31 results on '"Fangjun Zhang"'
Search Results
2. tBuOLi-Promoted Hydroboration of Esters and Epoxides
- Author
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Yinyin Shi, Yue Wang, Zhefan Huang, Fangjun Zhang, and Yinlin Shao
- Subjects
General Chemical Engineering ,General Chemistry - Published
- 2022
- Full Text
- View/download PDF
3. Manipulating the electronic configuration of Fe–N4 sites by an electron-withdrawing/donating strategy with improved oxygen electroreduction performance
- Author
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Yonggan Wu, Xiannong Tang, Fangjun Zhang, Longbin Li, Weijuan Zhai, Bingyu Huang, Ting Hu, Dirk Lützenkirchen-Hecht, Kai Yuan, and Yiwang Chen
- Subjects
inorganic chemicals ,Materials Chemistry ,General Materials Science - Abstract
A facile boron induced electron-withdrawing/donating strategy is demonstrated to regulate the electronic configuration of Fe–N4 sites in Fe–N–C catalysts to optimize the absorption/desorption of oxygen intermediates during the oxygen reduction reaction.
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- 2022
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4. Cooperative Rare‐Earth/Lithium‐Mediated Conversion of White Phosphorus
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Qing You, Jie Zhang, Fangjun Zhang, Jiamin Cai, and Xigeng Zhou
- Subjects
Organic Chemistry ,General Chemistry ,Catalysis - Published
- 2023
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5. Palladium(<scp>ii</scp>)-catalyzed three-component tandem reactions: synthesis of multiply substituted quinolines
- Author
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Lepeng Chen, Yetong Zhang, Zhongyan Chen, Fangjun Zhang, Jiuxi Chen, Ningning Lv, Yinlin Shao, and Renhao Li
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chemistry.chemical_compound ,Tandem ,Cascade reaction ,chemistry ,Component (thermodynamics) ,Organic Chemistry ,Functional group ,Halogen ,chemistry.chemical_element ,Combinatorial chemistry ,Catalysis ,Palladium - Abstract
The three-component tandem reaction of 2-aminobenzonitriles, arylboronic acids and ketones allowing the synthesis of polysubstitution quinolines is reported. This strategy presents a practical, efficient, one-pot procedure that delivers functional quinolines in moderate to good yields with high functional group tolerance. To enrich the synthetic applications in accessing diverse quinolines, a new method for the introduction of halogen substituents into target products has been developed as well, which shows potential for further synthetic elaborations.
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- 2021
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6. Samarium(<scp>iii</scp>) catalyzed synthesis of alkenylboron compounds via hydroboration of alkynes
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Qianrui Liu, Yinyin Shi, Fangjun Zhang, Caiyan Wu, Jiuxi Chen, Yaoyao Xie, Jichao Liu, and Yinlin Shao
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Isotopic labeling ,Lanthanide ,Samarium ,Hydroboration ,Reaction mechanism ,chemistry.chemical_compound ,Chemistry ,Organic Chemistry ,Proton NMR ,chemistry.chemical_element ,Homoleptic ,Combinatorial chemistry ,Catalysis - Abstract
The homoleptic lanthanide complex Sm[N(TMS)2]3 is an efficient rare-earth catalyst for the hydroboration of alkynes to the corresponding alkenylboron compounds. Practical applications were demonstrated through a gram-scale synthesis and further transformations of an alkenylboron ester to a series of functional compounds. Isotopic labeling experiments, 1H NMR monitoring and kinetic studies were conducted to elucidate the reaction mechanism.
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- 2021
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7. A versatile Pt-Ce6 nanoplatform as catalase nanozyme and NIR-II photothermal agent for enhanced PDT/PTT tumor therapy
- Author
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Qing Chen, Chunxia Li, Jianhua Liu, Zhigang Jin, Dongmei Wang, Su He, Fengzhi Cui, Man Wang, and Fangjun Zhang
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chemistry.chemical_classification ,Reactive oxygen species ,Materials science ,biology ,Tumor hypoxia ,Cytochrome c ,medicine.medical_treatment ,Photodynamic therapy ,02 engineering and technology ,Photothermal therapy ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry ,In vivo ,Catalase ,Biophysics ,biology.protein ,medicine ,General Materials Science ,Photosensitizer ,0210 nano-technology - Abstract
The hypoxic nature of solid tumors has severely negative effects on oxygen-based photodynamic therapy. In this study, we used porous Pt nanoparticles as a catalase (CAT) nanozyme, the second near-infrared (NIR-II) region photothermal transition agents (PTAs), and carriers of photosensitizer chlorin e6 (Ce6) to synthesize a composite nanosystem Pt-Ce6. In this system, Pt-Ce6 can continuously and stably decompose H2O2 into oxygen, thereby alleviating tumor hypoxia and improving the effect of photodynamic therapy (PDT). With 650 nm illumination, the reactive oxygen species (ROS) produced by Ce6 will decrease the mitochondrial membrane potential (MMP, ΔΨm) to release cytochrome c (Cyt-c) from the mitochondria into the cytoplasm, eventually leading to mitochondrial-mediated cellular apoptosis during the PDT process. In addition, Pt-Ce6 has good photothermal stability and high photothermal conversion efficiency (52.62%) in the NIR-II region. In U14 tumor-bearing mice, Pt-Ce6 completely suppressed tumor growth and recurrence under laser irradiation. Thus the nanocomposite shows excellent PDT/photothermal therapy (PTT) synergistic performance in vitro and in vivo.
