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Deoxygenative alkylation of tertiary amides using alkyl iodides under visible light

Science China Chemistry 2022年第11期65卷 2231-2237页

作者： feng Zhao Feng Jiang Xiaoming Wang The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials ScienceShanghai Normal UniversityShanghai 200234China State Key Laboratory of Organometallic Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou310024China

It is an unceasing goal for organic chemists to develop new catalytic methodologies for functional group transformations of widespread molecular structures. Amides are readily available from simple and reliable reactions, which are common structural units found in biologically active compounds. Consequently, they are attractive to be exploited in amine synthesis by reductive cross coupling. However, deoxygenative functionalization of amides is a long-standing challenge owing to the inertness of the resonance-stabilized amide C=O bond. In this work, a deoxygenative alkylation strategy was demonstrated, which combines amides and alkyl iodides to build structurally diverse tertiary alkylamines in a single step. Compared with previous deoxygenative alkylation of amides using organometallic reagents as functional partner, this work uses stable and easily available alkyl halides as functionalization reagents. The versatile and flexible strategy plus structural and functional diversity of readily available amides and alkyl iodides renders it highly appealing for the streamlined synthesis of tertiary amines and would be of much interest in areas such as pharmaceutical and agrochemical research.

关键词： deoxygenative alkylation amide transformation alkyl radical alkylamine visible light

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Effective Energy Density of Glass Rejuvenation

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Acta Mechanica Solida Sinica 2022年第5期35卷 746-754页

作者： Gan Ding Feng Jiang Lanhong Dai Minqiang jiang State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an710049China State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing100190China School of Engineering Science University of Chinese Academy of SciencesBeijing100049China

Glasses with rejuvenated structures usually exhibit improved room-temperature plasticity,which facilitates their applications.However,glass rejuvenation requires external energy injection to“shake up”the frozen-in disordered structure.In this work,we give the answer to how much the required energy is.According to the constitutive model of amorphous plasticity,we find that the applied stress higher than the steady-state flow value can effectively induce the structural disordering in terms of the generation of free volume.Therefore,the effective energy density(EED)of structural rejuvenation is defined as the integral of this effective stress on the corresponding strain.By tailoring the applied strain,strain rate,temperature and initial free volume,different degrees of structural rejuvenation are achieved,which show a generally linear correlation with the defined EED.This work deepens the understanding of glass rejuvenation from an energy perspective.

关键词： Glass Structural rejuvenation Effective energy density Shear transformations Free volume

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A novel homozygous loss-of-function mutation in RAD51AP2 induces male infertility with nonobstructive azoospermia

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Asian Journal of Andrology 2023年第3期25卷 435-437页

作者： Liu Liu Shu-Yan Tang feng Zhang Feng Jiang Obstetrics and Gynecology Hospital Institute of Reproduction and DevelopmentFudan UniversityShanghai 200011China Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases Shanghai 200011China Shanghai JIAI Genetics and IVF Institute-China USA Center Shanghai 200011China

Dear Editor,The most severe type of male infertility,nonobstructive azoospermia(NOA),is characterized by clinical heterogeneity,implying the involvement of different acquired and genetic factors.However,the cause of NOA is unidentified in a substantial number of patients after the exclusion of all-known acquired factors and routine genetic testing,such as karyotype and Y chromosome microdeletion analysis.1 With the recent rapid development of whole-exome sequencing(WES),an increasing number of novel monogenic causes have been identified.Recently,RAD51-associated protein 2(RAD51AP2)was reported to be a novel causative gene of NOA in a monogenic recessive manner in two sporadic patients.2 Here,we studied the WES data for a family with two NOA patients and found that both carried a novel homozygous loss-of-function(LoF)mutation in RAD51AP2.

关键词： RAD51 routine infertility

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Unraveling the threshold stress of structural rejuvenation of metallic glasses via thermo-mechanical creep

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Science China(Physics,Mechanics & Astronomy) 2022年第6期65卷 101-109页

作者： Gan Ding Feng Jiang Xuan Song LanHong Dai MinQiang jiang State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

The competition between physical aging and structural rejuvenation determines the physical and mechanical properties of glassy materials.Thus,the rejuvenation-aging boundary must be identified quantitatively.In this work,we unravel a stress boundary to distinguish rejuvenation from aging via the thermo-mechanical creep of a typical Zr-based metallic glass.The crept glasses were rejuvenated into high-enthalpy disordered states when the applied stress exceeded a threshold that was numerically close to the steady-state flow stress;otherwise,the glasses were aged.A theoretical model for glass creep was adopted to demystify the observed stress threshold of rejuvenation.The model revealed that the thermo-mechanical creep beyond the threshold stress could activate sufficient shear transformations to create a net free volume,thus leading to structural rejuvenation.Furthermore,we derived the analytical expressions for the threshold and flow stresses.Both stresses can act as the rejuvenation-aging boundary,which is well supported by experimental creep data.The present work procures a deeper understanding of the rejuvenation mechanism of glasses and provides useful implications for abstaining from glass aging.

