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Electron transfer reactions between vinylmagnesium bromide and phenyl-substituted methyl chlorides

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Chinese Journal of chemistry 1986年第1期4卷 20-28页

作者： liu you-cheng DANG Hai-Shan department of chemistry, lanzhou university, lanzhou department of chemistry Lanzhou University Lanzhou

The reaction of vinylmagnesium bromide （1） with trityl chloride （2） was investigatedand the products were identified as triphenylmethane （3）（81%）, acetylene （4）（74%）, trityl peroxide（6）（4%）, and minute amounts of triphenylpropene （7） and p-diphenylmethyltetraphenylmethane（8）. The results indicate that 1 possesses reducing property. The reaction mixture showed an ESRspectrum identical with that for trityl radical and the CIDNP of enhanced absorption for 4-H of1-diphenylmethylene-4-trityl-2, 5-cyclohexadiene （9）. Trapping experiment with styrene decreasedthe amount of 3 but had no effect on the formation of 4. The reducing property of 1 is discussedand one electron transfer mechanism for the reaction of 1 with 2 is proposed. S-T0mixing betweentrityl and MgBr occurred and the coupling of polarized trityl radical with another trityl radical resultedin the formation of polarized dimeric product. The different character between the reaction of 1 and 2and that of 1 and diphenylmethyl chloride （10） may be rationalized by the different electron-acceptingabilities between 2 and 10. The origin of CIDNP effect shown by the product tetraphenylethane（Ⅱ） for the reaction of 1 with 10 is also explained according to Kaptein's sign rule.

关键词： Electron transfer reactions between vinylmagnesium bromide and phenyl-substituted methyl chlorides CIDNP

RETINOBLASTOMA RELATED 1 switches mitosis to meiosis in rice

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Plant Communications 2024年第6期5卷 193-212页

作者： Yongjie Miao Hanli you Huixin liu Yangzi Zhao Jiangzhe Zhao Yafei Li Yi Shen Ding Tang Baohui liu Kewei Zhang Zhukuan cheng Guangdong Provincial Key Laboratory of Plant Adaptation and Molecular Design Innovative Center of Molecular Genetics and EvolutionSchool of Life SciencesGuangzhou UniversityGuangzhou 510006China Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Zhongshan Biological Breeding Laboratory/Key Laboratory of Plant Functional Genomics of the Ministry of Education Agricultural College of Yangzhou UniversityYangzhou 225009China State Key Laboratory of Plant Genomics Institute of Genetics and Developmental BiologyInnovation Academy for Seed DesignChinese Academy of SciencesBeijing 100101China Zhejiang Provincial Key Laboratory of Biotechnology on Specialty Economic Plants Department of BiologyCollege of Life SciencesZhejiang Normal UniversityJinhua 321004China Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops/Jiangsu Key Laboratory of Crop Genetics and Physiology Yangzhou UniversityYangzhou 225009China

The transition from mitosis to meiosis is a critical event in the reproductive development of all sexually reproducing ***,the mechanisms that regulate this process in plants remain largely ***,we find that the rice(Oryza sativa L.)protein RETINOBLASTOMA RELATED 1(RBR1)is essential to the transition from mitosis to *** of RBR1 function results in hyper-proliferative sporogenous-celllike cells(SCLs)in the anther locules during early stages of reproductive *** hyperproliferative SCLs are unable to initiate meiosis,eventually stagnating and degrading at late developmental stages to form pollen-free *** results suggest that RBR1 acts as a gatekeeper of entry into ***,cytokinin content is significantly increased in rbr1 mutants,whereas the expression of type-B response factors,particularly LEPTO1,is significantly *** the known close association of cytokinins with cell proliferation,these findings imply that hyper-proliferative germ cells in the anther locules may be attributed to elevated cytokinin concentrations and disruptions in the cytokinin *** a genetic strategy,the association between germ cell hyper-proliferation and disturbed cytokinin signaling in rbr1 has been *** summary,we reveal a unique role of RBR1 in the initiation of meiosis;our results clearly demonstrate that the RBR1 regulatory module is connected to the cytokinin signaling pathway and switches mitosis to meiosis in rice.