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- 2020
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8. Hexamethyldisilazane Lithium (LiHMDS)-Promoted Hydroboration of Alkynes and Alkenes with Pinacolborane
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Jichao Liu, Caiyan Wu, Tinghui Hu, Wei Yang, Yaoyao Xie, Yinyin Shi, Qianrui Liu, Yinlin Shao, and Fangjun Zhang
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Organic Chemistry - Abstract
Lithium-promoted hydroboration of alkynes and alkenes using commercially available hexamethyldisilazane lithium as a precatalyst and HBpin as a hydride source has been developed. This method will be appealing for organic synthesis because of its remarkable substrate tolerance and good yields. Mechanistic studies revealed that the hydroboration proceeds through the in situ-formed BH
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- 2022
9. Palladium-Catalyzed Three-Component Cascade Reaction of Nitriles: Synthesis of 2-Arylquinoline-4-carboxylates
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Yinan Chen, Yinlin Shao, Jinming Zheng, Jiuxi Chen, Renhao Li, Fangjun Zhang, Zhongyan Chen, Ge Zeng, and Zhao Zhiwei
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Chemistry ,Component (thermodynamics) ,Organic Chemistry ,chemistry.chemical_element ,Ring (chemistry) ,Biochemistry ,Combinatorial chemistry ,Fluorescence ,Catalysis ,chemistry.chemical_compound ,Cascade reaction ,Functional group ,Physical and Theoretical Chemistry ,Acetonitrile ,Palladium - Abstract
A new method for converting easy availability starting materials 2-(2-oxoindolin-3-yl)acetonitrile, arylboronic acids, and alcohols into 2-arylquinoline-4-carboxylates is reported. The procedure involves a three-component addition/ring expansion/esterification reaction in the presence of Pd(II) catalyst with high functional group tolerance under mild conditions. In addition, the photophysical properties of the resulting product were investigated and exhibited excellent polarity-sensitive fluorescence properties and AIE property.
- Published
- 2021
10. Rare‐Earth‐Metal‐Catalyzed Synthesis of Azaindolines and Naphthyridines via C−H Cyclization of Functionalized Pyridines
- Author
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Fangjun Zhang, Zou Jinxuan, Ye Pengqing, Yinlin Shao, Jiuxi Chen, and Xuanzeng Ye
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Metal ,Chemistry ,visual_art ,Rare earth ,Polymer chemistry ,visual_art.visual_art_medium ,General Chemistry ,Catalysis - Published
- 2019
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11. An Yttrium Organic cyclo-P4 Complex and Its Selective Conversions
- Author
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Xigeng Zhou, Linhong Weng, Fangjun Zhang, Jie Zhang, and Zhenxia Chen
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chemistry.chemical_classification ,010405 organic chemistry ,chemistry.chemical_element ,Yttrium ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Inorganic Chemistry ,Metal ,chemistry ,visual_art ,Yield (chemistry) ,Organophosphorus compound ,visual_art.visual_art_medium ,Physical and Theoretical Chemistry ,Alkyl - Abstract
The rare-earth-metal organic cyclo-P4 complex (LY·DMAP)2[1,2-R2- cyclo-P4] (2, L = N, N'-2,6-diisopropylphenyl-1,4-diazabutadiene, DMAP = 4- N, N'-dimethylpyridine, R = CH2C6H4NMe2-2) was synthesized by direct functionalization of P4 using the rare-earth-metal alkyl complex LYR(THF) (1) for the first time. Further investigations indicated that three selective conversions of the cyclo-P4 species have been realized by alkyl migration. Complex 2 was slowly transformed into a R2P-substituted cyclo-P3 cluster (LY·DMAP)2[ cyclo-P3PR2] (3) under heating conditions. The reaction of 2 with 1 equiv of KR gave the unsubstituted cyclo-P3 complex (LY·THF)2[ cyclo-P3]K (4) in quantitative yield, accompanied by the elimination of the organophosphorus compound PR3 (5). Treatment of 2 with HMPA afforded the structurally characterized Zintl-type P7 complex (LY·HMPA)3P7 (6). The formation of complexes 3, 4, and 6 revealed that unusual alkyl migrations in the polyphosphorus complexes occurred in these reactions, and the transformations from cyclo-P4 into cyclo-P3 also provided a new insight into the stepwise degradation of P4 using metal complexes.