关键词： metallic glass thermo-mechanical creep threshold stress shear transformations rejuvenation-aging boundary

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Modified strict sperm morphology threshold aids in the clinical selection of conventional in vitro fertilization(IVF)or intracytoplasmic sperm injection(ICSI)

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Asian Journal of Andrology 2022年第1期24卷 62-66页

作者： Yong Zhu feng Zhang Hua Cheng Xiao-Xi Sun Feng Jiang Obstetrics and Gynecology Hospital Fudan UniversityShanghai 200011China Shanghai Ji Ai Genetics and IVF Institute Obstetrics and Gynecology HospitalFudan UniversityShanghai 200011China

For infertility treatment,the selection of in vitro fertilization(IVF)or intracytoplasmic sperm injection(ICSI)is decided by multiplying indicators(including fallopian tube factors,semen count,and semen motility),except for sperm morphology.In this study,we conducted a retrospective analysis,from implantation to birth,over a period of 5 years.A total of 1873 couples with primary or secondary fallopian tube factors and an increased defective sperm morphology rate(DSMR)were divided into different groups to receive IVF or ICSI cycles.By comparing the outcomes,we found that the F1 group(DSMR98%,IVF group 3;P98%,ICSI group 3)had higher cleavage rate(P<0.001),biochemical pregnancy rate(P<0.05),clinical pregnancy rate(P<0.05)and live birth rate(P<0.05)than the F3 group.However,the ICSI subgroup had a lower two pronuclei fertilization rate than the IVF subgroup(P<0.05).Our data suggest that the sperm morphology should also be considered when selecting IVF or ICSI combined with other semen parameters before the first assisted reproductive technologies(ART)cycle,especially for males with severe sperm defects.

关键词： clinical outcome in vitro fertilization intracytoplasmic sperm injection sperm morphology

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温带老龄林功能性状对植物存活的影响依赖于环境背景和生活史阶段

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Journal of Plant Ecology 2021年第5期14卷 981-994页

作者： Feng Jiang Guangze Jin Center for Ecological Research Northeast Forestry UniversityHarbin 150040China Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education Northeast Forestry UniversityHarbin 150040China

功能性状通常在不考虑环境背景的情况下被用来预测植物动态。然而,前人的研究发现性状对植物动态有较弱的预测能力。本文假设加入环境背景而不仅仅关注性状能够提高对性状-植物动态关系的理解。本研究基于一个9 ha温带老龄林动态监测样... 详细信息

功能性状通常在不考虑环境背景的情况下被用来预测植物动态。然而,前人的研究发现性状对植物动态有较弱的预测能力。本文假设加入环境背景而不仅仅关注性状能够提高对性状-植物动态关系的理解。本研究基于一个9 ha温带老龄林动态监测样地,利用广义线性混合效应模型分析功能性状(叶、茎、种子和整个个体水平)、环境梯度(土壤养分、水分和海拔)以及两者的交互效应对14133个幼树、3289个成年树存活动态的影响。本文发现环境因子、邻体拥挤度和性状主效应能够影响植物存活。然而,后两者的影响在幼树和成年树间存在差异。性状-环境交互效应影响植物存活,即资源保守的性状在相对严酷的环境下提高植物存活而在相对温和的环境下降低植物存活。海拔梯度是本样地调节植物存活最重要的环境因子。我们的研究结果支持功能性状对局域尺度植物存活的影响依赖于环境背景的假设。该结果也暗示拥有有限性状变异的单一物种不能占据所有的环境梯度,从而提高物种多样性。

关键词：植物动态功能性状局域群落土壤养分和水分温带森林性状-环境交互效应

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Symmetric Semi-perfect Obstruction Theory Revisited

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Acta Mathematica Sinica,English Series 2023年第2期39卷 209-239页

作者： Yun Feng Jiang College of Mathematics and Statistics Sciences Shenzhen UniversityShenzhen518060China Department of Mathematics University of Kansas405 Snow Hall1460 Jayhawk BlvdLawrence66045USA

In this paper we survey some results on the symmetric semi-perfect obstruction theory on a Deligne-Mumford stack X constructed by Chang-Li,and Behrend’s theorem equating the weighted Euler characteristic of X and the virtual count of X by symmetric semi-perfect obstruction theories.As an application,we prove that Joyce’s d-critical scheme admits a symmetric semi-perfect obstruction theory,which can be applied to the virtual Euler characteristics by jiang-Thomas.

