to (N2)Oand NO, respectively. The 10 K low temperature photoluminescence (PL) spectra of the 200 °C sample exhibits an acceptor bound exciton peak at 3.351 eV and a donor–acceptor pair (DAP) peak at 3.228 eV, associated with NO acting as acceptors.
- Published
- 2009
21. Enhancement-mode thin film transistor with nitrogen-doped ZnO channel layer deposited by laser molecular beam epitaxy
- Author
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Zhen Bi, Weifeng Zhang, Xuming Bian, Xun Hou, Jingwen Zhang, Xin’an Zhang, and Dong Wang
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Silicon ,Chemistry ,Doping ,Metals and Alloys ,Analytical chemistry ,chemistry.chemical_element ,Surfaces and Interfaces ,Substrate (electronics) ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Threshold voltage ,Thin-film transistor ,Materials Chemistry ,Thin film ,Layer (electronics) ,Molecular beam epitaxy - Abstract
The thin film transistors (TFTs) based on nitrogen doped zinc oxide (ZnO) were investigated by laser molecular beam epitaxy. The increase of ZnO films' resistivity by nitrogen doping was found and applied in enhancement mode ZnO-TFTs. The ZnO-TFTs with a conventional bottom-gate structure were fabricated on thermally oxidized p-type silicon substrate. Electrical measurement has revealed that the devices operate as an n-channel enhancement mode and exhibit an on/off ratio of 10(4). The threshold voltage is 5.15 V. The channel mobility on the order of 2.66 cm(2) V-1 s(-1) has been determined. (c) 2007 Elsevier B.V. All rights reserved.
- Published
- 2008
22. Characterization and functional analysis of a novel double-guide C/D box snoRNA in the fission yeast
- Author
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Liang-Hu Qu, Hui Zhou, and Yan-Zhen Bi
- Subjects
Base Sequence ,biology ,TATA box ,Molecular Sequence Data ,Biophysics ,RNA ,RRNA methylation ,Cell Biology ,Methylation ,DNA Methylation ,Ribosomal RNA ,biology.organism_classification ,Biochemistry ,Molecular biology ,Schizosaccharomyces ,Schizosaccharomyces pombe ,RNA, Small Nucleolar ,Small nucleolar RNA ,Promoter Regions, Genetic ,Molecular Biology ,Gene - Abstract
Ribose methylation of eukaryotic rRNA is directed by box C/D small nucleolar RNAs (snoRNAs), which pinpoint the nucleotide to be methylated in specific position within the rRNA sequence. Here, we report the identification of a novel double-guide C/D box snoRNA termed snR88 that directs methylation of two previously undetermined sites in 25S rRNA from the fission yeast. Knockout of the predicted TATA box of the snR88 gene resulted in the complete blocking of its expression, showing that snR88 is an independently transcribed gene and dispensable for yeast viability. The depletion of snR88 abolished 25S rRNA methylation at U2304 and U2497 simultaneously. Interestingly, an unusual pause of reverse transcription at U2495 was observed, which implies an unknown structure of 25S rRNA related to ribose methylation at U2497 in the fission yeast.
- Published
- 2007
23. Glancing-incidence X-ray analysis of ZnO thin films and ZnO/ZnMgO heterostructures grown by laser-MBE
- Author
-
Weifeng zhang, Q.Y. Xu, Jingwen Zhang, Yongning He, Wang Hong-bo, Zhen Bi, Xun Hou, and Xiaodong Yang
- Subjects
Photoluminescence ,Materials science ,Analytical chemistry ,Heterojunction ,Surface finish ,Condensed Matter Physics ,Laser ,law.invention ,Inorganic Chemistry ,X-ray reflectivity ,law ,Materials Chemistry ,Thin film ,Layer (electronics) ,Molecular beam epitaxy - Abstract
In this paper, we report on glancing-incidence X-ray analysis (GIXA) of ZnO thin films, ZnO/ZnMgO and ZnO/Au heterostructures grown by laser molecular beam epitaxy (L-MBE) on c-plane Al2O3 substrates. The surface and interface sensitivity of X-ray reflectivity (XRR) has been exploited to evaluate the surfaces and interfaces of ZnO-based structures. The presence of smooth interfaces is responsible for the observation of intensity oscillation in XRR, which is well correlated to the clear Pendellosung fringes in high-resolution X-ray diffraction (HRXRD) measurements. In addition, the simulation of XRR data yields reliable and precise information of the layer thickness, the surface and interface roughness of each layer. The correlation of a smooth surface and high optical and structural quality is substantiated by time-integrated photoluminescence (TIPL) and XRD measurements of ZnO/ZnMgO heterostructure and ZnO thin films. The intense exciton-related emission, in contrast to a negligible deep-level radiation and the high c-axis orientation of ZnO films, indicates good optical and structural properties due to the superior surface and interface quality of our samples. (c) 2005 Elsevier B.V. All rights reserved.