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- 2019
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12. Selective Synthesis of β-Ketonitriles via Catalytic Carbopalladation of Dinitriles
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Zhongyan Chen, Ge Zeng, Renhao Li, Yinlin Shao, Jiuxi Chen, Fangjun Zhang, Jichao Liu, and Ningning Lv
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Scope (project management) ,Chemistry ,Reagent ,Organic Chemistry ,Highly selective ,Combinatorial chemistry ,Catalysis - Abstract
A practical, convenient, and highly selective method of synthesizing β-ketonitriles from the Pd-catalyzed addition of organoboron reagents to dinitriles has been developed. This method provides excellent functional-group tolerance, a broad scope of substrates, and the convenience of using commercially available substrates. The method is expected to show further utility in future synthetic procedures.
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- 2020
13. Homoleptic Bis(trimethylsilyl)amides of Yttrium Complexes Catalyzed Hydroboration Reduction of Amides to Amines
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Yinlin Shao, Renhao Li, Ye Pengqing, Sun Jiani, Xuanzeng Ye, Jiuxi Chen, Xu Beihang, and Fangjun Zhang
- Subjects
Lanthanide ,Reaction mechanism ,Trimethylsilyl ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Homogeneous catalysis ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Medicinal chemistry ,0104 chemical sciences ,Isotopic labeling ,Hydroboration ,chemistry.chemical_compound ,Nitro ,Physical and Theoretical Chemistry ,Homoleptic - Abstract
Homoleptic lanthanide complex Y[N(TMS)2]3 is an efficient homogeneous catalyst for the hydroboration reduction of secondary amides and tertiary amides to corresponding amines. A series of amides containing different functional groups such as cyano, nitro, and vinyl groups were found to be well-tolerated. This transformation has also been nicely applied to the synthesis of indoles and piribedil. Detailed isotopic labeling experiments, control experiments, and kinetic studies provided cumulative evidence to elucidate the reaction mechanism.
- Published
- 2020
14. Analysis of the genetic architecture of maize ear and grain morphological traits by combined linkage and association mapping
- Author
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Zhiqiang Zhou, Fangjun Zhang, Hongjun Yong, Chaoshu Zhang, Zhenhua Wang, Xinhai Li, Degui Zhang, Mingshun Li, Jianfeng Weng, Zhuanfang Hao, and Xiaochong Zhang
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0106 biological sciences ,0301 basic medicine ,Genetic Linkage ,Quantitative Trait Loci ,Population ,Locus (genetics) ,Environment ,Biology ,Quantitative trait locus ,Polymorphism, Single Nucleotide ,Zea mays ,01 natural sciences ,03 medical and health sciences ,Family-based QTL mapping ,Genetics ,Allele ,Association mapping ,education ,Genetic Association Studies ,education.field_of_study ,Chromosome Mapping ,food and beverages ,Genetic Pleiotropy ,General Medicine ,Genetic architecture ,030104 developmental biology ,Linkage based QTL mapping ,Seeds ,Edible Grain ,Agronomy and Crop Science ,010606 plant biology & botany ,Biotechnology - Abstract
Using combined linkage and association mapping, 26 stable QTL and six stable SNPs were detected across multiple environments for eight ear and grain morphological traits in maize. One QTL, PKS2, might play an important role in maize yield improvement. In the present study, one bi-parental population and an association panel were used to identify quantitative trait loci (QTL) for eight ear and grain morphological traits. A total of 108 QTL related to these traits were detected across four environments using an ultra-high density bin map constructed using recombinant inbred lines (RILs) derived from a cross between Ye478 and Qi319, and 26 QTL were identified in more than two environments. Furthermore, 64 single nucleotide polymorphisms (SNPs) were found to be significantly associated with the eight ear and grain morphological traits (−log10(P) > 4) in an association panel of 240 maize inbred lines. Combining the two mapping populations, a total of 17 pleiotropic QTL/SNPs (pQTL/SNPs) were associated with various traits across multiple environments. PKS2, a stable locus influencing kernel shape identified on chromosome 2 in a genome-wide association study (GWAS), was within the QTL confidence interval defined by the RILs. The candidate region harbored a short 13-Kb LD block encompassing four SNPs (SYN11386, PHM14783.16, SYN11392, and SYN11378). In the association panel, 13 lines derived from the hybrid PI78599 possessed the same allele as Qi319 at the PHM14783.16 (GG) locus, with an average value of 0.21 for KS, significantly lower than that of the 34 lines derived from Ye478 that carried a different allele (0.25, P
- Published
- 2017
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15. An Yttrium Organic cyclo-P
- Author
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Fangjun, Zhang, Jie, Zhang, Zhenxia, Chen, Linhong, Weng, and Xigeng, Zhou
- Abstract
The rare-earth-metal organic cyclo-P
- Published
- 2019
16. ReCoNet: Real-Time Coherent Video Style Transfer Network
- Author
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Yizhou Yu, Chang Gao, Fangjun Zhang, and Derun Gu
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Computer science ,business.industry ,media_common.quotation_subject ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Stability (learning theory) ,Optical flow ,020207 software engineering ,02 engineering and technology ,Luminance ,Convolutional neural network ,Image (mathematics) ,Constraint (information theory) ,Perception ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Computer vision ,Artificial intelligence ,Image warping ,business ,media_common - Abstract
Image style transfer models based on convolutional neural networks usually suffer from high temporal inconsistency when applied to videos. Some video style transfer models have been proposed to improve temporal consistency, yet they fail to guarantee fast processing speed, nice perceptual style quality and high temporal consistency at the same time. In this paper, we propose a novel real-time video style transfer model, ReCoNet, which can generate temporally coherent style transfer videos while maintaining favorable perceptual styles. A novel luminance warping constraint is added to the temporal loss at the output level to capture luminance changes between consecutive frames and increase stylization stability under illumination effects. We also propose a novel feature-map-level temporal loss to further enhance temporal consistency on traceable objects. Experimental results indicate that our model exhibits outstanding performance both qualitatively and quantitatively.