关键词： Symmetric semi-perfect obstruction theory the Behrend function algebraic d-critical scheme virtual signed Euler characteristics

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Effects of particle type on the particle fluidization and distribution in a liquid–solid circulating fluidized bed boiler

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Chinese Journal of Chemical Engineering 2023年第2期54卷 53-66页

作者： Feng Jiang Xiao Li Guopeng Qi Xiulun Li School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350China School of Biological and Environmental Engineering Tianjin Vocational InstituteTianjin 300410China Tianjin Key Laboratory of Chemical Process Safety and Equipment Technology Tianjin UniversityTianjin 300350China

A liquid-solid circulating fluidized bed boiler is designed and built for visualization research by applying the fluidized bed heat transfer and fouling prevention technology to the water side of the boiler. Four types of engineering plastic particles with different physical properties are selected as the solid working media. The effect of particle types on the fluidization and distribution of particles in the boiler is investigated under different feedwater flow rates and amount of added particles by using the charge couple device image measurement and acquisition system. The results show that all kinds of particles can't be normally fluidized and accumulate in the drum at low amount of added particles and feedwater flow rate. The particles with great density and low sphericity are more likely to accumulate. The average solid holdup in the riser tubes increases with the increase in feedwater flow rate and the amount of added particles. The non-uniform degree of particle distribution in the riser tubes generally decreases with the increase in feedwater flow rate and the amount of added particles. The particles with small density and settling velocity have high average solid holdup in the riser tubes under close sphericity. In generally,the smaller the density and settling velocity, the more uniform the particle distribution in the riser tubes.Three-dimensional diagrams of the non-uniform degree of particle distribution in the riser tubes of the boiler are established.

关键词： Circulating fluidized bed boiler Particle type Particle distribution Visualization Fouling prevention

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Permeability evolution and gas flow in wet coal under non-equilibrium state:Considering both water swelling and process-based gas swelling

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International Journal of Mining Science and Technology 2023年第5期33卷 585-599页

作者： Zhiyong Xiao Gang Wang Changsheng Wang Yujing jiang Feng Jiang Chengcheng Zheng Shandong Provincial Key Laboratory of Civil Engineering Disaster Prevention and Mitigation Shandong University of Science and TechnologyQingdao 266590China College of Civil Engineering Fujian University of TechnologyFuzhou 350118China c State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology Shandong University of Science and TechnologyQingdao 266590China

Accurate knowledge of gas flow within the reservoir and related controlling factors will be important for enhancing the production of coal bed methane.At present,most studies focused on the permeability evolution of dry coal under gas adsorption equilibrium,gas flow and gas diffusion within wet coal under the generally non-equilibrium state are often ignored in the process of gas recovery.In this study,an improved apparent permeability model is proposed which accommodates the water and gas adsorption,stress dependence,water film thickness and gas flow regimes.In the process of modeling,the water adsorption is only affected by water content while the gas adsorption is time and water content dependent;based on poroelastic mechanics,the effective fracture aperture and effective pore radius are derived;and then the variation in water film thickness for different pore types under the effect of water content,stress and adsorption swelling are modeled;the flow regimes are considered based on Beskok’s model.Further,after validation with experimental data,the proposed model was applied to numerical simulations to investigate the evolution of permeability-related factors under the effect of different water contents.The gas flow in wet coal under the non-equilibrium state is explicitly revealed.

关键词： Gas flow Apparent permeability Water film Adsorption Non-equilibrium state

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The Moduli Space of Stable Coherent Sheaves via Non-archimedean Geometry

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Acta Mathematica Sinica,English Series 2022年第10期38卷 1722-1780页

作者： Yun Feng Jiang Department of Mathematics University of Kansas405 Snow Hall1460 Jayhawk BlvdLawrence USA

We provide a construction of the moduli space of stable coherent sheaves in the world of non-archimedean geometry,where we use the notion of Berkovich non-archimedean analytic spaces.The motivation for our construction is Tony Yue Yu’s non-archimedean enumerative geometry in Gromov-Witten theory.The construction of the moduli space of stable sheaves using Berkovich analytic spaces will give rise to the non-archimedean version of Donaldson-Thomas invariants.In this paper we give the moduli construction over a non-archimedean field K.We use the machinery of formal schemes,that is,we define and construct the formal moduli stack of(semi)-stable coherent sheaves over a discrete valuation ring R,and taking generic fiber we get the non-archimedean analytic moduli space of semistable coherent sheaves over the fractional non-archimedean field K.We generalize Joyce’s dcritical scheme structure in[37]or Kiem-Li’s virtual critical manifolds in[38]to the world of formal schemes,and Berkovich non-archimedean analytic spaces.As an application,we provide a proof for the motivic localization formula for a d-critical non-archimedean K-analytic space using global motive of vanishing cycles and motivic integration on oriented formal d-critical schemes.This generalizes Maulik’s motivic localization formula for the motivic Donaldson-Thomas invariants.

关键词： Non-archimedean Donaldson-Thomas theory Berkovich space analytic d-critical scheme motivic localization

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