关键词： RETINOBLASTOMA RELATED1 meiosis initiation cytokinin rice

Quantum phase transition of the Jaynes-Cummings model

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 1-9页

作者： cheng liu Jin-Feng Huang Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Key Laboratory for Matter Microstructure and Function of Hunan ProvinceDepartment of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsInstitute of Interdisciplinary StudiesHunan Normal UniversityChangsha 410081China

Herein,we propose an experimentally feasible scheme to show the quantum phase transition of the Jaynes-Cummings(JC)model by modulating the transition frequency of a two-level system in a quantum Rabi model with strong *** tuning the modulation frequency and amplitude,the ratio of the effective coupling strength of the rotating terms to the effective cavity(atomic transition)frequency can enter the deep-strong coupling regime,while the counter-rotating terms can be ***,a deep-strong JC model is *** ratio of the coupling strength to resonance frequencies in the deep-strong JC model is two orders of magnitude larger than the corresponding ratio in the original quantum Rabi *** scheme can be employed in atom-cavity resonance and off-resonance cases,and it is valid over a broad *** nonzero average cavity photons of the ground state indicate the emergence of a quantum phase ***,we demonstrate the dependence of the phase diagram on the atom-cavity detuning and modulation *** the parameters used in our scheme are within the reach of current experimental *** scheme provides a new mechanism for investigating the critical phenomena of finite-sized systems without requiring classical field limits,thereby opening a door for studying fundamental quantum phenomena occurring in the ultrastrong and even deep-strong coupling regimes.

关键词： Jaynes-Cummings model quantum phase transition frequency modulation

Electrostatic Encapsulation of Cobalt Ions into Crystalline Framework Derived Polymer Aerogel:Ultra-light,Pressure Resistant,Hydrophobic,Photothermal Conversion,Heat Insulation and Infrared Stealth

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Chinese Journal of Polymer Science 2024年第7期42卷 946-957,I0007页

作者： Yi-Fan Kang Jin-Lu Tang Ming Song Wei Wang Jia-cheng Ma Zhan-you Ji Tong liu Wen-Huan Huang China Key Laboratory of Chemical Additives for China National Light Industry College of Chemistry and Chemical EngineeringShaanxi University of Science and TechnologyXi’an710021China College of New Energy Xi’an Shiyou UniversityXi’an710065China Xi’an Key Laboratory of Functional Supramolecular Structure and Materials College of Chemistry and Materials ScienceNorthwest UniversityXi’an710127China

A variety of electromagnetic wave absorption materials(EMWAs)have been reported,but the integration of powder materials and multifunctional devices should be investigated in-depth to adapt to practical ***,carbon-coated cobalt composites were prepared by adsorbing magnetic metal cations into an anionic crystalline framework through an electrostatic encapsulate *** reflection loss(RL_(min))of-40.49 d B and effective absorption bandwidth(EAB)of 5.36 GHz(RL<-10 d B,10.4-15.76 GHz)was achieved with an optimal radar cross section(RCS)reduction of 34.9 dB·m^(2) for the sample *** commercial applications,Co@CN-4 was integrated into sodium carboxymethyl cellulose(CMC)aerogel to create an ultra-lightweight composite aerogel that is compressive resistant and heat-holding while also having photothermal conversion *** hydrophobic modification makes it more widely *** study provides a new strategy for EWAMs to integrate versatility and improve their application prospects.

关键词： Electrostatic incorporation Magnetic nanoparticle Co@CN composites Electromagnetic wave absorbing Metal-organic framework

Microenvironmental control of photochemica reactions Ⅱ.Fluorescence quenching of naphthalene and 1,3-di-(a-naphthyl)propane by RNA and bases in aqueous methanol

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Chinese Journal of chemistry 1990年第4期8卷 340-349页

作者： LEI, Xue-Gong XIE, Rui-Qiang liu, you-cheng department of chemistry, lanzhou university, lanzhou 73.000 department of chemistry Lanzhou University Lanzhou 130000

The fluorescence quenching of naphthalene (2)and 1, 3-di(α-naphthyl)propane (1) by RNA and bases in methanol-water (v:v=1:1) binary solvents in the presence or absence of cyclodex- trin (CD) has been investigated. The results show that both the monomer and excimer fluorescence of 1 can be quenched by these quenchers. The quenching and rates depend on the quencher and tem- perature. It is shown that there is a critical temperature (Tc) for each quencher. Below Tc, the excimer fluorescence spectra show vibrational structures and the Stern-Volmer plots are straight lines (for ura- cil and cytosine); while above the Tc, the vibrational structures disappear and the Stern-Volmer plots deviate from linearity and curve upward. The former is a static process; while the latter is a mixture of both static and dynamic processes. The addition of α-CD has no effect on the fine structure, whereas β-CD prevents the appearance of this structure efficiently. The quenching rates both for the monomer and excimer of 1 by bases except cytosine in the presence of β-CD at ambient temperature are not changed; the quenching of fluorescence of 1 by RNA in the presence of β-CD, however, is hindered. Time-resolved fluorescence study shows that the excimer fine structures appear from the zero time. The intensity of fine structures depend on the fraction of water (φ) in binary solvents, and it is independent of the pH value of the solvents. It is suggested that bases and RNA induced aggregates (perhaps microcrystal) are formed, in which the motion of molecules 1 is limited.