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- 2019
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17. Isotope shift of the 2s 2S1/2 → 2p 2P1/2,3/2 transitions of Li-like Ca ions*
- Author
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Fangjun Zhang, Xiaobin Ding, Deng-Hong Zhang, and Chenzhong Dong
- Subjects
Physics ,Isotope ,Analytical chemistry ,General Physics and Astronomy - Abstract
The mass- and field-shift parameters of the two 2s 2S1/2 → 2p 2P1/2,3/2 transitions in the Li-like Ca ions are calculated by using multi-configuration Dirac–Hartree–Fock (MCDHF) and the relativistic configuration interaction (RCI) methods with the inclusion of the transverse photon (Breit) interaction, vacuum polarization and self-energy corrections. In addition, the mass shift and field shift of these two transitions are calculated, where the field shift is calculated by using the evaluated value δ〈 r 2〉 obtained by [Atomic Data and Nuclear Data Tables 99 69 (2013)]. It is found that the mass shift of Li-like Ca ions is greater than the field shift.
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- 2021
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18. Lanthanide-Catalyzed Reversible Alkynyl Exchange by Carbon-Carbon Single-Bond Cleavage Assisted by a Secondary Amino Group
- Author
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Fangjun Zhang, Yinlin Shao, Xigeng Zhou, and Jie Zhang
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Lanthanide ,chemistry.chemical_classification ,Reaction mechanism ,010405 organic chemistry ,Imine ,Alkyne ,General Medicine ,General Chemistry ,010402 general chemistry ,Metathesis ,01 natural sciences ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Polymer chemistry ,Alkyne metathesis ,Single bond ,Organic chemistry - Abstract
Lanthanide-catalyzed alkynyl exchange through C-C single-bond cleavage assisted by a secondary amino group is reported. A lanthanide amido complex is proposed as a key intermediate, which undergoes unprecedented reversible β-alkynyl elimination followed by alkynyl exchange and imine reinsertion. The in situ homo- and cross-dimerization of the liberated alkyne can serve as an additional driving force to shift the metathesis equilibrium to completion. This reaction is formally complementary to conventional alkyne metathesis and allows the selective transformation of internal propargylamines into those bearing different substituents on the alkyne terminus in moderate to excellent yields under operationally simple reaction conditions.
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- 2016
- Full Text
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19. Breeding potential of maize germplasm populations to improve yield and predominant heterotic pattern in Northeast China
- Author
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Degui Zhang, Lin Zhang, Zhuanfang Hao, Xianjun Liu, Li Gao, Xiaocong Zhang, Hongjun Yong, Shihuang Zhang, Fangjun Zhang, Xinhai Li, Zhenguo Jin, Jianfeng Weng, and Mingshun Li
- Subjects
0106 biological sciences ,0301 basic medicine ,Germplasm ,biology ,business.industry ,Heterosis ,Crop yield ,Plant Science ,Horticulture ,biology.organism_classification ,01 natural sciences ,Biotechnology ,03 medical and health sciences ,030104 developmental biology ,Inbred strain ,Agronomy ,Genetic variation ,Smut ,Genetics ,Genetic variability ,Plant breeding ,business ,Agronomy and Crop Science ,010606 plant biology & botany - Abstract
Increasing the frequency of favorable alleles in elite germplasm is necessary for germplasm improvement and innovation in maize (Zea mays L.) breeding programs. Jidan27 (Si287 × Si144), an elite commercial single cross hybrid that represents the predominant heterotic pattern Chinese Sipingtou × Stiff Stalk Synthetic, has been widely cultivated in the Northeast China Corn Belt. However, the use of the hybrid Jidan27 has been hampered gradually due to its low yield potential, lack of resistance to lodging, and considerable incidence of head smut disease. Previous studies have evaluated yield potential of exotic populations, but few have considered using these germplasms as donors with favorable alleles to overcome these deficiencies in the hybrid Jidan27. In the present study, 12 exotic populations from CIMMYT and the U.S. and three semi-exotic populations were investigated as sources of favorable alleles to increase yield and lodging resistance, and reducing head smut susceptibility of the hybrid Jidan27. The performance of a set of 30 inbred × populations crosses, the hybrid Jidan27, and the two parental inbred lines Si287 and Si144 was evaluated in three locations for 2 years. Two populations, BS10(FR)C10 and Pop43, were identified as the best donors of favorable alleles lacking in the hybrid for improving the target traits. Further, BS13(S)C7 and Cpop.16 were also found to be better choices for improving grain yield and head smut resistance of the hybrid. These results suggest that the elite exotic germplasms evaluated here could provide useful genetic variability to improve other Chinese Sipingtou × Stiff Stalk Synthetic crosses related to Si287 × Si144 that are widely grown in Northeast China.