- Published
- 2005
24. Fabrication and optical properties of spear-like ZnO nanostructures by chemical vapor deposition
- Author
-
Ya'nan Hu, Zhen Bi, Xin’an Zhang, Xuming Bian, Xun Hou, Dong Wang, Gaoming Li, and Jingwen Zhang
- Subjects
Materials science ,Nanostructure ,Photoluminescence ,Mechanical Engineering ,Analytical chemistry ,Chemical vapor deposition ,Condensed Matter Physics ,Nanomaterials ,Field emission microscopy ,Mechanics of Materials ,General Materials Science ,Emission spectrum ,Luminescence ,Powder diffraction - Abstract
Novel spear-like ZnO nanowires with a length of 2 μm and a width of 0.26 μm were synthesized on p-Si (100) substrates by chemical vapor deposition (CVD) method without catalysts. The crystal structures and morphographies of the products were characterized by X-ray powder diffraction (XRD) and high resolution field emission scanning electron microscope (FE-SEM). Energy dispersive X-ray spectrum (EDS) demonstrated that the spear-like microstuctures consist of element Zn and O. It indicated that the shapes of the products strongly depend on the growth conditions. The optical properties of spear-like ZnO nanostructures were investigated by temperature-depended photoluminescence (PL) measurements and all of the observed emission lines were well fitted by the Varshni formula.
- Published
- 2009
25. Decay of ▭ in hot matter
- Author
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Pin Zhen Bi and Johann Rafelski
- Subjects
Physics ,Nuclear physics ,Particle scattering ,Nuclear and High Energy Physics ,Particle physics ,High Energy Physics::Phenomenology ,Nuclear Theory ,Hadron ,High Energy Physics::Experiment ,Elementary particle ,Function (mathematics) ,Quantum field theory ,Nuclear Experiment - Abstract
We investigate how the presence of hadronic matter affects the width and the decay pattern of ▭ as a function of temperature and density and what this means qualitatively for the experiments studying ▭ production in relativistic nuclear collisions. We determine quantitatively in two models how the natural hadronic width of ▭ increases in a hot hadronic gas.
- Published
- 1991
26. Optical and structural properties of self-assembled ZnO QD chains by L-MBE
- Author
-
Zhen, Bi, primary, Jingwen, Zhang, additional, Xiaodong, Yang, additional, Dong, Wang, additional, Xin’an, Zhang, additional, Weifeng, Zhang, additional, and Xun, Hou, additional
- Published
- 2007
- Full Text
- View/download PDF
27. abundance and mass reduction in heavy ion collisions
- Author
-
Pin-zhen, Bi, primary
- Published
- 2000
- Full Text
- View/download PDF
28. The computer simulation of the temperature distribution on the surface of ceramic cutting tools
- Author
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Liu, You-Rong, primary, Liu, Jia-Jun, additional, Zhu, Bao-Liang, additional, Luo, Zhen-Bi, additional, and Miao, He-Zhuo, additional
- Published
- 1997
- Full Text
- View/download PDF
29. The influence of mass reduction on pion momentum spectra from relativistic collisions
- Author
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Pin-zhen, Bi, primary and Yao-ming, Shi, additional
- Published
- 1996
- Full Text
- View/download PDF
30. Prolate ellipsoidal bag model for heavy quarkonium
- Author
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Gia-zhan, Wang, primary, Pin-zhen, Bi, additional, and Pong-cheng, Yin, additional
- Published
- 1981
- Full Text
- View/download PDF
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