关键词： Fluorescence quenching of naphthalene and 1,3-di Microenvironmental control of photochemica reactions RNA

Effect of succinic acid on morphology transformation of the anhydrous magnesium carbonate particles prepared by magnesium chloride hexahydrate and urea

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Particuology 2024年第7期90卷 209-217页

作者： Song liu Guojun cheng Zhongfeng Tang School of Materials Science and Engineering Anhui University of Science and TechnologyHuainan232001China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China Anhui Province Key Laboratory of Environment-friendly Polymer Materials Anhui UniversityHefei230601China

The homogeneous and controllable morphology of anhydrous magnesium carbonate(MgCO_(3))particles with excellent properties is difficult to obtain because of a variety of synthetic *** effect of succinic acid as a crystal modifier on the particle morphology transformation of anhydrous MgCO_(3)was investigated by the hydrothermal *** effect of the addition of succinic acid on the particles was similar to that of temperature *** morphology of particles with a folded diamond-like shape was gradually uniform,and the particle size was between 3.3 and 7.5μ*** MgCO_(3)particles prepared at pH 9 could easily agglomerate,and the average particle size increased from diamond-like to cube-like as the reaction time *** interaction between succinic acid and magnesium ions at different concentrations was the main factor responsible for the morphological *** pH,temperature,and time affected the molecular motion rate and crystal growth.

关键词： MgCO_(3) MgCl_(2)·6H_(2)O Urea Succinic acid Morphology

Studies on the kinetics of decomposition of diacyl peroxides——VI. CIDNP in the products of thermolysis of lauroyl peroxide and 3,5,5-trimethylhexanoyl peroxide

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Chinese Journal of chemistry 1986年第2期4卷 116-122页

作者： LEI Xue-Gong GUO Qing-Xiang liu you-cheng*, department of chemistry, lanzhou university, lanzhou department of chemistry Lanzhou University Lanzhou

The1H NMR spectra recorded during the thermolysis of lauroyl peroxide and of 3,5,5-trimethylhexanoyl peroxide in ODCB containing 2-iodopropane show CIDNP multiplet effect. It wasobserved that the relative concentrations of 1-iodoundecane and 2-iodopropane. both polarized andnormal species. changed with time. The relaxation time T1of the a-protons in 1-iodoundecaneand vinyl protons of CH2in 1-undecene, enhancement factor of the protons of polarized species andthe rate constant of decomposition for lauroyl peroxide have been determined. The mechanismof the decomposition of the entitled peroxides is discussed in terms of the radical pair theory.

关键词： CIDNP in the products of thermolysis of lauroyl peroxide and 3,5,5-trimethylhexanoyl peroxide Studies on the kinetics of decomposition of diacyl peroxides VI

Two New Iridoid Glycosides from Caryopteris mongholica

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Chinese Chemical Letters 2000年第4期11卷 319-322页

作者： Yong Hong ZHANG Dong Liang cheng (department of chemistry, National Laboratory of Applied Organic chemistry, lanzhou university, lanzhou 73.000) department of chemistry Natl. Lab. of Appl. Organ. Chemistry Lanzhou University Lanzhou 730000 China

Two new iridoid glucosides were isolated from the whole plant of Caryopteris mongholica Bunge. On the basis of chemical and spectral evidence, they were determined as 8-acetyl-6'-O-(p-coumaroyl)harpagide and 6'-O-(p-c... 详细信息

关键词： Caryopteris mongholica verbanaceae 8-acetyl-6 '-O-(p-coumaroyl)harpagide 6 '-O-(p-coumaroyl)antirrinoside

Pre-MASLD:Should it be defined separately?

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Hepatobiliary & Pancreatic Diseases International 2024年第1期23卷 1-3页

作者： Hang-Kai Huang you-Ming Li cheng-Fu Xu department of Gastroenterology Zhejiang Provincial Clinical Research Center for Digestive Diseasesthe First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China

Nonalcoholic fatty liver disease(NAFLD)is one of the most common chronic liver diseases,yet it has not received sufficient attention[1].Over the past two decades,the overall global prevalence of NAFLD has risen from 25%to 37%[2].The disease burden of NAFLD is fueled by the epidemic of obesity and diabetes[3].It is estimated that more than half of patients with diabetes have NAFLD.

关键词： NAFLD liver diseases