- Published
- 2017
- Full Text
- View/download PDF
20. Facile Construction of Yttrium Pentasulfides from Yttrium Alkyl Precursors: Synthesis, Mechanism, and Reactivity
- Author
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Xigeng Zhou, Jie Zhang, and Fangjun Zhang
- Subjects
chemistry.chemical_classification ,010405 organic chemistry ,Inorganic chemistry ,chemistry.chemical_element ,Yttrium ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Reagent ,Yield (chemistry) ,Electrophile ,Reactivity (chemistry) ,Physical and Theoretical Chemistry ,Alkyl ,Stoichiometry ,Tetrahydrofuran - Abstract
Treatment of the yttrium dialkyl complex TpMe2Y(CH2Ph)2(THF) (TpMe2 = tri(3,5 dimethylpyrazolyl)borate, THF = tetrahydrofuran) with S8 in a 1:1 molar ratio in THF at room temperature afforded a yttrium pentasulfide TpMe2Y(κ4-S5) (THF) (1) in 93% yield. The yttrium monoalkyl complex TpMe2CpYCH2Ph(THF) reacted with S8 in a 1:0.5 molar ratio under the same conditions to give another yttrium pentasulfide [(TpMe2)2Y]+[Cp2Y(κ4-S5)]− (10) in low yield. Further investigations indicated that the S52– anion facilely turned into the corresponding thioethers or organic disulfides, and released the redundant S8, when it reacted with some electrophilic reagents. The mechanism for the formation of the S52– ligand has been investigated by the controlling of the reaction stoichiometric ratios and the stepwise reactions.
- Published
- 2017
21. Versatile Reactivity of β-Diketiminato-Supported Yttrium Dialkyl Complex toward Aromatic N-Heterocycles
- Author
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Xigeng Zhou, Fangjun Zhang, Jianquan Hong, Yin Zhang, Jie Zhang, and Linhong Weng
- Subjects
Chemistry ,Stereochemistry ,Organic Chemistry ,Benzoxazole ,Ring (chemistry) ,Medicinal chemistry ,Inorganic Chemistry ,Metal ,chemistry.chemical_compound ,Benzothiazole ,visual_art ,Yield (chemistry) ,Pyridine ,Proton NMR ,visual_art.visual_art_medium ,Reactivity (chemistry) ,Physical and Theoretical Chemistry - Abstract
The reactions of β-diketiminatoyttrium dialkyl complex LY(CH2Ph)2(THF) (1, L = [{N(2,6-iPr2C6H3)C(Me)}2CH]−) with a series of aromatic N-heterocycles such as 2-phenylpyridine, benzothiazole, and benzoxazole were studied and displayed discrete reactivity including C–H activation, C–C coupling, ring-opening/insertion, and dearomatization. The reaction of 1 with 2-phenylpyridine in 1:2 molar ratio in THF at 30 °C for 14 days afforded a structurally characterized metal complex, LY(η2-N,C-C5H4NC6H4-2)[C5H4N(CH2Ph-4)Ph] (2), in 73% isolated yield, indicating the occurrence of phenyl ring C(sp2)–H activation and pyridine ring 1,4-addition/dearomatization. However, when this reaction was done at 5 °C for 7 days, it gave the pyridine ring 1,2-addition product LY(η2-N,C-C5H4NC6H4-2)[C5H4N(CH2Ph-2)Ph] (3) in 54% isolated yield. Further investigations revealed that complex 2 is the thermodynamic controlled product and complex 3 is the kinetically controlled product; 3 converted slowly into 2, as confirmed by 1H NMR s...
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- 2014
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22. Rare-Earth-Metal-Catalyzed Addition of Terminal Monoalkynes and Dialkynes with Aryl-Substituted Symmetrical or Unsymmetrical Carbodiimides
- Author
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Jie Zhang, Yin Zhang, Jianquan Hong, Fangjun Zhang, and Xigeng Zhou
- Subjects
chemistry.chemical_classification ,Ligand ,Gadolinium ,Aryl ,Organic Chemistry ,Rare earth ,chemistry.chemical_element ,Medicinal chemistry ,Catalysis ,Inorganic Chemistry ,Metal ,chemistry.chemical_compound ,chemistry ,Terminal (electronics) ,visual_art ,visual_art.visual_art_medium ,Physical and Theoretical Chemistry ,Alkyl - Abstract
A high-efficiency and atom-economic route for the synthesis of N-aryl-substituted propiolamidines was established through the addition of terminal alkynes with aryl-substituted symmetrical or unsymmetrical carbodiimides catalyzed by mixed TpMe2/Cp rare-earth-metal alkyl complexes (TpMe2)CpLnCH2Ph(THF) (1Ln). Moreover, the gadolinium alkyl complex 1Gd can also serve as a catalyst for the double addition of dialkynes with carbodiimides. Mechanism studies indicated that the variable coordination modes (κ3 or κ2) of the TpMe2 ligand on the rare-earth-metal species may play an important role in the catalytic cycles.
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- 2014
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23. Auditory stimulation modulates CXCL12/CXCR4 expression in postnatal development of the newborn rat cochlea
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Ya Gao, Yu Han, Wen Zhang, Hui Liu, Yang Chen, Ye Wang, Jun Chen, Bo Yue, and Fangjun Zhang
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medicine.medical_specialty ,Receptors, CXCR4 ,Sensory system ,Biology ,Immunofluorescence ,Rats, Sprague-Dawley ,Internal medicine ,otorhinolaryngologic diseases ,medicine ,Animals ,Receptor ,Cochlea ,medicine.diagnostic_test ,General Neuroscience ,Gene Expression Regulation, Developmental ,medicine.disease ,Neural stem cell ,Chemokine CXCL12 ,Rats ,Endocrinology ,Auditory brainstem response ,Acoustic Stimulation ,Animals, Newborn ,Immunohistochemistry ,Sensorineural hearing loss ,sense organs - Abstract
Sensorineural hearing loss is one of the most common sensory deficits. Recently, inner-ear stem cell therapy has been proposed for auditory afferent rehabilitation. CXCR4 is the primary physiologic receptor for CXC chemokine ligand 12 (CXCL12) and the CXCL12-CXCR4 pathway has been implicated in the process of migration, differentiation, and maturation of vertebrate neural stem cells. In this study, we examined changes in the auditory brainstem response and CXCL12/CXCR4 expression in newborn rat cochleae under different acoustic environments by quantitative real-time PCR, western blot, enzyme-linked immunosorbent assay, immunohistochemistry, and immunofluorescence analyses. Rats were divided randomly into three groups: the augmented acoustic environment (AAE) group, the auditory deprivation (AD) group, and the control group. Auditory brainstem response thresholds were markedly increased in the AAE group and in the AD group. Compared with postnatal day 1, the expression of CXCL12/CXCR4 mRNA and protein under normal acoustic conditions was increased on postnatal day 14 and then decreased on postnatal day 28 in the cochlea. However, on postnatal day 28, CXCL12/CXCR4 expression, as well as its spatiotemporal distribution as detected by immunohistochemistry and immunofluorescence assays, was augmented by AAE treatment and inhibited by AD treatment. Therefore, our results confirmed that auditory stimulation influenced the spatiotemporal expression of CXCL12/CXCR4 in newborn rat cochlea, which might help to unravel the role of the CXCL12-CXCR4 pathway in the synaptic contacts and hearing function establishment in rat cochlea development.
- Published
- 2015
24. Versatile Reactivity of Scorpionate-Anchored Yttrium-Dialkyl Complexes towards Unsaturated Substrates
- Author
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Xigeng Zhou, Jie Zhang, Zhenxia Chen, Yin Zhang, Fangjun Zhang, and Weiyin Yi
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Phenyl isothiocyanate ,Organic Chemistry ,chemistry.chemical_element ,General Chemistry ,Yttrium ,Toluene ,Medicinal chemistry ,Small molecule ,Catalysis ,Metal ,chemistry.chemical_compound ,chemistry ,visual_art ,visual_art.visual_art_medium ,Organic chemistry ,Reactivity (chemistry) ,Boron ,Bond cleavage - Abstract
A series of unusual chemical-bond transformations were observed in the reactions of high active yttrium-dialkyl complexes with unsaturated small molecules. The reaction of scorpionate-anchored yttrium-dibenzyl complex [Tp(Me2)Y(CH2Ph)2(thf)] (1, Tp(Me2)=tri(3,5-dimethylpyrazolyl)borate) with phenyl isothiocyanate led to C=S bond cleavage to give a cubane-type yttrium-sulfur cluster, {Tp(Me2)Y(μ3-S)}4 (2), accompanied by the elimination of PhN-C(CH2Ph)2. However, compound 1 reacted with phenyl isocyanate to afford a C(sp(3)) H activation product, [Tp(Me2)Y(thf){μ-η(1):η(3)-OC(CHPh)NPh}{μ-η(3):η(2)-OC(CHPh)NPh}YTp(Me2)] (3). Moreover, compound 1 reacted with phenylacetonitrile at room temperature to produce γ-deprotonation product [(Tp(Me2))2Y](+)[Tp(Me2)Y(N=C=CHPh)3](-) (6), in which the newly formed N=C=CHPh ligands bound to the metal through the terminal nitrogen atoms. When this reaction was carried out in toluene at 120 °C, it gave a tandem γ-deprotonation/insertion/partial-Tp(Me2)-degradation product, [(Tp(Me2)Y)2(μ-Pz)2{μ-η(1):η(3)-NC(CH2Ph)CHPh}] (7, Pz=3,5-dimethylpyrazolyl).
- Published
- 2013
25. Breeding potential of maize germplasm populations to improve yield and predominant heterotic pattern in Northeast China.
- Author
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Hongjun Yong, Zhenguo Jin, Li Gao, Lin Zhang, Xianjun Liu, Fangjun Zhang, Xiaocong Zhang, Degui Zhang, Mingshun Li, Jianfeng Weng, Zhuanfang Hao, Shihuang Zhang, and Xinhai Li
- Abstract
Increasing the frequency of favorable alleles in elite germplasm is necessary for germplasm improvement and innovation in maize (Zea mays L.) breeding programs. Jidan27 (Si287 9 Si144), an elite commercial single cross hybrid that represents the predominant heterotic pattern Chinese Sipingtou 9 Stiff Stalk Synthetic, has been widely cultivated in the Northeast China Corn Belt. However, the use of the hybrid Jidan27 has been hampered gradually due to its low yield potential, lack of resistance to lodging, and considerable incidence of head smut disease. Previous studies have evaluated yield potential of exotic populations, but few have considered using these germplasms as donors with favorable alleles to overcome these deficiencies in the hybrid Jidan27. In the present study, 12 exotic populations from CIMMYT and the U.S. and three semi-exotic populations were investigated as sources of favorable alleles to increase yield and lodging resistance, and reducing head smut susceptibility of the hybrid Jidan27. The performance of a set of 30 inbred 9 populations crosses, the hybrid Jidan27, and the two parental inbred lines Si287 and Si144 was evaluated in three locations for 2 years. Two populations, BS10(FR)C10 and Pop43, were identified as the best donors of favorable alleles lacking in the hybrid for improving the target traits. Further, BS13(S)C7 and Cpop.16 were also found to be better choices for improving grain yield and head smut resistance of the hybrid. These results suggest that the elite exotic germplasms evaluated here could provide useful genetic variability to improve other Chinese Sipingtou 9 Stiff Stalk Synthetic crosses related to Si287 9 Si144 that are widely grown in Northeast China. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
26. Facile Construction of Yttrium Pentasulfides from Yttrium Alkyl Precursors: Synthesis, Mechanism, and Reactivity.
- Author
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Fangjun Zhang, Jie Zhang, and Xigeng Zhou
- Published
- 2017
- Full Text
- View/download PDF
27. Performance of Flame Retardant Wool Fabric Grafted with Vinyl Phosphate
- Author
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Jinping Guan, Guoqiang Chen, and Fangjun Zhang
- Subjects
Thermogravimetric analysis ,Materials science ,technology, industry, and agriculture ,Potassium persulfate ,chemistry.chemical_compound ,chemistry ,Wool ,Differential thermal analysis ,Ultimate tensile strength ,General Materials Science ,Char ,Composite material ,Flammability ,Fire retardant - Abstract
In this paper, a flame retardant dimethyl-2–(methacryloyloxyethyl) phosphate (DMMEP) was applied to wool fabrics by the graft copolymerization technique initiated with potassium persulfate (KPS) in water media. FTIR and SEM testing were used to explore the grafting evidence on the fiber surface, the SEM results show chemical deposition on the wool fiber surface and the scales could not be seen clearly. FTIR testing exhibited IR absorption of DMMEP on the wool fiber. Thermal gravimetric analysis, differential thermal analysis (DTA), and char residue morphology SEM observation show the decomposition mode of wool fabrics and infer the possible flame retardant mechanism. The phosphorus based flame retardant DMMEP was prone to promote more nonflammble char during combustion, and increased add-on of DMMEP produced increased fabric char. With a DMMEP add-on increase from 50% to 100% on the weight of wool fabric, the treated wool fabric demonstrated high flame retardancy with an LOI above 35% which means it can not be ignited with a candle like fire, and could pass the vertical flammability test. DMMEP treatment slightly affected whiteness and moisture regain, but yielded a relatively large decrease in permeability and tensile strength, which should be explored further in later research.
- Published
- 2014
- Full Text
- View/download PDF
28. Ln[N(SiMe3)2]3-catalyzed cycloaddition of terminal alkynes to azides leading to 1,5-disubstituted 1,2,3-triazoles: new mechanistic features
- Author
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Longcheng Hong, Weijia Lin, Xigeng Zhou, Fangjun Zhang, and Ruiting Liu
- Subjects
Azides ,Molecular Structure ,Tandem ,Stereochemistry ,Chemistry ,Rare earth ,Metals and Alloys ,General Chemistry ,Triazoles ,Triple bond ,Lanthanoid Series Elements ,Catalysis ,Cycloaddition ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Terminal (electronics) ,Cyclization ,Alkynes ,Organometallic Compounds ,Materials Chemistry ,Ceramics and Composites - Abstract
The first example of rare earth metal-catalyzed cycloaddition of terminal alkynes to azides resulting in the formation of 1,5-disubstituted 1,2,3-triazoles is described. Preliminary studies revealed that the present cycloaddition shows unprecedented mechanistic features involving a tandem anionic cascade cyclization and anti-addition across the C≡C triple bond.
- Published
- 2013
- Full Text
- View/download PDF
29. Auditory stimulation modulates CXCL12/CXCR4 expression in postnatal development of the newborn rat cochlea.
- Author
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Wen Zhang, Fangjun Zhang, Yu Han, Hui Liu, Ye Wang, Bo Yue, Jun Chen, Yang Chen, and Ya Gao
- Published
- 2015
- Full Text
- View/download PDF
30. Performance of Flame Retardant Wool Fabric Grafted with Vinyl Phosphate.
- Author
-
Fangjun Zhang, Jinping Guan, and Guoqiang Chen
- Abstract
In this paper, a flame retardant dimethyl-2-(methacryloyloxyethyl) phosphate (DMMEP) was applied to wool fabrics by the graft copolymerization technique initiated with potassium persulfate (KPS) in water media. FTIR and SEM testing were used to explore the grafting evidence on the fiber surface, the SEM results show chemical deposition on the wool fiber surface and the scales could not be seen clearly. FTIR testing exhibited IR absorption of DMMEP on the wool fiber. Thermal gravimetric analysis, differential thermal analysis (DTA), and char residue morphology SEM observation show the decomposition mode of wool fabrics and infer the possible flame retardant mechanism. The phosphorus based flame retardant DMMEP was prone to promote more nonflammble char during combustion, and increased add-on of DMMEP produced increased fabric char. With a DMMEP add-on increase from 50% to 100% on the weight of wool fabric, the treated wool fabric demonstrated high flame retardancy with an LOI above 35% which means it can not be ignited with a candle like fire, and could pass the vertical flammability test. DMMEP treatment slightly affected whiteness and moisture regain, but yielded a relatively large decrease in permeability and tensile strength, which should be explored further in later research. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
31. A computational method for determining oil expulsion efficiency based on the ideal effective oil expulsion mode
- Author
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Fangjun Zhang, Wenmin Jiang, Qiang Jin, Peipei Li, Fei Tian, and Qingjie Hou
- Subjects
chemistry.chemical_classification ,Petroleum engineering ,business.industry ,020209 energy ,Fossil fuel ,02 engineering and technology ,010502 geochemistry & geophysics ,Geotechnical Engineering and Engineering Geology ,01 natural sciences ,General Energy ,Hydrocarbon ,Oil generation ,chemistry ,Source rock ,0202 electrical engineering, electronic engineering, information engineering ,business ,Pyrolysis ,0105 earth and related environmental sciences - Abstract
The oil expulsion efficiency of hydrocarbon source rocks is a key parameter for predicting conventional oil and gas resources and is closely related to the source rock thickness. Pyrolysis experiments and oil expulsion models were used to establish an oil expulsion efficiency calculation formula and to then analyze the trend of the oil expulsion efficiency. We determine the theoretical maximum oil expulsion efficiency via pyrolysis experiments to investigate hydrocarbon generation and expulsion. Then, we establish three ideal and effective oil expulsion models based on the single-layer source rock thickness: full type, full and transition type, and full and transition and retention type. Finally, we derive a corresponding correction formula for the oil expulsion efficiency. Using a type II1 hydrocarbon source rock from the Dongying Sag as an example, we calculate the oil expulsion efficiencies. The oil expulsion efficiencies of single-layer source rocks of different thicknesses exhibit only small differences at a low-maturity stage but exhibit obvious differences at a high-maturity stage. The oil expulsion of thin hydrocarbon source rocks is high, even exceeding 70%, but the oil expulsion of super-thick hydrocarbon source rocks is only approximately 30%. Therefore, the thickness of a single-layer hydrocarbon source rock exerts an important influence on oil expulsion, particularly during the raw oil generation and peak discharge stages.
- Full Text
- View/download PDF
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